T 1663/06 01-10-2009

Main request

The claims of this request correspond to the claims considered by the examining division in its decision.

1. Inventive step

1.1 The appellant and the examining division considered that the closest prior art is D4 and the Board agrees with this view.

1.2 The subject-matter of claim 1 is distinguished over the disclosure of D4 by the features that the propellant is formed from at least 15 percent by weight, based on the total propellant, of a first gas selected from nitrogen gas and/or compressed air, which propellant further contains a second gas being acceptable from the viewpoint of food technology, which substantially dissolves in the food.

This was the conclusion reached by the examining division (see point 3.1 of the decision grounds, fourth paragraph) and the appellant has not challenged that conclusion. This is also the view of the Board.

1.3.1 The examining division considered that the problem to be solved is avoiding too high an overrun (see point 3.3 of the decision grounds). In this respect the examining division referred to page 2, line 18 of the application as originally filed, which indeed mentions that laughing gas (nitrous oxide) and carbon dioxide can give too high an overrun.

1.3.2 The appellant argued that the problem to be solved is "How to control the overrun of a food cream expelled from an aerosol can such that the overrun is not too high and that the overrun remains more constant when dosing several portions of food cream in combination with both providing a more stable food foam after dosing and a sufficient emptying of the can." (see appeal grounds, page 4, first paragraph).

The Board cannot agree with the reference to providing a more stable food foam as part of the problem. With its letter dated 16 March 2007 the appellant submitted test results which it argues are intended to show "the stability increasing effects of nitrogen gas". The test results show a series of photographs of a blob of discharged cream foam taken at 1 second, 1 minute, 2 minute, 5 minute, 10 minute, 15 minute, 30 minute and 60 minute intervals. No numerical measurements were presented and in the photographs only an outline of the blob is discernible. The reference example uses a propellant of 100% nitrous oxide and the examples of the invention have 15%, 25%, 50% and 75% nitrogen respectively with the other gas being either nitrous oxide or a mixture of nitrous oxide and carbon dioxide. As noted in the provisional opinion of the Board, which was communicated to the appellant along with the summons to oral proceedings, it seems that only the examples with 50% nitrogen might show some improvement over the reference example as concerns maintaining the form and even they do not appear to be better at all time intervals. The example with 75% nitrogen appears to be worse than the reference example.

1.3.3 In the oral proceedings before the Board the appellant for the first time in the proceedings argued that foam stability means volume stability (in terms of "maintaining nitrogen bubbles in the foam") and not form stability and that in this respect the examples, including the example with 75% nitrogen, showed this stability though the appellant admitted that this was not discernible from the photographs.

The application itself gives little indication as to what is meant by foam stability. The only indication is on page 13, lines 15 to 16 which is with reference to Example 1 and states that: "The foam is very stable and has not yet collapsed after half an hour." This indication seems to speak for a definition in the direction of form stability though there is no indication of what form may be considered to be "collapsed".

1.3.4 The Board considers therefore that there is no reliable definition of foam stability and that it has not been demonstrated that foam stability is present over the claimed range, irrespective of whether it is volume or form stability.

The Board therefore concludes that achieving foam stability cannot be part of the objective problem and that the problem proposed by the examining division (see point 1.3.1 above) is the objective problem to be considered for the assessment of inventive step.

1.4 In D4 four propellants are mentioned for use in food; carbon dioxide, nitrous oxide, nitrogen and argon. The first two of these are soluble and the second two are insoluble. Reference is made to overrun in the discussion of nitrous oxide and carbon dioxide. Nitrogen and argon are mentioned with respect to low solubility and minimum aeration. In the discussion of packing procedure starting on page 179 it is explained in the context of soluble propellants how whipped creams are packed. In this respect it is mentioned that the headspace is flushed before sealing the can with an inert gas which the appellant indicated would probably be nitrogen, with which the Board agrees.

1.4.1 The appellant suggested that the reference to "whipped cream" might mean that the cream was already whipped before being charged into the can and hence did not need whipping on discharge.

However, the reference at the end of the first paragraph on page 180 to the usual pressure of "whipping cream" makes it clear that the container holds whipping cream which is formed into whipped cream upon discharge.

In the second paragraph on page 180 it is noted that for an insoluble gas no agitation is necessary so that this reference indicates the use of an insoluble gas as a propellant for cream. This view is reinforced with the following paragraphs concerning a "Sterile Pack" and a "Novel Method of Packing" wherein reference is consistently made to cream. The Board concludes therefore that the skilled person is informed from D4 that insoluble propellants can be used with cream.

According to the last paragraph on page 182 of D4 "overrun" indicates the degree of aeration and is defined with respect to the amount of expansion from liquid cream to whipped cream, i.e. the expansion on discharge from the can. It is indicated that the overrun depends upon the pressure in the context of soluble propellants since that determines how much of the propellant has been dissolved.

1.4.2 In order to solve the problem of too high an overrun the skilled person could consider reducing the pressure. However, as noted by the examining division, if the pressure is reduced then there may be problems with completely emptying the can and the appellant when proposing the problem as solved by its invention included a requirement of sufficient emptying. The requirement of sufficient emptying is indeed a requirement which would have to be fulfilled when solving the objective problem since insufficient emptying would not be acceptable to a user. The skilled person must therefore consider ways of reducing overrun without reducing pressure.

On page 178 of D4 in the paragraph headed "Nitrogen and Argon" it is noted that the degree of aeration, i.e. overrun, is less with these gases. Also, as explained above, D4 refers to the use of an insoluble gas as a propellant for cream. The skilled person is therefore incited from D4 to turn to an insoluble propellant when wishing to reduce the overrun.

Since the skilled person is aware that more of a soluble propellant produces more overrun and more of an insoluble propellant produces less overrun he would consider introducing an insoluble propellant when a reduction in the overrun is required. In this respect it is known from D4 that nitrogen is an insoluble propellant.

1.4.3 There is nothing in D4 which suggests that it is not possible to mix soluble and insoluble propellants to achieve a desired degree of overrun.

D2 indicates that for foamable creams nitrous oxide is the preferred gas, i.e. a soluble gas, but gives examples of mixtures of gases which include a mixture of nitrous oxide and nitrogen in the ratios 1 : 0.5-1, i.e. approximately 33 to 50% nitrogen. There is thus no prejudice for the skilled person against mixing soluble and insoluble gases as propellants.

1.4.4 The appellant argued first of all that the technical area of D2 being cosmetic creams is different to that of food cream and secondly that according to D2 the question of cream stability is to be solved by the composition of the cream itself.

The Board cannot agree with the appellant in this respect. Whilst D2 is directed to creams for the skin (see page 2, lines 1 to 2) this technical area is subject to health requirements, as are foodstuffs, so that the skilled person dealing with foaming (dairy) cream considering which other technical areas deal with the problem of cream stability would not be prejudiced against considering the art available in this area. Although D2 indicates the cream composition as the primary mover regarding foam stability, it also indicates that also the choice of the propellant can give gradual improvements in this respect (see page 2, lines 14 to 15). This means that the choice of the propellant can influence the stability.

Claim 1 encompasses a broad range of 15% to almost 100% nitrogen as propellant. The description discloses only one example relating to a cream propellant which comprises 100% nitrogen respectively and a statement that the foam had not collapsed after 30 minutes. There is thus no evidence of any special effect being present throughout the above-mentioned claimed range. As already explained (see point 1.3.2 above) the Board does not accept that the experimental results filed by the appellant prove that a stable cream foam is achieved by the propellant claimed and in particular it is not proven throughout the claimed range.

1.4 Therefore, the subject-matter of claim 1 of the main request does not involve an inventive step in the sense of Article 56 EPC.

First auxiliary request

2. Inventive step

2.1 The subject-matter of claim 1 of this request differs from that of claim 1 of the main request in that the alternative of compressed air for the first gas is deleted and the second gas is specified to be laughing gas, i.e. nitrous oxide.

2.2 In the discussion of inventive step of claim 1 of the main request it was pointed out that nitrogen is known from D4 as an insoluble propellant gas and nitrous oxide as a soluble propellant gas. Also in D2 where it is indicated that the propellant gas can be a mixture, one of the disclosed mixtures can be nitrogen and nitrous oxide. Therefore the selection of these gases for the propellant would have been obvious to the skilled person.

2.3 Therefore, the subject-matter of claim 1 of the first auxiliary request does not involve an inventive step in the sense of Article 56 EPC.

Second auxiliary request

3. Inventive step

3.1 Claim 1 of this request is formulated as a second non-medical use claim in the sense of Enlarged Board of Appeal Decision G 6/88. The claim is directed to the use of the alleged property of nitrogen of forming a stable cream foam. The novelty of this feature and its support for the presence of an inventive step in the subject-matter of the claim depends upon nitrogen actually having this property. However, as already explained above with respect to the main request (see point 1.3.2) the Board is not satisfied that nitrogen has been demonstrated to possess this property and in particular throughout the claimed range. In the absence of this proof and hence that this property is a technical feature of nitrogen the alleged property cannot be taken into account for the assessment of inventive step.

3.2 The claim does not have any further feature beyond those of claim 1 of the first auxiliary request.

Therefore, the subject-matter of claim 1 of the second auxiliary request does not involve an inventive step in the sense of Article 56 EPC for the same reasons as explained with respect to claim 1 of the first auxiliary request.