Cationic electrodepositable coating composition comprising lignin
A cationic electrodepositable coating composition is disclosed. The present invention in directed to a cationic electrodepositable coating composition comprising a lignin-containing cationic salt resin, that comprises (A) the reaction product of: lignin, an amine, and a carbonyl compound; (B) the reaction product of lignin, epichlorohydrin, and an amine; or (C) combinations thereof.
1. A cationic electrodepositable coating comprising a lignin-containing cationic salt resin that comprises (A) the reaction product of lignin, an amine and a carbonyl compound wherein the lignin and carbonyl are reacted directly with each other; alone or in combination with (B) the reaction product of lignin, epichlorohydrin and an amine; wherein the carbonyl compound of reaction product (A) comprises formaldehyde and the amine comprises dimethylaminopropyl amine.
2. The cationic electrodepositable coating composition of claim 1 , wherein the lignin is reacted with a monofunctional compound prior to being reacted with the amine or carbonyl compound of reaction product (A).
3. The cationic electrodepositable coating composition of claim 2 , wherein the monofunctional compound comprises epoxide, cyclic carbonate, or combinations thereof.
4. The cationic electrodepositable coating composition of claim 3 , wherein the monofunctional epoxide comprises ethylene oxide, propylene oxide, or combinations thereof.
5. The cationic electrodepositable coating composition of claim 3 , wherein the monofunctional cyclic carbonate compound comprises ethylene carbonate.
6. The cationic electrodepositable coating composition of claim 1 , wherein the lignin-containing cationic salt resin comprises ≧50 weight percent of the coating composition based on the total resin solids of the coating composition.
7. A method of making the cationic electrodepositable coating composition of claim 1 wherein the reaction product comprises lignin, an amine and carboxyl compound comprising: (i) reacting lignin, a carbonyl compound, and an amine wherein the reaction product is synthesized via a Mannich reaction.
8. A cationic electrodepositable coating comprising a lignin-containing cationic salt resin that comprises (A) the reaction product of lignin, epichlorohydrin and an amine; alone or in combination with (B) the reaction product of lignin, an amine and a carboxyl compound; wherein the amine in reaction product (A) comprises methylethanol amine.
9. The cationic electrodepositable coating composition of claim 8 , wherein the lignin is reacted with a monofunctional compound prior to being reacted with epichlorohydrin or the amine of reaction product A.
10. The cationic electrodepositable coating composition of claim 9 , wherein the monofunctional compound comprises epoxide, cyclic carbonate, or combinations thereof.
11. The cationic electrodepositable coating composition of claim 10 , wherein the monofunctional epoxide comprises ethylene oxide, propylene oxide, or combinations thereof.
12. The cationic electrodepositable coating composition of claim 10 , wherein the monofunctional cyclic carbonate compound comprises ethylene carbonate.
13. The cationic electrodepositable coating composition of claim 8 , wherein the lignin-containing cationic salt resin comprises ≧50 weight percent of the coating composition based on the total resin solids of the coating composition.
14. A method of making the cationic electrodepositable coating composition of claim 8 wherein the reaction product comprises lignin, epichlorohydrin and an amine comprising: (i) reacting lignin and epichlorohydrin to form an intermediate reaction product, and then reacting the intermediate reaction product with an amine; and (ii) reacting the reaction product of (i) with an amine and an acid.
15. A cationic electrodepositable coating composition comprising a lignin-containing cationic salt resin that comprises the product of a Mannich reaction between lignin, an amine and a carbonyl compound, which reaction product is further reacted with an epoxy functional resin.
16. A cationic electrodepositable coating composition comprising a lignin-containing cationic salt resin that comprises the reaction product of lignin, epichlorohydrin and an amine, which reaction product is further reacted with an epoxy functional resin.