Hand-formable, light-curable sheet material - contains di- or tri- or poly-functional (meth)acrylate, mono- or di-functional urethane-acrylate oligomer, fillers, photoinitiators, etc.

摘要

A light-curable sheet material which can be shaped by hand is claimed (I), contg. finely-divided inorganic and/or organic fillers, hardenable synthetic resins, (II), photoinitiators and opt. other normal components. The novelty is that (II) is a mixt. of di-, tri- or poly-functional (meth)acrylate with mol. wt. 280-1000 (III) and a mono- or di-functional urethane-acrylate oligomer with mol. wt. 500-1500 (IV). (III) is a cpd. obtd. by reaction of 2,2,4- and 2,4,4,-trimethyhexa methylenedi isocyanate isomers with 2-hydroxyethyl and/or 2-hydroxypropyl (meth)acrylate, or (III) is triethylene- or tetraethylene -glycol di(meth)acrylate, glycerylpropyl triacrylate, PEG dimethyacrylate, dodecanediol dimethyacrylate, trimethylolpropyl ethoxy triacrylate, alkoxylated pentaerythrityl tetra-acrylate or Bisphenol A ethoxydi(meth)acrylate. (I) contains 15-75 wt. % (II). (IV) is 5-30 wt. % w.r.t. total mixts. Photoinitiators are benzil, benzil acetals, benzil dimethylketal, benzoyl alcohols, 2,3-borodione, 2-hydroxy-2 -methyl-1-phenyl propan-1-one and/or 2,4,6-trimethyl benzoyldiphenyl phosphine oxide. (I) also contains amine accelerators, pref. N,N-DMPT, N,N-dimethyl-(or -diethyl)-aminoethyl methacrylate, triethanolamine and methyldiethanolamine. (I) contains 25-85 wt. % fillers, pref. glass powder, fibre, flake, spheres or beads, quartz powder, finely-divided cristobalite, Al oxide, pyrogenic or pptd. silica, powdered plastic, fibres of polyamide, polyacrylate or polyacrylonitrile, and/or steel beads. USE/ADVANTAGE - (I) is useful for the prodn. of dimensionally stable hollow mouldings which are used to hold elastomeric moulding materials in the prodn. of duplicates or replicas. The material can be shaped by hand at room temp. and UV-cured without preheating and is non-toxic (contrast prior-art materials), it is therefore partic. suitable for making duplicates of art objects, etc.