T 0606/89 18-09-1990

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

2. It is the established jurisprudence of the Boards of Appeal that the objective assessment of inventive step has to be preceded by the determination of the technical problem which the invention addresses and solves and that the technical problem is to be formulated in the light of the closest state of the art.

Therefore, in order to apply this approach for objectively assessing inventive step, it is essential to establish the closest prior art. Generally, this requires that the claimed invention should be compared with the art concerned with a similar use which requires the minimum of structural and functional modifications. Thus, in the present case, this involves not only comparing the claimed compositions with those of the prior art, but also giving consideration to the particular properties which render the compositions suitable for the desired use.

2.1. The disputed patent relates to a particulate detergent composition comprising a water-soluble fatty acid soap, a nonionic surfactant, an alkaline buffering agent and a builder and an aqueous solution thereof. This aqueous solution, which contains 5 to 15% of the composition, is a so-called stock solution.

2.2. In contrast, document (3) is concerned with low-foaming detergent compositions comprising surfactants, organic and/or inorganic builders and water-insoluble addition products of polyglycerol and propylene oxide (cf. Claim 1). The fact that the foam depressant addition products are water-insoluble render the compositions unsuitable for the preparation of stock solutions which do not exhibit any turbidity and/or phase separation.

In view of the this, the Board does not consider that document (3) can represent the closest prior art in the light of which the technical problem underlying the disputed patent should be formulated.

2.3. Document (6) discloses a detergent composition comprising a mixture which consists of at least one anionic surfactant selected from sulphonates and sodium soaps and at least one nonionic surfactant selected from alkylphenol polyglycol ethers and alkyl polyglycol ethers, an alkali selected from sodium carbonate, sodium silicate having a mole ratio of Na2O:SiO2 such as 2:1 to 1:3 and pentasodium triphosphate and a sodium or triethanolamine salt of a primary alkyl sulphate having a straight chain containing 6 to 10 carbon atoms, and an aqueous solution containing 10 to 20% by weight thereof (cf. Claims 1 and 8).

According to the last paragraph on page 6 (typewritten numbering) of this document, in compositions in the form of an aqueous solution having a solids content of 10 to about 20% by weight there is no tendency for phase separation or solid deposition to occur. Further, there is no tendency for gelling to take place at low temperatures in concentrated aqueous solutions prepared from compositions containing 10% or more of soap.

Thus, like the patent in suit, this document is concerned with providing concentrated stock solutions which are stable and non-gelling at low temperatures. Therefore, in the Board's judgement, document (6) represents the closest state of the art.

2.4. In the light of this closest prior art, the technical problem underlying the patent in suit may be seen in providing further detergent compositions which, in the form of concentrated aqueous solutions, are stable and non-gelling at low temperatures.

According to the disputed patent, this technical problem is essentially solved by detergent compositions in which the detergent active system comprises a water-soluble fatty acid soap component having Krafft-temperatures of from 0° to less than 30°C and an alkoxylated alcohol nonionic component having an HLB-value of between 12 and 16.

In view of the results obtained in Examples 3 to 5, 7, 8 and 11 to 16, the Board is satisfied that the above-defined technical problem is solved.

3. After examination of the cited prior art, the Board has concluded that the claimed subject-matter is novel. Since novelty is no longer in dispute it is not necessary to consider this matter in detail.

4. It still remains to be examined whether the requirement of inventive step is met by the subject-matter of the patent in suit.

4.1. As previously mentioned, document (6) is concerned with the same technical problem as the one underlying the disputed patent. According to this document, it is solved by compositions comprising a detergent active system containing anionic and nonionic surfactants, an alkali and as a hydrotrope, an alkyl sulphate (cf. Claim 1). Particularly suitable soaps are those obtained from natural or hardened fatty acids, such as those derived from coconut oil, tallow or palm kernal oil (cf. page 4, lines 2 to 4). The nonionic surfactant, which may be selected from alkylphenol polyglycol ethers and alkyl polyglycol ethers, is preferably a mixture containing an alkylphenol polyglycol ether having an average of 4 to 6 glycol ether groups and an alkyl phenol polyglycol ether having an average of 8 to 12 glycol ether groups.

In the Board's judgement, the teaching of this document would not suggest to the skilled person that the problem addressed and solved in this document may also be solved, without the need to use a hydrotropic substance, if the components of the detergent active system are selected from fatty acid soaps having Krafft temperatures below 30°C and alkoxylated alcohols (alkyl polyglycol ethers) having HLB-values of between 12 and 16.

4.2. Document (3) discloses low-foaming laundry, dish-washing and cleaning compositions comprising surfactants, builders and water-insolube addition products of polyglycerol and propylene oxide (cf. Claim 1). Suitable anionic, nonionic and amphoteric surfactants are listed in column 3, line 52 to column 4, line 49. Alkali metal soaps of natural and synthetic fatty acids, such as those derived from coconut oil, palm kernal oil and tallow are mentioned as one of the many suitable surfactants (cf. sentence bridging columns 3 and 4). Similarly, reference is made to alkyl polyglycol ethers as being one of several suitable nonionic surfactants (cf. column 4, lines 19 to 49). Therefore, from the general teaching of this document, the skilled person would deduce that the choice of surfactant for use in those prior art compositions is not critical.

Example 2 describes a composition within those laundry compositions generally disclosed (cf. compositions B in columns 7 and 8).

This specific composition contains a detergent active system comprising sodium soaps of fatty acids having 12 to 18 carbon atoms, a mixture of nonionic surfactants having an HLB-value of 12.1 (according to the Appellant and uncontested by the Respondents) and n-dodecylbenzene- sulphonate. In view of the presence of two water-insoluble compounds viz. the addition product use as foam depressant and magnesium silicate, this composition would be unsuitable for the preparation of laundry stock solutions. Moreover, this document is wholly silent with regard to stock solutions and their preparation. In the light of this silence and the above-mentioned inherent incompatibility, the skilled person, seeking a solution to the technical problem underlying the patent in suit, would have considered the document to be irrelevant.

In view of the above, it is immaterial whether the fatty acid soaps derived from coconut oil and palm kernal oil have Krafft-temperatures of less than 30°C, since, even if the Board were to accept this assertion, it would not render document (3) any more relevant having regard to the technical problem underlying the patent in suit of providing detergent compositions, which, in the form of concentrated aqueous solutions, are stable and non-gelling at low temperatures.

5. Therefore, in the Board's judgement, the proposed solution to the technical problem underlying the patent in suit is inventive. Thus, independent Claims 1 and 7 are allowable. Dependent Claims 2 to 6, which relate to preferred embodiments of the compositions claimed in Claim 1, are also acceptable.