RESIN ADDITIVE, ITS PREPARATION, AND RESIN COMPOSITION CONTAINING THE SAME

摘要

PURPOSE:To improve the transparency and antiblocking properties of a resin compsn. contg. the title additive by modifying zeolite particles so as to have a specified change in the molar ratio of SiO2/Al2O3 and a specified refractive index. CONSTITUTION:A homogeneous aq. zeolite suspension is prepd. wherein the zeolite has a crystalline structure easily destroyed by an acid, a molar ratio of SiO2/Al2O3 of 5 or lower, and a means particle diameter of 0.1-10mum, and wherein particles having particle diameters of 1/2-3/2 of the mean diameter account for 50wt.% or higher of total particles. The suspension is mixed with aluminum ions in an amt. of at least 50% of the cation exchange equivalent of the zeolite to make the zeolite noncrystalline at a pH of 3.5-5 without destroying the state of particles, thus giving a resin additive comprising a noncrystalline aluminum silicate showing a decrease in the molar ratio of SiO2/Al2O3 before and after the treatment of 10-50%, having a refractive index of 1.45-1.55, and substantially retaining the state of particles of zeolite.