Aqueous cationic coating from amine-epoxy adduct, polyamide, and semi-blocked polyisocyanate, acid salt
AssigneeKansai Paint Co., Ltd.
InventorsAkira Tominaga, Yasuyuki Hirata
Life of this patent
Estimating the term…
Abstract
A cationic electrophoretic coating composition comprises a resinous binder which is prepared by reacting an epoxy resin-amine adduct (A) with a partially blocked polyisocyanate (C) and mixing or reacting a polyamide (B) with the resulting product, or by reacting a polyamide (B) with a partially blocked polyisocyanate (C) and mixing or reacting an epoxy resin-amine adduct (A) with the resulting product.
Claims21
A cationic electrophoretic coating composition comprising an aqueous medium and a resinous binder dissolved or dispersed therein, said resinous binder being an acid neutralized product said product being at least one selected from the group consisting of:
- (1) a mixture of
- (a) a reaction product of an epoxy-amine adduct (A) and a partially blocked polyisocyanate (C), in the weight ratio of from 90 to 15 of (A) to from 10 to 85 of (C), and
- (b) a polyamide (B), the weight ratio of (a) to (b) being from 30 to 90 of the former as calculated by the amount of (A) to from 70 to 10 of the latter;
- (2) a reaction product of
- (a) a reaction product of an epoxy-amine adduct (A) and a partially blocked polyisocyanate (C), and
- (b) a polyamide (B), the weight ratio of (A) to (C) in (a) and the weight ratio of (a) to (b) being the same as in (1);
- (3) a mixture of
- (c) a reaction product of a polyamide (B) and a partially blocked polyisocyanate (C), in the weight ratio of from 85 to 10 of (B) to from 15 to 90 of (C), and
- (d) an epoxy-amine adduct (A), the weight ratio of (c) to (d) being from 70 to 10 of the former as calculated by the amount of (B) to from 30 to 90 of the latter;
- and
- (4) a reaction product of
- (c) a reaction product of a polyamide (B) and a partially blocked polyisocyanate (C), and
- (d) an epoxy-amine adduct (A), the weight ratio of (B) to (C) in (c) and the weight ratio of (c) to (d) being the same as in (3), said epoxy-amine adduct (A) being a reaction product prepared by reacting an epoxy resin with a basic amino compound having at least one basic amino group, said polyamide (B) being a polyamide having at least one basic amino group and said partially blocked polyisocyanate (C) being a polyisocyanate compound having at least one blocked isocyanate group in the molecule and an average of more than zero to not more than one free isocyanate group per molecule.
A process for preparing a cationic electrophoretic coating composition comprising the steps (I) and (II), said step (I) being at least one selected from the group consisting of:
- 1. mixing or reacting
- (a) a reaction product of an epoxy-amine adduct (A) and a partially blocked polyisocyanate (C), in the weight ratio of from 90 to 15 of (A) to from 10 to 85 of (C), and
- (b) a polyamide (B), the weight ratio of (a) to (b) being from 30 to 90 of the former as calculated by the amount of (A) to from 70 to 10 of the latter;
- and
- 2. mixing or reacting
- (c) a reaction product of a polyamide (B) and a partially blocked polyisocyanate (C), in the weight ratio of from 85 to 10 of (B) to from 15 to 90 of (C), and
- (d) an epoxy-amine adduct (A), the weight ratio of (c) and (d) being from 70 to 10 of the former as calculated by the amount of (B) to from 30 to 90 of the latter;
- said step (II) consists essentially of dissolving or dispersing the resulting mixture or/and reaction product in an aqueous medium by neutralization with an acid.
Dependencies are inferred from the claim text.