Toner for developing electrostatic images and process for production thereof
AssigneeCanon Kabushiki Kaisha
InventorsToshiyuki Ugai, Kazumi Yoshizaki
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Abstract
An electrophotographic black toner containing carbon black in a good dispersion state as well as a combined charge control agent system including a specific azo iron metal compound of formula (1) shown below and an oxycarboxylic acid metal compound is produced through polymerization in an aqueous system. The combined charge control agent system shows an effects of synergistically improving the chargeability of spherical polymerized toner particles. The azo iron metal compound improves the dispersion of the carbon black in the toner particles. ##STR1## wherein the denotations of R.sub.1 -R.sub.6, n, n' and A.sup..sym. are omitted.
Claims38
A toner for developing electrostatic images, comprising toner particles containing a binder resin, carbon black, an azo iron compound represented by formula (1) below, and an oxycarboxylic acid metal compound,
- wherein the toner particles have been prepared by:
- preparing a polymerizable monomer composition comprising a polymerizable monomer, carbon black, an azo iron compound represented by the formula (1) below and an oxycarboxylic acid metal compound,
- dispersing the polymerizable monomer composition in an aqueous medium to form particles of the polymerizable monomer composition, and
- polymerizing the polymerizable monomer in the particles to form toner particles comprising the polymerized monomer as the binder resin;
- ##STR10## wherein R.sub.1 and R.sub.3 independently denote hydrogen, C.sub.1-18 alkyl, C.sub.2-18 alkenyl, sulfonamido group, mesyl, sulfonic acid group, hydroxy, C.sub.1-18 alkoxy, acetylamino, benzoylamino, halogen atom, or --O.CO.R.sub.7 wherein R.sub.7 is alkyl or aryl, n and n' are integers of 1-3,
- R.sub.2 and R.sub.4 independently denote hydrogen or nitro,
- R.sub.5 and R.sub.6 independently denote hydrogen, halogen, nitro, carboxy, C.sub.1-18 alkyl, C.sub.2-18 alkenyl, C.sub.7-18 aralkyl, C.sub.1-18 alkoxy, C.sub.6-18 aryl, --O.CO.R.sub.7 wherein R.sub.7 is C.sub.1-18 alkyl or C.sub.6-18 aryl, or ##STR11## wherein m is an integer of 1-3 and X denotes hydrogen, lower alkyl, lower alkoxy, nitro or halogen;
- and
- A.sup..sym. denotes H.sup.+, Na.sup.+, K.sup.+, NH.sub.4.sup.+ or a mixture of these ions.
A process for producing a toner for developing electrostatic images, comprising the steps of:
- (i) preparing a polymerizable monomer composition comprising a polymerizable monomer, carbon black, an azo iron compound represented by formula (1) below and an oxycarboxylic acid metal compound,
- (ii) dispersing the polymerizable monomer composition in an aqueous medium to form particles of the polymerizable monomer composition, and
- (iii) polymerizing the polymerizable monomer in the particles to form toner particles comprising the polymerized monomer as the binder resin;
- ##STR13## wherein R.sub.1 and R.sub.3 independently denote hydrogen, C.sub.1-18 alkyl, C.sub.2-18 alkenyl, sulfonamido group, mesyl, sulfonic acid group, hydroxy, C.sub.1-18 alkoxy, acetylamino, benzoylaminc, halogen atom, or --O.CO.R.sub.7 wherein R.sub.7 is alkyl or aryl, n and n' are integers of 1-3,
- R.sub.2 and R.sub.4 independently denote hydrogen or nitro,
- R.sub.5 and R.sub.6 independently denote hydrogen, halogen, nitro, carboxy, C.sub.1-18 alkyl, C.sub.2-18 alkenyl, C.sub.7-18 aralkyl, C.sub.1-18 alkoxy, C.sub.6-18 aryl, --O.CO.R.sub.7 wherein R.sub.7 is C.sub.1-18 alkyl or C.sub.6-18 aryl, or ##STR14## wherein m is an integer of 1-3 and X denotes hydrogen, lower alkyl, lower alkoxy, nitro or halogen;
- and
- A.sup..sym. denotes H.sup.+, Na.sup.+, K.sup.+, NH.sub.4.sup.+ or a mixture of these ions.
Dependencies are inferred from the claim text.