” >Compatibility of colorants and coatings
” >Finger grinding method to remove white paint 100 grams, add 2-3 grams of the color paste to be tested. Stir thoroughly and apply on the surface of the object to be coated. When it’s almost solidified. Use your fingers to grind the surface of the coating. After the paint film is completely dry, observe whether there is a color difference between the areas that have been rubbed with your fingers and those that have not been rubbed. If the difference is large, the compatibility of the color paste with the paint being tested is not good. Use this color paste to adjust the color. Paints are prone to color floating. If the colors are the same, there will generally be no floating color phenomenon.
” >The fineness of color paste
” >Fineness is an intuitive indicator that reflects the coloring power dispersion effect and storage stability of the color paste. Generally speaking, for the same pigment paste, the smaller the particle size, the greater the specific surface area, thus increasing the covering ability and the higher the tinting power; the smaller the fineness, the higher the gloss, and the dispersion effect and storage stability are poor. The better. Of course, the fineness of the color paste is not as fine as possible, because when the particles become smaller and their specific surface area increases, the absorbed light energy increases and the degree of damage also increases, resulting in a decrease in weather resistance; and the particle size is too large When the paint film forms and dries, as the water precipitates, the color paste migrates to the surface, which can easily lead to inaccurate color matching and color differences on the wall.
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” >Lightfastness and weather resistance of color paste
” >The light and weather resistance test of the color paste is passed Outdoor exposure (such as Florida in the United States, Turpan in my country and other places have exposure fields), but the actual outdoor exposure time is too long. Nowadays, most of the general color paste performance testing is through simulation tests such as instruments and equipment. Lightfastness test: Exposed under xenon lamp, measured with a blue wool ruler, 1- Level 8 means that level 8 is the best and level 1 is the worst. Weathering resistance test: Use ATLAS aging instrument, regularly expose to xenon lamp and spray with water for 500 hours. Color difference is expressed according to ISO gray scale 1-5, with level 5 being the best and level 1 being the worst. The color paste used for exterior walls needs to have light resistance of level 7 or above and weather resistance.Both conditions of level 4 and above must be met at the same time.
” >Pigment solid content of color paste
” >The pigment content is for reference only and cannot be used as an indicator to evaluate the performance of the color paste. The tinting power of color paste is not simply proportional to the pigment content. The same pigment content has great differences in tinting strength with different fineness. In order to ensure the stability of the tinting strength of the color paste, the pigment content of the color paste changes within a certain range. The value provided in the color paste data is a typical reference value.
” >Color differenceΔE
” >The stability and color reproducibility of color paste are mainly It is reflected in two aspects: tinting strength and color difference. The color difference of color paste includes the color difference between different production batches of the same color paste and the color difference between different packages of the same batch. The size of color difference is represented by ΔE, including color hue, lightness and darkness, and saturation. The calculation formula is as follows:
” >ΔE ＝ (Δa2+Δb2+ΔL2)1/2
” >The color difference of color paste affects the accuracy of color mixing and the stability of color mixing formula.
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” >The quality of the toner in the color paste (mainly depends on the international pigment number)
” >International pigment numbers are an important basis for one-to-one correspondence of product models of different colorant companies. When we test the quality of different brands of colorants, we should choose colorants of the same pigment number from different manufacturers for comparison. Any colorant company must provide customers with the international pigment number of its colorants. Fully understanding the quality of toner is the most important basis for latex paint manufacturers to select colorants for different application fields (such as interior and exterior wall paints).
” >Color intensity of color paste
” >The tinting power refers to the titanium dioxide containing titanium dioxideWhen 100 grams of white latex paint is adjusted to 1/25 standard color depth, the number of grams of a certain color paste used. The smaller the amount of color paste, the stronger the tinting power. For the comparison of water-based color pastes, tinting strength is an important indicator, which reflects the color concentration, color development performance and pigment dispersion flocculation of the color paste. The stronger the tinting power of the color paste, the less the amount of color paste used during color mixing, the smaller the impact on the coating film performance, and the lower the color mixing cost.
When comparing the quality of colorants of different brands, colorants of the same pigment number from different manufacturers should be selected for comparison. Any colorant company must provide customers with the international pigment number of its colorants. Fully understanding the quality of toner is the most important basis for latex paint manufacturers to select colorants for different application fields (such as interior and exterior wall paints).
” >Color intensity of color paste
” >The tinting power refers to the titanium dioxide containing titanium dioxideWhen 100 grams of white latex paint is adjusted to 1/25 standard color depth, the number of grams of a certain color paste used. The smaller the amount of color paste, the stronger the tinting power. For the comparison of water-based color pastes, tinting strength is an important indicator, which reflects the color concentration, color development performance and pigment dispersion flocculation of the color paste. The stronger the tinting power of the color paste, the less the amount of color paste used during color mixing, the smaller the impact on the coating film performance, and the lower the color mixing cost.
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