A method for efficiently producing polyvinylamine crosslinked polymer particles by simple operation without using an organic solvent is provided. In the present invention, polyvinylamine crosslinked polymer particles can be produced by performing suspension polymerization in salt water containing N-vinylcarboxylic acid amide and a polyvinyl compound in the presence of a dispersant to obtain particles of a polyvinyl carboxylic acid amide crosslinked polymer and subsequently hydrolyzing the polyvinyl carboxylic acid amide crosslinked polymer. Divinylbenzene is preferred as the polyvinyl compound. N-Vinylcarboxylic acid amide, acrylonitrile, and a polyvinyl compound may be used.

A method for efficiently producing polyvinylamine crosslinked polymer particles by simple operation without using an organic solvent is provided. In the present invention, polyvinylamine crosslinked polymer particles can be produced by performing suspension polymerization in salt water containing N-vinylcarboxylic acid amide and a polyvinyl compound in the presence of a dispersant to obtain particles of a polyvinyl carboxylic acid amide crosslinked polymer and subsequently hydrolyzing the polyvinyl carboxylic acid amide crosslinked polymer. Divinylbenzene is preferred as the polyvinyl compound. N-Vinylcarboxylic acid amide, acrylonitrile, and a polyvinyl compound may be used.

The present invention provides a water-soluble packaging film which is capable of packaging chemicals while maintaining appropriate flexibility without changes in the appearance or offensive odors over a long period of time, which takes much less time to dissolve in water, and which can achieve excellent water solubility, excellent visibility, and excellent chemical resistance. The present invention relates to a water-soluble packaging film containing: polyvinyl alcohol; a plasticizer; and an alkali metal, the water-soluble packaging film containing 3 to 15 parts by weight of the plasticizer based on 100 parts by weight of the polyvinyl alcohol, the water-soluble packaging film containing 0.3 to 5% by weight of the alkali metal based on 100% by weight of the water-soluble packaging film.

The present invention provides a water-soluble packaging film which is capable of packaging chemicals while maintaining appropriate flexibility without changes in the appearance or offensive odors over a long period of time, which takes much less time to dissolve in water, and which can achieve excellent water solubility, excellent visibility, and excellent chemical resistance. The present invention relates to a water-soluble packaging film containing: polyvinyl alcohol; a plasticizer; and an alkali metal, the water-soluble packaging film containing 3 to 15 parts by weight of the plasticizer based on 100 parts by weight of the polyvinyl alcohol, the water-soluble packaging film containing 0.3 to 5% by weight of the alkali metal based on 100% by weight of the water-soluble packaging film.

The present invention relates to a method for producing a cationic polyvinyl amine based copolymer. The present invention further relates to a cationic polyvinyl amine based copolymer and use of the copolymer in paper industry as a strength agent, a retention agent and a drainage agent.

The present invention relates to a method for producing a cationic polyvinyl amine based copolymer. The present invention further relates to a cationic polyvinyl amine based copolymer and use of the copolymer in paper industry as a strength agent, a retention agent and a drainage agent.

The present invention relates to a method for producing a cationic polyvinyl amine based copolymer. The present invention further relates to a cationic polyvinyl amine based copolymer and use of the copolymer in paper industry as a strength agent, a retention agent and a drainage agent.

Amphiphilic macromolecules having repeating structural units: structural units to adjust molecular weight and molecular weight distribution and charging property effects, high stereo-hindrance structural units, and amphiphilic structural units, which are suitable for fields such as oil field well drilling, well cementation, fracturing, oil gathering and transfer, sewage treatment, sludge treatment and papermaking, etc., and can be used as an oil-displacing agent for enhanced oil production, a heavy oil viscosity reducer, a fracturing fluid, a clay stabilizing agent, a sewage treatment agent, a papermaking retention and drainage aid or a reinforcing agent, etc.

Amphiphilic macromolecules having repeating structural units: structural units to adjust molecular weight and molecular weight distribution and charging property effects, high stereo-hindrance structural units, and amphiphilic structural units, which are suitable for fields such as oil field well drilling, well cementation, fracturing, oil gathering and transfer, sewage treatment, sludge treatment and papermaking, etc., and can be used as an oil-displacing agent for enhanced oil production, a heavy oil viscosity reducer, a fracturing fluid, a clay stabilizing agent, a sewage treatment agent, a papermaking retention and drainage aid or a reinforcing agent, etc.

Biocompatible copolymers and thermo-responsive hydrogels formed from the copolymers are disclosed. The biocompatible copolymers include monomers comprising polysaccharides or derivatives thereof, therapeutic agents or derivatives thereof and thermo-responsive monomers and are cross-linked with an acrylamide-containing crosslinker. The hydrogels are used as implant materials to treat or prevent joint damage or osteoarthritis in a subject.