JP6763258B2 - Toner for static charge image development, static charge image developer, toner cartridge, process cartridge, image forming apparatus, and image forming method - Google Patents

Description

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

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

For example, Patent Document 1 states that "a toner having toner particles containing at least a binder resin, a colorant, a mold release agent, and a polymer containing a sulfur element and an external agent, and the toner particles are magnesium and 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 30,000 ppm (based on the mass of toner particles). "

Further, Patent Document 2 describes "a toner having toner particles containing at least a binder resin, a colorant, a mold release agent and a resin having a sulfur atom, and a toner having inorganic fine powder mixed with 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) / (Sulfur element content (S): ppm) ≤30, ii) The weight average particle size (D4) of the toner is 3 μm to 10 μm, and iii) the average circularity of the toner. Is 0.950 to 0.995. ”Is disclosed.

Further, Patent Document 3 states, "At least in the static charge image developing toner composed of a binder resin and a colorant, the content (A) of an aluminum element contained in the vicinity of the surface of the toner measured by X-ray photoelectron spectroscopy. The ratio (A / B) of the element to the sulfur element content (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. The content (A) of the existing aluminum element is in the range of 0.02 to 0.08 atomic%. "Toner for developing an electrostatic charge image."

Japanese Unexamined Patent Publication No. 2002-108019 Japanese Unexamined Patent Publication No. 2005-06208 Japanese Unexamined Patent Publication No. 2006-267734

An object of the present invention is a metal measured by fluorescent X-ray analysis (XRF) in a static charge image developing toner having toner particles containing a binder resin, a mold release agent, and a metal having an ionic valence of 2 or more. The concentration Mx of Mx 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) satisfy the formula (1). Static charge that suppresses the generation of color spots that occur when images with low image density are repeatedly formed in a high temperature and high humidity environment, and the generation of color spots that occur due to poor fixing of toner images in a low temperature and low humidity environment. It is to provide a toner for image development.

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

The invention according to claim 1 is
The concentration Mx of the metal, which contains a binder resin, a mold release agent, and a metal capable of having an ionic valence of divalent or higher, and is measured by X-ray fluorescence analysis (XRF), is 0.02% by mass or more and 0.10. Has toner particles that are less than or equal to mass%
When the volume average particle diameter of the toner particles is D, the concentration of the metal Mes (Mes) measured by energy dispersive X-ray spectroscopy (EDX) under the condition of acceleration voltage = 0.6 × D + 0.9 (kV). The relationship between the unit:%) and the concentration Met (unit:%) of the metal measured by energy dispersive X-ray spectroscopy (EDX) under the condition of acceleration voltage = 1.8 × D + 4.9 (kV) , Toner for static charge image development that satisfies the following formula (1).
Equation (1): 0 ≦ Mes / Met <0.30

The invention according to claim 2 is
When the volume average particle size of the toner particles is D, the concentration of the metal is Mem (unit:%) measured by energy dispersion type X-ray spectroscopy (EDX) under the condition of acceleration voltage = 1.2 × D + 1.8 kV. The toner for static charge image development according to claim 1, wherein the relationship between the metal concentration Met (unit:%) satisfies the following formula (2).
-Equation (2): 0 ≤ Mem / Met <0.3

The invention according to claim 3 is
The toner for developing an electrostatic charge image according to claim 1 or 2, wherein the metal is aluminum.

The invention according to claim 4 is
A static charge image developer containing the toner for static charge image development according to any one of claims 1 to 3.

The invention according to claim 5 is
The toner for developing an electrostatic charge image according to any one of claims 1 to 3 is accommodated.
A toner cartridge that is attached to and detached from the image forming device.

The invention according to claim 6 is
A developing means for accommodating the electrostatic charge image developing agent according to claim 4 and developing the electrostatic charge image formed on the surface of the image holder as a toner image by the electrostatic charge image developing agent is provided.
A process cartridge that is attached to and detached from the image forming device.

The invention according to claim 7
Image holder and
The charging means for charging the surface of the image holder and
An electrostatic charge image forming means for forming an electrostatic charge image on the surface of the charged image holder, and
A developing means that accommodates the electrostatic charge image developer according to claim 4 and develops the electrostatic charge image formed on the surface of the image holder as a toner image by the electrostatic image developer.
A transfer means for transferring a toner image formed on the surface of the image holder to the surface of a recording medium, and
A fixing means for fixing the toner image transferred to the surface of the recording medium, and
An image forming apparatus comprising.

The invention according to claim 8 is
The charging process that charges the surface of the image holder,
A static charge image forming step of forming a static charge image on the surface of the charged image holder, and
A developing step of developing an electrostatic charge image formed on the surface of the image holder as a toner image by using the electrostatic charge image developer according to claim 4.
A transfer step of transferring a toner image formed on the surface of the image holder to the surface of a recording medium, and
A fixing step of fixing the toner image transferred to the surface of the recording medium, and
An image forming method having.

According to the invention of claim 1, a fluorescent X-ray analysis method is used in a toner for static charge image development having toner particles containing a binder resin, a mold release agent, and a metal having an ionic valence of 2 or more. Metal concentration Mx measured by XRF) is less than 0.02% by mass or more than 0.10% by mass, or metal concentration Mes and metal concentration Met measured by energy dispersive X-ray spectroscopy (EDX). Compared to the case where Eq. (1) is not satisfied, the color spots generated when images with low image density are repeatedly formed in a high temperature and high humidity environment, and the color spots caused by poor fixing of the toner image in a low temperature and low humidity environment. A toner for developing an electrostatic charge image that suppresses the generation of is provided.
According to the invention of claim 2, the temperature and humidity environment is higher than that in the case where the metal concentration Mem and the metal concentration Met measured by energy dispersive X-ray spectroscopy (EDX) do not satisfy the formula (2). Provided is a static charge image developing toner that suppresses the generation of color spots generated when an image having a low image density is repeatedly formed and the generation of color spots caused by poor fixing of the toner image in a low temperature and low humidity environment.
According to the invention of claim 3, black spots are generated when an image having a low image density is repeatedly formed in a high temperature and high humidity environment, and a toner image is generated in a low temperature and low humidity environment, as compared with the case where the metal is barium. Provided is a toner for static charge image development that suppresses the generation of color spots caused by poor fixing.
According to the invention according to claim 4, 5, 6, 7, or 8, for static charge image development having toner particles containing a binder resin, a mold release agent, and a metal having an ionic valence of 2 or more. For toner, the metal concentration Mx measured by X-ray fluorescence analysis (XRF) is less than 0.02% by mass or more than 0.10% by mass, or measured by energy dispersive X-ray spectroscopy (EDX). This occurs when an image with a low image density is repeatedly formed in a high temperature and high humidity environment, as compared with the case where a toner for static charge image development 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 for suppressing the generation of color spots and the generation of color spots caused by poor fixing of a toner image in a low temperature and low humidity environment. ..

It is a schematic block diagram which shows an example of the image forming apparatus of this embodiment. It is a schematic block diagram which shows an example of the process cartridge of this embodiment.

Hereinafter, embodiments that are an example of the present invention will be described in detail.

(Toner for static charge image development)
The toner for static charge image development according to the present embodiment (hereinafter, referred to as “toner”) is a binder resin, a mold release agent, and a metal capable of having an ionic valence of divalent or higher (hereinafter, also simply referred to as “metal”). The toner particles have a metal concentration Mx of 0.02% by mass or more and 0.10% by mass or less as measured by X-ray fluorescence analysis (XRF).
Then, when the volume average particle diameter of the toner particles is D, the concentration Mes of the metal measured by energy dispersive X-ray spectroscopy (EDX) under the condition of accelerating voltage = 0.6 × D + 0.9 (kV). Relationship between (unit:%) and the concentration Met (unit:%) of the metal measured by energy dispersive X-ray spectroscopy (EDX) under the condition of accelerating voltage = 1.8 × D + 4.9 (kV). However, the following equation (1) is satisfied.
Equation (1): 0 ≦ Mes / Met <0.30

According to the above configuration, the toner according to the present embodiment repeatedly forms an image having a low image density in a high temperature and high humidity environment (for example, an image having an image density of 1% in an environment of 40 ° C. and 85% RH is 10000 on A3 paper. It suppresses the generation of color spots caused by poor fixing of toner images in a low temperature and low humidity environment (for example, in an environment of 10 ° C. and 15% RH). The reason is presumed as follows.

For example, when a low image density image is repeatedly formed in a high temperature and high humidity environment, the toner consumption is small in the repeated low image density image formation, and the same toner continues to be subjected to mechanical load and thermal load in the developing means. Therefore, the toner particles may be cracked. In particular, when the toner particles contain a release agent, the release agent exists in the binder resin as the base material by forming a domain having weak mechanical strength. Therefore, the release agent domain (or its interface) is formed. As a starting point, toner cracks are likely to occur.
When the toner particles are cracked, the cracked toner particles are hard to be charged and fall from the developing member of the developing means, so that they may appear as black spots in the image.

On the other hand, in order to suppress cracking of toner particles, a method of increasing the amount of a metal (its ion) that forms an ion crosslink with a functional group (carboxyl group, hydroxyl group) of the binder resin, a resin having a high glass transition temperature as a binder resin. It is known that the hardness of the entire toner particle is increased by the method using.
However, if the hardness of the entire toner particles is increased, poor fixing of the toner image (particularly poor fixing 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. However, since it accumulates on the member (finger member) that peels off the recording medium from the fixing member and falls, it may appear as a color dot in the image.

On the other hand, in the toner according to the present embodiment, the metal concentration Mx is set to 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 the concentration of the metal measured by the fluorescent X-ray analysis method (XRF), it indicates the ratio (mass ratio) of the metal to the entire toner particles.
Since the metal concentration Mes is the metal concentration measured by energy dispersion X-ray spectroscopy (EDX) under the condition of a low accelerating voltage such as accelerating voltage = 0.6 × D + 0.9 (kV), the electron beam is formed. The ratio (mass ratio) of the metal in the surface layer of the toner particles on the irradiated 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.
Since the metal concentration Met is the metal concentration measured by energy dispersive X-ray spectroscopy (EDX) under the condition of a high accelerating voltage such as accelerating voltage = 1.8 × D + 4.9 (kV), the electron beam is emitted. Ratio (mass ratio) of metal in the entire toner particles in the irradiated area (the entire area from the front surface of the toner particles on the side to be irradiated with the electron beam to the back surface on the opposite side in the region to be irradiated with the electron beam). ) Is shown.

That is, "Mes / Met" in the formula (1) indicates the ratio of the metal concentration Mes to the toner particle surface layer on the side irradiated with the electron beam to the metal concentration Met in the entire toner particles. Then, when the equation (1): 0 ≦ Mes / Met <0.30 is satisfied, it means 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. It is considered that the metal ions form an ion crosslink with the functional groups (for example, carboxyl groups, hydroxyl groups, etc.) of the binder resin.

Then, by suppressing the metal concentration Mx with respect to the entire toner particles to the above range and unevenly distributing the metal ions inside the toner particles, more ion cross-links due to the metal ions are formed inside the toner particles as compared with the surface layer. Therefore, the apparent molecular weight of the binder resin is increased, the internal strength of the toner particles is increased, the toner particles are less likely to be 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, in the surface layer of the toner particles, since there is no or little ion cross-linking by metal ions, fixability is also ensured.

From the above, the toner according to the present embodiment generates black spots that occur when images with low image density are repeatedly formed in a high temperature and high humidity environment, and color spots that occur due to poor fixing of the toner image in a low temperature and low humidity environment. Is presumed to be suppressed.

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

The toner according to this embodiment has toner particles. The toner may have an external additive that adheres to the surface of the toner particles, if necessary.

(Toner particles)
Toner particles include, for example, binder resins, mold release agents, and metals. The toner particles may contain a colorant and other additives, if necessary.

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

As the binder resin, a polyester resin is suitable.
Examples of the polyester resin include known polyester resins.

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

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

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

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

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

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

As the binder resin, a styrene (meth) acrylic resin is also suitable.
Examples of the styrene (meth) acrylic resin include known styrene (meth) acrylic resins.

The styrene (meth) acrylic resin is a styrene-based polymerizable monomer (a polymerizable monomer having a styrene skeleton) and a (meth) acrylic-based polymerizable monomer (a polymerizable monomer having a (meth) acryloyl skeleton). ) And at least a copolymer.
In addition, "(meth) acrylic" is an expression including both "acrylic" and "methacryl".

Examples of the styrene-based 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. The styrene-based polymerizable monomer may be used alone or in combination of two or more.
Among these, as the styrene-based monomer, styrene is preferable in terms of ease of reaction, ease of control of the reaction, and availability.

Examples of the (meth) acrylic polymerizable monomer include (meth) acrylic acid and (meth) acrylic acid ester. Examples of the (meth) acrylic acid ester include (meth) acrylic acid alkyl ester (for example, methyl (meth) acrylic acid, ethyl (meth) acrylic acid, n-propyl (meth) acrylic acid, n (meth) acrylic acid. -Butyl, n-pentyl (meth) acrylate, n-hexyl acrylate, n-hebutyl (meth) acrylate, n-octyl (meth) acrylate, n-decyl (meth) acrylate, (meth) acrylate 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, amyl (meth) acrylate, neopentyl (meth) acrylate, isohexyl (meth) acrylate, isoheptyl (meth) acrylate, (meth) ) Isooctyl acrylate, 2-ethylhexyl (meth) acrylate, cyclohexyl (meth) acrylate, t-butylcyclohexyl (meth) acrylate, etc.), aryl (meth) acrylate (eg, phenyl (meth) acrylate, Biphenyl (meth) acrylate, diphenylethyl (meth) acrylate, t-butylphenyl (meth) acrylate, tarphenyl (meth) acrylate, etc.), dimethylaminoethyl (meth) acrylate, diethylamino (meth) acrylate Examples thereof include ethyl, methoxyethyl (meth) acrylate, 2-hydroxyethyl (meth) acrylate, β-carboxyethyl (meth) acrylate, and (meth) acrylamide. The (meth) acrylic acid-based polymerizable monomer may be used alone or in combination of two or more.

The copolymerization ratio of the styrene-based polymerizable monomer and the (meth) acrylic-based polymerizable monomer (mass basis, styrene-based polymerizable monomer / (meth) acrylic-based polymerizable monomer) is, for example, 85. It is preferably / 15 to 70/30.

The styrene (meth) acrylic resin may have a crosslinked structure. The styrene (meth) acrylic resin having a crosslinked structure is, for example, crosslinked by at least copolymerizing a styrene-based polymerizable monomer, a (meth) acrylic acid-based polymerizable monomer, and a crosslinkable monomer. Things can be mentioned.

Examples of the crosslinkable monomer include a bifunctional or higher functional crosslinker.
Examples of the bifunctional cross-linking 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 cross-linking agent include tri (meth) acrylate compounds (for example, pentaerythritol tri (meth) acrylate, trimethylolethanetri (meth) acrylate, trimethylolpropane tri (meth) acrylate, etc.) and tetra (meth) acrylate. Compounds (eg, tetramethylolmethanetetra (meth) acrylate, oligoester (meth) acrylate, etc.), 2,2-bis (4-methacryloxy, polyethoxyphenyl) propane, diallylphthalate, triallyl cyanurate, triallyl isocyanurate. , Triallyl trimethylate, diallyl chlorendate and the like.

The copolymerization ratio of the crosslinkable monomer to all the monomers (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 preferably, for example, 50 ° C. or higher and 75 ° C. or lower, preferably 55 ° C. or higher and 65 ° C. or lower, and more preferably 57 ° C. or higher and 60 ° C. or lower in terms of fixability. Is.
The glass transition temperature is obtained from the DSC curve obtained by differential scanning calorimetry (DSC), and more specifically described in JIS K 7121-1987 "Method for measuring transition temperature of plastics". It is obtained by the "external glass transition start temperature" of.

The weight average molecular weight of the styrene (meth) acrylic resin is, for example, preferably 30,000 or more and 200,000 or less, preferably 40,000 or more and 100,000 or less, and more preferably 50,000 or more and 80,000 or less 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 using a Tosoh GPC / HLC-8120GPC as a measuring device, a Tosoh column / TSKgel SuperHM-M (15 cm), and a THF solvent. The weight average molecular weight is calculated from this measurement result using a molecular weight calibration curve prepared from a monodisperse polystyrene standard sample.

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

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

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

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

-Metal-
The metal is a metal that can have an ionic valence of divalent or higher. However, the metal may be, for example, a metal having a divalent or higher ionic valence (preferably divalent or higher and tetravalent or lower).
Specifically, the metal is preferably a metal other than chromium, zirconium, and lead. Preferable 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 source (compound contained in the toner particles as an additive) include metal salts, inorganic metal salt polymers, metal complexes, and the like. The metal salt, the inorganic metal salt polymer, and the metal complex are added to the toner particles as an aggregating agent, for example, when the toner particles are produced by the aggregation and 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 (II) sulfate, calcium polysulfide and the like.
Examples of the metal complex include a metal salt of an aminocarboxylic acid. Specific examples of the metal complex include known chelate-based metal salts such as ethylenediaminetetraacetic acid, propanediaminetetraacetic acid, nitrile triacetic acid, triethylenetetramine-6 acetic acid, and diethylenetriamine5 acetic acid (eg, calcium salt, Magnesium salt, iron salt, aluminum salt, etc.) and the like.

The source of these metals may be added as a mere additive, not as a coagulant.

The higher the ionic valence of the metal, the easier it is to form a network-like ion bridge, and the metal element with a smaller atomic number has a smaller metal (the metal ion) and a smaller network structure of the bridge. , The strength inside the toner particles is improved by ion cross-linking of metal ions, which is suitable from the viewpoint of suppressing the generation of color spots.
Therefore, as the metal, a trivalent metal (particularly Al ion) is preferable. That is, as a metal supply source, aluminum salts (for example, aluminum sulfate, aluminum chloride, etc.) and aluminum salt polymers (for example, polyaluminum chloride, polyaluminum hydroxide, etc.) are preferable. Further, from the viewpoint of suppressing the generation of color spots, among the metal ion supply sources, the inorganic metal salt polymer is preferable to the metal salt even if the valence of the metal ions is the same.

The 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 the generation of color spots due to cracking of toner particles is suppressed. From the viewpoint of suppressing the generation of color spots due to poor fixing of the 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 fluorescent X-ray analysis (XRF).
First, the resin and the metal source are mixed to obtain a resin mixture having a known metal concentration. A pellet sample of 200 mg of this resin mixture is obtained using a tablet molding machine having a diameter of 13 mm. The mass of this pellet sample is precisely weighed, and the fluorescence X-ray intensity of the pellet sample is measured to obtain the peak intensity. Similarly, the pellet sample in which the amount of the metal source added is changed is also measured, and a calibration curve is prepared from these results. Then, using this calibration curve, the concentration Mx of the metal in the toner particles to be measured is quantitatively analyzed.

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

Further, it is measured by energy dispersive X-ray spectroscopy (EDX) under the condition of acceleration voltage = 1.2 × D + 1.8 (kV) when the metal concentration Mem (when the volume average particle size of the toner particles is D). The relationship between the metal concentration) and the metal concentration Met satisfies the following equation (2) from the viewpoint of suppressing the generation of color spots due to cracking of toner particles and suppressing the generation of color spots due to poor fixing of the toner image. It is more preferable that the following formula (2A) is satisfied, and it is further preferable that the following formula (2B) is satisfied.
-Equation (1): 0 ≤ Mem / Met <0.30
Formula (1A): 0 ≦ Mem / Met <0.25
Equation (1B): 0 ≤ Mem / Met <0.20

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

The metal concentration Mes is preferably 0% or more and 0.04% or less, and 0% or more and 0. From the viewpoint of suppressing the generation of color spots due to cracking of toner particles and suppressing the generation of color spots 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, preferably 0.04, from the viewpoint of suppressing the generation of color spots due to cracking of toner particles and suppressing the generation of color spots due to poor fixing of the toner image. % Or more and 0.09% or less are more preferable.

The metal concentration Mem is preferably 0% or more and 0.04% or less, and 0% or more and 0. From the viewpoint of suppressing the generation of color spots due to cracking of toner particles and suppressing the generation of color spots 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 as follows using energy dispersive X-ray spectroscopy (EDX).
A pellet sample is obtained from 120 mg of toner particles using a tablet molder having a diameter of 13 mm. The pellet sample is measured by setting an accelerating voltage using an SEM (scanning electron microscope) (manufactured by Horiba: Xmax) equipped with an energy dispersive X-ray spectroscope (EDX device). The content ratio of the metal element in the range obtained at an observation magnification of 1000 times is measured.

When the metal concentration is measured by fluorescent X-ray analysis (XRF) and energy dispersive X-ray spectroscopy (EDX), the metal concentration is superposed in water with respect to the toner particles when the external agent is externally added to the toner particles. This is performed on a sample obtained by washing and drying the toner particles from which the external additive (free) adhering to the surface of the toner particles has been removed by performing sound treatment (at 20 ° C., amplitude 180 μm, 30 minutes). This operation is repeated until the external additive can be removed.

-Colorant-
Colorants include, for example, carbon black, chrome yellow, Hansa yellow, benzine yellow, slene yellow, quinoline yellow, pigment yellow, permanent orange GTR, pyrazolone orange, vulcan orange, watch young red, permanent red, brilliant carmine 3B, brilliant. Carmin 6B, Dupont Oil Red, Pyrazolon Red, Resole Red, Rhodamine B Lake, Lake Red C, Pigment Red, Rose Bengal, Aniline Blue, Ultra Marine Blue, Calco Oil Blue, Methylene Blue Chloride, Phthalocyanine Blue, Pigment Blue, Phthalocyanine Green, Various pigments such as malachite green oxalate, or aclysine, xanthene, azo, benzoquinone, azine, anthraquinone, thioindico, dioxazine, thiazine, azomethine, indico, phthalocyanine, aniline black Examples thereof include various dyes such as system, polymethine type, triphenylmethane type, diphenylmethane type and thiazole type.
One type of colorant may be used alone, or two or more types may be used in combination.

As the colorant, a surface-treated colorant may be used if necessary, or may be used in combination with a dispersant. In addition, a plurality of types 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 well-known additives such as magnetic materials, charge control agents, and inorganic powders. These additives are contained in the toner particles as an internal additive.

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

The volume average particle size (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.

The various average particle sizes of the toner particles and various particle size distribution indexes were measured using Coulter Multisizer II (manufactured by Beckman-Coulter), and the electrolytic solution was measured using ISOTON-II (manufactured by Beckman-Coulter). Toner.
At the time of measurement, 0.5 mg or more and 50 mg or less of the measurement sample is added to 2 ml of a 5% aqueous solution of a surfactant (preferably sodium alkylbenzene sulfonate) as a dispersant. This is added to 100 ml or more and 150 ml or less of the electrolytic solution.
The electrolytic solution in which the sample is suspended is dispersed for 1 minute with an ultrasonic disperser, and the particle size distribution of particles having a particle size in the range of 2 μm or more and 60 μm or less is obtained by using an aperture with an aperture diameter of 100 μm by Coulter Multisizer II. Measure. The number of particles to be sampled is 50,000.
Cumulative distribution of volume and number is drawn from the small diameter side for each particle size range (channel) divided based on the measured particle size distribution, and the cumulative 16% particle size is volume particle size D16v and number particle size. The particle size having D16p and a cumulative 50% is defined as the volume average particle size D50v and the cumulative number average particle size D50p, and the particle size having a cumulative number of 84% is defined as the volume particle size D84v and the 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 0.94 or more and 1.00 or less, and more preferably 0.95 or more and 0.98 or less.

The average circularity of the toner particles is obtained by (circumferential peripheral length) / (peripheral length) [(circumferential length of a circle having the same projected area as the particle image) / (peripheral length of the particle projected image)]. Specifically, it is a value measured by the following method.
First, a flow-type particle image analyzer (Cysmex) that captures a particle image as a still image by sucking and collecting toner particles to be measured, forming a flat flow, and instantly emitting strobe light to analyze the particle image. Obtained by FPIA-2100) manufactured by the company. Then, the number of samplings when calculating the average circularity is set to 3500.
When the toner has an external additive, the toner (developer) to be measured is dispersed in water containing a surfactant, and then ultrasonic treatment is performed to obtain toner particles from which the external additive has been removed. ..

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

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

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

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

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

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

Specifically, for example, when the toner particles are produced by the aggregation and coalescence method,
In a mixed dispersion of the first resin particle dispersion in which the first resin particles to be the binder resin are dispersed and the release agent particle dispersion in which the release agent particles are dispersed (other particles as required). In the dispersion liquid after mixing the dispersion liquid), a step of aggregating the first resin particles (other particles if necessary) to form the first agglomerated particles (first agglomerated particle forming step), and
A step of heating the first agglomerated particle dispersion liquid in which the first agglomerated particles are dispersed to fuse and coalesce the first agglomerated particles to form core particles (first fusion and coalescence 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 to be the binding resin are dispersed are mixed and aggregated so that the second resin particles adhere to the surface of the core particles. And the step of forming the second agglomerated particles (second agglomerated particle forming step) and
A step of heating the second agglomerated particle dispersion liquid in which the second agglomerated particles are dispersed to fuse and coalesce the second agglomerated particles to form core particles (second fusion and coalescence step).
Toner particles are manufactured through the above.

The 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, but the colorant and the release agent are used as needed. Of course, other additives other than colorants and mold release agents may be used.

-Resin particle dispersion liquid preparation process-
First, the first and second resin particle dispersion liquids (hereinafter collectively referred to as "resin particle dispersion liquid") in which the first and second resin particles (hereinafter, collectively referred to as "resin particles") to be the binder resin are dispersed. (Also also referred to as), for example, a colorant particle dispersion in which colorant particles are dispersed and a release agent particle dispersion in which release agent particles are dispersed are prepared.

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

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

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

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

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

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

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

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

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

As the flocculant, for example, an inorganic metal salt or a metal complex capable of having a divalent value or higher is used.
Then, if necessary, after the completion of aggregation, an additive that forms a complex or a similar bond with the metal (metal ion) of the flocculant 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 concentration of the metal inside the toner particles to be formed (core particles) can be adjusted.

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

As the chelating agent, a water-soluble chelating agent may be used. Examples of the chelating agent include oxycarboxylic acids such as tartrate acid, citric acid and gluconic acid, iminodic acid (IDA), nitrilotriacetic acid (NTA) and ethylenediaminetetraacetic acid (EDTA).
The amount of the chelating agent added is, for example, preferably 0.01 parts by mass or more and 5.0 parts by mass or less, and more preferably 0.1 parts by mass or more and less than 3.0 parts by mass with respect to 100 parts by mass of the resin particles.

-First fusion / unification process-
Next, the aggregated particle dispersion liquid in which the first aggregated particles are dispersed is heated to, for example, a temperature equal to or higher than the glass transition temperature of the first resin particles (for example, a temperature 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.

Then, after the completion of the first fusion / unification step, the core particles formed in the solution are subjected to a solid-liquid separation step, a known cleaning step, and the like to obtain core particles. Further, after the washing step, a solid-liquid separation step and a drying step may be carried out to obtain dried core particles.

Before the completion of the first fusion / coalescence step, after obtaining the first aggregated particle dispersion liquid in which the first aggregated particles are dispersed, the first aggregated particle dispersion liquid and the resin particle dispersion in which the resin particles are dispersed are dispersed. A step of further mixing the liquid and agglomerating the first agglomerated particles so as to further adhere the resin particles to the surface of the first agglomerated particles to form the first agglomerated particles to which the resin particles are further adhered to the surface, and a first resin particle adhesion The first agglomerated particle dispersion liquid in which the agglomerated particles are dispersed is heated, and the first agglomerated particles adhering to the resin particles are fused and united to form core particles having a core / shell structure. Core particles may be produced.

-Second aggregate particle formation step-
Next, a core particle dispersion is prepared using the obtained core particles. Then, the core particle dispersion liquid and the second resin particle dispersion liquid are mixed.
Then, in the mixed dispersion, the second resin particles are heteroaggregated so that the second resin particles adhere to the surface of the core particles, and the second resin particles adhere to the surface of the core particles having a diameter close to the target toner particle diameter. 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 a dispersion stabilizer is added as necessary to disperse the mixed dispersion. The aggregated particles are agglomerated to form agglomerated particles.

By this operation, the resin coating the core particles (in the surface layer of the toner particles) contains no metal or the metal concentration is reduced.

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

Through the above steps, 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) can be obtained.
Here, the second aggregate particle forming step and the second fusion / coalescence step are repeated, and the thickness of the resin (binding resin) covering the core particles (the surface layer of the toner particles containing no metal or having a reduced metal concentration). Thickness) can be adjusted. That is, it becomes easier to obtain toner particles in which the metal is unevenly distributed inside.

On the other hand, if the dispersant in which the core particles using the 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 aggregate particle forming step, the system Since the flocculant is dispersed in the group, when the pH of the system is lowered at one time, the flocculant is incorporated into the surface layer of the formed toner particles. Therefore, 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 the fusion / coalescence step is completed, the toner particles formed in the solution are subjected to a known washing step, solid-liquid separation step, and drying step to obtain toner particles in a dried state.
In the cleaning step, it is preferable to sufficiently perform replacement cleaning with ion-exchanged water from the viewpoint of chargeability. The solid-liquid separation step is not particularly limited, but suction filtration, pressure filtration, or the like may be performed from the viewpoint of productivity. The drying step is also not particularly limited, but from the viewpoint of productivity, freeze-drying, air-flow drying, fluid drying, vibration-type fluid drying and the like may be performed.

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

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

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

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

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

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

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

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

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

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

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

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

FIG. 1 is a schematic configuration diagram showing an image forming apparatus according to the present embodiment.
The image forming apparatus shown in FIG. 1 is an electrophotographic first to output an image of each color of yellow (Y), magenta (M), cyan (C), and black (K) based on color-separated image data. A fourth image forming unit 10Y, 10M, 10C, 10K (image forming means) is provided. These image forming units (hereinafter, may be simply referred to as “units”) 10Y, 10M, 10C, and 10K are arranged side by side at a predetermined distance from each other in the horizontal direction. The units 10Y, 10M, 10C, and 10K may be process cartridges that are attached to and detached from the image forming apparatus.

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

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

The first unit 10Y has a photoconductor 1Y that acts as an image holder. Around the photoconductor 1Y, a charging roll (an example of charging means) 2Y that charges the surface of the photoconductor 1Y to a predetermined potential, and a laser beam 3Y based on a color-separated image signal expose the charged surface. An exposure device (an example of a static charge image forming means) 3 for forming an electrostatic charge image, and a developing device (an example of a developing means) 4Y for developing a static charge image by supplying charged toner to the static charge image. A primary transfer roll 5Y (an example of a primary transfer means) that transfers a toner image onto an intermediate transfer belt 20, and a photoconductor cleaning device (an example of a cleaning means) 6Y that removes the toner remaining on the surface of the photoconductor 1Y after the primary transfer. Are arranged in order.
The primary transfer roll 5Y is arranged inside the intermediate transfer belt 20 and is provided at a position facing the photoconductor 1Y. Further, a bias power supply (not shown) for applying a primary transfer bias is connected to each of the primary transfer rolls 5Y, 5M, 5C, and 5K. Each bias power supply changes the transfer bias applied to each primary transfer roll by control by a control unit (not shown).

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

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

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

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

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

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

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

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

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

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

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

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

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 (an example of an image holder) and the photoconductor 107 by, for example, a housing 117 provided with a mounting rail 116 and an opening 118 for exposure. The charged roll 108 (an example of the charging means), the developing device 111 (an example of the developing means), and the photoconductor cleaning device 113 (an example of the cleaning means) are integrally combined and held and configured to form a cartridge. There is.
In FIG. 2, 109 is an exposure device (an example of an electrostatic charge image forming means), 112 is a transfer device (an example of a transfer means), 115 is a fixing device (an example of a fixing means), and 300 is a recording paper (an example of a recording medium). An example) is shown.

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

The image forming apparatus shown in FIG. 1 is an image forming apparatus having a structure in which the toner cartridges 8Y, 8M, 8C, and 8K are attached and detached, and the developing apparatus 4Y, 4M, 4C, and 4K are each developing apparatus (color). ) Is connected to a toner cartridge (not shown). Further, when the amount of toner contained in the toner cartridge is low, the toner cartridge is replaced.

Hereinafter, the present embodiment will be described in detail with reference to Examples, but the present embodiment is not limited to these Examples. In the following description, unless otherwise specified, "parts" and "%" are all based on mass.

<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 mass-Fumaric acid: 80 parts by mass-terephthalic acid : A solution containing 49 parts by mass or more of components mixed and dissolved is produced during the reaction under a nitrogen atmosphere while depressurizing the air in the container by a depressurization operation and further creating an inert atmosphere with nitrogen gas. The water was reacted at 190 ° C. for 18 hours while being removed from the system, then gradually reduced in pressure to 220 ° C. for 9 hours, and then cooled to obtain 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-mouthed flask and heated to 45 ° C. with stirring to dissolve the resin, and then 25 parts by mass of a 10% ammonia aqueous solution. A resin particle dispersion (P1) having a volume average particle diameter of 150 nm was prepared by gradually adding 400 parts by mass of ion-exchanged water to carry out phase inversion emulsification, 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-1,9-nonanediol 75.0 parts by mass-Dibutyl tin oxide 0.12 parts by mass The solution in which or more of the components are mixed and dissolved is depressurized by depressurizing the air in the container. Further, the mixture was made into an inert atmosphere with nitrogen gas, and under a nitrogen atmosphere while mechanically stirring, the water generated during the reaction was removed from the system and reacted at 180 ° C. for 8 hours, and then gradually reduced to 230. After raising the temperature to ° C. and reacting for 7 hours, the mixture was cooled to obtain a polyester resin having a weight average molecular weight of 22,500.

100 parts by mass of the obtained polyester resin, 60 parts by mass of methyl ethyl ketone, and 20 parts by mass of isopropyl alcohol were heated to 45 ° C. with stirring to dissolve the resin, and then 25 parts by mass of a 10% aqueous ammonia solution was added. A resin particle dispersion (P2) having a volume average particle size of 174 nm was prepared by gradually adding 400 parts by mass of ion-exchanged water for phase inversion emulsification, 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 (S1))
-Styline: 320 parts by mass-n-Butyl acrylate: 80 parts by mass-Acrylic acid: 12 parts by mass-10-dodecanethiol: 2 parts by mass or more of a mixture of and dissolved components is a nonionic surfactant ( Nonipol 400, 6 parts by mass of Sanyo Kasei Co., Ltd. and 10 parts by mass of anionic surfactant (Neogen SC, manufactured by Daiichi Kogyo Seiyaku Co., Ltd.) dissolved in 550 parts by mass of ion-exchanged water in a flask. While emulsifying and dispersing and slowly mixing for 10 minutes, 50 parts by mass of ion-exchanged water in which 4 parts by mass of ammonium persulfate was dissolved was added thereto. After nitrogen substitution, the inside of the flask was heated with an oil bath until the contents reached 70 ° C. while stirring, and emulsion polymerization was continued for 5 hours. As a result, a resin particle dispersion liquid in which styrene acrylic resin particles having a volume average particle diameter D50v = 210 nm, a weight average molecular weight of 38,000, and a glass transition temperature of 50 ° C. were dispersed was obtained.

<Preparation of colorant particle dispersion>
(Preparation of colorant particle dispersion (1))
-Carbon black (manufactured by Cabot: BP1300): 50 parts by mass-Nonionic surfactant Nonipol 400 (manufactured by Kao): 5 parts by mass-Ion-exchanged water: 200 parts by mass or more of components are mixed and dissolved, and high-pressure impact Disperse for about 1 hour using a formula disperser Ultimateer (manufactured by Sugino Machine Co., Ltd., HJP30006), adjust the water content so that the colorant concentration of this dispersion is 25% by mass, and adjust the colorant dispersion. Got

-Preparation of mold release agent dispersion-
-Paraffin wax (manufactured by 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-exchanged water: 200 A solution containing parts by mass or more of the components is heated to 120 ° C., dispersed using a homogenizer (IKA: Ultratarax T50), and then dispersed with a manton-gorin high-pressure homogenizer (Gorin) to average the volume. A release agent dispersion solution prepared by dispersing a release agent having a particle size of 250 nm was prepared. 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 [PigmentBlue 15: 3, manufactured by Dainichiseika Kogyo Co., Ltd.]
-Anionic surfactant: 2 parts by mass [Neogen SC, manufactured by Dai-ichi Kogyo Seiyaku Co., Ltd.]
-Ion-exchanged water: 80 parts by mass The above components are mixed and dispersed for 1 hour with a high-pressure impact disperser Ultimizer [HJP30006, manufactured by Sugino Machine Co., Ltd.], and the volume average particle size is 180 nm and the solid content is 20% by mass. A colorant particle dispersion (1) was obtained.

<Preparation of release agent particle dispersion>
(Release agent particle dispersion (1))
-Paraffin wax (manufactured by 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-exchanged water: 200 A solution containing parts by mass or more of the components is heated to 120 ° C., dispersed using a homogenizer (IKA: Ultratarax T50), and then dispersed with a manton-gorin high-pressure homogenizer (Gorin) to average the volume. A release agent dispersion solution prepared by dispersing a release agent having a particle size of 250 nm was prepared. The water content was adjusted so that the release agent concentration of this dispersion was 30% by mass.

<Example 1>
(Preparation of toner (1))
-Core particle formation process-
・ 600 parts by mass of resin particle dispersion (P1) ・ 85 parts by mass of resin particle dispersion (P2) ・ 100 parts by mass of colorant dispersion ・ 110 parts by mass of release agent dispersion ・ Cationic surfactant (manufactured by Kao Co., Ltd.) : Sanizol B50) 1.5 parts by mass The above components are placed in a round stainless steel flask, and after adjusting the pH to 3.7 by adding 0.1N sulfuric acid, the concentration of polyaluminum chloride as a coagulant is increased. 30 parts by mass of a 10% by mass aqueous nitrate solution was added, and then the mixture was dispersed at 30 ° C. using a homogenizer (Ultratarax T50 manufactured by IKA). After heating to 45 ° C. at 1 ° C./min in a heating oil bath and holding at 45 ° C. for 2 hours, 340 parts by mass of resin particle dispersion (P1) was added to this dispersion for another 1 hour. Retained.
Then, after adding 0.1N sodium hydroxide to adjust the pH to 8.0, the mixture was heated to 85 ° C. at 1 ° C./min for 3 hours while continuing stirring, and then 20 ° C./min. The mixture was cooled to 20 ° C., filtered, and washed with ion-exchanged water to obtain core particles.

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

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

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

<Example 3>
Toner particles were produced in the same manner as in Example 2 except that the amount of the resin particle dispersion liquid (P1) was changed to 100 parts by mass in the toner particle forming step, 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 the aqueous nitrate solution having a polyaluminum chloride concentration of 10% by mass was changed to 15 parts by mass, and the toner particles were used. Obtained toner.

<Example 5>
In the core particle forming step, toner particles were produced in the same manner as in Example 1 except that the aqueous nitrate solution having a polyaluminum chloride concentration of 10% by mass was changed to 40 parts by mass, and the toner particles were used to prepare toner. 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 these toner particles.

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

<Example 8>
In the core particle forming step and the toner particle forming step, toner particles were produced in the same manner as in Example 1 except that the resin particle dispersion liquid (P1) was changed to the resin particle dispersion liquid (S2), and the toner particles were used. Obtained toner.

<Comparative example 1>
Toner particles were produced in the same manner as in Example 2 except that the amount of the resin particle dispersion liquid (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 aqueous nitrate solution having a polyaluminum chloride concentration of 10% by mass was changed to 10 parts by mass, and the toner particles were used. Obtained toner.

<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 the aqueous nitrate solution having a polyaluminum chloride concentration of 10% by mass was changed to 50 parts by mass, and the toner particles were used. Obtained toner.

<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 the toners (toner particles) of each example, the metal concentration Mx, the metal concentration Mes, the metal concentration Met, and the metal concentration Mem were measured according to the methods described above.
These results are shown in Table 1. The volume average particle size D of the toner particles (denoted as “particle size D” in the table) is also shown in Table 1.

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

-Manufacturing of carrier (A)-
-Ferite particles (volume average particle size 50 μm): 100 parts by mass-Toluene: 100 parts by mass-Stylite-methylmethacrylate copolymer (component molar ratio: 90/10): 2 parts by mass-Carbon black (R330, manufactured by Cabot) ): 0.25 parts by mass First, the above components excluding ferrite particles are stirred with a stirrer for 10 minutes to prepare a dispersed coating liquid, and then this coating liquid and ferrite particles are placed in a vacuum degassing type kneader, and 60 After stirring at ° C. for 25 minutes, the carrier A was prepared by further heating, depressurizing, degassing, and drying. This carrier (A) had a shape coefficient of 120, a true specific gravity of 4.4, a saturation magnetization of 63 emu / g, and a volume specific resistance value of 1000 V / cm at an applied electric field of 1000 Ω · cm.

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

-Evaluation of color points in a high temperature and high humidity environment-
Using this device, 10,000 images with an image density of 1% were output on A3 paper under an environment of 40 ° C. and 85% RH, and then 30 halftone images with an image density of 50% were output on A3 paper. Then, the number of color points of the images output on the 1st to 30th sheets was measured and evaluated according to the following evaluation criteria.

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

-Evaluation criteria-
A (◎): Color spots not generated B (○): 1 or more and 4 or less color spots of 0.2 mm or more are generated C (Δ): 5 or more and 8 or less color spots of 0.2 mm or more are generated D (×): 9 or more color dots of 0.2 mm or more are generated

From the above results, in this example, as compared with the comparative example, color spots are 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 dots is suppressed.

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

Claims (8)

The concentration Mx of the metal, which contains a binder resin, a mold release agent, and a metal capable of having an ionic valence of divalent or higher, and is measured by X-ray fluorescence analysis (XRF), is 0.02% by mass or more and 0.10. Has toner particles that are less than or equal to mass%
When the volume average particle diameter of the toner particles is D, the concentration of the metal Mes (Mes) measured by energy dispersive X-ray spectroscopy (EDX) under the condition of acceleration voltage = 0.6 × D + 0.9 (kV). The relationship between the unit:%) and the concentration Met (unit:%) of the metal measured by energy dispersive X-ray spectroscopy (EDX) under the condition of acceleration voltage = 1.8 × D + 4.9 (kV) , Toner for static charge image development that satisfies the following formula (1).
Equation (1): 0 ≦ Mes / Met <0.30 When the volume average particle size of the toner particles is D, the concentration of the metal is Mem (unit:%) measured by energy dispersion type X-ray spectroscopy (EDX) under the condition of acceleration voltage = 1.2 × D + 1.8 kV. The toner for static charge image development according to claim 1, wherein the relationship between the metal concentration Met (unit:%) satisfies the following formula (2).
-Equation (2): 0 ≤ Mem / Met <0.3 The toner for developing an electrostatic charge image according to claim 1 or 2, wherein the metal is aluminum. A static charge image developer containing the toner for static charge image development according to any one of claims 1 to 3. The toner for developing an electrostatic charge image according to any one of claims 1 to 3 is accommodated.
A toner cartridge that is attached to and detached from the image forming device. A developing means for accommodating the electrostatic charge image developing agent according to claim 4 and developing the electrostatic charge image formed on the surface of the image holder as a toner image by the electrostatic charge image developing agent is provided.
A process cartridge that is attached to and detached from the image forming device. Image holder and
The charging means for charging the surface of the image holder and
An electrostatic charge image forming means for forming an electrostatic charge image on the surface of the charged image holder, and
A developing means that accommodates the electrostatic charge image developer according to claim 4 and develops the electrostatic charge image formed on the surface of the image holder as a toner image by the electrostatic image developer.
A transfer means for transferring a toner image formed on the surface of the image holder to the surface of a recording medium, and
A fixing means for fixing the toner image transferred to the surface of the recording medium, and
An image forming apparatus comprising. The charging process that charges the surface of the image holder,
A static charge image forming step of forming a static charge image on the surface of the charged image holder, and
A developing step of developing an electrostatic charge image formed on the surface of the image holder as a toner image by using the electrostatic charge image developer according to claim 4.
A transfer step of transferring a toner image formed on the surface of the image holder to the surface of a recording medium, and
A fixing step of fixing the toner image transferred to the surface of the recording medium, and
An image forming method having.