Organic coatings epoxy resins

Epoxy resin paints, inferior to chlorinated rubber for resistance to strong acids, are excellent for dilute acids and strong alkalis. They produce a harder, more abrasion-resistant coating than does chlorinated rubber and are much better for resistance to fats, oils and many organic solvents. Table 3.50 gives data on the chemical resistance of epoxy resin coatings to different materials. 

Binders. Binders are organic resins that are composed of high-molecular-weight polymers that provide specific properties to the coatings. Epoxies and phenolics are good examples of these binders. 

Several classes of polymers including epoxies have been developed from 2-phenyl-l,l,l,3,3,3-hexafluoropropan-2-ol and its derivatives.1 Fluorinated epoxy resins are the key intermediates for the new types ofpractical organic coatings and plastics, which have fluorocarbon properties and convenient characteristics such as hydrophobicity, oleophobicity, light stability, low friction, and, in some cases, possibly high thermal stability. 

These data are consistent with the observation O) that increased crosslinking (i.e., epoxy resins with lower EEW s) will result in a decreased propensity for the cured polymer to absorb solvents. Thus, the solvent resistence of an organic coating can be controlled by the formulator via variations in the molecular weight between crosslinks. 

An epoxy resin formulation completely free of organic solvent was applied to carbon steel coupons using supercritical carbon dioxide (CO2) as the volatile solvent. Sleet coupons coated in this manner were compared to coupons coated with a standard military specification marine primer (MlL-P-24441) during exposure to aerated 0.5 nrl sodium chloride (NaCl). The solvent-free coating protected the steel from corrosion in this environment as well, if not better than, the solvent-based primer (Kendig et al., 1999). 

H. Lee and K. Neville, Epoxy Resins, Their Applications and Technology, McGraw-Hill, New York, 1957 Handbook of Epoxy Resins. New York McGraw-Hill, 1967 Encycl. Polym. Sci. Technol. 6, 209 (1967) I. Skeist, Epoxy Resins. Princeton, New Jersey Van Nostrand-Rheinhold, 1958 M. W. Ranney, Epoxy and Urethane Adhesives. New Jersey Noyes Data Corp., 1971 G. R. Somerville and P. D. Jones, Abstr. 168th Am. Chem. Soc. Meet., Atlantic City, N.J., 1974 Abstract ORPL, 146 in the Organic Coatings and Polymer Chemistry Division (1974). 

Several organic sealants such as epoxy resins, butyl rubber or silicones prove to be more or less permeable and the tiny amount of solvent in the cell is rapidly lost. Suitable organic sealing materials for this technology turn out to be thermoplastic materials, like polyethylene/carboxylate copolymers. So far, Surlyn 1702 ionomer from Dupont has been the main substance used to optimize cell performance and build module prototypes. However, the softening point of Surlyn is rather low (65° C) and at elevated temperatures (> 70°C), serious solvent loss is observed because the bond between Surlyn and TCO-coated glass is substantially weakened [7]. 

In certain cases the acidity Melamine Formaldehyde resins (MF resins) or alkaline Polyurethane (also known us PU) resin (PUR resin) and alkali hardener (epoxy resin) can corrode or even totally dissolve the metallic pigments. In case of bronze pigments a color shift is possible. For these applications special metallic pigments are recommended, which are protected by an organic or inorganic coatings [14]. 

Epoxy resins, mostly employed in the coating industry, are characterized by the presence of a phenolic Mannich base, usually deriving from bisphenol A or alkyl phenols, - " linked to an epoxy oligomer, mixed with various crosslinking agents,- 20.1.207 dispersed into aqueous solution in the presence of organic acid. 

Use Intermediate in adhesives, urethane coatings, and elastomers solvent diluent for epoxy resins synthetic fibers organic synthesis. 

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