The effect of color paste on paint
The use of color paste in coatings is very common, but there are many color paste products and they are uneven. Therefore, it is necessary to understand the influence of color paste on coatings, so as to choose suitable color paste
1. Solvent resistance
The color paste is prepared from a resin with good compatibility, and the main resin of the color paste is relatively soluble in organic solvents, which affects the solvent resistance of the final coating film.
2. Tinting power or tinting strength
Paint tint strength indicates how intense the color hue is on the surface to which it is applied. To adjust the same color, the stronger the tinting power, the less the amount of color paste, the lower the degree of water resistance of the color paste coating and the smaller the impact on the performance of the coating film. Therefore, for the same color, the quality of products from different manufacturers will vary greatly. The strength of tinting strength not only depends on the nature of the pigment, but also has a certain relationship with its degree of dispersion. The greater the degree of dispersion of the pigment in the color paste, the stronger the tinting power. How to make the dispersion of the pigment in the color paste better requires a good dispersant and a correct grinding method. At present, polymer-based dispersants are widely used, and the steric hindrance makes the pigments dispersed stably. The poor dispersion effect of pigments not only affects the hue and tinting strength, but also causes potential flocculation and even fading of the paint due to poor matching with the paint.
Color pastes with high tinting strength will also help increase production. For example, if you use a colorant with high concentration and high tinting strength, you can produce more products with the same weight of grinding colorant. The energy consumption and cost of production will also be reduced
3. Fineness
If the fineness of the color paste pigment is too large, it will affect the tinting strength, and also affect the gloss and other properties of the coating film. The finer the pigment in the color paste, the higher the tinting strength, but the finer the color paste, the better. If the fineness is too fine, the covering power will be affected. In addition, pigments such as phthalocyanine blue and phthalocyanine green are small molecular pigments, with too small fineness, large particle size difference, poor dispersion, poor compatibility with paint, increased coloring cost, and will cause floating Color hair flower.
4. Acid and alkali resistance
Acid and alkali resistance is an important performance index in architectural coatings. For example, iron blue or chrome yellow will decompose when encountering alkali, and gray calcium powder and calcium carbonate will react when encountering acid, so you should pay attention to the selection when using it. If the price is very low, yellow, blue, etc. produced by non-professional latex paint manufacturers are selected. Because the price is very low or the performance of the pigment is unknown, the latex paint will soon have fading, chalking, efflorescence and other phenomena. Color paste has a wide range of applications, so it is necessary to select suitable pigments for different fields to prepare color paste. When selecting color paste, customers should pay attention to the selection of color paste for coatings.
5. Compatibility
Compatibility tests, such as floating color observation, finger grinding test, etc., are required before using colorants in paints. Colorants with poor compatibility not only lead to floating and blooming of paint, but also fading and other phenomena. In addition, the leveling property of paint after adding color paste will also be affected by compatibility.
