Optimization Process Of A Kind Of Phenolic Antioxidant

1,3,5-trimethyl-2,4,6-tris(3,5-di-tertbutyl-4-hydroxybenzyl)benzene was compou nded by reacting mesitylene with paraformaldehyde and 2,6-di-tert-butylphenol vi a sulfuric acid as catalyst which results in a serious contamination because of a huge moment of waste water and acid.Firstly,a solution made by methane-sulfonic acid and sulfuric acid was used to replace simplex catalyst--sulfuric acid.The yield is 83.2%.Another way to reduce contamination was using a sulfonic acid resin.The yield is 79.2%.In this method,a second catalyzing used sulfuric acid was necessary.The additive moment of sulfuric acid was decreased by 0.35~0.40 g per gram raw material in the third method.Optimize the crystallization process of UV-1330 through a kind of toluene-methanol mixed solvents.This new process insure product meet the market requirements which can reach as high as that of the imported ones without re-crystallization.Especially,the transmittance(@425nm/500nm)and purity even exceed the best standards of BASF.Meanwhile,the author proposed a method of solvent recycle for the reason that the mixed solvent form a binary azeotropic system which can avoid wasting.The average yield is 90.2%,the average ratio of mother-liquid recycle is 75.0%.The purity>99%,T425>98%,T500>99%.Meanwhile,a production commissioning was conducted at plant which was 2.6T inventory in total.Various markers of product were all met the Spec.In this essay,the structure of intermediate and target products were characterized by IR and NMR.Meanwhile,the assay,light transmittance and Ash of final products were also analyzed in order to meet the spec of application.