Abstract: Provided are: a polyester-based pressure-sensitive adhesive composition which can be produced even from plant-derived raw materials with no need of using a costly silicone-based pressure-sensitive adhesive or the like and which is usable for producing a pressure-sensitive adhesive sheet excellent in wettability to an adherend, light peelability (removability), anti-staining property (little adhesive residues), and workability, and to provide a pressure-sensitive adhesive sheet using the composition. A polyester-based pressure-sensitive adhesive composition comprising a polyester obtained by condensation polymerization of at least a carboxylic acid component and a diol component, and a crosslinking agent, wherein the carboxylic acid component contains a dicarboxylic acid having a side chain in an amount of 50 to 90% by weight and a tricarboxylic acid having a side chain in an amount of 10 to 50% by weight, and wherein the polyester has a weight average molecular weight of 5000 to 150000.

Abstract: Provided are: a polyester-based pressure-sensitive adhesive composition which can be produced even from plant-derived raw materials with no need of using a costly silicone-based pressure-sensitive adhesive or the like and which is usable for producing a pressure-sensitive adhesive sheet excellent in wettability to an adherend, light peelability, removability, anti-staining property (little adhesive residues), and workability, and to provide a pressure-sensitive adhesive sheet using the composition. A polyester-based pressure-sensitive adhesive composition comprising a polyester obtained by condensation polymerization of at least a dicarboxylic acid having a side chain and an aliphatic diol having 3 to 10 carbon atoms and a crosslinking agent, wherein the polyester has a weight average molecular weight of 5000 to 60000.

Abstract: The present invention provides a separator including a separator substrate composed of a polylactic acid film or sheet having tear strength so as not to break or tear during production or processing of the separator. The separator is a separator including a separator substrate and a removable pressure-sensitive adhesive layer on at least one surface of the separator substrate, wherein the separator substrate is composed of a polylactic acid film or sheet comprising polylactic acid (A) wherein the tear strength of the film or sheet is not less than 100 N/mm when the film or sheet is torn at least in a flow direction (MD), a rate of dimensional change due to heating is not more than ±3% in the flow direction (MD) and a transverse direction (TD), and a rate of dimensional change due to loaded heating is not more than ±3% in the flow direction (MD).

Abstract: The present invention provides a protection film including a substrate composed of a polylactic acid film or sheet having tear strength so as not to break or tear during production or processing of the protection film. The protection film according to the present invention is a protection film including a substrate and a removable pressure-sensitive adhesive layer on at least one surface of the substrate, wherein the substrate is composed of a polylactic acid film or sheet comprising polylactic acid (A) wherein the tear strength is not less than 100 N/mm when the film or sheet is torn at least in a flow direction (MD), a rate of dimensional change due to heating is not more than ±3% in the flow direction (MD) and in a transverse direction (TD), and a rate of dimensional change due to loaded heating is not more than ±3% in the flow direction (MD).

Abstract: A radiation-cure removable type pressure-sensitive adhesive sheet includes: a pressure-sensitive adhesive layer made from a polyester-based pressure-sensitive adhesive composition containing a polyester including at least a lactic acid unit, a dibasic acid unit, and a glycol unit, a radiation-cure resin, a radiation reaction initiator, and a crosslinking agent. The dibasic acid unit includes a dimer acid, the polyester has a glass transition temperature of ?70 to ?20° C., a weight average molecular weight of 20,000 to 200,000, and a hydroxyl value of 1 to 60 mgKOH/g, the composition contains 30 to 70 parts by weight of the radiation-cure resin based on 100 parts by weight of the polyester and contains 3 to 10% by weight of the radiation reaction initiator based on the amount of the radiation-cure resin.

Abstract: Efficiently produced is a release liner including a plant-derived film as a substrate and having a good appearance, releasability, and adhesion. A method according to the present invention produces a release liner having a plant-derived film substrate and, on at least one side thereof, a release coat layer derived from a thermosetting silicone resin. The method includes the steps as follows: Step A of applying a thermosetting silicone release agent to at least one side of a plant-derived film substrate, the release agent containing 100 parts by weight of a thermosetting silicone resin and 0.05 to 0.55 part by weight of a curing catalyst; Step B of drying at 40° C. to 90° C. for 10 to 60 seconds after Step A; Step C of applying an ultraviolet ray at 50 to 300 mJ/cm2 after Step B; and Step D of aging at 30° C. to 70° C. for 12 to 240 hours after Step C.

Abstract: Provided is a release liner which includes a substrate derived from a poly(lactic acid), a biomass-derived plastic; and a releasable cured layer derived from a release agent. The releasable cured layer, even when employing an ultraviolet-curable silicone release agent as the release agent, is satisfactorily curable and exhibits good adhesion to the substrate. The release liner according to the present invention includes a poly(lactic acid) substrate; a release-treated layer present over at least one side of the substrate; and an undercoat layer lying between them. The undercoat layer is present in a mass of coating of typically from 0.1 to 5 g/m2 in solids content. The poly(lactic acid) substrate may contain a modifier. The release agent forming the release-treated layer may be an ultraviolet-curable silicone release agent. The ultraviolet-curable silicone release agent is preferably a cationically polymerizable ultraviolet-curable silicone release agent.

Abstract: Disclosed is a polylactic acid-based film or sheet as a resin film or sheet including a polylactic acid (A). The film or sheet has a melt endotherm ?Hc? of 10 J/g or more, where ?Hc? is of a region crystallized upon film formation and specified by following Expression (1): ?Hc?=?Hm??Hc??(1) wherein ?Hc represents an exotherm (J/g) associated with crystallization of the film or sheet in a temperature rise process after film formation; and ?Hm represents an endotherm (J/g) associated with subsequent melting of the film or sheet, each determined by DSC. The film or sheet has a tear strength of 2.5 N/mm or more both in a machine direction (MD) and a transverse direction (TD). The polylactic acid-based resin film or sheet is resistant to melting and deformation even at an elevated temperature higher than 100° C. and is resistant to breaking and tearing during winding into a roll.

Abstract: The present invention has an object to provide a solvent-free polyester-based adhesive composition having good coatability and capable of forming an adhesive that shows good adhesion performance. The present invention provides a polyester-based adhesive composition containing a polyester having Mw of from 1×103 to 20×103 as a main component and a trifunctional or more polyepoxy compound as a crosslinking agent, and containing substantially no organic solvent. The molar number, mOH, of hydroxyl group contained in a polyalcohol component constituting the polyester is from 0.5 to 0.98 times of the molar number, mCOOH, of carboxyl group contained in a polycarboxylic acid component. The composition has a viscosity at 23° C. of at most 80 Pa·s.

Abstract: The present invention provides a pressure-sensitive adhesive sheet containing a pressure-sensitive adhesive layer that contains a polyester resin as a main component, in which the pressure-sensitive adhesive layer having a laminate structure that contains at least one layer LA where a polyester resin EA having Mw of from 4×104 to 12×104 is crosslinked and at least one layer LB where a polyester resin EB having Mw of from 0.2×104 to 1×104 is crosslinked, and at least one surface of the pressure-sensitive adhesive layer is constituted by the layer LA.

Abstract: The present invention has an object to provide a pressure-sensitive adhesive composition that provides a polyester-based pressure-sensitive adhesive capable of realizing both of heat resistance and adhesive force at high levels and a pressure-sensitive adhesive sheet having a polyester-based pressure-sensitive adhesive. The pressure-sensitive adhesive composition provided by the present invention contains a polyester resin A with Mw of 4×104 to 12×104 and a polyester resin B with Mw of 0.3×104 to 1×104. The ratio (mA:mB) of the number of moles mA and mB of the polyester resins A and B is 1:0.35 to 1:1.4. The pressure-sensitive adhesive composition further contains a crosslinking agent, and has a gel fraction after crosslinking of 30 to 65%.

Abstract: A double sided pressure-sensitive adhesive sheet includes a pressure-sensitive adhesive layer made from a polyester-based pressure-sensitive adhesive composition containing a polyester including at least a lactic acid unit, a dibasic acid unit, and a glycol unit, a tackifier resin, and a crosslinking agent. The dibasic acid unit includes a dimer acid, the polyester has a weight average molecular weight of 20,000 to 200,000 and a glass transition temperature of ?70 to ?20° C. as measured using a differential scanning calorimeter at a temperature rise rate of 20° C./minute, the polyester has a hydroxyl value of 1 to 60 mgKOH/g, the adhesive composition contains 10 to 70 parts by weight of the tackifier resin based on 100 parts by weight of the polyester, and the pressure-sensitive adhesive layer has a gel fraction of 50 to 90% by weight.

Abstract: A thermally removable pressure-sensitive adhesive sheet includes a substrate and a pressure-sensitive adhesive layer that is provided on at least one side of the substrate and made from a polyester-based pressure-sensitive adhesive composition containing a polyester including at least a lactic acid unit, a dibasic acid unit, and a glycol unit, a foaming agent, and a crosslinking agent. The dibasic acid unit includes a dimer acid, the polyester has a weight average molecular weight of 20,000 to 200,000 and a glass transition temperature of ?70 to ?20° C. as measured using a differential scanning calorimeter at a temperature rise rate of 20° C./minute, and the polyester has a hydroxyl value of 1 to 60 mgKOH/g.

Abstract: A masking pressure-sensitive adhesive tape includes a substrate and a pressure-sensitive adhesive layer that is provided on at least one side of the substrate and made from a polyester-based pressure-sensitive adhesive composition containing a polyester including at least a lactic acid unit, a dibasic acid unit, and a glycol unit, and a crosslinking agent. The dibasic acid unit includes a dimer acid, the polyester has a weight average molecular weight of 20,000 to 200,000 and a glass transition temperature of ?70 to ?20° C. as measured using a differential scanning calorimeter at a temperature rise rate of 20° C./minute, the polyester has a hydroxyl value of 1 to 60 mgKOH/g, and the pressure-sensitive adhesive layer has a gel fraction of 40 to 90% by weight.

Abstract: A radiation-cure removable type pressure-sensitive adhesive sheet includes: a pressure-sensitive adhesive layer made from a polyester-based pressure-sensitive adhesive composition containing a polyester including at least a lactic acid unit, a dibasic acid unit, and a glycol unit, a radiation-cure resin, a radiation reaction initiator, and a crosslinking agent. The dibasic acid unit includes a dimer acid, the polyester has a glass transition temperature of ?70 to ?20° C., a weight average molecular weight of 20,000 to 200,000, and a hydroxyl value of 1 to 60 mgKOH/g, the composition contains 30 to 70 parts by weight of the radiation-cure resin based on 100 parts by weight of the polyester and contains 3 to 10% by weight of the radiation reaction initiator based on the amount of the radiation-cure resin.

Abstract: A surface-protecting pressure-sensitive adhesive sheet includes: a substrate; and a pressure-sensitive adhesive layer that is provided on at least one side of the substrate and made from a polyester-based pressure-sensitive adhesive composition containing a crosslinking agent and a polyester including at least a lactic acid unit, a dibasic acid unit, and a glycol unit. The dibasic acid unit includes a dimer acid, the polyester has a weight average molecular weight of 20,000 to 200,000 and a glass transition temperature of ?70 to ?20° C. as measured using a differential scanning calorimeter at a temperature rise rate of 20° C./minute, the polyester-based pressure-sensitive adhesive composition has a hydroxyl value of 20 to 60 mgKOH/g, and the pressure-sensitive adhesive layer has a gel fraction of 85 to 99% by weight.

Abstract: The present invention provides a polyester, a polyester composition and a pressure-sensitive adhesive composition capable of obtaining a pressure-sensitive adhesive which is global-environmentally friendly and is excellent in pressure-sensitive adhesion properties, using a plant-derived raw material; and a pressure-sensitive adhesive layer and a pressure-sensitive adhesive sheet which can be obtained by using the same. A polyester of the present invention is a polyester comprising at least a lactic acid unit, a dibasic acid unit and a glycol unit, wherein the dibasic acid unit contains dimer acid, and the polyester has a glass transition temperature as measured at a temperature rising rate of 20° C./minute using a differential scanning calorimeter, of ?70 to ?20° C., a weight average molecular weight of 20,000 to 300,000 and a hydroxyl value of 1 to 100 mgKOH/g.

Abstract: The present invention relates to a polyester-based masking sheet including: a substrate; and a pressure-sensitive adhesive layer provided on the substrate, which contains a polyester resin obtained by condensation-polymerizing a plant-derived dicarboxylic acid with a plant-derived diol in a ratio such that a content of hydroxyl group in the diol is from 1.01 to 1.40 mol per 1.00 mol of carboxyl group contained in the dicarboxylic acid, and a tackifier in an amount of from 10 to 50 parts by weight per 100 parts by weight of the polyester resin, and is crosslinked by a crosslinking agent to have a gel fraction of 40 to 90%.

Abstract: The purpose of the invention is to obtain a water-dispersible adhesive composition capable of coating in an aqueous system and, particularly, an adhesive composition capable of preparing a removable water-dispersible acrylic adhesive sheet with less contamination to the surface of an adherend and having high resistance to water intrusion during wafer polishing, which is particularly suitable as an adhesive sheet for use in semiconductor wafer processing. The invention relates to a water-dispersible acrylic adhesive composition, which includes an acryl emulsion polymer obtainable by an emulsion polymerization of a monomer mixture containing an alkyl (meth)acrylate ester; and a crosslinker which is a carbodiimide crosslinker or a hydrazine crosslinker, in which the acryl emulsion polymer has a glass transition temperature of from ?80 to ?20° C.

Abstract: The purpose of the invention is to obtain a water-dispersible adhesive composition capable of coating in an aqueous system and, particularly, an adhesive composition capable of preparing a removable water-dispersible acrylic adhesive sheet with less contamination to the surface of an adherend and having high resistance to water intrusion during wafer polishing, which is particularly suitable as an adhesive sheet for use in semiconductor wafer processing. The invention relates to a water-dispersible acrylic adhesive composition, which includes an acryl emulsion polymer obtainable by an emulsion polymerization of a monomer mixture containing an alkyl (meth)acrylate ester; and a crosslinker which is a carbodiimide crosslinker or a hydrazine crosslinker, in which the acryl emulsion polymer has a glass transition temperature of from ?80 to ?20° C.