Patent ID: 7531686

Claim:
A salt of the formula (I): wherein ring X represents polycyclic hydrocarbon group having tricycle or more and having 10 to 30 carbon atoms, and one or more hydrogen atom in the ring X is optionally substituted with alkyl group having 1 to 6 carbon atoms, alkoxy group having 1 to 6 carbon atoms, perfluoroalkyl group having 1 to 4 carbon atoms or cyano group; Q 1 and Q 2 each independently represent fluorine atom or perfluoroalkyl group having 1 to 6 carbon atoms; n is an integer of 1 to 12; and A + represents a cation selected from the group consisting of a cation of the following formulae (IIa), (IIb) and (IIc): cation of the formula (IIa): wherein P 1 and P 2 each independently represent hydrogen atom, hydroxyl group, alkyl group having 1 to 12 carbon atoms or alkoxy group having 1 to 12 carbon atoms, a cation of the formula (IIb): wherein P 3 and P 4 each independently represent alkyl group having 1 to 12 carbon atoms or cycloalkyl group having 3 to 12 carbon atoms, or P 3 and P 4 bond to form divalent acyclic hydrocarbon group having 3 to 12 carbon atoms which forms a ring together with the adjacent S + , and one or more —CH 2 — in the divalent acyclic hydrocarbon group is optionally substituted with —CO—, —O— or —S—, P 5 represents hydrogen atom, P 6 represents alkyl group having 1 to 12 carbon atoms, cycloalkyl group having 3 to 12 carbon atoms or aromatic ring group optionally substituted, or P 5 and P 6 bond to form divalent acyclic hydrocarbon group which forms 2-oxocycloalkyl together with the adjacent —CHCO—, and one or more —CH 2 — in the divalent acyclic hydrocarbon group is optionally substituted with —CO—, —O— or —S—, a cation of the formula (IIc): wherein P 7 , P 8 , P 9 , P 10 , P 11 , P 12 , P 13 , P 14 , P 15 , P 16 , P 17 and P 18 each independently represent hydrogen atom, hydroxyl group, alkyl group having 1 to 12 carbon atoms or alkoxy group having 1 to 12 carbon atoms, B represents sulfur atom or oxygen atom, and m is an integer of 0 or 1.