| 摘要 |
PURPOSE:To obtain a photocurable resin which can form a coating film having flexibility, such a low shrinkage as not to deform a substrate, surface stating resistance and mar resistance by introducing a specified organic modified polysiloxane structural units into a polyurethane acrylate. CONSTITUTION:A polyurethane acrylate is produced by reacting a polyester diol component with a diisocyanate component and a hydroxylated alpha,beta-unsaturat ed monomer in such a way that 0.5-20wt.%, based on the total amount of the polyester diol component used, organic modified polysiloxane having dimethylsiloxane structural units of the formula (wherein n is 4-500) and at least one active hydrogen atom reactive with the NCO group is used. A photocurable resin composition is obtained by using at least 30wt.% this polyure thane acrylate. Even when applied thickly, the above resin can form a coating film having flexibility, such a low shrinkage as not to deform a substrate during curing, and excellent surface staining resistance and mar resistance. |
