Appeal No. 1998-1737
Application No. 08/318,702
discloses a polyurethane prepolymer containing masked isocyanate
groups, there is no teaching that all the isocyanate groups are
masked or blocked. Since Münzmay discloses that the equivalent
ratio of isocyanate groups to blocking agents can be 1.15:1, it
is reasonable to conclude that the polyurethane prepolymer of
Münzmay contains free isocyanate groups in addition to the masked
isocyanate groups. Moreover, even if the claimed alternative
regarding a maximum of 20 weight percent of polyester polyol was
not optional, we concur with the examiner that it would have been
obvious for one of ordinary skill in the art to formulate a
polyurethane adhesive composition comprising the claimed amounts
of polyester and polyether polyols in order to achieve a desired
balance of mechanical properties at room temperature, impact
strength at low temperature, and stiffness at high temperature.
Concerning the melting point of 35-80°C of the optional
component, the examiner has correctly noted that Münzmay
discloses crystallizing polyester polyols that have a melting
point within the claimed range.
Finally, pertaining to the § 103 rejection of claims 54 and
57-59, appellants base no argument upon objective evidence of
nonobviousness, such as unexpected results.
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