Abstract: A curable composition may include 100 parts by weight of a polyisobutylene-based polymer (A) having 1.2 or more (meth)acryloyl groups per molecule, 15 to 900 parts by weight of a polyisobutylene-based polymer (B) having 0.5 to 1.0 (meth)acryloyl group per molecule, and 0.001 to 50 parts by weight, per 100 parts by weight of the total weight of the polymer (A) and the polymer (B), of a polymerization initiator (C). Each of the polymer (A) and the polymer (B) may have a number average molecular weight of 500 to 500,000 as measured by size exclusion chromatography based on polystyrene standards, and a molecular weight distribution (weight-average molecular weight Mw)/(number-average molecular weight Mn) of 1.0 to 2.0.

Abstract: A vinyl-based comb copolymer includes a polyisobutylene-based macromonomer unit and a vinyl-based monomer unit. A polyisobutylene-based macromonomer has at least 0.8 (meth)acryloyl groups represented by a specific formula at one end of a main chain per molecule, and is copolymerized with a vinyl-based monomer. A method for producing the vinyl-based comb copolymer includes copolymerizing the polyisobutylene-based macromonomer with the vinyl-based monomer. A viscosity index improver includes the comb copolymer. A lubricating oil composition includes the comb copolymer.

Abstract: A method for producing a (meth)acryloyl-terminated polyisobutylene polymer includes a step 1 of polymerizing an isobutylene monomer under the presence of a Lewis acid catalyst to prepare a halogen-terminated polyisobutylene polymer (B), a step 2 of reacting the halogen-terminated polyisobutylene polymer (B) with a compound (C) having a halogen group and a phenoxy group under the presence a Lewis acid catalyst to prepare a halogenated phenoxyalkyl-terminated polyisobutylene polymer (D), and a step 3 of reacting the halogenated phenoxyalkyl-terminated polyisobutylene polymer (D) with an acrylic acid compound (E) to prepare the (meth)acryloyl-terminated polyisobutylene polymer (A).

Abstract: A vinyl-based comb copolymer includes a polyisobutylene-based macromonomer unit and a vinyl-based monomer unit. A polyisobutylene-based macromonomer has at least 0.8 (meth)acryloyl groups represented by a specific formula at one end of a main chain per molecule, and is copolymerized with a vinyl-based monomer. A method for producing the vinyl-based comb copolymer includes copolymerizing the polyisobutylene-based macromonomer with the vinyl-based monomer. A viscosity index improver includes the comb copolymer. A lubricating oil composition includes the comb copolymer.

Abstract: A curable composition may include 100 parts by weight of a polyisobutylene-based polymer (A) having 1.2 or more (meth)acryloyl groups per molecule, 15 to 900 parts by weight of a polyisobutylene-based polymer (B) having 0.5 to 1.0 (meth)acryloyl group per molecule, and 0.001 to 50 parts by weight, per 100 parts by weight of the total weight of the polymer (A) and the polymer (B), of a polymerization initiator (C). Each of the polymer (A) and the polymer (B) may have a number average molecular weight of 500 to 500,000 as measured by size exclusion chromatography based on polystyrene standards, and a molecular weight distribution (weight-average molecular weight Mw)/(number-average molecular weight Mn) of 1.0 to 2.0.

Abstract: A method for producing a thermoplastic elastomer includes forming a first block by copolymerizing a C4-C7 isoolefin monomer and alkylstyrene in the presence of a polymerization initiator; and forming a second block by polymerizing aromatic vinyl monomers. The thermoplastic elastomer comprises the first block and the second block. An amount of unreacted portion of the alkylstyrene during the formation of the first block is maintained at a molar ratio of not more than 1/90 relative to a total amount of the isoolefin monomer. The alkylstyrene is represented by the general formula (1), and the polymerization initiator is represented by the general formula (2).

Abstract: A method for producing a (meth)acryloyl-terminated polyisobutylene polymer includes a step 1 of polymerizing an isobutylene monomer under the presence of a Lewis acid catalyst to prepare a halogen-terminated polyisobutylene polymer (B), a step 2 of reacting the halogen-terminated polyisobutylene polymer (B) with a compound (C) having a halogen group and a phenoxy group under the presence a Lewis acid catalyst to prepare a halogenated phenoxyalkyl-terminated polyisobutylene polymer (D), and a step 3 of reacting the halogenated phenoxyalkyl-terminated polyisobutylene polymer (D) with an acrylic acid compound (E) to prepare the (meth)acryloyl-terminated polyisobutylene polymer (A).

Abstract: A method for producing a halogenated isoolefin-based polymer includes irradiating an isoolefin-based polymer including alkylstyrene with light in presence of a halogen molecule. The isoolefin-based polymer has been polymerized by a living cationic polymerization using titanium chloride as a Lewis acid catalyst.

Abstract: A method for producing a thermoplastic elastomer includes forming a first block by copolymerizing a C4-C7 isoolefin monomer and alkylstyrene in the presence of a polymerization initiator; and forming a second block by polymerizing aromatic vinyl monomers. The thermoplastic elastomer comprises the first block and the second block. An amount of unreacted portion of the alkylstyrene during the formation of the first block is maintained at a molar ratio of not more than 1/90 relative to a total amount of the isoolefin monomer. The alkylstyrene is represented by the general formula (1), and the polymerization initiator is represented by the general formula (2).

Abstract: The purpose of the present invention is to provide a polymer having a low halogen atom content remaining in the polymer, a simple production method thereof, an active energy ray-curable composition that can be rapidly cured by an irradiation of a small amount of light, and a cured product thereof. These purpose can be achieved by an active energy ray-curable composition, including a polyisobutylene polymer (A) represented by the following general formula (1) (wherein R1 represents a monovalent or polyvalent aromatic hydrocarbon group, or a monovalent or a polyvalent aliphatic hydrocarbon group; A represents a polyisobutylene polymer; R2 represents a divalent saturated hydrocarbon group having 2-6 carbon atoms, which contains no hetero atoms; R3 and R4 each represent hydrogen, a monovalent hydrocarbon group having 1-20 carbon atoms, or an alkoxy group having 1-20 carbon atoms; R5 represents hydrogen or a methyl group; and n denotes a natural number), and an active energy ray polymerization initiator (B).

Abstract: The purpose of the present invention is to provide a polymer having a low halogen atom content remaining in the polymer, a simple production method thereof, an active energy ray-curable composition that can be rapidly cured by an irradiation of a small amount of light, and a cured product thereof. These purpose can be achieved by an active energy ray-curable composition, including a polyisobutylene polymer (A) represented by the following general formula (1) (wherein R1 represents a monovalent or polyvalent aromatic hydrocarbon group, or a monovalent or a polyvalent aliphatic hydrocarbon group; A represents a polyisobutylene polymer; R2 represents a divalent saturated hydrocarbon group having 2-6 carbon atoms, which contains no hetero atoms; R3 and R4 each represent hydrogen, a monovalent hydrocarbon group having 1-20 carbon atoms, or an alkoxy group having 1-20 carbon atoms; R5 represents hydrogen or a methyl group; and n denotes a natural number), and an active energy ray polymerization initiator (B).

Abstract: The purpose of the present invention is to provide a polymer having a low halogen atom content remaining in the polymer, a simple production method thereof, an active energy ray-curable composition that can be rapidly cured by an irradiation of a small amount of light, and a cured product thereof. These purpose can be achieved by an active energy ray-curable composition, including a polyisobutylene polymer (A) represented by the following general formula (1) (wherein R1 represents a monovalent or polyvalent aromatic hydrocarbon group, or a monovalent or a polyvalent aliphatic hydrocarbon group; A represents a polyisobutylene polymer; R2 represents a divalent saturated hydrocarbon group having 2-6 carbon atoms, which contains no hetero atoms; R3 and R4 each represent hydrogen, a monovalent hydrocarbon group having 1-20 carbon atoms, or an alkoxy group having 1-20 carbon atoms; R5 represents hydrogen or a methyl group; and n denotes a natural number), and an active energy ray polymerization initiator (B).

Abstract: The purpose of the present invention is to provide a polymer having a low halogen atom content remaining in the polymer, a simple production method thereof, an active energy ray-curable composition that can be rapidly cured by an irradiation of a small amount of light, and a cured product thereof. These purpose can be achieved by an active energy ray-curable composition, including a polyisobutylene polymer (A) represented by the following general formula (1) (wherein R1 represents a monovalent or polyvalent aromatic hydrocarbon group, or a monovalent or a polyvalent aliphatic hydrocarbon group; A represents a polyisobutylene polymer; R2 represents a divalent saturated hydrocarbon group having 2-6 carbon atoms, which contains no hetero atoms; R3 and R4 each represent hydrogen, a monovalent hydrocarbon group having 1-20 carbon atoms, or an alkoxy group having 1-20 carbon atoms; R5 represents hydrogen or a methyl group; and n denotes a natural number), and an active energy ray polymerization initiator (B).

Abstract: The present invention relates to a resin composition containing (A) 100 parts by weight of an isobutylene-based block copolymer having an unsaturated bond and comprising (a) a polymer block mainly comprised of isobutylene and (b) a polymer block mainly comprised of an aromatic vinyl-based compound, and (B) 0.1-50 parts by weight of a polythiol compound having two or more thiol groups in one molecule, which aims to provide an isobutylene-based block copolymer composition superior in air barrier property, flexibility, toughness and adhesiveness to rubber, and further, an inner liner as an inner liner layer of a pneumatic tire, which does not require a vulcanization step and superior in the balance between air barrier property, flexibility and toughness, and adhesiveness to carcass.

Abstract: In an information recording medium, a Bi—Ge—Te material is adopted as a phase-change recording layer material. A C—Ta—O material is used for at least any one of first and second boundary layers which are in contact with a recording layer.

Abstract: An phase-change optical disk comprises a substrate, a first protective layer, a first thermostable layer, a recording layer, a second thermostable layer, a second protective layer, an absorptance control layer, and a heat-diffusing layer which are provided in this order from a side on which a laser beam comes thereinto, wherein a recording layer material has composition ratios which are within a range surrounded by composition points of B3 (Bi3, Ge46, Te51), C3 (Bi4, Ge46, Te50), D3 (Bi5, Ge46, Te49), D5 (Bi10, Ge42, Te48), C5 (Bi10, Ge41, Te49), and B5 (Bi7, Ge41, Te52) on a triangular composition diagram. Recrystallization is not caused even when information is recorded on an inner circumferential portion, a reproduced signal is scarcely deteriorated even when rewriting is performed multiple times, and any erasing residue of amorphous matters scarcely appears at an outer circumferential portion.

Abstract: A phase-change optical recording medium capable of performing recording and reproduction at a high speed is provided, in which a reproduced signal output is not only sufficiently large but the phase-change optical recording medium also has excellent repeated rewriting performance. An interface layer 3, which is composed of a Ge—Si—N-based material, is formed on at least a surface of one side of a recording layer 4 of the phase-change optical recording medium 10. Accordingly, even when a phase-change material having a high melting point, for example, a Bi—Ge—Te-based phase-change material is used for the recording layer 4, it is possible to provide the phase-change optical recording medium in which the reproduced signal output is sufficiently large and the repeated rewriting performance is excellent.

Abstract: In an information recording medium, a Bi—Ge—Te material is adopted as a phase-change recording layer material. A C—Ta—O material is used for at least any one of first and second boundary layers which are in contact with a recording layer.

Abstract: A phase-change optical recording medium capable of performing recording and reproduction at a high speed is provided, in which a reproduced signal output is not only sufficiently large but the phase-change optical recording medium also has excellent repeated rewriting performance. An interface layer 3, which is composed of a Ge—Si—N-based material, is formed on at least a surface of one side of a recording layer 4 of the phase-change optical recording medium 10. Accordingly, even when a phase-change material having a high melting point, for example, a Bi—Ge—Te-based phase-change material is used for the recording layer 4, it is possible to provide the phase-change optical recording medium in which the reproduced signal output is sufficiently large and the repeated rewriting performance is excellent.

Abstract: In an optical disk for high density recording, for preventing the deformation of recording tracks caused by stress which may develop between the substrate and the recording stacked film formed thereon, a stress-compensation layer having a metal element such as Ti or Cr as a main component is provided. The stress-compensation layer undergoes contraction (tensile stress) to compensate for compression stress which develops in the stacked film during cooling after the thermal expansion of the substrate surface that occurs at the end of film formation. The stress-compensation layer has a pillar-like structure which, starting from the lower face, reaches the upper face of the film.