Cathodic electrocoat composition having latent functionality
AssigneeBASF SE
InventorsTimothy S. December, Paul J Harris
Life of this patent
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Abstract
A cationic resin having latent primary amine functionality is described. The latent amine functionality is obtained by reacting a cyclic anhydride with an amine compound having two primary amine groups and one secondary amine group. The cationic resin is combined with a curing agent having a plurality of cyclic carbonate groups in an electrocoat bath.
Claims26
A coating composition comprising, in an aqueous medium,
- (a) a cationic resin having latent amine functionality, comprising the reaction product of:
- (i) a resin having a functional group reactive with a secondary amine and
- (ii) a latent amine reaction product of
- (A) a cyclic anhydride and
- (B) a amine compound comprising two primary amine groups and one secondary amine group;
- and
- (b) a compound comprising a plurality of cyclic carbonate groups.
A coating composition comprising, in an aqueous medium,
- (a) a cationic resin comprising a structure ##STR10## wherein at least one of the amine nitrogens is covalently bonded to the principal resin, and further wherein L is a bivalent linking group in which the bonding valences are on two adjacent carbon atoms;
- and
- (b) a compound comprising a plurality of cyclic carbonate groups.
A method of coating a conductive substrate, comprising the steps of:
- (a) providing an aqueous coating composition comprising a cationic resin having latent primary amine functionality and a curing agent having a plurality of cyclic carbonate groups, wherein said latent primary amine functionality is obtained by reacting
- (i) a cyclic anhydride and
- (ii) a amine compound comprising two primary amine groups and one secondary amine group;
- (b) immersing a conductive substrate in said electrodeposition coating composition;
- and
- (c) applying a potential of electric current between an anode and the conductive substrate to deposit a coating layer onto the conductive substrate.
A cationic resin formed by the process comprising the steps of:
- (a) reacting a cyclic anhydride and an amine compound comprising two primary amine groups and one secondary amine group to form a latent amine compound;
- (b) reacting the latent amine compound with a resin having at least one group reactive with secondary amine functionality;
- and
- (c) salting the resin with an acid.
A coating composition comprising, in an aqueous medium,
- (a) a cationic resin having latent amine functionality, comprising the reaction product of:
- (i) a resin having a functional group reactive with a secondary amine and
- (ii) a latent amine reaction product of
- (A) a cyclic anhydride and
- (B) a amine compound comprising two primary amine groups and one secondary amine group,
- wherein (i) and (ii) are reacted at a temperature below the temperature at which the latent amine product (ii) would decompose to regenerate primary amine functionality;
- and
- (b) a compound comprising a plurality of cyclic carbonate groups.
A cationic resin formed by the process comprising the steps of:
- (a) reacting a cyclic anhydride and an amine compound comprising two primary amine groups and one secondary amine group to form a latent amine compound;
- (b) reacting the latent amine compound with a resin having at least one group reactive with secondary amine functionality at a temperature below the temperature at which the latent amine product (ii) would decompose to regenerate primary amine functionality;
- and
- (c) salting the resin with an acid.
Dependencies are inferred from the claim text.