T 0059/96 (Mould release/CASTROL) 07-04-1999

Reasons for the Decision

1. The appeal is admissible.

2. Novelty

2.1. The Respondent 1 contested the novelty of the subject-matter claimed in respect of document (8). The Appellant and the Respondent 1 were divided upon the matter whether or not the esters referred to in that document were of the particular type as defined in claim 1 of the patent in suit, i.e. of aliphatic carboxylic acids with mono- or dihydric alcohols.

Document (8) discloses a release agent based on an ester which is formed by combining a fatty acid with an alcohol. The generic term "alcohol" used in that document characterises the chemical compound as comprising a functional hydroxy group without, however, indicating the number of hydroxy groups contained in that compound. Thus there is no basis for the finding that that alcohol is indeed mono- or dihydric, i.e. comprises one or two hydroxy groups. Therefore, document (8) does not disclose, either explicitly or implicitly, the essential feature of the claimed invention to use a mono- or dihydric alcohol.

The Respondent 1 argued that the general term "alcohol" necessarily amounted to the disclosure of a monohydric alcohol for the skilled man. However, in view of the silence about the number of hydroxy groups contained in that alcohol, the generic disclosure of "an alcohol" in document (8) does not reveal to the skilled person any particular number of hydroxy groups comprised therein, in the present case of one or two hydroxy groups as required by claim 1 of the patent in suit. It appears that the Respondent 1 interprets the disclosure of that document with the knowledge of the present invention, which the Board cannot accept.

Thus, in the Board's judgement, document (8) does not anticipate the subject-matter of the claimed invention for the reasons given above.

2.2. The Board is satisfied that the subject-matter of the patent in suit is not disclosed in any of the further cited documents. This being not in dispute between the Parties during appeal proceedings and the Opposition Division having already acknowledged novelty for the present claims, it is not necessary to give detailed reasons for this finding.

2.3. For the above reasons, the Board concludes that the subject-matter of the patent in suit is novel and meets the requirements of Articles 52(1) and 54 EPC.

3. Inventive step

3.1. In accordance with the "problem-solution approach" consistently applied by the Boards of Appeal to assess inventive step on an objective basis, it is necessary to establish the closest state of the art to be used as the starting point, to determine in the light thereof the technical problem which the invention addresses and successfully solves, and to examine the obviousness of the claimed solution to this problem in view of the state of the art. In this context, the Boards of Appeal have developed certain criteria that should be adhered to in order to identify the closest state of the art to be treated as the starting point. One such criterion is that the "closest prior art" is normally a prior art document disclosing subject-matter aiming at the same objective as the claimed invention and having the most relevant technical features in common (see decisions T 686/91, point 4 of the reasons; T 482/92, point 4.1 of the reasons; T 298/93, point 2.2.2 of the reasons; none published in OJ EPO).

3.2. The patent in suit relates to a method for releasing a moulded concrete body from the mould by applying to the mould a release composition comprising an ester of aliphatic carboxylic acids with mono- or dihydric alcohols. The objective to be achieved, as indicated in the patent in suit, is that the concrete body should not adhere to the mould (page 2, line 18). In relation to that objective and to the relevant technical features in common, a selection among the documents cited in the proceedings must be made as to which is to be considered as the "closest prior art".

3.2.1. Document (5a) refers to a mould release agent for use in moulding concrete products (page 3, paragraph 1, line 7; page 4, paragraph 3, lines 5 and 6), which is to be applied on the mould (page 3, paragraph 2, penultimate line; page 4, last paragraph, penultimate line). The mould release agent comprises 1 part by weight of an oily agent and 1 to 20 parts by weight of a mineral oil. The oily agent comprises 4 to 50% by weight of a fatty acid ester of a C1-8-monohydric alcohol, for example butyl stearate (page 7, paragraph 2, line 4 and penultimate line; example 5), which is specifically listed in the patent in suit on page 8, line 56. The amount of fatty acid ester exemplified in examples 1 to 8 on page 11 of document (5a) does not exceed 5% by weight of the total mould release agent (cf. attachment F, page 2). Based on a purely arithmetical calculation, the fatty acid ester content cannot exceed 25% by weight of the total mould release agent, as the mould release agent comprises not more than 50% by weight of the oily agent, the latter comprising for its part not more than 50% by weight of a fatty acid ester.

That document aims at providing a mould release agent having an excellent mould releasing effect (page 3, paragraph 3, number (1); page 4, paragraph 3, line 3), i.e. avoiding a portion of the moulded product adhering to the mould (page 3, paragraph 2, lines 5 and 6).

Thus, document (5a) aims at the same objective as the claimed invention and has all relevant features in common, except for the feature of 26 to 100% by weight fatty acid ester in the total mould releasing composition.

3.2.2. Document (8) relates to a release agent based on an ester which is formed by combining a fatty acid with an alcohol. The number of hydroxy groups comprised in that alcohol is not indicated (see point 2.1 above).

That document aims at providing a form release agent permitting clean release of the form from hardened concrete during stripping (page 417, left hand column, paragraph 1).

Document (2) is directed to a mould releasing agent for concrete comprising optionally up to 50% by weight of a vegetable oil, i.e an ester of a fatty acid with glycerine; the latter, however, is a trihydric alcohol.

That document aims at avoiding the concrete material sticking on the mould (page 1, paragraph 1, line 3).

Thus, documents (2) and (8) aim at the same objective as the claimed invention, but do not point to the mould releasing composition comprising a fatty acid ester of an alcohol which is mono- or dihydric as in the patent in suit. The Board concludes therefore, that documents (2) and (8) represent prior art further away from the patent in suit than document (5a).

3.2.3. Document (7) relates to lubricants and document (16) to mould releasing agents in general without addressing the moulding of concrete. These technical fields, different to that of the patent in suit, disqualify those documents as closest prior art.

3.2.4. For these reasons, in the Board's judgement, document (5a) represents the prior art closest to the claimed invention and thus, the appropriate starting point in the assessment of inventive step.

3.3. In the next step, the technical problem which the invention addresses in the light of the closest state of the art is to be determined.

The technical problem as indicated in the patent in suit, which the Appellant emphasized also in appeal proceedings (Statement of Grounds of Appeal page 5, paragraph 4 to page 6, paragraph 1), consists in attaining several advantages when releasing a moulded concrete body from the mould, particularly with respect to the adherence to the mould, to the retardation of the curing of concrete, to the viscosity of the used mould releasing composition and to the health and environmental hazards occasioned by the used mould releasing composition (cf. specification of the patent in suit, page 2, lines 21 to 24 and 34 to 38; page 3, lines 18 and 19).

3.4. As the solution to this problem, the patent in suit suggests a method for releasing a moulded concrete body from the mould by applying to the mould a release composition comprising an ester of aliphatic carboxylic acids with mono- or dihydric alcohols in an amount of 26. to 100% by weight calculated on the total composition.

3.5. The Appellant and the Respondents were divided on the matter whether or not the evidence provided convincingly demonstrates that the proposed solution successfully solves the technical problem as defined in point 3.3 above, i.e. to attain advantages over the state of the art. In support of his submission that the alleged advantages are in fact obtained by the claimed invention, the Appellant referred to the results of example 3, of table I (attachment G), of table II (attachment H) and of table III of the patent in suit, and to the results of a fresh test report (attachment J).

3.5.1. Example 3 of the patent in suit does not comprise any comparative example; therefore it cannot back up any advantage of the claimed subject-matter over the state of the art.

3.5.2. Table I (attachment G) encompasses tests according to the invention and the comparative tests no. 1, 2, 3 and 5. The mould releasing compositions used in the latter comparative tests do not comprise any fatty acid ester. These comparative tests, however, do not truly reflect the closest state of the art, i.e. document (5a), which already discloses the use of mould releasing compositions comprising fatty acid ester. Therefore, table I (attachment G) does not support the alleged advantages of the claimed invention.

The same conclusion applies for table II (attachment H) since the mould releasing composition used in the sole comparative test no. 127 does not comprise any fatty acid ester.

3.5.3. Table III comprises tests using mould releasing compositions according to the invention comprising a fatty acid ester prepared with a mono- or dihydric alcohol and numerous comparative tests, wherein the mould releasing compositions used either do not contain any fatty acid ester or contain a fatty acid ester with a trihydric alcohol. Thus, the comparative tests are inconsistent with the closest document (5a), which already discloses the use of a mould releasing composition comprising the particular fatty acid esters of the present invention. For that reason, the Appellant cannot rely on table III as evidence for the alleged advantages of the claimed subject-matter over the closest state of the art.

3.5.4. Appellant's fresh test report (attachment J) relates to a method for mould releasing a concrete body from the mould by applying to the mould a releasing composition. That test report comprises overall 17 examples, all carried out in the same way, apart from the absence or the presence of fatty acid ester and the content thereof in the mould releasing composition. The absence of any fatty acid ester in the examples denoted "Ref. Example" 1 to 8 results in rejecting those examples as fair comparison since they do not reflect the closest document (5a), which already teaches to include fatty acid ester in the mould releasing composition. The examples denoted "Example" 1 to 8 are identical to the examples 1 to 8 of document (5a). Reflecting the closest state of the art, they are to be regarded as fair comparative examples. The mould releasing composition used therein contains at most 5% by weight of fatty acid ester calculated on the basis of the total composition (example 5). The example denoted "Comparative example according to EP 0328158" uses a mould releasing composition containing 96% by weight of fatty acid ester calculated on the basis of the total composition, and hence, it is the only one in attachment J according to the present invention. Therefore, a comparison of the results of the latter example according to the invention with the comparative example 5 truly reflects the impact of the higher content of fatty acid ester in the mould releasing composition, distinguishing the solution suggested in the patent in suit from the method of closest document (5a).

That test report addresses the strength and the discoloration of the surface of concrete. With respect to the strength, attachment J specifies exclusively that the example according to the invention gives a mechanically strong surface of the concrete "superior" to those of the comparative examples. However, that qualitative statement of "superiority" expresses merely Appellant's subjective rating of the comparison of undisclosed quantitative test results of the examples. In the absence of those quantitative test results, neither the other Parties nor the Board are in a position to adequately verify on an objective basis the pertinence of Appellant's subjective rating with the consequence that it cannot be given any consideration. With respect to the discoloration, attachment J specifies exclusively that it was "nearly" not observed in the example according to the invention. Due to the complete lack of indication of any discoloration occurring in the comparative examples, that test report cannot support the alleged advantageous discoloration of the claimed invention over the comparative closest state of the art.

Therefore, the fresh test report (attachment J) is unsuited to back up the advantages alleged by the Appellant.

3.5.5. To conclude, in the Board's judgement, the evidence on file does not properly demonstrate that the purported advantages of the claimed invention have successfully been achieved and that they are due to the higher content of fatty acid ester in the used mould releasing composition, i.e. the solution proposed by the patent in suit.

3.6. According to the jurisprudence of the Boards of Appeal, alleged but unsupported advantages cannot be taken into consideration in respect of the determination of the problem underlying the claimed invention (see e.g. decision T 20/81, OJ EPO 1982, 217, point 3, last paragraph of the reasons). Since in the present case the alleged advantages lack the required adequate support, the technical problem as defined in point 3.4 above needs reformulation. In view of the teaching of document (5a), the objective problem underlying the patent in suit can only be seen in providing merely a further method for releasing a moulded concrete body from the mould by applying to the mould a mould release composition.

During oral proceedings before the Board, the Respondent 3 formulated the problem underlying the patent in suit as to provide a further method for releasing a moulded concrete body from the mould by applying to the mould an ester containing mould release composition. However, the feature "ester containing", defining the mould releasing composition, forms already part of the solution to the problem. To incorporate parts of the solution offered by the invention into the definition of the problem is inadmissible. It is established jurisprudence of the Boards of Appeal that the technical problem addressed by the invention must be formulated in such a manner that there are no pointers to the solution, otherwise an ex post facto view being taken of inventive activity (see decisions T 99/85, OJ EPO 1987, 413; T 229/85, OJ EPO 1987, 237). Therefore the Board cannot accept Respondent 3's argument.

3.7. Finally, it remains to decide whether or not the proposed solution to the objective problem underlying the patent in suit is obvious in view of the state of the art.

3.7.1. Document (5a) is directed to a mould release agent for use in moulding concrete products comprising 1 to 20 parts by weight of a mineral oil and 1 part by weight of an oily agent. The latter consists of (a) 50 to 96% by weight of a fatty acid and (b) 4 to 50% by weight of a fatty acid ester of a C1-8-monohydric alcohol, i.e. having a structure which complies with the present invention. On page 8, paragraph 1, last sentence that document teaches with regard to the oily agent that "if the amount of the fatty acid ester exceeds 50 wt%, the mold releasing effect may be reduced". This teaching advises against increasing the amount of fatty acid ester above that specific upper limit, otherwise the deleterious reduction of the releasing effect occurs, which is in fact the core effect of a releasing agent.

Not only that explicit teaching of document (5a) would be taken at its face value by the skilled person, it is moreover corroborated by experimental evidence shown in the table on page 11 of that document. The comparative "Ref. Example" 7, using a mould release agent wherein the oily agent comprises (a) about 45% by weight of fatty acid and (b) about 55% by weight of fatty acid ester, i.e. only slightly exceeding the specific upper limit, shows the degree of mould releasing of "8", which is a poorer result than the degree of "10" indicated for each of the examples 1 to 8 according to the invention carried out in the same way, apart from incorporating into the oily agent the fatty acid ester in an amount smaller than the specific upper limit.

In the light of the above, the specific upper limit of 50% by weight of fatty acid ester in the oily agent taught in document (5a) is a purposive limit and not an arbitrary borderline, since it has been proven that even going slightly beyond (cf. comparative "Ref. Example" 7) entails defects to the releasing effect of the release agent.

For these reasons, the Board concludes that the skilled person would have been deterred from contemplating an increase in the amount of fatty acid ester in the oily agent above the specific upper limit indicated in document (5a), which corresponds to an absolute upper limit of 25% by weight of the total release agent on the basis of a purely arithmetical calculation (cf. point 3.2.1 above). The amount of fatty acid ester exemplified in document (5a) does even not exceed 5% by weight of the total release agent. Thus, the skilled person was discouraged from investigating that route as being unpromising when trying to solve the problem underlying the invention as defined in point 3.6 above. This means that going beyond the upper limit taught in that document, i.e to incorporate 26 to 100% by weight of fatty acid ester of a mono- or dihydric alcohol calculated on the total release agent, which is indeed the solution proposed by the claimed invention, cannot be treated as obvious.

The Board's conclusion having regard to the above teaching of that piece of prior art deviates from that of the Opposition Division in the decision under appeal since the document (5a) was not before the first instance. The Appellant has provided in appeal proceedings the fresh translation (5a) of document (5), the latter document having been considered by the Opposition Division, in order to correct misprinted values specified in the examples contained in the table of document (5). The correction of those values, which has never been contested by the Respondents, reverses the weight ratio of (a) fatty acid to (b) fatty acid ester in the oily agent and renders the examples consistent with the teaching of document (5a) as set out above.

3.7.2. Document (8) relates to the use of a release agent in the moulding of concrete "based on" an ester formed by combining a fatty acid with an alcohol and is silent about any specific teaching beyond that. However, that document neither provides a pointer to the relevant feature specified in the patent in suit to use a fatty acid ester of a mono- or dihydric alcohol, nor does the term "based on" teach any particular quantity of the fatty acid ester in the release agent, as required by the claimed invention. The Respondents' argument, that that term indicated an amount of ester exceeding 25% by weight, is not convincing as it is based on information available to the skilled person only from the disclosure of the patent in suit, i.e. on hindsight. Therefore, document (8) cannot render the proposed solution obvious.

3.7.3. Document (2) refers to a mould releasing agent for concrete comprising optionally up to 50% by weight of a vegetable oil, which is an ester of fatty acids with the trihydric alcohol glycerine (see point 3.2.2 above). However, that document diverges from the relevant feature specified in the claimed invention to use a fatty acid ester of a mono- or dihydric alcohol. Therefore, that document does not point to the proposed solution.

The Respondent 1 argued that the teaching of document (2) to use in the mould release agent optionally an amount of up to 50% by weight of vegetable oils, which are fatty acid esters of the trihydric alcohol glycerine, gave an incentive to the skilled person to increase the content of fatty acid ester in the release agent known from document (5a) above its upper limit of 25% by weight calculated on the total release agent, thus arriving at the claimed invention. However, in document (2) the feature to use an amount of up to 50% by weight in the release agent is taught only in combination with those particular fatty acid esters of a trihydric alcohol. Hence, the skilled person would not isolate that feature from those particular fatty acid esters and he would not separately transfer it to the mould release agent of document (5a) as the latter uses a different type of fatty acid esters, i.e. those of a monohydric alcohol. The skilled person is even more deterred from doing so since the teaching of document (5a) diverts him from exceeding the upper limit of 25% by weight calculated on the total release agent when using fatty acid esters of a mono- or dihydric alcohol, as set out in point 3.7.1. above.

For these reasons, the Board is convinced that document (2) does not give an incentive to arrive at the solution suggested by the patent in suit.

3.7.4. In view of document (7) the Respondent 3 argued that acid esters complying with the present invention were already known to show a lubricating effect which was essential for release agents according to document (16). Since the mould release agent of document (5a) comprised, in addition to the fatty acid and fatty acid ester forming the oily agent, mineral oils which were characterised on page 8, paragraph 1, line 2, to be inter alia a lubricating oil fraction, the skilled person would substitute the acid esters of document (7) for the lubricating oil fraction used as mineral oils in the release agent of document (5a) and arrive at the claimed invention. That substitution, so he argued, would not be rejected by the skilled person as the specification of the patent in suit acknowledged prior art suggesting replacing mineral oils by vegetable oils. The Respondent 1 supported that view and argued that the mould release agent of document (2) comprised alternatively either mineral oils or vegetable oils, both being considered equivalent.

However, it is to be noted that document (7) is directed to lubricants for turbine motors which is a technical field substantially different from and unrelated to that of the present invention, i.e. to the release of a moulded concrete body from the mould. Therefore, a person skilled in the art does not take that teaching into consideration at all when looking for a solution to the problem underlying the patent in suit. Moreover, the teaching of document (5a) deterring the skilled person from exceeding the upper limit of 25% by weight of acid ester calculated on the total release agent, as set out in point 3.7.1 above, discourages him even more from substituting the acid esters of document (7) for the lubricating oil fraction in the release agent of document (5a) as that substitution would entail exceeding that limit in order to arrive at the claimed invention.

Therefore, the skilled person would ignore document (7) when looking for a solution to the problem underlying the patent in suit.

3.7.5. To summarise, in the Board's judgement, none of the documents addressed above renders the claimed invention obvious, either taken alone or in combination.

The Respondents not relying on further documents in order to support their objection of obviousness, the Board is satisfied that none of the other documents in the proceedings renders the proposed solution obvious.

3.8. For these reasons, the Board concludes that the subject-matter of claim 1, and by the same token that of dependent claims 2 to 18 and of independent claim 19, referring to a mould releasing method by applying an emulsion of the oily component as defined in claim 1, involves an inventive step within the meaning of Articles 52(1) and 56 EPC.