Appeal No. 1997-2446
Application 08/223,351
v) from about 3 to about 50 weight percent,
based on the total weight of monomer added to
the reactor, of at least one monoethylenically
unsaturated dicarboxylic acid monomer, and
vi) from 0 to about 40 weight percent, based
on the total weight of monomer added to the
reactor, of one or more water soluble carboxyl-
free monoethylenically unsaturated monomers,
wherein the total weight percent of monomers iv),
v), and vi) equals 100 weight percent;
c) maintaining the reaction mixture at a temperature
of from about 60° to about 120°C over a reaction time;
d) maintaining the reaction mixture at a pH of 3 or
less over the reaction time; and
e) recovering a water soluble polymer product having
a weight average molecular weight less than 30,000;
wherein the chain transfer agent, initiator, and
monoethylenically unsaturated monocarboxylic acid
monomer iv) are added to the reactor over at least
25 percent of the reaction time.
The references of record relied upon by the examiner
are:
Hughes et al. (Hughes) 5,100,980 Mar. 31, 1992
Seelmann-Eggeberg et al. (SE) 5,104,951 Apr. 14, 1992
Holy et al. (Holy) 5,268,437 Dec. 7, 1993
The appealed claims stand rejected under 35 U.S.C. § 103
as unpatentable over the combined teachings of Hughes, Holy and SE.
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