Acrylic copolymer, acrylic pressure-sensitive adhesive composition, acrylic pressure-sensitive adhesive tape or sheet, and acrylic adhesive composition

An acrylic copolymer characterized as being prepared by grafting a polymer (e) to an acrylic copolymer made via copolymerization of (a) an alkyl (meth)acrylate ester containing 1-14 carbon atoms in the alkyl, (d) a polymerizable monomer containing one type of functional group selected from carboxyl, hydroxyl, epoxy and isocyanate and (b) an olefinic polymer or copolymer terminally modified by a free-radically polymerizable unsaturated double bond, said polymer (e) having at its one end a functional group reactive with the functional group in the polymerizable monomer (d) and also having a number average molecular weight of 2,000-30,000 and a glass transition temperature of at least 30° C.

An acrylic copolymer being prepared by grafting an olefinic polymer or copolymer (f) to an acrylic copolymer (X-2) made via copolymerization of (a) an alkyl (meth)acrylate ester containing 1-14 carbon atoms in the alkyl and (d) a polymerizable monomer containing one type of functional group selected from carboxyl, hydroxyl and isocyanate, said olefinic polymer or copolymer (f) having at its one end one type of functional group reactive with the functional group in the polymerizable monomer (d).

An acrylic copolymer characterized as being prepared by grafting an olefinic polymer or copolymer (f) to an acrylic copolymer (X-3) made via copolymerization of (a) an alkyl (meth)acrylate ester containing 1-14 carbon atoms in the alkyl, (d) a polymerizable monomer containing one type of functional group selected from carboxyl, hydroxyl, epoxy and isocyanate and (c) a polymer terminally modified by a free-radically polymerizable unsaturated double bond and having a number average molecular weight of 2,000-30,000 and a glass transition temperature of at least 30° C., said olefinic polymer or copolymer (f) having at its one end one type of functional group reactive with the functional group in the polymerizable monomer (d).

acrylic copolymer characterized as being prepared by:

• a first step wherein a compound (I) containing a free-radically polymerizable unsaturated double bond and a peroxide bond in a molecule, an alkyl (meth)acrylate ester (a) containing 1-14 carbon atoms in the alkyl and an olefinic polymer or copolymer (b) terminally modified by a free-radically polymerizable unsaturated double bond are allowed to undergo free-radical polymerization, with the aid of a photoinitiator, in the temperature range where the compound (I) is not caused to decompose;
• and
• a second step wherein a polymerizable monomer component (II) which differs in composition from the polymerizable monomer components used in the preceding free-radical polymerization is allowed to undergo free-radical polymerization, under the presence of the product of the preceding free-radical polymerization, in the temperature range where the compound (I) is caused to decompose.