| 摘要 |
<p>A cationic electrophoretic coating compsn. comprises an aq. medium having dissolved or dispersed in it an acid-neutralised resin binder which is (A) a mixture of, or a reaction prod. of, (a) 30-90 wt. pts. of the reaction prod. of 15-90 wt. % epoxy-amine adduct (I) and 85-10wt. % partially blocked polyisocyanate (II) and (b) 70-10 wt. pts. of a polyamide (III); or (B) a mixture of, or a reaction prod. of, (c) 10-70 wt. pts. of the reaction prod. of 10-85 wt. % (III) and 90-15 wt. % (II) and (d) 90-30 wt. pts. (I). (I) is the prod. of reacting an epoxy resin with a cpd. having >=1 basic amino gp. (II> is a polyisoxyanate having >=1 blocked NCO gp. in the molecule and an eye. >0 but is not >1 free NCO gp. pr molecule. (III) is a polyamide having >=1 basic amino gp. The compsn. can be applied to untreated steel, zinc phosphate-treated steel, iron phosphate-treated steel, zinc-plated steel, tin-plated steel, aluminium copper or copper alloy. Suitably it can be used as a primer for vehicles. The binder has more improved water-dispersibility than that of GB1501274, and coating films prepd. from it have excellent properties, particularly in corrosion resistance.</p> |
