JP2021196438A - Image forming method - Google Patents

Abstract

To provide an image forming method for stably providing high-quality images without the occurrence of initial toner slip and without the occurrence of ghost density unevenness even after durable use.SOLUTION: In an image forming method, a layer constituting an outermost surface of a photoreceptor contains polytetrafluoroethylene particles, and in the polytetrafluoroethylene particles, (i) the number average particle diameter of primary particles is 200 nm or more and 500 nm or less, (ii) the number average molecular weight is 20000 or more and 28000 or less, and (iii) the degree of crystallinity is 78.0% or more and less than 83.0%. A toner has toner particles containing a binder resin, and an external additive. In powder fluidity analysis of the toner, when a propeller-type blade is penetrated vertically into a toner powder layer while being rotated at a peripheral velocity at an outermost edge part of 100 mm/sec, and the blade is penetrated from a position 100 mm from a bottom face of the powder layer to a position 10 mm from the bottom face, the total sum Et of running torque and a vertical load is 100 mJ or more and 2000 mJ or less.SELECTED DRAWING: None

Description

The present invention relates to an image forming method for forming a toner image on an electrophotographic photosensitive member on which an electrostatic latent image is formed in an electrophotographic method, an electrostatic recording method, and an electrostatic printing method.

As the rotationally driven electrophotographic photosensitive member in the electrophotographic apparatus, a cylindrical one is generally used. Since electrical external forces such as charging and cleaning and mechanical external forces are applied to the surface (peripheral surface) of the electrophotographic photosensitive member, durability against these external forces (wear resistance, etc.) is required. In response to this demand, improved techniques such as using a resin having high wear resistance (curable resin or the like) for the surface layer of the electrophotographic photosensitive member have been conventionally used. However, by increasing the wear resistance of the peripheral surface of the electrophotographic photosensitive member, deterioration of cleaning performance has become an issue.
In particular, toner with low fluidity after durability does not easily run laterally in the longitudinal direction of the electrophotographic photosensitive member, so that the blocking layer becomes uneven in the longitudinal direction, and the amount of the external additive that can be passed through in the cleaning part differs. Is born, and there is a problem that uneven ghost concentration occurs. To solve this problem, if the initial toner fluidity is improved, the toner rushing speed into the blocking layer of the cleaning portion becomes too fast, and the toner slips through in the cleaning portion.
Therefore, in order to solve the above problems, a technique of containing fluorine-containing fine particles in the surface layer is disclosed as a technique for improving the wear resistance and lubricity of the surface layer of the electrophotographic photosensitive member. Patent Document 1 describes a technique for incorporating a charge-transporting polymer and fluorine-containing fine particles into a photosensitive layer, which is a surface layer of an electrophotographic photosensitive member. Further, Patent Document 2 describes a technique for effectively melting and spreading by contacting a magnetic brush with a developer with the outermost surface layer containing fluorine-containing fine particles.
However, while the electrophotographic photosensitive member of the above-mentioned prior art exhibits excellent wear resistance and lubricity, fluorine-containing fine particles dispersed in the surface layer of the photoconductor are partially aggregated, and the fluidity after durability is maintained. In order to suppress uneven ghost density of low toner, there was room for further improvement in wear resistance and lubricity.

Japanese Unexamined Patent Publication No. 2001-305773 Japanese Unexamined Patent Publication No. 2012-8398

There is still room for study as an image forming method for providing a stable and high-quality image without the occurrence of initial toner slip-through and the occurrence of ghost density unevenness even after durability.
The present invention provides an image forming method that solves the above problems. Specifically, it provides an image forming method using an electrophotographic photosensitive member containing fluorine-containing fine particles having a specific molecular weight and crystallinity, and a toner having a specific range of fluidity.

The present invention
The charging process that charges the surface of the photoconductor,
An electrostatic latent image forming step of forming an electrostatic latent image on the surface of the charged photoconductor,
A developing process of developing the electrostatic latent image with toner to form a toner image,
A transfer step of transferring the toner image to a transfer material, and
A cleaning step of removing residual toner remaining on the surface of the photoconductor after the transfer step using a cleaning blade, and a cleaning step of removing the residual toner.
A fixing step of fixing the toner image transferred to the transfer material to the transfer material, and
It is an image forming method having
The photoconductor has a support and a photosensitive layer on the support.
Polytetrafluoroethylene particles are contained in the layer constituting the outermost surface of the photoconductor.
The polytetrafluoroethylene particles are
(I) Number of primary particles The average particle size is 200 nm or more and 500 nm or less.
(Ii) The number average molecular weight is 20,000 or more and 28,000 or less.
(Iii) The crystallinity is 78.0% or more and less than 83.0%.
The toner has toner particles and an external additive containing a binder resin, and the toner has.
In the powder fluidity analysis of the toner, while rotating the peripheral speed of the outermost edge of the propeller type blade at 100 mm / sec, the toner is vertically penetrated into the toner powder layer in the measuring container, and the bottom surface of the powder layer is formed. The total Et of the rotational torque and the vertical load obtained when the measurement is started from the position of 100 mm and penetrated to the position of 10 mm from the bottom surface is 100 mJ or more and 2000 mJ or less.
The present invention relates to an image forming method.

According to the present invention, it is possible to provide an image forming method capable of stably providing a high-quality image without causing initial toner slip-through, without causing ghost density unevenness even after durability. ..

It is a figure which shows an example of the schematic structure of the process cartridge equipped with the electrophotographic photosensitive member of this invention, and the electrophotographic apparatus provided with said said process cartridge. It is explanatory drawing of the propeller type blade used for the measurement of Et.

In the present invention, the description of "○○ or more and XX or less" and "○○ to XX" indicating a numerical range means a numerical range including a lower limit and an upper limit which are end points, unless otherwise specified.

The image forming method of the present invention is
The charging process that charges the surface of the photoconductor,
An electrostatic latent image forming step of forming an electrostatic latent image on the surface of the charged photoconductor,
A developing process of developing the electrostatic latent image with toner to form a toner image,
A transfer step of transferring the toner image to a transfer material, and
A cleaning step of removing residual toner remaining on the surface of the photoconductor after the transfer step using a cleaning blade, and a cleaning step of removing the residual toner.
A fixing step of fixing the toner image transferred to the transfer material to the transfer material, and
It is an image forming method having
The photoconductor has a support and a photosensitive layer on the support.
Polytetrafluoroethylene particles are contained in the layer constituting the outermost surface of the photoconductor.
The polytetrafluoroethylene particles are
(I) Number of primary particles The average particle size is 200 nm or more and 500 nm or less.
(Ii) The number average molecular weight is 20,000 or more and 28,000 or less.
(Iii) The crystallinity is 78.0% or more and less than 83.0%.
The toner has toner particles and an external additive containing a binder resin, and the toner has.
In the powder fluidity analysis of the toner, while rotating the peripheral speed of the outermost edge of the propeller type blade at 100 mm / sec, the toner is vertically penetrated into the toner powder layer in the measuring container, and the bottom surface of the powder layer is formed. The total Et of the rotational torque and the vertical load obtained when the measurement is started from the position of 100 mm and penetrated to the position of 10 mm from the bottom surface is 100 mJ or more and 2000 mJ or less.
It is characterized by that.

By controlling to this range, it is possible to provide a stable and high-quality image without the occurrence of initial toner slip-through and the occurrence of ghost density unevenness even after durability.

We are thinking of a method that can stably provide high-quality images without the occurrence of initial toner slip-through and the occurrence of ghost density unevenness even after durability. The present inventors have focused on controlling the number average particle size, number average molecular weight, crystallinity, and toner powder fluidity of the polytetrafluoroethylene particles contained in the layer constituting the outermost surface of the photoconductor. did. By controlling the number average particle size, number average molecular weight, and crystallinity of the polytetrafluoroethylene particles within the range, the dispersibility of the polytetrafluoroethylene particles on the outermost surface of the photoconductor is enhanced, and wear resistance and lubricity are improved. In combination with a toner whose fluidity is controlled in this range, it is easy to run laterally in the longitudinal direction during cleaning even after the initial and durability in the longitudinal direction, and the blocking layer becomes uniform. It is considered possible to stably provide high-quality images without causing uneven ghost density.

Hereinafter, embodiments for carrying out the present invention will be described in detail.

[Electrophotophotoconductor]
The electrophotographic photosensitive member of the present invention has a conductive support and a charge generating layer and a charge transport layer on the outside of the conductive support in this order. Further, a conductive layer, an undercoat layer, or both may be provided between the conductive support and the charge generation layer. Further, a surface layer may be provided outside the charge transport layer.

Examples of the method for producing the electrophotographic photosensitive member of the present invention include a method of preparing a coating liquid for each layer described later, applying the coating liquid in the order of desired layers, and drying the coating liquid. At this time, examples of the coating method of the coating liquid include immersion coating, spray coating, inkjet coating, roll coating, die coating, blade coating, curtain coating, wire bar coating, and ring coating. Among these, dip coating is preferable from the viewpoint of efficiency and productivity.

Hereinafter, each component such as a conductive support, a conductive layer, an undercoat layer, a photosensitive layer, and a surface layer (protective layer) will be described. Then, in the description of the photosensitive layer, (1) the laminated photosensitive layer and (2) the single-layer photosensitive layer will also be described.

<Conductive support>
In the present invention, the electrophotographic photosensitive member has a conductive support. Further, examples of the shape of the conductive support include a cylindrical shape, a belt shape, a sheet shape, and the like. Above all, it is preferably cylindrical. Further, the surface of the conductive support may be subjected to an electrochemical treatment such as anodization, a blast treatment, a cutting treatment or the like.

As the material of the conductive support, metal, resin, glass or the like is preferable.

Examples of the metal include aluminum, iron, nickel, copper, gold, stainless steel, and alloys thereof. Above all, it is preferable that the support is made of aluminum using aluminum.

Further, it is preferable that the resin or glass is imparted with conductivity by a treatment such as mixing or coating a conductive material.

<Conductive layer>
In the present invention, a conductive layer may be provided on the conductive support. By providing the conductive layer, it is possible to conceal scratches and irregularities on the surface of the conductive support and control the reflection of light on the surface of the conductive support.

The conductive layer preferably contains conductive particles and a resin.

Examples of the material of the conductive particles include metal oxides, metals, carbon black and the like.

Examples of the metal oxide include zinc oxide, aluminum oxide, indium oxide, silicon oxide, zirconium oxide, tin oxide, titanium oxide, strontium titanate, magnesium oxide, antimony oxide, and bismuth oxide. Examples of the metal include aluminum, nickel, iron, nichrome, copper, zinc, silver and the like.

Among these, it is preferable to use a metal oxide as the conductive particles, and it is more preferable to use titanium oxide, tin oxide, and zinc oxide.

When a metal oxide is used as the conductive particles, the surface of the metal oxide may be treated with a silane coupling agent or the like, or the metal oxide may be doped with an element such as phosphorus or aluminum or an oxide thereof.

Further, the conductive particles may have a laminated structure having core material particles and a coating layer covering the particles. Examples of the core material particles include titanium oxide, barium sulfate, zinc oxide and the like. Examples of the coating layer include metal oxides such as tin oxide.

When a metal oxide is used as the conductive particles, the volume average particle diameter thereof is preferably 1 nm or more and 500 nm or less, and more preferably 3 nm or more and 400 nm or less.

Examples of the resin include polyester resin, polycarbonate resin, polyvinyl acetal resin, acrylic resin, silicone resin, epoxy resin, melamine resin, polyurethane resin, phenol resin, alkyd resin and the like.

Further, the conductive layer may further contain a hiding agent such as silicone oil, resin particles, and titanium oxide.

The average film thickness of the conductive layer is preferably 1 μm or more and 50 μm or less, and particularly preferably 3 μm or more and 40 μm or less.

The conductive layer can be formed by preparing a coating liquid for a conductive layer containing each of the above-mentioned materials and a solvent, forming the coating film, and drying the coating film. Examples of the solvent used for the coating liquid include alcohol-based solvents, sulfoxide-based solvents, ketone-based solvents, ether-based solvents, ester-based solvents, aromatic hydrocarbon-based solvents and the like. Examples of the dispersion method for dispersing the conductive particles in the coating liquid for the conductive layer include a method using a paint shaker, a sand mill, a ball mill, and a liquid collision type high-speed disperser.

<Underground layer>
In the present invention, the undercoat layer may be provided on the conductive support or the conductive layer. By providing the undercoat layer, the adhesive function between the layers is enhanced, and the charge injection blocking function can be imparted.

The undercoat layer preferably contains a resin. Further, the undercoat layer may be formed as a cured film by polymerizing a composition containing a monomer having a polymerizable functional group.

The resins include polyester resin, polycarbonate resin, polyvinyl acetal resin, acrylic resin, epoxy resin, melamine resin, polyurethane resin, phenol resin, polyvinylphenol resin, alkyd resin, polyvinyl alcohol resin, polyethylene oxide resin, polypropylene oxide resin, and polyamide resin. , Polyamic acid resin, polyimide resin, polyamideimide resin, cellulose resin and the like.

The polymerizable functional group of the monomer having a polymerizable functional group includes an isocyanate group, a blocked isocyanate group, a methylol group, an alkylated methylol group, an epoxy group, a metal alkoxide group, a hydroxyl group, an amino group, a carboxyl group and a thiol group. Examples thereof include a carboxylic acid anhydride group and a carbon-carbon double bond group.

Further, the undercoat layer may further contain an electron transporting substance, a metal oxide, a metal, a conductive polymer and the like for the purpose of enhancing the electrical characteristics. Among these, it is preferable to use an electron transporting substance and a metal oxide.

Examples of the electron transporting substance include a quinone compound, an imide compound, a benzimidazole compound, a cyclopentadienylidene compound, a fluorenone compound, a xanthone compound, a benzophenone compound, a cyanovinyl compound, an aryl halide compound, a silol compound, and a boron-containing compound. .. An undercoat layer may be formed as a cured film by using an electron transporting substance having a polymerizable functional group as the electron transporting substance and copolymerizing it with the above-mentioned monomer having a polymerizable functional group.

Examples of the metal oxide include indium tin oxide, tin oxide, indium oxide, titanium oxide, strontium titanate, zinc oxide, aluminum oxide, silicon dioxide and the like. Examples of the metal include gold, silver and aluminum.

Further, the undercoat layer may further contain an additive.

The average film thickness of the undercoat layer is preferably 0.1 μm or more and 50 μm or less, more preferably 0.2 μm or more and 40 μm or less, and particularly preferably 0.3 μm or more and 30 μm or less.

The undercoat layer can be formed by preparing a coating liquid for an undercoat layer containing each of the above-mentioned materials and solvents, forming this coating film, and drying and / or curing. Examples of the solvent used for the coating liquid include alcohol-based solvents, ketone-based solvents, ether-based solvents, ester-based solvents, aromatic hydrocarbon-based solvents and the like.

<Photosensitive layer>
The photosensitive layer of the electrophotographic photosensitive member is mainly classified into (1) a laminated photosensitive layer and (2) a single-layer photosensitive layer. (1) The laminated photosensitive layer has a charge generating layer containing a charge generating substance and a charge transporting layer containing a charge transporting substance. (2) The single-layer type photosensitive layer has a photosensitive layer containing both a charge generating substance and a charge transporting substance.

(1) Laminated Photosensitive Layer The laminated photosensitive layer has a charge generation layer and a charge transport layer.

(1-1) Charge generating layer The charge generating layer preferably contains a charge generating substance and a resin.

Examples of the charge generating substance include azo pigments, perylene pigments, polycyclic quinone pigments, indigo pigments, phthalocyanine pigments and the like. Among these, azo pigments and phthalocyanine pigments are preferable. Among the phthalocyanine pigments, oxytitanium phthalocyanine pigments, chlorogallium phthalocyanine pigments, and hydroxygallium phthalocyanine pigments are preferable.

The content of the charge generating substance in the charge generating layer is preferably 40% by mass or more and 85% by mass or less, and more preferably 60% by mass or more and 80% by mass or less with respect to the total mass of the charge generating layer. preferable.

As the resin, polyester resin, polycarbonate resin, polyvinyl acetal resin, polyvinyl butyral resin, acrylic resin, silicone resin, epoxy resin, melamine resin, polyurethane resin, phenol resin, polyvinyl alcohol resin, cellulose resin, polystyrene resin, polyvinyl acetate resin , Polyvinyl chloride resin and the like. Among these, polyvinyl butyral resin is more preferable.

Further, the charge generation layer may further contain additives such as an antioxidant and an ultraviolet absorber. Specific examples thereof include hindered phenol compounds, hindered amine compounds, sulfur compounds, phosphorus compounds, benzophenone compounds and the like.

The average film thickness of the charge generation layer is preferably 0.1 μm or more and 1 μm or less, and more preferably 0.15 μm or more and 0.4 μm or less.

The charge generation layer can be formed by preparing a coating liquid for a charge generation layer containing each of the above-mentioned materials and a solvent, forming the coating film, and drying the coating film. Examples of the solvent used for the coating liquid include alcohol-based solvents, sulfoxide-based solvents, ketone-based solvents, ether-based solvents, ester-based solvents, aromatic hydrocarbon-based solvents and the like.

(1-2) Charge transport layer The charge transport layer contains a charge transport substance and a resin.

Examples of the charge transporting substance include polycyclic aromatic compounds, heterocyclic compounds, hydrazone compounds, styryl compounds, enamine compounds, benzidine compounds, triarylamine compounds, and resins having a group derived from these substances. Be done. Among these, triarylamine compounds and benzidine compounds are preferable. These may be used alone or in combination of two or more.

The content of the charge transporting substance in the charge transport layer is preferably 25% by mass or more and 70% by mass or less, and more preferably 30% by mass or more and 55% by mass or less, based on the total mass of the charge transport layer. preferable.

Examples of the resin include polyester resin, polycarbonate resin, acrylic resin, polystyrene resin and the like. Among these, polycarbonate resin and polyester resin are preferable. As the polyester resin, a polyarylate resin is particularly preferable.

The content ratio (mass ratio) of the charge transporting substance and the resin is preferably 4: 10 to 20:10, more preferably 5: 10 to 12:10.

When the charge transport layer is the outermost surface of the electrophotographic photosensitive member (that is, when the surface layer described later is not provided), the charge transport layer is a polytetrafluoroethylene particle having an average primary particle diameter of 200 nm or more and 500 nm or less. Contains.

The number average molecular weight of the polytetrafluoroethylene particles is 20,000 or more and 28,000 or less, and the crystallinity is 78% or more and less than 83%. The number average molecular weight of the polytetrafluoroethylene particles is more preferably 20,000 or more and 26,000 or less. The crystallinity is more preferably 80% or more and less than 83%. Further, the average value of the roundness of the polytetrafluoroethylene particles measured from the secondary electron image by the scanning electron microscope is preferably 0.80 or more.

The polytetrafluoroethylene particles may be used alone or in combination of two or more.

The measurement of the average primary particle diameter, number average molecular weight, crystallinity, and roundness of the polytetrafluoroethylene particles of the present invention can be measured and calculated by the following method.

(Measuring method of average primary particle size and average roundness)
The roundness is measured from a secondary electron image obtained by a scanning electron microscope. This will be described in detail below.

The average particle size and average roundness of the PTFE particles were measured using a field emission scanning electron microscope (FE-SEM). The PTFE particles were attached to a commercially available carbon conductive tape, and the PTFE particles not attached to the conductive tape were removed by compressed air, and platinum vapor deposition was performed. The vapor-deposited PTFE particles were observed using FE-SEM (S-4700) manufactured by Hitachi High-Technology. The measurement conditions of FE-SEM are as follows.
Acceleration voltage: 2kV
WD: 5 mm
Magnification: 20,000 times Number of pixels: 1280 pixels vertically, 960 pixels horizontally (size per pixel: 5 nm)

From the obtained image, ImageJ (Open Source Software manufactured by National Institutes of Health (NIH)) was used to determine the ferret diameter of 100 particles, and the average value was calculated to obtain the average particle diameter.

Similarly, the area and the perimeter were obtained, the roundness was obtained from Eq. (2), and the average value was calculated to obtain the average roundness.
Roundness = 4 × π × (area) ÷ (square of perimeter) Equation (2)

(Measurement method of number average molecular weight)
The number average molecular weight is calculated from the measurement result by differential scanning calorimetry (hereinafter abbreviated as DSC). This will be described in detail below.

A DSC822e manufactured by METTTLER TOLEDO was used as the DSC, and the measurement was performed in a nitrogen atmosphere. Polytetrafluoroethylene particles were placed in a 40 μl aluminum sample pan and heated from 25 ° C. to 350 ° C. at a heating rate of 16 ° C./min. Next, after holding at 350 ° C. for 10 minutes, the temperature was lowered to 280 ° C. at a temperature lowering rate of 16 ° C./min. The heat of crystallization ΔHc was obtained from the peak at the time of this temperature decrease.

The number average molecular weight Mn was obtained from the crystallization heat ΔHc from the formula (3).
Mn = 2.1 × 10 ¹⁰ × ΔHc ^-5.16 Equation (3)

(Measuring method of crystallinity)
The crystallinity is measured by the wide-angle X-ray diffraction method under the following conditions.
X-ray diffractometer: Bruker AXS D8 ADVANCE
X-ray source: Cu-Kα ray (wavelength 0.15418 nm)
Output: 40kV, 40mA
Slit system: Slit DS, SS = 1 °, RS = 0.2mm
Measurement range: 2θ = 5 ° to 60 °
Step interval: 0.02 °
Scan speed: 1 ° / min

The wide-angle X-ray diffraction profile obtained under the above measurement conditions was separated into crystal peaks and amorphous scattering, and the crystallinity was calculated from the areas thereof from the equation (4).
Crystallinity (%) = Ic / (Ic + Ia) × 100 Equation (4)
Total area of crystal peaks detected in the range of Ic: 5 ≦ 2θ ≦ 60 Total area of amorphous scattering detected in the range of Ia: 5 ≦ 2θ ≦ 60

Further, the charge transport layer may contain additives such as an antioxidant, an ultraviolet absorber, a plasticizer, a leveling agent, a slipperiness imparting agent, and an abrasion resistance improving agent. Specifically, hindered phenol compound, hindered amine compound, sulfur compound, phosphorus compound, benzophenone compound, siloxane modified resin, silicone oil, fluororesin particles, polystyrene resin particles, polyethylene resin particles, silica particles, alumina particles, boron nitride particles. And so on.

The average film thickness of the charge transport layer is preferably 5 μm or more and 50 μm or less, and 30 μm or more and 45 μm or less when the electrolytic transport layer is the outermost surface of the electrophotographic photosensitive member (that is, when the surface layer is not provided). Is more preferable. When the surface layer is provided on the charge transport layer, the average film thickness of the charge transport layer is preferably 5 μm or more and 50 μm or less, more preferably 8 μm or more and 40 μm or less, and 10 μm or more and 30 μm or less. It is particularly preferable to have.

The charge transport layer can be formed by preparing a coating liquid for a charge transport layer containing each of the above-mentioned materials and a solvent, forming the coating film, and drying the coating film. Examples of the solvent used for the coating liquid include alcohol-based solvents, ketone-based solvents, ether-based solvents, ester-based solvents, and aromatic hydrocarbon-based solvents. Among these solvents, ether-based solvents or aromatic hydrocarbon-based solvents are preferable.

(2) Single-layer type photosensitive layer The single-layer type photosensitive layer is formed by preparing a coating liquid for a photosensitive layer containing a charge generating substance, a charge transporting substance, a resin and a solvent, forming this coating film, and drying the coating film. can do. The charge generating substance, the charge transporting substance, and the resin are the same as the examples of the materials in the above “(1) Laminated photosensitive layer”.

<Surface layer (protective layer)>
In the present invention, a surface layer may be provided on the photosensitive layer. By providing the surface layer, since the photosensitive layer is covered, the photosensitive layer can be protected from scraping, and the durability of the electrophotographic photosensitive member can be improved.

The surface layer contains an abrasion resistance improver, a charge transporting substance, and a resin.

Examples of the wear resistance improving agent include polytetrafluoroethylene particles having an average primary particle diameter of 200 nm or more and 500 nm or less.

The number average molecular weight of the polytetrafluoroethylene particles is 20,000 or more and 28,000 or less, and the crystallinity is 78.0% or more and less than 83.0%. The number average molecular weight of the polytetrafluoroethylene particles is more preferably 20,000 or more and 26,000 or less. The crystallinity is more preferably 80.0% or more and less than 83.0%. Further, the average value of the roundness of the polytetrafluoroethylene particles measured from the secondary electron image by the scanning electron microscope is preferably 0.80 or more.

The polytetrafluoroethylene particles may be used alone or in combination of two or more.

The measurement of the average primary particle diameter, number average molecular weight, crystallinity, and roundness of the polytetrafluoroethylene particles of the present invention can be measured and calculated by the above-mentioned method.

Examples of the charge transporting substance include polycyclic aromatic compounds, heterocyclic compounds, hydrazone compounds, styryl compounds, enamine compounds, benzidine compounds, triarylamine compounds, and resins having a group derived from these substances. Among these, triarylamine compounds and benzidine compounds are preferable.

Examples of the resin include polyester resin, acrylic resin, phenoxy resin, polycarbonate resin, polystyrene resin, phenol resin, melamine resin, epoxy resin and the like. Of these, (meth) acrylic resin is preferable.

Further, the surface layer may be formed as a cured film by polymerizing a composition containing a monomer having a polymerizable functional group. Examples of the reaction at that time include a thermal polymerization reaction, a photopolymerization reaction, and a radiation polymerization reaction. Examples of the polymerizable functional group of the monomer having a polymerizable functional group include a (meth) acrylic group. As the monomer having a polymerizable functional group, a material having a charge transporting ability may be used. The charge transporting ability is the ability obtained by having a charge transporting group.

Further, the surface layer may contain conductive particles. Examples of the conductive particles include particles of metal oxides such as titanium oxide, zinc oxide, tin oxide, and indium oxide.

The surface layer may contain additives such as antioxidants, UV absorbers, plasticizers, leveling agents, and slippering agents. Specific examples thereof include hindered phenol compounds, hindered amine compounds, sulfur compounds, phosphorus compounds, benzophenone compounds, siloxane-modified resins, silicone oils, polystyrene resin particles, polyethylene resin particles, silica particles, alumina particles, and boron nitride particles. ..

The average film thickness of the surface layer is preferably 0.5 μm or more and 10 μm or less, and preferably 1 μm or more and 7 μm or less.

The surface layer can be formed by preparing a coating liquid for a surface layer containing each of the above-mentioned materials and solvents, forming this coating film, and drying and / or curing it. Examples of the solvent used for the coating liquid include alcohol-based solvents, ketone-based solvents, ether-based solvents, sulfoxide-based solvents, ester-based solvents, and aromatic hydrocarbon-based solvents.

[Process cartridge, electrophotographic equipment]
The process cartridge of the present invention integrally supports the electrophotographic photosensitive member described above and at least one means selected from the group consisting of charging means, developing means, transfer means and cleaning means, and is an electrophotographic apparatus. It is removable to the main body.

Further, the electrophotographic apparatus of the present invention includes the electrophotographic photosensitive member, the charging means, the exposure means, the developing means and the transfer means described so far.

FIG. 1 shows an example of a schematic configuration of an electrophotographic apparatus having a process cartridge including an electrophotographic photosensitive member.

Reference numeral 1 denotes a cylindrical electrophotographic photosensitive member, which is rotationally driven at a predetermined peripheral speed in the direction of an arrow about a shaft 2. The surface of the electrophotographic photosensitive member 1 is charged to a predetermined positive or negative potential by the charging means 3. Although the roller charging method using the roller type charging member is shown in the figure, a charging method such as a corona charging method, a proximity charging method, or an injection charging method may be adopted. The surface of the charged electrophotographic photosensitive member 1 is irradiated with exposure light 4 from an exposure means (not shown), and an electrostatic latent image corresponding to the target image information is formed. The electrostatic latent image formed on the surface of the electrophotographic photosensitive member 1 is developed with the toner contained in the developing means 5, and the toner image is formed on the surface of the electrophotographic photosensitive member 1. The toner image formed on the surface of the electrophotographic photosensitive member 1 is transferred to the transfer material 7 by the transfer means 6. The transfer material 7 to which the toner image is transferred is conveyed to the fixing means 8, undergoes the fixing process of the toner image, and is printed out of the electrophotographic apparatus. The electrophotographic apparatus may have a cleaning means 9 for removing deposits such as toner remaining on the surface of the electrophotographic photosensitive member 1 after transfer. Further, a so-called cleanerless system may be used in which the above-mentioned deposits are removed by a developing means or the like without separately providing a cleaning means. The electrophotographic apparatus may have a static elimination mechanism for statically eliminating the surface of the electrophotographic photosensitive member 1 with the preexposure light 10 from the preexposure means (not shown). Further, in order to attach / detach the process cartridge of the present invention to / from the main body of the electrophotographic apparatus, a guide means 12 such as a rail may be provided.

The electrophotographic photosensitive member of the present invention can be used for a laser beam printer, an LED printer, a copying machine, a facsimile, a multifunction device thereof, and the like.

[toner]
The toner of the present invention has toner particles and an external additive containing a binder resin, and has
In the powder fluidity analysis of the toner, while rotating the peripheral speed of the outermost edge of the propeller type blade at 100 mm / sec, the toner is vertically penetrated into the toner powder layer in the measuring container, and the bottom surface of the powder layer is formed. The feature is that the total Et of the rotational torque and the vertical load obtained when the measurement is started from the position of 100 mm to the position of 10 mm from the bottom surface is 100 mJ or more and 2000 mJ or less (preferably 200 mJ or more and 1000 mJ or less). Is.

When the electrophotographic photosensitive member used in the present invention is used as the toner, the speed of entry into the blocking layer formed in the cleaning portion is suppressed even in the initial state, and sufficient lateral running in the blocking layer occurs even after durability. This makes it possible to provide an image forming method capable of stably providing a high-quality image without causing unevenness in ghost density.

The fluidity of the toner is determined by the selection of the crusher, the crushing condition, the selection of the classifier, the classification condition, the selection of the sphericalization processing device, the sphericalization processing condition, the center particle size, the particle size distribution, the selection of the external additive, and the external addition. It can be adjusted as appropriate depending on the conditions and the external formulation.

[External additive (inorganic fine particles)]
Examples of the inorganic fine particles of the present invention include alkaline earth metal titanates such as strontium titanate particles, calcium titanate particles and magnesium titanate particles; and alkali metal titanate particles such as potassium titanate particles.

Of these, strontium titanate particles, calcium titanate particles, and magnesium titanate particles having a perovskite crystal structure are preferable, and strontium titanate particles are more preferable, from the viewpoint that the fluidity of the toner particles can be easily controlled. ..

The number average particle diameter of the inorganic fine particles is preferably 20 nm or more and 300 nm or less, and more preferably 30 nm or more and 100 nm or less. Further, in those particle size distributions, it is preferable that the peak top of the number frequency is in the above particle size range.

It is preferable that the surface of the inorganic fine particles is made hydrophobic with a surface treatment agent. As the surface treatment agent, a fatty acid or a metal salt thereof, a disilylamine compound, a halogenated silane compound, a silicone oil, a silane coupling agent, a titanium coupling agent and the like are preferable because the fluidity of the toner particles can be easily controlled.

For mixing the toner particles and the inorganic fine particles, a known mixer such as a Henshell mixer, a mechano hybrid (manufactured by Nippon Coke Co., Ltd.), a super mixer, or Nobilta (manufactured by Hosokawa Micron Co., Ltd.) can be used, and the mixture is not particularly limited. No.

The strontium titanate particles as an example of the inorganic fine particles of the present invention can be obtained by a normal pressure heating reaction method. At this time, it is preferable to use a mineral acid deflated product of a hydrolyzate of the titanium compound as the titanium oxide source, and to use a water-soluble acidic strontium compound as the strontium oxide source. It can be produced by a method of reacting the mixed solution with an alkaline aqueous solution at 60 ° C. or higher while adding an alkaline aqueous solution, and then treating with an acid.

(Atmospheric pressure heating reaction method)
As the titanium oxide source, a mineral acid defoliated product of a hydrolyzate of a titanium compound can be used. _{Preferably, metatitanic acid having an SO 3} content of 1.0% by mass or less, preferably 0.5% by mass or less obtained by the sulfuric acid method is solved by adjusting the pH to 0.8 to 1.5 with hydrochloric acid. A glued one can be used.

As the strontium oxide source, metal nitrate, hydrochloride and the like can be used, and for example, strontium nitrate and strontium chloride can be used.

As the alkaline aqueous solution, caustic alkali can be used, but the sodium hydroxide aqueous solution is particularly preferable.

In the method for producing strontium titanate particles, factors that affect the particle size include the mixing ratio of the titanium oxide source and the strontium oxide source at the time of the reaction, the concentration of the titanium oxide source at the initial stage of the reaction, and the temperature at which the alkaline aqueous solution is added. And the addition rate and the like. These can be appropriately adjusted in order to obtain the desired particle size and particle size distribution. In addition, it is preferable to prevent the mixing of carbon dioxide gas by reacting in a nitrogen gas atmosphere in order to prevent the formation of carbon dioxide in the reaction process.

In the method for producing the obtained strontium titanate particles, factors that affect the dielectric constant include conditions / operations that disrupt the particle crystallinity. In particular, in order to obtain strontium titanate particles having a low dielectric constant, it is preferable to perform an operation of giving energy that disturbs crystal growth in a state where the concentration of the reaction solution is increased. As a specific method, for example, addition of micro-babbling with nitrogen to the crystal growth step can be mentioned. In addition, the content of cubic and rectangular parallelepiped particles can also be controlled by the flow rate of this nitrogen microbabbling.

The mixing ratio of the titanium oxide source and the strontium oxide source during the reaction is preferably 0.9 to 1.4, more preferably 1.05 to 1.20, in terms of the molar ratio of _{SrO / TiO 2.} Within the above range, unreacted titanium oxide is unlikely to remain. The concentration of the titanium oxide source at the initial stage of the reaction is preferably 0.05 to 1.3 mol / L, more preferably 0.08 to 1.0 mol / L as _{TiO 2.}

The temperature at which the alkaline aqueous solution is added is preferably 60 ° C to 100 ° C. As for the addition rate of the alkaline aqueous solution, the slower the addition rate, the larger the strontium titanate particles can be obtained, and the faster the addition rate, the smaller the strontium titanate particles can be obtained. The addition rate of the alkaline aqueous solution is preferably 0.001 to 1.2 equivalents / h, more preferably 0.002 to 1.1 equivalents / h with respect to the charged raw material, depending on the particle size to be obtained. It can be adjusted as appropriate.

(Acid treatment)
It is preferable to further acid-treat the strontium titanate particles obtained by the atmospheric heating reaction. When the strontium titanate particles are synthesized by performing an atmospheric heating reaction, if the mixing ratio of the titanium oxide source and the strontium oxide source _{exceeds 1.0 in the molar ratio of SrO / TiO 2} , it remains after the reaction is completed. An unreacted metal source other than titanium may react with carbon dioxide in the air to generate impurities such as metal carbonate. If impurities such as metal carbonate remain on the surface, the organic surface treatment agent cannot be uniformly coated due to the influence of the impurities when performing the organic surface treatment for imparting hydrophobicity. Therefore, after adding the alkaline aqueous solution, it is preferable to perform acid treatment in order to remove the unreacted metal source.

In the acid treatment, it is preferable to adjust the pH to 2.5 to 7.0, more preferably 4.5 to 6.0 using hydrochloric acid. As the acid, nitric acid, acetic acid and the like can be used for the acid treatment in addition to hydrochloric acid.

[Other external additives]
In addition to the above-mentioned inorganic fine particles, the toner may contain other inorganic fine powders, if necessary, in order to adjust the charge amount and fluidity. The inorganic fine powder may be added internally or externally to the toner particles. As the external additive, inorganic fine powders such as silica, titanium oxide, aluminum oxide, magnesium oxide and calcium carbonate are preferable. The inorganic fine powder is preferably hydrophobized with a hydrophobizing agent such as a silane compound, silicone oil or a mixture thereof.

As the specific surface area of the external additive used ^{, inorganic fine particles having a specific surface area of 10 m 2} / g or more and 50 m ² / g or less are preferable from the viewpoint of suppressing the embedding of the external additive.

Further, it is preferable that the external additive is used in an amount of 0.1 part by mass or more and 5.0 parts by mass or less with respect to 100 parts by mass of the toner particles.

A known mixer such as a Henschel mixer can be used for mixing the toner particles and the external additive, but the mixing is not particularly limited as long as the toner particles can be mixed.

The toner of the present invention is a toner containing toner particles containing a binder resin and strontium titanate particles A and silica particles B as the external additives.
The strontium titanate particles A have a rectangular parallelepiped particle shape and have a rectangular parallelepiped shape.
The content of the strontium titanate particles A is 0.3 parts by mass or more and 3.0 parts by mass or less with respect to 100 parts by mass of the toner particles.
The number average particle diameter of the primary particles of the silica particles B is 80 nm or more and 200 nm or less.
The adhesion rate of the strontium titanate particles A to the toner particles is 25% or more and 70% or less.
The separation amount of the strontium titanate particles A per 1 g of the toner when the sucrose solution in which the toner is dispersed is subjected to a centrifugation operation is defined as YA (mg), and the separation of the silica particles B per 1 g of the toner is defined as YA (mg). When the amount is YB (mg)
YA is 3.00 or more and 18.0 or less,
It is preferable that YA and YB satisfy the relationship of the following formula (1) from the viewpoint of improving cleanability.
YA / YB> 0.75 (1)

The adhesion rate of the strontium titanate particles A and the silica fine particles B and the separation amount of the external additive can be measured by the following methods.

Add 160 g of sucrose (manufactured by Kishida Chemical) to 100 mL of ion-exchanged water and dissolve in a water bath to prepare a concentrated sucrose aqueous solution. 31 g of the concentrated sucrose aqueous solution in a 20 mL glass bottle, 10% by mass aqueous solution of Contaminone N (a 10% by mass aqueous solution of a neutral detergent for cleaning a pH 7 precision measuring instrument consisting of a nonionic surfactant, an anionic surfactant, and an organic builder, Wako Pure Chemical Industries, Ltd.) Add 6 mL of (manufactured by Kogyo Co., Ltd.) to prepare a dispersion. Add 1.0 g of toner to this dispersion and loosen the toner lumps with a spatula or the like.

Shake the glass bottle containing the sample with a Yayoi shaker at 200 rpm and 5 min. After shaking, the solution is replaced with a glass tube for a swing rotor (50 mL), and a centrifugal separation operation is performed to separate the solution under the conditions of 3500 rpm and 30 min. By this operation, the toner particles and the removed external additive are separated. Visually confirm that the toner layer and the aqueous layer are sufficiently separated, and collect the toner in the uppermost layer (the interface with the aqueous layer) of the toner layer with a spatula or the like. The collected toner is filtered through a vacuum filter and then dried in a dryer for 1 hour or more to obtain toner particles from which the external additive has been separated.

The measurement of the adhesion rate of the strontium titanate particles A is as follows. First, the strontium titanate particles A contained in the toner before the separation step are quantified. This uses a wavelength dispersive fluorescent X-ray analyzer Axios advanced (manufactured by PANalytical) to measure the Sr element intensity: MB in the toner particles. Next, similarly, the Sr element strength: MA of the toner after the separation step is measured.

The fixing rate is calculated by (MA / MB) × 100 (%).

The separation amounts YA and YB are measured using the MA and MB measured when measuring the adhesion rate and the amounts (NA and NB) of the strontium titanate particles A and the silica particles B added to 1 g of the toner.

Separation amount YA is ((MB)-(MA)) × NA / (MB),
The separation amount YB is calculated by ((MB) − (MA)) × NB / (MB).

The adhesion rate of the strontium titanate particles A to the toner particles is 25% or more and 70% or less. When the adhesion rate of the strontium titanate particles A is within the above range, the fluidity of the toner forming the blocking layer in the cleaning portion can be easily controlled, and the cleaning property is improved.

The adhesion rate of the strontium titanate particles A is preferably 40% or more and 60% or less. The adhesion rate of the strontium titanate particles A can be controlled by a method such as changing the rotation speed and the rotation time when the toner particles are coated with the strontium titanate particles A with a mixer or the like.

Further, when the separation amount of strontium titanate particles A per 1 g of toner is YA (mg) and the separation amount of silica particles B per 1 g of toner is YB (mg), YA is 3.00 or more and 18.0 or less. Is. When the amount of YA is more than 18.0, the content of the strontium titanate particles A of the toner is lowered, so that the fluidity of the toner is lowered and the unevenness of the ghost concentration after durability is exacerbated. If the YA is less than 3.00, the blocking layer is not sufficiently formed and toner slips out.

YA is preferably 5.00 or more and 15.0 or less. YA can be controlled by a method such as changing the rotation speed and the rotation time when the toner particles are coated with the strontium titanate particles A with a mixer or the like.

YB is preferably 1.00 or more and 7.00 or less, and more preferably 2.00 or more and 6.00 or less.

Further, YA and YB satisfy the relationship of the following formula (1).
YA / YB> 0.75 (1)

When YA / YB is 0.75 or less, more silica particles B are desorbed from the strontium titanate particles A, so that the silica particles B easily slip through and the ghost concentration unevenness is exacerbated.

The upper limit of YA / YB is not particularly limited, but is preferably 3.00 or less, and more preferably 2.50 or less. The YA / YB can be controlled by a method such as changing the rotation speed and the rotation time when the silica particles B are coated with the toner particles by a mixer or the like. Further, when YA or YB is changed, it can be controlled by gradually coating the strontium titanate particles A and the silica particles B and changing the external addition order, the rotation speed and the rotation time of each.

The content of the strontium titanate particles A is 0.3 parts by mass or more and 3.0 parts by mass or less with respect to 100 parts by mass of the toner particles. It is preferably 0.8 parts by mass or more and 1.5 parts by mass or less. If it is less than 0.3 parts by mass, the effect is not exhibited, and if it is more than 3.0 parts by mass, the fluidity of the toner is improved too much and toner slipping occurs.

[Bundling resin]
The binder resin used for the toner of the present invention is not particularly limited, and the following polymers or resins can be used.

For example, homopolymers of styrene such as polystyrene, poly-p-chlorstyrene, polyvinyltoluene and its substitution products; styrene-p-chlorstyrene copolymer, styrene-vinyltoluene copolymer, styrene-vinylnaphthalin copolymer. , Styrene-acrylic acid ester copolymer, styrene-methacrylic acid ester copolymer, styrene-α-chlormethylmethacrylate copolymer, styrene-acrylonitrile copolymer, styrene-vinylmethyl ether copolymer, styrene-vinyl Stylized copolymers such as ethyl ether copolymers, styrene-vinylmethylketone copolymers, styrene-acrylonitrile-indene copolymers; polyvinyl chlorides, phenolic resins, naturally modified phenolic resins, natural resin modified maleic acid resins, Acrylic resin, methacrylic resin, polyvinyl acetate, silicone resin, polyester resin, polyurethane, polyamide resin, furan resin, epoxy resin, xylene resin, polyvinyl butyral, terpene resin, kumaron-inden resin, petroleum resin and the like can be used.

Among these, it is preferable to use a polyester resin from the viewpoint of improving the cleaning property.

The polyester resin used in the present invention is a resin having a "polyester unit" in the binder resin chain, and the component constituting the polyester unit is specifically a divalent or higher valent alcohol monomer. Examples thereof include a component and an acid monomer component such as a divalent or higher carboxylic acid, a divalent or higher carboxylic acid anhydride, and a divalent or higher carboxylic acid ester.

For example, as the divalent or higher valent alcohol monomer component, polyoxypropylene (2.2) -2,2-bis (4-hydroxyphenyl) propane, polyoxypropylene (3.3) -2,2-bis (4) -Hydroxyphenyl) propane, polyoxyethylene (2.0) -2,2-bis (4-hydroxyphenyl) propane, polyoxypropylene (2.0) -polyoxyethylene (2.0) -2,2- Alkylene oxide adducts of bisphenol A such as bis (4-hydroxyphenyl) propane, polyoxypropylene (6) -2,2-bis (4-hydroxyphenyl) propane, ethylene glycol, diethylene glycol, triethylene glycol, 1, 2 -Propylene glycol, 1,3-propylene glycol, 1,4-butanediol, neopentyl glycol, 1,4-butenediol, 1,5-pentanediol, 1,6-hexanediol, 1,4-cyclohexanedimethanol , Dipropylene glycol, polyethylene glycol, polypropylene glycol, polytetramethylene glycol, sorbit, 1,2,3,6-hexanetetrol, 1,4-sorbitan, pentaerythritol, dipentaerythritol, tripentaerythritol, 1,2 , 4-Butantriol, 1,2,5-Pentanetriol, Glycerin, 2-MethylPropylenetriol, 2-Methyl-1,2,4-Butanetriol, Trimethylolethane, Trimethylolpropane, 1,3,5- Examples thereof include trihydroxymethylbenzene.

Among these, the alcohol monomer component preferably used is an aromatic diol, and the alcohol monomer component constituting the polyester resin preferably contains the aromatic diol in a proportion of 80 mol% or more.

On the other hand, as the acid monomer component such as the divalent or higher carboxylic acid, the divalent or higher carboxylic acid anhydride and the divalent or higher carboxylic acid ester, aromatic dicarboxylic acids such as phthalic acid, isophthalic acid and terephthalic acid or the same thereof. Anhydrous: Alkyldicarboxylic acids such as succinic acid, adipic acid, sebacic acid and azelaic acid or anhydrides thereof; succinic acid or an anhydride thereof substituted with an alkyl group or an alkenyl group having 6 to 18 carbon atoms; fumaric acid, Unsaturated dicarboxylic acids such as maleic acid and citraconic acid or anhydrides thereof;

Among these, the acid monomer component preferably used is a polyvalent carboxylic acid such as terephthalic acid, succinic acid, adipic acid, fumaric acid, trimellitic acid, pyromellitic acid, benzophenone tetracarboxylic acid and its anhydride.

The acid value of the polyester resin is preferably 20 mgKOH / g or less from the viewpoint of improving cleanability. Further, it is more preferably 15 mgKOH / g or less. When the acid value exceeds 20 mgKOH / g, the hygroscopicity of the toner becomes uneven, so that the fluidity deteriorates and the cleaning property is affected.

The acid value can be set in the above range by adjusting the type and blending amount of the monomer used in the resin. Specifically, it can be controlled by adjusting the alcohol monomer component ratio / acid monomer component ratio and the molecular weight at the time of resin production. Further, after the ester polycondensation polymerization, it is possible to control the reaction of the terminal alcohol with a polyhydric acid monomer (for example, trimellitic acid).

[Crystalline polyester resin]
The toner of the present invention may also contain a crystalline polyester resin.

From the viewpoint of improving the cleaning property, the content of the crystalline polyester resin is preferably 5.0 parts by mass or more and 30.0 parts by mass or less with respect to 100.0 parts by mass of the binder resin. It is more preferably 0 parts by mass or more and 20.0 parts by mass or less.

In the present invention, the crystalline resin is a resin in which an endothermic peak is observed in differential scanning calorimetry (DSC).

The crystalline polyester resin can be obtained by reacting a polyvalent carboxylic acid having a divalent value or higher with a diol. Among them, a resin obtained by polycondensing an aliphatic diol and an aliphatic dicarboxylic acid is preferable. Further, in the present invention, only one kind of crystalline polyester resin may be used, or a plurality of kinds may be used in combination.

In the present invention, the crystalline polyester resin contains an alcohol component containing at least one compound selected from the group consisting of an aliphatic diol having 2 or more and 22 or less carbon atoms and a derivative thereof, and the crystalline polyester resin having 2 or more and 22 carbon atoms or less. It is preferable that the resin is obtained by shrink-polymerizing a carboxylic acid component containing at least one compound selected from the group consisting of an aliphatic dicarboxylic acid and a derivative thereof.

Among them, the crystalline polyester resin has an alcohol component containing at least one compound selected from the group consisting of aliphatic diols having 6 or more and 12 or less carbon atoms and derivatives thereof, and 6 or more and 12 or less carbon atoms. A crystalline polyester resin obtained by shrink-polymerizing a carboxylic acid component containing at least one compound selected from the group consisting of aliphatic dicarboxylic acids and derivatives thereof is more suitable from the viewpoint of improving cleanability. preferable.

The aliphatic diol having 2 or more and 22 or less carbon atoms (preferably 6 or more and 12 or less carbon atoms) is not particularly limited, but a chain-like (preferably linear) aliphatic diol has a cleaning property. Optimal from the viewpoint of improvement.

For example, ethylene glycol, diethylene glycol, triethylene glycol, 1,2-propylene glycol, dipropylene glycol, 1,3-propanediol, 1,4-butanediol, 1,4-butadiene glycol, 1,5-pentanediol, Neopentyl glycol, 1,6-hexanediol, 1,7-heptanediol, 1,8-octanezil, 1,9-nonanediol, 1,10-decanediol, 1,11-undecanediol, and 1,12 -Dodecanediol can be mentioned.

Among these, 1,6-hexanediol, 1,7-heptanediol, 1,8-octanediol, 1,9-nonanediol, 1,10-decanediol, 1,11-undecanediol, and 1,12 -Linear aliphatic α, ω-diol such as dodecanediol is preferably exemplified.

In the present invention, the derivative is not particularly limited as long as the same resin structure can be obtained by the above polycondensation. For example, a derivative obtained by esterifying the above diol can be mentioned.

In the present invention, at least one selected from the group consisting of the above-mentioned aliphatic diols having 2 or more and 22 or less carbon atoms (preferably 6 or more and 12 or less carbon atoms) and derivatives thereof in the alcohol component constituting the crystalline polyester resin. The compound of the above is preferably 50% by mass or more, more preferably 70% by mass or more, based on the total alcohol component.

In the present invention, polyhydric alcohols other than the above aliphatic diols can also be used.

Among the polyhydric alcohols, examples of diols other than the aliphatic diol include aromatic alcohols such as polyoxyethylene glycol A and polyoxypropylene glycol A; 1,4-cyclohexanedimethanol and the like.

Among the polyhydric alcohols, the trihydric or higher polyhydric alcohols include aromatic alcohols such as 1,3,5-trihydroxymethylbenzene; pentaerythritol, dipentaerythritol, tripentaerythritol, 1,2,4. -Butantriol, 1,2,5-pentanetriol, glycerin, 2-methylpropanetriol, 2-methyl-1,2,4-butanetriol, trimethylolethane, and aliphatic alcohols such as trimethylolpropane. Be done.

Further, in the present invention, a monohydric alcohol may be used to the extent that the characteristics of the crystalline polyester resin are not impaired. Examples of the monohydric alcohol include n-butanol, isobutanol, sec-butanol, n-hexanol, n-octanol, 2-ethylhexanol, cyclohexanol, and benzyl alcohol.

On the other hand, the aliphatic dicarboxylic acid having 2 or more and 22 or less carbon atoms (preferably 6 or more and 12 or less carbon atoms) is not particularly limited, but may be a chain (preferably linear) aliphatic dicarboxylic acid. ..

For example, oxalic acid, malonic acid, succinic acid, glutaric acid, adipic acid, pimelli acid, speric acid, glutaconic acid, azelaic acid, sebacic acid, nonandicarboxylic acid, decandicarboxylic acid, undecandicarboxylic acid, dodecandicarboxylic acid, maleic acid. , Fumaric acid, mesaconic acid, citraconic acid, itaconic acid and the like.

Hydrolyzed acid anhydrides or lower alkyl esters are also included.

In the present invention, the derivative is not particularly limited as long as the same resin structure can be obtained by the above polycondensation. For example, an acid anhydride of the dicarboxylic acid component, a derivative obtained by methyl esterifying, ethyl esterifying, or acid chlorideizing the dicarboxylic acid component can be mentioned.

In the present invention, in the carboxylic acid component constituting the crystalline polyester resin, at least selected from the group consisting of the above-mentioned aliphatic dicarboxylic acids having 2 or more and 22 or less carbon atoms (preferably 6 or more and 12 or less carbon atoms) and derivatives thereof. The amount of one compound is preferably 50% by mass or more, more preferably 70% by mass or more, based on the total carboxylic acid component.

In the present invention, a polyvalent carboxylic acid other than the above aliphatic dicarboxylic acid can also be used. Among the polyvalent carboxylic acids, the divalent carboxylic acid other than the aliphatic dicarboxylic acid is an aromatic carboxylic acid such as isophthalic acid and terephthalic acid; an aliphatic carboxylic acid such as n-dodecylsuccinic acid and n-dodecenylsuccinic acid. Acids; Examples include alicyclic carboxylic acids such as cyclohexanedicarboxylic acids, and these acid anhydrides or lower alkyl esters are also included.

Among other polyvalent carboxylic acids, the trivalent or higher polyvalent carboxylic acids include 1,2,4-benzenetricarboxylic acid (trimellitic acid), 2,5,7-naphthalenetricarboxylic acid, 1,2, Aromatic carboxylic acids such as 4-naphthalentricarboxylic acid and pyromellitic acid, 1,2,4-butanetricarboxylic acid, 1,2,5-hexanetricarboxylic acid, 1,3-dicarboxy-2-methyl-2- Examples thereof include aliphatic carboxylic acids such as methylenecarboxypropane, and derivatives such as acid anhydrides or lower alkyl esters thereof are also included.

Further, in the present invention, a monovalent carboxylic acid may be used to the extent that the characteristics of the crystalline polyester resin are not impaired. Examples of the monovalent carboxylic acid include benzoic acid, naphthalenecarboxylic acid, salicylic acid, 4-methylbenzoic acid, 3-methylbenzoic acid, phenoxyacetic acid, biphenylcarboxylic acid, acetic acid, propionic acid, butyric acid and octanoic acid. ..

In the present invention, the crystalline polyester resin can be produced according to a usual polyester synthesis method. For example, a crystalline polyester resin can be obtained by subjecting the carboxylic acid component and the alcohol component to an esterification reaction or a transesterification reaction, and then carrying out a polycondensation reaction under reduced pressure or by introducing nitrogen gas according to a conventional method. ..

The esterification or transesterification reaction may be carried out using conventional esterification catalysts or transesterification catalysts such as sulfuric acid, titanium butoxide, tin 2-ethylhexanoate, dibutyltin oxide, manganese acetate, and magnesium acetate, if necessary. It can be carried out.

Further, the above-mentioned polymerization reaction is carried out by a known polymerization catalyst such as a conventional polymerization catalyst such as titanium butoxide, tin 2-ethylhexanoate, dibutyltin oxide, tin acetate, zinc acetate, tin disulfide, antimony trioxide, and germanium dioxide. Can be done using. The polymerization temperature and the amount of catalyst are not particularly limited and may be appropriately determined.

In the esterification or transesterification reaction, or polycondensation reaction, all the monomers are charged in a batch to increase the strength of the obtained crystalline polyester resin, or the divalent monomer is first reacted to reduce the low molecular weight component. After that, a method such as adding a monomer having a valence of 3 or more and causing the reaction may be used.

[wax]
If necessary, the toner of the present invention may contain wax. Hydrocarbon waxes such as low molecular weight polyethylenes, low molecular weight polypropylenes, alkylene copolymers, microcrystallin waxes, paraffin waxes, Fishertropch waxes; oxides of hydrocarbon waxes such as polyethylene oxide waxes or block copolymers thereof; Waxes containing fatty acid esters such as carnauba wax as the main component; deoxidized waxes obtained by deoxidizing part or all of fatty acid esters such as carnauba wax. In addition, the following can be mentioned. Saturated linear fatty acids such as palmitic acid, stearic acid, and montanic acid; unsaturated fatty acids such as brushzic acid, eleostearic acid, and varinaric acid; Saturated alcohols such as sill alcohol; Polyhydric alcohols such as sorbitol; Fatty acids such as palmitic acid, stearic acid, behenic acid and montanic acid, and stearyl alcohol, aralkyl alcohol, behenyl alcohol, carnaubil alcohol, ceryl alcohol and meli Esters with alcohols such as silalic acid; fatty acid amides such as linoleic acid amide, oleic acid amide, lauric acid amide; methylene bisstearic acid amide, ethylene biscapric acid amide, ethylene bislauric acid amide, hexamethylene bissteare Saturated fatty acid bisamides such as acid amides; unsaturated fatty acid amides such as ethylene bisoleic acid amides, hexamethylene bisoleic acid amides, N, N'diorail adipic acid amides, N, N'diorail sebasic acid amides; m -Aromatic bisamides such as xylene bisstearate amide, N, N'distearyl isophthalic acid amide; fatty acid metal salts such as calcium stearate, calcium laurate, zinc stearate, magnesium stearate (generally referred to as metal soap). ); Waxes grafted with aliphatic hydrocarbon wax using vinyl monomer such as styrene and acrylic acid; Partial esterified products of fatty acid and polyhydric alcohol such as behenic acid monoglyceride; Hydrogen of vegetable fats and oils A methyl ester compound having a hydroxyl group obtained by addition.

Among these waxes, Fischer-Tropsch wax is preferable from the viewpoint of controlling the fluidity and improving the cleaning property.

The wax content is preferably 0.5 parts by mass or more and 20 parts by mass or less with respect to 100 parts by mass of the binder resin. Further, it is more preferably 3.0 parts by mass or more and 12 parts by mass or less. Further, from the viewpoint of improving the cleanability of the toner, the peak temperature of the maximum endothermic peak existing in the temperature range of 30 ° C. or higher and 200 ° C. or lower is set in the endothermic curve at the time of temperature rise measured by the differential scanning calorimetry device (DSC). , 50 ° C. or higher and 110 ° C. or lower is preferable. Further, it is more preferably 70 ° C. or higher and 100 ° C. or lower.

[Colorant]
Examples of the colorant (coloring material) that can be contained in the toner of the present invention include the following.

Examples of the black colorant include carbon black; those colored black with a yellow colorant, a magenta colorant, and a cyan colorant. The pigment may be used alone as the colorant, but it is more preferable to improve the sharpness by using the dye and the pigment in combination from the viewpoint of the image quality of the full-color image.

Examples of the magenta coloring pigment include the following. C. I. Pigment Red 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16, 17, 18, 19, 21, 22, 23, 30, 31, 32, 37, 38, 39, 40, 41, 48: 2, 48: 3, 48: 4, 49, 50, 51, 52, 53, 54, 55, 57: 1, 58, 60, 63, 64, 68, 81: 1, 83, 87, 88, 89, 90, 112, 114, 122, 123, 146, 147, 150, 163, 184, 202, 206, 207, 209, 238, 269, 282; C.I. I. Pigment Violet 19; C.I. I. Bat Red 1, 2, 10, 13, 15, 23, 29, 35.

Examples of the magenta coloring dye include the following. C. I. Solvent Red 1, 3, 8, 23, 24, 25, 27, 30, 49, 81, 82, 83, 84, 100, 109, 121; C.I. I. Disperse thread 9; C.I. I. Solvent Violet 8, 13, 14, 21, 27; C.I. I. Oil-soluble dyes such as Disper Violet 1, C.I. I. Basic Red 1, 2, 9, 12, 13, 14, 15, 17, 18, 22, 23, 24, 27, 29, 32, 34, 35, 36, 37, 38, 39, 40; C.I. I. Basic dyes such as Basic Violet 1, 3, 7, 10, 14, 15, 21, 25, 26, 27, 28.

Examples of the cyan coloring pigment include the following. C. I. Pigment Blue 2, 3, 15: 2, 15: 3, 15: 4, 16, 17; C.I. I. Bat Blue 6; C.I. I. Acid blue 45, a copper phthalocyanine pigment in which 1 to 5 phthalimide methyl groups are substituted in the phthalocyanine skeleton.

Examples of the cyan coloring dye include C.I. I. There is Solvent Blue 70.

Examples of the yellow coloring pigment include the following. C. I. Pigment Yellow 1, 2, 3, 4, 5, 6, 7, 10, 11, 12, 13, 14, 15, 16, 17, 23, 62, 65, 73, 74, 83, 93, 94, 95, 97, 109, 110, 111, 120, 127, 128, 129, 147, 151, 154, 155, 168, 174, 175, 176, 180, 181, 185; C.I. I. Bat Yellow 1, 3, 20.

Examples of the yellow coloring dye include C.I. I. There is Solvent Yellow 162.

The content of the colorant is preferably 0.1 part by mass or more and 30.0 parts by mass or less with respect to 100 parts by mass of the binder resin.

[Magnetic material]
The toner of the present invention may be a magnetic toner or a non-magnetic toner. When used as a magnetic toner, it is preferable to use magnetic iron oxide as the magnetic material. As the magnetic iron oxide, iron oxide such as magnetite, maghematite, and ferrite is used. The amount of magnetic iron oxide contained in the toner is preferably 25 parts by mass or more and 95 parts by mass or less, and more preferably 30 parts by mass or more and 45 parts by mass or less with respect to 100 parts by mass of the binder resin.

[Charge control agent]
The toner of the present invention may also contain a charge control agent, if necessary. As the charge control agent contained in the toner, known ones can be used, but in particular, a metal compound of an aromatic carboxylic acid which is colorless, has a high charge speed of the toner, and can stably maintain a constant charge amount is preferable.

Negative charge control agents include salicylate metal compounds, naphthoic acid metal compounds, dicarboxylic acid metal compounds, polymer compounds having sulfonic acid or carboxylic acid in the side chain, sulfonates or sulfonic acid esterified products in the side chain. Examples thereof include a high molecular weight compound, a high molecular weight compound having a carboxylate or a carboxylic acid esterified product in a side chain, a boron compound, a urea compound, a silicon compound, and a calix array. The charge control agent may be added internally or externally to the toner particles. The amount of the charge control agent added is preferably 0.2 parts by mass or more and 10 parts by mass or less with respect to 100 parts by mass of the binder resin.

[Developer]
Although the toner of the present invention can be used as a one-component developer, it is preferable to mix it with a magnetic carrier and use it as a two-component developer in order to further improve dot reproducibility. It is also preferable in that a stable image can be obtained for a long period of time.

Examples of the magnetic carrier include iron powder whose surface is oxidized, unoxidized iron powder, and metal particles such as iron, lithium, calcium, magnesium, nickel, copper, zinc, cobalt, manganese, chromium, and rare earth. A magnetic material such as a magnetic material such as alloy particles, oxide particles, and ferrite, or a magnetic material-dispersed resin carrier (so-called resin carrier) containing the magnetic material and a binder resin that holds the magnetic material in a dispersed state is generally known. Can be used.

When the toner of the present invention is mixed with a magnetic carrier and used as a two-component developer, the mixing ratio of the magnetic carriers at that time is preferably 2% by mass or more and 15% by mass as the toner concentration in the two-component developer. % Or less, more preferably 4% by mass or more and 13% by mass or less.

[Production method]
As a method for producing toner particles, a known method can be used. Hereinafter, the toner manufacturing procedure by the pulverization method will be described as an example.

In the raw material mixing step, as a material constituting the toner particles, for example, a polyester resin, a fatty acid metal salt, a colorant, and if necessary, other components such as a mold release agent and a charge control agent are weighed and blended in a predetermined amount. Mix. Examples of the mixing device include a double-con mixer, a V-type mixer, a drum-type mixer, a super mixer, a Henschel mixer, a Nauta mixer, a mechano hybrid (manufactured by Nippon Coke Industries, Ltd.) and the like.

Next, the mixed materials are melt-kneaded. The temperature of melt-kneading is preferably about 100 to 200 ° C. In the melt-kneading step, a batch-type kneader such as a pressure kneader or a Bambary mixer or a continuous-type kneader can be used, and a single-screw or twin-screw extruder is preferable because of the advantage of continuous production. For example, KTK type twin-screw extruder (manufactured by Kobe Steel), TEM type twin-screw extruder (manufactured by Toshiba Machine Co., Ltd.), PCM kneader (manufactured by Ikegai Iron Works), twin-screw extruder (manufactured by Kay-Cee). ), Co-kneader (manufactured by Bus Co., Ltd.), Kneedex (manufactured by Nippon Coke Industries Co., Ltd.), etc. Further, the resin composition obtained by melt-kneading is rolled with two rolls or the like, and is rapidly cooled with water or the like in the cooling step.

Then, the cooled product of the resin composition is pulverized to a desired particle size in the pulverization step. In the crushing process, after coarse crushing with a crusher such as a crusher, a hammer mill, or a feather mill, further, for example, a cryptron system (manufactured by Kawasaki Heavy Industries, Ltd.), a super rotor (manufactured by Nisshin Engineering Co., Ltd.), a turbo. Finely crush with a mill (manufactured by Turbo Industries) or a fine crusher using the air jet method.

After that, if necessary, inertial classification type elbow jet (manufactured by Nittetsu Mining Co., Ltd.), centrifugal force classification method turboplex (manufactured by Hosokawa Micron), TSP separator (manufactured by Hosokawa Micron), faculty (manufactured by Hosokawa Micron), etc. Classify using a classifier or a sieving machine to obtain a classified product (toner particles).

The obtained toner particles may be used as they are as toner. If necessary, the surface of the toner particles may be externally treated with an external additive to obtain toner. As a method of externalizing the external additive, a predetermined amount of toner particles and various known external additives are mixed, and a double-con mixer, a V-type mixer, a drum-type mixer, a super mixer, a Henschel mixer, a Nauta mixer, and a mechano hybrid ( A method of stirring and mixing using a mixing device such as Nippon Coke Industries Co., Ltd.) or Nobilta (Hosokawa Micron Co., Ltd.) as an external mixer can be mentioned.

The toner of the present invention preferably has a volume-based median diameter of 3.0 μm or more and 20.0 μm or less, and more preferably 5.0 μm or more and 12.0 μm or less.

In the present invention, the average circularity of the toner is preferably 0.960 or more and 1.000 or less, and more preferably 0.960 or more and 0.980 or less. When the average circularity of the toner is in the above range, the cleaning property of the toner is improved.

<Measurement of weight average particle size (D4) of toner>
The weight average particle size (D4) of the toner is measured by the precision particle size distribution measuring device "Coulter Counter Multisizer 3" (registered trademark, manufactured by Beckman Coulter) equipped with a 100 μm aperture tube by the pore electric resistance method. Using the attached dedicated software "Beckman Coulter Multisizer 3 Version 3.51" (manufactured by Beckman Coulter) for setting and analysis of measurement data, the measurement data is measured with 25,000 effective measurement channels. Perform analysis and calculate.

As the electrolytic aqueous solution used for the measurement, one in which special grade sodium chloride is dissolved in ion-exchanged water so that the concentration becomes about 1% by mass, for example, "ISOTON II" (manufactured by Beckman Coulter) can be used.

Before performing measurement and analysis, set the dedicated software as follows.

In the "Change standard measurement method (SOM) screen" of the dedicated software, set the total count number of the control mode to 50,000 particles, measure once, and set the Kd value to "Standard particles 10.0 μm" (Beckman Coulter). Set the value obtained using (manufactured by the company). By pressing the threshold / noise level measurement button, the threshold and noise level are automatically set. Also, set the current to 1600 μA, the gain to 2, and the electrolyte to ISOTON II, and check the flash of the aperture tube after measurement.

In the dedicated software "Pulse to particle size conversion setting screen", set the bin spacing to logarithmic particle size, the particle size bin to 256 particle size bins, and the particle size range to 2 μm or more and 60 μm or less.

The specific measurement method is as follows.
(1) Put about 200 mL of the electrolytic aqueous solution in a glass 250 mL round bottom beaker dedicated to Multisizer 3, set it on a sample stand, and stir the stirrer rod counterclockwise at 24 rpm. Then, the dirt and air bubbles in the aperture tube are removed by the "aperture flash" function of the dedicated software.
(2) Place about 30 mL of the electrolytic aqueous solution in a 100 mL flat-bottomed beaker made of glass, and use "Contaminone N" as a dispersant (nonionic surfactant, anionic surfactant, and organic builder for precise measurement of pH 7). Add about 0.3 mL of a diluted solution of a 10% by mass aqueous solution of a neutral detergent for cleaning the vessel (manufactured by Wako Pure Chemical Industries, Ltd.) diluted 3 times by mass with ion-exchanged water.
(3) Two oscillators with an oscillation frequency of 50 kHz are built in with the phase shifted by 180 degrees, and are installed in the water tank of the ultrasonic disperser "Ultrasonic Dispersion System Tetora 150" (manufactured by Nikkaki Bios) with an electrical output of 120 W. A predetermined amount of ion-exchanged water is added, and about 2 mL of the Contaminone N is added into the water tank.
(4) The beaker of (2) is set in the beaker fixing hole of the ultrasonic disperser, and the ultrasonic disperser is operated. Then, the height position of the beaker is adjusted so that the resonance state of the liquid level of the electrolytic solution in the beaker is maximized.
(5) With the electrolytic aqueous solution in the beaker of (4) being irradiated with ultrasonic waves, about 10 mg of toner is added little by little to the electrolytic aqueous solution and dispersed. Then, the ultrasonic dispersion processing is continued for another 60 seconds. For ultrasonic dispersion, the water temperature in the water tank is appropriately adjusted to be 10 ° C. or higher and 40 ° C. or lower.
(6) Using a pipette, the electrolytic aqueous solution of (5) in which toner is dispersed is dropped onto the round bottom beaker of (1) installed in the sample stand, and the measured concentration is adjusted to about 5%. .. Then, the measurement is performed until the number of measured particles reaches 50,000.
(7) The measurement data is analyzed by the dedicated software attached to the device, and the weight average particle size (D4) is calculated. The "average diameter" of the analysis / volume statistical value (arithmetic mean) screen when the graph / volume% is set by the dedicated software is the weight average particle diameter (D4).

<Measurement of average circularity>
The average circularity of the toner is measured by the flow type particle image analyzer "FPIA-3000" (manufactured by Sysmex Corporation) under the measurement and analysis conditions at the time of calibration work.

The specific measurement method is as follows.

First, about 20 mL of ion-exchanged water from which impure solids and the like have been removed in advance is placed in a glass container. Among them, as a dispersant, "Contaminone N" (a 10% by mass aqueous solution of a neutral detergent for cleaning a pH 7 precision measuring instrument consisting of a nonionic surfactant, an anionic surfactant, and an organic builder, manufactured by Wako Pure Chemical Industries, Ltd. ) Is diluted about 3 times by mass with ion-exchanged water, and about 0.2 mL of the diluted solution is added.

Further, about 0.02 g of the measurement sample is added, and the dispersion treatment is performed for 2 minutes using an ultrasonic disperser to prepare a dispersion liquid for measurement. At that time, the dispersion liquid is appropriately cooled so that the temperature is 10 ° C. or higher and 40 ° C. or lower. As the ultrasonic disperser, a desktop ultrasonic cleaner disperser (“VS-150” (manufactured by Vervocrea)) with an oscillation frequency of 50 kHz and an electrical output of 150 W is used, and a predetermined amount of ions are contained in the water tank. Add exchange water, and add about 2 mL of the Contaminone N to this water tank.

The flow-type particle image analyzer equipped with a standard objective lens (10x) was used for the measurement, and the particle sheath "PSE-900A" (manufactured by Sysmex Corporation) was used as the sheath liquid. The dispersion liquid adjusted according to the above procedure is introduced into the flow type particle image analyzer, and 3000 toners are measured in the total count mode in the HPF measurement mode.

Then, the binarization threshold value at the time of particle analysis is set to 85%, the diameter of the analyzed particle is limited to 1.985 μm or more and less than 39.69 μm, and the average circularity of the toner is obtained.

In the measurement, automatic focus adjustment is performed using standard latex particles (“RESEARCH AND TEST PARTICLES Latex Microsphere Suspensions 5200A” manufactured by Duke Scientific) diluted with ion-exchanged water before the start of the measurement. After that, it is preferable to perform focus adjustment every two hours from the start of measurement.

In the embodiment, a flow-type particle image analyzer that has been calibrated by Sysmex and has received a calibration certificate issued by Sysmex was used. The measurement was performed under the measurement and analysis conditions at the time of receiving the calibration certification, except that the diameter of the analysis particle was limited to 1.985 μm or more and less than 39.69 μm in equivalent circle diameter.

<Measurement method of Et>
For the measurement of Et, a powder fluidity analyzer equipped with a rotary blade (powder rheometer FT-4, manufactured by Freeman Technology) (hereinafter, also referred to as “FT-4”) was used.

The principle of the above device is to move the rotary blade in the powder sample to cause a constant pattern of flow. The particles in the powder sample flow when the blades are in close proximity and rest again when they pass. The energy required for the blade to move through the powder is measured and from this value various fluidity indices are calculated. The blade is a propeller type and moves upward or downward at the same time as it rotates, so the tip draws a spiral. The angle and speed of the spiral path of the blade can be adjusted by changing the rotation speed and the vertical movement. When the blade moves along a clockwise spiral path with respect to the surface of the powder layer, it has the effect of uniformly mixing the powder. Conversely, when the blade moves along a counterclockwise spiral path with respect to the surface of the powder layer, the blade receives resistance from the powder.

Specifically, the measurement was performed by the following operation. In all operations, the propeller type blade has a 48 mm diameter blade dedicated to FT-4 measurement (a rotation axis exists in the center of the 48 mm × 10 mm blade plate in the normal direction, and the blade plate has the specifications shown in FIG. Both outermost edges (24 mm from the rotation axis) are smoothly twisted counterclockwise, such as 70 ° and 12 mm from the rotation axis are smoothly twisted. The material is made of SUS. Model number: C210. , May be abbreviated as "blade").

First, a 50 mm x 160 ml split container for FT-4 measurement (model number: C203. Height 82 mm from the bottom of the container to the split part. The material is glass. Hereinafter, it may be abbreviated as a container) at 23 ° C. and 60% environment. A toner powder layer was formed by adding 100 g of toner left in the container for 3 days or more.

(1) Conditioning operation (a) The rotation speed of the blade (peripheral speed of the outermost edge of the blade) was set to 60 (mm / sec). The vertical approach speed to the powder layer is defined as the angle formed by the outermost edge of the moving blade and the surface of the powder layer (hereinafter, may be abbreviated as "deducted angle") of 5 (deg). ). The blade was inserted from the surface of the powder layer to a position 10 mm from the bottom surface of the toner powder layer in the clockwise rotation direction (the direction in which the powder layer is loosened by the rotation of the blade) with respect to the surface of the powder layer. After that, the rotation speed of the blade is 60 (mm / sec), the vertical approach speed to the powder layer is 2 (deg), and the rotation speed is clockwise with respect to the surface of the powder layer. , The operation of advancing the blade to a position 1 mm from the bottom surface of the toner powder layer was performed. After that, the rotation speed of the blade is 60 (mm / sec), the angle forming the extraction speed from the powder layer is 5 (deg), and the toner powder is rotated clockwise with respect to the surface of the powder layer. The blade was moved to a position 100 mm from the bottom surface of the layer and extracted. When the extraction was completed, the toner adhering to the blade was wiped off by rotating the blade clockwise and counterclockwise alternately.
(B) By performing the series of operations (1)-(a) five times, the air entrained in the toner powder layer was removed, and a stable toner powder layer was formed.

(2) Split operation The toner powder layer was scraped off at the split portion of the above-mentioned FT-4 measurement dedicated cell, and the toner on the upper part of the powder layer was removed to form a toner powder layer having the same volume.

(3) Measurement operation (a) The same operation as in (1)-(a) above was performed once.
(B) Next, the rotation speed of the blade was set to 100 (mm / sec), and the vertical approach speed to the powder layer was set to a speed with an angle of 5 (deg). The blade was inserted to a position 10 mm from the bottom surface of the toner powder layer in the direction of rotation counterclockwise (the direction in which the powder layer is pushed by the rotation of the blade) with respect to the surface of the powder layer. After that, the rotation speed of the blade is 60 (mm / sec), the vertical approach speed to the powder layer is 2 (deg), and the rotation speed is clockwise with respect to the surface of the powder layer. , The operation of advancing the blade to a position 1 mm from the bottom surface of the powder layer was performed. After that, the rotation speed of the blade is 60 (mm / sec), the angle forming the vertical extraction speed from the powder layer is 5 (deg), and the rotation speed is clockwise with respect to the surface of the powder layer. The blade was withdrawn from the bottom surface of the powder layer to a position 100 mm. When the extraction was completed, the toner adhering to the blade was wiped off by rotating the blade clockwise and counterclockwise alternately.
(C) The series of operations of (b) above was repeated 7 times.

In the operation (c) above, it is obtained when the blade is inserted from the bottom surface of the toner powder layer to a position of 100 mm to 10 mm when the rotation speed of the blade for the seventh time is 100 (mm / sec). Let Et (mJ) be the sum total Et of the rotational torque and the vertical load.

Hereinafter, the present invention will be described in more detail with reference to Production Examples and Examples, but these are not limited to the present invention. Unless otherwise specified, the number of copies in the following formulations are all based on mass.

<Manufacturing example of electrophotographic photosensitive member 1>
-Support A cylindrical aluminum cylinder (JIS-A3003, aluminum alloy, diameter 30 mm, length 357.5 mm, wall thickness 1.0 mm) was used as the conductive support.

-Formation of undercoat layer 60 parts of zinc oxide particles (average particle size: 70 nm, specific surface area value: 15 m ² / g) are stirred and mixed with 500 parts of tetrahydrofuran, and a silane coupling agent (compound name: N-2-) is mixed with this. (Aminoethyl) -3-aminopropyltrimethoxysilane, trade name: KBM603, manufactured by Shin-Etsu Chemical Co., Ltd.) 0.75 part was added, and the mixture was stirred for 2 hours. Then, tetrahydrofuran was distilled off under reduced pressure, and the mixture was heated and dried at 120 ° C. for 3 hours to obtain surface-treated zinc oxide particles.

Subsequently, 25 parts of butyral (trade name: BM-1, manufactured by Sekisui Chemical Co., Ltd.) and 22.5 parts of blocked isocyanate (trade name: Sumijour BL-3173, manufactured by Sumitomo Bavarian Urethane Co., Ltd.) were used as polyols. , Methyl ethyl ketone was dissolved in 142 parts. To this solution, 100 parts of the surface-treated zinc oxide particles and 1 part of anthraquinone were added, and these were dispersed in a sand mill using glass beads having a diameter of 1 mm for 5 hours.

After the dispersion treatment, 0.008 part of dioctyltin dilaurate and 6.5 parts of silicone resin particles (Tospearl 145, manufactured by GE Toshiba Silicone Co., Ltd.) were added and stirred to prepare a coating liquid for an undercoat layer.

The obtained undercoat layer coating liquid was immersed and applied onto the support to form a coating film, and the coating film was dried at 190 ° C. for 24 minutes to form an undercoat layer having a film thickness of 15 μm.

-Formation of charge generation layer Next, strong diffraction peaks are generated at Bragg angles (2θ ± 0.2 °) with respect to CuKα characteristic X-rays at least 7.4 °, 16.6 °, 25.5 ° and 28.3 °. Sandmill using glass beads with a diameter of 1 mm by mixing 15 parts of chlorogallium phthalocyanine crystals, 10 parts of vinyl chloride-vinyl acetate copolymer resin (VMCH, manufactured by Nippon Union Carbite), and 300 parts of n-butyl alcohol. A coating liquid for a charge generation layer was prepared by performing a dispersion treatment for 4 hours.

This coating liquid for a charge generation layer was immersed and coated on the undercoat layer, and the obtained coating film was dried at 150 ° C. for 5 minutes to form a charge generation layer having a film thickness of 0.2 μm.

-Formation of charge transport layer Next, 8 parts of polytetrafluoroethylene particles heat-treated at 150 ° C. for 3 hours (average primary particle size, number average molecular weight, crystallinity, and roundness are shown in Table 1), 0.015 parts of a resin (weight average molecular weight: 130,000) having a structural unit represented by the following structural formula (A), 4 parts of tetrahydrofuran, and 1 part of toluene were stirred and mixed for 48 hours at a liquid temperature of 20 ° C. Formulation A was obtained.

Next, N, N'-diphenyl-N, N'-bis (3-methylphenyl)-[1,1'] biphenyl-4,4'-diamine 4 parts, bisphenol Z type polycarbonate resin (viscosity average molecular weight:: 40,000) 6 parts and 0.1 part of 2,6-di-t-butyl-4-methylphenol as an antioxidant are mixed, and 24 parts of tetrahydrofuran and 11 parts of toluene are mixed and dissolved to prepare the preparation solution B. Got

The compounding solution A was added to the compounding solution B, and the mixture was stirred and mixed, and then passed through a high-pressure disperser (trade name: Microfluidizer M-110EH, manufactured by Microfluidics Co., Ltd., USA) to obtain a dispersion liquid.

After that, fluorine-modified silicone oil (trade name: FL-100 manufactured by Shinetsu Silicone Co., Ltd.) is added to the dispersion liquid so as to be 5 ppm, and filtered with a polyfluorocarbon filter (trade name: PF-040, manufactured by Advantech Toyo Co., Ltd.). To prepare a coating liquid for a charge transport layer.

The coating liquid for the charge transport layer was immersed and coated on the charge generation layer to form a coating film, and the obtained coating film was dried at 150 ° C. for 25 minutes to form a charge transport layer having a film thickness of 30 μm. ..

In this way, the electrophotographic photosensitive member 1 was produced.

<Manufacturing example of electrophotographic photosensitive members 2 to 13>
In the production example of the electrophotographic photosensitive member 1, the polytetrafluoroethylene particles were changed to those shown in Table 1 to prepare the electrophotographic photosensitive members 2 to 13.

<Manufacturing example of electrophotographic photosensitive member 14>
An aluminum cylinder having a diameter of 30 mm, a length of 357.5 mm, and a wall thickness of 1 mm was used as the conductive support.

Next, 100 parts of zinc oxide particles (specific surface area: 19 m ² / g, powder resistance: 4.7 × 10 ⁶ Ω · cm) as a metal oxide were stirred and mixed with 500 parts of toluene, and a silane coupling agent was added thereto. (Compound name: N-2- (aminoethyl) -3-aminopropylmethyldimethoxysilane, trade name: KBM602, manufactured by Shin-Etsu Chemical Co., Ltd.) 0.8 parts was added, and the mixture was stirred for 6 hours. Then, toluene was distilled off under reduced pressure, and the mixture was heated and dried at 130 ° C. for 6 hours to obtain surface-treated zinc oxide particles.

Next, as the polyol resin, 15 parts of butylal resin (trade name: BM-1, manufactured by Sekisui Chemical Industry Co., Ltd.) and 15 parts of blocked isocyanate (trade name: Sumijour 3175, manufactured by Sumitomo Bayer Urethane Co., Ltd.) were added to methyl ethyl ketone 73. It was dissolved in a mixed solution of 5 parts and 73.5 parts of 1-butanol. 80.64 parts of the surface-treated zinc oxide particles and 0.8 part of the compound represented by the structural formula (B) (manufactured by Tokyo Chemical Industry Co., Ltd.) are added to this solution, and these are glass beads having a diameter of 0.8 mm. The particles were dispersed for 3 hours in an atmosphere of 23 ± 3 ° C. with a sand mill device using the above. After dispersion, 0.01 part of silicone oil (trade name: SH28PA, manufactured by Toray Dow Corning Silicone), crosslinked polymethyl methacrylate (PMMA) particles (trade name: TECHPOLYMER SSX-103, manufactured by Sekisui Plastics Co., Ltd.) , Average primary particle size 3.1 μm) was added in 5.6 parts and stirred to prepare a coating liquid for the undercoat layer.

The undercoat layer coating liquid was immersed and applied onto the support to form a coating film, and the coating film was heated and dried at 145 ° C. for 40 minutes to form an undercoat layer having a film thickness of 18 μm.

Next, 11 parts of crystalline hydroxygallium phthalocyanine crystal (charge generator) having strong peaks at 7.4 ° and 28.2 ° of Bragg angle (2θ ± 0.2 °) in CuKα characteristic X-ray diffraction, polyvinyl. 5 parts of butyral (trade name: Eslek BX-1, manufactured by Sekisui Chemical Industry Co., Ltd.) and 130 parts of cyclohexanone are mixed, 500 parts of glass beads having a diameter of 1 mm are added thereto, and the mixture is cooled with cooling water at 18 ° C. While doing so, the dispersion treatment was performed for 2 hours under the condition of 1800 rpm. After the dispersion treatment, 300 parts of ethyl acetate and 160 parts of cyclohexanone were added and diluted to prepare a coating liquid for a charge generation layer. This coating liquid for a charge generation layer was immersed and coated on the undercoat layer, and the obtained coating film was dried at 110 ° C. for 10 minutes to form a charge generation layer having a film thickness of 0.16 μm. The average particle size (median) of hydroxygallium phthalocyanine crystals in the prepared coating liquid for the charge generation layer is measured by a centrifugal particle size measuring device based on the liquid phase sedimentation method (trade name: CAPA700, manufactured by HORIBA, Ltd.). ), It was 0.18 μm.

Next, 2 parts of the charge transporting compound represented by the structural formula (C), 7 parts of the charge transporting compound represented by the structural formula (D), 1 part of the charge transporting compound represented by the structural formula (E), and polycarbonate ( Product name: Iupilon Z400, manufactured by Mitsubishi Gas Chemicals, Ltd., 10 parts, and 0.002 parts of a polycarbonate (viscosity average molecular weight Mv: 20000) having a structural unit represented by the structural formula (F), 70 parts of monochlorobenzene and A coating liquid for a charge transport layer was prepared by dissolving 30 parts of dimethoxymethane in a mixed solvent. The coating liquid for the charge transport layer was immersed and coated on the charge generation layer, and the obtained coating film was dried at 100 ° C. for 30 minutes to form a charge transport layer having a film thickness of 18 μm.

Next, 70 parts of the compound represented by the structural formula (G) and 30 parts of 1-propanol were mixed, left overnight, and filtered through a PTFE membrane filter having a pore size of 0.2 μm to prepare a preparation solution A.

Next, 20 parts of polytetrafluoroethylene particles heat-treated at 150 ° C. for 3 hours (average primary particle size, number average molecular weight, crystallinity, and roundness are shown in Table 1), fluoroacrylic graft resin (Toa Synthetic). Non-volatile component of GF400 manufactured by GF400 Co., Ltd.) 1.4 parts, 1-propanol 30 parts, 1,1,2,2-tetrafluoroethyl-2,2,2-trifluoroethyl ether (trade name: AE-3000, 30 parts (manufactured by AGC Co., Ltd.) were stirred at a liquid temperature of 20 ° C. and then dispersed with a high-pressure homogenizer to obtain a mixed solution B.

The obtained preparation liquid A and preparation liquid B were mixed and stirred to obtain a coating liquid for a surface layer.

This coating liquid for the surface layer was immersed and coated on the charge transport layer, and the obtained coating film was heat-treated at 50 ° C. for 5 minutes. Then, the coating film was irradiated with an electron beam for 1.6 seconds under the conditions of an acceleration voltage of 70 kV and an absorbed dose of 50 kGy under a nitrogen atmosphere. Then, it was heat-treated for 25 seconds under the condition that the coating film became 130 ° C. under a nitrogen atmosphere. The oxygen concentration from the irradiation of the electron beam to the heat treatment for 25 seconds was 20 ppm. Next, a surface layer having a film thickness of 5 μm was formed by heat-treating in the air for 12 minutes under the condition that the coating film became 115 ° C.

In this way, the electrophotographic photosensitive member 14 having a support, a conductive layer, an undercoat layer, a charge generation layer, a charge transport layer, and a surface layer was manufactured.

<Manufacturing examples of electrophotographic photosensitive members 15 to 17>
In the production example of the electrophotographic photosensitive member 14, the polytetrafluoroethylene particles were changed to the description in Table 1 to prepare the electrophotographic photosensitive members 15 to 17.

<Manufacturing example of toner 1>
-Polyester resin 1: 100 parts [Composition (mol%) [Polyoxypropylene (2.2) -2,2-bis (4-hydroxyphenyl) Propane: Polyoxyethylene (2.2) -2,2-bis (4-Hydroxyphenyl) Propane: Terephthalic acid: Dodecylsuccinic acid: Trimellitic acid = 80: 20: 75: 10: 15], Mw = 152,000, Mw / Mn = 32, molecular weight 100 or more and 5000 or less = 25% by mass, acid value = 12mgKOH / g]
・ C. I. Pigment Blue 15: 37 parts, 3,5-di-t-butyl salicylate aluminum compound (Bontron E88, manufactured by Orient Chemical Industry Co., Ltd.) 0.3 parts, Fischer-Tropsch wax (melting point 78 ° C), 5 parts A twin-screw kneader (PCM-30 type, manufactured by Ikegai Co., Ltd.) set at a temperature of 130 ° C. after mixing using FM-75 type, manufactured by Mitsui Mine Co., Ltd. at a rotation speed of 20s- ^{1 and a rotation time of 5 min.} ) Was kneaded. The obtained kneaded product was cooled to 25 ° C. and coarsely pulverized to 1 mm or less with a hammer mill to obtain a coarsely crushed product. The obtained coarse crushed product was finely pulverized with a mechanical crusher (T-250, manufactured by Turbo Industries, Ltd.). Further, classification was performed using Faculty F-300 (manufactured by Hosokawa Micron Co., Ltd.) to obtain toner particles 1.

The number of primary particles surface-treated with strontium titanate particles A (1.0 part) and 20.0% by mass of hexamethyldisilazane on the obtained toner particles 1 (100.0 parts) is hydrophobic with an average particle size of 120 nm. Silica fine particles B (1.0 part) were added. The obtained additive is mixed with a Henshell mixer (FM75J type, manufactured by Mitsui Miike Machinery Co., Ltd.) at a rotation speed of 30 s ^-1 and a rotation time of 5 min, passed through an ultrasonic vibration sieve having a mesh opening of 54 μm, and the toner 1 is passed. Got

The weight average particle size (D4) of the toner 1 was 6.2 μm, and the average circularity was 0.970. Table 2 shows the adhesion rate of the strontium titanate particles A of the toner 1 and the separation amounts YA and YA / YB of the strontium titanate particles A.

<Manufacturing example of toners 2 to 14>
In the production example of the toner 1, the same operation as in the production example of the toner 1 was performed except that the addition amount of the strontium titanate particles A and the production conditions were changed according to Table 2, to obtain toners 2 to 14.

<Manufacturing example of magnetic core particle 1>
-Step 1 (Weighing / mixing step):
Fe ₂ O ₃ 62.7 parts MnCO ₃ 29.5 parts Mg (OH) ₂ 6.8 parts SrCO ₃ 1.0 parts The ferrite raw materials were weighed so that the above materials had the above composition ratio. Then, it was pulverized and mixed with a dry vibration mill using stainless beads having a diameter of 1/8 inch for 5 hours.

-Step 2 (temporary firing step):
The obtained pulverized product was made into pellets of about 1 mm square by a roller compactor. Coarse powder was removed from the pellets with a vibrating sieve having an opening of 3 mm, and then fine powder was removed with a vibrating sieve having an opening of 0.5 mm. It was calcined at a temperature of 1000 ° C. for 4 hours at 01% by volume) to prepare a calcined ferrite. The composition of the obtained calcined ferrite is as follows.
(MnO) _a (MgO) _b (SrO) _c (Fe ₂ O ₃ ) _d
In the above formula, a = 0.257, b = 0.117, c = 0.007, d = 0.393.

-Step 3 (crushing step):
The obtained calcined ferrite was crushed to about 0.3 mm with a crusher, and then 30 parts of water was added to 100 parts of the calcined ferrite using zirconia beads having a diameter of 1/8 inch, and the mixture was pulverized with a wet ball mill for 1 hour. .. The obtained slurry was pulverized with a wet ball mill using alumina beads having a diameter of 1/16 inch for 4 hours to obtain a ferrite slurry (a finely pulverized product of calcined ferrite).

・ Process 4 (granulation process):
To 100 parts of calcined ferrite, 1.0 part of ammonium polycarboxylate as a dispersant and 2.0 parts of polyvinyl alcohol as a binder were added to the ferrite slurry, and the particles were made into spherical particles by a spray dryer (manufacturer: Okawara Kakoki). Granulated. After adjusting the particle size of the obtained particles, the particles were heated at 650 ° C. for 2 hours using a rotary kiln to remove organic components of the dispersant and the binder.

-Step 5 (firing step):
In order to control the firing atmosphere, the temperature was raised from room temperature to a temperature of 1300 ° C. in 2 hours under a nitrogen atmosphere (oxygen concentration 1.00% by volume) in an electric furnace, and then fired at a temperature of 1150 ° C. for 4 hours. Then, over 4 hours, the temperature was lowered to 60 ° C., the nitrogen atmosphere was returned to the atmosphere, and the mixture was taken out at a temperature of 40 ° C. or lower.

・ Process 6 (sorting process):
After crushing the agglomerated particles, the low magnetic force product is cut by magnetic beneficiation and sieved with a sieve having a mesh size of 250 μm to remove coarse particles. Magnetic core particles 1 were obtained.

<Preparation of coating resin 1>
Cyclohexyl methacrylate monomer 26.8% by mass
Methyl methacrylate monomer 0.2% by mass
Methyl Methacrylate Macromonomer 8.4% by Mass
(Macrmonomer having a methacryloyl group at one end and having a weight average molecular weight of 5000)
Toluene 31.3% by mass
Methyl ethyl ketone 31.3% by mass
Azobisisobutyronitrile 2.0% by mass
Of the above materials, cyclohexyl methacrylate monomer, methyl methacrylate monomer, methyl methacrylate macromonomer, toluene, and methyl ethyl ketone are placed in a four-port separable flask equipped with a reflux condenser, a thermometer, a nitrogen introduction tube, and a stirrer, and nitrogen is placed. Gas was introduced and the inside of the system was replaced with nitrogen gas. Then, the mixture was heated to 80 ° C., azobisisobutyronitrile was added, and the mixture was refluxed for 5 hours for polymerization. Hexane was injected into the obtained reaction product to precipitate and precipitate a copolymer, and the precipitate was separated by filtration and then vacuum dried to obtain a coated resin 1.

Next, 30 parts of the coating resin 1 was dissolved in 40 parts of toluene and 30 parts of methyl ethyl ketone to obtain a polymer solution 1 (solid content: 30% by mass).

<Preparation of coating resin solution 1>
Polymer solution 1 (resin solid content concentration 30%) 33.3% by mass
Toluene 66.4% by mass
Carbon black (Regal330; manufactured by Cabot) 0.3% by mass
(Primary particle size 25 nm, nitrogen adsorption specific surface area 94 m ² / g, DBP oil absorption 75 mL / 100 g)
Was dispersed in a paint shaker for 1 hour using zirconia beads having a diameter of 0.5 mm. The obtained dispersion was filtered through a 5.0 μm membrane filter to obtain a coating resin solution 1.

<Manufacturing example of magnetic carrier 1>
(Resin coating process):
The magnetic core particles 1 and the coated resin solution 1 were charged into a vacuum degassing type kneader maintained at room temperature (the amount of the coated resin solution 1 charged was 2 as a resin component with respect to 100 parts of the magnetic core particles 1. Amount of .5 copies). After the addition, the mixture was stirred at a rotation speed of 30 rpm for 15 minutes, the solvent was volatilized above a certain level (80% by mass), the temperature was raised to 80 ° C. while mixing under reduced pressure, toluene was distilled off over 2 hours, and the mixture was cooled. The obtained magnetic carrier is separated into low magnetic force products by magnetic beneficiation, passed through a sieve having an opening of 70 μm, and then classified by a wind power classifier. I got 1.

<Production example of two-component developer 1>
8.0 parts of toner 1 was added to 92.0 parts of the magnetic carrier 1 and mixed with a V-type mixer (V-20, manufactured by Seishin Enterprise Co., Ltd.) to obtain a two-component developer 1.

<Production example of two-component developer 2 to 14>
In the production example of the two-component developer 1, the same operation as that of the two-component developer 1 was performed except that the toner was changed as shown in Table 3, to obtain the two-component developer 2 to 14.

[Example 1]
The electrophotographic photosensitive member 1 was attached to the cyan station of the modified Canon copying machine iR-ADV-C5255, which is an evaluation device, and the two-component developer 1 in Table 3 was set in the developer, and the following tests and evaluations were performed. gone.

Under a 30 ° C./80% RH environment, the conditions of the charging device and the exposure device were set so that the dark potential (Vd) of the electrophotographic photosensitive member was -500v and the bright potential (Vl) -180v, and the electrophotographic photosensitive member was set. The initial potential of was adjusted. Next, a polyurethane rubber cleaning blade having a hardness of 77 ° was set so that the contact angle was 28 ° and the contact pressure was 30 g / cm (29.4 N / m) with respect to the peripheral surface of the electrophotographic photosensitive member. Was evaluated.

[Evaluation 1: Ghost evaluation]
2000 images were imaged in a low temperature and low humidity environment (temperature 15 ° C./relative humidity 10% RH; L / L). As an image, a horizontal line with a printing rate of 1% was imaged in an intermittent mode. A plurality of solid images of 10 mm × 10 mm were formed on the front half of the transfer paper, and a halftone image of 2 dots and 3 spaces was formed on the back half. It is visually determined how much the trace of the solid image appears on the halftone image. The criteria for determining the ghost of a solid black image after endurance use of 1 sheet and 2000 sheets endurance use are as follows.

(Evaluation criteria)
A: Ghost does not occur B: Ghost occurs very slightly C: Ghost occurs slightly D: Ghost occurs remarkably

[Evaluation 2: Toner slip-through (HH streaks)]
With the heater (drum heater) for the electrophotographic photosensitive member turned on, 200 sheets of A4 horizontal 1% printed image evaluation charts are continuously output under a 30 ° C / 80% RH (H / H) environment. did. Then, a screen image having a density of 30% was output as a halftone image, and the H / H initial streaks on the image were evaluated according to the following evaluation criteria. After that, durability was performed up to 100,000 sheets, and the same evaluation was performed.

(Evaluation criteria)
A: No streaks are observed on the image. (Are better)
B: An image in which streaks are suspected can be obtained on the image, but it remains at a level at which it cannot be determined whether or not the streaks are clear. (Slightly better)
C: Very slight streaks are slightly generated on the image. (Allowable level in the present invention)
D: Clear streaks are generated on the image (unacceptable level in the present invention).

[Examples 2 to 21, Comparative Examples 1 to 9]
The combination of the two-component developer 2 to 14 and the electrophotographic photosensitive members 1 to 17 shown in Table 3 was evaluated in the same manner as in Example 1. The evaluation results are shown in Table 3.

1 Electrophotographic photosensitive member, 2 axes, 3 charging means, 4 exposure light, 5 developing means, 6 transfer means, 7 transfer material, 8 fixing means, 9 cleaning means, 10 pre-exposure light, 11 process cartridge, 12 guide means

Claims (6)

The charging process that charges the surface of the photoconductor,
An electrostatic latent image forming step of forming an electrostatic latent image on the surface of the charged photoconductor,
A developing process of developing the electrostatic latent image with toner to form a toner image,
A transfer step of transferring the toner image to a transfer material, and
A cleaning step of removing residual toner remaining on the surface of the photoconductor after the transfer step using a cleaning blade, and a cleaning step of removing the residual toner.
A fixing step of fixing the toner image transferred to the transfer material to the transfer material, and
It is an image forming method having
The photoconductor has a support and a photosensitive layer on the support.
Polytetrafluoroethylene particles are contained in the layer constituting the outermost surface of the photoconductor.
The polytetrafluoroethylene particles are
(I) Number of primary particles The average particle size is 200 nm or more and 500 nm or less.
(Ii) The number average molecular weight is 20,000 or more and 28,000 or less.
(Iii) The crystallinity is 78.0% or more and less than 83.0%.
The toner has toner particles and an external additive containing a binder resin, and the toner has.
In the powder fluidity analysis of the toner, while rotating the peripheral speed of the outermost edge of the propeller type blade at 100 mm / sec, the toner is vertically penetrated into the toner powder layer in the measuring container, and the bottom surface of the powder layer is formed. The total Et of the rotational torque and the vertical load obtained when the measurement is started from the position of 100 mm and penetrated to the position of 10 mm from the bottom surface is 100 mJ or more and 2000 mJ or less.
An image forming method characterized by that. The image forming method according to claim 1, wherein the crystallinity of the polytetrafluoroethylene particles is 80.0% or more and less than 83.0%. The image forming method according to claim 1 or 2, wherein the total Et is 200 mJ or more and 1000 mJ or less. The image forming method according to any one of claims 1 to 3, wherein the average value of roundness in the SEM image of the polytetrafluoroethylene particles is 0.80 or more. The image forming method according to any one of claims 1 to 4, wherein the average circularity of the toner particles is 0.960 or more and 0.980 or less. A toner containing strontium titanate particles A and silica particles B as the external additive.
The strontium titanate particles A have a rectangular parallelepiped particle shape and have a rectangular parallelepiped shape.
The content of the strontium titanate particles A is 0.3 parts by mass or more and 3.0 parts by mass or less with respect to 100 parts by mass of the toner particles.
The number average particle diameter of the primary particles of the silica particles B is 80 nm or more and 200 nm or less.
The adhesion rate of the strontium titanate particles A to the toner particles is 25% or more and 70% or less.
The separation amount of the strontium titanate particles A per 1 g of the toner when the sucrose solution in which the toner is dispersed is subjected to a centrifugation operation is defined as YA (mg), and the separation of the silica particles B per 1 g of the toner is defined as YA (mg). When the amount is YB (mg)
YA is 3.00 or more and 18.0 or less,
The image forming method according to any one of claims 1 to 5, wherein YA and YB satisfy the relationship of the following formula (1).
YA / YB> 0.75 (1)

Images