2-Hydroxy-3-naphthoyl o-toluidine and its production process and product standards

6.
Production process

In the salt-forming pot, add 4000L solvent chlorobenzene, 625kg 2,3-acid, 280kg sodium carbonate , and heat to 45°C.
After the carbon dioxide escapes, the temperature is increased for dehydration
.

When the temperature rises to 134～135℃, check that the steamed chlorobenzene is transparent and anhydrous, stop heating, and control the volume of the material to 2800L

Move the above-mentioned salt-forming dehydrated product into the condensation kettle, cool to about 90°C, add 358kg o-toluidine (98%), cool to 65～70°C, and evenly add the mixture of phosphorus trichloride and chlorobenzene within 2h (three Phosphorus chloride is 233kg, and about 170kg anhydrous chlorobenzene is used to make a 55%-60% mixture)
.

When the addition is complete, the temperature is at 118-120°C, and the heat preservation is condensed for 2 hours to obtain a condensate

Add 1000L of water and 330L of 30% liquid caustic soda into the still, and press the above condensate into it
.

After pressing, stir for 15 minutes, take a sample to determine the pH of the material in the range of 8.

7.
Product Standard

8.

Quality inspection

Content determination: Weigh 0.
75g of the sample (the scale is accurate to 0.
0002g), place it in a glass titration cup, and add 10 mL of absolute ethanol
.

Put in the electromagnetic stirring rod, cover the stopper, start the magnetic stirrer to fully wet the sample, add about 1.

Continue the titration.
When the pH is about 9 (that is, about 1.
5 pH from the titration end point of the total alkalinity), add the standard solution of hydrochloric acid, 1 drop each time, and record the corresponding pH and ml of the standard hydrochloric acid solution.
Count
.

When the difference between the two adjacent pH reaches the maximum, it is the end point of the total alkali titration (pH is about 1.

Blank experiment: In another glass titration cup, add 10 mL of absolute ethanol and 1.
1 mL of 10% sodium hydroxide
.

When the titration reaches pH 11, add 0.

In the formula: c——molar concentration of hydrochloric acid standard solution, mol/L;

V ₁ ——The volume of 0.

1mol/L hydrochloric acid standard solution used in the titration of free alkali, mL;

V ₂ ——The volume of 0.
1mol/L hydrochloric acid standard solution used in the titration of total alkali, mL;

△ _V ——The volume of 0.
1mol/L hydrochloric acid standard solution used in the blank experiment, mL;

G——The mass of the sample, g
.

9.
Product use

Ice dye naphthol
.

Mainly used as a bright red primer for cotton dyeing and cotton printing

10.
Security measures

(1) Toluidine, 2,3-acid, phosphorus trichloride, chlorobenzene and other toxic or strongly irritating raw materials are used in production
.
The reaction equipment should be sealed to prevent leakage
.
Operators should wear labor protection equipment and strengthen ventilation in the workshop
.

(2) The products are packaged in plastic bags lined with iron drums for external use, and stored in a cool, ventilated, dry warehouse, away from fire and heat sources, sun exposure, and heat and moisture
.
Store and transport in accordance with toxic chemicals regulations
.

Related links: 2-Hydroxy-3-naphthoyl o-toluidine and product performance and production principle