Latex paint is composed of emulsion, pigments, fillers, additives and water. Emulsion is the most important raw material that affects the performance of latex paint. It is usually synthetic resin emulsion. The common varieties of synthetic resin emulsion are: polyvinyl acetate, vinegar acrylic, vinegar shun, vinegar tert, VAE, styrene acrylic, pure acrylic, silicon acrylic, Fluorocarbon emulsion, etc., is made of some petrochemical raw materials such as vinyl acetate, acrylate, styrene, etc., through a chemical reaction in water, and its main function is to play the role of bonding, water resistance, alkali resistance and sunlight aging resistance. Most latex paints are white or light white-based colors, and the pigments are mainly titanium dioxide and lithopone (lithopone). Most of the color pigments are harmless to the human body. But inferior pigments contain lead. The filler acts as a filler. Commonly used fillers include calcium carbonate (white powder), talcum powder, kaolin (china clay), barium sulfate (barite powder), wollastonite powder, etc. These are all natural mineral raw materials and are harmless to the human body. There are many additives. There are enhancers, coalescents and fungicides. In order to prevent the latex paint from settling during storage and from falling when painting vertical surfaces, additives such as modifiers should be added, and cellulose ethers are commonly used. In order to make the latex paint film dry and prolong the construction season even in the case of low temperature, general manufacturers add some film-forming aids, such as polyols and their derivatives. Latex paint is susceptible to microbial contamination during storage or after drying into a film. In order to prevent the growth of microorganisms, manufacturers should add fungicides. Production feeding process: water; microbicides; film-forming aids; thickeners; pigment dispersants; defoamers, wetting agents; pigments and fillers; emulsions; pH regulators; other additives; water and/or thickening agent solution. Operating procedures: Put water into a high-speed mixer first, then add microbicides, film-forming aids, thickeners, pigment dispersants, defoamers, and wetting agents in sequence at a low speed. After mixing evenly, add pigments and fillers. The sieve is slowly sifted into the vortex stirred by the impeller. Shortly after the addition of pigments and fillers, the millbase gradually thickens. At this time, adjust the distance between the impeller and the bottom of the paint bucket to make the vortex into a shallow basin shape. After adding pigments and fillers, increase the speed of the impeller (the linear speed of the wheel edge is about 1640m/min). In order to prevent the temperature from rising too much, it should be stopped to cool down, and the pigments and fillers adhering to the side of the barrel should be scraped off when parking. Measure the fineness of the scraper at any time, and when the fineness is qualified, the dispersion is completed. After the dispersion is completed, gradually add the emulsion, pH regulator, and other additives at a low speed, then adjust the viscosity with water and/or thickener solution, and sieve the material out.
