Application of sodium isophthalic acid-5-sulfonate_Kain Industrial Additive

Overview^[1]

Dimethyl isophthalate-5-sodium sulfonate (commonly known as three monomers) is mainly used to synthesize the third monomer of cationic dyeable polyester (CDP), making CDP polyester fiber resistant to cationic fuels. Good affinity properties allow CDP fiber to be dyed under normal pressure. After dyeing, the color is bright, the color spectrum is complete, the color fastness is high, and it is not easy to fade. It also has good antistatic properties, hygroscopicity, anti-pilling properties and breathability, making it easy to wear. Comfortable. However, the current reported production method is to use different concentrations of fuming sulfuric acid or sulfur trioxide to sulfonate isophthalic acid, and then esterify with methanol, neutralize with soda ash or caustic soda, and refine the product. However, using trioxide Sulfonation causes the reaction to be violent and difficult to control, causing isophthalic acid to coke. The use of low-concentration sulfuric acid sulfonation results in excessive residual sulfuric acid and ultimately the production of a large amount of sodium sulfate. There are also many product by-products, and the mother liquor produced during the neutralization process (high Concentrated wastewater) is directly discharged from the system, which is difficult to treat and causes pollution to the environment.

Apply^[2-3]

Sodium 5-isophthalic acid sulfonate is a very important fine chemical product, mainly used as an intermediate and modifier for medicines, pesticides, and polyester.

1) Prepare a hydrophilic and easily dyeable cotton-like polyester, the raw materials of which include purified terephthalic acid and ethylene glycol, and are characterized in that the raw materials also include polypropylene glycol and isophthalic acid-5-sulfonic acid. Sodium, antimony ethylene glycol, cobalt acetate, stabilizer Irganox 1010, triphenyl phosphite, titanium dioxide, the polypropylene glycol, sodium 5-isophthalate sulfonate, antimony ethylene glycol, cobalt acetate, stabilizer Irganox 1010 , triphenyl phosphite, titanium dioxide, purified terephthalic acid, and ethylene glycol produce hydrophilic and easily dyeable cotton-like polyester through chemical reactions. The hydrophilic properties of polyester are achieved by adding polypropylene glycol, the easy dyeing properties of polyester are achieved by adding sodium 5-isophthalate, the matting properties of polyester are achieved by adding titanium dioxide, antimony ethylene glycol and cobalt acetate are added , stabilizer Irganox1010, and triphenyl phosphite to achieve polymerization reaction and stability of polyester, and ultimately achieve the hydrophilic and easy-dyeing cotton-like effect of polyester.

2) Prepare a polyester polyol aqueous dispersion by the following method: 1) Weigh neopentyl glycol, sodium 5-isophthalate sulfonate, Fascat 4100 and water; 2) Combine the steps 1. Mix each component, add nitrogen, raise the temperature while stirring, and heat at a constant temperature of 200-220°C until the acid value is less than 2 mg KOH/g. Cool down and grind while hot to powder to obtain a polyester polyol aqueous dispersion. Intermediate; 3) Weigh the intermediate, neopentyl glycol, isophthalic acid, trimethylolpropane and Fascat4100, then add adipic acid, trimethylolpropane and deionized water in sequence and stir to obtain the poly Ester polyol aqueous dispersion. Also disclosed is a quick self-repairing fluid for automobile scratches, which is composed of a polyester polyol aqueous dispersion and a curing agent, and the curing agent is isocyanate. The rapid self-repairing fluid for automobile scratches of the present invention has high gloss, high hardness, good repairability and is environmentally friendly.

Preparation^[1,4]

Method 1: Production process of sodium isophthalic acid-5-sulfonate, including the following steps:

1) Place high-purity terephthalic acid, 5-sodium sulfonate-diethyl isophthalate and 1,4-butanediol in a desiccator respectively, and dry at 130°C for 3 hours. The purity of formic acid is 85%;

2) Mix isophthalic acid and 60% fuming sulfuric acid at a weight ratio of 1:1, perform a sulfonation reaction at 140°C for 10 hours, and react with isophthalic acid and SO3 in fuming sulfuric acid to produce sulfonation. Product;

3) The obtained reaction product is placed in a polycondensation kettle, the reaction temperature is controlled to 350°C, and the polycondensation reaction is carried out under vacuum conditions for 2 hours;

4) Centrifuge the neutralized material, collect the neutralized mother liquor, then wash the material with water and centrifuge to obtain crude sodium dimethyl isophthalate-5-sulfonate, and collect the washed mother liquor;

5) Then add water 6 times the weight of isophthalic acid to the crude sodium dimethyl isophthalate-5-sulfonate and heat it to 90°C to dissolve, then cool it to below 50°C to crystallize, and collect the primary crystals mother liquor; then repeat the above hot melt crystallization step once to collect the secondary crystallization mother liquor; finally, the refined dimethyl isophthalate-5-sodium sulfonate after two crystallizations is dried to obtain the finished product.

Method 2: A production method of sodium isophthalic acid-5-sulfonate, which is characterized by: including the following steps:

Step 1: Take the following raw materials by weight: 1 part of oleum with a content of 30%, 2-5 parts of isophthalic acid; first put the 30% oleum into the reaction kettle, stir slowly Slowly add isophthalic acid; preferably, use the following weight ratio of raw materials: 1 part of fuming sulfuric acid with a content of 30%, and 2.2-2.8 parts of isophthalic acid;

Step 2: Turn on the electric heating, raise the temperature to 180-190°C and react for 4-8 hours; preferably, raise the temperature to 180-190°C and react for 4-6 hours;

Step 3: Stir and cool down to 40-80°C, slowly add water 0.3-0.5 times the amount of isophthalic acid for hydrolysis; preferably, stir and cool down to 60-80°C;

Step 4: During the hydrolysis process, stop adding water when the temperature range is 30-85°C. When the temperature is cooled to 25-35°C, centrifuge to obtain isophthalic acid-5-sulfonic acid; at this time, phthalic acid-5- The purity of sulfonic acid is above 99%; preferably, water addition is stopped when the temperature range is 50-75°C;

Step 5: Dissolve the above-mentioned 5-isophthalic acid-5-sulfonic acid in water, and put in the 5-isophthalic acid-5-sulfonic acid.The ratio of �� to water is 1:0.5, and with stirring, use 96% sodium hydroxide to adjust the pH to 7;

Step 6: Concentrate again, when the temperature is 45-95℃, sodium 5-sulfonate of isophthalate precipitates, then cool to 30-35℃ and centrifuge to obtain the product sodium 5-sulfonate of isophthalate and centrifuge Mother liquor, the purity of sodium phthalic acid-5-sulfonate is 95-99.6% at this time; preferably, when the temperature is 85-95°C, sodium phthalic acid-5-sodium sulfonate precipitates;

Step 7: Add the centrifuged mother liquor from step 6 to the isophthalic acid-5-sulfonic acid from step 4, heat to 50-100°C to dissolve, control the crystallization temperature to 45-95°C, and then cool to 30-35°C for centrifugation. The result of the product is sodium isophthalic acid-5-sulfonate and centrifugal mother liquor. The centrifugal mother liquor can be recycled and used. Preferably, the crystallization temperature is controlled to 89-95°C.