Manufacturing method of low-melting-point polyester granules

Abstract

The invention discloses a manufacturing method of low-melting-point polyester granules. Terephthalic acid and ethylene glycol are firstly adopted as raw materials, prepared into even size at a molar ratio of 1 : (1.1 to 1.3) and thrown into an esterification kettle for an esterification reaction, and then isophthalic acid and ethylene glycol which are prepared into even size are thrown into the esterification kettle for an esterification reaction, wherein the molar ratio of the isophthalic acid to the ethylene glycol is 1 : (11 to 2) and the molar ratio of the terephthalic acid to the isophthalic acid is (2 to 3.5) : 1; the distillation quantity of esterified water, which reaches a calculated value, is taken as the evidence for a reaction endpoint; then after a compression stage, a normalpressure stage, a low vacuum stage and a high vacuum stage of a condensation polymerization stage, when the motor power of a stirrer reaches a required numerical value, a condensation polymerization reaction is stopped; and after the processes of strip-casting material discharge, underwater material cutting, cooling, transportation, drying and packaging, the low-melting-point polyester granules are obtained. The method has the advantages of low manufacturing cost and excellent product performance and is suitable for spinning; and industrial production can be realized by utilizing a polymerization device.

Description

technical field [0001] The invention belongs to the technical field of polyester production, in particular to a method for preparing low-melting polyester pellets suitable for spinning. Background technique [0002] Low-melting point polyesters are divided into two categories according to different forms. One is hot-melt adhesive in the form of powder or granule, which is widely used in automobiles, textiles, construction, cable and wood processing, etc.; the other is hot-melt adhesive in the form of fiber. Melt fiber, that is, fiber-type adhesive, is widely used in the production of non-woven fabrics. Because the processing method of fiber-type adhesive is simple and the energy consumption is low, compared with other types of adhesives, it has the advantages of rapid bonding, high strength, Non-toxic, non-polluting and other excellent properties. The application prospect is broad. The performance requirements of the two types of products for the raw material low-melting p...

AI Technical Summary

Problems solved by technology

Most of China's patents such as publication numbers CN1618832A, CN101338023A, CN101367914A and CN101367915A etc. all select 1,4-butanediol as modifier. In the reaction of diol, the proportion of tetrahydrofuran produced by the side reaction is high, the control process conditions are high, and the product performance is unstable.

In addition, in the prior art, although the melting point and bonding performance of the produced low-melting point polyester meet the requirements for use, it has no practical value because its spinnability and processability are very poor. Coil, wool and broken filaments are serious during spinning and forming, and the production efficiency is low

Or the produced silk has bamboo knots, or the strength is low and the bulkiness is poor, it is difficult to meet the requirements of hard cotton

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