摘要 |
Capped amine hardeners for epoxy resins, which are reaction products of amines A having at least two primary amino groups, cyclic alkylene carbonates B, aliphatic carbonyl compounds C and compounds D having at least two groups which react with hydroxyl groups, such that in the first step, 0.1 to 1 mol of the primary amino groups for each 1 mol of the amine A are converted to hydroxyalkylurethane groups by reaction with the cyclic alkylene carbonate B, and the remaining primary amino groups are converted by reaction with the aliphatic carbonyl compound C in a second step to give ketimine or aldimine groups, and finally in the third step at least two of the molecules formed from A, B, and C are linked through reaction of the hydroxyl groups of the hydroxyalkylurethane groups with compound D. These capped amine hardeners are suitable for formulating water-dilutable monocomponent epoxy resin systems. The amines are released by addition of water, and are available for the curing reaction with the epoxy groups. Coatings formulated on the basis of this system are characterized by a very low content of auxiliary solvent. The cured coating films show outstanding leveling and film properties.
|