Patent ID: 8039667

Claim:
A compound having a structure represented by Formula I: wherein, R 1 and R 2 may be the same or different, each representing a methyl group or a hydrogen atom; R 3 and R 4 may be the same or different, each representing a substituted or unsubstituted alkanetriyl group having 2 to 10 carbon atoms in which a carbon atom is optionally replaced with an atom other than carbon; R 5 and R 6 may be the same or different, each representing a substituted or unsubstituted alkyl group having 1 to 6 carbon atoms or a hydrogen atom; R 7 represents a substituted or unsubstituted alkylene group having 1 to 6 carbon atoms or a substituted or unsubstituted phenylene group; X represents —SO 3 H, —PO 3 H 2 , —PO 4 H 2 , —R 8 SO 3 H, —R 8 PO 3 H 2 , or —R 8 PO 4 H 2 , where R 8 represents a substituted or unsubstituted alkylene group having 1 to 6 carbon atoms; and n and n′ are each independently an integer of 1 to 5, and m and m′ are each independently an integer of 0 to 4, where n+m is 5 and n′+m′ is 5.