Abstract: A heat-peelable pressure-sensitive adhesive sheet, which comprises a substrate, a heat-expandable adhesive layer formed on at least one surface thereof, and a surfactant, wherein the surfactant is contained in the heat-expandable adhesive layer as an adhesive surface.

Abstract: A method of overheating and releasing a chip cut piece from a thermal release type pressure sensitive adhesive sheet is a method by which a chip cut piece stuck onto a thermal release type pressure sensitive adhesive sheet having a base material, and a thermally expandable microsphere-containing thermally expandable pressure sensitive adhesive layer provided on a surface of the base material is thermally released from the thermal release type pressure sensitive adhesive sheet and which is characterized by including the step of overheating while restraining the overheat and release type pressure sensitive adhesive sheet to thereby release the chip cut piece. A means for restraining the thermal release type pressure sensitive adhesive sheet may be an absorption means using suction or may be a bonding means using an adhesive agent.

Abstract: A heat-peelable adhesive sheet which shows small increase in the degree of contamination caused by a heat treatment for lowering an adhesive force is disclosed. The heat-peelable pressure sensitive adhesive sheet comprises a heat-expandable layer containing heat-expandable microspheres and expanding upon heating, and a non-heat expandable pressure-sensitive adhesive layer formed on at least one side thereof. The heat-peelable pressure-sensitive adhesive sheet can achieve the desired adhesive properties such as an excellent adhesive force before heating and also show a quick lowering of the adhesive force upon heating. Further, it shows small increase in the degree of contamination due to the treatment for lowering the adhesive force. Due to those characteristics, the heat-peelable pressure-sensitive adhesive sheet is practically applicable to, for example, the production of electronic parts made of thinner semiconductor wafers.

Abstract: A heat-peelable adhesive sheet which comprises a substrate and, formed on at least one side thereof, a heat-expandable layer containing heat-expandable microspheres and an adhesive layer comprising an adhesive substance and in which the substrate has heat resistance and stretchability can be used to cut an adherend so as to form and secure a sufficient space between the resultant cut pieces and can withstand a heat treatment for expanding the heat-expandable layer. Consequently, the adhesive sheet can heighten the operating efficiency and working efficiency in the step of separating and recovering the cut pieces.

Abstract: A heat-peelable pressure-sensitive adhesive sheet which ensures an efficient contact area even in case where the area of an adherend to be adhered is decreased and thus makes it possible to avoid adhesion failures such as chip-scattering or chipping. The heat-peelable pressure-sensitive adhesive sheet comprises a substrate and a heat-expandable pressure-sensitive adhesive layer containing heat-expandable microspheres, formed on at least one side of the substrate, wherein the surface of the heat-expandable pressure-sensitive adhesive layer before heating has a center line average roughness of 0.4 ?m or less.

Abstract: An energy-beam-curable thermal-releasable pressure-sensitive adhesive sheet having, on at least one side of a base material, an energy-beam-curable thermo-expandable viscoelastic layer containing thermo-expandable microspheres and a pressure-sensitive adhesive layer stacked in this order. The pressure-sensitive adhesive layer has a thickness of about 0.1 to 10 ?m and can be formed from a pressure-sensitive adhesive. The energy-beam-curable thermo-expandable viscoelastic layer, on the other hand, can be formed from a tacky substance. The energy-beam-curable thermal-releasable pressure-sensitive adhesive sheet according to the invention has adhesion enough to withstand a carrying step of an adherend, causes neither winding up of the adhesive nor chipping upon cutting and facilitates peeling and collection of cut pieces after cutting. In addition, it exhibits low contamination on the adherend after peeling.

Abstract: A heat-peelable adhesive sheet which comprises a substrate and, formed on at least one side thereof, a heat-expandable layer containing heat-expandable microspheres and an adhesive layer comprising an adhesive substance and in which the substrate has heat resistance and stretchability can be used to cut an adherend so as to form and secure a sufficient space between the resultant cut pieces and can withstand a heat treatment for expanding the heat-expandable layer. Consequently, the adhesive sheet can heighten the operating efficiency and working efficiency in the step of separating and recovering the cut pieces.

Abstract: A method of thermal adherend release, wherein a part of adherends adherent to a heat-peelable pressure-sensitive adhesive sheet having a heat-expandable layer containing a foaming agent are selectively released from the pressure-sensitive adhesive sheet by partly heating the heat-peelable pressure-sensitive adhesive sheet, wherein the method comprises previously heating a sticking site of an adherend to be released at a temperature at which the heat-expandable layer of the heat-peelable pressure-sensitive adhesive sheet does not expand and then heating the sticking site of the adherend in the heat-peelable pressure-sensitive adhesive sheet at a temperature at which the heat-expandable layer expands to thereby selectively releasing the adherend.

Abstract: An energy-beam-curable thermal-releasable pressure-sensitive adhesive sheet has, on at least one side of a base material, an energy-beam-curable viscoelastic layer and a thermo-expandable pressure-sensitive adhesive layer containing thermo-expandable microspheres stacked in this order. The energy-beam-curable viscoelastic layer is, for example, composed of a composition of an organic viscoelastic body and an energy-beam-curable compound or an energy-beam-curable resin. The energy-beam-curable viscoelastic layer has a thickness of about 5 to 300 ?m or may be not greater than the maximum particle size of the thermo-expandable microspheres. The energy-beam-curable thermal-releasable pressure-sensitive adhesive layer according to the invention has adhesion enough to withstand a carrying step of an adherend, causes neither winding up of the adhesive nor chipping upon cutting and facilitates peeling and collection of cut pieces after cutting.

Abstract: A heat-peelable pressure-sensitive adhesive sheet which, even when used for temporarily fixing electronic parts having poor resistance to static electricity, such as magnetic heads, is effective in preventing the yield of such electronic parts from being reduced by electrostatic breakage, while ensuring its functions of adhesiveness before heating and peelability after heating. The heat-peelable pressure-sensitive adhesive sheet comprises a substrate and formed on at least one side thereof a heat-expandable pressure-sensitive adhesive layer containing heat-expandable microspheres, wherein the heat-expandable pressure-sensitive adhesive layer has a surface resistivity of 1012 ?/? or lower. In this heat-peelable pressure-sensitive adhesive sheet, the heat-expandable pressure-sensitive adhesive layer before heating may have a center line average surface roughness of 2 ?m or less and a maximum surface roughness of 5 ?m or less.

Abstract: The present invention intends to provide a method of thermal adherend release by which, when part of adherends on a heat-peelable pressure-sensitive adhesive sheet are desired to be thermally released therefrom, the desired part only can be easily and speedily released. A method of thermal adherend release, wherein part of adherends adherent to a heat-peelable pressure-sensitive adhesive sheet having a heat-expandable layer containing a foaming agent are selectively released from the pressure-sensitive adhesive sheet, wherein the method comprises partly heating the heat-peelable pressure-sensitive adhesive sheet in an atmosphere having a temperature of 50° C. or higher at which the heat-expandable layer does not expand to thereby selectively release the adherends.

Abstract: A heat-peelable adhesive sheet which comprises a substrate and, formed on at least one side thereof, a heat-expandable layer containing heat-expandable microspheres and an adhesive layer comprising an adhesive substance and in which the substrate has heat resistance and stretchability can be used to cut an adherend so as to form and secure a sufficient space between the resultant cut pieces and can withstand a heat treatment for expanding the heat-expandable layer. Consequently, the adhesive sheet can heighten the operating efficiency and working efficiency in the step of separating and recovering the cut pieces.

Abstract: A heat-peelable pressure-sensitive adhesive sheet, which comprises a substrate, a heat-expandable adhesive layer formed on at least one surface thereof, and a surfactant, wherein the surfactant is contained in the heat-expandable adhesive layer as an adhesive surface.

Abstract: A method of overheating and releasing a chip cut piece from a thermal release type pressure sensitive adhesive sheet is a method by which a chip cut piece stuck onto a thermal release type pressure sensitive adhesive sheet having a base material, and a thermally expandable microsphere-containing thermally expandable pressure sensitive adhesive layer provided on a surface of the base material is thermally released from the thermal release type pressure sensitive adhesive sheet and which is characterized by including the step of overheating while restraining the overheat and release type pressure sensitive adhesive sheet to thereby release the chip cut piece. A means for restraining the thermal release type pressure sensitive adhesive sheet may be an absorption means using suction or may be a bonding means using an adhesive agent.

Abstract: A heat-peelable pressure-sensitive adhesive sheet comprises: a base material; and a thermo-expandable pressure-sensitive adhesive layer containing thermo-expandable microspheres, the thermo-expandable pressure-sensitive adhesive layer having a surface to be adhered to an adherend, wherein the surface of the thermo-expandable pressure-sensitive adhesive layer before subjecting to heating has a centerline average roughness of greater than 0.4 &mgr;m, and has a convex portion resulting from the thermo-expandable microspheres.

Abstract: An energy-beam-curable thermal-releasable pressure-sensitive adhesive sheet having, on at least one side of a base material, an energy-beam-curable thermo-expandable viscoelastic layer containing thermo-expandable microspheres and a pressure-sensitive adhesive layer stacked in this order. The pressure-sensitive adhesive layer has a thickness of about 0.1 to 10 &mgr;m and can be formed from a pressure-sensitive adhesive. The energy-beam-curable thermo-expandable viscoelastic layer, on the other hand, can be formed from a tacky substance. The energy-beam-curable thermal-releasable pressure-sensitive adhesive sheet according to the invention has adhesion enough to withstand a carrying step of an adherend, causes neither winding up of the adhesive nor chipping upon cutting and facilitates peeling and collection of cut pieces after cutting. In addition, it exhibits low contamination on the adherend after peeling.

Abstract: An energy-beam-curable thermal-releasable pressure-sensitive adhesive sheet has, on at least one side of a base material, an energy-beam-curable viscoelastic layer and a thermo-expandable pressure-sensitive adhesive layer containing thermo-expandable microspheres stacked in this order. The energy-beam-curable viscoelastic layer is, for example, composed of a composition of an organic viscoelastic body and an energy-beam-curable compound or an energy-beam-curable resin. The energy-beam-curable viscoelastic layer has a thickness of about 5 to 300 &mgr;m or may be not greater than the maximum particle size of the thermo-expandable microspheres. The energy-beam-curable thermal-releasable pressure-sensitive adhesive layer according to the invention has adhesion enough to withstand a carrying step of an adherend, causes neither winding up of the adhesive nor chipping upon cutting and facilitates peeling and collection of cut pieces after cutting.

Abstract: A heat-peelable pressure-sensitive adhesive sheet which ensures an efficient contact area even in case where the area of an adherend to be adhered is decreased and thus makes it possible to avoid adhesion failures such as chip-scattering or chipping. The heat-peelable pressure-sensitive adhesive sheet comprises a substrate and a heat-expandable pressure-sensitive adhesive layer containing heat-expandable microspheres, formed on at least one side of the substrate, wherein the surface of the heat-expandable pressure-sensitive adhesive layer before heating has a center line average roughness of 0.4 &mgr;m or less.

Abstract: A heat-peelable adhesive sheet which comprises a substrate and, formed on at least one side thereof, a heat-expandable layer containing heat-expandable microspheres and an adhesive layer comprising an adhesive substance and in which the substrate has heat resistance and stretchability can be used to cut an adherend so as to form and secure a sufficient space between the resultant cut pieces and can withstand a heat treatment for expanding the heat-expandable layer. Consequently, the adhesive sheet can heighten the operating efficiency and working efficiency in the step of separating and recovering the cut pieces.

Abstract: The invention provides a method for thermally releasing an adherend, which comprises selectively releasing one or some of a plurality of substances adhered on a thermally releasable pressure-sensitive adhesive sheet having a thermally expandable layer containing therein thermo-expandable microspheres, by partly heating the pressure-sensitive adhesive sheet using a heating unit capable of partly heating the pressure-sensitive adhesive sheet. This thermally releasing method may further involve a step of cutting the substance adhered to the pressure-sensitive adhesive sheet. In this occasion, the heating unit has a heating portion of a shape in conformity with the shape of the adherend to be released, and may be provided on at lease one of the side to which the adherend is adhered and the opposite side thereto of the pressure-sensitive adhesive sheet.