Friday, May 18, 2012
Properties of Basic Dyes
1. The outstanding characteristics of the basic are brilliance and intensity of their colors.
2. The bright colors achieved from basic dyes do not usually occur with other dye classes.
3. Many of the basic dyes are sparingly soluble in water.
4. The addition of glacial acetic acid helps to dissolve the basic dye quickly in water.
5. Basic dyes are readily soluble in alcohol or mentholated spirit.
6. The basic dyes are poor fastness to light and vary with regard to washing fastness from poor to moderate.
7. An important property of basic dyes is that they will combine with tannic acid to form an insoluble compound provided mineral acid is absent.
8. The wet fastness of the basic dyes on protein fibres can also be improved by back tanning. This consists of after treating the dyed material with tannic acid in order to form the insoluble complex thereby reducing the tendency to migrate.
9. The basic dyestuff will combine with direct or sulphur or some acid dyestuffs. So they cannot be used together in the same bath. But basic dyestuffs are used in after treating cotton or other materials dyed with direct colors. Here the direct dyestuff acts as mordant.
10. When treated with a reducing agent most of the basic dyes get converted into their colors less leuco compounds, return to their original color by oxidizing agents or even by exposure to air.
11. Basic dyes can be removed from the material by boiling it with dilute acetic acid or hydrochloric acid.
12. Basic dyes are used for woolen goods when particularly bright shades are required which cannot be obtained with an acid dyes.
13. Basic dyes do not have affinity for cellulosic fibres like cotton. The use of basic dyes on cotton involves the troublesome process of mandating with tannic acid. But, sometimes, bright shades are demanded on cotton which can only be obtained with them.
14. Special cationic dyes are available for dyeing acrylic fibres.
15. Basic dyes are also used for making inks, typewriter ribbons and dyeing leather
1. The outstanding characteristics of the basic are brilliance and intensity of their colors.
2. The bright colors achieved from basic dyes do not usually occur with other dye classes.
3. Many of the basic dyes are sparingly soluble in water.
4. The addition of glacial acetic acid helps to dissolve the basic dye quickly in water.
5. Basic dyes are readily soluble in alcohol or mentholated spirit.
6. The basic dyes are poor fastness to light and vary with regard to washing fastness from poor to moderate.
7. An important property of basic dyes is that they will combine with tannic acid to form an insoluble compound provided mineral acid is absent.
8. The wet fastness of the basic dyes on protein fibres can also be improved by back tanning. This consists of after treating the dyed material with tannic acid in order to form the insoluble complex thereby reducing the tendency to migrate.
9. The basic dyestuff will combine with direct or sulphur or some acid dyestuffs. So they cannot be used together in the same bath. But basic dyestuffs are used in after treating cotton or other materials dyed with direct colors. Here the direct dyestuff acts as mordant.
10. When treated with a reducing agent most of the basic dyes get converted into their colors less leuco compounds, return to their original color by oxidizing agents or even by exposure to air.
11. Basic dyes can be removed from the material by boiling it with dilute acetic acid or hydrochloric acid.
12. Basic dyes are used for woolen goods when particularly bright shades are required which cannot be obtained with an acid dyes.
13. Basic dyes do not have affinity for cellulosic fibres like cotton. The use of basic dyes on cotton involves the troublesome process of mandating with tannic acid. But, sometimes, bright shades are demanded on cotton which can only be obtained with them.
14. Special cationic dyes are available for dyeing acrylic fibres.
15. Basic dyes are also used for making inks, typewriter ribbons and dyeing leather
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basic dye
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Textile Technology: Basic Dyes | Properties of Basic Dyes
Properties of Basic Dyes 1. The outstanding characteristics of the basic are brilliance and intensity of their colors. 2. The bright color...
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