The invention teaches an encapsulated curable adhesive composition
especially adapted for use as a structural adhesive. The adhesive
composition enables formation of a thin layer reactive composition of
microcapsules and a two-part curative. The adhesive composition comprises
a first population of microcapsules encasing a monomer and a first-part
curative comprising an initiator. The adhesive composition further
comprises a second-part curative. The second-part curative comprises an
activator and a catalyst. At least the activator of the second-part
curative is preferably encapsulated in a second population of
microcapsules. The catalyst and the second population of microcapsules
can be dispersed in a binder material, along with the first population of
microcapsules. The first population of microcapsules contain encapsulated
within the core a monomer having a Tg 35.degree. C. or less and the
first-part curative. The first population microcapsules contain
encapsulated within the core a monomer having a Tg 35.degree. C. or less
along with the first-part curative. The encapsulated monomer and
first-part curative constitute a blend which is a free flowing liquid
having a viscosity of less than 500 Cp (milliPascal-second), and more
preferably less than 10 Cp (milliPascal-second). The first population of
microcapsules with first-part curative, and a second-part curative and
second population of microcapsules are dispersed in a binder material.
Reactive contact of the monomer and first-part curative with the
second-part curative is affected by exuding the respective capsule
contents into reactive contact through breakage of the microcapsules such
as an interference fit of the substrate or substrates to which the
composition is applied.