| abstract |
The present invention relates to an alkaline earth metal salt or an organic amine salt of a compound representing by the formula (I): wherein R1 and R2 are each a hydrogen atom, a halogen atom, or a hydrocarbon group linear optionally substituted; ring A is an optionally substituted benzene ring, ring B is an optionally substituted benzene ring; R is a carboxyl group or a linear hydrocarbon group with a carboxyl group and the like. |