| abstract |
Described is an anthraquinone mixture comprising three different anthraquinone compounds. The compounds have the formula wherein: R1 and R2 are, independently, monohydroxy C2 -C6 alkyl, straight chain or branched chain, with the proviso that in two of the anthraquinones, R1 and R2 are the same. As a consequence those anthraquinones are symmetric. In the third of the anthraquinones, R1 and R2 differ. As a consequence that anthraquinone is asymmetric. The two symmetric anthraquinone compounds in combination are present in the mixture in an amount of about 30% to about 90% by weight, based on the total weight of the mixture. The asymmetric anthraquinone is present in the mixture in an amount of about 10% to about 70% by weight, based on the total weight of the mixture. |