| abstract |
(57) Abstract: A novel aminopolyether capable of imparting flexibility while improving the curability and corrosion resistance of an electrodeposition coating film and improving the adhesion to an intermediate coat or a top coat. A modified epoxy and a cationic electrodeposition coating composition using the same as a flexible resin. An aminopolyether represented by the following formula, having a molecular weight of 300 to 7000, A reaction product with a polyglycidyl ether having an epoxy equivalent of 0, wherein the reaction is performed by adding a primary amino group of the amino polyether to an epoxy group of the polyglycidyl ether in an equivalent ratio of 1.05 to 1.05. A cationic electrodeposition coating composition containing an aminopolyether-modified epoxy obtained by setting the ratio to 2.0: 1.0, and a flexible resin comprising the aminopolyether-modified epoxy. Embedded image Here, m is an integer of 2 or more, R is hydrogen, a methyl group or an ethyl group, and n and n ′ are each independently 2 or 3. |