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: 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: 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 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: 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 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: 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 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 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 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 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%.