Influence of color pastes on coatings
The use of color paste in coatings is very common, but nowadays there are a lot of color paste products, uneven. So it is necessary to understand the impact of color paste on paint, to facilitate the selection of suitable color paste.
1、Solvent resistance
Color paste is prepared by a good compatibility of the resin, the main body of the color paste resin is relatively soluble in organic solvents, thus affecting the final coating film solvent resistance.
2、Coloring power or coloring strength
Paint coloring strength indicates the intensity of the color hue on the application surface. Tune the same color, the stronger the coloring power, the less the amount of color paste, the lower the degree of reduction of water resistance of the color paste paint and film properties of the impact will be smaller. So the same color, the quality of products from different manufacturers will be very different. The strength of coloring power not only depends on the nature of pigment, but also has a certain relationship with its dispersion degree. The greater the dispersion of the pigment in the color paste, the stronger the coloring power. How to make the dispersion of pigment in color paste better, it needs good dispersant and correct grinding processing method. At present, polymer type dispersant is used more often, and the spatial site resistance effect makes the pigment stably dispersed. Poor pigment dispersion not only affects the hue and coloring power, but also the potential flocculation or even discoloration of the paint due to poor matching with the paint.
Color pastes with high coloring power will also be conducive to yield improvement. For example, by using a high concentration of colorants with high coloring power, more products can be produced with the same weight of ground colorants. The energy consumption and cost of production will also be reduced.
3、Fineness
The pigment fineness of color paste is too large to affect the coloring power, and it has influence on the gloss and other properties of the coating film. The finer the pigment in the color paste, the higher the coloring power, but not the finer the color paste, the better. The fineness is too fine, the covering power will be affected. In addition, such as phthalocyanine blue, phthalocyanine green pigment itself is a small molecule pigment, fineness is too small, the difference in particle size is large, poor dispersion, and the compatibility of the coating is not good, the cost of mixing increased, and will lead to floating color hair flower.
4、Acid and alkali resistance
Acid and alkali resistance in architectural coatings is an important performance indicator. For example, iron blue or chrome yellow will decompose when encountering alkali, gray calcium powder and calcium carbonate will react when encountering acid, thus attention should be paid to the choice of use. If you choose a very low price, non-professional production of latex paint manufacturers produce yellow, blue, etc., because the price is very low or do not know its pigment properties, latex paint will soon have faded chalky alkali and other phenomena. Color paste has a wide range of applications, so it is necessary to choose suitable pigments for the preparation of color paste in different fields, and customers need to pay attention to the selection of color paste for paint when choosing color paste.
5、Compatibility
Before using color paste for coating, it is necessary to carry out compatibility test, such as floating color observation and finger research test. Poor compatibility of the color paste will not only lead to paint floating color flower, but also fade and other phenomena. In addition, the leveling of the paint after adding color paste will also be affected by compatibility.
