Cathode-precipitating electrodeposition coating composition

A coating composition for cathode-precipitating electrodeposition consisting essentially of

• (A) 100 parts by weight of an unsaturated organic compound having a molecular weight of 500 to 10,000 containing a carbon-carbon double bond in an amount corresponding to an iodine value of 100 to 500, said unsaturated organic compound being selected from the group consisting of (a) a polymer of a conjugated diolefin containing 4 to 8 carbon atoms, (b) a copolymer of at least two conjugated diolefins containing 4 to 8 carbon atoms, (c) a copolymer of at least one conjugated diolefin containing 4 to 8 carbon atoms and a vinyl monomer having ethylenic unsaturation containing 2 to 20 carbon atoms, (d) a natural oil, (e) a natural fat and (f) a petroleum resin produced by cationic polymerization of petroleum cracking fractions containing 4 to 10 carbon atoms with a Friedel-Crafts catalyst, said unsaturated organic compound having bonded thereto, through a carbon-carbon bond, basic groups of the formula ##STR36## wherein R.sub.1 and R.sub.2, independently from each other, represent a hydrogen atom or a methyl group, R.sub.3 and R.sub.4, independently from each other, represent a hydrogen atom or an organic radical having 1 to 10 carbon atoms, at least one of R.sub.3 and R.sub.4 represents an organic radical, X represents a hydrogen atoms or a bond, and when X represents a bond, the carbon atom to which R.sub.1 is attached and the carbon atom to which R.sub.2 is attached may form part of the main chain, the amount of said basic groups in said component (A) being 0.02 to 0.3 mole per 100 g of said component (A), and
• (B) 3 to 100 parts by weight of at least one compound represented by the general formula ##STR37## wherein R.sub.5 and R.sub.6, independently from each other, represent a hydrogen atom or an alkyl group having 1 to 10 carbon atoms, n is an integer of from 0 to 20, m is 1 or 0, Y is a group of the formula ##STR38## in which R'.sub.3 represents an organic radical having 1 to 10 carbon atoms and R'.sub.4 represents a hydrogen atom or an organic radical having 1 to 10 carbon atoms, a residue of a carboxylic acid having 1 to 20 carbon atoms, or a residue of a phenolic compound having 6 to 20 carbon atoms, and Y' represents a hydrogen atom when m is 0 and Y when m is 1,
• said component (A) and said component (B) being neutralized with an organic acid or an inorganic acid and dissolved or dispersed in water.