| 摘要 |
There is described a negative charge control agent for use in electroreprography which comprises one or more azopyrazolones of Formula (I) which includes all electroreprographically effective forms of such compounds selected from one or more of the following (including mixtures thereof and combinations thereof in the same species): stereoisomers, zwitterions, polymorphs, solvates, isotopic forms; and salts thereof; where in Formula (I) n represents an integer from 0 to 4 inclusive; R<1> represents one or more substituents selected from one or more of: hydroxy, mercapto, amino, nitro, sulpho, sulpheno, sulphino, carboxy, halo, cyano, optionally substituted C1-30hydrocarbyl and an optionally substituted aryl ring fused to the ring to which R<1> is attached, R<2> and R<3>, which may be the same or different, each independently represents optionally substituted C1-30hydrocarbyl. |
