Appeal No. 96-0736
Application 07/984,596
amount of such diisocyanate in the polyisocyanates to less than
0.1% by weight. Appellants limit the content of free tolylene
diisocyanate by preparing the polyisocyanates from tolylene
diisocyanate and a polyhydroxyl polyether having a molecular
weight of from about 350 to about 500.
Appealed claims 1-6, 8, and 9 stand rejected under 35 U.S.C.
§ 103 as being unpatentable over Schnabel.
We have thoroughly reviewed the respective positions
advanced by appellants and the examiner. In so doing, we find
that the evidence of record supports a conclusion of non-
obviousness for the claimed subject matter. Accordingly, we will
not sustain the examiner’s rejection.
Like appellants, Schnabel discloses the preparation of
polyisocyanates by the reaction of a polyhydroxyl polyether and
tolylene diisocyanate. The reference teaches that the polyol
reactant has a molecular weight from about 62 to about 7,000,
which range encompasses the claimed range of 350-500. Also,
while Schnabel, like appellants, is directed towards preparing
polyisocyanates that have a free diisocyanate monomer content of
less than 0.1%, Schnabel accomplishes this by co-distilling the
3
Page: Previous 1 2 3 4 5 6 7 Next
Last modified: November 3, 2007