UV-härtbare Kratzfestlacke mit einpolymerisierendem Verdicker

摘要

A coating compsn. for scratch-proof coatings on plastics consists of (1) 1-30 wt.% polymerisable prepolymer (I) as thickener, (2) 20-80 wt.% polyfunctional (meth)acrylate(s) (II), (3) 5-75 wt.% diluent, (4) 0.01-10 wt.% UV initiator and (5) 0-20 wt.% usual additive esp. UV absorber. The novelty is that (I) is obtd. by free radical polymerisation of (a) 90-99 wt.% 1-8C alkyl (meth)acrylate and (b) 1-10 wt.% S regulator with at least 3 thiol gps.. Also claimed are polymethyl methacrylate and polycarbonate panels (partly) coated with the cured compsn.. Pref. (I) is prepd. form (a) methyl methacrylate (MMA) and butyl methacrylate (BMA) and (b) a regulator with 4 thio gps. esp. pentaerythrityl tetrathioglycolate (PETTG).