Cathode- depositing electrodepostion coating composition

Claim 1

A cathode-depositing electrodeposition coating composition having excellent low-temperature curability comprising as essential ingredients (A) 100 parts by weight of a reaction product of (1) a high molecular compound having a molecular weight of 500 to 5,000 and containing carbon-carbon double bonds with an iodine number of 50 to 500 and 3 to 12 % by weight of oxirane oxygen, (2) 30 to 300 millimoles, per 100 g of the high molecular compound (1), of an amine compound represented by the general formula wherein each of R 1 and R 2 represents a hydrocarbon group having 1 to 20 carbon atoms a part of which may be substituted by a hydroxyl group, and R 1 and R 2 may assume a ring structure which may contain an unsaturated group, and (3) 0 to 200 millimololes, per 100 g of the high molecular compound (1), of an alpha, beta-unsaturated carboxylic acid represented by the general formula wherein R 3 and R 4 represent a hydrogen atom or a methyl group, or an unsaturated fatty acid having a molecular weight of 100 to 350 and containing at least 10 % by weight of a carbon-carbon conjugated double bond or a mixture of both, (B) 10 to 200 parts by weight of a reaction product of a diglycidyl compound represented by the general formula wherein R S and R 6 represent a hydrogen atom or a methyl group, and n represents an integer of 0 to 20, preferably 1 to 10, with 1.9 to 2.1 moles, per molecule of the diglycidyl compound, of an alpha, beta-unsaturated carboxylic acid represented by the general formula wherein R 3 and R 4 represent a hydrogen atom or a methyl group, or an unsaturated fatty acid having a molecular weight of 100 to 350 and containing at least 10 % by weight of a carbon-carbon double bond, or a mixture of both, (C) 0.5 to 10 parts by weight of a reaction product of a high molecular compound having a molecular weight of 500 to 5,000 and containing a carbon-carbon double bond with an iodine number of 50 to 500 and 40 to 400 millisoles, per 100 g of the high molecular compound, of an alpha, beta-unsaturated dicarboxylic acid represented by the general formula wherein Ry represents a hydrogen or halogen atom or a methyl group, or a derivative of the reaction product such as its partial ester or partial amide, or 0.1 to 10 parts by weight of an unsaturated monocarboxylic acid having 6 to 24 carbon atoms or its dimer, and (D) 0.005 to 1.0 part by weight, as metal, of a water-soluble salt of an organic acid with a metal selected from manganese, cobalt, and copper.