Provided is a chemical compound represented by the general formula (A), in which each of substituents Q1 to Q6 is bonded to a nitrogen atom of melamine backbone. In the general formula (A), at least one of Q1 to Q6 is X, and at least one of Q1 to Q6 is Y. R1 is a hydrogen atom or an alkyl group having 1 to 12 carbon atoms. R2 is a hydrogen atom, or a monovalent hydrocarbon group selected from the group consisting of an alkyl group having 1 to 12 carbon atoms, an aryl group having 6 to 25 carbon atoms, and an aralkyl group having 7 to 30 carbon atoms. Each of R51 and R52 is a divalent organic group, and a is an integer of 1 to 3.