Are you still confused about organic pigments, inorganic pigments and dyes?
It is well known that colorants are basically classified into organic pigments, dyes, and inorganic pigments, and organic pigments have recently developed rapidly. What are the similarities and differences between the two other colorants?
The similarities and differences between organic pigments and dyes, that is, organic pigments and dyes are all colored organic compounds. From the chemical structure of organic pigments and dyes, the two are very similar, and even some organic compounds can be used both as dyes and as organic pigments. Used, but organic pigments and dyes are indeed two different concepts, the difference between them is mainly the application performance. The traditional use of dyes is to dye textiles, while the traditional use of pigments is to color non-textiles (eg, inks, paints, coatings, plastics, rubber, etc.). This is because the dye has affinity (or direct) to the textile, and can be adsorbed and fixed by the fiber molecules; and the pigment has no affinity for all the colored objects, mainly by combining other film-forming substances such as resin and adhesive with the coloring object. Together. The dye is generally dissolved in the use medium during use, even if it is a disperse dye or a vat dye, it undergoes a process of dyeing from the crystal state to the molecular state and then dyeing onto the fiber.
Therefore, the color of the dye itself does not represent its color on the fabric. Since the pigment is insoluble in the use medium during use, it always exists in the original crystal state. Therefore, the color of the pigment itself represents its color in the substrate. Because of this, the crystal state of the pigment is important to the pigment, and the crystal state of the dye is less important, or the crystal state of the dye itself is not closely related to its dyeing behavior. Pigments and dyes are different concepts, but they can be used in general under certain circumstances. For example, some anthraquinone vat dyes, which are insoluble dyes, can also be used as pigments after pigmentation. Such dyes are called pigmentary dyes, or dyed pigments.
Similarities and Differences Between Organic and Inorganic Pigments Organic pigments have many unique advantages over inorganic pigments. Organic pigments can produce a wide variety of varieties by changing the molecular structure, and have more vivid colors and brighter tones than inorganic pigments. Organic pigments also have much higher tinting strength than inorganic pigments, and can produce high coloring power and high transparency to meet the requirements of high-grade coatings and printing inks. Most organic pigments are less toxic, and most inorganic pigments contain heavy metals such as chrome yellow, red dan, and vermilion. Low-grade organic pigments are inferior to inorganic pigments in terms of light fastness, weather fastness, heat resistance and solvent resistance, but some high-grade organic pigments (such as quinacridone pigments, phthalocyanines) Pigments, etc.) have excellent light fastness, weather fastness, heat resistance and solvent resistance, and their acid/base resistance is superior to inorganic pigments because some inorganic pigments have poor acid/base resistance. For example, chrome yellow will turn black when it encounters hydrogen sulfide, and it will turn red when it is alkali; it is easily decomposed by acid. The variety, type, yield and application range of organic pigments are constantly growing and expanding, and have become an important class of fine chemical products.