JP6958184B2 - Toner for static charge image development, static charge image developer, toner cartridge, process cartridge, image forming apparatus and image forming method - Google Patents

Description

The present invention relates to an electrostatic charge image developing toner, an electrostatic charge image developing agent, a toner cartridge, a process cartridge, an image forming apparatus, and an image forming method.

In recent years, the electrophotographic process has been widely used not only for copiers but also for office network printers, personal computer printers, on-demand printing printers, etc. due to the development of equipment and the enhancement of communication networks in the computerized society. Regardless of the color, there is an increasing demand for high image quality, high speed, high reliability, miniaturization, weight reduction, and energy saving performance.

In the electrophotographic process, usually, an electrostatic charge image is electrically formed on a photoconductor (image holder) using a photoconductive substance by various means, and this electrostatic charge image is obtained by using a developer containing toner. The toner image on the photoconductor is transferred to a recording medium such as paper or directly to a recording medium, and then the transferred image is fixed to the recording medium. Is forming.

Here, in order to provide a toner for static charge image development having excellent chargeability and long life, the volume average particle size distribution index (GSDv) is at most 1.3, and the volume average particle size distribution index (GSDv). ) And the number average particle size distribution index (GSDp) (GSDv / GSDp) is disclosed at least 0.95 (see, for example, Patent Document 1). ).

Japanese Unexamined Patent Publication No. 10-301323

In recent years, in the commercial printing market, there is an increasing demand for continuously outputting high-quality images. In order to continuously output high-quality images, from the viewpoint of toner development, studies on reducing the particle size are being actively conducted for the purpose of achieving both low-temperature fixability and image quality.
As the particle size becomes smaller, the fluidity of the toner deteriorates, and the charge distribution may become non-uniform when the charge rises. Therefore, in Patent Document 1, the charge per toner particle is uniformly controlled by making the particle size distribution of the toner uniform.
However, when an image is output under a high temperature / high humidity / high speed stress state, even with the toner described in Patent Document 1 in which the charge per toner particle is uniformly controlled, the fluidity of the toner deteriorates and the inside of the developing machine is used. Insufficient stirring may result in toner with low charge when an image is output. Therefore, toner scattering due to the low-charged toner may occur. Further, such a phenomenon may occur not only in the toner having a small particle size but also in the toner having a non-small particle size.
In the present invention, the high temperature / high humidity / high speed stress state means that the environment for image formation is 28 ° C. or higher, the relative humidity is 80% or higher, and the image formation speed (process speed) is 400 mm / sec or higher. ..

The present invention has been made in view of the above-mentioned conventional circumstances, and an object of the present invention is to provide a toner for developing an electrostatic charge image that is hard to scatter.

Specific means for achieving the above-mentioned problems are as follows.
That is, the invention according to <1> is
The large diameter side volume particle size distribution index (GSDv (90/50)) is 1.20 or more and 1.40 or less.
The small diameter side number particle size distribution index (GSDp (50/10)) is 1.30 or more,
GSDv (90/50) / GSDp (50/10) is 0.93 or less,
A toner for developing an electrostatic charge image containing toner particles having an average circularity of 0.94 or more and 1.00 or less.

The invention according to <2> is
The large-diameter side volume particle size distribution index (GSDv (90/50)) of the toner particles is 1.25 or more and 1.38 or less, and the small-diameter side number particle size distribution index (GSDp (50/10)) is 1.35 or more. The toner for static charge image development according to <1> , wherein GSDv (90/50) / GSDp (50/10) is 0.92 or less, and the average circularity is 0.95 or more and 1.00 or less. ..

The invention according to <3> is
The average circularity of the toner particles having a particle size in the range of 0.1 times or more and 0.5 times or less of the volume average particle size (D50v) of the toner particles is 0.96 or more and 1.00 or less <1>. Alternatively, the toner for developing an electrostatic charge image according to <2>.

The invention according to <4> is
The basic fluid energy measured using a powder rheometer under the conditions that the tip speed of the rotor blade is 100 mm / sec, the approach angle of the rotor blade is -5 °, and the aeration flow rate is 0 ml / min is 150 mJ or more and 500 mJ or less. The toner for developing an electrostatic charge image according to any one of <1> to <3>.

The invention according to <5> is
The ventilation fluidity energy measured using a powder rheometer under the conditions that the tip speed of the rotary blade is 100 mm / sec, the approach angle of the rotary blade is -5 °, and the ventilation flow rate is 10 ml / min, and the basic fluidity energy. The static charge image developing toner according to <4> , wherein the aeration index (basic fluidity energy / aeration fluidity energy) based on the above is 25 or more and 80 or less.

The invention according to <6> is
Item 2. Static according to any one of <1> to <5> , wherein the toner particles contain a release agent and a resin having an acid value of 8.0 mgKOH / g or more and 18.0 mgKOH / g or less as a binder resin. Toner for charge image development.

The invention according to <7> is
The toner for static charge image development according to <6> , wherein the resin having an acid value of 8.0 mgKOH / g or more and 18.0 mgKOH / g or less contains a polyester resin.

The invention according to <8> is
A static charge image developer containing the toner for static charge image development according to any one of <1> to <7>.

The invention according to <9> is
The toner for static charge image development according to any one of <1> to <7> is accommodated, and the toner is accommodated.
A toner cartridge that is attached to and detached from the image forming device.

The invention according to <10> is
A developing means for accommodating the electrostatic charge image developing agent according to <8> and developing the electrostatic charge image formed on the surface of the image holder as a toner image by the electrostatic charge image developing agent is provided.
A process cartridge that is attached to and detached from the image forming device.

The invention according to <11> is
Image holder and
A charging means for charging the surface of the image holder and
An electrostatic charge image forming means for forming an electrostatic charge image on the surface of the charged image holder, and
A developing means for accommodating the electrostatic charge image developer according to <8> and developing the electrostatic charge image formed on the surface of the image holder as a toner image by the electrostatic image developer.
A transfer means for transferring a toner image formed on the surface of the image holder to the surface of a recording medium, and
A fixing means for fixing the toner image transferred to the surface of the recording medium, and
An image forming apparatus comprising.

The invention according to <12> is
The charging process that charges the surface of the image holder,
A static charge image forming step of forming a static charge image on the surface of the charged image holder, and
A developing step of developing an electrostatic charge image formed on the surface of the image holder as a toner image by using the electrostatic charge image developer according to <8>.
A transfer step of transferring a toner image formed on the surface of the image holder to the surface of a recording medium, and
A fixing step of fixing the toner image transferred to the surface of the recording medium, and
An image forming method having.

According to the invention according to <1> , whether the GSDv (90/50) of the toner particles is less than 1.20 or more than 1.40, or the GSDp (50/10) is less than 1.30. Provided is a toner for static charge image development that is less likely to scatter than when GSDv (90/50) / GSDp (50/10) exceeds 0.93 or the average circularity is less than 0.94. Will be done.
According to the invention according to <2> , whether the GSDv (90/50) of the toner particles is less than 1.25 or more than 1.38, or the GSDp (50/10) is less than 1.35. Toner scattering is further suppressed as compared to the case where GSDv (90/50) / GSDp (50/10) exceeds 0.92 or the average circularity is less than 0.95.
According to the invention according to <3> , as compared with the case where the average circularity of the toner particles having a particle diameter in the range of 0.1 times or more and 0.5 times or less of D50v of the toner particles is less than 0.96. , Toner scattering is further suppressed.
According to the invention according to <4> , the fluidity of the toner is further improved as compared with the case where the basic fluidity energy is less than 150 mJ or more than 500 mJ.
According to the invention according to <5> , the scattering of toner is further suppressed as compared with the case where the air permeability index is less than 25 or more than 80.
According to the invention according to <6> or <7> , the acid value of the resin contained as the binder resin is less than 8.0 mgKOH / g or more than 18.0 mgKOH / g. Scattering is further suppressed.

According to the invention according to <8> , whether the GSDv (90/50) of the toner particles is less than 1.20 or more than 1.40, or the GSDp (50/10) is less than 1.30. Provided is an electrostatic charge image developer that is less likely to scatter than when GSDv (90/50) / GSDp (50/10) is greater than 0.93 or the average circularity is less than 0.94. NS.
According to the invention according to <9> , whether the GSDv (90/50) of the toner particles is less than 1.20 or more than 1.40, or the GSDp (50/10) is less than 1.30. Contains toner for static charge image development that is less likely to scatter than when GSDv (90/50) / GSDp (50/10) exceeds 0.93 or the average circularity is less than 0.94. Toner cartridges are provided.
According to the invention according to <10> , whether the GSDv (90/50) of the toner particles is less than 1.20 or more than 1.40, or the GSDp (50/10) is less than 1.30. Contains an electrostatic charge image developer that is less likely to scatter than when GSDv (90/50) / GSDp (50/10) is greater than 0.93 or the average circularity is less than 0.94. Process cartridges are provided.
According to the invention according to <11> , whether the GSDv (90/50) of the toner particles is less than 1.20 or more than 1.40, or the GSDp (50/10) is less than 1.30. A static charge image developer that is less likely to scatter than when GSDv (90/50) / GSDp (50/10) exceeds 0.93 or has an average circularity of less than 0.94 was used. An image forming apparatus is provided.
According to the invention according to <12> , whether the GSDv (90/50) of the toner particles is less than 1.20 or more than 1.40, or the GSDp (50/10) is less than 1.30. A static charge image developer that is less likely to scatter than when GSDv (90/50) / GSDp (50/10) exceeds 0.93 or has an average circularity of less than 0.94 was used. An image forming method is provided.

It is a figure explaining the state of a screw about an example of the screw extruder used for manufacturing the toner which concerns on this embodiment. It is a figure for demonstrating the measuring method of the fluidity energy amount with a powder rheometer. It is a figure which shows the relationship between a vertical load and an energy gradient obtained by a powder rheometer. It is a schematic diagram for demonstrating the shape of the rotary blade used in a powder rheometer. It is a schematic block diagram which shows an example of the image forming apparatus which concerns on this embodiment. It is a schematic block diagram which shows an example of the process cartridge which concerns on this embodiment.

Hereinafter, embodiments of the electrostatic charge image developing toner, the electrostatic charge image developing agent, the toner cartridge, the process cartridge, the image forming apparatus, and the image forming method of the present invention will be described in detail.

<Toner for static charge image development>
The toner for static charge image development according to the present embodiment (hereinafter, may be simply referred to as “toner”) has a large-diameter side volume particle size distribution index (GSDv (90/50)) of 1.20 or more and 1.40. Below, the small diameter side number particle size distribution index (GSDp (50/10)) is 1.30 or more, GSDv (90/50) / GSDp (50/10) is 0.93 or less, and the average circularity. Contains toner particles with a value of 0.94 or more and 1.00 or less.

The toner for static charge image development according to this embodiment is difficult to scatter. The reason is not clear, but it can be inferred as follows.
When an image is output under a high temperature / high humidity / high speed stress state, as described above, the fluidity of the toner deteriorates and the stirring in the developing machine becomes insufficient, and when the image is output, a toner with low charge is generated. In some cases.
The toner according to this embodiment has GSDv (90/50) of 1.20 or more and 1.40 or less, GSDp (50/10) of 1.30 or more, and GSDv (90/50) / GSDp (50). / 10) contains toner particles having an average circularity of 0.94 or more and 1.00 or less, and therefore smaller than the volume average particle size (D50v) as compared with conventional toner particles. It exhibits a particle size distribution in which the distribution of toner particles on the diameter side is vast. In such toner particles, the ratio of fine powder toner particles to the total toner particles is relatively high. The fine-powdered toner particles perform a function as a spacer in the same manner as the external additive added to the toner particles. Therefore, the toner according to the present embodiment is unlikely to deteriorate in fluidity even when an image is output in a stress state of high temperature / high humidity / high speed, and stirring in the developing machine is unlikely to be insufficient. By stirring the toner in the developing machine, it becomes difficult to generate toner with low charge. As a result, it is presumed that the toner is less likely to scatter.

Hereinafter, the details of the toner according to this embodiment will be described.

The toner according to the present embodiment is composed of toner particles and, if necessary, an external additive.

(Toner particles)
The toner particles are composed of, for example, a binder resin, a colorant, a mold release agent, and other additives, if necessary.

-Bound resin-
Examples of the binder resin include styrenes (for example, styrene, parachlorostyrene, α-methylstyrene, etc.) and (meth) acrylic acid esters (for example, methyl acrylate, ethyl acrylate, n-propyl acrylate, acrylic acid). n-butyl, lauryl acrylate, 2-ethylhexyl acrylate, methyl methacrylate, ethyl methacrylate, n-propyl methacrylate, lauryl methacrylate, 2-ethylhexyl methacrylate, etc.), ethylenically unsaturated nitriles (eg, acrylonitrile, etc.) Methacronitrile, etc.), vinyl ethers (eg, vinyl methyl ether, vinyl isobutyl ether, etc.), vinyl ketones (vinyl methyl ketone, vinyl ethyl ketone, vinyl isopropenyl ketone, etc.), olefins (eg, ethylene, propylene, butadiene, etc.), etc. Examples thereof include a homopolymer of the above-mentioned monomer and a vinyl-based resin composed of a copolymer obtained by combining two or more kinds of these monomers.
Examples of the binder resin include non-vinyl resins such as epoxy resins, polyester resins, polyurethane resins, polyamide resins, cellulose resins, polyether resins, and modified rosins, mixtures of these with the vinyl resins, or these. Examples thereof include a graft polymer obtained by polymerizing a vinyl-based monomer in the coexistence.
These binder resins may be used alone or in combination of two or more.

As the binder resin, a resin having an acid value of 8.0 mgKOH / g or more and 18.0 mgKOH / g or less is preferable. The acid value of the resin is more preferably 9.0 mgKOH / g or more and 17.0 mgKOH / g or less, and further preferably 10.0 mgKOH / g or more and 16.0 mgKOH / g or less.
Since the toner particles contain a resin having an acid value of 8.0 mgKOH / g or more and 18.0 mgKOH / g or less as a binding resin with the release agent described later, fine powder toner is used because of compatibility with the release agent. The proportion of the release agent on the surface of the particles increases, and the proportion of the resin tends to decrease. By increasing the proportion of the release agent on the surface of the toner particles, moisture absorption on the surface of the toner particles is suppressed. Therefore, it is considered that the fluidity of the fine powder toner particles that can function as a spacer can be easily secured, and the fluidity of the toner at high temperature and high humidity is improved. It is presumed that the improvement in the fluidity of the toner makes it easier for the toner to be agitated in the developing machine, and as a result, the scattering of the toner is further suppressed.
The measurement of the acid value of the resin conforms to JIS K-0070-1992.
As the resin having an acid value of 8.0 mgKOH / g or more and 18.0 mgKOH / g or less, a polyester resin is suitable.
Examples of the polyester resin include known polyester resins.

Examples of the polyester resin include a condensed polymer of a polyvalent carboxylic acid and a polyhydric alcohol. As the polyester resin, a commercially available product may be used, or a synthetic resin may be used.

Examples of the polyvalent carboxylic acid include aliphatic dicarboxylic acids (for example, oxalic acid, malonic acid, maleic acid, fumaric acid, citraconic acid, itaconic acid, glutaconic acid, succinic acid, alkenyl succinic acid, adipic acid, sebacic acid, etc.). , Alicyclic dicarboxylic acid (eg cyclohexanedicarboxylic acid, etc.), aromatic dicarboxylic acid (eg, terephthalic acid, isophthalic acid, phthalic acid, naphthalenedicarboxylic acid, etc.), these anhydrides, or their lower grades (eg, 1 or more carbon atoms). 5 or less) Alkyl ester can be mentioned. Among these, as the polyvalent carboxylic acid, for example, an aromatic dicarboxylic acid is preferable.
As the polyvalent carboxylic acid, a trivalent or higher carboxylic acid having a crosslinked structure or a branched structure may be used in combination with the dicarboxylic acid. Examples of the trivalent or higher carboxylic acid include trimellitic acid, pyromellitic acid, anhydrides thereof, and lower (for example, 1 to 5 carbon atoms) alkyl esters thereof.
The polyvalent carboxylic acid may be used alone or in combination of two or more.

Examples of polyhydric alcohols include aliphatic diols (eg ethylene glycol, diethylene glycol, triethylene glycol, propylene glycol, butanediol, hexanediol, neopentyl glycol, etc.), alicyclic diols (eg cyclohexanediol, cyclohexanedimethanol, etc.). Hydrogenated bisphenol A, etc.), aromatic diols (for example, ethylene oxide adduct of bisphenol A, propylene oxide adduct of bisphenol A, etc.) can be mentioned. Among these, as the polyhydric alcohol, for example, aromatic diols and alicyclic diols are preferable, and aromatic diols are more preferable.
As the polyhydric alcohol, a trihydric or higher polyhydric alcohol having a crosslinked structure or a branched structure may be used in combination with the diol. Examples of the trihydric or higher polyhydric alcohol include glycerin, trimethylolpropane, and pentaerythritol.
The polyhydric alcohol may be used alone or in combination of two or more.

The glass transition temperature (Tg) of the polyester resin is preferably 50 ° C. or higher and 80 ° C. or lower, and more preferably 50 ° C. or higher and 65 ° C. or lower.
The glass transition temperature is obtained from the DSC curve obtained by differential scanning calorimetry (DSC), and more specifically, the method for obtaining the glass transition temperature in JIS K-7121-1987 "Method for measuring the transition temperature of plastics". It is determined by the described "external glass transition start temperature".

The weight average molecular weight (Mw) of the polyester resin is preferably 5000 or more and 1,000,000 or less, and more preferably 7,000 or more and 500,000 or less.
The number average molecular weight (Mn) of the polyester resin is preferably 2000 or more and 100,000 or less.
The molecular weight distribution Mw / Mn of the polyester resin is preferably 1.5 or more and 100 or less, and more preferably 2 or more and 60 or less.
The weight average molecular weight and the number average molecular weight are measured by gel permeation chromatography (GPC). The molecular weight measurement by GPC is performed using a Tosoh GPC / HLC-8120GPC as a measuring device, a Tosoh column / TSKgel SuperHM-M (15 cm), and a THF solvent. The weight average molecular weight and the number average molecular weight are calculated from the measurement results using a molecular weight calibration curve prepared from a monodisperse polystyrene standard sample.

The polyester resin is obtained by a well-known manufacturing method. Specifically, for example, the polymerization temperature is set to 180 ° C. or higher and 230 ° C. or lower, the pressure inside the reaction system is reduced as necessary, and the reaction is carried out while removing water and alcohol generated during condensation.
When the raw material monomer is not dissolved or compatible at the reaction temperature, a solvent having a high boiling point may be added as a dissolution aid to dissolve the monomer. In this case, the polycondensation reaction is carried out while distilling off the dissolution aid. If a monomer with poor compatibility is present in the copolymerization reaction, the monomer with poor compatibility, the monomer, and the acid or alcohol to be polycondensed are condensed in advance, and then weighted together with the main component. It is good to condense.

The content of the binder resin is, for example, preferably 40% by mass or more and 95% by mass or less, more preferably 50% by mass or more and 90% by mass or less, and 60% by mass or more and 85% by mass or less with respect to the entire toner particles. More preferred.

-Colorant-
As the colorant, a conventionally known colorant corresponding to the color of the toner can be used.
Scattering of toner, which is considered to be caused by deterioration of fluidity, is easily noticeable with toner having a color that is easily visible visually. Therefore, the toner according to the present embodiment is preferably a magenta toner having a magenta color that is easily visually recognized, or a cyan toner having a cyan color.
Further, the reproducibility of the monochromatic halftone is improved by suppressing the scattering of the magenta toner exhibiting a magenta color that is easily visually recognized or the cyan toner exhibiting a cyan color.

Examples of the cyan colorant include C.I. I. Pigment Blue 1, 2, 3, 4, 4, 5, 6, 7, 10, 10, 11, 12, 13, 14, 14, 15, 15: 1, 15: 2, 15: 3, 15: 4, 15: 6, 16, 17, 23, 60, 65, 73, 83, 180, C.I. I. Bat Cyan 1, 3, 20, 20 etc., Navy Blue, Cobalt Blue, Alkaline Blue Lake, Phthalocyanine Blue, Metallic Phthalocyanine Blue, Partially Chlorinated Phthalocyanine Blue, First Sky Blue, Induslen Blue BC Cyan Pigment, C.I. I. Cyan dyes such as Solvent Cyan 79 and 162 can be used.
The cyan colorant preferably contains at least one selected from the group consisting of pigment blue, phthalocyanine blue and solvent cyan.

Examples of the magenta colorant include C.I. I. Pigment Red 1, 2, 3, 4, 4, 5, 6, 7, 8, 8, 9, 10, 11, 12, 12, 13, 14, 15, 16, 16, 17, 18, 19, 21, 21, 22, 23, 30, 31, 31, 32, 37, 38, 39, 40, 41, 48, 49, 50, 51, 52, 53, 54, 55, 57, 58, 60, 63, 64, 68, 81, 83, 87, 88, 89, 90 , 112, 114, 122, 123, 163, 184, 202, 206, 207, 209, etc., Magenta pigment of Pigment Violet 19 and C.I. I. Solvent Red 1, 3, 8, 23, 24, 25, 27, 30, 49, 81, 82, 83, 84, 100, 109, 121, C .. I. Disperse Thread 9, C.I. I. Basic Red 1, Same 2, Same 9, Same 12, Same 13, Same 14, Same 15, Same 17, Same 18, Same 22, Same 23, Same 24, Same 27, Same 29, Same 32, Same 34, Same Magenta dyes such as 35, 36, 37, 38, 39, 40, etc., red iron oxide, cadmium red, lead tan, mercury sulfide, cadmium, permanent red 4R, resole red, pyrazolone red, watching red, calcium Salt, Lake Red D, Brilliant Carmine 6B, Eosin Lake, Rotamine Lake B, Alizarin Lake, Brilliant Carmin 3B and the like can be used.
The magenta colorant preferably contains at least one selected from the group consisting of Pigment Red, Pigment Violet and Basic Red.

Further, as the yellow colorant, for example, C.I. I. Pigment Yellow 2, 3, 15, 16, 16, 17, 97, 180, 185, 139, and the like can be used.

Other colorants include carbon black (acetylene black, furnace black, thermal black, channel black, ketjen black), copper oxide, manganese dioxide, aniline black, titanium black, activated carbon, non-magnetic ferrite, magnetite, etc. White coloring such as black colorant, titanium oxide, barium sulfate, lead oxide, zinc oxide, lead titanate, potassium titanate, barium titanate, strontium titanate, zirconia, antimony trioxide, lead white, zinc sulfide, barium carbonate, etc. Agents and the like can be mentioned.
The colorant may be used alone or in combination of two or more.

As the colorant, a surface-treated colorant may be used if necessary, or may be used in combination with a dispersant. Further, a plurality of kinds of colorants may be used in combination.

The content of the colorant is, for example, preferably 1% by mass or more and 30% by mass or less, and more preferably 3% by mass or more and 15% by mass or less with respect to the entire toner particles.

-Release agent-
Examples of the release agent include hydrocarbon waxes; natural waxes such as carnauba wax, rice wax and candelilla wax; synthetic or mineral / petroleum waxes such as montan wax; ester waxes such as fatty acid esters and montanic acid esters. ; And so on. The release agent is not limited to this.

The melting temperature of the release agent is preferably 50 ° C. or higher and 110 ° C. or lower, and more preferably 60 ° C. or higher and 100 ° C. or lower.
The melting temperature is determined from the DSC curve obtained by differential scanning calorimetry (DSC) according to the "melting peak temperature" described in the method for determining the melting temperature in JIS K-7121-1987 "Method for measuring transition temperature of plastics". Ask.

The content of the release agent is, for example, preferably 1% by mass or more and 20% by mass or less, and more preferably 5% by mass or more and 15% by mass or less with respect to the entire toner particles.

-Other additives-
Examples of other additives include well-known additives such as magnetic materials, charge control agents, and inorganic powders. These additives are contained in the toner particles as an internal additive.

-Characteristics of toner particles, etc.-
The toner particles may be toner particles having a single layer structure, or may be toner particles having a so-called core-shell structure composed of a core portion (core particles) and a coating layer (shell layer) covering the core portion. You may.
Here, the toner particles having a core-shell structure include, for example, a core portion composed of a binder resin and, if necessary, other additives such as a colorant and a mold release agent, and a binder resin. It is preferably composed of a composed coating layer.

The volume average particle size (D50v) of the toner particles is preferably 2 μm or more and 10 μm or less, and more preferably 4 μm or more and 8 μm or less.

In the present embodiment, the GSDv (90/50) of the toner particles is 1.20 or more and 1.40 or less, preferably 1.25 or more and 1.38 or less, and 1.30 or more and 1.35 or less. Is more preferable. When the GSDv (90/50) of the toner particles is less than 1.20, the problem of deterioration of fluidity due to the elimination of voids between the toners may occur. Further, when the GSDv (90/50) of the toner particles exceeds 1.40, there may be a problem of transfer failure due to variations in the charge distribution per toner particles due to the coarse powder.

In the present embodiment, the GSDp (50/10) of the toner particles is 1.30 or more, preferably 1.35 or more, and more preferably 1.38 or more. Further, the GSDp (50/10) of the toner particles may be 1.50 or less. When the GSDp (50/10) of the toner particles is less than 1.30, the problem of deterioration of fluidity due to the elimination of voids between the toners may occur.

In the present embodiment, the GSDv (90/50) / GSDp (50/10) of the toner particles is 0.93 or less, preferably 0.92 or less, and more preferably 0.90 or less. Further, the GSDv (90/50) / GSDp (50/10) of the toner particles may be 0.85 or more. When the GSDv (90/50) / GSDp (50/10) of the toner particles exceeds 0.93, a problem of transfer failure may occur due to variations in the charge distribution per toner particles due to the coarse powder.

Coulter Multisizer II (manufactured by Beckman Coulter) was used for various average particle sizes of toner particles and various particle size distribution indexes (GSDv (90/50) and GSDp (50/10)), and the electrolytic solution was ISOTON. -Measured using II (Beckman Coulter).
At the time of measurement, 0.5 mg or more and 50 mg or less of the measurement sample is added to 2 ml of a 5% aqueous solution of a surfactant (preferably sodium alkylbenzene sulfonate) as a dispersant. This is added to 100 ml or more and 150 ml or less of the electrolytic solution.
The electrolytic solution in which the sample is suspended is dispersed for 1 minute with an ultrasonic disperser, and the particle size distribution of particles having a particle size in the range of 2 μm or more and 60 μm or less is obtained by using a Coulter Multisizer II with an aperture of 100 μm. taking measurement. The number of particles to be sampled is 50,000.
Cumulative distribution of volume and number is drawn from the small diameter side for each particle size range (channel) divided based on the measured particle size distribution, and the cumulative particle size of 10% is the volume particle size D10v and several particle size. The particle size having D10p and a cumulative 50% is defined as the volume average particle size D50v and the number average particle size D50p, and the particle size having a cumulative 90% is defined as the volume particle size D90v and the number particle size D90p.
Using these, the large-diameter side volume particle size distribution index (GSDv (90/50)) is calculated as (D90v / D50v), and the small-diameter side number particle size distribution index (GSDp (50/10)) is calculated as (D50p / D10p). Will be done.

In the present embodiment, when calculating the large-diameter side volume particle size distribution index, D90v is used instead of D84v (particle size to be cumulative 84%) used for calculating the volume particle size distribution index (GSDv (84/16)). The reason is that the amount of coarse powder (toner particles having a large particle size) contained in the toner particles is more sensitively reflected in the value of the large-diameter side volume particle size distribution index.
Further, in the present embodiment, when calculating the small-diameter side number particle size distribution index, D10p is used instead of D16p (particle size that becomes a cumulative 16%) used for calculating the number particle size distribution index (GSDp (84/16)). The reason for using it is to more sensitively reflect the amount of fine particles (toner particles having a small particle size) contained in the toner particles in the value of the small diameter side number particle size distribution index.

The average circularity of the toner particles is 0.94 or more and 1.00 or less, preferably 0.95 or more and 1.00 or less, and 0.96 or more and 1.00 or less from the viewpoint of improving cleanability. Is more preferable. If the average circularity of the toner particles is less than 0.94, the stress on the cleaning blade is large and the problem of blade failure may occur.

The average circularity of the toner particles having a particle size in the range of 0.1 times or more and 0.5 times or less of the volume average particle size (D50v) of the toner particles is preferably 0.96 or more and 1.00 or less. It is more preferably 0.97 or more and 1.00 or less, and further preferably 0.98 or more and 1.00 or less. Toner particles having a particle size in the range of 0.1 times or more and 0.5 times or less of the volume average particle size (D50v) of the toner particles correspond to so-called fine powder toner particles. The average circularity of the fine powder toner particles of 0.96 or more and 1.00 or less indicates that the shape of the fine powder toner particles is substantially spherical. Since the shape of the fine powder toner particles is substantially spherical, the function as a spacer is easily exhibited. As a result, it is presumed that the fluidity of the toner is improved and the scattering of the toner is further suppressed.

The average circularity of the toner particles is obtained by (circumferential peripheral length) / (peripheral length) [(circumferential length of a circle having the same projected area as the particle image) / (peripheral length of the particle projected image)]. Specifically, it is a value measured by the following method.
First, a flow-type particle image analyzer (Sysmex) that sucks and collects toner particles to be measured, forms a flat flow, and instantly emits strobe light to capture a particle image as a still image and analyze the particle image. Obtained by FPIA-3000) manufactured by the company. Then, the number of samplings when calculating the average circularity is set to 3500.
The average circularity of toner particles having a particle size in the range of 0.1 times or more and 0.5 times or less of the volume average particle size (D50v) of the toner particles is also measured by the same method.
When the toner has an external additive, the toner (developer) to be measured is dispersed in water containing a surfactant, and then ultrasonic treatment is performed to obtain toner particles from which the external additive has been removed. ..

The toner particles of the present embodiment have a large-diameter side volume particle size distribution index (GSDv (90/50)) of 1.25 or more and 1.38 or less, and a small-diameter side number particle size distribution index (GSDp (50/10)). It is preferably 1.35 or more, GSDv (90/50) / GSDp (50/10) is 0.92 or less, and the average circularity is 0.95 or more and 1.00 or less, and the large diameter side volume. The particle size distribution index (GSDv (90/50)) is 1.30 or more and 1.35 or less, the small diameter side number particle size distribution index (GSDp (50/10)) is 1.38 or more, and GSDv (90/50). ) / GSDp (50/10) is 0.90 or less, and the average circularity is more preferably 0.96 or more and 1.00 or less.

(External agent)
Examples of the external additive include inorganic particles. As the inorganic particles, SiO ₂ , TiO ₂ , Al ₂ O ₃ , CuO, ZnO, SnO ₂ , CeO ₂ , Fe ₂ O ₃ , MgO, BaO, CaO, K ₂ O, Na ₂ O, ZrO ₂ , CaO. _{SiO 2, K 2 O · (} TiO 2) n, Al 2 O 3 · 2SiO 2, CaCO 3, MgCO 3, BaSO 4, MgSO 4 , and the like.

The surface of the inorganic particles as an external additive should be hydrophobized. The hydrophobizing treatment is performed, for example, by immersing the inorganic particles in a hydrophobizing agent. The hydrophobizing agent is not particularly limited, and examples thereof include a silane-based coupling agent, a silicone oil, a titanate-based coupling agent, and an aluminum-based coupling agent. These may be used alone or in combination of two or more.
The amount of the hydrophobizing agent is usually, for example, 1 part by mass or more and 10 parts by mass or less with respect to 100 parts by mass of the inorganic particles.

Examples of the external additive include resin particles (resin particles such as polystyrene, polymethylmethacrylate (PMMA), and melamine resin), cleaning activators (for example, metal salts of higher fatty acids typified by zinc stearate, and fluoropolymers). Particles) and the like.

The amount of the external additive added is preferably, for example, 0.01% by mass or more and 5% by mass or less, and more preferably 0.01% by mass or more and 2.0% by mass or less with respect to the toner particles.

(Toner manufacturing method)
Next, a method for producing toner according to this embodiment will be described.
The toner according to the present embodiment can be obtained by externally adding an external additive to the toner particles after producing the toner particles.

The toner particles may be produced by any of a dry production method (for example, a kneading and pulverizing method, etc.) and a wet production method (for example, an agglomeration coalescence method, a suspension polymerization method, a dissolution suspension method, etc.). The method for producing the toner particles is not particularly limited to these production methods, and a well-known production method is adopted.
Among these, it is preferable to obtain toner particles by the aggregation and coalescence method.

For example, in the dissolution / suspension method, a liquid in which raw materials (binding resin, colorant, etc.) constituting toner particles are dissolved or dispersed in an organic solvent in which the binding resin can be dissolved is contained as a particle dispersant. This is a method obtained by granulating toner particles by dispersing the particles in an aqueous solvent and then removing the organic solvent.
The agglutination-union method is a method of obtaining toner particles through an agglutination step of forming an agglomerate of raw materials (resin particles, a colorant, etc.) constituting the toner particles and a fusion step of fusing the agglomerates. ..

Among these, toner particles containing a urea-modified polyester resin as a binder resin may be obtained by the following dissolution / suspension method. In the following description of the dissolution / suspension method, a method of obtaining toner particles containing an unmodified polyester resin and a urea-modified polyester resin as a binder resin will be described, but the toner particles are only urea-modified polyester resin as a binder resin. It may be included.

[Oil phase liquid preparation process]
An oil phase liquid in which a toner particle material containing an unmodified polyester resin, a polyester prepolymer having an isocyanate group, an amine compound, a colorant, and a mold release agent is dissolved or dispersed in an organic solvent is prepared (oil phase liquid preparation step). .. This oil phase liquid preparation step is a step of dissolving or dispersing the toner particle material in an organic solvent to obtain a mixed liquid of the toner material.

The oil phase liquid is prepared by 1) a method of preparing by dissolving or dispersing the toner material in an organic solvent all at once, and 2) kneading the toner material in advance and then dissolving or dispersing this kneaded product in an organic solvent. 3) A method of preparing by dissolving an unmodified polyester resin, a polyester prepolymer having an isocyanate group, and an amine compound in an organic solvent, and then dispersing a colorant and a mold release agent in the organic solvent. ) A method of preparing by dissolving an unmodified polyester resin, a polyester prepolymer having an isocyanate group, and an amine compound in the organic solvent after dispersing the colorant and the release agent in an organic solvent, and 5) the isocyanate group. Toner particle materials (unmodified polyester resin, colorant and mold release agent) other than the polyester prepolymer and the amine compound are dissolved or dispersed in an organic solvent, and then the polyester prepolymer and the amine having an isocyanate group are dissolved in the organic solvent. Method for preparing by dissolving a compound, 6) After dissolving or dispersing a toner particle material (unmodified polyester resin, colorant and mold release agent) other than a polyester prepolymer having an isocyanate group or an amine compound in an organic solvent, Examples thereof include a method of preparing by dissolving a polyester prepolymer having an isocyanate group or an amine compound in this organic solvent. The method for preparing the oil phase liquid is not limited to these.

Examples of the organic solvent of the oil phase liquid include ester solvents such as methyl acetate and ethyl acetate; ketone solvents such as methyl ethyl ketone and methyl isopropyl ketone; aliphatic hydrocarbon solvents such as hexane and cyclohexane; dichloromethane, chloroform, trichloroethylene and the like. Examples thereof include halogenated hydrocarbon solvents. These organic solvents preferably dissolve the binder resin, dissolve in water at a rate of 0% by mass or more and 30% by mass or less, and have a boiling point of 100 ° C. or less. Among these organic solvents, ethyl acetate is preferable.

[Suspension preparation process]
Next, the obtained oil phase liquid is dispersed in the aqueous phase liquid to prepare a suspension (suspension preparation step).
Then, along with the preparation of the suspension, the reaction between the polyester prepolymer having an isocyanate group and the amine compound is carried out. Then, a urea-modified polyester resin is produced by this reaction. This reaction involves at least one of a molecular chain cross-linking reaction and an extension reaction. The reaction between the polyester prepolymer having an isocyanate group and the amine compound may be carried out together with the solvent removing step described later.
Here, the reaction conditions are selected based on the reactivity between the isocyanate group structure of the polyester prepolymer and the amine compound. As an example, the reaction time is preferably 10 minutes or more and 40 hours or less, and preferably 2 hours or more and 24 hours or less. The reaction temperature is preferably 0 ° C. or higher and 150 ° C., and preferably 40 ° C. or higher and 98 ° C. or lower. If necessary, a known catalyst (dibutyltin laurate, dioctyltin laurate, etc.) may be used to produce the urea-modified polyester resin. That is, the catalyst may be added to the oil phase liquid or the suspension.

Examples of the aqueous phase liquid include an aqueous phase liquid in which a particle dispersant such as an organic particle dispersant and an inorganic particle dispersant is dispersed in an aqueous solvent. Further, the aqueous phase liquid includes an aqueous phase liquid in which a particle dispersant is dispersed in an aqueous solvent and a polymer dispersant is dissolved in the aqueous solvent. A well-known additive such as a surfactant may be added to the aqueous phase liquid.

Examples of the aqueous solvent include water (usually ion-exchanged water, distilled water, pure water). The aqueous solvent is a solvent containing water and an organic solvent such as alcohol (methanol, isopropyl alcohol, ethylene glycol, etc.), dimethylformamide, tetrahydrofuran, cellsolves (methylcellsolve, etc.), lower ketones (acetone, methylethylketone, etc.). There may be.

Examples of the organic particle dispersant include hydrophilic organic particle dispersants. Examples of the organic particle dispersant include particles such as poly (meth) acrylic acid alkyl ester resin (for example, polymethyl methacrylate resin), polystyrene resin, and poly (styrene-acrylonitrile) resin. Examples of the organic particle dispersant include particles of styrene acrylic resin.

Examples of the inorganic particle dispersant include hydrophilic inorganic particle dispersants. Specific examples of the inorganic particle dispersant include particles such as silica, alumina, titania, calcium carbonate, magnesium carbonate, tricalcium phosphate, clay, diatomaceous earth, and bentonite, and calcium carbonate particles are preferable. As the inorganic particle dispersant, one type may be used alone, or two or more types may be used in combination.

The surface of the particle dispersant may be surface-treated with a polymer having a carboxyl group.
As the polymer having a carboxyl group, the carboxyl group of α, β-monoethylene unsaturated carboxylic acid or α, β-monoethylene unsaturated carboxylic acid is composed of alkali metal, alkaline earth metal, ammonia, amine or the like. Examples include a copolymer of at least one selected from neutralized salts (alkali metal salt, alkaline earth metal salt, ammonium salt, amine salt, etc.) and an α, β-monoethyl unsaturated carboxylic acid ester. Be done. As the polymer having a carboxyl group, the carboxyl group of the copolymer of α, β-monoethylene unsaturated carboxylic acid and α, β-monoethylene unsaturated carboxylic acid ester is an alkali metal or an alkaline earth metal. , Alkaline metal salts, alkaline earth metal salts, ammonium salts, amine salts, etc., which are neutralized with ammonia, amines and the like. As the polymer having a carboxyl group, one type may be used alone, or two or more types may be used in combination.

Typical examples of α, β-monoethylene unsaturated carboxylic acid are α, β-unsaturated monocarboxylic acid (acrylic acid, methacrylic acid, crotonic acid, etc.) and α, β-unsaturated dicarboxylic acid (maleic acid). Acid, fumaric acid, itaconic acid, etc.) and the like. Typical examples of α, β-monoethyl unsaturated carboxylic acid esters include alkyl esters of (meth) acrylic acid, (meth) acrylates having an alkoxy group, and (meth) acrylates having a cyclohexyl group. Examples thereof include (meth) acrylate having a hydroxy group and polyalkylene glycol mono (meth) acrylate.

Examples of the polymer dispersant include hydrophilic polymer dispersants. Specific examples of the polymer dispersant include water-soluble polymer dispersants (for example, carboxymethyl cellulose, carboxyethyl cellulose, etc.) having a carboxyl group and no parent oil group (hydroxypropoxy group, methoxy group, etc.). Sexual cellulose ether).

[Solvent removal step]
Next, the organic solvent is removed from the obtained suspension to obtain a toner particle dispersion (solvent removal step). This solvent removing step is a step of removing the organic solvent contained in the droplets of the aqueous phase liquid dispersed in the suspension to generate toner particles. The removal of the organic solvent from the suspension may be carried out immediately after the suspension preparation step, or may be carried out one minute or more after the completion of the suspension preparation step.
In the solvent removal step, it is preferable to remove the organic solvent from the suspension by cooling or heating the obtained suspension to, for example, 0 ° C. or higher and 100 ° C. or lower.

Specific methods for removing the organic solvent include the following methods.
(1) A method of forcibly updating the gas phase on the suspension surface by blowing an air flow on the suspension. In this case, gas may be blown into the suspension.
(2) A method of reducing the pressure. In this case, the gas phase on the suspension surface may be forcibly renewed by filling with gas, or gas may be further blown into the suspension.

Toner particles are obtained through the above steps.
Here, after the solvent removal step is completed, the toner particles formed in the toner particle dispersion liquid are obtained as dried toner particles through a known washing step, solid-liquid separation step, and drying step.
In the cleaning step, it is preferable to sufficiently perform replacement cleaning with ion-exchanged water from the viewpoint of chargeability.
The solid-liquid separation step is not particularly limited, but suction filtration, pressure filtration, or the like may be performed from the viewpoint of productivity. The drying step is also not particularly limited, but from the viewpoint of productivity, freeze-drying, air-flow drying, fluid-flow drying, vibration-type fluid-drying, and the like may be performed.

Then, the toner according to the present embodiment is produced, for example, by adding an external additive to the obtained dry toner particles and mixing them.
The mixing may be carried out by, for example, a V blender, a Henschel mixer, a Ladyge mixer or the like.
Further, if necessary, coarse particles of toner may be removed by using a vibration sieving machine, a wind sieving machine, or the like.

In the kneading and crushing method, after mixing each material such as a colorant, the above materials are melt-kneaded using a kneader, an extruder, etc., the obtained melt-kneaded product is roughly pulverized, and then pulverized by a jet mill or the like. , This is a method of obtaining toner particles having a target particle size by a wind power classifier.
More specifically, the kneading and pulverizing method is divided into a kneading step of kneading a toner forming material containing a colorant and a binder resin and a pulverizing step of pulverizing the kneaded product. If necessary, it may have other steps such as a cooling step of cooling the kneaded product formed by the kneading step.
Each step related to the kneading and crushing method will be described in detail.

-Kneading process-
In the kneading step, the toner forming material containing the colorant and the binder resin is kneaded.
In the kneading step, it is desirable to add 0.5 parts by mass or more and 5 parts by mass or less of an aqueous medium (for example, water such as distilled water or ion-exchanged water, alcohols, etc.) to 100 parts by mass of the toner forming material. ..

Examples of the kneading machine used in the kneading step include a single-screw extruder and a twin-screw extruder. Hereinafter, as an example of the kneading machine, a kneading machine having a feed screw portion and two kneading portions will be described with reference to the drawings, but the present invention is not limited to this.

FIG. 1 is a diagram illustrating a screw state with respect to an example of a screw extruder used in a kneading step in the toner manufacturing method according to the present embodiment.
The screw extruder 11 adds an aqueous medium to the barrel 12 provided with a screw (not shown), the injection port 14 for injecting the toner forming material which is the raw material of the toner into the barrel 12, and the toner forming material in the barrel 12. It is composed of a liquid addition port 16 for discharging the kneaded product formed by kneading the toner forming material in the barrel 12 and a discharge port 18 for discharging the kneaded product.

The barrel 12 has a feed screw portion SA that transports the toner forming material injected from the injection port 14 to the kneading portion NA in order from the side closest to the injection port 14, and the toner forming material is melt-kneaded by the first kneading step. Knee to form a kneaded product by melting and kneading the feed screw portion SB and the toner forming material for transporting the toner forming material melt-kneaded in the kneading portion NA and the kneading portion NA to the kneading portion NB by the second kneading step. It is divided into a ding portion NB and a feed screw portion SC that transports the formed kneaded material to the discharge port 18.

Further, inside the barrel 12, different temperature control means (not shown) are provided for each block. That is, the temperature may be controlled differently from the block 12A to the block 12J. FIG. 1 shows a state in which the temperatures of the blocks 12A and 12B are controlled to t0 ° C., the temperatures of the blocks 12C to 12E are controlled to t1 ° C., and the temperatures of the blocks 12F to 12J are controlled to t2 ° C. There is. Therefore, the toner forming material of the kneading portion NA is heated to t1 ° C., and the toner forming material of the kneading portion NB is heated to t2 ° C.
As described above, the temperature t1 ° C. in the kneading section NA is within the range of Ta-10 ° C. or higher and Ta + 10 ° C. or lower, and the temperature t2 ° C. in the kneading section NB is within the range of Tm-10 ° C. or higher and Tm + 20 ° C. or lower. be. Further, the temperature of the endothermic peak when the toner was measured by DSC was defined as Ta, and the melting temperature when the toner was measured by DSC was defined as Tm.

When the toner forming material containing the binder resin, the colorant and, if necessary, the mold release agent and the like is supplied from the injection port 14 to the barrel 12, the toner forming material is sent from the feed screw portion SA to the kneading portion NA. At this time, since the temperature of the block 12C is set to t1 ° C., the toner forming material is sent to the kneading section NA in a state of being heated and changed to a molten state. Since the temperatures of the blocks 12D and 12E are also set to t1 ° C., the toner forming material is melt-kneaded at the temperature of t1 ° C. in the kneading portion NA. The binder resin and the mold release agent are in a molten state at the kneading portion NA and are sheared by the screw.

Next, the toner forming material that has undergone kneading in the kneading portion NA is sent to the kneading portion NB by the feed screw portion SB.
Then, in the feed screw portion SB, the water-based medium is added to the toner-forming material by injecting the water-based medium into the barrel 12 from the liquid addition port 16. Further, FIG. 1 shows a form in which the water-based medium is injected into the feed screw portion SB, but the present invention is not limited to this, and the water-based medium may be injected into the kneading portion NB, and the feed screw portion SB and the kneading portion NB may be injected. An aqueous medium may be injected in both. That is, the position and injection location for injecting the aqueous medium are selected as necessary.

As described above, when the water-based medium is injected into the barrel 12 from the liquid addition port 16, the toner-forming material in the barrel 12 and the water-based medium are mixed, and the toner-forming material is cooled by the latent heat of evaporation of the water-based medium. The temperature of the toner forming material is maintained.
Finally, the kneaded product formed by melt-kneading by the kneading section NB is transported to the discharge port 18 by the feed screw section SC and discharged from the discharge port 18.
As described above, the kneading step using the screw extruder 11 shown in FIG. 1 is performed.

-Cooling process-
The cooling step is a step of cooling the kneaded product formed in the kneading step, and in the cooling step, the temperature of the kneaded product at the end of the kneading step is cooled to 40 ° C. or lower at an average temperature lowering rate of 4 ° C./sec or more. It is preferable to do so. When the cooling rate of the kneaded product is slow, a mixture of a mixture finely dispersed in the binder resin (colorant and, if necessary, an internal additive such as a release agent added to the toner particles) in the kneading process. ) May recrystallize and the dispersion diameter may increase. On the other hand, quenching at the above average temperature lowering rate is preferable because the dispersed state immediately after the completion of the kneading step is maintained as it is. The average temperature lowering rate is the average value of the rate at which the temperature of the kneaded product is lowered from the temperature of the kneaded product (for example, t2 ° C. when the screw extruder 11 in FIG. 1 is used) to 40 ° C. at the end of the kneading step.
Specific examples of the cooling method in the cooling step include a method using a rolling roll in which cold water or brine is circulated, a sandwiching type cooling belt, and the like. When cooling is performed by the above method, the cooling rate is determined by the speed of the rolling roll, the flow rate of brine, the supply amount of the kneaded product, the slab thickness at the time of rolling the kneaded product, and the like. The slab thickness is preferably as thin as 1 mm or more and 3 mm or less.

-Crushing process-
The kneaded product cooled by the cooling step is crushed by the crushing step to form particles. In the crushing step, for example, a mechanical crusher, a jet crusher, or the like is used. Further, if necessary, the particles may be heat-treated with hot air or the like to form a sphere.

-Classification process-
The particles obtained in the pulverization step may be classified by a classification step in order to obtain toner particles having a particle size distribution in a target range, if necessary. In the classification process, conventionally used centrifugal classifiers, inertial classifiers, etc. are used, and fine powder (particles smaller than the target particle size) and coarse powder (particle size in the target range) are used. Larger particles) are removed.

-External process-
Inorganic particles typified by silica, titania, and aluminum oxide may be added and adhered to the obtained toner particles for the purpose of adjusting charge, imparting fluidity, imparting charge exchange property, and the like. These are performed by, for example, a V-type blender, a Henschel mixer, a Ladyge mixer, or the like, and may be attached in stages.

-Sieve process-
If necessary, a sieving step may be provided after the external addition step. Specific examples of the sieving method include a gyro shifter, a vibration sieving machine, and a wind sieving machine. By sieving, coarse powder of the external additive is removed, and streaks on the photoconductor and spilled stains in the apparatus are suppressed.

In the present embodiment, the aggregation and coalescence method may be used, in which the shape of the toner particles and the particle size of the toner particles can be easily controlled, and the control range of the toner particle structure such as the core-shell structure is wide.
Hereinafter, a method for producing toner particles by the aggregation and coalescence method will be described in detail.

Specifically, for example, when the toner particles are produced by the aggregation and coalescence method,
A step of preparing a resin particle dispersion liquid in which resin particles to be a binder resin are dispersed (resin particle dispersion liquid preparation step) and a step of preparing the resin particle dispersion liquid (after mixing other particle dispersion liquids as necessary). (In the dispersion), resin particles (other particles if necessary) are agglomerated to form agglomerated particles (aggregated particle forming step), and the agglomerated particle dispersion in which the agglomerated particles are dispersed is heated. Toner particles are manufactured through a step of fusing and coalescing agglomerated particles to form toner particles (fusing and coalescing step).

The details of each step will be described below.
In the following description, a method of obtaining toner particles containing a colorant and a mold release agent will be described, but the colorant and the mold release agent are used as needed. Of course, other additives other than colorants and mold release agents may be used.

-Resin particle dispersion liquid preparation process-
First, together with the resin particle dispersion liquid in which the resin particles to be the binder resin are dispersed, for example, a colorant particle dispersion liquid in which the colorant particles are dispersed and a release agent particle dispersion liquid in which the release agent particles are dispersed are prepared. do.

Here, the resin particle dispersion liquid is prepared, for example, by dispersing the resin particles in a dispersion medium with a surfactant.

Examples of the dispersion medium used in the resin particle dispersion liquid include an aqueous medium.
Examples of the aqueous medium include distilled water, water such as ion-exchanged water, alcohols, and the like. These may be used alone or in combination of two or more.

Examples of the surfactant include anionic surfactants such as sulfate ester salt type, sulfonate type, phosphoric acid ester type and soap type; cationic surfactants such as amine salt type and quaternary ammonium salt type; polyethylene glycol. Examples thereof include nonionic surfactants such as systems, alkylphenol ethylene oxide adducts, and polyhydric alcohols. Among these, anionic surfactants and cationic surfactants are particularly mentioned. The nonionic surfactant may be used in combination with an anionic surfactant or a cationic surfactant.
The surfactant may be used alone or in combination of two or more.

Examples of the method for dispersing the resin particles in the dispersion medium in the resin particle dispersion liquid include general dispersion methods such as a rotary shear homogenizer, a ball mill having a medium, a sand mill, and a dyno mill. Further, depending on the type of the resin particles, the resin particles may be dispersed in the resin particle dispersion liquid by using, for example, a phase inversion emulsification method.
In the phase inversion emulsification method, the resin to be dispersed is dissolved in a hydrophobic organic solvent in which the resin is soluble, and a base is added to the organic continuous phase (O phase) to neutralize the resin, and then the aqueous medium is used. A method in which the (W phase) is charged to convert the resin from W / O to O / W (so-called phase inversion) to discontinue the phase, and the resin is dispersed in an aqueous medium in the form of particles. Is.

The volume average particle diameter of the resin particles dispersed in the resin particle dispersion is, for example, preferably 0.01 μm or more and 1 μm or less, more preferably 0.08 μm or more and 0.8 μm or less, and further preferably 0.1 μm or more and 0.6 μm or less. preferable.
The volume average particle size of the resin particles is determined by using the particle size distribution obtained by the measurement of a laser diffraction type particle size distribution measuring device (for example, manufactured by Horiba Seisakusho, LA-700) with respect to the divided particle size range (channel). , The cumulative distribution is subtracted from the small particle size side for the volume, and the particle size that is cumulatively 50% of all particles is measured as the volume average particle size D50v. The volume average particle diameter of the particles in the other dispersion is also measured in the same manner.

The content of the resin particles contained in the resin particle dispersion is, for example, preferably 5% by mass or more and 50% by mass or less, and more preferably 10% by mass or more and 40% by mass or less.

In addition, in the same manner as the resin particle dispersion liquid, for example, a colorant particle dispersion liquid and a release agent particle dispersion liquid are also prepared. That is, regarding the volume average particle size, dispersion medium, dispersion method, and particle content of the particles in the resin particle dispersion liquid, the colorant particles dispersed in the colorant particle dispersion liquid and the release agent particle dispersion liquid are used. The same applies to the disperse of the release agent particles.

-Agglomerated particle formation process-
Next, the colorant particle dispersion liquid and the release agent particle dispersion liquid are mixed together with the resin particle dispersion liquid.
Then, in the mixed dispersion, the resin particles, the colorant particles, and the release agent particles are heteroaggregated to form the resin particles, the colorant particles, and the release agent particles having a diameter close to the diameter of the target toner particles. Form agglomerated particles containing.

Specifically, for example, a flocculant is added to the mixed dispersion, the pH of the mixed dispersion is adjusted to be acidic (for example, the pH is 2 or more and 5 or less), and a dispersion stabilizer is added as necessary. The particles are heated to a temperature of the glass transition temperature of the resin particles (specifically, for example, the glass transition temperature of the resin particles is -30 ° C or higher and the glass transition temperature is -10 ° C or lower), and the particles dispersed in the mixed dispersion are aggregated. , Form agglomerated particles.
In the agglomerated particle forming step, for example, the mixed dispersion is stirred with a rotary shear homogenizer, the above-mentioned flocculant is added at room temperature (for example, 25 ° C. or higher and 30 ° C. or lower), and the pH of the mixed dispersion is acidic (for example, pH is). (2 or more and 5 or less) may be adjusted, and if necessary, a dispersion stabilizer may be added, and then the above heating may be performed.

Examples of the flocculant include a surfactant used as a dispersant added to the mixed dispersion, a surfactant having the opposite polarity, an inorganic metal salt, and a divalent or higher metal complex. In particular, when a metal complex is used as the flocculant, the amount of the surfactant used is reduced and the charging characteristics are improved.
If necessary, an additive that forms a complex or a similar bond with the metal ion of the flocculant may be used. As this additive, a chelating agent is preferably used.

Examples of the inorganic metal salt include metal salts such as calcium chloride, calcium nitrate, barium chloride, magnesium chloride, zinc chloride, aluminum chloride and aluminum sulfate, and inorganics such as polyaluminum chloride, polyaluminum hydroxide and calcium polysulfide. Examples include metal salt polymers.
As the chelating agent, a water-soluble chelating agent may be used. Examples of the chelating agent include oxycarboxylic acids such as tartrate acid, citric acid and gluconic acid, iminodic acid (IDA), nitrilotriacetic acid (NTA) and ethylenediaminetetraacetic acid (EDTA).
The amount of the chelating agent added is, for example, preferably 0.01 parts by mass or more and 5.0 parts by mass or less, and more preferably 0.1 parts by mass or more and less than 3.0 parts by mass with respect to 100 parts by mass of the resin particles.

-Fusion / unification process-
Next, the agglomerated particle dispersion liquid in which the agglomerated particles are dispersed is heated to, for example, a temperature equal to or higher than the glass transition temperature of the resin particles (for example, a temperature 10 to 30 ° C. higher than the glass transition temperature of the resin particles) to obtain the agglomerated particles. Are fused and united to form toner particles.

Toner particles are obtained through the above steps.
After obtaining the agglomerated particle dispersion liquid in which the agglomerated particles are dispersed, the agglomerated particle dispersion liquid and the resin particle dispersion liquid in which the resin particles are dispersed are further mixed, and the resin particles are further added to the surface of the agglomerated particles. The step of aggregating so as to adhere to form the second agglomerated particles and the second agglomerated particle dispersion liquid in which the second agglomerated particles are dispersed are heated to fuse and unite the second agglomerated particles. , Toner particles may be produced through a step of forming toner particles having a core / shell structure.

Here, after the fusion / coalescence step is completed, the toner particles formed in the solution are subjected to a known washing step, solid-liquid separation step, and drying step to obtain toner particles in a dried state.
In the cleaning step, it is preferable to sufficiently perform replacement cleaning with ion-exchanged water from the viewpoint of chargeability. The solid-liquid separation step is not particularly limited, but suction filtration, pressure filtration, or the like may be performed from the viewpoint of productivity. The drying step is also not particularly limited, but from the viewpoint of productivity, freeze-drying, air-flow drying, fluid-flow drying, vibration-type fluid-drying, and the like may be performed.

Then, the toner according to the present embodiment is produced, for example, by adding an external additive to the obtained dry toner particles and mixing them. The mixing may be carried out by, for example, a V blender, a Henschel mixer, a Ladyge mixer or the like. Further, if necessary, coarse particles of toner may be removed by using a vibration sieving machine, a wind sieving machine, or the like.

As described above, the toner particles according to the present embodiment exhibit a particle size distribution in which the distribution of toner particles on the smaller particle size side than the volume average particle size (D50v) is wider than that of the conventional toner particles. It may be difficult to form toner particles exhibiting such physical characteristics in a single step. When producing the toner particles according to the present embodiment, the particle size distribution of the toner particles may be adjusted by performing a centrifugation treatment or the like.
For example, the toner particles dispersed in a solvent such as water are subjected to a centrifugation treatment, and the toner particles collected from, for example, 30% by volume of the supernatant of the entire toner dispersion liquid are subjected to the centrifugation treatment. By adding it to ordinary toner particles that are not carried out, the distribution of toner particles on the smaller particle size side than the volume average particle size (D50v) can be widened.
When toner particles are produced by a dry method such as a kneading and pulverizing method, the obtained toner particles may be dispersed in a solvent such as water and then centrifuged or the like. When the toner particles are produced by the wet production method, the dispersion liquid of the toner particles may be subjected to a centrifugal separation treatment or the like.
In this case, the shape of the toner particles on the small particle size side may be made more spherical by subjecting the toner particles collected from the supernatant to heat treatment.

− Aeration fluid energy −
The toner of the present embodiment has a basic fluid energy measured by using a powder rheometer under the conditions that the tip speed of the rotary blade is 100 mm / sec, the approach angle of the rotary blade is -5 °, and the aeration flow rate is 0 ml / min. is preferably under 500mJ than above 150 mJ, more preferably less than 150 mJ 400 mJ, and more preferably less than 180 mJ 300 mJ. When ventilation fluidity energy is under 500mJ than above 150 mJ, scattering of toner is considered to be due to deterioration of the toner fluidity is further suppressed.

The toner of the present embodiment is the aeration fluidity energy measured by using a powder rheometer under the conditions that the tip speed of the rotary blade is 100 mm / sec, the approach angle of the rotary blade is -5 °, and the aeration flow rate is 10 ml / min. The aeration index (basic fluid energy / aeration fluid energy) based on the above-mentioned basic fluid energy is preferably 25 or more and 80 or less, more preferably 25 or more and 70 or less, and 30 or more and 60. The following is more preferable. When the air permeability index is 25 or more and 80 or less, the scattering of toner, which is considered to be caused by the deterioration of toner fluidity, is further suppressed. In particular, toner scattering is likely to be suppressed in a high stress environment.

Next, a method for measuring fluidity using a powder rheometer will be described.
The powder rheometer is a fluidity measuring device that directly obtains the fluidity by simultaneously measuring the rotational torque and the vertical load obtained by spirally rotating the rotary blade in the filled particles. By measuring both the rotational torque and the vertical load, the fluidity including the characteristics of the powder itself and the influence of the external environment can be detected with high sensitivity. In addition, since the measurement is performed after the state of particle filling is constant, data with good reproducibility can be obtained.

The measurement is performed using FT4 manufactured by freeman technology as a powder rheometer. In order to eliminate the influence of temperature and humidity before measurement, the developer (or toner) used is left at a temperature of 25 ° C. and a humidity of 45% RH for 8 hours or more.

First, the developer (or toner) is placed in a split container with an inner diameter of 25 mm (a cylinder with a height of 22 mm placed on a 25 mL container with a height of 61 mm so that it can be separated into upper and lower parts) in an amount exceeding 61 mm in height. Fill with a developer (or toner).

After filling the developer (or toner), the operation of homogenizing the sample is performed by gently stirring the filled developer (or toner). This operation will be referred to as conditioning below.

In conditioning, the rotor is gently agitated in a direction of rotation that does not receive resistance from the toner so as not to stress the developer (or toner) in the filled state, removing most of the excess air and partial stress. , Make the sample homogeneous. As a specific conditioning condition, the inside of the container is agitated from a height of 70 mm to 2 mm from the bottom surface at an approach angle of 5 ° and at a tip speed of a rotary blade of 40 mm / sec.

At this time, since the propeller-type rotor moves downward at the same time as the rotation, the tip draws a spiral, and the angle of the spiral path drawn by the tip of the propeller at this time is called an approach angle.

After repeating the conditioning operation four times, the upper end of the split vessel is gently moved to scrape off the developer (or toner) inside the vessel at a height of 61 mm to obtain toner that fills the 25 mL vessel. The conditioning operation is carried out because it is important to always obtain a powder having a constant volume in order to stably obtain the amount of fluid energy.

Further, after performing the conditioning operation once, the rotational torque when rotating at a tip speed of 100 mm / sec of the rotary blade while moving inside the container from a height of 55 mm to 2 mm from the bottom surface at an approach angle of -5 °. Measure the vertical load. The direction of rotation of the propeller at this time is opposite to that of the conditioning (clockwise when viewed from above).

The relationship between the rotational torque or the vertical load with respect to the height H from the bottom surface is shown in FIGS. 2 (A) and 2 (B). FIG. 3 shows the energy gradient (mJ / mm) with respect to the height H obtained from the rotational torque and the vertical load. The area (shaded portion in FIG. 3) obtained by integrating the energy gradient in FIG. 3 is the amount of fluid energy (mJ). The amount of fluid energy is obtained by integrating the section from the bottom surface with a height of 2 mm to 55 mm.
Further, in order to reduce the influence of the error, the average value obtained by performing this conditioning and energy measurement operation cycle five times is defined as the fluid energy amount (mJ).

The rotor has a diameter of φ23.5 mm of a two-blade propeller type shown in FIG. 4 manufactured by freeman technology.

Then, when measuring the rotational torque and the vertical load of the rotary blade, the amount of fluidity energy measured while flowing air at the target ventilation flow rate (ml / min) from the bottom of the container is the "ventilation fluidity energy". Yes, there is no ventilation from the bottom of the container, that is, the amount of fluidity energy measured at a ventilation flow rate of 0 ml / min is the "basic fluidity energy". In the FT4 manufactured by freeman technology, the inflow state of the aeration amount is controlled.

<Static charge image developer>
The electrostatic charge image developer according to the present embodiment contains at least the toner according to the present embodiment.
The electrostatic charge image developer according to the present embodiment may be a one-component developer containing only the toner according to the present embodiment, or a two-component developer mixed with the toner and a carrier.

The carrier is not particularly limited, and examples thereof include known carriers. As the carrier, for example, a coating carrier in which the surface of a core material made of magnetic powder is coated with a coating resin; a magnetic powder dispersion type carrier in which magnetic powder is dispersed and blended in a matrix resin; a porous magnetic powder is impregnated with resin. Resin-impregnated carrier; etc.
The magnetic powder dispersion type carrier and the resin impregnated type carrier may be carriers in which the constituent particles of the carrier are used as a core material and coated with a coating resin.

Examples of the magnetic powder include magnetic metals such as iron, nickel and cobalt, and magnetic oxides such as ferrite and magnetite.

Examples of the coating resin and matrix resin include polyethylene, polypropylene, polystyrene, polyvinyl acetate, polyvinyl alcohol, polyvinyl butyral, polyvinyl chloride, polyvinyl ether, polyvinyl ketone, vinyl chloride-vinyl acetate copolymer, and styrene-acrylic acid ester. Examples thereof include a copolymer, a straight silicone resin containing an organosiloxane bond or a modified product thereof, a fluororesin, a polyester, a polycarbonate, a phenol resin, an epoxy resin and the like.
The coating resin and the matrix resin may contain other additives such as conductive particles.
Examples of the conductive particles include metals such as gold, silver and copper, and particles such as carbon black, titanium oxide, zinc oxide, tin oxide, barium sulfate, aluminum borate and potassium titanate.

Here, in order to coat the surface of the core material with the coating resin, a method of coating with a coating resin and, if necessary, a coating layer forming solution in which various additives are dissolved in an appropriate solvent and the like can be mentioned. The solvent is not particularly limited, and may be selected in consideration of the coating resin to be used, coating suitability, and the like.
Specific resin coating methods include a dipping method in which the core material is immersed in a coating layer forming solution, a spray method in which the coating layer forming solution is sprayed on the core material surface, and a state in which the core material is suspended by flowing air. Examples thereof include a fluidized bed method in which a coating layer forming solution is sprayed, a kneader coater method in which a carrier core material and a coating layer forming solution are mixed in a kneader coater, and a solvent is removed.

The mixing ratio (mass ratio) of the toner and the carrier in the two-component developer is preferably toner: carrier = 1: 100 to 30: 100, and more preferably 3: 100 to 20: 100.

<Image forming device / Image forming method>
The image forming apparatus / image forming method according to the present embodiment will be described.
The image forming apparatus according to the present embodiment includes an image holder, a charging means for charging the surface of the image holder, a static charge image forming means for forming an electrostatic charge image on the surface of the charged image holder, and an electrostatic charge. A developing means that accommodates an image developer and develops an electrostatic charge image formed on the surface of the image holder as a toner image by the static charge image developer, and a recording medium that records the toner image formed on the surface of the image holder. It is provided with a transfer means for transferring to the surface of the recording medium and a fixing means for fixing the toner image transferred to the surface of the recording medium. Then, as the electrostatic charge image developer, the electrostatic charge image developer according to the present embodiment is applied.

In the image forming apparatus according to the present embodiment, a charging step of charging the surface of the image holder, a static charge image forming step of forming an electrostatic charge image on the surface of the charged image holder, and an electrostatic charge according to the present embodiment. A development step of developing an electrostatic charge image formed on the surface of an image holder as a toner image with an image developer, and a transfer step of transferring a toner image formed on the surface of the image holder to the surface of a recording medium. An image forming method (image forming method according to the present embodiment) having a fixing step of fixing a toner image transferred to the surface of a recording medium is carried out.

The image forming apparatus according to the present embodiment is a direct transfer type apparatus that directly transfers the toner image formed on the surface of the image holder to the recording medium; the toner image formed on the surface of the image holder is transferred to the intermediate transfer body. An intermediate transfer type device that first transfers the toner image to the surface and then secondarily transfers the toner image transferred to the surface of the intermediate transfer body to the surface of the recording medium; after the toner image is transferred, the surface of the image holder before charging is cleaned. A device provided with a cleaning means; a well-known image forming device such as a device provided with a static elimination means for irradiating the surface of an image holder with static elimination light after transfer of a toner image and before charging is applied.
In the case of an intermediate transfer type apparatus, the transfer means is, for example, an intermediate transfer body in which the toner image is transferred to the surface and a primary transfer in which the toner image formed on the surface of the image holder is primarily transferred to the surface of the intermediate transfer body. A configuration comprising means and secondary transfer means for secondary transfer of the toner image transferred to the surface of the intermediate transfer body to the surface of the recording medium is applied.

In the image forming apparatus according to the present embodiment, for example, the portion including the developing means may have a cartridge structure (process cartridge) that is attached to and detached from the image forming apparatus. As the process cartridge, for example, a process cartridge including a developing means containing the electrostatic charge image developer according to the present embodiment is preferably used.

Hereinafter, an example of the image forming apparatus according to the present embodiment will be shown, but the present invention is not limited thereto. The main parts shown in the figure will be described, and the other parts will be omitted.

FIG. 5 is a schematic configuration diagram showing an image forming apparatus according to the present embodiment.
The image forming apparatus shown in FIG. 5 is an electrophotographic first to output images of each color of yellow (Y), magenta (M), cyan (C), and black (K) based on color-separated image data. A fourth image forming unit 10Y, 10M, 10C, 10K (image forming means) is provided. These image forming units (hereinafter, may be simply referred to as “units”) 10Y, 10M, 10C, and 10K are arranged side by side at a predetermined distance from each other in the horizontal direction. The units 10Y, 10M, 10C, and 10K may be process cartridges that are attached to and detached from the image forming apparatus.

An intermediate transfer belt 20 as an intermediate transfer body is extended through each unit above the drawings of each unit 10Y, 10M, 10C, and 10K. The intermediate transfer belt 20 is provided by being wound around a drive roll 22 arranged apart from each other from the left to the right in the drawing and a support roll 24 in contact with the inner surface of the intermediate transfer belt 20, and the first unit 10Y to the fourth unit 10Y to the fourth. It is designed to run in the direction toward the unit 10K. A force is applied to the support roll 24 in a direction away from the drive roll 22 by a spring or the like (not shown), and tension is applied to the intermediate transfer belt 20 wound around the support roll 24. Further, an intermediate transfer body cleaning device 30 is provided on the side surface of the image holder of the intermediate transfer belt 20 so as to face the drive roll 22.
Further, the developing devices (development means) 4Y, 4M, 4C, and 4K of each unit 10Y, 10M, 10C, and 10K have yellow, magenta, cyan, and black contained in the toner cartridges 8Y, 8M, 8C, and 8K, respectively. Toner containing the four colors of toner is supplied.

Since the first to fourth units 10Y, 10M, 10C, and 10K have the same configuration, here, the first unit forming a yellow image arranged on the upstream side in the traveling direction of the intermediate transfer belt. 10Y will be described as a representative. The second to fourth units are provided with reference numerals having magenta (M), cyan (C), and black (K) instead of yellow (Y) in the portion equivalent to the first unit 10Y. The description of the units 10M, 10C, and 10K of the above is omitted.

The first unit 10Y has a photoconductor 1Y that acts as an image holder. Around the photoconductor 1Y, a charging roll (an example of charging means) 2Y that charges the surface of the photoconductor 1Y to a predetermined potential, and a laser beam 3Y based on a color-separated image signal expose the charged surface. An exposure device (an example of a static charge image forming means) for forming an electrostatic charge image (an example of a static charge image forming means) 3, a developing device (an example of a developing means) for developing a static charge image by supplying a charged toner to the static charge image, and developing the image. A primary transfer roll 5Y (an example of a primary transfer means) that transfers a toner image onto an intermediate transfer belt 20, and a photoconductor cleaning device (an example of a cleaning means) 6Y that removes toner remaining on the surface of the photoconductor 1Y after the primary transfer. Are arranged in order.
The primary transfer roll 5Y is arranged inside the intermediate transfer belt 20 and is provided at a position facing the photoconductor 1Y. Further, a bias power supply (not shown) for applying a primary transfer bias is connected to each of the primary transfer rolls 5Y, 5M, 5C, and 5K. Each bias power supply changes the transfer bias applied to each primary transfer roll by control by a control unit (not shown).

Hereinafter, the operation of forming a yellow image in the first unit 10Y will be described.
First, prior to the operation, the surface of the photoconductor 1Y is charged to a potential of −600V to −800V by the charging roll 2Y.
The photoconductor 1Y is formed by laminating a photosensitive layer on a conductive substrate (for example, volume resistivity at 20 ° C.: 1 × 10 ^{-6 Ωcm or less).} This photosensitive layer usually has a high resistivity (resistance of a general resin), but has a property that when the laser beam 3Y is irradiated, the specific resistance of the portion irradiated with the laser beam changes. Therefore, the laser beam 3Y is output to the surface of the charged photoconductor 1Y via the exposure apparatus 3 according to the image data for yellow sent from the control unit (not shown). The laser beam 3Y irradiates the photosensitive layer on the surface of the photoconductor 1Y, whereby an electrostatic charge image of a yellow image pattern is formed on the surface of the photoconductor 1Y.

The static charge image is an image formed on the surface of the photoconductor 1Y by charging. The laser beam 3Y reduces the specific resistance of the irradiated portion of the photosensitizer layer, and the charged charge on the surface of the photoconductor 1Y flows. On the other hand, it is a so-called negative latent image formed by the residual charge of the portion not irradiated with the laser beam 3Y.
The electrostatic charge image formed on the photoconductor 1Y is rotated to a predetermined development position as the photoconductor 1Y travels. Then, at this developing position, the electrostatic charge image on the photoconductor 1Y is converted into a visible image (developed image) as a toner image by the developing device 4Y.

In the developing apparatus 4Y, for example, a static charge image developing agent containing at least a yellow toner and a carrier is housed. The yellow toner is triboelectrically charged by being agitated inside the developing apparatus 4Y, and has a charge having the same polarity (negative electrode property) as the charged charge on the photoconductor 1Y, and is a developer roll (developing agent holder). Example) It is held on. Then, as the surface of the photoconductor 1Y passes through the developing device 4Y, the yellow toner is electrostatically adhered to the statically eliminated latent image portion on the surface of the photoconductor 1Y, and the latent image is developed by the yellow toner. .. The photoconductor 1Y on which the yellow toner image is formed is continuously traveled at a predetermined speed, and the toner image developed on the photoconductor 1Y is conveyed to a predetermined primary transfer position.

When the yellow toner image on the photoconductor 1Y is transferred to the primary transfer, a primary transfer bias is applied to the primary transfer roll 5Y, and an electrostatic force from the photoconductor 1Y toward the primary transfer roll 5Y is applied to the toner image to act on the photoconductor. The toner image on 1Y is transferred onto the intermediate transfer belt 20. The transfer bias applied at this time has a polarity (+) opposite to the polarity (−) of the toner, and is controlled to +10 μA by the control unit (not shown) in the first unit 10Y, for example.
On the other hand, the toner remaining on the photoconductor 1Y is removed by the photoconductor cleaning device 6Y and recovered.

Further, the primary transfer bias applied to the primary transfer rolls 5M, 5C, and 5K after the second unit 10M is also controlled according to the first unit.
In this way, the intermediate transfer belt 20 to which the yellow toner image is transferred in the first unit 10Y is sequentially conveyed through the second to fourth units 10M, 10C, and 10K, and the toner images of each color are superimposed and multiple transferred. NS.

The intermediate transfer belt 20 on which four color toner images are multiplex-transferred through the first to fourth units is arranged on the image holding surface side of the intermediate transfer belt 20, the support roll 24 in contact with the inner surface of the intermediate transfer belt, and the intermediate transfer belt 20. It leads to a secondary transfer unit composed of the secondary transfer roll (an example of the secondary transfer means) 26. On the other hand, the recording paper (an example of the recording medium) P is fed to the gap where the secondary transfer roll 26 and the intermediate transfer belt 20 are in contact with each other via the supply mechanism at a predetermined timing, and the secondary transfer bias is supported by the support roll. It is applied to 24. The transfer bias applied at this time is (-) polarity, which is the same polarity as the toner polarity (-), and the electrostatic force from the intermediate transfer belt 20 toward the recording paper P is applied to the toner image, and the transfer bias is applied on the intermediate transfer belt 20. The toner image of is transferred onto the recording paper P. The secondary transfer bias at this time is determined according to the resistance detected by the resistance detecting means (not shown) for detecting the resistance of the secondary transfer unit, and is voltage controlled.

After that, the recording paper P is sent to the pressure contact portion (nip portion) of the pair of fixing rolls in the fixing device (an example of the fixing means) 28, and the toner image is fixed on the recording paper P to form the fixing image.

Examples of the recording paper P for transferring the toner image include plain paper used in electrophotographic copying machines, printers, and the like. Examples of the recording medium include an OHP sheet and the like in addition to the recording paper P.
In order to further improve the smoothness of the image surface after fixing, the surface of the recording paper P is also preferably smooth, and for example, coated paper in which the surface of plain paper is coated with resin or the like, art paper for printing, or the like is preferably used. Will be done.

The recording paper P for which the color image has been fixed is carried out toward the ejection unit, and a series of color image forming operations is completed.

<Process Cartridge / Toner Cartridge>
The process cartridge according to this embodiment will be described.
The process cartridge according to the present embodiment contains the electrostatic charge image developer according to the present embodiment, and is a developing means for developing the electrostatic charge image formed on the surface of the image holder as a toner image by the electrostatic charge image developer. It is a process cartridge that is attached to and detached from the image forming apparatus.

The process cartridge according to the present embodiment is not limited to the above configuration, and includes a developing device and other means such as an image holder, a charging means, an electrostatic charge image forming means, and a transfer means, if necessary. It may be configured to include at least one selected from.

Hereinafter, an example of the process cartridge according to the present embodiment will be shown, but the present invention is not limited to this. The main parts shown in the figure will be described, and the other parts will be omitted.

FIG. 6 is a schematic configuration diagram showing a process cartridge according to the present embodiment.
The process cartridge 200 shown in FIG. 6 is provided around the photoconductor 107 (an example of an image holder) and the photoconductor 107 by, for example, a housing 117 provided with a mounting rail 116 and an opening 118 for exposure. The charged roll 108 (an example of the charging means), the developing device 111 (an example of the developing means), and the photoconductor cleaning device 113 (an example of the cleaning means) are integrally combined and held and configured to form a cartridge. There is.
In FIG. 6, 109 is an exposure device (an example of an electrostatic charge image forming means), 112 is a transfer device (an example of a transfer means), 115 is a fixing device (an example of a fixing means), and 300 is a recording paper (an example of a recording medium). An example) is shown.

Next, the toner cartridge according to this embodiment will be described.
The toner cartridge according to the present embodiment is a toner cartridge that houses the toner according to the present embodiment and is attached to and detached from the image forming apparatus. The toner cartridge accommodates a replenishing toner for supplying to the developing means provided in the image forming apparatus.

The image forming apparatus shown in FIG. 5 is an image forming apparatus having a structure in which the toner cartridges 8Y, 8M, 8C, and 8K are attached and detached, and the developing apparatus 4Y, 4M, 4C, and 4K are each developing apparatus (color). ) Is connected to a toner cartridge (not shown). When the amount of toner contained in the toner cartridge is low, the toner cartridge is replaced.

Hereinafter, the present embodiment will be described in more detail with reference to Examples and Comparative Examples, but the present embodiment is not limited to the following Examples. Unless otherwise specified, "parts" and "%" are based on mass.

(Preparation of resin particle dispersion)
・ Terephthalic acid: 30 mol parts ・ Fumaric acid: 70 mol parts ・ Bisphenol A ethylene oxide adduct: 5 mol parts ・ Bisphenol A propylene oxide adduct: 95 mol parts

The above materials were placed in a flask having a content of 5 liters equipped with a stirrer, a nitrogen introduction tube, a temperature sensor, and a rectification tower, and the temperature was raised to 220 ° C. over 1 hour for 100 parts of the above materials. 1 part of titanium tetraethoxydo was added. The temperature was raised to 230 ° C. over 0.5 hours while distilling off the generated water, and the dehydration condensation reaction was continued at that temperature for 1 hour, and then the reaction product was cooled. In this way, a polyester resin having a weight average molecular weight of 18,000, an acid value of 15 mgKOH / g, and a glass transition temperature of 60 ° C. was synthesized.
40 parts of ethyl acetate and 25 parts of 2-butanol were added to a container equipped with a temperature control means and a nitrogen substitution means to prepare a mixed solvent, and then 100 parts of a polyester resin was gradually added to dissolve the mixture. An aqueous ammonia solution (equivalent to 3 times the molar ratio of the acid value of the resin) was added and stirred for 30 minutes.
Next, the inside of the container was replaced with dry nitrogen, the temperature was maintained at 40 ° C., and 400 parts of ion-exchanged water was added dropwise at a rate of 2 parts / minute while stirring the mixed solution to emulsify. After completion of the dropping, the emulsion was returned to room temperature (20 ° C. to 25 ° C.) to obtain a resin particle dispersion liquid in which resin particles having a volume average particle size of 200 nm were dispersed. Ion-exchanged water was added to the resin particle dispersion liquid to adjust the solid content to 20% to obtain a resin particle dispersion liquid.

(Preparation of magenta colored particle dispersion)
・ C. I. Pigment Red 122: 50 parts ・ Ion-based surfactant Neogen RK (Daiichi Kogyo Seiyaku): 5 parts ・ Ion-exchanged water: 192.9 parts Mix the above components and use an ultimateizer (manufactured by Sugino Machine Limited) at 240 MPa for 10 Minute treatment was performed to prepare a magenta colored particle dispersion (solid content concentration: 20%).

(Preparation of mold release agent particle dispersion)
・ Paraffin wax (HNP-9 manufactured by Nippon Seiro Co., Ltd.): 100 parts ・ Anionic surfactant (manufactured by Dai-ichi Kogyo Seiyaku Co., Ltd., Neogen RK): 1 part ・ Ion-exchanged water: 350 parts

The above materials are mixed, heated to 100 ° C., dispersed using a homogenizer (Ultratarax T50 manufactured by IKA), and then dispersed by a manton Gorin high-pressure homogenizer (manufactured by Gorin Co., Ltd.), and separated by a volume average particle size of 200 nm. A mold release agent particle dispersion (solid content 20%) in which mold particles were dispersed was obtained.

<Making Magenta Toner 1>
・ Resin particle dispersion: 402.5 parts ・ Magenta colored particle dispersion: 12.5 parts ・ Release agent particle dispersion: 50 parts ・ Anionic surfactant (TaycaPower): 2 parts The above material is made of round stainless steel. After placing in a flask and adjusting the pH to 3.5 by adding 0.1 N nitric acid, 30 parts of an aqueous nitric acid solution having a polyaluminum chloride concentration of 10% was added. Subsequently, after dispersing at 30 ° C. using a homogenizer (Ultratarax T50 manufactured by IKA), the mixture was heated to 45 ° C. in a heating oil bath and held for 30 minutes. After that, 100 parts of the resin particle dispersion liquid was added and held for 1 hour, 0.1 N sodium hydroxide aqueous solution was added to adjust the pH to 8.5, and then the mixture was heated to 85 ° C. while continuing stirring. I kept the time. Then, the toner particles (1) having a volume average particle diameter of 6.0 μm were obtained by cooling to 20 ° C. at a rate of 20 ° C./min, filtering, thoroughly washing with ion-exchanged water, and drying.
After that, 100 parts of toner particles (1), 15 parts of anionic surfactant, and 200 parts of ion-exchanged water were mixed, dispersed for 20 minutes with an ultrasonic disperser, and used with a centrifuge (Himac CR22G manufactured by Hitachi Koki). After separating for 60 minutes at a gravitational acceleration of 5.5 × 104 G and allowing to stand for 40 minutes, 30% by volume of the total supernatant was collected and used as a toner dispersion liquid. This was filtered, thoroughly washed with ion-exchanged water, and dried to obtain toner particles (2).
70 parts of toner particles (1), 30 parts of toner particles (2), and 2.5 parts of hydrophobic silica particles (RY50 manufactured by Nippon Aerosil Co., Ltd.) were mixed using a Henshell mixer to obtain magenta toner 1.
Table 1 summarizes various parameters of the obtained mixture of the toner particles (1) and the toner particles (2) and the magenta toner 1.

<Making Magenta Toner 2>
The magenta toner 2 was produced by the same formulation as the magenta toner 1 except that the holding time after adding 100 parts of the resin particle dispersion liquid in the magenta toner 1 was set to 2 hours.
Table 1 summarizes various parameters for the obtained mixture of toner particles and magenta toner 2.

<Making Magenta Toner 3>
The magenta toner 3 was prepared by the same formulation as the magenta toner 1 except that the pH at which the 0.1 N sodium hydroxide aqueous solution was added to the magenta toner 1 was set to 7.8.
Table 1 summarizes various parameters of the obtained mixture of toner particles and magenta toner 3.

<Making Magenta Toner 4>
The magenta toner is the same as the magenta toner 1 except that the mixing amount of the toner particles (1) and the toner particles (2) in the magenta toner 1 is 80 parts for the toner particles (1) and 20 parts for the toner particles (2). 4 was prepared.
Table 1 summarizes various parameters of the obtained mixture of toner particles and magenta toner 4.

<Making Magenta Toner 5>
In the centrifugation of the toner particles (1) in the magenta toner 1 described above, 30% by volume of the supernatant and 30% by volume of the sediment were added to prepare a toner dispersion liquid. Subsequent steps were made in the same manner as magenta toner 1 to obtain magenta toner 5.
Table 1 summarizes various parameters of the obtained mixture of toner particles and magenta toner 5.

<Making Magenta Toner 6>
The magenta toner 6 was produced in the same manner as the magenta toner 1 except that the portion of the magenta toner 1 that was heated to 85 ° C. and held for 5 hours was held at 84 ° C. for 4 hours.
Table 1 summarizes various parameters of the obtained mixture of toner particles and magenta toner 6.

<Making Magenta Toner 7>
The magenta toner 7 was prepared in the same manner as the magenta toner 1 except that the hydrophobic silica particles in the magenta toner 1 were 5.0 parts.
Table 1 summarizes various parameters of the obtained mixture of toner particles and magenta toner 7.

<Making Magenta Toner 8>
The magenta toner 8 was prepared in the same manner as the magenta toner 1 except that the hydrophobic silica particles in the magenta toner 1 were 0.8 parts.
Table 1 summarizes various parameters of the obtained mixture of toner particles and magenta toner 8.

<Making Magenta Toner 9>
The magenta toner 9 was prepared in the same manner as the magenta toner 1 except that the terephthalic acid in the magenta toner 1 was converted to a trimellitic acid.
Table 1 summarizes various parameters of the obtained mixture of toner particles and magenta toner 9.

<Making Magenta Toner 10>
The magenta toner 10 was prepared in the same manner as the magenta toner 1 except that the terephthalic acid in the magenta toner 1 was changed to dodecenyl succinic acid.
Table 1 summarizes various parameters of the obtained mixture of toner particles and the magenta toner 10.

<Making Magenta Toner 11>
(Preparation of toner particles (11))
-Polyester resin: 176 parts-C. I. Pigment Red 122: 10 parts, paraffin wax (HNP-9 manufactured by Nippon Seiro Co., Ltd.): 14 parts or more of the components are mixed with a Henschel mixer, and then a continuous kneader having a screw configuration shown in FIG. 1 ( Kneading was carried out under the following conditions with a twin-screw extruder). The rotation speed of the screw was set to 500 rpm.
・ Feed section (blocks 12A and 12B) Set temperature: 20 ° C
・ Kneading part 1 kneading set temperature (blocks 12C to 12E): 100 ° C.
・ Kneading part 2 kneading set temperature (blocks 12F to 12J): 110 ° C
-Amount of water-based medium (distilled water) added (relative to 100 parts of raw material supply): 1.5 parts The temperature of the kneaded material at the discharge port (discharge port 18) at this time was 120 ° C.
The inside of the kneaded product was rapidly cooled by a rolling roll passing through brine at −5 ° C. and a cooling belt sandwiching a slab of cold water cooling at 2 ° C., and after cooling, it was crushed by a hammer mill. The rapid cooling rate was confirmed by changing the speed of the cooling belt. The average temperature drop rate was 10 ° C./sec.
After that, it was pulverized by a pulverizer (AFG400) built in a coarse powder classifier to obtain pulverized particles. Then, the classification treatment was performed at cut points of 4.5 μm and 7.4 μm with an inertial classifier to remove fine powder and coarse powder, and toner particles (11) having a volume average particle size of 6.8 μm were obtained.
The magenta toner 11 was produced in the same manner as the magenta toner 1 except that the toner particles (11) were changed.
Table 1 summarizes various parameters of the obtained toner particles and the magenta toner 11.

<Making Magenta Toner 12>
(Preparation of unmodified polyester resin (1))
・ Telephthalic acid: 124 parts ・ Fumaric acid: 110 parts ・ Bisphenol A ethylene oxide adduct: 183 parts ・ Bisphenol A propylene oxide adduct: 84 parts After heating and mixing the above components at 180 ° C, 0.3 parts of dibutyltin oxide Was added, and water was distilled off while heating at 220 ° C. to obtain an unmodified polyester resin. The glass transition temperature Tg of the obtained unmodified polyester resin was 60 ° C., the acid value was 3 mgKOH / g, and the hydroxyl value was 1 mgKOH / g.

(Preparation of polyester prepolymer (1))
-Terephthalic acid: 125 parts-Fumaric acid: 150 parts-Bisphenol A ethylene oxide adduct: 84 parts-Bisphenol A propylene oxide adduct: 184 parts After heating and mixing the above components at 180 ° C, 0.3 parts of dibutyltin oxide Was added, and water was distilled off while heating at 220 ° C. to obtain polyester. 35 parts of the obtained polyester, 5 parts of tolylene diisocyanate, and 50 parts of ethyl acetate are placed in a container, and the mixture is heated at 130 ° C. for 3 hours to prepare a polyester prepolymer (1) having an isocyanate group (hereinafter, “isocyanate-modified polyester”). Prepolymer (1) ") was obtained.

(Preparation of ketimine compound (1))
50 parts of methyl ethyl ketone and 150 parts of hexamethylenediamine were placed in a container and stirred at 60 ° C. to obtain ketimine compound (1).

(Preparation of magenta colorant dispersion liquid (2))
・ C. I. Pigment Red 122: 50 parts, ethyl acetate: 200 parts After mixing the above components, filtering the mixture and further mixing with 200 parts of ethyl acetate, the operation was repeated 5 times, and then the emulsion disperser Cavitron (manufactured by Pacific Kiko Co., Ltd.) , CR1010) for about 1 hour to obtain a magenta colorant dispersion (2) (solid content concentration: 20%).

(Preparation of release agent dispersion liquid (1))
-Paraffin wax (HNP-9 manufactured by Nippon Seiro Co., Ltd.): 30 parts-Ethyl acetate: 270 parts With the above components cooled to 10 ° C, wet pulverization with a microbead type disperser (DCP mill) and release. A mold release solution (1) was obtained.

(Preparation of oil phase liquid (1))
-Unmodified polyester resin (1): 30 parts-Magenta colorant dispersion liquid (2): 50 parts-Ethyl acetate: 10 parts After stirring and mixing the above components, the release agent dispersion liquid (1) 10 is added to the obtained mixture. Parts were added and stirred to obtain an oil phase liquid (1).

(Preparation of styrene acrylic resin particle dispersion liquid (1))
・ Styrene: 283 parts ・ n-butyl acrylate: 170 parts ・ Acrylic acid: 4 parts ・ Dodecanthiolu: 14 parts ・ Carbon tetrabromide: 4 parts (Sanyo Kasei Kogyo Co., Ltd .: Nonipol 400) and 10 parts of anionic surfactant (Daiichi Kogyo Seiyaku Co., Ltd .: Neogen SC) dissolved in 560 parts of ion-exchanged water in an aqueous solution in a flask. After emulsification, while mixing for 10 minutes, an aqueous solution prepared by dissolving 4 parts of ammonium persulfate in 10 parts of ion-exchanged water was added thereto, and after nitrogen substitution, the contents were brought to 70 ° C. while stirring the inside of the flask. It was heated in an oil bath until it became, and the emulsification polymerization was continued as it was for 5 hours. In this way, a styrene acrylic resin particle dispersion liquid (1) (resin particle concentration: 40%) obtained by dispersing resin particles having an average particle diameter of 180 nm and a weight average molecular weight (Mw) of 32,500 was obtained. The glass transition temperature of the styrene acrylic resin particles was 57 ° C.

(Preparation of aqueous phase liquid (1))
・ Styrene acrylic resin particle dispersion (1): 30 parts ・ 2% aqueous solution of cellogen BS-H (Daiichi Kogyo Seiyaku Co., Ltd.): 100 parts ・ Ion-exchanged water: 100 parts Stir and mix the above components and mix them in an aqueous phase. Liquid (1) was obtained.

(Preparation of toner particles (1))
-Oil phase liquid (1): 300 parts-Isocyanate-modified polyester prepolymer (1): 25 parts-Ketimine compound (1): 0.5 parts Put the above ingredients in a container and homogenizer (Ultratalax: manufactured by IKA). After stirring for 2 minutes to obtain an oil phase liquid (1P), 1000 parts of the aqueous phase liquid (1) was added to the container, and the mixture was stirred with a homogenizer for 10 minutes. Next, the mixed solution was stirred with a propeller-type stirrer at room temperature (25 ° C.) and normal pressure (1 atm) for 48 hours to react the isocyanate-modified polyester prepolymer (1) with the ketimine compound (1). A urea-modified polyester resin was produced, and the organic solvent was removed to form granules. Next, the granules were washed with water, dried and classified to obtain toner particles. In the subsequent centrifugation step, the magenta toner 12 was prepared under the same conditions as the magenta toner 1.
Table 1 summarizes various parameters for the obtained mixture of toner particles and the magenta toner 12.

<Making Magenta Toner 13>
[Preparation of resin particle dispersion liquid (X)]
-Styline: 300 parts-n-butyl acrylate: 90 parts-Acrylic acid: 0.2 parts-10-dodecanethiol: 2.0 parts A mixture of and dissolved components is a nonionic surfactant ( Nonionic 400, 6 parts manufactured by Sanyo Kasei Kogyo Co., Ltd. and 10 parts of anionic surfactant (Neogen SC, manufactured by Daiichi Kogyo Seiyaku Co., Ltd.) are emulsified and dispersed in a flask in 550 parts of ion-exchanged water for 10 minutes. While slowly mixing, 50 parts of ion-exchanged water in which 4 parts of ammonium persulfate was dissolved was added thereto. After nitrogen substitution, the inside of the flask was heated with an oil bath until the contents reached 70 ° C. while stirring, and emulsion polymerization was continued for 5 hours. As a result, a resin dispersion liquid in which styrene acrylic resin particles having a volume average particle diameter D50v = 104 nm, a glass transition temperature Tg = 59 ° C., and a weight average molecular weight Mw = 55,000 was dispersed was obtained.
[Preparation of toner 13]
Toner particles were prepared in the same manner as in Example 1 except that the resin particle dispersion was changed to 300 parts and 60 parts of the styrene acrylic resin particle dispersion (X) was further added to obtain a toner (13). ..
Table 1 summarizes various parameters of the obtained mixture of toner particles and the magenta toner 13.

<Making Magenta Toner 14>
Instead of adding 100 parts of the resin particle dispersion liquid in the above magenta toner 1, 100 parts of the resin particle dispersion liquid was added, and the magenta toner 14 was prepared in the same manner as the magenta toner 1 except that the holding for 1 hour was repeated 4 times. ..
Table 1 summarizes various parameters for the obtained mixture of toner particles and the magenta toner 14.

<Making Magenta Toner 15>
The magenta toner 15 was prepared by the same formulation as the magenta toner 1 except that the pH at which the 0.1 N sodium hydroxide aqueous solution was added to the magenta toner 1 was set to 7.0.
Table 1 summarizes various parameters for the obtained mixture of toner particles and the magenta toner 15.

<Making Magenta Toner 16>
The magenta toner 16 is the same as the magenta toner 1 except that the mixing amount of the toner particles (1) and the toner particles (2) in the magenta toner 1 is 95 parts of the toner particles (1) and 5 parts of the toner particles (2). Was produced.
Table 1 summarizes various parameters for the obtained mixture of toner particles and the magenta toner 16.

<Making Magenta Toner 17>
In the centrifugal separation step of the toner particles (2) in the magenta toner 1 described above, a toner dispersion liquid to which a sedimentation amount of 40% was added was used as a toner dispersion liquid. The subsequent steps were the same as for magenta toner 1, so that magenta toner 17 was obtained.
Table 1 summarizes various parameters of the obtained mixture of toner particles and the magenta toner 17.

<Making Magenta Toner 18>
The magenta toner 18 was produced in the same manner as the magenta toner 1 except that the step of heating the magenta toner 1 to 85 ° C. and holding it for 5 hours was held at 82 ° C. for 2 hours.
Table 1 summarizes various parameters of the obtained mixture of toner particles and magenta toner 18.

<Making Magenta Toner 19>
The magenta toner 1 was made the same as the magenta toner 1 except that 2.5 parts of hydrophobic silica particles (RY50) and 1.5 parts of titanium oxide (manufactured by TAYCA Corporation, JMT2000) were added at the time of external addition. Magenta toner 19 was produced.
Table 1 summarizes various parameters of the obtained mixture of toner particles and magenta toner 19.

<Making Magenta Toner 20>
After the external addition of the magenta toner 1 described above, the toner was seasoned at 40 ° C. and 50% for 24 hours.
The magenta toner 20 was produced in the same manner as the magenta toner 1 except for the above.
Table 1 summarizes various parameters for the obtained mixture of toner particles and the magenta toner 20.

<Making Magenta Toner 21>
At the time of external addition with the above magenta toner 1, 2.5 parts of hydrophobic silica particles (RY50) and 1.5 parts of titanium oxide (manufactured by TAYCA Corporation, JMT2000) were added, and then the toner was added at 40 ° C. and 50% for 24 hours. Seasoned under the conditions of. The magenta toner 21 was produced in the same manner as the magenta toner 1 except for the above.
Table 1 summarizes various parameters for the obtained mixture of toner particles and the magenta toner 21.

<Making Magenta Toner 22>
When externally added to the above magenta toner 1, 2.5 parts of hydrophobic silica particles (RY50), 1.5 parts of titanium oxide (manufactured by TAYCA Corporation, JMT2000), and sol-gel silica particles (manufactured by Shin-Etsu Chemical Co., Ltd.) , X24) was added in an amount of 2.5 parts. The magenta toner 22 was produced in the same manner as the magenta toner 1 except for the above.
Table 1 summarizes various parameters for the obtained mixture of toner particles and the magenta toner 22.

<Making Magenta Toner 23>
After dispersing the material in the same manner as in magenta toner 1, the material was heated to 50 ° C. in a heating oil bath and held for 60 minutes. After that, 100 parts of the resin particle dispersion liquid was added and held for 1 hour, 0.1 N sodium hydroxide aqueous solution was added to adjust the pH to 8.5, and then the mixture was heated to 85 ° C. while continuing stirring. I kept the time. Then, the mixture was cooled to 20 ° C. at a rate of 20 ° C./min, filtered, and thoroughly washed with ion-exchanged water to obtain toner particles (A). After that, 100 parts of toner particles (A), 15 parts of anionic surfactant, and 200 parts of ion-exchanged water were mixed, dispersed for 20 minutes with an ultrasonic disperser, and used with a centrifuge (Himac CR22G manufactured by Hitachi Koki). After separating for 60 minutes at a gravitational acceleration of 5.5 × 104 G and allowing to stand for 40 minutes, the supernatant for 10% by volume of the whole and the sedimentation for 10% by volume of the whole were removed. The remaining toner dispersion was filtered, thoroughly washed with ion-exchanged water, and dried to obtain toner particles (B). The magenta toner 23 was obtained in the same manner as the magenta toner 1 except that the toner particles (B) were used instead of the toner particles (1) and the toner particles (2).
Table 1 summarizes various parameters of the obtained toner particles and the magenta toner 23.

Each toner and carrier obtained as described above were placed in a V blender at a ratio of toner: carrier = 5:95 (mass ratio) and stirred for 20 minutes to obtain each developer.

The carrier used was prepared as follows.
-Ferrite particles (volume average particle size: 50 μm): 100 parts-Toluene: 14 parts-Styrene-methylmethacrylate copolymer: 2 parts (component ratio: 90/10, Mw = 80000)
-Carbon black (R330: manufactured by Cabot Corporation): 0.2 part First, the above components excluding ferrite particles were stirred with a stirrer for 10 minutes to prepare a dispersed coating liquid, and then this coating liquid and ferrite particles were used. Was placed in a vacuum degassing type kneader, stirred at 60 ° C. for 30 minutes, degassed under reduced pressure while further heating, and dried to obtain carriers.

[evaluation]
[Evaluation of halftone scattering under low temperature and low humidity]
The following work and image formation were performed in an environment of a temperature of 10 ° C. and a relative humidity of 10%.
When the image density is 100% with respect to high-quality paper (J paper, Fuji Xerox, basis weight 82 g / m ^{2) by filling the Fuji Xerox copier Versant 3100 Press with a developer and a toner cartridge.} The toner weight on the paper ^{was adjusted to 6.0 mg / cm 2,} and 100 magenta solid images having an image density of 100% were continuously output. The process speed at this time was 445 mm / sec. Then, 10 monochromatic images (dot charts) having an image density of 50% were output. The 10th output image was graded (G1-G4) against toner scattering using a loupe with a scale of × 100 times.

[Evaluation of halftone scattering under high temperature and high humidity]
The following work and image formation were performed in an environment of a temperature of 30 ° C. and a relative humidity of 85%.
The Versant 3100 Press, a copying machine manufactured by Fuji Xerox Co., Ltd., was filled with a developer and a toner cartridge, and the humidity was adjusted for 72 hours. After that, the toner weight on the paper is 6.0 mg / cm ² when the image density is 100% with respect to the coated paper (OS coated paper W, manufactured by Fuji Xerox Co., Ltd., basis weight 127 g / m ^2). After adjustment, 100 magenta solid images having an image density of 100% were continuously output. The process speed at this time was 445 mm / sec. Then, 10 monochromatic images (dot charts) having an image density of 50% were output. The 10th output image was graded (G1-G4) against toner scattering using a loupe with a scale of × 100 times.

-Evaluation criteria-
G1: Toner scattering cannot be confirmed.
G2: Toner scattering can be slightly confirmed.
G3: Although there is toner scattering, there is no problem in actual use.
G4: Toner may scatter, which may cause a problem in actual use.
G5: Toner is scattered, which causes a problem in actual use.

1Y, 1M, 1C, 1K, photoconductor (example of image holder)
2Y, 2M, 2C, 2K, charging roll (example of charging means)
3 Exposure device (an example of electrostatic charge image forming means)
3Y, 3M, 3C, 3K laser beam 4Y, 4M, 4C, 4K developing device (example of developing means)
5Y, 5M, 5C, 5K primary transfer roll (example of primary transfer means)
6Y, 6M, 6C, 6K Photoreceptor cleaning device (an example of cleaning means)
8Y, 8M, 8C, 8K Toner Cartridge 10Y, 10M, 10C, 10K Image Forming Unit 20 Intermediate Transfer Belt (Example of Intermediate Transfer)
22 Drive roll 24 Support roll 26 Secondary transfer roll (an example of secondary transfer means)
30 Intermediate transfer member cleaning device 107 Photoreceptor (example of image holder)
108 Charging roll (an example of charging means)
109 Exposure device (an example of static charge image forming means)
111 Developing equipment (an example of developing means)
112 Transfer device (an example of transfer means)
113 Photoreceptor cleaning device (an example of cleaning means)
115 Fixing device (an example of fixing means)
116 Mounting rail 117 Housing 118 Opening for exposure 200 Process cartridge 300 Recording paper (an example of recording medium)
P Recording paper (an example of recording medium)

Claims (11)

The large diameter side volume particle size distribution index (GSDv (90/50)) is 1.20 or more and 1.40 or less.
The small diameter side number particle size distribution index (GSDp (50/10)) is 1.30 or more,
GSDv (90/50) / GSDp (50/10) is 0.93 or less,
See contains toner particles having an average circularity of 0.94 to 1.00,
The basic fluid energy measured using a powder rheometer under the conditions that the tip speed of the rotor blade is 100 mm / sec, the approach angle of the rotor blade is -5 °, and the aeration flow rate is 0 ml / min is 150 mJ or more and 500 mJ or less. Toner for static charge image development. The large-diameter side volume particle size distribution index (GSDv (90/50)) of the toner particles is 1.25 or more and 1.38 or less, and the small-diameter side number particle size distribution index (GSDp (50/10)) is 1.35 or more. The toner for static charge image development according to claim 1, wherein GSDv (90/50) / GSDp (50/10) is 0.92 or less, and the average circularity is 0.95 or more and 1.00 or less. .. Claim 1 in which the average circularity of the toner particles having a particle diameter in the range of 0.1 times or more and 0.5 times or less of the volume average particle diameter (D50v) of the toner particles is 0.96 or more and 1.00 or less. Alternatively, the toner for developing an electrostatic charge image according to claim 2. The aeration fluidity energy measured using a powder rheometer under the conditions that the tip speed of the rotary blade is 100 mm / sec, the approach angle of the rotary blade is -5 °, and the aeration flow rate is 10 ml / min, and the basic fluidity energy. The static charge image developing toner according to any one of claims 1 to 3, wherein the aeration index (basic fluidity energy / aeration fluidity energy) based on the above is 25 or more and 80 or less. The static product according to any one of claims 1 to 4 , wherein the toner particles contain a release agent and a resin having an acid value of 8.0 mgKOH / g or more and 18.0 mgKOH / g or less as a binder resin. Toner for charge image development. The toner for static charge image development according to claim 5 , wherein the resin having an acid value of 8.0 mgKOH / g or more and 18.0 mgKOH / g or less contains a polyester resin. A static charge image developer containing the toner for static charge image development according to any one of claims 1 to 6. The toner for developing an electrostatic charge image according to any one of claims 1 to 6 is housed in the toner.
A toner cartridge that is attached to and detached from the image forming device. A developing means for accommodating the electrostatic charge image developing agent according to claim 7 and developing the electrostatic charge image formed on the surface of the image holder as a toner image by the electrostatic charge image developing agent is provided.
A process cartridge that is attached to and detached from the image forming device. Image holder and
A charging means for charging the surface of the image holder and
An electrostatic charge image forming means for forming an electrostatic charge image on the surface of the charged image holder, and
A developing means for accommodating the electrostatic charge image developer according to claim 7 and developing the electrostatic charge image formed on the surface of the image holder as a toner image by the electrostatic image developer.
A transfer means for transferring a toner image formed on the surface of the image holder to the surface of a recording medium, and
A fixing means for fixing the toner image transferred to the surface of the recording medium, and
An image forming apparatus comprising. The charging process that charges the surface of the image holder,
A static charge image forming step of forming a static charge image on the surface of the charged image holder, and
A developing step of developing an electrostatic charge image formed on the surface of the image holder as a toner image by using the electrostatic charge image developer according to claim 7.
A transfer step of transferring a toner image formed on the surface of the image holder to the surface of a recording medium, and
A fixing step of fixing the toner image transferred to the surface of the recording medium, and
An image forming method having.

Images