JP2011113027A - Electrophotographic toner, developer, image forming method, and process cartridge - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a toner capable of suppressing image degradation and extending the service life of an image forming apparatus and of a developer, and to provide a developer, an image forming method and a process cartridge using the toner. <P>SOLUTION: The toner comprises host particles containing a binder resin, a colorant and a release agent, and an external additive containing conductive glass particles, and is characterized in that: the conductive glass has an electric resistance value in the range from 1.1×10<SP>6</SP>to 5.0×10<SP>7</SP>Ωcm; the conductive glass has a particle diameter of 8 to 50 nm; and the conductive glass particles comprise a composition containing at least vanadium oxide. <P>COPYRIGHT: (C)2011,JPO&INPIT

Description

  The present invention relates to an electrophotographic toner, a developer, an image forming method, and a process cartridge.

Conventionally, fine toner external additives having an average primary particle size of several nanometers to several tens of nanometers have been used for toners used in electrophotography. By using this external additive, characteristics such as charging property, fluidity, and hydrophobic property are imparted to the toner. For example, silica fine particles that have been subjected to a hydrophobization treatment, and titanium oxide that has been subjected to a hydrophobization surface treatment are frequently used as external additives to suppress differences in chargeability and holding charge amount under environmental conditions.
By using a plurality of such external additives and adjusting the addition ratio, stability and performance in the electrophotographic process have been improved (see Patent Documents 1 to 3). And the above-mentioned external additive is surface-treated to give more preferable performance. However, since the toner is used repeatedly, the surface treatment agent of the external additive described above is damaged by stress, stirring, etc. over time, so that the hydrophobicity imparted initially is suitable as time passes. There was a problem that the property was lost.

  The present invention has been made in view of the above-described problems of the prior art, and is an electrophotographic toner capable of suppressing image deterioration and extending the life of an image forming apparatus and a developer. It is an object to provide a developer using toner, an image forming method, and a process cartridge.

As a result of careful consideration of the above-mentioned conventional problems, the present inventors have come up with the idea that the conductive glass particles are mixed in the toner base particles. That is, the conductive glass particles do not require a surface treatment for imparting hydrophobicity because the material itself has hydrophobicity. In addition, since the electric conductivity can be adjusted depending on the state of the metal oxide in the structure, the conductive glass particles can be used as a toner base if the resistance value can be adjusted to the same value as that of titanium oxide used as an external additive. The present inventors have wondered whether various adjustments relating to charging can be performed by toner mixed in particles, and new developments can be made in various image formations.
In this way, in view of the fact that the hydrophobicity change due to deterioration of the surface treatment agent can be reduced or can be reduced, and that the conductive glass particles to be mixed belong to the glass material, the hardness is also considered. By using a toner containing a material lower than titanium oxide, it is expected that the mechanical aggression on the photoconductor, that is, the property of scratching the surface of the photoconductor, the wearability, etc. will be milder and alleviated. The inventors of the present invention have conceived what can be done, and have reached the following solution.

The electrophotographic toner according to claim 1 is characterized in that it has base particles containing a binder resin, a colorant and a release agent, and an external additive containing conductive glass particles.
According to a second aspect of the present invention, in the electrophotographic toner according to the first aspect, the electrical resistance value of the conductive glass is in a range of 1.1 × 10 ^{6 to} 5.0 × 10 ⁷ Ωcm. It is characterized by.
According to a third aspect of the present invention, in the electrophotographic toner according to the first or second aspect, the conductive glass has a particle size of 8 to 50 nm.
According to a fourth aspect of the invention, in the electrophotographic toner according to any one of the first to third aspects, the conductive glass particles are composed of a composition containing at least vanadium oxide.
The invention according to claim 5 is the electrophotographic toner according to any one of claims 1 to 4, wherein the external additive contains two or more kinds of materials.
The invention according to claim 6 is the electrophotographic toner according to any one of claims 1 to 5, wherein the external additive is a material having a BET specific surface area of 20 m ² / g or more and 300 m ² / g or less. It contains at least 1 type.
The invention according to claim 7 is the electrophotographic toner according to any one of claims 1 to 6, wherein the external additive other than the conductive glass particles is silica, titanium compound, alumina, cerium oxide. , Calcium carbonate, magnesium carbonate, calcium phosphate, or a material selected from the group consisting of resin particles containing at least one of a fluorine atom, a silicon atom, and a nitrogen atom as a constituent component.
According to an eighth aspect of the present invention, in the electrophotographic toner according to the seventh aspect, the titanium compound reacts at least a part of TiO (OH) ₂ produced by a wet method with a silane compound or silicone oil. It is characterized by being obtained.
The invention according to claim 9 is the electrophotographic toner according to claim 8, wherein the titanium compound has a specific gravity of 2.8 or more and 3.6 or less.
According to a tenth aspect of the present invention, in the electrophotographic toner according to any one of the first to ninth aspects, the base particle contains a polyester-based resin capable of reacting with an active hydrogen group in an organic solvent. A solution or dispersion obtained by dissolving or dispersing the composition is dispersed in an aqueous medium containing resin particles, and then obtained by reacting the polyester resin with a compound having an active hydrogen group. Features.
According to an eleventh aspect of the present invention, in the electrophotographic toner according to any one of the first to tenth aspects, the base particles are obtained using a pulverization method.
The invention according to claim 12 is characterized by a developer containing the electrophotographic toner according to any one of claims 1 to 10.
The developer of the thirteenth aspect of the present invention is the developer of the eleventh aspect of the present invention, further comprising a carrier.
According to a fourteenth aspect of the present invention, there is provided the image forming method according to the twelfth or thirteenth aspect, wherein the step of forming an electrostatic latent image on the latent image carrier, and the electrostatic latent image formed on the latent image carrier. And developing with the developer described above to form a toner image; and transferring the toner image onto a transfer material to form a transfer image.
A process cartridge according to a fifteenth aspect of the present invention is a developing device for developing a latent image carrier and an electrostatic latent image formed on the latent image carrier using the developer according to the twelfth or thirteenth aspect. The developing device is integrally supported and is detachable from the main body of the image forming apparatus.

  According to the present invention, there are provided an electrophotographic toner capable of suppressing image deterioration and extending the life of an image forming apparatus and a developer, and a developer, an image forming method and a process cartridge using the toner. Can do.

It is a figure which shows an example of the process cartridge of this invention.

Next, the present invention will be described based on embodiments.
The toner for electrophotography of the present invention has base particles containing a binder resin, a colorant and a release agent, and an external additive containing conductive glass particles. Accordingly, since the surface treatment agent does not deteriorate even with a long-term stress, it becomes possible to impart a stable chargeability over a long period of time.

[Base particles]
There is no restriction | limiting in particular as binder resin contained in a base particle, According to the objective, it can select suitably from well-known things. For example, homopolymers of styrene such as polystyrene, poly (p-chlorostyrene), polyvinyltoluene and the like, and substituted products thereof, styrene-p-chlorostyrene copolymer, styrene-propylene copolymer, styrene-vinyltoluene copolymer Styrene-methyl acrylate copolymer, styrene-ethyl acrylate copolymer, styrene-methacrylic acid copolymer, styrene-methyl methacrylate copolymer, styrene-ethyl methacrylate copolymer, styrene-butyl methacrylate Copolymer, styrene-α-chloromethyl methacrylate copolymer, styrene-acrylonitrile copolymer, styrene-vinyl methyl ether copolymer, styrene-vinyl methyl ketone copolymer, styrene-butadiene copolymer, styrene- Isoprene copolymer, styrene-male Styrene copolymer such as acid ester copolymer, polymethyl methacrylate, polybutyl methacrylate, polyvinyl chloride, polyvinyl acetate, polyethylene, polyester, polyurethane, epoxy resin, polyvinyl butyral, polyacrylic acid, rosin, modified A rosin, a terpene resin, a phenol resin, an aliphatic or aromatic hydrocarbon resin, an aromatic petroleum resin and the like can be mentioned, and these can be used alone or in combination.

  The colorant contained in the base particles is not particularly limited and can be appropriately selected from known dyes and pigments according to the purpose. For example, carbon black, nigrosine dye, iron black, naphthol yellow S, Hansa Yellow (10G, 5G, G), Cadmium Yellow, Yellow Iron Oxide, Ocher, Yellow Lead, Titanium Yellow, Polyazo Yellow, Oil Yellow, Hansa Yellow (GR, A, RN, R), Pigment Yellow L, Benzidine Yellow (G, GR), Permanent Yellow (NCG), Vulcan Fast Yellow (5G, R), Tartrazine Lake, Quinoline Yellow Lake, Anthrazan Yellow BGL, Isoindolinone Yellow, Bengala, Lead Red, Lead Red, Cadmium Red, Cadmium Mercury Red, Antimony Zhu, Permanent Tread 4R, Parared, Phisera Red, p-Chloro-o-nitroaniline red, Resol Fast Scarlet G, Brilliant Fast Scarlet, Brilliant Carnmin BS, Permanent Red (F2R, F4R, FRL, FRLL, F4RH), Fast Scarlet VD, Belkanfast Rubin B, Brilliant Scarlet G, Risor Rubin GX, Permanent Red F5R, Brilliant Carmine 6B, Pigment Scarlet 3B, Bordeaux 5B, Toluidine Maroon, Permanent Bordeaux F2K, Helio Bordeaux BL, Bordeaux 10B, Bon Maroon Light, Bon Maroon Medium, Eosin Lake, Rhodamine Lake B, Rhodamine Lake Y, Alizarin Lake, Thioindigo Red B, Thioindigoma , Oil Red, Quinacridone Red, Pyrazolone Red, Polyazo Red, Chrome Vermilion, Benzidine Orange, Perinone Orange, Oil Orange, Cobalt Blue, Cerulean Blue, Alkaline Blue Lake, Peacock Blue Lake, Victoria Blue Lake, Metal-free Phthalocyanine Blue Phthalocyanine blue, fast sky blue, indanthrene blue (RS, BC), indigo, ultramarine, bitumen, anthraquinone blue, fast violet B, methyl violet lake, cobalt purple, manganese purple, dioxane violet, anthraquinone violet, chrome green, Zinc green, chromium oxide, pyridian, emerald green, pigment green B, naphthol green B, green gold Acid Green Lake, Malachite Green Lake, Phthalocyanine Green, Anthraquinone Green, Titanium Oxide, Zinc Hana, Lithbon and the like can be used alone or in combination of two or more.

  The content of the colorant in the base particles is preferably 1 to 15% by weight, and more preferably 3 to 10% by weight.

  The colorant contained in the base particles may be used as a master batch combined with the resin. Such a resin is not particularly limited and can be appropriately selected from known ones according to the purpose. For example, a homopolymer of styrene or a substituted product thereof, a styrene copolymer, polymethyl methacrylate, Polybutyl methacrylate, polyvinyl chloride, polyvinyl acetate, polyethylene, polypropylene, polyester, epoxy resin, epoxy polyol resin, polyurethane, polyamide, polyvinyl butyral, polyacrylic acid, rosin, modified rosin, terpene resin, aliphatic hydrocarbon resin , Alicyclic hydrocarbon resins, aromatic petroleum resins, chlorinated paraffins, paraffins and the like, and may be used alone or in combination of two or more.

  There is no restriction | limiting in particular in the mold release agent contained in a base particle, According to the objective, it can select suitably from well-known things, For example, waxes can be used. Examples of waxes include carbonyl group-containing waxes, polyolefin waxes, long-chain hydrocarbons, and the like, and these can be used alone or in combination of two or more. Among these, a wax having a carbonyl group is preferable.

  Examples of the wax having a carbonyl group include polyalkanoic acid esters, polyalkanol esters, polyalkanoic acid amides, polyalkylamides, dialkyl ketones, etc. Among them, polyalkanoic acid esters are particularly preferable. Examples of polyalkanoic acid esters include carnauba wax, montan wax, trimethylolpropane tribehenate, pentaerythritol tetrabehenate, pentaerythritol diacetate dibehenate, glycerin tribehenate, 1,18-octadecanediol. Examples include distearate. Examples of the polyalkanol ester include tristearyl trimellitic acid, distearyl maleate, and the like. Examples of the polyalkanoic acid amide include dibehenyl amide. Examples of the polyalkylamide include trimellitic acid tristearylamide. Examples of dialkyl ketones include distearyl ketone.

  Examples of the polyolefin wax include polyethylene wax and polypropylene wax.

  Examples of the long chain hydrocarbon include paraffin wax and sazol wax.

  The melting point of the release agent is not particularly limited and may be appropriately selected depending on the intended purpose, but is preferably 40 to 160 ° C, more preferably 50 to 120 ° C, and particularly preferably 60 to 90 ° C. When the melting point is less than 40 ° C., the release agent may adversely affect the heat-resistant storage stability, and when it exceeds 160 ° C., cold offset may easily occur during fixing at a low temperature.

  The melt viscosity of the release agent is preferably 5 to 1000 cps, more preferably 10 to 100 cps, as a measured value at a temperature 20 ° C. higher than the melting point of the release agent. If the melt viscosity is less than 5 cps, the releasability may be lowered, and if it exceeds 1000 cps, the effect of improving the hot offset resistance and the low-temperature fixability may not be obtained.

  There is no restriction | limiting in particular in content of the mold release agent in a base particle, Although it can select suitably according to the objective, It is preferable that it is 1-40 weight%, and 3-30 weight% is further more preferable. When the content exceeds 40% by weight, the fluidity of the toner may be lowered. On the other hand, when the amount is less than 1% by weight, the offset resistance may not be effective.

  In the base particles used in the electrophotographic toner of the present invention, other components can be appropriately selected and used according to the purpose. Examples of other components include a charge control agent, a fluidity improver, a cleaning property improver, a magnetic material, and a metal soap. The charge control agent in such other components is not particularly limited, and a positive or negative charge control agent can be appropriately selected and used depending on whether the charge charged on the photoreceptor is positive or negative.

  As the negative charge control agent, for example, a resin or compound having an electron-donating functional group, an azo dye, a metal complex of an organic acid, or the like can be used. Specifically, Bontron (product numbers: S-31, S-32, S-34, S-36, S-37, S-39, S-40, S-44, E-81, E-82, E -84, E-86, E-88, A, 1-A, 2-A, 3-A) (above, manufactured by Orient Chemical Industry Co., Ltd.), Kaya Charge (part numbers: N-1, N-2), Kaya Set black (product number: T-2, 004) (above, Nippon Kayaku Co., Ltd.)), Eisenspiron black (T-37, T-77, T-95, TRH, TNS-2) (above, Hodogaya Chemical Industry Co., Ltd.), FCA-1001-N, FCA-1001-NB, FCA-1001-NZ (manufactured by Fujikura Kasei Co., Ltd.) and the like can be used alone or in combination.

  As the positive charge control agent, for example, basic compounds such as nigrosine dyes, cationic compounds such as quaternary ammonium salts, metal salts of higher fatty acids, and the like can be used. Specifically, Bontron (part numbers: N-01, N-02, N-03, N-04, N-05, N-07, N-09, N-10, N-11, N-13, P -51, P-52, AFP-B) (above, manufactured by Orient Chemical Co., Ltd.), TP-302, TP-415, TP-4040 (above, manufactured by Hodogaya Chemical Co., Ltd.), Copy Blue PR, Copy Charge ( Product number: PX-VP-435, NX-VP-434) (manufactured by Hoechst), FCA (product number: 201, 201-B-1, 201-B-2, 201-B-3, 201-PB, 201-PZ, 301) (above, manufactured by Fujikura Kasei Co., Ltd.), PLZ (part numbers: 1001, 2001, 6001, 7001) (above, manufactured by Shikoku Kasei Kogyo Co., Ltd.) and the like. can do.

  The addition amount of the charge control agent is determined by the method of manufacturing the base particles including the type of the binder resin and the dispersion method, and is not uniquely limited, but based on the binder resin. 0.1 to 10% by weight, preferably 0.2 to 5% by weight. When the addition amount exceeds 10% by weight, the chargeability of the toner is too high, the effect of the charge control agent is reduced, the electrostatic attraction with the developing roller is increased, the flowability of the developer is reduced, the image The concentration may decrease. On the other hand, if the addition amount is less than 0.1% by weight, the rising property of charge and the charge amount are not sufficient, which may affect the toner image.

  The fluidity improver means a material that can be surface treated to increase hydrophobicity and prevent deterioration of flow characteristics and charging characteristics even under high humidity. For example, a silane coupling agent, a silylating agent, Examples thereof include a silane coupling agent having an alkyl fluoride group, an organic titanate coupling agent, an aluminum coupling agent, silicone oil, and modified silicone oil. It is particularly preferable that the silica and the titanium oxide are surface-treated with such a fluidity improver and used as hydrophobic silica and hydrophobic titanium oxide.

  The cleaning improver is added to the toner in order to remove the developer after transfer remaining on the photoreceptor or the primary transfer medium, and includes, for example, fatty acid metal salts such as zinc stearate, calcium stearate, stearic acid, and the like. Examples thereof include polymer fine particles produced by soap-free emulsion polymerization such as methyl methacrylate fine particles and polystyrene fine particles. The polymer fine particles preferably have a relatively narrow particle size distribution, and those having a volume average particle size of 0.01 to 1 μm are suitable.

  There is no restriction | limiting in particular as said magnetic material, According to the objective, it can select suitably from well-known things, For example, iron powder, a magnetite, a ferrite, etc. are mentioned. Among these, white is preferable in terms of color tone.

  The method for producing the base particles can be appropriately selected according to the purpose, but the pulverization method, the emulsion polymerization method for forming the base particles by emulsifying, suspending and aggregating the oil phase in an aqueous medium, suspension Examples of the polymerization method include a polymerization method and a polymer suspension method.

(Crushing method)
Next, a pulverization method that is one of the manufacturing methods of the base particles will be described.
First, a mixture in which the base particle materials are mixed is charged into a melt kneader and melt kneaded. As the melt kneader, for example, a uniaxial or biaxial continuous kneader or a batch kneader using a roll mill can be used. Specifically, a KTK type twin screw extruder (Kobe Steel Co., Ltd.), a TEM type extruder (Toshiba Machine Co., Ltd.), a twin screw extruder (Cay Kay), a PCM type twin screw extruder (Ikegai Iron Works) And Kneader (manufactured by Busus). The melt kneading is preferably performed under appropriate conditions so that the molecular chain of the binder resin is not broken. Specifically, if the melt-kneading temperature is too high above the softening point of the binder resin, cutting may become severe, and if it is too low, melt-kneading may not proceed.

  Next, the kneaded material obtained by melt kneading is pulverized. In order to pulverize the kneaded product, it is preferable that the kneaded product is coarsely pulverized and then finely pulverized. Specifically, a method of pulverizing by colliding with a collision plate in a jet stream, a method of pulverizing particles by colliding with each other in a jet stream, or a method of pulverizing with a narrow gap between a mechanically rotating rotor and a stator are used. It is preferable.

  Furthermore, the pulverized pulverized product is classified to adjust the particle size within a predetermined range. In classification, for example, fine particles are removed by a cyclone, a decanter, a centrifugal separator, or the like. Furthermore, the base particles are obtained by removing coarse particles and aggregated particles using a sieve of 250 mesh or more.

Next, one polymerization method other than the pulverization method will be described.
In the present invention, the base particles can be obtained by one of the polymerization methods described below.
A solution or dispersion obtained by dissolving or dispersing a toner composition containing a polyester resin (hereinafter referred to as prepolymer (A)) capable of reacting with active hydrogen groups in an organic solvent contains resin particles. It is preferably obtained by allowing the prepolymer (A) to react with a compound having an active hydrogen group after being dispersed in an aqueous medium. The toner composition can contain materials used for the base particles.

  The prepolymer (A) can be obtained by reacting a polyester resin having an active hydrogen group (hereinafter sometimes simply referred to as a polyester resin) with the polyisocyanate (3). This polyester resin is obtained by polycondensation of polyol (1) and polycarboxylic acid (2). Examples of the active hydrogen group of this polyester resin include hydroxyl groups (alcoholic hydroxyl groups and phenolic hydroxyl groups), amino groups, carboxyl groups, mercapto groups, and the like, and alcoholic hydroxyl groups are preferred.

  As the polyol (1), alkylene glycol such as ethylene glycol, 1,2-propylene glycol, 1,3-propylene glycol, 1,4-butanediol, 1,6-hexanediol and the like; alkylene ether glycol such as diethylene glycol, Triethylene glycol, dipropylene glycol, polyethylene glycol, polypropylene glycol, polytetramethylene ether glycol, etc .; alicyclic diols such as 1,4-cyclohexanedimethanol, hydrogenated bisphenol A, etc .; bisphenols such as bisphenol A, bisphenol F 4,4′-dihydroxybiphenyls such as bisphenol S, 3,3′-difluoro-4,4′-dihydroxybiphenyl; (Luoro-4-hydroxyphenyl) methane, 1-phenyl-1,1-bis (3-fluoro-4-hydroxyphenyl) ethane, 2,2-bis (3-fluoro-4-hydroxyphenyl) propane, 2,2 -Bis (3,5-difluoro-4-hydroxyphenyl) propane (also known as: tetrafluorobisphenol A), 2,2-bis (3-hydroxyphenyl) -1,1,1,3,3,3-hexafluoro Bis (hydroxyphenyl) alkanes such as propane; Bis (4-hydroxyphenyl) ethers such as bis (3-fluoro-4-hydroxyphenyl) ether; Alkylene oxides (ethylene oxide, propylene oxide) of the above alicyclic diols , Butylene oxide, etc.) adducts; alkylene oxides of the above bisphenols De (ethylene oxide, propylene oxide, butylene oxide, etc.) adducts. Among them, preferred are alkylene glycols having 2 to 12 carbon atoms and alkylene oxide adducts of bisphenols, and particularly preferred are alkylene oxide adducts of bisphenols and alkylene glycols having 2 to 12 carbon atoms. It is a combined use.

Further, the trivalent or higher polyol (1) includes a trivalent or higher polyhydric aliphatic alcohol such as glycerin, trimethylolethane, trimethylolpropane, pentaerythritol, sorbitol, etc .; a trivalent or higher phenol such as trisphenol. PA, phenol novolak, cresol novolak and the like; and alkylene oxide adducts of the above trivalent polyphenols and the like.
In addition, the said polyol can be individual or can use 2 or more types together, and is not limited above.

  Examples of the polycarboxylic acid (2) include alkylene dicarboxylic acids such as succinic acid, adipic acid and sebacic acid; alkenylene dicarboxylic acids such as maleic acid and fumaric acid; aromatic dicarboxylic acids such as phthalic acid, isophthalic acid and terephthalic acid , Naphthalenedicarboxylic acid, 3-fluoroisophthalic acid, 2-fluoroisophthalic acid, 2-fluoroterephthalic acid, 2,4,5,6-tetrafluoroisophthalic acid, 2,3,5,6-tetrafluoroterephthalic acid, 5 -Trifluoromethylisophthalic acid, 2,2-bis (4-carboxyphenyl) hexafluoropropane, 2,2-bis (4-carboxyphenyl) hexafluoropropane, 2,2-bis (3-carboxyphenyl) hexafluoro Propane, 2,2'-bis (trifluoromethyl ) -4,4′-biphenyldicarboxylic acid, 3,3′-bis (trifluoromethyl) -4,4′-biphenyldicarboxylic acid, 2,2′-bis (trifluoromethyl) -3,3′-biphenyl Dicarboxylic acid, hexafluoroisopropylidene diphthalic anhydride, etc.). Of these, preferred are alkenylene dicarboxylic acids having 4 to 20 carbon atoms and aromatic dicarboxylic acids having 8 to 20 carbon atoms.

  In addition, examples of the trivalent or higher valent polycarboxylic acid include aromatic polycarboxylic acids having 9 to 20 carbon atoms, such as trimellitic acid and pyromellitic acid. Anhydrides and lower alkyl esters of the above aromatic polycarboxylic acids. (For example, methyl ester, ethyl ester, isopropyl ester, etc.) can also be included in the polycarboxylic acid. In addition, the said polycarboxylic acid can be used individually or in combination of 2 or more types, It is not limited to the above.

  Regarding the ratio of the polyol (1) and the polycarboxylic acid (2) when synthesizing the polyester resin, the equivalent ratio [OH] / [COOH] of the hydroxyl group [OH] and the carboxyl group [COOH] is usually 2/1. To 1/1, preferably 1.5 / 1 to 1/1, and more preferably 1.3 / 1 to 1.02 / 1.

The peak molecular weight of the polyester resin is usually 1000 to 30000, preferably 1500 to 10000, and more preferably 2000 to 8000. When the peak molecular weight is less than 1000, the heat resistant storage stability may be lowered, and when it exceeds 10,000, the low-temperature fixability may be lowered.
Examples of the polyisocyanate (3) include aliphatic polyisocyanates (tetramethylene diisocyanate, hexamethylene diisocyanate, 2,6-diisocyanatomethylcaproate, etc.); alicyclic polyisocyanates (isophorone diisocyanate, cyclohexylmethane diisocyanate, etc.); aromatic Diisocyanates (tolylene diisocyanate, diphenylmethane diisocyanate, etc.); araliphatic diisocyanates (α, α, α ′, α′-tetramethylxylylene diisocyanate, etc.); isocyanurates, phenol derivatives, oximes, caprolactams, etc. It may be blocked. In addition, these can use 2 or more types together.

  Regarding the ratio of the polyisocyanate (3) and the polyester resin having an active hydrogen group when synthesizing the prepolymer (A), the equivalent ratio [NCO] of the isocyanate group [NCO] and the hydroxyl group [OH] of the polyester resin having a hydroxyl group is used. ] / [OH] is usually 5/1 to 1/1, preferably 4/1 to 1.2 / 1, and more preferably 2.5 / 1 to 1.5 / 1. When [NCO] / [OH] exceeds 5, the low-temperature fixability may be deteriorated. When it is less than 1, the content of urethane groups and / or urea groups in the modified polyester resin is decreased, and offset resistance is reduced. May decrease.

  The content of the component derived from the polyisocyanate (3) in the prepolymer (A) is usually 0.5 to 40% by weight, preferably 1 to 30% by weight, more preferably 2 to 20% by weight. It is. When the content is less than 0.5% by weight, the offset resistance may be lowered, and when it exceeds 40% by weight, the low-temperature fixability may be lowered.

  The number of isocyanate groups per molecule of the prepolymer (A) is usually 1 or more, preferably 1.5 to 3, more preferably 1.8 to 2.5. When the number of isocyanate groups is less than 1, the molecular weight of the modified polyester resin is lowered, and offset resistance may be lowered.

  In the present invention, amines (B) can be used as the compound having an active hydrogen group (elongating agent and / or crosslinking agent). As amines (B), diamine (B1), trivalent or higher polyamine (B2), aminoalcohol (B3), aminomercaptan (B4), amino acid (B5), amino group blocked B1 to B5 (B6) Etc.

  Examples of the diamine (B1) include aromatic diamines (phenylenediamine, diethyltoluenediamine, 4,4′-diaminodiphenylmethane, tetrafluoro-p-xylylenediamine, tetrafluoro-p-phenylenediamine, etc.); alicyclic diamines ( 4,4′-diamino-3,3′-dimethyldicyclohexylmethane, diaminocyclohexane, isophoronediamine, etc .; aliphatic diamines (ethylenediamine, tetramethylenediamine, hexamethylenediamine, dodecafluorohexylenediamine, tetracosafluorododecylene) Amine) and the like.

Examples of the trivalent or higher polyamine (B2) include diethylenetriamine and triethylenetetraamine.
Examples of amino alcohol (B3) include ethanolamine and hydroxyethylaniline.
Examples of amino mercaptan (B4) include aminoethyl mercaptan and aminopropyl mercaptan.
Examples of the amino acid (B5) include aminopropionic acid and aminocaproic acid.
Examples of B1 to B5 (B6) in which an amino group is blocked include B1 to B5 and ketimine compounds and oxazoline compounds obtained from ketones (acetone, methyl ethyl ketone, methyl isobutyl ketone, etc.).

  Furthermore, a terminator can be used in the extension reaction and / or the cross-linking reaction as necessary, and the molecular weight of the modified polyester resin can be adjusted. Examples of the terminator include monoamines (diethylamine, dibutylamine, butylamine, laurylamine, etc.), and those obtained by blocking these (ketimine compounds).

  Regarding the ratio of the prepolymer (A) to the amines (B) when the prepolymer (A) and the amines (B) are reacted, the isocyanate group [NCO] of the prepolymer (A) and the amines (B) The equivalent ratio [NCO] / [NHx] of the amino group [NHx] is usually 1/2 to 2/1, preferably 1.5 / 1 to 1 / 1.5, more preferably 1 2/1 to 1 / 1.2. When [NCO] / [NHx] is larger than 2 or smaller than 1/2, the molecular weight of the resulting modified polyester resin is decreased, and the hot offset resistance may be lowered.

  The organic solvent that dissolves or disperses the toner composition is preferably volatile with a boiling point of less than 100 ° C. because it can be easily removed later. Examples of such organic solvents include toluene, xylene, benzene, carbon tetrachloride, methylene chloride, 1,2-dichloroethane, 1,1,2-trichloroethane, trichloroethylene, chloroform, monochlorobenzene, dichloroethylidene, methyl acetate, Examples include ethyl acetate, methyl ethyl ketone, methyl isobutyl ketone, and the like. These can be used alone or in combination of two or more. Particularly preferred are ester solvents such as methyl acetate and ethyl acetate, aromatic solvents such as toluene and xylene, and halogenated hydrocarbons such as methylene chloride, 1,2-dichloroethane, chloroform and carbon tetrachloride. The toner composition may be dissolved or dispersed at the same time, but is usually dissolved or dispersed independently, and the organic solvents used at that time may be different or the same, but considering the subsequent solvent treatment, Is preferred.

  The solution or dispersion of the toner composition preferably has a resin concentration of 40 to 80% by weight. When the resin concentration exceeds 80% by weight, it becomes difficult to dissolve or disperse, and the viscosity becomes so high that it is difficult to handle. On the other hand, if it is less than 40% by weight, the amount of toner produced is reduced. When mixing the polyester resin and the prepolymer, they may be mixed in the same solution or dispersion, or may be prepared separately, but considering the solubility and viscosity of each, separate dissolution Alternatively, it is preferable to prepare a dispersion.

  The colorant may be dissolved or dispersed alone, or may be mixed in a polyester resin solution or dispersion. If necessary, a dispersion aid or a polyester resin may be added, or a master batch may be used.

  When a wax is dissolved or dispersed as a mold release agent, an organic solvent that does not dissolve the wax is used as a dispersion. This dispersion is prepared by a general method. That is, an organic solvent and wax may be mixed and dispersed with a disperser such as a bead mill. Further, after mixing the organic solvent and the wax, heating to the melting point of the wax, cooling with stirring, and then dispersing with a disperser such as a bead mill may shorten the dispersion time. Further, a plurality of waxes may be mixed and used, or a dispersion aid or a polyester resin may be added.

  As an aqueous medium, water alone may be used, but a solvent miscible with water may be used in combination. Examples of miscible solvents include alcohols (methanol, isopropanol, ethylene glycol, etc.), dimethylformamide, tetrahydrofuran, cellosolves (methyl cellosolve, etc.), lower ketones (acetone, methyl ethyl ketone, etc.), and the like. The amount of the aqueous medium used relative to 100 parts by weight of the toner composition is usually 50 to 2000 parts by weight, preferably 100 to 1000 parts by weight. When the amount of the aqueous medium used is less than 50 parts by weight, the dispersion state of the toner composition may be deteriorated. Moreover, when it exceeds 2000 weight part, it is not economical.

  When the toner composition solution or dispersion is dispersed in the aqueous medium, it is preferable to disperse the inorganic dispersant or the resin particles in the aqueous medium in advance. Thereby, the particle size distribution can be narrowed and stably dispersed.

As the inorganic dispersant, tricalcium phosphate, calcium carbonate, titanium oxide, colloidal silica, hydroxyapatite and the like are used.
Further, as the resin forming the resin particles, any resin can be used as long as it can form an aqueous dispersion, and it may be a thermoplastic resin or a thermosetting resin, For example, vinyl resin, polyurethane resin, epoxy resin, polyester resin, polyamide resin, polyimide resin, silicon resin, phenol resin, melamine resin, urea resin, aniline resin, ionomer resin, polycarbonate resin and the like can be mentioned. These resins may be used in combination of two or more. Of these, vinyl resins, polyurethane resins, epoxy resins, polyester resins, and combinations thereof are preferred because an aqueous dispersion of fine spherical resin particles can be easily obtained.

In the polymerization method for producing the base particles used in the electrophotographic toner of the present invention, an aqueous dispersion of resin particles can be used as the resin particles.
Although the method of manufacturing the aqueous dispersion of resin particles is not particularly limited, the following (a) to (h) can be mentioned.
(A) In the case of a vinyl resin, an aqueous dispersion of resin particles is directly produced by a polymerization reaction such as a suspension polymerization method, an emulsion polymerization method, a seed polymerization method, or a dispersion polymerization method using a monomer as a starting material.
(B) In the case of polyaddition or condensation resin such as polyester resin, polyurethane resin, epoxy resin, etc., a precursor (monomer, oligomer, etc.) or a solution thereof is dispersed in an aqueous medium in the presence of an appropriate dispersant, and then Or an aqueous dispersion of resin particles is produced by polymerizing and curing by adding a curing agent.
(C) In the case of polyaddition or condensation resins such as polyester resins, polyurethane resins, and epoxy resins, precursors (monomers, oligomers, etc.) or solutions thereof (preferably liquids may be liquefied by heating). A suitable emulsifier is dissolved therein, and water is added to carry out phase inversion emulsification.
(D) Resin produced in advance by a polymerization reaction (any polymerization reaction mode such as addition polymerization, ring-opening polymerization, polyaddition, addition condensation, condensation polymerization, etc.) After pulverizing and classifying using a fine pulverizer, resin particles are obtained, and then dispersed in water in the presence of an appropriate dispersant.
(E) A resin solution prepared in advance by a polymerization reaction (any polymerization reaction mode such as addition polymerization, ring-opening polymerization, polyaddition, addition condensation, condensation polymerization, etc.) is sprayed in the form of a mist. Thus, the resin particles are obtained and then dispersed in water in the presence of a suitable dispersant.
(F) A resin solution obtained by dissolving a resin prepared in advance in a polymerization reaction (any polymerization reaction mode such as addition polymerization, ring-opening polymerization, polyaddition, addition condensation, condensation polymerization, etc.) in a solvent. The resin particles are precipitated by adding a solvent or by cooling a resin solution previously dissolved in a solvent by heating, and after removing the solvent to obtain resin particles, in a water-based medium in the presence of an appropriate dispersant. Disperse.
(G) A resin solution prepared in advance by a polymerization reaction (any polymerization reaction mode such as addition polymerization, ring-opening polymerization, polyaddition, addition condensation, condensation polymerization, etc.) is used as an appropriate dispersant. After the dispersion in an aqueous medium, the solvent is removed by heating, decompression or the like.
(H) An appropriate emulsifier is added to a resin solution prepared in advance by a polymerization reaction (any polymerization reaction mode such as addition polymerization, ring-opening polymerization, polyaddition, addition condensation, condensation polymerization, etc.). After dissolving, water is added and phase inversion emulsified.

  In addition, a surfactant or the like may be used as necessary in order to emulsify and disperse the toner composition solution or dispersion in an aqueous medium. Surfactants include alkylbenzene sulfonate, α-olefin sulfonate, anionic surfactants such as phosphate esters, alkylamine salts, amino alcohol fatty acid derivatives, polyamine fatty acid derivatives, amine salt types such as imidazoline, alkyl Quaternary ammonium salt type cationic surfactants such as trimethylammonium salt, dialkyldimethylammonium salt, alkyldimethylbenzylammonium salt, pyridinium salt, alkylisoquinolinium salt, benzethonium chloride, fatty acid amide derivative, polyhydric alcohol derivative, etc. Nonionic surfactants such as alanine, dodecyl bis (aminoethyl) glycine, bis (octylaminoethyl) glycine, and N-alkyl-N, N-dimethylammonium betaine.

Further, by using a surfactant having a fluoroalkyl group, the effect can be increased in a very small amount. As an anionic surfactant having a fluoroalkyl group, a fluoroalkyl carboxylic acid having 2 to 10 carbon atoms (C _{2 to} C ₁₀ being described as C _{2 to} C ₁₀ , hereinafter the same shall be indicated). Acids and metal salts thereof, disodium perfluorooctanesulfonyl glutamate, 3- [ω-fluoroalkyl (C ₆ -C ₁₁ fluoroalkyl) oxy] -1-alkyl (C ₃ -C ₄ alkyl) sulfonic acid sodium, 3- [.omega.-fluoroalkanoyl _{(-fluoroalkanoyl} of C 6 ~C ₈₎ -N- ethylamino] -1-sodium sulfonic acid, carboxylic acid and metal salts _(fluoroalkyl C 11 _{-C 20)} fluoroalkyl , perfluoroalkyl of perfluoroalkyl carboxylic acids _(C 7 _{-C 13} Carboxylic acid) and metal salts thereof, perfluoroalkyl (C _{4 to} C ₁₂ perfluoroalkyl) sulfonic acid and metal salts thereof, perfluorooctanesulfonic acid diethanolamide, N-propyl-N- (2-hydroxyethyl) per perfluorooctane sulfonamide, sulfonamide propyl trimethyl ammonium salts _{(perfluoroalkyl} of C 6 _{-C 10)} perfluoroalkyl, _{(perfluoroalkyl} of C 6 _{-C 10)} perfluoroalkyl -N- ethylsulfonyl glycine salts, Monopa ethyl phosphate ester _(mono perfluoroalkyl of C 6 _{-C 16)} fluoroalkyl and the like. Examples of the cationic surfactant include aliphatic primary, secondary or tertiary amine acids having a fluoroalkyl group, perfluoroalkyl (C _{6 to} C ₁₀ perfluoroalkyl) sulfonamidopropyltrimethylammonium salt, and the like. Aliphatic quaternary ammonium salts, benzalkonium salts, benzethonium chloride, pyridinium salts, imidazolinium salts and the like can be mentioned.

  Further, the dispersion liquid may be stabilized by a polymeric protective colloid. Polymeric protective colloids include acids (acrylic acid, methacrylic acid, α-cyanoacrylic acid, α-cyanomethacrylic acid, itaconic acid, crotonic acid, fumaric acid, maleic acid, maleic anhydride, etc.); (Meth) acrylic monomer (β-hydroxyethyl acrylate, β-hydroxyethyl methacrylate, β-hydroxypropyl acrylate, β-hydroxypropyl methacrylate, γ-hydroxypropyl acrylate, γ-hydroxy methacrylate) Propyl, 3-chloro-2-hydroxypropyl acrylate, 3-chloro-2-hydroxypropyl methacrylate, diethylene glycol monoacrylate, diethylene glycol monomethacrylate, glycerol monoacrylate, glycerol monomethacrylate, N-methylolacrylate Rilamide, N-methylol methacrylamide, etc.); vinyl alcohol or ethers with vinyl alcohol (vinyl methyl ether, vinyl ethyl ether, vinyl propyl ether, etc.); esters of vinyl alcohol and compounds containing a carboxyl group (vinyl acetate, Vinyl propionate, vinyl butyrate, etc.); acrylamide, methacrylamide, diacetone acrylamide or their methylol compounds; acid chlorides (acrylic acid chloride, methacrylic acid chloride, etc.); those having a nitrogen atom or its heterocyclic ring ( Homopolymers or copolymers of vinyl pyridine, vinyl pyrrolidone, vinyl imidazole, ethyleneimine, etc.); polyoxyethylenes such as polyoxyethylene, polyoxypropylene, polyoxyethylene alkylamine, Reoxypropylene alkylamine, polyoxyethylene alkylamide, polyoxypropylene alkylamide, polyoxyethylene nonyl phenyl ether, polyoxyethylene lauryl phenyl ether, polyoxyethylene stearyl phenyl ester, polyoxyethylene nonyl phenyl ester, etc .; celluloses, For example, methyl cellulose, hydroxyethyl cellulose, hydroxypropyl cellulose and the like can be used.

  As a dispersion stabilizer for stabilizing the dispersion, an acid such as calcium phosphate, or a compound that can be dissolved in alkali is used, such as by dissolving the calcium phosphate with an acid such as hydrochloric acid and then washing with water. The calcium phosphate salt can be removed from the base particles. In addition, it can be removed by an operation such as enzymatic degradation. When a dispersant is used, it can be used in a state where the dispersant remains on the surface of the base particles, but it is preferable to remove it by washing from the charged surface of the toner.

  When preparing a dispersion liquid or dispersing a toner composition solution or dispersion liquid in an aqueous medium, the dispersion method is not particularly limited, but a low-speed shear method, a high-speed shear method, a friction method, a high-pressure jet method, an ultrasonic wave A known method such as the above can be applied. In order to make the average particle size of the dispersion 2 to 20 μm, a high-speed shearing method is preferable. When a high-speed shearing disperser is used, the number of rotations is not particularly limited, but is usually 1000 to 30000 rpm, and preferably 5000 to 20000 rpm. The dispersion time is not particularly limited, but in the case of a batch method, it is usually 0.1 to 5 minutes. The temperature at the time of dispersion is usually 0 to 150 ° C. (under pressure), preferably 20 to 80 ° C.

  In order to remove the organic solvent from the obtained emulsified dispersion, a method of gradually raising the temperature of the whole system under normal pressure or reduced pressure and evaporating and removing the organic solvent in the droplets can be employed. It is also possible to spray the emulsified dispersion in a dry atmosphere to remove the organic solvent in the droplets and to evaporate and remove the surfactant. As the dry atmosphere in which the emulsified dispersion is sprayed, a gas obtained by heating air, nitrogen, carbon dioxide gas, combustion gas, or the like can be used, but various airflows heated to a temperature equal to or higher than the boiling point of the organic solvent are generally used. . At this time, the processing time can be shortened by using a spray dryer, a belt dryer, a rotary kiln or the like.

  The amines (B) may be mixed in an organic solvent before dispersing the toner composition in the aqueous medium, or may be added to the aqueous medium. The time required for the reaction of the prepolymer (A) and the amines (B) is appropriately selected depending on the reactivity of the prepolymer (A) and the amines (B), but is usually 1 minute to 40 hours, preferably Is 1 to 24 hours. The reaction temperature is usually 0 to 150 ° C., preferably 20 to 98 ° C. In this reaction, a known catalyst can be used as necessary.

  In the base particles used in the electrophotographic toner of the present invention, it is preferable to obtain the base particles using a process of washing and drying after reacting the prepolymer (A) with the compound having an active hydrogen group. A known method is used for the washing and drying steps. That is, after solid-liquid separation with a centrifuge, a filter press, etc., the obtained toner cake is redispersed in ion-exchanged water at room temperature to about 40 ° C., and if necessary, pH adjusted with acid or alkali, The process of solid-liquid separation is repeated several times. Thereby, after removing impurities, surfactants, etc., the base particles are obtained by drying with an air dryer, circulation dryer, vacuum dryer, vibration fluid dryer or the like. At this time, the fine particle component may be removed by centrifugation or the like, and after drying, a desired particle size distribution can be obtained using a known classifier as necessary.

[External additive]
The toner of the present invention has an external additive containing conductive glass particles. First, the external additive excluding the conductive glass will be described.
[External additives excluding conductive glass]
The external additive excluding the conductive glass used in the electrophotographic toner of the present invention is not particularly limited and may be appropriately selected depending on the intended purpose. For example, silica (medium / small particle size), Examples thereof include resins containing at least one of a titanium compound, alumina, cerium oxide, calcium carbonate, magnesium carbonate, calcium phosphate, fluorine atom, silicon atom, and nitrogen atom as a constituent component. These may be used individually by 1 type and may use 2 or more types together.

The external additive excluding the conductive glass preferably contains a titanium compound, and the titanium compound reacts part or all of TiO (OH) ₂ prepared by a wet method with a silane compound or silicone oil. What is obtained is more preferable.

A silane coupling agent is preferably used as the silane compound. Examples of the silane coupling agent include CH ₃ Si (Cl) ₃ , CH ₃ Si (OCH ₃ ) ₃ , CH ₃ Si (OC ₂ H ₅ ) ₃ , CH ₃ CH ₂ Si (OCH ₃ ) ₃ , CH ₃ (CH ₂ ) ₂ Si (OCH ₃ ) ₃ , CH ₃ (CH ₂ ) ₃ Si (OCH ₃ ) ₃ , CH ₃ (CH ₂ ) ₄ Si (OCH ₃ ) ₃ , CH ₃ (CH ₂ ) ₅ Si ( OCH ₃ ) ₃ , CH ₃ (CH ₂ ) ₆ Si (OCH ₃ ) ₃ , CH ₃ (CH ₂ ) ₇ Si (OCH ₃ ) ₃ , CH ₃ (CH ₂ ) ₈ Si (OCH ₃ ) ₃ , CH ₃ ( CH ₂ ) ₉ Si (OCH ₃ ) ₃ , CH ₃ (CH ₂ ) ₁₀ Si (OCH ₃ ) ₃ , CH ₃ (CH ₂ ) ₁₁ Si (OCH ₃ ) ₃ , CH ₃ (CH ₂ ) ₁₂ Si (OCH ₃ ) ₃ , CH ₃ (CH ₂ ) ₁₃ Si (OCH ₃ ) ₃ , CH ₃ (CH ₂ ) ₁₄ Si (OCH ₃ ) ₃ , CH ₃ (CH ₂ ) ₁₅ Si (OCH ₃ ) ₃ , CH ₃ (CH ₂ ) ₁₆ Si ( OCH ₃ ) ₃ , CH ₃ (CH ₂ ) ₁₇ Si (OCH ₃ ) ₃ , CH ₃ (CH ₂ ) ₁₈ Si (OCH ₃ ) ₃ , CH ₃ (CH ₂ ) ₁₉ Si (OCH ₃ ) ₃ , CH ₃ ( CH ₂ ) ₅ Si (OC ₂ H ₅ ) ₃ , CH ₃ (CH ₂ ) ₆ Si (OC ₂ H ₅ ) ₃ , CH ₃ (CH ₂ ) ₇ Si (OC ₂ H ₅ ) ₃ , CH ₃ (CH ₂ ) ₈ Si (OC ₂ H ₅ ) ₃ , CH ₃ (CH ₂ ) ₉ Si (OC ₂ H ₅ ) ₃ , CH ₃ (CH ₂ ) ₁₀ Si (OC ₂ H ₅ ) ₃ , CH ₃ (CH ₂ ) ₁₁ Si (OC ₂ H ₅ ) ₃ , CH ₃ (CH ₂ ) ₁₂ Si (OC ₂ H ₅ ) ₃ , CH ₃ (CH ₂ ) ₁₃ Si (OC ₂ H ₅ ) ₃ , CH ₃ (CH ₂ ) ₁₄ Si (OC ₂ H ₅ ) ₃ , CH ₃ ( CH ₂ ) ₁₅ Si (OC ₂ H ₅ ) ₃ , CH ₃ (CH ₂ ) ₁₆ Si (OC ₂ H ₅ ) ₃ , CH ₃ (CH ₂ ) ₁₇ Si (OC ₂ H ₅ ) ₃ , CH ₃ (CH ₂ ) ₁₈ Si (OC ₂ H ₅ ) ₃ , CH ₃ (CH ₂ ) ₁₉ Si (OC ₂ H ₅ ) ₃ , CF ₃ Si (OCH ₃ ) ₃ , CH ₃ Si (NCO) ₃ , (CH ₃ ) ₂ SiCl ₂ , (CH ₃ ) ₂ Si (OCH ₃ ) ₂ , (CH ₃ ) ₂ Si (OC ₂ H ₅ ) ₂ , (CH ₃ ) (CH ₃ CH ₂ ) Si (OCH ₃ ) ₂ , (CH ₃ ) [ CH ₃ (CH ₂ ) ₂ ] Si (OCH ₃ ) ₂ , (CH ₃ ) [CH ₃ (CH ₂ ) ₃ ] Si (OCH ₃ ) ₂ , (CH ₃ ) [CH ₃ (CH ₂ ) ₄ ] Si (OCH ₃ ) ₂ , (CH ₃ ) [CH ₃ ( CH ₂ ) ₅ ] Si (OCH ₃ ) ₂ , (CH ₃ ) [CH ₃ (CH ₂ ) ₆ ] Si (OCH ₃ ) ₂ , (CH ₃ ) [CH ₃ (CH ₂ ) ₇ ] Si (OCH ₃ ) ₂ , (CH ₃ ) [CH ₃ (CH ₂ ) ₈ ] Si (OCH ₃ ) ₂ , (CH ₃ ) [CH ₃ (CH ₂ ) ₉ ] Si (OCH ₃ ) ₂ , (CH ₃ ) [CH ₃ ( CH ₂ ) ₁₀ ] Si (OCH ₃ ) ₂ , (CH ₃ ) [CH ₃ (CH ₂ ) ₁₁ ] Si (OCH ₃ ) ₂ , (CH ₃ ) [CH ₃ (CH ₂ ) ₁₂ ] Si (OCH ₃ ) _2, (CH _{3) [CH} 3 _{(CH 2) 13]} Si (OCH _{3 2,} (CH _{3) [CH} 3 _{(CH 2) 14] Si (OCH 3) 2, (} CH 3) _[CH 3 _{(CH 2) 15] Si (OCH 3) 2, (} CH 3) _[CH 3 ( CH _{2) 16] Si (OCH 3) 2, (} CH 3) _[CH 3 _(CH 2) 17] _{Si (OCH 3) 2, (} CH 3) _[CH 3 _{(CH 2) 18]} Si _(OCH 3) ₂ , (CH ₃ ) [CH ₃ (CH ₂ ) ₁₉ ] Si (OCH ₃ ) ₂ , (CH ₃ ) ₂ Si (NCO) ₂ , (CH ₃ ) ₃ SiCl, (CH ₃ ) ₃ Si (OCH ₃ ) , (CH ₃ ) ₃ Si (OC ₂ H ₅ ), (CH ₃ ) ₂ (CH ₃ CH ₂ ) Si (OCH ₃ ), (CH ₃ ) ₂ [CH ₃ (CH ₂ ) ₂ ] Si (OCH ₃ ) , _{(CH 3) 2 [CH} 3 _{(CH 2) 3]} Si ( _{CH 3), (CH 3)} 2 _[CH 3 _{(CH 2) 4] Si (OCH 3), (CH} 3) 2 _[CH 3 _{(CH 2) 5] Si (OCH 3), (CH} 3) 2 [ CH ₃ (CH ₂ ) ₆ ] Si (OCH ₃ ), (CH ₃ ) ₂ [CH ₃ (CH ₂ ) ₇ ] Si (OCH ₃ ), (CH ₃ ) ₂ [CH ₃ (CH ₂ ) ₈ ] Si ( OCH ₃ ), (CH ₃ ) ₂ [CH ₃ (CH ₂ ) ₉ ] Si (OCH ₃ ), (CH ₃ ) ₂ [CH ₃ (CH ₂ ) ₁₀ ] Si (OCH ₃ ), (CH ₃ ) ₂ [ CH ₃ (CH ₂ ) ₁₁ ] Si (OCH ₃ ), (CH ₃ ) ₂ [CH ₃ (CH ₂ ) ₁₂ ] Si (OCH ₃ ), (CH ₃ ) ₂ [CH ₃ (CH ₂ ) ₁₃ ] Si ( _{OCH 3), (CH 3)} 2 _[CH 3 _{(CH 2) 14]} S _{(OCH 3), (CH 3} ) 2 _[CH 3 _{(CH 2) 15] Si (OCH 3), (CH} 3) 2 _[CH 3 _{(CH 2) 16] Si (OCH 3), (CH} 3) 2 [CH ₃ (CH ₂ ) ₁₇ ] Si (OCH ₃ ), (CH ₃ ) ₂ [CH ₃ (CH ₂ ) ₁₈ ] Si (OCH ₃ ), (CH ₃ ) ₂ [CH ₃ (CH ₂ ) ₁₉ ] Si (OCH ₃₎ and the like.

  Examples of the silicone oil include dimethyl silicone oil, methylphenyl silicone oil, chlorophenyl silicone oil, methyl hydrogen silicone oil, alkyl-modified silicone oil, fluorine-modified silicone oil, polyether-modified silicone oil, alcohol-modified silicone oil, amino-modified. Silicone oil, epoxy-modified silicone oil, epoxy-polyether-modified silicone oil, phenol-modified silicone oil, carboxyl-modified silicone oil, mercapto-modified silicone oil, (meth) acryl-modified silicone oil, α-methylstyrene-modified silicone oil, etc. .

Examples of the reaction include a method of immersing TiO (OH) ₂ in a solution of these materials and drying. The treatment with the coupling agent is, for example, a method in which TiO (OH) ₂ fine particles are immersed in a solution containing the coupling agent and dried, or a solution containing the coupling agent is sprayed on the TiO (OH) ₂ fine particles. And a drying method. The adhesion amount of the coupling agent is preferably 0.1 to 25% by mass with respect to the TiO (OH) ₂ fine particles. The titanium compound preferably has a specific gravity of 2.8 to 3.6.

  In the present invention, when two or more external additives are used, silica, titanium oxide, barium titanate, magnesium titanate, calcium titanate subjected to a hydrophobic surface treatment as an external additive excluding conductive glass particles And strontium titanate. For example, if hydrophobic silica is used in order to impart the necessary fluidity and chargeability to the toner, the required functions can be provided. In this case, for example, under high temperature and high humidity, low temperature and low humidity. A large difference may occur in the charge amount, and the difference in the retained charge amount (charge amount per g) affects the image quality and controllability. Therefore, simultaneous use of metal oxide fine particles such as titanium oxide makes it possible to suppress excessive charging under low temperature and low humidity. As a result, the difference in retained charge between high temperature and high humidity and low temperature and low humidity is reduced. It is possible to improve the image quality and controllability. As described above, no external additive satisfying all expected functions has been found with one external additive, and it is suitable to use a plurality of additives in combination according to the expected function and expression function. Yes.

The BET specific surface area of the external additive is characterized by containing at least one material having a BET specific surface area of 20 m ² / g or more and 300 m ² / g or less. The BET specific surface area is more preferably 20 to ²⁰⁰ m ² / g.
Here, the specific surface area is calculated according to the BET method, for example, by using a specific surface area measuring device (“Autosorb 1”, manufactured by Yuasa Ionics Co., Ltd.), adsorbing nitrogen gas on the sample surface, and using the BET multipoint method. be able to.

  The average particle diameter of the external additive is preferably 10 to 300 nm, and more preferably 10 to 180 nm.

The content of the external additive in the toner is preferably 0.1 to 8.0% by mass, and more preferably 0.2 to 3.0% by mass.
Further, in order to improve the fluidity, storage stability, developability, and transferability of the toner, a general powder mixer can be used to add and mix the external additive to the base particles. It is preferable to adjust the internal temperature. In order to change the load history applied to the external additive, the external additive may be added midway or gradually. In this case, you may change the rotation speed, rolling speed, time, temperature, etc. of a mixer. Also, a strong load may be given first, then a relatively weak load, or vice versa. Examples of the mixer include a V-type mixer, a rocking mixer, a Roedige mixer, a Nauter mixer, and a Henschel mixer.

[Conductive glass particles]
The external additive used in the electrophotographic toner of the present invention contains conductive glass particles.
The external additive used in the electrophotographic toner of the present invention contains conductive glass particles.
It is conceivable to use conductive glass having an electric conductivity of about 10 ⁻¹⁴ to 10 ⁻¹³ mho / cm or an electric resistance value of about 1 × 10 ¹⁴ to 1 × 10 ¹⁸ Ωcm.
The conductive glass has, for example, a volume average particle diameter in the range of 8 to 150 nm, preferably 8 to 50 nm.
If the volume average particle system is smaller than 8 nm, it is embedded or easily embedded in the toner base surface due to external stress, and if it exceeds 150 nm, the tendency to detach from the toner particle surface increases, or Problems such as scratches and chipping at the cleaning blade may occur.
Such a volume average particle diameter is obtained as follows.
300 SEM images of silica particles obtained by FE-SEM (S-4200) manufactured by Hitachi, Ltd. were randomly sampled, and the image information was sent to an image analysis device (manufactured by Nireco Corporation, (Luzex AP) and can be obtained by analysis.
The conductive glass particles used in the electrophotographic toner of the present invention are preferably composed of a composition containing at least vanadium oxide.

The conductive glass particles are produced, for example, as follows.
First, in addition to vanadium oxide, a mixture containing, for example, barium oxide, iron oxide, potassium oxide, magnesium oxide, phosphorus oxide and the like is prepared. This mixture is heated to the melting point temperature or higher to melt and then rapidly cooled to obtain a glass composition. Next, the conductive glass particles can be obtained by pulverizing the conductive glass.
The conductive glass particles can be obtained, for example, after being roughly pulverized, using a pulverizer such as (Nanojet Mill NJ-100: manufactured by Deoksugaku Kosakusho).

  The fact that the conductive glass used in the present invention is a glass material can be understood from the fact that there are few peaks based on the crystal phase using, for example, the X-ray diffraction method.

The electrical conductivity of the conductive glass is measured by using a glass piece having a glass composition A sample thickness of 1 mm or less, a DC two-terminal method or a DC four-terminal method, and an electrical conductivity value of 1 ×. In the case of 10 ^<-5 > S * cm ^<-1 > or more, it can obtain | require by the value in room temperature using the alternating current four terminal method. By such measurement, for example, the electrical resistance value of the conductive glass used in the electrophotographic toner of the present invention is preferably in the range of 5.0 × 10 ^{7 to} 1.1 × 10 ⁶ Ωcm. Any glass may be used as long as it falls within this range, but in the present invention, conductive glass containing vanadium is particularly preferable.

(Developer)
The developer of the present invention may be either a one-component developer composed of the electrophotographic toner of the present invention or a two-component developer composed of the toner of the present invention and a carrier. When used in a high-speed printer or the like corresponding to an improvement in information processing speed, it is preferable to use a two-component developer from the viewpoint of life. The mixing ratio of the toner and the carrier in the two-component developer is preferably 1 to 10 parts by weight of the toner with respect to 100 parts by weight of the carrier.

  When the toner of the present invention is used as a one-component developer, even if the balance of the toner is performed, there is little fluctuation in the particle size of the toner, the filming of the toner on the developing roller, and a blade for thinning the toner The toner is not fused to a member such as the above, and good and stable developability and an image can be obtained even with stirring by long-term use of the developing device. In addition, when the toner of the present invention is used as a two-component developer, even if the balance of the toner for a long time is performed as in the case of the one-component developer, the toner particle size in the developer is small, and the long-term in the developing device In this stirring, good and stable developability can be obtained.

  When used as a two-component developer, the carrier to be used is not particularly limited and can be appropriately selected according to the purpose, but preferably has a core material and a resin layer covering the core material. .

  The core material is not particularly limited and can be appropriately selected from known materials. For example, 50 to 90 emu / g manganese-strontium (Mn-Sr) -based material, manganese-magnesium (Mn-Mg) A high-magnetization material such as iron powder (100 emu / g or more) and magnetite (75 to 120 emu / g) is preferable from the viewpoint of securing image density. In addition, charging due to friction with the carrier can weaken the mechanical impact and scratching performance that hits the photoconductor when developing with toner in which the toner is in a so-called spiked state on the carrier. A weakly magnetized material such as a copper-zinc (Cu—Zn) -based (30 to 80 emu / g) is preferable in terms of image quality. These can be used individually or in mixture of 2 or more types.

  The weight average particle diameter of the core material is preferably 10 to 200 μm, and more preferably 40 to 100 μm. When the weight average particle diameter is less than 10 μm, the fine powder component of the carrier increases, and the magnetization per particle may be lowered and carrier scattering may occur. When the weight average particle diameter exceeds 200 μm, the specific surface area decreases, and the toner May occur, and the reproducibility of the solid portion may be deteriorated particularly in a full color having many solid portions.

  The material of the resin layer covering the core material is not particularly limited and can be appropriately selected from known resins according to the purpose. For example, amino resin, polyvinyl resin, polystyrene resin, halogenated resin Olefin resin, polyester resin, polycarbonate resin, polyethylene, polyvinyl fluoride, polyvinylidene fluoride, polytrifluoroethylene, polyhexafluoropropylene, copolymer of vinylidene fluoride and acrylic monomer, vinylidene fluoride and fluoride Copolymers with vinyl, fluoroterpolymers such as terpolymers of tetrafluoroethylene, vinylidene fluoride, and non-fluorinated monomers, silicone resins, etc. may be mentioned, and these may be used alone or in combination of two or more. it can.

  Examples of the amino resin include urea-formaldehyde resin, melamine resin, benzoguanamine resin, urea resin, polyamide resin, and epoxy resin. Examples of the polyvinyl resin include acrylic resin, polymethyl methacrylate, polyacrylonitrile, polyvinyl acetate, polyvinyl alcohol, and polyvinyl butyral. Examples of the polystyrene resin include polystyrene and styrene-acrylic copolymer. Examples of the halogenated olefin resin include polyvinyl chloride. Examples of the polyester-based resin include polyethylene terephthalate and polybutylene terephthalate.

  If necessary, conductive powder or the like may be added to the resin layer covering the core material. Examples of the conductive powder include metal powder, carbon black, titanium oxide, tin oxide, and zinc oxide. The average particle size of the conductive powder is preferably 1 μm or less. When the average particle size exceeds 1 μm, it may be difficult to control the electric resistance.

  The resin layer covering the core material is prepared by, for example, preparing a coating liquid by dissolving a silicone resin or the like in a solvent, and then uniformly applying the coating liquid to the surface of the core material by a known coating method, followed by drying. It can be formed by baking. Examples of the application method include a dipping method, a spray method, and a brush coating method.

  The solvent used for the preparation of the coating solution is not particularly limited and may be appropriately selected depending on the intended purpose. Examples thereof include toluene, xylene, methyl ethyl ketone, methyl isobutyl ketone, methyl cellosolve, and butyl acetate.

  The baking is not particularly limited, and may be either an external heating method or an internal heating method. For example, a method using a fixed electric furnace, a fluid electric furnace, a rotary electric furnace, a burner furnace, or the like, Examples include a method using waves.

  The content of the resin layer in the carrier is preferably 0.01 to 5.0% by weight. If the content is less than 0.01% by weight, the resin layer may not be uniformly formed on the surface of the core material. If the content exceeds 5.0% by weight, the resin layer becomes too thick and the carriers are May generate a carrier larger than a predetermined range of particle diameter.

  The image forming apparatus used in the present invention includes at least a photoconductor, a charging device, an exposure device, a developing device, and a transfer device, and other means appropriately selected as necessary, for example, a fixing device, a charge eliminating device, and a cleaning device. You may further have an apparatus, a recycling apparatus, a control apparatus, etc.

(Image forming method)
The image forming method of the present invention is carried out using the above-described image forming apparatus, and has at least an electrostatic latent image forming step, a developing step, and a transfer step, and other appropriately selected as necessary. You may further have a process, for example, a fixing process, a static elimination process, a cleaning process, a recycling process, a control process, etc.

  The electrostatic latent image forming step is a step of forming an electrostatic latent image on the photoreceptor. The electrostatic latent image is formed, for example, by charging the surface of the photosensitive member uniformly by applying a voltage using a charging device and then exposing it like an image using an exposure device. Can do.

  The material, shape, structure, size and the like of the photoreceptor are not particularly limited and can be appropriately selected from known ones, but the shape is preferably a drum shape. Examples of the photoconductor include inorganic photoconductors such as amorphous silicon and selenium, and organic photoconductors (OPC: Organic Photo-Conductor) such as polysilane and phthalopolymethine. In terms of long life, the photoconductor is amorphous. A silicon photoreceptor is preferred but not particularly limited.

  The charging device is not particularly limited and can be appropriately selected depending on the purpose. For example, a known contact charger including a conductive or semiconductive roll, brush, film, rubber blade, Examples thereof include a non-contact charger using corona discharge such as corotron and scorotron. The charging device is preferably arranged in contact or non-contact with the photoreceptor, and charges the surface of the photoreceptor by applying a DC voltage and an AC voltage in a superimposed manner. The charging device is a charging roller that is disposed in close proximity to the photoconductor via a gap tape, and charges the surface of the photoconductor by applying a DC voltage and an AC voltage superimposed on the charging roller. Those that do are preferred.

  The exposure apparatus is not particularly limited as long as it can image-wise expose the surface of the photoreceptor charged by the charging apparatus, and can be appropriately selected according to the purpose. Examples thereof include a rod lens array system, a laser optical system, and a liquid crystal shutter optical system. In addition, you may employ | adopt the light back system which performs imagewise exposure from the back surface side of a photoreceptor.

The developing step is a step of forming a visible image by developing the electrostatic latent image with the developer of the present invention using a developing device.
The developing device used in this developing step is not particularly limited as long as it can be developed using the developer of the present invention, and can be appropriately selected from known ones. For example, the developer containing the developer according to the present invention and having at least a developer carrier capable of bringing the developer into contact or non-contact with the electrostatic latent image may be mentioned, and the container containing the developer is detachably provided. It is preferable. The developing device used in the present invention may be either a dry developing method or a wet developing method, and may be either a single color developing device or a multicolor developing device. For example, a stirrer for charging the developer by frictional stirring and a rotatable magnet roller may be used. In the developing device, for example, the toner and the carrier are mixed and stirred, and the toner is charged by friction at that time, and held on the surface of the rotating magnet roller in a raised state to form a magnetic brush. Since the magnet roller is disposed in the vicinity of the photoconductor, a part of the toner constituting the magnetic brush formed on the surface of the magnet roller moves to the surface of the photoconductor by an electric attractive force. As a result, the electrostatic latent image is developed with toner, and a visible image is formed on the surface of the photoreceptor. Note that an alternating electric field is preferably applied when the toner is moved to the surface of the photoreceptor.

  The transfer process is a process in which a visible image is transferred to a transfer target using a transfer device. After the primary transfer of the visible image onto the intermediate transfer member using the intermediate transfer member, the visible image is transferred to the transfer target. A mode in which secondary transfer is performed on a transfer body is preferred. Furthermore, it is preferable that the toner uses two or more colors, preferably a full color toner. The visible image can be transferred by charging the photoconductor using, for example, a transfer charger.

  The transfer device preferably has a primary transfer device that transfers a visible image onto an intermediate transfer member to form a composite transfer image, and a secondary transfer device that transfers the composite transfer image onto a transfer target. The transfer device (primary transfer device, secondary transfer device) preferably has at least a transfer device that peels and charges the visible image formed on the photosensitive member toward the transfer target. There may be one transfer device or two or more transfer devices. Examples of the transfer device include a corona transfer device using corona discharge, a transfer belt, a transfer roller, a pressure transfer roller, and an adhesive transfer device.

The intermediate transfer member is not particularly limited and can be appropriately selected from known transfer members according to the purpose. Examples thereof include a transfer belt.
The transfer target is not particularly limited and can be appropriately selected from known recording media (recording paper).

  The fixing step is a step of fixing the visible image transferred to the transfer target using a fixing device, and may be fixed for each color toner each time it is transferred to the transfer target. The toners may be fixed simultaneously at the same time in a state where the toners are laminated.

  The fixing device is not particularly limited and may be appropriately selected according to the purpose. However, a fixing device that is heat-pressed and fixed using a known fixing member is preferable. The fixing member is preferably in the form of a roller or a belt, and examples thereof include a combination of a heating roller and a pressure roller, and a combination of a heating roller, a pressure roller and an endless belt. At this time, it is preferable that heating temperature is 80-200 degreeC normally.

In the present invention, the fixing device includes a heating body having a heating element, a film in contact with the heating body, and a pressure member in pressure contact with the heating body through the film. It is possible to use means for heating and press-fixing by passing the transfer body on which the received image is formed.
Depending on the purpose, for example, a known optical fixing device may be used together with the fixing device or instead of the fixing device.

The neutralization step is a step of performing neutralization by applying a neutralization bias to the photoconductor using a neutralization device.
The neutralization device is not particularly limited, and may be any one as long as it can apply a neutralization bias to the photosensitive member, and can be appropriately selected from known neutralization devices. Examples thereof include a neutralization lamp.

The cleaning step is a step of removing toner remaining on the photoreceptor using a cleaning device.
The cleaning device is not particularly limited as long as the toner remaining on the photoreceptor can be removed by cleaning, and can be appropriately selected from known cleaners. Examples thereof include a magnetic brush cleaner, an electrostatic brush cleaner, a magnetic roller cleaner, a blade cleaner, a brush cleaner, and a web cleaner.

The recycling process is a process in which the toner removed in the cleaning process is recycled to the developing device using a recycling apparatus.
There is no restriction | limiting in particular in a recycling apparatus, For example, a well-known conveyance means etc. are mentioned.

A control process is a process of controlling each process using a control device.
The control device is not particularly limited as long as the movement of each step can be controlled, and can be appropriately selected according to the purpose. Examples thereof include devices such as a sequencer and a computer.

(Process cartridge)
The process cartridge of the present invention has at least a photosensitive member, which is a latent image carrier on which an electrostatic latent image is formed, and a developing device that develops the electrostatic latent image formed on the latent image carrier. The image forming apparatus main body is supported and can be attached to and detached from the image forming apparatus main body, and the developing device develops using the developer described above. It should be noted that the process cartridge of the present invention may further support other means appropriately selected as needed.

  FIG. 1 shows an example of the process cartridge of the present invention. The process cartridge includes the photosensitive member 10 and has at least a developing device 40. The process cartridge of the present invention may further include at least one selected from the charging device 20, the exposure device 30, the cleaning device 60, and the transfer device 80. Each of these devices can be the same as those used in an image forming apparatus described later.

  Hereinafter, the present invention will be described in more detail with reference to examples. In addition, this invention is limited to a following example and is not interpreted. Moreover, the part and% used below are a weight basis, ie, a weight part and weight%.

(Development of developer)
~ Synthesis of fine particle dispersion ~
In a reaction vessel in which a stir bar and a thermometer were set, 683 parts of water, 11 parts of sodium salt Eleminol RS-30 (manufactured by Sanyo Chemical Industries), ethylene oxide methacrylate adduct sulfate, 83 parts of styrene, 83 parts of methacrylic acid, When 110 parts of butyl acrylate and 1 part of ammonium persulfate were added and stirred at 400 rpm for 15 minutes, a white emulsion was obtained. This was heated to raise the temperature in the system to 75 ° C. and reacted for 5 hours. Further, 30 parts of a 1% ammonium persulfate aqueous solution was added, and the mixture was aged at 75 ° C. for 5 hours, and an aqueous vinyl resin (a copolymer of styrene-methacrylic acid-butyl acrylate-methacrylic acid ethylene oxide adduct sulfate sodium salt). A dispersion [fine particle dispersion 1] was obtained. The weight average particle diameter of this [fine particle dispersion 1] measured by LA-920 was 105 nm. A portion of [Fine Particle Dispersion 1] was dried to isolate the resin component. The Tg of the resin component was 59 ° C., and the weight average molecular weight was 150,000.

-Adjustment of aqueous phase-
990 parts of water, 83 parts of [fine particle dispersion 1], 37 parts of 48.5% aqueous solution of sodium dodecyl diphenyl ether disulfonate, Eleminol MON-7 (manufactured by Sanyo Chemical Industries), and 90 parts of ethyl acetate were mixed and stirred to give a milky white liquid. Got. This is designated as [Aqueous Phase 1].

~ Synthesis of low molecular weight polyester ~
229 parts of bisphenol A ethylene oxide 2-mole adduct, 529 parts of bisphenol A propylene oxide 3-mole adduct, 208 parts of terephthalic acid, 46 parts of adipic acid and dibutyltin in a reaction vessel equipped with a condenser, stirrer and nitrogen inlet tube Add 2 parts of oxide, react at normal pressure and 230 ° C for 8 hours, and further react for 5 hours under reduced pressure of 10 to 15 mmHg, then add 44 parts of trimellitic anhydride to the reaction vessel at 180 ° C and normal pressure. The mixture was reacted for 2 hours to obtain [Low molecular weight polyester 1]. [Low molecular polyester 1] had a number average molecular weight of 2500, a weight average molecular weight of 6700, a Tg of 43 ° C., and an acid value of 25 mgKOH / g.

~ Synthesis of intermediate polyester and prepolymer ~
In a reaction vessel equipped with a cooling pipe, a stirrer and a nitrogen introduction pipe, 682 parts of bisphenol A ethylene oxide 2-mole adduct, 81 parts of bisphenol A propylene oxide 2-mole adduct, 283 parts of terephthalic acid, trimellitic anhydride 22 parts of acid and 2 parts of dibutyltin oxide were added, reacted at normal pressure and 230 ° C. for 8 hours, and further reacted at reduced pressure of 10 to 15 mmHg for 5 hours to obtain [Intermediate Polyester 1]. [Intermediate Polyester 1] had a number average molecular weight of 2,100, a weight average molecular weight of 9,500, Tg of 55 ° C., an acid value of 0.5 mgKOH / g, and a hydroxyl value of 51 mgKOH / g. Next, 410 parts of [Intermediate polyester 1], 89 parts of isophorone diisocyanate, and 500 parts of ethyl acetate are placed in a reaction vessel equipped with a cooling pipe, a stirrer, and a nitrogen introduction pipe, and reacted at 100 ° C. for 5 hours. [Prepolymer 1] was obtained. [Prepolymer 1] had a free isocyanate weight% of 1.53%.

~ Synthesis of ketimine ~
In a reaction vessel equipped with a stirrer and a thermometer, 170 parts of isophoronediamine and 75 parts of methyl ethyl ketone were charged and reacted at 50 ° C. for 5 hours to obtain [ketimine compound 1]. The amine value of [ketimine compound 1] was 418 mgKOH / g.

~ Master batch synthesis ~
35 parts of water, 40 parts of phthalocyanine pigment FG7351 (manufactured by Toyo Ink Co., Ltd.) and 60 parts of polyester resin RS801 (manufactured by Sanyo Kasei Co., Ltd.) are mixed with a Henschel mixer (manufactured by Mitsui Mining Co., Ltd.), and the mixture is 150 using two rolls. After kneading at 30 ° C. for 30 minutes, the mixture was cooled and rolled, and pulverized with a pulverizer to obtain [Masterbatch 1].

~ Creation of oil phase ~
In a container equipped with a stirrer and a thermometer, 378 parts of [Low molecular polyester 1], 110 parts of carnauba wax, 22 parts of CCA (salicylic acid metal complex) E-84 (manufactured by Orient Chemical Co., Ltd.), 947 parts of ethyl acetate The mixture was charged, heated to 80 ° C. with stirring, kept at 80 ° C. for 5 hours, and then cooled to 30 ° C. in 1 hour. Next, 500 parts of [Masterbatch 1] and 500 parts of ethyl acetate were charged in a container and mixed for 1 hour to obtain [Raw material solution 1].

  [Raw material solution 1] 1324 parts are transferred to a container, and using a bead mill, Ultra Visco Mill (manufactured by Imex), zirconia beads having a liquid feeding speed of 1 kg / hour, a disk peripheral speed of 6 m / second, and a particle diameter of 0.5 mm. The carbon black and the wax were dispersed under the condition of 3 passes. Next, 1324 parts of a 65% ethyl acetate solution of [low molecular weight polyester 1] was added, followed by one pass with a bead mill under the above conditions to obtain [Pigment / Wax Dispersion 1]. The solid content concentration of [Pigment / Wax Dispersion 1] (measurement conditions: 130 ° C., 30 minutes) was 50%.

~ Emulsification ~
[Pigment / Wax Dispersion 1] 648 parts, [Prepolymer 1] 154 parts, [Ketimine Compound 1] 6.6 parts are put in a container, and mixed for 1 minute at 5000 rpm with a TK homomixer (manufactured by Tokushu Kika). After that, 1200 parts of [Aqueous phase 1] was added to the container and mixed with a TK homomixer at 13000 rpm for 20 minutes to obtain [Emulsified slurry 1].

~ Shape control ~
While 18 parts of ion-exchanged water are being stirred at 2,000 rpm with a TK homomixer (manufactured by Tokushu Kika), 0.75 part of Serogen BS-H (Daiichi Kogyo Seiyaku Co., Ltd.) is added little by little. Stir for 30 minutes while maintaining the addition at 20 ° C. In the obtained serogen solution, 725 parts of ion-exchanged water, 58 parts of [fine particle dispersion 1], 48.5% aqueous solution of sodium dodecyl diphenyl ether disulfonate (Eleminol MON-7: Sanyo Chemical Industries) 147 parts, ethyl acetate 90 parts were mixed and stirred to obtain a milky white liquid. This is designated as [Aqueous Phase 1].

  3. Selogen BS-H (Daiichi Kogyo Seiyaku Co., Ltd.) 3.15 parts was added little by little to 75.6 parts of ion-exchanged water being stirred at 2,000 rpm with a TK homomixer (made by Tokushu Kika). did. The addition was completed and the mixture was stirred for 30 minutes while maintaining at 20 ° C. 43.3 parts of 48.5% aqueous solution of sodium dodecyl diphenyl ether disulfonate (Eleminol MON-7: manufactured by Sanyo Kasei Kogyo Co., Ltd.) was added to the obtained serogen solution, and the mixture was stirred for 5 minutes while maintaining at 20 ° C. In this, 2000 parts of [Emulsion slurry 1] was added and mixed with a TK homomixer at 2,000 rpm for 1 hour to obtain [Shape Control Slurry 1].

~ Solvent removal ~
[Shape control slurry 1] was put into a container equipped with a stirrer and a thermometer, and after removing the solvent at 30 ° C. for 8 hours, aging was carried out at 45 ° C. for 4 hours to obtain [Dispersion slurry 1].

~ Washing⇒Drying ~
[Dispersion Slurry 1] After filtering 100 parts under reduced pressure,
(1) 100 parts of ion-exchanged water was added to the filter cake, mixed with a TK homomixer (12000 rpm for 10 minutes), and then filtered.
(2) 100 parts of a 10% sodium hydroxide aqueous solution was added to the filter cake of (1), mixed with a TK homomixer (30 minutes at 12000 rpm), and then filtered under reduced pressure.
(3) 100 parts of 10% hydrochloric acid was added to the filter cake of (2), mixed with a TK homomixer (12000 rpm for 10 minutes), and then filtered.
(4) 300 parts of ion-exchanged water was added to the filter cake of (3), mixed with a TK homomixer (10 minutes at 12000 rpm), and then filtered twice to obtain [Filter cake 1].
Using a circulating dryer, [Filtration cake 1] was dried at 45 ° C. for 48 hours and sieved with a mesh of 75 μm to obtain [Toner base particle A].

Preparation of toner base particles by pulverization method Binder resin (bisphenol-type polyester resin mainly composed of bisphenol A ethylene oxide adduct and terephthalic acid (weight average molecular weight = 1.1 × 10 ⁴ , number average molecular weight = 3.9) × 10 ³ , η (140 ° C.) = 90 Pa · s, 100 parts by mass of glass transition temperature (Tg) = 69 ° C., high melt viscosity resin (terpene-modified novolak resin, weight average molecular weight = 2500, Tm = 165 ° C., η (140 ° C.) = 85,000 Pa · s) 20 parts by mass, carbon black (trade name BPL: manufactured by Cabot) 5 parts by mass, charge control agent (trade name: Bontron E84, manufactured by Orient Chemical Co.), 2 parts by mass, and low 5 parts by mass of molecular weight polypropylene (trade name viscose 660P, manufactured by Sanyo Chemical Industries) was charged into an air-cooled two-roll mill, After charging, the mixture was melt-kneaded for 15 minutes, cooled, finely pulverized with a jet mill, and classified with an air classifier to obtain “toner base particle B” having a volume average particle diameter of 6 μm.

[Production of conductive glass particles]
Conductive glass particles are produced as follows. First, a mixture containing a predetermined amount of vanadium oxide, barium oxide, and iron oxide is prepared. The mixture is heated to its melting point or higher and melted, and then quenched with, for example, ice water to obtain a glass composition. Next, a conductive glass having a predetermined electrical conductivity can be obtained by holding this glass composition at a temperature of an annealing treatment not lower than the glass transition temperature but not higher than the crystallization temperature for a predetermined time. By pulverizing the conductive glass, conductive glass particles can be obtained.

In order to obtain 50 g of raw material mixture A, the following operation was performed.
BaO: 6.6 g, V ₂ O ₅ : 36.53 g and Fe ₂ O ₃ : 6.875 g of powder were accurately measured, and a mixed powder in which each material was mixed well in advance was put in a platinum crucible and heated at 1000 ° C. for 1 hour. Heating and melting were performed. The heated melt thus obtained was quenched with ice water to obtain a raw material mixture A.

  The raw material mixture A was placed in an electric furnace heated to 370 ° C., and 60 min. Removed after heating. The heat-treated raw material mixture thus obtained is wrapped with a cloth, coarsely pulverized with a hammer or the like, and then finely pulverized with a scramjet pulverizer (RM400) manufactured by Deoksugaku Kosakusho. Conductive glass fine particles A having a number average diameter of 35 nm Got.

  Similarly, the raw material mixture A was placed in an electric furnace heated to 370 ° C., heated for 90 minutes, taken out, and rapidly cooled with ice water. The heat-treated raw material mixture thus obtained is wrapped with a cloth, coarsely pulverized with a hammer or the like, and then finely pulverized with a scramjet pulverizer (RM400) manufactured by Deoksugaku Kosakusho. Conductive glass fine particles B having a number average diameter of 28 nm Got.

  The raw material mixture A was placed in an electric furnace heated to 370 ° C., heated for 120 minutes, taken out, and rapidly cooled with ice water. The heat-treated raw material mixture thus obtained is wrapped with a cloth, coarsely pulverized with a hammer or the like, and then finely pulverized with a scramjet pulverizer (RM400) manufactured by Deoksugaku Kosakusho. Conductive glass fine particles C having a number average diameter of 18 nm are obtained. Got.

  The raw material mixture A was placed in an electric furnace heated to 370 ° C., heated for 180 minutes, taken out, and rapidly cooled with ice water. The heat-treated raw material mixture thus obtained is wrapped with a cloth, coarsely pulverized with a hammer or the like, and then finely pulverized with a scramjet pulverizer (RM400) manufactured by Deoksugaku Kosakusho. Conductive glass fine particles D having a number average diameter of 8 nm are obtained. Got.

Preparation of developer Carrier used for preparation of developer and measurement of toner charge amount is 200 parts of silicone resin solution (trade name “KR-9706” manufactured by Shin-Etsu Chemical Co., Ltd.) with respect to 2500 parts of ferrite core material, carbon A coating liquid in which 3 parts of black (Mitsubishi Chemical Co., Ltd .: trade name # 25) is dispersed in toluene is applied by a fluidized bed spray method, and the surface of the core material is coated, and then an electric furnace at 300 ° C. It was prepared by firing for 2 hours. A carrier having a relatively sharp particle size distribution and an average particle size of 30 to 60 μm was used.

Example 1
First, 100 parts of (toner base particle A) and 0.5 part of (conductive glass fine particles A) having a number average diameter of 35 nm are mixed with a Henschel mixer under the condition that the peripheral speed of the stirring blade is 20 m / sec. [Toner A] was prepared by mixing 0.8 parts of hexamethyldisilazane-treated hydrophobic silica having a diameter of 8 nm with a Henschel mixer under the condition that the peripheral speed of the stirring blade was 35 m / sec.

(Example 2)
First, 100 parts of (toner base particle A) and 0.85 part of (conductive glass fine particle B) having a number average diameter of 28 nm are mixed with a Henschel mixer under the condition that the peripheral speed of the stirring blade is 20 m / sec. [Toner B] was prepared by mixing 1.0 part of hydrophobic silica treated with hexamethyldisilazane having a diameter of 12 nm with a Henschel mixer under the condition that the peripheral speed of the stirring blade was 35 m / sec.

(Example 3)
First, 100 parts of (toner base particle A) and 1.0 part of (conductive glass fine particles C) having a number average diameter of 18 nm are mixed with a Henschel mixer under the condition that the peripheral speed of the stirring blade is 20 m / sec. [Toner C] was prepared by mixing 1.2 parts of hexamethyldisilazane-treated hydrophobic silica having a particle size of 20 nm with a Henschel mixer under conditions where the peripheral speed of the stirring blade was 35 m / sec.

Example 4
First, 100 parts of (toner base particle A) and 1.2 parts of (conductive glass fine particles D) having a number average diameter of 8 nm are mixed with a Henschel mixer under the condition that the peripheral speed of the stirring blade is 20 m / sec. [Toner D] was prepared by mixing 0.8 parts of hydrophobic silica treated with hexamethyldisilazane having a particle size of 12 nm using a Henschel mixer under conditions where the peripheral speed of the stirring blade was 35 m / sec.

(Example 5)
First, 100 parts of (toner base particle B) and 0.5 part of (conductive glass fine particles A) having a number average diameter of 35 nm are mixed with a Henschel mixer under the condition that the peripheral speed of the stirring blade is 20 m / sec. [Toner I] was prepared by mixing 0.8 parts of hexamethyldisilazane-treated hydrophobic silica having a particle diameter of 8 nm with a Henschel mixer under the condition that the peripheral speed of the stirring blade was 35 m / sec.

(Example 6)
First, 100 parts of (toner base particles B) and 1.2 parts of (conductive glass fine particles B) having a number average diameter of 8 nm are mixed with a Henschel mixer under the condition that the peripheral speed of the stirring blade is 20 m / sec. [Toner J] was prepared by mixing 1.2 parts of hexamethyldisilazane-treated hydrophobic silica having a particle size of 12 nm with a Henschel mixer under conditions where the peripheral speed of the stirring blade was 35 m / sec.

(Comparative Example 1)
First, 100 parts of (toner base particle A) and 0.75 part of rutile titanium oxide having an average particle diameter of 15 nm are mixed with a Henschel mixer under the condition that the peripheral speed of the stirring blade is 20 m / sec. [Toner E] was prepared by mixing 0.8 parts of 8 nm hexamethyldisilazane-treated hydrophobic silica with a Henschel mixer under conditions where the peripheral speed of the stirring blade was 35 m / sec.

(Comparative Example 2)
(Toner base particle A) 100 parts and 1.0 part of hexamethyldisilazane-treated hydrophobic silica having an average particle diameter of 20 nm were mixed with a Henschel mixer under the condition that the peripheral speed of the stirring blade was 35 m / second. Thus, [Toner F] was produced.

(Comparative Example 3)
First, 100 parts of (toner base particle A) and 0.75 part of rutile titanium oxide having an average particle diameter of 15 nm are mixed with a Henschel mixer under the condition that the peripheral speed of the stirring blade is 20 m / sec. [Toner G] was prepared by mixing 1.2 parts of 12 nm hexamethyldisilazane-treated hydrophobic silica with a Henschel mixer under conditions where the peripheral speed of the stirring blade was 35 m / sec.

(Comparative Example 4)
First, 100 parts of (toner base particle A) and 1.0 part of rutile titanium oxide having an average particle diameter of 15 nm are mixed with a Henschel mixer under the condition that the peripheral speed of the stirring blade is 20 m / sec. [Toner H] was prepared by mixing 0.8 parts of 8 nm hexamethyldisilazane-treated hydrophobic silica with a Henschel mixer under conditions where the peripheral speed of the stirring blade was 35 m / sec.

(Comparative Example 5)
First, 100 parts of (toner base particle B) and 0.75 part of rutile type titanium oxide having an average particle diameter of 15 nm are mixed with a Henschel mixer under the condition that the peripheral speed of the stirring blade is 20 m / sec. [Toner K] was prepared by mixing 0.8 parts of 12 nm hexamethyldisilazane-treated hydrophobic silica with a Henschel mixer under conditions where the peripheral speed of the stirring blade was 35 m / sec.

(Comparative Example 6)
(Toner base particles B) 100 parts and 1.0 part of hexamethyldisilazane-treated hydrophobic silica having an average particle diameter of 20 nm were mixed with a Henschel mixer under the condition that the peripheral speed of the stirring blade was 35 m / second. [Toner L] was prepared.

  Examples 1 to 6 (A to D and I to J in Table 1 below) and Comparative Examples 1 to 6 (E to H and K to L in Table 1 below) are external additives as shown in Table 1 below. Were added to prepare toners A to L.

(Image forming device)
The form of the image forming apparatus used in the following evaluation will be described.
A charging roller for charging a uniform charge on the photosensitive drum in proximity to or in contact with the periphery of the photosensitive drum as an image carrier, and an exposure unit for forming an electrostatic latent image on the photosensitive drum. An exposure device, a developing device that visualizes an electrostatic latent image into a toner image, a transfer belt that transfers the toner image onto transfer paper, a cleaning device that removes residual toner on the photosensitive drum, and a residual charge on the photosensitive drum There are disposed a static elimination lamp for eliminating static electricity, a photosensor for controlling the voltage applied by the charging roller and the toner concentration of the developer. Further, the toner of the embodiment or the comparative example is supplied to the developing device from the toner supply device through the toner supply port. The image forming method is performed as follows. The photosensitive drum rotates counterclockwise. The photosensitive drum is neutralized by neutralizing light, and the surface potential is averaged to a reference potential of 0 to -150V. Next, it is charged by the charging roller, and the surface potential becomes around -1000V. Next, the surface potential of the portion (image portion) that is exposed by the exposure apparatus and irradiated with light is 0 to −200V. The toner on the sleeve adheres to the image portion by the developing device. The photosensitive drum on which the toner image is made rotates and moves, and the transfer paper is fed from the paper feeding unit at a timing such that the leading edge of the paper and the leading edge of the image coincide with each other on the transfer belt. The toner image on the surface is transferred to the transfer paper. Thereafter, the transfer paper is sent to the fixing unit, and the toner is fused to the transfer paper by heat and pressure and discharged as a copy. Residual toner remaining on the photosensitive drum is scraped off by a cleaning blade in the cleaning device, and then the residual charge is neutralized by the neutralizing light, and the photosensitive drum is in an initial state without toner, and the next image formation is performed again. Move to the image forming process by the method.

(Evaluation item)
In the above image forming apparatus, the following items were evaluated using the toners and developers of Examples and Comparative Examples.
(1) Cleaning performance Cleaning performance is as follows. In an experimental room at 10 ° C. and humidity 15% RH, an image forming apparatus (manufactured by Ricoh Co., Ltd.) is used to pass 5000 sheets, and then a blank image is stopped during the passing of paper. The transfer residual toner on the photosensitive member that has passed the cleaning process is transferred to a white paper with a scotch tape (manufactured by Sumitomo 3M), and measured with a Macbeth reflection densitometer RD514 type. Quantitative evaluation was made with a good one as ◯, 0.01 to 0.02 which was not good cleaning property but an acceptable one was Δ, and a thing exceeding 0.02 was poor in cleaning property as x.

(2) Image Quality Image quality was comprehensively determined as degradation of image quality after the paper was passed (specifically, transfer failure and generation of a background image). The transfer failure was judged by passing 5000 sheets through an image forming apparatus (manufactured by Ricoh Co., Ltd.) and then passing a black solid image and visually ranking the transfer failure level of the image. For the background image, 5000 sheets are passed through an image forming apparatus (manufactured by Ricoh Co., Ltd.), and then a blank paper image is stopped during development, and the developer on the photoconductor after development is scotch tape (Sumitomo). 3M)), and the difference from the image density of the untransferred tape is measured by a spectrodensitometer (X-Rite) and quantitatively evaluated. If the difference is less than 0.30, A product having a value of 0.30 or more was regarded as defective. These two were evaluated as good when the image quality was good, ◯ when the image quality was not good but acceptable, and x when the image quality was poor.

(3) Photoreceptor scratch 100,000 sheets of 4% density A4 images were printed with an image forming apparatus (manufactured by Ricoh Co., Ltd.), and the occurrence of the photoconductor scratch was evaluated. ○ that there is no scratch or scratches that are very fine and very good, that there are some scratches, but that are within the acceptable range without appearing in the image, and that those that appear in the image or have unrecoverable scratches × As judged.
The evaluation results are shown in Table 2.

(4) Evaluation of charging stability To the carrier prepared by the above method, the toner to be charged is mixed, weighed so that the toner concentration becomes 7%, and stirred and mixed for 5 minutes with a ball mill to obtain an electrostatic charge. An image developer was prepared. The developer thus prepared was conditioned all day and night in an environment of 23 ° C. and a humidity of 55% RH in a normal temperature environment, and in a high temperature and high humidity environment of 35 ° C. and a humidity of 85% RH.
Each developer thus conditioned is stirred again with a ball mill for one minute, and the charge amount after humidity adjustment is measured with a blow-off charge measuring device (TB-200 type manufactured by Toshiba Chemical Corporation). As the charge amount QH at high humidity and the charge amount QN at normal temperature and normal humidity, the stability of the charge amount against the difference in environmental conditions was evaluated using the following formula.

Formula: Qst value = | 1-((QH / N) | × 100
According to the above formula, the Qst value was evaluated as 20 or less as ◯, 20 or more and 40 or less as Δ, and 41 or more as ×.
The evaluation results are shown in Table 2.

  As shown in Table 2, by mixing conductive glass particles that satisfy certain conditions into the toner, the difference in the amount of charge that has occurred greatly under the environmental conditions that have been considered as a problem in the electrophotographic process has been heretofore known. Compared with metal oxides such as titanium oxide, which can be effectively suppressed and used to suppress the difference in charge amount under conventional environmental conditions, scratches generated on the surface of the photoreceptor due to addition are reduced. It turns out that generation | occurrence | production can be suppressed effectively.

DESCRIPTION OF SYMBOLS 10 Photoconductor 20 Charging apparatus 30 Exposure apparatus 40 Development apparatus 60 Cleaning apparatus 80 Transfer apparatus

JP2007-248911 JP2007-156099 JP2007-279702

Claims (15)

  An electrophotographic toner comprising: base particles containing a binder resin, a colorant and a releasing agent; and an external additive containing conductive glass particles. 2. The electrophotographic toner according to claim 1, wherein an electric resistance value of the conductive glass is in a range of 1.1 × 10 ^{6 to} 5.0 × 10 ⁷ Ωcm.   The toner for electrophotography according to claim 1, wherein the conductive glass has a particle size of 8 to 50 nm.   The electrophotographic toner according to claim 1, wherein the conductive glass particles are composed of a composition containing at least vanadium oxide.   The toner for electrophotography according to claim 1, wherein the external additive contains one or more kinds of materials. The electrophotographic toner according to claim 1, wherein the external additive contains at least one material having a BET specific surface area of 20 m ² / g or more and 300 m ² / g or less.   The external additive excluding the conductive glass particles is a resin containing at least one of silica, titanium compound, alumina, cerium oxide, calcium carbonate, magnesium carbonate, calcium phosphate or fluorine atom, silicon atom, nitrogen atom as a constituent component The toner for electrophotography according to claim 1, wherein the toner is selected from the group of particles. The electrophotographic toner according to claim 7, wherein the titanium compound is obtained by reacting at least a part of TiO (OH) ₂ produced by a wet method with a silane compound or silicone oil.   The toner for electrophotography according to claim 7 or 8, wherein the titanium compound has a specific gravity of 2.8 or more and 3.6 or less.   The base particles are obtained by dispersing a solution or dispersion obtained by dissolving or dispersing a composition containing a polyester resin capable of reacting with active hydrogen groups in an organic solvent in an aqueous medium containing resin particles. The toner for electrophotography according to claim 1, wherein the toner is obtained by reacting the polyester resin with a compound having an active hydrogen group.   The electrophotographic toner according to claim 1, wherein the base particles are obtained using a pulverization method.   A developer comprising the electrophotographic toner according to claim 1.   The developer according to claim 12, further comprising a carrier.   A step of forming an electrostatic latent image on the latent image carrier, and developing the electrostatic latent image formed on the latent image carrier using the developer according to claim 12 or 13, thereby forming a toner image. An image forming method comprising: a forming step; and a step of transferring the toner image onto a transfer material to form a transfer image.   A developing device that develops the latent image carrier and the electrostatic latent image formed on the latent image carrier using the developer according to claim 12 or 13 at least integrally is supported on the image forming apparatus main body. A process cartridge that is detachable.

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