Cathodic electrocoat compositions containing self-crosslinking polymers
AssigneeBASF SE
InventorsPaul J. Harris, Timothy S. December
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Abstract
Cathodic electrocoat compositions containing self-crosslinking polymers are described. The polymers of the invention are formed from an epoxide-functional prepolymer having polyepoxide and extender segments. Each extender segment has at least one pendant hydroxyalkyl carbamate group. The prepolymer is reacted with an amine compound having at least one blocked primary amine group and at least one epoxide-reactive group. The primary amine group is unblocked and the resultant polymer is dispersed in water with the aid of a neutralizing acid.
Claims24
A coating composition comprising an aqueous dispersion of a self-crosslinkable cationic polymer, wherein the self-crosslinkable cationic polymer is prepared according to a method comprising the steps of:
- (a) forming an epoxide-functional prepolymer having polyepoxide and extender segments, wherein each extender segment has at least one pendant hydroxyalkylene carbamate group;
- (b) reacting the epoxide groups of the prepolymer with an amine compound having at least one epoxide-reactive group and at least one blocked primary amine group to form a polymer;
- (c) forming an aqueous dispersion of the polymer by means of unblocking the primary amine groups and at least partially neutralizing the amine groups of the polymer before or during addition of a sufficient amount of water to form a dispersion of the polymer.
Dependencies are inferred from the claim text.