Organic pigments

Organic pigment refers to colored material made of organic compound with pigment properties. Common types include azo pigments, lake pigments, phthalocyanine pigments and quinacridone pigments. They are all artificially synthetic organic compounds. The intermediate, synthesis process and equipment required by such kind of pigments are generally the same as that required by organic dyes, therefore usually manufactured in the dye industry. However, as pigments, they are, after all, different from the organic dyes.

The organic pigment has no affinity to the colored substance, instead being attached to the surface of the colored substance through adhesive or film-forming material to achieve the purpose of coloring the object.

Organic pigment is a class of insoluble organic compounds of high coloring strength. The so-called insolubility means that they have extremely small solubility in water, organic solvent, and various kinds of media. For organic compounds used as pigments, they should also have a series of pigment characteristics, namely sunshine-resistant, resistant to flooding, acid-resistant, alkali resistant, organic solvents resistant, heat resistant and excellent dispersion property in the application medium and so on. From the perspective of the chemical structure, organic pigments are similar as the dyes with the difference of the two being that the former has no affinity to the substrate while the latter has certain affinity.

Therefore, the binding of the organic pigment to the substrate should rely on the adhesive or film-forming substances to fix them at the substrate surface. The organic pigments are widely used in the coloring of inks, paints, rubber products, plastic products and coating printing size. Organic pigments are generally classified according to their chemical structure with common varieties including azo pigments, lake pigments, phthalocyanine pigments, quinacridone pigments, diazine pigments, perylene red pigment and isoindolinone-based pigments.

Some properties of organic pigments such as bright color, good dispersion property, high tinting strength, etc. are not there immediately during the synthesis of this kind of compound and must be obtained through fine pigmentation processing steps. This kind of fine pigmentation processing technology is currently the major subject of the producers of organic pigment.

Organic pigments are mainly applied in the ink (50%), paint (25%), plastics (12%) and rubber (10%), four areas with other areas only accounting for about 3%. Pigments can provide many excellent performances such as color, durability, mobility and appropriate viscosity to the inks; as the coloring agents of plastics and synthetic fibers so that they have a beautiful color; in the rubber industry, it can be used as fillers and reinforcing agents. With different application conditions, the demands for the performance of the organic pigments are also different. But the general requirement is bright color, strong coloring power, heat and light, excellent dispersion, less oil absorption and strong hiding power.

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