Abstract: The present invention makes a water-dispersed PSA composition capable of forming a PSA that exhibits good adhesiveness to a non-polar adherend such as polyethylene and polypropylene at a low temperature. The water-dispersed PSA composition comprises a (meth)acrylic polymer obtained by polymerizing a monomer composition comprising as a primary component an alkyl(meth)acrylate having an alkyl group with 1 to 18 carbon atoms, and a latex containing a rubber component that is immiscible with the (meth)acrylic polymer, the (meth)acrylic polymer and the latex being mixed at a weight ratio ((meth)acrylic polymer/rubber latex) within a range of 95/5 to 25/75 based on solid contents; wherein a storage modulus in a range of ?15° C. to 25° C. is 1 MPa or smaller, the storage modulus being determined by a dynamic viscoelastic measurement in which shear strain is applied at a frequency of 1 Hz, the measurement being taken with respect to the water-dispersed PSA composition dried at 100° C. for 3 minutes.

Abstract: Provided is an active energy ray-curable pressure-sensitive adhesive for re-release, which has a small influence on an environment or a human body, can be easily handled, can largely change its pressure-sensitive adhesiveness before and after irradiation with an active energy ray, and can express high pressure-sensitive adhesiveness before the irradiation with the active energy ray and express high releasability after the irradiation with the active energy ray. The active energy ray-curable pressure-sensitive adhesive for re-release includes an active energy ray-curable polymer (P), in which the polymer (P) includes one of a polymer obtained by causing a carboxyl group-containing polymer (P3) and an oxazoline group-containing monomer (m3) to react with each other, and a polymer obtained by causing an oxazoline group-containing polymer (P4) and a carboxyl group-containing monomer (m2) to react with each other.

Abstract: Provided is a water-dispersed pressure-sensitive adhesive composition capable of forming a pressure-sensitive adhesive that exhibits good adhesiveness to a non-polar adherend and maintains its properties at a low temperature. The water-dispersed pressure-sensitive adhesive composition according to the present invention comprises a (meth)acrylic polymer obtained by polymerizing a monomer composition containing as a primary component an alkyl (meth)acrylate having an alkyl group with 1 to 18 carbon atoms, a latex containing a rubber component that is immiscible with the (meth)acrylic polymer and has a loss tangent peak temperature of ?5° C. or below when determined by a dynamic viscoelastic measurement in which shear strain is applied at a frequency of 1 Hz, and a tackifier that is miscible with the rubber component, but immiscible with the (meth)acrylic polymer.

Abstract: Provided is a water-dispersed pressure-sensitive adhesive composition capable of forming a pressure-sensitive adhesive that exhibits good adhesiveness to a non-polar adherend and maintains its properties at a low temperature. The water-dispersed pressure-sensitive adhesive composition according to the present invention comprises a (meth)acrylic polymer obtained by polymerizing a monomer composition containing as a primary component an alkyl (meth)acrylate having an alkyl group with 1 to 18 carbon atoms, a latex containing a rubber component that is immiscible with the (meth)acrylic polymer and has a loss tangent peak temperature of ?5° C. or below when determined by a dynamic viscoelastic measurement in which shear strain is applied at a frequency of 1 Hz, and a tackifier that is miscible with the rubber component, but immiscible with the (meth)acrylic polymer.

Abstract: Provided is a water-dispersed pressure-sensitive adhesive composition useful for purposes of producing a pressure-sensitive adhesive sheet having high rough surface adhesiveness also in a good balance with the other properties, and so on. The pressure-sensitive adhesive composition comprises an acrylic polymer pAX, and an acrylic polymer pAY having a Mw of 1×103 to 50×103, at a mass ratio of 100:6-35. In pAX, 60 to 99.5% by mass of a C2-18 alkyl (meth)acrylate M1X and 0.5 to 12% by mass of a functional-group-containing monomer M2X are copolymerized while in pAY, 60 to 95% by mass of a C2-18 alkyl (meth)acrylate M1Y and 5 to 40% by mass of a functional-group-containing monomer M2Y are copolymerized. When SPX and SPY are solubility parameters calculated from M1X and M1Y, the solubility difference ?SP defined as |SPY?SPX| is 0.25 (cal/cm3)1/2 or greater.

Abstract: Provided is a water-dispersed pressure-sensitive adhesive composition useful for purposes of producing a pressure-sensitive adhesive sheet having high rough surface adhesiveness also in a good balance with the other properties, and so on. The pressure-sensitive adhesive composition comprises an acrylic polymer pAX, and an acrylic polymer pAY having a Mw of 1×103 to 50×103 and a glass transition temperature of ?15° C. or below, at a mass ratio of 100:6-35. pAX comprises a C1-18 alkyl (meth)acrylate M1X as a primary component. pAY has a copolymer composition containing, as its constituting monomers, a C1-18 alkyl(meth)acrylate M1Y and a functional-group-containing monomer M2Y. The number of the functional groups derived from the monomer M2Y contained per 100 g of pAY is greater than 0 12 mol up to 0.50 mol.

Abstract: An object of the present invention is to provide an acrylic pressure-sensitive adhesive composition capable of forming a pressure-sensitive adhesive, which has excellent adhesiveness to an adherend having surface polarity of every kind and can exhibit excellent repulsion resistance even in a moist heat environment, and a pressure-sensitive adhesive sheet using the composition. The pressure-sensitive adhesive composition provided by the present invention contains a copolymerization reaction product of a monomer mixture. The monomer mixture contains an alkyl (meth)acrylate having an alkyl group with a carbon number of from 4 to 20 and N-vinylcaprolactam. The total sum amount thereof is 95% by mass or more of the whole of monomer components. An amount of N-vinylcaprolactam is from 12 to 40% by mass.

Abstract: An object of the present invention is to provide a double-coated pressure-sensitive adhesive sheet for optical use satisfying both high corrosion resistance and adhesion reliability. The double-coated pressure-sensitive adhesive sheet for optical use according to the present invention has a pressure-sensitive adhesive layer having a resistance ratio determined by a specific corrosion resistance test of from 90 to 120 and an average air bubble diameter of air bubbles determined by a specific bubbling delamination resistance test of 1.0 mm or less. Further, the double-coated pressure-sensitive adhesive sheet for optical use according to the present invention preferably has a total light transmittance of 90% or more and a haze of 1.5% or less.

Abstract: Provided is an active energy ray-curable pressure-sensitive adhesive for re-release, which has a small influence on an environment or a human body, can be easily handled, can largely change its pressure-sensitive adhesiveness before and after irradiation with an active energy ray, and can express high pressure-sensitive adhesiveness before the irradiation with the active energy ray and express high releasability after the irradiation with the active energy ray. The active energy ray-curable pressure-sensitive adhesive for re-release includes an active energy ray-curable polymer (P), in which the polymer (P) includes one of a polymer obtained by causing a carboxyl group-containing polymer (P3) and an oxazoline group-containing monomer (m3) to react with each other, and a polymer obtained by causing an oxazoline group-containing polymer (P4) and a carboxyl group-containing monomer (m2) to react with each other.

Abstract: The present invention relates to an acrylic pressure-sensitive adhesive composition comprising a copolymerization reaction product of a monomer mixture satisfying the following both conditions: (a) the monomer mixture includes a monomer m1 in an amount of 50% by mass or more based on whole monomer components constituting the monomer mixture, wherein the monomer m1 is an alkyl (meth)acrylate represented by the following formula (I): CH2?C(R1)COOR2??(I) wherein R1 represents a hydrogen atom or a methyl group, and R2 represents an alkyl group having from 1 to 20 carbon atoms; and (b) the monomer mixture includes a monomer m2 in an amount of 12% by mass or more based on the whole monomer components constituting the monomer mixture, or a monomer m2 and a monomer m3 in an amount in total of 12% by mass or more based on the whole monomer components constituting the monomer mixture, wherein the monomer m2 is an imidazole group-containing unsaturated monomer, and the monomer m3 is an amide group-containing unsatura