Production process and product standard of 2-amino-5-naphthol-7-sulfonic acid

6.
Production process

In the sulfonation reactor, add fuming sulfuric acid and 2-naphthylamine-1-sulfonic acid, react at 35-45°C for 2h, then heat up to 105-115°C, keep warm and react for 10h
.

The above-mentioned sulfonate is added to it, and the temperature is kept at 110-120°C and stirred for 4 hours until the total acidity is about 500g/L
.

7.

8.
Quality inspection

Assay: Accurately weigh 16g of the sample, add 50mL of 10% sodium carbonate solution, dilute to a 500mL volumetric flask, add water to the mark, and shake well
.

Use a pipette to draw 50 mL into a beaker, add 50 mL 10% Na ₂ CO ₃ and 200 mL distilled water, and titrate with 0.
1 mol/L aniline diazonium salt at 0-5°C
.

In the formula: c——molar concentration of aniline diazonium salt standard solution, mol/L;

V——The volume of aniline diazonium salt standard solution consumed by the sample, mL;

G——The mass of the sample, g
.

9.
Product use

It is an important dye intermediate for the manufacture of azo dyes, such as direct green lotus R, direct light fast ash 2BL, direct acid violet, direct pink, direct copper dyed navy blue, light fast blue B2R, reactive scarlet, brilliant orange, grass green brown and red dyes can be used to manufacture scarlet acid and phenyl J acid, bis J acid and the like
.

10.
Security measures

(1) When using 2-aminonaphthalenesulfonic acid, fuming concentrated sulfuric acid, caustic soda and other toxic or corrosive raw materials in production, the equipment should be sealed, the operators should wear labor protection equipment, and the ventilation in the workshop should be strengthened
.

(2) The product is poisonous.
It is packed in wooden boxes lined with plastic bags and stored in a cool, dry and ventilated place
.