ADHESIVE FOR OPTICAL FIBER

PURPOSE:To obtain the titled adhesive, consisting of an epoxy compound having F in the molecule and specific two kinds of photopolymerizable compounds, having refractive index conformity with a quartz based optical fiber and excellent adhesive strength, water resistance and curability in a short time. CONSTITUTION:An adhesive obtained by blending (a) an epoxy compound having F, at least two epoxy groups in the molecule and 100-400 epoxy equiv. (e.g. bisphenol type epoxy resin) with (b) at least one photopolymerizable compound selected from compounds expressed by the formula (R1 is H or methyl; R2 and R3 are aliphatic, aromatic or alicyclic residue or the residue in which H thereof is substituted by F; A is ester bond; m and n are 1-3) and unsaturated carboxylic acid compounds (e.g. acrylic acid) and (c) a photopolymerizable compound having one or more photopolymerizable double bonds in the molecule without any carboxyl group [e.g. methyl (meth)acrylate] at 10:90-90:10 weight ratio of the component (a) to the total amount of the components (b) and (c) so as to provide 10-100wt.% component (b) based on the total amount of the components (b) and (c).