Appeal 2007-2337
Application 10/437,919
higher flex fatigue resistance, and higher tensile strength and percent
elongation (Br. 4). Representative claim 11 reads as follows:
11. A polyurethane elastomer comprising:
the acellular reaction product of a prepolymer comprising:
the reaction product of:
1) from 20 to 80 parts by weight of an aromatic ester polyol
having the structure:
wherein:
R1 is a divalent radical selected from the group consisting of:
(a) alkylene radicals of from 2 to 6 carbon atoms, and
(b) radicals of the formula:
- (R2O)n- R2 -
wherein R2 is an alkylene radical of 2 or 3 carbon atoms, n is an integer of
from 1 to 3, and m is an integer sufficient to provide a polyol having a
number average molecular weight of about 2000; and,
2) correspondingly, from 80 to 20 parts by weight of a second,
hydroxyl containing, polyol different from said aromatic ester polyol;
with
3) at least one diisocyanate;
with a chain extender selected from the group consisting of water, aliphatic
diols, aromatic diamines, and mixtures thereof.
2
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Last modified: September 9, 2013