Patent ID: 6057034
Filing Date: 2000-05-02
Classification: C03C,C08F,C08G,Y10T

Abstract:
A coating composition for an optical fiber which comprises:(A) a polyurethane (meth)acrylate oligomer containing (d) a component with a number average molecular weight of 800 or less and (e) a component with a number average molecular weight of 1,000 or more, a proportion of the total amount of (d) and (e) to the total amount of (A) being 30% by weight or more, and a weight ratio of (d) to (e) being 51/49-70/30, which is obtained by subjecting (a) a polyisocyanate, (b) a polyol and (c) a (meth)acrylate monomer containing a hydroxyl group to a urethanation reaction; (B) an ethylenically unsaturated compound; and (C) a photopolymerization initiator, wherein said urethanation reaction is conducted under conditions that an equivalent ratio of NCO group in (a) to OH group in (b) is 3.1 to 30, and that a ratio of a remaining equivalent of NCO group calculated by subtracting the equivalent of OH group in (b) from the equivalent of NCO group in (a) to an equivalent of OH g roup in (c) is within a range of 0.9-1.1.