NOVEL MALEIMIDE-STYRENE COPOLYMER, ITS PRODUCTION AND QUADRATIC NONLINEAR OPTICAL MATERIAL

摘要

PROBLEM TO BE SOLVED: To obtain a novel polymeric substance which does not show the relaxation of an aligned structure at high temperatures and having good heat stability and quadratic nonlinear optical properties by using a maleimide/styrene copolymer comprising three types of structural units having specified structures and having a specified number-average molecular weight. SOLUTION: This copolymer comprises structural units of formulas I, II and III (wherein R is H or methyl) and has a number-average molecular weight of 10,000-200,000. This is obtained by the following reactions. A mixture of N-(4-hydroxyphenyl)maleimide represented by formula I with anα-methylstyrene represented by formula II is heated to 50-100 deg.C in the presence of a radical polymerization initiator (e.g. acetyl peroxide) in a polymerization solvent (the ratio between the constituents of the mixture is in the range of 2:1 to 1:2). The obtained white solid is reacted with a red dye represented by formula IV (wherein R is H or methyl) in the presence of a condensing agent in a reaction solvent to obtain a compound comprising structural units of formulas I to III and being in the form of a reddish brown solid.