Process for manufacturing coloration additive for producing positive ionic dye dyeable polypropylene

Abstract

The preparation process of the dyeing additive includes the ester exchange reaction of 5-sodium sulfodimethyl isophthalate and glycol in the presence of catalyst to obtain 5-sodium sulfodihydroxyethyl isophthalate; the esterification reaction of terephthalic acid and glycol in the presence of catalyst and stabilizer to obtain dihydroxyethyl terephthalate; the pre-polycondensation of 5-sodium sulfodihydroxyethyl isophthalate and dihydroxyethyl terephthalate at 210-240 deg.c; the polycondensation of the reactant system at 240-290 deg.c and vacuum degree lower than 100 Pa and final casting and pelletizing to obtain the additive product. The additive product has high 5-sodium sulfodimethyl isophthalate content and may be used in mixing melt spinning process to produce dyeable polypropylene fiber capable of being dyed with cationic dye in high dyeing degree.

Description

technical field [0001] The invention relates to a method for preparing modified polyester by copolymerization of terephthalic acid, 5-sodium sulfonate dimethyl isophthalate and ethylene glycol, and the modified polyester is used as a dyeing additive for dyeable polypropylene fiber. Background technique [0002] Polypropylene has many advantages such as light specific gravity, high strength, good warmth retention, breathability, good moisture conductivity, strong chemical corrosion resistance, etc., and the source of manufacturing raw materials is abundant, and the price is low. It has developed rapidly in recent years and its application fields have also continued to expand. However, due to the high crystallinity and compact structure of polypropylene, and the lack of polar groups that can combine with dye molecules on the molecular chain, that is, the lack of dyeing seats, it cannot be dyed by conventional methods. Usually, people use the method of dope dyeing or masterbatc...

AI Technical Summary

Problems solved by technology

However, such good dyeing performance in the prior art can only be achieved by dyeing with disperse dyes, and there are few reports about dyeing with cationic dyes and having a higher dye uptake rate. Color diversity and color fastness are better than disperse dyes