Appeal No. 1995-0770
Application No. 07/929,457
DECISION ON APPEAL
This is a decision on appeal under 35 U.S.C. § 134 from the final rejection of claims
1-21 and 28, all the claims pending in the application.
Appellants’ claims are directed to a process for preparing copolymers of
monomers having unsaturated carbon-to-carbon bonds. Claims 1 and 4 are
representative of the claims on appeal and are reproduced below:
1. A process for preparing copolymers which comprises, in the order stated: (1)
adding monomers containing unsaturated carbon-to-carbon bonds, two polymerization
initiators, namely a first polymerization initiator with a 10 hour half-life temperature of from
about 50EC to about 95EC and a second polymerization initiator with a 10 hour half-life
temperature of from about 85EC to about 130EC, and a solvent to a reaction vessel; (2)
purging the resulting solution with an inert gas; (3) sealing the reaction vessel and
pressurizing it by the addition of an inert gas to a pressure of from about 20 to about 600
kilopascals above ambient atmospheric pressure; (4) maintaining the temperature within
the pressurized reaction vessel at a substantially constant temperature within the range of
from about 50 to about 100EC for a period of from about 60 to about 300 minutes; (5)
thereafter maintaining the temperature within the pressurized reaction vessel at a
substantially constant temperature within the range of from about 80 to about 115EC for a
period of from about 30 to about 300 minutes, wherein the temperature in step 5 is higher
than the temperature in step 4; and (6) subsequently maintaining the temperature within the
pressurized reaction vessel at a substantially constant temperature within the range of from
about 115 to about 160EC for a period of from about 30 to about 180 minutes, wherein the
temperature in step 6 is higher than the temperature in step 5, wherein the resulting
copolymer is substantially free of gel formation
4. A process according to claim 1 wherein the monomers are styrene, ethyl acrylate,
and acrylic acid.
The examiner relies on the following references:
Kamath (Kamath ‘696) 4,125,696 November 14, 1978
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