No. of citations: 103
In such cases, T 181/82 generally held that the alleged advantages cannot be taken into account unless sufficient evidence is provided of that alleged advantage in form of a comparison of the invention with the closest prior art.
In the case at hand claim 1 related to a UV absorbing compound (a UV stabiliser), which was defined by a generic chemical formula. The Examining Division had refused the application for lack of inventive step over structurally rather similar UV stabilisers known from D1.
The applicant appealed against the refusal. In order to prove inventive step, the appellant provided experimental data on a technically useful effect, namely the "resistance to extraction" of an exemplary compound of the invention with a structurally quite similar UV stabiliser disclosed in document D1.
The Board did not accept the evidence. They were of the opinion that the the compound chosen from D1 for comparison was not the most similar compound to the compound of the invention chosen for comparison.
For the chemists: the applicant chose 8-allyl-2,2,4,4-tetramethyl-7-oxa-3,20-diaza- 21-oxo-dispiro-(5,1,11,2)-heneicosane of the invention for comparison, and compared its "resistance to extraction" with that of 2,2,4,4-tetramethyl-7-oxa-3,20-diaza-21-oxo-dispiro-(5,1,11,2)-heneicosane of D1. The Board was of the opinion that the 8-unsubstituted 2,2,4,4-tetramethyl-7-oxa-3,20-diaza- 21-oxo-dispiro-(5,1,11,2)-heneicosane of D1 was not the closest analogue to the 8-allyl-2,2,4,4-tetramethyl-7-oxa-3,20-diaza- 21-oxo-dispiro-(5,1,11,2)-heneicosane of the invention. Instead, the applicant should have compared the "resistance to extraction" of 8-methyl-2,2,4,4-tetramethyl-7-oxa-3,20-diaza- 21-oxo-dispiro-(5,1,11,2)-heneicosane, which was also disclosed in D1, with that of the 8-allyl-2,2,4,4-tetramethyl-7-oxa-3,20-diaza- 21-oxo-dispiro-(5,1,11,2)-heneicosane of the invention.
Since the comparison of the alleged technical effect was not carried out with the respect to the closest prior art, the Board refused the applicant's inventive step argument, which was based on that technical effect. If a meaningful statement is to be made in order to render an inventive step plausible, compounds having a maximum structural resemblance must be compared with one another.
Therefore, the appeal was dismissed.
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Headnote:
I. An effect which may be said to be unexpected can be regarded as an indication of inventive step; where comparative tests are sub submitted as evidence of this, there must be the closest possible structural approximation - in a comparable type of use - to the subject-matter of the invention.The full text of the decision can be found here.
II. Only known substances - not notionally described ones - qualify for use in comparisons of compounds. Such substances include those which are the inevitable result of the starting materials and the process applied thereto, even if one of the two reactants manifests itself as a chemical entity (C1 alkyl bromide) from a group of generically defined compounds (C1 - C4 alkyl bromides) (see "Diastereomers" T 12/81, OJ EPO 1982,296).
See also T 20/81 on a related issue.
