Wednesday, 1 December 2010

T 530/08 – It’s For Real

The present case deals with appeals filed after the Opposition Division (OD) had maintained the patent in amended form.

Claim 1 before the Board read:

Composition for dyeing keratinous fibres and in particular human keratinous fibres such as hair, containing in an appropriate dyeing medium, (i) at least compound chosen from those of the following formulae [follow 77 formulae filling 33 pages (!) in the decision], the said composition being characterized in that it contains, in addition,
(ii) at least one anionic surfactant chosen from the group comprising:
(ii-1) - acyl isethionates;
(ii-2) - acyl taurates;
(ii-10) - mixtures thereof.

In order to establish inventive step, the patent proprietor filed comparative trials, which were criticized by the opponents. The Board had some interesting things to say on such trials.

*** Translated from the French ***

[3.1.3] The Board agrees with the parties and the OD and considers that document D2 constitutes the closest prior art and, therefore, the starting point for the assessment of inventive step.

[3.2] According to the [patent proprietor] the technical problem to be solved with respect to this prior art was to provide dyeing compositions resulting in colorations on keratinous fibres having improved selectivity.

[3.3] The solution proposed by the impugned patent is the composition according to claim 1 characterised by the presence of a surfactant chosen among acyl isethionates, acyl taurates and mixtures thereof.

[3.4] The [patent proprietor] refers to the results of comparative trials […] comparing the selectivity of colorations obtained with one of the claimed compositions and with one composition according to D2, in order to demonstrate that the desired improvement had its origin in the claimed compositions.

The trials allow a comparison of the selectivity of colorations obtained with a comparative composition B containing the direct cationic colouring agent, Basic Red 51, and sodium lauryll ether carboxylate (Akypo RLM 45 N) as surfactant, and reflecting a composition according to document D2, on the one hand, and with composition C according to the invention, which differs from composition B only by the equimolar replacement of the sodium lauryll ether carboxylate by sodium methyl cocoyl taurate, on the other hand.

The results obtained establish a higher colouring difference on natural hair comprising 90% of white hair, with respect to permed hair comprising 90% of white hair, when the coloration is obtained with composition B according to the prior art (selectivity ΔE = 2.8) as compared to the colour obtained with composition C according to the invention (ΔE = 0.7). These comparative trials, therefore, demonstrate in a convincing manner that the replacement of the surfactant in the composition of document D2 by an acyl taurate leads to a coloration of improved selectivity, and which, as a consequence, is more homogeneous, when compared to the coloration obtained with the composition according to document D2. The acyl taurate surfactants and the acyl isethionates have the general formula R1-CH2-CH2-SO3(-)M(+) and, therefore, possess the same ethylsulfonate function which is linked to the acyl group via un oxygen or nitrogen atom, respectively. These surfactants are structurally very close, which makes it credible that the effect on selectivity demonstrated with an acyl taurate is also obtained with an acyl isethionate. Furthermore, the Board notes that during the oral proceedings, when confronted with one of its questions, the [opponents] have declared that they did not object to the breadth of claim 1 as finally filed by the [patent proprietor].

[3.4.1] Nevertheless, the [opponents] have objected to the relevance of those trials that composition B illustrating the prior art did not exactly reproduce the composition exemplified in document D2 but in particular used a different cationic surfactant.

The Board cannot follow this argumentation which would imply that a comparative trial could only be carried out by reproducing exactly a composition exemplified by the prior art. As a matter of fact, a comparative trial is also relevant if it shows that the alleged effect has its origin in the feature(s) distinguishing the invention from the closest prior art (see T 197/86 [6.3]).

In the case under consideration, the [opponent] has not contested the fact that the composition according to the invention causes a reduced selectivity difference when compared, under identical conditions, to a composition of the closest prior art, wherein the difference consists only in the nature of the surfactant, which is the feature distinguishing the invention from the prior art. Therefore, the comparative trials carried out by the [patent proprietor] are sufficient because they convincingly show that the improvement of the selectivity is caused by the distinguishing feature of the invention. Thus the trials are convincing and the argument of the [opponents] has to be dismissed.

[3.4.2] According to the [opponents], the selectivity difference observed when comparing a coloration obtained with a composition according to the invention and a composition according to the prior art is not significant because it is a difference of only two units, which falls within the margins of error.

However, the selectivity differences reported in the comparative trials have been demonstrated by carrying out measurements with a spectrophotometer. Thus the differences have been measured objectively. Moreover, the selectivity difference observed during those trials comparing the colorations is not negligible because a difference of two units in ΔE is considerable with respect to the absolute values measured, i.e. 2.8 and 0.7, respectively. As a consequence, in the absence of evidence to the contrary, which is incumbent on the parties contesting the experimental results, i.e. the [opponents], the improvement of the coloration selectivity is considered credible.

Therefore, in the case under consideration, the credible results of the trials filed by the [patent proprietor] cannot be dismissed on the basis of the mere allegation of the [opponent] that the improvement is within the margins of error (see T 1050/07 [4.4.2]).

[3.4.3] The [opponents] have also pointed out that the improvement was imaginary because the selectivity difference that had been demonstrated was not perceptible to the naked eye. The Board cannot follow this speculation because, in the present case, the technical effect is significant and it is demonstrated by means of a precise and reproducible technical measurement method. Therefore, this unfounded argument also has to be dismissed (see T 235/04 [4.5]).

[3.4.4] Finally, the argument according to which there was no improvement of the coloration intensity has to be dismissed as not relevant, because the intensity is only one of the three parameters that make up the selectivity. As a matter of fact, the [patent proprietor] has demonstrated a significant improvement of the coloration selectivity which comprises not only a parameter related to the intensity of the coloration but also the chromaticity parameters a* and b*.

The reader having come so far will not be surprised to learn that the Board concluded that the claims under consideration involved an inventive step.

Should you wish to download the whole decision (in French), just click here.