Patent ID: 8741871

Claim:
A compound represented by the following formula (1): wherein X represents phenyl, naphthyl, or a group represented by R 1 —CHR 2 —, and X′ represents phenyl, naphthyl, or a group represented by R 1 ′—CHR 2 ′—, wherein R 1 , R 1 ′, R 2 and R 2 ′ independently represent a hydrogen atom or a C 1 -C 21 alkyl group, and with regard to R 1 , R 1 ′, R 2 and R 2 ′, a hydrogen atom in each alkyl group may be replaced by an alkoxy group, all or some of alkyl groups may form a 4- to 8-membered ring, and R 1 and R 2 , and R 1 ′ and R 2 ′ may bind to each other to form a 4- to 8-membered ring, and wherein n and n′ independently represent an integer of 0 to 3, with the proviso that the compound is not the following compounds: (1) a compound, in which X represents R 1 —CHR 2 —, X′ represents R 1 ′—CHR 2 ′—, R 1 , R 1 ′, R 2 and R 2 ′ independently represent a hydrogen atom or an unsubstituted linear C 1 -C 6 alkyl group, and n and n′ represent 0; (2) a compound, in which X represents R 1 —CHR 2 —, X′ represents and any one of R 1 ′—CHR 2 ′—, R 1 , R 1 ′, R 2 and R 2 ′ represent a C 14 linear alkyl group, and n and n′ represent 0; (3) a compound, in which X represents R 1 —CHR 2 —, X′ represents R 1 ′—CHR 2 ′—, all of R 1 , R 1 ′, R 2 and R 2 ′ represent a hydrogen atom, and n and n′ independently represent 0 to 3; (4) a compound, in which X represents R 1 —CHR 2 —, X′ represents R 1 ′—CHR 2 ′—, any three of R 1 , R 1 ′ R 2 and represent a hydrogen atom, the remaining one of R 1 , R 1 ′, R 2 and R 2 ′ represents a C 1 -C 21 linear alkyl group, and n and n′ independently represent 0 to 3. (5) a compound, in which X represents R 1 —CHR 2 —, X′ represents R 1 ′—CHR 2 ′—, any one of R 1 and R 2 represents a hydrogen any one of R 1 ′ and R 2 ′ represents a hydrogen atom, and both the remaining one of R 1 and R 2 and the remaining one of R 1 ′ and R 2 ′ independently represent a C 1 -C 21 linear alkyl group, and n and n′ independently represent 0 to 3; and (6) a compound, in which X represents phenyl, X′ represents phenyl, and n and n′ represent 0.