Japan Elastomer Co., Ltd.

Asahi Kasei Chemicals Corporation

Asahi Kasei Kabushiki Kaisha

Yukinori Nakamichi

Shigeo Nakajima

Takahiro Hisasue

Masahiro Fujiwara

Yoshifumi Araki

Kenji Ebara

Keiichi Toda

A block copolymer composition including: 10% by mass or more and 90% by mass or less of a component (a), and 10% by mass or more and 90% by mass or less of a component (b), wherein the component (a) is a block copolymer containing a polymer block (A) primarily including a vinyl aromatic monomer unit and a polymer block (B) primarily including a conjugated diene monomer unit, wherein the block copolymer has a weight average molecular weight of 30,000 or higher and 150,000 or lower; and the component (b) is a block copolymer containing a polymer block (A) primarily including a vinyl aromatic monomer unit and a polymer block (B) primarily including a conjugated diene monomer unit.

Block copolymer composition and adhesive composition

It is an object to provide a block copolymer composition for a viscous adhesive, which will be a viscous adhesive composition excellent in balance of the adhesive properties such as tack strength and tackiness, having a low melt viscosity, and excellent solubility, coating properties, ejection stability, and surface skin quality. The block copolymer composition for a viscous adhesive having:

Block copolymer composition for viscous adhesive, and adhesive composition

An adhesive composition having good balance in tackiness properties such as tack strength and retentivity, low melt viscosity, high processability, and high stability in melt viscosity under high temperature heating is provided. An adhesive composition containing two hydrogenated block copolymers and a predetermined tackifier is provided, the two hydrogenated block copolymers each having a different structure obtained by controlling the degree of hydrogenation of a block copolymer of a conjugated diene compound and a vinyl aromatic hydrocarbon in a particular range.

Adhesive composition

The present invention relates to an adhesive composition comprising (A) a block copolymer composition comprising a block copolymer (a) formed from at least two polymer blocks composed mainly of a monoalkenyl aromatic compound and at least one polymer block composed mainly of a conjugated diene compound and a block copolymer (b) formed from a polymer block composed mainly of a monoalkenyl aromatic compound and a polymer block composed mainly of a conjugated diene compound, wherein the block copolymer (a) has a GPC peak molecular weight of 60,000 to 110,000 in terms of standard polystyrene, the polymer block composed mainly of a monoalkenyl aromatic compound has a peak molecular weight of 10,000 to 30,000 and a molecular weight distribution Mw/Mn of 1.0 to 1.6, the block copolymer composition (A) has a content of the block copolymer (b) of 50 to 90% by weight, the block copolymer composition (A) has a total monoalkenyl aromatic compound content of more than 40% by weight and 50% by weight or less, the conjugated diene unit has a vinyl bond content of less than 20%, and the block copolymer composition (A) has a viscosity in a 15% toluene solution of 10 to 40 cP at 25&#xb0; C.

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Tokyo, Japan

Yukinori Nakamichi