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For conservation of petochemical solvents and reduction of air pollution, the water soluble polymers will play an important role in surface coating industry. The coatings based on water soluble polymers are thinned with water instead of petroleum solvent. Basically, the water based coatings may be made from oils, alkyds, polyesters, aminoes, phenolics, epoxies and acrylics. In spite of a large number of other synthetic resins being available for use in coating formulations, the alkyd resins surpass all of them in versatility, and low cost; combining a broad spectrum of performance properties with economy. Water soluble alkyd resins are similar to their solvent borne counterparts. The major difference is that their formulation is modified to introduce pendant carboxylic acid groups along the polymer backbone. These pendant acid groups can be neutralised with basic compounds to produce water solubility. Several workers studied preparation and evaluation of film characteristics of water soluble alkyd resins using various types of polybasic acids, polyhydric alcohols and fatty acids. The curing of these resins has been satisfactorily accomplished by stoving in presence of water soluble amino resins.

Water soluble epoxy resins were prepared from epoxy resin, linseed fatty acids, maleic anhydride, trimellitic anhydride, maleinised dehydrated castor oil and maleopimaric acid. Pigmented coating compositions for anodic electrodepositions were prepared from water soluble epoxy resins using red oxide of iron and zinc phosphate as pigment. The electrodeposition parameters such as voltage, time, solid content and pH value were optimised. The mechanical and chemical film properties of different electrocoating compositions were studied.

Water soluble alkyds were prepared from phthalic anhydride, maleic anhydride, trimellitic anhydride and maleopimaric acid separately by monoglyceride process. Pigmented electro coating compositions were prepared from water soluble alkyd resin, red oxide of iron and zinc phosphate. The anodic electrodeposition parameters such as voltage, time, solid content and pH were optimised. The mechanical and chemical properties of different electrocoating compositions were studied. The coating compositions prepared from water soluble alkyd resin based in maleopimaric acid showed good mechanical and chemical properties.