T 0778/98 07-08-2000

Reasons for the Decision

1. The appeal is admissible.

2. Prior art

2.1. Document (1)

Claim 1 of this document relates to a copolymer derived from the polymerisation of about 60 to about 95 weight percent of lactic acid and about 40 to about 5 weight percent of glycolic acid having a molecular weight of about 6000 to 35000.

(1) is silent about the additional presence of polycarboxylic acid moieties in the glycolic acid/ lactic acid copolymer.

2.2. Document (2)

Claim 1 of this document relates to a polymer having a molecular weight between about 2,000 and 70,000 produced by heating a mixture of glycolic acid, its homopolymers, its low molecular weight esters, or mixtures thereof, with a dihydroxyalkane and a dibasic acid, the dibasic acid being present in an amount from about 1% to about 40% by weight of the polymer, and the dihydroxyalkane being present in an amount from about equimolar with, up to a 10 mol% excess over, the dibasic acid.

Preferably, the diacid and the dihydroxyalkane are used in equimolar quantities (column 3, lines 20 to 26).

3. Article 113 EPC

Paragraph (1) of this article requires that the decisions of the European Patent Office may only be based on grounds or evidence on which the parties concerned have had an opportunity to present their comments.

According to the established jurisprudence of the boards of appeal the term "grounds" in Article 113(1) EPC refers to the essential reasoning, both legal and factual, which leads to refusal of an application. In other words, before a decision is issued an applicant must be informed of the case which he has to meet, and must have an opportunity of meeting it (cf. Reasons 3 (v), second paragraph of T 951/92, OJ EPO 1996, 53).

Since this "right to be heard" is an obligation of utmost importance its observation by the decision under appeal has to be examined by the Board under Article 114(1) EPC even when the violation of this principle was not censured by the Appellant.

4. The objection of lack of inventive step raised in the decision under appeal is essentially based on the argument that it was obvious to modify the glycolic acid/lactic acid copolymer disclosed in (1) with small amounts of polycarboxylic moieties, because

(i) it was known from (2) that terpolymers of glycolic acid, dibasic acid and dihydroxyalkane are

(i-1) flexible and

(i-2) have a melting point below that of a glycolic acid homopolymer,

and because

(ii) the skilled person would immediately recognize that the same effect could be achieved using only one of the two modifiers proposed in (2), thus,

(iii) providing a clear teaching to modify polyglycolic acid with small amounts of a polycarboxylic compound in order to prepare a derivative which melts under 180 C (cf. particularly points III (i), (iii), (vii), (x) and (xi) supra).

5. The statement summarized in point III (ii) supra is the key argument in the logical chain established by the Examining Division in order to substantiate the conclusion of obviousness drawn according to point III (vii), (x) and (xi) supra.

6. However, as may be concluded from the following analysis of the examination proceedings, this argument was presented to the Appellant for the first time in the decision under appeal.

6.1. The relevant content of section 2 of the single communication of 7 April 1997 preceding the decision of refusal reads as follows:

(i) "The closest prior art is considered to be represented by homopolymers and copolymers of the hydroxyalkanoic acids .... described in US-A-4273920 (1)."

(ii) "The subject-matter of the application differs from this closest prior art in that the polymers are modified by small amounts (up to 10 mol.-%) of a polycarboxylic compound."

(iii) "... For these reasons, the technical problem underlying the application can objectively only be defined as being to provide a class of hydroxyalkanoate polymers which can be melt-processed under 180 C."

"The solution proposed to this problem is to modify these polymers by copolymerizing the hydroxyalkanoic acid with small amounts of a polycarboxylic compound."

(iv) "US-A-4139525 (2) describes terpolymers of glycolic acid, dicarboxylic acids and dihydroxyalkanes. The diacid and the diol are used preferably in equimolecular amounts, although a slight excess of diol is possible. Copolymerized amounts of dicarboxylic acid as low as 9.5 mol.-% ... lead to a marked melting point depression. The terpolymers melt under 180 C ..."

(v) "It appears thus obvious from (2) to modify the polymers of a hydroxyalkanoic acid with a dicarboxylic acid compound in order to provide for polymers of reduced melting point. The subject-matter of the application does not involve an inventive step (Article 56 EPC)."

6.2. In response to this obviousness objection the Applicant in its submission dated 25 July 1997 made the following observations:

(i) "Document (2) does not overcome the deficiencies of [in] document (1) with respect to rendering obvious the finding of the inventors of the present application."

(ii) "In particular, document (2) does not teach that significantly lower melting points would be achieved by adding the bicarboxylic acid. Although terpolymers disclosed in document (2) have melting points below 180 C, nothing in the description attributes the particular melting point to the bicarboxylic acid. Indeed, the melting point of the terpolymers described in document (2) could be just as likely due to the dihydroxy alkane, mixtures or [of] it with the bicarboxylic acid, or specific amounts in the examples."

6.3. From the exchange of arguments referred to in points 6.1 and 6.2 supra the following may be concluded:

6.3.1. That the obviousness objection raised by the Examining Division in its communication (cf. point 6.1 (v) supra) lacks a reasoning, namely to indicate why a modification of the hydroxyalkanoic acid polymers according to document (1) with dicarboxylic acid compounds would have been obvious in the light of document (2), which relates to hydroxyalkanoic acid polymers modified by dicarboxylic acid compounds and dihydroxyalkanes and does not foresee the possibility to omit the dihydroxyalkane moieties.

6.3.2. That the Applicant in its response to the Examining Division's communication pointed at this lacuna in the chain of arguments presented in that communication and identified the information which was missing in document (2), but which would be required in order to satisfy the obviousness objection raised by the Examining Division (cf. point 6.2 (ii) supra).

6.3.3. That only in the decision of refusal the Examining Division supplemented its reasoning with respect to the afore-mentioned lacuna by the statement quoted in points III (x) and (xi) supra, i.e. by alleging that "the skilled person knows" that in order to obtain the desired depression of the melt-processing temperature he could use any one of the two modifying moieties dibasic acid or dihydroxyalkane employed according to (2).

7. This conduct of the Examining Division deprived the Applicant of its legitimate right according to Article 113(1) EPC to comment on the most decisive issue at stake in this case before being confronted with the decision of refusal.

8. The Examining Division's failure to give the Applicant an opportunity to comment on the crucial argument of its reasoning of obviousness (cf. points III (x) and (xi), 3 (iii) and 5.2 (ii) supra) cannot be explained by assuming that the conclusion drawn therefrom, i.e. that the introduction of polycarboxylic moieties into the polymers according to (1) was obvious, was already implicitly contained in the Examining Division's communication (cf. point 5.1 (v) supra). Rather, a conclusion without any reasoning is per se inconclusive and cannot form the basis of a valid decision.

9. It can also not be validly argued that the obviousness conclusion raised in the Examining Division's communication (cf. point 6.1 supra) was "self-explanatory" or that the reasoning supplemented in the decision under appeal (cf. point III (x) and (xi)) was "trivial" and that, therefore, said decision would not contravene Article 113(1) EPC, because neither is the supplemented reasoning foreshadowed in said communication, nor does it belong to generally accepted and uncontestable chemical principles.

10. Nor can the later supplementing of a reasoning be considered to be within the realm of a "matter of judgement" (cf. T 568/89 of 10 January 1990, not published in the OJ EPO, Reasons point 5), because a missing reasoning cannot be equated with a wrong judgment.

11. The decision under appeal, therefore, contravenes the requirement of Article 113(1) EPC. This amounts to a substantial procedural violation and requires the reimbursement of the appeal fee pursuant to Rule 67 EPC, although this was not requested by the Appellant (J 7/82, OJ EPO 1982, 391).

The Board notes that this finding is not motivated by the fact that the decision of refusal was preceded by only one communication, but rather by the incomplete reasoning therein and the presentation of a proper reasoning only with the decision of refusal.