Cathodic electrocoating compositions
View Patent ↗Disclosed herein are functionalized polymers comprising ethylene and substituted ethylene segments. These functionalized polymers are useful as film forming resins in cathodic electrocoating compositions. Also disclosed herein are aqueous dispersion compositions comprising the functionalized polymers and a process for coating various electrically conductive substrates.
1. A polymer comprising:
a) at least one ethylene segment of structure 1
b) at least one substituted ethylene segment of structure 2
and
c) at least one substituted ethylene segment of structure 3
wherein: x and y are integers from 10 to 30,000, and z is an integer from 1 to 10;
R′ is H, —C q H 2q+1 , or —C q H q−k ; R″ is H or CH 3 ; and
each R is independently at least one member selected from the group consisting of: —(CH 2 ) m N(CH 3 ) 2 , —(CH 2 ) n —(CH═CH)—(CH 2 ) r CH 3 , —(CH 2 ) v CH 3 , —(CH 2 ) p OH, —(CH 2 ) s N(CH 2 CH 2 OH) 2 , and —(CH 2 ) t OPO 3 H 2 , where q, r, s, t, m, n, v, and p are independently selected from the group of integers from 1 to 20 and k is the number of rings in —C q H 2q−k .
2. The polymer according to claim 1 , wherein R′ is H, and R is —(CH 2 ) m N(CH 3 ) 2 , —(CH 2 ) n —(CH═CH)—(CH 2 ) r CH 3 , and —(CH 2 ) p OH in the at least one substituted ethylene segment of structure 2 and the at least one substituted ethylene segment of structure 3.
3. The polymer according to claim 2 wherein m=3, n=8, r=7, and p=2.
4. The polymer according to claim 1 , wherein R′ is H, and R is —(CH 2 ) n —(CH═CH)—(CH 2 ) r CH 3 , and —(CH 2 ) p OH in the at least one substituted ethylene segment of structure 2 and the at least one substituted ethylene segment of structure 3.
5. The polymer according to claim 4 wherein n=8, r=7, and p=2.
6. The polymer according claim 1 , wherein R′ is H, and R is —(CH 2 ) n —(CH═CH)—(CH 2 ) r CH 3 , and —(CH 2 ) s N(CH 2 CH 2 OH) 2 in the at least one substituted ethylene segment of structure 2 and the at least one substituted ethylene segment of structure 3.
7. The polymer according to claim 6 wherein n=8, r=7, and s=3.
8. The polymer according to claim 1 , wherein R′ is H, and R —(CH 2 ) m N(CH 3 ) 2 , and —(CH 2 ) p OH in the at least one substituted ethylene segment of structure 2 and the at least one substituted ethylene segment of structure 3.
9. The polymer according to claim 8 wherein m=3, and p=2.
10. The polymer according to claim 1 , wherein R′ is —C q H 2q+1 , and R is —(CH 2 ) p OH in the at least one substituted ethylene segment of structure 2 and the at least one substituted ethylene segment of structure 3.
11. The polymer according to claim 10 wherein q=2 and p=2.
12. The polymer according claim 1 , wherein R′ is H, and R is —(CH 2 ) t OPO 3 H 2 in the at least one substituted ethylene segment of structure 2 and the at least one substituted ethylene segment of structure 3.
13. The polymer according to claim 12 wherein t=2.
14. An aqueous dispersion composition comprising:
a) a polymer of claim 1 ; and
b) water;
wherein said aqueous dispersion composition has a pH of 5.0 to 7.0.
15. The aqueous dispersion composition according to claim 14 further comprising at least one crosslinking agent.
16. The aqueous dispersion composition according to claim 15 , wherein the at least one crosslinking agent is a blocked isocyanate.
17. The aqueous dispersion composition according to claim 15 , wherein the at least one crosslinking agent is an alkoxysilane.
18. The aqueous dispersion composition according to claim 14 further comprising at least one additive selected from the group consisting of: surfactants, pigments, light stabilizers, anti-crater agents, flow aids, dispersion stabilizers, adhesion promoters, corrosion inhibitors, and fillers.
19. The aqueous dispersion composition according to claim 14 having a pH of 6.0 to 7.0.
20. The aqueous dispersion composition according to claim 14 having a pH of 6.5 to 7.0.
21. A process comprising the steps of:
a) providing an electrochemical cell comprising:
i) an aqueous dispersion composition of claim 14 ;
ii) a substrate to be coated, wherein the substrate is in contact with the aqueous dispersion composition and the substrate serves as a cathode of the electrochemical cell;
iii) an anode in contact with the aqueous dispersion composition; and
iv) a power supply in electrical contact with the anode and cathode; and
b) applying a voltage between the cathode and the anode to electrodeposit a polymer coating onto at least a portion of the substrate.
22. The process according to claim 21 further comprising the step of: heating the polymer coating.
23. The process according to claim 21 wherein the aqueous dispersion further comprises a crosslinking agent.
24. The process according to claim 21 wherein the aqueous dispersion further comprises at least one additive selected from the group consisting of: surfactants, pigments, light stabilizers, anti-crater agents, flow aids, dispersion stabilizers and fillers.
25. An article produced by the process of claim 21 .