Why do disperse dyes add glacial acetic acid

Why do disperse dyes add glacial acetic acid,
domestic glacial acetic acid, Glacial Acetic Acid, Glacial acetic acid manufacturers, Glacial Acetic Acid Suppliers, Hebei glacial acetic acid,
Quality specification(GB/T 1628-2008)

Physicochemical properties:
1. Colorless liquid and irritating dour.
2. Melting point 16.6 ℃; boiling point 117.9℃; Flash point : 39 ℃.
3. Solubility  water, ethanol, benzene and ethyl ether immiscible, insoluble in carbon disulphide.

Storage:
1. Stored in a cool, ventilated warehouse.
2. Keep away from the fire, heat. The cold season should maintain a temperature higher than 16 DEG C, to prevent solidification. During cold season, temperature should be maintained above 16 DEG C to prevent/avoid solidification.
3. Keep the container sealed. Should be separated from the oxidant and alkali. Mixing should be avoided by all means.
4. Use explosion-proof lighting, ventilation facilities.
5. Mechanical equipment and tools that prohibit the use of easy to produce sparks.
6. Storage areas should be equipped with emergency treatment equipment and suitable housing materials.

Use:

1.Derivative:Mainly used in synthetising acetic anhydride,acetic ether,PTA, VAC/PVA,CA,ethenone,chloroacetic acid,etc
2.Pharmaceutical:Acetic acid as solvent and pharmaceuticalraw materials, mainly used for production of penicilin G potas-sium, penicilin G sodium, penicillin procaine, acetanilide,sulfadiazine, and sulfamethoxazole isoxazole, norfloxacin,ciprofloxacin, acetyl salicylic acid, non phenacetin, prednisone,caffeine, etc.
3.Intermediate:acetate ,sodium hydrogen di,peracetic acid,etc
4.Dyestuff and textile printing and dyeing:Mainly used inproducing disperse dyes and vat dyes,and textile printing anddyeing processing
5. Synthesis ammonia: In the form of cuprammonia acetate,used in refining syngas to remove a litl CO and CO2
6. Photograph: Developer
7. Natural rubber: Coagulant
8. Construction industry: Preventing concrete from frezing9. In addtin also widely used in the water treatment, syntheticfiber, pesticides, plastics, leather, paint, metal processing andrubber industry

Disperse dyes are used every day, but you can immediately say, why do disperse dyes add glacial acetic acid to adjust PH? (Organic acids are now added to adjust PH, with the exception of alkaline disperse staining.)

The reason is:

The stability of disperse dyes in dye bath is closely related to pH value. Especially at high temperature and high pressure, if the pH value of the dye bath is not strictly controlled, it will often cause the variation of color light, the main reasons are as follows.

(1) Cause the accelerated hydrolysis of disperse dyes, in the process of dye manufacturing, often add a large number of dispersant, such as diffuser NNO, lignin, sodium carbonate, so that the dye solution is weak alkaline, in
When dyeing at 130% high temperature, it is easy to hydrolyze, resulting in light color and faint light.
(2) Due to the reduction decomposition of disperse dyes, the loss of hair base group, this phenomenon is often in the azo structure of dyes.
(3) The phenolic group in the molecular structure of dyes causes ionic reactions due to the action of alkali, and the water solubility is enhanced, while the upper dyeing is weakened correspondingly. Often, the dispersing liquid of dyes is weak alkaline due to the addition of dispersant in the dyeing bath.