Fujikura Kasei Co., Ltd.

Hiroshi Nagase

Masao Watanabe

Seiichi Yamamoto

Katsuro Funato

Akira Otsu

Tsuyoshi Aoyama

Shigeo Miyamori

Yoshimasa Hayashi

Michio Nagano

Norihide Sugiyama

A negatively chargeable toner for use in dry electrophotography, said toner comprising (A) a resinous binder composed of at least one resin selected from copolymers of styrene and/or alpha-methylstyrene with alkyl (meth)acrylates, (B) 2 to 10 parts by weight, per 100 parts by weight of the resinous binder, of a copolymer containing a sulfonic acid group, said copolymer having a weight average molecular weight of from 2,000 to 15,000 and composed of 80 to 98% by weight of recurring units represented by the formula ##STR1## wherein R.sub.1 represents a hydrogen atom or a methyl group, and 20 to 2% by weight of recurring units represented by the formula ##STR2## and (C) a coloring agent.

Negatively chargeable toner for use in dry electrophotography

A positively chargeable toner for use in dry electrophotography, said toner comprising (A) a resinous binder composed of at least one resin selected from copolymers of styrene and/or alpha-methylstyrene with alkyl (meth)acrylates, polyester resins and epoxy resins, (B) 1 to 100 parts by weight, per 100 parts by weight of the resinous binder, of a copolymer containing a quaternary ammonium salt group, said copolymer having a weight average molecular weight of from 2,000 to 10,000 and composed of 65 to 97% by weight of recurring units represented by the formula ##STR1## wherein R.sub.1 represents a hydrogen atom or a methyl group, and 35 to 3% by weight of recurring units represented by the formula ##STR2## wherein R.sub.2 represents a hydrogen atom or a methyl group, R.sub.3 represents an alkylene group, and each of R.sub.4, R.sub.5 and R.sub.6 represents an alkyl group, and (C) a coloring agent.

Positively chargeable toner for use in dry electrophotography

A pressure-fixable toner is produced by: dispersing or dissolving a mixture containing (a) a colorant and/or magnetic particles, (b) a pressure fixable binding material, and (c) a capsule wall-forming resin, in an organic solvent; dispersing the resulting dispersion or solution in a dispersion-stabilizing solution; heating the dispersion to evaporate off the solvent; dispersing the resulting encapsulated toner in a lower alcohol to remove the solvent remaining within the encapsulated toner; and thereafter drying the toner. The toner can be used to develop images in electrophotographic systems.

Process for producing pressure-fixable electrophotographic toners

A process for producing an absorbent resin, which comprises polymerizing 1 mole of a lower alkyl acrylate and 0.07 to 0.5 mole of a polyhydric alcohol ester of a monoethylenically unsaturated carboxylic acid in an aqueous medium in the absence of an emulsifying agent, saponifying the resulting polymer with a basic substance in a water-lower alcohol medium, and then neutalizing the saponification product with an acid.

Process for producing water-absorbing resins

The present invention relates to a process for producing a large architectural precast concrete panel for use in outside walls and applicable to the curtain wall technique of architecture, wherein a resinous substance and an inorganic material are placed in a mold, then a hydraulic cement composition is placed on the layer of above mixture. The polymerization of the resinous substance and the hydration of the cement composition are carried out in the mold simultaneously. A particularly preferred process employs the following critical conditions: 1. The viscous methyl methacrylate syrup is one obtained by mixing about 100 parts by weight of viscous methyl methacrylate syrup with from about 0.5 to about 15 parts by weight of a radical polymerizable cross-linking monomer having .alpha., .beta.-unsaturated groups to obtain a resin solution; 2. The particle size of the aggregates is between 0.6 and 15mm diameter; 3. The thickness of the layer of the aggregates and the thermosetting acryl resin is between about 10 and 30mm; 4. The weight ratio of parts of water to parts of the cement in the hydraulic cement composition is about 50:60 to 40:50, respectively; 5. The thickness of the hydraulic cement composition is about 40 to 100mm.

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Tokyo, Japan

Hiroshi Nagase