pigment

The pigment is a white or colored fine powdery substance which is insoluble in a medium such as water or oil and can be uniformly dispersed in a medium. In this system, the pigment is a dispersed phase, the medium is a continuous phase, and various The medium (including the color developing agent) is mixed together to color the object, and the pigment itself is insoluble in the coloring matter, and the object can be rendered in a certain color. Such a substance is called a pigment. Some literature also defines that the pigment does not chemically react with the pigmented material. With the advancement of science and technology, this definition has been broken because some pigments can play a certain chemical role with the coloring matter. As the pigment, it should have an appropriate color (including white), coloring power, hiding power, high dispersibility, stability to light, and vivid color. According to the chemical composition, it is divided into inorganic pigments and organic pigments; according to the color, it is divided into white, red, yellow, black and other pigments; according to the source, it is divided into natural and synthetic pigments, and natural pigments are divided into animal pigments, plant pigments and mineral pigments. Mineral (inorganic) such as Heshi, cinnabar, laterite, realgar, etc., animal and plant (organic) such as garcinia, cochineal, etc., synthetic pigments also have two major categories of inorganic and organic; according to the use of color pigments, Body pigments and functional pigments. Coloring pigments are inorganic and organic pigments that impart various colors to the application medium. Body pigments are pigments that have no coloring power and no hiding power. They were mainly used to reduce product cost and improve the performance of coatings, plastics, rubber and other products. It is called a filler. Nowadays, there are natural and synthetic products processed into ultrafine particle size. Because the synthetic products have low impurity content, fine particles and can be artificially synthesized and various surface modifications as needed, they can be used to reduce the hiding power. The amount of (such as titanium dioxide) and the improvement of product properties are now more suitable as physical (incremental) pigments. The main varieties of body pigments are processed natural minerals such as natural calcium carbonate, barite powder and talcum powder. , mica powder, diatomaceous earth, quartz powder, china clay, asbestos, etc., a few are synthetic products such as precipitated calcium carbonate, precipitated barium sulfate, synthetic silica, etc.; functional pigments are pigments that impart specific functions to the product, such as The color-changing temperature-changing pigment, the antifouling pigment having the function of poisonous water-killing organism, the luminescent pigment which can emit light in the dark, the rust-preventing pigment which can prevent rust, the pearlescent pigment having pearl luster and the like. The difference between pigments and dyes is that the dyes are soluble in the medium, and some can even be colored after being dissolved in the dye and chemically reacting with the dye. However, they can sometimes be used interchangeably. For example, some dyes can be used as dyes and as pigments. Sometimes pigments and dyes can be converted, for example, dyes can be converted into insoluble lakes. . Pigments are indispensable raw materials for the coatings industry. They are also widely used in the printing industry, rubber industry, plastics industry, chemical fiber industry, paper industry, ceramic industry, glass industry, enamel industry, printing and dyeing industry, building materials industry, inks, paints, colors. Lead (wax) pens, make-up pigments, etc. The product can be decorative, opaque, durable or special. As technology advances, various high performance pigments will be further developed.