Coating technology: selection of water-based coating paste

Key tips: 1 Introduction to water-based color paste The water-based pigment paste is a kind of concentrated pigment paste with uniform, stable, certain fluidity or thixotropic fluidity and strong coloring strength, which is formed by wetting and dispersing organic or inorganic pigments with surfactant (or adding water-soluble resin) There are two kinds of water-based color paste system: one is resin free system with high pigment content; the other is resin (general resin, other single resin) system with low pigment content Among them, the former has high pigment concentration, strong coloring power, good color development performance, good compatibility and thixotropic flow Application scope and advantages of roller ceramic coating Recommended introduction: the surface of ceramic rubber plate used for roller ceramic coating is cast into durable rubber plate by hundreds of independent small ceramic pieces Each ceramic piece has raised characteristics Under general conveyor belt pressure, thousands of unique cast bumps can produce positive traction, prevent slipping and extend the service life of conveyor belt roller At the same time, the bottom layer adopts high-quality rubber, which has strong elasticity and can play a good impact resistance role The scope of application of roller ceramic coating is one three six 83857180 (the same as V) 1 Roller coating in extremely harsh working environment 2 The belt joint is not suitable for fixing with iron buckle; 3 It is suitable for leather Paint Home News: 1 Introduction to water-based color paste water-based color paste refers to the uniform and stable concentrated color paste formed by organic or inorganic pigments under the wetting and dispersing action of surfactants (water-soluble resin can also be added), with certain fluidity or thixotropic fluidity and strong color strength There are two kinds of water-based color paste system: one is resin free system with high pigment content; the other is resin (general resin, other single resin) system with low pigment content Among them, the former has high pigment concentration, strong coloring power, good color development performance, good compatibility, thixotropic fluidity, generally does not cause floating color and blooming, and the selection of additives is reasonable and universal The latter pigment concentration is relatively low, but it has good coloring power, good color development, relatively stable fluidity and viscosity The system contains resin, and compatibility needs to be tested, otherwise it is easy to cause paint floating and blooming 2、 Main technical index of color paste 1 Quality of color powder in color paste (mainly according to its international pigment number) International Pigment number: it is simply understood as the pigment code uniformly formulated according to the different molecular structure of the color powder The pigment number determines the light resistance (weather resistance) and chemical resistance (acid and alkali resistance) of the color paste, as well as the approximate color phase of the color paste Due to the different production processes of various color paste companies, the color phase of the color paste may be slightly different International Pigment number is an important basis for matching the product models of different color paste companies one by one When we examine the quality of different brands of color pastes, we should choose different color pastes of the same pigment number from different manufacturers for comparison Any color paste company must provide customers with the international color number of its color paste Fully understanding the color powder quality is the most important basis for latex paint manufacturers to select color paste for different application fields (such as interior and exterior wall color paint) 2 Colouring strength (colouring power) colouring power refers to the number of grams of a certain color paste used when 100g white emulsion paint containing titanium dioxide is adjusted to 1 / 25 of the standard color depth The less the color paste is used, the stronger the colouring power For the comparison of water-based color pastes, the color strength is an important index, which reflects the color concentration, color development performance and flocculation of pigment dispersion The stronger the coloring power of the color paste is, the less the amount of color paste is used in color matching, the less the effect on the performance of the coating film is, and the lower the cost of color matching is 3 The stability and color reproducibility of color difference ∆ e color paste are mainly reflected in two aspects: coloring power and color difference The color difference of color paste includes the color difference between different batches of the same color paste and the color difference between different packages of the same batch The size of color difference is expressed by ∆ e the color difference of color paste affects the accuracy of color matching and the stability of color matching formula 4 The light resistance and weather resistance of color paste are tested by outdoor exposure, but the actual outdoor exposure time is too long Now, the performance test of general color paste mostly passes the simulation test of instruments and equipment Light resistance test: exposure under xenon light, measured by blue wool ruler, expressed by level 1-8, level 8 is the best, level 1 is the worst y Weather resistance test: Atlas aging instrument is used, and xenon lamp is used for exposure and water spray regularly The exposure lasts for 500 hours, and the color difference is expressed according to ISO gray scale 1-5, level 5 is the best, level 1 is the worst The color paste for exterior wall needs two conditions of light resistance above grade 7 and weather resistance above grade 4 5 The pigment content of the color paste is only for reference, and can not be used as an index to evaluate the performance of the color paste The coloring power of the color paste is not directly proportional to the pigment content With the same pigment content, the different fineness and colouring power also have great differences In order to ensure the stability of the color paste, the pigment content of the color paste is the change value within a certain range, and the value provided in the color paste data is a typical reference value 6 The fineness and fineness of color paste is a direct index reflecting the dispersing effect and storage stability of color paste Generally, for the same pigment paste, the smaller the particle size is, the larger the specific surface area is, so the covering capacity is increased, and the higher the coloring power is; the smaller the fineness is, the higher the luster is, and the better the dispersion effect and storage stability are Of course, the fineness of the color paste is not as fine as possible, because when the particle becomes smaller and its specific surface area increases, the absorbed light energy increases and the degree of damage increases, leading to the decrease of its weather resistance; and when the particle size is too small, when the coating film is dry, with the precipitation of water, the color paste moves to the surface together, which is easy to cause color matching inaccuracy and wall color difference 7 Compatibility of color paste and coating Take 100g white paint with finger grind method, add 2-3g color paste to be tested, mix it well, apply it on the surface of the coating, when it is about to set, grind the surface part of the coating with finger, after the paint film is dry, observe whether there is any color difference between the places that have been rubbed with finger and the places that have not been rubbed If there is a big difference, the compatibility between the color paste and the tested paint is not good, and the paint produced by this color paste is easy to produce Floating color phenomenon If the color is the same, there will be no floating phenomenon When choosing the color paste, the above factors should be taken into account The color paste of other brands can basically reach and have little difference Of course, the color paste should be selected from the perspective of economy and environmental protection For example, the color paste with poor weather resistance can be selected for the color paste of interior wall Meanwhile, the color paste containing heavy metals such as chrome yellow should not be selected for the color paste of interior wall, but azo and amine should be selected Home of coatings is specialized in coatings, diatom mud, paint coating, coating technology, fire retardant coating news and coating, diatom mud, paint coating, coating technology, fire retardant coating decoration knowledge and decoration renderings,