| 摘要 |
<p>PROBLEM TO BE SOLVED: To provide an ultraviolet-curable ink compsn. which can yield a curing film having high adhesion, excellent chemical resistance, high hardness, and, in addition, excellent abrasion resistance and gloss. SOLUTION: This compsn. is prepd. by continuously polymerizing not less than 30wt.% (meth)acrylate having one or more hydroxyl group and not more than 70wt.% monomer having one ethylenically unsatd. group at 150 to 350 deg.C to obtain a copolymer having an no. average mol.wt. of 1,000 to 10,000. This copolymer in its hydroxyl group is esterified with a monomer having one or more ethylenically unsatd. groups and one carboxyl group to prepare a reactive resin. This reactive resin is mixed with a reactive diluent comprising at least one ultraviolet-curable monomer and a photoinitiator. Use of a high-temp. continuous polymn. method for the polymerization can provide a copolymer having a relatively high mol.wt. and low viscosity and hence can reduce cure shrinkage of the compsn. and improve the adhesion of the cured film to a substrate and the like. The reactive diluent is pref. a difunctional or higher monomer.</p> |
