Method for preparing SIPE from SIPA by direct esterification method

Abstract

The invention discloses a method of preparing m-phthalic acid diglycol ester-5-sulphonate by directly esterifying m-phthalic acid-5-sulphonate. The m-phthalic acid-5-sulphonate (SIPA) and glycol (EG) are used as raw material and are directly esterified to prepare the m-phthalic acid diglycol ester-5-sulphonate (SIPE); the esterification rate is more than 99 percent, the acid value is less than 1(mgKOH / g), and the content of diglycol (DEGA) is less than 2.0 percent. Therefore, the m-phthalic acid diglycol ester-5-sulphonate (SIPE) which is manufactured by adopting the method is almost esterified completely; the disadvantages of high equipment investment, high recovery cost of methanol, and going against environment protection are elminated when the m-phthalic acid diglycol ester-5-sulphonate (SIPE) is prepared by using dimethyl-m-phthalate-5-sulphonate (SIPM) through an interesterification method; the m-phthalic acid diglycol ester-5-sulphonate (SIPE) has the characteristics of low acid value, high purity, less byproducts, etc.; the m-phthalic acid diglycol ester-5-sulphonate (SIPE) is used as a dye modifier or a third monomer and is added in polyester, so that the mass-producing demand is achieved; the method is a preparation method with stable way and excellent quality.

Description

technical field

[0001] The invention relates to a method for preparing diethylene glycol isophthalate-5-sulfonate by direct esterification of isophthalic acid-5-sulfonate. Background technique

[0002] The polyester industry has developed rapidly in my country in recent years, and various enterprises are developing differentiated polyesters, which can be used as polyester dyeing modifiers and the third monomer diethylene glycol isophthalate- The research on 5-sulfonate (SIPE) is being carried out a lot. SIPE is suitable for the large-scale PTA process route to produce the third monomer of cationic dyeable polyester, which can endow CDP polyester fiber with good softness to cationic dyes , so that the dyed CDP fiber has bright color, complete color spectrum, fast coloring degree, good antistatic property, hygroscopicity and air permeability, and at the same time plays a role in reducing dyeing cost and improving environmental protection. But what report at present mostly is to...

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