Appeal No. 1997-2446
Application 08/223,351
levels (from about 3 to 25 weight percent) of monethylenically
unsaturated dicarboxylic acid units, such as maleic acid, and rela-
tively high levels (from about 75 to 97 weight percent) of
monoethylenically unsaturated monocarboxylic acid units, such as
acrylic acid. See column 2, lines 59 through 64, of Hughes. In this
regard, the copolymers produced by EXAMPLES 1, 7, 9, and 12 of Hughes
each have a weight average molecular weight of less than 30,000, and
Figure 1 of Hughes demonstrates how the use of a copper metal
promoter "allows for better control of the molecular weight over a
wide
range of maleic acid content in the copolymer." See column 5, lines
49 through 56, of Hughes. Accordingly, while appellants argue that
the attainment of a low molecular weight copolymer
containing low amounts of monoethylenically unsaturated dicarboxylic
acid monomer is not a trivial problem, Hughes has disclosed a
prior art process for achieving this goal.
In addition to the monomer components and the copper
promoter, the reaction mixture of Hughes also includes water soluble
initiators. See column 4, line 6, and line 66 to column 5, line 7,
of Hughes. The Hughes polymerization reaction is conducted within a
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