Composition for UV-curable cationic electrodeposition coating and coating film thereof

摘要

The present invention provides an ultraviolet curing type cation electrodeposition coating composition which has advantages of excellent liquid aging stability, high sensitivity, excellent surface curability, excellent adhering property, excellent corrosion resistance, excellent wearing resistance and excellent medicine resistance. The ultraviolet curing type cation electrodeposition coating composition comprises the following compositions: A: 50-80 parts of water-soluble or water-dispersion vinyl copolymer which is obtained through the copolymerization of components a to c and is provided with unsaturated group at the end of one part of principal chain, and the components a-c are described as follows: a: 4-15 parts of copolymerized vinyl monomer which has t-aminoalkyl, b: 85-96 parts of copolymerized vinyl monomer except for a, and c: 0.05-20 parts of addition cracking chain transfer agent relatively to total 100 parts of a and b, B: 20-50 parts of composition with more than three unsaturated groups in one molecule; and C: a photopolymerization initiating agent which has a dissolving amount lower than 0.02g to 100g of water containing 3% of alcohol dissolvent and has a molar absorptivity of maxium absorption of 10 in 200nm to 400nm, wherein 0.1-8 parts of photopolymerization initiating agent exist relatively to total 100 parts of a and b.