Japan Synthetic Rubber Co., Ltd.

Kanzaki Paper Manufacturing Co., Ltd.

Eijiro Tagami

Taiji Higaki

Toyomi Akiyama

Eiichiro Shiratsuchi

Yoshiyuki Ishibashi

Yoshiyuki Harita

Kunihiro Harada

Yoshihiro Hosaka

Takao Matsushita

Teruo Hiraharu

Mitsuo Kurokawa

Shiro Yasukawa

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.

Polymer particles comprising ethylenically unsaturated monomers as main

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. This photosensitive resin composition is excellent in storage stability, quick in photosetting upon exposure to actinic light rays including ultraviolet rays, that is, high in sensitivity, capable of development with water or a dilute aqueous alkaline solution and possesses satisfactory rubber elasticity, and a printing plate formed from the composition is excellent in water resistance though the composition is developable with an aqueous developing solution, so that the composition can be used for a flexographic printing plate, to which an aqueous flexographic printing ink can be applied. Said composition can also be used for a pohote-resist which is high in sensitivity, developable with water or a dilute alkaline solution and excellent in resolving power.

Photosensitive compositions and printing plates containing same

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. C, in a weight ratio of the copolymer to the pigment of 100/20 to 100/200, in the presence of an alkaline material in such a proportion that the viscosity of the aqueous dispersion of the copolymer becomes at least 350 cps, adjusting the viscosity of the aqueous dispersion containing the copolymer and the hydrophobic pigment to 10 to 5,000 cps, coating the resulting coating composition on the surface of an electroconductive base sheet and drying the same. Said process can produce, with a high production efficiency, an electrostatic recording material having a substantially glossless appearance like ordinary paper of office use, being excellent in writability with a pencil and an aqueous ink, stampability and printability, and being capable of recording clear copy images thereon.

Process for producing electrostatic recording material

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-isoluble polymer prepared from at least one monomer selected from the group consisting of (1) conjugated diolefinic monomers and (2) ethylenic monomers selected from the group consisting of linear olefins, branched olefins, aromatic vinyl compounds, vinyl cyanide compounds, alkyl acrylates, alkyl methacrylates, vinyl ethers, and vinyl halides, and (B) 1 to 200 parts by weight of at least one water-soluble salt selected from the group consisting of an ammonium salt and organic amine salt of a copolymer selected from the group consisting of (1) copolymers of unsaturated carboxylic acids and ethylenic monomers selected from the group consisting of linear olefins, branched olefins, aromatic vinyl compounds, vinyl cyanide compounds, alkyl acrylates, alkyl methacrylates, vinyl halides, acrylamide, methacyrlamide, and vinyl ethers, (2) copolymers of conjugated diolefinic monomers and unsaturated carboxylic acids, and (3) copolymers of conjugated diolefinic monomers, unsaturated carboxylic acids and ethylenic monomers selected from the group consisting of linear olefins, branched olefins, aromatic vinyl compounds, vinyl cyanide compounds, alkyl acrylates, alkyl methacrylates, vinyl halides, acrylamide, methacrylamide, and vinyl ethers, said water soluble salt of the copolymer containing 8 to 50 mole percent of 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 conventional nonionic emulsifier and/or a conventional anionic emulsifier together with said components.

Electrostatic recording material

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.

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Yokohama, Japan

Eijiro Tagami