Benzenesulfonic acid, 4-[(phenylmethyl)amino]-, sodium salt (1:1)

Add 400kg of water into the reaction kettle, add 86kg of sodium pudding under stirring, and then slowly add p-aminobenzenesulfonic acid above 90°C and stir until fully dissolved. Start dropping 100 kg of benzyl chloride around 95°C. The pH value was around 9 during the reaction. After the addition is completed, react at 90～95℃ for 5h. Sampling to measure the end point (the sample is opaque at the end point, without stratification, and the pH value is 7-9). Cool down, filter, put the filtrate into the pickling kettle, add ice water at a double speed, cool to 20°C, acidify with hydrochloric acid to a pH of 2. After filtering, the filter cake is p-benzylaminobenzenesulfonic acid. Neutralize with Na2CO3 aqueous solution, concentrate, cool and crystallize, filter and dry, pulverize and mix to mix with cosolvent B.

This product is mainly used as a co-solvent, diffusing agent and leveling agent for printing of vat dyes, sulfide vat dyes and soluble vat dyes. It can also be used as a whitening agent for ice dyes and direct dyes.