T 0981/02 22-03-2005

I. European patent application No. 96 910 564.2, based on International application No. PCT/US96/04110, filed on 26. March 1996, claiming the priorities of 27 March 1995 and 5 March 1996 of two earlier applications in the United States of America (08/411,183 and 08/611,114), respectively, and published under No. WO-A-96/30418 on 3. October 1996, was refused by a decision of the Examining Division, announced at the end of oral proceedings on 25 April 2002 and issued in writing on 4. June 2002.

In order to illustrate the core issue on which the decision of the Examining Division was based, it is sufficient to reproduce the wording of Claim 7 as originally filed:

"7. An aqueous latex adhesive composition which comprises

a) a mercaptan-modified or xanthogen disulfide- modified 2-chloro-1,3-butadiene crystalline homopolymer having a gel content of 5-70 percent by weight;

b) 1 to 75 parts by weight of rosin per 100 parts by weight of a); and

c) a sufficient amount of water to provide a composition having a solids content of 25-65 weight percent based on the weight of component a)

with the proviso that the mercaptan-modified or xanthogen disulfide-modified 2-chloro-1,3- butadiene homopolymer is prepared by free radical emulsion polymerization of 2-chloro-1,3-butadiene at a temperature of 5°C-20°C, to a conversion of 70-95%, and the amount of mercaptan or xanthogen disulfide modifier present during polymerization is within the range of 1.5 x 10/-4-2.5 x 10/-4 moles per mole of 2-chloro-1,3-butadiene."

II. The decision was based on a Main Request containing a set of 16 claims and Auxiliary Requests 1 to 4, containing sets of 10, 18, 12 and 11 claims, respectively. All these requests had been submitted during the oral proceedings. Whilst the Main request and Auxiliary Requests 1 to 3 contained claims to an elastomer composition and claims to an aqueous latex composition, all claims relating to an elastomer composition had been deleted from Auxiliary Request 4.

In view of the facts and submissions to be dealt with in this decision, further reference need only be made to the Main Request and Auxiliary Request 4.

The independent claims according to the Main Request read as follows:

"1. An elastomer composition which comprises a mercaptan-modified or xanthogen disulphide- modified crystalline 2-chloro-1,3-butadiene homopolymer having a gel content of from 5 to 70% by weight based on the amount of the tetrahydrofuran-insoluble polymer which is prepared by free radical emulsion polymerisation at a temperature of from 5°C to 20°C, to a conversion of from 70-95% in the presence of 1.0. x 10/-5 to 3.9 x 10/-4 moles of mercaptan modifier or xanthogen disulphide modifier per mole of 2-chloro-1,3-butadiene homopolymer.

8. An aqueous latex adhesive composition which comprises

(a) a mercaptan-modified or xanthogen disulphide-modified 2-chloro-1,3-butadiene crystalline homopolymer having a gel content of from 5 to 70% by weight based on the amount of the tetrahydrofuran-insoluble polymer;

(b) 1 to 75 parts by weight of rosin per 100 parts by weight of (a); and

(c) a sufficient amount of water to provide a composition having a solids content of 25-65 weight percent based on the weight of composition (a)

with the proviso that the mercaptan-modified or xanthogen disulphide-modified 2-chloro-1,3- butadiene homopolymer is prepared by free radical emulsion polymerization of 2-chloro-1,3-butadiene at a temperature of from 5°C to 20°C, to a conversion of 70-95%, and the amount of mercaptan modifier or xanthogen disulphide modifier present during the polymerization is within the range of 1.0. x 10/-5 to 3.9 x 10/-4 moles of modifier per mole of 2-chloro-1,3-butadiene homopolymer."

Independent Claim 1 according to Auxiliary Request 4 read as follows:

"1. An aqueous latex adhesive composition which comprises

(a) a mercaptan-modified or xanthogen disulfide- modified 2-chloro-1,3-butadiene crystalline homopolymer having a gel content of from 5 to 70% by weight based on the amount of the tetrahydrofuran-insoluble polymer;

(b) 1 to 75 parts by weight of rosin per 100 parts by weight of (a); and

(c) a sufficient amount of water to provide a composition having a solids content of 25-65 weight percent based on the weight of component (a)

with the proviso that the mercaptan-modified or xanthogen disulfide-modified 2-chloro-1,3- butadiene homopolymer is prepared by free radical emulsion polymerization of 2-chloro-1,3-butadiene at a temperature of from 5°C to 20°C, to a conversion of 80-95%, and the amount of mercaptan or xanthogen disulfide modifier present during the polymerization is within the range of 1.0 x 10/-5 to 1.0. x 10/-3 moles of modifier per mole of 2-chloro- 1,3-butadiene."

The remaining Claims 2 to 7 and 9 to 16 of the Main Request and the remaining Claims 2 to 11, according to Auxiliary Request 4, were dependent claims concerning elaborations of the subject-matter defined in the respective preceding independent claim.

III. According to the decision, none the five requests, filed at the oral proceedings, met the requirements of Article 123(2) EPC.

(a) Thus, in each of the five requests, the core issue with regard to Article 123(2) EPC concerned the replacement of the original range of modifier concentration ("... 1.5 x 10/-4-2.5 x 10/-4 moles ...") by other ranges of modifier concentrations introduced into the new independent claims, after it had been found that the respective amounts of modifiers used in all the examples had been outside the above original range.

(b) The lower limit of this feature as amended in Claims 1 and 8 of the Main Request (ie 1.0 x 10/-5 mol; section II, above) had been based on the range disclosed on page 6, lines 22 to 24 ("Generally, the useful range of chain transfer agent is between 1 x 10/-5 to 1 x 10/-3 moles of chain transfer agent per mole of chloroprene monomer", this range will be referred herein as the "useful range").

(c) The Examining Division found that it had not been clearly and unambiguously derivable from the above wording of the passage disclosing the useful range, that the statement made therein applied to the invention as originally claimed. The term "generally" might rather have indicated that the concentration range specified therein related to a range of chain transfer agents which was generally used in the field of crystalline chloroprene homopolymers and that the range specified in the original independent claims represented an inventive selection over that broader range. Moreover, the useful range had been disclosed in the relevant sentence "in complete isolation from the remaining essential process features (i.e. the temperature, the conversion percentage and the kind of modifier) and also from the essential product feature [sic] (i.e. the gel content, and implicitly the specific end groups introduced into the homopolymer due to the specific modifier selected)". However, it had been clear from the context that these process and product features were interconnected to a great extent. Therefore, the lower amount of modifier in the independent claims might not have been reduced by a factor of more than 10 (in comparison to the initial lower limit of the range) "without having possibly to adjust in parallel the ranges specified for the other process features in order to be able, in fine, to keep the product feature (i.e., essentially the gel content) within the range specified" (Reasons: 3.a).

(d) With regard to the upper limit of the above range, which had been derived by calculation from the amounts of modifier and chloroprene used in two specific examples, it was held that the concentration had been extracted from examples, irrespective of the other process and product features specifically associated with this concentration in those examples. It was concluded that the insertion of the new upper limit of the range also contravened Article 123(2) EPC (Reasons: 3.b).

(e) The same arguments were also held valid for the respective amended ranges of the modifier concentration in each of Auxiliary Requests 1 to 3.

(f) As regards Auxiliary Request 4 (section II, above), it was held that, apart from the conversion degree further limited from "70-95%" to "80-95%, the core issue had been the same as in the previous requests. Since the new range of the modifier concentration extended beyond both the lower and the upper limits of the range as initially claimed (see original Claim 7 reproduced in section I, above) and had not been disclosed in combination with the remaining features of the independent claim in their original scope, the reasons referred to in section III(c), above, with respect to the lower limit of this range in Claim 8 of the Main Request were also valid for both limits of this range in Claim 1 of Auxiliary Request 4.

Consequently, the application was refused.

IV. On 29 July 2002, a Notice of Appeal against the above decision, including the Statement of Grounds of Appeal, was lodged by the Appellant (Applicant) who contested the findings of the Examining Division. The prescribed fee was paid on the same date.

Together with the Notice of Appeal, a new Main Request was filed which corresponded to previous Auxiliary Request 4 (section II, above).

The Appellant argued that the level of modifier as amended had had its basis on page 6, lines 22 to 24 of the application as originally filed and that the above finding in the decision under appeal was not correct in view of this general statement in the description and that, hence, this range had been disclosed in combination with any further features of the claim such as conversion levels. Therefore, the new Main Request would meet the requirements of Article 123(2) EPC.

Furthermore, the Appellant referred to some discussion during the oral proceedings before the Examining Division and requested interlocutory revision under Article 109 EPC and reimbursement of the appeal fee under Rule 67 EPC.

V. By communication dated 6 November 2002, the Appellant was informed that the case had been referred to this Board of Appeals, and, by communication dated 10 August 2004, that it was, therefore, necessary for the Appellant to reconsider its requests, because Article 109 EPC was no longer applicable. Moreover, the Appellant was invited to clearly establish the reasons why, in its opinion, a reimbursement of the appeal fee was equitable by reason of a substantial procedural violation and to explain in detail which steps taken by the Opposition Division were deemed to amount to such a violation.

Furthermore, preliminary, provisional observations to the wording of Claim 1 under consideration were made (i) with regard to the requirements of Article 123(2) EPC and (ii) as regards the definition of the "gel content".

With respect to issue (i), it was pointed out that page 6 of the description as filed referred to an amount of modifier of "1 x 10/-5 to 1 x 10/-3 moles of chain transfer agent ...". Whilst the substitution of the term "modifier" for the term "chain transfer agent" in this formulation in Claim 1 was not objected to, since both terms had been used in the application as synonyms (cf. page 4, line 23), the amended wording of the range in the claim was deemed not to comply with Article 123(2) EPC, because the replacement of "1" by "1.0" at both occurrences involved a change of information, and, therefore, constituted an extension beyond the contents of the application as filed.

Furthermore, (ii) the gel content of component (a) was obviously not independent of the method of its determination, but, rather, the result of a measurement carried out in specific conditions and subjected to a calculation on the basis of a specific equation (cf. page 3, line 32 to page 4, line 16). Therefore, it was deemed necessary to recite these particulars in Claim 1 in order unambiguously to define this feature.

By letter dated 6 October 2004, the Appellant requested that the decision under appeal be set aside, withdrew the request for reimbursement of the appeal fee and submitted a sole request containing a new set of 11 claims differing from the previous set (cf. sections II and IV, above) only in a new version of independent Claim 1 wherein the two issues (i) and (ii) addressed in the communication (see the three previous paragraphs, above) were dealt with.

VI. In reply to a conversation by telephone on 10 February 2005, wherein some issues of inconsistency in Claim 1 in relation to the method of determination of the gel content had been discussed, a further amended set of Claims 1 to 11 was filed on the same date, Claim 1 thereof reading as follows:

"1. An aqueous latex adhesive composition which comprises

(a) a mercaptan-modified or xanthogen disulfide- modified 2-chloro-1,3-butadiene crystalline homopolymer having a gel content of from 5 to 70% by weight based on the amount of the tetrahydrofuran-insoluble polymer;

(b) 1 to 75 parts by weight of rosin per 100 parts by weight of (a); and

(c) a sufficient amount of water to provide a composition having a solids content of 25-65 weight percent based on the weight of component (a)

with the proviso that the mercaptan-modified or xanthogen disulfide-modified 2-chloro-1,3- butadiene homopolymer is prepared by free radical emulsion polymerization of 2-chloro-1,3-butadiene at a temperature of from 5°C to 20°C, to a conversion of 80-95%, and the amount of mercaptan or xanthogen disulfide modifier present during the polymerization is within the range of 1 x 10/-5 to 1. x 10/-3 moles of modifier per mole of 2-chloro- 1,3-butadiene;

wherein the gel content of component (a) is determined by the following method:

approximately 2 ml of latex (W), having solids content (L) is weighed and injected into a vessel containing 100 ml of tetrahydrofuran; the vessel is rolled for not less than 30 minutes and not more than 120 minutes to dissolve the soluble polymer; a 40 ml aliquot of the mixture is then centrifuged for 1 hour to separate the insoluble gel polymer from the tetrahydrofuran solution; a 20. ml portion of the supernatant liquid is removed and the solvent is evaporated; the weight of the soluble polymer (A) is then measured and the gel content is calculated according to the following equation;

% gel = 100 - 100[(F x A)/(W x L)]

where F = normalization factor of 5.1

A = dried solids content of soluble portion

W = weight of latex sample, and

L = latex solids content."