Abstract: The present invention provides a protolytically leaving group-containing copolymer having improved characteristics such as increased solubility in alkaline aqueous solution in the presence of a proton, thus finding application with advantage in various uses, and a process for producing the copolymer. A protolytically leaving group-containing copolymer represented by the following general formula (1): in the formula, R1, R2 and R3 are the same or different and each represents a protolytically leaving group and a, b and c represent the amounts of existence (mole %) of repeating units (A), (B) and (C), respectively, in the copolymer, which comprises the repeating unit (A) as well as the repeating unit (B) and/or the repeating unit (C) and has a weight average molecular weight of 2000˜30000, said a, b and c satisfying the condition that a is 5 to 30 mole % and (b+c) is 70 to 95 mole %.

Abstract: The present invention provides a protolytically leaving group-containing copolymer having improved characteristics such as increased solubility in alkaline aqueous solution in the presence of a proton, thus finding application with advantage in various uses, and a process for producing the copolymer.

Abstract: A carbon black-graft polymer, produced by causing a polymer possessing within the molecular unit thereof at least one reactive group selected from the class consisting of aziridine group, oxazoline group. N-hydroxyalkylamide group, epoxy group, and thioepoxy group to react with carbon black. The polymer can be used as a toner for electrostatically charged image, resin composition, coating composition, ink for thermographic transfer, coating agent for magnetic recording medium, rubber composition, and carbon black dispersion and the like.

Abstract: A carbon black-graft polymer, produced by causing a polymer possessing within the molecular unit thereof at least one reactive group selected from the class consisting of aziridine group, oxazoline group. N-hydroxyalkylamide group, epoxy group, and thioepoxy group to react with carbon balck. The polymer can be used as a toner for electrostatically charged image, resin composition, coating composition, ink for thermographic transer, coating gent for magnetic recording medium, rubber composition, and carbon black dispersion and the like.

Abstract: A carbon black-graft polymer, produced by causing a polymer possessing within the molecular unit thereof at least one reactive group selected from the class consisting of aziridine group, oxazoline group. N-hydroxyalkylamide group, epoxy group, and thioepoxy group to react with carbon black. The polymer can be used as a toner for electrostatically charged image, resin composition, coating composition, ink for thermographic transer, coating gent for magnetic recording medium, rubber composition, and carbon black dispersion and the like.