JP2009198707A - Electrophotographic photoreceptor, process cartridge, and image forming apparatus - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an electrophotographic photoreceptor which prevents image defects due to leak from occurring and enables to achieve longer service life and higher image quality, and a process cartridge and an image forming apparatus equipped with the electrophotographic photoreceptor. <P>SOLUTION: The electrophotographic photoreceptor is obtained by disposing a photosensitive layer on a conductive support surface, and includes the undercoat layer of the photosensitive layer containing a complex of an accepting compound and metal oxide particles, and the outermost surface layer of the photosensitive layer containing a crosslinked product using a compound of a specific structure synthesized using guanamine or melamine and formaldehyde and a charge transport material having -OH, -NH<SB>2</SB>, -SH or -COOH. The photosensitive layer has a dynamic hardness of 20×10<SP>9</SP>to 20×10<SP>10</SP>N/m<SP>2</SP>and an elastic deformation rate of 25-70%. The process cartridge and the image forming apparatus equipped with the electrophotographic photoreceptor are also provided. <P>COPYRIGHT: (C)2009,JPO&INPIT

Description

  The present invention relates to an electrophotographic photosensitive member, a process cartridge, and an image forming apparatus.

2. Description of the Related Art Conventionally, as an electrophotographic image forming apparatus, an apparatus that sequentially performs processes such as charging, exposure, development, transfer, and cleaning using an electrophotographic photosensitive member (hereinafter sometimes referred to as “photosensitive member”) is widely known. ing. In the field of such image forming apparatuses, recently, there are increasing demands for higher image quality and longer life of the apparatus. In order to meet such demands, improvement of each member and system has been studied, and the outermost surface layer of the photosensitive layer. For preventing scratches on the surface of the photosensitive member and loss of members in contact with the photosensitive member by defining the dynamic hardness of the photosensitive member at 13.0 × 10 ⁹ N / m ² or more and 100.0 × 10 ⁹ N / m ² or less Has been proposed (see, for example, Patent Document 1).
JP 2002-318459 A

  In the photoconductor described in Patent Document 1, a photoconductor used for image writing is easily subjected to stress during charging or cleaning, and if the surface of the photoconductor is scratched or worn, it causes image defects. On the other hand, a member (for example, a charging roller or a cleaning blade) that comes into contact with the photosensitive member is also stressed, so that it is necessary to prevent the loss of such a member.

  By the way, in recent years, since the degree of freedom of paper to be transferred is widened, a method of transferring using an intermediate transfer member is actively used. However, in an image forming apparatus provided with an intermediate transfer body, foreign matter generated in the apparatus or mixed in the apparatus may be sandwiched between the intermediate transfer body and the photoconductor, which may damage the photoconductor or It is likely that a foreign object that has pierced the body reaches the conductive support. In particular, when the intermediate transfer member is harder than the electrophotographic photosensitive member, these problems are likely to occur. When such a problem occurs, a photoconductor leak (a phenomenon in which a local excessive current flows in the photoconductor) occurs, and an image quality defect such as a color point occurs in the formed image.

In recent years, a contact charging type charging device such as a charging roll has been used as a charging device for an electrophotographic apparatus instead of a non-contact type charging device such as a corona discharger. The contact-type charging device has the advantages of low ozone and low power, but when this contact-type charging device is used, a higher voltage is applied to the photoconductor than the non-contact type charging device. If this problem occurs, a leak is likely to occur.
As described above, with the long-term use of the image forming apparatus, the amount of foreign matter discharged from the apparatus (for example, from a deteriorated developing device or intermediate transfer member) or mixed in the apparatus increases. In order to achieve high quality and high image quality at a high level, it is important to prevent the above-described leakage.

  On the other hand, the method described in Patent Document 1 is intended to prevent scratches on the photoreceptor, but according to the study by the present inventors, it is not always a sufficient solution for preventing leakage. It has been found that there is no such thing, and even the photoreceptor described in Patent Document 1 needs further improvement from the viewpoint of leak prevention.

  The present invention has been made in view of the above circumstances, and can provide an electrophotographic photosensitive member that can sufficiently prevent the occurrence of image quality defects due to leakage, and that can achieve a long life and high image quality, and such an electrophotographic photosensitive member. An object of the present invention is to provide a process cartridge and an image forming apparatus that have a body and can achieve a long life and high image quality.

The above problem is solved by the following means. That is,
The invention according to claim 1
A photosensitive layer is provided on the surface of the conductive support,
The layer on the most conductive support side of the photosensitive layer is an undercoat layer containing a complex of an acceptor compound and metal oxide particles,
The outermost layer of the photosensitive layer, at least one compound represented by the following general formula _{(A), -OH, -NH 2} , -SH, charge having at least one or more substituents selected from -COOH Comprising a cross-linked product using at least one transport material,
The dynamic hardness of the photosensitive layer is 20 × 10 ⁹ N / m ² or more and 20 × 10 ¹⁰ N / m ² or less, and the elastic deformation rate of the photosensitive layer is 25% or more and 70% or less. An electrophotographic photoreceptor.

(In the general formula (A), R ¹ represents a linear or branched alkyl group having 1 to 10 carbon atoms or a substituted or unsubstituted phenyl group having 6 to 10 carbon atoms. R ^{2 to} R ⁵ each independently represent a hydrogen atom, —CH ₂ —OH, or —CH ₂ —O—R ^6. R ⁶ represents a hydrogen atom, a linear or branched group having 1 to 5 carbon atoms. Indicates a chain alkyl group.)

The invention according to claim 2
2. The electrophotographic photosensitive member according to claim 1, wherein the outermost surface layer of the photosensitive layer contains an electron accepting material.

The invention according to claim 3
The electrophotographic photosensitive member according to claim 1, wherein the outermost surface layer of the photosensitive layer contains particles.

The invention according to claim 4
The electrophotographic photosensitive member according to any one of claims 1 to 3,
Charging means for charging the electrophotographic photosensitive member, developing means for developing the electrostatic latent image formed on the electrophotographic photosensitive member with toner, and toner removal for removing toner remaining on the surface of the electrophotographic photosensitive member At least one selected from the group consisting of means.

The invention according to claim 5
The electrophotographic photosensitive member according to any one of claims 1 to 3, a charging unit for charging the electrophotographic photosensitive member, and an electrostatic latent image for forming an electrostatic latent image on the charged electrophotographic photosensitive member. An image forming apparatus comprising: an image unit; a developing unit that develops the electrostatic latent image formed on the electrophotographic photosensitive member with toner; and a transfer unit that transfers the toner image to a transfer target. It is.

The invention according to claim 6
The image forming apparatus according to claim 5, further comprising a discharging unit that discharges a residual potential on the surface of the electrophotographic photosensitive member, wherein the charging unit is a charged scorotron having two or more discharge wires. is there.

The invention according to claim 7 provides:
At the reference point of the electrophotographic photosensitive member, T ₁ (sec) is the time from the start of the discharging operation by the discharging unit according to the rotation of the electrophotographic photosensitive member until the end of the charging operation by the charging unit. When the film thickness of the outermost surface layer of the electrophotographic photosensitive member is d (mm) and the relative dielectric constant of the outermost surface layer of the photosensitive layer is ε, the following relational expression (a) is satisfied. The image forming apparatus according to claim 6.
-Relational expression (a)
120 ≦ 2.5 × 10 ³ / √T ₁ × exp (0.724 d / ε) / d ≦ 255

The invention according to claim 8 provides:
8. The image forming apparatus according to claim 7, wherein a dielectric film thickness (d / ε) of the outermost surface layer of the photosensitive layer is 0.2 μm or more and 3.5 μm or less.

The invention according to claim 9 is:
The time _{T 1} is an image forming apparatus according to claim 7 or claim 8, characterized in that less than 55mmsec 200mmsec.

According to the first aspect of the present invention, the occurrence of image quality defects due to leaks can be sufficiently prevented.
According to the invention of claim 2, the cycle characteristics of the residual potential can be stabilized, or the residual potential can be lowered.

According to the invention of claim 3, the residual potential can be lowered or the strength can be raised.
According to the invention which concerns on Claim 4, the process cartridge which can achieve lifetime improvement and image quality improvement can be provided.

According to the fifth aspect of the present invention, it is possible to provide an image forming apparatus capable of achieving a long life and high image quality.
According to the invention of claim 6, uneven charging can be reduced.

According to the seventh aspect of the present invention, the electrophotographic photosensitive member has a long life, and can suppress deterioration in charging performance and image quality due to uneven charging.
According to the invention of claim 8, image quality defects are less likely to appear.
According to the invention of claim 9, it is possible to suppress a decrease in sensitivity and blurring of an image.

(Electrophotographic photoreceptor)
The electrophotographic photoreceptor of the present invention (hereinafter sometimes referred to as “the photoreceptor of the present invention”) is provided with a photosensitive layer on the surface of a conductive support, and the layer closest to the conductive support of the photosensitive layer is the same. , A subbing layer containing a complex of an acceptor compound and metal oxide particles, wherein the outermost surface layer (the layer farthest from the conductive support) of the photosensitive layer is a compound represented by the following general formula (A) And a cross-linked product using at least one charge transport material having at least one substituent selected from —OH, —NH ₂ , —SH, and —COOH, The dynamic hardness of the photosensitive layer is 20 × 10 ⁹ N / m ² or more and 20 × 10 ¹⁰ N / m ² or less, and the elastic deformation rate of the photosensitive layer is 25% or more and 70% or less. .
In the present invention, the photosensitive layer is a general term for all layers from the undercoat layer to the outermost layer.

In the general formula (A), R ¹ represents a linear or branched alkyl group having 1 to 10 carbon atoms, or a substituted or unsubstituted phenyl group having 6 to 10 carbon atoms. R ^{2 to} R ⁵ each independently represent a hydrogen atom, —CH ₂ —OH, or —CH ₂ —O—R ⁶ . R ⁶ represents a hydrogen atom or a linear or branched alkyl group having 1 to 5 carbon atoms.

Here, “dynamic hardness” as used in the present invention is defined as follows. In other words, the dynamic hardness of the present invention means that the Belkovic indenter (triangular pyramid type, diamond indenter with an edge angle of 115 ° and a tip curvature radius of 0.1 μm or less) is perpendicular to the surface of the electrophotographic photosensitive member. The value calculated based on the following formula (1) from the indentation depth when indented with a stress of 3 mN. The value measured at 22 ° C. and 55% RH is defined as dynamic hardness in the present invention.
DH = 3.8854 × (P / D ² ) (1)
In formula (1), DH represents dynamic hardness [N / m ² ], P represents indentation load [N], and D represents indentation depth [m]. Here, the diamond indenter is attached to a micro hardness measuring device (manufactured by Shimadzu Corporation, “DUH-201”). read.

The “elastic deformation rate” as used in the present invention is defined as follows. That is, the elastic deformation rate of the present invention means that the Belkovic indenter (triangular pyramid type, diamond indenter with an edge angle of 115 ° and a tip curvature radius of 0.1 μm or less) is perpendicular to the surface of the photosensitive layer of the electrophotographic photosensitive member. From the indentation depth when the indenter was pushed in with a stress of 0.3 mN and the displacement of the indenter after releasing the stress when the indenter was again pushed back to 0 mN with a stress of 0.3 mN. The value calculated based on the following formula (2). The value measured under the conditions of 22 ° C. and 55% RH is the elastic deformation rate in the present invention.
ED = (D−M) / D × 100 (2)
In equation (2), ED represents the elastic deformation rate (%), M represents the displacement of the indenter after the stress release [m], and D represents the indentation depth [m]. Here, the diamond indenter is attached to a microhardness measuring device (“DUH-201” manufactured by Shimadzu Corporation), the indentation depth is from the displacement of the indenter, and the indentation load is from a load cell attached to the indenter. read.

Here, the elastic deformation rate will be further described with reference to the drawings. FIG. 11 is a graph showing the relationship between the indenter indentation load and the indenter displacement when the above measurement is performed. In the present invention, P _{1 in} FIG. 11 is 0.3 mN. The stress applied to the indenter is pushed into the photosensitive layer by increasing from 0 to P _1, the displacement of the indenter biting into the photosensitive layer is increased to D ₁ (graph A-B). Thereafter, by reducing the stress applied to the indenter from P ₁ to 0, the indenter is pushed back by the amount of elastic deformation of the photosensitive layer, and the displacement of the indenter is reduced from D ₁ to M ₁ (graph BC). In this case, M ₁ is meant plastic deformation amount of the photosensitive layer, from the total deformation amount D ₁ by subtracting the amount of plastic deformation M ₁ (D _{1 -M 1)} means the amount of elastic deformation of the photosensitive layer. Therefore, the elastic deformation rate of the photosensitive layer can be obtained by calculating (D ₁ −M ₁ ) / D ₁ × 100.

The photoreceptor of the present invention can sufficiently prevent the occurrence of image quality defects due to leakage, and can achieve a long life and high image quality at a high level.
The reason why the above-described effects are achieved by the present invention is presumed as follows. That is, if the surface layer of the photosensitive layer is simply hardened as in the method described in Patent Document 1 described above, when a toner carrier piece or a hard foreign material that has entered the apparatus pierces the photosensitive layer, It is considered that a crack or chipping occurs as a starting point, or a stuck foreign object is difficult to remove. For this reason, it is considered that leaks cannot be sufficiently prevented when foreign matter discharged from the apparatus increases with long-term use of the image forming apparatus.

  On the other hand, in the photoconductor of the present invention, when the hardness and elasticity of the photosensitive layer are balanced within the above range, when the foreign object is stuck while the foreign object is stuck, It is considered that the foreign matter is easily removed by the elasticity before reaching the conductive support or the vicinity thereof, and the occurrence of cracks and chips is prevented. In other words, according to the photoconductor of the present invention, even when the image forming apparatus is used for a long period of time, the occurrence factor of the leak can be sufficiently reduced, so that the occurrence of the image quality defect due to the leak can be sufficiently prevented, It is presumed that long life and high image quality were achieved at a high level.

  In addition, since the hardness and elasticity of the photosensitive layer are balanced within the above range, it is possible to prevent the photosensitive layer from being scratched and to cause a stick-slip phenomenon between the photosensitive member and the member that contacts the photosensitive member. The fact that it can be sufficiently prevented is considered to be one of the factors that can achieve a long life and high image quality at a high level.

  In addition, when applied to a color image forming apparatus, the photoconductor of the present invention can achieve a long life and high image quality compared to the prior art for the following reasons. That is, when a color image is formed on a recording medium, it is preferable to use an intermediate transfer member. However, when a conductive foreign substance penetrates into the photosensitive member and a leak occurs, a color point sequence in which point defects of each color are continuous. Defects may be formed on the recording medium. On the other hand, according to the electrophotographic photosensitive member of the present invention, even if an intermediate transfer member is used, it is possible to sufficiently prevent foreign matter from entering the photosensitive member and scratching the photosensitive member. In the color image forming apparatus, it is possible to sufficiently prevent the color point continuous defect from being formed on the recording medium.

The dynamic hardness of the photosensitive layer is 20 × 10 ⁹ N / m ² or more and 20 × 10 ¹⁰ N / m ² or less, and 20 × 10 ⁹ N / m ² or more and 15 × 10 ¹⁰ N / m ² or less. Is preferably 25 × 10 ⁹ N / m ² or more and 75 × 10 ⁹ N / m ² or less, more preferably 25 × 10 ⁹ N / m ² or more and 45 × 10 ⁹ N / m ² or less. Further preferred. When the dynamic hardness is less than 20 × 10 ⁹ N / m ² , the conductive foreign matter is likely to pierce the photosensitive layer, and the pierced conductive foreign matter easily reaches the conductive support, resulting in image quality due to pinhole leak. The occurrence of defects cannot be sufficiently prevented over a long period of time. On the other hand, when the dynamic hardness exceeds 150 × 10 ⁹ N / m ² , it is considered that when a foreign object pierces the photosensitive layer, cracks and chips are likely to occur from that point. It is not possible to sufficiently prevent the occurrence of this over a long period of time.

  The elastic deformation rate of the photosensitive layer is 25% or more and 70% or less, and preferably 25% or more and 45% or less. When the elastic deformation rate is less than 25%, the photosensitive layer is likely to be scratched or cracked by a toner carrier piece or a hard foreign matter that has entered the apparatus, and the conductive foreign matter pierces the photosensitive layer. It is considered that cracks and chips generated from the origin cause leakage, and image quality defects due to leakage cannot be sufficiently prevented over a long period of time. On the other hand, if the elastic deformation rate is 70% or more, it is considered that stick-slip phenomenon is likely to occur between the photosensitive member and the member that contacts the photosensitive member (particularly, the cleaning blade and the intermediate transfer member). Image quality defects such as these occur and sufficient image quality cannot be achieved.

The photoreceptor of the present invention can be obtained, for example, by appropriately selecting the composition and thickness of each layer constituting the photosensitive layer described later so that the photosensitive layer satisfies the dynamic hardness and elastic deformation rate conditions. .
In the present invention, the photosensitive layer has a protective layer (outermost surface layer) and an undercoat layer from the viewpoint of achieving long life and high image quality more reliably and easily, and the composition of these layers and It is particularly preferable to form a photosensitive layer satisfying the above conditions by controlling the layer thickness.

Hereinafter, preferred embodiments of the present invention will be described in detail with reference to the accompanying drawings. In the description of the drawings, the same or corresponding elements are denoted by the same reference numerals, and redundant description is omitted.
(Electrophotographic photoreceptor)
FIG. 1 is a schematic cross-sectional view showing a preferred embodiment of the electrophotographic photosensitive member of the present invention. An electrophotographic photosensitive member 1 shown in FIG. 1 includes a conductive support 2 and a photosensitive layer 3. The photosensitive layer 3 has a structure in which an undercoat layer 4, a charge generation layer 5, a charge transport layer 6 and a protective layer 7 are laminated in this order on a conductive support 2.
2 and 3 are schematic sectional views showing other preferred embodiments of the electrophotographic photosensitive member of the present invention. The electrophotographic photosensitive member shown in FIG. 2 includes the photosensitive layer 3 in which the functions are separated into the charge generation layer 5 and the charge transport layer 6 in the same manner as the electrophotographic photosensitive member shown in FIG. In FIG. 3, the charge generation material and the charge transport material are contained in the same layer (single-layer type photosensitive layer 8).

The electrophotographic photoreceptor 1 shown in FIG. 2 has a structure in which an undercoat layer 4, a charge transport layer 6, a charge generation layer 5, and a protective layer 7 are sequentially laminated on a conductive support 2.
In addition, the electrophotographic photoreceptor 1 shown in FIG. 3 has a structure in which an undercoat layer 4, a single-layer type photosensitive layer 8, and a protective layer 7 are sequentially laminated on a conductive support 2.

As described above, the photosensitive layer provided in the photoreceptor of the present invention is a single-layer type photosensitive layer containing a charge generation material and a charge transport material in the same layer, or a layer containing a charge generation material (charge generation layer). And a functional separation type photosensitive layer in which a layer containing a charge transport material (charge transport layer) is separately provided. In the case of the function-separated type photosensitive layer, any of the stacking order of the charge generation layer and the charge transport layer may be the upper layer. In the case of a function-separated photosensitive layer, it is possible to achieve functional separation because it is possible to perform functional separation in which each layer only has to satisfy each function.
Hereinafter, each element will be described based on the electrophotographic photosensitive member 1 shown in FIG. 1 as a representative example.

-Conductive support-
Examples of the conductive support 2 include a metal plate, a metal drum, and a metal belt formed using a metal or an alloy such as aluminum, copper, zinc, stainless steel, chromium, nickel, molybdenum, vanadium, indium, gold, or platinum. Etc. Further, as the conductive support 2, paper, plastic film, belt or the like coated, vapor-deposited or laminated with a conductive polymer, a conductive compound such as indium oxide, or a metal or alloy such as aluminum, palladium, or gold can be used. Here, “conductive” means that the volume resistivity is less than 10 ¹³ Ωcm. In the present invention, the volume resistivity is a volume resistivity at 20 ° C.

  The surface of the conductive support 2 is preferably roughened to a centerline average roughness Ra of 0.04 μm or more and 0.5 μm or less in order to prevent interference fringes generated when laser light is irradiated. If Ra on the surface of the conductive support 2 is less than 0.04 μm, the effect of preventing interference tends to be insufficient because it is close to a mirror surface. On the other hand, if Ra exceeds 0.5 μm, the image quality tends to be insufficient even if a film is formed. When non-interfering light is used as a light source, it is not particularly necessary to roughen the interference fringes, and it is possible to prevent the occurrence of defects due to irregularities on the surface of the conductive support 2, which is suitable for longer life.

Surface roughening methods include wet honing by suspending the abrasive in water and spraying it on the support, or centerless grinding and anodic oxidation in which the support is pressed against a rotating grindstone and continuously ground. Treatment etc. are preferred.
Further, as another roughening method, a conductive or semiconductive powder is dispersed in a resin without roughening the surface of the conductive support 2 to form a layer on the surface of the support. Further, a method of roughening with particles dispersed in the layer is also preferably used.

  The anodizing treatment is to form an oxide film on the aluminum surface by anodizing in an electrolyte solution using aluminum as an anode. Examples of the electrolyte solution include a sulfuric acid solution and an oxalic acid solution. However, the intact porous anodic oxide film is chemically active, easily contaminated, and has a large resistance fluctuation due to the environment. Therefore, the pores of the anodic oxide film are sealed with pressurized water vapor or boiling water (a metal salt such as nickel may be added) by volume expansion due to a hydration reaction, and a sealing process is performed to change to a more stable hydrated oxide. It is preferable.

  The thickness of the anodized film is preferably 0.3 μm or more and 15 μm or less. When this film thickness is less than 0.3 μm, the barrier property against implantation tends to be poor and the effect tends to be insufficient. On the other hand, when it exceeds 15 μm, there is a tendency that the residual potential increases due to repeated use.

  Further, the conductive support 2 may be subjected to treatment with an acidic aqueous solution or boehmite treatment. The treatment with an acidic treatment liquid comprising phosphoric acid, chromic acid and hydrofluoric acid is carried out as follows. First, an acidic treatment liquid is prepared. The mixing ratio of phosphoric acid, chromic acid and hydrofluoric acid in the acidic treatment liquid is such that phosphoric acid is in the range of 10% by mass to 11% by mass, chromic acid is in the range of 3% by mass to 5% by mass, and hydrofluoric acid is 0.5%. The concentration of these acids is preferably in the range of 13.5% by mass to 18% by mass. The treatment temperature is preferably 42 ° C. or more and 48 ° C. or less. However, by keeping the treatment temperature high, a thicker film can be formed faster. The film thickness is preferably from 0.3 μm to 15 μm. If it is less than 0.3 μm, the barrier property against injection tends to be poor and the effect tends to be insufficient. On the other hand, when it exceeds 15 μm, there is a tendency that the residual potential increases due to repeated use.

  The boehmite treatment can be performed by immersing in pure water at 90 ° C. or more and 100 ° C. or less for 5 minutes or more and 60 minutes or less, or by contacting with heated steam at 90 ° C. or more and 120 ° C. or less for 5 minutes or more and 60 minutes or less. . 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 4 is formed on the conductive support 2. The undercoat layer 4 prevents the injection of charges from the conductive support 2 to the photosensitive layer 3 when the photosensitive layer 3 having a laminated structure is charged, and the photosensitive layer 3 with respect to the conductive support 2. It has an action as an adhesive layer that can be integrally bonded and held. Moreover, the undercoat layer 4 can show the antireflection effect of the light of the electroconductive support body 2, etc. depending on the case. In particular, when using a support subjected to acidic solution treatment or boehmite treatment, it is preferable to form an undercoat layer because the defect concealing power of the support tends to be insufficient.
Furthermore, since the electrophotographic photosensitive member according to the present invention includes an undercoat layer, it is easy to control the elastic deformation rate of the photosensitive layer and while suppressing an increase in residual potential during repeated use. Leak prevention can be further improved.

In the present invention, the undercoat layer 4 includes a composite of an acceptor compound and metal oxide particles.
As the acceptor compound contained in the complex, any compound can be used as long as the desired properties can be obtained, but a compound having a quinone group is particularly preferably used. Furthermore, an acceptor compound having an anthraquinone structure is preferably used. Examples of the compound having an anthraquinone structure include hydroxyanthraquinone compounds, aminoanthraquinone compounds, aminohydroxyanthraquinone compounds, and the like in addition to anthraquinone, and any of them can be preferably used. More specifically, anthraquinone, alizarin, quinizarin, anthralfin, pullpurin and the like are particularly preferably used.

The metal oxide particles contained in the composite are preferably those having a powder resistance (volume resistivity) of about 10 ² Ω · cm to 10 ¹¹ Ω · cm. As a result, the undercoat layer 4 can obtain an appropriate resistance for obtaining leak resistance. If the resistance value of the metal oxide particles is lower than the lower limit of the above range, sufficient leakage resistance may be difficult to obtain. On the other hand, if the resistance value is higher than the upper limit of the range, the residual potential may be easily increased.

In the present invention, it is preferable to use metal oxide particles such as tin oxide, titanium oxide, zinc oxide and zirconium oxide having the above resistance values. In particular, zinc oxide is preferably used. Further, two or more kinds of metal oxide particles having different surface treatments or different particle diameters can be used in combination.
As the metal oxide particles, those having a specific surface area of 10 m ² / g or more are preferably used. Those having a specific surface area value of 10 m ² / g or less tend to cause a decrease in chargeability and tend to make it difficult to obtain good electrophotographic characteristics.

  As a method of obtaining a complex of an acceptor compound and metal oxide particles, for example, while stirring metal oxide particles with a mixer having a large shearing force, an acceptor compound dissolved in an organic solvent is dropped, dried air or A method of uniformly applying the acceptor compound to the metal oxide particles by spraying with nitrogen gas is mentioned. When the acceptor compound is added or sprayed, it is preferably carried out at a temperature below the boiling point of the solvent, and if sprayed at a temperature above the boiling point of the solvent, the solvent evaporates before stirring uniformly, and the acceptor compound is localized. In some cases, it is difficult to achieve uniform processing. After addition or spraying, drying can be performed at a temperature higher than the boiling point of the solvent. Further, the metal oxide particles are stirred in a solvent, dispersed using ultrasonic waves, a sand mill, an attritor, a ball mill, etc., and an organic solvent solution of an acceptor compound is added and stirred or dispersed below the boiling point of the organic solvent. Then, it is uniformly applied by removing the solvent. Moreover, the solvent removal method is distilled off by filtration, distillation, or heat drying.

  The amount of the acceptor compound applied can be arbitrarily set as long as the desired characteristics are obtained, but preferably 0.01% by mass or more and 20% by mass or less with respect to the metal oxide particles. More preferably, 0.05 mass% or more and 10 mass% or less are provided with respect to a metal oxide particle. If the amount of the acceptor compound applied is less than 0.01% by mass, sufficient acceptor property that contributes to the improvement of charge accumulation in the undercoat layer 4 cannot be imparted. May be difficult to obtain. Moreover, when it exceeds 20 mass%, it is easy to cause aggregation of metal oxides, and it becomes difficult to form a good conductive path in the undercoat layer 4 when the undercoat layer 4 is formed. Not only is it likely to deteriorate sustainability such as an increase in residual potential, but it may also cause image quality defects such as black spots.

  Further, the metal oxide particles can be subjected to a surface treatment before the acceptor compound is applied. Any surface treatment agent may be used as long as it has desired characteristics, and can be selected from known materials. For example, a silane coupling agent, a titanate coupling agent, an aluminum coupling agent, a surfactant, and the like can be given. In particular, silane coupling agents are preferably used because they give good electrophotographic characteristics. Further, a silane coupling agent having an amino group is preferably used because it gives a good blocking property to the undercoat layer 4.

  Any silane coupling agent having an amino group can be used as long as it can obtain desired electrophotographic photoreceptor characteristics. Specific examples include γ-aminopropyltriethoxysilane, N-β-. (Aminoethyl) -γ-aminopropyltrimethoxysilane, N-β- (aminoethyl) -γ-aminopropylmethylmethoxysilane, N, N-bis (β-hydroxyethyl) -γ-aminopropyltriethoxysilane, etc. However, it is not limited to these.

  Moreover, 2 or more types of silane coupling agents can also be mixed and used. Examples of the silane coupling agent that can be used in combination with the above-mentioned silane coupling agent having an amino group include vinyltrimethoxysilane, γ-methacryloxypropyl-tris (β-methoxyethoxy) silane, β- (3, 4-epoxycyclohexyl) ethyltrimethoxysilane, γ-glycidoxypropyltrimethoxysilane, vinyltriacetoxysilane, γ-mercaptopropyltrimethoxysilane, γ-aminopropyltriethoxysilane, N-β- (aminoethyl)- γ-aminopropyltrimethoxysilane, N-β- (aminoethyl) -γ-aminopropylmethylmethoxysilane, N, N-bis (β-hydroxyethyl) -γ-aminopropyltriethoxysilane, γ-chloropropyltri Examples include methoxysilane, etc. The present invention is not limited to.

As the surface treatment method, any known method can be used, but a dry method or a wet method can be used.
When surface treatment is performed by a dry method, a silane coupling agent dissolved directly or in an organic solvent is added dropwise and sprayed with dry air or nitrogen gas while stirring the metal oxide particles with a mixer having a large shearing force. Can be processed uniformly. The addition or spraying is preferably carried out at a temperature below the boiling point of the solvent. Spraying at a temperature equal to or higher than the boiling point of the solvent is not preferred because it causes the solvent to evaporate before being stirred uniformly, causing the silane coupling agent to locally accumulate and making uniform processing difficult. After addition or spraying, baking can be performed at 100 ° C. or higher. Baking can be carried out in an arbitrary range as long as the temperature and time allow the desired electrophotographic characteristics to be obtained.

  As a wet method, metal oxide particles are stirred in a solvent, dispersed using ultrasonic waves, a sand mill, an attritor, a ball mill, etc., added with a silane coupling agent solution and stirred or dispersed, and then the solvent is removed. Uniformly processed. The solvent removal method is distilled off by filtration or distillation. After removing the solvent, baking can be performed at 100 ° C. or higher. Baking can be carried out in an arbitrary range as long as the temperature and time allow the desired electrophotographic characteristics to be obtained. In the wet method, the water containing metal oxide particles can be removed before adding the surface treatment agent. For example, a method of removing with stirring and heating in the solvent used for the surface treatment, removing by azeotroping with the solvent. It is also possible to use a method of

  The amount of the silane coupling agent relative to the metal oxide particles in the undercoat layer 4 can be arbitrarily set as long as desired electrophotographic characteristics can be obtained.

  As the binder resin contained in the undercoat layer 4, any known resin can be used as long as it can form a good film and can obtain desired characteristics. For example, acetal such as polyvinyl butyral can be used. Resin, polyvinyl alcohol resin, casein, polyamide resin, cellulose resin, gelatin, polyurethane resin, polyester resin, methacrylic resin, acrylic resin, polyvinyl chloride resin, polyvinyl acetate resin, vinyl chloride-vinyl acetate-maleic anhydride resin, silicone resin , Using known polymer resin compounds such as silicone-alkyd resin, phenol resin, phenol-formaldehyde resin, melamine resin, urethane resin, charge transport resin having a charge transport group, or conductive resin such as polyaniline, etc. CanAmong them, a resin insoluble in the upper coating solvent is preferably used, and in particular, a butyral resin, a phenol resin, a phenol-formaldehyde resin, a melamine resin, a urethane resin, an epoxy resin, and the like are preferably used.

  In the present invention, the complex of the acceptor compound and the metal oxide particles includes a metal oxide particle, an acceptor compound having a group capable of reacting and binding to the metal oxide particle (hereinafter referred to as “reactive functional group”). It may also be referred to as an “acceptor compound having a group”.

  Any acceptor compound having a reactive functional group may be used as long as it has a group capable of reacting with metal oxide particles capable of obtaining desired characteristics, but a compound having a hydroxyl group is particularly preferably used. . Furthermore, an acceptor compound having an anthraquinone structure having a hydroxyl group is preferably used. Examples of the compound having an anthraquinone structure having a hydroxyl group include a hydroxyanthraquinone compound and an aminohydroxyanthraquinone compound, and any of them can be preferably used. More specifically, alizarin, quinizarin, anthralfin, purpurin, 1-hydroxyanthraquinone, 2-amino-3-hydroxyanthraquinone, 1-amino-4-hydroxyanthraquinone and the like are particularly preferably used.

  As the metal oxide particles, the same metal oxide particles as those used in the above composite are used. Further, the metal oxide particles can be subjected to a surface treatment, and the surface treatment agent and the surface treatment method can be the same as described above.

  The acceptor compound having a reactive functional group is preferably 0.01% by mass to 20% by mass with respect to the metal oxide particles, more preferably 0.05% by mass to 10% by mass. Thus, it is blended in the undercoat layer 4.

In the present invention, by setting the thickness of the undercoat layer 4 to be large, even if the elastic deformation rate of the photosensitive layer is in the range described above, it is possible to sufficiently prevent an increase in residual potential due to repeated use. It can prevent more reliably that a conductive foreign material reaches a conductive support body, suppressing sufficiently. Thereby, a higher level of image quality can be achieved.
From the viewpoint of obtaining the above-described effect more reliably, the thickness of the undercoat layer 4 is preferably 15 μm or more and 50 μm or less, and more preferably 17 μm or more and 30 μm or less.

  The undercoat layer 4 can be formed using an undercoat layer forming coating solution obtained by dispersing each component constituting the above undercoat layer in a solvent. In the coating solution for forming the undercoat layer, the blending ratio of the composite and the binder resin, or the acceptor compound having a reactive functional group and the metal oxide particles and the binder resin is the desired electrophotographic photoreceptor characteristics. Can be set arbitrarily within the range that can be obtained.

  Various additives can be used in the coating liquid for forming the undercoat layer in order to improve electrical characteristics, environmental stability, and image quality. As additives, quinone compounds such as chloranil and bromoanil, tetracyanoquinodimethane compounds, fluorenone compounds such as 2,4,7-trinitrofluorenone, 2,4,5,7-tetranitro-9-fluorenone, 2- (4-biphenyl) -5- (4-t-butylphenyl) -1,3,4-oxadiazole, 2,5-bis (4-naphthyl) -1,3,4-oxadiazole, Oxadiazole compounds such as 2,5-bis (4-diethylaminophenyl) -1,3,4-oxadiazole, xanthone compounds, thiophene compounds, 3,3 ′, 5,5′-tetra-t- Electron transporting substances such as diphenoquinone compounds such as butyldiphenoquinone, polycyclic condensation systems, azo-based electron transporting pigments, zirconium chelate compounds, titanium chelates Compounds, aluminum chelate compounds, titanium alkoxide compounds, organic titanium compounds, there can be used a known material such as a silane coupling agent.

  The silane coupling agent is used for the surface treatment of the metal oxide particles, but it can also be used as an additive added to the coating solution. Specific examples of the silane coupling agent used here include vinyltrimethoxysilane, γ-methacryloxypropyl-tris (β-methoxyethoxy) silane, β- (3,4-epoxycyclohexyl) ethyltrimethoxysilane, γ- Glycidoxypropyltrimethoxysilane, vinyltriacetoxysilane, γ-mercaptopropyltrimethoxysilane, γ-aminopropyltriethoxysilane, N-β- (aminoethyl) -γ-aminopropyltrimethoxysilane, N-β- (Aminoethyl) -γ-aminopropylmethylmethoxysilane, N, N-bis (β-hydroxyethyl) -γ-aminopropyltriethoxysilane, γ-chloropropyltrimethoxysilane and the like.

  Examples of zirconium chelate compounds 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 titanium chelate compounds include tetraisopropyl titanate, tetranormal butyl titanate, butyl titanate dimer, tetra (2-ethylhexyl) titanate, titanium acetylacetonate, polytitanium acetylacetonate, titanium octylene glycolate, 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 compounds can be used alone or as a mixture or polycondensate of a plurality of compounds.

  Solvents for preparing the coating solution for forming the undercoat layer include known organic solvents such as alcohols, aromatics, halogenated hydrocarbons, ketones, ketone alcohols, ethers, esters, etc. It can be selected arbitrarily. More specifically, for example, methanol, ethanol, n-propanol, iso-propanol, n-butanol, benzyl alcohol, methyl cellosolve, ethyl cellosolve, acetone, methyl ethyl ketone, cyclohexanone, methyl acetate, ethyl acetate, n-acetate Usual organic solvents such as butyl, dioxane, tetrahydrofuran, methylene chloride, chloroform, chlorobenzene, and toluene can be used. These solvents can be used alone or in combination of two or more. When two or more types are mixed and used, any combination can be used as long as the solvent can dissolve the binder resin as a mixed solvent.

  As a dispersion method, it can be dispersed by a method using a known disperser such as a roll mill, a ball mill, a vibrating ball mill, an attritor, a sand mill, a colloid mill, and a paint shaker.

  As a method for applying the coating solution for forming the undercoat layer, a normal method such as 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, or a curtain coating method is used. be able to.

  The undercoat layer is formed by drying the applied layer, but drying may be performed at a temperature at which the solvent can be evaporated to form a film.

  The undercoat layer 4 can be set to any thickness as long as a predetermined dynamic hardness and elastic deformation rate can be obtained, but the thickness is preferably 15 μm or more, more preferably 15 μm or more. 50 μm or less. If the thickness of the undercoat layer is less than 15 μm, sufficient leakage resistance may be difficult to obtain, and if it exceeds 50 μm, residual potential tends to remain during long-term use, and thus tends to cause abnormal image density. It is in.

  Further, the surface roughness of the undercoat layer 4 is preferably adjusted to ¼n (n is the refractive index of the upper layer) or more and ½λ or less of the exposure laser wavelength λ used to prevent moire images. . In order to adjust the surface roughness, particles such as a resin can be added to the undercoat layer. As the resin particles, silicone resin particles, cross-linked PMMA (polymethyl methacrylate) resin particles, and the like can be used.

  Also, the undercoat layer can be polished to adjust the surface roughness. As a polishing method, buffing, sand blasting, wet honing, grinding, or the like can be used.

-Charge generation layer-
The charge generation layer 5 includes a charge generation material or includes a charge generation material and a binder resin.
Examples of the charge generating material include azo pigments such as bisazo and trisazo, condensed aromatic pigments such as dibromoanthanthrone, perylene pigments, pyrrolopyrrole pigments, phthalocyanine pigments, zinc oxide, and trigonal selenium. Among these, for near-infrared laser exposure, metal and metal-free phthalocyanine pigments are preferable. In particular, hydroxygallium phthalocyanine disclosed in JP-A-5-263007, JP-A-5-279591, and the like. Chlorogallium phthalocyanine disclosed in JP-A-5-98181, dichlorotin phthalocyanine disclosed in JP-A-5-140472, JP-A-5-140473, etc., JP-A-4-189873, More preferred is titanyl phthalocyanine disclosed in Kaihei 5-43823. For near-ultraviolet laser exposure, condensed ring aromatic pigments such as dibromoanthanthrone, thioindigo pigments, porphyrazine compounds, zinc oxide, trigonal selenium and the like are more preferable.

  The binder resin used for the charge generation layer 5 can be selected from a wide range of insulating resins. It can also be selected from organic photoconductive polymers such as poly-N-vinylcarbazole, polyvinylanthracene, polyvinylpyrene, and polysilane. Preferred binder resins include polyvinyl butyral resins, polyarylate resins (polycondensates of bisphenols and aromatic divalent carboxylic acids, etc.), polycarbonate resins, polyester resins, phenoxy resins, vinyl chloride-vinyl acetate copolymers, polyamides. Resins, acrylic resins, polyacrylamide resins, polyvinyl pyridine resins, cellulose resins, urethane resins, epoxy resins, caseins, polyvinyl alcohol resins, polyvinyl pyrrolidone resins, and the like. These binder resins can be used alone or in combination of two or more. The mixing ratio of the charge generation material and the binder resin is preferably in the range of 10: 1 to 1:10 by mass ratio.

  The charge generation layer 5 can be formed using a coating solution in which a charge generation material and a binder resin are dispersed in a predetermined solvent. Solvents used for dispersion include methanol, ethanol, n-propanol, n-butanol, benzyl alcohol, methyl cellosolve, ethyl cellosolve, acetone, methyl ethyl ketone, cyclohexanone, methyl acetate, n-butyl acetate, dioxane, tetrahydrofuran, and methylene chloride. , Chloroform, chlorobenzene, toluene and the like, and these can be used alone or in admixture of two or more.

  Moreover, as a method for dispersing the charge generating material and the binder resin in the solvent, a usual method such as a ball mill dispersion method, an attritor dispersion method, a sand mill dispersion method, or the like can be used. By these dispersion methods, it is possible to prevent a change in the crystal form of the charge generation material due to the dispersion. Further, at the time of this dispersion, it is effective that the average particle size of the charge generating material is 0.5 μm or less, preferably 0.3 μm or less, more preferably 0.15 μm or less.

When forming the charge generation layer 5, a usual method such as a blade coating method, a Meyer bar coating method, a spray coating method, a dip coating method, a bead coating method, an air knife coating method, a curtain coating method, or the like can be used. .
The thickness of the charge generation layer 5 thus obtained is preferably 0.1 μm or more and 5 μm or less, more preferably 0.2 μm or more and 2.0 μm or less.

-Charge transport layer-
The charge transport layer 6 includes a charge transport material and a binder resin, or a polymer charge transport material.
Examples of charge transport materials include quinone compounds such as p-benzoquinone, chloranil, bromanyl, anthraquinone, tetracyanoquinodimethane compounds, fluorenone compounds such as 2,4,7-trinitrofluorenone, xanthone compounds, benzophenone compounds Electron transporting compounds such as cyanovinyl compounds and ethylene compounds, triarylamine compounds, benzidine compounds, arylalkane compounds, aryl-substituted ethylene compounds, stilbene compounds, anthracene compounds, hydrazone compounds, etc. Examples thereof include pore-transporting compounds. These charge transport materials can be used alone or in combination of two or more.

  A polymer charge transport material can also be used as the charge transport material. As the polymer charge transporting material, known materials having charge transporting properties such as poly-N-vinylcarbazole and polysilane can be used. In particular, polyester polymer charge transport materials disclosed in JP-A-8-176293, JP-A-8-208820 and the like have a high charge transporting property and are particularly preferable. The polymer charge transport material can be formed by itself, but may be formed by mixing with a binder resin described later.

  As the charge transport material, a compound represented by the following general formula (a-1), (a-2) or (a-3) is preferable from the viewpoint of mobility.

In the above formula (a-1), R ³⁴ represents a hydrogen atom or a methyl group, and k10 represents 1 or 2. Ar ⁶ and Ar ⁷ are each independently a substituted or unsubstituted aryl group, —C ₆ H ₄ —C (R ³⁸ ) ═C (R ³⁹ ) (R ⁴⁰ ), or —C ₆ H ₄ —. CH = CH—CH═C (Ar) ₂ represents a substituent, substituted with a halogen atom, an alkyl group having 1 to 5 carbon atoms, an alkoxy group having 1 to 5 carbon atoms, or an alkyl group having 1 to 3 carbon atoms. Substituted amino groups. R ³⁸ , R ³⁹ and R ⁴⁰ are a hydrogen atom, a substituted or unsubstituted alkyl group, a substituted or unsubstituted aryl group, and Ar is a substituted or unsubstituted aryl group.

In the above formula (a-2), R ³⁵ and R ³⁵ ′ each independently represents a hydrogen atom, a halogen atom, an alkyl group having 1 to 5 carbon atoms or an alkoxy group having 1 to 5 carbon atoms, R ³⁶ , R ³⁶ ′. R ³⁷ and R ³⁷ ′ are each independently a halogen atom, an alkyl group having 1 to 5 carbon atoms, an alkoxy group having 1 to 5 carbon atoms, an amino group substituted with an alkyl group having 1 to 2 carbon atoms, A substituted aryl group, —C (R ³⁸ ) ═C (R ³⁹ ) (R ⁴⁰ ), or —CH═CH—CH═C (Ar) ₂ , R ³⁸ , R ³⁹ and R ⁴⁰ are each independently A hydrogen atom, a substituted or unsubstituted alkyl group, or a substituted or unsubstituted aryl group, Ar represents a substituted or unsubstituted aryl group. M4 and m5 each independently represents an integer of 0 to 2.

Here, in the formula (a-3), R ⁴¹ represents a hydrogen atom, an alkyl group having 1 to 5 carbon atoms, an alkoxy group having 1 to 5 carbon atoms, a substituted or unsubstituted aryl group, or —CH═CH. -CH = C (Ar) ₂ is shown. Ar represents a substituted or unsubstituted aryl group. R ⁴² , R ⁴² ′, R ⁴³ , and R ⁴³ ′ are each independently a hydrogen atom, a halogen atom, an alkyl group having 1 to 5 carbon atoms, an alkoxy group having 1 to 5 carbon atoms, or an alkyl having 1 to 2 carbon atoms. An amino group substituted with a group, or a substituted or unsubstituted aryl group is shown.

  The binder resin used for the charge transport layer 6 is 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-vinyl carbazole, polysilane, etc. are mentioned. Also, as described above, polymer charge transport materials such as polyester polymer charge transport materials disclosed in JP-A-8-176293 and JP-A-8-208820 can be used. These binder resins can be used alone or in combination of two or more. The compounding ratio of the charge transport material and the binder resin is preferably 10: 1 to 1: 5 by mass ratio.

  The charge transport layer 6 can be formed using a charge transport layer forming solution coating solution in which a charge transport material and a binder resin are dispersed in a predetermined 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. Ordinary organic solvents such as cyclic or straight chain ethers such as ether can be used alone or in admixture of two or more.

  As a coating method of the charge transport layer forming solution coating solution, a normal method such as a blade coating method, a Mayer bar coating method, a spray coating method, a dip coating method, a bead coating method, an air knife coating method, or a curtain coating method should be used. Can do.

  The thickness of the charge transport layer 6 is preferably 5 μm or more and 50 μm or less, more preferably 10 μm or more and 30 μm or less.

-Protective layer-
The protective layer 7 is at least a charge transport material having at least one compound represented by the following general formula (A) and at least one substituent selected from —OH, —NH ₂ , —SH, and —COOH. It is comprised including the crosslinked material using 1 type.

In the general formula (A), R ¹ represents a linear or branched alkyl group having 1 to 10 carbon atoms, or a substituted or unsubstituted phenyl group having 6 to 10 carbon atoms. R ^{2 to} R ⁵ each independently represent a hydrogen atom, —CH ₂ —OH, or —CH ₂ —O—R ⁶ . R ⁶ represents a hydrogen atom or a linear or branched alkyl group having 1 to 5 carbon atoms.

In general formula (A), R ¹ is a linear or branched alkyl group having 1 to 10 carbon atoms, a substituted or unsubstituted phenyl group having 6 to 10 carbon atoms, or 4 to 10 carbon atoms. The following substituted or unsubstituted alicyclic hydrocarbon groups are shown. R ^{2 to} R ⁵ each independently represent a hydrogen atom, —CH ₂ —OH, or —CH ₂ —O—R ⁶ . R ⁶ represents a hydrogen atom or a linear or branched alkyl group having 1 to 10 carbon atoms.

In the general formula (A), the alkyl group represented by R ¹ has 1 to 10 carbon atoms, preferably 1 to 8 carbon atoms, more preferably 1 to 5 carbon atoms. is there. The alkyl group may be linear or branched.

In general formula (A), the phenyl group represented by R ¹ has 6 to 10 carbon atoms, more preferably 6 to 8 carbon atoms. Examples of the substituent substituted with the phenyl group include a methyl group, an ethyl group, and a propyl group.

In general formula (A), the alicyclic hydrocarbon group represented by R ¹ has 4 to 10 carbon atoms, and more preferably 5 to 8 carbon atoms. Examples of the substituent substituted with the alicyclic hydrocarbon group include a methyl group, an ethyl group, and a propyl group.

In the general formula (A), in “—CH ₂ —O—R ⁶ ” represented by R ^{2 to} R ⁵ , the alkyl group represented by R ⁶ has 1 to 10 carbon atoms, Carbon number is 1 or less and 8 or more, More preferably, carbon number is 1 or more and 6 or less. The alkyl group may be linear or branched.

As the compound represented by the general formula (A), particularly preferably, R ¹ represents a substituted or unsubstituted phenyl group having 6 to 10 carbon atoms, and R ^{2 to} R ⁵ are each independently —CH ₂ —O. It is a compound represented by —R ₆ . R ⁶ is preferably selected from a methyl group and an n-butyl group.

  The compound represented by the general formula (A) can be synthesized by a known method using guanamine or melamine and formaldehyde (for example, Experimental Chemistry Course 4th Edition, Volume 28, page 430).

  Hereinafter, as specific examples of the compound represented by the general formula (A), exemplary compounds (A) -1 to (A) -22 are shown, but are not limited thereto. Moreover, although the following specific examples show the thing of a monomer, the multimer (oligomer) which uses these as a structural unit may be sufficient. Furthermore, the following specific examples may be used alone or in combination, but are more preferable because solubility can be improved by mixing or using as an oligomer. In the following specific examples, “Me” represents a methyl group, “Et” represents an ethyl group, and “Bu” represents a butyl group.

In addition, Super Becamine (R) L-148-55, Super Becamine (R) 13-535, Super Becamine (R) L-145-60, Super Becamine (R) TD-126 (Dainippon Ink Co., Ltd.) Manufactured), Nicarak BL-60, Nicarac BX-4000 (manufactured by Nippon Carbide Co., Ltd.), etc., can be used as they are.
Furthermore, in order to remove the influence of the residual catalyst, it may be dissolved in an appropriate solvent such as toluene, xylene, ethyl acetate and washed with distilled water, ion exchange water, or removed by treatment with ion exchange resin. May be.

Next, a charge transport material having at least one substituent selected from —OH, —NH ₂ , —SH, and —COOH (hereinafter sometimes referred to as “specific charge transport material”) will be described.
The specific charge transporting material is preferably a compound represented by the following general formula (I).
^{_{F - ((- R 7 -X}} ) n1 R 8 -Y) n2 (I)

In general formula (I), F is an organic group derived from a compound having a hole transporting ability, R ⁷ and R ⁸ are each independently a linear or branched alkylene group having 1 to 5 carbon atoms. N1 represents 0 or 1, and n2 represents an integer of 1 or more and 4 or less. X represents an oxygen, NH, or sulfur atom, and Y represents —OH, —NH ₂ , —SH, or —COOH.

  In general formula (I), an arylamine derivative is preferably used as the compound having a hole transporting ability in an organic group derived from a compound having a hole transporting ability represented by F. Preferred examples of the arylamine derivative include a triphenylamine derivative and a tetraphenylbenzidine derivative.

  And it is preferable that the compound shown by general formula (I) is a compound shown by the following general formula (II). The compound represented by the general formula (II) is particularly excellent in charge mobility, stability against oxidation and the like.

In general formula (II), Ar ^{1 to} Ar ⁴ may be the same or different and each independently represents a substituted or unsubstituted aryl group, and Ar ⁵ represents a substituted or unsubstituted aryl group or a substituted or unsubstituted group. D represents — (— R ⁷ —X) _n1 R ⁸ —Y, c represents 0 or 1 independently, k represents 0 or 1, and the total number of D is 1 or more and 4 It is as follows. R ⁷ and R ⁸ each independently represents a linear or branched alkylene group having 1 to 5 carbon atoms, n1 represents 0 or 1, X represents an oxygen, NH, or sulfur atom. , Y represents —OH, —NH ₂ , —SH, or —COOH.

In the general formula (II), “— (— R ₇ —X) _n1 R ⁸ —Y” represented by D is the same as in the general formula (I), and R ⁷ and R ⁸ each independently has 1 carbon atom. It is a linear or branched alkylene group having 5 or less. N1 is preferably 1. X is preferably oxygen. Y is preferably a hydroxyl group. In addition, the total number of D in General formula (II) is equivalent to n2 in General formula (I), Preferably it is 2-4, More preferably, it is 3-4. That is, in the general formula (I) and the general formula (II), when the molecular weight is preferably 2 or more and 4 or less, more preferably 3 or more and 4 or less in one molecule, the crosslinking density increases and a crosslinked film with higher strength can be obtained. .
In general formula (II), Ar _{1 to} Ar ₄ are preferably any of the following formulas (1) to (7). Incidentally, the following equation (1) to (7) can be coupled to each _Ar 1 to Ar ₄ - together with _{"(D) C".}

In the formulas (1) to (7), R ⁹ is phenyl substituted with a hydrogen atom, an alkyl group having 1 to 4 carbon atoms, an alkyl group having 1 to 4 carbon atoms, or an alkoxy group having 1 to 4 carbon atoms. Represents one selected from the group consisting of a group, an unsubstituted phenyl group, and an aralkyl group having 7 to 10 carbon atoms, wherein R ^{10 to} R ¹² are a hydrogen atom, an alkyl group having 1 to 4 carbon atoms, and a carbon number, respectively. One selected from the group consisting of an alkoxy group having 1 to 4 carbon atoms, a phenyl group substituted with an alkoxy group having 1 to 4 carbon atoms, an unsubstituted phenyl group, an aralkyl group having 7 to 10 carbon atoms, and a halogen atom Ar represents a substituted or unsubstituted arylene group, D and c are the same as “D” and “c” in formula (II), s represents 0 or 1, and t is 1 or more, respectively. An integer less than or equal to 3 The ]

  Here, as Ar in Formula (7), what is represented by following formula (8) or (9) is preferable.

[In formulas (8) and (9), R ¹³ and R ¹⁴ are each a hydrogen atom, an alkyl group having 1 to 4 carbon atoms, an alkoxy group having 1 to 4 carbon atoms, or an alkoxy group having 1 to 4 carbon atoms. 1 represents one selected from the group consisting of a phenyl group substituted with, an unsubstituted phenyl group, an aralkyl group having 7 to 10 carbon atoms and a halogen atom, and t represents an integer of 1 to 3. ]

  Moreover, as Z 'in Formula (7), what is represented by either of following formula (10)-(17) is preferable.

[In the formulas (10) to (17), R ¹⁵ and R ¹⁶ are each a hydrogen atom, an alkyl group having 1 to 4 carbon atoms, an alkoxy group having 1 to 4 carbon atoms, or an alkoxy group having 1 to 4 carbon atoms. Represents a phenyl group substituted with, an unsubstituted phenyl group, an aralkyl group having 7 to 10 carbon atoms, and a halogen atom, W represents a divalent group, q and r each represent Represents an integer of 1 to 10, and t represents an integer of 1 to 3. ]

  W in the above formulas (16) to (17) is preferably any one of divalent groups represented by the following (18) to (26). However, in formula (25), u represents an integer of 0 or more and 3 or less.

In general formula (II), Ar ⁵ is an aryl group exemplified in the description of Ar ^{1 to} Ar ⁴ when k is 0, and when k is 1, a predetermined hydrogen atom is taken from the aryl group. Excluded arylene group

  Specific examples of the compound represented by the general formula (I) include the following exemplary compounds (I-1) to (I-25). In addition, the compound shown by the said general formula (I) is not limited at all by these.

As a ratio of the compound represented by the general formula (A) and the specific charge transporting material, from the viewpoint of electrical characteristics and strength, a specific charge is used with respect to 1 part by mass of the compound represented by the general formula (A). The transport material is preferably 0.2 parts by mass or more and 4 parts by mass or less, more preferably 0.3 parts by mass or more and 3 parts by mass or less, and further preferably 0.4 parts by mass or more and 2 parts by mass or less. is there.
In the photoreceptor of the present invention, it is preferable that the protective layer 7 contains an electron-accepting material from the viewpoint of improvement of electric characteristics, particularly high residual potential and residual potential cycle stability. As the electron-accepting material, any material can be used as long as it has desired characteristics. However, quinone compounds such as chloranil and bromoanil, tetracyanoquinodimethane compounds, 2,4,7-trinitro Fluorenone, fluorenone compounds such as 2,4,5,7-tetranitro-9-fluorenone, 2- (4-biphenyl) -5- (4-t-butylphenyl) -1,3,4-oxadiazole and 2 , 5-bis (4-naphthyl) -1,3,4-oxadiazole, oxadiazole compounds such as 2,5-bis (4-diethylaminophenyl) 1,3,4 oxadiazole, xanthone compounds , Thiophene compounds, electron transporting materials such as diphenoquinone compounds such as 3,3 ′, 5,5 ′ tetra-t-butyldiphenoquinone, etc. are preferred. Compounds having Torakinon structure is preferred. Furthermore, acceptor compounds having an anthraquinone structure such as hydroxyanthraquinone compounds, aminoanthraquinone compounds, aminohydroxyanthraquinone compounds, and the like are preferably used, and specific examples include anthraquinone, alizarin, quinizarin, anthralfin, and purpurin.

  The content of the electron-accepting material in the protective layer 7 is preferably 0.005 parts by mass or more and 4 parts by mass or less with respect to 1 part by mass of the compound represented by the general formula (I). The part or less is most preferable. When the content of the electron-accepting material in the protective layer 7 exceeds 5% by mass, image quality defects may occur, and when it is less than 0.01% by mass, a high residual potential may be obtained.

  In the photoreceptor of the present invention, the protective layer 7 preferably contains at least one kind of phenol resin or melamine resin. Since the abrasion resistance of the surface of the photosensitive layer can be improved by containing at least one of the phenol resin or the melamine resin, the conductive foreign matter can reach the conductive support by reducing the film thickness by long-term use. It is possible to more reliably prevent it from being easily reached. Furthermore, since both the mechanical strength and the electrical characteristics of the photosensitive layer are enhanced, higher image quality and longer life can be achieved at a higher level.

  For the purpose of adjusting the film formability, flexibility, lubricity, and adhesiveness of the film, the protective layer 7 may be mixed with another coupling agent or a fluorine compound. As this compound, various silane coupling agents and commercially available silicone hard coat agents are used.

  Examples of the silane coupling agent include vinyltrichlorosilane, vinyltrimethoxysilane, vinyltriethoxysilane, γ-glycidoxypropylmethyldiethoxysilane, γ-glycidoxypropyltrimethoxysilane, and γ-glycidoxypropyltri Methoxysilane, γ-aminopropyltriethoxysilane, γ-aminopropyltrimethoxysilane, γ-aminopropylmethyldimethoxysilane, N-β (aminoethyl) γ-aminopropyltriethoxysilane, tetramethoxysilane, methyltrimethoxysilane , Dimethyldimethoxysilane, and the like can be used. As a commercially available hard coat agent, KP-85, X-40-9740, X-8239 (manufactured by Shin-Etsu Silicone), AY42-440, AY42-441, AY49-208 (manufactured by Toray Dow Corning) Etc. can be used. In order to impart water repellency and the like, (tridecafluoro-1,1,2,2-tetrahydrooctyl) triethoxysilane, (3,3,3-trifluoropropyl) trimethoxysilane, 3- (hepta) Fluoroisopropoxy) propyltriethoxysilane, 1H, 1H, 2H, 2H-perfluoroalkyltriethoxysilane, 1H, 1H, 2H, 2H-perfluorodecyltriethoxysilane, 1H, 1H, 2H, 2H-perfluorooctyl Fluorine-containing compounds such as triethoxysilane may be added. The silane coupling agent can be used in any amount, but the amount of the fluorine-containing compound is preferably 0.25 times or less by mass with respect to the compound not containing fluorine. If this amount is exceeded, there may be a problem with the film formability of the crosslinked film.

Also, a resin that dissolves in alcohol can be added for the purpose of discharge gas resistance, mechanical strength, scratch resistance, particle dispersibility, viscosity control, torque reduction, wear amount control, pot life extension, and the like of the protective layer 7.
Examples of resins soluble in alcohol solvents include polyvinyl butyral resins, polyvinyl formal resins, and polyvinyl acetal resins such as partially acetalized polyvinyl acetal resins in which a part of butyral is modified with formal or acetoacetal (for example, manufactured by Sekisui Chemical Co., Ltd.) ESREC B, K, etc.), polyamide resin, cellulose resin, polyvinylphenol resin and the like. In particular, polyvinyl acetal resin and polyvinyl phenol resin are preferable in terms of electrical characteristics. The weight average molecular weight of the resin is preferably from 2,000 to 100,000, and more preferably from 5,000 to 50,000. If the weight average molecular weight of the resin is less than 2,000, the effect due to the addition of the resin tends to be insufficient, and if it exceeds 100,000, the solubility decreases and the addition amount is limited. It tends to cause film formation defects. The amount of the resin added is preferably 1% by mass or more and 40% by mass or less, more preferably 1% by mass or more and 30% by mass or less, and still more preferably 5% by mass or more and 20% by mass or less with respect to the solid content. If the addition amount of the resin is less than 1% by mass, the effect due to the addition of the resin tends to be insufficient, and if it exceeds 40% by mass, image blurring under high temperature and high humidity tends to occur.

  Preparation of the coating solution for the surface layer containing these components is carried out in the absence of a solvent or, if necessary, alcohols such as methanol, ethanol, propanol, butanol; ethylene glycol monomethyl ether, 1-methoxy-2-propanol And the like; ketones such as acetone, methyl ethyl ketone, 3-hydroxy-3-methyl-2-butanone; ethers such as tetrahydrofuran, diethyl ether, and dioxane. Such solvents can be used singly or in combination of two or more, but preferably have a boiling point of 100 ° C. or lower. The amount of the solvent can be arbitrarily set, but if it is too small, the compound represented by the general formula (A) or the general formula (I) is likely to be precipitated. It is used in an amount of 0.5 to 30 parts by mass, preferably 1 to 20 parts by mass.

  Further, when the coating liquid is obtained by reacting the above components, it may be simply mixed and dissolved, but it is room temperature to 100 ° C., preferably 30 ° C. to 80 ° C., 10 minutes to 100 hours, preferably 1 You may heat for 50 hours or less more than time. In this case, it is also preferable to irradiate ultrasonic waves. Thereby, a partial reaction probably proceeds, the uniformity of the coating liquid is increased, and a uniform film without coating film defects is easily obtained.

  It is preferable to add a deterioration preventing agent to the protective layer 7 for the purpose of preventing deterioration due to an oxidizing gas such as ozone generated in the charging device. When the mechanical strength of the surface of the photoconductor is increased and the photoconductor has a long life, the photoconductor is in contact with the oxidizing gas for a long time, and therefore, stronger oxidation resistance is required than before. As the deterioration inhibitor, hindered phenols or hindered amines are preferable, organic sulfur antioxidants, phosphite antioxidants, dithiocarbamate antioxidants, thiourea antioxidants, benzimidazole antioxidants. , Etc., may be used. The addition amount of the deterioration inhibitor is preferably 20% by mass or less, and more preferably 10% by mass or less.

Examples of the hindered phenol antioxidant include “Irganox 1076”, “Irganox 1010”, “Irganox 1098”, “Irganox 245”, “Irganox 1330”, “Irganox 3114”, “Irganox 1076”. And “3,5-di-tert-butyl-4-hydroxybiphenyl”.
As the hindered amine antioxidant, “Sanol LS2626”, “Sanol LS765”, “Sanol LS770”, “Sanol LS744”, “Tinuvin 144”, “Tinuvin 622LD”, “Mark LA57”, “Mark LA67”, “Mark” LA62 "," Mark LA68 ", and" Mark LA63 "are listed," Sumizer-TPS "and" Smilizer TP-D "are listed as thioethers, and" Mark 2112 "and" Mark PEP-8 "are listed as phosphites. , “Mark PEP-24G”, “Mark PEP-36”, “Mark 329K”, “Mark HP-10”, and the like.

Further, particles may be added to the protective layer 7 in order to lower the residual potential. Examples of the particles include conductive particles (particles having a volume resistance of 10 or more and 10 ⁷ or less), and particles such as organic and inorganic particles described later. Examples of the conductive particles include metals, metal oxides, and carbon black, but metals or metal oxides are more preferable. Examples of the metal include aluminum, zinc, copper, chromium, nickel, silver and stainless steel, or those obtained by depositing these metals on the surface of plastic particles. Examples of the metal oxide include zinc oxide, titanium oxide, tin oxide, antimony oxide, indium oxide, bismuth oxide, indium oxide doped with tin, tin oxide doped with antimony and tantalum, and zirconium oxide doped with antimony. .
These conductive particles can be used alone or in combination of two or more. When two or more types are used in combination, they may be simply mixed, or may be in the form of a solid solution or fusion.

The volume average particle diameter of these conductive particles is preferably 0.3 μm or less, particularly preferably 0.1 μm or less, from the viewpoint of the transparency of the protective layer 7.
The content of the conductive particles in the protective layer 7 is preferably 0.05% by mass or more and 15% by mass or less based on the total solid content of the protective layer 7 in terms of film forming properties, electrical characteristics, and image quality characteristics, preferably Is used in the range of 0.3 mass% to 10 mass%.

  Further, in order to lower the residual potential or increase the strength, particles such as organic and inorganic particles may be added to the protective layer 7 in addition to the conductive particles. An example of the particles may include silicon-containing particles. The silicon-containing particles are particles containing silicon as a constituent element, and specific examples include colloidal silica and silicone particles. The colloidal silica used as the silicon-containing particles is obtained by dispersing silica having an average particle diameter of 1 nm or more and 100 nm or less, preferably 10 nm or more and 30 nm or less in an acidic or alkaline aqueous dispersion or an organic solvent such as alcohol, ketone, or ester. A commercially available product can be used. The solid content of colloidal silica in the protective layer 7 is not particularly limited, but 0.1% based on the total solid content of the protective layer 7 in terms of film forming properties, electrical characteristics, and strength. It is used in the range of from mass% to 50 mass%, preferably from 0.1 mass% to 30 mass%.

  The silicone particles used as the silicon-containing particles are selected from silicone resin particles, silicone rubber particles, and silicone surface-treated silica particles, and commercially available particles can be used. These silicone particles are spherical, and the average particle diameter is preferably 1 nm to 500 nm, more preferably 10 nm to 100 nm. Silicone particles are small particles that are chemically inert and excellent in dispersibility in resins, and since the content required to obtain more sufficient properties is low, the crosslinking reaction is not hindered. The surface properties of the photographic photoreceptor can be improved. In other words, it improves the lubricity and water repellency of the surface of the electrophotographic photosensitive member while being uniformly incorporated in a strong cross-linked structure, and maintains good wear resistance and contamination resistance adhesion over a long period of time. Can do. The content of the silicone particles in the protective layer 7 is preferably 0.1% by mass or more and 30% by mass or less, more preferably 0.5% by mass or more and 10% by mass or less, based on the total solid content of the protective layer 7. It is.

Other particles include fluorine-based particles such as ethylene tetrafluoride, ethylene trifluoride, propylene hexafluoride, vinyl fluoride, and vinylidene fluoride, and “8th Polymer Material Forum Lecture Proceedings p89”. Particles made of a resin obtained by copolymerizing a fluororesin and a monomer having a hydroxyl group, ZnO—Al ₂ O ₃ , SnO ₂ —Sb ₂ O ₃ , In ₂ O ₃ —SnO ₂ , ZnO ₂ —TiO ₂ , Examples thereof include semiconductive metal oxides such as ZnO—TiO ₂ , MgO—Al ₂ O ₃ , FeO—TiO ₂ , TiO ₂ , SnO ₂ , In ₂ O ₃ , ZnO, and MgO.

  For the same purpose, an oil such as silicone oil can be added. Silicone oils include silicone oils such as dimethylpolysiloxane, diphenylpolysiloxane, and phenylmethylsiloxane; amino-modified polysiloxane, epoxy-modified polysiloxane, carboxyl-modified polysiloxane, carbinol-modified polysiloxane, methacryl-modified polysiloxane, mercapto-modified poly Reactive silicone oils such as siloxane and phenol-modified polysiloxane; cyclic dimethylcyclosiloxanes such as hexamethylcyclotrisiloxane, octamethylcyclotetrasiloxane, decamethylcyclopentasiloxane and dodecamethylcyclohexasiloxane; 1,3,5- Trimethyl-1.3.5-triphenylcyclotrisiloxane, 1,3,5,7-tetramethyl-1,3,5,7-tetraphenylcyclo Cyclic methylphenylcyclosiloxanes such as trasiloxane, 1,3,5,7,9-pentamethyl-1,3,5,7,9-pentaphenylcyclopentasiloxane; cyclic phenylcyclosiloxanes such as hexaphenylcyclotrisiloxane Fluorine-containing cyclosiloxanes such as 3- (3,3,3-trifluoropropyl) methylcyclotrisiloxane; Hydrosilyl group-containing cyclosiloxanes such as methylhydrosiloxane mixture, pentamethylcyclopentasiloxane, and phenylhydrocyclosiloxane And vinyl group-containing cyclosiloxanes such as pentavinylpentamethylcyclopentasiloxane.

  In the protective layer 7, a catalyst can be used to accelerate the curing of the compound represented by the general formula (A) and the specific charge transport material, and an acid-based catalyst can be preferably used as the curing catalyst. Acid-based catalysts include acetic acid, chloroacetic acid, trichloroacetic acid, trifluoroacetic acid, oxalic acid, maleic acid, malonic acid, lactic acid and other aliphatic carboxylic acids, benzoic acid, phthalic acid, terephthalic acid, trimellitic acid, etc. Aromatic carboxylic acids, methane sulfonic acids, dodecyl sulfonic acids, benzene sulfonic acids, aliphatics such as dodecyl benzene sulfonic acids, naphthalene sulfonic acids, and aromatic sulfonic acids are used, but sulfur-containing materials should be used. preferable.

  When the protective layer 7 uses a sulfur-containing material as a curing catalyst, the sulfur-containing material exhibits an excellent function as a curing catalyst for the compound represented by the general formula (A) or a specific charge transport material, and a curing reaction. It is possible to further improve the mechanical strength of the protective layer obtained by sufficiently promoting the above. In addition, when the compound represented by the general formula (I) is further included, the sulfur-containing material exhibits an excellent function as a dopant for these charge transport materials, and further improves the electrical characteristics of the obtained functional layer. be able to. As a result, when the electrophotographic photosensitive member of the present invention is formed, this catalyst that can achieve all of mechanical strength, film formability and electrical properties at high levels also exhibits acidity at room temperature or after heating. The organic sulfonic acid and / or its derivative are most preferable from the viewpoint of adhesiveness, ghost, and electrical properties. The presence of these catalysts in the protective layer can be easily confirmed by XPS or the like.

  Examples of the organic sulfonic acid and / or a derivative thereof include p-toluenesulfonic acid, dinonylnaphthalenesulfonic acid (DNNSA), dinonylnaphthalenedisulfonic acid (DNNDSA), dodecylbenzenesulfonic acid, and phenolsulfonic acid. Among these, paratoluenesulfonic acid and dodecylbenzenesulfonic acid are preferable from the viewpoint of catalytic ability and film formability. Moreover, an organic sulfonate can also be used if it can dissociate to some extent in a curable resin composition.

  In addition, by using a so-called thermal latent catalyst that increases the catalytic ability when a temperature above a certain level is applied, the catalytic ability is low at the liquid storage temperature and the catalytic ability is high at the time of curing. And storage stability can be achieved.

  As a heat latent catalyst, for example, a microcapsule in which an organic sulfone compound or the like is encapsulated in a polymer form, an adsorbed acid or the like on a pore compound such as zeolite, and a proton acid and / or proton acid derivative is blocked with a base Thermal latent proton acid catalyst, proton acid and / or proton acid derivative esterified with primary or secondary alcohol, proton acid and / or proton acid derivative blocked with vinyl ethers and / or vinyl thioethers , Boron trifluoride monoethylamine complex, boron trifluoride pyridine complex, and the like.

  Among them, those obtained by blocking the protonic acid and / or the protonic acid derivative with a base in terms of catalytic ability, storage stability, availability, and cost are preferable.

  As the protonic acid of the thermal latent protonic acid catalyst, sulfuric acid, hydrochloric acid, acetic acid, sulfuric acid, formic acid, nitric acid, phosphoric acid, sulfonic acid, monocarboxylic acid, polycarboxylic acids, propionic acid, oxalic acid, benzoic acid, acrylic acid, methacrylic acid Acid, itaconic acid, phthalic acid, maleic acid, benzenesulfonic acid, o, m, p-toluenesulfonic acid, styrenesulfonic acid, dinonylnaphthalenesulfonic acid, dinonylnaphthalenedisulfonic acid, decylbenzenesulfonic acid, undecylbenzenesulfone Examples include acids, tridecylbenzenesulfonic acid, tetradecylbenzenesulfonic acid, dodecylbenzenesulfonic acid, and the like. In addition, as protonic acid derivatives, neutralized products such as alkali metal salts of alkaline acids or alkaline earth metal circles such as sulfonic acid and phosphoric acid, and polymer compounds in which a protonic acid skeleton is introduced into the polymer chain (polyvinylsulfone) Acid, etc.). Examples of the base that blocks the protonic acid include amines.

  The amines are classified as primary, secondary or tertiary amines. There is no restriction | limiting in particular, In this invention, all can be used.

  Primary amines include methylamine, ethylamine, propylamine, isopropylamine, n-butylamine, isobutylamine, t-butylamine, hexylamine, 2-ethylhexylamine, 2-ethylhexylamine, secondary butylamine, allylamine, methylhexylamine, etc. Can be mentioned.

  As secondary amines, dimethylamine, diethylamine, di-n-propylamine, diisopropylamine, di-n-butylamine, diisobutylamine, di-t-butylamine, dihexylamine, di (2-ethylhexyl) amine, N-isopropyl N-isobutylamine , Di (2-ethylhexyl) amine, disecondary butylamine, diallylamine, N-methylhexylamine, 3-pipecoline, 4-pipecoline, 2,4-lupetidine, 2,6-lupetidine, 3,5-lupetidine, morpholine, N -Methylbenzylamine and the like.

  As tertiary amines, trimethylamine, triethylamine, tri-n-propylamine, triisopropylamine, tri-n-butylamine, triisobutylamine, tri-t-butylamine, trihexylamine, tri (2-ethylhexyl) amine, N-methylmorpholine, N, N-dimethylallylamine, N-methyldiallylamine, triallylamine, N, N-dimethylallylamine, N, N, N ′, N′-tetramethyl-1,2-diaminoethane, N, N, N ′, N′-tetramethyl-1,3 -Diaminopropane, N, N, N ', N'-tetraallyl-1,4-diaminobutane, N-methylpiperidine, pyridine, 4-ethylpyridine, N-propyldiallylamine, 3-dimethylaminopropanol, 2-ethylpyrazine, 2,3-di Tylpyrazine, 2,5-dimethylpyrazine, 2,4 lutidine, 2,5 lutidine, 3,4 lutidine, 3,5 lutidine, 2,4,6-collidine, 2-methyl-4-ethylpyridine, 2-methyl-5-ethylpyridine, N, N, N ', N'-tetramethylhexamethylenediamine, N-ethyl-3-hydroxypiperidine, 3-methyl-4-ethylpyridine, 3-ethyl-4-methylpyridine, 4- (5-nonyl) pyridine, imidazole, N-methylpiperazine and the like can be mentioned.

Commercially available products include “NACURE2501” (toluenesulfonic acid dissociation, methanol / isopropanol solvent, pH 6.0 to 7.2, dissociation temperature 80 ° C.) manufactured by King Industries, Ltd., and “NACURE2107” (p-toluenesulfonic acid dissociation, isopropanol). Solvent, pH 8.0-9.0, dissociation temperature 90 ° C.), “NACURE 2500” (p-toluenesulfonic acid dissociation, isopropanol solvent, pH 6.0-7.0, dissociation temperature 65 ° C.), “NACURE 2530” (p- Toluenesulfonic acid dissociation, methanol / isopropanol solvent, pH 5.7 to 6.5, dissociation temperature 65 ° C.), “NACURE2547” (p-toluenesulfonic acid dissociation, aqueous solution, pH 8.0 to 9.0, dissociation temperature 107 ° C.) "NACURE2558" (p-toluenesulfo Acid dissociation, ethylene / glycol solvent, pH 3.5-4.5, dissociation temperature 80 ° C., “NACUREXP-357” (p-toluenesulfonic acid dissociation, methanol solvent, pH 2.0-4.0, dissociation temperature 65 ° C. ), “NACUREXP-386” (p-toluenesulfonic acid dissociation, aqueous solution, pH 6.1-6.4, dissociation temperature 80 ° C.), “NACUREXC-2211” (p-toluenesulfonic acid dissociation, pH 7.2-8. 5, dissociation temperature 80 ° C), "NACURE 5225" (dodecylbenzenesulfonic acid dissociation, isopropanol solvent, pH 6.0-7.0, dissociation temperature 120 ° C), "NACURE5414" (dodecylbenzenesulfonic acid dissociation, xylene solvent, dissociation temperature) 120 ° C.), “NACURE 5528” (dodecylbenzenesulfonic acid dissociation, isopropyl Nord solvent, pH 7.0-8.0, dissociation temperature 120 ° C., “NACURE 5925” (dodecylbenzenesulfonic acid dissociation, pH 7.0-7.5, dissociation temperature 130 ° C.), “NACURE 1323” (dinonylnaphthalene sulfonic acid) Dissociation, xylene solvent, pH 6.8-7.5, dissociation temperature 150 ° C., “NACURE1419” (dinonylnaphthalenesulfonic acid dissociation, xylene / methylisobutylketone solvent, dissociation temperature 150 ° C.), “NACURE1557” (dinonylnaphthalene) Sulfonic acid dissociation, butanol / 2-butoxyethanol solvent, pH 6.5-7.5, dissociation temperature 150 ° C., “NACUREX 49-110” (dinonylnaphthalenedisulfonic acid dissociation, isobutanol / isopropanol solvent, pH 6.5-7 .5, dissociation temperature 90 ° C.), “NACURE 3525” (dinonyl naphthalene disulfonic acid dissociation, isobutanol / isopropanol solvent, pH 7.0 to 8.5, dissociation temperature 120 ° C.), “NACUREXP-383” (dinonyl naphthalene disulfonic acid dissociation, xylene solvent, dissociation temperature 120 ° C), "NACURE3327" (dinonylnaphthalenedisulfonic acid dissociation, isobutanol / isopropanol solvent, pH 6.5-7.5, dissociation temperature 150 ° C), "NACURE4167" (phosphoric acid dissociation, isopropanol / isobutanol solvent, pH 6. 8 to 7.3, dissociation temperature 80 ° C., “NACUREXP-297” (phosphate dissociation, water / isopropanol solvent, pH 6.5 to 7.5, dissociation temperature 90 ° C., “NACURE 4575” (phosphate dissociation, pH 7. 0-8.0, dissociation temperature 1 0 ℃), and the like.
These heat latent catalysts can be used alone or in combination of two or more.

  The blending amount of the heat latent catalyst is preferably 0.01% by mass or more and 20% by mass or less, and particularly preferably 0.1% by mass or more and 10% by mass or less with respect to 100 parts by mass of the solid content in the resin solution. ing. If the addition amount exceeds 20% by mass, it may precipitate as a foreign substance after the calcination treatment, and if it is 0.01% by mass or less, the catalytic activity will be low.

  The content of the charge generating material in the single-layer type photosensitive layer (charge generation / charge transport layer) 8 is about 10% by mass to 85% by mass, preferably 20% by mass to 50% by mass. The content of the charge transport material is preferably 5% by mass or more and 50% by mass or less. The method for forming the single-layer type photosensitive layer (charge generation / charge transport layer) 6 is the same as the method for forming the charge generation layer 3 and the charge transport layer 4. The film thickness of the single-layer type photosensitive layer (charge generation / charge transport layer) 6 is preferably about 5 μm to 50 μm, more preferably 10 μm to 40 μm.

  Further, since the protective layer 7 formed from the above-mentioned coating solution for forming a protective layer has excellent mechanical strength and sufficient photoelectric properties, it can be used as it is as a charge transport layer of a multilayer photoreceptor. it can.

  When the single-layer type photosensitive layer 8 is configured as in the electrophotographic photosensitive member shown in FIG. 3, the single-layer type photosensitive layer 8 is formed containing a charge generation material, a charge transport material, and a binder resin. As these components, those similar to those exemplified in the description of the charge generation layer 5 and the charge transport layer 6 can be used. The content of the charge generating material in the single layer type photosensitive layer 8 is preferably 10% by mass or more and 85% by mass or less, more preferably 20% by mass or more and 50% by mass or less, based on the total solid content in the single layer type photosensitive layer. It is. The content of the charge transport material in the single-layer type photosensitive layer 6 is preferably 5% by mass or more and 50% by mass or less. A charge transport material or a polymer charge transport material may be added to the single-layer type photosensitive layer for the purpose of improving photoelectric characteristics. The addition amount is preferably 5% by mass or more and 50% by mass or less based on the total solid content in the single-layer type photosensitive layer. Moreover, the solvent and coating method used for coating can be the same as those for the above layers. The film thickness of the single-layer type photosensitive layer is preferably about 5 μm to 50 μm, and more preferably 10 μm to 40 μm.

In the present invention, a protective layer is not necessarily provided on the photosensitive layer as long as the photosensitive layer satisfies the dynamic hardness and elastic deformation rate. Specifically, for example, in the electrophotographic photosensitive member of FIG. 1, the charge transport layer 6 is selected from at least one compound represented by the general formula (A) and —OH, —NH ₂ , —SH, —COOH. In the case of including a cross-linked product using at least one kind of charge transport material having at least one substituent, the protective layer 7 can be omitted. That is, the photosensitive layer can have a configuration of undercoat layer / charge generation layer / charge transport layer.

  The photosensitive layer 3 can contain at least one electron accepting substance for the purpose of improving sensitivity, reducing residual potential, reducing fatigue during repeated use, and the like.

Examples of the electron acceptor include succinic anhydride, maleic anhydride, dibromomaleic anhydride, phthalic anhydride, tetrabromophthalic anhydride, tetracyanoethylene, tetracyanoquinodimethane, o-dinitrobenzene, m-dinitrobenzene, Examples include chloranil, dinitroanthraquinone, trinitrofluorenone, picric acid, o-nitrobenzoic acid, p-nitrobenzoic acid, and phthalic acid. Of these, fluorenone-based, quinone-based, and benzene derivatives having an electron-withdrawing substituent such as Cl, CN, NO ₂ are particularly preferable.

  The photosensitive layer 3 may be added with an antioxidant, a light stabilizer, a heat stabilizer, etc. for the purpose of preventing deterioration of the photoreceptor due to ozone, oxidizing gas, or light or heat generated in the image forming apparatus. An agent can be added.

  Examples of the antioxidant include hindered phenol, hindered amine, paraphenylenediamine, arylalkane, hydroquinone, spirochroman, spiroidanone and derivatives thereof, organic sulfur compounds, and organic phosphorus compounds. Examples of the light stabilizer include derivatives such as benzophenone, benzotriazole, dithiocarbamate, and tetramethylpiperidine.

  Furthermore, if the protective layer 7 which is the outermost layer of the electrophotographic photosensitive member 1 is treated with an aqueous dispersion containing a fluorine-based resin, torque required for rotation of the electrophotographic photosensitive member can be reduced and transfer efficiency can be improved. preferable.

(Image forming apparatus and process cartridge)
The image forming apparatus of the present invention comprises the above-described electrophotographic photosensitive member of the present invention, a charging means for charging the electrophotographic photosensitive member, and an electrostatic latent image for forming an electrostatic latent image on the charged electrophotographic photosensitive member. Means, developing means for developing the electrostatic latent image formed on the electrophotographic photosensitive member with toner, and transfer means for transferring the toner image to the transfer target.
The process cartridge of the present invention develops the above-described electrophotographic photosensitive member of the present invention, charging means for charging the electrophotographic photosensitive member, and an electrostatic latent image formed on the electrophotographic photosensitive member with toner. And at least one selected from the group consisting of developing means and toner removing means for removing toner remaining on the surface of the electrophotographic photosensitive member. The image forming apparatus and process cartridge of the present invention will be described below with reference to the drawings.

  FIG. 4 is a schematic configuration diagram showing a preferred embodiment of the image forming apparatus of the present invention. An image forming apparatus 100 shown in FIG. 4 includes, in an image forming apparatus main body (not shown), a process cartridge 20 including the electrophotographic photosensitive member 1, an exposure device (electrostatic latent image means) 30, and a transfer device (transfer means). ) 40 and an intermediate transfer member 50. In the image forming apparatus 100, the exposure device 30 is disposed at a position where the electrophotographic photosensitive member 1 can be exposed from the opening of the process cartridge 20, and the transfer device 40 is interposed between the electrophotographic photosensitive member via the intermediate transfer member 50. The intermediate transfer member 50 is disposed so that a part of the intermediate transfer member 50 is in contact with the electrophotographic photosensitive member 1.

  The process cartridge 20 is a case in which a charging device (charging means) 21, a developing device (developing means) 25, and a cleaning device 27 are combined with an electrophotographic photosensitive member 1 by a mounting rail. The case is provided with an opening for exposure.

  As the charging device 21, for example, a contact charger using a conductive or semiconductive charging roller, a charging brush, a charging film, a charging rubber blade, a charging tube or the like can be used. Further, a non-contact type roller charger using a charging roller in the vicinity of the photoreceptor 1, a known charger such as a scorotron charger using a corona discharge or a corotron charger can be used.

  As the developing device 25, for example, a general developing device that performs development by bringing a magnetic or non-magnetic one-component developer or two-component developer into contact or non-contact with each other can be used. Such a developing device is not particularly limited as long as it has the functions described above, and can be appropriately selected according to the purpose. For example, a known developing device having a function of attaching the one-component developer or the two-component developer to the photosensitive member 1 using a brush, a roller, or the like can be used.

Next, the toner used in the developing device 25 (the present invention) will be described.
The toner used in the present invention preferably has an average shape factor SF1 of 100 or more and 150 or less, more preferably 105 or more and 145 or less, and more preferably 110 or more, from the viewpoint of obtaining high developability and transferability and high image quality. More preferably, it is 140 or less.
Here, the shape factor SF1 is obtained by the following equation.
SF1 = (ML ² / A) × (π / 4) × 100
In the above formula, ML represents the absolute maximum length of the toner particles, and A represents the projected area of the toner particles.

  Furthermore, the toner used in the present invention preferably has a volume average particle diameter of 3 μm or more and 12 μm or less, more preferably 3.5 μm or more and 10 μm or less, and further preferably 4 μm or more and 9 μm or less. By using a toner satisfying such an average shape factor and volume average particle diameter, developability and transferability are improved, and a high-quality image called so-called photographic image quality can be obtained.

  The method for producing the toner used in the present invention is not particularly limited. For example, kneading, pulverizing, and classifying by adding a binder resin, a colorant and a release agent, and a charge control agent as necessary. Grinding method; Method of changing the shape of particles obtained by kneading and grinding method by mechanical impact force or thermal energy; Emulsion polymerization of a polymerizable monomer of a binder resin, and formation of a dispersion and coloring An emulsion polymerization aggregation method in which a toner particle is obtained by mixing an agent, a release agent, and, if necessary, a dispersion of a charge control agent, and agglomerating and heat-fusing to obtain toner particles; a polymerizable monomer for obtaining a binder resin A suspension polymerization method in which a solution of a colorant and a release agent, and if necessary, a charge control agent is suspended in an aqueous solvent for polymerization; a binder resin, a colorant and a release agent, and if necessary Manufactured by a solution suspension method in which a solution such as a charge control agent is suspended in an aqueous solvent and granulated. Toner is used.

  Further, a known method such as a production method in which the toner obtained by the above method is used as a core, and agglomerated particles are further adhered and heat-fused to have a core-shell structure can be used. The toner production method is preferably a suspension polymerization method, an emulsion polymerization aggregation method, or a dissolution suspension method in which an aqueous solvent is used from the viewpoint of shape control and particle size distribution control, and an emulsion polymerization aggregation method is particularly preferable.

  The toner used in the present invention includes a binder resin, a colorant, and a release agent, and if necessary, includes a silica and a charge control agent.

  Examples of the binder resin used in the toner used in the present invention include styrenes such as styrene and chlorostyrene, monoolefins such as ethylene, propylene, butylene, and isoprene, vinyl acetate, vinyl propionate, vinyl benzoate, and butyric acid. Α- such as vinyl esters such as vinyl, methyl acrylate, ethyl acrylate, butyl acrylate, dodecyl acrylate, octyl acrylate, phenyl acrylate, methyl methacrylate, ethyl methacrylate, butyl methacrylate, dodecyl methacrylate Homopolymers such as methylene aliphatic monocarboxylic esters, vinyl ethers such as vinyl methyl ether, vinyl ethyl ether and vinyl butyl ether, vinyl ketones such as vinyl methyl ketone, vinyl hexyl ketone and vinyl isopropenyl ketone Beauty copolymer, polyester resins by copolymerization of dicarboxylic acids and diols.

  Particularly representative binder resins include polystyrene, styrene-alkyl acrylate copolymer, styrene-alkyl methacrylate copolymer, styrene-acrylonitrile copolymer, styrene-butadiene copolymer, styrene-maleic anhydride copolymer. A polymer, polyethylene, polypropylene, a polyester resin, etc. can be mentioned. In addition, polyurethane, epoxy resin, silicone resin, polyamide, modified rosin, paraffin wax and the like can also be mentioned.

  In addition, as colorants, magnetic powders such as magnetite and ferrite, carbon black, aniline blue, caryl blue, chrome yellow, ultramarine blue, Dupont oil red, quinoline yellow, methylene blue chloride, phthalocyanine blue, malachite green oxalate, Lamp Black, Rose Bengal, C.I. I. Pigment red 48: 1, C.I. I. Pigment red 122, C.I. I. Pigment red 57: 1, C.I. I. Pigment yellow 97, C.I. I. Pigment yellow 17, C.I. I. Pigment blue 15: 1, C.I. I. Pigment Blue 15: 3 can be exemplified as a representative one.

  Typical examples of the release agent include low molecular weight polyethylene, low molecular weight polypropylene, Fischer tropic wax, montan wax, carnauba wax, rice wax, and candelilla wax.

As the charge control agent, known ones can be used, and azo metal complex compounds, metal complex compounds of salicylic acid, and resin type charge control agents containing polar groups can be used. When the toner is manufactured by a wet manufacturing method, it is preferable to use a material that is difficult to dissolve in water in terms of controlling ionic strength and reducing wastewater contamination.
In addition, the toner used in the present invention may be either a magnetic toner containing a magnetic material or a non-magnetic toner not containing a magnetic material.

  The toner used in the present invention can be produced by mixing the toner base particles and the external additive with a Henschel mixer or a V blender. Further, when the toner is manufactured by a wet method, it can be externally added by a wet method.

  Lubricating particles may be added to the toner used in the developing device 11. Lubricating particles include solid lubricants such as graphite, molybdenum disulfide, talc, fatty acids and fatty acid metal salts, low molecular weight polyolefins such as polypropylene, polyethylene and polybutene, silicones having a softening point upon heating, oleic amides Aliphatic amides such as erucic acid amide, ricinoleic acid amide, stearic acid amide, etc., plant waxes such as carnauba wax, rice wax, candelilla wax, tree wax, jojoba oil, animals such as beeswax Minerals such as system waxes, montan waxes, ozokerites, ceresins, paraffin waxes, microcrystalline waxes, Fischer-Tropsch waxes, etc., petroleum waxes, and modified products thereof can be used. These can be used individually by 1 type or in combination of 2 or more types. However, the average particle size is preferably in the range of 0.1 μm or more and 10 μm or less, and those having the above chemical structure may be pulverized to make the particle sizes uniform. The amount added to the toner is preferably in the range of 0.05 mass% to 2.0 mass%, more preferably 0.1 mass% to 1.5 mass%.

  To the toner used in the present invention, inorganic particles, organic particles, composite particles obtained by adhering inorganic particles to the organic particles, and the like can be added for the purpose of removing deposits and deteriorated substances on the surface of the electrophotographic photosensitive member. .

  Inorganic particles include silica, alumina, titania, zirconia, barium titanate, aluminum titanate, strontium titanate, magnesium titanate, zinc oxide, chromium oxide, cerium oxide, antimony oxide, tungsten oxide, tin oxide, tellurium oxide, Various inorganic oxides such as manganese oxide, boron oxide, silicon carbide, boron carbide, titanium carbide, silicon nitride, titanium nitride, and boron nitride, nitrides, borides, and the like are preferably used.

  In addition, the inorganic particles may be mixed with titanium coupling agents such as tetrabutyl titanate, tetraoctyl titanate, isopropyl triisostearoyl titanate, isopropyl tridecylbenzene sulfonyl titanate, bis (dioctyl pyrophosphate) oxyacetate titanate, γ- (2- Aminoethyl) aminopropyltrimethoxysilane, γ- (2-aminoethyl) aminopropylmethyldimethoxysilane, γ-methacryloxypropyltrimethoxysilane, N-β- (N-vinylbenzylaminoethyl) γ-aminopropyltrimethoxy Silane hydrochloride, hexamethyldisilazane, methyltrimethoxysilane, butyltrimethoxysilane, isobutyltrimethoxysilane, hexyltrimethoxysilane, octyltrimethoxysilane The treatment may be performed with a silane coupling agent such as run, decyltrimethoxysilane, dodecyltrimethoxysilane, phenyltrimethoxysilane, o-methylphenyltrimethoxysilane, and p-methylphenyltrimethoxysilane. In addition, those hydrophobized with higher fatty acid metal salts such as silicone oil, aluminum stearate, zinc stearate and calcium stearate are also preferably used.

  Examples of the organic particles include styrene resin particles, styrene acrylic resin particles, polyester resin particles, and urethane resin particles.

  As the particle diameter of the composite particles and the like, those having a number average particle diameter of preferably 5 nm to 1000 nm, more preferably 5 nm to 800 nm, and further preferably 5 nm to 700 nm are used. If the average particle size is less than the lower limit, the polishing ability tends to be lacking. On the other hand, if the average particle size exceeds the upper limit, the surface of the electrophotographic photoreceptor tends to be damaged. Moreover, it is preferable that the sum of the addition amount of the particle | grains mentioned above and lubricity particle | grains is 0.6 mass% or more.

Other inorganic oxides added to the toner are small-diameter inorganic oxides with a primary particle size of 40 nm or less for powder flowability, charge control, etc. It is preferable to add a larger-diameter inorganic oxide. These inorganic oxide particles can be known ones, but it is preferable to use silica and titanium oxide in combination for precise charge control.
Further, the surface treatment of the small-diameter inorganic particles increases the dispersibility and increases the effect of increasing the powder fluidity. Furthermore, it is also preferable to add carbonates such as calcium carbonate and magnesium carbonate and inorganic minerals such as hydrotalcite in order to remove the discharge purified product.

  Composite particles and the like may be used by mixing with a carrier. As the carrier, iron powder, glass beads, ferrite powder, nickel powder or the like having a surface coated with a resin coating is used. The mixing ratio with the carrier can be set as appropriate.

  Examples of the exposure apparatus 30 include optical system devices that can expose the surface of the photoreceptor 1 with light such as semiconductor laser light, LED light, and liquid crystal shutter light in a desired image-like manner. The wavelength of the light source is in the spectral sensitivity region of the photoreceptor. As the wavelength of the semiconductor laser, near infrared having an oscillation wavelength near 780 nm is the mainstream. However, it is not limited to this wavelength, and a laser having an oscillation wavelength in the 600 nm range or a laser having an oscillation wavelength in the vicinity of 400 nm to 450 nm as a blue laser can be used. For color image formation, a surface-emitting laser light source capable of multi-beam output is also effective.

  As the transfer device 40, for example, a contact transfer charger using a belt, a roller, a film, a rubber blade, etc., or a known transfer charger such as a scorotron transfer charger using a corona discharge or a corotron transfer charger. Can be mentioned.

As the intermediate transfer member 50, a belt-like member (intermediate transfer belt) made of polyimide, polyamideimide, polycarbonate, polyarylate, polyester, rubber or the like having semiconductivity is used. Further, as the form of the intermediate transfer member 50, a drum-like member can be used in addition to the belt-like member.
In addition to the above-described devices, the image forming apparatus 100 may include, for example, an optical static elimination device that performs optical static elimination on the photoreceptor 1.

FIG. 5 is a schematic configuration diagram showing another preferred embodiment of the image forming apparatus of the present invention. In the image forming apparatus 110 shown in FIG. 5, the electrophotographic photosensitive member 1 is fixed to the main body of the image forming apparatus, and the charging device (charging means) 22, the developing device (developing means) 25, and the cleaning device 27 are each formed as a cartridge. Are provided independently as a charging cartridge, a developing cartridge, and a cleaning cartridge, respectively. Note that the charging device 22 includes a charging device for charging by a corona discharge method.
In the image forming apparatus 110, the electrophotographic photosensitive member 1 and other apparatuses are separated, and the charging device 22, the developing device 25, and the cleaning device 27 are fixed to the image forming apparatus main body by screws, caulking, adhesion, or welding. It is possible to detach it by the operation by pulling out and pushing in without being done.

In the image forming apparatus of the present invention, since the electrophotographic photoreceptor 1 is the above-described photoreceptor of the present invention, the surface of the photoreceptor can be sufficiently suppressed. In addition, the electrophotographic photosensitive member 1 has excellent resistance to foreign matters generated in the apparatus or mixed in the apparatus and has a long life. Thereby, there is a case where it is not necessary to make a cartridge. Therefore, the charging device 22, the developing device 25, or the cleaning device 27 can be detached and attached by an operation by pulling out and pushing in without being fixed to the main body by screws, caulking, adhesion, or welding. The member cost per hit can be reduced. Further, two or more of these devices can be detachable as an integrated cartridge, thereby further reducing the member cost per print.
The image forming apparatus 110 has the same configuration as that of the image forming apparatus 100 except that the charging device 22, the developing device 25, and the cleaning device 27 are each formed as a cartridge.

  FIG. 6 is a schematic configuration diagram showing another preferred embodiment of the image forming apparatus of the present invention. The image forming apparatus 120 is a tandem full-color image forming apparatus equipped with four process cartridges 20. In the image forming apparatus 120, four process cartridges 20 are arranged in parallel on the intermediate transfer member 50, and one electrophotographic photosensitive member can be used for one color. The image forming apparatus 120 has the same configuration as that of the image forming apparatus 100 except that it is a tandem system.

  The tandem image forming apparatus 120 includes the electrophotographic photosensitive member of the present invention as a photosensitive member for forming a toner image of each color, thereby preventing pinhole leaks due to conductive foreign matter even when used for a long time. Since it can be sufficiently suppressed, the occurrence of color continuous point defects can be sufficiently prevented, and a high-quality image can be formed over a long period of time.

  FIG. 7 is a schematic configuration diagram showing another preferred embodiment of the image forming apparatus of the present invention. An image forming apparatus 130 shown in FIG. 7 is a so-called four-cycle image forming apparatus that forms toner images of a plurality of colors with one electrophotographic photosensitive member. The image forming apparatus 130 includes an electrophotographic photosensitive member 1 that is rotated in a direction indicated by an arrow A in the drawing at a predetermined rotational speed by a driving device (not shown). A charging device 22 for charging the outer peripheral surface of the electrophotographic photosensitive member 1 is provided. The electrophotographic photoreceptor 1 has the same configuration as the electrophotographic photoreceptor 1.

  Further, an exposure device 30 having a surface emitting laser array as an exposure light source is disposed above the charging device 22. The exposure device 30 modulates a plurality of laser beams emitted from a light source in accordance with an image to be formed and deflects the laser beams in the main scanning direction, so that the electrophotographic photosensitive member 1 is formed on the outer peripheral surface of the electrophotographic photosensitive member 1. It is made to scan in parallel with the axis. Thereby, an electrostatic latent image is formed on the outer peripheral surface of the charged electrophotographic photosensitive member 1.

  A developing device (developing means) 25 is disposed on the side of the electrophotographic photosensitive member 1. The developing device 25 includes a roller-shaped container that is rotatably arranged. Four containers are formed inside the container, and developing units 25Y, 25M, 25C, and 25K are provided in each container. The developing devices 25Y, 25M, 25C, and 25K each include a developing roller 26, and store Y, M, C, and K color toners therein.

  The full-color image is formed by the image forming apparatus 130 while the electrophotographic photosensitive member 1 is rotated four times. That is, while the electrophotographic photosensitive member 1 rotates four times, the charging device (charging means) 22 charges the outer peripheral surface of the electrophotographic photosensitive member 1, and the exposure device (electrostatic latent image means) 20 represents a color image to be formed. Each time the electrophotographic photosensitive member 1 rotates, the laser beam modulated according to any of the image data of Y, M, C, and K is scanned on the outer peripheral surface of the electrophotographic photosensitive member 1. Repeated while switching the image data used for beam modulation.

  Further, the developing device 25 includes a developing device corresponding to the outer peripheral surface in a state where any of the developing rollers 26 of the developing devices 25Y, 25M, 25C, and 25K corresponds to the outer peripheral surface of the electrophotographic photosensitive member 1. The electrophotographic photosensitive member 1 is operated to develop the electrostatic latent image formed on the outer peripheral surface of the electrophotographic photosensitive member 1 to a specific color and to form a toner image of the specific color on the outer peripheral surface of the electrophotographic photosensitive member 1; Each time the photoconductor 1 rotates once, the process is repeated while rotating the container so that the developing unit used for developing the electrostatic latent image is switched. Thus, every time the electrophotographic photoreceptor 1 rotates in the A direction, Y, M, C, and K toner images are formed on the outer peripheral surface of the electrophotographic photoreceptor 1.

  An endless intermediate transfer belt 50 is disposed substantially below the electrophotographic photoreceptor 1. The intermediate transfer belt 50 is wound around rollers 51, 53, and 55, and is disposed so that the outer peripheral surface is in contact with the outer peripheral surface of the electrophotographic photosensitive member 1. The rollers 51, 53, and 55 are rotated by a driving force of a motor (not shown) and rotate the intermediate transfer belt 50 in the direction of arrow B in FIG.

  A transfer device (transfer means) 40 is disposed on the opposite side of the electrophotographic photosensitive member 1 across the intermediate transfer belt 50, and the toner image formed on the outer peripheral surface of the electrophotographic photosensitive member 1 is transferred by the transfer device 40. The image is transferred to the image forming surface of the intermediate transfer belt 50. As the electrophotographic photosensitive member 1 rotates, the intermediate transfer belt 50 also rotates. When the electrophotographic photosensitive member 1 rotates four times, a full-color toner image is formed on the intermediate transfer belt 50.

  Further, a lubricant supply device 31 and a cleaning device 27 are arranged on the outer peripheral surface of the electrophotographic photosensitive member 1 on the opposite side of the developing device 25 with the electrophotographic photosensitive member 1 interposed therebetween. When the toner image formed on the outer peripheral surface of the electrophotographic photosensitive member 12 is transferred to the intermediate transfer belt 50, the lubricant is supplied to the outer peripheral surface of the electrophotographic photosensitive member 1 by the lubricant supply device 31, and the outer peripheral surface. Of these, the area carrying the transferred toner image is cleaned by the cleaning device 27.

  A tray 60 is disposed below the intermediate transfer belt 50, and a large number of sheets (sheets to be transferred) P as recording materials are accommodated in the tray 60 in a stacked state. A roller pair 63 and a roller 65 are arranged in this order on the downstream side of the tray 60 in the left oblique direction. The uppermost recording sheet in the stacked state is taken out from the tray 60 by the take-out roller 61 rotating, and is conveyed by the roller pair 63 and the roller 65.

  A transfer device 42 is disposed on the opposite side of the roller 55 with the intermediate transfer belt 50 interposed therebetween. The sheet P conveyed by the roller pair 63 and the roller 65 is sent between the intermediate transfer belt 50 and the secondary transfer device 42, and the toner image formed on the image forming surface of the intermediate transfer belt 50 is the secondary transfer device 42. Is transcribed by. A fixing device 44 having a pair of fixing rollers is disposed downstream of the secondary transfer device 42 in the conveyance direction of the paper P. The paper P on which the toner image is transferred is transferred to the fixing device. After being fused and fixed by 44, it is discharged out of the image forming apparatus 130 and placed on a paper discharge tray (not shown).

  As the fixing device 44, for example, a commonly used device such as a heat roll fixing device or an oven fixing device can be used. The toner image transferred onto the transfer medium can be fixed by the fixing device 44.

Next, the process cartridge of the present invention will be described. FIG. 8 is a schematic configuration diagram showing a preferred embodiment of the process cartridge of the present invention.
The process cartridge 300 includes, in the case 311, a charging device (charging means) 21, an exposure device (electrostatic latent image means) 30, a developing device (developing means) 25, a cleaning device 27, and the electrophotographic photosensitive member 1, The mounting rails 313 are combined and integrated. The process cartridge 300 is detachably attached to an image forming apparatus main body including a transfer device (transfer means) 40, a fixing device (fixing means) 44, and other components not shown. The image forming apparatus is configured together with the apparatus main body.

Further, the image forming apparatus of the present invention is preferably a charging scorotron further provided with a discharging means for discharging the residual potential on the surface of the electrophotographic photosensitive member, wherein the charging means has two or more discharge wires.
FIG. 9 is a schematic view of an embodiment of the image forming apparatus of the present invention provided with charging means that is a charging scorotron having two or more discharge wires.

The image forming apparatus shown in FIG. 9 includes a photoconductor (electrophotographic photoconductor) 121 that rotates in the direction of arrow B. Around the photoconductor 121, the photoconductor 121 rotates in the direction of rotation (arrow B direction). A charging device (charging unit) 123 that charges the surface of the photosensitive member 121 in order, an exposure device (electrostatic latent image unit) 124 that forms a latent image by exposing the surface of the photosensitive member 121 imagewise, and a photosensitive member. A developing device (developing unit) 125 that develops the latent image by supplying toner to the surface of 121; a transfer unit (transfer unit) 126 that transfers the developed toner image to a transfer medium (transfer object) P; A cleaning device (cleaning unit) 127 that removes residual toner after transfer and cleans the surface of the photoconductor 121 and a neutralizing device (static elimination unit) 122 that neutralizes residual potential on the surface of the photoconductor 121 are arranged. Reference numeral 128 denotes a fixing device (fixing means), and P denotes a transfer medium (transfer medium) such as paper.
The charging device 123 is supplied with a potential by a power supply device 129. The cleaning device 127 has a cleaning blade 127 ′ and is disposed so as to contact the surface of the photoconductor 121.
The photoreceptor 121 is the above-described electrophotographic photoreceptor of the present invention.

  The image forming apparatus shown in FIG. 9 can prevent the occurrence of leakage because the conductive foreign matter can be prevented from being stuck even when the charging device 123 is in contact with the surface of the photoreceptor 121. Therefore, color points on the image can be prevented.

  FIG. 10 is an enlarged view in which only a portion between the charge removal device 122 and the charging device 123 in FIG. 9 is extracted. The neutralization device 122 emits neutralization light 122 ′ toward the photosensitive member 121. The charging device 123 is a charging scorotron having two discharge wires 123a and 123b, and the surface of the photoconductor 121 is charged by the discharge from the discharge wires 123a and 123b.

At this time, a static elimination start point X that is a point at which the static elimination operation by the static elimination device 122 starts (that is, a start point at which the static elimination light 122 ′ is irradiated), and a point at which the charging operation by the charging device 123 ends (2). Among the two discharge wires, a reference point (a reference point) of the photosensitive member 121 is between a charging end point Y that is a point where the charging wire 23b on the downstream side in the rotation direction of the photosensitive member 121 (in the direction of arrow B) is charged). In the present invention, the “reference point” refers to an arbitrary point on the outer peripheral surface of the electrophotographic photosensitive member for obtaining the following relational expression (a)): T ₁ (sec) When the thickness of the outermost surface layer of the photoreceptor 121 (thickness of the outermost surface layer of the photosensitive layer) is d (mm) and the relative dielectric constant of the outermost surface layer of the photoreceptor 121 is ε, the following relational expression (a) By satisfying the above, the photoconductor 121 has a long life. Deterioration of image quality is reduced accordingly and uneven charging of the charging performance can be provided an image forming apparatus can be suppressed.
-Relational expression (a)
120 ≦ 2.5 × 10 ³ / √T ₁ × exp (0.724 d / ε) / d ≦ 255

In the above relational expression (a), if the central side expression (2.5 × 10 ³ / √T ₁ × exp (0.724 d / ε)) is F, charging is terminated when F exceeds 255. Subsequent charge reduction on the surface of the electrophotographic photosensitive member significantly affects the image quality. On the other hand, when the F is less than 120, there is no problem with charging, but the charge tends to accumulate in the outermost surface layer of the photosensitive layer, so that a cycle-up phenomenon may occur.
The lower limit value of F is preferably 120 or more, more preferably 125 or more, and still more preferably 135 or more. Further, the upper limit value of F is preferably 255 or less, more preferably 250 or less, and even more preferably 247 or less.
By satisfying the relational expression (a), it is not clear why the photoreceptor 121 has a long life, but can suppress deterioration in charging performance and deterioration in image quality due to uneven charging. The effect is proved by the verification test. For some of them, please refer to the examples described later.

Next, the reasoning examined by the present inventors about the validity of the relational expression (a) will be described.
First, the outermost surface layer in the electrophotographic photosensitive member of the present invention described above is strong, and ozone generated from the charging device is difficult to adhere. Although it has an effective feature, on the other hand, the movement speed of the positive charge may be relatively slow.
For this reason, when static elimination light is used in the static elimination process to erase the charge remaining on the surface of the electrophotographic photosensitive member after transfer, a large amount of positive charge reaches the outermost surface layer of the photosensitive layer from the charge generation layer through the charge transport layer. To do.

At this time, if the movement speed of the charge in the outermost surface layer of the photosensitive layer is slow, the charge moves to the surface of the electrophotographic photosensitive member even after the charging process of the next cycle or even after the charging process is completed. It is considered that as the amount of positive charge generated by the static elimination light that reaches the surface of the electrophotographic photosensitive member after the completion of the charging process is larger, the charge is lowered in the charging process, and the electrophotographic photosensitive member is poorly charged.
From this, the present inventors obtained the idea that the time from the start of static elimination to the end of charging becomes very important.

Further, it was expected that the film thickness of the outermost surface layer of the photosensitive layer, particularly the dielectric film thickness (d / ε), would have a great influence on the time until the charge reaches the surface of the electrophotographic photosensitive member.
In addition, the amount of charge generated by static elimination light differs between the image area and the non-image area, and the degree of charge decrease after the end of charging changes, resulting in uneven charging between the image area and the non-image area. It was also expected to be easier.
From the above examination results, the present inventors have verified variously about the influencing factors, and there is a correlation between these influencing factors and the achievement of the object.

The dielectric film thickness (d / ε) of the outermost surface layer of the electrophotographic photosensitive member is preferably 0.2 μm or more and 3.5 μm or less, and more preferably 0.25 μm or more and 3.3 μm or less. preferable. When the dielectric film thickness is less than 1 μm, scratches caused by foreign matters mixed in the toner such as carrier pieces and metal pieces can easily reach the charge transport layer, and as a result, image defects can easily appear. If it exceeds, the potential after exposure may increase with long-term use in a high-temperature and high-humidity environment.
Here, the dielectric film thickness (d / ε) is a value obtained by dividing the actual film thickness d (mm) of the outermost surface layer of the photosensitive layer by ε by the relative dielectric constant of the outermost surface layer of the photosensitive layer. The relative dielectric constant was measured under the conditions of a temperature of 22 ° C., a humidity of 55%, and a frequency of 1 Hz using a frequency response analyzer 1260 manufactured by Solartron.

In addition, the time T _{1 from the} start of the charge removal operation by the charge removal unit to the end of the charge operation by the charging unit (hereinafter referred to as “charge removal start-charging end”) T ₁ is 55 msec or more and 200 mmsec or less. It is preferable that it is 60 mmsec or more and 150 mmsec or less. If the time between the start of charge removal and the end of charging is less than 55 mmsec, the charge transfer in the charge transport layer (in the case of a single layer type, “single layer type photosensitive layer” described later) does not follow, resulting in a decrease in sensitivity. If it exceeds 200 mmsec, the charge on the surface of the electrophotographic photosensitive member is likely to move in the direction of the surface particularly under high temperature and high humidity, so that the possibility of blurring of the image may be increased.
Further, as a result of further studies, the present inventors have found that charging unevenness can be reduced by using a scorotron having a plurality of wires as a charging device.

  This not only increases the charging capability of the charging device itself, but also increases the width of the charging device. As a result, it is considered that the time from the start of static elimination to the end of charging becomes longer. .

A preferred embodiment of the charging means and the discharging means in the image forming apparatus of the present invention provided with a charging means that is a charging scorotron having two or more discharge wires will be described.
In this embodiment, the charging means (corresponding to the charging device 123 for charging the surface of the photosensitive member 121 in FIG. 9) is a charging scorotron having a plurality of discharge wires. A charged scorotron is a type of non-contact charger that uses corona discharge, and for a corotron that is composed of a casing electrode that occupies a half space around the discharge wire and a discharge wire placed in the center of the casing electrode. Furthermore, a grid electrode is added.

The charged scorotron generally has one discharge wire and two discharge wires. In the present invention, the latter is used. In the present invention, the number of discharge wires is not particularly limited as long as it is a plurality, and may be 3 or more.
In this embodiment, the charged scorotron is not particularly limited as long as it has two or more discharge wires, and any conventionally known one in the electrophotographic field can be used.

  In this embodiment, the neutralization means (corresponding to the neutralization device 122 that neutralizes the residual potential on the surface of the photosensitive member 121 in FIG. 9) is a so-called neutralization lamp that emits light like the neutralization device 122 depicted in FIG. In addition, electrostatic discharge means using a corotron or scorotron, a conductive brush, or the like may be employed. In these cases, the charge removal capability can be controlled by the magnitude of the electrostatic force. The charging voltage is preferably a superimposed voltage of alternating current and direct current.

When a static elimination lamp is used, the light source includes a tungsten lamp, LED, EL (Electro Luminescence), a fluorescent lamp, and the like. Moreover, as the light quality, white light, such as a tungsten lamp, red light, such as LED light, etc. are mentioned, for example. The irradiation light intensity in the photostatic process is usually set to output several times to about 30 times the amount of light indicating the half exposure sensitivity of the electrophotographic photosensitive member.
Note that the static elimination start point X described with reference to FIG. 10 by taking as an example the case where a static elimination lamp (static elimination device 122) is used as the static elimination means is used when an electrostatic static elimination means or a conductive brush is employed. Corresponds to the point at which static elimination action has started to occur by these methods (the point at which an electrostatic effect has started to act and the point at which the conductive brush has started to be charged in contact).

  EXAMPLES Hereinafter, the present invention will be described more specifically with reference to examples, but the present invention is not limited thereto. In the following Examples, “part” means “part by mass” and “%” means “% by mass” unless otherwise specified.

<Production of electrophotographic photoreceptor>
Preparation of coating solution (U-1) for undercoat layer 100 parts of zinc oxide (manufactured by Teika, “MZ-300”, average particle diameter 70 nm, specific surface area value 15 m ² / g) and 500 parts of tetrahydrofuran were mixed with stirring. Then, 1.25 parts of a silane coupling agent (“KBM603”, manufactured by Shin-Etsu Chemical Co., Ltd.) was added and stirred for 2 hours. Tetrahydrofuran was then distilled off under reduced pressure and baked at 150 ° C. for 2 hours to obtain a silane coupling agent surface-treated zinc oxide.
100 parts of the silane coupling agent surface-treated zinc oxide obtained above and 500 parts of tetrahydrofuran are stirred and mixed, and to this mixture is added a solution prepared by dissolving 1 part of alizarin in 50 parts of tetrahydrofuran, at 50 ° C. Stir for 5 hours. Then, the zinc oxide to which alizarin was imparted was separated by filtration under reduced pressure, followed by drying under reduced pressure at 60 ° C. to obtain an alizarin imparted zinc oxide pigment (complex containing alizarin and zinc oxide).

  Next, 100 parts of the alizarin-added zinc oxide pigment obtained above, 13.5 parts of blocked isocyanate (“Sumijour 3175”, manufactured by Sumitomo Bayern Urethane Co., Ltd.) as a curing agent, butyral resin (“BM-1”) 15 parts of Sekisui Chemical Co., Ltd.) and 85 parts of methyl ethyl ketone were mixed, and then 38 parts of this solution and 25 parts of methyl ethyl ketone were mixed and dispersed for 2 hours in a sand mill using 1 mmφ glass beads. To obtain a dispersion. As a catalyst, 0.005 part of dioctyltin dilaurate and 40 parts of silicone resin particles ("Tospearl 145", manufactured by GE Toshiba Silicone Co., Ltd.) are added as a catalyst to the resulting dispersion, and a coating liquid for forming an undercoat layer (U- 1) was obtained.

Preparation of coating liquid for undercoat layer (U-2) 100 parts of zinc oxide (manufactured by Teika, “MZ-300”, average particle diameter 70 nm) and 500 parts of tetrahydrofuran were mixed with stirring to obtain a silane coupling agent (“ KBM603 "(manufactured by Shin-Etsu Chemical Co., Ltd.) was added and stirred for 2 hours. Tetrahydrofuran was then distilled off under reduced pressure and baked at 120 ° C. for 3 hours to obtain silane coupling agent surface-treated zinc oxide.

  Next, 60 parts of the silane coupling agent surface-treated zinc oxide obtained above, 0.6 parts of alizarin, and 13.5 of blocked isocyanate (“Sumidule 3175”, manufactured by Sumitomo Bayern Urethane Co., Ltd.) as a curing agent are used. 15 parts of butyral resin ("BM-1", manufactured by Sekisui Chemical Co., Ltd.) and 85 parts of methyl ethyl ketone were mixed, and then 38 parts of this solution and 25 parts of methyl ethyl ketone were mixed to prepare 1 mmφ glass beads. The resulting mixture was dispersed in a sand mill for 2 hours to obtain a dispersion. As a catalyst, 0.005 part of dioctyltin dilaurate and 40 parts of silicone resin particles ("Tospearl 145", manufactured by GE Toshiba Silicone Co., Ltd.) are added as a catalyst to the resulting dispersion, and a coating liquid for forming an undercoat layer (U- 2) was obtained.

<Guanamine resin-1 (G-1)>
500 parts of Super Becamine (R) L-145-60 (Dainippon Ink Co., Ltd.) was dissolved in 500 parts of xylene, and each was washed 7 times with 400 ml of distilled water. The solvent was distilled off from the solution under reduced pressure to obtain 250 parts of a candy-like resin. This is designated as guanamine resin-1.

<Guanamine resin-2 (G-2)>
The exemplified compound: 500 parts of A- (7) was dissolved in 500 parts of xylene, and each was washed seven times with 400 ml of distilled water. The solvent was distilled off from the solution under reduced pressure to obtain 270 parts of a candy-like resin. This is designated as guanamine resin-2.

<Guanamine resin-3 (G-3)>
Super Becamine (R) L-148-60 is directly used as guanamine resin-3.

<Guanamine resin-4 (G-4)>
The exemplified compound: (A) -7 is used as it is as guanamine resin-4.

<Catalyst-1>
Dodecylbenzenesulfonic acid is catalyst-1.

<Catalyst-2>
NACURE 5225 (manufactured by King Industry) is referred to as catalyst-2.

<Conductive particles-1>
Zinc oxide (manufactured by Taika Co., Ltd., MZ150: average particle size 70 nm) is defined as conductive particles-1.

<Conductive particles-2>
In 100 ml of toluene, 25 g of zinc oxide (MZ150, average particle diameter 70 nm, manufactured by Teika) in which 2.5 g of a hydrolyzable organosilicon compound having a sulfonate group was dissolved was added. The mixture was refluxed at 95 ° C. for 2.5 hours, and then the solvent was distilled off under reduced pressure. When the solvent was exhausted, the temperature was raised to 150 ° C. and maintained for 1.5 hours to obtain zinc oxide having a sulfonic acid group. . This is designated as Conductive Particle-2.

Example 1
First, a cylindrical aluminum substrate (diameter 30 mm, length 404 mm, wall thickness 1 mm) was prepared.
(Preparation of undercoat layer)
The undercoat layer coating solution (U-1) was applied onto the above aluminum substrate by a dip coating method, followed by drying and curing at 163 ° C. for 33 minutes to obtain an undercoat layer having a thickness of 23 μm.

(Preparation of charge generation layer)
15 parts of hydroxygallium phthalocyanine having strong diffraction peaks at Bragg angles (2θ ± 0.2 °) of at least 7.3 °, 16.0 °, 24.9 °, and 28.0 ° in the X-ray diffraction spectrum 10 parts of vinyl-vinyl acetate copolymer resin (VMCH, manufactured by Nippon Unicar Co., Ltd.) and 200 parts of n-butyl acetate were mixed and dispersed with a glass bead having an outer diameter of 1 mm for 4 hours in a sand mill. A coating solution for forming a charge generation layer was prepared by adding 175 parts of n-butyl acetate and 180 parts of methyl ethyl ketone to the obtained dispersion. The obtained coating solution was dip-coated on a conductive support provided with an undercoat layer, and dried at room temperature to form a charge generation layer having a thickness of 0.2 μm.

(Preparation of charge transport layer)
4 parts N, N'-diphenyl-N, N'-bis (3-methylphenyl)-[1,1 '] biphenyl-4,4'-diamine and bisphenol Z polycarbonate resin (viscosity average molecular weight 40,000) 6 Was sufficiently dissolved in 80 parts of chlorobenzene to prepare a charge transport layer coating solution. The obtained coating solution was dip-coated on the charge generation layer and heated at 130 ° C. for 45 minutes to form a charge transport layer having a thickness of 20 μm.

(Preparation of protective layer)
3 parts of guanamine resin-1 (G-1), 3 parts of the exemplified compound (I-3), 0.2 part of polyvinylphenol resin (weight average molecular weight of about 8000, manufactured by Aldrich), 1-methoxy-2- 8 parts of propanol, 0.2 part of 3,5-di-t-butyl-4-hydroxytoluene (BHT) and 0.01 part of dodecylbenzenesulfonic acid (catalyst-1) were mixed. Further, 0.3 part of conductive particles-1 was added and dispersed for 5 hours with a sand mill to prepare a protective layer coating solution. This coating solution is applied onto the charge transport layer by a dip coating method, and is cured by heat treatment at 150 ° C. for 0.8 hours to form a protective layer having a thickness of about 7 μm. Produced.

(Examples 2 to 10)
In the production of the photoreceptor A of Example 1, the type of the undercoat layer coating solution, the type of the compound represented by the general formula (A) used in the protective layer coating solution, the type of the charge transport material, the conductive particles Photoconductors B to J were prepared in the same manner as the photoconductor A of Example 1 except that the type and addition amount, and the type and addition amount of the catalyst were changed as shown in Table 1.

Example 11
Photoreceptor K was produced in the same manner as in Example 1 except that 0.3 part of alizarin was added to the protective layer coating solution in the production of Photoreceptor A of Example 1.

Example 12
Photoreceptor L was produced in the same manner as in Example 11 except that the thickness of the protective layer was changed to 11 μm in the production of photoconductor A of Example 1.

(Comparative Example 1)
In the preparation of the photoreceptor A of Example 1, the charge transport layer was formed in the same manner as the preparation of the photoreceptor A. Next, 2 parts of the compound represented by the following formula (CT-1) and 2 parts of the compound represented by the following formula (CP-1) were mixed with 5 parts of isopropyl alcohol, 3 parts of tetrahydrofuran and 0.3 part of distilled water. In addition, 0.05 parts of an ion exchange resin (Amberlyst 15E, manufactured by Rohm and Haas) was further added to this mixture, followed by stirring at room temperature for 24 hours. In formula (CT-1), -i-Pr represents an isopropyl group.

0.02 part of aluminum trisacetylacetonate (Al (aqaq) ₃ ) was added to 2 parts of the solution obtained by filtering and separating the ion exchange resin from the hydrolyzed product to obtain a coating solution for forming a protective layer. This coating solution was applied onto the charge transport layer by a ring-type dip coating method and air-dried at room temperature for 10 minutes. Thereafter, it is cured by heat treatment at 140 ° C. for 40 minutes to form a protective layer having a thickness of 2.8 μm, and a photosensitive layer comprising an undercoat layer / charge generation layer / charge transport layer / protective layer on a conductive support. An electrophotographic photosensitive member provided with is obtained. This electrophotographic photoreceptor was designated as photoreceptor a.

(Comparative Example 2)
In the preparation of the photoreceptor A of Example 1, the charge transport layer was formed in the same manner as the preparation of the photoreceptor A. Next, 10 parts of a polysiloxane resin (containing 1% silanol group) consisting of 80 mol% of methylsiloxane units and 20 mol% of methyl-phenylsiloxane units was dissolved in 8 parts of toluene, and then methyltrisiloxane 12.0 was dissolved therein. And 0.2 part of dibutyltin diacetate were further added to obtain a solution. Then, 20 parts of toluene and 4 parts of 4- [N, N-bis (3,4-dimethylphenyl) amino]-[2- (triethoxysilyl) ethyl] benzene were added to 10 parts of this solution. A coating solution for forming a protective layer was obtained. This coating solution was applied onto the charge transport layer by a spray coating method and air-dried at 110 ° C. for 10 minutes. Thereafter, it is cured by heat treatment at 170 ° C. for 2 hours to form a protective layer having a thickness of about 2.8 μm, and a photosensitive layer comprising a subbing layer / charge generation layer / charge transport layer / protective layer on a conductive support. An electrophotographic photoreceptor provided with a layer was obtained. This electrophotographic photoreceptor was designated as photoreceptor b.

(Comparative Example 3)
In the preparation of the photoreceptor A of Example 1, the charge transport layer is formed in the same manner as the preparation of the photoreceptor A, and a photosensitive layer composed of an undercoat layer / charge generation layer / charge transport layer is provided on a conductive support. An electrophotographic photoreceptor was obtained. This electrophotographic photosensitive member was designated as a photosensitive member c.

(Comparative Example 4)
In the preparation of the photoreceptor B of Example 2, the charge transport layer is formed in the same manner as the preparation of the photoreceptor A, and the charge transport layer is formed in the same manner, and the undercoat layer / charge generation is performed on the conductive support. An electrophotographic photosensitive member provided with a photosensitive layer comprising a layer / charge transport layer was obtained. This electrophotographic photoreceptor was designated as photoreceptor d.

(Comparative Example 5)
First, a cylindrical aluminum substrate (diameter 30 mm, length 404 mm, wall thickness 1 mm) was prepared. Next, 30 parts by mass of an organic zirconium compound (acetylacetone zirconium butyrate), 3 parts of an organic silane compound (γ-aminopropyltrimethoxysilane), polyvinyl butyral resin (trade name “ESREC BM-S”, manufactured by Sekisui Chemical Co., Ltd.) 4 The coating solution for forming the undercoat layer obtained by stirring and mixing 170 parts of n-butyl alcohol was applied onto the aluminum substrate by a dip coating method, followed by curing at 150 ° C. for 1 hour. A subbing layer having a thickness of 1.2 μm was formed.

  Next, in the same manner as in the preparation of the photoreceptor A of Example 1, a charge generation layer was formed on the undercoat layer, and a charge transport layer was further formed thereon.

  Next, a coating solution for forming a protective layer was prepared in the same manner as in Example 1 except that 0.2 part of dodecylbenzenesulfonic acid was used, and this coating solution was applied onto the charge transport layer by a ring-type dip coating method. Coating, curing at 200 ° C. for 1 hour to form a protective layer having a thickness of 2.8 μm, and comprising an undercoat layer / charge generation layer / charge transport layer / protective layer on a conductive support. An electrophotographic photosensitive member provided with a photosensitive layer was obtained. This electrophotographic photoreceptor was designated as photoreceptor e.

<Measurement of dynamic hardness and elastic deformation rate>
For the electrophotographic photoreceptors A to L obtained in Examples 1 to 12 and the electrophotographic photoreceptors a to e obtained in Comparative Examples 1 to 5, the dynamic hardness and elastic deformation rate of the photosensitive layer are determined according to the following methods. It was. The obtained results are shown in Table 2.

(Dynamic hardness)
The above photoconductor is placed on a 10 mm square on a micro hardness tester (Shimadzu Corporation "DUH-201") equipped with a Belkovic indenter (diamond triangular pyramid indenter with an edge angle of 115 ° and a tip curvature radius of 0.07 μm). It was set after cutting, and the hardness of the photosensitive layer was measured in an indenter indentation measurement mode (indentation speed was 0.045 mN / sec). In the measurement, the indenter is pushed in from the protective layer side of the photosensitive layer with a load of 0.3 mN, the pressure of 0.3 mN is held for 1 second, and then the pressure applied to the indenter is returned to 0 mN (the pressure release speed is 0. 0). 045 mN / sec). The hardness was calculated using the following formula (1) from the indentation depth when the indenter was indented with an indentation load of 0.3 mN, and this calculated value was defined as the dynamic hardness of the photosensitive layer. The indentation depth was read from the displacement of the indenter, and the indentation load was read from a load cell connected to the indenter.
DH = 3.8854 × (P / D ² ) (1)
In the formula, DH represents dynamic hardness, P represents indentation load (unit: N), and D represents indentation depth (unit: m).

(Elastic deformation rate)
The elastic deformation rate is calculated based on the following equation (2) from the indentation depth when the indenter is pushed in with a pushing load of 0.3 mN and the displacement of the indenter after releasing the pressure applied to the indenter in the above measurement. did.
ED = (D−M) / D × 100 (2)
In the equation, ED represents the elastic deformation rate (%), M represents the displacement of the indenter after the stress release (plastic deformation amount) [m], and D represents the indentation depth [m].

  The electrophotographic photoreceptors A to L obtained in Examples 1 to 12 and the electrophotographic photoreceptors a to e obtained in Comparative Examples 1 to 5 were respectively mounted on a full color printer DocuCenter Color A450 manufactured by Fuji Xerox Co., Ltd. A forming apparatus was prepared, and the following image forming test 1 and image forming test 2 were performed.

<Image formation test 1>
Using the image forming apparatus prepared above, 30,000 sheets of images were continuously formed in an environment of 30 ° C. and 85% RH. Thereafter, an image (A3 size) was formed under the same environment, and the image quality at that time was visually evaluated based on the following evaluation criteria. The results are shown in Table 2.
A: Good B: Slight color point defects are observed C: Color points or color line defects are conspicuous Further, the number of generated color point defects (number of generated color points) was counted. The results are shown in Table 2.

<Image formation test 2>
With the long-term use of the image forming apparatus, it is assumed that a conductive material is released from a deteriorated developing device or intermediate transfer member, and the carbon fiber is intentionally formed into a cylindrical carbon fiber ( (Diameter: 5 μm to 10 μm, length: 3 μm to 300 μm) were added to the toner cartridge of the image forming apparatus produced above. The carbon fiber was added so that the mass ratio of the toner to the carbon fiber was a ratio of toner: carbon fiber = 1000: 1. Using this image forming apparatus, 10 images were continuously formed in an environment of 30 ° C. and 85% RH, and the 10th image (A3 size) was visually evaluated based on the following evaluation criteria. . The results are shown in Table 2.
A: Good B: Very slight color point defect is observed C: Color point or color line defect is conspicuous In addition, for the generated color point defect, the number of color points exceeding 0.2 mm and the number of color points being 0.2 mm or less, respectively The results are shown in Table 2.

As shown in Table 2, the dynamic hardness of the photosensitive layer is 20 × 10 ⁹ N / m ² or more and 200 × 10 ⁹ N / m ² or less, and the elastic deformation rate of the photosensitive layer is 20% or more and 80% or less. It was confirmed that the image forming apparatuses of Examples 1 to 10 including the photoreceptor can form a good image even in the image forming test 2. Therefore, according to the present invention, it is possible to sufficiently prevent the occurrence of image quality defects due to leakage, and it is possible to form high-quality images over a long period of time.

On the other hand, the image forming apparatus of the comparative example provided with the photoconductor whose dynamic hardness of the photosensitive layer is less than 20 × 10 ⁹ N / m ² cannot form good image quality in the image forming test 1 and the image forming test 2. It was confirmed. Further, in the image forming test 2, the image forming apparatus of the comparative example provided with the photosensitive member having the dynamic hardness of the photosensitive layer exceeding 200 × 10 ⁹ N / m ² is considered to be 0.2 mm which is considered to be caused by scratches or cracks of the photosensitive layer. It was found that a large number of color points exceeding. In addition, it was confirmed that the image forming apparatus of Comparative Example 5 including the photoconductor having the elastic deformation rate of the photosensitive layer of less than 15% cannot form good image quality in the image forming test 1 and the image forming test 2. In addition, it was found that a large number of color points exceeding 0.2 mm, which may be caused by scratches or cracks in the photosensitive layer, occurred.

<Image formation test 3>
Furthermore, in each of the DocuCentre Color A450 equipped with the electrophotographic photoreceptor A obtained in Example 1 and the electrophotographic photoreceptor K obtained in Example 11, low temperature and low humidity (8 ° C., 20% RH), and Under the conditions of high temperature and high humidity (28 ° C., 85% RH), when the single image (A3 size) was formed, the state of the image and the residual potential were formed, and 10,000 images (A3 size) were formed. Table 3 shows the state of the image and the state of the residual potential.

<Image formation test 4>
A time T from the start of static elimination to the end of charging after changing the electrophotographic photosensitive member A modified from the full color printer Docu Color 1250 manufactured by Fuji Xerox Co. to the electrophotographic photosensitive member A obtained in Example 1. An image forming apparatus was prepared in which the position of the static eliminator was changed so that ₁ was 100 mmsec. This image forming apparatus uses a scorotron as a charging device and has two discharge wires.
Table 4 shows the value of the central side (2.5 × 10 ³ / √T ₁ × exp (0.724 d / ε)) of the relational expression (a) under this condition together with the relative dielectric constant of the protective layer.

Further, by using the image forming apparatus (the Docu Color 1250 modified machine), image output test image density of 20% halftone image (the number of output sheets: A3 paper lengthwise five = about 22 cycles) was carried out, further A3 After 1000 sheets of paper were output, ghost evaluation was performed and evaluated according to the following criteria. The results are shown in Table 4.
Evaluation criteria ○: Neither density unevenness nor ghost was observed.
Δ: Slight occurrence was observed in either or both of density unevenness and ghost.
X: Occurrence was observed in either or both of density unevenness and ghost.

Further, in place of the electrophotographic photosensitive member L obtained in Example 1, the electrophotographic photosensitive member L obtained in Example 12 was used, and the time T ₁ from the start of static elimination to the end of charging was set to 205 mmsec. Test 4 was performed and a ghost evaluation was performed. The results are shown in Table 4.

1 is a schematic cross-sectional view showing a preferred embodiment of an electrophotographic photoreceptor of the present invention. FIG. 6 is a schematic cross-sectional view showing another preferred embodiment of the electrophotographic photosensitive member of the present invention. FIG. 6 is a schematic cross-sectional view showing another preferred embodiment of the electrophotographic photosensitive member of the present invention. 1 is a schematic configuration diagram illustrating a preferred embodiment of an image forming apparatus of the present invention. It is a schematic block diagram which shows other suitable embodiment of the image forming apparatus of this invention. It is a schematic block diagram which shows other suitable embodiment of the image forming apparatus of this invention. It is a schematic block diagram which shows other suitable embodiment of the image forming apparatus of this invention. 1 is a schematic configuration diagram showing a preferred embodiment of a process cartridge of the present invention. It is a schematic block diagram which shows other suitable embodiment of the image forming apparatus of this invention. It is the schematic block diagram which extracted only between the static elimination apparatus and charging device in FIG. It is a graph which shows the relationship between the indentation load of an indenter at the time of measuring the elastic deformation rate of a photosensitive layer, and the displacement of an indenter.

Explanation of symbols

  DESCRIPTION OF SYMBOLS 1 ... Electrophotographic photosensitive member, 2 ... Conductive support body, 3 ... Photosensitive layer, 4 ... Undercoat layer, 5 ... Charge generation layer, 6 ... Charge transport layer, 7 ... Protective layer, 8 ... Single layer type photosensitive layer, 21 ... 22 charging device, 24 ... developing device, 27 ... cleaning device, 30 ... exposure device, 40 ... transfer device, 50 ... intermediate transfer member, 100, 110, 120, 130 ... image forming device, 121 ... photoreceptor, DESCRIPTION OF SYMBOLS 122 ... Static elimination apparatus, 123 ... Charging apparatus, 123a, 123b ... Discharge wire, 124 ... Exposure apparatus, 125 ... Developing apparatus, 126 ... Transfer apparatus, 127 ... Cleaning apparatus, 127 '... Cleaning blade, 128 ... Fixing apparatus, 129 ... Power supply device, 300... Process cartridge.

Claims (9)

A photosensitive layer is provided on the surface of the conductive support,
The layer on the most conductive support side of the photosensitive layer is an undercoat layer containing a complex of an acceptor compound and metal oxide particles,
The outermost layer of the photosensitive layer, at least one compound represented by the following general formula _{(A), -OH, -NH 2} , -SH, charge having at least one or more substituents selected from -COOH Comprising a cross-linked product using at least one transport material,
The dynamic hardness of the photosensitive layer is 20 × 10 ⁹ N / m ² or more and 20 × 10 ¹⁰ N / m ² or less, and the elastic deformation rate of the photosensitive layer is 25% or more and 70% or less. An electrophotographic photoreceptor.

(In the general formula (A), R ¹ represents a linear or branched alkyl group having 1 to 10 carbon atoms or a substituted or unsubstituted phenyl group having 6 to 10 carbon atoms. R ^{2 to} R ⁵ each independently represent a hydrogen atom, —CH ₂ —OH, or —CH ₂ —O—R ^6. R ⁶ represents a hydrogen atom, a linear or branched group having 1 to 5 carbon atoms. Indicates a chain alkyl group.)   The electrophotographic photosensitive member according to claim 1, wherein the outermost surface layer of the photosensitive layer contains an electron accepting material.   The electrophotographic photosensitive member according to claim 1, wherein the outermost surface layer of the photosensitive layer contains particles. The electrophotographic photosensitive member according to any one of claims 1 to 3,
Charging means for charging the electrophotographic photosensitive member, developing means for developing the electrostatic latent image formed on the electrophotographic photosensitive member with toner, and toner removal for removing toner remaining on the surface of the electrophotographic photosensitive member A process cartridge comprising: at least one selected from the group consisting of means.   The electrophotographic photosensitive member according to any one of claims 1 to 3, a charging unit for charging the electrophotographic photosensitive member, and an electrostatic latent image for forming an electrostatic latent image on the charged electrophotographic photosensitive member. An image forming apparatus comprising: an image unit; a developing unit that develops the electrostatic latent image formed on the electrophotographic photosensitive member with toner; and a transfer unit that transfers the toner image to a transfer target. .   6. The image forming apparatus according to claim 5, further comprising a discharging unit that discharges a residual potential on the surface of the electrophotographic photosensitive member, wherein the charging unit is a charged scorotron having two or more discharge wires. At the reference point of the electrophotographic photosensitive member, T ₁ (sec) is the time from the start of the discharging operation by the discharging unit according to the rotation of the electrophotographic photosensitive member until the end of the charging operation by the charging unit. When the film thickness of the outermost surface layer of the electrophotographic photosensitive member is d (mm) and the relative dielectric constant of the outermost surface layer of the photosensitive layer is ε, the following relational expression (a) is satisfied. The image forming apparatus according to claim 6.
-Relational expression (a)
120 ≦ 2.5 × 10 ³ / √T ₁ × exp (0.724 d / ε) / d ≦ 255   The image forming apparatus according to claim 7, wherein a dielectric film thickness (d / ε) of the outermost surface layer of the photosensitive layer is 0.2 μm or more and 3.5 μm or less. The time _{T 1} is, the image forming apparatus according to claim 7 or claim 8, characterized in that at 200mmsec inclusive 55Mmsec.

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