Appeal No. 1997-3416 Page 4
Application No. 08/339,340
constituent of appellants' claim and a surfactant, such as
ammonium alkyl polyether sulfate (answer, page 3). The
examiner acknowledges that BP '830 does not disclose the
diphenyl ether compound of the formula required by appellants'
claim (answer, page 3).
To allegedly remedy the admitted deficiency of BP '830,
the examiner relies on the teachings of Hashimoto and
Matsumoto. According to the examiner, Hashimoto discloses
that developing solutions used in silicon based semi-conductor
manufacturing should not include alkali metals. The examiner
further argues (answer, page 4):
[i]t is also well-known in the surfactant art
that alkyl diphenyl ether disulfonates are
equivalent to alkyl polyether sulfates, as anionic
surfactants, as disclosed by Matsumoto et al. (Col.
4, lines 61-68).
We disagree. Matsumoto, together with the other applied
references, furnishes insufficient evidence to establish the
general equivalency of alkyl diphenyl ether disulfonates and
alkyl polyether sulfates as anionic surfactants. Rather,
Matsumoto discloses several surfactants at column 4, lines 61-
64 of the patent, which are taught as alternatives for
assisting in the uniform application of the treating solution
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