Claims
- 1. In a method of electrocoating an electrically-conductive surface serving as a cathode which comprises passing electric current between said cathode and an anode in contact with an aqueous electrodepositable composition,
- the improvement wherein said electrodepositable composition comprises:
- A. a hydroxyl-containing adduct which is the reaction product of a primary or secondary amine and a polyepoxide, said adduct being solubilized with acid to provide cationic groups in said adduct,
- B. a blocked organic polyisocyanate stable at room temperature in the presence of hydroxyl or amino groups but reactive with hydroxyl or amino groups at elevated temperatures.
- 2. A method according to claim 1 wherein (B) is the reaction product of an organic polyisocyanate and a compound selected from the group consisting of an aliphatic alkyl monoalcohol, a cycloaliphatic alkyl monoalcohol, an aromatic alkyl monoalcohol, a ketoxime, and a tertiary hydroxylamine.
- 3. A method according to claim 1 wherein B is the reaction product of an organic polyisocyanate and an aliphatic alkyl monoalcohol.
- 4. A method according to claim 1 wherein (A) and (B) are present in a ratio of about 0.5 to about 2.0 blocked isocyanate groups per hydroxyl group.
- 5. A method according to claim 1 wherein (A) is an acid-solubilized adduct of a primary or secondary amine and a polyglycidyl ether of a polyphenol.
- 6. A method according to claim 5 wherein (B) is the reaction product of an organic polyisocyanate and a compound selected from the group consisting of an aliphatic alkyl monoalcohol, a cycloaliphatic alkyl monoalcohol, an aromatic alkyl monoalcohol, a phenol, a ketoxime, and a tertiary hydroxylamine.
- 7. A method according to claim 5 wherein (A) and (B) are present in a ratio of about 0.5 to about 2.0 blocked isocyanate groups per hydroxyl group.
- 8. A method according to claim 1 wherein (A) is an acid-solubilized adduct of a secondary amine and a polyglycidyl ether of Bisphenol A.
- 9. A method according to claim 8 wherein (B) is the reaction product of an organic polyisocyanate and a compound selected from the group consisting of an aliphatic alkyl monoalcohol, a cycloaliphatic alkyl monoalcohol, an aromatic alkyl monoalcohol, a phenol, a ketoxime, and a tertiary hydroxylamine.
- 10. A method according to claim 1 wherein (A) is an acid-solubilized adduct of a secondary amine and a carboxylic acid-modified, epoxy group-containing polyglycidyl ether of a polyphenol.
- 11. An article electrocoated by the method of claim 1.
CROSS-REFERENCE TO RELATED APPLICATIONS
This application is continuation-in-part of copending application Ser. No. 193,590 filed Oct. 28, 1971, now abandoned, which in turn is a continuation-in-part of application Ser. No. 47,917, filed June 19, 1970, now U.S. Pat. No. 3,799,854.
US Referenced Citations (3)
Number |
Name |
Date |
Kind |
3617367 |
Cummings |
Nov 1971 |
|
3773729 |
Wakimoto et al. |
Nov 1973 |
|
3804786 |
Sekmakas |
Apr 1974 |
|
Foreign Referenced Citations (1)
Number |
Date |
Country |
679,761 |
Feb 1964 |
CA |
Continuation in Parts (2)
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Number |
Date |
Country |
Parent |
193590 |
Oct 1971 |
|
Parent |
47917 |
Jun 1970 |
|