Baked epoxy resin finishes yield coatings which give maximum resistance to alkalies, solvents, most acids and general chemical fumes. With the air-dried system in which the epoxy resin is reacted with oil fatty acids to form an ester, the coatings have limited solvent and chemical resistance. The resistance to corrosion, however, is good. With the air-dried system in which the basic epoxy resin is dissolved in suitable solvents and blended with an amine, the coating does not develop full chemical resistance for several days. After this time it shows generally good resistance to chemical fumes, alkalies, acids and salt solutions.
Recommendations are made regarding the use of epoxy resins in various media. Corrosives in which tests were made include three concentrations of sulfuric acid, three concentrations of hydrochloric acid, two concentrations of nitric acid, two concentrations of phosphoric acid, glacial acetic acid, water, two concentrations of sodium hydroxide, ammonium hydroxide, oxidizing agents, three fats and oils, three gases, aldehydes, amines, eight solvents, five salts, and four miscellaneous materials. Epoxy phenolic baked coatings, epoxy amine cured coatings and epoxy ester coatings are considered separately in connection with recommendations for use in the above media.
Application of epoxy resin coatings is considered briefly. Topics discussed include coverages, surface preparation, primers and application methods. Physical properties of epoxy resins are outlined briefly.
