Preparation method of hydrolysis-resistant PBT polyester resin

Abstract

The invention relates to a preparation method of hydrolysis-resistant PBT polyester resin. The preparation method comprises the following steps: mixing terephthalic acid, 1, 4-butanediol, an organic titanate compound and magnesium phosphate to prepare slurry; carrying out esterification reaction to obtain a prepolymer; carrying out melt phase polycondensation reaction to obtain a PBT polyester resin substrate; and finally, mixing the PBT polyester resin substrate, an end-capping modifier and an organic phosphate compound in a twin-screw extruder, thereby obtaining the hydrolysis-resistant PBTpolyester resin. 97-99 parts by mass of the PBT polyester resin substrate, 0.5-1 part by mass of the end-capping modifier and 0.01-1 part by mass of the organophosphate compound are added in the mixing process. The end capping modifier is hyperbranched polyester of which the number of terminal hydroxyl groups is 6-100 and a branch unit contains 2, 2-dimethylolpropionic acid. The preparation methodis simple, and the prepared hydrolysis-resistant PBT polyester resin has excellent comprehensive performance.

Description

technical field [0001] The invention belongs to the technical field of polyester resin and relates to a preparation method of hydrolysis-resistant PBT polyester resin. Background technique [0002] Polybutylene terephthalate (PBT) is a thermoplastic polyester formed by polycondensation of terephthalic acid (PTA) and butanediol (BDO). It has excellent mechanical, physical and chemical properties, such as easy processing, High temperature resistance, chemical resistance, oil resistance, good mechanical strength and other properties, have been widely used in the fields of automobiles, machinery, instruments, electronics, household appliances, textiles and civilian use. [0003] PBT resin has excellent hydrolysis resistance under dry and hot conditions, but in many applications, such as underground optical cables, automotive parts, electrical appliances, solar films, etc., PBT resin is very prone to hydrolysis in the case of a large amount of moisture and high temperature aging....

AI Technical Summary

Problems solved by technology

[0008] The invention provides a method for preparing a hydrolysis-resistant PBT polyester resin, the purpose of which is to solve the problem of poor hydrolysis resistance of PBT resins in the prior art, resulting in a decrease in product molecular weight, serious loss of mechanical properties, and limited applications, as well as the improvement of PBT in the prior art. The preparation process of the hydrolysis resistance of polyester resin is complicated, and it is necessary to add chain extender, nucleating agent and other additives at the same time as the end-capping agent, which will affect its processing performance and color value.