One-part curable elastic sealant

摘要

A one-part curable elastic sealant comprising a dehydrated blend of (I) 100 parts by weight of an acrylic isocyanate elastomer having free isocyanate groups in the molecules, (II) about 0.1 to 15 parts by weight of a reaction promoting catalyst, and (III) about 30 to 200 parts by weight of a filler; said acrylic isocyanate elastomer being the reaction product of an acrylic low molecular weight copolymer with about two equivalents of an organic diisocyanate based on the functional groups in the acrylic low molecular weight copolymer said acrylic low molecular weight copolymer being prepared by copolymerizing (a) an ethylenically unsaturated monomer having a functional group capable of reacting with an organic diisocyanate compound, with (b) an unsaturated monomer of the general formula <IMAGE> wherein R1 represents a hydrogen atom or a methyl group, and R2 represents a straight or branched chain alkyl group having 2 to 14 carbon atoms, in the presence of a polymerization initiator having a functional group whose reactivity with the isocyanate compound is equal to or higher than that of the functional group of the monomer (a), and/or a chain transfer agent similarly having a functional group whose reactivity with the isocyanate compound is equal to or higher than that of the functional group of the monomer (a), the mole ratio of monomer (a) to monomer (b) being about 1:5 to 1:500, and the amount of said polymerization initiator and/or chain transfer agent being about 0.1 to 20 parts by weight per 100 parts by weight of monomer (b).