Asahi Glass Company, Limited

Agc Inc.

Hitoshi Shimoma

Hisashi Sato

Makito Nakamura

Teruhiko Yasuda

Yasuhito Adachi

Haru Kawasaki

Hiroshi Wada

Provided are a urethane prepolymer from which is obtained an adhesive which has excellent moisture permeability and which attains both low adhesion to skin and high adhesion to a base material, an adhesive, a skin patch material, an adhesive tape, a wearable device, and a wearable device kit. The urethane prepolymer is a hydroxyl-group-terminated urethane prepolymer obtained by reacting an oxyalkylene polymer A having an average number of hydroxyl groups per molecule of 2.1 to 3, an oxyalkylene polymer B in which the number of hydroxyl groups per molecule is 1, and a diisocyanate compound, the number-average molecular weight of the oxyalkylene polymer B being 5000 or greater, and the content of ethylene oxide units in the hydroxyl-group-terminated urethane prepolymer being more than 10 mass %.

Urethane prepolymer, adhesive, skin patch material, adhesive tape, wearable device, and wearable device kit

To provide an adherence substance which has a low viscosity and good coatability, can be made solvent free, has a low adhesive strength, of which increase with time is small, has good adhesion to a substrate, has excellent adhesion to an adherend and excellent removability, and has a good wettability. An adherence substance which is obtained by curing a curable composition comprising a silyl group-containing polymer (S) obtained by introducing a hydrolyzable silyl group to a molecular terminal of a polyurethane prepolymer obtained by reacting a polyol compound with a polyisocyanate compound, and which has a peel adhesive strength of at most 8N/25 mm.

Adherence substance, pressure sensitive adhesive sheet and its use

An object of the invention is to provide a process for urethane resin production in which the molecular weight of the urethane resin can be easily controlled regardless of the kind of polyisocyanate compound and which can yield a urethane resin for use as a removable pressure-sensitive adhesive usable in extensive applications ranging from a strong-tack region to a slight-tack region. The process for urethane resin production of the invention is a process for producing a urethane resin which comprises reacting a polyol with a first polyisocyanate compound in such a proportion that isocyanate groups are present in excess to thereby obtain an isocyanate-group-terminated prepolymer, subsequently reacting the isocyanate-group-terminated prepolymer with a chain extender, and further reacting the resultant polymer with a chain terminator, wherein the chain extender comprises a polyfunctional compound (X) having three or more functional groups reactive with an isocyanate group, wherein two of the functional groups of the polyfunctional compound (X) are primary hydroxyl groups and the remaining functional group(s) is secondary hydroxyl or tertiary hydroxyl group(s).

Process for production of urethane resin and adhesive agent

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Tokyo, Japan

Hitoshi Shimoma