T 0226/85 (Stable bleaches) 17-03-1987

I. European patent No. 9942 was granted on 27 April 1983 with 8 claims in response to the European patent application No. 79 302 043.9 filed on 28 September 1979 claiming the priority of the earlier application of 2 October 1978, Claim 1 is worded as follows:

"A pourable scouring cleanser composition comprising an anionic surfactant, a water-soluble polar nonionic surfactant, an electrolyte, a chlorine-releasing bleaching agent and a suspended particulate abrasive characterised in that the polar nonionic surfactant comprises an amine oxide and the chlorine-releasing bleaching agent comprises sodium hypochlorite, the total surfactant concentration being from 0.1 to 0.5 moles/kg based on the total composition other than the abrasive, and the molar ratio anionic surfactant: amine oxide is from 60:40 to 20:80, the composition showing a loss of no more than half the initial available chlorine in a storage period of 30 hours at 50°C and being capable of suspending abrasive without allowing a layer of unsuspended material to settle for 1 month at 37°C."

II. Two admissible notices of opposition were filed against the European patent requesting that it be revoked on the ground of non-patentability because of lack of inventive step. The first Appellant (second Opponent) also raised lack of novelty, and the second one (first Opponent) insufficiency, as further grounds. In the latter case comparative test results were submitted purporting to show that the claimed compositions neither possessed the advantage of stability, i.e. absence of sedimentation, nor did they retain, as promised, half the chlorine after the specified storage. As to lack of novelty and obviousness GB-A-1 418 671(1) was raised as the most relevant state of the art.

III. The Opposition Division rejected the oppositions in a decision notified on 26 July 1985. The reason for the rejection was that the claimed compositions were novel in view of the fact that (1) had not disclosed the specific ratios or concentrations of the components of the claimed formulations. As to inventive step, the invention was directed to a problem which had not been previously recognised, i.e. the elimination of interaction between chlorine in the bleach and soap filaments at higher temperatures of storage. Since the cited document (1) led away from the invention, the solution requiring no soap filaments, was not obvious. Insufficiency was not recognisable either, since the methods given in the specification gave adequate guidance, and the skilled person would have had enough information to deduce what action should be taken in case of failure. Whilst impurities and minor components might make a critical difference to the properties of the compositions such problems could be resolved by some testing. In any case the tests did not strictly correspond to the examples (e.g. no perfume component was incorporated) and this might account for lack of success in reproducing the same results.

IV. The Appellants (former Opponents) filed appeals against the decision on 24 August and 30 September 1985, respectively, with the payment of the appropriate fee, and submitted Statements of Grounds within the prescribed time limits. The second Appellant also submitted new comparative test results and raised new objections on ground of lack of industrial applicability (Article 57 EPC). An oral hearing was held on 17 March 1987. Although duly invited the first Appellant decided not to be represented at the hearing.

V. The Appellants submitted in the proceedings and at the oral hearing substantially the following arguments:

(a) Whilst it was very doubtful that the elimination of the successful filament forming soap from the formulation could lead to a stable formulation, such step would only become non-obvious if the promised result was truly achieved and was reproducible.

(b) The tests were repeated and care had been taken to chose only components (e.g. chlorstabil standard perfume) which complied with the general instructions of the specification concerning testing for suitability. This time the chlorine losses were within the prescribed limits but the substantial sedimentation at an elevated temperature (30°C) consistently demonstrated the instability of the formulation according to various examples of the patent.

(c) Even if there were embodiments which would satisfy the functional criteria for the claimed subject-matter, the finding of the correct combination of conditions is each case would be an undue burden in view of extensive investigations. There was no common general knowledge or any other advice or theory available which could resolve the dilemma facing the skilled person trying to reproduce the subject-matter of the main claim in each instance.

(d) As regards the specified absence of undue chlorine loss within 30 hours at 50°C, this was itself irrelevant for practice which required sufficient stability for a longer time at a lower temperature. The alleged correlation between the stated accelerated test and the real requirement was not confirmed by the experiments since the chlorine loss became unacceptably high at a temperature slightly above room temperature. There was no reproducible teaching as to the solution of the problem and therefore no justification for patentability.

(e) If an essential feature for success was missing from the claim, this should itself amount to insufficient disclosure. In addition, the claim itself was not limited to the case where filaments had been excluded from the composition, although this was alleged to be an essential characteristic of the solution of the problem. The functional limitations of the claim were rather characteristics of the technical problem than features of the solution to achieve the desired result. The problem itself, to have storage stability at higher temperatures, was only applicable in some southern areas of the Member States of the Convention and was therefore irrelevant for the rest. In addition, all features of the claimed subject-matter were disclosed in the cited art (1). Without a distinctive effect no invention could be recognised.

VI. The Respondent (Patentee) argued substantially as follows:

(a) As to the alleged irreproducibility of results, it was unknown why precipitations occurred with the cleanser compositions prepared by the Appellant. Structured liquids were, of course, extremely sensitive and suffered from "physical instability". Nevertheless, the disclosure was extremely detailed with respect of the preparations of the compositions and it was apparent that the Appellant had failed to repeat the Example exactly. It was possible that at least some of the preliminary tests for suitability of components might not have been carried out.

(b) As regards the more relevant long-term chlorine stability at room temperature, it was well known that a bleach loss after 30 hours at 50°C was roughly equivalent to loss after one month at room temperature. Industry often relied on accelerated tests which were indicative of long-term characteristics.

(c) Although all features of the invention could be found in the disclosures of (1), the state of the art achieved success with a three-dimensional network of entangled filaments, whilst the invention did not use such system and avoided its disadvantages.

(d) There was no doubt that the skilled practitioners of the Appellant had tried to repeat the invention in their new tests with the materials available to them, but the appropriate adjustment of conditions was necessary in view of the delicacy of the composition. In such circumstances it was not possible to pin-point where the Appellant had gone wrong and what could have been done to rectify the position. Although it was possible that the earlier tests were unsuccessful because perfume was not incorporated, this should not mean that perfume was an essential feature of the invention in other circumstances.

VII. The Appellants request that the decision under appeal be set aside and the patent be revoked. The Respondent requests that the appeal be dismissed and that the patent be maintained.