Claims
- 1. An aqueous electrocoating bath containing synthetic resins capable of deposition on a cathode to form a coating and also containing contaminants capable of forming defects in a surface of the coating deposited from the bath, the bath also including an amount of a copolymer of an alkyl vinyl ether of the general formula CH.sub.2 .dbd.CH--O--R, wherein R represents an alkyl radical having 2 to 4 carbon atoms, with a copolymerizable monomer selected from the group consisting of styrene and alkyl (meth)acrylates effective to abate formation of defects caused by the contaminants in the deposited coating surface.
- 2. A method for reducing surface defects in electrodeposited films on electrically conducting substrates comprising
- a. immersing the substrate in an aqueous electrocoating bath containing at least one synthetic resin to be deposited on a cathode, and surface defect forming contaminants, as well as an amount of a copolymer of an alkyl vinyl ether of the general formula CH.sub.2 .dbd.CH--O--R, wherein R represents an alkyl radical of 2 to 4 carbons, effective to reduce defect formation by the contaminants,
- b. connecting the substrate as the cathode,
- c. depositing a film on the substrate by means of direct current,
- d. removing the substrate from the electrocoating bath, and
- e. baking the deposited paint film, to provide a coating substantially free of surface defects caused by contaminants.
- 3. The method according to claim 2, wherein the electrocoating bath contains as the synthetic resin deposited on the cathode, a cationic, amine-modified epoxide resin.
- 4. In a method of electrocoating from a cathodic deposition bath which contains in addition to coating film formers, contaminants causing surface defects in the film, an improvement comprising the step of including in the bath an amount of copolymer of an alkyl vinyl ether of the formula CH.sub.2 .dbd.CH--O--R wherein R is 2 to 4 carbon atoms effective to abate formation of surface defects in the film caused by contaminants.
- 5. The method according to claim 4 wherein the bath includes a polymer selected from the group consisting of cationic amine-modified epoxy resins.
- 6. The method according to claim 5 wherein the resin is the reaction product of a polyepoxide, an amine and a component selected from the group consisting of polyols, polycarboxylic acids, polyamines and polysulfides.
- 7. The method according to claim 6 wherein the polyepoxide contains two epoxy groups per molecule and has a molecular weight of not higher than about 750.
- 8. The method according to claim 4 wherein the copolymer of the alkyl vinyl ether is prepared by polymerizing about 80 to 100% of an alkyl vinyl ether with up to 20% by weight of a copolymerizable monomer.
- 9. The method of claim 4 wherein the copolymer is a copolymer of an alkyl vinyl ether with styrene or alkyl(meth)acrylate.
- 10. The method according to claim 4 containing about 10 to 10,000 ppm of copolymer of the alkyl vinyl ether.
- 11. The method according to claim 10 wherein the bath contains 150-500 ppm of the copolymer of the alkyl vinyl ether.
- 12. The method according to claim 4 wherein the alkyl vinyl ether is ethyl vinyl ether.
Priority Claims (2)
Number |
Date |
Country |
Kind |
87110956 |
Jul 1987 |
EPX |
|
37 38 827.4 |
Nov 1987 |
DEX |
|
Parent Case Info
This is a division of application Ser. No. 08/168,969 filed Dec. 16, 1993, now U.S. Pat. No. 5,427,661, which was a continuation of Ser. No. 08/027,938 filed Mar. 8, 1993, now abandoned, which was a continuation of Ser. No. 07/918,153 filed Jul. 17, 1992, now abandoned, which was a continuation of Ser. No. 07/458,702 originally filed on Jan. 19, 1990, and now abandoned.
US Referenced Citations (1)
Number |
Name |
Date |
Kind |
4192929 |
Wingfield, Jr. |
Mar 1980 |
|
Divisions (1)
|
Number |
Date |
Country |
Parent |
168969 |
Dec 1993 |
|
Continuations (3)
|
Number |
Date |
Country |
Parent |
27938 |
Mar 1993 |
|
Parent |
918153 |
Jul 1992 |
|
Parent |
458702 |
Jan 1990 |
|