Cyclic diol compound, method for producing said compound, and use of said compound

The present invention provides a modifier for resins such as polyester resins, polyester carbonate resins, and polycarbonate resins. The present invention further provides a cyclic diol compound useful as a resin modifier and a method for producing the compound. The present invention relates to a resin modifier comprising a compound represented by general formula (1). [In the formula, the R1 moieties may be the same or different and each represent a hydrogen atom, a fluorine atom, a chlorine atom, a bromine atom, a phenyl group, or a C1-C4 linear or branched alkyl group, and ring A represents a benzene ring optionally substituted by one to four groups selected from the group consisting of a fluorine atom, a chlorine atom, a bromine atom, a phenyl group, C1-C6 linear or branched alkoxy groups, and C1-C6 linear or branched alkyl groups.].