T 0484/99 25-07-2000

I. The mention of the grant of European patent No. 0 529 910, in respect of European patent application No. 92 307 527.9, filed on 18 August 1992 and claiming a JP priority of 23 August 1991 (JP 212335/91) was published on 13 March 1996 (Bulletin 1996/11). Claim 1 read as follows:

"A biodegradable hydrophilic crosslinked polymer; in which a bond having as a composition unit at least one group (II) represented by the chemical formula -CO-O- and/or group (III) represented by the chemical formula -CO-NH- cross-links main chains, said main chains being made of a water-soluble oligomer which contains an ingredient having a molecular weight of 5,000 or less in 50% or more by weight of the water-soluble oligomer and which has a functional group (I) represented by the general formula -COOM (herein, M denotes any one of a hydrogen atom, monovalent metal, divalent metal, trivalent metal, an ammonium group and organic amine group); said cross-linked polymer showing a viscosity of 1,000 cP or less at 20 C by a 20% by weight aqueous solution of said crosslinked polymer."

Claim 2, an independent claim, was directed to a builder formed from the hydrophilic crosslinked polymer according to Claim 1.

Claims 3 to 6 were further independent claims directed, respectively, to a detergent composition, a fiber-treating agent, an inorganic pigment dispersant and a water treatment agent containing the hydrophilic crosslinked polymer according to Claim 1.

Claim 7, an independent claim, was worded as follows:

"A process for producing a biodegradable hydrophilic crosslinked polymer, of which 20% by weight aqueous solution shows a viscosity of 1,000 cP or less at 20 C, comprising a step of combining a water-soluble oligomer by a crosslinking agent:

said water-soluble oligomer has an ingredient of 5,000 or less in molecular weight in 50% by weight or more and the functional group (I) represented by the general formula -COOM (herein, M denotes anyone of a hydrogen atom, monovalent metal, divalent metal, trivalent metal, an ammonium group and organic amine group); and

said crosslinking agent has either (not only) at least one of a group (II) represented by the chemical formula -CO-O- and a group (III) represented by the chemical formula -CO-NH- as a composition unit, or (but also) is capable of forming at least one of the above-described groups (II) and (III)."

Claims 8 to 13 were dependent claims, directed to elaborations of the process according to Claim 7.

II. Two Notices of Opposition were filed on 13 December 1996, by Opponent I on the grounds of insufficient disclosure, lack of novelty and lack of inventive step, and by Opponent II on the grounds of lack of novelty and lack of inventive step. In a response received on 20. May 1997, the Patentee filed amendments to Claims 1, 7. and 8 of the patent in suit. In a further submission, received on 16 April 1998, the Patentee filed additional Claims 14, 15, 16 and 17. Finally, on 9. December 1998, the Patentee filed further sets of amended claims forming a main request and four auxiliary requests. In particular, the second auxiliary request was a set of Claims 1 to 13, of which Claim 1 read as follows:

"A biodegradable hydrophilic crosslinked polymer; in which a bond cross-links main chains;

said main chains being made of a water-soluble oligomer which contains an ingredient having a molecular weight of 5,000 or less in 50% or more by weight of the water-soluble oligomer and which has a functional group (I) represented by the general formula -COOM (herein M denotes any one of a hydrogen atom, monovalent metal, divalent metal, trivalent metal, an ammonium group and organic amine group);

said bond is formed by a reaction of said water-soluble oligomer with a cross-linking agent of at least one group (V) selected from polyglycidyl compounds, tartaric acid, citric acid and malic acid;

said cross-linked polymer showing a viscosity of 1,000 cP or less at 20 C in a 20% by weight aqueous solution of said crosslinked polymer."

Claim 2, a dependent claim, was directed to the biodegradable hydrophilic crosslinked polymer of Claim 1, wheren the cross-linking agent was selected from polyglycidyl compounds, tartaric acid and citric acid.

Claim 3, an independent claim, was directed to a builder formed from the hydrophilic crosslinked polymer according to Claim 1 or Claim 2.

Claims 4 to 7 were further independent claims directed, respectively, to a detergent composition, a fiber-treating agent, an inorganic pigment dispersant and a water treatment agent containing the hydrophilic crosslinked polymer according to Claim 1 or Claim 2.

Claim 8, an independent claim, was worded as follows:

"A process for producing a biodegradable hydrophilic crosslinked polymer, of which 20% by weight aqueous solution shows a viscosity of 1,000 cP or less at 20 C, comprising a step of combining a water-soluble oligomer by a cross-linking agent:

said water-soluble oligomer has an ingredient of 5,000 or less in molecular weight in 50% by weight or more and the functional group (I) represented by the general formula -COOM (herein, M denotes anyone of a hydrogen atom, monovalent metal, divalent metal, trivalent metal, an ammonium group and organic amine group); and

said crosslinking agent is at least one group (V) selected from polyglycidyl compounds, tartaric acid, citric acid and malic acid."

Claim 9, a dependent claim, was directed to the process of Claim 8, wheren the cross-linking agent was selected from polyglycidyl compounds, tartaric acid and citric acid.

Claims 10 to 13 were dependent claims, directed to elaborations of the process according to Claim 8.

III. By a decision taken at oral proceedings on 10 February 1999 and issued in writing on 4 March 1999, the Opposition Division revoked the patent. The decision was based on the sets of claims forming the main and four auxiliary requests filed on 9 December 1998, subject to the cancellation of Claims 14 to 17 of the main request which did not meet the requirements of Rule 57a EPC. A further request by the Patentee, made at the oral proceedings, to change the sequence of the requests had been refused inter alia under Rule 71a EPC.

According to the decision, the claims of all the requests under consideration contained embodiments not directly or implicitly derivable from the granted form of the patent. They thus included added subject-matter in contravention of Article 123(2) EPC.

IV. On 3 May 1999, a Notice of Appeal against the above decision was filed, the prescribed fee being paid on the same day.

In the Statement of Grounds of Appeal, filed on 6 July 1999, the Appellant (Patentee) argued in substance as follows:

(i) Procedure

At the oral proceedings before the Opposition Division, the representative of the Patentee had not been given opportunity to be heard, in the sense of Article 113(1) EPC, in the following respects:

(a) No opportunity had been given to submit further amendments at the beginning of the oral proceedings, since these had not been acceptable in accordance with Rule 71a EPC, or to comment. Consequently there had been a substantial procedural violation.

(b) No opportunity had been given to comment on the necessity of cancelling Claims 14 to 17 of the main request, which had been required in accordance with Rule 57a EPC, even though a communication issued by the Opposition Division on 10 July 1998 had indicated that there was no objection to these claims under Article 123(2) EPC.

(c) Following the announcement of the decision to refuse the main request on the basis of objections which were also held to be valid for the first and third auxiliary requests, no opportunity had been afforded to comment on the latter requests. The wording of the decision under appeal did not reflect the oral proceedings in its suggestion that there had been further discussion of the first and third auxiliary requests (point 4 of the Reasons for the Decision). On the contrary, it was clear from the Minutes of the oral proceedings, that the discussion had been limited to the admissibility of the second auxiliary request. Nor had the discussion in any way related to the phrase "selected from polyglycidyl compounds etc".

(d) No opportunity had been given to comment on the allowability of the fourth auxiliary request.

(ii) Content

In the second auxiliary request, it was clear that there was a basis for the cross-linking agent being selected from "polyglycidyl compounds, tartaric acid, citric acid and malic acid" on page 6, lines 29 to 45 of the patent in suit. The inclusion of this amendment was not, therefore, contrary to Article 123(2) EPC.

The Statement of Grounds of Appeal was accompanied by the following sets of claims:

1. a first set of Claims 1 to 13 headed "Main auxilliary [sic] request";

2. a set of Claims 1 to 11 headed "First auxilliary [sic] request"

3. a set of Claims 1 to 13 headed "Second auxiliary request"; and

4. a set of Claims 1 to 13 headed "Third auxiliary request".

The "Main auxilliary request" (main request) corresponded to the second auxiliary request in the oral proceedings before the Opposition Division (section II, above).

The "First auxilliary request" differed from the main request in that the selection of cross-linkers presented in Claims 2 and 9 of the main request had been incorporated in the independent Claims 1 and 8, respectively, with deletion of Claims 2 and 9 of the main request, the phrase "at least one group (V)" in Claim 1 furthermore being suppressed, and the remaining claims renumbered consequent upon deletion of Claims 2 and 9.

The "Second auxiliary request" differed from the main request, firstly in that the definition of the "bond" in Claim 1 had been amplified to read "a bond having as a composition unit at least one group (II) represented by the chemical formula -CO-O-...", and secondly in that the phrase "at least one group (V)" introducing the definition of the cross-linking agents had been suppressed in both Claim 1 and Claim 8.

The "Third auxiliary request" differed from the Second auxiliary request in that the definition of the polyglycidyl compounds had been amplified, in Claims 1 and 8, to read, "wherein the polyglycidyl compounds are chosen from the group comprising ethylene glycol polyglycidyl ether, polyethylene glycol diglycidyl ether, glycerol polyglycidyl ether, diglycerol polyglycidyl ether, polyglycerol polyglycidyl ether, sorbitol polyglycidyl ether, pentaerythritol polyglycidyl either, propylene glycol diglycidyl ether, polypropylene glycol diglycidyl ether, resorcinol diglycidyl ether, 1,6-hexanediol diglycidyl ether, adipinic acid diglycidyl ester, o-phthalmic acid diglycidyl ester, terephthalic acid diglycidyl ester and p-hydroxy-bennzoic [sic] acid glycidyl ester ether....". The corresponding definition in Claims 2 and 9 had been amplified to recite a more specific selection of the compounds mentioned in Claims 1 and 8, respectively, specifically (after correction of a spelling error in Claim 2), adiphinic [sic] acid diglycidyl ester and terephthalic acid diglycidyl ester.

V. Respondent RI (Opponent OI) disagreed, in a submission filed on 23 October 1999, with the arguments of the Appellant, and argued in essence as follows:

(i) Procedure

The Opposition Division had given the parties involved in the proceedings sufficient opportunity to comment on the requests made in writing as to their allowability.

(ii) Content;

Main request

(a) The listings of the crosslinking agents in Claims 1, 2, 8 and 9 comprised added subject-matter in the sense of Article 123(2) EPC, since each listing corresponded to a selection having no support in the original description.

(b) The omission, from Claims 1 and 8 at least, of the requirement for the presence of at least one group (II) represented by the chemical formula -CO-O- and/or group (III) represented by the chemical formula -CO-NH- offended against Article 123(3) EPC, since this limitation had been present in the claims of the patent in suit as granted.

(c) The definition of the crosslinking compound (B) in Claim 10 was obscure in its back reference to Claims 8 and 9 (Article 84 EPC).

First auxiliary request

The objections raised in relation to the Main request applied mutatis mutandis to the First auxiliary request.

Second auxiliary request

Objections (a) and (c) applied mutatis mutandis. Furthermore, (d) the phrase "at least one of" introduced in front of the listing of crosslinking compounds in Claim 8 was contrary to Article 123(3) EPC.

Third auxiliary request

Objections (a), (c) and (d) applied mutatis mutandis, a further infringement of Article 123(2) EPC being seen in the formulation "comprising" in relation to the listing.

VI. Respondent RII (Opponent OII) also disagreed, in a submission received on 11 November 1999, with the arguments of the Appellant, in essence as follows:

(i) Procedure

The sequence in which the various requests were dealt with during the oral proceedings was reviewed in detail, and the opinion expressed that, whilst there had been no right simply to "cancel" certain claims under Rule 57a EPC, this had not been a ground of revocation, and there had been no violation of Article 113 EPC. Also the decision not to allow the Proprietor to file further auxiliary requests was within the Opposition Division's discretion pursuant to Rule 71a EPC, especially in view of the numerous amendments already offered before, and did not amount to a substantial procedural violation.

(ii) Content

Whilst objection was raised under Article 123(2) EPC against the wording of the main request and the first and second auxiliary requests, no such objection was raised against the third auxiliary request. Nevertheless, the third auxiliary request was considered open to objection under this Article in combination with Article 84 and/or 83 EPC to the extent that the crosslinking agent was citric or malic acid, since these acids had only one OH group and were consequently incapable of crosslinking the oligomer chains.

VII. In a communication issued on 17 March 2000 accompanying a summons to oral proceedings before the Board, the preliminary, provisional opinion was given, that it had not been possible to discern any objective irregularity which would amount to a substantial procedural violation.

VIII. In a further submission of the Appellant, received on 23. June 2000, certain of the allegations concerning a contravention of the provisions of Article 113 EPC were repeated, and expanded to include allegations of "highly unusual behaviour" by the Opposition Division as well as incompleteness of the Minutes. On the substance of the case, it was argued that none of the amended definitions involved added subject-matter or extended the protection conferred by the claims, and it was furthermore asserted that citric acid and malic acid were suitable for cross-linking the main chains.

The submission was stated to be accompanied by a main claim set and auxiliary claim sets 1, 2 and 3.

The main and first auxiliary claim sets corresponded to the "Main auxilliary request" and "First auxilliary request", respectively, filed with the Statement of Grounds of Appeal (section IV, above).

Auxiliary claim set 2 differed from the "Second auxiliary request", filed with the Statement of Grounds of Appeal, in that the definition, in Claim 8, of the crosslinking agent had been amended to read, "said crosslinking agent has at least one of a group (II) represented by the chemical formula -CO-O- as a composition unit or is capable of forming at least one group (II) and is selected from polyglycidyl compounds, tartaric acid, citric acid and malic acid.".

Auxiliary claim set 3 differed from the "Third auxiliary request" filed with the Statement of Grounds of Appeal, in the following respects:

(i) in Claim 1, the wording "consisting of" was used instead of "comprising" in relation to the group from which the polyglycidyl compounds were chosen;

(ii) in Claim 2, the crosslinking agent was stated to be "selected from" rather than being "at least one of" the specified compounds; and

(iii) in Claim 8, the introductory wording of the definition of the crosslinking agent, had been amended to read, "said crosslinking agent has at least one of a group (II) represented by the chemical formula -CO-O- as a composition unit or is capable of forming at least one group (II) and is selected from ....".

IX. Oral proceedings were held before the Board of Appeal on 25 July 2000.

At the oral proceedings, the representative of the Appellant indicated that only the sets of claims forming second and third auxiliary requests filed with the submission of 23 June 2000, i.e. auxiliary claim sets 2 and 3, would be further defended.

(i) On the procedural point, the representative re-iterated in particular:

(a) the refusal, at the oral proceedings before the Opposition Division, even to consider the proposed re-arrangement of the requests under Rule 71a EPC had been an unreasonable exercise of discretion and amounted to a procedural violation; and

(b) contrary to what appeared in the decision under appeal, there had been no discussion of the phrase "selected from polyglycidyl compounds, etc." upon which the decision to revoke the patent in suit had been based (Reasons for the Decision, point 4a)).

Consequently, there had been a substantial procedural violation in respect of both these items.

The Respondents disagreed with this view, and re-iterated in substance the observations they had already made in writing.

(ii) On the substantive issues, the Appellant dealt with both the second and third auxiliary requests together, and argued substantially as follows:

Claim 1 in each case was identical with Claim 1 as granted, except that, of the two alternative groups II and III, group III had been cancelled, and the restricted choice of cross-linking agents had a basis in the list of compounds in the originally filed application on page 6 of the latter; in particular, the repeated use of the expression "and the like" was evidence that other similar compounds were envisaged.

Claim 2 contained a further restricted choice of cross-linkers.

Claim 8 contained the same restricted group of cross-linkers as Claim 1.

Claim 9 contained a further restricted choice of cross-linkers.

Claim 10 was dependent on Claim 8 and consequently it was not necessary to repeat the list of cross-linkers, since these were already present in Claim 8.

Respondent I disagreed that the particular selections of cross-linkers presented in the Claims 1, 2, 8 and 9 were derivable from the examples, since in the latter they were associated with particular co-reactants, proportions and experimental conditions, rather than simply with the generality of oligomers as now claimed. Nor were the selections derivable from the passage of description of the patent in suit relied upon (page 6), since this presented a larger number of classes of cross-linkers as equivalent, with no indication that the small group now considered was in any way crucial or even preferred. Consequently, the listings of the cross-linkers themselves mounted to added subject-matter in the sense of Article 123(2) EPC.

Furthermore, although the phrase "at least one" used in Claim 9 in relation to the list of cross-linkers permitted a combination of, say, citric acid with tartaric acid, no such combination had been provided in the examples of the patent in suit, since these only used one cross-linker, and the relevant passage of description relied upon by the Appellant permitted only the mixture of compounds of "two or more kinds", but not of compounds of the same kind. Citric and tartaric acids belonged, however, to the same group as listed (page 6, line 46), and therefore were of the same "kind". Consequently, there was added subject-matter in the sense of Article 123(2) EPC in this respect.

Finally, whilst Claim 10, which was dependent on Claim 8, required that the cross-linker B had "at least two of the functional group (IV) capable of reacting with a functional group which the water-soluble oligomer (A) has...", neither Claim 8 nor Claim 10 contained the requirement, present in Claim 8 as granted, that the group II (-CO-O-), which was in any case a necessary component of the cross-linked product, was formed "by a reaction of the functional group (IV) of the cross-linker with the functional group which the water-soluble oligomer has". Consequently, in the case of the cross-linker being, say, a polyglycidyl, which itself contained no group II and furthermore did not necessarily form a group II on reaction with a functional group of the oligomer, the possibility was opened up by Claim 10 of the necessary crosslinking group II being formed by some other means than the selected cross-linker. Thus Claim 10 was broader in scope than the corresponding claims as granted, and hence open to objection under Article 123(3) EPC.

Respondent II supported the objections of Respondent I and furthermore saw a contradiction between the selection, according to Claim 8 and Claim 9, of citric acid or malic acid as a cross-linker, and the requirement in Claim 1 and Claim 7 as granted that a group II (-CO-O-) must always be formed, since citric and malic acids had only one OH- group and were consequently incapable of forming such a group. There was thus an unclarity in the sense of Article 84 EPC.

X. The Appellant requested that the decision under appeal be set aside, and the patent maintained on the basis of the second auxiliary request (main request), alternatively on the basis of the third auxiliary request (auxiliary request), both filed on 23 June 2000. It requested also the reimbursement of the appeal fee.

The Respondents requested that the appeal be dismissed.