A preparation method of a hydrogel of a mercapto-modified macromolecular compound includes the steps of combining the mercapto-modified macromolecular compound with an acrylated macromolecular compound and/or an acrylated micromolecular crosslinker. The mercapto-modified macromolecular compound can be crosslinked with the acrylated macromolecular compound and/or the acrylated micromolecular crosslinker under physiological conditions to form the hydrogel. Due to the rapid mercapto-vinyl crosslinking reaction, the formed hydrogel system can be quickly gelled in situ after being injected into the body. The hydrogel is thus suitable for use in the fields of biomedicine, medical cosmetic plastic surgery and cosmetics.

A binder for a secondary battery includes a copolymer having a first repeating unit, a second repeating unit, and a third repeating unit. A ratio of a number of the first repeating unit (A) and a sum of a number of the second repeating unit and a number of the third repeating unit (B) is 90:10 to 52:48. A ratio of the number of the second repeating unit and the number of the third repeating unit is 67:33 to 1:99. A weight average molecular weight of the copolymer is 225,000 to 2,000,000.

A binder for a secondary battery includes a copolymer having a first repeating unit, a second repeating unit, and a third repeating unit. A ratio of a number of the first repeating unit (A) and a sum of a number of the second repeating unit and a number of the third repeating unit (B) is 90:10 to 52:48. A ratio of the number of the second repeating unit and the number of the third repeating unit is 67:33 to 1:99. A weight average molecular weight of the copolymer is 225,000 to 2,000,000.

A vinyl alcohol copolymer, wherein the vinyl alcohol copolymer includes a vinyl alcohol unit and a constituent unit derived from an unsaturated monomer (A), the unsaturated monomer (A) is at least one selected from the group consisting of an unsaturated carboxylic acid, a salt thereof, an anhydride thereof, and an alkyl ester thereof, a content of the constituent unit derived from the unsaturated monomer (A) with respect to total constituent units of the vinyl alcohol copolymer is 1.00 mol % or more and 5.00 mol % or less, and 70 mol % or more of the constituent unit derived from the unsaturated monomer (A) forms a lactone ring structure.

A vinyl alcohol copolymer, wherein the vinyl alcohol copolymer includes a vinyl alcohol unit and a constituent unit derived from an unsaturated monomer (A), the unsaturated monomer (A) is at least one selected from the group consisting of an unsaturated carboxylic acid, a salt thereof, an anhydride thereof, and an alkyl ester thereof, a content of the constituent unit derived from the unsaturated monomer (A) with respect to total constituent units of the vinyl alcohol copolymer is 1.00 mol % or more and 5.00 mol % or less, and 70 mol % or more of the constituent unit derived from the unsaturated monomer (A) forms a lactone ring structure.

A resin composition comprises: a modified vinyl alcohol-based polymer (A) containing from 1 to 20 mol % of a structural unit represented by a formula (1) below; and a layered inorganic compound (B). Such a resin composition is excellent in water vapor barrier properties, recyclability, and productivity during coating.

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A resin composition comprises: a modified vinyl alcohol-based polymer (A) containing from 1 to 20 mol % of a structural unit represented by a formula (1) below; and a layered inorganic compound (B). Such a resin composition is excellent in water vapor barrier properties, recyclability, and productivity during coating.

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A PVA excellent in resistance to melting at high temperature is provided. The polyvinyl alcohol-based polymer is a saponificated product of a homopolymer composed of a vinyl ester monomer, a copolymer of a vinyl ester monomer and a monofunctional monomer other than the vinyl ester, a copolymer of a vinyl ester monomer and a polyfunctional monomer, or a copolymer of a vinyl ester monomer, a monofunctional monomer other than vinyl ester, and a polyfunctional monomer has a particle size of 50 nm or more at a cumulative frequency of 50% in particle size distribution by dynamic light scattering measurement of a 0.4 mass % aqueous solution of the polyvinyl alcohol-based polymer at 25° C.

A PVA excellent in resistance to melting at high temperature is provided. The polyvinyl alcohol-based polymer is a saponificated product of a homopolymer composed of a vinyl ester monomer, a copolymer of a vinyl ester monomer and a monofunctional monomer other than the vinyl ester, a copolymer of a vinyl ester monomer and a polyfunctional monomer, or a copolymer of a vinyl ester monomer, a monofunctional monomer other than vinyl ester, and a polyfunctional monomer has a particle size of 50 nm or more at a cumulative frequency of 50% in particle size distribution by dynamic light scattering measurement of a 0.4 mass % aqueous solution of the polyvinyl alcohol-based polymer at 25° C.

Provided herein is a solvent-based pressure sensitive adhesive comprising a polymer comprising a vinyl acetate monomer, an acrylic ester monomer, and a monomer having hydroxyl or amine functionality. The adhesive also comprise a crosslinker. The coated and dried adhesive has outgassing of less than 2000 ng/cm.sup.2, even when applied to an electronic device that is operated at elevated temperature.