Canadian Industries Limited v. Australian Paper Manufacturers Limited

[1983] APO 21

In the Matter of the Patents Act 1952

‑ and ‑

In the Matter of Patent Application 507893 in the Name of CANADIAN INDUSTRIES LIMITED

‑ and ‑

In the Matter of Opposition thereto by AUSTRALIAN PAPER MANUFACTURERS LIMITED.

DECISION OF A SUPERVISING EXAMINER OF PATENTS:
Background
         Patent Application No. 507893 entitled "Delignification of Ligno‑
cellulosic Material with an Alkaline Liquor in the Presence of Diels‑Alder Adduct of Benzoquinone or Napthoquinone" by Canadian Industries Limited (CIL) was lodged on 23 November, 1977.   Acceptance was advertised on 28 February, 1980 and Notice of Opposition to the grant of a patent was lodged by Australian Paper Manufacturers Limited (APM) on 28 August, 1980 after the granting of an extension of time in which to do so.   After APM had completed service of evidence‑in‑support, CIL, on 27 August, 1982, gave notice under Regulation 57A that it did not wish to serve or lodge evidence‑in‑answer.   On 25 October, 1982, APM applied for a time and place for a hearing of the opposition.  The matter was heard on 8 February, 1983 in the Melbourne Sub‑Office.   Dr. J.McL. Emmerson of Counsel, instructed by Mr. P.W. Jones, patent attorney of Phillips, Ormonde & Fitzpatrick appeared for the applicant CIL and Mr. D.B. Mischlewski, patent attorney of Edwd. Waters & Sons represented the opponent APM.

At the hearing Mr. Mischlewski indicated that the grounds upon which the opponent sought to rely were prior claiming in a patent, prior claiming in a complete specification of an application, non‑compliance with section 40, prior publication and want of novelty.
THE SPECIFICATION
         The description opens by stating that the invention relates to a process for the delignification of lignocellulosic material such as wood, straw and bagasse.   It then discusses the prior art methods of delignification and their attendant problems.
         At page 2 it refers to the use of anthraquinone‑2‑monosulphonic acid (AMS) as a means of improving yields in the soda process and the soda‑oxygen process.   It explains that the economic advantages resulting from higher yields are largely offset by the relatively high cost of AMS and the odour problem caused when the sulphur derived from the additive is converted into sulphide.
         The specification then discusses the disclosure of United States Patent 4,012,280 (which was not published before the priority date of the present claims) which relates to the use of, instead of AMS as an additive in an alkaline pulping liquor, a sulphur‑free quinone compound such as, amongst others, naphthoquinone, anthraquinone, anthrone, phenanthrenequinone, and alkyl, alkoxy and amino‑derivatives of said quinones.   It asserts that compared to AMS, these quinone additives have the very great advantage not contributING to pollution and that for a given concentration and under comparable pulping conditions, are more effective.
         The description then indicates that it has been found that ligno‑
cellulosic material can be delignified in high yield by a process which comprises a digestion with an alkaline pulping liquor in the presence of a diketo anthracene selected from the group consisting of the unsubstituted and lower alkyl‑substituted Diels Alder adducts of naphthOquinone and benzoquinone. The specification then sets out the advantages of the invention in the follow‑
ing terms:

"The compounds of this group, which are not quinones, have surprisingly been found to afford pulping results at least as good as those obtained with the quinones of the above‑

identified patent application while offering the major advantage that they can be prepared more readily and more economically.   Optionally, the digestion with alkaline pulping liquor may be followed by a second stage digestion in alkaline medium with oxygen or an oxygen‑containing gas under pressure.   The novel process provides a pulp in higher yield at an increased rate of delignification in comparison to similar processes without additive.   In addition, the diketo anthracene additives proposed in this invention are free of sulphur and hence have the marked advantage over the anthra‑

quinone monosulphonic acid proposed in East German Patent No. 98,549 of producing no polluting sulphur compounds.   Furthermore, the concentrations of the diketo anthracene additives required are at an economically advantageous level and often are less than that required with the known quinone additives."

It then sets out the objects of the invention:

"Thus the main object of the invention is to provide a pulping process which gives a high yield of cellulosic pulp. Another object is to provide a pulping process having a high rate of delignification, thus achieving a lower energy consumption and a higher throughput.   A further object is to provide a pulping process which has a low pollution potential.   A still further object is to provide a pulping process employing additives more readily and more economic‑

ally prepared than AMS and the quinone additives."

Then follows a consistory statement in terms similar to claim 1 and a more detailed description of the invention including examples of "diketo anthracene" compounds at page 7 and five examples illustrating the invention.  The specification ends with ten claims, claim 1 being the sole independent claim.  It reads:

"1.A process for the delignification of lignocellulosic material comprising the steps of (1) treating the ligno‑

cellulosic material in a closed reaction vessel with an alkaline pulping liquor containing from 0.001% to 10.0% by weight, based on the lignocellulosic material, of a diketo anthracene selected from the group consisting of the unsubstituted and lower alkyl substituted Diels Alder adducts of naphthoquinone or benzoquinone, the treatment taking place at a maximum temperature in the range of from 150`C. to 200`C. for a period of 0.5 to 480 minutes, and (2) displacing the pulping liquor from the lignocellulosic material with water or an aqueous liquor inert to the lignocellulosic material to obtain a delignified lignocellulosic material."

SECTION 40
Clarity
         Claim 1 refers to the particular additive to be used in the process of the invention as a "diketo anthracene".   Professor R.W. Warrener, a professor of chemistry at A.N.U., indicates in paragraph 4 of his declaration that "diketo anthracene is loose terminology for anthraquinone".   there is no suggestion in his declaration nor in the declaration of Mr. C.M. Saul that any difficulty has been encountered as a result of the means by which claim 1 defines these additives.     As the compound is described as a diketo anthracene, that is, a tricyclic compound having 10 carbon atoms in the basic ring with diketo groups present, the compound to be reacted with naphthoquinone or benzoquinone to produce the adduct must be 1,3‑butadiene or a lower alkyl substituted 1,3‑butadiene.   The unsubstituted Diels Alder adduct of naphthoquinone is 1,4,4a,9a, tetrahydro‑9,10‑anthraquinone (THAQ) or in the nomenclature of the specification 1,4,4a,9a‑tetrahydro‑9,10‑diketo anthracene.  The Diels Alder adduct of benzoquinone and 1,3‑butadiene is 1,4,4a,4b,5,8,8a, 8b‑octahydro‑9,10‑anthraquinone or 1,4,4a,5,8,8a,8b‑octahydro‑ 9,10, diketo anthracene.   The numbering system used in the specification in respect of the octahydro compounds is slightly different to that used by Professor Warrener, however I do not consider any lack of clarity arises.
         Mr. Mischlewski submitted that claim 1 is unclear in that step (1) of the claim contains the wording "... an alkaline pulping liquor containing ... a diketo anthracene selected from ... Diels Alder adducts of naphthoquinone or hydroquinone".   He argued that under the pulping conditions stated in the claim, the adducts, on the evidence of Professor Warrener and Mr. Saul, would be converted to oxidised and reduced forms which would then equilibrate with their various tautomers.   He asserted that it would be quite likely within a short time, that there would be no diketo anthracene compound present.  Hence, according to Mr. Mischlewski, the claim is unclear, imprecise and misleading in its use of the word "containing" when more appropriate wording such as "to which has been added" could have been used.   I do not agree with the opponent on this point.   The specification must be given a "purposive construction" and it appears to me that if it is understood, as Mr. Mischlewski contends, that there would be conversion of the diketo anthracene compounds, it would be equally understood that the claim seeks to define the amount of these compounds at the beginning of the process ‑ if there is any doubt then a reading of the specification as a whole readily resolves any perceived difficulties.  
         Mr. Mischlewski also indicated that there was a minor section 40 problem with claim 2 which reads:

"A process as claimed in claim 1 wherein the lower alkyl substituted Diels Alder adducts are adducts substituted with 1 to 4 alkyl groups which may be the same or different and may each contain 1 to 4 Carbon atoms."

He argued that the use of the word "may" renders the claim unclear.
         It could be, on a cursory appraisal, that some small confusion would be encountered, however I consider that on a more thorough reading any confusion would dissolve.   Thus I understand the first use of the word "may" in the claim ‑ "with 1 to 4 alkyl groups which may be the same or different" ‑ to mean that when there are 2 to 4 substituent alkyl groups these substituents are the same or different; and when the claim indicates that: "may each contain 1 to 4 carbon atoms" it simply means that the 1 to 4 alkyl group can each have from 1 to 4 carbon atoms.
         I therefore find that the opponent has failed to establish any of the section 40 objections it has argued.
ANTICIPATION and PRIOR CLAIMING
         The present application is a Convention application based on US Serial No. 750,448 filed in the US on 14 December, 1976.   There was no argument that the claims of the present application should not be accorded 14 December, 1976 as their priority date; I am satisfied that the priority date of the present claims is that date.
         The documents relied on by the opponent are:

1.Japanese application No. 43403/76 by Honshu Seishi Kabushiki Kaisha available in the Patent Office 1 June, 1976.

2.Australian Patent No. 513517 by Honshu Seishi Kabushiki Kaisha, earliest priority date 10 December, 1976.

3.Australian patent application No. 505746 by Australian Paper Manufacturers Ltd., earliest priority date 2 June, 1976.

Thus the opponent is arguing prior publication and want of novelty based on Japanese application 43403/76 and prior claiming with Australian Patent No. 513517 and patent application No. 505746.
         Mr. Mischlewski submitted that the process defined in claim 1 is conventional in all respects for alkaline pulping processes save for the inclusion of the diketo anthracene compound defined in the claim.   This submission is supported by the comments made by Mr. Saul in paragraphs 3 to 6 of his declaration.
         Mr. Mischlewski further submitted that the Diels Alder reaction is well known to students ‑ the reaction of naphthoquinone and butadiene is a classic reaction.   Referring to paragraph 11 of the Saul declaration, he explained that it was known that when THAQ is treated with hot alkali in the presence of air it is converted to anthraquinone.   Indeed Mr. Saul asserts:

"... That the conditions prevailing at the commencement of an alkaline delignification involve a substantial excess of alkali, a temperature in the range 150` to 200`C and an excess of air.   These conditions are conducive to the immediate conversion in‑situ of THAQ to anthraquinone."

Mr. Saul's assertions may subsequently be proved correct, however he does not provide experimental evidence clearly establishing that there is complete conversion of THAQ to anthraquinone under the pulping condition defined in claim 1.   Indeed he does not provide any evidence establishing his assertion that the net effect of diketo anthracene compound is exactly equivalent to anthraquinone addition.   His assertions are based on the behaviour of THAQ in alkaline solutions at high temperatures, however it appears to me that an alkaline pulping liquor is a chemically complex animal, possibly containing both oxidising and reducing agents, as as such less predictable than a simple alkaline solution.
         I am not satisfied that Mr. Saul has provided evidence which establishes, with the degree of certainty required at this stage of proceed‑
ings, that letters patent granted on the specification would be held invalid.  I am of the opinion that there is, at the very least, a doubt on the matter of THAQ, anthraquinone equivalence and that this doubt should be resolved in the applicant's favour.
         This matter of THAQ conversion is more fully discussed in the declaration by Professor Warrener.   In paragraph 6 he refers to the original paper by Diels Alder which mentions that, in the presence of alkali (KOH) and air, THAQ will oxidise to 9,10 anthraquinone.   At paragraph 15 he indicates that "it is not unreasonable to expect" that THAQ does not exist in a single form but exists in several different tautomeric forms interconvertable one from the other.   One of these tautomeric forms is shown as 1,4‑dihydro‑9,10‑
dihydroxy anthracene (DDA).   Professor Warrener, after making this apparently cautious statement, asserts in paragraph 17 that DDA is a tautomeric form of THAQ.   Further, in paragraph 18 he indicates that in the alkaline solution THAQ will convert to a tautomeric mixture not distinguishable from that derived from alkali treatment of DDA.   He then concludes:

"Consequently the addition of THAQ or D.D.A. to an alkaline pulping liquor must be considered as being equivalent chemically to the addition of anthraquinone to an alkaline pulping liquor."

It seems to me that Professor Warrener's conclusions are theoretically based.   He provides no experimental evidence to establish what actually occurs in an alkaline delignification liquor.   I note from the list of qualifications and experience given in paragraph 1 of his declaration he does not list anything related to the pulping of lignocellulosic materials.   I also refer to my previous comments relating to Mr. Saul's evidence as I consider them relevant to Professor Warrener's evidence.   I therefore do  not find Professor Warrener's evidence to be conclusive.
         To support its accusation that the addition of THAQ to a pulping liquor is equivalent to the addition of anthraquinone, the opponent has carried out tests comparing the two.  The results of these tests are set out in the declaration by Dr. Napthali Nachenja Vanderhoek.   In these tests Dr. Vanderhoek compares the effectiveness of kraft pulping of pine and eucalypt wood with the addition to the pulping liquid of anthraquinone, THAQ and DDA.  The tests appear to have been carried out according to instructions given in the Honshu Technical Bulletin attached to Dr. Vanderhoek's declaration (NV1).   From the data gained, from what seems to be to be a limited number of cooks, Dr. Vanderhoek declares:

"That the conclusion to be drawn from the comparative study is that in kraft pulping processes the addition to the pulping liquid of DDA and THAQ is no more effective than AQ in improving pulp yield at a Kappa number, in kraft pulping of pine and eucalypt wood."

However, as Dr. Emmerson pointed out, the Honshu Technical Bulletin itself does not arrive at a similar conclusion.   On the contrary, it appears to indicate that there is a difference in effectiveness between THAQ and anthraquinone.   Thus in figures 224 and 311 of the bulletin THAQ is shown to give better results than anthraquinone and at page 20 it states:

"Distinctive feature of THAQ is in its stronger effects on cooking in comparison with THAQ to AQ and in its liquid form for easy addition to white cooking liquor."

Mr. Mischlewski submitted that the Honshu Bulletin refers to DDA as "THAQ" however I believe that a reading of the formula given at page 12 of the bulletin clearly shows that this is not the case.
         I am not satisfied that the opponent has established beyond doubt, that the addition of the diketo anthracene compound according to the present invention is equivalent to the addition of anthraquinone or DDA.   Having said this I now turn to the citations relied on by the opponent.
Japanese application 43403/76
         As indicated previously, this document was published in the Japanese language before the priority date of the present claims.   The translation of the document indicates that the invention relates to a method of making alkali pulp by digestion.   It states that specifically the invention is related to a method of making alkali pulp by digestion characterised by the addition to an ordinary digestion solution, of one compound selected from the group consisting of aldehyde compounds, ethanol amines and quinone compounds.   It further states that one can use benzoquinone, naphthoquinone and anthraquinone as the quinone compound.   Two examples using a quinone compound are given, one using alpha‑naphthoquinone, the other, anthraquinone.   I can find nothing in this document to suggest that reduced quinone compounds are to be used let alone a teaching of the use of THAQ.   There is no evidence establishing that the skilled addressee, on reading the term "quinone", would include THAQ within the range of compounds covered by that term.   Indeed the present specification asserts that the diketo anthracene compounds are not quinones.   I thus conclude that the Honshu specification fails to give clear and unmistakeable directions to carry out the present invention; the document does not contain a clear description of, or clear instructions to do something that would infringe the present claims if carried out after grant of a patent.   I find that the opponents have not established prior publication.
         Then there is the question of the novelty of the present invention in light of the Honshu document.   The claimed advantages of the present invention are, in summary:

1.Pulping results are at least as good as those obtained with quinones;

2.The diketo anthracene compounds are more readily and economically prepared than the quinones discussed in US patent 4,012,280;

3.The diketo anthracene compounds are free of sulphur and thus have an advantage over AMS in regard to pollution;

4.In the case of THAQ, as it is a liquid form it is more readily added to the pulping liquor.

Mr. Mischlewski asserted that all but one of these advantages accrue from the use of anthraquinone itself.   The only remaining advantage claimed in the present specification, relating to ease and cost of preparation of the diketo anthracene compounds over that of anthraquinone, was disputed by Mr. Mischlewski.   He asserted that THAQ was well known as an intermediate in the preparation of anthraquinone and that it was unlikely that an intermediate would be easier to make because of the way chemical plants are structured ‑ it would be uneconomic to pull out as intermediate.   Although Mr. Mischlewski may be correct in relation to some processes for preparing compounds it is quite conceivable that the reduction in energy, reagents, labour and equipment resulting from not having to carry out the further step of converting THAQ to anthraquinone would make preparation easier and less costly.   Neither party submitted evidence on this point; however I believe there is a doubt as to whether there is no cost advantage in the use of diketo anthracene compounds and I resolve this doubt in the applicant's favour.
         As will be seen from my previous comments, I do not believe that the evidence established that the use of diketo anthracene compounds is a mere well known alternative to using anthraquinone.   I consider that the use of the diketo anthracene compounds in question contribute to the working of the invention in that they have a direct effect on the yield of a delignification process.   Thus I do not believe that the opponent has succeeded in establish‑

ing want of novelty.
Australian Patent 513517 (Honshu Seiki K.K.)
         This specification was not published before the priority date of the preset claims, thus the issue relates to prior claiming in a patent.   Claim 1 of 513517 reads as follows:

"A process for the production of pulp from lignocellulosic materials characterized in that by subjecting the ligno‑

cellulosic materials to cooking in a conventional alkaline or sulfite cooking liquor in the presence of a cooking aid comprising at least one member selected from the group consisting of the compounds having the general formula:

Rm

(1)

(OA)n

wherein R represents H or COOX, wherein X represents H or Na, or SO3Y, wherein Y represents H or Na; A represents H or Na; m represents 9, 1 or 2; and n represents 1 or 2; and when R represents H, it means the case in which a carbon atom in the anthracene nucleus takes the form of CH2 instead of CH losing its double bond."

As will be seen, the general formula given in this claim does not include the diketo anthracene compounds claimed in the present specification.
         The opponent relies on the fact that DDA is covered by the formula and is specifically mentioned in appended claims 2 and 3.   Mr. Mischlewski argued that DDA is a Diels Alder adduct and, according to Professor Warrener, is a tautomer of THAQ ‑ thus the two are indistinguishable.
         The proper test for prior claiming is whether there is, in the earlier specification, a distinct claim to what is claimed by the later claim (Kromschroder A.G.'s Application 1960 RPC 75). I believe that the opponent's evidence attempting to establish the alleged equivalence between DDA and THAQ is even more tenuous than that presented for THAQ and anthraquinone. Thus, in the results of a limited number of 3 DDA cooks given at page 4 of Dr. Vanderhoek's declaration, the figures given for 0.01% and 0.05% addition appear to me to show that the effect of THAQ and DDA addition is not equivalent, particularly in relation to the 0.05% cook.
         I can find nothing in the Honshu patent suggesting the use of diketo anthracene as a cooking aid.   It is true that THAQ is mentioned at page 6 of Honshu, however only as an intermediate in the preparation of DDA.   One would have thought that if Honshu had considered THAQ as a viable addition compound it would have suggested its direct use rather than teaching the reader to convert it to the desired DDA.   I am not satisfied that the claims of Honshu are directed to the same invention as that presently claimed.   Accordingly I find that the Honshu claims do not prior claim the present claims.
Australian Application 505746 (APM)
         The opponent contends that the present claims are prior claimed by claim 1 of patent application 505746 by APM.   This application is a cognate of three provisionals ‑ PC6141 lodged 2 June, 1976; PC7473 lodged 23 September, 1976 and PC8455 lodged 13 December, 1976.   All of these provisionals were thus lodged before the priority date of the present claims (14 December, 1976).  Claim 1 of 513517 reads:

"A process for the delignification of lignocellulosic material wherein the lignocellulosic material is cooked with an alkaline (as hereinbefore defined) pulping liquor and the pulping liquor contains at least .001% by weight based on dry lignocellulosic material of an additive compound or mixture of additive compounds selected from phenanthrenequinones, anthrones, anthrahydroquinones, naphthohydroquinones, phenanthrahydroquinones, benzohydroquinones, the alkyl‑, alkoxy‑, hydroxy‑, amino‑, halo‑ or carboxy‑ derivatives of said quinones or hydroquinones or the alkyl‑, alkoxy‑, hydroxy‑, amino, halo‑ or carboxy‑ derivatives of anthra‑

quinone, naphthoquinone or benzoquinone and the tautomeric forms of all said additive compounds."

Mr. Mischlewski submitted that the anthrahydroquinones and their alkyl derivative defined in the claim are the reduced forms of anthraquinone.   He asserted that the members of the group anthrahydroquinones will simply be identified as anthraquinone to which hydrogen has been added; these include dihydroanthraquinone, tetrahydroanthraquinone (THAQ) and octahydroanthraquinone and their alkyl derivatives.   He submitted that the APM claim includes within its scope a process of using a class of compounds identical to the class of compounds named in the CIL claim.
         Dr. Emmerson disputed this submission and asserted that nowhere in Professor Warrener's declaration is there an indication that he believes claim 1 of APM to include all reduced forms of anthraquinone.   In any case, Dr. Emmerson submitted, Professor Warrener's evidence, if anything, goes in the opposite direction.   He directed my attention to paragraph 14 of the declaration where the Professor alternatively refers to anthrahydroquinone as 1,10‑dihydroxyanthracene, not THAQ.   Dr. Emmerson submitted that THAQ is quite different to anthrahydroquinone.
         I agree with Dr. Emmerson on this point.   Claim 1 of 513517 refers to anthrahydroquinones not hydroanthraquinones.   At line 10 it refers to "said quinone or hydroquinones".   The reference to hydroquinones must relate to the anthrahydroquinones, napthohydroquinones, phenanthrahydroquinones, and benzohydroquinones previously mentioned in the claim.   At page 5 of the specification 9,10‑anthrahydroquinone is given as an example of an hydroquinone compound; this accords with the compound described in paragraph 14 of the Warrener declaration, as referred to by Dr. Emmerson.   Hackh's Chemical Dictionary, fourth edition, defines hydroquinone (hydroquinol) as p‑dioxybenzene or p‑hydroxyphenol.   I understand the hydroquinone compounds, including the anthrahydroquinones defined in claim 1 of 505746, to be based on the hydroquinone nucleus and thus to be dihydroxy compounds, whereas the compounds of the claims in suit are diketo compounds.   It is true that the compounds in the respective claims would be classified as reduced compounds of anthraquinone, however the way in which they are reduced is different ‑ the diketo anthracene compounds of present claim 1 are reduced in the sense that they have a lower degree of unsaturation compared to anthraquinone whereas the anthrahydroquinones are reduced in the sense that the keto groups of anthra‑
quinone are converted by addition of hydrogen to form hydroxy groups.   I am also not satisfied that there is an equivalence between anthrahydroquinones and the present diketo anthracenes in the brew; I refer to my previous comments on the evidence submitted in support of this proposition.
         It will be seen that claim 1 of 513517 ends with the phrase:  "and the tautomeric forms of all said additive compounds".   The number of tautomers would appear to be extremely large.   Mr. Mischlewski drew my attention to page 5 of the APM specification which indicates "Other tautomers of interest are dihydroanthraquinone and tetrahydroanthraquinone (i.e. THAQ).   The specification of the APM application as lodged does not include a reference to dihydroanthraquinone or tetrahydroanthraquinone; it was introduced by section 49 amendment after the priority date of the present claims.   The three provisional specifications, of which the APM  specification is a cognate, do not describe the use of tautomeric compounds as additive compounds and certainly do not mention the diketo anthracene compounds of present claim 1. There is the question of whether claim 1 of 513517 can be rewritten to a notional claim defining a process using THAQ as an additive.   However I do not believe I have to answer this question as I do not believe that any such notionally rewritten claim would be fairly based on the disclosure of the provisionals and would therefore have a later priority date than that of the claims in suit.   Accordingly I find that no claim of 513517 prior claims any of the present claims.
CONCLUSION
         Dr. Emmerson submitted that the onus of proof is on the opponent at this stage of proceeding ‑ it must make it clear that no valid patent could be granted.   He cited the authorities in Stamp v. W.J. Powell (1918, 24 CLR 339), Henry Berry & Co. v. Potter (1924, 35 CLR 132) and Joos v. Commissioner of Patents (126 CLR 161) to support this submission. It is also true that there can be a shift in this onus depending on the state of evidence submitted by the parties. However in the present case I do not believe that the opponent's evidence shifts the onus to the applicant. The opponent's evidence is based on hypothesis and inconclusive experimental evidence which I find does not enable me to be practically certain that a patent granted on the specification would be held invalid.
         Accordingly I find that the opponent has failed to establish any of the grounds of opposition on which it relied.   I am also satisfied that there are no other lawful objections to the specification.   I direct that the application and complete specification may proceed to sealing, subject to any appeal.   I award costs against the opponent.

(P.A. KILBORN)