Appeal No. 95-0757
Application 07/795,307
Flesher et al. (Flesher) 4,599,379 Jul. 8, 1986
Claims 3, 6, 8, and 9 stand rejected under 35 USC § 103 over
Flesher in view of Yamasaki and Anderson. Appealed claim 5
stands similarly rejected under the same section of the statute
further in view of Elfers. Appealed claim 10 stands similarly
rejected in view of the prior art references above further in
view of Friedrich.
We reverse.
The subject matter on appeal is directed to a water-in-oil
emulsion polymerization process for producing a finely divided
polymer powder in the form of an agglomeration of primary
particles having a mean particle size of from 0.1 to 20 Fm.
According to the claimed process, water-soluble monomers are
polymerized in the aqueous phase of a water-in-oil emulsion in
the presence of a water-in-oil emulsifier, a cross-linking agent,
an oil-in-water emulsifier and an initiator; a protective colloid
is added after polymerization is completed; water is removed by
azeotropic distillation; and the finally divided polymer powder
is isolated as an agglomerate. Basically, appellants have
discovered that the addition of a protective colloid to the
water-in-oil emulsion after polymerization allows for the
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