Thursday, 18 March 2010

T 662/07 – Incredible Detergents

When there is no clear-cut evidence that a technical problem has been solved, the credibility that the problem has indeed been solved becomes crucial for the assessment of inventive step. In the present case, the Board comes to the conclusion that the problem has not been credibly solved and reformulates a less ambitious problem.

[…] During the oral proceedings, both parties have used document D3 as basis for the assessment of inventive step. The Board has no reason not to follow this choice. [2.1.1]

Document D3 discloses multiphase detergent tablets made of compacted particulate washing composition for washing laundry in a washing machine […] comprising surfactant(s), builder(s), disintegration auxiliary based on cellulose, and optionally further washing composition constituents, and which can consist of at least two phases, i.e. of different layers […]. It is possible for the different layers to have different solution rates, which may entail properties that are advantageous for the application of the tablets. […]

D3 does not disclose the feature according to which the surfactant content of the individual phases varies by no more than 1.5 % by weight, as well as the use of the tablets in domestic washing machines. [2.1.2]

According to the explanations of the [patent proprietor], the examples of the contested patent show that the claimed subject-matter solves, with respect to the prior art known from D3, the technical problem mentioned in paragraph 7 of the contested patent, i.e. the problem of providing detergent tablets which have a high hardness and high disintegration and solution rates in all phases. There was no indication in the available prior art that this technical problem can be solved if the surfactant content varies by no more than 1.5 % by weight between the phases. [2.1.3]

However, the Board does not find this argument persuasive because there is no indication in the examples that this technical problem is actually solved by the above mentioned distinguishing features, i.e. the use in domestic washing machines and the relatively low admissible variation of the surfactant content.

First of all it has to be noted that the feature concerning the use of the detergent tablets in particular in domestic washing machines apparently does not contribute to the solution of the said technical problem. Such a contribution was not invoked by the [patent proprietor] and is not disclosed in the contested patent. Neither do the examples show that they have been carried out in a domestic washing machine, let alone that this would lead to a special effect.

Therefore, the use of the detergent tablets in a domestic washing machine is only an option that is independent from the said technical problem and which the skilled person exercises in case of need.

Apart from that, there are three sets (examples 1, 2, and 3), each comprising one example according to the invention and a comparative example, from which one can allegedly derive that detergent tablets of particularly high hardness and disintegration rate are obtained as a result of the small variation of the surfactant content of the phases by no more than 1.5 % by weight. Within these exemplary sets, the comparative example differs from the example according to the invention not only, as expected, by the differing surfactant content in the phases but also by different contents of other constituents. In examples 1 to 3 the content of different constituents was varied in order to compensate for the varying surfactant content.

However, these examples are not comparable with each other because different surfactant granulates have also been used in the three sets of examples. Therefore, the argument of the [patent proprietor] according to which the examples show that the differing contents of further constituents are not relevant, is not persuasive. [2.1.4]

Therefore, it is not credible that the claimed detergent tablets have high hardness and disintegration rates in all phases in comparison to the tablets disclosed in prior art D3.

However, it is credible that the detergent tablets defined in claim 1 have practically the same hardness and an identical disintegration profile in all phases, with respect to the tablets disclosed in document D3, which is presented as an essential requirement for multiphase detergent tablets in paragraph 4 of the contested patent. As a matter of fact, according to claim 1, all phases of the detergent tablet can have a practically identical composition and can differ from each other only by say a different coloration.

Therefore, the problem that is actually solved with respect to prior art D3 may be seen in providing a detergent tablet that has practically the same hardness and an identical disintegration profile in all phases. [2.1.5]

As so often, this the preamble to a revocation for lack of inventive step. 

To read the whole decision (in German), click here.