| 摘要 |
Photosensitive compositions Liquid photosensitive compositions comprising, based on the entire composition (a) 10-50 % by weight of an epoxy di(meth)acrylate and/or a urethane di(meth)acrylate, (b) 15-45 % by weight of one or more than one bifunctional (meth)acrylate having a molecular weight in the ralnge from 150 to 450, (c) 0-20 % by weight of a trifunctional (meth)acrylate, (d) 0-10 % by weight of N-vinylpyrrolidone or N-vinylcaprolactam, (e) 0-10 % by weight of a monofunctional (meth)acrylate, (f) 15-30 % of one or more than one inert diluent selected from the group consisting of C2-C12alkohols, C4-Cl2alkanediols, C4-C12dialkylketonels, polyalkylene glycols, di- or triterpenes, hydroxyalkyl esters of .beta.-hydroxycarboxylic acids, caprolactams, chloropalraffins and diphthalates, diadipates or citrates, obtainable by reacting phthalic acid, adipic acid or citric acid with C1-C12alkohols, and (g) 3-7 % by weight of a photoinitiator, can be polymerised by actinic radiation and are particularly suitable for producing three dimensional objects by stereolithography. These objects may be used as models for producing ceramic shells for the investment casting technique.
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