Robert B. Clay v Ireco Chemicals and ICI Australia Operations Pty Ltd

[1987] APO 8

In the Matter of the Patents Act 1952

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In the Matter of Application No. 522734 for a Patent by ROBERT B. CLAY

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In the Matter of Oppositions thereto under Section 59 by IRECO CHEMICALS and ICI AUSTRALIA OPERATIONS PTY. LTD.

DECISION OF A SUPERVISING EXAMINER OF PATENTS:
Background
         Patent application No. 522734 entitled "Blasting Composition" is a Convention application based on US application No. 834772, thereby acquiring a priority date of 19 September, 1977;  acceptance of the application and complete specification was notified in the Official Journal dated 24 June, 1982.
         On 13 August, 1982 IRECO CHEMICALS (IRECO) lodged notice of opposition under s.59 and service of evidence was completed on 12 September, 1985.  On 24 September, 1982 ICI AUSTRALIA OPERATIONS PTY. LTD. (ICI) lodged notice of opposition and service of evidence was completed on 18 May, 1984.  The oppositions were heard sequentially in Melbourne on 13 and 14 August, 1986.  The applicant was represented by Mr. A. Chernov QC and Mr. B.N. Caine of Counsel, instructed by Mr. J.A. Waters, patent attorney of Phillips, Ormonde & Fitzpatrick, assisted by the applicant, Dr. Clay and an associate Mr. G.L. Hansen.  IRECO was represented by Dr. C.N. Jessup of Counsel, instructed by Dr. I. Ernst, patent attorney of Shelston Waters.  ICI was also represented by Dr. C.N. Jessup of Counsel, instructed by Mr. D.W. Berryman, patent attorney of ICI, assisted by Dr. V. Sujansky.

The Specification
         The specification relates to an ammonium nitrate explosive composition.  An important object of the invention is to avoid the necessity of using costly modifiers, especially where they must be used in significant quantities and, to make use of the natural porosity of compositions which include dry particulate ammonium nitrate solids.  A further object is to simplify the procedures required for making up the blasting composition, to further reduce costs.
         The specific description of the invention is in different terms from those of claim 1 and I will discuss this later in the decision.
         The description continues as follows:

"The composition of the present invention when finally put together consists of two main and relatively simple constituents, namely, (1) a water‑in‑oil emulsion and (2) ANFO or simple AN (ammonium nitrate).  With ANFO, each of these two constituents is approximately oxygen balanced before they are combined and the resulting produce necessarily is balanced also, at least approximately."

The emulsion, before it is blended into the dry oxidizer particles to fill the interstices, may resemble a soft grease or it may be nearly liquid in consistency.  The emulsion is prepared by combining the water with the oxidizer salt, which can consist of entirely ammonium nitrate or mixtures of ammonium nitrate with other oxidizers such as calcium nitrate or perchlorates.  All or part of the oil containing the emulsifier is then added to the aqueous solution.  If not all the oil is used to make the emulsion, the remainder can be combined with the solid ammonium nitrate.  The emulsifier may be any one of the many available.  Supplementary fuels may also be added as is known in the art.
         The emulsion is combined with the essentially dry solid ingredient by very simple procedures, for example, the emulsion may be fed along with the dry material into the auger of conventional ANFO loading equipment.  After mixing, the blasting composition may be a fairly wet, or rather dry grout‑like material, however it does have some flow properties.
         The compositions of the present invention consist of those having 60 to 90% by weight of solid ingredient, into which is blended 10 to 40% of the emulsion.  The quantity of emulsion is sufficient to fill some but not all of the pores or interstices between the solids.  The emulsion itself should comprise about 3 to 15% by weight of water, about 2 to 15% of oil along with 70 to 90% by weight of the salt dissolved in the aqueous phase.  Proportions of emulsifier should be adequate to obtain a stable water‑in‑oil emulsion and the emulsifier may comprise 1 to 8% by weight of the emulsion itself and may vary from 0.1 to 5% by weight in the total composition.
         The amount of water in the emulsion may vary but it is desirable to keep it to a practical minimum, consistent with fluidity requirements.  Excess water detracts from energy as well as causing greater problems with detonation, thus tending to reduce the efficiency of the explosive.  Preferably water should not make up more than 15% by weight of the emulsion and proportions as low as 3% can be used.  Based on the finished composition the water content will be only one fourth to one third of these proportions.
         The claims defining the invention read as follows:

"1.A blasting composition consisting of 10 to 40% by weight of a greasy water‑in‑oil emulsion and 60 to 90% of a solid undissolved particulate oxidizer salt constituent, wherein the emulsion comprises 3 to 15% by weight of water, 70 to 90% of powerful oxidizer salt comprising ammonium nitrate and optionally other powerful oxidizer salts, wherein the solid constituent comprises ammonium nitrate or ANFO and in which sufficient aeration is entrapped to enhance sensitivity, and wherein the emulsion component is emulsified by inclusion of 0.1 to 5% by weight, based on the total composition, of a water‑in‑oil emulsifier to hold the aqueous content in the disperse or internal phase.

2.An explosive composition according to claim 1 wherein the solid constituent consists of ammonium nitrate in particulate form and a small amount of fuel to provide some oxygen balance for said nitrate.

3.An explosive composition according to claim 1 in which the solid constituent consists primarily of ammonium nitrate.

4.A composition according to any one of claims 1 to 3 in which the oil of the water‑in‑oil emulsion is a hydrocarbon fuel oil and solid constituent comprises at least a major proportion of ammonium nitrate.

5.A composition according to any one of claims 1 to 4 in which the water‑in‑oil emulsion includes calcium nitrate and ammonium nitrate in aqueous media as the disperse phase of said emulsion.

6.A composition according to claim 5 which also contains sodium nitrate in the disperse phase.

7.An explosive composition according to claim 1 wherein the emulsion includes an aqueous solution of ammonium nitrate, calcium nitrate and sodium nitrate, and additionally contains a water soluble fuel selected from the group which includes ethylene glycol, propylene glycol, alcohol, and formamide.

8.A composition according to any one of the preceding claims wherein the emulsion includes a normally solid hydrocarbon.

9.An explosive composition according to any one of the preceding claims wherein the emulsion includes a fuel selected from the group which consists of fuel oil, kerosene, naphtha, paraffin wax, vegetable oil, fish oil, reclaimed motor oil and derivatives of olefins which can be melted to liquid form in preparing the emulsion.

10.An explosive composition according to claim 9 in which a liquid oil is included both in the emulsion and in the solids into which the emulsion is combined.

11.An explosive composition which comprises in combination,

(1)a solid particulate and undissolved nitrate oxidizer salt in proportions of at least 50% by weight of the total,

(2)0 to 10% of hydrocarbon mixed with the particulate oxidizer salt wherein sufficient aeration is entrapped to enhance sensitivity,

(3)a solid particulate fuel, and

(4)10 to 40% by weight of a dense water‑in‑oil emulsion, which contains an oil as continuous phase and comprising as its disperse phase 3 to 15% by weight water and 70 to 90% of a powerful oxidizer salt selected from the group which consists of the nitrates, chlorates and perchlorates of ammonium, alkali metal and alkaline earth metal said emulsion being stabilized by inclusion of 0.1 to 5.0% by weight, based on total composition, of a water‑in‑oil emulsifier.

12.A composition according to claim 11 which contains as solid particulate oxidizer ammonium nitrate and at least one other nitrate.

13.Composition according to claim 11 in which the particulate oxidizer salt consists of ammonium nitrate.

14.A composition according to any one of claims 11 to 13 which includes gas filled particles to impart sensitivity to the composition and to reduce its specific gravity.

15.A composition according to any one of claims 11 to 14 in which the emulsion contains a water soluble fuel.

16.A composition according to claim 1 in which the emulsion is a slurry containing particulate fuel as well as an aqueous solution of nitrates of ammonium, calcium and sodium, and in which the solid constituent consists of ammonium nitrate treated with fuel oil to improve oxygen balance."

Claim 1 above is in the form in which it was proposed to be amended by the applicant before acceptance and not in the form in which the claim occurs in the printed specification.  I have previously mentioned that the claimed invention is different from the invention as specifically described.  The difference is that the specific description (on page 3 of the specification) does not state that the solid constituent can be ANFO.
The Evidence
         The evidence in support of the IRECO opposition consists of statutory declarations made by Walter Bentley Sudweeks, Ian Thomas Ernst and Vladimir Sujansky.
         Dr. Sudweeks is employed in the USA as a Senior Research Scientist and Director of Product Development for IRECO, and he has over 11 years of industrial experience in the research and development of commercial explosives.  He has also been named as the inventor of numerous patents that deal directly with water‑in‑oil emulsion explosives.
         There are 15 exhibits of a technical nature attached to Dr. Sudweek's declaration and each of them is discussed in relation to the present claims.  In particular he discusses the disclosures of US Patent No. 3,161,551 (exhibit WBS6) and Australian patent application No. 29408/71 (exhibit WBS10).
         The declaration made by Dr. Ernst establishes the Australian publication dates for the documents exhibited to Dr. Sudweeks' and Dr. Sujansky's declarations.
         Dr. Sujansky declares that he is a chemist employed in the Development Section of the ICI explosives factory in Australia and that during the period 1978 to 1981 he was seconded to ICI in the United Kingdom to form part of a special team continuing fundamental research in new explosives.  He states that since 1971 a routine part of his duties has been to monitor developments in the area of emulsion explosives by reading relevant patent specifications and abstracts when they are published in Australia.  Dr. Sujansky declares that the area of water‑in‑oil explosives was well known to him at the priority date of the present specification and was common general knowledge to the technical personnel of the Explosive Division of ICI Australia.  He states that he was aware of US patents Nos. 3,447,978 (exhibit WB57) and 3,161,551, and of their significance in the art.  He declares that he used the disclosures contained in Australian patent No. 281537 (to Coxon) in his own work on explosives though the specification in his possession was the equivalent South African patent application (No. 655118).
         Dr. Sujanksy points out that he was aware of the patents filed by Dupont de Nemours disclosing the use of gas entrapping material to enhance the sensitivity of emulsion explosives.  He does not remember reading Australian patent application No. 29408/71 before the publication date of the present application.  However he recalls an incident in the United Kingdom in 1979 when he read an abstract of the present application and immediately wondered what was new over the Coxon patent (No. 281537).  At the same time a colleague pointed out to him the relevance of UK patent No. 1,306,546 which is equivalent to Australian application No. 29408/71.  He thus concludes that it was known in Australia that an explosive composition could be made by mixing a water‑in‑oil emulsion with solid ammonium nitrate.  Dr. Sujansky deposes that research and development personnel of Dupont in Australia would have known about water‑in‑oil emulsions before the priority date of the present application because research and development of explosive compositions in Australia is mainly carried out by Dupont and ICI.
         Dr. Sujansky then compares the disclosures of the present specification with the disclosures of Australian application No. 29408/71.  He also refers to the file wrapper of US application No. 834772 (on which the present application is based) wherein the present applicant distinguishes example 25 of UK patent No. 1,306,546 from the invention defined by the claims of the US document.  Dr. Sujansky also discusses the disclosures of the South African document referred to above.
         The evidence in answer consists of a statutory declaration made by Dr. Robert B. Clay, the inventor named in the present application.  He declares that he understood that ammonium nitrate/
fuel oil explosives had the disadvantages of having a relative low bulk density and no water resistance.  He also states that he had previously made emulsion blasting agents similar to those disclosed in US patent No. 3,447,978.  It occurred to him that an emulsion could be added to a solid ammonium nitrate/fuel oil explosive to increase both its bulk strength and its water resistance.  After considerable experimentation Dr. Clay discovered the idea did have merit and arrived at the presently claimed composition.
         Dr. Clay declares as follows:

"The difference between the bulk density (apparent density) of the prilled AN and the crystal density (1.725 gm/cc) is caused by (a) the intersticial free space i.e. the space between the randomly stacked prills, (b) the pore free space i.e. the external voids in each prill caused mainly by the evaporating water and (c) the internal free space in the prills caused by crystal structure changes during the prilling process."

He states that commonly used ANFO has more intersticial free space than is necessary for sensitization.  He continues as follows:

"From the inception of ANFO in the 1950's many attempts have been made to increase the bulk strength (energy per volume) of ANFO.  The most common was to fill the interstices with ground ANFO.  Other methods are described in WBS1, 2, 4 and 5.  My 734 application has proven to be a superior method to increase the bulk strength of ANFO up to 50% by simply filling a portion of the interstices of the prills with a high density oxygen balanced water‑in‑oil emulsion."

Dr. Clay further states that a search in the United States Patent Office files turned up several related patents including US patent No. 3,161,551.  He also admits to being aware of United Kingdom patent No. 1,306,546 but states he was not aware of Australian patent No. 281537.  Dr. Clay then compares the disclosures contained in these patents with the present specification.  He also disputes some of the submissions made by Dr. Sudweeks.
         The evidence in reply consists of another statutory declaration made by Dr. Sudweeks, in which he criticises Dr. Clay's interpretation of the disclosures in exhibits WBS6 and WBS10.  He also gives some specific examples, based on analyses conducted under his supervision, of the proportion of water in commercially used heavy ANFO ‑ that is, ANFO combined with a water‑in‑oil emulsion to increase its density.
         IRECO was also granted leave to lodge further evidence.  This evidence consists of a page which was omitted from Dr. Sujansky's declaration.  On this page Dr. Sujansky declares what Australian patent application 29408/71 would have taught him if he had read it.  He also comments that explosive compositions are normally oxygen balanced within plus or minus 10% and points out that in the claims of application No. 522734 there is no limitation to oxygen balance in that no minimum oil/fuel composition is set.
         The evidence in support of the ICI opposition consists of statutory declarations made by Vladimir Sujansky and Timothy Nicholls Hagan.
         The declaration made by Dr. Sujansky differs from that lodged in support of the IRECO opposition only in that the South African equivalent of Australian patent No. 281537 is exhibited with the declaration.
         Dr. Hagan was Senior Mining Engineer with the Explosives Division of ICI Australia in 1977 but has subsequently left the company to work as Principal Blasting Consultant of Golder Associates.  In 1977 he had dicussions with technical personnel from the Explosives Division of Canadian Industries Ltd. (CIL) which is one of the ICI family of companies.  Subsequently Dr. Hagan produced a report on the discussions but he has been unable to find a copy of the report; there is, however, an annexure to his declaration which is a memo from him to Mr. J.K. Mercer.  The memo which is entitled "Technical Dialogue between CIL and Atlas Powder Company On Small Diameter Water Gels" does not contain any technical details, but is concerned with the nature of the information that ICI should seek from Atlas Powder Company when it shared its knowledge with the ICI family.  I will not consider this declaration further.
         The evidence in answer consists of a statutory declaration made by Dr. Clay which is similar to that lodged in answer to the IRECO opposition.  However in this declaration Dr. Clay states that when he prepared a blasting composition which is described in patent No. 281537 the composition became quite cold because of the endothermic reaction of the ammonium nitrate going into solution.  The blasting composition was not sufficiently sensitive and failed to detonate completely.  Similarly Dr. Clay reports that the composition described in Example 25 of application No. 29408/71 failed to detonate completely.
         The evidence in reply consists of a further declaration made by Dr. Sujansky.  He states that he has prepared the compositions from the same examples which Dr. Clay described in his evidence in answer using high porosity ammonium nitrate and in both cases the blasting composition detonated completely.
Section 40
Dr. Jessup submitted that claim 1 was not clear for reasons similar to those given in my earlier decision concerning the same applicant (Clay v. ICI Operations Pty. Ltd. 3 IPR 439 at page 442). He argued that the term "oxidizer salt" in the phrase "solid undissolved particulate oxidizer salt constituent" implied that this constituent released oxygen. However later in the claim this constituent is stated to comprise ammonium nitrate or ANFO, and the latter substance, as admitted in the specification, may be oxygen balanced and thus unable to release oxygen.
         Mr. Chernov submitted that the earlier decision was not relevant to the present situation because the claims in question did not use the same wording.  He also argued that the words in the present claim 1 would present no difficulty to the appropriately skilled person and he supported this argument by pointing out that the opponent's expert, Dr. Sujansky, had not found the wording of the claim unclear.
         It seems to me that the phrase "a solid undissolved particulate oxidizer salt constituent" defines a constituent which only has to contain a solid undissolved particulate oxidizer salt.  This constituent may, or may not release oxygen and includes ANFO within its scope.  The phrase considered in the decision cited by Dr. Jessup was "a substantially solid particulate oxidizer" which defines a substance which is substantially solid and particulate but which also releases oxygen.  Therefore I agree with Mr. Chernov  that my earlier decision is not relevant with respect to the clarity of the present claim 1.  The phrase to which Dr. Jessup objected, would in my opinion, present no difficulty to the appropriately skilled person.

         Dr. Jessup submitted that none of the preferred embodiments fall within the scope of the claims in respect of the definiton of the emulsion comprising 3 to 15% by weight of water.  He argued that "NHCN" which is a component of all the embodiments, contains 15% water of crystallization and if this water is added to the amount of water used to make up the emulsion then the percentage of water falls outside the claimed range.  Mr. Chernov did not dispute the correctness of the arithmetic used in the opponent's calculations but he attacked the premise on which it was based.  That is, he argued that the emulsion contained two types of water, chemically bound water as well as free or added water and he argued that the claims only defined the added water.
         Firstly, I should point out that there is an error in the general description of the embodiment on page 6.  In order to conform with the table of examples given on page 7 this description should include 5 parts by weight of sodium nitrate instead of the "5% by weight" described on page 6.
         Neither Dr. Sudweeks nor Dr. Sujansky discuss the amount of water added in the embodiments in the form of water of crystallization even though the description makes it clear that the water content is an important aspect of the present blasting composition.
However I consider that the question of the amount of water in the emulsion can be answered by using a purposive construction of this feature (Catnic Components Ltd. v. Hill and Smith Ltd. (1982) RPC 183 at page 243). For example claim 1 claims the emulsion as follows:

"the emulsion comprises 3 to 15% by weight of water, 70 to 90% of powerful oxidizer salt comprising ammonium nitrate and optionally other powerful oxidizer salts,"

In my opinion this phrase defines the amounts of water and powerful oxidizer salt which are used to make the emulsion rather than defining the amounts which can be found by analysis of the finished emulsion.  Therefore I consider that the emulsion as defined in claim 1 contains 3 to 15% by weight of added water irrespective of the amount of chemically bound water present in the oxidizer salts.  I note that the description on page 3 and also claims 1 and 11 do not specify whether the amount of powerful oxidizer salt is 70 to 90% by weight, although the description on page 10 states that this amount is by weight.  Even so I am satisfied that the preferred embodiments lie within the scope of the composition defined in the claims.
         Dr. Jessup submitted that claim 11 was not fairly based on the description because the claim does not state that the total amount of solid particulate and undissolved nitrate oxidizer salt and hydrocarbon is at least 60% of the total composition.  I agree with this submission.
         The emulsion described in the specification contains about 2 to 15% of oil whereas the emulsion defined in claims 1 and 11 is not limited in this manner.  Therefore I consider that these claims are not fairly based in this regard. 
Obviousness
         Both Mr. Chernov and Dr. Jessup agreed that none of the prior patent specifications were part of common general knowledge in Australia, and they also agreed that it was well known that air acted as a sensitizer in blasting compositions.
Dr. Jessup, basing his submission on the declarations of Dr. Sudweeks and Dr. Sujansky, submitted that the blasting composition, as defined in the claims, was obvious. Mr. Chernov in response drew my attention to the law set out in Minnesota Mining & Manufacturing Co. v. 3M Australia Pty. Ltd. (29 ALR 29 at pages 57 to 59) and Graham Hart Pty. Ltd. v. S.W. Hart Pty. Ltd. (18 ALR 625 at pages 634 and 636). He argued that Dr. Sudweeks was not able to declare to what was common general knowledge in Australia because he was not resident in Australia at the relevant time. He also pointed out that all Dr. Sujansky's declaration established was his own personal knowledge rather than what was common general knowledge.
         I agree entirely with Mr. Chernov's submission on this matter and will say no more on it.
Anticipation
         Although the opponent's evidence contained several prior art documents Dr. Jessup confined his submissions on anticipation to three of these documents, namely, US patent No. 3,161,551, Australian patent application No. 29408/71 and Australian patent No. 281537.  All of these citations were published in Australia before the present priority date.
US Patent No. 3,161,551
         US patent No. 3,161,551 relates to sensitizers for blasting agents in emulsion form.  The specification states that to produce highly efficient ammonium nitrate blasting agents, the sensitizer used must not only provide complete sensitization of each ammonium nitrate particle by covering the entire surface area of the particle but also fill all spaces in between each particle to give added density to the blasting agent.  In addition, in order to enable ammonium nitrate to be used under conditions where water is present such as in wet bore holes, it is necessary that the sensitizer provide maximum resistance to water.
         The object of the invention therefore is to produce sensitizers which not only intimately cover each particle and completely fill spaces in between the various particles so as to give greater density to the blasting agent but have good resistance to water.
         These objects are accomplished by forming water in oil emulsions containing from about 50 to 70% by weight of ammonium nitrate, from about 15 to 35% water, and from about 5 to 20% of a liquid organic sensitizer which has low solubility in water.  Emulsions with this composition, when thoroughly mixed with ammonium nitrate in amounts of about one part by weight of emulsion to about 4 to 0.5 parts by weight of ammonium nitrate, produce sensitized blasting agents.
         The term "liquid organic sensitizers" is synonymous with oil, including hydrocarbon fuel oils.  The emulsion can be formed by any suitable means and also includes 1 to 5% by weight of any emulsifier which will form a water‑in‑oil emulsion.
         An important feature of the invention is the fact that it can be used in wet bore holes without being placed in a sealed bag or cartridge.  Thus, solid ammonium nitrate can be dropped into the hole and the sensitized emulsion can be poured into the hole to completely cover the ammonium nitrate particles and fill the spaces between each particle.
         Dr. Jessup submitted that US patent No. 3,161,551 anticipated the present claims because it disclosed blasting compositions which contained the same ingredients in similar proportions to those defined in the claims.  He stated that in Dr. Sudweeks' opinion the composition disclosed in the citation must contain some entrapped air, even though the voids between the particles are largely filled.
         Mr. Chernov countered that the composition defined in the claims did not merely contain some entrapped air but the claimed compositions contained an amount of air which was controlled by the critical proportions of emulsion and solid constituent.  He also argued that the citation taught that the spaces between ammonium nitrate were completely filled because the object of the invention was to provide a blasting composition with water resistance and added density.
         I agree with Mr. Chernov that one of the factors which determines the amount of entrapped air is the relative proportions of emulsion and ammonium nitrate or ANFO.  However I also consider that some of the blasting compositions defined in claims 1 and 11 contain the same ingredients in the same proportions as those disclosed in the citation.  In particular I note that in both compositions the water‑in‑oil emulsion can contain 70% by weight of oxidiser salt, 15% by weight of water, 1‑5% by weight of emulsifier and 5‑15% by weight of fuel oil.  I also note that in both cases the composition can contain 60‑80% by weight of emulsion in combination with 20‑40% of ammonium nitrate.  Therefore the compositions described in the citation will prior publish the compositions defined in the claims if the ammonium nitrate entraps sufficient air to enhance sensitivity.
         In his declaration Dr. Sudweeks states that in the composition described in the citation air is entrapped when the emulsion is mixed with ammonium nitrate.  Dr. Clay in his declaration does not state that air is not entrapped, rather he states that compositions made according to the citation do not perform in a commercially acceptable manner.  Thus it seems to me that both Dr. Sudweeks and Dr. Clay agree that in the compositions described in the citation air is entrapped with solid ammonium nitrate.  Earlier in this decision I stated that the applicant conceded that it was well known that air acts as a sensitizer in blasting composition.  Therefore I consider that the entrapped air would enhance sensitivity because the citation describes the emulsion itself as a sensitizer for the solid ammonium nitrate.
         Therefore I am satisfied that US patent No. 3,161,551 prior publishes the claims in respect of blasting compositions in which the emulsion is mixed with solid ammonium nitrate.
         I consider the fact that where the present claims also use ANFO or other solid particulate and undissolved nitrate oxidizer salts as the solid constituent, this does not require an inventive step beyond the disclosure of the citation.  Therefore I am satisfied that US patent No. 3,161,551 renders the present claims not novel.
Australian Patent No. 281537
         The invention described in Australian patent No. 281537 consists of an inorganic nitrate based explosive wherein ammonium nitrate has mixed with it a hydrocarbon, water and an anionic surface active agent.  The hydrocarbon, water and anionic surface active agent can either constitute a solution, emulsion, or colloidal mixture.
         By means of this invention, the sensitivity of an ANFO mix can be greatly increased without increasing the danger hazard which is essentially present with any explosive.  Although both oil‑in‑water or water‑in‑oil emulsions can be produced, generally the emulsions which are stable are of the oil‑in‑water type.  Several specific examples of surface active agents and fuel oils are given as well as several specific examples of emulsions formed from water, hydrocarbon and surface active agents.  The emulsion is thoroughly mixed with ammonium nitrate prills to form a mixture in which all the liquid is fully absorbed to form a dry explosive mixture or a mixture in which the liquid is partly absorbed to form an explosive slurry.
         Mr. Chernov submitted that the disclosure in this citation differed from the invention claimed in some essential respects namely:

(1)The citation does not teach the same critical proportions of emulsion and solid constituent used in the present composition,

(2)The emulsion used in the citation does not contain an oxidiser salt,

(3)The emulsion described in the citation contains a larger proportion of water than the emulsion defined in the claims,

(4)The emulsion described in the citation is an oil‑in‑water emulsion whereas the emulsion defined in the claims is a water‑in‑oil emulsion.

Dr. Jessup responded by pointing out that Dr. Sujansky and Dr. Clay declare that some of the solid ammonium nitrate dissolves so that the emulsion will contain an oxidiser salt.  He also pointed out that Dr. Sujansky had calculated that the proportion of water in the cited total composition fell within the range which Dr. Clay calculated for the present total composition.  Dr. Jessup also argued that the citation did disclose oil‑in‑water emulsions because this kind of emulsion was described.
         The citation describes a blasting composition which has similar overall proportions of ingredients to those compositions defined in the present claims.  However the composition described in the citation consists of an emulsion of unspecified kind, which does not contain an oxidizing salt, which is then mixed with ANFO.  Dr. Clay comments as follows in his declaration:

"A functional composite explosive is not generally equivalent to a weight percent list of ingredients any more than a man is just a weight percent list of elements.

...

a satisfactory blasting agent is not generally equivalent to the sum of the  ingredients.  The correct balance of physical properties is indispensible for a satisfactory final product."

These comments were not contradicted by the opponent's declarants. Thus it seems to me that the description in the citation is not for the purposes of practical utility equal to that given in the present application (see Hills v. Evans, quoted in Olin Corporation v. Super Cartridge Co. Pty. Ltd. 14 ALR 149 at page 169). Therefore I am satisfied that the claims are not prior published by Australian patent No. 281537. I also consider that the differences highlighted by Mr. Chernov contribute to the working of the present invention. Therefore I am also satisfied that the invention defined in the claims is novel in the light of this Australian patent.
Australian Application No. 29408/71
         The specification of Australian application No. 29408/71 states that the invention relates to a substantially waterproof blasting explosive composition with a grease‑like consistency.  The object of the invention is to produce blasting explosive that can be loaded directly into a water‑filled borehole without being deleteriously affected by the water and having a viscosity sufficiently high to substantially prevent segregation of any solids present but sufficiently low enough to allow the explosive to be poured or pumped into boreholes.  Then follows a description of the invention in identical terms to those of claim 1 and the density of the composition is stated to normally lie in the range of 0.3 to 1.7 g./cc.  Then there is a more detailed description of each of the components of the composition which includes a description of non‑
explosive sensitizers as both particles containing an entrapped gas, e.g. phenolic resin microballoons, and gas bubbles produced in situ, e.g. from hydrogen peroxide.
         The description continues as follows:

"The blasting explosive composition of the invention will generally contain water in an amount of from 7 to 27% by weight of the total composition, preferably from 10 to 23%."

The description states that the blasting composition of the invention may contain one or more solid particulate oxygen‑
releasable substances dispersed in the grease and gives ammonium nitrate as an example.  The ammonium nitrate may be in fine or coarse crystalline form or in the form of porous or non‑porous prills.
         When a solid particulate oxygen‑releasable substance is incorporated in the grease it is preferable to provide additional fuel material so as to keep the overall oxygen balance of the composition near to zero.  Such additional fuel may be an additional quantity of the non‑explosive hydrocarbon fuel or a quantity of non‑
explosive sensitizer or mixtures of these substances.
         The amount of solid oxygen‑releasable substance present in the blasting explosive composition depends on the particle size and porosity and is normally between 0 and 70% by weight of the total composition.  Where the solid oxygen‑releasable substance is porous prilled ammonium nitrate and the additional fuel material is fuel oil a particularly advantageous composition may be made by first mixing the porous prilled ammonium nitrate with the additional fuel oil and then mixing this mixture with the grease.
         If at least 50% by weight of the total composition consists of porous prilled ammonium nitrate and fuel oil incorporated in the grease, it is possible for this mixture to act as the sole sensitizer when the blasting composition is used in boreholes at least 4 inches in diameter.
         Example 2 describes a grease‑like emulsion which is sensitised with hydrogen peroxide.  Example 25 describes an explosive composition which consists of 44 parts by weight of the grease‑like emulsion described in Example 2 without the hydrogen peroxide and 56 parts by weight of a mixture of 94% by weight of ammonium nitrate porous prills and 6% by weight of fuel oil.
         The relevant claims read as follows:

"1.A blasting explosive composition having a grease‑

like consistency comprising at least one water‑soluble inorganic oxygen‑releasable salt, at least one substantially water‑insoluble non‑self‑explosive hydro‑

carbon or halogenated hydrocarbon fuel, water, a surfactant capable of imparting a grease‑like consistency to the composition, and at least one sensitizer distributed substantially homogeneously throughout the composition in an amount sufficient to sensitize the composition.

10.A composition as claimed in any preceding claim, wherein the water is present in an amount of from 7 to 27% by weight of the total composition.

22.A composition as claimed in any preceding claim and further comprising one or more solid particulate oxygen‑

releasable substances dispersed therein.

23.A composition as claimed in Claim 22, wherein said substance is ammonium nitrate.

24.A composition as claimed in Claim 23, wherein the ammonium nitrate is in the form of prills.

25.A composition as claimed in Claim 22, 23 or 24, wherein said substance is present in an amount of up to 70% by weight of the total composition."

Mr. Chernov submitted that application No. 29408/71 did not anticipate the claims because the blasting compositions described in the citation contain more water than the compositions defined in the claims.  He also said that the composition described in Example 25 contains too much of the grease‑like emulsion to prior publish the compositions defined in the claims.
         Dr. Jessup considered that the proportion of water described in the citation overlapped the claimed range because the citation disclosed the proportion of water as "7 to 27% by weight of the total composition".  Dr. Jessup also submitted that the citation broadly disclosed compositions which contain a solid particulate oxygen‑releasable substance dispersed in the grease‑like emulsion and thus the disclosure was not restricted to the embodiment described in Example 25.
         I agree with Mr. Chernov that the blasting composition described in Example 25 does not prior publish the blasting compositions defined in the claims.  This is because the cited composition contains 44% by weight of the grease‑like emulsion which lies outside the presently claimed range of 10‑40% of a dense water‑in‑oil emulsion.  However I also agree with Dr. Jessup that the question I have to consider is whether the blasting compositions defined in the present claims lie within the broad disclosures of the citation.
         Dr. Jessup's interpretation of the description of the water content means that the phrase "total composition" should only refer to the amount of grease‑like emulsion.  On the other hand the alternative interpretation relied on by Mr. Chernov means that this phrase refers to the amount of blasting composition irrespective of whether it consists of a grease‑like emulsion only or a solid particulate oxygen‑releasable  substance dispersed in the grease‑
like emulsion.
         In my opinion the blasting compositions which contain solid particulate oxygen‑releasable substance dispersed in the grease‑like emulsion are described in Australian application 29408/71 as forming part of the invention.  Thus the first paragraph which describes this kind of blasting composition commences as follows:

"The blasting compositions of the invention may contain one or more solid particulate oxygen‑releasable substances dispersed in the grease."

I consider that it is also apparent, from the description that the proportion of solid particulate oxygen‑releasable substance dispersed in the grease‑like emulsion is referred to the total weight of both components.  This is because the description states that the amount of solid particulate oxygen‑releasable substance can be "between 0 and 70%, preferably between 0 and 50%, by weight of the total composition".

         It seems to me, therefore, that the phrase "total composition" should be given its plain meaning in the cited specification.  In other words the compositions described in the citation contain 7 to 27% by weight of water irrespective of whether the composition consists of a grease‑like emulsion only or a solid particulate oxygen‑releasable substance dispersed in the grease‑like emulsion.  According to Drs. Sudweeks and Sujansky the compositions described in the preferred embodiments contain 9.8 to 27% by weight of water.
         In that case I am satisfied that Australian Application No. 29408/71 does not prior publish the present claims, because the present specification describes explosives containing 0.3 to 6% by weight of water in the total composition.  I also consider that the present specification clearly describes how the lower water content contributes to the working of the present compositions.  Therefore I am satisfied that Australian application No. 29408/71 does not render the present claims not novel.
Summary
         I have found that the present specification does not comply with s.40 and that it is anticipated by US patent No. 3,161,551.  However I am satisfied that there is patentable subject matter disclosed in the specification and for this reason I allow the applicant 60 days from the date of this decision in which to lodge amendments to my satisfaction.  I award costs against ROBERT B. CLAY.

(J.L. ROVETA)