ULTRAVIOLET-CURABLE INK COMPOSITION, FORMATION OF CURED COATING FILMS AND USE OF ULTRAVIOLET-CURABLE INK COMPOSITION

摘要

PURPOSE: To provide an ultraviolet-curable ink composition which can be suitably used to form tentative coatings for protecting flexible substrates by using urethane (meth)acrylate oligomer, reactive diluents and ultraviolet-polymerization initiator as the major components. ;CONSTITUTION: The ultraviolet-curable ink composition comprises (A) 30 to 60wt.% of a urethane oligomer having more than 4,000 molecular weight and bears 2 or 3 (meth)acryloyl groups in one molecule, (B) 10 to 40wt.% of a reactive diluent such as N-vinyl-2-pyrrolidone, polyfunctional (meth)acrylate), and (C) 1 to 10wt.% of an ultraviolet-polymerization initiator such as benzoin, azoisobutyronitrile, as major components. Coating films are formed with the composition, irradiated with ultraviolet rays to give cured, films of 50 to 200kg/cm² tensile strength, more than 200% elongation, having rubber elastic properties. When a flexible print circuit is plated, the coating films of the composition are formed on the parts not to be plated and cured by irradiation of ultraviolet rays.;COPYRIGHT: (C)1993,JPO&Japio