CSR Building Products Limited v United States Gypsum Company - [2017] APO 64

IP AUSTRALIA
AUSTRALIAN PATENT OFFICE
CSR Building Products Limited v United States Gypsum Company [2017] APO 64

Patent Application: 2014201626

Title:Lightweight, reduced density fire rated gypsum panels

Patent Applicant:  United States Gypsum Company
Opponent:  CSR Building Products Limited
Delegate:  Dr D.A.S. Beck
Decision Date:  15 December 2017
Hearing Date:  10 and 11 August 2017, in Sydney

Catchwords: PATENTS – opposition to the grant of a patent – opposition governed by the Patents Act as amended by the “Raising the Bar”
provisions – construction of “fire resistant” vs “fire rated” – technical contribution to the art – general principle of application – disclosure – sufficiency – the work involved in testing does not pose an undue burden – support – the technical contribution to the art is that high expansion vermiculite particles can produce a lightweight fire resistant gypsum panel – inventive step – it would not be a matter of routine to arrive at the claimed invention – opposition fails on all grounds

Representation: Patent applicant: E. Heerey of counsel
Opponent: N. Murray of counsel

IP AUSTRALIA
AUSTRALIAN PATENT OFFICE
Patent Application: 2014201626

Title:Lightweight, reduced density fire rated gypsum panels

Patent Applicant: United States Gypsum Company
Date of Decision: 15 December 2017
DECISION
The opposition fails on all grounds.
I award costs against the opponent.
Subject to appeal I direct that the application proceed to grant.
REASONS FOR DECISION

The present opposition is governed by the Patents Act 1990 (the Act) as amended by the
Intellectual Property Laws Amendment (Raising the Bar) Act 2012 (the Raising the Bar Act).
Amendments to sections 7, 40 and 60 of the Act apply to the present case as a consequence of
Schedule 1, items 55(1)(e) and 55(4)(b) of the Raising the Bar Act – the applicant had not asked
for examination before 15 April 2013 (the request for examination was filed on 18 March
2014). These facts are not in dispute.
Background
Patent application number 2014201626 (the application) was filed as a divisional application on 18 March 2014, claiming priority from parent application 2012222102 (the parent). The applicant is United States Gypsum Company (the applicant). The application was examined and accepted by the Commissioner, and subsequently opposed by CSR Building Products Limited (the opponent). A hearing was held on 10 and 11 August 2017 in Sydney to decide the opposition. The applicant was represented by Ed Heerey of counsel, assisted by Ben Gardiner, Philip Petti (from the applicant), and Gus Hazel and Andrew Scott (from James and Wells, New Zealand). The opponent was represented by Neil Murray of counsel, assisted by David French (from the opponent), and Derek Baigent, Robert Wulff, and Samin Raihan (from Griffith Hack).
The parent was previously opposed, leading to the decision CSR Building Products Limited v United States Gypsum Company [2016] APO 41 (the ‘102 decision) on 6 November 2015 finding that it was invalid due to deficiencies arising from section 40(2)(a) and section 40(3). The applicant was given the opportunity to amend in order to address these deficiencies but the amendments were deemed insufficient to remedy the issues in CSR Building Products Limited v United States Gypsum Company [2017] APO 15 on 28 March 2017, ultimately resulting in the refusal of the parent.
The opposition
The statement of grounds and particulars was filed on 16 October 2015. The statement identifies the same seven grounds of opposition raised in the ‘102 decision: lack of entitlement, lack of manner of manufacture, lack of novelty, lack of inventive step, lack of utility, section 40(2) and section 40(3). At the hearing only the grounds of lack of inventive step, section 40(2) (insufficient disclosure) and section 40(3) (lack of support) were pressed.
The parties relied upon evidence by several declarants. Evidence in support consists of a
declaration by Bob Bruce. Evidence in answer consists of declarations by Timothy Keith Ball, Robert M. Berhinig, Peter James Aird and Dick Charles Engbrecht. Evidence in reply consists of a further declaration by Bob Bruce. Each of the declarants attached as exhibits, their corresponding declarations made in the ‘102 decision. I will refer to the relevant parts of the evidence where appropriate.
The standard of proof that applies to this opposition is the balance of probabilities (as a consequence of the amendment to section 60(3A) that allows the Commissioner to refuse a patent application if satisfied on the balance of probabilities that a ground of opposition exists), and it is the opponent who carries the onus of proof.
The Specification
The specification relates to building panels made from gypsum. Panels made from gypsum are in
widespread use in domestic and commercial building construction.

The application claims priority from US provisional patent application 61/446,941 filed on 25 February 2011, the contents of which are incorporated in the parent and the present specification by reference. The written description runs to page 87, followed by 27 claims and 54 pages of Figures. There are three independent claims: claim 1, claim 10 and claim 22.
While the claims of the parent were directed to fire resistant gypsum panels per se, the claims of the present application are directed to a method for making such panels, and differ in regard to a number of claimed integers which will be discussed below under the heading “Construction of the claims”. The only other significant differences between the parent and the present application are the addition to the present application of paragraphs [00171a] to [00171dddd] which provide a list of exemplary embodiments, paragraphs [0291] to [0292] which respectively define “comprises” and like terms as non-exclusive and declare that references in the specification to any prior art do not constitute an admission that such prior art is common general knowledge, and the deletion of all data in the fourth column in TABLE XI of FIG 29C (at page 34/54 of the figures).
What is the invention as described?
Before commencing to construe the specification, I note what Middleton J said in Eli Lilly and
Company Limited v Apotex Pty Ltd [2013] FCA 214, 100 IPR 451 at [139]:
“It is well settled that the Court should, from the outset, approach the task of patent construction with a generous measure of common sense. The Court must place itself in the position of a person skilled in the relevant art, being the subject matter of the patent. From this perspective, the patent is to be read as a whole, in the context of the specification and in light of the prevailing common general knowledge and state of the relevant art at the priority date.”
The person skilled in the art
It has long been established that many of the issues arising in an opposition are answered by viewing the patent through the eyes of the person skilled in the art:
“He is the person to whom the patent is addressed and who must construe it. He is the person whose knowledge will determine whether a patent is novel. He is the person who will judge whether a patent is obvious.”
(Root Quality Pty Ltd v Root Control Technologies Pty Ltd [2000] FCA 980 at [70])
However the skilled addressee is not a real person but an artificial construct that is used to analyse and interpret the patent, and there is a danger in trying to identify them as an actual person or persons:
“The notional person is not an avatar for expert witnesses whose testimony is accepted by the court. It is a pale shadow of a real person – a tool of analysis which guides the court in determining, by reference to expert and other evidence, whether an invention as claimed does not involve an inventive step.”
AstraZeneca AB v Apotex Pty Ltd [2015] HCA 30 at [23]
Our understanding of the skilled addressee is informed by evidence from persons with knowledge in the art as to the things that they know and do, and what they understand to be commonly known and done in the course of their work. The weighting and evaluating of this evidence in order to decide the characteristics of the person skilled in the art is part of the normal work of a delegate of the Commissioner of patents.
In the present case the art is the production of gypsum panels for building construction. The skilled addressee must have knowledge of the production of such panels, and an understanding of the development of new panels. Since the problem relates to fire resistant gypsum panels, the person skilled in the art must also have a degree of knowledge in this area.
In the ‘102 decision (at [60]), the delegate adopted the approach taken in a similar case; CSR Building Products Limited v United States Gypsum Company [2015] APO 21, where it was concluded that a range of persons could provide useful evidence as to the characteristics of the person skilled in the art. Similarly in this case I will have regard to the evidence of all declarants. Where there is conflict in their evidence, I will resolve that conflict in the normal way.
The background to the invention
Before discussing the invention, it is useful to have a general understanding of the art.
In the ‘102 decision, the delegate (at [11] – [15]) provided an analysis of some background terminology, including “boards or panels” and the interchangeable nature of these terms, “gypsum panels” and their construction, and “light weight gypsum panels” with reduced density due to the inclusion of air voids and their tendency towards reduced core strength, as well as the use of core additives to ameliorate this problem. For the purposes of the present decision I see no reason to depart from that analysis.
The delegate then went on (at [16] – [23]) to discuss the background behind “fire resistant gypsum panels” and “fire rated gypsum panels” in relation to the evidence before him at that time. In light of the new evidence submitted in relation to the present opposition, I will consider afresh what was known about these terms in the art of gypsum panels.
Fire resistant gypsum panels: Applying the plain meaning of the words would bring one to the conclusion that this phrase refers to panels made of gypsum, which are capable of resisting fire. However all gypsum panels are capable of resisting fire to some extent.
Mr Engbrecht states at paragraph [78]:
“… gypsum panels are fire resistant to some degree. This is because fire resistance is a natural property of gypsum panels that results from the dehydration of two molecules of water from the gypsum crystal upon exposure to heat i.e, fire.”
Mr Berhinig says at paragraph [40]:
“… all panels that contain gypsum will have some sort of level of fire resistance inherently. The more gypsum in a panel, the more fire resistant it will be because there will be more water (associated with the gypsum) for chemical dehydration.”
Mr Aird states at paragraph [38]:
“In my experience, all gypsum board has some degree of fire resistance. Gypsum board contains a significant quantity of calcium sulfate dihydrate – that is, calcium sulfate with two molecules of bound water. This water is progressively driven off by the application of heat to the board, until the calcium sulfate is effectively calcined and loses its structural integrity.
Mr Ball confirms this at paragraph [8]:
“… standard gypsum panels might be considered as having some ability to resist fire to a limited extent (typically of the order of less than 30 minutes).”
And at paragraph [98]:
“All gypsum wallboard resists fire to some extent. The major component is gypsum which, on exposure to heat, undergoes a dehydration process (calcination). This process retards the progress of heat transfer by absorbing heat as the dehydration is endothermic and also leads to the emission of steam which also slows the rate of heat transfer.”
And Dr Bruce also confirms this at paragraph [71] of his first declaration:
“The term ‘fire resistant’ is used in the gypsum industry to describe a board that is capable of preventing heat transmission. As noted above at paragraph [50], I note that all gypsum boards are fire resistant to a certain extent. This is due to the existence of chemically combined water in the core that acts to retard heat transmission in a fire.
This inherent property of gypsum panels to resist fire is also disclosed in the specification at page 2, paragraph [008]:
“Should the finished gypsum panels be exposed to relatively high temperatures, such as those produced by high temperature flames or gases, portions of the gypsum core may absorb sufficient heat to start the release of water from the gypsum dihydrate crystals of the core. The absorption of heat and release of water from the gypsum dihydrate may be sufficient to retard heat transmission through or within the panels for a time.”
To apply the plain meaning to the phrase “fire resistant gypsum panels” would therefore be tautologous as the property is inherent in the article, rendering the preamble to the phrase redundant. The declarants resolve this issue by comparing the phrase “fire resistant gypsum panels” to the phrase “fire rated gypsum panels”.
Fire rated gypsum panels vs Fire resistant gypsum panels: Much of the outcome of the ‘102 decision turned on the finding that the term “fire resistant” was interchangeable with, and equivalent to the term “fire rated” in the art of gypsum panels, and this was reflected in each of the declarants submissions in that case, none of whom made any apparent distinction between the terms. In the present case however, all of the expert witnesses have devoted some effort to explaining the scope of these two terms and how they differ:
Mr Ball at paragraph [112] of his declaration:
“While ‘fire resistant’ refers to the improved performance of panels when exposed to fire compared with standard panels the descriptor ‘fire rated’ applies to the assembly of which the board is only one part, and the fire rating is tied to the testing of the specific assembly. Boards themselves are not fire rated.”
Mr Engbrecht at paragraphs [75] to [77] of his declaration:
“When I use the phrase ‘fire rated,’ I mean that the panel has passed a fire test when assembled in a certain accepted design. With this qualification, to me, a ‘fire resistant gypsum panel’ and a ‘fire rated gypsum panel’ mean two different things. The phrase ‘fire resistant’ pertains to the properties of the panel. This is how the term is used in AU '626. On the other hand, the phrase ‘fire rated’ as used in AU '626 relates to the testing of assemblies incorporating gypsum panels as a component.”
Dr Bruce at paragraph [70] of his first declaration:
“Technically speaking, the two terms carry different meanings in the gypsum industry and using them interchangeably can create confusion.”
Mr Berhinig at paragraph [35] of his declaration:
“There is no such thing as a ‘fire rated gypsum panel.’ Despite this, in the construction and architectural communities, the terms ‘fire rated gypsum panel’ or ‘fire rated gypsum board’ are often used, and typically refer to a gypsum panel bearing a certification mark of a third-party (such as UL) identifying the panel as a component in a fire resistive assembly.”
Dr Bruce at paragraph [72] of his first declaration:
“Gypsum boards, in themselves, are not fire rated, but are loosely described in the industry as being ‘fire rated’ when included as part of a specific fire rated assembly. Construction assemblies that use fire resistant gypsum boards may be ‘fire rated’. The term ‘fire rated’ is properly used in the gypsum industry to describe systems (assemblies) that typically use special fire resistant gypsum boards that have been tested and found to comply with certain endurance standards when undergoing standard fire tests. Type X gypsum board is one such special fire resistant gypsum board that, when used in specific systems, allows those systems to ‘pass’ certain fire tests and achieve a ‘rating’, such as a ‘1-hour rating’.”
Mr Aird confirms this interpretation of the term “fire rated” at paragraphs [138] to [140] of his declaration:
“A fire rating will be obtained by testing an assembly, which consists of at least one panel (typically two or more) plus the framing material, screws, jointing compound, etc. The fire rating is determined by testing the assembly as a whole to see whether the assembly resists the passage of heat for the duration required… The panel is only a part of the assembly and isn't tested by itself so as to achieve a rating, per se. I believe that the team of ordinary skill in the art would understand that there is a difference between the panel and the assembly/structure used to obtain a fire rating.”
Dr Bruce reiterates this interpretation at paragraph [12] of his second declaration:
“As I previously mentioned at paragraphs [72]-[73] of my First '626 Declaration, a ‘fire resistant’ gypsum panel is not in and of itself ‘fire rated’, even though gypsum panels may be loosely described in the industry as ‘fire rated’ when included as a part of a specific fire rated assembly. The assembly also specifies other materials to be used in the assembly, such as the type of studs, screws, etc., as well as the way in which the assembly is assembled, and it is the assembly in its entirety that is ‘fire rated’.”
While the specification utilises both terms, it does not provide an explicit definition of the distinction between the two. See for example the specification at page 3, paragraph [010]:
“…fire resistant gypsum panels or ‘fire rated’ typically are formulated to enhance the panels’ ability to delay the passage of heat through wall or ceiling structures”.
It is therefore left to the skilled addressee to understand the difference between the scope of the two terms. In addition to the passages of the declarants cited above, Mr Engbrecht states at paragraphs [78] to [79] of his declaration:
“…those in the industry understand that panels referred to as ‘fire resistant’ or a panel that is part of a ‘fire rated’ assembly to have been formulated and manufactured in such a way as to provide improved fire resistance. All gypsum panels approved for use in a fire rated assembly are fire resistant. However, not all fire resistant panels are suitable for use in a fire rated assembly. That is, a panel that is fire resistant is one that demonstrates improved fire resistance performance characteristics, compared to at least a standard panel of equivalent thickness, when subjected to high temperatures, for example, shrink resistance and structural integrity. It is my opinion that the team of ordinary skill in the art would find a ‘fire rated gypsum panel’ (with the above-noted qualification that it is a fire resistant panel that is a part of a fire rated assembly) to always be a ‘fire resistant gypsum panel’ but would not find the converse to always be true.”
In light of the evidence I therefore find it logical to conclude that the phrase “fire rated gypsum panels” is narrower in scope than the phrase “fire resistant gypsum panels”, the former requiring the application of a strict and standardised regime of testing as part of a large scale apparatus in order to be applicable.
This leaves open the question of what sensible construction can be given to the broader term “fire resistant gypsum panels”. The declarants for the applicant point to parts of the specification to support the view that a fire resistant gypsum panel is one which shows performance characteristics comparable to a fire rated gypsum panel. See for example Mr Ball’s declaration at [100]:
“AU'626 makes boards that are comparable in performance to (if not better than) ‘commercial fire rated gypsum panels with a much greater gypsum content, weight and density’ (abstract, [028], [029], [032], [087], [090], [095], etc) such as Type X board, Type C board and/or glass faced 5/8" board. Such a comparison can be drawn from laboratory testing and/or large-scale testing.”
However, as discussed above, all gypsum panels are fire resistant to some extent. In order to determine the metes and bounds of the term “fire resistant gypsum panels” one must also be able to make a reasonable comparison to commercially available gypsum panels which do not possess a fire rating. This view is supported by Mr Engbrecht (at [78]):
“… a panel that is fire resistant is one that demonstrates improved fire resistance performance characteristics, compared to at least a standard panel of equivalent thickness, when subjected to high temperatures, for example, shrink resistance and structural integrity.”

Mr Aird, at [482] of his declaration, and referring to statements he made made during the ‘102 decision, expresses a consistent opinion:
“…I stated that the fire resistant gypsum panel must provide superior fire resistance compared to a standard board.”
In relation to commercially available gypsum panels, the opponent submitted that only those Sample Runs of the specification which passed their respective Underwriters Laboratories (UL) one hour fire ratings could be regarded as being commercially useful (see opponent’s written submissions from [112], referring to examples of the specification which failed these tests, to [116] at which paragraph the following is stated):
“In the present case, fewer than half of the relevant Samples in the application, have industrial utility.”
In response the applicant pointed to the declaration of Mr Berhinig (see applicant’s written submissions at paragraphs [72] to [73] and [80] to [81]). Mr Berhinig states that in an industry publication by the opponent, known as the CSR Red Book, there are numerous examples of fire resistant gypsum panels marketed by the opponent having “Fire Resistance Levels” assessed via a testing regime comparable to that of the UL fire rating tests, but in which those Fire Resistance Levels are reported as 30 minutes. See the declaration of Mr Berhinig at paragraphs [186] to [191]:
“Page A17 of CSR's Red Book (November 2011) explains that the specimen assemblies are subjected to furnace temperatures in accordance with the time-temperature curve set forth in AS 1530.4. I discussed AS 1530.4 above in paragraphs 68-73. Page A17 also explains that the specimen assemblies are assessed by criteria known as "Fire Resistance Levels (FRL)." These criteria are structural adequacy, integrity, or insulation. Failure under the insulation criteria occurs when the average temperature of the unexposed surface increases by more than 140°C (252°F) above the initial temperature, or when the temperature at any point increases by more than 180°C (324°F) above the initial temperature. I found two wall and partition designs that use either steel or wood studs that have fire endurance ratings of ½ hour. These designs are referenced in the table below:
The Red Book – November 2011

System Number Page Number Gypsum Panel Thickness (mm)

CSR 038 B11 16

CSR 906 C22 16

A copy of each of these pages from CSR's Red Book referenced in the
above table is attached and marked as Exhibit "RB-11."
In my opinion, each of the sample panels 1-20 from Example 4E of AU '626 would be capable of achieving a 30 minute fire rating in each of the above-noted systems found in the Red Book.”

It is a clear from this evidence that there are numerous commercially available gypsum panels marketed as “fire resistant”, despite the fact that they have not demonstrated sufficient performance levels to achieve a “fire rating” as part of a fire rated assembly, according to the one hour UL fire rating tests.
I therefore conclude that a “fire resistant gypsum panel” is one which demonstrates fire resistance performance characteristics preferably comparable to a gypsum panel which has achieved a fire rating as part of a fire rated assembly, and at least possesses improved fire resistance performance characteristics when compared to a standard panel of equivalent thickness, a standard panel being one which has not achieved a fire rating and which is not marketed as being fire resistant.
The aim of the invention
The specification says at page 1:
“This disclosure generally pertains to reduced weight and density gypsum panels with improved thermal insulation properties, heat shrinkage resistance, and fire resistance.”
This is consistent with the statement at paragraph [014] of the specification:
“It has been recognized, however, that reducing the weight and/or density of the core of gypsum panels by reducing the amount of gypsum in the core will adversely affect the structural integrity of the panels and their resistance to fire and high heat conditions.”
And at paragraph [027] of the specification:
“Thus there is a need in the art for a method of producing low weight and density fire-resistant gypsum panels…”
I conclude that the aim of the invention is to provide gypsum panels that are both light weight and have fire resistance, as well as methods for producing them.
The nature of the invention
The specification does not provide an explicit consistory statement, setting out the invention in clear terms. The applicant submitted that the nature of the invention resides in the fact that high expansion vermiculite which expands about 300% in volume after being heated for one hour at about 1560 degrees F can be used to provide a light weight gypsum panel with fire resistant properties (applicant’s submissions at paragraphs [5] to [6]).
At page 7 under the heading “summary”, paragraph [028] appears to provide some confirmation of this premise:
“In some embodiments, high expansion particulates, such as high expansion vermiculite, for example, can be incorporated in the gypsum core in amounts effective to provide fire resistance in terms of shrinkage resistance comparable to commercial Type X gypsum panels and other much heavier and denser gypsum panels.”
This is followed by several pages of embodiments, not all of which refer to high expansion particulates or for that matter, vermiculite.
The “detailed description of the invention” section, commencing at page 16 of the specification, also appears to provide some support for the proposition that the use of high expansion vermiculite is the main embodiment, where it states at paragraph [087]:
“The present disclosure provides embodiments using combinations of stucco, high expansion particulates, such as high expansion vermiculite, in an unexpanded condition, and other noted ingredients, examples of which are mentioned in Table I in FIG 19. These formulations provide fire resistant, reduced weight and density gypsum panels that provide desired fire resistance properties not previously believed feasible for gypsum panels of such reduced weights and densities.”
It is noteworthy that although this paragraph refers generally to high expansion particulates, the exemplary formulations of the invention referred to in Table I (FIG 19) all contain high expansion vermiculite.
Further on at paragraphs [0104] to [0116] the specification defines high expansion particulates. Commencing with paragraph [0104]:
“Reduced weight and density gypsum panels formed according to principles of the present disclosure can achieve unique and unexpected results in terms of resistance to fire and the associated extreme heat conditions, without relying on increased quantities of gypsum hemihydrates typical of conventional fire rated gypsum panels or relying predominantly on conventional, relatively low expansion vermiculite, such as that referred to as "Grade No. 5" unexpanded vermiculite (with a typical particle size of less than about 0.0157 inches (0.40 mm)). As mentioned above, panels formed according to principles of the present disclosure can utilize high expansion particulates in the form of vermiculite with a high volume of expansion relative to Grade No. 5 vermiculite (U.S. grading system) and other low expansion vermiculites which have been used in commercial fire rated gypsum panels.”
This paragraph appears to be correlating the use of high expansion vermiculite particles with the desired fire resistance properties of the panel, however it still refers generally to high expansion particulates and taken at face value, presents the use of high expansion vermiculite as a particular embodiment of the invention.
The paragraphs which follow ([0105] to [0116]) all discuss high expansion vermiculite, and its use in the invention, in detail. At paragraphs [0105] to [0106], high expansion vermiculite is defined with reference to the U.S. grading system referred to above in the previous paragraph:
“The vermiculites referred to herein as "high expansion vermiculite" have a volume expansion after heating for one hour at about 1560 °F (about 850 °C) of about 300% or more of their original volume. In contrast, Grade No. 5 unexpanded vermiculite typically has a volume expansion at about 1560 °F (about 850 °C) of about 225%. Other particulates with properties comparable to high expansion vermiculite also may be utilized in embodiments of panels formed according to principles of the present disclosure, as well. In some embodiments, high expansion vermiculites can be used that have a volume expansion of about 300% to about 380% of their original volume after being placed for one hour in a chamber having a temperature of about 1560 °F (about 850 °C).
One such high expansion vermiculite is often referred to as Grade No. 4 unexpanded
vermiculite (U.S. grading system).”
“Other particulates” are defined in this paragraph with reference to having properties comparable to the defined high expansion vermiculite. This is a consistent theme in the specification, which only provides guidance as to the identity of high expansion particulates other than high expansion vermiculite, by reference to the properties of high expansion vermiculite. For example at paragraph [0109]:
“In yet other embodiments, vermiculites that have been chemically treated or otherwise modified such that they exhibit volume expansion behavior under heating similar to the high expansion vermiculites discussed herein also may be used. The high expansion vermiculate useful in panels formed according to principles of the present disclosure can also include other vermiculites, vermiculite mixes and/or vermiculite containing compositions (and other particle sizes and size distributions), as well as other particulate materials with comparable expansion properties that provide the panel shrinkage and expansion characteristics typical of the panels disclosed herein. Other suitable high expansion vermiculites and other particulates also may differ from those disclosed herein in respects that are not material to providing the reduced weight and density, fire resistant gypsum panels disclosed herein.”
Beyond this, the specification does not identify any examples of high expansion particulates useful for the invention other than high expansion vermiculite, which it appears to define as unexpanded vermiculite of Grade No. 4 or less (U.S. grading system) or equivalent.
The specification lists embodiments of the invention on pages 41-52, beginning with an overarching statement at paragraph [00171a] that they “should not be construed as in any way limiting its scope”. The language used to describe the embodiments (paragraphs [00171b] to [00171dddd]) is consistent with, although broader in scope than the language of the claims (discussed below) and although “high expansion particulates” are mentioned, the only ones specifically identified are high expansion vermiculites.
The examples commence on page 53 and are also portrayed (at paragraph [0172]) as illustrative but non-limiting:
“The following examples further illustrate aspects of the invention but, of course, should not be construed as in any way limiting its scope.”
There are twenty samples whose formulation and preparation are detailed in the specification in example 4, all of them containing the same basic ingredients of high expansion vermiculite, starch, dispersant, phosphate, stucco, mineral wool/glass fiber and accelerator. The quantities of the various components in each of the samples is detailed in TABLE VII, FIG 25A.
All twenty samples are tested for mechanical strain (example 4A at page 60), high temperature shrinkage and high temperature thickness expansion (example 4B at page 61 with results reported in TABLE VIII, FIG 26A), Thermal Insulation Index and ratio of Thermal Insulation to density (example 4D at page 65 with results reported in TABLES IX & X, FIGS 27 & 28A), full scale fire testing (example 4E at page 67 with results reported in TABLE XI, FIGS 29A-C), and nail pull resistance (example 5 at page 75 with results reported in TABLE XII, FIG 30).
Samples 17-19 only are subjected to further testing, including flexural strength (example 6 at page 76 with results reported in TABLE XIII, FIG 31), core, end and edge hardness (example 7 at page 77 with results reported in TABLE XIV, FIGS 32A-C), and sound transmission (example 8 at page 78 with results reported in TABLE XV, FIG 33), while sample 13 is tested for shrink resistance (example 3 at page 57 with results reported in TABLE VI, FIG 24), and samples 2-5 were visualised with X-ray CT scans (FIGS 2-6).
For many of the above tests, comparative tests were also conducted with commercially available fire rated gypsum panel samples of “Type X”, “Type C” and “Glass Faced” plasterboard, including the high temperature shrinkage and high temperature thickness expansion test, Thermal Insulation Index and ratio of Thermal Insulation to density test, full scale fire testing (Type X and Glass Faced only), nail pull resistance (Type X only) and the shrink resistance test (Type X and Type C only).
Taken as a whole, the examples set forth a disclosure of twenty gypsum panels (samples 1-20), each containing high expansion vermiculite. The panels have a relatively low density (35 – 38 pounds per cubic foot) compared to their commercially available counterparts and they generally have desirable thermal properties. Some of the panels are shown to have desirable strength and sound transmission properties and the specification clearly infers that the remainder will also have these properties.
It appears that the relatively low density, in combination with the desirable thermal properties, are attributable to the use of high expansion vermiculite. The applicant submitted that this is a principle of general application.
Fire resistance testing of samples
Fire resistance properties of the gypsum boards of the invention were assessed by subjecting samples to a number of different tests as referred to briefly, above, in relation to the examples of the specification. For the purposes of this decision, it is useful to separate the fire resistance tests into two categories, namely “full scale tests” which a gypsum panel must pass in order to be regarded as fire rated, and “bench top tests” which provide a means to assess the general fire resistance performance characteristics of a gypsum panel.
Full scale tests: Full scale fire testing was carried out on samples according to the methodology of the Underwriters Laboratories. The different standards applied are referred to as U305, U419 and U423, and these standards prescribe the design assemblies and time periods required to achieve their respective fire ratings.
The specification also refers to the standard published by the American Society for Testing and Materials (ASTM) known as the ASTM E119 test method, for the purposes of the heating regime employed in each of the UL standard tests (eg; at [053] with reference to FIG 9 of the specification): “…a plot of the ASTM E119 temperature curve used for the furnace temperatures in the tests.”
In order to pass these tests and achieve approval as a one hour fire rated gypsum panel, the temperature measured on the unexposed side of a panel must be below a certain temperature after one hour. At paragraph [0244] this is explained in the context of U419 :
“… a single sensor maximum temperature on the unexposed side of less than the ambient temperature at the start of the test plus 325°F and an average sensor temperature of less than the ambient temperature plus 250°F.”
The same calculations are used for U305 and U423 (see paragraph [0245] of the specification). The specification does not record the ambient temperature used for the fire testing.
Dr Bruce calculates that the relevant temperatures must be below 400°F for a single sensor, and below 325°F for an average, based on the assumption that the ambient temperature was 75 °F (at [142] of his first declaration);
“Assuming a reasonable ambient temperature of 75 °F at the beginning of each test (this information is not provided, and the graphs in Figures 9, 10 and 16 are not clear enough to determine the starting ambient temperature), then the maximum temperature limits for both single sensors and the maximum average temperature limits for all sensors is 400 °F and 325 °F, respectively.”
The declarants for the applicant dispute that 75°F is a reasonable estimate for the ambient temperature, on the basis that the specification clearly states that sample run 17 passes the requirements of U419 for a 1 hour fire rating (at [0244]). See for example Mr Ball’s declaration, at [180]:
“However, we are told explicitly at [0244] that Sample Run 17 passes the full scale testing, which means therefore that the ambient temperature was at least 77°F.”
Mr Aird’s declaration, at [479] also makes this point:
“Furthermore, paragraph [0244] of AU'626 states that Sample Run 17 passes, which is a teaching that the ambient temperature for that run was at least 77°F. This data point alone casts some doubt on the assumption made by Dr Bruce that the ambient temperature was 75°F. Figures 9 and 10 of AU'102 and AU'626 show that the ambient temperature for each of the tests was not the same. I conclude that Dr Bruce has made an incorrect assumption regarding the ambient temperature.”
Mr Berhinig explains that a broad range of ambient temperatures are also acceptable under the standard, in his declaration at [143]:
“E119 mandates that the ambient temperature at the beginning of the test fall within the range of 50-90°F (10-32°C). Thus, under E119, the highest temperature that the maximum single value must be less than is 415°F (325°F +90°F).”
On balance the evidence is therefore in favour of the ambient temperature for at least Sample Run 17 being as high as 77°F. Based on Figures 9 and 10 of the specification it is clear that a range of ambient temperatures occurred throughout the testing of Sample Runs 1-20, however it is far from clear exactly what those temperatures were. For the purposes of this decision I will proceed on the assumption that the ambient temperatures for the full scale tests were at least 75°F, and potentially as high as 90°F.
The three UL standards tests applied differ primarily in regards to the details of their respective assemblies, and the minimum amount of time of heat exposure required to achieve a fire rating.
Standard U305 (see exhibit RB-6 to Berhinig and Mr Berhinig’s declaration at [61] to [62]) is for a bearing wall rating at a minimum of 1 hour using wooden studs, where the gypsum board must be a minimum of 5/8” thick and may be hung horizontally or vertically.
Standard U419 (see exhibit RB-7 to Berhinig and Mr Berhinig’s declaration at [61] to [62]) is for a non-bearing wall rating at a minimum of 1 hour using steel studs, where the gypsum board must be a minimum of 5/8” thick (or optionally 1/2” thick but only if used with a 1&1/2” thick layer of insulation in the wall cavity) and may be hung horizontally or vertically.
Standard U423 (see exhibit RB-8 to Berhinig and Mr Berhinig’s declaration at [63] to [64]) is for a bearing wall rating at a minimum of 45 minutes (when a 1/2” thick panel is tested) or 1 hour (when a 5/8” thick panel is tested) using steel studs and where the gypsum board may be hung horizontally or vertically. In the context of the examples of the specification, the requirement to obtain a fire rating under this standard would be 1 hour because it appears that the examples are all approximately 5/8” thick (see TABLE VII, FIG 25B, column 6 of the specification).
Turning to the examples of the specification, assuming that the ambient temperature for all sample runs was as high as 90°F, Sample Runs 2, 6 to 10, 15 and 16 fail to demonstrate sufficient levels of fire resistance required to achieve a fire rating under their respective UL standards. If we assume that the ambient temperature was at the lower end of the spectrum at 75°F, then Sample Runs 3, 11 and 17 would also fail (these results are summarised in columns 3 and 4 of Table 1, attached at the end of this decision). As I have already stated, although the ambient temperatures for the individual runs has not been clearly disclosed in the specification, it is a reasonable assumption that they showed a degree of variation within this range, based on Figures 9 and 10 and the requirements of the standards.

Bench top tests: The specification describes a number of other tests which are not full scale fire resistance tests, but which it infers provide an objective evaluation of fire resistance or thermal performance characteristics of gypsum panels. These include the measurement of the parameters it describes as High Temperature Core Cohesion (at [0197]), Thermal Insulation Index (at [0219]), High Temperature Thickness Expansion (at [0207]), and High Temperature Shrinkage (at [0202]).
The specification infers that the basis for these tests being generally accepted in the gypsum panel industry is a publication it refers to as ASTM Pub. WK25392 (see for example paragraphs [0197] and [0273] of the specification).
The opinions of the declarants differ on the validity of this inference, and both parties argued over this point extensively at the hearing. Dr Bruce states (at paragraphs [104] to [105] of his first declaration):
“… the above parameters / tests referred to in the '626 Application are not widely accepted by the gypsum industry, and seem to have been more or less newly introduced by USG. As I noted in paragraphs [39], [96]-[98], [151], [154], [158] and [180]-[181] of my Second '102 Declaration, the TI test has been found to be unreliable and inconsistent based on round robin testing conducted for ASTM Committee C11.”
However Mr Ball points out that this is not the case and that the bench top methods disclosed in the specification have now been accepted by the industry (at paragraph [157] of his declaration):
“Attached and marked Exhibit "KB-4" is a copy of ASTM C1795-15 Standard Test Methods for High Temperature Characterization of Gypsum Boards and Panels that I have purchased. The standard includes the Thermal Insulation Index test and the High Temperature Shrinkage test. The standard was accepted in December 2015 and published in January 2016. The ASTM approval is recognition that the tests provide the team of ordinary skill in the art with the tools to modify formulations to rapidly gain confidence that a given formulation and board will perform similarly to an existing board and to improve an existing formulation where a tested formulation has been found lacking or needs performance improvements.”
The evidence therefore shows that at least some of the tests which are cross referenced in the specification as being published in ASTM Pub. WK25392 were approved and accepted by ASTM (on 1 December 2015), and published (in January 2016) approximately 5 years after the priority date of the application (being 25 February 2011) in ASTM C1795-15.
The declaration of Mr Engbrecht (at paragraph [15]) shows that the bench top tests were indeed known within the industry:
“… one of my work areas included the evaluation of gypsum panel products to improve the understanding of fire resistant type X gypsum panel performance with respect to three small scale tests (high temperature core cohesion test, high temperature shrinkage test, and high temperature thermal insulation test)… The Gypsum Association study began in 2003 and continued for six years. The results demonstrated a strong correlation between predicted results from the small scale testing of type X gypsum panels and the actual results from full scale furnace testing of type X gypsum panels and were published in the Conference Proceedings for the Fire and Materials 2011, 12^th International Conference and Exhibition, January 31-February 2, 2011, San Francisco, California, United States, a copy of which is attached and marked Exhibit "DE-2." These small scale test methods were approved by ASTM on December 1, 2015 as C1795 - 15, "Standard Test Methods for High-Temperature Characterization of Gypsum Boards and Panels."”
The document “Proceedings of the Fire and Materials 2011 Conference, 12^th International Conference and Exhibition, San Francisco, 31^st January – 2^nd February 2011” (Conference Proceedings) referred to here by Mr Engbrecht is also cross referenced in the specification (at paragraph [0210]). This document was published before the priority date of the opposed application, which is 25 February 2011.
Since patent applications by their very nature teach things hitherto unknown, fundamentally the question of whether or not the bench top tests of the ASTM C1795-15 standard were available to the skilled addressee before the priority date is irrelevant to the construction of the specification, which teaches how to perform them and that they represent a useful means of assessing the fire resistance performance characteristics of gypsum panel samples. I note however that ASTM C1795-15 contains an important caveat (at paragraph [1.4]), as pointed out in Dr Bruce’s 2^nd declaration (at paragraph [50]):
“While these tests are useful for evaluating fire properties of gypsum boards and panels, they are not suitable for predicting the Test Methods E119 fire resistance performance of a specific gypsum protected assembly that has not previously been tested in accordance with Test Methods E119 and correlated to these tests.”
The Conference Proceedings publication provides such a correlation, in which the relationship between Thermal Insulation Index and High Temperature Shrinkage is correlated to the performance of commercially available 5/8” thick Type X gypsum board under its associated ASTM E119 one hour fire rating test (see Conference Proceedings at page 425, equations [6b] and [9b]). Importantly, the paper points out that according to this correlation, for the purposes of assessing fire resistance, the two parameters are not mutually exclusive but rather they are interdependent:
“Eqs. 9a and 9b provide a proportionality constant by which the thermal insulation index must increase to maintain the specified fire resistance performance whenever shrinkage increases. Likewise, if high temperature shrinkage is reduced it is possible for the thermal insulation index to decrease proportionately and still maintain a given level of fire resistance performance.”
Although the test described in the specification for measuring High Temperature Thickness Expansion does not appear in the ASTM C1795-15 standard, the specification also clearly teaches the measurement of this property, and that it is a useful means for assessing the fire resistance performance characteristics of gypsum panel samples.
Construction of the claims
The correct approach to the construction of claims was discussed by Bennett J in H Lundbeck A/S v Alphapharm Pty Ltd [2009] FCAFC 70, 81 IPR 228 at [118] – [120]:
“the words in a claim should be read through the eyes of the skilled addressee in the context in which they appear … while the claims define the monopoly claimed in the words of the patentee's choosing, the specification should be read as a whole … it is not permissible to read into a claim an additional integer or limitation to vary or qualify the claim by reference to the body of the specification … terms in the claim which are unclear may be defined or clarified by reference to the body of the specification.”
Claim 1 is the first independent claim. It reads:
“A method for making a fire resistant gypsum panel, the method comprising:
(A)preparing a gypsum slurry having high expansion particles of unexpanded vermiculite dispersed therein, wherein the volume expansion of the vermiculite particles average about 300% or more of their original volume after being heated for about one hour at about 1560 °F;
(B)disposing the gypsum slurry between a first cover sheet and a second cover sheet to form an assembly comprising a set gypsum core with the high expansion particles generally distributed throughout the gypsum core;
(C)cutting the assembly into a panel of predetermined dimensions; and
(D)drying the panel;
such that the set gypsum core has a density (D) of about 40 pounds per cubic foot or less and a core hardness of at least about 11 pounds, and the gypsum core and amount and distribution of the vermiculite particles within the core are effective to provide a Thermal Insulation Index (TI) of about 20 minutes or greater.”
The plain meaning of the claim is that it is directed to a method of making fire resistant gypsum panels in a particular series of steps:
preparing a gypsum slurry containing unexpanded vermiculite (of a specified type), disposing the slurry between two cover sheets,
cutting into desired dimensions, and
drying the resultant panel
and having several properties:
a defined core density,
a defined core hardness, and
a defined Thermal Insulation Index.
The type of unexpanded vermiculite is specified by reference to the degree to which the average volume of the particles will expand (at least approximately 300%) when subjected to specified conditions (approximately one hour at approximately 1560 °F). The specification (at [0106]) states that “One such high expansion vermiculite is often referred to as Grade No. 4 unexpanded vermiculite (U.S. grading system).”
The Thermal Insulation Index (TI) is explained in Example 4D of the specification (at [0219]). It is calculated by the formula:
TI = t_200°C – t_40°C
In other words it is the time taken (in minutes) for a test specimen to rise in temperature from 40°C to 200°C.
Finally, the fact that the preamble of the claim refers to a “fire resistant” gypsum panel cannot be overlooked. This may be interpreted as either a reference to the intended field of application for the panels, or as a limiting feature of the claim. The latter is the more reasonable construction. A panel is not “fire resistant” if it does not, in fact, possess fire resistance. As discussed previously, the skilled addressee understands this to mean a panel that shows enhanced fire resistance, in that it possesses fire resistance characteristics comparable to commercially available “fire rated” panels which meet the recognised standards of fire resistance, and better than that of a standard panel which does not possess a fire rating. I believe that a person skilled in the art would appreciate that this comparison is intended to be evaluated via the claimed Thermal Insulation Index, as defined in the now accepted ASTM C1795-15 industry standard.
Claims 2 to 8 are dependent on claim 1, and place further limitations on the scope of claim 1 by imposing upper and/or lower limits on the parameters and variables that find their antecedence in the independent claim. In addition they introduce new features to, or impose further limitations upon, the gypsum slurry and set gypsum core, such features and limitations being regarded as matters of routine in the art, for example air voids with walls separating them, a crystalline matrix, defined shrink resistance, heat sink additives, fibre additives and defined nail pull resistance. Since nothing in this decision turns on the interpretation of claims 2 to 8 I will not provide a detailed construction of these claims.
Claim 9 is dependent on any one of claims 1 to 8. It reads:
“The method of any one of claims 1 to 8, wherein the panel satisfies at least one of the one hour fire-rated panel standards of UL U305, UL U419, and UL U423.”
This claim places the further limitation that the fire resistant gypsum panel must pass at least one of the specified UL standards required to meet the criterion of being a fire rated gypsum panel.
Claim 10 is the second independent claim. It reads:
A method for making a fire resistant gypsum panel, the method comprising:
(A)preparing a gypsum slurry having high expansion particles of unexpanded vermiculite dispersed therein, wherein the volume expansion of the vermiculite particles average about 300% or more of their original volume after being heated for about one hour at about 1560 °F;
(B)disposing the gypsum slurry between a first cover sheet and a second cover sheet to form an assembly comprising a crystalline matrix of set gypsum with the high expansion particles generally distributed throughout the gypsum core;
(C)cutting the assembly into a panel of predetermined dimensions; and
(D)drying the panel;
such that the panel comprises a density of about 40 pounds per cubic foot or less and a core hardness of at least about 11 pounds, and the crystalline matrix of set gypsum and the high expansion particles are effective to provide the panel with a High Temperature Shrinkage (S) of about 10% or less and a ratio of High Temperature Thickness Expansion to High Temperature Shrinkage (TE)/S of about 0.2 or more.

103. Claim 10 is similar to claim 1, however the “set gypsum core” of part (B) of claim 1 has been replaced with a “crystalline matrix of set gypsum”, and instead of defining the Thermal Insulation Index, it defines High Temperature Shrinkage (S) and the ratio of the High Temperature Thickness Expansion (TE) to High Temperature Shrinkage of the panel as the measure of fire resistance. As I have stated previously, the High Temperature Shrinkage parameter was known at the priority date of the application, and subsequently approved as an industry standard in the publication known as ASTM C1795-15, as a means for preliminary assessment of fire resistance performance. The parameter of High Temperature Thickness Expansion has been sufficiently described (at example 4B) within the specification for the skilled addressee to perform it.
104. Claims 11 to 17 and 21 are dependent on claim 10. These claims are similar to claims 2 to 8 in that they impose further features and limitations on the scope of claim 10 upon which nothing in this decision turns. For this reason I will not provide a detailed construction of these claims.

105. Claim 18 is dependent on any one of claims 10 to 17. It reads:
“The method of any one of claims 10 to 17, wherein the panel satisfies at least one of the one hour fire-rated panel standards of UL U305, UL U419, and UL U423.”

106. This claim is similar to claim 9 in that it places the further limitation that the fire resistant gypsum panel must pass at least one of the specified standards required to meet the criterion of being a fire rated gypsum panel.

107. Claim 19 is dependent on any one of claims 10 to 18. It specifies that the panel must pass the one hour fire rated panel standard UL U305.

108. Claim 20 is dependent on any one of claims 10 to 19. It specifies that the panel must pass the one hour fire rated panel standard UL U419.

Claim 22 is the third, and last, independent claim. It reads:
A method for making a fire resistant gypsum panel, the method comprising:
(A)preparing a gypsum slurry having high expansion particles of unexpanded vermiculite dispersed therein, the vermiculite particles expandable from a first unexpanded volume to a second average expanded volume of about 300% or more of the original unexpanded volume when heated for about one hour at about 1560 °F;
(B)disposing the gypsum slurry between a first cover sheet and a second cover sheet to form an assembly comprising a set gypsum core with the expandable particles generally distributed throughout the gypsum core;
(C)cutting the assembly into a panel of predetermined dimensions; and
(D)drying the panel;
the assembly formed to provide the panel with a density of about 40 pounds per cubic foot or less and a core hardness of at least about 11 pounds, the panel has a nominal panel thickness of about 5/8-inch, and a gypsum core and distribution of the expandable vermiculite particles therein effective to inhibit the transmission of heat through an assembly of said panels prepared and heated pursuant to the procedures of UL U419, where surfaces of the panels on one side of the assembly are exposed to a heat source and surfaces of the panels on the opposite, unheated side of the assembly are provided with a plurality of temperature sensors pursuant to UL U419, such that the maximum single value of the temperature sensors on the unheated side of the assembly is less than about 500 °F after about 60 minutes when the assembly is heated in accordance with the time-temperature curve of ASTM standard Ell9-09a.
Claim 22 is similar to claims 1 and 10, however it specifies the thickness of the panel and defines the measure of fire resistance by reference to the means by which heat transmission must be determined: The panels must be part of the assembly defined in the UL U419 fire rating standard, and they must be heated in accordance with the conditions defined in the ASTM standard Ell9-09a.
Despite the requirement of a UL U419 assembly, the temperature requirements of the claim are not as stringent as the standard itself. The claim requires a maximum temperature (at any single sensor) of less than 500°F after 60 minutes, whereas the standard requires less than 400-415°F (assuming ambient temperature ranges of 75-90°F) after 60 minutes.
Claim 23 is dependent on claim 22. It reads:
“The method of claim 22, wherein the panel is effective to inhibit the transmission of heat through the assembly such that the average value of the temperature sensors on the unheated side of the assembly measured pursuant to UL U419 is less than about 380 °F after about 60 minutes of heating in accordance with the time-temperature curve of ASTM standard E119-09a.”
This claim additionally requires that the average value of all the sensors is less than 380°F after 60 minutes. Again the requirement is less stringent than the UL U419 standard requires. In order to pass UL U419 the maximum value for the average temperature of all sensors must be 325-340°F (assuming ambient temperature ranges of 75-90°F) after 60 minutes.
Claim 24 is dependent on claim 22 or claim 23. It reads:
“The method of claim 22 or claim 23, wherein the panel is effective to inhibit the transmission of heat through the assembly such that the maximum single value of the temperature sensors on the unheated side of the assembly measured pursuant to UL U419 is less than about 410 °F after about 55 minutes of heating in accordance with the time-temperature curve of ASTM standard Ell9-09a.”
This claim brings the maximum value of a single sensor at 55 minutes down to 410°F, which is within the range that would pass the UL U419 fire rating test (assuming ambient temperature is at 85°F or above), however time requirement is less stringent as this would have to be the maximum temperature at 60 minutes (not 55 minutes) in order to achieve the fire rating.
Claim 25 is dependent on any one of claims 22 to 24. It reads:
“The method of any one of claims 22 to 24, wherein the panel is effective to inhibit the transmission of heat through the assembly such that the average value of the temperature sensors on the unheated side of the assembly measured pursuant to UL U419 is less than about 320 °F after about 55 minutes of heating in accordance with the time-temperature curve of ASTM standard El19-09a.”
This claim brings the maximum average value of all sensors at 55 minutes down to 320°F, which is within the range that would pass the UL U419 fire rating test (assuming ambient temperature is at 70°F or above), however time requirement is less stringent as this would have to be the maximum average temperature at 60 minutes (not 55 minutes) in order to achieve the fire rating.
Claim 26 is dependent on any one of claims 22 to 25. It reads:
“The method of any one of claims 22 to 25, wherein the panel is effective to inhibit the transmission of heat through the assembly such that the maximum single value of the temperature sensors on the unheated side of the assembly measured pursuant to UL U419 is less than about 260 °F and the average value of the temperature sensors on the unheated surface of the assembly measured pursuant to UL U419 is less than about 250 °F after about 50 minutes of heating in accordance with the time-temperature curve of ASTM standard Ell9-09a.”
This claim reduces the time requirement of both the single sensor and average sensor values down to 50 minutes (compared to the 60 minutes required by the UL U419 standard for a gypsum panel that is 5/8” thick), while the maximum temperature values are also reduced further, to 260°F and 250°F respectively.

Claim 27 is dependent on any one of claims 22 to 26. It reads:
“The method of any one of claims 22 to 26, wherein the panel is effective to inhibit the transmission of heat through the assembly such that the panel satisfies at least one of the one hour fire-rated panel standards of UL U305, UL U419, and UL U423.”

This claim is similar to claims 9 and 18 in that it places the further limitation that the fire resistant gypsum panel must pass at least one of the specified UL standards required to meet the criterion of being a fire rated gypsum panel.
Disclosure and Support
The Raising the Bar Act introduced two new provisions to section 40: a requirement for
disclosure and a requirement for support. The two concepts are closely connected.
The disclosure requirements were introduced in subsection 40(2) under paragraphs (a) and (aa), which state that the specification must:
(a) disclose the invention in a manner which is clear enough and complete enough for the invention to be performed by a person skilled in the relevant art; and
(aa) disclose the best method known to the applicant of performing the invention; …
The purpose of these provisions is explained in the Explanatory Memorandum, Intellectual Property Laws Amendment (Raising the Bar) Bill 2011 (the Explanatory Memorandum) pages 47 – 48:
“The item is intended to modify the wording of paragraph 40(2)(a) of the Act so as to require enablement across the full width of the claims, while adopting language that is consistent with that used in other jurisdictions. The wording in the amendment is similar to s 14(3) of the UK patents legislation, which has been interpreted as imposing this requirement. The wording is also similar to art 83 of the European Patent Convention, which has been interpreted with similar effect. The intention is that paragraph 40(2)(a) be given, as close as is practicable, the same effect as the corresponding provisions of UK legislation and the European Patent Convention.
A specification that provides a single example of the invention may satisfy the requirements, but only where the skilled person can extend the teaching of the specification to produce the invention across the full width of the claims, without undue burden, or the need for further invention.
However, it is expected to be more likely that, where the claims are broad, the specification will need to give a number of examples or describe alternative embodiments or variations extending over the full scope of the claims. This ensures that the monopoly extends only to that which could reasonably be said to be disclosed and no further.
If, on its face, the specification would appear to the skilled person to lack sufficient disclosure, the onus of establishing that the invention is described in enough detail lies with the applicant.”
The requirement for support lies in subsection 40(3), which states:
The claim or claims must be clear and succinct and supported by matter disclosed in the specification.
This provision was introduced as a replacement for the former requirement of fair basis. The purpose of this change is also explained in the explanatory memorandum at page 49:
“This item is intended to align the Australian requirement with overseas jurisdictions' requirements (such as the UK). Overseas case law and administrative decisions in respect of the 'support' requirement will be available to Australian courts and administrative decision-makers to assist in interpreting the new provision.”
Both concepts relate to the need for an enabling disclosure of the invention, as explained in Generics (UK) Ltd v H Lundbeck A/S [2009] RPC 13 (Generics), a decision of the House of Lords, by Lord Walker of Gestingthorpe, at paragraph [20]:
“The disclosure must be such as to enable the invention to be performed (that is, to be carried out if it is a process, or to be made if it is a product) to the full extent of the claims.”
Despite the similarity of the concepts, they each require distinct tests which must be conducted separately according to their own criteria.
Disclosure
The general approach to deciding sufficiency of disclosure was summarised succinctly by Lord Hoffmann in Kirin-Amgen Inc v Hoechst Marion Roussel Ltd [2005] RPC 9 (Kirin-Amgen) at [103]:
“The first step is to identify the invention and decide what it claims to enable the skilled man to do. Then one can ask whether the specification enables him to do it.”
Lord Hoffmann provided a more detailed discussion in Biogen Inc v Medeva plc [1997] RPC 1 (Biogen) at 48:
“…the specification must enable the invention to be performed to the full extent of the monopoly claimed. If the invention discloses a principle capable of general application, the claims may be in correspondingly general terms. The patentee need not show that he has proved its application in every individual instance. On the other hand, if the claims include a number of discrete methods or products, the patentee must enable the invention to be performed in respect of each of them.”
As the delegate explained in the ‘106 decision, at [95], in order to decide whether sufficiency of disclosure has been satisfied according to section 40(2), one must:
i) construe the claims to determine the scope of invention as claimed,
ii) construe the description to determine what it discloses to the person skilled in the art, and
iii) decide whether the specification provides an enabling disclosure of all the things that fall within the scope of the claims.
What is the invention as claimed?
Above I have construed claims 1, 10 and 22 as being directed to a method of making fire resistant gypsum panels via a particular series of steps:
- preparing a gypsum slurry containing high expansion vermiculite (of a specified type), and
- disposing the slurry between two cover sheets,
- cutting into desired dimensions, and
- drying the resultant panel
and producing a gypsum panel having several properties:
- a defined core density,
- a defined core hardness, and
- a defined Thermal Insulation Index (claim 1) or;
- a defined High Temperature Shrinkage and ratio of High Temperature Thickness Expansion to High Temperature Shrinkage (claim 10) or;
- a defined maximum temperature of 500°F after 60 minutes of heating within an assembly pursuant to UL U419 in accordance with the time-temperature curve of ASTM E119-09a (claim 22), and;
- the panel is fire resistant.
What does the specification disclose?
The specification discloses information on the preparation and composition of twenty gypsum panels, and details of how to carry out testing of them, as well as the results of such tests, including tests conducted on three different types of commercially available fire rated gypsum panels for the purposes of comparison to the panels of the invention, as I have discussed above.
Does the specification enable all of the things that fall within the scope of the claims?
The claims all require high expansion vermiculite (defined as those which expand by at least 300% of their volume when subjected to 1560°F for an hour). The applicant submitted that the use of high expansion vermiculite to achieve the desired properties of low density combined with fire resistance, was a principle of general application.
In Kirin-Amgen at [112] – [113], Lord Hoffmann described a principle of general application as follows:
“It simply means an element of the claim which is stated in general terms. Such a claim is sufficiently enabled if one can reasonably expect the invention to work with anything which falls within the general term… the notion of a 'principle of general application' applies to any element of the claim, however humble, which is stated in general terms.”
While it seems reasonable that high expansion vermiculite could be applied generally by the person skilled in the art to prepare gypsum panels, without undue burden, the more important question relates to whether the parameters required by the claims could plausibly be achieved without undue burden, in particular, the parameters relating to core density, core hardness and fire resistance properties.
Where a claim is defined in terms of parameters, rather than the technical features that will achieve those parameters, the question of whether there is a sufficient description is very difficult. In amorphous silica/INEOS T 1743/06 (amorphous silica) the Board of Appeal said at [1.2]:
“The board however observes that the definition of 'amorphous silica' comprises a host of possible chemical compounds which may or may not satisfy the multiplicity of parameters defined in the claims of the requests at issue and in this context, the question arises whether the patent contains sufficient information about how these parameters are to be reliably achieved so that the person skilled in the art has at his disposal a process which leads him in a direct way to the amorphous silicas claimed.”
and at [1.9]:
“The skilled person is thus confronted with the uncontested fact that he has a lot of process variables affecting the claimed parameters, but once he has encountered failure in one parameter value, there is no clear guidance enabling him to adjust the multitude of process steps in order to arrive with certitude at silicas meeting the parameter requirements defined in claim 1 of both requests in issue. Even though a reasonable amount of trial and error is permissible when it comes to assessing sufficiency of disclosure, there must still be adequate instructions in the specification, or on the basis of common general knowledge, leading the skilled person necessarily and directly towards success, through evaluation of initial failures.”
This approach was reaffirmed by Kitchin J in Eli Lilly & Co v Human Genome Sciences, Inc [2008] RPC 29 (Eli Lilly) at [243]:
“Even though a reasonable amount of trial and error is permissible, when it comes to sufficiency of disclosure, for example in an unexplored field or where there are many technical difficulties, the skilled person has to have at his disposal, either in the specification or on the basis of his common general knowledge, adequate information leading necessarily and directly towards success through the evaluation of initial failures.”
The present case is analogous to the amorphous silica case in that there are a lot of process and starting material variables that will affect whether a gypsum panel has both the claimed parameters and the required property of being fire resistant. However, as Lord Hoffmann stated in Kirin-Amgen (at [128]), the skilled addressee must be assumed to be trying to carry out the invention and achieve success:
“The skilled person is taken to be trying to make the invention work. If the skilled person would quickly realise that one method would work and another would fail, the specification is not insufficient because the claim is expressed in terms broad enough to include both methods.”
The question which then arises is whether the specification provides clear guidance to the skilled addressee on how to adjust the materials and the process in order to arrive at the complete combination of properties, including the property of fire resistance, with certitude. If the work involved in making these adjustments requires more than reasonable trial and error, then it represents an undue burden, and the specification has failed to provide a sufficient disclosure.
The first of the parameters to appear in the claims is core density. The familiarity of the skilled addressee with the characterisation of gypsum boards via this parameter is not in dispute. See for example the first declaration of Dr Bruce at [41]:
“It has always been standard practice in the industry to characterise boards according to board weight and core density.”
Similarly, in regard to core hardness, the second parameter to appear in the claims, I can find nothing in the evidence to indicate that its determination in a sample of gypsum board is anything more than routine in the art.
The real question in regard to sufficiency of disclosure relates to the claimed requirement of fire resistance, and the degree to which it can be arrived at without undue burden, by adjusting the formulations of the invention within the remaining claimed parameters of Thermal Insulation Index, High Temperature shrinkage and the UL tests, in order to produce a fire resistant gypsum panel.
As I have already stated, there are a number of examples of the specification which fail the UL U419 one hour fire rating test, even where the ambient temperature is assumed to be at the uppermost allowable level of 90°F. These are the examples of Sample Runs 2, 6 to 10, 15 and 16. The specification at paragraph [0235] notes that Sample 6 was of the lowest weight and density of any of the samples, and at paragraph [0247], comments on the fact that of these test failures, all but Sample 2 and 16 were subject to manufacturing defects during their preparation:
“One concern during the testing, in addition, was that the panels from Sample Runs 1, 6 to 10 and 15 were subject to issues during manufacturing that might affect their resistance to high temperatures in the assemblies subject to fire testing. Such issues were potential core stucco hydration problems (Sample Run 1), potential over drying (Sample Runs 7 to 10) and greater levels of impurities in the gypsum source (Sample Runs 8 and 15). The results of the fire tests indicate that such manufacturing issues may have affected some of the exemplary panels formed according to principles of the present disclosure (e.g., Sample Runs 6, 7, 9, and 15). The results also demonstrate that such issues may be overcome and/or compensated for by core formulation and methods for making panels following principles of the present disclosure. Furthermore, the tests results confirm that any necessary adjustments to the fire performance of reduced weight and density panels of the present disclosure can be made by adjusting the relative amounts of high expansion vermiculite and gypsum to achieve the desired fire performance.”
The opponent particularly drew attention to Samples 3 and 4 at the hearing, pointing out that while they appear to have identical formulations (see TABLE VIII, FIG 26A of the specification), Sample 4 passes the U419 fire rating test and Sample 3 does not.
Firstly this is based on the presumption that the ambient temperature for the relevant test was 75°F. As I have stated previously, in light of the new evidence before me I am proceeding on the basis that the ambient temperatures for the tests varied between the range 75°F and 90°F, and that the ambient temperature for any particular Sample run is not possible to clearly ascertain from the specification. Referring to FIG 29C of the specification, in order for Sample 3 to have passed the U419 fire rating, the ambient temperature would have been required to be 81°F or more. Since this is well within the acceptable range of 75°F to 90°F I am willing to accept that Sample 3 may well have in fact passed the U419 fire rating test, and that its reduced fire resistance compared to Sample 4 can be explained in terms of its somewhat lower density and board weight as reported in TABLE VII, FIG 25B, presumably due to having a greater amount of air voids.
Secondly, as the applicant submitted during the hearing, referring to paragraphs [177] to [178] of Mr Berhinig’s declaration, the specification voluntarily opted for the harshest possible conditions under which to conduct the U419 test, involving a horizontal and non-staggered configuration.
In any case, whether or not Sample 3 passed the U419 fire rating, it appears to have at least attained the required level of performance to be regarded as fire resistant.
Since the specification clearly discloses the fact that Samples 6 to 10 and 15 were subject to manufacturing defects, I find it useful to also consider Samples 2 and 16, which despite not being reported as having experienced issues during manufacturing, failed to pass the U419 fire rating, even where their relevant ambient temperatures are considered to be at the upper acceptable limit of 90°F. Sample 2 is virtually identical in formulation to Samples 3, 4 and 5, which passed U419 (see TABLE VII, FIG 25A & 25B), with the notable exception that Sample 2 has considerably less high expansion vermiculite (5.8% compared to 7.8% by weight of stucco). Similarly, Sample 16 is virtually identical in formulation to Samples 17, 18 and 19 (which passed U419, U423 and U305 respectively), with the notable exception that it has considerably more gypsum (1328 compared to 1308 kg/m²) and more accelerator (136.7 compared to 131.8 g/m²).
The applicant submitted at the hearing that there are two groups of samples in the Sample Runs of the specification which together provide full disclosure in respect of the scope of the claims that require satisfaction of at least one of the UL fire rating tests, and also provide guidance to the skilled addressee as to how to make adjustments to the formulations, in order to produce with certitude, a fire resistant gypsum panel. The first group is that of Samples 3, 4, 5 and 20, which are made to the same formula, and while differing only slightly in respect of their board density, are all approximately 36.9 kg/m³ (see TABLE VII, FIG 25A and FIG 25B, column 7). The second group is that of Samples 17, 18 and 19, all made to the same formula, and different to the formula used for the first group in that it has more stucco (gypsum), more starch and less accelerator.
Sample 20 (from the first group) and Sample 19 (from the second group) both pass the U305 one hour fire rating, therefore satisfying the requirements of claims 9, 18 and 27, insofar as these claims each specify this test as one of three alternatives, and they also satisfy claim 19, which requires the U305 test alone.
Sample 18 (from the second group) passes the U423 one hour fire rating and therefore satisfies claims 9, 18 and 27, insofar as these claims each specify this test as one of three alternatives. None of the claims requires satisfaction of the U423 test as the only alternative. No other samples were subjected to the U423 fire rating test.
Samples 3, 4 and 5 (from the first group) and sample 17 (from the second group) pass the most stringent U419 one hour fire rating (albeit assuming that the ambient temperature was at least 81°F in respect of sample 3 as I have already discussed). Further disclosure of formulations passing the U419 test is provided by Samples 12, 13 & 14, each of which are prepared with a formula very similar to the second group discussed above, but using an increased amount of stucco (gypsum). These samples therefore satisfy the requirements of claims 9, 18 and 27, insofar as these claims each specify this test as one of three alternatives, and they also satisfy claim 20, which requires the U419 test alone.
Declarants for the applicant state that the test results of the application which fail the UL fire rating tests are equally as useful in providing guidance to the skilled addressee as those which pass, because they provide an indication of how to make adjustments to the formulations in order to improve fire resistance. For example, Mr Engbrecht sates, at [119] of his declaration:
“AU '626 discloses a range of ingredients that may be included when making gypsum panels. Thus, it is to be expected that the test results from the specimens made from the different formulations of AU '626 could also differ. In my opinion, the team of ordinary skill in the art would understand this aspect of AU '626, as well as benefit from the formulae provided in AU '626 that meet the claims of AU '626. AU '626 also informs the team of ordinary skill in the art how to adjust the levels of ingredients, such as vermiculite and stucco, to compensate for variations in manufacturing conditions or raw material quality and to modify fire resistance properties. (See AU '626 paragraphs [0236] and [0247].)”
And at [161] to [162] referring to the specification:
“I agree with the conclusion in paragraph [0235] that these manufacturing and material conditions would affect the fire resistance performance of the assemblies using these panels as compared to the other inventive samples. For example, over drying of the panels would result in calcination of some of the gypsum core, leaving less water to evaporate when the panel is heating during the fire test. Impurities in the gypsum source may also reduce the calcination point of the gypsum, causing the water in the gypsum to evaporate earlier than it otherwise normally would. Thus, I would exclude these panels from any evaluation of the overall assessment of the performance of the gypsum panels in a full scale fire test… However, the results of these tests are still useful. For instance, when comparing any decreased performance in fire resistance of these "flawed" inventive samples with the remaining samples, it would be apparent to one of ordinary skill in the art what adjustments would need to be made to achieve the desired fire performance - that is, the person of ordinary skill in the art would be able to look at the data in Figures 29A, 29B and 29C, along with the formulations for the inventive samples found in Figures 25A and 25B, and determine that simple adjustments could be made: first, correct any manufacturing problems, such as by properly drying the panels or using a gypsum source free of deleterious impurities; and second, adjust the amount of vermiculite and/or the amount of gypsum in the panel in order to achieve the desired fire resistance.

Nevertheless, the specification itself clearly refers to prior art information in the form of document D4 (see the specification at paragraphs [022] to [024]). This document is directed towards gypsum panels which are both light weight and fire resistant, hence I must conclude that knowledge of the problem, if not common general knowledge, is at least s7(3) information and therefore to be attributed to the skilled addressee for the purpose of assessing obviousness.
Thus the invention does not appear to reside in the decision to try to produce a gypsum panel that is both lightweight and fire resistant, rather the invention appears to reside in the identification of the particular combination of features claimed that solves that problem, and the question to be answered therefore, is whether or not that particular combination of features would have been arrived at by the skilled addressee, as a matter of routine.
The common general knowledge
The common general knowledge was described by Aickin J in Minnesota Mining and Manufacturing Co v Beiersdorf (Australia) Ltd (1980) 144 CLR 253 at 292 in the following way:
“The notion of common general knowledge itself involves the use of that which is known or used by those in the relevant trade. It forms the background knowledge and experience which is available to all in the trade in considering the making of new products, or the making of improvements in old, and it must be treated as being used by an individual as a general body of knowledge.”
The opponent asserted that 20 matters were all part of the common general knowledge, and further submitted that the delegate in the ‘102 decision did not give adequate consideration to obviousness in light of the common general knowledge alone, by failing to consider each of these 20 matters in detail (see opponent’s written submissions at [198] to [199], referring to the ‘102 decision at [153]).
According to the opponent, citing in each instance various passages of the first declarations of Dr Bruce for this opposition and for the ‘102 decision, these matters of alleged common general knowledge include the following:
While the majority of these matters of alleged common general knowledge do not appear to be contentious, the applicant submitted that this list was produced by Dr Bruce with the benefit of hindsight (see applicant’s written submissions at [122] to [126]). Be that as it may I will proceed on the assumption that the bulk of these matters might be regarded as common general knowledge in the art of gypsum panels, with the exception of the following:
The assertion of inherency in regards to matters q. and r. in the above list requires evidence, that the dimensions referred to, of air voids and walls within the gypsum core, would be inevitably arrived at by gypsum board manufacturers in the normal course of conducting their work. This can be done by showing that the prior art reports the properties, by independently preparing the panels of the prior art and measuring their properties, or otherwise showing that they are inherent to the panels. But whatever way it is done, the onus of doing it rests with the opponent. I am not satisfied on the balance of probabilities that the opponent has discharged their onus in this regard.
Similarly in regards to matters j. and p., while I can accept that it is widely known that the properties of unexpanded vermiculite must be matched to the gypsum board core formulation being used, the opponent has not provided any convincing evidence relating to how this matching process is normally conducted. It is therefore reasonable to infer that the properties of the gypsum board are the result of a complex and subtle interaction between the various components that go to make it up, and that the process of matching unexpanded vermiculite to core formulation goes beyond what could be regarded as common general knowledge.
Matters of routine: modifying existing panels
There are numerous submissions made by the declarants of both parties in relation to what teams in the art would or would not do, when faced with the problem of producing a gypsum panel that is both lightweight and fire resistant. This evidence is of assistance in that it sheds light on what the skilled addressee would have done.
Dr Bruce, at paragraph [51] of his first declaration, repeats the submission he made in the ‘102 decision (see the ‘102 decision at [155]), that he would have started out by modifying an existing lightweight board:
“My approach would be to start with the formulation for an existing lightweight gypsum board which I would seek to modify. As stated above, there has been a general trend in the industry towards the production of lightweight gypsum boards to be well known and widely available. I would seek to modify the formulation for such a lightweight board by using one or more additives in order to produce the requisite fire resistant properties in the board whilst retaining its lightweight properties. This is how fire resistant boards were made in the past. I note that in the past, boards were not as light as they were at the Priority Date because the weights of boards have progressively decreased.”
Mr Engbrecht does not agree with this perspective, at paragraph [280] of his declaration:
“Dr. Bruce offers no support showing that the team of ordinary skill in the art would start with lightweight panels of this type. I disagree that the team of ordinary skill would consider this type of gypsum panel as a logical starting point because from their perspective, such a lightweight panel requires removing the primary heat sink component, gypsum.”
Mr Ball offers a consistent view at paragraph [377] of his declaration:
“Even if Dr Bruce's approach were viable, the very first additive that would be added would be gypsum to increase the heat sink capacity of the board, thus increasing the density.”
Mr Aird considers the matter of modifying existing panels from the alternative perspective of reducing the weight of existing fire resistant panels, at paragraphs [365] to [367]:
“…the team of ordinary skill in the art did not routinely vary the formulation of fire resistant gypsum panels… In my view, in order to arrive at the invention defined in claims 1 to 27 of AU'626, the team of ordinary skill in the art would have to vary his or her routine work practice and investigate at length and at significant cost a completely different formulation with two major changes - namely the introduction of a new type of expandable particle while also forcing a significant reduction in panel density. In my view, setting out on such an investigation, unprompted by any knowledge of different vermiculite types and with a weight of evidence suggesting that gypsum mass is important to fire resistance, would have been unlikely.”
To the extent that it is indicative that the gypsum panel industry is generally not highly innovative, the evidence of Messrs Engbrecht, Ball and Aird is of assistance. However, for the purposes of determining whether or not there is an inventive step, the skilled addressee must be assumed to want to find a solution to the problem.
It is clear from the evidence that the properties of fire resistance and low density are both well known as desirable properties in the gypsum panel industry, and that considerable effort has been exerted in the past in pursuit of each of these properties.
As I have discussed above, in relation to references in the specification itself to prior art document D4, it is also known in the art to seek to produce gypsum panels possessing both of these properties simultaneously.
It follows that the starting point proposed by the delegate in the ‘102 decision (at [161]) represents a reasonable starting point for the purposes of assessing inventive step in this instance, namely:
“it is a safe inference that a person could either start with a fire resistant panel and reduce its weight, or start with a low weight panel and increase its fire resistance.”
Matters of routine: vermiculite
An additional issue upon which this opposition turns is whether the use of unexpanded vermiculite in fire resistant gypsum panels was a matter of routine.
Dr Bruce provides a list of additives that he says he would have considered when faced with the problem of producing a light weight fire resistant gypsum board, the first of which is unexpanded vermiculite (see the first declaration of Dr Bruce at paragraph [53]):
“The additives that I would have selected as being potentially suitable for the purposes of producing a lightweight fire resistant gypsum board as at the Priority Date would include:
a. Unexpanded Vermiculite;”
Mr Engbrecht supports the view that it was well known to include vermiculite in fire resistant gypsum panels, at paragraph [45]:
“The head of manufacturing of the team of ordinary skill in the art would likely know that vermiculite is used in making a gypsum panel with enhanced fire resistance properties and may possibly know that adding vermiculite to the panel improves the stability of the panel under high temperature situations due to the exfoliation and expansion of the vermiculite in the core. If the plant where the technical support person of the team of ordinary skill in the art works uses vermiculite in making fire resistant gypsum panels, then the technical support person would likely know that vermiculite is used in making a gypsum panel with enhanced fire resistance properties and would also likely know that it expands because such person probably tests the vermiculite as part of routine testing of the ingredients used in the plant, but that technical support person would most likely not know any more about vermiculite. I note that not all plants make gypsum panels with enhanced fire resistance properties using vermiculite.”
Mr Aird, at paragraph [96] of his declaration, reiterates this position:
“The person in the formulations area within the R&D group, having some understanding of the chemistry of the formulation, would appreciate that vermiculite was used in fire resistant gypsum panels to counteract some of the shrinking that occurs when gypsum is heated.
Similarly Mr Berhinig says at paragraph [109] of his declaration:
“The head of manufacturing of the team of ordinary skill in the art would know that vermiculite and glass fibers are used in some fire resistant gypsum panels and that glass fibers help to keep the panel from failing at high temperatures. The head of manufacturing may possibly know that vermiculite expands to counter the shrinking gypsum as the heat increases.”
As does Mr Ball at paragraph [70] of his declaration:
“…fine vermiculite was used to at least partially compensate for shrinkage of the panel during heating…”
The evidence, including the reference above by Mr Ball to “fine vermiculite” gives clear indications that the particle size of unexpanded vermiculite being used is a key issue, as none of the prior art documents raised discloses the usage of vermiculite particles as large as those used in the present application (or with the resultant high level of expansion of 300% when exposed to sufficient heat as claimed).
In this regard Mr Aird also goes on to say, at paragraph [378] of his declaration:
“In my view, the use of larger particle size, high expansion vermiculite is not a known method of enhancing fire resistance particularly when coupled with the significant reduction in density for the claimed gypsum panels - the team of ordinary skill in the art would consider that either modification (let alone both in combination) would have a negative impact on fire resistance.”
I therefore conclude that unexpanded vermiculite was well known as an additive that had been used to improve fire resistance in gypsum panels, and that there is sufficient basis to believe that this was common general knowledge in the art. However I am not satisfied that it would necessarily be a matter of routine to try unexpanded vermiculite, particularly of the high expansion variety claimed, in the absence of other motivations.
Obviousness in light of the common general knowledge alone
The invention is a gypsum panel which addresses the problem of being both light and weight fire resistant, and (as defined by the claims) has a combination of physical integers. The opponent must show that it would have been a matter of routine to combine that combination of integers in order to solve the particular problem.
Dr Bruce for the opponent, at paragraph [76] of his first declaration submits that:
“The alleged invention merely constitutes the use of an additive with known properties combined with an existing formulation for a lightweight gypsum board.”
However, the evidence falls short of establishing that the use of unexpanded vermiculite of a large particle size (defined in the specification at [0106] as I have discussed above as “Grade No. 4” vermiculite or larger) in fire resistant gypsum panels was a matter of routine. The only submission made in this regard is an assertion by Dr Bruce at paragraph [81] of his first declaration that:
“The use of unexpanded vermiculite to create a fire resistant gypsum board was within the common general knowledge as it existed at the Priority Date. For instance, Grade No. 4 and Grade No. 5 vermiculite was commonly used at Domtar for this purpose since the 1980s.”
With nothing further to support this assertion it is difficult to give it much weight, and in any case it must be considered together with substantial evidence from all parties that the use of high expansion vermiculite presents difficulties in the formulation of gypsum panels, due to its propensity to compromise structural integrity. See for example Dr Bruce’s first declaration at paragraph [55]:
“… I am aware that it is particularly important to use the right grade of unexpanded vermiculite to correspond with the gypsum core formulation. Since unexpanded vermiculite can expand to approximately 300% of its original volume when exposed to extreme heat, use of an excessive amount, or the 'wrong' grade of vermiculite, can cause spalling (fragmenting, flaking and peeling) as well as premature cracking of the gypsum board when it is exposed to heat. This adversely affects the structural integrity and thermal insulation properties of the board.”
Dr Bruce goes on to submit (at [92] of his first declaration) that larger particles of unexpanded vermiculite would be obvious to use with lightweight gypsum board formulations because these are known to have larger internal voids which could then accommodate the increased expansion associated with the vermiculite, without being structurally compromised:
“As boards become lighter, the choice of grades of vermiculite that may be used to advantage will obviously increase. This is because the larger voids present in lightweight boards as compared to heavier boards would be able to accommodate any additional expansion of a selected vermiculite, thereby reducing the chance of spalling. It would be far from being a surprising effect.”
However this submission fails to address the specific integers claimed by the applicant which solve the problem, namely the specified maximum core density and minimum core hardness, in combination with high expansion vermiculite of a grade apparently hitherto unused in the art of fire resistant gypsum panels with any degree of success, due to the difficulties with structural integrity that this presents. In this regard I am reminded of the words of Justice Whitford in Lucas and Another v Gaedor Ltd and Others [1978] RPC 297 at page 358:
“If an invention has resulted in the solution of a problem which has been troubling industry for years and achieves immediate success upon its introduction, then the suggestion after the event that the step was obvious inevitably rings a little hollow… This is not a case in which there was a problem by which people were plainly being baffled. There are however cases in which the materials needed to arrive at the allegedly obvious solution were available to a number of skilled persons or groups of persons and in which all but one of them failed to take what is eventually said to be the obvious step, and this to my mind is just such a case.”
In the present context, the evidence falls short of establishing that the skilled addressee would have a significant expectation of success when employing larger particles of vermiculite in existing formulations for light weight gypsum boards, with a view to solving the problem of providing gypsum boards that are both light weight and fire resistant. As discussed in AstraZeneca AB v Apotex Pty Ltd [2015] HCA 30, the expectation of success is a legitimate consideration when assessing obviousness and the motivations of the skilled addressee. In the words of Justice Nettle, at [123]:
“…the evidence also disclosed that trials of that kind would conventionally be carried out. Accordingly, carrying out the trials fell within the concept of working towards an invention with an expectation of success and that was consistent with the conclusion that the invention was obvious.”
Above I stated that it would not have been a matter of routine to use unexpanded vermiculite of a large particle size (or to use the language of the claims, vermiculite with a volume expansion of 300% or more when heated at 1560°F for about one hour), in the absence of other motivations.

I also stated above that I am not satisfied the opponent has discharged their onus in regard to showing that the claimed dimensions of air voids and walls within the gypsum core, would be inevitably arrived at by gypsum board manufacturers in the normal course of conducting their work. Nor has it been established that the process of matching a particular grade of unexpanded vermiculite to a particular gypsum core formulation could be regarded as common general knowledge.
It follows that it has not been shown that the invention lacks an inventive step in light of the common general knowledge alone.
Obviousness in light of the citations
US 2005/0263925 (designated D1) was published on 1 December 2005. Consequently it is part of the prior art base. The disclosure of D1 was discussed in detail by the delegate in the ‘102 decision (at paragraphs [125] to [131]). For the sake of brevity I will incorporate by reference this part of the ‘102 decision as I believe it is an accurate representation of what D1 discloses.
As noted by the delegate in the ‘102 decision, D1 discloses the principles of preparing fire resistant gypsum panels containing additives that could fall within the scope of claim 1 if the right combination is selected. In this situation, the question to be answered is whether this is mere verification of the teaching of D1, or whether it is something more. On the face of it, preparing a panel that is within the broad teaching of D1 and confirming that it is a fire resistant panel is no more than verification.
As I have discussed above, this would be a matter of routine if the expectation of success is high. D1 sets out the invention at paragraph [0025] as the use of calcium sulfate dehydrate and reinforcing by resilient, flexible, glass fibers. Foaming agents are an optional additive at paragraph [0031], and unexpanded vermiculite is an optional additive at paragraph [0063]. There is no disclosure of the use of unexpanded vermiculite with a volume expansion of 300% or more when subjected to sufficient heat. There is no disclosure of a core hardness of at least 11 pounds. There is no data that shows that such panels meet the UL or ASTM fire resistance standards. I consider that D1 conjectures that panels with unexpanded vermiculite would be fire resistant. In my view D1 does not clearly predict that there is a high expectation of success for the particular combination of features claimed in the present application. I am not satisfied that on the balance of probabilities the opponent has shown that in light of D1 there would be a high expectation of success in solving the problem.
It follows that it has not been shown that the claims lack inventive step in the light of D1.
US 3,616,173 (designated D4) was published on 26 October 1971. Consequently it is part of the prior art base. The disclosure of D4 was discussed in detail by the delegate in the ‘102 decision (at paragraphs [132] to [140]). For the sake of brevity I will incorporate by reference this part of the ‘102 decision as I believe it is an accurate representation of what D4 discloses.
As noted by the delegate in the ‘102 decision, D4 teaches the possibility of preparing fire resistant gypsum panels with a density as low as 35 pounds per cubic foot. However, the document provides a clear indication that densities below 40 pounds per cubic foot should be avoided (column 12):
“On the other hand it has been found that as the core density is decreased below about 40 lbs per cubic foot, problems are encountered in forming good bonds between the core and the facing paper.”
This is a clear indication that D4 teaches away from producing gypsum panels of densities below 40 pounds per cubic foot. The opponent submitted that nevertheless, D4 provides an example of a panel which is 41 pounds per square foot, arguing that this meets the limitations of the present claims which require a density of “about” 40 pounds per cubic foot or less. As Dr Bruce states in his second declaration at paragraph [81]:
“D4 does in fact disclose a panel with a density of 41 pcf (see Sample E at column 6 lines 45 to 48). Within manufacturing tolerances generally accepted in the gypsum panel industry, I would consider a manufactured panel having a density of 41 pcf to be 'about' 40 pcf, as required by each of claims 1 to 30 of the '626 Application.”
Even if I were to accept this argument, I must also consider the other integers of the claims. D4 contains no disclosure of a core hardness of at least 11 pounds. There is no data in D4 that shows that such panels meet the UL or ASTM fire resistance standards. Perhaps most importantly there is no disclosure of the use of unexpanded vermiculite with a volume expansion of 300% or more when subjected to sufficient heat.
Further in this regard there are substantial indications in D4 that larger quantities of vermiculite are not preferred. Referring to the declaration of Mr Ball at paragraphs [298] to [299]:
“Table 4 shows that where clay, fibreglass and vermiculite were used (Examples 23-31}, as clay was increased the shrink resistance of the samples increased from about 76.4% to 83.5%, while in each formula where vermiculite was increased the shrink resistance actually decreased or stayed the same. I refer to the comparison between Examples 23 and 24, 25 and 26, 27 and 28, 29 and 30. The best shrink resistance result was obtained with the maximum clay and fibreglass percentage and the minimum vermiculite percentage. This suggests that vermiculite should be replaced with clay and fibreglass, which is a very different teaching to the invention taught in AU'626.”
I consider that D4 conjectures that panels with unexpanded vermiculite would be fire resistant. It is noteworthy that D4 appears to teach away from lower core densities and larger quantities of vermiculite. In my view D4 does not clearly predict that there is a high expectation of success for the particular combination of features claimed in the present application. I am not satisfied that on the balance of probabilities the opponent has shown that in light of D4 there would be a high expectation of success in solving the problem.
It follows that it has not been shown that the claims lack inventive step in the light of D4.
US 4,647,486 (designated D5) was published on 3 March 1987. Consequently it is part of the prior art base. The disclosure of D5 was discussed in detail by the delegate in the ‘102 decision (at paragraphs [184] to [189]). For the sake of brevity I will incorporate by reference this part of the ‘102 decision as I believe it is an accurate representation of what D5 discloses.
As noted by the delegate in the ‘102 decision, D5 discloses the principles of preparing fire resistant gypsum panels containing additives (including unexpanded vermiculite) that could fall within the scope of claim 1 if the right combination is selected. In this situation, the question to be answered is whether this is mere verification of the teaching of D5, or whether it is something more. On the face of it, preparing a panel that is within the broad teaching of D5 and confirming that it is a fire resistant panel is no more than verification.
As I have discussed above, this would be a matter of routine if the expectation of success is high. D5 discloses foaming agents as an optional additive, and unexpanded vermiculite is included in samples #12, #13 and #14. There is no disclosure of the use of unexpanded vermiculite with a volume expansion of 300% or more when subjected to sufficient heat. There is no disclosure of a core hardness of at least 11 pounds. There is no data that shows that such panels meet the UL or ASTM fire resistance standards. I consider that D5 conjectures that panels with unexpanded vermiculite would be fire resistant. In my view D5 does not clearly predict that there is a high expectation of success for the particular combination of features claimed in the present application. I am not satisfied that on the balance of probabilities the opponent has shown that in light of D5 there would be a high expectation of success in solving the problem.
It follows that it has not been shown that the claims lack inventive step in the light of D5.
US 2008/0087366 (designated D8) was published on 17 April 2008. Consequently it is part of the prior art base. The disclosure of D8 was discussed in detail by the delegate in the ‘102 decision (at paragraphs [141] to [145]). For the sake of brevity I will incorporate by reference this part of the ‘102 decision as I believe it is an accurate representation of what D8 discloses.
As noted by the delegate in the ‘102 decision, D8 discloses the principle of preparing fire resistant gypsum panels containing additives that could fall within the scope of claim 1 if the right combination is selected. In this situation, the question to be answered is whether this is mere verification of the teaching of D8, or whether it is something more. On the face of it, preparing a panel that is within the broad teaching of D8 and confirming that it is a fire resistant panel is no more than verification.
For similar reasons to those explained for D1, this would be a matter of routine if the expectation of success is high. None of the declarants address this point. D8 sets out the essential ingredients of the panel as gypsum (paragraph [0019]) and high temperature shrinkage resistant material (paragraph [0025]). Intumescent materials such as vermiculite are added to the slurry (paragraph [0036]). There is no disclosure of the use of unexpanded vermiculite with a volume expansion of 300% or more when subjected to sufficient heat. There is no disclosure of a core hardness of at least 11 pounds. The panels exemplified have a density of 43.1 to 49.5 pounds per cubic foot. None of the exemplified panels have a density of 40 pounds per cubic foot or less. There is no data that shows that these panels meet the UL or ASTM fire resistance standards.
D8 does not teach or suggest reducing the density of the panels to below 40 pounds per cubic foot. The opponent pointed to claim 9, which claims a panel with a density "of about 1800 to about 2600 lb/1000 ft² with 5/8" thickness". By my calculation, this equates to a density of 34.6 to 49.9 pounds per cubic foot. I consider that D8 conjectures that a panel with a density below 40 pounds per cubic foot could be produced, and that this panel would be fire resistant. In my view D8 does not clearly predict that there is a high expectation of success for this combination. I am not satisfied that on the balance of probabilities the opponent has shown that in light of D8 there would be a high expectation of success in solving the problem.
It follows that it has not been shown that the claims lack inventive step in the light of D8.
Conclusion
The opposition fails on all grounds.
Costs
Both parties submitted at the hearing that costs should follow the event. I see no reason to depart from that general principal.
Dr D.A.S. Beck
Delegate of the Commissioner of Patents
Table 1: Fire resistance tests of samples
[Values that fail the claimed requirements for fire resistance are shown as shaded.]

Full Scale Tests Bench Top Tests

Sample Full Scale Test Type^‡ Max Temp at 60 Min
Unexposed, Single Sensor °F^* Ave Temp at 60 Min
Unexposed, Ave of Sensors °F^* Thermal Insulation Index (TI) mins^** High Temp Shrinkage %^*** Ratio of High Temp Thickness Expansion (TE) % to High Temp Shrinkage (S) %^***

Pass value < 400-415°F^§ < 325-340°F^§ ≥ 20mins ≥ 0.2

Required by Claims 9, 18-20, 27 Claims 9, 18-20, 27 Claim 1 Not claimed in isolation Claim 10

1 U419 398 322 22.95 4.5 5.56

2 U419 443 308 24 3.7 3.78

3 U419 406 305 25.06 3.3 7.88

4 U419 375 398 25.19 3.3 7.88

5 U419 354 285 25.19 3.3 7.88

6 U419 468 336 23 3.5 3.14

7 U419 499 338 21.7 3.1 7.42

8 U419 423 326 23.13 3.1 7.42

9 U419 508 373 24 2.4 10.83

10 U419 420 330 24 3.5 6.57

11 U419 405 318 23.7 4.0 7.00

12 U419 394 307 23.5 4.1 5.61

13 U419 395 306 24.1 2.3 12.17

14 U419 351 292 23.4 1.8 16.11

15 U419 465 358 23.5 2.5 8.80

16 U419 435 336 23.1 2.3 10.43

17 U419 391 327 22.9 2.4 12.08

18 U423 307 274 22.9 1.9 17.37

19 U305 261 243 22.9 1.9 17.37

20 U305 245 235 25.13 3.3 7.88

Type X U419 361 292 25.5 5.4 -1.67

Glass faced U423 363 259 28 2.0 N/A

Type C N/A N/A N/A 28 3.0 0.00
^‡Extracted from FIG 29A
^*Extracted from FIG 29C
^**Extracted from FIGS 28A & 28B
^***Extracted from FIGS 26A & 26B
^§Assumes ambient temperatures in the range of 75-90°F
Would fail test if ambient temperature was at lower end of assumed range (75°F)
Table 2: Fire resistance tests of samples
[Values that fail the claimed requirements for fire resistance are shown as shaded.]

Sample Full Scale Test Rig Type^‡ Claimed Requirements

Max Temp at 60 Min
Unexposed, Single Sensor °F^* Ave Temp at 60 Min
Unexposed, Ave of Sensors °F^* Max Temp at 55 Min
Unexposed, Single Sensor °F Ave Temp at 55 Min
Unexposed, Ave of Sensors °F Max Temp
Unexposed, Single Sensor & Ave Temp
Unexposed, Ave of Sensors at 50 Min °F

Pass value <500°F <380°F <410°F <320°F <260°F & <250°F

Required by Claim 22 Claim 23 Claim 24 Claim 25 Claim 26

1 U419 398 322 267 256 247 & 234

2 U419 443 308 270 251 249 & 229

3 U419 406 305 267 255 246 & 237

4 U419 375 398 261 256 251 & 242

5 U419 354 285 263 250 245 & 236

6 U419 468 336 314 273 251 & 243

7 U419 499 338 357 277 253 & 241

8 U419 423 326 283 259 248 & 235

9 U419 508 373 297 266 252 & 243

10 U419 420 330 263 254 244 & 236

11 U419 405 318 261 253 246 & 237

12 U419 394 307 264 251 246 & 232

13 U419 395 306 262 252 246 & 237

14 U419 351 292 259 250 243 & 234

15 U419 465 358 273 260 254 & 243

16 U419 435 336 267 257 252 & 241

17 U419 391 327 260 252 245 & 238

18 U423 307 274 261 242 251 & 230

19 U305 261 243 257 235 235 & 222

20 U305 245 235 238 224 226 & 212

Type X U419 361 292 258 250 248 & 234

Glass faced U423 363 259 253 226 230 & 215
^‡Extracted from FIG 29A
^*Extracted from FIG 29C
Extracted from FIG 29B

System Number	Page Number	Gypsum Panel Thickness (mm)
CSR 038	B11	16
CSR 906	C22	16

Full Scale Tests			Bench Top Tests
Sample	Full Scale Test Type^‡	Max Temp at 60 Min Unexposed, Single Sensor °F^*	Ave Temp at 60 Min Unexposed, Ave of Sensors °F^*	Thermal Insulation Index (TI) mins^**	High Temp Shrinkage %^***	Ratio of High Temp Thickness Expansion (TE) % to High Temp Shrinkage (S) %^***
Pass value		< 400-415°F^§	< 325-340°F^§	≥ 20mins	≥ 0.2
Required by		Claims 9, 18-20, 27	Claims 9, 18-20, 27	Claim 1	Not claimed in isolation	Claim 10
1	U419	398	322	22.95	4.5	5.56
2	U419	443	308	24	3.7	3.78
3	U419	406	305	25.06	3.3	7.88
4	U419	375	398	25.19	3.3	7.88
5	U419	354	285	25.19	3.3	7.88
6	U419	468	336	23	3.5	3.14
7	U419	499	338	21.7	3.1	7.42
8	U419	423	326	23.13	3.1	7.42
9	U419	508	373	24	2.4	10.83
10	U419	420	330	24	3.5	6.57
11	U419	405	318	23.7	4.0	7.00
12	U419	394	307	23.5	4.1	5.61
13	U419	395	306	24.1	2.3	12.17
14	U419	351	292	23.4	1.8	16.11
15	U419	465	358	23.5	2.5	8.80
16	U419	435	336	23.1	2.3	10.43
17	U419	391	327	22.9	2.4	12.08
18	U423	307	274	22.9	1.9	17.37
19	U305	261	243	22.9	1.9	17.37
20	U305	245	235	25.13	3.3	7.88
Type X	U419	361	292	25.5	5.4	-1.67
Glass faced	U423	363	259	28	2.0	N/A
Type C	N/A	N/A	N/A	28	3.0	0.00

Sample	Full Scale Test Rig Type^‡	Claimed Requirements
Sample	Full Scale Test Rig Type^‡	Max Temp at 60 Min Unexposed, Single Sensor °F^*	Ave Temp at 60 Min Unexposed, Ave of Sensors °F^*	Max Temp at 55 Min Unexposed, Single Sensor °F	Ave Temp at 55 Min Unexposed, Ave of Sensors °F	Max Temp Unexposed, Single Sensor & Ave Temp Unexposed, Ave of Sensors at 50 Min °F
Pass value		<500°F	<380°F	<410°F	<320°F	<260°F & <250°F
Required by		Claim 22	Claim 23	Claim 24	Claim 25	Claim 26
1	U419	398	322	267	256	247 & 234
2	U419	443	308	270	251	249 & 229
3	U419	406	305	267	255	246 & 237
4	U419	375	398	261	256	251 & 242
5	U419	354	285	263	250	245 & 236
6	U419	468	336	314	273	251 & 243
7	U419	499	338	357	277	253 & 241
8	U419	423	326	283	259	248 & 235
9	U419	508	373	297	266	252 & 243
10	U419	420	330	263	254	244 & 236
11	U419	405	318	261	253	246 & 237
12	U419	394	307	264	251	246 & 232
13	U419	395	306	262	252	246 & 237
14	U419	351	292	259	250	243 & 234
15	U419	465	358	273	260	254 & 243
16	U419	435	336	267	257	252 & 241
17	U419	391	327	260	252	245 & 238
18	U423	307	274	261	242	251 & 230
19	U305	261	243	257	235	235 & 222
20	U305	245	235	238	224	226 & 212
Type X	U419	361	292	258	250	248 & 234
Glass faced	U423	363	259	253	226	230 & 215