Silicate paints

The tendency to hydrolyze by a relatively slow and controllable stepwise reaction is characteristic of all the silicon orthoesters. When ethyl silicate, for example, is poured into water it remains immiscible and hydrolyzes at the interface over a period of many days or even months. If both the ester and the water are dissolved in alcohol, however, a much faster reaction in the homogeneous medium becomes possible. If a drop of strong acid then is added to the solution, the hydrolysis is further accelerated to such an extent that the solution becomes warm and silica is precipitated as solid or gel. If less than the equivalent amount of water is used, there is formed a viscous nonvolatile liquid which may be stored for long periods. The addition of further water (as in mixing an ethyl silicate paint) then... 

Although there are many varieties of paint in use, Haynie (6) has chosen to simplify them into two types according to the composition of the extender, or thickener. Of the two paint types, the more pollutant-resistant contains silicate extenders while older, carbonate extender paints are less pollutant-resistant. Silicate extender paints have become dominant in the exterior paint market only in the last decade, accounting for most (probably over 80 percent) of current sales. The proportion of silicate paint on buildings is unknown, however, but is conservatively assuned to be 85 percent. The switch to silicate paints may have occurred partially as a result of concern with the ervironmental susceptibility of the carbonate extender paints. Tliese substitution costs are not factored into the damage estimates provided in this analysis. 

The results are summarized in Table II. Monetary estimates of annual damages are shown by city as a function of material, building type and pollutant source. The estimates are presented in range form using the assumptions listed in Table I. Essentially, three main sources of uncertainty are captured in the range estimates uncertain physical damages, an uncertain split between carbonate and silicate paint extenders, and uncertain maintenance and replacement costs. 

Special attention was drawn to the difficulties encountered in meeting the BSA demands for improved lighting levels in their section of the factory and the provision of dedicated bus parks for their employees. Soon after production began it was found that the sodium silicate paint used to render the walls and ceiling dustproof was virtually useless, and expensive remedial measures were taken to repaint the whole quarry with a specially developed, highly reflective and dust-free cement-based finish. 

Properties, The special properties of silicate paints are imparted by the binder, generally potassium water glass. The paint coats harden physically by evaporation of water, as well as chemically by several reactions. These stabilization and consolidation processes are termed silicification [2.176]. The water glass reacts as follows with atmospheric carbon dioxide ... 

The good resistance of silicate paints to weathering, environmental influences, and temperature is a result of their mineral, chemically resistant structure and the almost exclusive use of lightfast inorganic pigments. Silicate paints dry to give a matt surface. 

On account of their properties, silicate paints are used as weather-resistant and wash-resistant coatings on mineral substrates in both exterior and interior applications. Substrates include lime, lime cement, cement renders (mortar groups I, II, and III), concrete, sandy limestone, as well as old silicate or mineral coatings. Old lime coats should be removed completely, and gypsum substrates should be treated only... 

Aqueous systems such as silicate paints and vinyl or acrylic emulsion paints are suitable for opaque and semitransparent coatings. Silicate paints have a high degree of hardness and good permeability to water vapor and gas. Evaporation of moisture is not hindered, peeling and flaking are therefore avoided. 

Uses Defoamer for aq. systems, med. and high vise, emulsion-based paint and coating systems, syn. renderings, adhesives, silicate paints, aq. epoxy resin systems Features Highly effective silicone-fiee... 

Uses Defoamer for emulsion paints, emulsion polymers, food pkg. adhesives, aq. systems, silicate paints, coating colors starch defoamer in food-contact paper prod. 

Chem. Descrip. Blend of liq. hydrocarbons, silicones, alkoxylated compds., modified fats, and nonionic emulsifiers Uses Defoamer for emulsion paints, hydrosols, aq. coatings, adhesives, silicate paints, impregnations, water-dilutable resin systems Properties Yish. dull oil emulsifiable in water dens. 0.98 g/ml (20 C) ... 

Chem. Deserp. Aqueous dispersion of sttyrene/n-butylacrylate/acrylic acid/actylamide copolymer (50%), ammonia (< 5%), emulsifier Uses Film-fomier in paints, pasty building and tile adhesives, high-grade plastics-bound plasters, silicate paints primer for min. substrates Features Free from film-fomning aids, soivs., and plasticizers compat. with pigments and fillers... 

Uses Hydrophobing agent, cobinder for silicone resin paints and plasters, facade coatings/plasters, silicate paints, wood coatings Features Water-thinnable good semb resist., exc. compat. with most org. resin emulsions good color development with commercial dispersed colordnts... 

Use Level 2% on formulation wt. (silicate paints, plasters), 40-60% of binder content (silicone resin paints, plasters), 1.5-10% of formulation wt. (emulsion and quartz paints, water-beading effect additive) Toxicology TSCA listed Environmental Environmentally friendly... 

Features Water-beading effect gives resist, to driving rain in silicate paints Regulatory EINECS listed (act. ingred.)... 

Uses Thickener, water retention aid, stabilizer for emulsion paints, silicate paints, full-color paints, ready-mixed tile adhesives, ready-mixed joint compds. 

Chem. Descrip. Vinyl acetate/ethylene/vinyl ester terpolymer disp. with protective colloid (cellulose derivs.), surfactant emulsifier Uses Binder for syn. resin-bound plaster and exterior thermal insulation composite systems, low-odor interior emulsion paints, interior/exterior masonry coatings, silicate paints... 

Uses Hammer finish additive for solv.-based paints masonry water repellent, waterproofing hydrophobe for silicate paints wetting agent ... 

Mineral spirits 1,3,5-Trimethylbenzene paint, zinc primer anticorrosion Ethyl silicate paint/coating additive Lithium oxidized polyethylene painting porcelain Cobalt phosphate (ous) painting, porcelain... 

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