JP2020144359A - Toner, toner container, developer, developer container, process cartridge, and image forming device - Google Patents

Abstract

To provide a toner which exhibits charge stability and is capable of forming a high-quality image with image graininess and image sharpness.SOLUTION: A toner is provided, comprising inorganic particles containing at least either of boehmite and pseudo-boehmite, and silica.SELECTED DRAWING: None

Description

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

Conventionally, particles having an average primary particle size of several nm to several tens of nm have been used as the inorganic particles of the toner, and are hydrophobized from the viewpoints of imparting chargeability, fluidity, and hydrophobicity. Silica is used. Further, from the viewpoint of maintaining chargeability under temperature and humidity environment conditions and suppressing fluctuations in the retained charge amount, hydrophobized titanium oxide is used.

In recent years, the demand for alternative materials for titanium oxide has been increasing, and for example, alumina, sol-gel silica, strontium titanate, aluminum hydroxide and the like have been studied. Further, a toner that can use aluminum hydroxide has been proposed (see, for example, Patent Document 1).

An object of the present invention is to provide a toner which has charge stability and can form a high-quality image having image graininess and image sharpness.

The toner of the present invention as a means for solving the above-mentioned problems is a toner containing inorganic particles and silica, and the inorganic particles contain at least one of boehmite and pseudo boehmite, and silica.

According to the present invention, it is possible to provide a toner that has charge stability and can form a high-quality image having image graininess and image sharpness.

FIG. 1 is a schematic view showing an example of an image forming apparatus having the process cartridge of the present invention. FIG. 2 is a schematic explanatory view showing an example of the image forming apparatus of the present invention. FIG. 3 is a schematic explanatory view showing another example of the image forming apparatus of the present invention. FIG. 4 is a schematic explanatory view showing an example of using the tandem type color image forming apparatus of the image forming apparatus of the present invention. FIG. 5 is an enlarged view showing an example of the image forming unit of FIG. FIG. 6 is a schematic view showing a charge amount distribution curve of the developer of the present invention.

(toner)
The toner of the present invention is a toner containing inorganic particles, and the inorganic particles contain at least one of boehmite and pseudo boehmite, and silica, and further contain other components as necessary.

The toner of the prior art contains aluminum hydroxide and silica, and boehmite can be used as the aluminum hydroxide, but boehmite is the most preferable, and the toner containing inorganic particles, the inorganic particles are said to be. It is disclosed that by containing at least one of boehmite and pseudo-boehmite, and silica, it is possible to provide a toner capable of forming a high-quality image having charge stability, image granularity and image sharpness. It has not been.

As a result of diligent studies by the present inventors, it has been found that aluminum hydroxide has a potential as a substitute material for titanium oxide due to its low electrical resistance. Aluminum hydroxide has a wide variety of crystal systems and mixed crystal systems such as amorphous, boehmite crystal, pseudo-boehmite crystal, gibbsite crystal, bayarite crystal, and diaspore crystal. Pseudo-boehmite is conventional titanium oxide. It has the effect of suppressing the generation of inversely charged particles in the environment, suppressing the difference in the acquired charge amount depending on the environmental conditions, and sharpening the charge amount distribution. Further, it has been found that since the pseudo-bemite has a low hardness, there is little possibility of damaging the surface of the photoconductor used in the electrophotographic development method, and it satisfies the image quality maintenance function for a long period of time.
Therefore, the toner of the present invention is a toner containing inorganic particles.
By containing at least one of boehmite and pseudo boehmite, and silica, the inorganic particles can adjust the charge amount and the charge characteristics in the environment, have excellent charge stability, and have the same level of image grain as the offset printed image. It is possible to form a high-quality image having characteristics and image sharpness, and it is possible to impart a function equal to or higher than the function of conventional titanium oxide.

The toner of the present invention preferably contains inorganic particles and has toner matrix particles.

<Inorganic particles>
The inorganic particles contain at least one of boehmite and pseudo boehmite, as well as silica, and if necessary, other particles.

<< Boehmite and Pseudo-Boehmite >>
The boehmite and the pseudo boehmite are hydrolysis products of aluminum alkoxide.
The boehmite is an α-type (trigonal) aluminum oxide monohydrate obtained by dehydrating one molecule of water from aluminum hydroxide.
The pseudo-bemite contains more water than the bemite, and both can be distinguished by X-ray diffraction.
Examples of the hydrolysis product of the aluminum alkoxide include aluminum hydroxide. The hydrolysis product may have at least a part of the aluminum alkoxide hydrolyzed, and the entire aluminum alkoxide may be hydrolyzed.

The boehmite and the pseudo boehmite are preferably in the form of particles. Examples of the shape of the particles include a spherical shape, a needle shape, and a non-spherical shape obtained by combining several spherical particles.
The average particle diameter (median diameter) of the boehmite and the pseudo boehmite is preferably 5 nm or more and 135 nm or less, and more preferably 8 nm or more and 120 nm or less.
The median diameters of the boehmite and the pseudo boehmite are measured by using a scanning electron microscope SU8200 series (Hitachi High-Technologies Corporation) with boehmite or pseudo boehmite adhering to the toner surface after external addition. Images were taken at 5 k∨ and a magnification of 50,000 times, and the obtained images were binarized with image processing software A image (manufactured by Asahi Kasei Engineering Co., Ltd.). The diameter of a perfect circle corresponding to the area was calculated from any 1000 pieces of boehmite or pseudo boehmite in the obtained image, and the median diameter was calculated.
By containing the boehmite having a median diameter of 5 nm or more and 135 nm or less and the pseudo boehmite, changes in the amount of charge, fluidity, cohesion, etc. are small, and deterioration of image quality (for example, transfer failure, occurrence of background stain image) Etc.) can be suppressed. Further, when a toner containing pseudo-bemite having a median diameter of 5 nm or more and 135 nm or less is used, image formation with stable image quality can be performed.

The content of the boehmite and the pseudo-boehmite is preferably 0.5 parts by mass or more and 10 parts by mass or less, and more preferably 0.5 parts by mass or more and 2.0 parts by mass or less with respect to 100 parts by mass of the toner base particles.
When the contents of the boehmite and the pseudo boehmite are 0.5 parts by mass or more, the difference in the acquired charge amount in the environment can be reduced. Further, when the content is 1.0 part by mass or less, the difference in the environmental charge amount can be suppressed while suppressing the decrease in charge due to the addition amount.

Examples of the method for producing the boehmite and the pseudo-boehmite include a method in which an aluminum compound is reacted with an alcohol to synthesize an aluminum alkoxide, the synthesized aluminum alkoxide is hydrolyzed, and then dried.

The aluminum compound is not particularly limited and may be appropriately selected depending on the intended purpose. Examples thereof include aluminum and aluminum oxide.

The alcohol is not particularly limited and may be appropriately selected depending on the intended purpose. For example, ethyl alcohol, n-propyl alcohol, n-butyl alcohol, n-pentyl alcohol, n-hexyl alcohol, n-octyl alcohol. , 1-dodecanol, dodecyl alcohol, tridecyl alcohol, oleyl alcohol, stearyl alcohol, 2-decyl alcohol, 2-hexyl alcohol, phenylpropanol, phenylpentanol and the like.

The boehmite and the pseudo boehmite can be analyzed, for example, by confirming the peak position by X-ray diffraction and the absorption band by the infrared absorption spectrum.

From the viewpoint of chargeability and hydrophobicity, the boehmite and the pseudo-bemite are preferably silicon-containing boehmite and silicon-containing pseudo-bemite treated with a silicon compound.

-Silicon-containing boehmite and silicon-containing pseudo-boehmite-
Examples of the silicon-containing boehmite and the silicon-containing pseudo-bemite include boehmite and pseudo-bemite surface-treated with a silicon compound. Examples of the silicon compound include a silane coupling agent and a silicone oil.

The silane coupling agent is not particularly limited and may be appropriately selected depending on the intended purpose. For example, tetramethoxysilane, tetraethoxysilane, methyltrimethoxysilane, methyltriethoxysilane, dimethyldimethoxysilane, dimethyldiethoxy. Alkoxysilanes such as silane, methyldimethoxysilane, methyldiethoxysilane, diphenyldimethoxysilane, isobutyltrimethoxysilane, decyltrimethoxysilane, γ-aminopropyltorethoxysilane, γ-glycidoxypropyltrimethoxysilane, γ- Silane coupling agents such as glycidoxypropylmethyldiethoxysilane, γ-methachloxipropyltrimethoxysilane, γ-mercaptopropyltrimethoxysilane, vinyltriethoxysilane, methylvinyldimethoxysilane, vinyltrichlorosilane, dimethyldichlorosilane, Methylvinyldichlorosilane, methylphenyldichlorosilane, phenyltrichlorosilane, N, N'-bis (trimethylsilyl) urea, N, O-bis (trimethylsilyl) acetamide, dimethyltrimethylsilylamine, hexamethyldisilazane, cyclic silazane, etc. Be done. These may be used alone or in combination of two or more. Of these, hexamethyldisilazane is preferred.

The silicone oil is not particularly limited and may be appropriately selected depending on the intended purpose. For example, dimethyl silicone oil, methylphenyl silicone oil, chlorphenyl silicone oil, methylhydrogen silicone oil, alkyl-modified silicone oil, and 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, methacryl-modified silicone Examples thereof include oil, α-methylstyrene-modified silicone oil, polydimethylsiloxane, methylphenylpolysiloxane, methylhydrogenpolysiloxane, methyltrimethicone, methylsiloxane, and methylphenylsiloxane. These may be used alone or in combination of two or more. Of these, polydimethylsiloxane is preferred.

<< Silica >>
Examples of the silica include hydrophobic silica that has been hydrophobized.
The hydrophobic silica is not particularly limited and may be appropriately selected depending on the intended purpose. Examples thereof include those treated with a silicon compound. Examples of the silicon compound include those used for surface treatment of the boehmite and the pseudo boehmite.

<< Other particles >>
The other particles are not particularly limited and may be appropriately selected depending on the intended purpose. For example, fatty acid metal salts such as zinc stearate and calcium stearate, layered double hydroxides such as hydrotalcite, and titanic acid. Examples include particles such as strontium, zinc oxide, and tin oxide. These may be used alone or in combination of two or more.

<Toner matrix particles>
The toner base particles preferably contain a resin and a colorant, and further contain other components, if necessary.

<< Resin >>
The resin is not particularly limited and may be appropriately selected depending on the intended purpose. For example, homopolymers of styrene such as polystyrene, poly (p-chlorostyrene) and polyvinyltorene and its substitution products, polyester and styrene-. p-chlorostyrene copolymer, styrene-propylene copolymer, styrene-vinyltoluene copolymer, styrene-methyl acrylate copolymer, styrene-ethyl acrylate copolymer, styrene-methacrylate 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 Styrene-based copolymers such as copolymers, styrene-vinylmethylketone copolymers, styrene-butadiene copolymers, styrene-isoprene copolymers, styrene-maleic acid ester copolymers, polymethylmethacrylate, polymethacryl Butyl acid, polyvinyl chloride, polyvinyl acetate, styrene, polyurethane, epoxy resin, polyvinyl butyral, polyacrylic acid, rosin, modified rosin, terpene resin, phenol resin, aliphatic or aromatic hydrocarbon resin, aromatic petroleum resin And so on. These may be used alone or in combination of two or more. Among these, a combination of a polyester resin, a non-crystalline polyester resin and a crystalline polyester resin is preferable.

-Polyester resin-
The polyester resin is a resin obtained by polycondensation of a polyvalent hydroxy compound and a polybasic acid.
Examples of the polyvalent hydroxy compound include glycols such as ethylene glycol, diethylene glycol, triethylene glycol, and propylene glycol; alicyclic compounds containing two hydroxyl groups such as 1,4-bis (hydroxymethyl) cyclohexane; and bisphenol. Examples thereof include divalent phenol compounds such as A. The multivalent hydroxy compound also includes a compound containing three or more hydroxyl groups.

Examples of the polybasic acid include divalent carboxylic acids such as maleic acid, fumaric acid, phthalic acid, isophthalic acid, terephthalic acid, succinic acid and malonic acid; 1,2,4-benzenetricarboxylic acid, 1,2,5. −benzenetricarboxylic acid, 1,2,4-cyclohexanetricarboxylic acid, 1,2,4-naphthalenetricarboxylic acid, 1,2,5-hexanetricarboxylic acid, 1,3-dicarboxy-2-methylenecarboxypropane, 1, Examples thereof include trivalent or higher valent carboxylic acids such as 2,7,8-octanetetracarboxylic acid. These may be used alone or in combination of two or more.

The polyester resin may contain a monomer forming an amide component in addition to the above-mentioned monomer raw material.
Examples of the monomer forming the amide component include polyamines such as ethylenediamine, pentamethylenediamine, hexamethylenediamine, phenylenediamine and triethylenetetramine; aminocarboxylic acids such as 6-aminocaproic acid and ε-caprolactam. These may be used alone or in combination of two or more.
The glass transition temperature (Tg) of the polyester resin is preferably 55 ° C. or higher, more preferably 57 ° C. or higher, from the viewpoint of heat-resistant storage.

-Crystalline polyester resin-
The crystalline polyester resin is a polyester resin obtained by the reaction of an alcohol component and an acid component and having at least a melting point.
The alcohol component is not particularly limited and may be appropriately selected depending on the intended purpose. Examples thereof include saturated aliphatic diol compounds having 2 to 12 carbon atoms.
Examples of the saturated aliphatic diol compound having 2 or more and 12 or less carbon atoms include 1,4-butanediol, 1,6-hexanediol, 1,8-octanediol, 1,10-decanediol, and 1,12-. Dodecanediol, derivatives thereof and the like can be mentioned.

The acid component is not particularly limited and may be appropriately selected depending on the intended purpose. Examples thereof include dicarboxylic acids having 2 or more and 12 or less carbon atoms.
The dicarboxylic acid having 2 or more and 12 or less carbon atoms may be, for example, a saturated dicarboxylic acid or an unsaturated dicarboxylic acid.
Examples of the dicarboxylic acid having 2 or more and 12 or less carbon atoms include fumaric acid, 1,4-butanedioic acid, 1,6-hexanedioic acid, 1,8-octanedioic acid, and 1,10-decanedioic acid. Examples thereof include 1,12-dodecanedioic acid and derivatives thereof. These may be used alone or in combination of two or more.

By using the crystalline polyester resin, for example, the problem of contamination of carriers and charged members by wax existing on the toner surface having toner matrix particles is suppressed while maintaining the releasability function at the time of fixing without deterioration. , Good results are obtained.

The content of the crystalline polyester is preferably 1 part by mass or more and 30 parts by mass or less with respect to 100 parts by mass of the toner base particles. If the content is less than 1 part by mass, the low temperature fixing effect may not be sufficiently obtained, and if it exceeds 30 parts by mass, the amount of crystalline polyester present on the outermost surface of the toner is too large, so that the photoconductor , Other components may be contaminated, resulting in deterioration of image quality, deterioration of developer fluidity, and reduction of image density. In addition, the surface properties of the toner deteriorate, the carriers are contaminated, sufficient chargeability cannot be maintained for a long period of time, and there is a risk of impairing environmental stability.

As the resin (toner binder), for example, the unmodified polyester and the modified polyester (polyester containing an ester bond and a bonding unit other than the ester bond) are blended, and the unmodified polyester and the crystalline polyester are blended. Any one can be selected, such as one obtained by blending the modified polyester, the unmodified polyester and the crystalline polyester. In these formulations, it is important to take care to achieve both hot offset resistance, heat storage resistance, and low temperature fixability. By coexisting urea-modified polyester as the modified polyester in the present invention, the heat-resistant storage property tends to be good even if the glass transition point is low as compared with the known polyester-based toner.

<< Colorant >>
The colorant is not particularly limited and may be appropriately selected depending on the intended purpose. For example, carbon black, niglosin dye, iron black, naphthol yellow S, Hansa yellow (10G, 5G, G), cadmium yellow, etc. Yellow Iron Oxide, Yellow Clay, 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), Tartrajin Lake, Kinolin Yellow Lake, Anthracan Yellow BGL, Isoindrinon Yellow, Bengala, Lead Tan, Lead Zhu, Cadmium Red, Cadmium Mercuri Red, Antimon Zhu, Permanent Red 4R, Para Red, Faise Red, p-Chloro-o-Nitroaniline Red, Resole Fast Scarlet G, Brilliant Fast Scarlet, Brilliant Carmine BS, Permanent Red (F2R, F4R, FRL, FRLL, F4RH), Fast Scarlet VD, Belkan Fast Rubin B, Brilliant Scarlet G, Resole Rubin GX, Permanent Red F5R, Brilliant Carmin 6B, Pigment Scarlet 3B, Bordeaux 5B, Truisin Maroon, Permanent Bordeaux F2K, Helio Bordeaux BL, Bordeaux 10B, Bonmaroon Light, Bonmaroon Medium, Eosin Lake, Rhodamin Lake B, Rhodamin Lake Y, Alizarin Lake, Thioinjigo Red B, Thioinjigo Maroon, Oil Red, Kinakridon Red, Pyrazolone Red, Polyazo Red, Chrome Vermilion, Benzidine Orange, Perinon Orange, Oil Orange, Cobalt Blue, Cerulean Blue, Alkaline Blue rake, peacock blue rake, Victoria blue rake, metal-free phthalocyanine blue, phthalocyanine blue, fast sky blue, indanslen blue (RS, BC), indigo, ultramarine, dark blue, anthracinone blue, fast violet B, methyl violet lake, Cobalt Purple, Manganese Purple, Dioxane Violet, Anthraquinone Violet, Chrome Green, Zink Green, Chromium Oxide, Pyridian, Emerald Green, Pigment Green B, Naftor Green B, Green Gold, Acid Green Lake, Malakite Green Examples include rake, phthalocyanine green, anthraquinone green, titanium oxide, zinc oxide, and lithobon. These may be used alone or in combination of two or more.
The content of the colorant is not particularly limited and may be appropriately selected depending on the intended purpose, but is preferably 1 part by mass or more and 15 parts by mass or less with respect to 100 parts by mass of the toner base particles. More than 10 parts by mass or less is more preferable.

The colorant may be used as a masterbatch compounded with a resin. The resin used for the master batch is not particularly limited and may be appropriately selected from known ones according to the purpose. For example, a homopolymer of styrene or a substitute thereof, a styrene-based copolymer, or a polymethyl methacrylate , Polybutyl methacrylate, Polyvinyl chloride, Polyvinyl acetate, Polyethylene, Polypropylene, Polyester, Epoxy resin, Epoxy polyol resin, Polyurethane, Polypropylene, Polyvinyl butyral, Polyacrylic acid, Rosin, Modified rosin, Terpen resin, aliphatic hydrocarbons Examples thereof include resins, alicyclic hydrocarbon resins, aromatic petroleum resins, chlorinated paraffins, and paraffins. These may be used alone or in combination of two or more.

<< Other ingredients >>
The other components are not particularly limited and may be appropriately selected depending on the intended purpose. Examples thereof include a mold release agent and a charge control agent.

-Release agent-
The release agent is not particularly limited and may be appropriately selected depending on the intended purpose. Examples thereof include waxes.
Examples of waxes include waxes having a carbonyl group, polyolefin waxes, long-chain hydrocarbons and the like. These may 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 ester, polyalkanol ester, polyalkanoic acid amide, polyalkylamide, dialkylketone and the like. Of these, polyalkanoic acid esters are preferred.
Examples of polyalkanoic acid esters include carnauba wax, montane wax, trimethylolpropane tribehenate, pentaerythritol tetrabehenate, pentaerythritol diacetate dibehenate, glycerin tribehenate, and 1,18-octadecanediol. Examples include distearate.
Examples of the polyalkanol ester include tristearyl trimellitic acid and distearyl maleate.
Examples of the polyalkanoic acid amide include dibehenyl amide.
Examples of the polyalkylamide include trimellitic acid tristearylamide.
Examples of the dialkyl ketone include distearyl ketone and the like.
Examples of the polyolefin wax include polyethylene wax and polypropylene wax.
Examples of long-chain hydrocarbons include paraffin wax and sazole 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 45 ° C. or higher and 120 ° C. or lower. When the melting point is 45 ° C. or higher, the release agent does not adversely affect the heat-resistant storage stability. Further, when the melting point is 120 ° C. or lower, cold offset is less likely to occur during fixing at a low temperature.

The melt viscosity of the release agent is preferably 5 cps or more and 1000 cps or less, and more preferably 10 cps or more and 100 cps or less, as a measured value at a temperature 20 ° C. higher than the melting point of the release agent. When the melt viscosity is 5 cps or more, the releasability is improved. When the melt viscosity is 1000 cps or less, the hot offset resistance and the low temperature fixability are improved.
The content of the release agent in the base particles (colored particles) is not particularly limited and may be appropriately selected depending on the intended purpose, but is preferably 1% by mass or more and 40% by mass or less, and 3% by mass or more and 30% by mass. % Or less is more preferable. When the content is 40% by mass or less, the fluidity of the toner is improved.

-Charge control agent-
The charge control agent is not particularly limited, and a positive or negative charge control agent can be appropriately selected and used depending on the positive and negative charges of the charge charged on the photoconductor.
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 (part 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 (Product No .: N-1, N-2), Kaya Set Black (Product No .: T-2,004) (above, manufactured by Nippon Kayaku Co., Ltd.), Eisenspiron Black (T-37, T-77, T-95, TRH, TNS-2) (above, Hodogaya Chemical) (Manufactured by Kogyo Co., Ltd.), FCA-1001-N, FCA-1001-NB, FCA-1001-NZ (all manufactured by Fujikura Kasei Co., Ltd.) and the like. These may be used alone or in combination of two or more.
As the positive charge control agent, for example, a basic compound such as a niglosin dye, a cationic compound such as a quaternary ammonium salt, a metal salt of a higher fatty acid, or the like can be used. Specifically, Bontron (Product No .: 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 Industry Co., Ltd.), TP-302, TP-415, TP-4040 (above, manufactured by Hodogaya Chemical Co., Ltd.), copy blue PR, copy charge (above) Product numbers: PX-VP-435, NX-VP-434) (above, manufactured by Hoechst), FCA (Product numbers: 201, 201-B-1, 201-B-2, 201-B-3, 201-PB, 201-PZ, 301) (above, manufactured by Fujikura Kasei Co., Ltd.), PLZ (product numbers: 1001, 2001, 6001, 7001) (above, manufactured by Shikoku Kasei Kogyo Co., Ltd.) and the like. These may be used alone or in combination of two or more.

The amount of the charge control agent added is determined by the type of resin and the method for producing colored particles including the dispersion method, and is not uniquely limited, but is 0.05 with respect to the total amount of resin. It is preferably parts by mass or more and 1.0 part by mass or less. When the addition amount is 1.0 part by mass or less, the chargeability of the toner is appropriate, the effect of the charge control agent is improved, the fluidity of the developer is improved, and the image density is improved. is there. Further, when the addition amount is 0.05 parts by mass or more, the charge rising property and the charge amount are sufficient, and the influence on the toner image can be suppressed.

<Toner manufacturing method>
The method for producing the toner of the present invention is not particularly limited and may be appropriately selected depending on the intended purpose. Examples thereof include a pulverization method, an emulsion polymerization method, a suspension polymerization method, a massive polymerization method, and a solution polymerization method. ..

As a pulverization method, the toner materials constituting the toner matrix particles are mixed to obtain a mixture. Then, the obtained mixture is melt-kneaded using a melt-kneader to obtain a kneaded product.
Examples of the melt kneader include a single-screw or double-screw continuous kneader, a batch type kneader using a roll mill, and the like, for example, a KTK type twin-screw extruder (manufactured by Kobe Steel) and a TEM type extruder (manufactured by Toshiba Machine Co., Ltd.). ), Twin-screw extruder (manufactured by Ktk Inc.), PCM type twin-screw extruder (manufactured by Ikekai Iron Works), Conider (manufactured by Bus), and the like.
The melt-kneading is preferably performed under appropriate conditions (melt-kneading temperature, etc.) so that the molecular chains of the resin are not broken. If the melt-kneading temperature is too high above the softening point of the resin, cutting may become severe, and if it is too low, melt-kneading may not proceed.
Next, the kneaded product obtained by melt-kneading is pulverized to obtain a pulverized product. When pulverizing the kneaded product, it is preferable that the kneaded product is roughly pulverized and then finely pulverized.
Examples of the method for crushing the kneaded material include a method of colliding with a collision plate in a jet stream to crush the kneaded material, a method of colliding particles with each other in a jet stream to crush them, and a narrow gap between a mechanically rotating rotor and a stator. Examples include a method of crushing.
Further, the crushed pulverized product is classified to adjust the particle size within a predetermined range.
Examples of the classification include a method of removing fine particles by cyclone, decanter, centrifugation or the like. Further, by removing coarse particles and agglomerated particles using a sieve of 250 mesh or more, toner base particles can be obtained.

As an emulsification method, a toner material liquid (oil phase) is emulsified or dispersed in an aqueous medium (aqueous phase) to obtain toner matrix particles. Specifically, a step of preparing a toner material liquid (oil phase) by dissolving or dispersing a resin or a resin precursor, a colorant, and a toner material containing a release agent if necessary in an organic solvent, and an oil phase. Toner matrix particles are obtained through a step of emulsifying or dispersing in an aqueous medium (aqueous phase) and then removing the solvent.

The volume average particle diameter (Dv) of the toner base particles is preferably 3.0 μm or more and 6.0 μm or less. When the volume average particle diameter (Dv) is 3.0 μm, when a one-component developer is used, it is possible to prevent the toner from fusing to members such as a developing roller and a blade, and the two-component developer can be used. When used, it is possible to prevent a decrease in the charging ability of the carrier due to fusion of toner to the surface of the carrier. Further, when the volume average particle diameter (Dv) is 6.0 μm or less, a high-resolution and high-quality image can be obtained.
The ratio (Dv / Dn) of the volume average particle diameter (Dv) of the toner population particles to the number average particle diameter (Dn) of the toner population particles is preferably 1.05 or more and 1.25 or less. When the ratio (Dv / Dn) is 1.25 or less, a high-resolution and high-quality image can be obtained. Further, when the ratio (Dv / Dn) is 1.05 or more, the chargeability and cleanability of the toner become good.

(Toner container)
The toner container of the present invention means a container containing toner.
By mounting the toner containing container of the present invention on an image forming apparatus to form an image, a high-quality image having excellent charge stability and the same level of image graininess and image sharpness as an offset printed image. It is possible to perform image formation utilizing the characteristics of the toner that can realize the above.

(Developer)
The developer of the present invention may be either a one-component developer composed of the toner of the present invention alone or a two-component developer composed of the toner and the carrier of the present invention, but the high speed corresponding to the improvement of the information processing speed. When used in a printer or the like, it is preferable to use a two-component developer from the viewpoint of life and the like.
When the toner of the present invention is used as a one-component developer, the particle size of the toner does not fluctuate much even if the toner is balanced, and the blade for forming the toner on the developing roller and thinning the toner. There is no fusion of toner to such members, and good and stable developability and images can be obtained even after long-term use (stirring) of the developing device.
Further, when the toner of the present invention is used as a two-component developer, the toner particle size does not fluctuate even if the toner is balanced, and the developability is good and stable even in long-term use (stirring) of the developing device. Is obtained.

<Career>
The carrier is not particularly limited and may be appropriately selected depending on the intended purpose, but it is preferable to have a core material and a resin layer covering the core material.
The material of the core material is not particularly limited and may be appropriately selected depending on the intended purpose. For example, manganese-strontium (Mn-Sr) -based material (50 emu / g or more and 90 emu / g or less) and manganese-magnesium. (Mn-Mg) -based material, iron powder (100 emu / g or more), highly magnetized material such as magnetite (75 emu / g or more and 120 emu / g or less), copper-zinc (Cu-Zn) -based weakly magnetized material (30 emu) / G or more and 80 emu / g or less) and the like. These can be used alone or in admixture of two or more.
From the viewpoint of ensuring the image density, highly magnetized materials such as iron powder (100 emu / g or more) and magnetite (75 emu / g or more and 120 emu / g or less) are preferable.
Weakly magnetized materials such as copper-zinc (Cu-Zn) (30 emu / g or more) can weaken the contact of the toner in the spiked state with the photoconductor, which is advantageous for improving the image quality. 80 emu / g or less) is preferable.

The weight average particle size of the core material is preferably 10 μm or more and 200 μm or less, and more preferably 40 μm or more and 100 μm or less. When the weight average particle diameter is 10 μm or more, the amount of fine powder components of the carrier is reduced, so that the magnetization per particle is increased and the carrier can be prevented from scattering. When the weight average particle size is 200 μm or less, the specific surface area is increased to prevent the toner from scattering, and the reproducibility of the solid portion is particularly good in the full color having many solid portions.

The material of the resin layer is not particularly limited and may be appropriately selected depending on the intended purpose. For example, amino-based resin, polyvinyl-based resin, polystyrene-based resin, halogenated olefin resin, polyester-based resin, polycarbonate-based resin, etc. Polyethylene, polyvinyl fluoride, vinylidene fluoride, polytrifluoroethylene, polyhexafluoropropylene, copolymer of vinylidene fluoride and acrylic monomer, copolymer of vinylidene fluoride and vinyl fluoride, tetrafluoroethylene Examples thereof include fluoroterpolymers such as tarpolymers of vinylidene fluoride and non-fluorinated monomers, and silicone resins. These may be used alone or in combination of two or more.
Examples of the amino resin include urea-formaldehyde resin, melamine resin, benzoguanamine resin, urea resin, polyamide resin, epoxy resin and the like.
Examples of the polyvinyl-based resin include acrylic resin, polymethylmethacrylate, polyacrylonitrile, polyvinyl acetate, polyvinyl alcohol, polyvinyl butyral and the like.
Examples of the polystyrene-based resin include polystyrene and a styrene-acrylic copolymer.
Examples of the halogenated olefin resin include polyvinyl chloride and the like.
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.
Examples of the conductive powder include metal powder, carbon black, titanium oxide, tin oxide, zinc oxide and the like. The average particle size of the conductive powder is preferably 1 μm or less. When the average particle size is 1 μm or less, the electric resistance can be easily controlled.
The content of the resin layer is preferably 0.01% by mass or more and 5.0% by mass or less with respect to the carrier. When the content is 0.01% by mass or more, the resin layer can be uniformly formed on the surface of the core material. Further, when the content is 5.0% by mass or less, the thickness of the resin layer is appropriate, and granulation between carriers can be prevented.
As a method for forming the resin layer, for example, a silicone resin or the like is dissolved in a solvent to prepare a coating liquid, the coating liquid is uniformly applied to the surface of the core material by a known coating method, dried, and then baked. It can be formed by doing.
The solvent 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.
Examples of the coating method of the coating liquid include a dipping method, a spraying method, and a brush coating method.
The baking method may be either an external heating method or an internal heating method. For example, a method using a fixed electric furnace, a fluidized electric furnace, a rotary electric furnace, a burner furnace, or the like, or a method using microwaves. And so on.

The mixing ratio of the toner and the carrier of the present invention in the two-component developer is preferably 1 part by mass or more and 10 parts by mass or less of the toner with respect to 100 parts by mass of the carrier.

(Developer container)
The developing agent container refers to a container in which the developing agent of the present invention is contained in the container.
Here, examples of the mode of the developer container include a developer, a process cartridge, and the like.
A developer has a means for accommodating and developing a developer.

The developer-containing container of the present invention is a high-quality image having excellent cleanability, image quality, and durability by forming an image by an electrophotographic method using the developer of the present invention contained in the container. Is formed.

(Process cartridge)
In the process cartridge of the present invention, an electrostatic latent image carrier that carries an electrostatic latent image and an electrostatic latent image that is supported on the electrostatic latent image carrier are developed with a developer and a visible image. It has at least a developing means for forming the above, and further has other means appropriately selected as needed.
As the developing means, a developer accommodating container for accommodating the toner or the developing agent of the present invention and a developing agent carrier for supporting and transporting the toner or the developing agent contained in the developing agent accommodating container are used. , At least, and may further have a layer thickness regulating member for regulating the thickness of the toner layer to be supported.
The process cartridge of the present invention can be detachably provided in various image forming devices, and it is preferable that the process cartridge of the present invention is detachably provided in the image forming apparatus of the present invention described later.
The process cartridge of the present invention is excellent in convenience, and by using the toner of the present invention, it has excellent cleanability, image quality, and durability, and a high quality image can be formed.

The toner of the present invention also exerts an excellent effect when it is loaded into an image forming apparatus having a process cartridge to perform image forming. That is, by using the toner of the present invention, it is possible to provide a process cartridge having excellent image quality.

Here, FIG. 1 is a schematic view showing an example of the process cartridge of the present invention. The process cartridge 1 of FIG. 1 includes a photoconductor 2, a charging means 3, a developing means 4, and a cleaning means 5. Have.

In an image forming apparatus having a process cartridge, the photoconductor 2 is rotationally driven at a predetermined peripheral speed.
In the rotation process, the photoconductor 2 is uniformly charged with a positive or negative predetermined potential on its peripheral surface by the charging means 3, and then receives image exposure light from an exposure means such as slit exposure or laser beam scanning exposure. Electrostatic latent images are sequentially formed on the peripheral surface of the photoconductor 2, and the formed electrostatic latent image is then developed with toner by the developing means 4, and the developed toner image is transferred from the paper feed unit to the photoconductor. The transfer means sequentially transfers the image to a recording medium fed to and from the transfer means in synchronization with the rotation of the photoconductor.
The recording medium that has undergone image transfer is separated from the surface of the photoconductor, introduced into the fixing means, image-fixed, and printed out as a copy to the outside of the apparatus.
The surface of the photoconductor after transfer is cleaned by removing the transfer residual toner by the cleaning means 5, and after further static elimination, it is repeatedly used for image formation.

(Image forming method and image forming device)
The image forming method in the present invention is an electrostatic latent image forming step of forming an electrostatic latent image on an electrostatic latent image carrier, and the electrostatic latent image can be developed by using the developer of the present invention. It includes a developing step of forming a visual image, a transfer step of transferring the visible image onto a recording medium, and a fixing step of fixing the transferred image transferred on the recording medium, and is appropriately selected as necessary. Other steps such as static elimination step, cleaning step, recycling step, control step and the like are included.

The image forming apparatus of the present invention uses an electrostatic latent image carrier, an electrostatic latent image forming means for forming an electrostatic latent image on the electrostatic latent image carrier, and a developing agent of the present invention. A developing means for developing an electrostatic latent image to form a visible image, a transfer means for transferring the visible image onto a recording medium, and a fixing means for fixing the transferred image transferred on the recording medium. Have. Further, it has other means appropriately selected as necessary, such as static elimination means, cleaning means, recycling means, control means and the like.

<Electrostatic latent image forming process and electrostatic latent image forming means>
The electrostatic latent image forming step is a step of forming an electrostatic latent image on an electrostatic latent image carrier.
The material, shape, structure, size, etc. of the electrostatic latent image carrier (sometimes referred to as "electrophotographic photosensitive member" or "photoreceptor") are not particularly limited, and among known ones. Although it can be appropriately selected, the shape thereof is preferably drum-shaped, and the material thereof includes, for example, an inorganic photoconductor such as amorphous silicon and selenium, and an organic photoconductor (OPC) such as polysilane and phthalopolymethine. Can be mentioned. Among these, an organic photoconductor (OPC) is preferable in that a higher-definition image can be obtained.

The formation of the electrostatic latent image can be performed, for example, by uniformly charging the surface of the electrostatic latent image carrier and then exposing it to an image, and by using an electrostatic latent image forming means. Can be done.
The electrostatic latent image forming means includes, for example, a charging means (charger) that uniformly charges the surface of the electrostatic latent image carrier, and an exposure that exposes the surface of the electrostatic latent image carrier in an image manner. It is provided with at least means (exposure device).
The charging can be performed, for example, by applying a voltage to the surface of the electrostatic latent image carrier using the charging device.
The charger is not particularly limited and may be appropriately selected depending on the intended purpose. For example, a contact charger known per se including a conductive or semi-conductive roll, brush, film, rubber blade or the like. , Corotron, non-contact charger using corona discharge such as Scorotron, and the like.
As the charger, it is preferable that the charger is arranged in a contacting or non-contacting state with the electrostatic latent image carrier and charges the surface of the electrostatic latent image carrier by superimposing and applying DC and AC voltages.
Further, the charger is a charging roller that is placed close to the electrostatic latent image carrier in a non-contact manner via a gap tape, and the electrostatic latent image is supported by superimposing and applying direct current and alternating voltage to the charging roller. Those that charge the body surface are preferable.
The exposure can be performed, for example, by exposing the surface of the electrostatic latent image carrier as an image using the exposure device.
The exposure device is not particularly limited as long as the surface of the electrostatic latent image carrier charged by the charger can be exposed to an image to be formed, and may be appropriately selected depending on the intended purpose. Examples thereof include various exposure devices such as a copying optical system, a rod lens array system, a laser optical system, and a liquid crystal shutter optical system.
In the present invention, an optical back surface method may be adopted in which the back surface side of the electrostatic latent image carrier is exposed in an image-like manner.

<Development process and development means>
The developing step is a step of developing the electrostatic latent image with the toner to form a visible image.
The visible image can be formed, for example, by developing the electrostatic latent image with the toner, and can be performed by the developing means.
The developing means preferably has, for example, a developer that accommodates the toner and is capable of contacting or non-contacting the toner to the electrostatic latent image, and is provided with a container containing the toner. Etc. are more preferable.
The developer may be a monochromatic developer or a multicolor developer, and has, for example, a stirrer for frictionally agitating and charging the toner, and a rotatable magnet roller. Those and the like are preferably mentioned.
In the developing device, for example, the toner and the carrier are mixed and agitated, and the toner is charged by friction at that time and is held in a spiked state on the surface of a rotating magnet roller to form a magnetic brush. .. Since the magnet roller is arranged in the vicinity of the electrostatic latent image carrier (photoreceptor), a part of the toner constituting the magnetic brush formed on the surface of the magnet roller is electrically attracted. It moves to the surface of the electrostatic latent image carrier (photoreceptor) by force. As a result, the electrostatic latent image is developed by the toner, and a visible image by the toner is formed on the surface of the electrostatic latent image carrier (photoreceptor).

<Transfer process and transfer means>
The transfer step is a step of transferring the visible image to a recording medium. After using an intermediate transfer body to first transfer the visible image onto the intermediate transfer body, the visible image is transferred onto the recording medium. A mode of secondary transfer to the medium is preferable, and a primary transfer step of transferring a visible image onto an intermediate transfer body to form a composite transfer image by using two or more colors, preferably a full-color toner as the toner, and the composite. A mode including a secondary transfer step of transferring the transferred image onto a recording medium is more preferable.
The transfer can be performed, for example, by charging the electrostatic latent image carrier (photoreceptor) with the transfer charger using the visible image, and can be performed by the transfer means. The transfer means includes a primary transfer means for transferring a visible image onto an intermediate transfer medium to form a composite transfer image, and a secondary transfer means for transferring the composite transfer image onto a recording medium. Aspects are preferred.
The intermediate transfer body is not particularly limited and may be appropriately selected from known transfer bodies according to the purpose. For example, a transfer belt or the like is preferably used.
The transfer means (the primary transfer means, the secondary transfer means) transfers and charges the visible image formed on the electrostatic latent image carrier (photoreceptor) to the recording medium side. It is preferable to have at least a vessel. The transfer means may be one or two or more.
Examples of the transfer device include a corona transfer device by corona discharge, a transfer belt, a transfer roller, a pressure transfer roller, and an adhesive transfer device.
The recording medium is not particularly limited, and can be appropriately selected from known recording media (recording paper).

<Fixing process and fixing means>
The fixing step is a step of fixing the visible image transferred to the recording medium by using a fixing device, and may be performed every time the developer of each color is transferred to the recording medium, or the developer of each color. On the other hand, it may be carried out at the same time in a state where these are laminated.
The fixing device is not particularly limited and may be appropriately selected depending on the intended purpose, but known heating and pressurizing means are suitable. Examples of the heating and pressurizing means include a combination of a heating roller and a pressurizing roller, a combination of a heating roller, a pressurizing roller, and an endless belt.
The fixing device has a heating element including a heating element, a film in contact with the heating element, and a pressurizing member that presses against the heating element via the film, and the film and the pressurizing member It is preferable that the means is for heating and fixing by passing a recording medium on which an unfixed image is formed between them. The heating in the heating and pressurizing means is usually preferably 80 ° C. or higher and 200 ° C. or lower.
In the present invention, for example, a known optical fixing device may be used together with or in place of the fixing step and fixing means, depending on the purpose.

<Other processes and other means>
The static electricity elimination step is a step of applying a static electricity elimination bias to the electrostatic latent image carrier to perform static electricity elimination, and can be preferably performed by the static electricity elimination means.
The static eliminating means is not particularly limited as long as it can apply a static eliminating bias to the electrostatic latent image carrier, and can be appropriately selected from known static eliminators, for example, a static eliminating lamp or the like. Preferred.

The cleaning step is a step of removing the toner remaining on the electrostatic latent image carrier, and can be preferably performed by a cleaning means.
The cleaning means is not particularly limited as long as the toner remaining on the electrostatic latent image carrier can be removed, and can be appropriately selected from known cleaners, for example, a magnetic brush cleaner. , Electrostatic brush cleaners, magnetic roller cleaners, blade cleaners, brush cleaners, web cleaners and the like are preferred.

The recycling step is a step of causing the developing means to recycle the toner removed by the cleaning step, and can be preferably performed by the recycling means. The recycling means is not particularly limited, and examples thereof include known transportation means.

The control step is a step of controlling each of the steps, and each step can be preferably performed by a control means.
The control means is not particularly limited as long as the movement of each of the means can be controlled, and can be appropriately selected depending on the intended purpose. Examples thereof include devices such as sequencers and computers.

Here, FIG. 2 shows an example of the image forming apparatus of the present invention. The image forming apparatus 100A includes a photoconductor drum 10, a charging roller 20, an exposure apparatus, a developing apparatus 40, an intermediate transfer belt 50, a cleaning apparatus 60 having a cleaning blade, and a static elimination lamp 70.
The intermediate transfer belt 50 is an endless belt stretched by three rollers 51 arranged inside, and can be moved in the direction of the arrow in FIG. A part of the three rollers 51 also functions as a transfer bias roller capable of applying a transfer bias (primary transfer bias) to the intermediate transfer belt 50. Further, a cleaning device 90 having a cleaning blade is arranged in the vicinity of the intermediate transfer belt 50. Further, a transfer roller 80 capable of applying a transfer bias (secondary transfer bias) for transferring the toner image to the transfer paper 95 is arranged so as to face the intermediate transfer belt 50.
Further, around the intermediate transfer belt 50, a corona charging device 58 for applying an electric charge to the toner image transferred to the intermediate transfer belt 50 is provided with the photoconductor drum 10 in the rotation direction of the intermediate transfer belt 50. It is arranged between the contact portion of the intermediate transfer belt 50 and the contact portion between the intermediate transfer belt 50 and the transfer paper 95.

The developing device 40 is composed of a developing belt 41, a black developing unit 45K, a yellow developing unit 45Y, a magenta developing unit 45M, and a cyan developing unit 45C, which are arranged around the developing belt 41. The developing unit 45 for each color includes a developing agent accommodating portion 42, a developing agent supply roller 43, and a developing roller (developer carrier) 44. Further, the developing belt 41 is an endless belt stretched by a plurality of belt rollers, and can be moved in the direction of the arrow in FIG. Further, a part of the developing belt 41 is in contact with the photoconductor drum 10.

Next, a method of forming an image using the image forming apparatus 100A will be described. First, the surface of the photoconductor drum 10 is uniformly charged using the charging roller 20, and then the exposure light L is exposed to the photoconductor drum 10 using an exposure apparatus (not shown) to obtain an electrostatic latent image. To form. Next, the electrostatic latent image formed on the photoconductor drum 10 is developed with the toner supplied from the developing apparatus 40 to form a toner image. Further, the toner image formed on the photoconductor drum 10 is transferred (primary transfer) onto the intermediate transfer belt 50 by the transfer bias applied from the roller 51, and then transferred by the transfer bias applied from the transfer roller 80. , Transferred on transfer paper 95 (secondary transfer). On the other hand, the photoconductor drum 10 on which the toner image is transferred to the intermediate transfer belt 50 is statically eliminated by the static elimination lamp 70 after the toner remaining on the surface is removed by the cleaning device 60.

FIG. 3 shows a second example of the image forming apparatus used in the present invention. In the image forming apparatus 100B, the black developing unit 45K, the yellow developing unit 45Y, the magenta developing unit 45M, and the cyan developing unit 45C are directly opposed to each other around the photoconductor drum 10 without providing the developing belt 41. Other than that, it has the same configuration as the image forming apparatus 100A.
FIG. 4 shows a third example of the image forming apparatus used in the present invention. The image forming apparatus 100C is a tandem type color image forming apparatus, and includes a copying apparatus main body 150, a paper feed table 200, a scanner 300, and an automatic document transporting apparatus (ADF) 400.

The intermediate transfer belt 50 provided in the central portion of the copying apparatus main body 150 is an endless belt stretched on the three rollers 14, 15 and 16, and can be moved in the direction of the arrow in FIG. .. In the vicinity of the roller 15, a cleaning device 17 having a cleaning blade for removing the toner remaining on the intermediate transfer belt 50 on which the toner image is transferred to the recording paper is arranged. Yellow, cyan, magenta, and black image forming units 120Y, 120C, 120M, and 120K are juxtaposed along the transport direction while facing the intermediate transfer belt 50 stretched by the rollers 14 and 15.

Further, an exposure apparatus 21 is arranged in the vicinity of the image forming unit 120. Further, the secondary transfer belt 24 is arranged on the side of the intermediate transfer belt 50 opposite to the side on which the image forming unit 120 is arranged. The secondary transfer belt 24 is an endless belt stretched on a pair of rollers 23, and the recording paper and the intermediate transfer belt 50 conveyed on the secondary transfer belt 24 are between the rollers 16 and 23. Can be contacted.
Further, in the vicinity of the secondary transfer belt 24, a fixing device 25 including a fixing belt 26 which is an endless belt stretched on a pair of rollers and a pressure roller 27 which is pressed and arranged by the fixing belt 26. Is placed. A sheet reversing device 28 for reversing the recording paper is arranged in the vicinity of the secondary transfer belt 24 and the fixing device 25 when an image is formed on both sides of the recording paper.

Next, a method of forming a full-color image using the image forming apparatus 100C will be described. First, a color document is set on the platen 130 of the automatic document transfer device (ADF) 400, or a color document is set on the contact glass 32 of the scanner 300 by opening the automatic document transfer device 400 and automatically transporting the document. Close the device 400. When the start switch is pressed, when the original is set in the automatic document transfer device 400, the original is conveyed and moved onto the contact glass 32, and then the original is set on the contact glass 32. Immediately, the scanner 300 is driven, and the first traveling body 33 including the light source and the second traveling body 34 including the mirror travel. At this time, after the light reflected from the document surface of the light emitted from the first traveling body 33 is reflected by the second traveling body 34, the document is received by the reading sensor 36 via the imaging lens 35, so that the document is formed. It is read and image information of black, yellow, magenta and cyan is obtained.

The image information of each color is transmitted to the image forming unit 120 of each color, and a toner image of each color is formed. As shown in FIG. 5, the image forming unit 120 of each color includes the photoconductor drum 10, the charging roller 160 that uniformly charges the photoconductor drum 10, and the photoconductor drum 10 based on the image information of each color. An exposure device that exposes the exposure light L to form an electrostatic latent image of each color, a developing device 61 that develops the electrostatic latent image with a developer of each color to form a toner image of each color, and an intermediate toner image. A transfer roller 62 for transferring onto the transfer belt 50, a cleaning device 63 having a cleaning blade, and a static elimination lamp 64 are provided. The toner images of each color formed by the image forming unit 120 of each color are sequentially transferred (primary transfer) on the intermediate transfer belt 50 which is stretched and moved by the rollers 14, 15 and 16, and superposed to form a composite toner image. It is formed.
On the other hand, in the paper feed table 200, one of the paper feed rollers 142 is selectively rotated, and the recording paper is fed out from one of the paper feed cassettes 144 provided in the paper bank 143 in multiple stages, and one by one by the separation roller 145. It is separated and sent out to the paper feed path 146, conveyed by the transport roller 147, guided to the paper feed passage 148 in the copying apparatus main body 150, and abutted against the resist roller 49 to be stopped. Alternatively, the paper feed roller is rotated to feed out the recording paper on the manual feed tray 54, the sheets are separated one by one by the separation roller 52, guided to the manual paper feed path 53, and abutted against the resist roller 49 to be stopped.

Although the resist roller 49 is generally grounded and used, it may be used in a state where a bias is applied to remove paper dust from the recording paper. Next, by rotating the resist roller 49 in time with the composite toner image formed on the intermediate transfer belt 50, the recording paper is sent out between the intermediate transfer belt 50 and the secondary transfer belt 24, and the composite toner image is formed. The toner image is transferred (secondary transfer) onto the recording paper. The toner remaining on the intermediate transfer belt 50 on which the composite toner image is transferred is removed by the cleaning device 17.
The recording paper on which the composite toner image is transferred is conveyed by the secondary transfer belt 24, and then the composite toner image is fixed by the fixing device 25. Next, the transport path of the recording paper is switched by the switching claw 55, and the recording paper is discharged onto the paper ejection tray 57 by the ejection roller 56. Alternatively, the transport path of the recording paper is switched by the switching claw 55, the sheet is inverted by the sheet reversing device 28, an image is formed on the back surface in the same manner, and then the recording paper is ejected onto the output tray 57 by the ejection roller 56. ..

According to the image forming apparatus and the image forming method of the present invention, the toner of the present invention capable of forming a high-quality image having excellent charge stability and having the same level of image graininess and image sharpness as an offset printed image. Therefore, a high-quality image can be formed over a long period of time.

Examples of the present invention will be described below, but the present invention is not limited to these examples.

(Example of preparation of pseudo-bemite)
Aluminum alkoxide was synthesized from the reaction of metallic aluminum with alcohol and hydrolyzed to obtain alumina hydrate having a pseudo-boehmite structure. At this time, by changing the production conditions, pseudo-boehmite A (8 nm), B (120 nm), C (5 nm), and D (135 nm) having different average particle diameters (median diameters) were obtained.

(Preparation Example 1 of Inorganic Particles)
-Preparation of pseudo-bemite AA-
Pseudo-bemite A was surface-treated with polydimethylsiloxane to obtain pseudo-bemite AA.

(Preparation Example 2 of Inorganic Particles)
-Preparation of pseudo-bemite AB-
In the preparation example 1 of the inorganic particles, pseudo-bemite AB was obtained in the same manner as in the preparation example 1 of the inorganic particles, except that the pseudo-bemite A was changed to the pseudo-bemite B and the pseudo-bemite B was surface-treated with hexamethyldisilazane. It was.

(Preparation Example 3 of Inorganic Particles)
-Preparation of pseudo-bemite AC-
Pseudo-bemite AC was obtained in the same manner as in Preparation Example 1 of inorganic particles except that pseudo-bemite A was changed to pseudo-bemite C.

(Preparation Example 4 of Inorganic Particles)
-Preparation of pseudo-bemite AD-
Pseudo-boemite AD was obtained in the same manner as in Preparation Example 1 of inorganic particles, except that pseudo-bemite A was changed to pseudo-bemite D and pseudo-bemite B was surface-treated with hexamethyldisilazane.

(Preparation example of amorphous aluminum hydroxide)
-Preparation of amorphous aluminum hydroxide A-
A sodium hydroxide solution was added to the aluminum chloride aqueous solution. A precipitate was formed at pH 8 and aged in the mother liquor for 24 hours to obtain amorphous aluminum hydroxide A.

(Preparation Example 5 of Inorganic Particles)
-Preparation of amorphous aluminum hydroxide BA-
Amorphous aluminum hydroxide A was surface-treated with polydimethylsiloxane to obtain amorphous aluminum hydroxide BA. Amorphous aluminum hydroxide has an amorphous crystal phase and is different from boehmite and pseudo boehmite.

(Example of preparation of barrier light)
-Preparation of Bayerite B-
A sodium hydroxide solution was added to the aluminum chloride aqueous solution. A precipitate was formed at pH 11 and aged in the mother liquor for 24 hours to obtain Bayerite B.

(Preparation Example 6 of Inorganic Particles)
-Preparation of Bayerite BB-
Biyalite B was surface-treated with polydimethylsiloxane to obtain Biyalite BB.
Bayarite is a β-type (hexagonal) trihydrated aluminum oxide, and differs from boehmite and pseudo-boehmite in the number of crystal phases and hydrates.

(Example of preparation of hydralgilite)
-Preparation of hydralgilite C-
A sodium hydroxide solution was added to the aluminum chloride aqueous solution. A precipitate was formed at pH 12 and aged in the mother liquor for 24 hours to obtain hydralgilite C.

(Preparation Example 7 of Inorganic Particles)
-Preparation of hydralgilite BC-
Hydraldilite C was surface-treated with hexamethyldisilazane to obtain hydraldilite BC.
Hydral dilite is an α-type (trigonal) trihydrated aluminum oxide, and differs from boehmite and pseudo-boehmite in the number of hydrates.

(Production example of crystalline polyester)
2. 300 g of 1,10-decanedioic acid, 2,530 g of 1,8-octanediol, and hydroquinone in a 5 L 4-neck flask equipped with a nitrogen introduction tube, a dehydration tube, a stirrer and a heat transfer pair. 9 g was added and reacted at 180 ° C. for 10 hours, then reacted at 200 ° C. for 3 hours, and further reacted at 8.3 kPa for 2 hours. After that, it was measured by the contact method of DSC measurement, and the glass transition temperature (Tg) was 65 ° C., the melting point peak temperature was 70 ° C., the weight average molecular weight (Mw) was 10,000, and the number average molecular weight (Mn) was 3,000. A crystalline polyester resin A having a Mw / Mn of 3.3 was obtained. When the obtained crystalline polyester resin A was analyzed using a crystal analysis X-ray diffractometer, the peak half of the peak having the highest peak intensity among the peaks obtained in the range of diffraction peak 20 ° <2θ <25 ° The price range was 0.5.

(Production Example 1 of Amorphous Polyester Resin)
18.4 parts by mass of fumaric acid, 10.5 parts by mass of trimellitic anhydride, and an ethylene oxide adduct of bisphenol A (2.2 mol of ethylene oxide) in a 4-neck flask with a capacity of 5 L equipped with a thermometer, a stirrer and a condenser. Addition) 34.2 parts by mass and 36.8 parts by mass of propion oxide adduct of bisphenol A (addition of 2.2 mol of propion oxide) (total 4,000 g), set the flask in the mantle heater, and set the flask in the mantle heater to 4 parts by mass of dibutyltin oxide. Parts were added and reacted at 220 ° C. for 8 hours. Then, the reaction was carried out at 8.3 kPa until a predetermined softening point was reached to obtain an amorphous polyester resin B-H1.

(Production Example 2 of Amorphous Polyester Resin)
Propion oxide adduct (propion oxide 2.2 mol) of 16.9 parts by mass of fumaric acid, 10.4 parts by mass of terephthalic acid, and bisphenol A was added to a 4-neck flask with a capacity of 5 L equipped with a thermometer, agitator and a condenser. ) 72.7 parts by mass was added (4,000 g in total), the flask was set in a mantle heater, 4 parts by mass of dibutyltin oxide was added, and the mixture was reacted at 220 ° C. for 8 hours. Then, the reaction was carried out at 8.3 kPa until a predetermined softening point was reached to obtain an amorphous polyester resin B-L1.
Table 1 shows the physical property values of the amorphous polyester resins B-H1 and B-L1.

(Example 1)
[Toner prescription]
・ Crystalline polyester resin A: 20 parts by mass ・ Amorphous polyester resin B-H1: 20 parts by mass ・ Amorphous polyester resin B-L1: 60 parts by mass ・ Salicylic acid Zr salt (TN-105: manufactured by Hodogaya Chemical Co., Ltd.) ): 1 part by mass ・ Defreed fatty acid type carnauba wax (Tg: 83 ° C): 7 parts by mass ・ Carbon black (# 44: manufactured by Mitsubishi Chemical Corporation) :: 13 parts by mass

The toner formulation is stirred and mixed with a Henshell mixer, melted by heating at a temperature of 125 ° C to 130 ° C for 40 minutes with a roll mill, cooled to room temperature (25 ° C), and then the obtained kneaded product is pulverized and classified with a jet mill. Then, toner matrix particles A having a volume average particle diameter of 7.0 μm and particles having a volume average of 5 μm or less having a particle size distribution of 35% by number were obtained.

-Mixing process-
Next, 1.5 parts by mass of silica (H2000, manufactured by Wacker, volume average particle diameter: 12 nm, hexamethyldisilazane treatment) was added to 100 parts by mass of the toner base particles A, and a Henschel mixer was used. The stirring blades were mixed at a rotational speed of 35 m / sec. Then, 1 part by mass of pseudo-boehmite AA was added and mixed using a Henschel mixer at a rotation speed of the stirring blade at 35 m / sec to obtain toner X1.

(Example 2)
In the same manner as in Example 1 except that the rotation speed of the stirring blade of the Henschel mixer in the mixing step of Example 1 was changed from 35 m / sec to 55 m / sec and the pseudo-bemite AA was replaced with the pseudo-bemite AB. Toner X2 was obtained.

(Example 3)
In Example 1, the silica (H2000, manufactured by Wacker) was replaced with silica (NY50, manufactured by Nippon Aerosil Co., Ltd., volume average particle diameter: 25 nm, polydimethylsiloxane treatment), except that the silica (H2000, manufactured by Wacker) was replaced with the silica (NY50, manufactured by Polydimethylsiloxane). Toner X3 was obtained.

(Example 4)
In Example 2, the silica (H2000, manufactured by Wacker) was replaced with silica (RY300, manufactured by Nippon Aerosil Co., Ltd., volume average particle diameter: 10 nm, polydimethylsiloxane treatment) in the same manner as in Example 2. Toner X4 was obtained.

(Example 5)
Toner X5 was obtained in the same manner as in Example 1 except that the pseudo-bemite AA was replaced with the pseudo-bemite AC.

(Example 6)
Toner X6 was obtained in the same manner as in Example 4 except that the pseudo-bemite AB was replaced with the pseudo-bemite AD.

(Comparative Example 1)
In Example 1, toner Y1 was obtained in the same manner as in Example 1 except that the pseudo-bemite AA was replaced with amorphous aluminum hydroxide BA.

(Comparative Example 2)
In Example 1, toner Y2 was obtained in the same manner as in Example 1 except that the pseudo-bemite AA was replaced with a biasite BB.

(Comparative Example 3)
Toner Y3 was obtained in the same manner as in Example 1 except that the pseudo-bemite AA was replaced with hydralgilite BC.

(Manufacturing example 1 of carrier)
A coating solution in which 200 parts by mass of a silicone resin solution (manufactured by Shin-Etsu Chemical Co., Ltd.) and 3 parts by mass of carbon black (manufactured by Cabot Corporation) are dispersed in toluene is applied by a fluidized layer spray method to 2500 parts by mass of a ferrite core material. And coated the surface of the core material. Then, a carrier was obtained by firing in an electric furnace at 300 ° C. for 2 hours. The carrier having a volume average particle diameter (Dv) of 30 μm or more and 60 μm or less was used.

(Preparation of developer)
7 parts by mass of each toner obtained in Examples 1 to 6 and Comparative Examples 1 to 3 and 93 parts by mass of the carrier are mixed and stirred to obtain developing agents X1 to X6 and developing agents Y1 to Y3 having a toner concentration of 7% by mass. It was.

<Image formation>
Image formation using an image forming apparatus and a digital full-color copying machine (imagecolor2800, manufactured by Ricoh Co., Ltd.) using the developing agents X1 to X6 of Examples 1 to 6 and the developing agents Y1 to Y3 of Comparative Examples 1 to 3. Was done.
Next, the charge stability, image quality, image graininess and image sharpness, and heat-resistant storage stability were evaluated as follows. The results are shown in Tables 2 and 3.

<Charging stability>
Static charge prepared for each developed developer using a blow-off charge measuring device (device name: TB-200, manufactured by Toshiba Chemical Co., Ltd.) and E-SAPRT (Model EST-II, manufactured by Hosokawa Micron Co., Ltd.). A charge distribution curve of the image developer was obtained (see FIG. 6).
The number N of particles with the peak value Qc of the obtained charge distribution curve was calculated (Qc, N), and the intersections of N / 2 and the charge distribution curve were (Qn, N / 2), (Qp, N /). 2) (Qn <Qp). From the obtained Qn, Qc, and Qb, Wa and Wb were calculated using the following formulas (1) and (2).
Wa = | (Qn-Qc) / Qc | × 100 ... Equation (1)
Wb = | (Qp-Qc) / Qc | × 100 ... Equation (2)
Using the values of Wa and Wb, the charge stability of the developer was evaluated based on the following evaluation criteria.
[Electrification stability evaluation criteria]
◯: Wa and Wb are 20 or less Δ: Wa is 20 or less and Wb is 20 or more, or Wa is 20 or more and Wb is 20 or less ×: Wa and Wb are 20 or more

<Image quality>
Each developer was used to evaluate the image quality (specifically, transfer failure, occurrence of background stain image) after passing the paper.
For transfer defects, 5,000 sheets were passed through a digital full-color copier (Imagio Neo C600 remodeling machine, manufactured by Ricoh Co., Ltd.). Then, a solid black image was passed through the paper, and the transfer defect level of the image was visually judged.
For the ground stain image, 5,000 sheets were passed through a digital full-color copier (Imagio Neo C600 remodeling machine, manufactured by Ricoh Co., Ltd.). Then, the blank image was stopped during development, and the developer on the photoconductor after development was transferred with Scotch tape (manufactured by Sumitomo 3M Ltd.). The image density of the transferred Scotch tape and the untransferred Scotch tape is measured and quantitatively evaluated with a spectrodensitometer (trade name: X-Rite938, manufactured by X-Rite), and the difference is less than 0.30. Was good, and those with 0.30 or more were considered defective.
The image quality, which is a combination of poor transfer and ground stain image, was evaluated according to the following criteria.
[Evaluation criteria]
◯: Image quality is good Δ: Image quality is not good but acceptable ×: Image quality is poor

<Image graininess and sharpness>
Using each developer, a single-color photographic image was output with a digital full-color copying machine (imagecolor2800, manufactured by Ricoh Co., Ltd.), and the degree of image graininess and sharpness was visually evaluated.
[Evaluation criteria for image graininess and sharpness]
⊚: Equivalent to offset printed image ○: Inferior to offset printed image but good Δ: Worse to offset printed image ×: Equivalent to conventional electrophotographic image

<Heat-resistant storage>
The heat-resistant storage stability was measured using a needle insertion degree tester (manufactured by Nikka Engineering Co., Ltd.).
Specifically, 10 g of each toner was weighed, placed in a 30 ml glass container (screw vial) in an environment of a temperature of 20 ° C. to 25 ° C. and 40 to 60% RH, and the lid was closed. After tapping the glass container containing the toner 100 times, it was left in a constant temperature bath whose temperature was set to 50 ° C. for 24 hours. After that, the needle insertion degree was measured with a needle insertion degree tester, and the heat storage stability was evaluated according to the following evaluation criteria. The larger the value of the needle insertion degree, the better the heat storage stability.
〔Evaluation criteria〕
⊚: Needle insertion degree is 30 mm or more ○: Needle insertion degree is 25 mm or more and less than 30 mm Δ: Needle insertion degree is 20 mm or more and less than 25 mm ×: Needle insertion degree is less than 20 mm

From the results of Tables 2 to 3, all the toners of Examples 1 to 6 have better charging stability, image quality, image graininess, image sharpness, and heat-resistant storage stability than those of Comparative Examples 1 to 6. It turned out to be excellent.

Examples of aspects of the present invention are as follows.
<1> Toner containing inorganic particles
The toner is characterized in that the inorganic particles contain at least one of boehmite and pseudo boehmite, and silica.
<2> The toner according to <1>, wherein the boehmite and the pseudo boehmite are hydrolysis products of aluminum alkoxide.
<3> Has toner matrix particles,
The content of at least one of the boehmite and the pseudo boehmite is any one of <1> to <2>, which is 0.5 parts by mass or more and 10 parts by mass or less with respect to 100 parts by mass of the toner base particles. The toner described.
<4> The toner according to any one of <1> to <3>, wherein at least one of the boehmite and the pseudo-bemite is at least one of the silicon-containing boehmite and the silicon-containing pseudo-bemite.
<5> The toner according to any one of <1> to <4>, wherein the average particle size of the boehmite and the pseudo boehmite is 5 nm or more and 135 nm or less.
<6> A toner container containing the toner according to any one of <1> to <5>.
<7> A developing agent comprising the toner according to any one of <1> to <5>.
<8> A developing agent containing the toner according to any one of <1> to <5> and a carrier.
<9> The developer container is characterized by containing the developer according to any one of <7> to <8>.
<10> It has an electrostatic latent image carrier and a developing means for developing the electrostatic latent image formed on the electrostatic latent image carrier by using development with a developing agent to form a visible image. , A process cartridge that can be attached to and detached from the image forming apparatus body.
The process cartridge is characterized in that the developer is the developer according to any one of <7> to <8>.
<11> An electrostatic latent image carrier and a charging means for charging the surface of the electrostatic latent image carrier.
An exposure means that exposes the surface of a charged electrostatic latent image carrier to form an electrostatic latent image,
A developing means that develops the electrostatic latent image with a developer to form a visible image,
A transfer means for transferring the visible image to a recording medium,
A fixing means for fixing the transferred image transferred to the recording medium, and
It is an image forming apparatus having
The image forming apparatus is characterized in that the developer is the developer according to any one of <7> to <8>.

The toner according to any one of <1> to <5>, the toner container according to <6>, the developer according to any one of <7> to <8>, and the developer according to <9>. According to the developer container, the process cartridge according to <10>, and the image forming apparatus according to <11>, the conventional problems can be solved and the object of the present invention can be achieved.

1 Process cartridge 2 Photoreceptor 3 Charging means 4 Developing means 5 Cleaning means 10 Electrostatic latent image carrier (photoreceptor drum)
18 Image forming means 20 Charging roller 21 Exposure device 25 Fixing device 40 Developing device 61 Developing device 95 Transfer paper 100A, 100B, 100C Image forming device 120 Image forming unit

Special Table 2005-534967

Claims (11)

Toner containing inorganic particles
A toner characterized in that the inorganic particles contain at least one of boehmite and pseudo boehmite, and silica. The toner according to claim 1, wherein the boehmite and the pseudo boehmite are hydrolysis products of aluminum alkoxide. Has toner matrix particles,
The toner according to any one of claims 1 to 2, wherein the content of at least one of the boehmite and the pseudo boehmite is 0.5 parts by mass or more and 10 parts by mass or less with respect to 100 parts by mass of the toner base particles. .. The toner according to any one of claims 1 to 3, wherein at least one of the boehmite and the pseudo boehmite is at least one of the silicon-containing boehmite and the silicon-containing pseudo-boehmite. The toner according to any one of claims 1 to 4, wherein the average particle size of the boehmite and the pseudo boehmite is 5 nm or more and 135 nm or less. A toner container containing the toner according to any one of claims 1 to 5. A developer comprising the toner according to any one of claims 1 to 5. A developer comprising the toner according to any one of claims 1 to 5 and a carrier. A developer container containing the developer according to any one of claims 7 to 8. It has an electrostatic latent image carrier and a developing means for developing a electrostatic latent image formed on the electrostatic latent image carrier by using development with a developing agent to form a visible image, and forms an image. A process cartridge that can be attached to and detached from the device body.
A process cartridge according to any one of claims 7 to 8, wherein the developer is the developer. An electrostatic latent image carrier, a charging means for charging the surface of the electrostatic latent image carrier, and
An exposure means that exposes the surface of a charged electrostatic latent image carrier to form an electrostatic latent image,
A developing means that develops the electrostatic latent image with a developer to form a visible image,
A transfer means for transferring the visible image to a recording medium,
A fixing means for fixing the transferred image transferred to the recording medium, and
It is an image forming apparatus having
An image forming apparatus according to any one of claims 7 to 8, wherein the developer is the developer.