| abstract |
(A) A polyalkylene polyether, a polyalkylene polyester and a polyalkylene polyether containing at least one organic group selected from an imide bond, an amide bond, a urea bond, a urethane bond and an ester bond. An oligomer having at least one structure selected from siloxane bonded to the organic group and having an ethylenically unsaturated group, (B) a reactive diluent, and (C) a general formula (1) shown below. (Wherein, R 1 to R 4 represent a monovalent organic group, and R 5 represents a divalent organic group). A photocurable resin composition comprising a photopolymerization initiator represented by the following formula: The composition of the present invention exhibits excellent curability even at a low UV irradiation dose, and when used as an optical fiber coating material, can achieve high productivity. Since it has excellent heat resistance and wet heat resistance, it is extremely useful as a coating material for optical fibers. |