Nitto-denko Corporation

Yasunobu Ina

Tomoo Yamaguchi

Shuzo Fujiwara

Isao Hirose

Yoshihiro Kitamura

Minoru Yagi

Mitsuhiko Tsuji

Tomoaki Uchiyama

Kunihiko Kaita

A rubber-based pressure-sensitive adhesive composition comprising a rubbery polymer, and a natural rubber having a weight-average molecular weight of from 100,000 to 400,000, wherein the amount of the natural rubber is 5 parts by weight or more and less than 100 parts by weight, based on 100 parts by weight of the rubbery polymer.

Rubber-based pressure-sensitive adhesive composition and pressure-sensitive adhesive sheet of the same

The present invention relates to a solid type rubber-based pressure-sensitive adhesive composition, which is prepared by adding a tackifier, a softener, and an isocyanate-based crosslinking agent reactable with active hydrogen into an acrylic rubber containing a monomer having an active hydrogen-containing functional group as a copolymerization component to thereby obtain a solventless and nonaqueous pressure-sensitive adhesive composition, and particularly it relates to a solid type rubber-based pressure-sensitive adhesive composition having the above-mentioned constitution, in which the above-mentioned acrylic rubber includes a copolymer containing butyl acrylate as a main component, and as the copolymerization component a monomer having a hydroxyl group or a carboxyl group as the active hydrogen-containing functional group.

Solid type rubber-based pressure-sensitive adhesive composition and pressure-sensitive adhesive sheet thereof

A solid type pressure-sensitive adhesive composition capable of being applied without the necessity of using an organic solvent or water and a pressure-sensitive adhesive sheet, which are excellent in both adhesive force and holding power and, in particular, undergo no decrease in low-temperature adhesive force even when the adhesive layer thickness is small. The crosslinked solid type pressure-sensitive adhesive composition comprising (a) a rubbery polymer, (b) a tackifier, and (c) a crosslinking agent comprising at least one member selected from the group consisting of thiuram vulcanizing agents, quinoid vulcanizing agents, quinone dioxime vulcanizing agents, and maleimide vulcanizing agents.

Crosslinked solid type pressure-sensitive adhesive composition, pressure-sensitive adhesive sheet comprising the composition, and pressure-sensitive adhesive sheet for waterproofing/airproofing comprising the sheet

A method for producing a masticated rubber, which comprises the steps of masticating rubber at a shear rate of from 500 to 4,500 (l/s); and obtaining masticated rubber having a weight-average molecular weight of from 100,000 to 1,300,000.

Method for producing masticated rubber

A solid type pressure-sensitive adhesive composition containing a rubbery polymer as the main polymer; and pressure-sensitive adhesive sheets which use the pressure-sensitive adhesive composition, are excellent in adhesive strength and holding power, retain the intact holding power even when allowed to stand at high temperatures or made to have a reduced adhesive layer thickness, and are free from the problem of adhesive protrusion or adhesive remaining. The pressure-sensitive adhesive sheets comprise a substrate and formed thereon a layer comprising a solid type pressure-sensitive adhesive composition obtained by a method comprising adding a tackifier to a rubbery polymer and treating the resultant mixture with an isocyanate crosslinking agent to crosslink the polymer.

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Ibaraki, Japan

Yasunobu Ina