Abstract: A process for producing an emulsion pressure-sensitive adhesive comprises (co)polymerizing a main monomer in the presence of a protective colloid, the protective colloid being an acrylic copolymer comprising (A-1) at least one hydrophilic monomer selected from the group consisting of acrylamide, methacrylamide, hydroxyethyl acrylate and hydroxyethyl methacrylate and (B-1) an alkyl (meth)acrylate that is copolymerizable with the hydrophilic monomer (A-1) and whose alkyl group has 4 to 18 carbon atoms, or (A-2) a hydrophilic monomer being acrylic acid and/or methacrylic acid and (B-2) an alkyl (meth)acrylate that is copolymerizable with the hydrophilic monomer (A-2) and whose alkyl group has 4 to 9 carbon atoms; the hydrophilic monomer and the alkyl (meth)acrylate being copolymerized in a weight ratio in the range of 40-70:60-30; the acrylic copolymer having a weight-average molecular weight in the range of 500 to 50000.

Abstract: A process for producing an emulsion pressure-sensitive adhesive comprises (co)polymerizing a main monomer in the presence of a protective colloid, the protective colloid being an acrylic copolymer comprising (A-1) at least one hydrophilic monomer selected from the group consisting of acrylamide, methacrylamide, hydroxyethyl acrylate and hydroxyethyl methacrylate and (B-1) an alkyl (meth)acrylate that is copolymerizable with the hydrophilic monomer (A-1) and whose alkyl group has 4 to 18 carbon atoms, or (A-2) a hydrophilic monomer being acrylic acid and/or methacrylic acid and (B-2) an alkyl (meth)acrylate that is copolymerizable with the hydrophilic monomer (A-2) and whose alkyl group has 4 to 9 carbon atoms; the hydrophilic monomer and the alkyl (meth)acrylate being copolymerized in a weight ratio in the range of 40-70:60-30; the acrylic copolymer having a weight-average molecular weight in the range of 500 to 50000.

Abstract: A process for producing an emulsion pressure-sensitive adhesive comprises (co)polymerizing a main monomer in the presence of a protective colloid, the protective colloid being an acrylic copolymer comprising (A-1) at least one hydrophilic monomer selected from the group consisting of acrylamide, methacrylamide, hydroxyethyl acrylate and hydroxyethyl methacrylate and (B-1) an alkyl (meth)acrylate that is copolymerizable with the hydrophilic monomer (A-1) and whose alkyl group has 4 to 18 carbon atoms, or (A-2) a hydrophilic monomer being acrylic acid and/or methacrylic acid and (B-2) an alkyl (meth)acrylate that is copolymerizable with the hydrophilic monomer (A-2) and whose alkyl group has 4 to 9 carbon atoms; the hydrophilic monomer and the alkyl (meth)acrylate being copolymerized in a weight ratio in the range of 40-70:60-30; the acrylic copolymer having a weight-average molecular weight in the range of 500 to 50000.

Abstract: A highly water resistant tackifier resin comprising an acrylic (co)polymer incorporating therein while taking up at least part of a tackifying component as a raw material on or around seed particles of 0.05 to 15 &mgr;m in average particle size having polar groups on their surfaces. The above tackifier resin can be produced by a process comprising the steps of: dispersing a tackifying component as a raw material, an oil-soluble peroxide or oil-soluble azo initiator and an acrylic monomer in an aqueous medium in which seed particles of 0.05 to 15 &mgr;m in average particle size having polar groups at their surfaces are dispersed; and polymerizing the acrylic monomer while at least part of the tackifying component is incorporated in the acrylic (co)polymer on or around the seed particles so that the seed particles grow.

Abstract: A highly water resistant tackifier resin comprising an acrylic (co)polymer incorporating therein while taking up at least part of a tackifying component as a raw material on or around seed particles of 0.05 to 15 &mgr;m in average particle size having polar groups on their surfaces.

Abstract: A highly water resistant tackifier resin comprising an acrylic (co)polymer incorporating therein while taking up at least part of a tackifying component as a raw material on or around seed particles of 0.05 to 15 &mgr;m in average particle size having polar groups on their surfaces. The above tackifier resin can be produced by a process comprising the steps of: dispersing a tackifying component as a raw material, an oil-soluble peroxide or oil-soluble azo initiator and an acrylic monomer in an aqueous medium in which seed particles of 0.05 to 15 &mgr;m in average particle size having polar groups at their surfaces are dispersed; and polymerizing the acrylic monomer while at least part of the tackifying component is incorporated in the acrylic (co)polymer on or around the seed particles so that the seed particles grow.