| 摘要 |
<p>Coatings are formed by the electrophoretic deposition of a cationic resin together with a finely-divided nonionic resin, from an aq. dispersion, on a conductive workpiece switched as cathode, and hardening. Novelty consists of effecting deposition at pH 7-9, from an aq. soln. and/or aq. dispersion contg. (1) an acid-protonised reaction prod. (I) of (a) epoxide gp.-free Mannich bases, (A), with (b) epoxy resins, (B), and also (2) dispersed finely-divided nonionic resins (II). The Mannich bases (A) are prepd. from (a1) ether gp.-free condensed phenols contg. at least 2 aromatic rings and at least 2 phenolic OH gps. and/or (a2) ether gp.-contg. phenols contg. at least 2 aromatic rings and at least 1 phenolic OH gp.; (a3) sec. amines contg. at least 1 hydroxyalkyl gp., opt. mixed with (a4) sec. dialkyl- or dialkoxyalkylamines contg. no free OH gps. and (a5) HCHO or HCHO-dissociating cpds. The aliphatic OH gps. derived from (a) and/or (b) are converted, at least partly, to urethane gps., esp. by reaction with partly masked isocyanates. The compsns. can be used for the electro-dip lacquering of metal parts, esp. of brass, Al, Cu, Fe, steel and Fe alloys.</p> |
