Dainippon Ink and Chemicals, Incorporated

Munekazu Hayashi

Hideki Watanabe

Satoshi Idemura

Kinji Shinzo

Seiichi Uno

Toshikazu Ohtake

Kazumi Ohi

Yuji Kunitake

A novel manufacturing method for toner used in electrophotography employing no organic solvent is disclosed. The method comprises the steps of: (1) combing a colored melted resin (a) and an aqueous medium (b), wherein the colored melted resin (a) is prepared by heating and melting a kneaded material containing a synthetic resin for use in an electrophotographic toner having an ionic group and a coloring pigment, and the aqueous medium (b) contains a substance capable of neutralizing the ionic group, and possesses a raised temperature not lower than the softening point of the synthetic resin by way of heating with application of pressure where necessary; (2) dispersing the colored melted resin (a) in the aqueous medium (b) by mechanical means while maintaining a mixture of the colored melted resin (a) and the aqueous medium (b) at a temperature not lower than the softening point of the synthetic resin; (3) producing an aqueous suspension of colored resin microparticles by means of sudden cooling; (4) separating the colored resin microparticles from the suspension; and (5) drying the separated colored resin microparticles.

Manufacturing method for toner used in electrophotography

A process for producing a prepreg and a process for producing a laminated sheet therefrom are disclosed, the process for producing a prepreg comprising impregnating a fibrous base with an impregnating resin composition essentially comprising (A.sub.1) a room temperature liquid epoxy resin, (A.sub.2) an epoxy resin curing agent, (B.sub.1) a resin containing a polymerizable unsaturated group, (B.sub.2) a room temperature liquid polymerizable vinyl monomer, and (B.sub.3) a polymerization initiator and containing no solvent other than said polymerizable vinyl monomer (B.sub.2), to obtain an impregnated base, and then removing the polymerizable vinyl monomer present in said impregnated base and converting the resin components to the B-stage. The prepreg is tack-free and soft, and the laminated sheet obtained therefrom has improved metal foil peel strength and interlaminar peel strength.

Process for producing prepreg and laminated sheet

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Chiba, Japan

Munekazu Hayashi