Appeal No. 1997-3609
Application No. 08/483,349
addition, adhesives prepared according to the
invention, although used without primer, exhibit
excellent high temperature bonding strength.
Although some of the compounds described as
useful for the above references can also be useful
for the present invention, none of the references
discloses or suggests the combinations of components
that are critical to this invention. In particular,
none discloses the use of a curative component
containing a mixture of a relatively high equivalent
weight polyether polyol or aromatic amine terminated
polyether, a relatively low equivalent weight diol-
containing chain extender or crosslinker, and an
amine for resistance to sag. [Emphasis added.]
Dormish continues (col. 8, line 61-col. 9, line 2):
Both the isocyanate component and the curative
component of the present invention are characterized
by low viscosities, a characteristic that
facilitates bulk handling. As used herein, the term
"low viscosity" refers to a Brookfield viscosity at
25E C. of less than about 15,000 mPa.s. Each
component used in the present invention is
characterized by viscosities at 25E C. of less than
15,000 mPa.s. Despite the use of such low viscosity
components . . . , the mixed adhesive exhibits
excellent resistance to sag.
Thus, we agree with appellants that one having ordinary skill
in the art would have recognized that the amines are an
essential element in the polyurethane adhesive disclosed in
Dormish.
Turning to the rejection before us, the examiner arrives
at the claimed invention by eliminating the diamine/triamine
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