European patent 2 790 657 was granted with claim 1 as follows:
"1. Cosmetic composition for coating keratinous fibres of the emulsion type, comprising:
- an aqueous phase,
- at least one wax, and
- an emulsifying system comprising:
i) at least one anionic surfactant in the salt form chosen from C16-C18 monoalkyl phosphate,
ii) at least one cationic counterion, and
iii) at least one basic amino acid,
in which the total content of basic amino acid(s) and the total content of anionic surfactant(s) in the salt form are such that the ratio by weight of the basic amino acid(s) to the anionic surfactant(s) in the salt form is greater than or equal to 0.05."
An opposition was filed against the patent which was rejected by the opposition division.
The opponent (appellant) lodged an appeal and requested that the patent be revoked.
The respondent requested that the patent be maintained on the basis of the main request or the auxiliary request, both filed with the reply to the grounds of appeal on 16 September 2020.
Documents D6 to D8 were filed by the appellant with the statement setting the grounds of appeal.
D6 was filed in support of a new objection of lack of novelty raised for the first time in the appeal proceedings. D7 and D8 were  filed to further support the disclosure of D6.
The appellant argued that these documents should be admitted into the appeal proceedings because they support a novelty objection and this ground had been raised in the first instance proceedings.
Document D6 is a European patent application available long before the filing of the notice of opposition. Furthermore, the document supports an entirely new objection of lack of novelty, which does not appear to have been triggered by any late turn of events in the first instance proceedings or to be in response to the reasoning of the first instance decision. The Board does therefore not recognise any reason justifying the late-filing of said document.
Therefore, the Board does not to admit D6, D7 and D8 into the appeal proceeding.
Inventive step
The patent in suit relates to cosmetic compositions for coating keratinous fibres such as a mascara or eyebrow product. In particular the patent aims at overcoming the stability issue encountered with some ionic surfactants, which may lead to a non homogenous dispersion of waxes and pigments in the composition.
The opposition division as well as the respondent considered D5 as the closest prior art. In its written submissions the appellant presented some arguments staring from D2 as closest prior art.
D5 pertains to cosmetic compositions for coating human keratinous fibres, in particular the human eyelashes and eyebrows, wherein the compositions may be emulsions containing all the presently claimed components.
On the other hand, D2 relates to gel-like emulsions and o/w emulsions obtained therefrom as cosmetics such as creams. The compositions of D2 contain a monoalkyl phosphate as surfactant wherein the counterion may generally be a basic amino acid. Even if the aim in D2 is also to obtain fine and uniform emulsions, the issue of crystallization of the phosphate surfactant is not addressed. It cannot therefore be concluded that the effects in D2 and the patent in suit are the same.
Hence, D5 clearly constitutes the closest prior art to the presently claimed subject-matter in terms of both the technical field and the nature of the components in the cosmetic composition.
The claimed compositions differ from D5 in the weight ratio of L-Arginine to the phosphate compound. The technical effect was disputed by the appellant.
The appellant contested the choice of the comparative example, which in its opinion was not representative of the closest prior art examples. It followed that no improved effect had been made credible over the closest prior art emulsions.
The Board notes that the comparative study provided in the patent in suit fulfills the fundamental requirement for comparative tests that the nature of the comparison must be such that any effect would convincingly have its origin in the distinguishing feature. Comparative example 3 and the example according to the invention do indeed differ only in the nature of the presently claimed ratio.
However, no comparison versus the closest prior art compositions has been performed. It is therefore doubtful whether the emulsions of the invention are indeed improved compared to those of examples 1 and 2 of D5.
It remains nevertheless that good properties in terms of texture and homogeneity have been substantiated for the claimed composition, and are attributable to the claimed ratio.
The objective technical problem to be solved starting from D5 resides in the provision of a further cosmetic emulsion for coating keratinous fibres having good texture and homogeneity.
D5 does not teach to increase the ratio of arginine to the ionic surfactant. The skilled person would not have considered it obvious to increase the amount of arginine to solve the problem posed. The Board is of the opinion that the skilled person willing to increase the relative amount of the water soluble arginine in the emulsions would have considered modifying the amounts of other components such as water and surfactant accordingly, so as to maintain an emulsion. Moreover, arginine being disclosed as an active agent in D5 and not as an excipient, there is no indication that increasing its amount compared to the anionic surfactant would be beneficial in terms of texture and homogeneity.
As a result, the main request meets the requirements of Article 56 EPC.
?    The decision under appeal is set aside. The case is remitted to the opposition division with the order to maintain the patent on the basis of  claims filed as the main request with letter dated 16 September 2020, and the description thereto filed with the same letter.