Vat Blue 4

Application Features

Vat Blue 4(Vat Blue  RSN) appearance is generally blue-black powder. It is insoluble in water, acetic acid, acetone, alcohol, pyridine, xylene and toluene; slightly soluble in chloroform (hot), o-chlorophenol, quinoline. It is brown in concentrated sulfuric acid and blue after dilution. Color precipitation. The leuco body formed by the dye in the alkaline powder solution is blue, and the acid powder solution is red blue.

Mainly used in yarn leuco dye and super fine powder can be used for cotton and polyester/cotton blended fabric of the suspension milk dye, also can be used for cotton direct printing and resist printing. Also can dye rayon, nylon and vinylon. Can be used for Peacekeeping/cotton, polyester/cotton blended fabric two bath dyeing set. Can also be processed into organic pigments used in ink and paint.

Vat Blue 4 Use condition:

1.Vat blue 4 is suitable for dyeing of cotton products when dyeing or dip dyeing. It is suitable for full-bath reduction. The reduction temperature is 55~60°C, and the temperature is not more than 60°C. The maximum time is 10min. Otherwise, It is very likely to produce crystallization, and it is prone to excessive reduction and cause dim light. In severe cases, the color is light, so the amount of insurance powder should be strictly controlled.

2. The leuco body has high affinity to cotton fiber, and the leveling property is general. The dyeing curve is shown in Figure 4-5-21. The dye leuco body has low solubility and is sensitive to hard water. It is advisable to use soft water to prepare dye solution. And dyeing. Due to the high dyeing rate of leuco body, it is easy to produce uneven dyeing and chromatic aberration when dyeing, especially light color.Vat blue RSN has poor hiding power for dead cotton, but its color is blue, light and light. It has excellent weather fastness. After dyeing, it is usually rinsed with cold water and oxidized by air. It can also be oxidized with hydrogen peroxide. If sodium borate or soda is added during soaping, it can be fully colored. Reduced blue RSN dyeing process The output is low, the quality is not easy to control, and most of them adopt the suspension padding. In order to make the dyed fabric bright and bright, it is necessary to strengthen the soaping.

3. Vat  blue 4 is used for direct printing. It needs to add urea and dissolved salt B in the printing paste without adding bismuth. The reducing agent is made of white powder. The oxidizing agent is suitable for sodium perborate. It can be dyed but not dyed.

4. When the vat blue RSN low-temperature dyed viscose fiber is reduced, the color is lighter, the dyeing temperature is increased, and the color light is slightly darker than the dyed cotton. When the cotton-cotton blend fabric is dyed at 60 ° C, the viscose fiber component is darker than cotton. The reduced vat blue RSN is used for the dyeing of the cotton blended (50/50) fabric. The color of the vinylon component is generally darker than cotton, and the shade is reddish and dark. The pure vinylon is dyed separately from the cotton red.

5. printing and dyeing fabrics are finished with BHES resin, and the color becomes green and dark.

Precautions

1. Vat blue 4 is prone to abnormal reactions such as excessive reduction and molecular rearrangement. Therefore, while strictly controlling the amount of insurance powder and the reduction and dyeing temperature, it is also necessary to pay attention to the amount of caustic soda, especially when the cylinder is dyed. Insufficient, it will cause the dye molecules to rearrange, forming a poorly water-soluble hydroxy fluorenone compound and not all dissolved, resulting in precipitation.

2. leuco body is sensitive to hard water, and the chemical and dyeing water must be softened first, or sodium phosphate is added to the dyeing solution. When immersed in leuco body, the permeability is poor, often producing “white core”. Suspension dyeing can be used if necessary.

3 leuco body is prone to excessive oxidation, and it is not suitable to carry alkali oxidation, otherwise the color is dim and green.

4.dyeing products are not resistant to chlorine bleaching. If the sodium hypochlorite bleaching liquid is easily over-oxidized, the color is green and dark. At this time, it is treated with a thin insurance powder solution (about 1g/L) to make it return to bright blue. color.

5. Vat blue 4 should be stored in a dry, ventilated place to avoid moisture.