T 0077/87 (Erroneous abstract) of 16.3.1989

Summary of Facts and Submissions

I. The mention of the grant of the patent No. 30080 in respect of European patent application No. 80 303 804.1 filed on 27 October 1980 and claiming priority of 21 November 1979 from the earlier application GB 79/40267, was published on 1 August 1984 on the basis of 8 claims.

Claim 1 reads as follows:

An aqueous latex comprising a copolymer of (i) vinylidene chloride, (ii) vinyl chloride, (iii) one or more alkyl acrylates or alkyl methacrylates having from 1 to 12 carbon atoms in the alkyl group and (iv) one or more aliphatic alpha- beta unsaturated carboxylic acids, characterised in that (a) the proportion of vinylidene chloride is from 50 to 75 parts by weight per hundred parts by weight of total vinylidene chloride and vinyl chloride, (b) the proportion of vinylidene chloride is not more than 75 parts by weight per hundred parts by weight of total vinylidene chloride, vinyl chloride and the said acrylate(s) and/or methacrylate(s), and (c) the proportion of the said acrylate(s) and/or methacrylate(s) is more than 15 but less than 45 parts by weight per hundred parts by weight of total vinylidene chloride and vinyl chloride, said latex having a minimum film-forming temperature within the range of 6°C to 25°C."

II. On 26 April 1985 the Appellant (Opponent) filed a notice of opposition requesting the revocation of the whole patent on the ground of lack of inventive step with regard to the teaching of following documents: ...

III. The Opposition Division rejected the opposition in a decision dated 5 December 1986 ...

IV. The Appellant thereafter filed a notice of appeal on 5 February 1987 and paid the prescribed fee at the same time. In the Statement of Grounds filed on 7 April 1987 the issue of novelty was raised for the first time; more specifically, it was objected that the subject-matter of Claim 1 was not novel with regard to the disclosure of the following additional documents: (7) "Surface treatment to improve the adhesion of coatings on polyester substrates" by August J. Van Paesschen, published in Chemical Abstracts, 1972, Volume 76, No. 115002p. The Appellant accepted that the disclosure of this abstract did not correspond with the original document, DE-A- 2 128 006 (Document (7')), from which it was abstracted, in a vital respect as far as his argument of lack of novelty was concerned; the abstract discloses a ratio of 50/30 for vinylidene chloride/vinyl chloride in the latex, whereas the original document (7') discloses a corresponding ratio of 30/50. In the abstract, vinylidene chloride and vinyl chloride have been wrongly inverted. Nevertheless, the Appellant submitted that the abstract had to be considered as a separate publication, and as such it destroyed novelty. ...

V. In his various submissions and in oral proceedings held on 16 March 1989 the Respondent put forward essentially the following arguments: Document (7) is an abstract and is therefore inextricably linked with document (7'); as an abstract, it is not an independent publication and cannot disclose more as an anticipating document than the original document which it purports to abstract. ..... During oral proceedings the Respondent submitted two auxiliary sets of claims differing from the granted version by the fact that the proportion of (meth)acrylate in Claim 1 is from 16 to less than 45 parts by weight per hundred parts by weight of total vinylidene chloride and vinyl chloride according to the first auxiliary set of claims, whereas this proportion is from 18 to less than 45 in Claim 1 according to the second auxiliary set of claims.

VI. The Appellant requested that the decision under appeal be set aside and that the patent be revoked. The Respondent requested that the appeal be dismissed and that the patent be maintained as granted as main request or, alternatively, on the basis of the first auxiliary set of claims as first auxiliary request or on the basis of the second auxiliary set of claims as second auxiliary request. At the end of the oral proceedings the decision was announced that the impugned decision was set aside and the patent maintained in accordance with the Respondent's second auxiliary request.

Reasons for the Decision

1. The appeal complies with Articles 106 to 108 and Rule 64 EPC and is, therefore, admissible.

2. ...

3. The patent in suit concerns a vinylidene chloride latex composition and the use thereof as protective coatings on metallic substrates. As already acknowledged in the introduction of the description which refers to GB-A- 1 558 411 which corresponds to document (1), similar compositions suitable for similar applications are well known in the art. Document (1) discloses water-based coating compositions comprising copolymers derived from (a) 65 to 90 parts by weight of vinylidene chloride, (b) vinyl chloride, (c) 2 to 15 parts by weight of one or more alkyl acrylates having from 1 to 12 carbon atoms in the alkyl group and/or one or more alkyl methacrylates having from 2 to 12 carbon atoms in the alkyl group and (d) 0.2 to 8 parts by weight of one or more aliphatic ", ß-unsaturated carboxylic acid(s) per hundred parts by weight of the total vinylidene chloride and vinyl chloride (Claim 1). Although the films obtainable for these latices exhibit excellent protective properties, in particular a low permeability to water vapour, on a variety of substrates, especially metallic substrates, their thermostability was regarded unsatisfactory for certain specific applications. In the light of this prior art the technical problem underlying the patent in suit may thus be seen in providing a copolymer which would confer an improved thermostability measured by the yellowing index to the coatings without impairing the low permeability thereof to water vapour. This problem is solved essentially by increasing the relative amount of alkyl acrylate(s) and/or alkyl methacrylate(s) in the copolymer. More specifically, the solution claimed by the Respondent involves the presence of more than 15 but less than 45 parts by weight of alkyl acrylate(s) and/or alkyl methacrylate(s) per hundred parts by weight of total vinylidene chloride and vinyl chloride according to the main request, this range being 16 to less than 45 according to the first auxiliary request and 18 to less than 45 according to the second auxiliary request. In the three cases the proportion of vinylidene chloride is from 50 to 75 parts by weight per hundred parts by weight of total vinylidene chloride and vinyl chloride.

4. For the first time during the appeal stage of the opposition proceedings the Appellant has raised the issue of novelty having regard to documents (7) and ...

4.1 Document (7) is on its face sufficiently relevant to be admitted in the proceedings. It discloses the coating of biaxially oriented polyester films with an aqueous composition comprising, besides organic solvents and an aqueous dispersion of finely divided silica containing chloral hydrate, a latex of a copolymer of vinylidene chloride, vinyl chloride, butyl acrylate and itaconic acid in the proportions of respectively 50, 30, 18 and 2. The relative amounts of these monomer ingredients meet all the quantitative requirements specified in Claim 1 of each of the three sets of claims on file.

4.1.1 As conceded by the Appellant in the Statement of Grounds, the corresponding original document (7'), and more specifically Example 1 thereof, does not disclose the above 50:30:18:2 vinylidene chloride-vinyl chloride-butyl acrylate-itaconic acid copolymer, but a 50:30:18:2 vinyl chloride-vinylidene chloride-butyl acrylate-itaconic acid copolymer. In the abstract document (7), the vinyl chloride and vinylidene chloride positions have thus been mistakenly inverted to give a different tetrapolymer compound having 62.5 parts of vinylidene chloride per hundred parts by weight of total vinylidene chloride and vinyl chloride which is not disclosed in the corresponding original document (7').

4.1.2 When determining the state of the art for the purpose of Article 54 EPC, what has to be considered is what has been made available to a skilled man. A skilled man is interested in technical reality. The literal disclosure of a prior published document prima facie stands on its own when assessing novelty. This is the general rule.

4.1.3 The first question which arises is whether the skilled reader would immediately interpret the monomer composition disclosed in document (7) as a technical impossibility and, therefore, as an obvious error or whether the specific tetrapolymer according to this prior art is a plausible copolymer. Whereas document (1) describes similar tetrapolymers based on the same four monomers but containing possibly even more vinylidene chloride as major ingredient (Claim 1), as well be discussed hereinafter, Table II of document (4) mentions a whole series of vinylidene chloride-vinyl chloride copolymers wherein the relative amounts of the two monomers vary from 92:8 to 10:90 (page 2301). Further, in the paragraph 2.1.2.6, page 50 of Kunststoff-Handbuch, Volume II, published by Carl Hanser Verlag München, 1963, devoted to the copolymerization of vinyl chloride with various comonomers, vinyl chloride appears as the major component and vinylidene chloride is the minor ingredient (paragraph 2, lines 1 to 5). Although admittedly tetrapolymers are more complex entities than copolymers derived from two monomers only, there are thus clear indications in the prior art that either monomer can be the major component in a copolymer with the other monomer. This means that the composition disclosed in document (7) would not strike the skilled reader as being unconceivable.

4.1.4 As already stated, document (7) is an abstract of document (7') which is the original document and was also prior published, and the title of the abstract makes this clear by means of a cross-reference. Thus the disclosure of abstract document (7) should be interpreted by reference to its original, i.e. to document (7'), for the purpose of ascertaining the technical reality of what has been disclosed and should not be regarded as an independent document in isolation. The original document is the primary source of what has been made available as a technical teaching and its abstract is by its nature merely a secondary and derivative source. It is axiomatic that an original basic document and its abstract cannot disclose two different subject-matters as a matter of technical reality. When, as in the present case, there is a substantial inconsistency between the original document and its abstract, it is clearly the disclosure of the original document that must prevail. The disclosure in the original document provides the strongest evidence as to what has been made available to the skilled man. When, as here, it is clear from related contemporaneously available evidence that the literal disclosure of a document is erroneous and does not represent the intended technical reality, such an erroneous disclosure should not be considered as part of the state of the art. The general rule in relation to the literal disclosure of a document set out in paragraph 4.1.2 above does not then apply. Thus, in the Board's judgment, the literal disclosure of document (7) does not form part of the state of the art, because document (7') must be considered as providing the definitive description of the monomer composition in question. It follows that document (7) does not deprive Claim 1 of the patent in suit of novelty.

4.1.5 A further submission provided by the Respondent during oral proceedings was that the mere content of an abstract would never be the starting point of experimental work. The skilled man, having found a potentially interesting teaching in an abstract, would not embark upon an expensive investigation program without referring to and scrutinizing the corresponding original document wherein the various alternatives and/or embodiments are mentioned. This would apply all the more in the present case in view of the discrepancy between the abstract document (7) and the corresponding original document (7'), which in practice would lead the skilled man to disregard the content of document (7). In the Board's view, this submission constitutes relevant evidence to confirm the skilled man's primary interest in technical reality.

4.1.6 Summarising, the inconsistency between abstract document (7) and its basic original document (7') would lead the man skilled in the art to ignore the abstract as erroneous and to consider as relevant teaching only the description according to the basic document. Since the amount of vinylidene chloride in the composition according to document (7') to be considered lies outside the range defined in (a) of Claim 1 of the three sets of claims on file, novelty with regard to document (7) should be acknowledged on that basis. ...

4.3 After examination of the documents (1) to (6) already considered in opposition procedure the Board has reached the conclusion that the claimed subject-matter is not disclosed in any of them. Since novelty is not disputed in this regard, it is not necessary to consider this matter in detail.

5. It still remains to be examined whether the subject-matter of the patent in suit involves an inventive step with regard to the teaching of the cited documents. ...

5.5 In conclusion, for the reasons given above the content of alkyl acrylate(s) and/or alkyl methacrylate(s) from 18 to less than 45 parts by weight per hundred parts by weight of total vinylidene chloride and vinyl chloride is regarded as an inventive feature so that Claim 1 of the second auxiliary request is allowable. ...

ORDER

For these reasons, it is decided that:

The decision of the Opposition Division is set aside. The case is remitted to the first instance with an order to maintain the patent with text in accordance with the second auxiliary request filed at the oral proceedings.