Imperial Chemical Industries PLC v E.I. Du Pont De Nemours and Co
[1999] APO 63
•11 October 1999
OFFICIAL NOTICE
DECISION OF A DELEGATE OF THE COMMISSIONER OF PATENTS
Application : No. 654176 in the name of Imperial Chemical Industries PLC
Title: Refrigerant Compositions
Action: Opposition under section 59 by E.I. Du Pont De Nemours and Company
Decision: Issued
Abstract
The opposition fails on all grounds.
a)The application is entitled to priority from the basic document. The changes from the basic document can be regarded as a working out of material broadly described in the basic document.
Coopers Animal Health Australia Ltd v Western Stock Distributors Pty Ltd (1987) 15 FCR 382 applied.
b)The application is novel. The citations disclose the use of HFC's as refrigerants, but do not disclose all the essential features.
Meyers Taylor Pty Ltd v Vicarr Industries Ltd (1977) 137 CLR 228 followed.
c)The application is not obvious. The problem-solution approach is applied.
Rhone-Poulenc Rorer S.A.'s Application [1995] APO 50 followed.
When viewed in the light of the problem, none of the citations suggest the solution provided by the claimed invention.
d)The specification complies with section 40.
PATENTS ACT 1990
DECISION OF A DELEGATE OF THE COMMISSIONER OF PATENTS
Re:Patent Application No. 654176 by Imperial Chemical Industries PLC and opposition under section 59 by E.I. Du Pont De Nemours and Company.
BACKGROUND
Patent application 13959/92 in the name of Imperial Chemical Industries PLC (hereafter referred to as ICI) was filed on 1 April 1992, claiming priority from the basic application GB 9108527 dated 18 April 1991. Following examination by the Commissioner, the application was advertised accepted on 27 October 1994 under the serial number 654176.
On 27 January 1995 a notice of opposition were filed by E.I. Du Pont De Nemours and Company (hereafter referred to as Du Pont). A statement of grounds and particulars was filed on 27 April 1995. The statement of grounds and particulars was amended on several occasions, the last being on 26 February 1996. The service of evidence was completed on 23 October 1998.
The opposition was heard in Sydney on 5 and 6 July 1999. ICI was represented by Mr David Catterns QC, instructed by Mr Ray Evans of Phillips Ormonde & Fitzpatrick, Melbourne. Du Pont was represented by Mr Justin Gleeson of counsel, assisted by Dr Elizabeth Sutherland, patent attorney of Callinan Lawrie.
THE GROUNDS OF OPPOSITION
The patent application was filed under the Patents Act 1990. Consequently, the present oppositions are governed by section 59 of the Act and Chapter 5 of the Regulations. The statement of grounds and particulars identifies the grounds of opposition as:
ØNovelty;
ØInventive step; and
ØSection 40 matters.
THE SPECIFICATION
Background to the invention
The specification relates to heat transfer compositions for heat transfer devices (such as refrigerators and air conditioners), comprised of a lubricant and a heat transfer fluid (also referred to as a refrigerant). Heat transfer devices operate by circulating the refrigerant within a closed system. In one zone, the refrigerant takes in heat from the environment and evaporates at low pressure. In another zone the vapour condenses and gives off heat. The condensate is then returned through an expansion valve to the evaporation zone. The refrigerant is circulated by means of a pump or compressor. The operation of heat transfer devices of the type involved in the present application are described by Emmett J in ICI Chemicals & Polymers Ltd v Lubrizol Corp Inc [1999] FCA 345 (the first Lubrizol decision) at [8] to [33]. The refrigerants traditionally include chlorofluorocarbons (known as CFC's). Heat transfer devices frequently utilise lubricants such as mineral oils in conjunction with the circulating refrigerant. The solubility of mineral oils in CFC's allows the mineral oil to circulate around the heat transfer device together with the CFC, which provides proper lubrication of the compressor.
However, CFC's have been implicated in the destruction of the ozone layer, and their use is limited by international agreement. Consequently there is a need for a CFC-free heat transfer composition.
A table of the designation codes used in relation to refrigerant fluids is given in Annex 1 of this decision.
The consistory statement
The present specification provides a heat transfer composition (referred to as a "refrigerant composition") comprising:
(I) a ternary or higher mixture of
(a) tetrafluoroethane (R-134 or R-134a) and/or heptafluoropropane (R-227ea);
(b)difluoromethane (R-32) and/or 1,1,1-trifluoroethane (R-143a); and optionally
(c) pentafluoroethane (R-125); and
(II) a lubricant comprising a polyalkylene glycol and/or an ester.
The body of the description
The specification exemplifies 15 refrigerant mixtures of R-32/134a/125 in varying ratios of the components. The exemplified mixtures do not contain a lubricant. The lubricant is briefly discussed at pages 10 - 11:
"As stated above the refrigerant will be formulated into a refrigerant composition together with a lubricant. Polyalkylene glycols and especially esters are the lubricants used in the refrigerant compositions of the invention. By selecting a lubricant with a high thermal stability, it is possible to operate with higher compressor discharge temperature than is currently possible using conventional hydrocarbon lubricants and this can improve the thermodynamic efficiency of the refrigeration system."
No specific lubricants are stated in the description.
The claims
The claims of the specification are reproduced in full in Annex 2. In approaching the construction of the claims I am conscious of the need to construe terms in the context of the specification and the state of the art: "one should not pick one’s way through a claim wearing blinkers that exclude from sight the context in which the claim is set. In the modern cases, it is frequently said that a specification should be given a purposive construction rather than a purely literal one" (International Business Machines Corp v Commissioner of Patents (1991) 22 IPR 417 at 421).
There are two independent claims: claim 1 and claim 10. Claim 1 is directed to a composition "comprising" two integers, designated I and II. I consider that in the context of a composition of a refrigerant and lubricant, it is reasonable to construe the composition as including other standard additives (such as antioxidants). Thus I construe "comprising" in an inclusive sense.
Integer I is a refrigerant that is itself a ternary or higher mixture of refrigerants. One of the components is identified as "tetrafluoroethane", which can exist in two isomeric forms: R-134 and R-134a. I consider that the generic name should be regarded as referring to either of the forms. However, I believe that tetrafluoroethane cannot make up two of the components of the mixture, i.e. it is either R-134 or R-134a that is included.
The refrigerants are presented as a list, which can be simplified to:
(a) (R-134 or R-134a) and/or (R-227ea);
(b)(R-32) and/or (R-143a); and optionally
(c) (R-125).
I consider that mixture must have three or more refrigerants selected such that there must be component (a) AND component (b) present, AND OPTIONALLY component (c). The refrigerant does not contain anything outside components (a), (b) and (c).
Integer II is a lubricant "comprising" a glycol and/or an ester. Lubricants are often mixtures of compounds, so it would be expected that "comprising" is used in an inclusive sense.
Claim 10 is directed to a composition "comprising" two integers I and II. For the reasons stated above, I consider that "comprising" is used in an inclusive sense. Integer I is defined as "comprising" three refrigerants: R-134a, R-32 and R-125. While mixtures of a large number of refrigerants are not normal, in the context of the specification I can see no reason why this mixture could not include additional refrigerants (higher mixtures are envisaged by the specification, and specifically included within the scope of claim 1). Integer II is the same as that in claim 1.
PRIORITY DATES OF THE CLAIMS
The priority date of the claims of the opposed specification was the subject of detailed submissions by counsel.
The relevant law
The priority date of a claim is determined by section 43(2), which states:
"(2) The priority date of a claim is:
(a) the date of filing of the specification; or(b)where the regulations provide for the determination of a different date as the priority date - the date determined under the regulations."
Consequently, the starting point is the date of filing of the specification. In the present case the application is a Convention application, and the regulations provide for a different priority date. The relevant regulation is 3.12:
"3.12 (1) Subject to regulations 3.13 ("priority dates: certain persons and applications") and 3.14 ("priority dates: certain amended claims") and subregulation (2), the priority date of a claim of a specification is the earliest of the following dates:
(a) the date of filing of the specification;
(b)if the claim is fairly based on matter disclosed in 1 or more priority documents, the date of filing the priority document in which the matter was first disclosed; …
(2) For the purposes of paragraph (1)(b): …
(b)if the application that relates to the specification containing the claim is a Convention application, a document of any of the following kinds is a priority document:
(i)a basic application that is related to the Convention application;"
Thus a claim takes the filing date of the priority document as it's priority date if it is fairly based on that priority document. The fair basis test for priority can be expressed as a "real and reasonably clear disclosure" test (F.Hoffman-La Roche & Co Aktiengesellschaft v Commissioner of Patents (1971) 123 CLR 529 at 539). In approaching this task, the courts have recognised that priority documents have a different role to that of complete specifications. In Coopers Animal Health Australia Ltd v Western Stock Distributors Pty Ltd (1987) 15 FCR 382 at 389, Fox J (with whom Spender J agreed) stated in relation to provisional specifications:
"Where the holder of the provisional specification proceeds with a complete specification with a view to the grant of a patent, it is recognised that greater definition, as a result of further experimentation or otherwise, may be achieved before the later step is taken and the result expressed therein. Some generality of expression in the provisional specification is accepted. In language which he would not have used as a definition, but is nevertheless a guide, Lloyd-Jacob J in Imperial Chemical Industries Ltd (Clark's Application) [1969] RPC 574 at 583 said of the function of a provisional specification that it is: '…a description of the general nature of the invention, its field of application and the anticipated result.' …
The fact that there may be a further working out of details before the complete specification is lodged does not mean that the provisional specification can always be used as giving a priority date to something which is worked out and contained in the specification. In particular, the selection of one compound with special qualities from a class of compounds disclosed in the provisional is not permissible for that purpose"
In Hoffman-La Roche v Commissioner at 544 Gibbs J accepted that the opportunity for development is applicable to both provisional applications and Convention applications. It is clear that a basic document can be expressed in more general language than the complete specification, and it is legitimate for there to be some development between the basic document and the complete specification. However, the development cannot be such as to amount to a different invention. This is made very clear in Stauffer Chemical Co.'s Application [1977] RPC 33 (quoted in CCOM Pty Ltd v Jiejing Pty Ltd (1994) 28 IPR 481 at 501):
"If a new feature were a development along the same line of thought which constitutes or underlies the invention described in the earlier document, it might be that that development could properly be regarded as fairly based on the matter disclosed in the earlier document, and that the new process described in the later document which incorporates that development could as a whole be regarded as fairly based upon the matter disclosed in the earlier document. If, on the other hand, the additional feature involves a new inventive step or brings something new into the combination which represents a departure from the idea of the invention described in the earlier document, it could not, I think, be properly described as fairly based upon the earlier document."
If the application is not entitled to priority from the basic document, it will take the date of filing as its priority date unless the claimed subject matter was included in the specification as a result of a later amendment (section 114, and regulation 3.14). It is possible for different aspects of a claim to be accorded different priority dates (section 43(3)).
GB 9108527
The starting point is to ascertain the invention that is described in the basic document (GB 9108527). The basic document relates to a heat transfer composition, particularly for low temperature applications. The conventional hydrochlorofluorocarbon refrigerants (known as HCFC's) are damaging to the ozone layer (page 2, lines 15 to 31). The invention is described as "comprising a mixture of tetrafluoroethane and/or heptafluoropropane with difluoromethane and/or 1,1,1-trifluoroethane and optionally pentafluoroethane" (page, 2 line 34 to page3 line 3).
The mixture is described in preferred forms as a binary composition (page 3, lines 11 to 15) and as a ternary composition (lines 16 to 24). An example of a 50/50 mixture of R-134a/32 is given (with no lubricant included). The specification states "the Tables show that compositions according to the invention can inhibit parameters similar to those of R-22 and R-502 which they could replace" (page 4, lines 27 to 30).
The lubricant is mentioned on page 5 (lines 17 to 25):
"The refrigerant composition may and usually will contain a lubricant. Any conventional lubricant may be employed but polyalkylene glycols and especially esters are preferred. By selecting a lubricant with a high thermal stability it is possible to operate with higher compressor discharge superheat than is currently possible using conventional hydrocarbon lubricants and this can improve the thermodynamic efficiency of the refrigeration system."
It seems clear that the basic document discloses heat transfer compositions wherein an HFC mixture is used. Binary and ternary refrigerant mixtures are exemplified.
The present claims differ from the basic document in several regards. These are:
a) The use of a lubricant is essential
The basic document foreshadowed the inclusion of a polyalkylene glycol or ester lubricant, but did not exemplify this. I consider that the reference to the lubricant is as a trivial component - something that would be included as a matter of routine, and is not in itself inventive. In the present claims the lubricant is included. This is not a new feature. The lubricant claimed is essentially that which was foreshadowed. This appears to be no more than elevating to the claim a feature that was optional in the basic.
b) The lubricant can be a mixture of a polyol and an ester
The basic document referred to the lubricant in the following terms:
"The refrigerant composition may and usually will contain a lubricant. Any conventional lubricant may be employed but polyalkylene glycols and especially esters are preferred."
[page 5, lines 17 - 20]This suggests to me that polyalkylene glycols and esters are alternative lubricants (with esters being especially preferred). I do not read this passage as suggesting the use of a mixture of a polyalkylene glycol and an ester. Integer II includes the possibility of either lubricant separately (the "or" option), as well as a mixture of the two (the "and" option). If the use of a mixture represents an inventive step or a departure from the idea of the invention, then this aspect is not fairly based on the basic document.
The use of a mixture of the two preferred lubricants does not seem to me, prima facie, to be an inventive advance. It is more in the nature of a development along the same line as that already disclosed. I consider that this feature should be regarded as fairly based on the basic document.
c) The refrigerant is a ternary or higher mixture, rather than a binary or ternary mixture
It is true that the binary mixture has been discarded in the present claims, and the focus is on the ternary mixtures. The ternary mixture described in the basic document is selected from the same five refrigerants as listed in the opposed specification. Thus there is a broad statement that is equivalent to that in the opposed specification. There is no specific exemplification of the ternary mixture in the basic. The broad statement is sufficiently precise to provide a fair basis for the claim.
The basic document does not explicitly mention higher mixtures. However, at its broadest, the basic document relates to mixtures of CFC's (selected from five listed CFC's) that can be used to replace HCFC's. Binary and ternary mixtures are preferred forms. Consequently the basic is not totally silent on higher mixtures - they are implicit in the broadest statement. Additionally, an explicit extension to higher mixtures is not prima facie an inventive step. I am satisfied that this aspect is fairly based on the basic document.
The claims are entitled to priority from GB 9108527, and thus take 18 April 1991 as their priority date.
NOVELTY
At the hearing the opponents argued novelty on several different bases depending on the priority date accorded to the claims. I shall only consider those documents that are relevant to the priority date of 18 April 1991. The documents relevant to novelty are AU 55763/90, US 4971712, US 4851144 and AU 54480/90.
The relevant law
The test for novelty is the reverse infringement test. The classic formulation of this test is that given by Aickin J in Meyers Taylor Pty Ltd v Vicarr Industries Ltd (1977) 137 CLR 228 at 235:
"The basic test for anticipation or want of novelty is the same as that for infringement and generally one can properly ask oneself whether the alleged anticipation would, if the patent were valid, constitute an infringement."
A more recent summary of the law on novelty is in Nicaro Holdings Pty Ltd v Martin Engineering Co (1990) 91 ALR 513 at 517:
"It is well accepted that the prior art must disclose all features of the invention embodied in the patent in suit and must do so in clear, unequivocal and unmistakable terms. The prior art must enable the notionally skilled addressee at once to perceive and understand and be able practically to apply the discovery without the necessity of making further experiments. Whatever is essential to the invention must be read out of or gleaned from the prior publications"
In order to apply the reverse infringement test it is necessary to determine the disclosure of the citation, and then decide whether that subject matter would infringe the claims of the application under opposition. The disclosure of the citation is referred to in the classic statement of Sach LJ in General Tire & Rubber Co v Firestone Tyre & Rubber Co Ltd [1972] RPC 457 at 485 - 486 in the terms:
"a signpost, however clear, upon the road to the patentee's invention will not suffice. A prior inventor must be clearly shown to have planted his flag at the precise destination before the patentee."
The question of the disclosure of a citation, or the area where the prior inventor has planted his flag, is not to be confused with the scope of the claims of the citation. Mr Gleeson agreed that the disclosure of a citation is a question of the technical disclosure of the document. In Pharmacia Aktiebolag v Ueno Fine Chemicals Industry Ltd (1995) 34 IPR 445 I adopted such an approach, and stated that a distinction needs to be drawn between the intellectual content of a chemical shorthand (i.e. the materials encompassed by the shorthand) and the technical information that the citation would make public to the instructed reader (though not necessarily revealed in every detail).
AU 55763/90
This citation discloses heat transfer compositions described as:
"Specifically, this invention relates to lubricants for use with tetrafluoroethanes e.g. 1,1,1,2-tetrafluoroethane (HFC-134a), and 1,1,2,2-tetrafluoroethane (HFC-134, etc. and of lesser importance, pentafluoroethane (HFC-125)."
[page 1A, lines 12 - 15]
The refrigerant gases "could be blended with each other, as well as with other refrigerants" (page 7, lines 1 - 2). The examples are restricted to the use of R-134a alone. The lubricant is "at least one fluorinated hydrocarbon, saturated or unsaturated, in which the weight ratio of fluorine-to-carbon is from about 0.5 to 5" (page 5, lines 8 - 10). The exemplified lubricants are the polymerisation product of Rf-(CH2)-CH=CH2 (example 1) and the copolymerisation product of Rf-CH=CH2 and C4H9O-CH=CH2 (example 2) (where Rf is perfluoroalkyl).
The citation encompasses the possibility of HFC blends of the type in the present specification. However, the lubricants are not polyalkylene glycol or esters. The prior art referred to in the citation states that polyalkylene glycols were known for use with R-134a (page 4, lines 14 - 26). I do not consider it appropriate to combine the prior art discussion with the disclosure of the invention as there is no clear indication to do so. Consequently the citation does not anticipate the invention as claimed by any of the claims.
US 4971712
This citation discloses heat transfer compositions described as:
"The present invention is based on the discovery that … at least one mono-functional random polyalkylene glycol (PAG), also referred to as polyoxyalkylene glycol … will be completely miscible with tetrafluoroethane and pentafluoroethane … e.g., HFC-134 and HFC-134a or pentafluoroethane, HFC-125, or blends thereof with each other and with other refrigerants"
[column 2, line 57 to column 3, line 3]
The refrigerant is further described in preferred terms as R-134a, R-134 and R-125:
"They could be blended with each other, as well as with other refrigerants including … HFC-32 (CH2F2), HFC-143a (CH3CF3) … HFC-125 (CF3CHF2) … and for purposes of the present invention such blends are not excluded."
[column 3, lines 49 - 57]
The examples are restricted to the use of R-134a. It is apparent that the citation also includes the possibility of refrigerant blends used with polyalkylene glycol lubricants. Blends of R-134, R-134a and R-125 with each other, and with R-32, R-143a or R-125 are part of the intellectual content of the disclosure. I believe that a person reading the citation would have considered that it had been made public that polyalkylene glycol lubricants can be used with R-134a, since this is the exemplified refrigerant. The reader would reasonably have considered that this could be extended to the other specifically disclosed refrigerants, and to blends. The critical question is which blends are clearly disclosed, or form part of the technical information that the citation makes public. While no blends are exemplified, I consider it is reasonable to regard the citation as clearly disclosing mixtures of those fluorocarbons that are themselves specifically disclosed. Consequently, it is likely that a reader would consider that they had been taught mixtures of HFC's including (i) any one or more of R-134a, R-134 and R-125, optionally blended with (ii) any one or more of R-32, R-143a and R-125. The only remaining question is how many components are used in the disclosed blends. It seems reasonable that binary blends are suggested, as these are the simplest blends. Ternary and higher blends are encompassed by the expression "blended with … other refrigerants". However, I can find nothing else in the citation that indicates the nature of the blend. In the absence of anything else in the citation, I am not satisfied that this is a clear direction to prepare a ternary (or higher) blend.
Since both claim 1 and claim 10 require a ternary blend of refrigerants, it follows that this citation does not anticipate the invention as claimed in any of the claims.
US 4851144
This citation discloses heat transfer compositions of lubricants and refrigerants. The refrigerant is described as:
"Examples of hydrofluorocarbon refrigerants useful in this invention are 1,1,1,2-tetrafluoroethane, 1,1,2,2-tetrafluoroethane, 1,1,1-trifluoroethane, 2,2-difluoroethane, trifluoromethane, methylene fluoride, methyl fluoride, difluoroethylene and pentafluoroethane."
[column 4, lines 10 - 14]
Clearly HFC's are envisaged as refrigerants, and R-134a is used in the examples. However, I cannot see anything in this citation that suggests blends of HFC's. Consequently, this citation does not clearly and unmistakably disclose the invention as claimed in any of the claims.
AU 54480/90 (the Lubrizol patent)
The Lubrizol patent discloses heat transfer compositions which are described in the consistory statement as:
"A liquid composition is described which comprises
(A) a major amount of at least one fluorine containing hydrocarbon containing one or two carbon atoms; and
(B) a minor amount of at least one soluble organic lubricant comprising at least one carboxylic ester of a polyhydroxy compound containing at least 2 hydroxy groups and characterised by the general formula
R[OC(O)R1]n (I)
wherein R is a hydrocarbyl group, each R1 is independently hydrogen, a straight chain lower hydrocarbyl group, a branched chain hydrocarbyl group, or a straight chain hydrocarbyl group containing from 8 to about 22 carbon atoms provided that at least one R1 group is hydrogen, a lower straight chain hydrocarbyl or a branched chain hydrocarbyl group, or a carboxylic acid- or carboxylic acid ester-containing hydrocarbyl group, and n is at least 2."
The expression "at least one fluorine containing hydrocarbon containing one or two carbon atoms" is a shorthand way of specifying a huge range of refrigerant compositions. It is clear that as a purely intellectual exercise, this includes the mixtures of HFC's that are claimed as integer (I) of claim 1 of the present application. The lubricant is an ester, and is thus of the type covered by integer (II). Thus the intellectual content of the Lubrizol patent encompasses the present claims. But this is not sufficient to establish lack of novelty. In order to determine where the Lubrizol patent has planted its flag, it is necessary to ask what refrigerant compositions would the Lubrizol patent make public to the instructed reader. For this purpose it is necessary to look to the body of the description.
From page 8 to page 10 there is a description under the heading "(A) Fluorine-Containing Hydrocarbon", which is the preferred embodiment in relation to the fluorocarbon. The relevant portions of this description read:
"The liquid compositions of the present invention comprise a major amount of at least one fluorine-containing hydrocarbon. That is, the fluorine-containing hydrocarbons contain at least one C-H bond as well as C-F bonds. In addition to these two essential types of bonds, the hydrocarbon also may contain other carbon-halogen bonds such as C-Cl bonds. … in one preferred embodiment, the hydrocarbon contains only carbon, hydrogen and fluorine. …Specific examples of the fluorine-containing hydrocarbons useful in the liquid compositions of the present invention, and their reported ozone depletion potentials are shown in the following Table I.
TABLE I
Compound
Designation Formula ODP*HCFC-22 CHClF2 0.05
HCFC-123 CHCl2CF3 <0.05
HCFC-141b CH3CCl2F <0.05
HFC-134a CH2FCF3 0__________
*Ozone depletion potential as reported in Process Engineering, pp 33-34, July, 1988.
Examples of other fluorine-containing hydrocarbons which may be useful in the liquid compositions of the present invention include trifluoromethane (HFC-23), 1,1,1,-trifluoroethane (HFC-143a), 1,1-difluoroethane (HFC-152a), 2-chloro-1,1,1,2-tetrafluoroethane (HCFC-124), 1-chloro-1,1,2,2-tetrafluoroethane (HCFC-124a), 1-chloro-1,1-difluoroethane (HCFC-142b), and 1,1,2,2-tetrafluoroethane (HFC-134). In the refrigerant art, the fluorohydrocarbons are often identified merely with the prefix 'R' in place of the above letters. For example HFC-23 is R-23, HCFC-124 is R-124, etc. … Mixtures of fluorine-containing hydrocarbons may be used, and the amount of each fluorocarbon in the mixture may be varied as desired. Examples of fluorohydrocarbon mixtures useful as (A) include: 142(b)/22; 134(a)/23; 22/124/152(a), etc."
The anticipation explicitly refers to single HFC's, and especially to R-134a. Mixtures of HFC's are mentioned towards the end of the above quote. The intellectual content of the disclosure includes mixtures of HFC's, thus including compositions of the present application.
The critical question is which mixtures of HFC's are clearly disclosed, or form part of the technical information that the citation makes public. I do not believe that mixtures of any fluorocarbons should be regarded as clearly disclosed. I consider it is reasonable to regard the citation as clearly disclosing mixtures of those fluorocarbons that are themselves specifically disclosed, either as individual components or components of mixtures. [In the present case, that is those that are identified by their code number, e.g. R-134, R-134a, R-143a, etc.] R-32, R-125 and R-227ea are not specifically referred to in the description. Consequently, it is unlikely that a reader would consider that they had been taught mixtures of HFC's including R-32, R-125 or R-227ea. On this basis I consider that the Lubrizol patent does not disclose a mixture including R-32, R-125 or R-227ea.
Taking the three HFC's that are disclosed in the citation, it is not possible to create a ternary blend according to the invention according to claim 1, since both R-134 and R-134a cannot be used. The absence of R-32 and R-125 means that claim 10 is not anticipated. Consequently this citation does not anticipate the invention as claimed in any of the claims.
OBVIOUSNESS
Obviousness was argued on two different bases. First, it was submitted that there was no invention in the light of admissions of common general knowledge in the specification itself. Second, it was submitted that there is no inventive step in the light of certain documents.
a) The relevant law
Section 7(2) provides a definition of inventive step for the purposes of the Patents Act.
"(2) For the purposes of this Act, an invention is to be taken to involve an inventive step when compared with the prior art base unless the invention would have been obvious to a person skilled in the relevant art in the light of the common general knowledge as it existed in the patent area before the priority date of the relevant claim, whether that knowledge is considered separately or together with either of the kinds of information mentioned in subsection (3), each of which must be considered separately.
(3) For the purposes of subsection (2), the kinds of information are:(a)prior art information made publicly available in a single document or through doing a single act; and
(b)prior art information made publicly available in 2 or more related documents, or through doing 2 or more related acts, if the relationship between the documents or acts is such that a person skilled in the relevant art in the patent area would treat them as a single source of that information;
being information that the skilled person mentioned in subsection (2) could, before the priority date of the relevant claim, be reasonably expected to have ascertained, understood and regarded as relevant to work in the relevant art in the patent area."
[The prior art base is defined in Schedule 1 of the Act.]
It is clear that inventive step is a matter that is presumed, unless it is demonstrated that the invention is obvious. The assessment of obviousness can be made against the common general knowledge alone, or the common general knowledge together with a document (or act) of the type covered by section 7(3). Section 7(3) documents must satisfy several requirements: the document must be publicly available inside or outside Australia (see the definition of "prior art base"); and the document would have reasonably been expected to have been ascertained, understood and regarded as relevant.
The normal approach to obviousness is the problem-solution approach: for instance, see Rhone-Poulenc Rorer S.A.'s Application [1995] APO 50. I note in passing that the problem-solution concept is evident in judicial decisions such as Minnesota Mining and Manufacturing Co v Beiersdorf (Australia) Ltd (1980) 144 CLR 253 (e.g. at 298: "this solution to the known problem") and Winner v Ammar Holdings Pty Ltd (1993) 113 ALR 63 (e.g. at 67: "The problem and the solution were readily apparent"). Once the problem has been formulated, and the common general knowledge or prior art base has been determined, the question of whether the claimed solution is obvious must be addressed. The test for obviousness is whether it would have been a matter of routine to proceed to the claimed invention.
"It is still correct to say that a valid patent may be obtained for something stumbled upon by accident, remembered from a dream or imported from abroad, if it otherwise satisfies the requirements of the legislation. What is important is that the patent itself should involve an inventive step, whether or not it was consciously taken by the patentee and whether or not it appeared obvious to the patentee himself. The test is whether the hypothetical addressee faced with the same problem would have taken as a matter of routine whatever steps might have led from the prior art to the invention, whether they be the steps of the inventor or not."
[Wellcome Foundation Ltd v V.R. Laboratories (Aust.) Pty Ltd (1981) 148 CLR 262 286]
The question of what would be routine can be considered using the "obvious to try" approach. This approach is well explained in Beecham Group Ltd's (Amoxycillin) Application [1980] RPC 261 (which has been approved in Coopers Animal Health Australia Ltd v Western Stock Distributors Ltd (1986) 67 ALR 390 at 410 and W R Grace & Co v Asahi Kasei Kogyo Kabushiki Kaisha (1993) 25 IPR 481 at 492 - 494) at 290 - 291:
"It is clearly established that, for a particular step or process to be obvious for the purpose of either section, it is not necessary to establish that its success is clearly predictable. It will suffice if it is shown that it would appear to anyone skilled in the art but lacking in inventive capacity that to try the step or process would be worthwhile. Worthwhile to what end? It must, in my opinion, be shown to be worth trying in order to solve some recognised problem or meet some recognised need."
[citations omitted]
This approach suggests that an invention is obvious if it would have been considered well worth trying, with the likelihood of success being sufficient to warrant the actual trial. However, it must always be remembered that there is an unclear line between normal trial and error and an inventive step:
"However, the test of whether something was 'worth trying' involves questions of degree … If the expectation of success is sufficiently predictable, and the effort involved is not going to be very great, it may well be that there is no inventive step. On the other hand, if the expectation of ultimate success is doubtful and the effort involved is great, the person undertaking the work should be entitled to a monopoly. A patent monopoly is awarded, not to reward genius but to encourage the disclosure of information which is of value to the public in that it takes the store of knowledge ahead by the requisite 'inventive step'."
[ICI Chemicals & Polymers Ltd v Lubrizol Corp Inc [1999] FCA 345 at [115], citations omitted]
What was the problem
In the Rhone-Poulenc decision I decided that the problem can be formulated from a reading of the specification in the light of surrounding facts (see also my recent decision in Emory University v Biochem Pharma Inc [1999] APO 50). The present specification lies in the field of heat transfer compositions. The specification makes it clear that the known CFC's and HCFC's (which had been promoted as an alternative for CFC's) are ozone depleting:
"In recent years, however, there has been increasing international concern that fully and partially halogenated chlorofluorocarbons, such as dichlorodifluoromethane and chlorodifluoromethane, may be damaging the earth's protective ozone layer, and there is general agreement that their manufacture and use should be severely restricted and eventually phased out completely."
[page 2, lines 12 - 19]
The specification goes on to give a formulation of the problem: "It is important, therefore, to replace fully and partially halogenated chlorofluorocarbon refrigerants by material having zero ozone depletion potentials." (page 2, lines 24 - 27) I would add to this the qualification that the particular problem relates to low temperature refrigeration, which is temperatures below -30º (see page 1a, lines 4 - 7; page 2, lines 6 - 11). Consequently, I consider it reasonable to formulate the problem as: to find a low temperature heat transfer composition that is zero ozone depleting.
What was the common general knowledge
Common general knowledge was defined by Aickin J in Minnesota Mining and Manufacturing Co v Beiersdorf (Australia) Ltd (1980) 144 CLR 253 at 292:
"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"
Mr Gleeson asserted that the following matters were common general knowledge:
a)Low temperature refrigeration applications including vapour compression refrigeration systems
b)The use of CFC refrigerants in low temperature refrigeration applicants and their replacement by HFC's
c)HFC refrigerants and mixtures, including ternary mixtures
d)Conventional lubricants for use with CFC's include mineral oils
e)Conventional lubricants such as mineral oils were unsuitable for use with HFC's
f)Alternative lubricants for use with HFC's include synthetic oils such as polyalkylene glycols and esters
I will only consider whether these elements are common general knowledge as they are necessary below.
Is the invention obvious in the light of the common general knowledge alone
It is not apparent from the evidence whether the ozone depletion potential of HFC's was common general knowledge. Consequently, I must assume that it was not common general knowledge. I do not consider it could be a matter of routine to prepare HFC-containing mixtures unless there was a reason to believe that they at least had a low ozone depletion potential. In the absence of this information, it would have to be shown that it would have been a matter of routine to determine the ozone depletion potential of a wide range of possible refrigerants as a first step; this has not been established. Consequently, the claimed solution was not an obvious solution to the problem.
What documents are part of the prior art base
At the hearing the opponents argued obviousness on several different bases depending on the priority date accorded the claims. I shall only consider those documents that are relevant to the priority date of 18 April 1991: AU 55763/90, US 4971712, US 4851144 and AU 54480/90. These are the same documents considered under novelty, so I will not repeat in detail the disclosure of these documents.
All of the citations relate to heat transfer compositions, and were published before the priority date of the present application. I consider that they are prior art for the purposes of section 7(3).
Is the invention obvious in the light of the prior art documents
The essence of Mr Gleeson's submissions was that the invention claimed in the present application amounts to a mere verification of information disclosed in the prior art documents.
AU 55763/90
This citation encompasses the possibility of CFC blends of the type in the present specification. However, the lubricants are not polyalkylene glycol or esters. Also, the citation does not refer to the ozone depletion potential of the refrigerants. Rather, the citation is concerned with producing a composition in which the refrigerant is miscible with the lubricant at the operating temperatures. Given that the ozone depletion potentials were not common general knowledge, this citation provides no motivation to prepare compositions for solving the problem.
US 4971712
This citation discloses refrigerants combined with polyalkylene glycol lubricants. The technical content of the citation includes appropriate refrigerants, but does not clearly include ternary blends. The intellectual content suggests other refrigerants (CFC's, HCFC's and HFC's) and ternary (and higher) blends, providing a clear signpost to try other compositions. However, the citation does not refer to the ozone depletion potential of the refrigerants. Rather, the citation is concerned with producing a composition in which the refrigerant is miscible with the lubricant at the operating temperatures. Given that the ozone depletion potentials have not been shown to be common general knowledge, the citation provides no motivation to prepare compositions for solving the problem.
The invention as claimed by any claim is not obvious in the light of this citation.
US 4851144
This citation discloses that HFC's are envisaged as refrigerants, and R-134a is used in the examples. The citation refers to the fact that R-134a "has the advantage that it does not deplete atmospheric ozone" (column 1, lines 17 - 18). This seems to be equivalent to a zero (or very low) ozone depletion potential. I consider that this document would be particularly relevant to a problem which includes the ozone reduction potential of the refrigerant.
The lubricant in the citation is referred to as:
"In general, the compositions consist of
(A) about 5 to 95% of a polyether polyol … and
(B) about 95 to 5% of an ester"
[column 2, lines 8 - 28]
Mr Gleeson asserted that the specification also refers to blends. I was directed to claim 7 of the citation, which states:
"The composition of claim 4 wherein said hydrofluorocarbons are selected from …"
The reference to the refrigerant gas in the plural could indicate that a blend is envisaged. However, claim 4 refers to the refrigerant component as "a refrigerant selected from the group consisting of hydrochlorofluorocarbons and hydrofluorocarbons". I consider it more likely than not that the claims refer to a single component refrigerant, and blends are not suggested by the document itself. It seems that the citation teaches a solution to the problem that does not use HFC blends, and it is not apparent why a person would seek to vary the compositions disclosed by the citations. This is probably enough to dispose of the question of obviousness. However, assuming that it would have been a matter of routine to look beyond the citations, I will consider whether it would have been a matter of routine to use HFC blends. This is not a case of mere verification.
The important question here is whether it would have been a matter of routine to prepare an appropriate blend, given the information about single refrigerants. I note that blends are used in refrigerants (and that some even have standard abbreviations, such as R-500, R-501 and R-502 in Annex 1), and it would not be surprising if blends were common general knowledge. I considered Mr Dobney's first declaration (in particular the paragraphs referred to by Mr Gleeson) and I can see no evidence that HFC blends specifically were common general knowledge.
Mr Dobney's declaration in reply states:
"Given that it was known prior to 18 April 1991 that polyalkylene glycols and esters are suitable for use with R134a and the other hydrocarbon refrigerants specifically listed including R134, R143a, R32 and R125, then I consider that these lubricants have properties which would make them suitable for use with blends containing any one of these refrigerants. I believe that this would be a matter of routine for the skilled person."
[paragraph 9.2]
It is not apparent whether HFC blends were in fact part of the common general knowledge. It is clear that Mr Dobney is asserting that it would have been a matter of routine to extrapolate the teaching of single component refrigerants to a blend of any of the specifically listed refrigerants (which may imply that such blends were common general knowledge). However, Mr Dobney does not state whether it would have been routine to prepare ternary blends, as against binary blends. I am not satisfied that it would have been obvious to replace R-134a with the specific blends claimed.
Additionally, the specification is directed to applications where the temperature range is from -20º to greater than 65º, which is not a low temperature refrigeration. The specification specifically refers to the problem of phase separation with temperature. In the absence of clear evidence that it would have been a matter of routine to use these heat transfer compositions at low temperatures, I conclude that it would not have been obvious on this point as well.
The invention as claimed by any claim is not obvious in the light of this citation.
AU 54480/90 (the Lubrizol patent)
The Lubrizol patent discloses heat transfer compositions, including mixtures of HFC's that are claimed as integer (I) of claim 1 of the present application, and an ester lubricant of the type covered by integer (II). The intellectual content of the disclosure includes mixtures of HFC's. The citation is concerned with refrigerants with a zero ozone depletion potential, so it is particularly relevant to the problem. However, it appears that R-32, R-125 and R-227ea are not part of the technical content of the disclosure. It seems that the citation teaches a solution to the problem that uses different HFC blends, and it is not apparent why a person would seek to vary the compositions disclosed by the citations. This is probably enough to dispose of the question of obviousness. However, assuming that it would have been a matter of routine to look beyond the citation, I will consider whether it would have been a matter of routine to use HFC blends not mentioned in the citation. This is not a case of mere verification.
The invention is obvious if it would have been a matter of routine to prepare other blends incorporating HFC's not suggested by the citation itself. There would need to be very clear evidence that ternary blends of the specific HFC's were common general knowledge in order to accept this proposition. The evidence of Mr Dobney does not clearly establish this point. I consider that it has not been established that it would have been a matter of routine. With regard to the low temperature issue, the citation refers to a temperature range of -40º to 80º. This includes low temperature applications.
The invention as claimed in any claim is not obvious in the light of this citation.
SECTION 40 MATTERS
Mr Gleeson raised the section 40 issues of best method of performance, full description and fair basis.
Best method of performance
It was alleged that the specification does not contain a best method of performing the invention as there are no examples of compositions containing a lubricant. It is true that there are no examples of compositions containing a lubricant. The specification indicates that the composition is prepared by mixing:
"The refrigerant and the compositions containing them may be prepared by a simple mixing process.
As stated above the refrigerant will be formulated into a refrigerant composition together with a lubricant. Polyalkylene glycols and especially esters are the lubricants used in the refrigerant compositions of the invention. By selecting a lubricant with a high thermal stability, it is possible to operate with higher compressor discharge temperatures than is currently possible using conventional hydrocarbon lubricants and this can improve the thermodynamic efficiency of the refrigeration system."[page 10, line 24 to page 11, line 6]
It appears that the lubricant is easily incorporated into the composition, and that any lubricant of the polyalkylene glycol or ester type can be successfully used. It does not appear from this that it is necessary to exemplify the selection of a lubricant and mixing it with the refrigerant, as this is not the inventive aspect of the composition. A number of refrigerant blends are exemplified.
I am satisfied that the specification provides a best method of performance.
Full description
It was alleged that the specification does not fully describe the invention because (i) there is no exemplification of how to select useful polyalkylene glycols or esters, and (ii) there is no disclosure of specific amounts or ranges of lubricant in the composition.
Mr Dobney's first declaration states:
"Not all PAGs [polyalkylene glycols] are suitable as lubricants but rather there are specific classes of PAG that are used as lubricants. Also, 'esters' is a very broad class of chemical compounds. Not all esters can be used as lubricants. The opposed patent application does not tell me which PAGs or esters are useful as lubricants."
[page 10]
I accept that not all polyalkylene glycols and esters are lubricants. However, the claims refer to lubricants that are polyalkylene glycols or esters. This means that it is only those lubricants that fall into the classes known as polyalkylene glycols and esters are included, not all polylalkylene glycols and esters. The evidence of the declarants as a whole suggests that they understand what is meant by polyalkylene glycol lubricants and ester lubricants.
It further appears from the evidence that not all ester lubricants would be effective. In the ASHRAE Journal 1990 (Exhibit WED-1) at page 8.3 it is stated that "the phosphate esters are unsuitable for refrigeration use because of their poor thermal stability". In Mr Dobney's evidence in reply he states that a great deal of testing would be needed before selecting a suitable lubricant:
"I do not believe that the opposed patent application gives sufficient information to allow a manufacturer of lubricants for use with refrigerant compositions to manufacture a suitable lubricant due to the specific needs of refrigerant systems without drawing on his own knowledge. An enormous amount of trial and experimentation would need to be done. With regard to this I refer to the ASHRAE Journal 1990 extract at Exhibit WED-1 where it states the 'Extreme caution must be exercised in considering a synthetic oil for refrigeration purposes. In mineral oils, characteristics such as hydrolytic stability or thermal decomposition are taken for granted and are only cursorily examined. Within the same chemical class, the properties of industrial synthetic compounds can vary widely depending on the compound's structure. Every conceivable property should be determined for each formulation, and extensive accelerated system tests should be made prior to actual field use. Otherwise, unforeseen field problems can occur …'."
[page 6]
Later Mr Dobney states:
"In addition, the use of synthetic lubricants containing polyalkylene glycols and/or esters were so well known for use with R134a and mixtures containing R134a prior to 18 April 1991 that it would have been a matter of routine to have selected a synthetic lubricant from one of these groups of lubricants."
[page 9]
This evidence suggests to me that some ester lubricants are less well suited to use in heat transfer systems, although they would work. This is sufficient for a full description. It is unclear whether a reader would have selected the more useful lubricants as a matter of course, but I do not think this matters. In this regard, the specification provides a full description.
The second point was that there is no disclosure of specific amounts or ranges of lubricant in the composition. It is true that the amounts or ranges of the components is not specified. However, ranges only need to be specified if it is necessary to do so, and I can see nothing to suggest that this is a case where ranges should have been specified. I consider that the specification provides a full description in this regard.
Fair basis
It was alleged that the claims are not fairly based because they include lubricants which are inefffective or have undesirable properties or have characteristics contrary to the implied objects of the invention.
It is true that the lubricant is claimed in very broad terms. However, as stated above, the full range of lubricants would apparently produce a workable system, but some lubricants would be better than others. The fact that there may be variation does not mean that there is a lack of fair basis. There is a real and reasonably clear disclosure that a range of lubricants can be used, and I regard this as providing fair basis for the claims.
CONCLUSION
The opposition is unsuccessful on all grounds. Subject to any appeal, I direct that the application proceed to sealing.
COSTS
The opponent has been unsuccessful on all grounds, so I consider it appropriate to award costs against it. I can see no reasons to vary the costs from the full amount specified in the Schedule.
I award costs according to Schedule 8 against the opponent.
Dr S.D.Barker
Delegate of the Commissioner of Patents
Patent attorneys for the applicant : Phillips Ormonde & Fitzpatrick, Melbourne
Patent attorneys for the opponent : Callinan Lawrie, Melbourne
ANNEX 1: DESIGNATIONS OF REFRIGERANT FLUIDS
| Designation | Type | Chemical Name | Chemical Formula |
| R-11 | CFC | Trichlorofluoromethane | CCl3F |
| R-12 | CFC | Dichlorodifluoromethane | CCl2F2 |
| R-13 | CFC | Chlorotrifluoromethane | CClF3 |
| R-22 | HCFC | Chlorodifluoromethane | CHClF2 |
| R-23 | HFC | Trifluoromethane | CHF3 |
| R-32 | HFC | Difluoromethane | CH2F2 |
| R-113 | CFC | 1,1,2-Trichlorotrifluoroethane | CCl2FCClF2 |
| R-114 | CFC | 1,2-Dichlorotetrafluoroethane | CClF2CClF2 |
| R-115 | CFC | Chloropentafluoroethane | CClF2CF3 |
| R-123 | HCFC | 1,1-Dichloro-2,2,2-trifluoroethane | CHCl2CF3 |
| R-125 | HFC | Pentafluoroethane | CHF2CF3 |
| R-134 | HFC | 1,1,2,2-Tetrafluoroethane | CHF2CHF2 |
| R-134a | HFC | 1,1,1,2-Tetrafluoroethane | CH2FCF3 |
| R-141b | HCFC | 1,1-Dichloro-1-fluoroethane | CCl2FCH3 |
| R-142b | HCFC | 1-Chloro-1,1-difluoroethane | CClF2CH3 |
| R-143 | HFC | 1,1,2-Trifluoroethane | CHF2CH2F |
| R-143a | HFC | 1,1,1-Trifluoroethane | CF3CH3 |
| R-152a | HFC | 1,1-Difluoroethane | CHF2CH3 |
| R-227ca | HFC | 1,1,1,2,2,3,3-Heptafluoropropane | CF3CF2CF2H |
| R-227ea | HFC | 1,1,1,2,3,3,3-Heptafluoropropane | CF3CHFCF3 |
| R-245ca | HFC | 1,1,2,2,3-Pentafluoropropane | CHF2CF2CFH2 |
| R-500 | CFC/HFC | R-12/152a (73.8/26.2 wt %) | |
| R-501 | HCFC/CFC | R-22/12 (75/25 wt %) | |
| R-502 | HCFC/CFC | R-22/115 (48.8/51.2 wt %) |
ANNEX 2
A refrigerant composition comprising:
a refrigerant comprising a ternary or higher mixture of:
(a) tetrafluoroethane and/or heptafluoropropane;
(b) difluoromethane and/or 1,1,1-trifluoroethane; and optionally
(c) pentafluoroethane; anda lubricant comprising a polyalkylene glycol and/or an ester.
A refrigerant composition as claimed in claim 1, wherein component (a) of the refrigerant is 1,1,1,2-tetrafluoroethane, 1,1,2,2-tetrafluoroethane, heptafluoropropane and or a combination of heptafluoropropane and 1,1,1,2-tetrafluoroethane or 1,1,2,2-tetrafluoroethane.
A refrigerant composition as claimed in claim 1 or claim 2, wherein component (a) of the refrigerant is heptafluoropropane, optionally together with 1,1,1,2-tetrafluoroethane or 1,1,2,2-tetrafluoroethane.
A refrigerant composition as claimed in claim 3, wherein component (b) of the refrigerant is difluoromethane.
A refrigerant composition as claimed in claim 3 or claim 4 wherein the refrigerant comprises pentafluoroethane.
A refrigerant composition as claimed in claim 1 or claim 2, wherein component (a) of the refrigerant is 1,1,1,2-tetrafluoroethane or 1,1,2,2-tetrafluoroethane.
A refrigerant composition as claimed in claim 6, wherein component (a) of the refrigerant is 1,1,1,2-tetrafluoroethane.
A refrigerant composition as claimed in claim 6 or claim 7. Wherein component (b) of the refrigerant is difluoromethane.
A refrigerant composition as claimed in any one of claims 6 to 8 wherein the refrigerant comprises pentafluoroethane.
A refrigerant composition comprising:
a refrigerant comprising:
(a) 1,1,1,2-tetrafluoroethane;
(b) difluoromethane; and
(c) pentafluoroethane; anda lubricant comprising a polyalkylene glycol and/or an ester.
A refrigerant composition as claimed in any one of claims 1 to 10, wherein the lubricant comprises an ester.
A heat transfer device in which the working fluid comprises a refrigerant composition as claimed in any one of claims 1 to 11.
A refrigerant composition as claimed in claim 1 to claim 10 substantially as herein before described with reference to any one of the preferred embodiments.
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