Disperse Dye

Dyeing of cellulose acetate the disperse dye was originally developed. Disperse dye is water insoluble dye. Disperse dye can be used to dye polyester, acrylic fiber, nylon and triacetate. To dyeing with disperse dye there is needed 130ºC temperature and the dye bath must be pressurized.

Properties of Disperse dyes: The properties of disperse dye is given below,

1. Disperse dyes are nonionic dyes. So they are free from ionizing group.
2. Disperse dyes are ready made dyes and they are insoluble in water or have very low water solubility.
3. They are organic coloring substances which are suitable for dyeing hydrophobic fibers.
4. Disperse dyes are used for dyeing man made cellulose ester and synthetic fibers specially acetate and polyester fibers and sometimes nylon and acrylic fibers.
5. Carrier or dispersing agents are required fir dyeing with disperse dyes.
6. Disperse dyes have fair to good light fastness with rating about 4-5.
7. The wash fastness of these dyes is moderate to good with rating about 3-4.
8. Of all dyestuffs disperse dyes are of smallest molecular size.
9. Generally disperse dyes are derivatives of azo, anthroquinone, nitro and quinine group.
10. They do dot undergo any chemical change during dyeing.
11. In presence of nitrous oxide, textile materials dyed with certain blue and violet disperse dyes with an anthraquinone structure will fade. This is called gas fading of disperse dyes which is a defect of this dye.

Classification of Disperse Dyes:

1. According to the chemical structure:
1. Nitro dyes.
2. Amino ketone dyes.
3. Anthraquinonoid dyes.
4. Mono azo dyes.
5. Di-azo dyes.
2. According to fastness property:
1. Group A: These dyes have excellent dyes properties and good fastness properties.
2. Group B: These dyes are excellent in high temperature and for carrier dyeing with moderate fastness.
3. Group C: These dyes are moderate for carrier and high temperature dyeing with higher fastness property than group B dyes.
4. Group D: These dyes are of excellent fastness to heat but for dyeing properties on carrier method.
3. According to energy requirement:
1. Low energy dyes: These dyes are used to dye with carrier. For dyeing 77ºC temperature is required. They have extremely poor resistance to sublimation.
2. Medium energy dyes: These dyes are used to dye mostly in between temperature 104ºC -110ºC which provides better sublimation fastness than that of low energy dyes.
3. High energy dyes: These dyes are used to dye at temperature above 129ºC and are suitable for continuous dyes. They provide all round fastness properties.

Trade names of Disperse Dyes:

Name of dye	Manufacturer	Origin
Foron	Sandoz	Switzerland
Terasil	Ciba-Geigy	Switzerland
Dispersol	ICI	UK
Samaron	Hoechst	Germany
SRA	British Celanese Ltd.	UK
Setile	ACNA	Italy

Fastness properties of disperse dyes:

Fastness	Acetate	Triacetate	Nylon	Polyester	Acrylic
Washing	Moderate	Good	Poor -fair	Good	Very good
Light	Good	Good	Moderate-good	Good	Good
Crocking	Good	Good	Good	Moderate-good	Moderate
Gasfume fading	Fair	Moderate	Fair	Moderate	good