T 0025/99 (Refrigerating apparatus/HITACHI) 15-05-2002

1. The appeal is admissible.

Main request, auxiliary requests 1 to 3

2. Articles 100(c) and 123(2) EPC - Amendments

2.1. The question to be decided is whether the disclaimers present in Claims 1 of the main request and the auxiliary requests 1 to 3 (cf. points II and VI above) comply with the requirements of Article 123(2) EPC or give rise to objections pursuant to Article 100(c) EPC.

2.2. The Board observes that the disclaimers have no basis in the application as filed, and this was conceded by the Appellant.

2.3. According to the established jurisprudence of the Board of Appeal, it may be permissible in exceptional cases to exclude a specific prior art from the claimed invention by means of a disclaimer, even if the original application provides no basis for such an exclusion. However, the first condition to allow such an amendment is that the prior art to be disclaimed must be novelty-destroying to the subject-matter claimed without the incorporation of the disclaimer (cf. Case Law of the Boards of Appeal of the European Patent Office, 4th edition 2001, III.A.1.6.3, pages 210 to 212, in particular, T 1071/97, point 3.2 of the reasons and T 934/97, point 2.3 of the reasons). In the present case, the Board concurs with the Appellant that document (20) is not novelty-destroying since a refrigerating apparatus which comprises a refrigeration cycle comprising a compressor comprising a particular closed vessel in combination with the ester oils as defined in Claim 1 does not emerge unambiguously from this document. For this reason, the disclaimers cannot find a basis in document (20) since that document is not an anticipation of the claimed invention. It follows that the disclaimers are not allowable as they extend the subject- matter claimed beyond the content of the application as filed which is a ground for opposition pursuant to Article 100(c) EPC and contrary to the requirements of Article 123(2) EPC.

2.4. The Board does not concur with the Appellant that the present case was an inescapable trap as addressed in the decision of the Enlarged Board of Appeal G 1/93. Nor can the Board accept, in the present case, the view of the Appellant that in line with this decision the ground for opposition under Article 100(c) EPC does not prejudice the maintenance of the patent in suit since the disclaimers would merely limit the scope of protection conferred without providing a technical contribution to the subject-matter of the claimed invention.

2.4.1. Firstly, the decision G 1/93 relates to the situation where an undisclosed limiting, technically meaningful feature cannot be deleted or replaced by any other feature properly disclosed in the application as filed without extending the protection conferred by the patent as granted in contravention of Article 123(3) EPC. Thus, that decision refers only to the situation of a Patentee being caught in an inescapable trap (cf. points 4 and 13 of the reasons). However, it appears immediately that the situation in the present case does not correspond to an inescapable trap as dealt with in decision G 1/93. The Appellant (Patentee) could redraft Claim 1 such that the subject matter thereof is properly disclosed in the application as filed. Thus, he did so in submitting e.g. amended Claim 1 according to the auxiliary request 4 which extends neither the subject-matter claimed beyond the content of the original application nor the protection conferred beyond the patent in suit as granted (cf. point 3 below). Already on that ground the Appellant cannot successfully rely on decision G 1/93 in order to maintain in Claim 1 the disclaimers objected to.

2.4.2. Secondly, the Board observes that the disclaimers provide a technical contribution to the subject matter claimed and, give an unwarranted advantage to the Patentee.

Document (20) discloses ester oils as defined in formulae (2) and (3) of Claim 1 useful for lubricating heat pumps and air conditioning compressors operating with hydrofluorocarbon refrigerants as defined in Claim 1. Therefore, in the absence of any disclaimer in Claim 1, document (20) is highly relevant for the assessment of inventive step and would even qualify as the closest state of the art.

However, when a disclaimer, as in the present case, aims at distancing the patent further from the state of the art (here: from document (20)) which is highly relevant when assessing inventive step, it provides a technical contribution to the claimed invention and its admissibility would give the patent proprietor an unwarranted advantage (cf. T 526/92, point 6.2 of the reasons and T 934/97, point 2.7 of the reasons). Therefore, the disclaimers in Claim 1 according to the main request and the auxiliary requests 1 to 3, also in the light of the decision G 1/93, are to be considered as subject matter which extends beyond the content of the application as filed.

2.5. For those reasons the main request and auxiliary requests 1 to 3 must fail as their Claim 1 contravenes the requirements of Article 123(2) EPC, thereby, supporting the ground for opposition pursuant to Article 100(c) EPC.

Auxiliary request 4

3. Articles 123(2) and (3) EPC - Amendments.

3.1. The question to decide is whether the amendments in Claim 1 regarding the replacement of the term "comprising" by "consisting of" in combination with the restriction of the ester oil to the esters of formula (1) may be derived directly and unambiguously from the application as filed.

3.2. The Board observes that in all the original examples related to oils containing esters of formula (1), namely Examples No. 1 to 5, said oils consist of esters of formula (1) without any other ester. For this reason, the Board concludes that the person skilled in the art derives directly and unambiguously that feature from the application as filed, so that the requirements of Article 123(2) EPC are satisfied.

3.3. Furthermore, that amendment also restricts the scope of the protection conferred and thus satisfy the requirements of Article 123(3) EPC.

4. Articles 54(1) and (2) EPC - Novelty

4.1. Document (6) discloses liquid compositions useful as refrigeration liquids comprising a major amount of at least one fluorine-containing hydrocarbon (chlorine-free or not), and a minor amount of at least one soluble lubricant comprising at least one carboxylic ester of a polyhydroxy compound containing at least 2 hydroxy groups and characterized by the general formula

R[OC(O)R1]n

wherein R is the rest of a polyhydroxy compound such as neopentyl glycol and R1 is hydrogen, independently a straight chain alkyl group containing from 1 to about 5 carbon atoms, a branched chain alkyl group containing from about 5 to about 20 carbon atoms, or a straight chain alkyl group containing from 8 to about 12 carbon atoms, provided that at least one R1 is hydrogen, a straight chain alkyl group containing 1 to about 5 carbon atoms or a branched chain alkyl group containing from about 5 to about 20 carbon atoms, n is an integer of from 3 to about 10 (cf. page 1, "field of the invention"; pages 5 and 6, "summary of the invention"; page 9, Table I and first paragraph; page 11, last line; Claim 18). Those liquid compositions are particularly useful as refrigerants in various refrigeration systems which are compression-type systems such as refrigerators, freezers, and air-conditioners (cf. page 27, second paragraph).

4.2. The Board finds, and it was not contested by the Appellant, that the subject matter of the present Claim 1 is generally encompassed by the disclosure of document (6). However, in the present case, the Board observes that the claimed particular refrigerating apparatus operating with a particular hydrofluorocarbon and using a particular ester as refrigerating machine oil is not disclosed in that document. In view of the silence about any feature characterizing the refrigerating apparatus in document (6), the general disclosure of the refrigerating apparatus does not reveal to the skilled reader the presence of a particular compressor, namely a specific closed vessel, and a particular drying agent, namely a specific synthetic zeolithe, indicated in Claim 1 of the patent in suit. Furthermore, the particular combination claimed of a chlorine-free hydrofluorocarbon having a critical temperature of at least 40 C with the ester oil of formula (1) results from a multiple selection, within optional and alternative features given in document (6), namely of particular hydrofluorocarbons from the list of individual, optionally chlorine containing hydrofluorocarbons on page 9, paragraph 2 and of neopentyl glycol from the list of individual polyhydroxy compounds forming the ester oil on page 11, last paragraph to page 12, first paragraph. For these reasons, the Board concludes that the claimed embodiment does not emerge unambiguously for the skilled reader from the prior art. Hence the general disclosure of document (6) does not destroy the novelty of the particular subject-matter claimed (cf. T 651/91, points 4.3 and 4.4 of the reasons).

5. Article 56 EPC - Inventive step

5.1. The Board considers, as held by the Opposition Division and in agreement with both parties, that document (6) represents the closest state of the art and, thus, the starting point in the assessment of inventive step for the subject matter of Claim 1 according to the auxiliary request 4. Indeed, this document aims at the same objective as the claimed invention, namely to provide ester oils for use as machine oil in refrigerating apparatus (cf. point 4.1 above).

5.2. The Appellant submitted that, in view of document (6), the technical problem to be solved was to provide a refrigerating apparatus comprising improved refrigerating machine oils exhibiting after use no increase in the total acid numbers which was a measure for their stability. To formulate that technical problem, he relied upon the experiments submitted during the appeal proceedings comparing the acid numbers of some of the ester oils exemplified in document (6) and of an ester oil according to Claim 1.

5.3. The patent in suit proposes as the solution to this problem a refrigerating apparatus which comprises a mixture of a refrigerant comprising a chlorine-free (hydro) fluorocarbon having a critical temperature of 40. C or higher and of a refrigerating machine oil which is characterized by the presence of an ester oil according to formula (1). The Appellant conceded at the oral proceedings that the features defining the refrigerating apparatus, including the specified drying agent, provided no inventive ingenuity; these features are thus disregarded when assessing inventive step (cf. T 955/93, point 3.5 of the reasons).

5.4. In the present case, the solution proposed by the patent in suit comprises the preferred embodiment of adding an acidic extreme pressure agent, namely a phosphoric acid partial ester, to the refrigerating machine oil in an amount of 0.05 to 10wt% (cf. dependent Claim 5). Contrary to the submissions of the Appellant, it cannot be a critical issue for the claimed invention to avoid a slight increase of the total acid number of the machine oil which increase results from the ester oil comprised therein where, as it is preferred, a so substantial amount of acidic agent is present in the refrigerating machine oil. It follows that the formulation of the technical problem as put forward by the Appellant cannot be accepted, since the purported improvement does not arise within the whole area of the subject matter of Claim 1. When defining the technical problem, an effect cannot be retained if the promised result is not attainable throughout the entire range covered by the claimed subject matter (cf. T 626/90, point 4.3.2 of the reasons). Thus, the objective technical problem to be solved can only be seen in the provision of a further refrigerating apparatus comprising an ester oil.

5.5. The Examples No. 1 to 5 of the patent in suit show convincingly that this technical problem is solved within the claimed area. This finding has never been contested by the Respondents.

5.6. It remains to be decided whether or not the claimed solution is obvious over the cited prior art.

The relevant question is whether the person skilled in the art having studied the document (6) and being guided by the technical problem as defined in point 5.4 above would have been directed to select ester oils of formula (1) for use in a refrigerating apparatus. The specific choice neopentyl glycol (page 11, last line) as alcohol and of an aliphatic carboxylic acid having a hydrocarbyl group of 5, 6, 7 or 8 carbon atoms (page 13, penultimate line; page 14, lines 1 and 2) which results in an ester of formula (1) is within the scope envisaged by the disclosure of document (6). The Board observes that document (6) teaches that the ester oils including neopentylglycol hydrocarbyl esters, and refrigerants, including chlorine-free (hydro) fluorocarbons (page 9, paragraph 1) form compatible and stable mixtures over a wide temperature range. The presumption prevails, therefore, that the selected ester oils of formula (1) will exhibit the same valuable properties. In the absence of evidence to the contrary, the Board concludes that it would have been obvious for the person skilled in the art, faced with the technical problem defined in point 5.4 above, to select arbitrarily neopentyl glycol and a C5-8 aliphatic carboxylic acid, thereby arriving without inventive ingenuity at the ester oils of formula (1) comprised in a refrigerating apparatus which is the solution proposed by the patent in suit. This finding was actually conceded by the Appellant during the oral proceedings before the Board. For this reason, Claim 1 does not meet the requirements of Article 56 EPC.

5.7. Since the Board can only decide on a request as a whole, the patent in suit cannot be maintained in the form as submitted in this auxiliary request and this request must be rejected for lack of inventive step.