LIGHT DIFFUSING PLASTIC AND FINE PARTICLE SUITABLE THEREFOR

摘要

PURPOSE:To obtain a light diffusing plastic having a high brightness in the front and great diffusion half-value angle by dispersing transparent fine particles having an average particle diameter and refractive index satisfying specific relations in a transparent plastic. CONSTITUTION:A light diffusing plastic obtained by dispersing (B) fine particles having a particle diameter [(d)mu] and refractive index (Np) satisfying formulas I and II and preferably containing particles having pores therein in an amount of <=3wt.% based on the total fine particles and nonspherical particles in an amount of <=10wt.% based on the total fine particles in (A) a transparent plastic (preferably methacrylic resin or copolymer resin of methyl methacrylate and styrene) consisting of a refractive index (Ns). The above-mentioned fine particles preferably consist of a crosslinked polymer, especially a copolymer of methyl methacrylate, styrene, an alkyl methacrylate and polyfunctional (meth)acrylate.