Abstract: Water-dilutable binders for air drying coating compositions, the content of the auxiliary organic solvent being below 15% of the binder solids are described. The binders comprise the partial condensation products of(A) 30-70% by weight of a film forming fatty acid modified alkyd resin intermediate with an acid value of between 30 and 200 mg KOH/g, an intrinsic viscosity .zeta..sub.A of from 4.5 to 8 ml/g and an oil length of from 5 to 60%, with(B) 70-30% by weight of a film forming fatty acid modified alkyd resin intermediate with an acid value of below 5 mg KOH/g, a hydroxyl value of from 50 to 300 mg KOH/g, an intrinsic viscosity .zeta..sub.B of from 8 to 12 ml/g and an oil length of from 5 to 60%,the ratio between the intrinsic viscosities .zeta.B/.zeta.A lying between 1.4 and 2.7. Solutions of the binders ready for application are obtained which have a high solids content.

Abstract: A process of making water-soluble coating compositions is described characterized in that (A) an adduct of an alpha-beta ethylenically unsaturated dicarboxylic acid or anhydride with olefinic, unaltered or polymerized, oil fatty acids, or mixtures of such acids with other unsaturated carboxylic acids or natural esters thereof, or hydroxy-free polyol esters thereof; (B) a polyhydroxy compound; and (C) a water-insoluble, hardenable phenol-aldehyde condensation product of a phenol substituted in the ortho- or para-position with an alkyl radical having at least three carbon atoms, are combined at an elevated temperature to form a homogeneous resinous body; and the resin thereafter made water-soluble through the addition of a water-soluble nitrogen base. The water-soluble coating compositions are particularly useful for electrodeposition providing films having improved surface characteristics and corrosion resistance.