JP2015152864A - Image forming apparatus, and process cartridge - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an image forming apparatus in which sensitivity of a photoreceptor is increased, and picture quality durability and longer life of the photoreceptor and a cleaning blade are both achieved.SOLUTION: The image forming apparatus includes; a photoreceptor 10 with a photosensitive layer which contains at least one kind of charge generation material selected out of hydroxy gallium phthalocyanine pigment and chloro gallium phthalocyanine pigment, a positive hole transportation material and electron transportation material, with contents of the positive hole transportation material and electron transportation material being within a specific range; and a cleaning blade 72 comprising a member of which at least a portion contacting the photoreceptor contains polyurethane rubber, with an endothermic peak top temperature measured by differential scan heat value measurement being in the range of 180°C to 220°C.

Description

  The present invention relates to an image forming apparatus and a process cartridge.

  In a conventional electrophotographic image forming apparatus, a toner image formed on the surface of an electrophotographic photosensitive member is transferred to a recording medium through processes of charging, exposure, development, and transfer.

It is known to use a charge transport material having an improved charge transport capability for the photosensitive layer of an electrophotographic photoreceptor used in such an electrophotographic image forming apparatus.
For example, an electron transport material having a specific molecular structure, improved electron transport properties, and increased sensitivity is known (see Patent Documents 1 and 2). A hole transport material having a specific molecular structure and improved hole transportability is also known (see Patent Document 3). In addition, various materials are known as charge transport materials (see Patent Document 4).

  In addition, by using a toner made of polymer resin powder, zinc stearate powder, silica powder or the like, or by applying zinc stearate powder on the photoconductor, the surface of the photoconductor is exposed from the contact position of the cleaning blade. An image forming apparatus is disclosed that forms a low-friction film with a predetermined area on the upstream side in the moving direction of the photoreceptor (see Patent Document 5).

The polyurethane member is a cast type polyurethane member obtained by curing and molding a polyurethane composition part containing at least a polyol and an isocyanate compound, and the polyurethane member comprises a hard segment aggregate having an outer diameter of 0.5 μm or more and less than 12 μm. In addition, a cleaning blade is disclosed in which a × b per 1000 μm ² is 70 or more and less than 1050 when the outer diameter of the hard segment is a (μm) and the number is b (pieces) (patent) Reference 6).

JP-A-6-123981 JP 2005-215679 A JP-A-8-295655 JP 2008-15208 A JP-A-5-119676 JP 2010-134111 A

  SUMMARY OF THE INVENTION An object of the present invention is to provide an image forming apparatus that achieves both high sensitivity of an electrophotographic photosensitive member and improvement in durability of image quality and long life of an electrophotographic photosensitive member and a cleaning blade.

  The above problem is solved by the following means.

The invention according to claim 1
A conductive layer and a single-layer type photosensitive layer provided on the conductive substrate, wherein the photosensitive layer is at least one selected from a binder resin, a hydroxygallium phthalocyanine pigment, and a chlorogallium phthalocyanine pigment. A charge generation material, a hole transport material represented by the following general formula (1), and an electron transport material represented by the following general formula (2), wherein the content of the electron transport material in the photosensitive layer is the binding The mass ratio of the hole transport material to the electron transport material (hole transport material / electron transport material) of the photosensitive layer is from 60/40 to 80/20 with respect to the resin. An electrophotographic photoreceptor which is:
Charging means for charging the surface of the electrophotographic photosensitive member;
An electrostatic latent image forming means for forming an electrostatic latent image on the surface of the charged electrophotographic photosensitive member;
Developing means for developing the electrostatic latent image formed on the surface of the electrophotographic photosensitive member with a developer containing toner to form a toner image;
Transfer means for transferring the toner image to the surface of the recording medium;
A cleaning blade for cleaning the surface of the electrophotographic photosensitive member, wherein at least a portion in contact with the electrophotographic photosensitive member contains polyurethane rubber, and an endothermic peak top temperature by differential scanning calorimetry is 180 ° C. or higher and 220 ° C. or lower. Cleaning means having a cleaning blade constituted by members having a range;
An image forming apparatus comprising:

(In General Formula (1), R ¹ , R ² , R ³ , R ⁴ , R ⁵ , and R ⁶ are each independently a hydrogen atom, a lower alkyl group, an alkoxy group, a phenoxy group, a halogen atom, or (A phenyl group optionally having a substituent selected from a lower alkyl group, a lower alkoxy group and a halogen atom. M and n each independently represents 0 or 1.)

(In the general formula (2), R ¹¹ , R ¹² , R ¹³ , R ¹⁴ , R ¹⁵ , R ¹⁶ , and R ¹⁷ are each independently a hydrogen atom, a halogen atom, an alkyl group, an alkoxy group, or an aryl group. R ¹⁸ represents a linear alkyl group having 5 to 10 carbon atoms.)

The invention according to claim 2
The polyurethane rubber of the cleaning blade has a hard segment and a soft segment, the average particle diameter of the hard segment aggregate is 5 μm or more and 20 μm or less, and the particle size distribution of the hard segment aggregate (standard deviation σ) The image forming apparatus according to claim 1, wherein is 2 μm or more.

The invention according to claim 3
The image forming apparatus according to claim 1, wherein the hole transport material represented by the general formula (1) is a hole transport material in which m and n are 1.

The invention according to claim 4
A conductive layer and a single-layer type photosensitive layer provided on the conductive substrate, wherein the photosensitive layer is at least one selected from a binder resin, a hydroxygallium phthalocyanine pigment, and a chlorogallium phthalocyanine pigment. A charge generation material, a hole transport material represented by the following general formula (1), and an electron transport material represented by the following general formula (2), wherein the content of the electron transport material in the photosensitive layer is the binding The mass ratio of the hole transport material to the electron transport material (hole transport material / electron transport material) of the photosensitive layer is from 60/40 to 80/20 with respect to the resin. An electrophotographic photoreceptor which is:
A cleaning blade for cleaning the surface of the electrophotographic photosensitive member, wherein at least a portion in contact with the electrophotographic photosensitive member contains polyurethane rubber, and an endothermic peak top temperature by differential scanning calorimetry is 180 ° C. or higher and 220 ° C. or lower. Cleaning means having a cleaning blade constituted by members having a range;
And a process cartridge which is detachable from the image forming apparatus.

(In General Formula (1), R ¹ , R ² , R ³ , R ⁴ , R ⁵ , and R ⁶ are each independently a hydrogen atom, a lower alkyl group, an alkoxy group, a phenoxy group, a halogen atom, or (A phenyl group optionally having a substituent selected from a lower alkyl group, a lower alkoxy group and a halogen atom. M and n each independently represents 0 or 1.)

(In the general formula (2), R ¹¹ , R ¹² , R ¹³ , R ¹⁴ , R ¹⁵ , R ¹⁶ , and R ¹⁷ are each independently a hydrogen atom, a halogen atom, an alkyl group, an alkoxy group, or an aryl group. R ¹⁸ represents a linear alkyl group having 5 to 10 carbon atoms.)

  According to the first or third aspect of the invention, compared with the case where the specific electrophotographic photosensitive member and the cleaning blade are not combined, the sensitivity of the electrophotographic photosensitive member is improved and the durability of the image quality is improved and the electrophotographic photosensitive member is improved. Provided is an image forming apparatus that achieves both a long life of a body and a cleaning blade.

  According to the second aspect of the present invention, the image quality durability is improved as compared with the case where the average particle diameter of the hard segment aggregates and the particle size distribution (standard deviation σ) of the hard segment aggregates do not satisfy the above requirements. An image forming apparatus is provided which realizes both improvement in the performance and longevity of the electrophotographic photosensitive member and the cleaning blade.

  According to the invention of claim 3, compared with the case where the specific electrophotographic photosensitive member and the cleaning blade are not combined, the sensitivity of the electrophotographic photosensitive member is improved and the durability of the image quality is improved, and the electrophotographic photosensitive member and cleaning are performed. Provided is a process cartridge that achieves both a long blade life.

1 is a schematic configuration diagram illustrating an image forming apparatus according to an exemplary embodiment. 1 is a schematic partial cross-sectional view showing an electrophotographic photosensitive member according to the present embodiment. It is a schematic block diagram which shows the image forming apparatus which concerns on other this embodiment.

  Embodiments that are examples of the present invention will be described below.

<Image forming apparatus>
The image forming apparatus according to the present embodiment includes an electrophotographic photosensitive member, a charging unit that charges the surface of the electrophotographic photosensitive member, and an electrostatic latent image formation that forms an electrostatic latent image on the surface of the charged electrophotographic photosensitive member. Means, developing means for developing the electrostatic latent image formed on the surface of the electrophotographic photosensitive member with a developer containing toner to form a toner image, and transfer means for transferring the toner image to the surface of the recording medium. And a cleaning means having a cleaning blade for cleaning the surface of the electrophotographic photosensitive member.

The electrophotographic photoreceptor is a positively charged organic photoreceptor (hereinafter sometimes referred to as “single-layer photoreceptor”) having a conductive substrate and a single-layer type photosensitive layer on the conductive substrate.
The single-layer type photosensitive layer includes a binder resin, at least one charge generation material selected from hydroxygallium phthalocyanine pigment and chlorogallium phthalocyanine pigment, and a hole transport material represented by the general formula (1) And an electron transport material represented by the general formula (2). The content of the electron transport material in the photosensitive layer is 20% by mass or more and 40% by mass or more with respect to the binder resin. The mass ratio (hole transport material / electron transport material) of the hole transport material and the electron transport material of the photosensitive layer is 60/40 or more and 80/20 or less.
The single-layer type photosensitive layer is a photosensitive layer having hole transporting properties and electron transporting properties as well as charge generation ability.

  The cleaning blade is composed of a member having at least a portion in contact with the electrophotographic photosensitive member containing polyurethane rubber and having an endothermic peak top temperature in a range of 180 ° C. or higher and 220 ° C. or lower by differential scanning calorimetry.

Here, conventionally, the electrophotographic photoreceptor is preferably a single-layer photoreceptor from the viewpoint of manufacturing cost and image quality stability.
On the other hand, a single layer type photoreceptor contains a charge generation material, a hole transport material, and an electron transport material in the single layer type photosensitive layer, so that it is as much as an organic photoreceptor having a laminated type photosensitive layer. Sensitivity cannot be obtained, and higher sensitivity is required.
However, in order to obtain sensitivity in a single layer type photoreceptor, high sensitivity can be achieved by simply using a hole transport material and an electron transport material having a high charge transport property, but the image quality durability is improved. May get worse. When the sensitivity of the single layer type photoreceptor is increased, the amount of toner to be cleaned increases as the amount of toner attached to the single layer type photoreceptor increases. For this reason, when image formation is repeatedly performed, cleaning defects such as toner slipping from the cleaning blade are likely to occur, and it is considered that the image quality deteriorates due to the cleaning defects, and the image quality durability deteriorates.

  For example, when the hardness of the cleaning blade is increased for the purpose of improving the durability of the image quality, the lifetime of the single layer type photoreceptor is reduced due to uneven wear. On the other hand, if the wear of the single-layer photoconductor is reduced for the purpose of suppressing uneven wear of the single-layer photoconductor, the life of the cleaning blade is reduced due to wear, permanent deformation (sagging) or chipping (breaking).

  Therefore, at present, it is difficult to realize both improvement in image quality durability and long life of the electrophotographic photosensitive member and the cleaning blade.

Therefore, in the image forming apparatus according to the present embodiment, by combining the specific electrophotographic photosensitive member and cleaning, the sensitivity of the electrophotographic photosensitive member is improved, the durability of the image quality is improved, and the electrophotographic photosensitive member and the cleaning blade are combined. It is possible to achieve both a long service life.
The reason for this is not clear, but is presumed to be as follows.

  First, regarding the electrophotographic photosensitive member, the hole transport material and the electron transport material having the specific structure described above have high charge transport properties, and the photosensitive layer is made highly sensitive by including the specific content. At the same time, it is considered that the mechanical properties of the photosensitive layer are enhanced.

  On the other hand, regarding the cleaning blade, it is considered that a polyurethane member having an endothermic peak top temperature (melting temperature) of 180 ° C. or higher and 220 ° C. or lower is moderately imparted with high crystallinity of polyurethane and is improved in wear resistance. Furthermore, in addition to low friction due to high crystallization, a high bonding effect between the crystal part and the amorphous part is expected. A cleaning blade having a polyurethane member having this specification in a portion in contact with the electrophotographic photosensitive member has improved wear resistance, permanent deformation resistance (sag resistance), and chipping resistance (breaking resistance).

  As described above, in the image forming apparatus according to the present embodiment, by combining the electrophotographic photosensitive member having these specifications and the cleaning blade, the sensitivity of the electrophotographic photosensitive member is improved, and the durability of the image quality is improved and the electrophotographic photosensitive member is improved. In addition, it is presumed that the cleaning blade has a long service life.

  Conventionally, a lubricant such as zinc stearate has been applied to the contact portion from the viewpoint of reducing friction at the contact portion of the cleaning blade with the electrophotographic photosensitive member. However, in the image forming apparatus according to this embodiment including the cleaning blade having the above-described specification, the use of a lubricant can be reduced or cleaning can be performed without using a lubricant, so that contamination due to adhesion of the lubricant is suppressed. Can do.

  The image forming apparatus according to the present embodiment will be described in detail below with reference to the drawings.

FIG. 1 is a schematic configuration diagram illustrating an image forming apparatus according to the present embodiment.
As shown in FIG. 1, the image forming apparatus 101 according to the present embodiment includes, for example, an electrophotographic photosensitive member 10 that rotates clockwise as indicated by an arrow A, and an electrophotographic photosensitive member 10 that A charging device 20 (an example of a charging unit) that is provided relative to the photographic photosensitive member 10 and charges the surface of the electrophotographic photosensitive member 10, and the surface of the electrophotographic photosensitive member 10 charged by the charging device 20 is exposed to light. An exposure device 30 (an example of an electrostatic latent image forming unit) that forms an electrostatic latent image, and a toner contained in a developer is attached to the electrostatic latent image formed by the exposure device 30 to form an electrophotographic photosensitive member 10. A developing device 40 (an example of a developing unit) that forms a toner image on the surface and a recording paper P (an example of a recording medium) are charged to a polarity different from the charging polarity of the toner, and the recording paper P is placed on the electrophotographic photoreceptor 10. Transfer device for transferring toner images Comprising 0, a cleaning device 70 for cleaning the surface of the electrophotographic photosensitive member 10 (an example of a cleaning unit), a. The image forming apparatus 101 according to the present exemplary embodiment includes a fixing device 60 that fixes the toner image while conveying the recording paper P on which the toner image is formed.

  Details of main components in the image forming apparatus 101 according to the present embodiment will be described below.

[Electrophotographic photoreceptor]
FIG. 2 schematically shows a partial cross section of the electrophotographic photoreceptor 10 according to the present exemplary embodiment.
The electrophotographic photoreceptor 10 shown in FIG. 2 includes, for example, a conductive substrate 4, and an undercoat layer 1, a single-layer type photosensitive layer 2, and a protective layer 3 are provided on the conductive substrate 4 in this order. Is configured.
In addition, the undercoat layer 1 and the protective layer 3 are layers provided as necessary.

  Hereinafter, each element of the electrophotographic photoreceptor 10 will be described. Note that the reference numerals are omitted.

(Conductive substrate)
Examples of the conductive substrate include metal plates (eg, aluminum, copper, zinc, chromium, nickel, molybdenum, vanadium, indium, gold, platinum, etc.) or alloys (stainless steel, etc.), metal drums, metal belts, etc. Is mentioned. In addition, as the conductive substrate, for example, paper, resin film, belt, etc. coated, vapor-deposited or laminated with a conductive compound (for example, conductive polymer, indium oxide, etc.), metal (for example, aluminum, palladium, gold, etc.) or an alloy, etc. Also mentioned. Here, “conductive” means that the volume resistivity is less than 10 ¹³ Ωcm.

  When the electrophotographic photosensitive member is used in a laser printer, the surface of the conductive substrate has a center line average roughness Ra of 0.04 μm or more and 0.5 μm for the purpose of suppressing interference fringes generated when laser light is irradiated. The surface is preferably roughened below. When non-interfering light is used as a light source, roughening for preventing interference fringes is not particularly required, but it is suitable for extending the life because it suppresses generation of defects due to irregularities on the surface of the conductive substrate.

  As a roughening method, for example, wet honing performed by suspending an abrasive in water and spraying it on a support, centerless grinding in which a conductive substrate is pressed against a rotating grindstone, and grinding is continuously performed, Anodizing treatment etc. are mentioned.

  As a roughening method, without roughening the surface of the conductive substrate, conductive or semiconductive powder is dispersed in the resin to form a layer on the surface of the conductive substrate. The method of roughening by the particle | grains disperse | distributed in a layer is also mentioned.

  In the roughening treatment by anodic oxidation, a metal (for example, aluminum) conductive substrate is used as an anode, and an oxide film is formed on the surface of the conductive substrate by anodizing in an electrolyte solution. Examples of the electrolyte solution include a sulfuric acid solution and an oxalic acid solution. However, the porous anodic oxide film formed by anodic oxidation is chemically active as it is, easily contaminated, and has a large resistance fluctuation due to the environment. Therefore, the pores of the oxide film are blocked by the volume expansion due to the hydration reaction in pressurized water vapor or boiling water (a metal salt such as nickel may be added) against the porous anodic oxide film, and more stable hydration oxidation It is preferable to perform a sealing treatment for changing to a product.

  The thickness of the anodized film is preferably, for example, 0.3 μm or more and 15 μm or less. When this film thickness is within the above range, the barrier property against implantation tends to be exhibited, and the increase in residual potential due to repeated use tends to be suppressed.

The conductive substrate may be treated with an acidic treatment liquid or boehmite treatment.
The treatment with the acidic treatment liquid is performed as follows, for example. First, an acidic treatment liquid containing phosphoric acid, chromic acid and hydrofluoric acid is prepared. The mixing ratio of phosphoric acid, chromic acid and hydrofluoric acid in the acidic treatment liquid is, for example, in the range of 10% by mass to 11% by mass of phosphoric acid, in the range of 3% by mass to 5% by mass of chromic acid, The concentration of these acids is preferably in the range of 13.5% by mass or more and 18% by mass or less. The treatment temperature is preferably 42 ° C. or higher and 48 ° C. or lower, for example. The film thickness is preferably from 0.3 μm to 15 μm.

  The boehmite treatment is performed, for example, by immersing in pure water of 90 ° C. or higher and 100 ° C. or lower for 5 minutes to 60 minutes, or by contacting with heated steam of 90 ° C. or higher and 120 ° C. or lower for 5 minutes to 60 minutes. The film thickness is preferably 0.1 μm or more and 5 μm or less. This may be further anodized using an electrolyte solution with low film solubility such as adipic acid, boric acid, borate, phosphate, phthalate, maleate, benzoate, tartrate, citrate, etc. Good.

(Undercoat layer)
The undercoat layer is, for example, a layer containing inorganic particles and a binder resin.

Examples of the inorganic particles include inorganic particles having a powder resistance (volume resistivity) of 10 ² Ωcm or more and 10 ¹¹ Ωcm or less.
Among these, as the inorganic particles having the resistance value, for example, metal oxide particles such as tin oxide particles, titanium oxide particles, zinc oxide particles, and zirconium oxide particles are preferable, and zinc oxide particles are particularly preferable.

The specific surface area of the inorganic particles by the BET method is preferably 10 m ² / g or more, for example.
The volume average particle diameter of the inorganic particles is, for example, preferably from 50 nm to 2000 nm (preferably from 60 nm to 1000 nm).

  For example, the content of the inorganic particles is preferably 10% by mass or more and 80% by mass or less, and more preferably 40% by mass or more and 80% by mass or less with respect to the binder resin.

  The inorganic particles may be subjected to a surface treatment. Two or more inorganic particles having different surface treatments or particles having different particle diameters may be mixed and used.

  Examples of the surface treatment agent include a silane coupling agent, a titanate coupling agent, an aluminum coupling agent, and a surfactant. In particular, silane coupling agents are preferred, and silane coupling agents having amino groups are preferred.

  Examples of the silane coupling agent having an amino group include 3-aminopropyltriethoxysilane, N-2- (aminoethyl) -3-aminopropyltrimethoxysilane, and N-2- (aminoethyl) -3-amino. Examples include, but are not limited to, propylmethyldimethoxysilane, N, N-bis (2-hydroxyethyl) -3-aminopropyltriethoxysilane, and the like.

  Two or more silane coupling agents may be used in combination. For example, a silane coupling agent having an amino group and another silane coupling agent may be used in combination. Other silane coupling agents include, for example, vinyltrimethoxysilane, 3-methacryloxypropyl-tris (2-methoxyethoxy) silane, 2- (3,4-epoxycyclohexyl) ethyltrimethoxysilane, 3-glycol. Sidoxypropyltrimethoxysilane, vinyltriacetoxysilane, 3-mercaptopropyltrimethoxysilane, 3-aminopropyltriethoxysilane, N-2- (aminoethyl) -3-aminopropyltrimethoxysilane, N-2- ( Aminoethyl) -3-aminopropylmethyldimethoxysilane, N, N-bis (2-hydroxyethyl) -3-aminopropyltriethoxysilane, 3-chloropropyltrimethoxysilane, and the like, but are not limited thereto. It is not a thing.

  The surface treatment method using the surface treatment agent may be any method as long as it is a known method, and may be either a dry method or a wet method.

  The treatment amount of the surface treatment agent is preferably 0.5% by mass or more and 10% by mass or less with respect to the inorganic particles, for example.

  Here, the undercoat layer may contain an electron-accepting compound (acceptor compound) together with the inorganic particles from the viewpoint of enhancing the long-term stability of the electric characteristics and the carrier blocking property.

Examples of the electron accepting compound include quinone compounds such as chloranil and bromoanil; tetracyanoquinodimethane compounds; 2,4,7-trinitrofluorenone, 2,4,5,7-tetranitro-9-fluorenone, and the like. 2- (4-biphenyl) -5- (4-t-butylphenyl) -1,3,4-oxadiazole, 2,5-bis (4-naphthyl) -1,3,4- Oxadiazole compounds such as oxadiazole and 2,5-bis (4-diethylaminophenyl) -1,3,4 oxadiazole; xanthone compounds; thiophene compounds; 3,3 ′, 5,5 ′ tetra- electron transporting substances such as diphenoquinone compounds such as t-butyldiphenoquinone;
In particular, the electron-accepting compound is preferably a compound having an anthraquinone structure. As the compound having an anthraquinone structure, for example, a hydroxyanthraquinone compound, an aminoanthraquinone compound, an aminohydroxyanthraquinone compound, and the like are preferable, and specifically, for example, anthraquinone, alizarin, quinizarin, anthralfin, and purpurin are preferable.

  The electron-accepting compound may be dispersed and included in the undercoat layer together with the inorganic particles, or may be included in a state of being attached to the surface of the inorganic particles.

  Examples of the method for attaching the electron accepting compound to the surface of the inorganic particles include a dry method or a wet method.

  In the dry method, for example, while stirring inorganic particles with a mixer having a large shearing force or the like, an electron-accepting compound dissolved directly or in an organic solvent is dropped and sprayed with dry air or nitrogen gas. It is a method of adhering to the surface of inorganic particles. When the electron-accepting compound is dropped or sprayed, it is preferably performed at a temperature not higher than the boiling point of the solvent. After dropping or spraying the electron-accepting compound, baking may be performed at 100 ° C. or higher. The baking is not particularly limited as long as it is a temperature and time for obtaining electrophotographic characteristics.

  In the wet method, for example, an electron-accepting compound is added while dispersing inorganic particles in a solvent by stirring, ultrasonic waves, a sand mill, an attritor, a ball mill, etc., and after stirring or dispersing, the solvent is removed to remove electrons. This is a method of attaching a receptive compound to the surface of inorganic particles. The solvent removal method is distilled off by filtration or distillation, for example. After removing the solvent, baking may be performed at 100 ° C. or higher. The baking is not particularly limited as long as it is a temperature and time for obtaining electrophotographic characteristics. In the wet method, the water content of the inorganic particles may be removed before adding the electron-accepting compound. Examples thereof include a method of removing while stirring and heating in a solvent, and a method of removing by azeotropic distillation with a solvent. Can be mentioned.

  The attachment of the electron-accepting compound may be performed before or after the surface treatment with the surface treatment agent is performed on the inorganic particles, or may be performed simultaneously with the attachment of the electron-accepting compound and the surface treatment with the surface treatment agent.

  The content of the electron-accepting compound is, for example, from 0.01% by mass to 20% by mass with respect to the inorganic particles, and preferably from 0.01% by mass to 10% by mass.

Examples of the binder resin used for the undercoat layer include acetal resins (eg, polyvinyl butyral), polyvinyl alcohol resins, polyvinyl acetal resins, casein resins, polyamide resins, cellulose resins, gelatin, polyurethane resins, polyester resins, and unsaturated polyesters. Resin, methacrylic resin, acrylic resin, polyvinyl chloride resin, polyvinyl acetate resin, vinyl chloride-vinyl acetate-maleic anhydride resin, silicone resin, silicone-alkyd resin, urea resin, phenol resin, phenol-formaldehyde resin, melamine resin, Known polymer compounds such as urethane resin, alkyd resin, epoxy resin; zirconium chelate compound; titanium chelate compound; aluminum chelate compound; titanium alkoxide compound ; Organic titanium compounds; known materials silane coupling agent, and the like.
Examples of the binder resin used for the undercoat layer include a charge transport resin having a charge transport group, a conductive resin (for example, polyaniline) and the like.

Among these, as the binder resin used for the undercoat layer, a resin insoluble in the upper coating solvent is preferable, and in particular, a urea resin, a phenol resin, a phenol-formaldehyde resin, a melamine resin, a urethane resin, and an unsaturated polyester. Thermosetting resins such as resins, alkyd resins, and epoxy resins; at least one resin selected from the group consisting of polyamide resins, polyester resins, polyether resins, methacrylic resins, acrylic resins, polyvinyl alcohol resins, and polyvinyl acetal resins; Resins obtained by reaction with curing agents are preferred.
When these binder resins are used in combination of two or more, the mixing ratio is set as necessary.

The undercoat layer may contain various additives for improving electrical characteristics, improving environmental stability, and improving image quality.
Additives include known materials such as electron transport pigments such as polycyclic condensation systems and azo systems, zirconium chelate compounds, titanium chelate compounds, aluminum chelate compounds, titanium alkoxide compounds, organic titanium compounds, and silane coupling agents. It is done. The silane coupling agent is used for the surface treatment of the inorganic particles as described above, but may be further added to the undercoat layer as an additive.

  Examples of the silane coupling agent as the additive include vinyltrimethoxysilane, 3-methacryloxypropyl-tris (2-methoxyethoxy) silane, 2- (3,4-epoxycyclohexyl) ethyltrimethoxysilane, 3- Glycidoxypropyltrimethoxysilane, vinyltriacetoxysilane, 3-mercaptopropyltrimethoxysilane, 3-aminopropyltriethoxysilane, N-2- (aminoethyl) -3-aminopropyltrimethoxysilane, N-2- (Aminoethyl) -3-aminopropylmethylmethoxysilane, N, N-bis (2-hydroxyethyl) -3-aminopropyltriethoxysilane, 3-chloropropyltrimethoxysilane and the like can be mentioned.

  Examples of the zirconium chelate compound include zirconium butoxide, zirconium zirconium acetoacetate, zirconium triethanolamine, acetylacetonate zirconium butoxide, ethyl acetoacetate butoxide, zirconium acetate, zirconium oxalate, zirconium lactate, zirconium phosphonate, zirconium octoate, Zirconium naphthenate, zirconium laurate, zirconium stearate, zirconium isostearate, methacrylate zirconium butoxide, stearate zirconium butoxide, isostearate zirconium butoxide and the like.

  Examples of the titanium chelate compound include tetraisopropyl titanate, tetranormal butyl titanate, butyl titanate dimer, tetra (2-ethylhexyl) titanate, titanium acetylacetonate, polytitanium acetylacetonate, titanium octylene glycolate, and titanium lactate ammonium salt. , Titanium lactate, titanium lactate ethyl ester, titanium triethanolamate, polyhydroxy titanium stearate and the like.

  Examples of the aluminum chelate compound include aluminum isopropylate, monobutoxy aluminum diisopropylate, aluminum butyrate, diethyl acetoacetate aluminum diisopropylate, aluminum tris (ethyl acetoacetate) and the like.

  These additives may be used alone or as a mixture or polycondensate of a plurality of compounds.

The undercoat layer preferably has a Vickers hardness of 35 or more.
The surface roughness (ten-point average roughness) of the undercoat layer is adjusted from 1 / 4n (n is the refractive index of the upper layer) to 1 / 2λ of the exposure laser wavelength λ used to suppress moire images. It should be done.
Resin particles or the like may be added to the undercoat layer for adjusting the surface roughness. Examples of the resin particles include silicone resin particles and cross-linked polymethyl methacrylate resin particles. Further, the surface of the undercoat layer may be polished for adjusting the surface roughness. Examples of the polishing method include buffing, sandblasting, wet honing, and grinding.

  There is no particular limitation on the formation of the undercoat layer, and a well-known formation method is used. For example, a coating film for forming an undercoat layer in which the above components are added to a solvent is formed, and the coating film is dried. And heating as necessary.

Solvents for preparing the coating solution for forming the undercoat layer include known organic solvents such as alcohol solvents, aromatic hydrocarbon solvents, halogenated hydrocarbon solvents, ketone solvents, ketone alcohol solvents, ether solvents. Examples include solvents and ester solvents.
Specific examples of these solvents include methanol, ethanol, n-propanol, iso-propanol, n-butanol, benzyl alcohol, methyl cellosolve, ethyl cellosolve, acetone, methyl ethyl ketone, cyclohexanone, methyl acetate, ethyl acetate, Examples include ordinary organic solvents such as n-butyl acetate, dioxane, tetrahydrofuran, methylene chloride, chloroform, chlorobenzene, and toluene.

  Examples of the dispersion method of the inorganic particles when preparing the coating liquid for forming the undercoat layer include known methods such as a roll mill, a ball mill, a vibration ball mill, an attritor, a sand mill, a colloid mill, and a paint shaker.

  Examples of the method for applying the coating liquid for forming the undercoat layer onto the conductive substrate include, for example, a blade coating method, a wire bar coating method, a spray coating method, a dip coating method, a bead coating method, an air knife coating method, and a curtain coating method. The usual methods, such as these, are mentioned.

  The thickness of the undercoat layer is, for example, preferably set in the range of 15 μm or more, more preferably 20 μm or more and 50 μm or less.

(Middle layer)
Although illustration is omitted, an intermediate layer may be further provided between the undercoat layer and the photosensitive layer.
An intermediate | middle layer is a layer containing resin, for example. Examples of the resin used for the intermediate layer include an acetal resin (for example, polyvinyl butyral), polyvinyl alcohol resin, polyvinyl acetal resin, casein resin, polyamide resin, cellulose resin, gelatin, polyurethane resin, polyester resin, methacrylic resin, acrylic resin, Polymer compounds such as polyvinyl chloride resin, polyvinyl acetate resin, vinyl chloride-vinyl acetate-maleic anhydride resin, silicone resin, silicone-alkyd resin, phenol-formaldehyde resin, melamine resin, and the like can be given.
The intermediate layer may be a layer containing an organometallic compound. Examples of the organometallic compound used for the intermediate layer include organometallic compounds containing metal atoms such as zirconium, titanium, aluminum, manganese, and silicon.
The compounds used for these intermediate layers may be used alone or as a mixture or polycondensate of a plurality of compounds.

  Among these, the intermediate layer is preferably a layer containing an organometallic compound containing a zirconium atom or a silicon atom.

The formation of the intermediate layer is not particularly limited, and a well-known formation method is used. For example, a coating film of an intermediate layer forming coating solution in which the above components are added to a solvent is formed, and the coating film is dried and necessary. It is performed by heating according to.
As the coating method for forming the intermediate layer, usual methods such as a dip coating method, a push-up coating method, a wire bar coating method, a spray coating method, a blade coating method, a knife coating method, and a curtain coating method are used.

  For example, the thickness of the intermediate layer is preferably set in a range of 0.1 μm to 3 μm. An intermediate layer may be used as the undercoat layer.

(Single layer type photosensitive layer)
The single-layer type photosensitive layer includes a binder resin, a charge generation material, a hole transport material, an electron transport material, and, if necessary, other additives.

-Binder resin-
The binder resin is not particularly limited. For example, polycarbonate resin, polyester resin, polyarylate resin, methacrylic resin, acrylic resin, polyvinyl chloride resin, polyvinylidene chloride resin, polystyrene resin, polyvinyl acetate resin, styrene-butadiene. Copolymer, vinylidene chloride-acrylonitrile copolymer, vinyl chloride-vinyl acetate copolymer, vinyl chloride-vinyl acetate-maleic anhydride copolymer, silicone resin, silicone alkyd resin, phenol-formaldehyde resin, styrene-alkyd resin , Poly-N-vinylcarbazole, polysilane and the like. These binder resins may be used alone or in combination of two or more.
Among these binder resins, in particular, from the viewpoint of film formability of the photosensitive layer, for example, a polycarbonate resin having a viscosity average molecular weight of 30,000 to 80,000 is preferable.

  The content of the binder resin with respect to the total solid content of the photosensitive layer may be 35% by mass or more and 60% by mass or less, and preferably 20% by mass or more and 35% by mass or less.

-Charge generation material-
As the charge generation material, at least one selected from hydroxygallium phthalocyanine pigment and chlorogallium phthalocyanine pigment is applied.
As the charge generation material, these pigments may be used alone or in combination as required. The charge generating material is preferably a hydroxygallium phthalocyanine pigment from the viewpoint of increasing the sensitivity of the photoreceptor and suppressing point defects in the image.

The hydroxygallium phthalocyanine pigment is not particularly limited, but a V-type hydroxygallium phthalocyanine pigment is preferable.
In particular, as a hydroxygallium phthalocyanine pigment, for example, in a spectral absorption spectrum in a wavelength region of 600 nm to 900 nm, a hydroxygallium phthalocyanine pigment having a maximum peak wavelength in a range of 810 nm to 839 nm can provide more excellent dispersibility. It is preferable from the viewpoint. When used as a material for an electrophotographic photosensitive member, excellent dispersibility, sufficient sensitivity, chargeability, and dark decay characteristics are easily obtained.

The hydroxygallium phthalocyanine pigment having the maximum peak wavelength in the range of 810 nm or more and 839 nm or less preferably has an average particle diameter in a specific range and a BET specific surface area in a specific range. Specifically, the average particle size is preferably 0.20 μm or less, more preferably 0.01 μm or more and 0.15 μm or less, while the BET specific surface area is preferably 45 m ² / g or more. 50 m ² / g or more, more preferably 55 m ² / g or more and 120 m ² / g or less. The average particle size is a volume average particle size (d50 average particle size) measured by a laser diffraction / scattering particle size distribution analyzer (LA-700, manufactured by Horiba, Ltd.). Moreover, it is the value measured by the nitrogen substitution method using the BET-type specific surface area measuring device (Shimadzu Corporation make: Flow soap II2300).
Here, when the average particle diameter is larger than 0.20 μm, or when the specific surface area value is less than 45 m ² / g, the pigment particles tend to be coarse or aggregates of the pigment particles tend to be formed. In addition, defects such as dispersibility, sensitivity, chargeability, and dark decay characteristics tend to easily occur, which may easily cause image quality defects.

  The maximum particle size (maximum primary particle size) of the hydroxygallium phthalocyanine pigment is preferably 1.2 μm or less, more preferably 1.0 μm or less, and more preferably 0.3 μm or less. When the maximum particle size exceeds the above range, black spots tend to occur.

  The hydroxygallium phthalocyanine pigment has an average particle size of 0.2 μm or less and a maximum particle size of 1.2 μm or less from the viewpoint of suppressing density unevenness due to exposure of the photoreceptor to a fluorescent lamp or the like, and The specific surface area value is preferably 45 m2 / g or more.

  The hydroxygallium phthalocyanine pigment has a Bragg angle (2θ ± 0.2 °) of at least 7.3 °, 16.0 °, 24.9 °, 28.0 ° in an X-ray diffraction spectrum using CuKα characteristic X-rays. It is preferable that it is V type which has a diffraction peak.

On the other hand, the chlorogallium phthalocyanine pigment is not particularly limited, but a Bragg angle (2θ ± 0.2 °) of 7.4 °, 16.6 °, 25.25 can be obtained as an electrophotographic photosensitive material. It is preferable to have diffraction peaks at 5 ° and 28.3 °.
The maximum peak wavelength, average particle diameter, maximum particle diameter, and specific surface area value of a suitable spectral absorption spectrum of the chlorogallium phthalocyanine pigment are the same as those of the hydroxygallium phthalocyanine pigment.

  The content of the charge generating material is, for example, preferably 0.05% by mass to 30% by mass with respect to the binder resin, preferably 1% by mass to 15% by mass, and more preferably 2% by mass to 10% by mass. It is as follows.

-Hole transport material-
As the hole transport material, a hole transport material represented by the general formula (1) is applied.

In general formula (1), R ¹ , R ² , R ³ , R ⁴ , R ⁵ , and R ⁶ are each independently a hydrogen atom, a lower alkyl group, an alkoxy group, a phenoxy group, a halogen atom, or a lower group. A phenyl group optionally having a substituent selected from an alkyl group, a lower alkoxy group and a halogen atom is shown. m and n. Each independently represents 0 or 1.

In the general formula (1), examples of the lower alkyl group represented by R ^{1 to} R ⁶ include linear or branched alkyl groups having 1 to 4 carbon atoms. Specifically, for example, Examples thereof include a methyl group, an ethyl group, an n-propyl group, an isopropyl group, an n-butyl group, and an isobutyl group.
Among these, the lower alkyl group is preferably a methyl group or an ethyl group.

In the general formula (1), examples of the alkoxy group represented by R ^{1 to} R ⁶ include an alkoxy group having 1 to 4 carbon atoms, and specifically include a methoxy group, an ethoxy group, a propoxy group, and a butoxy group. Etc.

In general formula (1), examples of the halogen atom represented by R ^{1 to} R ⁶ include a fluorine atom, a chlorine atom, a bromine atom, and an iodine atom.

In the general formula (1), examples of the phenyl group represented by R ^{1 to} R ⁶ include an unsubstituted phenyl group; a phenyl group substituted with a lower alkyl group such as a p-tolyl group or a 2,4-dimethylphenyl group; -A phenyl group substituted with a lower alkoxy group such as a methoxyphenyl group; a phenyl group substituted with a halogen atom such as a p-chlorophenyl group;
Examples of the substituent that can be substituted on the phenyl group include a lower alkyl group, an alkoxy group, and a halogen atom represented by R ^{1 to} R ⁶ .

The hole transport material represented by the general formula (1) is preferably a hole transport material in which m and n are 1 from the viewpoints of increasing sensitivity and suppressing point defect of an image, and in particular, R ^{1 to} R ^6. Each independently represents a hydrogen atom, a lower alkyl group, or an alkoxy group, and a hole transport material in which m and n are 1 is preferable.

  Hereinafter, exemplary compounds of the hole transport material represented by the general formula (1) will be shown, but not limited thereto. In addition, the following exemplary compound numbers are described as an exemplary compound (1-number) below. Specifically, for example, Exemplified Compound 15 is represented below as “Exemplified Compound (1-15)”.

In addition, the abbreviations in the above exemplary compounds have the following meanings.
4-Me: a methyl group substituted at the 4-position of the phenyl group, 3-Me: a methyl group substituted at the 3-position of the phenyl group, 4-Cl: a chlorine atom substituted at the 4-position of the phenyl group, 4 -MeO: methoxy group substituted at the 4-position of the phenyl group, 4-F: fluorine atom substituted at the 4-position of the phenyl group, 4-Pr: propyl group substituted at the 4-position of the phenyl group, 4-PhO : Phenoxy group substituted at 4-position of phenyl group

The content of the hole transporting material is, for example, preferably from 10% by mass to 98% by mass with respect to the binder resin, preferably from 60% by mass to 95% by mass, and more preferably from 70% by mass to 90% by mass. It is.
In addition, content of this hole transport material is content of the whole hole transport material, when the hole transport material represented by General formula (1) and another hole transport material are used together.

-Electron transport material-
As the electron transport material, an electron transport material represented by the general formula (2) is applied.

In the general formula (2), R ¹¹ , R ¹² . R ¹³ . R ¹⁴ , R ¹⁵ , R ¹⁶ , and R ¹⁷ each independently represent a hydrogen atom, a halogen atom, an alkyl group, an alkoxy group, or an aryl group. R ¹⁸ represents a linear alkyl group having 5 to 10 carbon atoms.

In the general formula (2), examples of the halogen atom represented by R ^{11 to} R ¹⁷ include a fluorine atom, a chlorine atom, a bromine atom, and an iodine atom.

In general formula (2), examples of the alkyl group represented by R ^{11 to} R ¹⁷ include linear or branched alkyl groups having 1 to 4 carbon atoms (preferably 1 to 3 carbon atoms), Specific examples include a methyl group, an ethyl group, an n-propyl group, an isopropyl group, an n-butyl group, and an isobutyl group.

In the general formula (2), examples of the alkoxy group represented by R ^{11 to} R ¹⁷ include an alkoxy group having 1 to 4 carbon atoms (preferably 1 to 3 carbon atoms), specifically, a methoxy group, An ethoxy group, a propoxy group, a butoxy group, etc. are mentioned.

In the general formula (2), examples of the aryl group represented by R ^{11 to} R ¹⁷ include a phenyl group, a benzyl group, and a tolyl group.
Among these, a phenyl group is preferable.

As the electron transport material represented by the general formula (2), from the viewpoint of increasing sensitivity and suppressing point defects in images, in particular, R ^{11 to} R ¹⁷ each independently represents a hydrogen atom, a halogen atom, or an alkyl group. And an electron transport material in which R ¹⁸ represents a linear alkyl group having 5 to 10 carbon atoms is preferred.

  Hereinafter, exemplary compounds of the electron transport material represented by the general formula (2) will be shown, but not limited thereto. In addition, the following exemplary compound numbers are described as an exemplary compound (2-number) below. Specifically, for example, Exemplified Compound 15 is represented below as “Exemplified Compound (2-15)”.

The content of the electron transport material is 20% by mass or more and 40% by mass or less with respect to the binder resin, and preferably 20% by mass or more and 35% by mass or less from the viewpoint of high sensitivity of the photosensitive layer and high mechanical strength. More preferably, it is 20 mass% or more and 30 mass% or less.
In addition, content of this electron transport material is content of the whole electron transport material, when the electron transport material represented by General formula (2) and another electron transport material are used together.

-Other charge transport materials-
In addition to the specific hole transport material and electron transport material, other charge transport materials (other hole transport materials and other electron transport materials) may be used in combination as long as the function is not impaired. However, the other charge transport material is preferably used in combination with less than 50% by mass with respect to the whole of the hole transport material and the electron transport material.

  Other charge transport materials include, for example, quinone compounds such as p-benzoquinone, chloranil, bromanyl, anthraquinone, tetracyanoquinodimethane compounds, fluorenone compounds such as 2,4,7-trinitrofluorenone, and xanthone compounds. Electron transporting compounds such as benzophenone compounds, cyanovinyl compounds, ethylene compounds; triarylamine compounds, benzidine compounds, arylalkane compounds, aryl-substituted ethylene compounds, stilbene compounds, anthracene compounds, hydrazone compounds And hole transporting compounds such as compounds. These other charge transport materials may be used alone or in combination of two or more, but are not limited thereto.

  As other charge transport materials, from the viewpoint of charge mobility, a triarylamine derivative represented by the following structural formula (B-1) and a benzidine derivative represented by the following structural formula (B-2) are preferable.

In Structural Formula (B-1), R ^B1 represents a hydrogen atom or a methyl group. n11 represents 1 or 2. Ar ^B1 and Ar ^B2 are each independently a substituted or unsubstituted aryl group, —C ₆ H ₄ —C (R ^B3 ) ═C (R ^B4 ) (R ^B5 ), or —C ₆ H ₄ —CH═CH—. CH = C (R ^B6 ) (R ^B7 ), wherein R ^{B3 to} R ^B7 each independently represent a hydrogen atom, a substituted or unsubstituted alkyl group, or a substituted or unsubstituted aryl group. The substituent is a halogen atom, an alkyl group having 1 to 5 carbon atoms, an alkoxy group having 1 to 5 carbon atoms, or a substituted amino group substituted with an alkyl group having 1 to 3 carbon atoms.

(In Structural Formula (B-2), R ^B8 and R ^{B8 ′} may be the same or different, and each independently represents a hydrogen atom, a halogen atom, an alkyl group having 1 to 5 carbon atoms, or 1 to 5 carbon atoms. R ^B9 , R ^{B9 ′} , R ^B10 and R ^{B10 ′} may be the same or different and each independently represents a hydrogen atom, a halogen atom, an alkyl group having 1 to 5 carbon atoms, or 1 carbon atom. Or more, an alkoxy group having 5 or less, an amino group substituted with an alkyl group having 1 to 2 carbon atoms, a substituted or unsubstituted aryl group, -C (R ^B11 ) = C (R ^B12 ) (R ^B13 ), ^{or- CH = CH-CH = C (} R B14) indicates ^{(R B15),} representing the ^{R B11} to ^{R B15} are each independently a hydrogen atom, a substituted or unsubstituted alkyl group or a substituted or unsubstituted aryl group, .m 2, m13, n12 and n13 represents 2 the following integers each independently 0 or greater.)

Here, among the triarylamine derivative represented by the structural formula (B-1) and the benzidine derivative represented by the structural formula (B-2), in particular, “—C ₆ H ₄ —CH═CH—CH═C Triarylamine derivatives having “(R ^B6 ) (R ^B7 )” and benzidine derivatives having “—CH═CH— ^CH═C (R ^B14 ) (R ^B15 )” are preferred.

-Mass ratio of hole transport material and electron transport material-
The mass ratio of the hole transporting material and the electron transporting material (hole transporting material / electron transporting material) is 60/40 or more and 80/20 or less, from the viewpoint of high sensitivity of the photosensitive layer and high mechanical strength. Preferably they are 65/35 or more and 75/25 or less.
In addition, this ratio is a ratio in total when other charge transport materials are used in combination.

-Other additives-
The single-layer type photosensitive layer may contain other known additives such as an antioxidant, a light stabilizer, and a heat stabilizer. Further, when the single-layer type photosensitive layer is a surface layer, it may contain fluororesin particles, silicone oil and the like.

-Formation of single-layer type photosensitive layer-
The single-layer type photosensitive layer is formed using a photosensitive layer forming coating solution in which the above components are added to a solvent.
Solvents include aromatic hydrocarbons such as benzene, toluene, xylene and chlorobenzene, ketones such as acetone and 2-butanone, halogenated aliphatic hydrocarbons such as methylene chloride, chloroform and ethylene chloride, tetrahydrofuran and ethyl. Common organic solvents such as cyclic or linear ethers such as ether can be mentioned. These solvents are used alone or in combination of two or more.

  As a method for dispersing particles (for example, charge generation material) in the coating solution for forming a photosensitive layer, a media disperser such as a ball mill, a vibrating ball mill, an attritor, a sand mill, a horizontal sand mill, an agitator, an ultrasonic disperser, a roll mill, Medialess dispersers such as high-pressure homogenizers are used. Examples of the high-pressure homogenizer include a collision method in which the dispersion liquid is dispersed by liquid-liquid collision or liquid-wall collision in a high-pressure state, and a penetration method in which a fine flow path is dispersed in a high-pressure state.

  Examples of the method for applying the photosensitive layer forming coating solution onto the undercoat layer include dip coating, push-up coating, wire bar coating, spray coating, blade coating, knife coating, and curtain coating. .

  The film thickness of the single-layer type photosensitive layer is preferably set in the range of 5 μm to 60 μm, more preferably 10 μm to 50 μm.

(Protective layer)
The protective layer is provided on the photosensitive layer as necessary. The protective layer is provided, for example, for the purpose of preventing chemical change of the photosensitive layer during charging or further improving the mechanical strength of the photosensitive layer.
Therefore, it is preferable to apply a layer composed of a cured film (crosslinked film) as the protective layer. Examples of these layers include the layers shown in 1) or 2) below.

1) A layer composed of a cured film of a composition containing a reactive group-containing charge transporting material having a reactive group and a charge transporting skeleton in the same molecule (that is, a polymer or cross-linking of the reactive group-containing charge transporting material) Layer containing body)
2) a layer composed of a cured film of a composition comprising a non-reactive charge transport material and a reactive group-containing non-charge transport material having a reactive group and having no charge transport skeleton (that is, A layer comprising a non-reactive charge transport material and a polymer or a cross-linked product of the reactive group-containing non-charge transport material)

The reactive group of the reactive group-containing charge transport material includes a chain polymerizable group, an epoxy group, —OH, —OR [wherein R represents an alkyl group], —NH ₂ , —SH, —COOH, —SiR. ^Q1 _3-Qn (OR ^Q2 ) _Qn [wherein R ^Q1 represents a hydrogen atom, an alkyl group, or a substituted or unsubstituted aryl group, and R ^Q2 represents a hydrogen atom, an alkyl group, or a trialkylsilyl group. _Qn represents an integer of 1 to 3], and the like, and other well-known reactive groups.

  The chain polymerizable group is not particularly limited as long as it is a functional group capable of radical polymerization. For example, it is a functional group having a group containing at least a carbon double bond. Specific examples include groups containing at least one selected from a vinyl group, vinyl ether group, vinyl thioether group, styryl group, acryloyl group, methacryloyl group, and derivatives thereof. Among them, the chain polymerizable group is preferably a group containing at least one selected from a vinyl group, a styryl group, an acryloyl group, a methacryloyl group, and derivatives thereof because of its excellent reactivity. .

  The charge transporting skeleton of the reactive group-containing charge transporting material is not particularly limited as long as it is a known structure in an electrophotographic photoreceptor, and examples thereof include triarylamine compounds, benzidine compounds, hydrazone compounds, and the like. And a structure conjugated from a nitrogen-containing hole transporting compound and conjugated with a nitrogen atom. Among these, a triarylamine skeleton is preferable.

  The reactive group-containing charge transport material having a reactive group and a charge transport skeleton, a non-reactive charge transport material, and a reactive group-containing non-charge transport material may be selected from well-known materials.

  In addition, the protective layer may contain known additives.

  The formation of the protective layer is not particularly limited, and a known formation method is used.For example, a coating film of a coating liquid for forming a protective layer in which the above components are added to a solvent is formed, and the coating film is dried. It is performed by performing a curing process such as heating as necessary.

Solvents for preparing the coating solution for forming the protective layer include aromatic solvents such as toluene and xylene; ketone solvents such as methyl ethyl ketone, methyl isobutyl ketone and cyclohexanone; ester solvents such as ethyl acetate and butyl acetate; tetrahydrofuran And ether solvents such as dioxane; cellosolv solvents such as ethylene glycol monomethyl ether; alcohol solvents such as isopropyl alcohol and butanol. These solvents are used alone or in combination of two or more.
The protective layer forming coating solution may be a solventless coating solution.

  As a method for applying the coating solution for forming the protective layer on the photosensitive layer (for example, charge transport layer), dip coating method, push-up coating method, wire bar coating method, spray coating method, blade coating method, knife coating method, curtain coating method. Ordinary methods such as a method may be mentioned.

  The thickness of the protective layer is, for example, preferably set in the range of 1 μm to 20 μm, more preferably 2 μm to 10 μm.

[Charging device]
Examples of the charging device 20 include a contact charger using a conductive charging roller, a charging brush, a charging film, a charging rubber blade, a charging tube, and the like. Further, examples of the charging device 20 include a non-contact type roller charger and a known charger such as a scorotron charger using a corona discharge or a corotron charger. As the charging device 20, a contact charger is preferable.

[Exposure equipment]
Examples of the exposure apparatus 30 include optical system devices that expose the surface of the electrophotographic photoreceptor 10 with light such as semiconductor laser light, LED light, and liquid crystal shutter light imagewise. The wavelength of the light source is preferably within the spectral sensitivity region of the electrophotographic photoreceptor 10. The wavelength of the semiconductor laser is preferably near infrared having an oscillation wavelength of around 780 nm, for example. However, the present invention is not limited to this wavelength, and an oscillation wavelength laser in the 600 nm range or a laser having an oscillation wavelength of 400 nm to 450 nm as a blue laser may be used. As the exposure apparatus 30, for example, a surface-emitting laser light source of a multi-beam output type is also effective for color image formation.

[Developer]
An example of the developing device 40 is a configuration in which a developing roll 41 disposed in the developing region facing the electrophotographic photosensitive member 10 is provided in a container that stores a two-component developer composed of toner and a carrier. The developing device 40 is not particularly limited as long as it is a device that develops with a two-component developer, and a known configuration is employed.

  Here, the developer used in the developing device 40 may be a one-component developer made of toner, or may be a two-component developer including toner and carrier.

[Transfer device]
As the transfer device 50, for example, a contact transfer charger using a belt, a roller, a film, a rubber blade or the like, or a known transfer charger such as a scorotron transfer charger using a corona discharge or a corotron transfer charger. Can be mentioned.

[Cleaning device]
The cleaning device 70 includes, for example, a casing 71, a cleaning blade 72, and a cleaning brush 73 disposed on the downstream side of the cleaning blade 72 in the rotation direction of the electrophotographic photosensitive member 10. Further, for example, a solid lubricant 74 is disposed in contact with the cleaning brush 73.

The force NF (Normal Force) against which the cleaning blade 72 is pressed against the electrophotographic photosensitive member 10 is preferably in the range of 1.3 gf / mm to 2.3 gf / mm, and more preferably 1.6 gf / mm to 2.0 gf / mm. More preferably, it is in the range of mm or less.
The length that the tip of the cleaning blade 72 bites into the electrophotographic photosensitive member 10 is preferably in the range of 0.8 mm to 1.2 mm, and more preferably in the range of 0.9 mm to 1.1 mm. .
The angle W / A (Working Angle) at the contact portion between the cleaning blade 72 and the electrophotographic photoreceptor 10 is preferably in the range of 8 ° to 14 °, and more preferably in the range of 10 ° to 12 °. preferable.

  Here, the cleaning blade 72 is a member (hereinafter referred to as “a member having the endothermic peak top temperature in the range of 180 ° C. or more and 220 ° C. or less” in which at least the portion in contact with the electrophotographic photoreceptor contains polyurethane rubber and the differential scanning calorimetry is performed. Also referred to as “specific member”).

-Endothermic peak top temperature-
The endothermic peak top temperature (melting temperature) by differential scanning calorimetry was measured by differential scanning calorimetry (DSC) according to ASTM D3418-99. For the measurement, a Diamond-DSC manufactured by PerkinElmer was used, the temperature of the apparatus detection unit was corrected using the melting temperature of indium and zinc, and the heat of heat was corrected using the heat of fusion of indium. An aluminum pan was used as a measurement sample, and an empty pan was set as a control for measurement. At this time, the rate of temperature increase during the DSC measurement was 3 ° C./mim, and the measurement temperature range was 20 ° C. to 250 ° C.

Examples of means for controlling the endothermic peak top temperature (melting temperature) within the above range include a method for controlling the endothermic peak top temperature (melting temperature) within an appropriate range while enhancing the crystallinity of the polyurethane member. Although not particularly limited, in order to further increase the crystallinity, a method of further growing hard segment aggregates in polyurethane is exemplified. More specifically, chemical cross-linking (crosslinking is performed during formation of a crosslinked structure in polyurethane. The method of adjusting so that physical bridge | crosslinking (bridge | crosslinking by the hydrogen bond of hard segments) may advance more efficiently than the bridge | crosslinking by an agent. Note that the aging time becomes longer as the polymerization temperature is set lower during the polymerization of polyurethane, and as a result, more physical crosslinking tends to proceed.
Details of the control method will be described later.

-Particle size and particle size distribution of hard segment aggregates (standard deviation σ)-
The polyurethane rubber preferably has a hard segment and a soft segment, and the average particle size of the hard segment aggregate is preferably 5 μm or more and 20 μm or less.
When the average particle diameter of the hard segment aggregates is 5 μm or more, the crystal area on the surface of the cleaning blade 72 is increased, and there is an advantage of improving the slidability (lowering friction). On the other hand, by being 20 μm or less, there is an advantage that toughness (chip resistance) is not lost while maintaining low friction.
The average particle size of the hard segment aggregates is more preferably 5 μm to 15 μm, and still more preferably 5 μm to 10 μm.

The particle size distribution (standard deviation σ) of the hard segment aggregates is preferably 2 μm or more.
The particle size distribution (standard deviation σ) of the hard segment aggregates is 2 μm or more, which means that particles of various particle sizes are mixed, and the contact area with the soft segment increases due to the small aggregates. As a result, the effect of increasing the hardness can be obtained. On the other hand, the effect of improving the slidability can be obtained by the large aggregate.
The particle size distribution (standard deviation σ) of the hard segment aggregates is more preferably 2 μm or more and 5 μm or less, and further preferably 2 μm or more and 3 μm or less.

In addition, the average particle diameter and particle size distribution (standard deviation (sigma)) of a hard segment aggregate are measured with the following method. Using a polarizing microscope (Olympus BX51-P), an image was taken at a magnification of × 20, image processing was performed to binarize the image, and 5 points per cleaning blade 72 (5 points per point) The particle diameter is measured for 20 cleaning blades 72, and the average particle diameter is calculated from a total of 500 cleaning blades 72.
For image binarization, image processing software OLYMPUS Stream essentials (manufactured by Olympus) is used, and the hue / saturation / luminance threshold is adjusted so that the crystal part is black and the amorphous part is white.

Then, the particle size distribution (standard deviation σ) is calculated from the measured 500 particle diameters by the following equation.
Standard deviation σ = √ {[(X1-M) ² + (X2-M) ² +...
... + (X500-M) ² ] / 500}
Xn: measured particle diameter n (n = 1 to 500)
M: Average value of measured particle diameter

  The means for controlling the average particle size and particle size distribution (standard deviation σ) of the hard segment aggregate to the above range is not particularly limited, but for example, reaction control by a catalyst, three-dimensional network control by a crosslinking agent, Examples include a method of controlling crystal growth according to aging conditions.

Next, the configuration of the cleaning blade 72 will be described.
The cleaning blade 72 has a specific member (a member containing polyurethane rubber and having an endothermic peak top temperature in the range of 180 ° C. or higher and 220 ° C. or lower as measured by differential scanning calorimetry) at least in a portion in contact with the electrophotographic photosensitive member. It only has to be. That is, it may have a two-layer configuration in which a first layer made of a specific member and in contact with the surface of the electrophotographic photosensitive member 10 and a second layer as a back layer provided on the back surface of the first layer, Three or more layers may be used. Further, it may be configured such that only the corner portion of the portion in contact with the electrophotographic photosensitive member is made of a specific member and the periphery thereof is made of another material.
Normally, the cleaning blade 72 is used by being bonded to a rigid plate-like support material.

-Composition of specific members-
The specific member of the cleaning blade 72 contains polyurethane rubber.
Polyurethane rubber is usually synthesized by polymerizing polyisocyanate and polyol. Moreover, you may use resin which has a functional group which can react with an isocyanate group other than a polyol. The polyurethane rubber preferably has a hard segment and a soft segment.
Here, the “hard segment” and the “soft segment” are the materials constituting the former in the polyurethane rubber material, the material constituting the former being relatively harder than the material constituting the latter. Means a segment made of a material relatively softer than the material constituting the former.

  The combination of the material constituting the hard segment (hard segment material) and the material constituting the soft segment (soft segment material) is not particularly limited. One is relatively hard with respect to the other and the other is against the other. However, in the present embodiment, the following combinations are suitable.

-Soft segment materials Examples of soft segment materials include polyester polyols obtained by dehydration condensation of diols and dibasic acids, and polyols such as polycarbonate polyols, polycaprolactone polyols, polyether polyols obtained by the reaction of diols and alkyl carbonates. . In addition, as a commercial item of the polyol used as a soft segment material, Daicel Chemical Co., Ltd. Plaxel 205, Plaxel 240, etc. are mentioned, for example.

Hard segment material As the hard segment material, it is preferable to use a resin having a functional group capable of reacting with an isocyanate group. Further, it is preferably a flexible resin, and more preferably an aliphatic resin having a linear structure from the viewpoint of flexibility. Specifically, it is preferable to use an acrylic resin containing two or more hydroxyl groups, a polybutadiene resin containing two or more hydroxyl groups, an epoxy resin having two or more epoxy groups, or the like as the hard segment material.

As a commercial item of acrylic resin containing two or more hydroxyl groups, Act Flow (grade: UMB-2005B, UMB-2005P, UMB-2005, UME-2005, etc.) manufactured by Soken Chemical Co., Ltd., and the like can be given.
As a commercial item of the polybutadiene resin containing two or more hydroxyl groups, Idemitsu Kosan Co., Ltd. make, R-45HT etc. are mentioned, for example.

The epoxy resin having two or more epoxy groups is not hard and brittle like conventional general epoxy resins, and is preferably flexible and tougher than conventional epoxy resins. As this epoxy resin, for example, in terms of molecular structure, those having a structure (flexible skeleton) that can increase the mobility of the main chain in the main chain structure are suitable. Examples include an alkylene skeleton, a cycloalkane skeleton, and a polyoxyalkylene skeleton, and a polyoxyalkylene skeleton is particularly preferable.
As the epoxy resin having two or more epoxy groups, an epoxy resin having a lower viscosity than the conventional epoxy resin is preferable from the viewpoint of physical properties. Specifically, the weight average molecular weight is in the range of 900 ± 100, the viscosity at 25 ° C. is preferably in the range of 15000 ± 5000 mPa · s, and more preferably in the range of 15000 ± 3000 mPa · s. preferable. As a commercial item of the epoxy resin which has this characteristic, the product made from DIC, EPLICON EXA-4850-150, etc. are mentioned, for example.

When a hard segment material and a soft segment material are used, the mass ratio of the material constituting the hard segment to the total amount of the hard segment material and the soft segment material (hereinafter referred to as “hard segment material ratio”) is 10% by mass or more and 30% by mass or less. Preferably, it is in the range of 13% by mass or more and 23% by mass or less, and more preferably in the range of 15% by mass or more and 20% by mass or less.
When the hard segment material ratio is 10% by mass or more, wear resistance is obtained, and good cleaning properties are easily maintained over a long period of time. On the other hand, when the hard segment material ratio is 30% by mass or less, it does not become too hard, and flexibility and extensibility are obtained, chipping is suppressed, and good cleaning properties are maintained over a long period of time. It becomes easy to be done.

-Polyisocyanate Examples of the polyisocyanate include 4,4'-diphenylmethane diisocyanate (MDI), 2,6-toluene diisocyanate (TDI), 1,6-hexane diisocyanate (HDI), and 1,5-naphthalene diisocyanate (NDI). And 3,3-dimethylphenyl-4,4-diisocyanate (TODI).
The polyisocyanate is 4,4′-diphenylmethane diisocyanate (MDI) or 1,5-naphthalene diisocyanate (NDI) from the viewpoint of easy formation of a hard segment aggregate having the required size (average particle diameter). More preferred is hexamethylene diisocyanate (HDI).

20 mass parts or more and 40 mass parts or less are preferable, and, as for the compounding quantity with respect to 100 mass parts of resin which has a functional group which can react with respect to the isocyanate group of polyisocyanate, 20 mass parts or more and 35 mass parts or less are more preferable, 20 More preferably, it is at least 30 parts by mass.
When the amount is 20 parts by mass or more, a large amount of urethane bonds is secured, and the hard segment grows, and the required hardness is easily obtained. On the other hand, when the amount is 40 parts by mass or less, the hard segment does not become too large, the extensibility is obtained, and the occurrence of chipping of the cleaning blade 72 is easily suppressed.

-Crosslinking agent As a crosslinking agent, diol (bifunctional), triol (trifunctional), tetraol (tetrafunctional), etc. are mentioned, You may use these together. An amine compound may be used as a crosslinking agent. In addition, it is preferable that it was bridge | crosslinked using the trifunctional or more than trifunctional crosslinking agent. Examples of the trifunctional crosslinking agent include trimethylolpropane, glycerin, triisopropanolamine and the like.

  As for the compounding quantity with respect to 100 mass parts of resin which has a functional group which can react with respect to the isocyanate group of a crosslinking agent, 2 mass parts or less are preferable. By being 2 parts by mass or less, molecular motion is not restricted by chemical crosslinking, and a hard segment derived from a urethane bond by aging grows greatly, and the required hardness is easily obtained.

-Polyurethane rubber production method Polyurethane rubber is produced by a general polyurethane production method such as a prepolymer method or a one-shot method. The prepolymer method is suitable because a polyurethane having excellent strength and abrasion resistance can be obtained, but is not limited by the production method.

  Examples of means for controlling the endothermic peak top temperature (melting temperature) of the specific member within the above range include a method of controlling the polyurethane rubber to an appropriate range while enhancing the crystallinity of the polyurethane rubber. There is a method of growing the aggregate more. Specifically, a method of adjusting so that physical crosslinking (crosslinking by hydrogen bonding between hard segments) proceeds more efficiently than chemical crosslinking (crosslinking by a crosslinking agent) at the time of forming a crosslinked structure in polyurethane rubber. In the polymerization of polyurethane rubber, the aging time becomes longer as the polymerization temperature is set lower, and as a result, the physical crosslinking tends to proceed more.

The polyurethane rubber is molded under molding conditions that can suppress unevenness in molecular arrangement by blending an isocyanate compound and a crosslinking agent into the polyol described above.
Specifically, when the polyurethane rubber composition is adjusted, the temperature of the polyol or prepolymer is lowered, or the temperature of curing and molding is lowered so that the progress of the crosslinking is delayed. By setting these temperatures (polyol and prepolymer temperatures, curing and molding temperatures) low to lower the reactivity, the urethane bonds are aggregated and hard segment crystals are obtained. The temperature is adjusted so that the average particle diameter is the crystal diameter required.
Thereby, the molecules contained in the polyurethane rubber composition are arranged side by side, and when the DSC is measured, a polyurethane rubber containing a crystal having an endothermic peak top temperature of crystal melting energy in the above range is formed.
The amounts of polyol, polyisocyanate, and crosslinking agent, the ratio of crosslinking agent, and the like are adjusted to the required ranges.

  The cleaning blade 72 is formed by forming the cleaning blade-forming composition prepared by the above-described method into a sheet shape using, for example, centrifugal molding or extrusion molding, and performing a cutting process or the like. The

  Here, an example is given and the detail of the manufacturing method of the cleaning blade 72 is demonstrated.

First, a soft segment material (for example, polycaprolactone polyol) and a hard segment material (for example, an acrylic resin containing two or more hydroxyl groups) are mixed (for example, a mass ratio of 8: 2).
Next, an isocyanate compound (for example, 4,4′-diphenylmethane diisocyanate) is added to the mixture of the soft segment material and the hard segment material, and the reaction is performed in, for example, a nitrogen atmosphere. The temperature at this time is preferably 60 ° C. or higher and 150 ° C. or lower, and more preferably 80 ° C. or higher and 130 ° C. or lower. The reaction time is preferably from 0.1 hours to 3 hours, more preferably from 1 hour to 2 hours.

Subsequently, an isocyanate compound is further added and reacted in, for example, a nitrogen atmosphere to obtain a prepolymer. The temperature at this time is preferably 40 ° C. or higher and 100 ° C. or lower, and more preferably 60 ° C. or higher and 90 ° C. or lower. The reaction time is preferably 30 minutes or more and 6 hours or less, and more preferably 1 hour or more and 4 hours or less.
Next, the prepolymer is heated and degassed under reduced pressure. The temperature at this time is preferably 60 ° C. or higher and 120 ° C. or lower, and more preferably 80 ° C. or higher and 100 ° C. or lower. The reaction time is preferably 10 minutes or more and 2 hours or less, and more preferably 30 minutes or more and 1 hour or less.
Thereafter, a crosslinking agent (eg, 1,4-butanediol, trimethylolpropane, etc.) is added to the prepolymer and mixed to prepare a polyurethane rubber composition for forming a cleaning blade.

Next, a polyurethane rubber composition for forming a cleaning blade is poured into a mold of a centrifugal molding machine to cause a curing reaction. In this case, the mold temperature is preferably 80 ° C. or higher and 160 ° C. or lower, and more preferably 100 ° C. or higher and 140 ° C. or lower. The reaction time is preferably 20 minutes or longer and 3 hours or shorter, and more preferably 30 minutes or longer and 2 hours or shorter.
Further, a cross-linking reaction is performed, and after cooling, cutting is performed to form a cleaning blade 72. The temperature of the aging heating during this crosslinking reaction is preferably 70 ° C. or higher and 130 ° C. or lower, more preferably 80 ° C. or higher and 130 ° C. or lower, and further preferably 100 ° C. or higher and 120 ° C. or lower. The reaction time is preferably 1 hour to 48 hours, more preferably 10 hours to 24 hours.

Physical Properties In the specific member of the cleaning blade 72, the ratio of physical crosslinking (crosslinking by hydrogen bonding between hard segments) to chemical crosslinking (crosslinking by a crosslinking agent) “1” in polyurethane rubber is 1: 0.8 to 1 Is preferably 2.0, and more preferably 1: 1 to 1: 1.8.
When the ratio of physical crosslinking to chemical crosslinking is not less than the above lower limit value, the hard segment aggregate is further grown and the effect of low friction derived from crystals is obtained. On the other hand, the effect of toughness maintenance is acquired by being below the said upper limit.

In addition, the ratio of the said chemical bridge | crosslinking and a physical bridge | crosslinking is computed using the following Moobee-Riviliin formula.
σ = 2C ₁ (λ−1 / λ ² ) + 2C ₂ (1-1 / λ ³ )
σ: Stress, λ: Strain, C ₁ : Chemical crosslink density, C ₂ : Physical crosslink Here, σ and λ at 10% elongation are used from the stress-strain curve by the tensile test.

In the specific member, the ratio of the hard segment to the soft segment “1” in the polyurethane rubber is preferably 1: 0.15 to 1: 0.3, and more preferably 1: 0.2 to 1: 0. 25 is preferable.
When the ratio of the hard segment to the soft segment is equal to or more than the above lower limit value, the amount of hard segment aggregates is increased, so that an effect of low friction is obtained. On the other hand, the effect of toughness maintenance is acquired by being below the said upper limit.

The ratio between the soft segment and the hard segment, using ^{1 H-NMR,} calculated isocyanate, chain extender, the composition ratio from the spectrum area of polyol as a soft segment material as a hard segment material.

  The weight average molecular weight of the polyurethane rubber of the specific member is preferably in the range of 1000 to 4000, and more preferably in the range of 1500 to 3500.

-Back layer in a two-layer configuration The cleaning blade 72 may have a multi-layer configuration in which the specific member is a first layer that contacts the electrophotographic photosensitive member, and a back layer is further provided on the back of the first layer.

  Examples of the material used for the back layer include polyurethane rubber, silicon rubber, fluorine rubber, propylene rubber, and butadiene rubber. Of these, polyurethane rubber is preferable. Examples of the polyurethane rubber include ester polyurethane and ether polyurethane, and ester polyurethane is particularly preferable.

In addition, when manufacturing a polyurethane rubber, there exists a method of using a polyol and polyisocyanate.
Examples of the polyol include polytetramethyl ether glycol, polyethylene adipate, and polycaprolactone.
As polyisocyanates, 2,6-toluene diisocyanate (TDI), 4,4′-diphenylmethane diisocyanate (MDI), paraphenylene diisocyanate (PPDI), 1,5-naphthalene diisocyanate (NDI), 3,3-dimethyldiphenyl- Examples include 4,4′-diisocyanate (TODI). Of these, MDI is preferred.
Further, examples of the curing agent for curing the polyurethane include curing agents such as 1,4-butanediol, trimethylolpropane, ethylene glycol, and mixtures thereof.

  A specific example will be described as an example. For example, 1,4-butadiol and trimethylolpropane are added as curing agents to a prepolymer produced by mixing and reacting diphenylmethane-4,4-diisocyanate with dehydrated polytetramethyl ether glycol. It is preferable to use those used in combination. In addition, you may add additives, such as a reaction regulator.

As a method for producing the member for the back layer, a conventionally known method is used according to the raw material used for production, for example, a sheet is formed using centrifugal molding or extrusion molding, and is cut into a predetermined shape. It is produced by processing.
In the case of a multi-layer configuration, the first layer and the back layer obtained by the above method (a plurality of back layers in the case of 3 or more layers) are bonded together. . As the bonding method, a double-sided tape, various adhesives and the like are preferably used.
Alternatively, the cleaning blade 72 may be obtained by pouring the material of each layer with a time difference at the time of molding and bonding the materials without providing an adhesive layer.

  Hereinafter, the operation of the image forming apparatus 101 according to the present embodiment will be described. First, the electrophotographic photoreceptor 10 rotates along the direction indicated by the arrow a, and at the same time is positively charged by the charging device 20.

  The electrophotographic photoreceptor 10 whose surface is positively charged by the charging device 20 is exposed by the exposure device 30 to form a latent image on the surface.

  When the portion where the latent image is formed on the electrophotographic photosensitive member 10 approaches the developing device 40, toner is attached to the latent image by the developing device 40 (developing roll 41), and a toner image is formed.

When the electrophotographic photosensitive member 10 on which the toner image is formed is further rotated in the direction of arrow a, the toner image is transferred onto the recording paper P by the transfer device 50. As a result, a toner image is formed on the recording paper P.
Thereafter, the surface of the electrophotographic photosensitive member 10 is cleaned by the cleaning device 70. Then, charging is again performed by the charging device 20, and the next cycle (image process) is performed.

  The toner image is fixed on the recording paper P on which the image is formed by the fixing device 60.

For example, as illustrated in FIG. 3, the image forming apparatus 101 according to the present embodiment includes an electrophotographic photosensitive member 10, a charging device 20, an exposure device 30, a developing device 40, and a cleaning device 70 in a housing 11. May be provided with a process cartridge 101 </ b> A in which are integrally stored. The process cartridge 101A integrally contains a plurality of members and is attached to and detached from the image forming apparatus 101.
The configuration of the process cartridge 101A is not limited to this. For example, the process cartridge 101A only needs to include at least the electrophotographic photosensitive member 10 and the light neutralizing device 80. For example, the charging device 20, the exposure device 30, the developing device 40, At least one selected from the transfer device 50 and the cleaning device 70 may be provided.

  In addition, the image forming apparatus 101 according to the present embodiment is not limited to the above configuration, and is, for example, a cleaning device around the electrophotographic photosensitive member 10 and downstream of the transfer device 50 in the rotation direction of the electrophotographic photosensitive member 10. A first neutralization device may be provided on the upstream side of the rotation direction of the electrophotographic photosensitive member from 70 so that the polarity of the remaining toner is aligned and easy to remove with a cleaning brush. Alternatively, a configuration may be adopted in which a second static elimination device for neutralizing the surface of the electrophotographic photosensitive member 10 is provided on the downstream side in the rotation direction of the electrophotographic photosensitive member and on the upstream side in the rotational direction of the electrophotographic photosensitive member relative to the charging device 20. .

  The image forming apparatus 101 according to the present embodiment is not limited to the above-described configuration, and a known configuration, for example, a toner image formed on the electrophotographic photosensitive member 10 is transferred to the intermediate transfer member and then transferred to the recording paper P. An intermediate transfer type image forming apparatus or a tandem type image forming apparatus may be used.

  EXAMPLES Hereinafter, although this invention is demonstrated more concretely based on an Example and a comparative example, this invention is not limited to a following example at all.

<Preparation of electrophotographic photoreceptor 1>
The Bragg angle (2θ ± 0.2 °) of an X-ray diffraction spectrum using Cukα characteristic X-ray as a charge generation material (indicated as “CGM” in Table 1) is at least 7.3 °, 16.0 °, 24. Table 1 shows 3 parts by mass of a V-type hydroxygallium phthalocyanine pigment having diffraction peaks at 9 ° and 28.0 °, and 47 parts by mass of a bisphenol Z polycarbonate resin (viscosity average molecular weight: 50,000) as a binder resin. 13 parts by mass of an electron transport material (indicated as “ETM” in Table 1), 37 parts by mass of a hole transport material (indicated as “HTM” in Table 1) shown in Table 1, and 250 parts by mass of tetrahydrofuran as a solvent, The mixture consisting of was dispersed for 4 hours in a sand mill using glass beads having a diameter of 1 mmφ to obtain a coating solution for forming a photosensitive layer.
This photosensitive layer forming coating solution is applied by dip coating on an aluminum substrate having a diameter of 30 mm and a length of 244.5 mm, followed by drying and curing at 140 ° C. for 30 minutes to obtain a single-layer type having a thickness of 30 μm. A photosensitive layer was formed.
Through the above steps, an electrophotographic photoreceptor 1 (indicated as “OPC1” in Table 1) was produced.

<Preparation of electrophotographic photoreceptors 2 to 10>
According to Table 1, the electrophotographic photoreceptor 2 is the same as the electrophotographic photoreceptor 1 except that the types and amounts of the electron transport material (ETM), the hole transport material (HTM), and the charge generation material (CGM) are changed. To 10 (indicated as “OPC2 to 10” in Table 1). In Table 1, “parts” indicates parts by mass. Further, “mass%” of the electron transport material (ETM) indicates a ratio with respect to the binder resin.

<Preparation of comparative electrophotographic photoreceptors 1-7>
According to Table 1, the electrophotographic photoreceptor 2 is the same as the electrophotographic photoreceptor 1 except that the types and amounts of the electron transport material (ETM), the hole transport material (HTM), and the charge generation material (CGM) are changed. To 7 (indicated as “C-OPC 1 to 7” in Table 1) were prepared. In Table 1, “parts” indicates parts by mass. Further, “mass%” of the electron transport material (ETM) indicates a ratio with respect to the binder resin.

<Preparation of cleaning blade 1>
First, polycaprolactone polyol (Daicel Chemical Industries, Plaxel 205, average molecular weight 529, hydroxyl value 212 KOHmg / g) and polycaprolactone polyol (Daicel Chemical Industries, Plaxel 240, average molecular weight 4155, hydroxyl value 27 KOHmg) / G) was used as the soft segment material of the polyol component. Also, an acrylic resin containing two or more hydroxyl groups (Akaflow UMB-2005B, manufactured by Soken Chemical Co., Ltd.) is used as a hard segment material, and the soft segment material and the hard segment material are in a ratio of 8: 2 (mass ratio). Mixed.

Next, 6.26 parts of 4,4′-diphenylmethane diisocyanate (manufactured by Nippon Polyurethane Industry Co., Ltd., Millionate MT) is added as an isocyanate compound to 100 parts of the mixture of the soft segment material and the hard segment material. The reaction was performed at 70 ° C. for 3 hours under a nitrogen atmosphere. The amount of isocyanate compound used in this reaction is selected so that the ratio of isocyanate group to hydroxyl group contained in the reaction system (isocyanate group / hydroxyl group) is 0.5.
Subsequently, 34.3 parts of the above isocyanate compound was further added and reacted at 70 ° C. for 3 hours under a nitrogen atmosphere to obtain a prepolymer. The total amount of isocyanate compound used in the use of the prepolymer was 40.56 parts.

  Next, this prepolymer was heated to 100 ° C. and degassed for 1 hour under reduced pressure. Thereafter, 7.14 parts of a mixture of 1,4-butanediol and trimethylolpropane (mass ratio = 60/40) is added to 100 parts of the prepolymer, and mixed for 3 minutes so as not to cause bubbles, and cleaned. A blade-forming composition A1 was prepared.

  Next, the cleaning blade forming composition A1 was poured into a centrifugal molding machine whose mold was adjusted to 140 ° C., and a curing reaction was performed for 1 hour. Next, it was aged and heated at 110 ° C. for 24 hours, cooled and then cut to obtain a cleaning blade 1 (indicated as “BLD1” in Table 2) having a length of 8 mm and a thickness of 2 mm.

<Preparation of cleaning blade 2>
A cleaning blade 2 (indicated as “BLD2” in Table 2) was obtained in the same manner as the cleaning blade 1 except that the aging heating temperature was changed to 75 ° C. in the production of the cleaning blade 1.

<Preparation of cleaning blade 3>
A cleaning blade 3 (indicated as “BLD3” in Table 2) was obtained in the same manner as the cleaning blade 1 except that the aging heating temperature was changed to 75 ° C. and the thermal heating time was changed to 32 hours. It was.

<Preparation of cleaning blade 4>
The cleaning blade 1 was the same as the cleaning blade 1 except that the aging heating temperature was changed to 70 ° C. and the mass ratio of the mixture of 1,4-butanediol and trimethylolpropane was changed to 35/65. 4 (denoted as “BLD4” in Table 2) was obtained.

<Preparation of cleaning blade 5>
The cleaning blade 1 was the same as the cleaning blade 1 except that the aging heating temperature was changed to 70 ° C. and the mass ratio of the mixture of 1,4-butanediol and trimethylolpropane was changed to 35/65. 5 (denoted as “BLD5” in Table 2) was obtained.

<Preparation of cleaning blade 6>
The cleaning blade 1 was prepared in the same manner as the cleaning blade 1 except that the aging heating temperature was changed to 100 ° C. and the mass ratio of the mixture of 1,4-butanediol and trimethylolpropane was changed to 50/50. 6 (denoted as “BLD6” in Table 2) was obtained.

<Preparation of cleaning blade 7>
A cleaning blade 7 (indicated as “BLD7” in Table 2) was obtained in the same manner as the cleaning blade 1 except that the aging heating temperature was changed to 85 ° C. in the production of the cleaning blade 1.

<Preparation of comparative cleaning blade 1>
In the production of the cleaning blade 1, comparative cleaning was performed in the same manner as the cleaning blade 1, except that the aging heating temperature was changed to 75 ° C. and the mass ratio of the mixture of 1,4-butanediol and trimethylolpropane was changed to 70/30. Blade 1 (denoted as “C-BLD1” in Table 2) was obtained.

<Preparation of comparative cleaning blade 2>
In the production of the cleaning blade 1, the comparative cleaning blade 2 is the same as the cleaning blade 1 except that the soft segment material is changed to 1,9-ND adipate having a molecular weight of 2000 obtained from 1,9-nonanediol and adipic acid. (Denoted as “C-BLD2” in Table 2).

<Physical properties of the cleaning blade>
Endothermic peak top temperature (expressed as “endothermic PH temperature” in Table 2) by differential scanning calorimetry of urethane rubber of cleaning blade, average particle diameter of hard segment aggregates (expressed as “HS aggregate particle diameter” in Table 2) ), The particle size distribution of hard segment aggregates (indicated as “HS aggregate particle size distribution” in Table 2) was measured by the method described above.

  Further, the ratio of chemical cross-linking (CB: cross-linking with a cross-linking agent) and physical cross-linking (PB: cross-linking by hydrogen bonding between hard segments) in polyurethane rubber (indicated as “CB / PB ratio” in Table 2), polyurethane rubber The ratio between the hard segment (HS) and the soft segment (SS) (shown as “HS / SS ratio” in Table 2) was measured by the method described above.

Furthermore, the hardness (JIS-A) of the cleaning blade was measured by the following method.
The hardness (JIS-A) is a hardness measured using a type A durometer described in JIS K6253 (1997), and measured by measuring three points in the axial direction of the contact surface of the photosensitive member of the blade and calculating an average value. did.

  These physical properties are listed in Table 2.

<Examples 1-16, Comparative Examples 1-9>
The electrophotographic photosensitive member (OPC) and the cleaning blade (BLD) were mounted on the image forming apparatus “Remodeling machine for HL5340D manufactured by Brother” in a combination according to Table 3. This image forming apparatus is referred to as Examples 1 to 16 and Comparative Examples 1 to 9.

<Evaluation>
The following evaluation was performed on the image forming apparatus, electrophotographic photosensitive member, and cleaning blade of each example.

(Photosensitive sensitivity)
The sensitivity of the photoreceptor was evaluated as follows.
Using an electrostatic copying paper tester (electrostatic analyzer EPA-8100, manufactured by Kawaguchi Electric Co., Ltd.), after charging to + 800V in an environment of 20 ° C. and 40% RH, the light from the tungsten lamp was used using a monochromator. The light was adjusted to a monochromatic light of 800 nm, adjusted to 1 μW / cm ² on the surface of the photoreceptor, and irradiated.
Then, a half-exposure amount E _1/2 (μJ / cm ² ) that is half the surface potential V ₀ (V) of the surface of the photoreceptor immediately after charging was measured.
The evaluation criteria are as follows.
A: half decay exposure is 0.15μJ / cm ² or less B: half exposure amount 0.15μJ / cm ^2, greater 0.2μJ / cm ² or less: C: half-life exposure exceeds 0.2μJ / cm ² or less 0.25 μJ / cm ² or less D: Half exposure amount exceeds 0.25 μJ / cm ² or less

(Image quality durability)
Image quality durability was evaluated as follows.
With the above-mentioned remodeling machine, output 10,000 sheets of halftone image with 30% image density on A4 paper, and what percentage of the density of the 10,000th print image is compared to the density of the first print image It was measured.
The evaluation criteria are as follows.
A: The density of the 10,000th print image is 95% or more of the density of the first print image. B: The density of the 10,000th print image is less than 95% and 90% of the density of the first print image. C: The density of the 10,000th print image is less than 90% and 85% or more with respect to the density of the first print image. D: The density of the 10,000th print image is 85 with respect to the density of the first print image. %Less than

(Life of the photoconductor (indicated as “OPC life” in Table 3))
The life of the photoreceptor was evaluated as follows.
Photoreceptor film thickness was measured with an eddy current film thickness measurement device (Fischer Instruments) before and after the image quality durability test, and the film thickness reduction rate was calculated by dividing the film thickness reduction amount by the number of test cycles. . The evaluation criteria are as follows.
A: 20 nm / kcy or less B: Over 20 nm / kcy and 30 nm / kcy or less C: Over 30 nm / kcy and 40 nm / kcy or less D: Over 40 nm / kcy

(Life of the cleaning blade (indicated as “BLD life” in Table 3))
The life of the cleaning blade was evaluated as follows.
After the image quality durability test, the maximum depth of the edge missing portion on the surface side of the photosensitive member observed with a laser microscope VK-8510 manufactured by Keyence Corporation from the cross-sectional side of the cleaning blade was evaluated. Further, a sheet on which a solid image with no toner fixed was formed after the above test, and was fed between the photosensitive member and the cleaning blade, and the presence or absence of toner slipping was confirmed.
The evaluation criteria are as follows.
A: Edge missing part is 3 μm or less, and no toner slips out B: Edge missing part is more than 3 μm and no more than 5 μm, no toner slips out C: Edge missing part is over 3 μm and 5 μm or less, and toner slips out D: Edge missing part exceeds 5μm and toner slips out

  From the above results, it can be seen that in this example, the photoconductor sensitivity, image quality durability, photoconductor life and cleaning blade life were all better than those of the comparative example.

  The details of the abbreviations in Table 1 are shown below.

-Electron transport material (ETM)-
(C7H15): Exemplary compound (2-1) of electron transport material represented by general formula (2)
(C8H17): Exemplary compound (2-2) of an electron transport material represented by the general formula (2)
(C9H19): Exemplary compound (2-13) of an electron transport material represented by the general formula (2)
ETM1: Electron transport material with the following structure

-Hole Transport Material (HTM)-
(1,1 H): Example compound (1-1) of hole transport material represented by general formula (1)
(1,1 CH3): Example compound (1-2) of hole transport material represented by general formula (1)
(1,0 H): Example compound (1-21) of hole transport material represented by general formula (1)
HTM-A: N, N′-diphenyl-N, N′-bis (3-methylphenyl)-[1,1 ′] biphenyl-4,4′-diamine

-Charge generation material (CGM)-
HOGaPC (V type): Bragg angles (2θ ± 0.2 °) of X-ray diffraction spectrum using Cukα characteristic X-ray are at least 7.3 °, 16.0 °, 24.9 °, 28.0 ° V-type hydroxygallium phthalocyanine pigment having a diffraction peak at the position (maximum peak wavelength in spectral absorption spectrum in wavelength range of 600 nm to 900 nm = 820 nm, average particle size = 0.12 μm, maximum particle size = 0.2 μm , Specific surface area value = 60 m ² / g)
ClGaPC: X-ray diffraction spectrum using Cukα characteristic X-rays is diffracted at Bragg angles (2θ ± 0.2 °) of at least 7.4 °, 16.6 °, 25.5 ° and 28.3 °. Chlorogallium phthalocyanine pigment having a peak (maximum peak wavelength in spectral absorption spectrum in wavelength range of 600 nm to 900 nm = 780 nm, average particle size = 0.15 μm, maximum particle size = 0.2 μm, specific surface area value = 56 m ² / g)
・ TiOPC (Type II): titanyl phthalocyanine

DESCRIPTION OF SYMBOLS 1 Undercoat layer, 2 Photosensitive layer, 3 Protective layer, 4 Conductive substrate, 10 Electrophotographic photosensitive member, 11 Case, 20 Charging device, 30 Exposure device, 40 Developing device, 41 Developing roll, 50 Transfer device, 60 Fixing Apparatus, 70 cleaning apparatus, 71 housing, 72 cleaning blade, 73 cleaning brush, 74 lubricant, 101A process cartridge, 101 image forming apparatus

Claims (4)

At least one charge selected from a binder resin, a hydroxygallium phthalocyanine pigment, and a chlorogallium phthalocyanine pigment, comprising: a conductive substrate; and a single layer type photosensitive layer provided on the conductive substrate. The binder resin includes a generating material, a hole transport material represented by the following general formula (1), and an electron transport material represented by the following general formula (2), wherein the content of the electron transport material in the photosensitive layer is: The mass ratio of the hole transport material to the electron transport material (hole transport material / electron transport material) of the photosensitive layer is from 60/40 to 80/20. An electrophotographic photoreceptor,
Charging means for charging the surface of the electrophotographic photosensitive member;
An electrostatic latent image forming means for forming an electrostatic latent image on the surface of the charged electrophotographic photosensitive member;
Developing means for developing the electrostatic latent image formed on the surface of the electrophotographic photosensitive member with a developer containing toner to form a toner image;
Transfer means for transferring the toner image to the surface of the recording medium;
A cleaning blade for cleaning the surface of the electrophotographic photosensitive member, wherein at least a portion in contact with the electrophotographic photosensitive member contains polyurethane rubber, and an endothermic peak top temperature by differential scanning calorimetry is 180 ° C. or higher and 220 ° C. or lower. Cleaning means having a cleaning blade constituted by members having a range;
An image forming apparatus comprising:

(In General Formula (1), R ¹ , R ² , R ³ , R ⁴ , R ⁵ , and R ⁶ are each independently a hydrogen atom, a lower alkyl group, an alkoxy group, a phenoxy group, a halogen atom, or (A phenyl group optionally having a substituent selected from a lower alkyl group, a lower alkoxy group and a halogen atom. M and n each independently represents 0 or 1.)

(In the general formula (2), R ¹¹ , R ¹² , R ¹³ , R ¹⁴ , R ¹⁵ , R ¹⁶ , and R ¹⁷ are each independently a hydrogen atom, a halogen atom, an alkyl group, an alkoxy group, or an aryl group. R ¹⁸ represents a linear alkyl group having 5 to 10 carbon atoms.)   The polyurethane rubber of the cleaning blade has a hard segment and a soft segment, the average particle diameter of the hard segment aggregate is 5 μm or more and 20 μm or less, and the particle size distribution of the hard segment aggregate (standard deviation σ) The image forming apparatus according to claim 1, wherein is 2 μm or more.   The image forming apparatus according to claim 1, wherein the hole transport material represented by the general formula (1) is a hole transport material in which m and n are 1. A conductive layer and a single-layer type photosensitive layer provided on the conductive substrate, wherein the photosensitive layer is at least one selected from a binder resin, a hydroxygallium phthalocyanine pigment, and a chlorogallium phthalocyanine pigment. A charge generation material, a hole transport material represented by the following general formula (1), and an electron transport material represented by the following general formula (2), wherein the content of the electron transport material in the photosensitive layer is the binding The mass ratio of the hole transport material to the electron transport material (hole transport material / electron transport material) of the photosensitive layer is from 60/40 to 80/20 with respect to the resin. An electrophotographic photoreceptor which is:
A cleaning blade for cleaning the surface of the electrophotographic photosensitive member, wherein at least a portion in contact with the electrophotographic photosensitive member contains polyurethane rubber, and an endothermic peak top temperature by differential scanning calorimetry is 180 ° C. or higher and 220 ° C. or lower. Cleaning means having a cleaning blade constituted by members having a range;
And a process cartridge which is detachable from the image forming apparatus.

(In General Formula (1), R ¹ , R ² , R ³ , R ⁴ , R ⁵ , and R ⁶ are each independently a hydrogen atom, a lower alkyl group, an alkoxy group, a phenoxy group, a halogen atom, or (A phenyl group optionally having a substituent selected from a lower alkyl group, a lower alkoxy group and a halogen atom. M and n each independently represents 0 or 1.)

(In the general formula (2), R ¹¹ , R ¹² , R ¹³ , R ¹⁴ , R ¹⁵ , R ¹⁶ , and R ¹⁷ are each independently a hydrogen atom, a halogen atom, an alkyl group, an alkoxy group, or an aryl group. R ¹⁸ represents a linear alkyl group having 5 to 10 carbon atoms.)