JP2018049150A - Toner for electrostatic charge image development, electrostatic charge image developer, toner cartridge, process cartridge, image forming apparatus, and image forming method - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a toner for electrostatic charge image development that reduces the occurrence of color spots occurring when an image with a low image density is repeatedly formed in a high-temperature and high-humidity environment, and reduces the occurrence of color spots occurring due to poor fixing of a toner image in a low-temperature and low-humidity environment.SOLUTION: A toner for electrostatic charge image development includes toner particles each containing a binder resin, a mold release agent, and a metal that can take an ionic valence of divalent or more, where the density Mx of the metal measured by X-ray fluorescence analysis (XRF) is 0.02 mass% or more and 0.10 mass% or less; when the volume average particle diameter of the toner particles is D, the relationship between the density Mes (unit: %) of the metal measured by energy dispersive X-ray spectroscopy (EDX) in a condition: acceleration voltage=0.6×D+0.9(kV) and the density Met (unit: %) of the metal measured by energy dispersive X-ray spectroscopy (EDX) in a condition: acceleration voltage=1.8×D+4.9(kV) satisfies the formula (1): 0≤Mes/Met<0.30.SELECTED DRAWING: None

Description

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

  A method for visualizing image information through an electrostatic charge image by electrophotography or the like is currently used in various fields. In electrophotography, image information is formed as an electrostatic charge image on the surface of an image carrier (for example, a photoreceptor), and a toner image is developed on the surface of the image carrier using a developer containing toner. The image is visualized as an image through a transfer process for transferring the image to a recording medium such as paper and a fixing process for fixing the toner image on the surface of the recording medium.

  For example, Patent Document 1 discloses that “a toner having at least a binder resin, a colorant, a release agent, and a sulfur element-containing polymer, and a toner having an external additive, the toner particles being magnesium, calcium, , A toner containing at least one element selected from the group consisting of barium, zinc, aluminum and phosphorus and having a total content of the above elements of 100 to 30000 ppm (toner particle mass basis).

  Patent Document 2 states that “a toner having toner particles containing at least a binder resin, a colorant, a release agent, and a resin having a sulfur atom, and inorganic fine powder mixed in the toner particles. I) The toner particles contain at least one element selected from the group consisting of magnesium, calcium, barium, zinc, aluminum and phosphorus, and the following formula: 4 ≦ (total content of the above elements (T ): Ppm) / (content of elemental sulfur (S): ppm) ≦ 30, ii) the weight average particle diameter (D4) of the toner is 3 μm to 10 μm, and iii) the average circularity of the toner Is a toner having an A of 0.950 to 0.995.

  Patent Document 3 states that “the content of aluminum element contained in the vicinity of the surface of the toner measured by X-ray photoelectron spectroscopy (A) in the electrostatic image developing toner comprising at least a binder resin and a colorant. (A / B) between the content of sulfur and the content of sulfur element (B) is in the range of 0.05 to 0.20, and the depth from the surface is in the range of 0.01 to 0.5 μm. An electrostatic image developing toner in which the aluminum element content (A) is in the range of 0.02 to 0.08 atomic%.

JP 2002-108019 A Japanese Patent Laying-Open No. 2005-062807 JP 2006-267743 A

  An object of the present invention is to provide a metal measured by fluorescent X-ray analysis (XRF) in a toner for developing an electrostatic image having toner particles containing a binder resin, a release agent, and a metal ion having a valence of 2 or more. The metal concentration Mes and the metal concentration Met measured by energy dispersive X-ray spectroscopy (EDX) satisfy the formula (1). Electrostatic charge that suppresses the generation of color points when low-density images are repeatedly formed in a high-temperature and high-humidity environment and the generation of color points due to poor fixing of toner images in a low-temperature and low-humidity environment, compared to the case where there is no To provide a toner for image development.

  The above problem is solved by the following means. That is,

The invention according to claim 1
Including a binder resin, a release agent, and a metal capable of taking a divalent or higher ionic valence, the metal concentration Mx measured by X-ray fluorescence analysis (XRF) is 0.02% by mass or more and 0.10. Having toner particles that are less than or equal to mass percent,
When the volume average particle diameter of the toner particles is D, the metal concentration Mes (measured by energy dispersive X-ray spectroscopy (EDX) under the condition of acceleration voltage = 0.6 × D + 0.9 (kV) (Unit:%) and the metal concentration Met (unit:%) measured by energy dispersive X-ray spectroscopy (EDX) under the condition of acceleration voltage = 1.8 × D + 4.9 (kV) An electrostatic charge image developing toner satisfying the following formula (1).
Formula (1): 0 ≦ Mes / Met <0.30

The invention according to claim 2
When the volume average particle diameter of the toner particles is D, the metal concentration Mem (unit:%) measured by energy dispersive X-ray spectroscopy (EDX) under the condition of acceleration voltage = 1.2 × D + 1.8 kV And the concentration Met (unit:%) of the metal satisfy the following formula (2).
Formula (2): 0 ≦ Mem / Met <0.3

The invention according to claim 3
The electrostatic image developing toner according to claim 1, wherein the metal is aluminum.

The invention according to claim 4
An electrostatic charge image developer comprising the electrostatic charge image developing toner according to claim 1.

The invention according to claim 5
An electrostatic charge image developing toner according to any one of claims 1 to 3 is accommodated,
A toner cartridge to be attached to and detached from the image forming apparatus.

The invention according to claim 6
A developing means for containing the electrostatic charge image developer according to claim 4 and developing the electrostatic charge image formed on the surface of the image carrier as a toner image by the electrostatic charge image developer,
A process cartridge attached to and detached from the image forming apparatus.

The invention according to claim 7 provides:
An image carrier,
Charging means for charging the surface of the image carrier;
An electrostatic charge image forming means for forming an electrostatic charge image on the surface of the charged image carrier;
Development means for containing the electrostatic charge image developer according to claim 4 and developing the electrostatic charge image formed on the surface of the image carrier as a toner image by the electrostatic charge image developer;
Transfer means for transferring a toner image formed on the surface of the image carrier to the surface of a recording medium;
Fixing means for fixing the toner image transferred to the surface of the recording medium;
An image forming apparatus comprising:

The invention according to claim 8 provides:
A charging step for charging the surface of the image carrier;
An electrostatic charge image forming step of forming an electrostatic charge image on the surface of the charged image carrier;
A developing step of developing an electrostatic charge image formed on the surface of the image carrier as a toner image with the electrostatic charge image developer according to claim 4;
A transfer step of transferring a toner image formed on the surface of the image carrier to the surface of a recording medium;
A fixing step of fixing the toner image transferred to the surface of the recording medium;
An image forming method comprising:

According to the first aspect of the present invention, in an electrostatic charge image developing toner having a toner particle containing a binder resin, a release agent, and a metal capable of taking an ionic valence of 2 or more, fluorescent X-ray analysis ( The metal concentration Mx measured by XRF) is less than 0.02% by mass or more than 0.10% by mass, or the metal concentration Mes and the metal concentration Met measured by energy dispersive X-ray spectroscopy (EDX). Compared with the case where does not satisfy the formula (1), a color point generated when an image having a low image density is repeatedly formed in a high-temperature and high-humidity environment, and a color point caused by poor fixing of a toner image in a low-temperature and low-humidity environment An electrostatic charge image developing toner that suppresses the occurrence of the above is provided.
According to the second aspect of the present invention, the metal concentration Mem and the metal concentration Met measured by energy dispersive X-ray spectroscopy (EDX) do not satisfy the formula (2). Thus, there is provided a toner for developing an electrostatic charge image that suppresses the generation of a color point when a low image density image is repeatedly formed and the generation of a color point due to poor fixing of the toner image in a low temperature and low humidity environment.
According to the third aspect of the invention, compared to the case where the metal is barium, black spots are generated when an image having a low image density is repeatedly formed under a high temperature and high humidity environment, and the toner image is generated under a low temperature and low humidity environment. There is provided a toner for developing an electrostatic image that suppresses the generation of a color point caused by a fixing failure.
According to the invention according to claim 4, 5, 6, 7, or 8, for developing an electrostatic image having toner particles containing a binder resin, a release agent, and a metal capable of taking a divalent or higher ionic valence. The toner has a metal concentration Mx of less than 0.02% by mass or more than 0.10% by mass measured by fluorescent X-ray analysis (XRF), or measured by energy dispersive X-ray spectroscopy (EDX). This occurs when an image having a low image density is repeatedly formed in a high-temperature and high-humidity environment as compared with the case where an electrostatic charge image developing toner in which the metal concentration Mes and the metal concentration Met do not satisfy the formula (1) is applied. Provided are an electrostatic charge image developer, a toner cartridge, a process cartridge, an image forming apparatus, and an image forming method that suppress the generation of a color point and the occurrence of a color point due to poor fixing of a toner image in a low temperature and low humidity environment. .

1 is a schematic configuration diagram illustrating an example of an image forming apparatus according to an exemplary embodiment. It is a schematic block diagram which shows an example of the process cartridge of this embodiment.

  Hereinafter, an embodiment which is an example of the present invention will be described in detail.

(Static image developing toner)
The toner for developing an electrostatic charge image (hereinafter referred to as “toner”) according to the present embodiment includes a binder resin, a release agent, and a metal that can take a divalent or higher ion valence (hereinafter simply referred to as “metal”). And a toner particle having a metal concentration Mx of 0.02 mass% or more and 0.10 mass% or less as measured by X-ray fluorescence analysis (XRF).
When the volume average particle diameter of the toner particles is D, the metal concentration Mes measured by energy dispersive X-ray spectroscopy (EDX) under the condition of acceleration voltage = 0.6 × D + 0.9 (kV). (Unit:%) and the metal concentration Met (unit:%) measured by energy dispersive X-ray spectroscopy (EDX) under the condition of acceleration voltage = 1.8 × D + 4.9 (kV) Satisfies the following formula (1).
Formula (1): 0 ≦ Mes / Met <0.30

  The toner according to the exemplary embodiment has the above-described configuration when a low image density image is repeatedly formed in a high-temperature and high-humidity environment (for example, an image having an image density of 1% is 10000 on A3 paper in an environment of 40 ° C. and 85% RH). Generation of a color point generated when a sheet is output) and generation of a color point due to poor fixing of a toner image in a low-temperature and low-humidity environment (for example, in an environment of 10 ° C. and 15% RH). The reason is estimated as follows.

For example, when an image having a low image density is repeatedly formed in a high temperature and high humidity environment, the toner consumption is small in the repeated image formation with a low image density, and the same toner continues to be subjected to a mechanical load and a thermal load in the developing unit. Therefore, the toner particles may be broken. In particular, when a release agent is included in the toner particles, the release agent is present in the binder resin as a base material by forming a domain with low mechanical strength. As a starting point, the toner is likely to crack.
When the toner particles are broken, the broken toner particles are difficult to be charged and fall from the developing member of the developing means, and may appear as black spots in the image.

On the other hand, in order to suppress cracking of the toner particles, a method of increasing the amount of the functional group (carboxyl group, hydroxyl group) of the binder resin and the metal (its ion) that forms ionic crosslinks, a resin having a high glass transition temperature as the binder resin It is known to increase the hardness of the entire toner particles by a method using the toner.
However, if the hardness of the entire toner particle is increased, fixing failure of the toner image (particularly fixing failure of isolated toner such as dots when forming a halftone image) occurs, and a part of the toner image is transferred to the fixing member. In addition, since it accumulates and falls on a member (finger member) that peels the recording medium from the fixing member, it may appear in the image as a color point.

  In contrast, in the toner according to the present exemplary embodiment, the metal concentration Mx is set in the above range, and the relationship between the metal concentration Mes and the metal concentration Met satisfies the formula (1).

Here, since the metal concentration Mx is a metal concentration measured by X-ray fluorescence analysis (XRF), it indicates the ratio (mass ratio) of the metal to the entire toner particles.
The metal concentration Mes is a metal concentration measured by energy dispersive X-ray spectroscopy (EDX) under the condition of a low acceleration voltage such as an acceleration voltage = 0.6 × D + 0.9 (kV). The ratio (mass ratio) of the metal in the toner particle surface layer on the irradiation side (for example, a depth region within 15% of the volume average particle diameter of the toner particles from the surface of the toner particles) is shown.
The metal concentration Met is a metal concentration measured by energy dispersive X-ray spectroscopy (EDX) under the condition of high acceleration voltage such as acceleration voltage = 1.8 × D + 4.9 (kV). Ratio of metal (mass ratio) in the entire toner particles in the irradiated area (the entire area from the surface of the toner particle irradiated with the electron beam to the back surface on the opposite side). ).

  That is, “Mes / Met” in the formula (1) indicates the ratio of the metal concentration Mes in the toner particle surface layer on the side irradiated with the electron beam to the metal concentration Met in the entire toner particles. The expression (1): satisfying 0 ≦ Mes / Met <0.30 indicates that the metal contained in the toner particles is unevenly distributed inside the toner particles.

  On the other hand, the metal contained in the toner particles is considered to exist as metal ions. The metal ion is considered to form an ionic bridge with a functional group (for example, carboxyl group, hydroxyl group, etc.) of the binder resin.

Further, by suppressing the metal concentration Mx with respect to the entire toner particles within the above range and by making the metal ions unevenly distributed inside the toner particles, more ionic crosslinks due to metal ions are formed inside than the surface layer of the toner particles. Therefore, the apparent molecular weight of the binder resin is increased, the internal strength of the toner particles is increased, the toner particles are hardly deformed, and cracking of the toner particles is suppressed. Further, since the strength of the binder resin surrounding the release agent domain is increased inside the toner particles, cracking of the toner starting from the release agent domain (or its interface) is also suppressed.
On the other hand, since the surface layer of the toner particles has little or no ionic crosslinking by metal ions, the fixing property is also ensured.

  As described above, the toner according to the exemplary embodiment generates black spots that are generated when an image having a low image density is repeatedly formed in a high temperature and high humidity environment, and color spots that are generated due to poor fixing of the toner image in a low temperature and low humidity environment. It is estimated that

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

  The toner according to this embodiment has toner particles. The toner may have an external additive attached to the surface of the toner particles as necessary.

(Toner particles)
The toner particles include, for example, a binder resin, a release agent, and a metal. The toner particles may contain a colorant and other additives as necessary.

-Binder resin-
Examples of the binder resin include styrenes (eg, styrene, parachlorostyrene, α-methylstyrene, etc.), (meth) acrylic acid esters (eg, 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 (for example, acrylonitrile, Methacrylonitrile, 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, etc.) Emissions, a homopolymer of a monomer such as butadiene) and the like, or a vinyl-based resin composed of these monomers with two or more combinations copolymer.
As the binder resin, for example, epoxy resin, polyester resin, polyurethane resin, polyamide resin, cellulose resin, polyether resin, non-vinyl resin such as modified rosin, a mixture of these with the vinyl resin, or these Examples also include a graft polymer obtained by polymerizing a vinyl monomer in the coexistence.
These binder resins may be used alone or in combination of two or more.

A polyester resin is suitable as the binder resin.
Examples of the polyester resin include known polyester resins.

  As a polyester resin, the condensation polymer of polyhydric carboxylic acid and polyhydric alcohol is mentioned, for example. In addition, as a polyester resin, a commercial item may be used and what was synthesize | combined may be used.

Examples of the polyvalent carboxylic acid include aliphatic dicarboxylic acids (eg, 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 acids (for example, cyclohexanedicarboxylic acid), aromatic dicarboxylic acids (for example, terephthalic acid, isophthalic acid, phthalic acid, naphthalenedicarboxylic acid, etc.), their anhydrides, or lower (for example, having 1 or more carbon atoms) 5 or less) alkyl esters. Among these, as polyvalent carboxylic acid, aromatic dicarboxylic acid is preferable, for example.
The polyvalent carboxylic acid may be used in combination with a dicarboxylic acid or a trivalent or higher carboxylic acid having a crosslinked structure or a branched structure. Examples of the trivalent or higher carboxylic acid include trimellitic acid, pyromellitic acid, anhydrides thereof, and lower (for example, having 1 to 5 carbon atoms) alkyl esters.
Polyvalent carboxylic acid may be used individually by 1 type, and may use 2 or more types together.

Examples of the polyhydric alcohol include aliphatic diols (for example, ethylene glycol, diethylene glycol, triethylene glycol, propylene glycol, butanediol, hexanediol, neopentyl glycol, etc.), alicyclic diols (for example, cyclohexanediol, cyclohexanedimethanol, Hydrogenated bisphenol A, etc.) and aromatic diols (for example, ethylene oxide adducts of bisphenol A, propylene oxide adducts of bisphenol A, etc.). 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 together with the diol. Examples of the trihydric or higher polyhydric alcohol include glycerin, trimethylolpropane, and pentaerythritol.
A polyhydric alcohol may be used individually by 1 type, and may use 2 or more types together.

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 determined from a DSC curve obtained by differential scanning calorimetry (DSC), and more specifically described in the method for determining the glass transition temperature in JIS K 7121-1987 “Method for Measuring Plastic Transition Temperature”. Of “extrapolated glass transition start temperature”.

The weight average molecular weight (Mw) of the polyester resin is preferably from 5,000 to 1,000,000, and more preferably from 7,000 to 500,000.
The number average molecular weight (Mn) of the polyester resin is preferably from 2,000 to 100,000.
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 with a THF solvent using a Tosoh GPC / HLC-8120GPC as a measuring device and a Tosoh column / TSKgel SuperHM-M (15 cm). The weight average molecular weight and the number average molecular weight are calculated using a molecular weight calibration curve prepared from a monodisperse polystyrene standard sample from this measurement result.

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 in the reaction system is reduced as necessary, and the reaction is performed while removing water and alcohol generated during the condensation.
In addition, when the monomer of the raw material is not dissolved or compatible at the reaction temperature, a solvent having a high boiling point may be added and dissolved as a solubilizing agent. In this case, the polycondensation reaction is performed while distilling off the solubilizer. If there is a monomer with poor compatibility, it is recommended to condense the monomer with poor compatibility with the monomer and the acid or alcohol to be polycondensed in advance before polycondensing with the main component. .

A styrene (meth) acrylic resin is also suitable as the binder resin.
Examples of the styrene (meth) acrylic resin include known styrene (meth) acrylic resins.

Styrene (meth) acrylic resin is composed of styrene polymerizable monomer (polymerizable monomer having styrene skeleton) and (meth) acrylic polymerizable monomer (polymerizable monomer having (meth) acryloyl skeleton). ) At least a copolymer.
“(Meth) acryl” is an expression including both “acryl” and “methacryl”.

Examples of the styrenic polymerizable monomer include styrene and alkyl-substituted styrene (for example, α-methylstyrene, 2-methylstyrene, 3-methylstyrene, 4-methylstyrene, 2-ethylstyrene, 3-ethylstyrene, 4-ethylstyrene, etc.), halogen-substituted styrene (for example, 2-chlorostyrene, 3-chlorostyrene, 4-chlorostyrene, etc.), vinylnaphthalene and the like. A styrene-type polymerizable monomer may be used individually by 1 type, and may use 2 or more types together.
Among these, as the styrene monomer, styrene is preferable in terms of easy reaction, easy control of reaction, and availability.

  Examples of the (meth) acrylic polymerizable monomer include (meth) acrylic acid and (meth) acrylic acid ester. Examples of (meth) acrylic acid esters include (meth) acrylic acid alkyl esters (for example, methyl (meth) acrylate, ethyl (meth) acrylate, n-propyl (meth) acrylate, and (meth) acrylic acid n. -Butyl, n-pentyl (meth) acrylate, n-hexyl acrylate, n-hexyl (meth) acrylate, n-octyl (meth) acrylate, n-decyl (meth) acrylate, (meth) acrylic acid n-dodecyl, n-lauryl (meth) acrylate, n-tetradecyl (meth) acrylate, n-hexadecyl (meth) acrylate, n-octadecyl (meth) acrylate, isopropyl (meth) acrylate, (meth) Isobutyl acrylate, t-butyl (meth) acrylate, isopentyl (meth) acrylate, (meth) acrylic acid Mill, neopentyl (meth) acrylate, isohexyl (meth) acrylate, isoheptyl (meth) acrylate, isooctyl (meth) acrylate, 2-ethylhexyl (meth) acrylate, cyclohexyl (meth) acrylate, (meth) acryl Acid t-butylcyclohexyl, etc.), (meth) acrylic acid aryl esters (for example, phenyl (meth) acrylate, biphenyl (meth) acrylate, diphenylethyl (meth) acrylate, t-butylphenyl (meth) acrylate), (Meth) acrylic acid terphenyl etc.), (meth) acrylic acid dimethylaminoethyl, (meth) acrylic acid diethylaminoethyl, (meth) acrylic acid methoxyethyl, (meth) acrylic acid 2-hydroxyethyl, (meth) acrylic acid β-carboxyethyl, (meta ) Acrylamide and the like. The (meth) acrylic acid-based polymerizable monomer may be used alone or in combination of two or more.

  The copolymerization ratio (mass basis, styrene polymerizable monomer / (meth) acrylic polymerizable monomer) between the styrene polymerizable monomer and the (meth) acrylic polymerizable monomer is, for example, 85. / 15 to 70/30 is preferable.

  The styrene (meth) acrylic resin may have a crosslinked structure. The styrene (meth) acrylic resin having a cross-linked structure is, for example, a cross-linked cross-link by at least copolymerizing a styrene polymerizable monomer, a (meth) acrylic acid polymerizable monomer, and a cross-linkable monomer. Things.

Examples of the crosslinkable monomer include bifunctional or higher functional crosslinking agents.
Examples of the bifunctional crosslinking agent include divinylbenzene, divinylnaphthalene, and di (meth) acrylate compounds (for example, diethylene glycol di (meth) acrylate, methylenebis (meth) acrylamide, decanediol diacrylate, glycidyl (meth) acrylate, etc.) , Polyester type di (meth) acrylate, 2-([1′-methylpropylideneamino] carboxyamino) ethyl methacrylate, and the like.
Examples of the polyfunctional crosslinking agent include tri (meth) acrylate compounds (for example, pentaerythritol tri (meth) acrylate, trimethylolethane tri (meth) acrylate, trimethylolpropane tri (meth) acrylate, etc.), tetra (meth) acrylate Compound (for example, tetramethylolmethane tetra (meth) acrylate, oligoester (meth) acrylate, etc.), 2,2-bis (4-methacryloxy, polyethoxyphenyl) propane, diallyl phthalate, triallyl cyanurate, triallyl isocyanurate , Triallyl trimellitate, diaryl chlorendate and the like.

  The copolymerization ratio of the crosslinkable monomer to the total monomer (mass basis, crosslinkable monomer / total monomer) is preferably, for example, 2/1000 to 30/1000.

The glass transition temperature (Tg) of the styrene (meth) acrylic resin is, for example, 50 ° C. or higher and 75 ° C. or lower, preferably 55 ° C. or higher and 65 ° C. or lower, more preferably 57 ° C. or higher and 60 ° C. or lower. It is.
The glass transition temperature is determined from a DSC curve obtained by differential scanning calorimetry (DSC), and more specifically described in the method for determining the glass transition temperature in JIS K 7121-1987 “Method for Measuring Plastic Transition Temperature”. Of “extrapolated glass transition start temperature”.

The weight average molecular weight of the styrene (meth) acrylic resin is, for example, from 30,000 to 200,000, preferably from 40,000 to 100,000, and more preferably from 50,000 to 80,000 in terms of storage stability.
The weight average molecular weight is measured by gel permeation chromatography (GPC). The molecular weight measurement by GPC is performed with a THF solvent using a Tosoh GPC / HLC-8120GPC as a measuring device and a Tosoh column / TSKgel SuperHM-M (15 cm). The weight average molecular weight is calculated from the measurement result using a molecular weight calibration curve prepared with a monodisperse polystyrene standard sample.

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

-Release agent-
Examples of mold release agents include hydrocarbon waxes; natural waxes such as carnauba wax, rice wax, and candelilla wax; synthetic or mineral / petroleum waxes such as montan wax; and 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.
Note that the melting temperature is obtained from the DSC curve obtained by differential scanning calorimetry (DSC) according to “melting peak temperature” described in JIS K 7121-1987 “Method for measuring the melting temperature of plastics”. .

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

-Metal-
As a metal, it is a metal which can take the ion valence more than bivalence. However, as the metal, for example, a metal having an ionic valence of 2 or more (preferably 2 to 4) is preferable.
Specifically, the metal is preferably a metal other than chromium, zirconium, or lead. Suitable examples of the metal include at least one metal ion selected from the group consisting of aluminum, magnesium, zinc, calcium, iron, and copper.

Examples of the metal supply source (compound to be included in the toner particles as an additive) include metal salts, inorganic metal salt polymers, metal complexes, and the like. The metal salt, inorganic metal salt polymer, and metal complex are added to the toner particles as an aggregating agent, for example, when the toner particles are produced by an aggregation coalescence method.
Examples of the metal salt include aluminum sulfate, aluminum chloride, magnesium chloride, magnesium sulfate, iron (II) chloride, zinc chloride, calcium chloride, calcium sulfate and the like.
Examples of the inorganic metal salt polymer include polyaluminum chloride, polyaluminum hydroxide, polyiron sulfate (II), and calcium polysulfide.
Examples of the metal complex include a metal salt of aminocarboxylic acid. Specific examples of the metal complex include metal salts based on known chelates such as ethylenediaminetetraacetic acid, propanediaminetetraacetic acid, nitriletriacetic acid, triethylenetetraminehexaacetic acid, diethylenetriaminepentaacetic acid (for example, calcium salts, Magnesium salt, iron salt, aluminum salt, etc.).

  In addition, you may add these metal supply sources as a mere additive instead of a coagulant | flocculant use.

The higher the ionic valence of the metal, the easier it is to form a network ion bridge, and the metal element having a smaller atomic number has a smaller metal (the metal ion) and a smaller network structure of the bridge. From the viewpoint of improving the internal strength of the toner particles by ionic cross-linking of metal ions and suppressing the occurrence of color points.
For this reason, as a metal, a trivalent metal (especially Al ion) is preferable. That is, the metal supply source is preferably an aluminum salt (for example, aluminum sulfate, aluminum chloride, etc.) or an aluminum salt polymer (for example, polyaluminum chloride, polyaluminum hydroxide). Furthermore, from the viewpoint of suppressing the occurrence of color points, an inorganic metal salt polymer is preferable to a metal salt even if the metal ions have the same valence among the metal ion supply sources.

  Metal concentration Mx (concentration of the metal measured by X-ray fluorescence analysis (XRF)) is 0.02% by mass or more and 0.10% by mass or less, but suppression of color point generation due to toner particle cracking. In addition, from the viewpoint of suppressing generation of a color point due to poor fixing of a toner image, 0.03% by mass or more and 0.08% by mass or less is preferable, and 0.04% by mass or more and 0.07% by mass or less is more preferable.

Here, the metal concentration Mx is measured as follows using a fluorescent X-ray analysis method (XRF).
First, a resin and a metal supply source are mixed to obtain a resin mixture having a known metal concentration. A pellet sample is obtained from 200 mg of this resin mixture using a tableting machine having a diameter of 13 mm. The mass of the pellet sample is precisely weighed, and the fluorescent X-ray intensity of the pellet sample is measured to determine the peak intensity. Similarly, measurement is also performed on a pellet sample in which the addition amount of the metal supply source is changed, and a calibration curve is created from these results. Then, using this calibration curve, the metal concentration Mx in the toner particles to be measured is quantitatively analyzed.

Metal concentration Mes (when the volume average particle size of toner particles is D, the metal concentration measured by energy dispersive X-ray spectroscopy (EDX) under the condition of acceleration voltage = 0.6 × D + 0.9 (kV)) Concentration) and metal concentration Met (measured by energy dispersive X-ray spectroscopy (EDX) under the condition of acceleration voltage = 1.8 × D + 4.9 (kV) where D is the volume average particle diameter of toner particles). The following relationship (1) is satisfied, but from the viewpoint of suppressing the generation of color points due to toner particle cracking and suppressing the generation of color points due to poor fixing of the toner image: It is preferable to satisfy the formula (1A), and it is more preferable to satisfy the following formula (1B).
Formula (1): 0 ≦ Mes / Met <0.30
Formula (1A): 0 ≦ Mes / Met <0.25
Formula (1B): 0 ≦ Mes / Met <0.20

Further, it is measured by energy dispersive X-ray spectroscopy (EDX) under the condition of metal concentration Mem (acceleration voltage = 1.2 × D + 1.8 (kV) where D is the volume average particle diameter of toner particles). The relationship between the metal concentration) and the metal concentration Met satisfies the following expression (2) from the viewpoint of suppressing the generation of color points due to cracking of toner particles and suppressing the generation of color points due to poor fixing of the toner image. Is more preferable, it is more preferable to satisfy | fill following formula (2A), and it is still more preferable to satisfy | fill following formula (2B).
Formula (1): 0 ≦ Mem / Met <0.30
Formula (1A): 0 ≦ Mem / Met <0.25
Formula (1B): 0 ≦ Mem / Met <0.20

Here, the metal concentration Mem is a metal concentration measured by energy dispersive X-ray spectroscopy (EDX) under a medium acceleration voltage condition of acceleration voltage = 1.2 × D + 1.8 (kV). In the surface layer of a region deeper than the surface of the toner particle on the side irradiated with the electron beam than the metal concentration Mes (for example, a region within 40% of the volume average particle diameter of the toner particle from the surface of the toner particle). The ratio of metal (mass ratio) is shown.
That is, “Mem / Met” in the formula (2) is a surface layer in a region deeper from the surface of the toner particle irradiated with the electron beam than the metal concentration Mes with respect to the metal concentration Met in the entire toner particles. Shows the ratio of the metal concentration Mem. The expression (2): satisfying 0 ≦ Mem / Met <0.3 means that the metal contained in the toner particles is unevenly distributed in the toner particles as compared with the case where the expression (1) is satisfied. Show.

  The metal concentration Mes is preferably 0% or more and 0.04% or less, preferably 0% or more and 0.04% or less, from the viewpoint of suppressing the generation of color points due to toner particle cracking and suppressing the generation of color points due to poor fixing of the toner image. 03% or less is more preferable.

  The metal concentration Met is preferably 0.03% or more and 0.12% or less from the viewpoint of suppressing the generation of color points due to toner particle cracks and suppressing the generation of color points due to poor fixing of toner images. % To 0.09% is more preferable.

  The metal concentration Mem is preferably from 0% to 0.04%, preferably from 0% to 0.04% from the viewpoint of suppressing the generation of color points due to toner particle cracking and suppressing the generation of color points due to poor fixing of the toner image. 03% or less is more preferable.

Here, the metal concentration Mes, the metal concentration Met, and the metal concentration Mem are measured using energy dispersive X-ray spectroscopy (EDX) as follows.
A pellet sample is obtained from 120 mg of toner particles using a tablet molding machine having a diameter of 13 mm. The pellet sample is measured using an SEM (scanning electron microscope) with an energy dispersive X-ray spectrometer (EDX apparatus) (manufactured by Horiba: Xmax) with an acceleration voltage set. In addition, the content rate of the metal element in the range obtained by observation magnification 1000 times is measured.

  Note that the measurement of metal concentration by X-ray fluorescence analysis (XRF) and energy dispersive X-ray spectroscopy (EDX) is carried out when the external additive is externally added to the toner particles. The sample is subjected to sonication (at 20 ° C., amplitude 180 μm, 30 minutes) to remove the external additive adhering to the surface of the toner particles (free), and the collected toner particles are washed and dried. This operation is repeated until the external additive can be removed.

-Colorant-
Examples of the colorant include carbon black, chrome yellow, hansa yellow, benzidine yellow, sren yellow, quinoline yellow, pigment yellow, permanent orange GTR, pyrazolone orange, vulcan orange, watch young red, permanent red, brilliant carmine 3B, and brilliant. Carmine 6B, Dupont Oil Red, Pyrazolone Red, Resol Red, Rhodamine B Lake, Lake Red C, Pigment Red, Rose Bengal, Aniline Blue, Ultramarine Blue, Calco Oil Blue, Methylene Blue Chloride, Phthalocyanine Blue, Pigment Blue, Phthalocyanine Green, Various pigments such as malachite green oxalate, or acridine, xanthene, , Benzoquinone, azine, anthraquinone, thioindico, dioxazine, thiazine, azomethine, indico, phthalocyanine, aniline black, polymethine, triphenylmethane, diphenylmethane, thiazole, and other dyes Etc.
A colorant may be used individually by 1 type and may use 2 or more types together.

  As the colorant, a surface-treated colorant may be used as necessary, or it may be used in combination with a dispersant. A plurality 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.

-Other additives-
Examples of other additives include known additives such as a magnetic material, a charge control agent, and inorganic powder. These additives are contained in the toner particles as internal additives.

-Toner particle characteristics-
The toner particles may be toner particles having a single layer structure, or toner particles having a so-called core / shell structure composed of a core (core particle) and a coating layer (shell layer) covering the core. May be.
Here, the core / shell structure toner particles include, for example, a core portion including a binder resin and, if necessary, other additives such as a colorant and a release agent, and a binder resin. It is good to be comprised with the comprised coating layer.
In addition, a metal is contained in a core part. Moreover, although the metal may be contained in both the core part and the coating layer, it is contained in the core part higher than the coating part.

  The volume average particle diameter (D50v) of the toner particles is preferably 2 μm or more and 15 μm or less, and more preferably 3 μm or more and 9 μm or less.

In addition, various average particle diameters and various particle size distribution indexes of the toner particles are measured using Coulter Multisizer II (manufactured by Beckman-Coulter), and the electrolyte is measured using ISOTON-II (manufactured by Beckman-Coulter) The
In the measurement, 0.5 mg to 50 mg of a measurement sample is added as a dispersant to 2 ml of a 5% aqueous solution of a surfactant (preferably sodium alkylbenzenesulfonate). This is added to 100 ml or more and 150 ml or less of the electrolytic solution.
The electrolyte 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 to 60 μm is measured using a 100 μm aperture with a Coulter Multisizer II. taking measurement. The number of particles to be sampled is 50,000.
For the particle size range (channel) divided based on the measured particle size distribution, the cumulative distribution is drawn from the smaller diameter side to the volume and number, respectively, and the particle size to be 16% is the volume particle size D16v, the number particle size D16p, a particle size that is 50% cumulative is defined as a volume average particle size D50v, a cumulative number average particle size D50p, and a particle size that is 84% cumulative is defined as a volume particle size D84v and a number particle size D84p.
Using these, the volume particle size distribution index (GSDv) is calculated as (D84v / D16v) ^1/2 and the number particle size distribution index (GSDp) is calculated as (D84p / D16p) ^1/2 .

  The average circularity of the toner particles is preferably from 0.94 to 1.00, more preferably from 0.95 to 0.98.

The average circularity of the toner particles is obtained by (circle equivalent perimeter) / (perimeter) [(perimeter of a circle having the same projection area as the particle image) / (perimeter of the particle projected image)]. Specifically, it is a value measured by the following method.
First, the toner particles to be measured are collected by suction, a flat flow is formed, a flash image is instantaneously emitted, a particle image is captured as a still image, and the particle image is analyzed (Sysmex). FPIA-2100) manufactured by the company. The number of samplings for obtaining the average circularity is 3500.
When the toner has an external additive, the toner (developer) to be measured is dispersed in water containing a surfactant and then subjected to ultrasonic treatment to obtain toner particles from which the external additive has been removed. .

(External additive)
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 is preferably subjected to a hydrophobic treatment. The hydrophobic treatment is performed, for example, by immersing inorganic particles in a hydrophobic treatment agent. The hydrophobizing agent is not particularly limited, and examples thereof include silane coupling agents, silicone oils, titanate coupling agents, and aluminum coupling agents. These may be used individually by 1 type and may use 2 or more types together.
The amount of the hydrophobizing agent is usually 1 part by mass or more and 10 parts by mass or less with respect to 100 parts by mass of the inorganic particles, for example.

  Examples of external additives include resin particles (resin particles such as polystyrene, PMMA, and melamine resin), cleaning activators (for example, metal salts of higher fatty acids typified by zinc stearate, particles of a fluorine-based high molecular weight substance), and the like. Can be mentioned.

  The external addition amount of the external additive is, for example, preferably 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 production method)
Next, a toner manufacturing method according to this embodiment will be described.
The toner according to the exemplary embodiment can be obtained by externally adding an external additive to the toner particles after the toner particles are manufactured.

The toner particles may be produced by any of a dry production method (for example, a kneading and pulverizing method) and a wet production method (for example, an aggregation coalescence method, a suspension polymerization method, a dissolution suspension method, etc.). The production method of the toner particles is not particularly limited, and a known production method is adopted.
Among these, from the viewpoint of obtaining toner particles satisfying the metal concentration Mx and the formula (1), it is preferable to obtain toner particles by an aggregation coalescence method.

Specifically, for example, when toner particles are produced by an aggregation coalescence method,
In a mixed dispersion of the first resin particle dispersion in which the first resin particles serving as the binder resin are dispersed and the release agent particle dispersion in which the release agent particles are dispersed (other particles as required) A step of aggregating the first resin particles (if necessary, other particles) to form first aggregated particles (first aggregated particle forming step) in the dispersion after mixing the dispersion;
Heating the first agglomerated particle dispersion in which the first agglomerated particles are dispersed, fusing and coalescing the first agglomerated particles to form core particles (first fusing and coalescing step);
The core particle dispersion liquid in which the core particles are dispersed and the second resin particle dispersion liquid in which the second resin particles serving as the binder resin are dispersed are mixed so that the second resin particles adhere to the surface of the core particles. And forming a second aggregated particle (second aggregated particle forming process);
Heating the second agglomerated particle dispersion in which the second agglomerated particles are dispersed, and fusing and coalescing the second agglomerated particles to form core particles (second fusing and coalescing step);
Then, toner particles are manufactured.

Details of each step will be described below.
In the following description, a method of obtaining toner particles containing a colorant and a release agent will be described. However, the colorant and the release agent are used as necessary. Of course, you may use other additives other than a coloring agent and a mold release agent.

-Preparation step of resin particle dispersion-
First, first and second resin particle dispersions (hereinafter collectively referred to as “resin particle dispersions”) in which first and second resin particles (hereinafter collectively referred to as “resin particles”) serving as a binder resin are dispersed. In addition, for example, a colorant particle dispersion liquid in which colorant particles are dispersed and a release agent particle dispersion liquid in which release agent particles are dispersed are prepared.

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

Examples of the dispersion medium used for the resin particle dispersion include an aqueous medium.
Examples of the aqueous medium include water such as distilled water and ion exchange water, and alcohols. These may be used individually by 1 type and may use 2 or more types together.

Examples of the surfactant include anionic surfactants such as sulfate ester, sulfonate, phosphate, and soap; cationic surfactants such as amine salt type and quaternary ammonium salt type; polyethylene glycol And nonionic surfactants such as polyphenols, alkylphenol ethylene oxide adducts, and polyhydric alcohols. Among these, an anionic surfactant and a cationic surfactant are particularly mentioned. The nonionic surfactant may be used in combination with an anionic surfactant or a cationic surfactant.
Surfactant may be used individually by 1 type and may use 2 or more types together.

Examples of the method for dispersing the resin particles in the dispersion medium in the resin particle dispersion include a general dispersion method such as a rotary shear homogenizer, a ball mill having media, a sand mill, and a dyno mill. Depending on the type of resin particles, the resin particles may be dispersed in the resin particle dispersion using, for example, a phase inversion emulsification method.
The phase inversion emulsification method is a method in which a 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 aqueous medium. (W phase) is added to convert the resin from W / O to O / W (so-called phase inversion) to form a discontinuous phase and disperse the resin in an aqueous medium in the form of particles. It is.

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

  As content of the resin particle contained in a resin particle dispersion liquid, 5 to 50 mass% is preferable, for example, and 10 to 40 mass% is more preferable.

  For example, a colorant particle dispersion and a release agent particle dispersion are also prepared in the same manner as the resin particle dispersion. In other words, regarding the volume average particle diameter of the particles in the resin particle dispersion, the dispersion medium, the dispersion method, and the content of the particles, the colorant particles dispersed in the colorant particle dispersion and the release agent particle dispersion The same applies to the release agent particles to be dispersed.

-First aggregated particle forming step-
Next, the colorant particle dispersion and the release agent particle dispersion are mixed together with the first resin particle dispersion.
Then, in the mixed dispersion liquid, the first resin particles, the colorant particles, and the release agent particles are heteroaggregated, and the aggregate includes the first resin particles, the colorant particles, and the release agent particles having a target diameter. Form particles.

Specifically, for example, the flocculant is added to the mixed dispersion, and the pH of the mixed dispersion is adjusted to acidic (for example, the pH is 2 or more and 5 or less), and a dispersion stabilizer is added as necessary. The first resin particles are heated to a glass transition temperature (specifically, for example, the glass transition temperature of the resin particles −30 ° C. or higher and the glass transition temperature −10 ° C. or lower), and the particles dispersed in the mixed dispersion are aggregated. To form aggregated particles.
In the agglomerated particle forming step, for example, the aggregating agent is added at room temperature (for example, 25 ° C.) while stirring the mixed dispersion with a rotary shearing homogenizer, and the pH of the mixed dispersion is acidic (for example, the pH is 2 or more and 5 or less). ), And after adding a dispersion stabilizer as necessary, the heating may be performed.

As the flocculant, for example, an inorganic metal salt, a metal complex capable of taking divalent or higher valence, and the like are used.
Then, if necessary, after completion of aggregation, an additive that forms a complex or a similar bond with the metal (metal ion) of the aggregating agent is added. As this additive, a chelating agent is preferably used. By adding this chelating agent, a part of the flocculant is removed from the core particles to be formed, and the metal concentration inside the toner particles to be formed (core particles) can be adjusted.

  Here, the metal salt, metal salt polymer, and metal complex as the flocculant are used as a metal supply source. These examples are as described above.

A water-soluble chelating agent may be used as the chelating agent. Examples of the chelating agent include oxycarboxylic acids such as tartaric acid, citric acid, and gluconic acid, iminodiacid (IDA), nitrilotriacetic acid (NTA), ethylenediaminetetraacetic acid (EDTA), and the like.
As addition amount of a chelating agent, 0.01 mass part or more and 5.0 mass part or less are preferable with respect to 100 mass parts of resin particles, for example, and 0.1 mass part or more and less than 3.0 mass parts are more preferable.

-First fusion / unification process-
Next, the agglomerated particle dispersion in which the first agglomerated particles are dispersed is heated to, for example, a glass transition temperature or higher of the first resin particles (for example, a temperature of 10 to 30 ° C. higher than the glass transition temperature of the resin particles). Then, the first aggregated particles are fused and united to form core particles.

  And after completion | finish of a 1st fusion | combination and uniting process, a solid-liquid separation process, a well-known washing | cleaning process, etc. are implemented for the core particle formed in the solution, and a core particle is obtained. Moreover, after passing through the washing process, the solid-liquid separation process and the drying process may be performed to obtain the dried core particles.

  Before obtaining the first coalescence / union process, after obtaining the first aggregated particle dispersion in which the first aggregated particles are dispersed, the first aggregated particle dispersion and the resin particle dispersion in which the resin particles are dispersed are obtained. A liquid is further mixed, the resin particles are agglomerated to adhere to the surface of the first agglomerated particles, and further the resin particles are adhered to the surface to form first agglomerated particles; The first agglomerated particle dispersion in which the agglomerated particles are dispersed is heated, and the resin particle-adhered first agglomerated particles are fused and united to form core particles having a core / shell structure. Core particles may be produced.

-Second aggregated particle forming step-
Next, a core particle dispersion is prepared using the obtained core particles. Then, the core particle dispersion and the second resin particle dispersion are mixed.
Then, in the mixed dispersion, the second resin particles adhere to the surface of the core particles having a diameter close to the target toner particle diameter by heteroaggregating so that the second resin particles adhere to the surface of the core particles. 2 Form aggregated particles.

  Specifically, for example, the pH of the mixed dispersion is adjusted from neutral to alkaline (for example, the pH is 7 or more and 8.5 or less), and the dispersion is dispersed in the mixed dispersion as necessary. Aggregated particles are formed to form aggregated particles.

  By this operation, the resin that coats the core particles (in the surface layer of the toner particles) does not contain metal or the metal concentration is reduced.

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

Through the above-described steps, the toner particles satisfying the above-mentioned range and the relationship between the metal concentration Mes and the metal concentration Met satisfying the formula (1) can be obtained.
Here, the second agglomerated particle forming step and the second fusing / merging step are repeated, and the thickness of the resin (binder resin) covering the core particles (the surface layer of the toner particles not containing metal or having a reduced metal concentration) (Thickness) can be adjusted. That is, it becomes easier to obtain toner particles in which metal is unevenly distributed.

  On the other hand, if a dispersant in which core particles using a flocculant are dispersed is used as it is, or if a flocculant such as a metal salt, a metal salt polymer, or a metal complex is used in the second aggregated particle formation step, Since the aggregating agent is dispersed in the agglomerated agent, the aggregating agent is incorporated into the surface layer of the formed toner particles when the pH of the agglomerated particles is lowered at the time of aggregation. For this reason, it is difficult to obtain toner particles in which the metal concentration Mx satisfies the above range and the relationship between the metal concentration Mes and the metal concentration Met also satisfies the formula (1).

Here, after completion of the fusion / unification process, toner particles formed in the solution are dried through a known washing process, solid-liquid separation process, and drying process to obtain toner particles.
In the washing step, it is preferable to sufficiently carry out substitution washing with ion-exchanged water from the viewpoint of chargeability. The solid-liquid separation step is not particularly limited, but suction filtration, pressure filtration, etc. are preferably performed from the viewpoint of productivity. In addition, the drying process is not particularly limited, but from the viewpoint of productivity, freeze drying, airflow drying, fluidized drying, vibration fluidized drying, or the like is preferably performed.

  The toner according to the exemplary embodiment is manufactured, for example, by adding an external additive to the obtained dry toner particles and mixing them. Mixing may be performed by, for example, a V blender, a Henschel mixer, a Laedige mixer, or the like. Furthermore, if necessary, coarse particles of toner may be removed using a vibration sieving machine, a wind power classifier, or the like.

<Electrostatic image developer>
The electrostatic charge image developer according to the exemplary embodiment includes at least the toner according to the exemplary embodiment.
The electrostatic image developer according to this embodiment may be a one-component developer including only the toner according to this embodiment, or may be a two-component developer mixed with the toner and a carrier.

There is no restriction | limiting in particular as a carrier, A well-known carrier is mentioned. As a carrier, for example, a coated carrier in which the surface of a core made of magnetic powder is coated with a coating resin; a magnetic powder dispersion type carrier in which magnetic powder is dispersed and mixed in a matrix resin; a porous magnetic powder is impregnated with a resin And a resin-dispersed carrier in which conductive particles are dispersed and blended in a matrix resin.
The magnetic powder dispersion type carrier, the resin impregnated type carrier, and the conductive particle dispersion type carrier may be a carrier 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 the matrix resin include polyethylene, polypropylene, polystyrene, polyvinyl acetate, polyvinyl alcohol, polyvinyl butyral, polyvinyl chloride, polyvinyl ether, polyvinyl ketone, vinyl chloride-vinyl acetate copolymer, styrene-acrylic acid ester. Examples thereof include a straight silicone resin comprising a copolymer, an organosiloxane bond, or a modified product thereof, a fluororesin, a polyester, a polycarbonate, a phenol resin, and an epoxy resin.
The coating resin and matrix resin may contain other additives such as conductive particles.
Examples of the conductive particles include particles of metals such as gold, silver, and copper, 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 layer forming solution obtained by dissolving the coating resin and, if necessary, various additives in an appropriate solvent may 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 the coating layer forming solution, a spray method in which the coating layer forming solution is sprayed on the surface of the core material, 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 the 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 Apparatus / 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 carrier, a charging unit that charges the surface of the image carrier, an electrostatic image forming unit that forms an electrostatic image on the surface of the charged image carrier, and an electrostatic charge. Development means for containing an image developer and developing the electrostatic image formed on the surface of the image carrier as a toner image with the electrostatic image developer, and the toner image formed on the surface of the image carrier as a recording medium Transfer means for transferring to the surface of the recording medium, and fixing means for fixing the toner image transferred to the surface of the recording medium. The electrostatic charge image developer according to this embodiment is applied as the electrostatic charge image developer.

  In the image forming apparatus according to this embodiment, a charging process for charging the surface of the image carrier, an electrostatic charge image forming process for forming an electrostatic image on the surface of the charged image carrier, and an electrostatic charge according to this embodiment. A developing step of developing an electrostatic charge image formed on the surface of the image carrier as a toner image with an image developer; a transfer step of transferring the toner image formed on the surface of the image carrier to the surface of the recording medium; An image forming method (an image forming method according to the present embodiment) including a fixing step of fixing the toner image transferred onto the surface of the recording medium is performed.

The image forming apparatus according to the present embodiment is a direct transfer type apparatus that directly transfers a toner image formed on the surface of an image carrier to a recording medium; the toner image formed on the surface of the image carrier is transferred to an intermediate transfer member An intermediate transfer type apparatus that primarily transfers the toner image transferred to the surface of the intermediate transfer body and then secondary transfer the toner image to the surface of the recording medium; after the toner image is transferred, the surface of the image carrier before charging is cleaned. An apparatus provided with a cleaning unit; a known image forming apparatus such as an apparatus provided with a charge removing unit that discharges the surface of an image holding member by irradiating a discharge light after charging a toner image and before charging is applied.
In the case of an intermediate transfer type apparatus, the transfer means includes, for example, an intermediate transfer body on which a toner image is transferred to the surface, and a primary transfer that primarily transfers the toner image formed on the surface of the image holding body to the surface of the intermediate transfer body. And a secondary transfer unit that secondarily transfers the toner image transferred onto the surface of the intermediate transfer member onto the surface of the recording medium.

  In the image forming apparatus according to the present embodiment, for example, the part including the developing unit may have a cartridge structure (process cartridge) that is detachable from the image forming apparatus. As the process cartridge, for example, a process cartridge including a developing unit 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 described, but the present invention is not limited thereto. In addition, the main part shown to a figure is demonstrated and the description is abbreviate | omitted about others.

FIG. 1 is a schematic configuration diagram illustrating an image forming apparatus according to the present embodiment.
The image forming apparatus shown in FIG. 1 is a first to first electrophotographic method that outputs yellow (Y), magenta (M), cyan (C), and black (K) images based on color-separated image data. Fourth image forming units 10Y, 10M, 10C, and 10K (image forming means) are provided. These image forming units (hereinafter sometimes simply referred to as “units”) 10Y, 10M, 10C, and 10K are arranged in parallel at a predetermined distance from each other in the horizontal direction. The units 10Y, 10M, 10C, and 10K may be process cartridges that are detachable from the image forming apparatus.

Above each of the units 10Y, 10M, 10C, and 10K, an intermediate transfer belt 20 as an intermediate transfer member is extended through each unit. The intermediate transfer belt 20 is provided by being wound around a drive roll 22 and a support roll 24 that are in contact with the inner surface of the intermediate transfer belt 20 that are spaced apart from each other in the left to right direction in the drawing. The vehicle travels in the direction toward the unit 10K. The support roll 24 is applied with a force 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. An intermediate transfer member cleaning device 30 is provided on the side of the image carrier of the intermediate transfer belt 20 so as to face the drive roll 22.
Further, each of the developing devices (developing means) 4Y, 4M, 4C, and 4K of the units 10Y, 10M, 10C, and 10K has yellow, magenta, cyan, and black contained in the toner cartridges 8Y, 8M, 8C, and 8K. The toner including the four color toners is supplied.

  Since the first to fourth units 10Y, 10M, 10C, and 10K have the same configuration, here, the first unit that forms a yellow image disposed on the upstream side in the intermediate transfer belt traveling direction. 10Y will be described as a representative. It should be noted that reference numerals with magenta (M), cyan (C), and black (K) are attached to the same parts as those of the first unit 10Y instead of yellow (Y). Description of the units 10M, 10C, and 10K will be omitted.

The first unit 10Y includes a photoreceptor 1Y that functions as an image holding member. Around the photoreceptor 1Y, a charging roll (an example of a charging unit) 2Y that charges the surface of the photoreceptor 1Y to a predetermined potential, and the charged surface is exposed by a laser beam 3Y based on the color-separated image signal. Then, an exposure device (an example of an electrostatic image forming unit) 3 that forms an electrostatic image, and a developing device (an example of a developing unit) 4Y that develops the electrostatic image by supplying toner charged to the electrostatic image, developed A primary transfer roll 5Y (an example of a primary transfer unit) that transfers a toner image onto the intermediate transfer belt 20, and a photoconductor cleaning device (an example of a cleaning unit) 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 disposed inside the intermediate transfer belt 20, and is provided at a position facing the photoreceptor 1Y. Further, a bias power source (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 source varies the transfer bias applied to each primary transfer roll under the control of a control unit (not shown).

Hereinafter, an operation of forming a yellow image in the first unit 10Y will be described.
First, prior to operation, the surface of the photoreceptor 1Y is charged to a potential of −600V to −800V by the charging roll 2Y.
The photoreceptor 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 resistance (general resin resistance), but has a property that the specific resistance of the portion irradiated with the laser beam changes when irradiated with the laser beam 3Y. Therefore, a laser beam 3Y is output to the surface of the charged photoreceptor 1Y via the exposure device 3 in accordance with yellow image data sent from a control unit (not shown). The laser beam 3Y is applied to the photosensitive layer on the surface of the photoreceptor 1Y, whereby an electrostatic charge image having a yellow image pattern is formed on the surface of the photoreceptor 1Y.

The electrostatic charge image is an image formed on the surface of the photoreceptor 1Y by charging, and the specific resistance of the irradiated portion of the photosensitive layer is lowered by the laser beam 3Y, and the charged charge on the surface of the photoreceptor 1Y flows. On the other hand, this is a so-called negative latent image formed by the charge remaining in the portion not irradiated with the laser beam 3Y.
The electrostatic charge image formed on the photoreceptor 1Y is rotated to a predetermined development position as the photoreceptor 1Y travels. At this development position, the electrostatic charge image on the photoreceptor 1Y is visualized (developed image) as a toner image by the developing device 4Y.

  In the developing device 4Y, for example, an electrostatic charge image developer containing at least yellow toner and a carrier is accommodated. The yellow toner is triboelectrically charged by being agitated inside the developing device 4Y, and has a charge of the same polarity (negative polarity) as the charged electric charge on the photoreceptor 1Y, and has a developer roll (a developer holding member). Example) is held on. As the surface of the photoreceptor 1Y passes through the developing device 4Y, the yellow toner is electrostatically attached to the latent image portion on the surface of the photoreceptor 1Y, and the latent image is developed with the yellow toner. . The photoreceptor 1Y on which the yellow toner image is formed continues to run at a predetermined speed, and the toner image developed on the photoreceptor 1Y is conveyed to a predetermined primary transfer position.

When the yellow toner image on the photoreceptor 1Y is conveyed to the primary transfer, a primary transfer bias is applied to the primary transfer roll 5Y, and an electrostatic force from the photoreceptor 1Y toward the primary transfer roll 5Y is applied to the toner image, so that the photoreceptor is exposed. 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 photoreceptor 1Y is removed and collected by the photoreceptor cleaning device 6Y.

Further, the primary transfer bias applied to the primary transfer rolls 5M, 5C, and 5K after the second unit 10M is also controlled in accordance with the first unit.
Thus, the intermediate transfer belt 20 onto which the yellow toner image has been transferred by the first unit 10Y is sequentially conveyed through the second to fourth units 10M, 10C, and 10K, and the toner images of the respective colors are superimposed and transferred in a multiple manner. The

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

  Thereafter, the recording paper P is fed into the pressure contact portions (nip portions) of a pair of fixing rolls in a fixing device (an example of a fixing unit) 28, and the toner image is fixed on the recording paper P to form a fixed image.

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

  The recording paper P on which the color image has been fixed is carried out toward the discharge 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 accommodates the electrostatic charge image developer according to the present embodiment, and develops the electrostatic charge image formed on the surface of the image carrier as a toner image by the electrostatic charge image developer. And a process cartridge that can be attached to and detached from the image forming apparatus.

  Note that the process cartridge according to the present embodiment is not limited to the above-described configuration, and other means such as a developing device and other units such as an image carrier, a charging unit, an electrostatic charge image forming unit, and a transfer unit, if necessary. And at least one selected from the above.

  Hereinafter, an example of the process cartridge according to the present embodiment will be shown, but the present invention is not limited to this. In addition, the main part shown to a figure is demonstrated and the description is abbreviate | omitted about others.

FIG. 2 is a schematic configuration diagram showing a process cartridge according to the present embodiment.
The process cartridge 200 shown in FIG. 2 is provided around the photoconductor 107 and the photoconductor 107 by, for example, a housing 117 provided with an attachment rail 116 and an opening 118 for exposure. A charging roller 108 (an example of a charging unit), a developing device 111 (an example of a developing unit), and a photoconductor cleaning device 113 (an example of a cleaning unit) are integrally combined and held to form a cartridge. Yes.
In FIG. 2, 109 is an exposure device (an example of an electrostatic charge image forming unit), 112 is a transfer device (an example of a transfer unit), 115 is a fixing device (an example of a fixing unit), and 300 is a recording paper (a recording medium). An example).

Next, the toner cartridge according to this embodiment will be described.
The toner cartridge according to the present exemplary embodiment is a toner cartridge that accommodates the toner according to the present exemplary embodiment and is detachable from the image forming apparatus. The toner cartridge contains toner for replenishment to be supplied to the developing means provided in the image forming apparatus.

  The image forming apparatus shown in FIG. 1 is an image forming apparatus having a configuration in which toner cartridges 8Y, 8M, 8C, and 8K are attached and detached, and the developing devices 4Y, 4M, 4C, and 4K are each developing devices (colors). And a toner supply pipe (not shown). Further, when the amount of toner stored in the toner cartridge becomes low, the toner cartridge is replaced.

  Hereinafter, although an embodiment explains this embodiment in detail, this embodiment is not limited to these examples at all. In the following description, “part” and “%” are all based on mass unless otherwise specified.

<Preparation of resin particle dispersion>
(Preparation of resin particle dispersion (P1))
Bisphenol A ethylene oxide adduct (average number of moles added 2.1): 85 parts by mass Bisphenol A propylene oxide adduct (average number of moles added 2.2): 217 parts by weight Fumaric acid: 80 parts by weight Terephthalic acid : 49 parts by mass A solution in which the above components are mixed and dissolved is reduced in pressure by reducing the air in the container and then in an inert atmosphere with nitrogen gas. It is generated during the reaction in a nitrogen atmosphere with mechanical stirring. Water was removed from the system and reacted at 190 ° C. for 18 hours, then gradually reduced in pressure to 220 ° C. and reacted for 9 hours, then cooled to a polyester resin having a weight average molecular weight of 42500. Got.

  100 parts by mass of the obtained polyester resin, 45 parts by mass of methyl ethyl ketone, and 10 parts by mass of isopropyl alcohol were placed in a three-necked flask and heated to 45 ° C. with stirring to dissolve the resin. The resin particle dispersion (P1) having a volume average particle size of 150 nm was prepared by gradually adding 400 parts by mass of ion-exchanged water and carrying out phase inversion emulsification, and then reducing the pressure and removing the solvent. The water content was adjusted so that the resin particle concentration of this dispersion was 30% by mass.

(Preparation of resin particle dispersion (P2))
-Dimethyl decanoate: 100 parts by mass-75.0 parts by mass of 1,9-nonanediol-0.12 parts by mass of dibutyltin oxide A solution prepared by mixing and dissolving the above components is depressurized to reduce the air in the container. Further, an inert atmosphere was established with nitrogen gas, and the reaction was carried out at 180 ° C. for 8 hours while removing the water produced during the reaction under a nitrogen atmosphere while stirring mechanically, and then gradually reduced in pressure while being reduced in pressure. The temperature was raised to 0 ° C. and reacted for 7 hours, followed by cooling to obtain a polyester resin having a weight average molecular weight of 22500.

  100 parts by weight of the obtained polyester resin, 60 parts by weight of methyl ethyl ketone, and 20 parts by weight of isopropyl alcohol were heated to 45 ° C. while stirring to dissolve the resin, and then 25 parts by weight of 10% aqueous ammonia solution was added. Phase-change emulsification was performed by gradually adding 400 parts by mass of ion-exchanged water, and then the pressure was reduced and the solvent was removed to prepare a resin particle dispersion (P2) having a volume average particle size of 174 nm. The water content was adjusted so that the resin particle concentration of this dispersion was 30% by mass.

(Preparation of resin particle dispersion (S1))
-Styrene: 320 parts by mass-n-butyl acrylate: 80 parts by mass-Acrylic acid: 12 parts by mass-10-dodecanethiol: 2 parts by mass A mixture of the above components dissolved therein is dissolved in a nonionic surfactant ( Nonipol 400 (manufactured by Sanyo Chemical Co., Ltd.) 6 parts by mass and anionic surfactant (Neogen SC, Daiichi Kogyo Seiyaku Co., Ltd.) 10 parts by mass in ion-exchanged water 550 parts by mass in a flask While emulsifying and dispersing, slowly mixing for 10 minutes, 50 parts by mass of ion-exchanged water having 4 parts by mass of ammonium persulfate dissolved therein was added thereto. After carrying out nitrogen substitution, while stirring the inside of the flask, the contents were heated in an oil bath until the temperature reached 70 ° C., and emulsion polymerization was continued for 5 hours. As a result, a resin particle dispersion was obtained in which styrene acrylic resin particles having a volume average particle diameter D50v = 210 nm, a weight average molecular weight of 38000, and a glass transition temperature of 50 ° C. were dispersed.

<Preparation of colorant particle dispersion>
(Preparation of colorant particle dispersion (1))
Carbon black (Cabot Corp .: BP1300): 50 parts by mass Nonionic surfactant Nonipol 400 (Kao Co., Ltd.): 5 parts by mass Ion-exchanged water: 200 parts by mass Dispersion for about 1 hour using a type disperser Ultimateizer (manufactured by Sugino Machine Co., Ltd., HJP30006), adjusting the amount of water so that the colorant concentration of this dispersion is 25% by mass, Got.

-Preparation of release agent dispersion-
Paraffin wax (Nippon Seiwa Co., Ltd .: HNP9, melting point 77 ° C.): 60 parts by mass Anionic surfactant (Daiichi Kogyo Seiyaku Co., Ltd .: Neogen RK): 4 parts by mass Ion exchange water: 200 Part by mass A solution in which the above components are mixed is heated to 120 ° C. and dispersed using a homogenizer (manufactured by IKA: Ultra Tarrax T50), then dispersed with a Menton Gorin high-pressure homogenizer (Gorin), and volume averaged. A release agent dispersion was prepared by dispersing a release agent having a particle size of 250 nm. The water content was adjusted so that the release agent concentration of this dispersion was 30% by mass.

<Preparation of colorant particle dispersion>
(Preparation of colorant particle dispersion (1))
Cyan pigment: 10 parts by mass [Pigment Blue 15: 3, manufactured by Dainichi Seika Kogyo Co., Ltd.]
Anionic surfactant: 2 parts by mass [Neogen SC, manufactured by Daiichi Kogyo Seiyaku Co., Ltd.]
-Ion-exchanged water: 80 parts by mass The above components are mixed and dispersed for 1 hour by a high-pressure impact disperser optimizer [HJP30006, manufactured by Sugino Machine Co., Ltd.], with a volume average particle size of 180 nm and a solid content of 20% by mass. A colorant particle dispersion (1) was obtained.

<Preparation of release agent particle dispersion>
(Releasing agent particle dispersion (1))
Paraffin wax (Nippon Seiwa Co., Ltd .: HNP9, melting point 77 ° C.): 60 parts by mass Anionic surfactant (Daiichi Kogyo Seiyaku Co., Ltd .: Neogen RK): 4 parts by mass Ion exchange water: 200 Part by mass A solution in which the above components are mixed is heated to 120 ° C. and dispersed using a homogenizer (manufactured by IKA: Ultra Tarrax T50). A release agent dispersion was prepared by dispersing a release agent having a particle size of 250 nm. The water content was adjusted so that the release agent concentration of this dispersion was 30% by mass.

<Example 1>
(Production of Toner (1))
-Core particle formation process-
Resin particle dispersion (P1) 600 parts by weight Resin particle dispersion (P2) 85 parts by weight Colorant dispersion 100 parts by weight Release agent dispersion 110 parts by weight Cationic surfactant (manufactured by Kao Corporation) : Sanisol B50) 1.5 parts by mass The above components were placed in a round stainless steel flask, and 0.1N sulfuric acid was added to adjust the pH to 3.7. 30 parts by mass of a 10% by mass nitric acid aqueous solution was added, and then dispersed at 30 ° C. using a homogenizer (manufactured by IKA, Ultra Turrax T50). After heating to 45 ° C. at 1 ° C./min in an oil bath for heating and holding at 45 ° C. for 2 hours, 340 parts by mass of the resin particle dispersion (P1) is added to this dispersion, and further for 1 hour. Retained.
Thereafter, 0.1N sodium hydroxide was added to adjust the pH to 8.0, and then the mixture was heated to 85 ° C. at 1 ° C./min while maintaining stirring and held for 3 hours, and then 20 ° C./min. The solution was cooled to 20 ° C. at a rate of, and this was filtered and washed with ion-exchanged water to obtain core particles.

-Toner particle formation process-
The obtained core particles were dispersed in a solution obtained by adding 2.0 parts by mass of a cationic surfactant (manufactured by Kao Corporation: Sanizol B50) to 2500 parts by mass of ion-exchanged water to obtain a dispersion.
Next, after adding 200 parts by mass of the resin particle dispersion (P1) to this dispersion, 0.1 N sodium hydroxide is added to adjust the pH to 7.5, and while stirring is continued, 1 After heating to 85 ° C at 85 ° C / min and holding for 3 hours, it was cooled to 20 ° C at a rate of 20 ° C / min, filtered, washed with ion-exchanged water, and the volume average particle size was 6.5 µm. Toner particles were obtained.

-Toner preparation process-
Thereafter, 3.3 parts by mass of hydrophobic silica particles (produced by Nippon Aerosil Co., Ltd., RY50) were added as an external additive to 100 parts by mass of the toner particles (1). Next, the mixture was mixed for 3 minutes at a peripheral speed of 30 m / s using a Henschel mixer. Thereafter, the toner (1) was obtained by sieving with a vibration sieve having an opening of 45 μm.

<Example 2>
Toner particles were prepared in the same manner as in Example 1 except that the holding time was 4 hours in the core particle forming step and the amount of the resin particle dispersion (P1) was changed to 150 parts by mass in the toner particle forming step. A toner was obtained using the toner particles.

<Example 3>
In the toner particle forming step, toner particles were produced in the same manner as in Example 2 except that the amount of the resin particle dispersion (P1) was changed to 100 parts by mass, and toner was obtained using the toner particles.

<Example 4>
In the core particle forming step, toner particles were prepared in the same manner as in Example 1 except that the amount of nitric acid aqueous solution having a polyaluminum chloride concentration of 10% by mass was changed to 15 parts by mass. A toner was obtained.

<Example 5>
In the core particle forming step, toner particles were prepared in the same manner as in Example 1 except that the nitric acid aqueous solution having a polyaluminum chloride concentration of 10% by mass was changed to 40 parts by mass. Obtained.

<Example 6>
Toner particles were produced in the same manner as in Example 1 except that polyaluminum chloride was changed to polymagnesium chloride in the core particle forming step, and toner was obtained using the toner particles.

<Example 7>
Toner particles were prepared in the same manner as in Example 1 except that polyaluminum chloride was changed to polycalcium chloride in the core particle forming step, and a toner was obtained using the toner particles.

<Example 8>
Toner particles were prepared in the same manner as in Example 1 except that the resin particle dispersion (P1) was changed to the resin particle dispersion (S2) in the core particle formation step and the toner particle formation step. A toner was obtained.

<Comparative Example 1>
Toner particles were produced in the same manner as in Example 2 except that the amount of the resin particle dispersion (P1) was changed to 80 parts by mass in the toner particle forming step, and toner was obtained using the toner particles.

<Comparative example 2>
In the core particle forming step, toner particles were prepared in the same manner as in Example 1 except that the amount of the nitric acid aqueous solution having a polyaluminum chloride concentration of 10% by mass was changed to 10 parts by mass. A toner was obtained.

<Comparative Example 3>
In the core particle forming step, toner particles were prepared in the same manner as in Example 1 except that the amount of nitric acid aqueous solution having a polyaluminum chloride concentration of 10% by mass was changed to 50 parts by mass. A toner was obtained.

<Comparative Example 4>
Toner particles were produced in the same manner as in Example 1 except that polyaluminum chloride was changed to polysodium chloride in the core particle forming step, and toner was obtained using these toner particles.

<Measurement / Evaluation>

(Various measurements)
For each of the toners (toner particles), the metal concentration Mx, the metal concentration Mes, the metal concentration Met, and the metal concentration Mem were measured according to the method described above.
These results are shown in Table 1. Table 1 also shows the volume average particle diameter D (expressed as “particle diameter D” in the table) of the toner particles.

(Development of developer)
8 parts by mass of the toner prepared in each example and 92 parts by mass of the following carrier (A) were placed in a V blender and stirred for 20 minutes, and then sieved with a 105 μm mesh to prepare a developer.

-Production of carrier (A)-
Ferrite particles (volume average particle size 50 μm): 100 parts by mass Toluene: 100 parts by mass Styrene-methyl methacrylate copolymer (component molar ratio: 90/10): 2 parts by mass Carbon black (R330, manufactured by Cabot Corporation) ): 0.25 parts by mass First, the above components excluding ferrite particles were stirred with a stirrer for 10 minutes to prepare a dispersed coating solution, and then this coating solution and ferrite particles were put in a vacuum degassing type kneader. After stirring at 25 ° C. for 25 minutes, carrier A was prepared by further depressurizing while heating and degassing and drying. This carrier (A) had a shape factor = 120, a true specific gravity = 4.4, a saturation magnetization = 63 emu / g, and a volume resistivity value of 1000 Ω · cm at an applied electric field of 1000 V / cm.

(Color point evaluation)
The obtained developer was filled in a developing device of an image forming apparatus (“D110” manufactured by Fuji Xerox Co., Ltd.).

-Color point evaluation under high temperature and high humidity environment-
Using this apparatus, under an environment of 40 ° C. and 85% RH, an image with an image density of 1% was output to 10000 on A3 paper, and 30 halftone images with an image density of 50% were output on A3 paper. And the number of color points of the image output to the 1st-30th sheet was measured, and the following evaluation criteria evaluated.

-Evaluation of sunspot under low temperature and low humidity environment-
Next, the apparatus was turned off in a 15% Rno environment at 10 ° C., left for 5 hours or more, turned on, and 30 halftone images with an image density of 50% were output on A3 paper. And the number of color points of the image output to the 1st-30th sheet was measured, and the following evaluation criteria evaluated.

-Evaluation criteria-
A (◎): No color point generated B (◯): 1 or more and 4 or less color points of 0.2 mm or more C (Δ): 5 or more and 8 or less color points of 0.2 mm or more generated D (×): 9 or more color points of 0.2 mm or more are generated.

  From the above results, in this embodiment, compared to the comparative example, the color point is generated when an image having a low image density is repeatedly formed in a high temperature and high humidity environment, and the toner image is poorly fixed in a low temperature and low humidity environment. It can be seen that the generation of color points is suppressed.

1Y, 1M, 1C, 1K photoconductor (an example of an image carrier)
2Y, 2M, 2C, 2K charging roll (an example of charging means)
3. Exposure device (an example of electrostatic charge image forming means)
3Y, 3M, 3C, 3K Laser beams 4Y, 4M, 4C, 4K Developing device (an example of developing means)
5Y, 5M, 5C, 5K primary transfer roll (an example of primary transfer means)
6Y, 6M, 6C, 6K Photoconductor cleaning device (an example of cleaning means)
8Y, 8M, 8C, 8K Toner cartridge 10Y, 10M, 10C, 10K Image forming unit 20 Intermediate transfer belt (an example of an intermediate transfer member)
22 Drive roll 24 Support roll 26 Secondary transfer roll (an example of secondary transfer means)
30 Intermediate transfer member cleaning device 107 Photosensitive member (an example of an image holding member)
108 Charging roll (an example of charging means)
109 Exposure apparatus (an example of electrostatic charge image forming means)
111 Developing device (an example of developing means)
112 Transfer device (an example of transfer means)
113 photoconductor cleaning device (an example of cleaning means)
115 Fixing device (an example of fixing means)
116 Attachment rail 118 Opening 117 for exposure 117 Case 200 Process cartridge 300 Recording paper (an example of recording medium)
P Recording paper (an example of a recording medium)

Claims (8)

Including a binder resin, a release agent, and a metal capable of taking a divalent or higher ionic valence, the metal concentration Mx measured by X-ray fluorescence analysis (XRF) is 0.02% by mass or more and 0.10. Having toner particles that are less than or equal to mass percent,
When the volume average particle diameter of the toner particles is D, the metal concentration Mes (measured by energy dispersive X-ray spectroscopy (EDX) under the condition of acceleration voltage = 0.6 × D + 0.9 (kV) (Unit:%) and the metal concentration Met (unit:%) measured by energy dispersive X-ray spectroscopy (EDX) under the condition of acceleration voltage = 1.8 × D + 4.9 (kV) An electrostatic charge image developing toner satisfying the following formula (1).
Formula (1): 0 ≦ Mes / Met <0.30 When the volume average particle diameter of the toner particles is D, the metal concentration Mem (unit:%) measured by energy dispersive X-ray spectroscopy (EDX) under the condition of acceleration voltage = 1.2 × D + 1.8 kV And the concentration Met (unit:%) of the metal satisfy the following formula (2).
Formula (2): 0 ≦ Mem / Met <0.3   The electrostatic image developing toner according to claim 1, wherein the metal is aluminum.   An electrostatic charge image developer comprising the electrostatic charge image developing toner according to claim 1. An electrostatic charge image developing toner according to any one of claims 1 to 3 is accommodated,
A toner cartridge to be attached to and detached from the image forming apparatus. A developing means for containing the electrostatic charge image developer according to claim 4 and developing the electrostatic charge image formed on the surface of the image carrier as a toner image by the electrostatic charge image developer,
A process cartridge attached to and detached from the image forming apparatus. An image carrier,
Charging means for charging the surface of the image carrier;
An electrostatic charge image forming means for forming an electrostatic charge image on the surface of the charged image carrier;
Development means for containing the electrostatic charge image developer according to claim 4 and developing the electrostatic charge image formed on the surface of the image carrier as a toner image by the electrostatic charge image developer;
Transfer means for transferring a toner image formed on the surface of the image carrier to the surface of a recording medium;
Fixing means for fixing the toner image transferred to the surface of the recording medium;
An image forming apparatus comprising: A charging step for charging the surface of the image carrier;
An electrostatic charge image forming step of forming an electrostatic charge image on the surface of the charged image carrier;
A developing step of developing an electrostatic charge image formed on the surface of the image carrier as a toner image with the electrostatic charge image developer according to claim 4;
A transfer step of transferring a toner image formed on the surface of the image carrier to the surface of a recording medium;
A fixing step of fixing the toner image transferred to the surface of the recording medium;
An image forming method comprising: