Appeal No. 1998-3229 Page 5
Application No. 08/575,976
Hostettler discloses microcellular polyurethane elastomer
products and methods of preparing same. Hostettler (column 2,
lines 12-29) teaches that their elastomer products are
prepared from, inter alia, a component comprising prepolymers,
a polyol and a blowing agent. The prepolymers are formed by
reacting poly(oxyethyleneoxypropylene)polyols having hydroxyl
equivalent weights ranging from 750-3000 and a hydroxyl
functionality of 2 to 3 with diisocyanates.
Similarly, all of the claims on appeal either require a
process that includes the steps of reacting a component
comprising prepolymers, a polyol and a blowing agent or a
product obtained from such a process. In addition to
requiring that the prepolymer is prepared from the reaction of
polyisocyanates with a polyoxypropylenediol having a number
average molecular weight of about 3,000 Da to about 10,000 Da
and an actual functionality of about 1.95, the claimed
reactant prepolymer is required to have a free NCO group
content of from about 6 to about 16.
Hence, to arrive at the appellant’s claimed invention,
one of ordinary skill in the art would have to not only select
a poly(oxyethyleneoxypropylene)diol having a number average
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