A colored substance having affinity to the substrate to which it is being applied is a Dye.
Types Of Dyes:
-Direct dyes:These dyes are water soluble anionic dyes,when dyed from aqueous solution in the presence of electrolytes,have high affinity for cellulosic fibers.Used in dyeing of cotton and regenerated cellulose,paper,leather,nylon.
-Vat dyes:These dyes are water-insoluble, are applied mainly to cellulosic fibers as soluble leuco salts after reduction in an alkaline bath, by sodium Hydrosulphite.
-Sulfur dyes:These dyes are applied to cotton from an alkaline reducing bath with sodium sulfide as the reducing agent.
-Cationic dyes:These dyes are water-soluble cationic dyes which are applied to paper,polyacrylonitrile (e.g. Dralon), modified nylons, and modified polyesters.
(Source-Google images)
Advantages-
A material that changes the color of reflected or transmitted light as the result of wavelength-selective absorption is a Pigment.Types Of Dyes:
-Direct dyes:These dyes are water soluble anionic dyes,when dyed from aqueous solution in the presence of electrolytes,have high affinity for cellulosic fibers.Used in dyeing of cotton and regenerated cellulose,paper,leather,nylon.
-Vat dyes:These dyes are water-insoluble, are applied mainly to cellulosic fibers as soluble leuco salts after reduction in an alkaline bath, by sodium Hydrosulphite.
-Sulfur dyes:These dyes are applied to cotton from an alkaline reducing bath with sodium sulfide as the reducing agent.
-Cationic dyes:These dyes are water-soluble cationic dyes which are applied to paper,polyacrylonitrile (e.g. Dralon), modified nylons, and modified polyesters.
(Source-Google images)
Advantages-
- Obtained from renewable source.
- No disposable problems as they are biodegradable.
- Natural dyes are cost effective.
- Possible to obtain a full range of colours using various mordants.
- Unsophisticated and harmonized with nature.
Types Of Pigments-
Inorganic Pigments- Generally are metallic oxides or synthetics. These Mineral-earth type pigments are very simple and naturally occurring colored substances.
Organic Pigments-Not usually found in nature,these pigments are chemically synthesized.Used as mass colorants;popular in plastics, synthetic fibres and as surface coatings-paints and inks.
Characteristics Of Organic Pigments-
- Very bright, pure, rich colors.
- Very good stability to solvents, light, heat, and weathering
- Good tinctorial strength.
- Consistency and unique shades.
(COLORANTS: MARKET SHARE, BY GEOGRAPHY, 2013)
The global pigments market is projected to grow at a CAGR of 4% from 2013 to 2018. In the pigments market, TiO2 holds the maximum share. The demand for organic pigments is expected to grow mainly due to increasing demand for high performance pigments. However, growth in the organic pigments will be restricted due to its high cost as compared to inorganic pigments.
For more info,visit-
No comments:
Post a Comment