An anthraquinone compound represented by formula (1): (where R.sub.1 and R.sub.4 represent H, a C1-C12 alkyl group, a C1-C12 alkyl group, a halogen atom, CO.sub.2R.sub.9, OCOR.sub.9, COR.sub.9, a cyano group, or CF.sub.3, R.sub.2, R.sub.3, R.sub.5 and R.sub.6 represent H, a C1-C4 alkyl group, a C1-C4 alkoxy group, a halogen atom, CO.sub.2R.sub.9, OCOR.sub.9, COR.sub.9, a cyano group, or CF.sub.3. R.sub.7 and R.sub.8 represent H, a C1-C12 alkyl group, or a C1-C12 alkoxy group. R.sub.9 represents a C1-C12 alkyl group, or a substituent represented by formula (a) (where R.sub.10 represents H, a C1-C8 alkyl group, or a C1-C8 alkoxy group) or formula (b) (where R.sub.11 represents H or a C1-C8 alkyl group); however, at least one of R.sub.1 through R.sub.6 represents a halogen atom, CO.sub.2R.sub.9, COR.sub.9, a cyano group, or CF.sub.3).

##STR00001##

An anthraquinone compound represented by formula (1): (where R.sub.1 and R.sub.4 represent H, a C1-C12 alkyl group, a C1-C12 alkyl group, a halogen atom, CO.sub.2R.sub.9, OCOR.sub.9, COR.sub.9, a cyano group, or CF.sub.3, R.sub.2, R.sub.3, R.sub.5 and R.sub.6 represent H, a C1-C4 alkyl group, a C1-C4 alkoxy group, a halogen atom, CO.sub.2R.sub.9, OCOR.sub.9, COR.sub.9, a cyano group, or CF.sub.3. R.sub.7 and R.sub.8 represent H, a C1-C12 alkyl group, or a C1-C12 alkoxy group. R.sub.9 represents a C1-C12 alkyl group, or a substituent represented by formula (a) (where R.sub.10 represents H, a C1-C8 alkyl group, or a C1-C8 alkoxy group) or formula (b) (where R.sub.11 represents H or a C1-C8 alkyl group); however, at least one of R.sub.1 through R.sub.6 represents a halogen atom, CO.sub.2R.sub.9, COR.sub.9, a cyano group, or CF.sub.3).

##STR00001##

An anthraquinone compound represented by formula (1): (where R.sub.1 and R.sub.4 represent H, a C1-C12 alkyl group, a C1-C12 alkyl group, a halogen atom, CO.sub.2R.sub.9, OCOR.sub.9, COR.sub.9, a cyano group, or CF.sub.3, R.sub.2, R.sub.3, R.sub.5 and R.sub.6 represent H, a C1-C4 alkyl group, a C1-C4 alkoxy group, a halogen atom, CO.sub.2R.sub.9, OCOR.sub.9, COR.sub.9, a cyano group, or CF.sub.3. R.sub.7 and R.sub.8 represent H, a C1-C12 alkyl group, or a C1-C12 alkoxy group. R.sub.9 represents a C1-C12 alkyl group, or a substituent represented by formula (a) (where R.sub.10 represents H, a C1-C8 alkyl group, or a C1-C8 alkoxy group) or formula (b) (where R.sub.11 represents H or a C1-C8 alkyl group); however, at least one of R.sub.1 through R.sub.6 represents a halogen atom, CO.sub.2R.sub.9, COR.sub.9, a cyano group, or CF.sub.3). ##STR00001##

An anthraquinone compound represented by formula (1): (where R.sub.1 and R.sub.4 represent H, a C1-C12 alkyl group, a C1-C12 alkyl group, a halogen atom, CO.sub.2R.sub.9, OCOR.sub.9, COR.sub.9, a cyano group, or CF.sub.3, R.sub.2, R.sub.3, R.sub.5 and R.sub.6 represent H, a C1-C4 alkyl group, a C1-C4 alkoxy group, a halogen atom, CO.sub.2R.sub.9, OCOR.sub.9, COR.sub.9, a cyano group, or CF.sub.3. R.sub.7 and R.sub.8 represent H, a C1-C12 alkyl group, or a C1-C12 alkoxy group. R.sub.9 represents a C1-C12 alkyl group, or a substituent represented by formula (a) (where R.sub.10 represents H, a C1-C8 alkyl group, or a C1-C8 alkoxy group) or formula (b) (where R.sub.11 represents H or a C1-C8 alkyl group); however, at least one of R.sub.1 through R.sub.6 represents a halogen atom, CO.sub.2R.sub.9, COR.sub.9, a cyano group, or CF.sub.3). ##STR00001##