EP0718704A1 - Elektrophotographischer Toner und Enwickler - Google Patents

Elektrophotographischer Toner und Enwickler Download PDF

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Publication number
EP0718704A1
EP0718704A1 EP95308608A EP95308608A EP0718704A1 EP 0718704 A1 EP0718704 A1 EP 0718704A1 EP 95308608 A EP95308608 A EP 95308608A EP 95308608 A EP95308608 A EP 95308608A EP 0718704 A1 EP0718704 A1 EP 0718704A1
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EP
European Patent Office
Prior art keywords
toner
weight
parts
graft polymer
polymer
Prior art date
Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
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Application number
EP95308608A
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English (en)
French (fr)
Inventor
Kenshi c/o Mita Ind. Co. Ltd. Matsui
Kazuhiko c/o Mita Ind. Co. Ltd. Yamamura
Tanida c/o Mita Ind. Co. Ltd. Keiichi
Toyoda c/o Mita Ind. Co. Ltd. Keitaro
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Kyocera Mita Industrial Co Ltd
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Mita Industrial Co Ltd
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Priority claimed from JP29538394A external-priority patent/JPH08152746A/ja
Priority claimed from JP32352394A external-priority patent/JPH08160665A/ja
Priority claimed from JP32352494A external-priority patent/JPH08160666A/ja
Application filed by Mita Industrial Co Ltd filed Critical Mita Industrial Co Ltd
Publication of EP0718704A1 publication Critical patent/EP0718704A1/de
Withdrawn legal-status Critical Current

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    • G—PHYSICS
    • G03—PHOTOGRAPHY; CINEMATOGRAPHY; ANALOGOUS TECHNIQUES USING WAVES OTHER THAN OPTICAL WAVES; ELECTROGRAPHY; HOLOGRAPHY
    • G03G—ELECTROGRAPHY; ELECTROPHOTOGRAPHY; MAGNETOGRAPHY
    • G03G9/00—Developers
    • G03G9/08—Developers with toner particles
    • G—PHYSICS
    • G03—PHOTOGRAPHY; CINEMATOGRAPHY; ANALOGOUS TECHNIQUES USING WAVES OTHER THAN OPTICAL WAVES; ELECTROGRAPHY; HOLOGRAPHY
    • G03G—ELECTROGRAPHY; ELECTROPHOTOGRAPHY; MAGNETOGRAPHY
    • G03G9/00—Developers
    • G03G9/08—Developers with toner particles
    • G03G9/087—Binders for toner particles
    • G03G9/08784—Macromolecular material not specially provided for in a single one of groups G03G9/08702 - G03G9/08775
    • G03G9/08786—Graft polymers
    • G—PHYSICS
    • G03—PHOTOGRAPHY; CINEMATOGRAPHY; ANALOGOUS TECHNIQUES USING WAVES OTHER THAN OPTICAL WAVES; ELECTROGRAPHY; HOLOGRAPHY
    • G03G—ELECTROGRAPHY; ELECTROPHOTOGRAPHY; MAGNETOGRAPHY
    • G03G9/00—Developers
    • G03G9/08—Developers with toner particles
    • G03G9/087—Binders for toner particles
    • G03G9/08702—Binders for toner particles comprising macromolecular compounds obtained by reactions only involving carbon-to-carbon unsaturated bonds
    • G03G9/08706—Polymers of alkenyl-aromatic compounds

Definitions

  • the present invention relates to an electrophotographic toner which is used in image forming apparatus such as electrostatic copying machines, plain paper facsimile apparatus, laser beam printers, etc.
  • the electrophotographic toner is normally produced by dispersing a colorant, an electric charge controlling material, etc. in a suitable fixing resin, followed by pulverizing and additional classification.
  • One of the important characteristics of such an electrophotographic toner include fixing properties to paper, etc. That is, the toner transferred on the paper surface is molten by passing through heated fixing rollers in the image forming apparatus, and then fixed on the paper surface.
  • the fixing temperature is liable to decrease according to recent demands on the image forming apparatus, such as miniaturization, speeding-up, electric power saving, etc. Therefore, a toner showing good fixing properties at low temperature has been required in response to the above demands.
  • a toner composition wherein a styrene polymer oligomer having a number-average molecular weight of not more than 1,000 is contained in a fixing resin comprising a styrene copolymer as a main component.
  • Another one of important characteristics of the electrophotographic toner includes dispersion properties of the colorant.
  • the carbon blacks which have widely been used as the colorant for black toner particularly a carbon black having a particle size of not more than 40 nm, which has high coloring properties, is not easily uniformly dispersed in the toner. Therefore, the above carbon black is liable to agglomerate in the toner to form a huge mass. It has been studied to use the above carbon black for a toner wherein the particle size is liable to decrease in response to the accomplishment of high-quality image of the formed image.
  • the carbon black falls out from the above mass part or a fracture is formed on the toner when the toner is stirred repeatedly in a developing vessel of the image forming apparatus.
  • the magnetic carrier circulating in the developing vessel together with the toner or the interior of developing vessel is contaminated with the fragments of toner particles, fallen-out carbon black.
  • Japanese Laid-Open Patent Publication No. 2-52362 there is disclosed a toner wherein a terminal amide-modified polyester is contained in a fixing resin as a pigment surface treating agent, so as to improve the dispersion properties of the pigment.
  • the pigment surface treating agent to be used is expensive and an amine is used for amidation of the terminal end of the polyester as this treating agent and, therefore, the toner is positively charged by the residual amine, thereby causing a problem of lack of toner density due to over charging.
  • an electric charge controlling material comprising a graft polymer consisting of a polystyrene main chain and a graft chain having a skeleton represented by the following general formula (5): wherein R A is a C 11 -C 17 hydrocarbon group; R B and R C independently indicate a hydrogen atom or a C 1 -C 8 hydrocarbon group, and R B and R C may bond together to form an aromatic ring; R D is a C 1 -C 12 alkylene group which may contain an ether bond; X - is an anion; and m is an integer of 2 to 100, or an electric charge controlling material comprising this glaft polymer and a polymer represented by the following general formula (6): wherein R A to R D and X - are as defined above; and n is an integer of 2 to 100.
  • the above electric charge controlling material is superior in dispersion properties of the toner to the fixing resin.
  • a toner using this electric charge controlling material can obtain a sharp charged amount distribution, and is also superior in stability to an environmental change such as temperature, etc.
  • this electric charge controlling material has a drawback that the charged amount is not sufficient. There is a problem that, when the amount of the electric charge controlling material to be added is increased so as to improve the charged amount, the heat resistance of the toner deteriorates, to cause blocking, offset, etc.
  • a graft polymer consisting of a main chain of a styrene polymer having a glass transition temperature Tg of 30 to 60 °C and a number-average molecular weight Mn of 2,000 to 10,000 and a graft chain represented by the general formula (1): wherein R 1 is a hydrogen atom, an alkyl having 11 to 17 carbon atoms or an aryl group; R 2 and R 3 are the same or different and indicate a hydrogen atom or an alkyl group having 1 to 17 carbon atoms; R 4 is an alkyl group having 1 to 12 carbon atoms; R 5 is a hydrogen atom, a hydroxyl group or a methyl group; X - is an anion; and n is an integer of not less than 2, is contained in a fixing resin in the amount of 1 to 10 parts by weight
  • the above graft polymer is not miscible with the fixing resin, like a conventional low-melting point substance.
  • the dispersion properties to the fixing resin are improved by adjusting the glass transition temperature, polymerization degree, etc. of a styrene polymer constituting the main chain. Therefore, if only the graft polymer is molten and kneaded, together with the fixing resin, colorant, etc., it can be uniformly dispersed in the toner as fine particles.
  • a graft polymer is scarcely exposed on the surface of an electrophotographic toner wherein the graft polymer is blended. Even if the graft polymer is exposed, a part comprising fine particles of the graft polymer is exposed only sporadically. Accordingly, it is possible to effectively improve the low-temperature fixing properties of the toner alone without generating blocking, offset, etc.
  • the above graft polymer in the present invention also functions as a dispersant for the colorant agent and is of superior effect in uniformlydispersing a colorant which is not easily dispersed in the fixing resin uniformly.
  • a colorant which is not easily dispersed in the fixing resin uniformly.
  • a carbon black having a particle size of 40 nm or less, etc.
  • the graft polymer defined in claim 1 is present in an amount within the range of 1 to 20 parts by weight, based on 100 parts by weight of the fixing resin, in a particulately dispersed state and, at the same time, the colorant is retained in or on the fine particles of the above graft polymer.
  • a graft polymer wherein the colorant is uniformly dispersed therein, and/or is adhered on the surface thereof is dispersed in the fixing resin.
  • the graft polymer as a lot of fine particles is dispersed in the fixing resin and a large amount of the colorant is retained in the interior or on the surface of the above fine particles, thereby further improving dispersion properties of the colorant in the toner.
  • the above graft polymer in the present invention has improved dispersion properties to the fixing resin in comparison with the low-molecular weight quaternary ammonium salt to be used as the electric charge controlling material for a conventional positive charging toner, and has charging properties.
  • the present inventors have studied intensively in order to make the above graft polymer develop a function as the electric charge controlling material, effectively. As a result, it has been found that, when using a magnetic carrier wherein the surface of magnetic particles is coated with a coat layer of a silicone resin or a fluororesin as a carrier to be used in combination with the toner containing the above graft polymer, the charged amount of the toner can be improved to a level enough to put to practical use. The reason is assumed that the above coating type carrier is superior in action of positively charging the toner because of its high negative charging properties.
  • the polymer having a repeating unit represented by the above formula (1) is superior in affinity with colorants such as carbon black, etc. Accordingly, a function as the dispersant of the colorant is expected, similar to the above graft polymer.
  • the above polymer has a problem that the dispersion properties are not sufficient and it is liable to agglomerate in the fixing resin.
  • the present inventors have studied intensively in order to eliminate the drawback of the above polymer.
  • the dispersion properties of the polymer in the fixing resin are improved when the polymer having a repeating unit represented by the above formula (1) is contained in the fixing resin in the proportion of 1 to 10 parts by weight, based on 100 parts by weight of the fixing resin and, at the same time, the inorganic fine particles are contained in the proportion of 0.1 to 10 parts by weight, based on 100 parts by weight of the fixing resin, thereby improving the dispersion properties of the colorant in the toner.
  • the reason why the dispersion properties of the polymer are improved by containing the inorganic fine particles is assumed as follows. That is, when the polymer where colorants such as carbon black are dispersed is mixed with the inorganic fine particles, it is finely ground by the inorganic fine particles, and the inorganic fine particles adhered on the surface of the ground product prevent the ground product from reagglomerating. As a result, the dispersion properties of the polymer to the fixing resin is improved, thereby improving the dispersion properties of the colorant.
  • Fig. 1 is a transmission electron micrograph (15,000X magnification) showing the section of the electrophotographic toner of Example 4.
  • Fig. 2 is a transmission electron micrograph (15,000X magnification) showing the section of the electrophotographic toner of Comparative Example 1.
  • Fig. 3 is a transmission electron micrograph (30,000X magnification) showing the section of the electrophotographic toner of Example 11.
  • Fig. 4 is a transmission electron micrograph (30,000X magnification) showing the section of the electrophotographic toner of Comparative Example 19.
  • the electrophotographic toner of the present invention can be formed by formulating the above-described graft polymer comprising the styrene chain and graft chain represented by the general formula (1), colorant and, if necessary, other additives such as electric charge controlling material, etc. in the fixing resin.
  • the electric charge controlling material has a moiety corresponding to the quaternary ammonium salt in the graft chain, it also has a function as the electric charge controlling material in case of positive charging toner. Accordingly, when using this positive charging toner containing the graft polymer in combination with the above-described specific coating type carrier, the other electric charge controlling material is not required necessarily, but an electric charge controlling material which has hitherto been known may be formulated, together with the graft polymer.
  • the electrophotographic toner of the present invention can be produced by melting and kneading a mixture, obtained by preliminary mixing the above respective components using a dry blender, Henshel mixer, ball mill, etc., using a Banbury mixer, roll, single-screw or twin-screw extruder, etc., cooling the resulting kneaded product, followed by pulverizing and optional classifying.
  • the electrophotographic toner can be produced by melting and kneading the graft polymer and colorant according to the same manner as that described above to give a mixture wherein the colorant is uniformly dispersed in the graft polymer, preliminary mixing the mixture with the fixing resin, electric charge controlling material and other additives, melting and kneading them, cooling the resulting kneaded product, followed by optional classification.
  • the fixing resin examples include styrene resin (homopolymer or copolymer containing styrene or a styrene substitute) such as polystyrene, chloropolystyrene, poly- ⁇ -methylstyrene, styrene-chlorostyrene copolymer, styrene-propylene copolymer, styrene-butadiene copolymer, styrene-vinyl chloride copolymer, styrene-vinyl acetate copolymer, styrene-maleic acid copolymer, styrene-acrylate copolymer (e.g.,
  • styrene-methyl acrylate copolymer styrene-ethyl acrylate copolymer, styrene-butyl acrylate copolymer, styreneoctyl acrylate copolymer, styrene-phenyl acrylate copolymer, etc.
  • styrene-methacrylate copolymer e.g.
  • styrene-methyl methacrylate copolymer styrene-ethyl methacrylate copolymer, styrene-butyl methacrylate copolymer, styrene-phenyl methacrylate copolymer, etc.
  • styrene- ⁇ -chloromethyl acrylate copolymer styrene-acrylonitrile-acrylate copolymer, etc.
  • polyvinyl chloride low-molecular weight polyethylene, low-molecular weight polypropylene, ethylene-ethyl acrylate copolymer, polyvinyl butyral, ethylene-vinyl acetate copolymer, rosin-modified maleic acid resin, phenol resin, epoxy resin, polyester resin, ionomer resin, polyurethane resin, silicone resin, ketone resin, xylene resin, polyamide resin, etc. These may be used alone or in any combination thereof.
  • styrene-acrylic resins such as styrene-acrylate copolymer, styrene-methacrylate copolymer, etc. among them, as the fixing resin.
  • the colorant to be formulated in the fixing resin there can be used various dyes, pigments, etc., which have hitherto been known.
  • black toner a carbon black is mainly used.
  • carbon black there can be used various carbon blacks which have hitherto been known, such as channel black, roller black, disc black, gas furnace black, oil furnace black, thermal black or acetylene black.
  • a carbon black having a particle diameter of not more than 40 nm is suitably used in view of coloring properties, as described above.
  • another normal type carbon black may be used.
  • the carbon black itself has a conductivity, it also plays a role as control means of electric characteristics related to charging of the toner. Accordingly, it is preferred to set a preferable range of the amount to be formulated according to the objective toner performances. It is preferred in view of charging properties of the electrophotographic toner that the amount of the carbon black to be formulated is normally about 1 to 15 parts by weight, based on 100 parts by weight of the fixing resin.
  • the electric charge controlling material is formulated so as to control the friction charging properties of the electrophotographic toner, and any one of electric charge controlling materials for controlling positive electric charge and negative electric charge may be used according to the charged polarity of the toner.
  • the electric charge controlling material for controlling positive electric charge there are various electric charge controlling materials which have hitherto been known, such as organic compounds containing a basic nitrogen atom, e.g. basic dyes, aminopyridine, pyrimidine compounds, polynuclearpolyamino compounds, aminosilanes, etc.
  • organic compounds containing a basic nitrogen atom e.g. basic dyes, aminopyridine, pyrimidine compounds, polynuclearpolyamino compounds, aminosilanes, etc.
  • the electric charge controlling material for controlling negative electric charge there are oil-soluble dyes such as nigrosine base (CI5045), oil black (CI26150), bonthrone S, spiron black, etc.; electric charge controlling resins such as styrene-styrenesulfonic acid copolymer, etc.; compounds containing a carboxyl group, such as metal chelate alkyl salicylate, etc.; metal complex dye, fatty metal soap, fatty acid soap, metal naphthenate, etc.
  • oil-soluble dyes such as nigrosine base (CI5045), oil black (CI26150), bonthrone S, spiron black, etc.
  • electric charge controlling resins such as styrene-styrenesulfonic acid copolymer, etc.
  • compounds containing a carboxyl group such as metal chelate alkyl salicylate, etc.
  • metal complex dye such as fatty metal soap, fatty acid soap, metal naphthenate, etc
  • the electric charge controlling material is used in the proportion of 0.1 to 10 parts by weight, preferably 0.5 to 8 parts by weight, based on 100 parts by weight of the fixing resin.
  • the graft polymer in the present invention is composed of a main chain of a styrene polymer having a glass transition temperature Tg of 30 to 60 °C and a number-average molecular weight Mn of 2,000 to 10,000, and a graft chain represented by the above general formula (1).
  • the proportion of styrene by which the monomer is occupied is preferably not less than 50 molar %.
  • the dispersion properties to the fixing resin are likely to become insufficient, thereby making it impossible to disperse uniformly, although they vary depending on the value of the glass transition temperature Tg and number-average molecular weight Mn of the main chain, kind of the binding resin, etc.
  • Tg glass transition temperature
  • Mn number-average molecular weight
  • Examples of the other monomers constituting the above main chain, together with styrene include styrene derivatives, acrylic monomers, viny ester monomers, vinyl ether monomers, diolefin monomers, monoolefin monomers, olefin halide monomers, polyvinyl monomers, etc.
  • examples of the styrene derivative include ⁇ -methylstyrene, vinyltoluene, ⁇ -chlorostyrene, o-chlorostyrene, m-chlorostyrene, p-chlorostyrene, p-ethylstyrene, sodium styrene sulfonate, etc.
  • acrylic monomer examples include acrylic acid, methyl acrylate, ethyl acrylate, butyl acrylate, acrylic acid-2-ethylhexyl, cyclohexyl acrylate, phenyl acrylate, methacrylic acid, methyl methacrylate, ethyl methacrylate, butyl methacrylate, methacrylic acid-2-ethylhexyl, cyclohexyl methacrylate, phenyl methacrylate, ⁇ -hydroxyethyl methacrylate, ⁇ -aminopropyl acrylate, ⁇ -N,N-diethylaminopropyl acrylate, ethylene glycol dimethacrylate, tetraethylene glycol dimethacrylate, etc.
  • vinyl ester monomer examples include vinyl formate, vinyl acetate, vinyl propionate, etc.
  • vinyl ether monomer examples include vinyl methyl ether, vinyl ethyl ether, vinyl-n-butyl ether, vinyl phenyl ether, vinyl cyclohexyl ether, etc.
  • diolefin monomer examples include butadiene, isoprene, chloroprene, etc.
  • Examples of the monoolefin monomer include ethylene, propylene, butene-1, pentene-1, 4-methylpentene-1, etc.
  • olefin halide examples include vinyl chloride, vinylidene chloride, etc.
  • examples of the polyvinyl monomer include divinylbenzene, diallyl phthalate, trivinylcyanurate, etc.
  • the reason why the glass transition temperature Tg and number-average molecular weight Mn of the above main chain are limited within the above range is as follows. That is, when the glass transition temperature Tg of the main chain is less than the above range or the number-average molecular weight Mn is less than the above range, the heat resistance of the electrophotgraphic toner deteriorates to cause problems such as offset, blocking, fusing onto the photo-conductor, drum, etc. On the other hand, when the glass transition temperature Tg of the main chain exceeds the above range or the number-average molecular weight Mn exceeds the above range, the dispersion properties of the graft polymer to the fixing resin are deteriorated.
  • the number-average molecular weight of the main chain is about 2,000 to 8,000 within the above range, taking a function of the graft polymer as the fixing auxiliary into consideration.
  • examples of the alkyl group having 11 to 17 carbon atoms which corresponds to the group R 1 , include straight-chain or branched alkyl groups such as undecyl group, dodecyl group, tridecyl group, tetradecyl group, pentadecyl group, hexadecyl group, heptadecyl group, etc.
  • aryl group examples include phenyl group, biphenyl group, naphtyl group, anthryl group, a phenanthryl group, o-terphenyl group, etc.
  • alkyl group having 11 to 17 carbon atoms among alkyl groups having 1 to 17 carbon atoms, which correspond to the groups R 2 and R 3 , include the same groups as those described above.
  • alkyl group having 1 to 10 carbon atoms examples include straight-chain or branched alkyl groups such as methyl group, ethyl group, normal propyl group, isopropyl group, normal butyl group, isobutyl group, secondary butyl group, tertiary butyl group, pentyl group, hexyl group, heptyl group, octyl group, nonyl group, decyl group, etc.
  • Examples of the alkyl group having 1 to 12 carbon atoms, which corresponds to the group R 4 include groups from methyl group to dodecyl group among the above groups.
  • anion corresponding to X - examples include halogen ions such as chlorine ion, bromine ion, fluorine ion, iodine ion, etc.; sulfonic ions such as hydroxynaphthosulfonic ion represented by the formula (2): p-toluenesulfonic ion, methylsulfonic ion, etc.; sulfuric ion, nitric ion, phosphoric ion, boric ion, oxo ion, carboxylic ion, etc.
  • halogen ions such as chlorine ion, bromine ion, fluorine ion, iodine ion, etc.
  • sulfonic ions such as hydroxynaphthosulfonic ion represented by the formula (2): p-toluenesulfonic ion, methylsulfonic ion, etc.
  • the polymerization degree corresponding to n is limited to 2 or more. When n is 1, it becomes miscible with the toner and blocking, offset, etc. are liable to be generated. Even if polymerization degree may be not less than 2, the upper limit is not specifically limited. When the polymerization degree is too high, the dispersion properties of the graft polymer to the fixing resin deteriorate and a large mass of the graft polymer is likely to be formed, as described above, to cause fracture of the toner, blocking, offset, etc. Therefore, it is preferred that the polymerization degree is about 2 to 100.
  • the molar ratio (M:G) of the main chain M to graft chain G in the above graft polymer is within a range of 2:1 to 18:1.
  • the glass transition temperature Tg of the whole graft polymer becomes high, which may result in insufficient effect of improving the low-temperature fixing properties.
  • the fluidity of the toner deteriorates or the graft polymer is fused onto the blades of a mixer at the time of premixing before the respective components are molten and kneaded in the process of producing the toner.
  • the graft chain is related to an affinity with the colorant and, therefore, the dispersion properties of the colorant in the toner may deteriorate to fracture the toner, and thereby to form a mass of the toner, which causes image failures such as toner scattering, image fog.
  • the number-average molecular weight of the main chain becomes smaller than the above range because the molecular weight of the whole graft polymer is inhibited. Therefore, the heat resistance of the toner may deteriorate to cause problems such as offset, blocking, fusing onto the photoconductor drum, etc.
  • the molar ratio (M:G) of the main chain M to graft chain G is preferably within a range of 3:1 to 10:1.
  • the above polymer may be reacted with an imidazole derivative represented by the general formula (3): wherein R 1 , R 2 and R 3 respectively indicate the same group as that described above, and a dihalide represented by the general formula (4): wherein Y is a halogen atom such as chlorine, bromine, etc.; and R 4 and R 5 respectively indicate the same group as that described above.
  • the reaction may be conducted in a solvent which is inert to the imidazole derivative and dihalide.
  • solvent include aromatic solvents such as benzene, toluene, xylene, etc.; ketone solvents such as acetone, methyl ethyl ketone, etc.; aprotic solvents such as dimethylformamide, dimethylacetamide, dimethyl sulfoxide, etc.; mixed solvents of these solvents and alcohol solvents such as methanol, ethanol, isopropanol, etc. or water, etc.
  • aromatic solvents such as benzene, toluene, xylene, etc.
  • ketone solvents such as acetone, methyl ethyl ketone, etc.
  • aprotic solvents such as dimethylformamide, dimethylacetamide, dimethyl sulfoxide, etc.
  • mixed solvents of these solvents and alcohol solvents such as methanol, ethanol, isopropanol,
  • Monohalide or N-substituted imidazole may be optionally added to the above reaction system so as to block the terminal end of the graft group.
  • alkalis such as sodium hydroxide, potassium hydroxide, sodium carbonate, etc. may be added to the reaction system so as to neutralize hydrogen halide generated by the reaction.
  • the monohalide or N-substituted imidazole for terminal blocking is added to the reaction system at the point of time where the reaction has proceeded to some extent, not at the beginning of the reaction.
  • the reaction may be conducted at a temperature of 30 to 200 °C, preferably 60 to 180 °C, for about 2 to 20 hours.
  • the reaction product obtained by the above reaction is that in which the anion corresponding to X - in the general formula (1) is a halogen. Therefore, in order to substitute an anion other than the halogen for it, the reaction product may be added to an aqueous solution of a salt of the anion (e.g. alkali metal salt, ammonium salt, etc.), followed by stirring.
  • a salt of the anion e.g. alkali metal salt, ammonium salt, etc.
  • the amount of the above graft polymer is 1 to 10 parts by weight, preferably 0.5 to 8 parts by weight, based on 100 parts by weight of the fixing resin. However, when the colorant is dispersed in the graft polymer, it is permitted that the amount of the graft polymer exceeds the above range, e.g. 1 to 20 parts by weight.
  • the amount of the graft polymer is less than the above broadest range, the effect of improving the low-temperature fixing properties cannot be obtained.
  • the effect of dispersing the colorant into the toner becomes insufficient to form a mass of the toner, which can cause fracture of the toner, and image failures due to it, such as toner scattering due to it or image fog.
  • the amount of the graft polymer exceeds the above broadest range, the heat resistance of the toner deteriorates to cause problems such as offset, blocking, fusing onto the photoconductor drum, etc.
  • additives such as release agents (anti-offset agents), magnetic material powders, etc. may be formulated in the electrophotographic toner, in addition to the above respective components.
  • release agent examples include aliphatic hydrocarbons, aliphatic metal salts, higher fatty acids, fatty acid esters or partially saponified material thereof, silicone oil, various waxes, etc.
  • aliphatic hydrocarbons having a weight-average molecular weight of about 1,000 to 10,000 are particularly preferred.
  • examples thereof include low-molecular weight polypropylene, low-molecular weight polyethylene, paraffin wax, low-molecular weight olefin polymer of an olefin unit having carbon atoms of not less than 4, etc., and they may be suitably used alone or in combination thereof.
  • the anti-offset agent may be used in the amount of 0.1 to 10 parts by weight, preferably 0.5 to 8 parts by weight, based on 100 parts by weight of the fixing resin.
  • the magnetic material powder When the magnetic material powder is added, a magnetic toner as the one-component developer can be obtained.
  • the magnetic material is a substance which is strongly magnetized by the magnetic field in the direction thereof. Those which are chemically stable are preferred and they may be fine powders having a particle size of about not more than 1 ⁇ m, particularly about 0.01 to 1 ⁇ m.
  • Examples of the typical magnetic material include iron oxides such as magnetite, hematite, ferrite, etc.; metals such as iron, cobalt, nickel, etc.; alloys or mixtures of these metals and aluminum, cobalt, copper, lead, magnesium, tin, zinc, antimony, beryllium, bismuth, cadmium, calcium, manganese, selenium, titanium, tungsten, vanadium, etc.
  • the amount of the magnetic material powder to be formulated is preferably 20 to 300 parts by weight, more preferably 50 to 150 parts by weight, based on 100 parts by weight of the fixing resin.
  • additives such as a stabilizer, etc. may be formulated in the appropriate amount.
  • the particle size of the electrophotographic toner is preferably 3 to 30 ⁇ m, particularly 4 to 20 ⁇ m. In case of small-particle size toner for the purpose of accomplishing high-image quality of the formed image, the particle size is preferably about 4 to 10 ⁇ m.
  • a surface treating agent can be added to the resulting toner particles for the purpose of improving the fluidity.
  • the surface treating agent there can be used various surface treating agents which have hitherto been used, such as inorganic fine particles, fluororesin particles, etc.
  • silica surface treating agents containing hydrophobic or hydrophilic silica fine particles e.g. ultrafine-particulate anhydrous silica or colloidal silica, etc. may be suitably used.
  • the amount of the surface treating agent to be added is preferably about 0.1 to 3.0 parts by weight, based on 100 parts by weight of the electrophotographic toner particles. In some case, it may deviate from this range.
  • the electrophotographic toner of the present invention can be used alone as a non-magnetic one-component developer, or applied for various toners which have hitherto been known, such as non-magnetic toner constituting a magnetic two-component developer together with a magnetic carrier, magnetic toner to be used alone as a magnetic one-component toner, photosensitive toner which itself has a photosensitivity, etc.
  • the toner concentration in the case of a magnetic two-component developer is typically the same as that of a conventional one, i.e. about 2 to 15% by weight.
  • a magnetic pigment may be formulated in a fixing resin.
  • a photoconductive pigment and a cyanine pigment etc. as a sensitizing component thereof may be blended in the fixing resin.
  • the magnetic carrier to be used in combination with the above toner there can be suitably used a coating type carrier of which surface is coated with a coat layer of a silicone resin or a fluororesin, as described above.
  • the magnetic particle As the magnetic particle as the base of the coating type carrier, there can be used a magnetic particle having various constructions which have hitherto been known.
  • the magnetic particle include particles of iron, iron subjected to an oxidation treatment, reduced iron, magnetite, copper, silicon steel, ferrite, nickel, cobalt, etc.; particles of alloys of these materials and manganese, zinc, aluminum, etc.; particles of iron-nickel alloy, iron-cobalt alloy, etc.; particles wherein fine powders of the above various materials are dispersed in a binding resin; particles of ceramics such as titanium oxide, aluminum oxide, copper oxide, magnesium oxide, lead oxide, zirconium oxide, silicon carbide, magnesium titanate, barium titanate, lithium titanate, lead titanate, lead zirconate, lithium niobate, etc.; particles of high dielectric constant substances such as ammonium dihydrogen phosphate (NH 4 H 2 PO 4 ), potassium dihydrogen phosphate (KH 2 PO 4 ), Rochelle salt, etc.
  • iron powders e.g. iron oxide, reduced iron, etc.
  • ferrite particles are particularly preferred. These particles can form an image having a good image quality because a change in electric resistance due to an environmental change or a change with time is small and a head of a magnetic brush is soft, and they are also cheap.
  • Examples of the ferrite particle include particles of zinc ferrite, nickel ferrite, copper ferrite, nickel-zinc ferrite, manganese-magnesium ferrite, copper-magnesium ferrite, manganese-zinc ferrite, manganese-copper-zinc ferrite, etc.
  • the particle size of the magnetic carrier to be formed is preferably about 10 to 200 ⁇ m, more preferably about 30 to 150 ⁇ m. Furthermore, the saturation magnetization of the magnetic carrier is not specifically limited, but is preferably about 35 to 70 emu/g.
  • the silicone resin which is a material of the coat layer for coating the surface of the magnetic particles there can be used various thermosetting type silicone resin.
  • a methyl silicone resin more particularly, a methyl-dimethyl silicone resin having CH 3 SiO 3/2 and (CH 3 ) 2 SiO as a main structural unit can be suitably used.
  • the methyl-dimethyl silicone resin include products No. SR2400, SR2410 and SR2411 (manufactured by Toray-Dow Corning Co.,Ltd.) or product No. KR251 and KR255 (manufactured by Shinetsu Kagaku Co., Ltd.).
  • the coat layer of the silicone resin is formed by applying a coating material, obtained by dissolving the silicone resin in a suitable solvent, on the surface of a magnetic carrier, heating the solvent to remove it, and then subjecting the resin to a curing reaction. Further, if a hydroxy group remains in the coat layer, the negative charging properties thereof may deteriorate and the effect of positively charging the toner is likely to become insufficient. Therefore, it is preferred to exclude the hydroxyl group to the utmost by setting the heating temperature at the time of curing to a temperature higher than a normal value.
  • the coat layer of the fluororesin there can be used those in which fine particles of fluororesins such as ethylene tetrafluoride resin, etc. are dispersed in binding resins such as polyamideimide or epoxy resin.
  • those wherein the amount of the polyamideimide is 10 to 40 % by weight are preferred in those using the polyamideimide as the binding resin.
  • examples thereof include Teflon S958-207, Teflon S958P-10255 (trade name, manufactured by Du Pont Co.), etc.
  • the amount of the epoxy resin is 10 to 40 % by weight are preferred in those using the epoxy resin as the binding resin.
  • examples thereof include Teflon 5954-100, Teflon S954-101 (trade name, manufactured by Du Pont Co.), etc.
  • the coat layer of the fluororesin is formed by applying a coating material, obtained by dissolving the fluororesin in a suitable solvent, on the surface of a magnetic carrier, heating to remove the solvent, and then subjecting a polyamideimide or an epoxy resin as the binding resin to a curing reaction.
  • any method such as
  • the film thickness of the coat layer is preferably about 0.05 to 1 ⁇ m, more preferably about 0.1 to 0.7 ⁇ m.
  • Additives for adjusting the characteristics of the coat layer can be optionally contained in the coat layer.
  • Another electrophotographic toner of the present invention may be formed by formulating a polymer having a repeating unit represented by the general formula (1), inorganic fine particles, a colorant, an electric charge controlling material and, if necessary, other additives in the fixing resin.
  • This toner may be produced by grinding a mixture obtained by dispersing the colorant in the above polymer, using the inorganic fine particle, and then dispersing the ground mixture in the fixing resin, together with the electric charge controlling material. More concretely, the above polymer may be ground by adding the inorganic fine particles to a mixture, wherein the colorant is uniformly dispersed in the polymer by mixing the polymer with the colorant using a dry blender, Henshel mixer, ball mill, etc., followed by mixing.
  • the kind and amount of the fixing resin, colorant, electric charge controlling material and other additives may be the same as those described above.
  • examples of R 1 to R 5 and X - include the same groups as those described above.
  • the polymerization degree may be 2 or more, and the upper limit thereof is not specifically limited.
  • the polymerization degree n is about 2 to 100 within the above range.
  • the above polymer may be synthesized by reacting the imidazole derivative represented by the general formula (3) with the dihalide represented by the general formula (4) in a suitable molar ratio according to the same manner as that described above.
  • the amount of the above polymer to be blended is limited to 1 to 10 parts by weight, based on 100 parts by weight of the fixing resin.
  • the amount of the polymer is less than the above range, the effect of dispersing the colorant in the toner becomes insufficient to fracture the toner, and thereby to form a mass of the toner, which causes image failures such as toner scattering, image fog, etc.
  • the amount of the polymer to be blended exceeds the above range, the heat resistance of the toner is deteriorated to cause problems such as offset, blocking, fusing onto the photoconductor drum, etc.
  • the proportion (M:C) of the above polymer M to colorant C is not specifically limited, but the weight ratio thereof is preferably about 1:5 to 3:1.
  • the proportion (M:C) of the polymer M to colorant C deviates to the side where the amount of the polymer is less than the above range (M:C ⁇ 1:5), the effect of dispersing the colorant in the toner due to the polymer is likely to become insufficient to fracture the toner, and thereby to form a mass of the toner, which causes image failures such as toner scattering, image fog, etc.
  • Examples of the inorganic fine particle include titanium oxide, silica, alumina, etc., as described above.
  • the particle size of the inorganic fine particles is not specifically limited, but is preferably about 0.005 to 1 ⁇ m.
  • the particle size of the inorganic fine particles is less than the above range, the dispersion properties of the polymer, wherein the colorant is dispersed, to the fixing resin are likely to become insufficient.
  • the particle size of the inorganic fine particles exceeds the above range, the charging properties of the toner are likely to be changed or the photoconductor is injured by the inorganic fine particle.
  • the amount of the inorganic fine particles to be formulated is 0.1 to 10 parts by weight, preferably 0.2 to 5 parts by weight, based on 100 parts by weight of the total amount of the polymer and colorant.
  • the amount of the inorganic fine particles to be blended is less than the above range, the effect of adding the inorganic fine particles cannot be obtained sufficiently and the dispersion properties of the polymer, wherein the colorant is dispersed, to the fixing resin becomes insufficient. Therefore, it is likely to become impossible to be dispersed uniformly.
  • a large mass of the above polymer is likely to be formed and the toner is liable to be fractured. Otherwise, the above mass is exposed on the surface of the toner to cause blocking, offset, etc.
  • the amount of the inorganic fine particle to be formulated exceeds the above range, the charging properties of the toner are likely to be changed or the photoconductor is injured by the inorganic fine particles.
  • styrene content 90 molar %, glass transition temperature Tg: 40 °C, number-average molecular weight Mn: 5,000
  • an imidazole derivative of the above general formula (2) wherein the group R 1 is an undecyl group; R 2 is a hydrogen atom; and R 3 is a methyl group, and 50 parts by weight of a dihalide of the general formula (3) wherein the group R 4 is a methyl group; R 5 is a hydrogen atom; and Y is a chlorine atom were dissolved in dimethylformamide, together with 10 parts by weight of sodium carbonate.
  • reaction product obtained by the above reaction was introduced into an aqueous solution prepared by dissolving 200 parts by weight of sodium hydroxynaphthosulfonate to 2,000 parts by weight of water with stirring, using a homomixer to obtain a precipitate.
  • the precipitate was washed with water, filtered, and then dried to obtain a graft polymer I wherein a molar ratio (M:G) of the main chain M to graft chain G is 5:1.
  • graft polymer II having a molar ratio (M:G) of 5:1 was synthesized.
  • graft polymer III having a molar ratio (M:G) of 5:1 was synthesized.
  • graft polymer IV having a molar ratio (M:G) of 5:1 was synthesized.
  • a graft polymer V having a molar ratio (M:G) of 5:1 was synthesized.
  • graft polymer VI having a molar ratio (M:G) of 20:1 was synthesized.
  • graft polymer VII having a molar ratio (M:G) of 1:1 was synthesized.
  • a styrene-acrylic resin as the fixing resin was mixed with 8 parts by weight of a carbon black as the colorant, 4 parts by weight of the graft polymer produced in the above synthesis 1 of graft polymer, 3 parts by weight of a polypropylene wax as the release agent and 2 parts by weight of a low-molecular weight quaternary ammonium salt as the electric charge controlling material and, after melting and kneading, the mixture was pulverized and classified to produce a positive charging type electrophotographic toner having a particle size of 5 to 20 ⁇ m.
  • a toner was cut with a microtome (MT6000, manufactured by DuPont Co.) and the fracture surface was observed by a transmission electron microscope (TEM) to evaluate the dispersion properties of the carbon black. Further, the dispersion properties were evaluated according to the following four-grade criteria.
  • MT6000 microtome
  • TEM transmission electron microscope
  • Dispersion properties are particularly good (o) when it is in a dispersion state where the carbon black is dispersed, nearly uniformly, as shown in Fig. 1 illustrating the fracture surface of the toner obtained in Example 4.
  • Dispersion properties are inferior (X) when it is in a dispersion state where a large mass due to the agglomeration the carbon black exists, as shown in Fig. 2 illustrating the fracture surface of the toner obtained in Comparative Example 1.
  • Dispersion properties are good ( ⁇ ) or slightly inferior ( ⁇ ) when it is in an intermediate state between the above states.
  • a toner (20 g) was charged in a glass cylinder (inner diameter: 26.5 mm) and a weight (100 g) was placed on the toner. After standing at a predetermined temperature for 30 minutes, a cylinder was removed and the toner was observed to record the temperature at which the toner does not go to pieces (B 1 , °C).
  • a toner 100 Parts by weight of a toner was subjected to a surface treatment using 0.2 parts by weight of a hydrophobic silica (product No. RP130, manufactured by Nihon Aerogyl Co., Ltd.), and then mixed with a silicone-coated ferrite carrier having an average particle size of 90 ⁇ m (manufactured by Powder Tec Co.) to produce a developer having a toner concentration of 3.0 % by weight.
  • a hydrophobic silica product No. RP130, manufactured by Nihon Aerogyl Co., Ltd.
  • the resulting developer was used for a reversal developing type plain paper facsimile apparatus having a positive charging type photoconductor (model No. AF-1000, manufactured by Mita Industrial Co., Ltd.), which was modified so that a fixing temperature of a heat fixing roller (circumferential velocity: 150 mm/second) can be adjusted, and a black solid image was printed while changing the fixing temperature.
  • a positive charging type photoconductor model No. AF-1000, manufactured by Mita Industrial Co., Ltd.
  • the image density of the printed image fixed on the paper surface by the above heat fixing roller was measured using a reflection densitometer (model No. TC-6D, manufactured by Tokyo Denshoku Co., Ltd.) and the surface was forced to rub five times with a weight (20 g/cm 2 ) obtained by coating the bottom of a column (26 mm in height x 50 mm in diameter) made of a mild steel with a cotton cloth.
  • Fixing rate (%) [(Image density after rubbing)/(Image density before rubbing)] x 100 Thereafter, a minimum fixing temperature at which the fixing rate becomes 95 % or more (F 1 , °C) was recorded.
  • graft polymer VIII having a molar ratio (M:G) of 5:1 was synthesized.
  • graft polymer IX having a molar ratio (M:G) of 5:1 was synthesized.
  • styrene content 90 molar %, glass transition temperature Tg: 40 °C, number-average molecular weight Mn: 6,000
  • an imidazole derivative of the above general formula (2) wherein the group R 1 is an undecyl group; R 2 is a hydrogen atom; and R 3 is a methyl group, and 50 parts by weight of a dihalide of the general formula (3) wherein the group R 4 is a methyl group; R 5 is a hydrogen atom; and Y is a chlorine atom were dissolved in dimethylformamide, together with 20 parts by weight of sodium carbonate.
  • reaction product obtained by the above reaction was introduced into an aqueous solution prepared by dissolving 200 parts by weight of sodium hydroxynaphthosulfonate to 2,000 parts by weight of water with stirring, using a homomixer to obtain a precipitate.
  • the precipitate was washed with water, filtered, and then dried to obtain a graft polymer X wherein a molar ratio (M:G) of the main chain M to graft chain G is 5:1.
  • a graft polymer XI was synthesized.
  • a graft polymer XII was synthesized.
  • a graft polymer XIII was synthesized.
  • a graft polymer XIV was synthesized.
  • a styrene-acrylic resin as the fixing resin 100 Parts by weight of a styrene-acrylic resin as the fixing resin was mixed with 8 parts by weight of a carbon black, 4 parts by weight of the graft polymer X produced in the above synthesis 10 of graft polymer and 3 parts by weight of a polypropylene wax and, after melting and kneading, the mixture was pulverized and classified to produce a positive charging type electrophotographic toner having a particle size of 5 to 20 ⁇ m.
  • a coating material prepared by dissolving a silicone resin (product No. SR2400, manufactured by Toray Dow Corning Co., Ltd.) in toluene was applied on the surface of ferrite particles having a particle size of 80 ⁇ m using a fluidized bed method, followed by subjecting to a heat treatment at 300 °C for one hour, to produce a magnetic carrier wherein the surface of the above magnetic particles are coated with a coat layer of 1.0 % by weight of a silicone resin.
  • the above toner and magnetic carrier were mixed so that a toner concentration became 3 % by weight to produce an electrophotographic developer.
  • Example 7 According to the same manner as that described in Example 7 except for changing the amount of the graft polymer X to be formulated into the toner to 0.5 parts by weight, a toner was prepared. Then, this toner was mixed with the same magnetic carrier as that produced in Example 7 in the same proportion to produce an electrophotographic developer.
  • Example 7 According to the same manner as that described in Example 7 except for changing the amount of the graft polymer X to be formulated into the toner to 12 parts by weight, a toner was prepared. Then, this toner was mixed with the same magnetic carrier as that produced in Example 7 in the same proportion to produce an electrophotographic developer.
  • Example 2 According to the same manner as that described in Example 1 except for using 2 parts by weight of a nigrosine dye in place of the graft polymer X, a toner was prepared. Then, this toner was mixed with the same magnetic carrier as that produced in Example 1 in the same proportion to produce an electrophotographic developer.
  • Example 7 According to the same manner as that described in Example 7 except for using 2 parts by weight of a low-molecular weight quaternary ammonium salt in place of the graft polymer X, a toner was prepared. Then, this toner was mixed with the same magnetic carrier as that produced in Example 7 in the same proportion to produce an electrophotographic developer.
  • electrophotographic developers of the above Examples and Comparative Examples were subjected to the evaluation of dispersion properties, heat resistance test, fixing properties test, offset resistance test and practical machine test according to the same manner as that described above, and their characteristics were evaluated.
  • Example 7 According to the same manner as that described in Example 7 except for using 4 parts by weight of the graft polymer XI produced in the above synthesis 11 of graft polymer in place of the graft polymer X, a toner was prepared. Then, this toner was mixed with the same magnetic carrier as that produced in Example 7 in the same proportion to produce an electrophotographic developer.
  • Example 7 According to the same manner as that described in Example 7 except for using 4 parts by weight of the graft polymer XII produced in the above synthesis 12 of graft polymer in place of the graft polymer X, a toner was prepared. Then, this toner was mixed with the same magnetic carrier as that produced in Example 7 in the same proportion to produce an electrophotographic developer.
  • Example 7 According to the same manner as that described in Example 7 except for using 4 parts by weight of the graft polymer XIII produced in the above synthesis 13 of graft polymer in place of the graft polymer X, a toner was prepared. Then, this toner was mixed with the same magnetic carrier as that produced in Example 7 in the same proportion to produce an electrophotographic developer.
  • Example 7 According to the same manner as that described in Example 7 except for using 4 parts by weight of the graft polymer XIV produced in the above synthesis 14 of graft polymer in place of the graft polymer X, a toner was prepared. Then, this toner was mixed with the same magnetic carrier as that produced in Example 7 in the same proportion to produce an electrophotographic developer.
  • Example 7 The same toner as that produced in Example 7 was mixed with the following magnetic carrier in the same proportion to produce an electrophotographic developer.
  • a coating material prepared by dissolving a fluororesin (trade name of Teflon S594-100, manufactured by Du Pont Co.) in tetrahydrofuran was applied on the surface of ferrite particles having a particle size of 80 ⁇ m using a fluidized bed method, followed by subjecting to a heat treatment at 200 °C for 0.5 hours, to produce a magnetic carrier wherein the surface of the above magnetic particles are coated with a coat layer of 0.5 % by weight of a fluororesin.
  • Example 7 The same toner as that produced in Example 7 was mixed with an iron powder carrier (particle size: 80 ⁇ m) of which surface is not coated with a coat layer in the same proportion to produce an electrophotographic developer.
  • electrophotographic developers of the above Examples and Comparative Examples were subjected to the above practical machine test and the following build-up charging properties test, and their characteristics were evaluated.
  • An electrophotographic developer was charged in a plurality of polypropylene containers (polyethylene container, content: 3 ml) and subjected to moisture conditioning by standing one day under an operating environment, respectively.
  • the above test was conducted repeatedly by setting the number of revolutions of the miniature bottle to 50, 100, 500, 1,000 or 3,000. Then, the build-up charging characteristics of the electrophotographic developers of the respective Examples and Comparative Examples were evaluated by a change in charged amount due to the number of revolutions of the miniature bottle.
  • reaction product obtained by the above reaction was introduced into an aqueous solution prepared by dissolving 200 parts by weight of sodium hydroxynaphthosulfonate to 2,000 parts by weight of water with stirring, using a homomixer to obtain a precipitate.
  • the precipitate was washed with water, filtered, and then dried to obtain a polymer.
  • this ground product was mixed with 100 parts by weight of a styrene-acrylic resin as the fixing resin, 3 parts by weight of a polypropylene wax and 2 parts by weight of a nigrosine dye using a Henshel mixer.
  • the mixture was molten and kneaded using a twin-screw extruder, pulverized using a jet mill, and then subjected to air classification to produce a positive charging type electrophotographic toner having a particle size of 5 to 20 ⁇ m.
  • Example 11 According to the same manner as that described in Example 11 except for using 8.1 parts by weight of a mixture containing no polymer, obtained by mixing 8 parts by weight of a carbon black and 0.1 parts by weight of titanium oxide having a particle size of 0.05 ⁇ m using a Henshel mixer, in place of the ground product, an electrophotographic toner was produced.
  • Example 11 According to the same manner as that described in Example 11 except for using 12.0 parts by weight of a mixture containing no inorganic fine particles, obtained by mixing 4 parts by weight of a polymer and 8 parts by weight of a carbon black using a Henshel mixer, in place of the ground product, an electrophotographic toner was produced.
  • Example 11 According to the same manner as that described in Example 11 except for using 11.08 parts by weight of a ground product, obtained by mixing 3 parts by weight of a polymer, 11 parts by weight of a carbon black and 0.1 parts by weight of alumina having a particle size of 0.02 ⁇ m using a Henshel mixer, an electrophotographic toner was produced.
  • Example 11 According to the same manner as that described in Example 11 except for using 14.1 parts by weight of a ground product, obtained by mixing 10 parts by weight of a polymer, 4 parts by weight of a carbon black and 0.1 parts by weight of alumina having a particle size of 0.02 ⁇ m using a Henshel mixer, an electrophotographic toner was produced.
  • Example 11 According to the same manner as that described in Example 11 except for using 11.08 parts by weight of a ground product, obtained by mixing 2 parts by weight of a polymer, 11 parts by weight of a carbon black and 0.1 parts by weight of alumina having a particle size of 0.02 ⁇ m using a Henshel mixer, an electrophotographic toner was produced.
  • Example 11 According to the same manner as that described in Example 11 except for using 14.09 parts by weight of a ground product, obtained by mixing 12 parts by weight of a polymer, 3 parts by weight of a carbon black and 0.1 parts by weight of alumina having a particle size of 0.02 ⁇ m using a Henshel mixer, an electrophotographic toner was produced.
  • dispersion properties were evaluated according to the following four-grade criteria.
  • Dispersion properties are particularly good (o) when it is in a dispersed state of Example 11 shown in Fig. 3 .
  • Dispersion properties are inferior (X) when it is in a dispersion state where a large mass due to the agglomeration of the carbon black exists, as Comparative Example 19 shown in Fig. 4 .
  • Dispersion properties are good ( ⁇ ) or slightly inferior ( ⁇ ) when it is in an intermediate state between the above states.

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  • Physics & Mathematics (AREA)
  • General Physics & Mathematics (AREA)
  • Spectroscopy & Molecular Physics (AREA)
  • Developing Agents For Electrophotography (AREA)
EP95308608A 1994-11-29 1995-11-29 Elektrophotographischer Toner und Enwickler Withdrawn EP0718704A1 (de)

Applications Claiming Priority (6)

Application Number Priority Date Filing Date Title
JP295383/94 1994-11-29
JP29538394A JPH08152746A (ja) 1994-11-29 1994-11-29 電子写真用現像剤
JP32352394A JPH08160665A (ja) 1994-11-30 1994-11-30 電子写真用トナー
JP32352494A JPH08160666A (ja) 1994-11-30 1994-11-30 電子写真用トナー
JP323523/94 1994-11-30
JP323524/94 1994-11-30

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Cited By (3)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
EP1616624A3 (de) * 2004-07-13 2006-03-15 Ricoh Company, Ltd. Vorrichtung zur Zerkleinerung und Klassifikation, Pneumatische Prallmühle, Sichter und Verfahren zur Herstellung von Tonern
US7438245B2 (en) 2004-07-13 2008-10-21 Ricoh Company, Ltd. Milling and classifying apparatus, collision mill, air classifier, toner, and method for producing toner
US7514194B2 (en) 2005-07-07 2009-04-07 Fuji Xerox Co., Ltd. Toner for developing electrostatic latent image and production method thereof, electrostatic latent image developer, image forming method, and image forming apparatus

Citations (9)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JPS62191858A (ja) 1986-02-18 1987-08-22 Mitsui Toatsu Chem Inc 電子写真用トナ−組成物
JPS62264066A (ja) * 1986-05-10 1987-11-17 Minolta Camera Co Ltd 正荷電性トナ−
JPH0252362A (ja) 1988-08-15 1990-02-21 Tomoegawa Paper Co Ltd 電子写真用トナーとその製造方法
EP0402882A2 (de) 1989-06-14 1990-12-19 Bando Chemical Industries, Limited Teig für die Herstellung von Tonern für Elektrophotographie
DE4018986A1 (de) * 1989-06-13 1990-12-20 Sanyo Chemical Ind Ltd Elektrophotographischer toner und zugehoeriger ladungsregler
JPH03155568A (ja) 1989-06-14 1991-07-03 Bando Chem Ind Ltd 静電潜像現像用トナー及びそのためのマスターバツチの製造方法
JPH04202305A (ja) * 1990-11-29 1992-07-23 Sanyo Chem Ind Ltd ４級塩変性スチレン系樹脂
JPH04277753A (ja) 1991-03-06 1992-10-02 Hitachi Chem Co Ltd フラッシュ定着用静電荷像現像用トナー及び現像剤
JPH05165259A (ja) * 1991-12-13 1993-07-02 Sanyo Chem Ind Ltd 荷電制御剤および電子写真用トナー

Patent Citations (9)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JPS62191858A (ja) 1986-02-18 1987-08-22 Mitsui Toatsu Chem Inc 電子写真用トナ−組成物
JPS62264066A (ja) * 1986-05-10 1987-11-17 Minolta Camera Co Ltd 正荷電性トナ−
JPH0252362A (ja) 1988-08-15 1990-02-21 Tomoegawa Paper Co Ltd 電子写真用トナーとその製造方法
DE4018986A1 (de) * 1989-06-13 1990-12-20 Sanyo Chemical Ind Ltd Elektrophotographischer toner und zugehoeriger ladungsregler
EP0402882A2 (de) 1989-06-14 1990-12-19 Bando Chemical Industries, Limited Teig für die Herstellung von Tonern für Elektrophotographie
JPH03155568A (ja) 1989-06-14 1991-07-03 Bando Chem Ind Ltd 静電潜像現像用トナー及びそのためのマスターバツチの製造方法
JPH04202305A (ja) * 1990-11-29 1992-07-23 Sanyo Chem Ind Ltd ４級塩変性スチレン系樹脂
JPH04277753A (ja) 1991-03-06 1992-10-02 Hitachi Chem Co Ltd フラッシュ定着用静電荷像現像用トナー及び現像剤
JPH05165259A (ja) * 1991-12-13 1993-07-02 Sanyo Chem Ind Ltd 荷電制御剤および電子写真用トナー

Non-Patent Citations (3)

* Cited by examiner, † Cited by third party
Title
DATABASE WPI Week 8731, Derwent World Patents Index; AN 87-360336 *
DATABASE WPI Week 9236, Derwent World Patents Index; AN 92-295472 *
DATABASE WPI Week 9331, Derwent World Patents Index; AN 93-245563 *

Cited By (3)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
EP1616624A3 (de) * 2004-07-13 2006-03-15 Ricoh Company, Ltd. Vorrichtung zur Zerkleinerung und Klassifikation, Pneumatische Prallmühle, Sichter und Verfahren zur Herstellung von Tonern
US7438245B2 (en) 2004-07-13 2008-10-21 Ricoh Company, Ltd. Milling and classifying apparatus, collision mill, air classifier, toner, and method for producing toner
US7514194B2 (en) 2005-07-07 2009-04-07 Fuji Xerox Co., Ltd. Toner for developing electrostatic latent image and production method thereof, electrostatic latent image developer, image forming method, and image forming apparatus

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