The research focus of organic pigment workers is on improving the post-treatment of pigments, such as choosing a better crystal form, making finer particles with a narrow particle size distribution, and improving the wettability of pigments, so that organic pigments can play a greater role. utility.
Organic pigments refer to a class of pigments made of organic compounds that have the characteristics of color and a series of other pigments. Pigment characteristics include light resistance, water immersion resistance, acid resistance, alkali resistance, organic solvent resistance, heat resistance, crystal form stability, dispersion and hiding power. The difference between organic pigments and dyes is that it has no affinity with the object to be colored, only the organic pigment is attached to the surface of the object through an adhesive or a film-forming substance, or mixed inside the object to color the object. The intermediates, production equipment and synthesis process required for its production are similar to the production of dyes, so organic pigments are often organized in the dye industry. Compared with general inorganic pigments, organic pigments usually have higher coloring power. The particles are easy to grind and disperse, not easy to precipitate, and the color is more vivid, but the light resistance, heat resistance and weather resistance are poor. Organic pigments are commonly used for the coloration of inks, coatings, rubber products, plastic products, cultural and educational supplies and building materials.
Organic pigments are classified by structure
(1) Azo pigments account for 59%
(2) Phthalocyanine pigment accounts for 24%
(3) Triarylmethane pigment accounts for 8%
(4) Special pigments account for 6%
(5) Polycyclic pigments account for 3%
Organic pigment physical properties
Organic pigments have bright colors and strong coloring power; they have low density and no toxicity, but some varieties are often inferior to inorganic pigments in light resistance, heat resistance, solvent resistance and migration resistance.
The variety of colors is endless and colorful, but there is a certain internal relationship between various colors. Each color can be determined by 3 parameters, namely hue, lightness and saturation. Hue is a characteristic that distinguishes colors from each other. It depends on the chromatographic composition of the light source and the perception of each wavelength emitted by the surface of the object to the human eye. It can distinguish red, yellow, green, blue, and purple. Brightness, also known as brightness, is a characteristic value that represents the change in the degree of lightness and darkness on the surface of an object; by comparing the brightness of various colors, the color has the difference between lightness and darkness. Saturation, also known as chroma, is a characteristic value that represents the shades of colors on the surface of an object, making colors different from bright and dark. Hue, lightness and saturation constitute a three-dimensional, using these three to establish a scale, we can use numbers to measure color. The colors in nature are ever-changing, but the most basic ones are red, yellow and blue, which are called primary colors.