Flame-retardant polyester and producing method thereof

Abstract

The invention relates to flame-retardant polyester and a producing method thereof. The flame-retardant polyester comprises a phosphorous compound structure unit, wherein the content of phosphorus is in a range of 8,000-12,000 ppm and the content of diglycol is lower than 2.0wt% when compared with the total amount of the flame-retardant polyester. The polyester is mainly prepared from terephthalic acid and glycol through an esterification reaction and a polymerization reaction, a phosphorus-containing flame retardant is added after the esterification reaction is finished and before the polymerization reaction is started, and the temperature in a polymerization kettle is controlled to range from 210 DEG C to 230 DEG C during addition of the flame retardant. The polyester is excellent in flame-retardant performance and good in crystallinity and keeps the melting point of ordinary polyester. Fibers produced from the polyester are excellent in dry heat shrinkage and applicable to nonflammable materials such as curtains and the like.

Description

technical field [0001] The invention relates to a flame-retardant polyester with high phosphorus content and a manufacturing method thereof. Background technique [0002] Polyester fibers, represented by polyethylene terephthalate, are widely used to make clothing materials due to their excellent mechanical strength and heat resistance. However, since polyester fiber is combustible, its application in fields requiring flame retardancy is greatly limited. With the improvement of people's awareness of fire protection, the research and application of flame-retardant polyester fibers are becoming more and more active all over the world, and various flame-retardant polyester fiber products are constantly coming out. [0003] At present, most of the flame retardants used in polyester fibers are phosphorus-containing flame retardants, and the existing production technology of flame-retardant fibers is becoming more and more mature. The current flame-retardant polyester fa...

AI Technical Summary

Problems solved by technology

Regarding flame-retardant fiber products with a phosphorus content of more than 8000ppm, although there are related technical introductions, as the amount of copolyphosphorus compounds increases, the crystallinity of polyester decreases, and the melting point of polyester decreases significantly, resulting in an increase in fiber shrinkage. The final product is greatly compromised in feel

[0004] Chinese patent application CN201110073511.2 discloses a flame-retardant polyester fiber and its production method, wherein the phosphorus content is 5000-7500ppm, and the DEG content is below 2.5wt%. Compared with flame retardant varieties with phosphorus content above 8000ppm, there is still a certain gap

In this patent, the melting point of polyester fiber is controlled by controlling DEG content below 4mol% (equivalent to 2.2wt%) so that it will not be too low, but once the phosphorus content in polyester fiber exceeds 8000ppm, excessive phosphorus compounds will still This leads to a serious drop in the melting point of the fiber. Although this polyester fiber has good flame retardancy, its shrinkage rate is relatively high, which affects the feel of the fabric and greatly limits its application.

This patent does not give a method and hint for maintaining high processing performance of polyester while having high phosphorus content and high flame retardancy

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