T 0322/04 (Thickened composition/SOLVAY) 10-02-2006

Reasons for the Decision

Patent as granted (Main request)

1. Inventive step (Article 100(a) EPC in combination with Articles 52(1) and 56 EPC): claim 1

1.1 The Appellant, after having opposed the patent in suit under Article 100(a) EPC only on the ground that the claims lack an inventive step (Article 56 EPC), has argued at the oral proceedings before the Board that no difference would be present between the subject-matter claimed in the patent in suit and the prior art disclosed in document (4).

The Enlarged Board of Appeal the EPO has decided (see the order of G 7/95, OJ 1996, 626) that when a patent has only been opposed under Article 100(a) EPC on the ground that the claims lacked an inventive step in view of documents cited in the notice of opposition, to dispute novelty vis-à-vis the said documents is a fresh ground for opposition that cannot be allowed in the appeal proceedings without the agreement of the patentee. However, the allegation that the claims lack novelty can be considered in the context of deciding on the ground of lack of inventive step.

Hence, in the present case the assessment of inventive step requires to establish whether or not the subject-matter of the granted claims was already known in the prior art disclosed in document (4) and, thus, obvious for the skilled person.

1.2 Claim 1 as granted defines a thickened aqueous composition comprising a soluble peracid in solution, AAE and a surfactant.

1.3 The Board notes initially that the wording used in this claim does not require per se that the peracid ingredient must be completely dissolved in the claimed composition, but only the presence of some "soluble peracid" dissolved in the aqueous phase (see in claim 1 "… comprising a soluble peracid in solution …", emphasis added).

On the other hand, the skilled person, who would interpret the claim in the context of the whole patent disclosure, would not find in the patent description any reason excluding the possible presence of solid (undissolved) peracid in addition to the dissolved one. Instead, the fact that the patent mentions explicitly among the examples of "soluble" peracid ingredients also MPA (see paragraph 14 of the patent in suit),i.e. a "substantially insoluble" peracid (see document (4) (see document (4), formula at page 3, lines 10 to 12, in combination with page 2, lines 48 to 50) confirms that in the claimed compositions the peracid ingredients may also be only partially dissolved.

At the oral proceedings before the Board none of the parties has finally disputed this interpretation of the claim. Hence, the Board concludes that the compositions according to claim 1 may also comprise undissolved peracid in addition to the dissolved one.

1.4 Nevertheless, the Respondent has maintained that the claimed thickened compositions would differ from those disclosed in document (4) in that the peracid would be completely dissolved in the former but substantially undissolved in the latter.

The Board finds, however, this argument manifestly inconsistent with the above conclusion on the interpretation of granted claim 1 and, thus, not convincing.

1.5 The Board notes also that the compositions disclosed in document (4) also comprise (in addition to the peracid at least partially dissolved in water such as MPA) ethoxylated fatty alcohols and secondary alkane sulphonate surfactants (see e.g. the claims 1 and 4 and the description at page 3, lines 42 to 43 and 46 to 47), i.e. ingredients respectively falling under the generic definitions given for ingredients "(a)" and "(b)" in present claim 1.

This has not been disputed by the Respondent.

Hence, the Board finds that the prior art compositions disclosed document (4) already display all the technical features of the invention defined in claim 1 of the patent in suit.

1.6 Since the subject-matter of claim 1 of the patent as granted was already known in the prior art, the Board concludes that it was not new and, therefore, obvious. Hence, the patent as granted does not comply with the requirements of Article 56 EPC.

Auxiliary request

2. Admissibility of the amendments in view of Rule 57a and Articles 84, 123(2) and (3) EPC

2.1 The Board notes that claims 1 and 2 of this request differ from the corresponding claims as granted only in that the peracid ingredient has been limited to the aliphatic peracids with up to 6 carbon atoms (see above point VI).

The wording used to amend these claims is unambiguous and supported by the disclosure at page 5, lines 3 to 5, of the patent application as filed. Since the Appellant has raised no objection in these respects, no further details need to be given.

2.2 Accordingly, the Board finds that the amended claims of the auxiliary request comply with the requirements of Articles 84 and 123(2) and (3) EPC as well as with Rule 57a EPC.

3. Inventive step (Article 100(a) EPC in combination with Articles 52(1) and 56 EPC): claim 1

3.1 This claim defines aqueous thickened disinfectant compositions based on an aliphatic peracid with up to 6 carbon atoms dissolved in the aqueous phase, AAE and surfactants.

3.2 It is undisputed that also the suspensions disclosed in document (4) (see claims and examples) are viscous disinfectant compositions based on peracids, AAE and surfactants. Instead, the solutions disclosed in document (3) (see claim 1) contain neither AAE nor other thickeners.

Hence, the Board concurs with the Appellant that the prior art disclosed in document (4) represents a reasonable starting point for the assessment of inventive step.

3.3 The Appellant has maintained that at least the aliphatic peracids with 6 carbon atoms according to claim 1 would also be encompassed in the group of "substantially water insoluble" peracids disclosed at page 2, lines 48 to 50, of document (4) to have "at least about 7 carbon atoms" (emphasis added).

The Board observes instead that the used expression "about 7" is intrinsically ambiguous and does not equate per se to a clear disclosure of the value "6". Moreover, the peracids of document (4) are also precisely defined by means of a general formula requiring 7 or more carbon atoms (see from page 2, line 51 to page 3, line 1). Hence, document (4) identifies clearly in "7" the minimum number of carbon atoms of the "substantially water insoluble" peracids.

This fact implicitly confirms that, as argued by the Respondent, all the peracid ingredients of the presently claimed compositions - i.e. the aliphatic peracids with up to 6 carbon atoms - are instead substantially "soluble" in water. This is also consistent with the common general knowledge of the chemistry practitioner that these low molecular weight aliphatic peracids are liquid and miscible at any ratio with water.

Hence, it is apparent to the skilled person that the presently claimed compositions differ from those disclosed in document (4) not only in the number of carbon atoms of the peracid ingredients, but also in the fact that these peracids are substantially dissolved in the aqueous phase and not simply suspended therein.

3.4 The Respondent has argued that the physical stability of the suspensions disclosed in document (4) would refer exclusively to the absence of precipitation of the particulate peracid contained therein, but would not necessarily demand constancy of the viscosity as well. Hence, in the opinion of the Respondent this citation provided no information on the level of stability upon storage of the viscosity in these prior art compositions.

3.4.1 The Board observes instead that, as correctly pointed out by the Appellant too, the expression "chemical and physical stability" used at page 4, lines 12 to 14, or 33 to 34 of document (4) must reasonably make reference to the chemical and physical stability in general of the peracid suspensions disclosed in this citation. Indeed, this expression is normally used to indicate the general stability of the chemical and physical state of a composition of matter and, thus, also of all the measurable chemical and physical properties of such composition. It is for this very reason that exactly the same expression has also been used e.g. in paragraph 13 of the patent in suit as a general expression indicating, in particular, stability of the viscosity and of the peracid ingredient in the composition of the invention.

Hence, in the absence of any evidence to the contrary, document (4) indicates to the skilled person the "chemical and physical stability" in general of these prior art suspensions and, thus, also of their viscosity.

3.4.2 For the above reasons, the Board concludes that both the claimed compositions and those of the prior art disclosed in document (4) are physically and chemically stable under any respect, including in their viscosity.

Therefore, the Board concurs with the Appellant that the technical problem credibly solved by the claimed subject-matter vis-à-vis this prior art is that of providing further viscous and stable disinfectants based on peracids, i.e. an alternative to the viscous suspensions of particulate peracids disclosed in document (4).

3.5 In view of the existing technical problem of providing an alternative, the assessment of inventive step boils down to establishing whether or not the skilled person would have expected that further viscous disinfectant compositions that are chemically and physically stable upon storage could be obtained by replacing the peracids with at least 7 carbon atoms suspended in the viscous disinfectant compositions disclosed in document (4) with aliphatic peracids with up to 6 carbon atoms dissolved in the water phase.

3.6 The Board observes that, although solutions of aliphatic peracids with less than 6 carbon atoms had already been used for producing disinfecting compositions (e.g. in document (3)), still - as evident from both the patent (see paragraph 5) and from document (3) (see page 1, lines 10 to 24, page 4, lines 28 to 29, and from page 5, lines 22 to page 6, line 2) - their stability was also known to the skilled person to be problematic and to require an accurate selection of the other ingredients in order to avoid degradation of the very reactive peracid. Actually, disinfectant compositions based on suspensions of peracid particulates have been developed precisely with the aim of overcoming the insufficient stability of the already known peracid solutions, since the separation in different physical states of the peracid and of the other potentially interacting chemical species clearly aims at minimising the interaction between the peracid and the chemical species present in solution (see paragraph 6 of the patent in suit and page 2, lines 8 to 17 of document (4)).

The Appellant has never disputed the existence of this common general knowledge, as resumed in the patent in suit and confirmed in documents (3) and (4).

Under these circumstances, the Board concludes that the skilled person would necessarily expect that the replacement of the substantially insoluble peracid in the compositions of document (4) by a more soluble one would normally produce a decreased chemical stability in respect of the peracid ingredient in the disinfecting composition.

Hence, the presently claimed compositions represent a non-obvious solution to the existing technical problem.

3.7 Therefore, the Board finds that the subject-matter of claim 1 is based on an inventive step and, thus, complies with the requirements of Article 56 EPC.

4. Inventive step (Article 100(a) EPC in combination with Articles 52(1) and 56 EPC): claims 2 to 26

The reasoning given above in respect of the thickening composition of claim 1 applies also the process for thickening solutions of soluble aliphatic peracids with up to 6 carbon atoms as defined in claim 2, as well as, to the preferred embodiments of this composition and/or process as defined in claims 2 to 25 and to the method for using this thickening composition as claimed in claim 26.