Abstract: Polymer particles composed of particles of a polymer (I) consisting of 96 to 100% by weight of at least one ethylenically unsaturated monomer and 4 to 0% by weight of at least one .alpha.,.beta.-ethylenically unsaturated carboxylic acid, and a (co-)polymer (II) comprising 100 to 10% by weight of a conjugated diolefin which is localized on the surface layer of the particles of the polymer (I) at a (I)/(II) weight ratio of 100/5-100/90. The localized polymer part of the polymer particles is very active, and the polymer particles are easy to modify with a monomer having any functional group, and hence are elemental materials having a high function and being utilizable for various purposes.

Abstract: A photosensitive resin composition comprising (I) a copolymer containing (A) 10 to 95 mol % of a conjugated diolefinic hydrocarbon, (B) 5 to 90 mol % of an .alpha.,.beta.-ethylenically unsaturated carboxylic acid and (C) 0 to 85 mol % of a monoolefinically unsaturated compound, (II) a photosensitizer and/or a photosensitive crosslinking agent, and, if necessary, (III) a photopolymerizable unsaturated monomer. Said copolymer may have been reacted with an inorganic alkali, an alkali salt or an amine compound in a proportion of 0.05 to 1.0 equivalent per equivalent of the carboxyl group of the .alpha.,.beta.-ethylenically unsaturated carboxylic acid in said copolymer.

Abstract: A process for producing an electrostatic recording material which comprises kneading a hydrophobic pigment having a critical surface tension of 50 dynes/cm or less with an aqueous dispersion of a copolymer consisting of (I) 10 to 50% by weight of methacrylic acid, (II) 5 to 50% by weight of a alkenyl aromatic compound and (III) 30 to 85 % by weight of at least one member selected from the group consisting of conjugated diolefins, alkyl acrylates and alkyl methacrylates; having a glass transition temperature (Tg) of 40.degree. C or less; and having an intrinsic viscosity [.eta.] of 0.1 to 1.0 dl/g as measured in tetrahydrofuran at 25.degree.

Abstract: An electrostatic recording material having a good workability and a very good recording characteristic is prepared by coating such a base sheet as paper, plastic film, metal plate, etc.

Abstract: An electrostatic recording material having a good workability and a very good recording characteristic is prepared by coating such a base sheet as paper, plastic film, metal plate, etc. with an aqueous dispersion comprising (A) 100 parts by weight of at least one water-insoluble polymer comprising at least one monomer selected from ethylenic monomers and conjugated diolefinic monomers, and (B) 1-200 parts by weight of at least one water-soluble salt of polymer containing carboxyl groups by means of an air knife coater, roll coater, etc. It is possible to use not more than 6 parts by weight of the heretofore well-known nonionic emulsifier and/or the well-known anionic emulsifier together with said component.