US 12,534,635 B2 · Aqueous coating composition

Abstract

The present invention provides an aqueous coating composition which is capable of forming a coating film that has excellent cissing resistance and water resistance. An aqueous coating composition which contains (A) at least one hydroxyl group-containing resin that is selected from among (A1) hydroxyl group-containing acrylic resins and (A2) hydroxyl group-containing polyester resins, (B) an oligomer and (C) an alkyl etherified melamine resin, wherein: the oligomer (B) has a number average molecular weight within the range of from 200 to 800 and a solubility parameter within the range of from 10.0 to 13.5; and the molar ratio of methyl groups to butyl groups in the alkyl etherified melamine resin (C), namely (methyl group)/(butyl group) molar ratio is from 50/50 to 0/100.

Claims19

Dependent claims

A method for forming a multilayer coating film, comprising applying an aqueous coating composition onto an article to be coated comprising an exterior plate of automobile body or an automobile part to form a base coating film, and applying a clear coating composition (Z) on the base coating film to form a clear coating film, the aqueous coating composition comprising (A) one or more hydroxyl group-containing resins selected from the group consisting of (A1) hydroxyl group-containing acrylic resins and (A2) hydroxyl group-containing polyester resins, (B) an oligomer and (C) an alkyl etherified melamine resin, wherein

the oligomer (B) has a number-average molecular weight in the range of 200 to 800 and a solubility parameter in the range of 10.0 to 13.5, and
the molar ratio of methyl groups and butyl groups in the alkyl etherified melamine resin (C) is 50/50 to 0/100 as the (methyl group)/(butyl group) molar ratio.

Dependencies are inferred from the claim text.

Aqueous coating composition

Life of this patent

Aqueous coating composition

Life of this patent

Abstract

Claims19