Epoxy resins solvent-containing coatings

Both types are based on low molecular epoxy resin. Solvent-free coatings, for instance epoxy and polyurethane, do not contain an active solvent unlike the conventional solvent-borne coatings (coatings in which a solvent is used to dissolve the binder). Solvent-free coatings offer... 

Furfuryl alcohol is shipped in bulk or dmms. Although not corrosive to metals, it is a powerful solvent and penetrant containers, tanks, lines, and valves need to be in good condition to avoid potential leakage. Furfuryl alcohol can be stored in containers lined with baked phenoHc resin coatings however, it should not be put in containers that are coated with lacquers, varnishes, or epoxy resins because it is an excellent solvent for many such coatings. 

MAJOR USES Used in the manufacture of epoxy resins, glycerol, pharmaceuticals, agricultural chemicals, coatings, ion excheinge resins glycidyl esters insecticides textile chemicals adhesives plasticizers solvent for natural and synthetic resins, gums, cellulose esters and ethers, paints, varnishes and nail enamels and lacquers stabilizer in chlorine containing materials and an intermediate in the preparation of condensates with polyfiinctional substances. 

Although two-pack epoxy primers and polyurethane intermediate coats have high solids contents, they still contain significant amounts (20-30 wt%) of organic solvents. In polyurethane topcoats, the VOC is even higher. Anticorrosive, waterborne primers based on aqueous dispersions of two-pack epoxy resins and one-pack acrylic resins have been developed to decrease solvent emission. Waterborne, one-pack acrylic topcoats are also used. All of these waterborne paints contain 2 - 5 % organic cosolvents that are required for film formation. 

For many years, paints used to coat cans contained considerable amounts of volatile organic solvents. Waterborne can coatings were developed to reduce solvent emissions and are used worldwide. Binders used in waterborne can coatings are modified epoxy resins (see Section 2.10). Acidic acrylate chains are grafted onto an epoxy molecule. After partially neutralizing with amines, the resins can be dispersed in water. 

Solvent-based coatings can be classified as conventional low-solids and high-solids ( 60% solids) coatings. Glycol ethers and acetates act as active solvents to dissolve the film-forming resins and to suspend pigments and additives. Conventional low-solids coatings contain alkyd, epoxy, nitrocellulose, poly-... 

The solvent-less coatings contain a very low solvent content (5.2 volume%). The coatings are based on low molecular epoxy resins. Health regulations now often specify their use, to avoid solvent vapors. 

Powder adhesives can be prepared by reacting carboxylic elastomers with epoxy resins to convert the system into a RT solid which can be ground into a powder. Powders can be electrostatically applied or coated using a fluidized bed. Films are prepared by solvent coating or by melt coating the carboxyl containing elastomer or compound onto a suitable carrier. 

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