Adhesive composition, adhesive agent, adhesive tape, and airtight waterproof adhesive tape

Abstract

An adhesive composition contains an acrylic resin (A) obtained by copolymerizing a copolymerization formulation (a), the copolymerization formulation (a) including predetermined proportions of: (a1) at least one selected from the group consisting of a (meth)acrylate having a C1 to C3 alkyl group, t-butyl (meth)acrylate, a cyclic structure-containing monomer, and a C3 to C10 vinyl ester monomer; (a2) a (meth)acrylate having a C4 to C24 alkyl group (excluding t-butyl (meth)acrylate); (a3) a terminal carboxyl-containing monomer having a specific structure; and (a4) (meth)acrylic acid. The adhesive composition provides firm adhesion to a higher-polarity adherend, a lower-polarity adherend, a poor-adhesion adherend such as of ethylene propylene diene rubber (EPDM), and a rough surface, and is excellent in holding force and adhesiveness in a high-temperature/high-humidity environment, with reduced susceptibility to deterioration in adhesiveness over time.

Dependencies are inferred from the claim text.