Triazine-ring-containing polymer and composition including same

A triazine ring-containing polymer comprising a recurring unit structure of formula (1) below

• {wherein R and R′ are each independently a hydrogen atom, an alkyl group, an alkoxy group, an aryl group or an aralkyl group;
• and
• Ar1 is at least one moiety selected from the group consisting of moieties of formulas (2) to (13)
• [R1 to R92 being each independently a hydrogen atom, a halogen atom, a sulfo group, an alkyl group of 1 to 10 carbon atoms which may have a branched structure, or an alkoxy group of 1 to 10 carbon atoms which may have a branched structure;
• R93 and R94 being each a hydrogen atom or an alkyl group of 1 to 10 carbon atoms which may have a branched structure;
• W1 and W2 being each independently a single bond, CR95R96 (wherein R95 and R96 are each independently a hydrogen atom or an alkyl group of 1 to 10 carbon atoms which may have a branched structure, and R95 and R96 may together form a ring), C═O, O, S, SO, SO2 or NR97 (wherein R97 is a hydrogen atom or an alkyl group of 1 to 10 carbon atoms which may have a branched structure);
• and
• X1 and X2 being each independently a single bond, an alkylene group of 1 to 10 carbon atoms which may have a branched structure, or a group of formula (14)
• (wherein R98 to R101 are each independently a hydrogen atom, a halogen atom, a sulfo group, an alkyl group of 1 to 10 carbon atoms which may have a branched structure, or an alkoxy group of 1 to 10 carbon atoms which may have a branched structure;
• and
• Y1 and Y2 are each independently a single bond or an alkylene group of 1 to 10 carbon atoms which may have a branched structure)]} and having at least one triazine ring end, wherein at least a portion of the triazine ring ends is capped with carboxyl group-substituted arylamino groups.