Patent ID: 7645889

Claim:
A separating medium comprising a carrier supporting the optically active polymaleimide derivative represented by the following formula (3): wherein each of X 1 to X 8 is independently a methylene group, an oxygen atom, a carbonyl group, a carbonyloxy group, a carbonylamino group, an aminocarbonyl group, an aminocarbonyloxy group or a single bond, each of R 1 to R 8 is independently a hydrogen atom, a methyl group, an ethyl group, a C 3-10 linear, branched or cyclic alkyl group, a methoxy group, an ethoxy group, a C 3-10 linear, branched or cyclic alkoxy group, a C 5-10 aromatic group, a C 5-10 aromatic group having 1 to 4 methyl groups on the aromatic group instead of hydrogen, a C 5-10 aromatic group having 1 to 4 ethyl groups on the aromatic group instead of hydrogen, a C 5-10 aromatic group having 1 to 4 C 3-6 linear, branched or cyclic alkyl groups on the aromatic group instead of hydrogen, a C 5-10 aromatic group having 1 to 4 methoxy groups on the aromatic group instead of hydrogen, a C 5-10 aromatic group having 1 to 4 ethoxy groups on the aromatic group instead of hydrogen, a C 5-10 aromatic group having 1 to 4 C 3-6 linear, branched or cyclic alkoxy groups on the aromatic group instead of hydrogen, a benzyl group, a benzyl group having 1 to 4 methyl groups on the aromatic group instead of hydrogen, a benzyl group having 1 to 4 ethyl groups on the aromatic group instead of hydrogen, a benzyl group having 1 to 4 C 3-6 linear, branched or cyclic alkyl groups on the aromatic group instead of hydrogen, a benzyl group having 1 to 4 methoxy groups on the aromatic group instead of hydrogen, a benzyl group having 1 to 4 ethoxy groups on the aromatic group instead of hydrogen, a benzyl group having 1 to 4 C 3-6 linear, branched or cyclic alkoxy groups on the aromatic group instead of hydrogen, a 2-phenylethyl group, a 2-phenylethyl group having 1 to 4 methyl groups on the aromatic group instead of hydrogen, a 2-phenylethyl group having 1 to 4 ethyl groups on the aromatic group instead of hydrogen, a 2-phenylethyl group having 1 to 4 C 3-6 linear, branched or cyclic alkyl groups on the aromatic group instead of hydrogen, a 2-phenylethyl group having 1 to 4 methoxy groups on the aromatic group instead of hydrogen, a 2-phenylethyl group having 1 to 4 ethoxy groups on the aromatic group instead of hydrogen, a 2-phenylethyl group having 1 to 4 C 3-6 linear, branched or cyclic alkoxy groups on the aromatic group instead of hydrogen or a 5 to 10-membered heterocyclic aromatic group, provided that not all of R 1 —X 1 , R 2 —X 2 , R 3 —X 3 , R 4 —X 4 , R 5 —X 5 , R 6 —X 6 , R 7 —X 7 and R 8 —X 8 are the same substituents, n is from 2 to 10000, and * indicates asymmetric carbon.