T 0357/00 (C12-alcohol/UNILEVER) 26-05-2003

I. This appeal is from the Opposition Division's decision revoking European patent No. 0 598 586 relating to detergent compositions and containing 14 claims.

Claim 1 reads:

"1. A tablet of compacted detergent powder comprising a surfactant system comprising a nonionic surfactant, which comprises a condensation product of ethylene oxide with aliphatic alcohol, at least one detergency builder and optionally other detergent ingredients, characterised in that at least 25% by weight of the alcohol from which the nonionic condensation product is derived has an alkyl chain length below C12, so that the average alkyl chain length is below C12."

Independent Claim 14 was directed to the use of the nonionic surfactant.

II. An opposition was filed, requesting revocation of the patent on the grounds of added subject-matter (Article 100(c) EPC), insufficiency of disclosure (Article 100(b) EPC), lack of novelty and of inventive step (Articles 100(a), 52(1), 54(1), 56 EPC). In support the following documents were cited, inter alia:

(1) US-A-5 133 892

(2) US-A-4 320 026

(3) US-A-4 536 314

(5) EP-A-0 466 485

(6) US-A-4 370 250

(7) EP-A-0 355 626

In the course of the opposition procedure, under cover of the letter dated 23 September 1999, the opponent (now the respondent) filed

(10) "Dobanol", Technical Bulletin UD/014, high quality detergent range primary alcohols, Shell Chemicals UK Ltd, April 1988.

III. In its decision, the Opposition Division held that the subject-matter of Claim 1 as granted as well as of the respective Claim 1 of the two auxiliary requests submitted by the proprietors (now appellants) in the course of the opposition procedure was novel over documents (1), (2), (3) and (6), but did not involve an inventive step over documents (10) and (5), or (10) and (7).

IV. The appellants filed an appeal against this decision.

V. The appellants requested that the decision under appeal be set aside and that the European patent be maintained as granted and the Opposition dismissed, or failing that, be maintained in the amended form set forward in any of the auxiliary requests which were annexed to the written decision of the Opposition Division.

A first auxiliary request and a second auxiliary request were annexed to the impugned decision.

V.1 First auxiliary request

The set of Claims 1 to 14 of the first auxiliary request differed from the set of Claims 1 to 14 as granted in that the passage "a surfactant system comprising a nonionic surfactant, which comprises a condensation product of ethylene oxide with aliphatic alcohol, at least one detergency builder" of Claim 1 of the main request was replaced by "from 5 to 50% by weight of a surfactant system comprising from 5 to 30% by weight of the tablet of nonionic surfactant, which comprises a condensation product of ethylene oxide with aliphatic alcohol so as to contain only ethylene oxide groups attached to the aliphatic alcohol, from 5 to 80% by weight of at least one detergency builder".

V.2 Second auxiliary request

The set of claims 1 to 13 of the second auxiliary request differed from the set of claims 1 to 14 of the first auxiliary request in that the passage "of at least one detergency builder" of Claim 1 of the first auxiliary request was replaced by "(anhydrous basis) of an alkali metal aluminosilicate"; further, in claim 14 of the first auxiliary request the amounts of detergent active and of alkali metal aluminosilicate were specified. Claim 12 of the first auxiliary request was deleted and the remaining claims renumbered.

VI. The appellants' arguments were in summary as follows:

1. By simply referring to document (10), the Opposition Division failed to apply correctly the problem-solution approach. This document described Dobanol 91-6, comprising 18±4% C9-alcohol, 50±6% C10-alcohol, 32±5% C11-alcohol (table 1 of page 6) (i.e. at least 25% of the alcohol has an alkyl chain length below C12 and also the average alkyl chain length is below C12) which by a conventional ethoxylation technique led to a conventional detergent. However, document (10) did not mention compacted detergent powder tablets and was not a proper starting point for evaluating inventive step. Since the claimed tablets displayed a surprising effect consisting in a high dissolution and dispersion rate which had been ignored by the Opposition Division, T 130/89 relating to the use of a known material having known properties, did not apply to the present case.

2. A promising starting point could have been document (5) dealing with the same technical problem as the patent in suit, i.e. high dissolution and dispersion rate of the detergent tablets (page 2, lines 14 to 15). It would have been clear that the solution according to document (5) would not have led the skilled person to the claimed subject-matter.

3. According to document (5), rapid dissolution and high tablet strength was obtained with condensation products comprising alcohols of 8 to 22 carbon atoms whereas according to the patent in suit the alcohol had an alkyl chain below C12 (abbreviated by "

4. The comparative tests submitted by the appellants under cover of the letter of 26 February 2001 showed that the dissolution rates of tablets comprising a nonionic surfactant comprising a C12- alcohol.

VII. The respondent disputed these submissions. Its arguments can be summarized as follows:

1. The invention was not sufficiently disclosed to achieve a beneficial effect with all the embodiments covered by Claim 1 (Article 100(b) EPC).

2. The subject-matter of Claim 1 lacked novelty

- over document (1), since Claim 1 did not exclude a condensation product of an aliphatic alcohol and ethylene oxide in which the aliphatic alcohol has chain length of from C6 to C10 and contains 4 to 15 ethylene oxide units;

- over document (2), which disclosed tablets comprising non- ionic surfactants resulting from Neodol 91-6 (column 2, line 38, column 2, line 47), which is Dobanol 91-6, sold under the tradename Neodol in the US (document (10), page 5, right- hand column, paragraph 5, first sentence). This material was a condensation product of ethylene oxide with an aliphatic alcohol having an average alkyl chain length of from 9 to 11, i.e. less than 12;

- over document (5), which disclosed the use of nonionic surfactants being a condensation product of ethylene oxide with a C8-alcohol (page 6, line 15).

3. The subject-matter of Claim 1 lacked an inventive step

- because the problem of rapid dissolution and dispersion and tablet strength was not solved

- by a tablet containing 0.5% or less of the condensation product which amount could not reasonably be expected to make any useful contribution to the properties of the product;

- by a tablet which was allowed to contain further non specified amounts of other condensation products of ethylene oxide with other aliphatic alcohols than those specified in Claim 1;

- by a tablet containing a condensation product of which the length of the ethoxy chain was not defined, and thus the properties might vary in function of said chain length (letter of 26 October 2000, page 3, paragraphs 1, 2 and 3).

- because Dobanol 91-5, 6 or 8 were conventional detergent primary alcohol products (see letter dated 26 October 2000, page 4, lines 5 to 8, and document (10), page 7, table 4) falling within the range of nonionic condensation products derived from alcohol with an average alkyl chain length below C12 and inevitably would have been used by a skilled person in view of their contribution to the cleaning performance of the tablet.

VIII. The appellants requested in writing that the decision under appeal be set aside and the patent be maintained on the basis of the main request or alternatively on the basis of one of the auxiliary requests 1 or 2.

The respondent requested that the appeal be dismissed.

IX. Under cover of the letter dated 17 March 2003 the appellants withdrew their request for oral proceedings which had been scheduled for 26 May 2003 and so did the respondent under cover of its letter dated 25 March 2003. At the beginning of the oral proceedings, which took place as scheduled, the Chairman noted that none of the parties were present and announced that the Board would take a decision based on the written appeal proceedings. After deliberation of the Board, the Chairman announced the decision of the Board.