Method for producing amphoteric resin having dispersing function

摘要

A process for producing an amphoteric resin which process comprises graft copolymerizing, on the main chain of an alpha , beta -ethylenically unsaturated component C, a copolymerizable basic prepolymer A2 which is obtainable by reacting together (i) a prepolymer A1 which is obtainable by polymerization of a first alpha , beta -ethylenically polymerizable compound and a polymerization initiator containing a terminal carboxyl group, and (ii) a compound having an epoxy group of formula (I): <CHEM> wherein R<1> is H or methyl and R is straight or branched C1-C10 alkyl, in an amount of 0.1-1.0 equivalents to the amino group equivalent of the prepolymer A1; and an alpha , beta -ethylenically polymerizable acidic prepolymer B2 which is obtainable by an analogous procedure to that used to prepare A2. The resulting resin has superior dispersibility for functional compounds such as various pigments and improved weather resistance.