Claims
- 1. A liquid aqueous dispersion suitable for use in cathodic electrocoating art and comprising:
- (A) an aqueous medium having pH from about 3 to 9 and containing an acid with a pK.sub.a not greater than about 5;
- (B) a substantially oxirane-free, non-gelled, resinous adduct of
- (i) a substantially oxirane-free precursor adduct of a polyether diepoxide having molecular weight from about 300 to 10,000 and a polyamine having molecular weight from about 60 to 600 and
- (ii) a mono-epoxide having molecular weight from about 100 to 500 and having a normal alkyl group of at least about 4 carbon atoms pendant through only hydrolysis-resistant linkages from the epoxy group of said mono-epoxide,
- the mole ratio of residues of said mono-epoxide to residues of said diepoxide in said resinous adduct being from about 0.2:1 to 2:1, the mole ratio of residues of said polyamine to residues of said diepoxide in said resinous adduct being from about 1.25:1 to 2:1, and said polyamine having from 2 to 5 amine groups per molecule and at least sufficient amino hydrogens to react with substantially all of the epoxy groups of both said diepoxide and said mono-epoxide; and
- (C) from about 0.05 to 0.4 weight parts, per weight part of said resinous adduct, of an aminoplast resin having at least about 1 gram-equivalent, per 1,000 grams of said aminoplast resin, of carboxylic acid groups with pK.sub.a from about 2 to 6 for catalyzing the heat-induced cure of said resinous adduct with said aminoplast resin.
- 2. A dispersion according to claim 1 wherein said polyamine has only one primary or secondary amine group.
- 3. A dispersion according to claim 2 wherein said polyamine is a diamine.
- 4. A dispersion according to claim 1 wherein said diepoxide is a diglycidyl ether of an alkylene bisphenol or of an alternating alkylene bisphenol-glycerol polyether.
- 5. A dispersion according to claim 4 wherein said polyamine is dimethylaminopropyl amine and said alkylene bisphenol is bisphenol-A.
- 6. A dispersion according to claim 1 wherein a pigment is mixed into part or all of said oxirane-free, non-gelled, resinous adduct.
- 7. A dispersion according to claim 1 wherein said aqueous dispersion also contains an additional resin similarly cured by said aminoplast resin.
- 8. A dispersion according to claim 7 wherein a pigment is mixed into part or all of said additional resin and/or said resinous adduct.
- 9. A dispersion according to claim 8 wherein a pigment is mixed into part or all of said resinous adduct and said additional resin is a hydroxyalkyl monoamine-aminated polyhydroxy polyether resin.
Parent Case Info
This is a division, of application Ser. No. 874,809, filed Feb. 3, 1978 U.S. Pat. No. 4,159,233, issued June 26, 1979.
US Referenced Citations (4)
Divisions (1)
|
Number |
Date |
Country |
Parent |
874809 |
Feb 1978 |
|