T 0826/98 (Non-flammable mixtures/DU PONT DE NEMOURS) of 8.7.2004

European Case Law Identifier: ECLI:EP:BA:2004:T082698.20040708
Date of decision: 08 July 2004
Case number: T 0826/98
Application number: 91905195.3
IPC class: C11D 7/50
Language of proceedings: EN
Distribution: C
Download and more information:
Decision text in EN (PDF, 19.801K)
Documentation of the appeal procedure can be found in the Register
Bibliographic information is available in: EN
Versions: Unpublished
Title of application: Azeotropic composition of 1,1,1,2-tetrafluoroethane and dimethyl ether
Applicant name: E.I. DU PONT DE NEMOURS AND COMPANY
Opponent name: -
Board: 3.3.01
Headnote: -
Relevant legal provisions:
European Patent Convention 1973 Art 54(3)
European Patent Convention 1973 Art 82
European Patent Convention 1973 Art 123(2)
Keywords: Sole request: novelty (yes) - unity of invention (yes)
Catchwords:

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Cited decisions:
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Citing decisions:
-

Summary of Facts and Submissions

I. The appeal lies from the Examining Division's decision, despatched on 25 March 1998, refusing European patent application No. 91 905 195.3, published as WO 91/13968, due to lack of novelty, since the exclusion of the binary mixtures specifically disclosed in document

(1) EP-A-0 443 912

by disclaimers was not suitable for distinguishing the claimed subject-matter from the disclosure of document (1) and since the novel subject-matter was not based on a single general inventive concept.

The decision was based on a set of 9 claims comprising the following three independent product claims:

"2. An azeotropic or constant-boiling composition which comprises 45 to 55 weight percent HFC-134a and 55 to 45 weight percent of dimethyl ether but excluding binary mixtures of 50 weight percent of HFC-134a and 50 weight percent of dimethyl ether."

"3. A non-flammable binary mixture which comprises from 91. to 99.5 weight percent of HFC-134a and 0.5 to 9 weight percent of dimethyl ether."

"5. A binary mixture comprising from 40 to 99.5 weight percent of HFC-134a and 0.5 to 60 weight percent of dimethyl ether but excluding binary mixtures consisting of 40 weight percent of HFC-134a and 60 weight percent of dimethyl ether, 50 weight percent of HFC-134a and 50. weight percent of dimethyl ether, 60 weight percent of HFC-134a and 40 weight percent of dimethyl ether, 62.3. weight percent of HFC-134a and 37.3 weight percent of dimethyl ether, 70 weight percent of HFC-134a and 30. weight percent of dimethyl ether, 80 weight percent of HFC-134a and 20 weight percent of dimethyl ether and 90. weight percent of HFC-134a and 10 weight percent of dimethyl ether."

II. At the oral proceedings, which took place on 8 July 2004, the Appellant filed, as a sole request, a set of three claims, reading:

"1. A non-flammable binary mixture which consists essentially of 91 to 99.5 weight percent of HFC-134a and 0.5 to 9 weight percent of dimethyl ether."

"2. A mixture as claimed in claim 1 which consists essentially of 91 to 95 weight percent of HFC-134a and 5. to 9 weight percent of dimethyl ether."

"3. A process for producing refrigeration which comprises evaporating a mixture as claimed in claim 1 or 2 in the vicinity of a body to be cooled."

III. The Appellant requested that the decision under appeal be set aside and that the case be remitted to the first instance for further prosecution.

Reasons for the Decision

1. The appeal is admissible.

2. Article 123(2) EPC

The binary mixtures of Claims 1 and 2 correspond with the ones of Claims 3 and 4 as originally filed and the process of Claim 3 corresponds with the process described in Claims 7 and 8 as originally filed.

Consequently, the requirement of Article 123(2) EPC is met.

3. Novelty

Document (1) has a filing date and a priority date before the filing date and respective priority date of the present application and was published after the filing date of the present application. Moreover, its content is identical with the content of French application number 90 02012, from which it claims the priority date. Document (1) represents, thus, state of the art according to Article 54(3) EPC.

This document discloses, in general, on page 2, lines 27. to 30, compositions containing 5 to 85% of HFC-134a and 15 to 95% of dimethyl ether and it specifically cites in Table 1 compositions containing 0, 10, 20, 30, 40, 50, 60, 62.3, 70, 80, 90 and 100% of HFC-134a, the remaining part of the compositions consisting of dimethyl ether. Moreover, graph 1 represents a curve obtained by plotting the pressure of compositions consisting of 100% and less than 80% of HFC-134a, the remaining component being dimethyl ether.

As, thus, compositions consisting of 91 to 99.5 weight percent of HFC-134a and 0.5 to 9 weight percent of dimethyl ether are not disclosed therein, document (1) is not novelty destroying for Claims 1 to 3.

4. Unity of invention

Since all claims are related to binary mixtures consisting of 91 to 99.5 weight percent of HFC-134a and 0.5. to 9 weight percent of dimethyl ether, which are non-flammable and which are useful for being evaporated in the vicinity of a body to be cooled, the claimed subject-matter is incontestably linked so as to form a single general inventive concept.

ORDER

For these reasons it is decided that:

1. The decision under appeal is set aside.

2. The case is remitted to the first instance for further prosecution.

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