Self-crosslinking cationic paint binders based on ureide-modified epoxy resins and their preparation
AssigneeVianova Kunstharz, A.G.
InventorWillibald Paar
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Abstract
Self-crosslinking cationic paint binders based on ureide-modified epoxy resins; the preparation of these binders and their use, particularly in electrodeposition paints, is described. The modification is effected with carboxylic compounds carrying ureide groups, blocked isocyanate groups and, optionally, tertiary amino groups. The carboxylic compounds are obtained through reaction of dicarboxylic acid anhydrides or compounds carrying dicarboxylic acid anhydrides with a substituted urea or a substituted biuret. The products show excellent resistance and adhesion characteristics.
Claims7
Self-crosslinking cationic paint binders based on amino-modified epoxy resin esters comprising the esterification product of 5 to 100 mole-% of the epoxy groups of a polyepoxy resin having an epoxy equivalent weight of 160 to about 2000, with a carboxylic compound of the formula
- HOOC-R.sub.1 -CO-NR.sub.2 -CO-NH-R.sub.3 -/NCO/,
- wherein
- R.sub.1 is a saturated or unsaturated aliphatic, cycloaliphatic, or aromatic hydrocarbon radical,
- R.sub.2 is an aliphatic hydrocarbon radical,
- R.sub.3 is an aliphatic, cycloaliphatic, or aromatic hydrocarbon radical, and
- -/NCO/ is a blocked isocyanate group, or the group -NR.sub.2 -CO-NH-R.sub.3 -/NCO/ is a radical formed from a substituted urea or a substituted biuret carrying at least one blocked isocyanate group,
- and the reaction any of remaining epoxy groups of the reaction product with primary and/or secondary amines to provide an epoxy group free amine modified epoxy resin ester having an amine value of at least 30 mg KOH/g.
Dependencies are inferred from the claim text.