UV-CURABLE COATING COMPOSITION AND COATED ARTICLES

摘要

An ultraviolet-curable coating composition obtained by blending (A) an at least tetrafunctional ultraviolet-curable (meth)acrylate which bears four or more (meth)acryloyl groups in the molecule and has a number-average molecular weight of 300 to 2,000 with (B) a lactone-modified polyhydric alcohol mono(meth)acrylate polymer which contains 20 to 60 % by mass of open-ring adducts of ϵ-caprolactone and has a hydroxyl number resulting from the modification with lactone of 100 to 180 mgKOH/g and/or a lactone-modified polyester resin which contains 10 to 50 % by mass of open-ring adducts of lactone and has a hydroxyl number of 50 to 180 mgKOH/g, (C) a non-yellowing polyisocyanate and/or an amino resin, (D) a light stabilizer and (E) a photopolymerization initiator at a mass ratio of (A)/[(B)+(C)] ranging from 10:90 to 50:50 and at a (B)/(C) mass ratio ranging from 90:10 to 20:80 in such a way as to give a cured coating film which has a Knoop hardness of 10 to 18 and a molecular weight of the crosslinked resin component between crosslinks ranging from 150 to 300. The composition can give coating film excellent in mar resistance, decorativeness, tight adhesion, and gasoline resistance at high productivity.