Appeal No. 1998-3147
Application 08/564,304
place in a solvent, acetone and methyl ethyl ketone being
particularly suitable solvents, and reacting the free
isocyanate groups of the intermediate with specified polyols
(col. 3, line 8 - col. 4, line 21).
Chandalia discloses a coating composition which is to be
subsequently moisture cured and which consists essentially of
at least one polyisocyanate prepolymer which is the reaction
product of a polyisocyanate with an active hydrogen-containing
compound which can be a polyol (col. 2, lines 53-61; col. 6,
lines 37-41). The composition can contain a solvent, the
disclosed suitable solvents including methyl ethyl ketone and
ethoxyethyl propionate (col. 6, lines 1-17).1
The examiner argues that it would have been obvious to
one of ordinary skill in the art to use ethoxyethyl propionate
as Hille’s solvent because Chandalia teaches the equivalence
of ethoxyethyl propionate and methyl ethyl ketone as solvents
(answer, page 4).
Hille teaches that his solvents preferably are inert to
isocyanate groups (col. 4, lines 14-15; col. 7, lines 28-34).
Blum is relied upon by the examiner (answer, page 3) only for a disclosure of butoxypropanol1
as recited in the appellants’ dependent claim 3.
4
Page: Previous 1 2 3 4 5 6 7 8 9 Next
Last modified: November 3, 2007