Introduction of various properties of pigments

The following is the "various properties of pigments" shared by PU pigment manufacturers for you：

1. The color of the paint

The color of the pigment is due to the selective absorption of light of different wavelengths in the visible light by the pigment, and is affected by physical properties such as crystal shape, particle size and dispersion performance. The increase in diameter changes from orange-red to purple-red; the color of the pigment is also affected by the light shining on it, for example, in the dark, the pigment does not show any color, and the color in strong light is stronger than in dark light. The same pigment can show different colors under different light sources (such as sunlight, incandescent light, fluorescent light, etc.).
2. The tinting strength of the pigment

The tinting strength of a pigment refers to the ability of a pigment to show shades of color when mixed with another pigment. When the same color is adjusted, the stronger the tinting strength, the less the amount of color paste, the less the water resistance of the color paste coating and the less influence on the performance of the coating film. Therefore, the same color, the quality of the products of different manufacturers will be very different. The strength of pigment tinting strength not only depends on its properties, but also has a certain relationship with its dispersion degree. The greater the dispersion, the stronger the tinting strength.
3. Lightfastness and weatherability of pigments
The color of the pigment will change to some extent under the action of light. Inorganic pigments will gradually darken in color when exposed to sunlight for a long time, and some pigments will also chalk under the action of ultraviolet rays in sunlight. The exterior wall coating should use pigments with good light resistance and weather resistance. Generally, the light resistance is greater than 7~8 grades, 8 grades, and the weather resistance is greater than 4~5 grades, 5 grades. Inorganic pigments such as iron oxide series generally have good light resistance, and the color retention of the corresponding color coatings is very good; organic pigments are relatively poorer than inorganic pigments, and the price is much higher. The higher the light resistance of organic pigments, the higher the price. For each level of light resistance, the price and weather resistance and color retention will be very different. When the light resistance is less than or equal to 6, and the weather resistance is less than or equal to 3, the price will differ by more than 4 times. Therefore, exterior wall coatings, especially organic color coatings, are worth every penny.
4. The hiding power of pigments
The ability of the pigment in the coating film to cover the surface of the object to be painted, so that the substrate can no longer be exposed through the coating film. The hiding power of pigments mainly depends on factors such as refractive index, ability to absorb light, crystal structure, and degree of dispersion. The hiding power of a pigment depends not only on the ability of the coating to reflect light, but also its ability to absorb light impinging on the surface of the coating. For example, carbon black can completely absorb the light that falls on it, so it has excellent hiding power. The hiding power of opaque color pigments also depends on their selective absorption of light. The pigment is evenly dispersed in the base material, the particle size is small, the specific surface area is increased, and the covering power is also increased. However, if the size of the pigment particle size is equal to half of the wavelength of light, the light will Proceed through the particle without refraction, leaving the particle transparent. The higher the crystallinity of the pigment, the stronger the hiding power. The hiding power of mixed pigments cannot be calculated according to the addition law of the hiding power of each component of the mixture. In fact, the hiding power of most mixed pigments is larger than the calculated value. Therefore, mixing the pigment and the filler in an appropriate ratio will not affect its covering power, and is conducive to reducing costs. The covering power of the coating is high, the brushing area is high, and the project cost is low.