Dainippon Ink and Chemicals, Incorporated

Hiroaki Shimada

Takashi Kojima

Yoshihiro Yamano

Yoshio Itoh

Tadami Ueno

Yoshiki Itoh

Norio Yokomichi

An aqueous resin composition comprising prepared by a process comprising the steps of: reacting epoxy resins comprising: (A) an aromatic epoxy resin having a number average molecular weight of at least 9,000 and an epoxy equivalent of not larger than 9,000; and (B) an aromatic epoxy resin having a number average molecular weight of less than 9,000 and an epoxy equivalent of not larger than 5,000, and (C) a carboxyl group-containing acrylic resin having a glass transition temperature of at least 100&deg; C., to undergo partial-esterification to obtain an acryl-modified epoxy resin; neutralizing said acryl-modified epoxy resin with a base and dispersing the neutralized resin in an aqueous medium. Also disclosed is a coated metal material having a cured coated film of the aqueous resin composition.

Aqueous resin composition and coated metal material having cured coating of the same

An aqueous coating resin composition, the improvement wherein a microgel composed of a resin reaction product having a three-dimensional network structure, which is obtained by the esterification reaction of (1) 40 to 90 parts by weight of an aromatic epoxy resin with (2) 10 to 60 parts by weight of a carboxyl group-containing vinyl polymer comprising (a) a carboxyl group-containing vinyl monomer, (b) an aromatic vinyl monomer and (c) at least one monomer selected from the group consisting of an alkyl ester, a hydroxyalkyl ester and an N-hydroxyalkylamide of an alpha,beta-ethylenically unsaturated carboxylic acid, is dispersed into an aqueous medium; and a process for production thereof.

Aqueous coating resin compositions and process for producing same

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Saitama, Japan

Hiroaki Shimada