Appeal No. 1997-1863 Page 2
Application No. 08/408,087
BACKGROUND
Appellant's invention relates to a moisture-curing hot
melt adhesive containing a polyurethane prepolymer and
isocyanurates. An understanding of the invention can be
derived from a reading of exemplary claim 1, which is
reproduced below.
1. A moisture-curing hotmelt adhesive containing:
a) polyurethane prepolymers with a content of NCO
groups of 0.16 to 0.84 moles of NCO groups per kg of
prepolymer formed by reaction of (i) at least partly
crystalline polyester polyols which are solid at room
temperature and have a degree of crystallization of at least
30% and a number average molecular weight in the range from
2000 to 10,000, optionally in admixture with liquid polyester
polyols which are liquid at 20°C and have a glass temperature
below 0°C, with amorphous polyester polyols which are solid at
ambient temperature and have a glass temperature above 0°C,
with polyether polyols having a number average molecular
weight of 500 to 10,000, or with mixtures of any two or more
of said liquid polyester polyols, amorphous polyester polyols,
and polyether polyols with (ii) isocyanates; having a
functionality of more than 1 which are not isocyanurates and
(b) isocyanurates that are trimers of diisocyanates.
The sole prior art references of record relied upon by
the examiner in rejecting the appealed claims is:
Pedain et al. (Pedain) 4,801,675 Jan. 31,
1989
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