Synthesis method for acid red R3G adapted for virgin pulp spray

Abstract

The invention relates to a synthesis method of protoplasm spray drying acid red R3G, comprising the steps of dissolution of 2-amino-5-naphthol-7-sulfonic acid, one-step condensation, diazoniation, coupling and finally two-step condensation. The 2-amino-5-naphthol-7-sulfonic acid is dissolved before the one-step condensation through that the 2-amino-5-naphthol-7-sulfonic acid is added to water and stirred evenly; then pH of the solution is adjusted to 7 through sodium hydroxide solution of 30 percent and the temperature rises to 60-70 DEG C; after the full dissolution, the solution is provided with a bush, the temperature is decreased to 25-15 DEG C and the solution is stirred for two hours under the temperature; then precipitated 2-amino-5-naphthol-7-sulfonic acid is filtered and filtering cake is pressed and dried for purpose in one-step condensation; the finished process is after the completion of dye synthesis, the strength of the 2-amino-5-naphthol-7-sulfonic acid is adjusted to the strength of finished product through glauber salt and spay dried under the temperature of outlet ranging from 90-110 DEG C and the finished produce can be packed directly at last. Compared with the products of the prior art, the acid red R3G of the invention improves 10 percent of yield, and eliminates waste water with salt generated from salt precipitation technique, which not only saves raw materials but also shortens production time, improves product economic benefit, eliminate discharge of waste water and facilitates environmental protection.

Description

Technical field [0001] The present invention relates to the technical field of reactive dyes, in particular to a method for synthesizing acid red R3G suitable for pure slurry spraying for dyeing cotton, wool, nylon and other fiber fabrics with acid red dye. Background technique [0002] Acid red R3G molecular formula: C 37 H 40 Cl 1 N 9 Na 2 O 7 S 2 The molecular weight is: 867.38. The dye has obvious characteristics such as bright color, excellent application performance, convenient use and strong applicability. There are factories at home and abroad for production. The current synthesis method of Acid Red R3G is as follows: [0003] 1) One-step condensation: Add cyanuric chloride to ice water, stir at 0-10°C for 10 minutes, and slowly add industrial acid. After the addition, adjust the pH to 5-6 with 10% sodium carbonate solution at 0--10°C. Under these conditions, react for 4-5 hours. [0004] 2) Diazotization: Add p-aminoazobenzene-4 sulfonic acid to the water to adjust the c...

AI Technical Summary

Problems solved by technology

[0009] However, the existing process adopts the salting-out refining process, which produces a large amount of salty and colored wastewater, which increases the difficulty and cost of environmental protection treatment

Moreover, the loss of dyestuff is inevitable in the process of salting out, about 8-10%, resulting in low yield, high consumption, and long working hours.

Especially the dye particles precipitated from the salt are irregular, and the dye solubility after drying is poor