Water-based paints (water-dispersion paints, latex paints, emulsion paints), a suspension of pigments and fillers in aqueous dispersions (latexes) film formers. Water emulsions are the last major manner by emulsion polymerization of the monomers (synthetic latex), as well as film-forming dispersion in water (so-called artificial latexes). Latex paint contains in its consisting usually of 10-15 components, including (% by weight): 40-60% probability aqueous dispersion of film-forming 35-40, 30-37 pigments and fillers, plasticizer 0-7; functional additives 2-6. Content in water-based paints dry residue of 50-60%. The most common film-forming water-based paints: copolymers of acrylates (acrylic water-based paints), polyvinyl acetate or copolymers of vinyl acetate with small amounts of acrylates.
alkilmaleinatov, ethylene, etc. (PVA water-based paints), copolymers of styrene with butadiene, methacrylic acid, etc. (styrene-butadiene water-based paints). Restrictions shall also apply Artificial latexes nitrate cellulose, epoxy, alkyd, polyester resins. polyurethanes, etc.
The range of pigments and fillers for water-based paints is limited to the specific requirements (minimum content of water-soluble impurities, sufficient hydrophilicity, etc.). Most often produce white water-based paints, paint color produced by adding a white podtsvetochnyh (tinting), pastes and color inks are be very diverse. Limit the number of pigments and fillers is usually 75-85% of the critical volume content of the pigment, or pigmentoemkosti (Table 1), – a dimensionless quantity characterizing the maximum density of “packing” of pigment in a monolithic film. Table. 1.-Aqueous Dispersions HIGHLIGHTS film former used to prepare water-based paints acrylic dispersions Index copolymer dispersions of homo-and copolymers of vinyl acetate, styrene-butadiene latex content,% 40-50 50-60 45-50 polymer residual monomer. less than 0.1 0.1 0.05 Particle size of the polymer, 0.1-0.3 mm 0,1-2,0 0,12-0,2 critical. content by volume of pigment 0,45-0,48 0.35-0.45 0.3-0.35