Appeal No. 1997-1991 Page 6
Application No. 08/376,270
with dimethoyl propionic acid” (answer, page 2). Moreover,
the examiner urges that Mosbach discloses “making these
products at excess NCO/OH ratios”, the product’s usefulness as
coatings and forming dispersions thereof in water (answer,
page 2). The examiner acknowledges that Mosbach does not
disclose the use of an amine chain extender in forming a
coating composition as called for in the herein claimed
subject matter (answer, page 2).
According to the examiner (answer, page 3),
It would have been obvious to one of ordinary
skill in the art at the time of [sic] the invention
was made to crosslink Mosbach’s prepolymer with
excess amine compounds rather than water because
Coogan shows this to be well known in the art. It’s
known that amine chain extension takes place more
rapidly than the water chain extension reaction, and
no foaming (release of carbon dioxide) occurs with
amine extension versus water chain extension.
The examiner further urges that the amount of amine chain
extender disclosed by Coogan overlaps the claimed amount.
Moreover, the examiner indicates that “Coogan teaches that
amine chain extension can be used in lieu of water chain
extension,” and that motivation for the proposed modification
such as “faster reactions” and “less foaming” would have
been well known in the art (answer, page 3).
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