Copolymers of a polyvinyl butyral backbone with polylactic acid grafts and their compounds are disclosed, which can be used to produce clear, flexible and ductile bio-based films. The copolymers are amorphous and have been shown to maintain clarity, flexibility, and ductility after continuous exposure to thermal aging at 80 C. for one week.

Copolymers of a polyvinyl butyral backbone with polylactic acid grafts and their compounds are disclosed, which can be used to produce clear, flexible and ductile bio-based films. The copolymers are amorphous and have been shown to maintain clarity, flexibility, and ductility after continuous exposure to thermal aging at 80 C. for one week.

There is provided a vinyl alcohol-based polymer having an olefin in side chain, comprising 0.001 to 10 mol % of a structural unit represented by Formula (1) based on the total amount of structural units, wherein the total carbon number of X, R.sup.1, R.sup.2, R.sup.3 and R.sup.4 is 2 or more. The vinyl alcohol-based polymer having an olefin in side chain has excellent storage stability, good solubility in water or an organic solvent even after thermal treatment, and excellent reactivity to high energy beam. In Formula (1), X represents an optionally substituted divalent aliphatic hydrocarbon group, an optionally substituted divalent alicyclic hydrocarbon group, an optionally substituted divalent aromatic hydrocarbon group, or a group consisting of two or more of these groups which are linked via at least one bond selected from the group consisting of an amide bond, an ester bond, an ether bond, and a sulfide bond; R.sup.1, R.sup.2, R.sup.3 and R.sup.4, independently of each other, represents a hydrogen atom, an optionally substituted aliphatic hydrocarbon group, an optionally substituted alicyclic hydrocarbon group, or an optionally substituted aromatic hydrocarbon group; and X, R.sup.1, R.sup.2, R.sup.3 and R.sup.4 can be arbitrarily combined to form a ring structure).

There is provided a vinyl alcohol-based polymer having an olefin in side chain, comprising 0.001 to 10 mol % of a structural unit represented by Formula (1) based on the total amount of structural units, wherein the total carbon number of X, R.sup.1, R.sup.2, R.sup.3 and R.sup.4 is 2 or more. The vinyl alcohol-based polymer having an olefin in side chain has excellent storage stability, good solubility in water or an organic solvent even after thermal treatment, and excellent reactivity to high energy beam. In Formula (1), X represents an optionally substituted divalent aliphatic hydrocarbon group, an optionally substituted divalent alicyclic hydrocarbon group, an optionally substituted divalent aromatic hydrocarbon group, or a group consisting of two or more of these groups which are linked via at least one bond selected from the group consisting of an amide bond, an ester bond, an ether bond, and a sulfide bond; R.sup.1, R.sup.2, R.sup.3 and R.sup.4, independently of each other, represents a hydrogen atom, an optionally substituted aliphatic hydrocarbon group, an optionally substituted alicyclic hydrocarbon group, or an optionally substituted aromatic hydrocarbon group; and X, R.sup.1, R.sup.2, R.sup.3 and R.sup.4 can be arbitrarily combined to form a ring structure).

The present invention provides: a water-soluble film that is superior in cold water solubility and in practical properties such as strength and stiffness and that can resist deterioration in various properties such as chemical resistance over time; and a modified polyvinyl alcohol used for the water-soluble film. The present invention relates to a modified polyvinyl alcohol containing 0.05 to 10 mol % of a monomer unit having two carboxyl groups. In .sup.1H-NMR spectroscopy of the modified polyvinyl alcohol, an integral (X) from 6.8 to 7.2 ppm and an integral (Y) from 5.3 to 5.5 ppm satisfy the following expression:
0.60X/(X+Y)<1.0.

The present invention provides: a water-soluble film that is superior in cold water solubility and in practical properties such as strength and stiffness and that can resist deterioration in various properties such as chemical resistance over time; and a modified polyvinyl alcohol used for the water-soluble film. The present invention relates to a modified polyvinyl alcohol containing 0.05 to 10 mol % of a monomer unit having two carboxyl groups. In .sup.1H-NMR spectroscopy of the modified polyvinyl alcohol, an integral (X) from 6.8 to 7.2 ppm and an integral (Y) from 5.3 to 5.5 ppm satisfy the following expression:
0.60X/(X+Y)<1.0.

A process can be used for manufacturing an acrylic copolymer having increased heat resistance, high transparency, and improved adhesion to metal surfaces. The process involves polymerizing a monomer mixture, optional heating of the copolymer mixture, and removing volatile components from the copolymer mixture by degassing. Moulding compositions containing this copolymer are highly suitable for manufacturing optical elements for optoelectronic devices containing acrylic and metallic or ceramic parts.

A process can be used for manufacturing an acrylic copolymer having increased heat resistance, high transparency, and improved adhesion to metal surfaces. The process involves polymerizing a monomer mixture, optional heating of the copolymer mixture, and removing volatile components from the copolymer mixture by degassing. Moulding compositions containing this copolymer are highly suitable for manufacturing optical elements for optoelectronic devices containing acrylic and metallic or ceramic parts.

A modified vinyl alcohol polymer powder having a structural unit derived from a derivative of an ethylenically unsaturated dicarboxylic acid, and containing a reduced amount of methanol, and a trace amount of a component that does not dissolve in water. The present invention relates to a modified vinyl alcohol polymer powder containing a structural unit derived from a derivative (A) of an ethylenically unsaturated dicarboxylic acid in a content (X) of 0.05 mol % or more and 10 mol % or less, and having a degree of saponification of 80.0 mol % or more and 99.9 mol % or less, the modified vinyl alcohol polymer powder has a methanol content of 0.01 weight % or more and less than 3.0 weight %, the modified vinyl alcohol polymer powder contains 0.1 ppm or more and less than 2,000 ppm of a component that is insoluble in a 90 C., 5 weight % aqueous solution.

A modified vinyl alcohol polymer powder having a structural unit derived from a derivative of an ethylenically unsaturated dicarboxylic acid, and containing a reduced amount of methanol, and a trace amount of a component that does not dissolve in water. The present invention relates to a modified vinyl alcohol polymer powder containing a structural unit derived from a derivative (A) of an ethylenically unsaturated dicarboxylic acid in a content (X) of 0.05 mol % or more and 10 mol % or less, and having a degree of saponification of 80.0 mol % or more and 99.9 mol % or less, the modified vinyl alcohol polymer powder has a methanol content of 0.01 weight % or more and less than 3.0 weight %, the modified vinyl alcohol polymer powder contains 0.1 ppm or more and less than 2,000 ppm of a component that is insoluble in a 90 C., 5 weight % aqueous solution.