Appeal No. 1996-2115
Application 08/809,933
of MBA is a result effective variable. The discovery of an optimum value of a result
effective variable is ordinarily considered to be within the skill of the art. In re Boesch, 617
F.2d 272, 276, 205 USPQ 215, 219 (CCPA 1980). One of ordinary skill in the art would
have found it obvious to optimize the amount of MBA used in Candau guided by the
disclosure of Zweigle as to its function in creating a cross-linked final product.
As for the solution viscosity requirement of at least about 2.0 mPa.s, we note that
Candau expressly teaches that the viscosity should be low so that the polymerization takes
place in the micelles (column 4, lines 35-40). Accordingly, one of ordinary skill in the art at
the time the invention was made would have recognized the effect that the solution
viscosity has on the polymerization process. Therefore, one of ordinary skill in the art
would have routinely optimized the solution viscosity of the polymer to assure the
polymerization occurs in the micelles. Id.
As to the question of water solubility, appellants argue that Candau is directed
solely to the preparation of water-insoluble polymers (brief, page 8). However, the
evidence of record does not support appellants’ position. Claim 23 requires the presence
of MBA in an amount of from 2 to 80 molar parts per million. According to claim 23,
polymeric microparticles having this content of MBA would be water-soluble as this term is
used in the present invention.
As seen from Example 2 of Table I of the present specification, a content of MBA of
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