A kind of production method of unsaturated polyester resin

Abstract

The invention discloses a production method of unsaturated polyester resin. By improving the end-capping process—by using benzoic acid monoester as the end-capping agent, the energy consumption generated in the heating and cooling process in the secondary feeding is avoided, so as to improve its durability. Properties of corrosion resistance, tensile strength and heat deflection temperature.

Description

Background technique [0001] UPR, Unsaturated Polyester Resin, unsaturated polyester resin, is the most common type of thermosetting resin. It is a linear polymer formed by polycondensation of saturated dibasic acid, unsaturated dibasic acid and diol. A resin solution with a certain viscosity formed by diluting a cross-linking monomer (generally styrene) or an active solvent. Unsaturated polyester resin is the most used variety of thermosetting resins in my country, and it is also the most used matrix resin in domestic glass fiber reinforced plastics, artificial stone, handicrafts, etc. From 2001 to the present, UPR has continued to grow, from 500,000 in that year tons increased to 1.85 million tons in 2014, an increase of 3.7 times. [0002] UPR produced by traditional methods generally has performance defects, mainly because: 1. General unsaturated polyester resins have more active groups, such as hydroxyl groups, carboxyl groups and other hydrophilic groups, and are extremel...

AI Technical Summary

Problems solved by technology

First of all, benzoic acid is used as an end-capping agent to participate in the reaction in the later stage of the reaction. The material must be lowered from about 220°C to about 150°C. After the feeding is completed, the temperature will be raised again to react, which will virtually increase the energy consumption of the product and prolong the production cycle. Affect the product color index; Secondly, the inherent characteristics of benzoic acid slightly soluble in water and easy to sublime make it in the high temperature reaction process, very easy to enter the condensation pipe with the esterification water to separate out, block the condensation pipe or enter the production waste water, increase Sewage treatment pressure, at the same time, the loss of benzoic acid per unit of product also increases

[0004] This technology aims to effectively reduce the end group activity of polyester by providing a benzoic acid end-capping improvement technology. Benzoic acid first reacts with diols to form a monoester, and then puts it into the reactor as an end-capping agent for UPR Capped to overcome the problems caused by the direct input of benzoic acid as a capping agent in the later stage of the reaction

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