Abstract: To provide a polyurethane prepolymer whereby a pressure-sensitive adhesive having excellent moisture permeability and also having both low adhesion to skin and high adhesion to a substrate can be obtained, a pressure-sensitive adhesive, an adhesive skin patch, a pressure-sensitive adhesive tape, a wearable device and a wearable device kit. A hydroxy group-terminated polyurethane prepolymer which is obtained by reacting an oxyalkylene polymer A having an average number of hydroxy groups per molecule of from 2.1 to 3, an oxyalkylene polymer B having one hydroxy group per molecule, and a diisocyanate compound, wherein the number average molecular weight of the oxyalkylene polymer B is at least 5,000, and the content of ethylene oxide units in the hydroxy group-terminated polyurethane prepolymer is more than 10 mass %, a pressure-sensitive adhesive, an adhesive skin patch, a pressure-sensitive adhesive tape, a wearable device and a wearable device kit.

Abstract: 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.

Abstract: To provide a touch panel having a surface protective film laminated on a touch pad via an adherence substance layer having a low adhesive strength and excellent removability, having a good holding power, and having an adhesive strength with a small increase with time. A touch panel comprising a display module 1, a touch pad 2 laminated on a display screen of the display module 1 and a surface protective film 3 laminated on the viewer side of the touch pad 2, wherein between the surface protective film 3 and the touch pad 2, a first adherence substance layer 11 obtained by curing a first curable composition containing a silyl group-containing polymer (S) is interposed. The silyl group-containing polymer (S) is a polymer having a polyether chain, a polyester chain and/or a polycarbonate chain in its main chain and having a hydrolyzable silyl group at its molecular terminal.

Abstract: To provide an adhesive laminate with which an adhesive deposit does not result even when a polyester-type substrate layer is used. An adhesive laminate comprising a polyester-type substrate layer and an adherence substance layer, wherein one surface of the polyester-type substrate layer is a treated surface subjected to adhesion-facilitating treatment, the adherence substance layer is in contact with the treated surface, and the adherence substance layer is a layer obtained by curing a curable composition containing the following silyl group-containing polymer (S). The silyl group-containing polymer (S) is a silyl group-containing polymer having a polyether chain, a polyester chain and/or a polycarbonate chain in its main chain and having a hydrolyzable silyl group at its molecular terminal.

Abstract: 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.

Abstract: To provide an adherence substance which has a low viscosity and good coatability, can be made solvent free, is less likely to undergo an increase in the adhesive strength with time and has good adhesion to an adherend while the adhesive strength is low, is excellent in removability and has a good wettability.

Abstract: 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.

Abstract: To provide an adherence substance which has a low viscosity and good coatability, can be made solvent free, has good adhesion to an adherend and at the same time has excellent removability, can suppress peel electrostatic charge and is excellent in high speed peeling performance.

Abstract: A process for producing a urethane resin having a low viscosity and usable as a wide range of pressure-sensitive adhesives ranging from a strong-tack region to a slight-tack region, and a pressure-sensitive adhesive are provided. The process for producing a urethane resin comprises reacting a polyol with a polyisocyanate compound in such a proportion that isocyanate groups are in excess to thereby obtain an isocyanate-group-terminated prepolymer, thereafter reacting the isocyanate-group-terminated prepolymer with a chain extender, and reacting the resultant polymer with a chain terminator, wherein the chain extender has three or more functional groups reactive with an isocyanate group, wherein one of the functional groups is a primary amino group or a secondary amino group, another is a primary hydroxyl group, and the remaining functional group(s) are a secondary hydroxyl group or a tertiary hydroxyl group. The pressure-sensitive adhesive comprises the urethane resin obtained.

Abstract: 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.

Abstract: Provided is a polyurethane elastomer with a low hardness, a high strength and a high elongation. The polyurethane elastomer is obtained by reacting and curing an isocyanate-terminated prepolymer (i) obtained by reacting a polyoxyalkylene polyol having an average number of hydroxyl groups of over 2, a total degree of unsaturation of less than 0.05 meq/g and a number-average molecular weight of from 4000 to 20000, with a polyisocyanate compound, and a curing agent (ii) containing as curing components a polyoxytetramethylene polyol (a) and a chain extender (b) having two active-hydrogen-containing groups and having a number-average molecular weight of not more than 500.