Cathode-depositing electrodeposition coating composition

Claim 1

A cathode-precipitating electrodeposition coating having excellent low-temperature curability, said composition consisting essentially of (A) 100 parts by weight of a high molecular compound having a molecular weight of 500 to 10,000 and containing carbon-carbon double bonds with an iodine value of 50 to 500 and 30 to 300 millimoles of amino groups per 100 g, (B) 10 to 200 parts by weight of a product of reaction of a diglycidyl compound represented by the general formula ##STR32## wherein R 1 , R 2 and R 3 represent a hydrogen atom or a methyl group and n represents an integer of from 0 to 20, with at least one organic acid component selected from the group consisting of (a) both an alpha, beta-unsaturated dicarboxylic acid and an alpha, beta-unsaturated monocarboxylic acid, (b) an unsaturated fatty acid containing at least 10% by weight of carbon-carbon conjugated double bonds and having a molecular weight of 100 to 350, and (c) an alpha, beta-unsaturated monocarboxylic acid, a 1,2-dicarboxylic acid anhydride represented by the general formula ##STR33## wherein R 4 and R 5 represent a hydrogen atom or an alkyl group having 1 to 20 carbon atoms, provided that either R 4 or R 5 may contain one molecule of a carboxylic acid group, and R 4 and R 5 together may be of a 6-membered ring structure or a heterocyclic structure having a 5-membered ring and a 6-membered ring, said ring structure optionally containing an unsaturated group; and X 1 and X 2 represent a hydrogen atom, an organic group having 1 to 10 carbon atoms, or a bond, provided that when X 1 and X 2 are bonds, the carbon atoms to which X 1 and X 2 are attached will together form a double bond, and a monoepoxy compound represented by the following formula ##STR34## wherein Y represents a hydrogen atom or an organic group having 1 to 10 carbon atoms, in this sequence, and (C) 0.005 to 1.0 part by weight as metal of a manganese salt of an organic acid or manganese dioxide.