Appeal No. 1998-3242
Application No. 08/700,133
agent which comprises a dihydrazide compound, wherein this
combination is rheologically stable at room temperature, cures at
about 100-125BC, and has a durometer Shore A of less than 95 upon
cure to provide a flexible and reworkable epoxy bond. This
appealed subject matter is adequately illustrated by independent
claim 1 which reads as follows:
1. A flexible epoxy adhesive consisting of a combination of
the following components:
(a) at least one epoxide resin having a hardness not
exceeding a durometer Shore D reading of 45 when cured with a
stoichiometric amount of diethylene triamine, said epoxide resin
being selected from the group consisting of the diglycidyl ether
of 4,4-butanediol, the diglycidyl ether of neopentyl glycol, the
diglycidyl ether of cyclohexane dimethanol, the diglycidyl ether
of polyoxypropylene glycol, and the polyglycidyl ether of an
aliphatic polyol; and
(b) about 42-100 parts by weight of at least one latent
epoxy resin curing agent per 100 parts by weight of resin, said
latent epoxy resin curing agent comprising a dihydrazide
compound,
wherein said combination is rheologically stable at room
temperature, cures at about 100-125BC, and has a durometer Shore
A of less than 95 upon cure to provide a flexible and reworkable
epoxy bond.
The references set forth below are relied upon by the
examiner as evidence of obviousness:
Kamio et al. (Kamio) 4,360,649 Nov. 23, 1982
Bagga et al. (Bagga) 4,734,332 Mar. 29, 1988
Vachon et al. (Vachon) 4,866,108 Sep. 12, 1989
Lee et al. (Lee), “Handbook of Epoxy Resins,” McGraw Hill,
pp. 2-16 through 2-18 (1982).
2
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