Patent ID: 6951706

Claim:
A sulfonate of the formula (I): wherein Q 1 , Q 2 , Q 3 , Q 4 and Q 5 each independently represent hydrogen, alkyl having 1 to 16 carbon atoms, alkoxy having 1 to 16 carbon atoms, halogen, aryl having 6 to 12 carbon atoms, aralkyl having 7 to 12 carbon atoms, cyano, sulfide, hydroxy, nitro or a group of the formula (I′) —COO—X—Cy 1 (I′) wherein X represents alkylene and at least one —CH 2 — in the alkylene may be substituted by —O— or —S—, and Cy 1 represents alicyclic hydrocarbon having 3 to 20 carbon atoms, and A + represents a counter ion, with the proviso that at least one of Q 1 , Q 2 , Q 3 , Q 4 and Q 5 is the group of the formula (I′).