JP6360720B2 - Electrophotographic photosensitive member and image forming apparatus using the same - Google Patents

Description

  The present invention relates to an electrophotographic photosensitive member and an image forming apparatus using the same. More specifically, in the present invention, the charge transport layer in the multilayer electrophotographic photosensitive member transports a specific tetraaryl enamine compound as a binder together with filler fine particles composed of at least one of fluororesin fine particles or silica fine particles. The present invention relates to an electrophotographic photosensitive member containing 1 to 15% by weight of a substance and an image forming apparatus including the same.

  As a defect of an electrophotographic photosensitive member (hereinafter also simply referred to as a photosensitive member), light resistance is mentioned. Since the electrophotographic photosensitive member is built in the image forming apparatus, the image forming apparatus on which the electrophotographic photosensitive member is mounted is not exposed to external light such as a fluorescent lamp. However, when maintenance of the image forming apparatus, replacement of the electrophotographic photosensitive member, or when a paper jam occurs, it is necessary to open the cover of the image forming apparatus during those operations, and the electrophotographic photosensitive member is exposed to external light. May be exposed. In that case, when the electrophotographic photosensitive member is exposed to external light for a long time, the photosensitive member may be greatly damaged, resulting in a problem in image formation.

This is because light emitted from a fluorescent lamp often has a sharp and strong light component having a wavelength of around 440 nm, and the light passes through the charge transport layer and reaches the charge generation layer to generate a light trap. Is considered to be the cause.
As one of these measures, addition of an ultraviolet absorber to the charge transport layer (for example, JP-A-05-019497: Patent Document 1) and use of a charge transport material excellent in light resistance have been attempted (for example, Japanese Patent No. 3718508: Patent Document 2).

  Another problem is that the surface of the photoconductor is abraded due to the printing of a cleaner around the photoconductor in the cleaning step of the image forming process. As a means for overcoming this drawback, it has been attempted to improve the mechanical and physical properties of the material on the surface of the photoreceptor.

  As such an approach, addition of filler fine particles such as fluororesin fine particles and silica fine particles to the surface layer of the photoreceptor has been studied (for example, Japanese Patent No. 3416310: Japanese Patent Laid-Open No. 2008-176056: Japanese Patent No. 2008-176056). ). Fluororesin not only improves the mechanical properties of the photoconductor, but also improves the lubricity of the photoconductor surface by adding it to the photoconductor as filler particles due to its dense structure and excellent properties derived from the material as a lubricant. Is considered to contribute to the improvement of the printing durability of the surface of the photoreceptor, as a result of reducing the frictional force with the members arranged around the photoreceptor that are in contact during the image forming process of the photoreceptor. It has been.

Japanese Patent Laid-Open No. 05-019497 Japanese Patent No. 3718508 Japanese Patent No. 3416310 JP 2008-176056 A

  As described above, the addition of fluorine-based fine particles or silica fine particles to the charge transport layer, which is the outermost surface layer of the photoconductor, is effective for improving the printing durability of the photoconductor surface in the image forming process. However, when improving light resistance, the charge transport layer containing fluororesin fine particles and silica fine particles traps the fluororesin fine particles themselves. It becomes a problem. Further, when dispersing the fluororesin fine particles or silica fine particles, a high-pressure homogenizer or a high-pressure liquid collision is used. However, the charge transport material as disclosed in Patent Document 2 is decomposed / deteriorated, and an electric potential such as an increase in residual potential is generated. It adversely affects the characteristics and makes it difficult to achieve both the light resistance and the printing durability.

  As a result of intensive studies to solve the above-mentioned problems, the present inventors have found that the charge transport layer in the laminated electrophotographic photosensitive member contains a specific enamine derivative, fluororesin fine particles or silica in a binder (also referred to as a binder resin). It has been found that the above problems can be solved by the electrophotographic photosensitive member containing 1 to 15% by weight of the charge transport material together with filler fine particles comprising at least one fine particle, and the present invention has been completed.

  Thus, according to the present invention, on the conductive support, the charge generation layer containing the charge generation material via the undercoat layer, and the filler fine particles comprising at least one of the charge transport material, the binder and the fluororesin fine particles or the silica fine particles. And a charge transport layer including the charge transport layer, wherein the charge transport layer has the following general formula (A):

(Where
a represents a hydrogen atom, a halogen atom, or an alkyl group, alkoxy group, dialkylamino group or aryl group which may have a substituent;
e is an integer of 1 to 6, and when e is 2 or more, a plurality of a may be the same or different and may be bonded to each other to form a ring structure;
b, c and d are the same or different from each other, and each represents an alkyl group, an alkoxy group, a dialkylamino group, an aryl group, an aryloxy group or an arylthio group, which may have a hydrogen atom, a halogen atom, or a substituent. And

f, g and h are the same or different from each other, and are integers of 1 to 5, and when f, g or h is 2 or more, each of a plurality of b, c or d may be the same or different from each other. Or each of b, c or d bonded to adjacent carbon atoms of the benzene ring may be bonded together to form a ring structure;
Ar ¹ and Ar ² are the same or different from each other, and each represents an alkyl group, aryl group, aralkyl group or heterocyclic group which may have a hydrogen atom or a substituent, provided that Ar ¹ and Ar ² Cannot simultaneously be hydrogen atoms, and Ar ¹ and Ar ² may be bonded to each other via an atom or atomic group to form a ring structure)
Containing 1 to 15% by weight of the tetraaryl enamine compound represented by

The charge transport material has the following general formula (B):

(In the formula, R ₁ and R ₂ are the same or different from each other and represent a hydrogen atom, a halogen atom, an alkyl group or an alkoxy group, and R ₃ , R ₄ , R ₅ and R ₆ are the same or different from each other. Represents a hydrogen atom, an alkyl group or an alkoxy group, and i, j, k and l are 1 or 2)
And is contained in an amount of 30.0 to 45.0% by weight in the charge transport layer,
The filler fine particles are contained in the charge transport layer in an amount of 1.0 to 20.0% by weight ,
The binder, the filler fine particles, the tetraaryl enamine compound represented by the general formula (A) and the bistriphenylamine compound represented by the general formula (B) as a charge transport material are all contained in the same charge transport layer. An electrophotographic photosensitive member is provided.

According to the invention, in the general formula (A), the following partial structure:
But the following:

And the following substructure:

But independently of each other:

And the following substructure:

But the following:

Wherein Ar ¹ or Ar ² is the following substituent:

Or said Ar ² or Ar ¹ is the following substituent:

Or said Ar ¹ and Ar ² together are the following substituents:

The above electrophotographic photoreceptor is provided.

According to the invention, in the general formula (B), R ₁ and R ₂ are the same as or different from each other, and represent a hydrogen atom, a C ₁ -C ₄ alkyl group, or a C ₁ -C ₄ alkoxy group. , R ₃ , R ₄ , R ₅ and R ₆ are the same or different from each other, and are a hydrogen atom, a 2-, 3- or 4-C ₁ -C ₄ alkyl group, or 2-, 3- or 4-C _1. The above-mentioned electrophotographic photoreceptor, which means a C ₄ alkoxy group and i, j, k and l are 1 or 2, is provided.

  In addition, according to the present invention, there is provided an electrophotographic photoreceptor in which the charge transport material is contained in an amount of 30.0 to 45.0% by weight in the charge transport layer.

  Further, according to the present invention, there is provided the electrophotographic photosensitive member, wherein the filler fine particles are contained in an amount of 1.0 to 20.0% by weight in the charge transport layer.

  The present invention also provides the electrophotographic photosensitive member, wherein the fluororesin microparticles are tetrafluoroethylene resin (PTFE) microparticles.

  Further, according to the present invention, the electrophotographic photosensitive member, a charging unit that charges the electrophotographic photosensitive member, and an exposing unit that exposes the charged electrophotographic photosensitive member to form an electrostatic latent image; Developing means for developing the electrostatic latent image with toner to form a toner image; transfer means for transferring the toner image onto a recording material; and fixing for fixing the transferred toner image on the recording material An image forming apparatus including the means is provided.

  According to the present invention, the charge transport layer of the multilayer electrophotographic photoreceptor contains a charge transport material, a binder, filler fine particles composed of at least one of fluororesin fine particles or silica fine particles, and a specific tetraaryl enamine compound. There has been no problem even when exposed to external light, and it has become possible to provide an electrophotographic photoreceptor having high wear resistance and being electrically stable for a long period of time and an image forming apparatus including the photoreceptor.

FIG. 2 is a schematic cross-sectional view illustrating a configuration of a main part of a photoconductor according to the present invention. 1 is a schematic side cross-sectional view illustrating a configuration of a main part of an image forming apparatus according to the present invention. It is a figure which shows the 340-460 nm ultraviolet * visible absorption spectrum of the compound A-1 in this invention. It is a figure which shows the 340-460 nm ultraviolet * visible absorption spectrum of the compound B-1 in this invention.

In the multilayer electrophotographic photoreceptor according to the present invention, the charge transport layer has the following general formula (A):

(Where
a represents a hydrogen atom, a halogen atom, or an alkyl group, alkoxy group, dialkylamino group or aryl group which may have a substituent;
e is an integer of 1 to 6, and when e is 2 or more, a plurality of a may be the same or different and may be bonded to each other to form a ring structure;
b, c and d are the same or different from each other, and each represents an alkyl group, an alkoxy group, a dialkylamino group, an aryl group, an aryloxy group or an arylthio group, which may have a hydrogen atom, a halogen atom, or a substituent. And

  f, g and h are the same or different from each other, and are integers of 1 to 5, and when f, g or h is 2 or more, each of a plurality of b, c or d may be the same or different from each other. Or each of b, c or d bonded to adjacent carbon atoms of the benzene ring may be bonded together to form a ring structure;

Ar ¹ and Ar ² are the same or different from each other, and each represents an alkyl group, aryl group, aralkyl group or heterocyclic group which may have a hydrogen atom or a substituent, provided that Ar ¹ and Ar ² Cannot simultaneously be hydrogen atoms, and Ar ¹ and Ar ² may be bonded to each other via an atom or atomic group to form a ring structure)
The tetraaryl enamine compound represented by the formula (1) is contained in an amount of 1 to 15% by weight based on the charge transport material.

In the provision of the above Formula (A), the alkyl group which may have a substituent a, C ₁ -C ₄ alkyl group, optionally substituted by C ₁ -C ₄ alkoxy group or a halogen atom An alkyl group is mentioned. More specifically, methyl group, ethyl group, n-propyl group, isopropyl group, n-butyl group, isobutyl group, 1-methoxyethyl group, fluoromethyl group, trifluoromethyl group and the like can be mentioned. Particularly preferred are methyl, isopropyl and trifluoromethyl groups.

As the alkoxy group which may have a substituent a, C ₁ -C ₄ alkyl groups include alkoxy group which may be substituted by C ₁ -C ₄ alkoxy group or a halogen atom. More specifically, a methoxy group, an ethoxy group, an n-propoxy group, an isopropoxy group, an n-butoxy group, an isobutoxy group, and the like can be given. Among these, a methoxy group is particularly preferable.
As the good dialkylamino group which may have a substituent a, C ₁ -C ₄ alkyl group, and a good dialkylamino group optionally substituted with C ₁ -C ₄ alkoxy group or a halogen atom. More specifically, a dimethylamino group, a diethylamino group, a diisopropylamino group, etc. are mentioned.

As the aryl group which may have a substituent a, C ₁ -C ₄ alkyl group, an aryl group which may be substituted by C ₁ -C ₄ alkoxy group or a halogen atom. More specifically, a phenyl group, tolyl group, xylyl group, methoxyphenyl group, 4-chlorophenyl group, 4-fluorophenyl group, naphthyl group, methoxynaphthyl group and the like can be mentioned.
Furthermore, as a halogen atom as a substituent of a, a fluorine atom, a chlorine atom, a bromine atom, an iodine atom, etc. are mentioned, Among these, a fluorine atom is particularly preferable.

The alkyl group which may have substituents b, c and d in the definition of the general formula (A) has the same meaning as the above a, and a methyl group is particularly preferable.
Moreover, the alkoxy group which may have a substituent of b, c, and d is synonymous with said a, and a methoxy group is especially preferable.
Moreover, the dialkylamino group which may have a substituent of b, c, and d is synonymous with said a, and a dimethylamino group is especially preferable.

Further, b, as the aryl group which may have a substituent group c and d, are substituted by C ₁ -C ₄ alkyl group, C ₁ -C ₄ alkoxy groups, C ₆ -C ₁₀ aryl group or a halogen atom An aryl group which may be present. More specifically, phenyl group, tolyl group, xylyl group, methoxyphenyl group, 4-chlorophenyl group, 4-fluorophenyl group, biphenylyl group, naphthyl group, methoxynaphthyl group and the like can be mentioned. And the groups phenyl and biphenylyl are particularly preferred.

In addition, examples of the aryloxy group which may have a substituent of b, c, and d include a 4-methylphenoxy group.
In addition, examples of the arylthio group which may have a substituent of b, c and d include a phenylthio group.
Furthermore, the halogen atom as a substituent of b, c, and d is synonymous with said a.

The alkyl group which may have a substituent for Ar ¹ and Ar ² has the same meaning as a above, and a methyl group is particularly preferable.
As the aryl group which may have a substituent of Ar ¹ and Ar ⁵ , for example, a C ₁ -C ₄ alkyl group, a C ₁ -C ₄ alkoxy group, a C ₂ -C ₆ dialkylamino group or a halogen atom is substituted. An aryl group which may be used is mentioned.

  More specifically, phenyl group, tolyl group, xylyl group, isopropylphenyl group, methoxyphenyl group, methylmethoxyphenyl group, t-butylphenyl group, 4-diethylaminophenyl group, 4-chlorophenyl group, 2-fluorophenyl group 4-fluoroethylphenyl group, naphthyl group, methoxynaphthyl group and the like. Among these, phenyl group, tolyl group, methoxyphenyl group and naphthyl group are particularly preferable.

Examples of the arylalkyl group which may have a substituent for Ar ¹ and Ar ² include a benzyl group.
Examples of the heterocyclic group which may have a substituent for Ar ¹ and Ar ² include a chromanyl group, a thienyl group, a 5-methylthienyl group, and a furyl group.

More specifically, in the general formula (A), the partial structure:
But the following:

And the following substructure:

But independently of each other:

And the following substructure:

But the following:

Wherein Ar ¹ or Ar ² is the following substituent:

Or said Ar ² or Ar ¹ is the following substituent:

Or said Ar ¹ and Ar ² together are the following substituents:

Means.
The tetraaryl enamine compound represented by the general formula (A) can be synthesized by the method described in JP-A No. 2004-151666, and specific compounds thereof are shown in Table 1 below.

Among these compounds, compounds A-1, A-43 and A-111 are particularly preferable.
Moreover, in embodiment of this invention, it is preferable to contain 1-15 weight% of compounds of general formula (A) with respect to the said charge transport material, and it is more preferable to contain 3-10 weight%.
If the content is less than 1% by weight, the light resistance effect cannot be obtained.
In the multilayer electrophotographic photosensitive member according to the present invention, the charge transport material has the following general formula (B):

(In the formula, R ₁ and R ₂ are the same or different and each represents a hydrogen atom, a halogen atom, an alkyl group or an alkoxy group, and R ₃ , R ₄ , R ₅ and R ₆ are the same or different from each other. Represents a hydrogen atom, an alkyl group or an alkoxy group, and i, j, k and l are 1 or 2)
It is a bistriphenylamine compound represented by

More specifically, in each of the substituents in the general formula (B), preferably R ₁ and R ₂ are the same or different from each other, and are a hydrogen atom, a halogen atom, a C ₁ -C ₄ alkyl group, or C _{1 to} C ₄ alkoxy group, R ₃ , R ₄ , R ₅ and R ₆ are the same or different from each other, and represent a hydrogen atom, a C _{1 to} C ₄ alkyl group, a C _{1 to} C ₄ alkoxy group, i , J, k or l represents an integer of 1 or 2.
These charge transport materials are conventionally known and can be produced according to the method described in JP-A No. 2000-256276. Specific examples thereof are shown in Table 2 below.

  FIG. 3 is a diagram showing an ultraviolet / visible absorption spectrum of Compound A-1 at 340 to 460 nm in the present invention. As can be seen from this figure, the substance absorbs light around 440 nm.

  FIG. 4 is a diagram showing an ultraviolet / visible absorption spectrum of Compound B-1 at 340 to 460 nm in the present invention. As can be seen from this figure, the substance transmits light around 440 nm.

  In addition, said absorption spectrum is the result of having melt | dissolved compound A-1 and B-1 in tetrahydrofuran (THF) in 0.01% concentration, respectively, and measuring with the spectrophotometer (Hitachi Co., Ltd. U-2000). is there.

  In general, damage caused by external light such as a fluorescent lamp to the photoreceptor is caused by the external light passing through the charge transport layer and the transmitted light acting on the charge generating material to generate a charge trap. Normally, external light such as a fluorescent lamp has a light wavelength component near 440 nm, and when this light passes through the charge transport layer, it acts on the charge generating material and generates a charge trap.

  As seen in FIG. 3, the tetraaryl enamine compound of the general formula (A) absorbs light in the vicinity of 400 to 450 nm. As a result, most of the external light does not reach the charge generation layer, so that it is expected to improve the light resistance of the phthalocyanine-based charge generation material, and thus improve the light resistance of the photoreceptor.

  As shown in FIG. 4, the bistriphenylamine compound of the general formula (B) does not absorb near 440 nm, and polycarbonate and polyarylate generally used as binders also do not absorb near 440 nm. Until the light reaches. Further, trap generation is remarkable in a phthalocyanine-based charge generating material that is generally used.

Therefore, in the present invention, it is considered that the tetraaryl enamine compound of the general formula (A) has a light transmission protective action around 440 nm on the charge generation layer.
In addition, photoreceptors having a charge transport layer containing fluororesin fine particles and silica fine particles themselves become traps of charges, so that electric characteristics such as increase in residual potential are easily deteriorated, and an ultraviolet absorber or the like is added. When the agent is added, the electrical characteristics are greatly deteriorated.

However, when the filler fine particles composed of fluororesin fine particles and / or silica fine particles and the tetraaryl enamine compound of the general formula (A) are used in combination, the reason is not well understood, but light in the vicinity of 400 to 450 nm is absorbed. There is no adverse effect on the electrical characteristics of the charge transport layer due to the addition of the fluororesin fine particles or silica fine particles even in the charge transport layer to which the fluororesin fine particles or silica fine particles are added by adding the tetraaryl enamine compound of the general formula (A). It has been found that deterioration due to external light can be improved.
Therefore, in the present invention, the tetraaryl enamine compound represented by the general formula (A) contains filler particles composed of fluororesin fine particles and / or silica fine particles due to the light transmission protection action around 440 nm on the charge generation layer. It is considered that the filler particles are added when added to the filler.

  Hereinafter, embodiments and examples of the present invention will be described in detail with reference to FIGS. Note that the embodiments and examples described below are merely specific examples of the present invention, and the present invention is not limited thereto.

Embodiment 1
FIG. 1 is a schematic cross-sectional view showing the configuration of the electrophotographic photoreceptor according to the first exemplary embodiment of the present invention.
The electrophotographic photoreceptor 1 according to the first embodiment includes an undercoat layer 18, a charge generation layer 15 containing a charge generation material 12, and a charge transport material on a cylindrical conductive substrate 11 made of a conductive material. 13 is a laminated type photoreceptor composed of a photosensitive layer 14 in which a charge transport layer 16 containing 13 is laminated in this order.

Conductive substrate 11 (hereinafter also referred to as a conductive support)
The conductive substrate 11 serves as an electrode of the photoreceptor 1 and also functions as a support member for the undercoat layer 18 and the photosensitive layer 14 disposed thereon.
In addition, although the shape of the electroconductive base | substrate 11 is cylindrical shape in this Embodiment 1, it is not limited to this, A column shape, a sheet form, or an endless belt shape etc. may be sufficient.

Examples of the conductive material constituting the conductive substrate 11 include conductive metals such as aluminum, copper, brass, zinc, nickel, stainless steel, chromium, molybdenum, vanadium, indium, titanium, gold, and platinum; or aluminum alloys And metal oxides such as tin oxide and indium oxide can be used.
Also, without being limited to these metal materials, a polymer material such as polyethylene terephthalate, nylon, polyester, polyoxymethylene or polystyrene, a laminate of the metal foil on the surface of hard paper or glass; A vapor-deposited material or a material obtained by vapor-depositing or coating a conductive compound layer such as a conductive polymer, tin oxide, or indium oxide can also be used.
These conductive materials are used after being processed into a predetermined shape.

If necessary, the surface of the conductive substrate 11 is irregularly reflected within a range that does not affect the image quality, such as anodic oxide film treatment, surface treatment with chemicals or hot water, coloring treatment, or roughening the surface. Processing may be performed.
In the electrophotographic image forming process using a laser as an exposure light source, the wavelengths of the laser light are uniform, so the laser light reflected on the surface of the photoconductor and the laser light reflected inside the photoconductor cause interference, and this interference Interference fringes due to may appear on the image and cause image defects.
However, by performing the above-described treatment on the surface of the conductive substrate 11, image defects due to interference of laser light having the same wavelength can be prevented.

Undercoat layer 18 (hereinafter also referred to as an intermediate layer)
When the undercoat layer 18 is not provided between the conductive substrate 11 and the photosensitive layer 14, the charging property is reduced in a minute region due to defects in the conductive substrate 11 or the photosensitive layer 14, and black spots or the like are caused. Image fogging may occur, resulting in significant image defects. However, by providing the undercoat layer 18, it is possible to prevent injection of charges from the conductive substrate 11 to the photosensitive layer 14.

Therefore, the provision of the undercoat layer 18 can prevent the chargeability of the photosensitive layer 14 from being lowered, suppress the reduction of the surface charge other than the portion to be erased by exposure, and cause defects such as fogging on the image. Can be prevented.
Further, by providing the undercoat layer 18, it is possible to cover the unevenness of the surface of the conductive substrate 11 to obtain a uniform surface, so that the film formability of the photosensitive layer 14 is improved and the conductive substrate 11 of the photosensitive layer 14 is improved. Can be prevented from being peeled off, and the adhesion between the conductive substrate 11 and the photosensitive layer 14 can be improved.
For the undercoat layer 18, a resin layer or an alumite layer made of various resin materials is used.

  As the resin material constituting the undercoat layer 18, polyethylene resin, polypropylene resin, polystyrene resin, acrylic resin, vinyl chloride resin, vinyl acetate resin, polyurethane resin, epoxy resin, polyester resin, melamine resin, silicone resin, polyvinyl butyral resin And resins such as polyvinylpyrrolidone resin, polyacrylamide resin and polyamide resin, and copolymer resins containing two or more of repeating units constituting these resins. Further, casein, gelatin, polyvinyl alcohol, cellulose, nitrocellulose, ethylcellulose and the like are also included.

Among these resins, it is preferable to use a polyamide resin, and it is particularly preferable to use an alcohol-soluble nylon resin.
Preferred alcohol-soluble nylon resins include so-called nylons such as 6-nylon, 6,6-nylon, 6,10-nylon, 11-nylon, 2-nylon and 12-nylon, and N-alkoxymethyl-modified nylon and Examples thereof include resins obtained by chemically modifying nylon such as N-alkoxyethyl-modified nylon.

In order to give the undercoat layer a charge adjusting function, filler fine particles which are metal oxide fine particles can be added. Examples of such filler fine particles include fine particles such as titanium oxide, aluminum oxide, aluminum hydroxide, and tin oxide. The fine particle diameter of the metal oxide is suitably about 0.01 to 0.3 μm, and preferably about 0.02 to 0.1 μm.
The undercoat layer 18 is prepared, for example, by dissolving or dispersing the above resin in an appropriate solvent to prepare a coating solution for an intermediate layer, applying this coating solution to the surface of the conductive substrate 11, and drying it. It is formed.

When the undercoat layer 18 contains fine particles such as the above metal oxide fine particles, for example, the metal oxide fine particles such as titanium oxide are dispersed in a resin solution obtained by dissolving the above resin in an appropriate solvent. The undercoat layer 18 can be formed by preparing an undercoat layer coating solution and applying this coating solution to the surface of the conductive substrate 11.
As the solvent for the coating solution for the undercoat layer, water, various organic solvents, or a mixed solvent thereof is used. For example, water or alcohol such as methanol, ethanol or butanol alone, or water and alcohol, a mixture of two or more alcohols, acetone or dioxolane and alcohol, halogen organic solvents such as dichloroethane, chloroform or trichloroethane and alcohol, etc. A mixed solvent is used.

Among these solvents, non-halogen organic solvents are preferably used in consideration of the global environment.
As a method for dispersing the fine particles in the resin solution, a general dispersion method using a ball mill, a sand mill, an attritor, a vibration mill, an ultrasonic disperser, a paint shaker, or the like can be used.

In addition, a more stable dispersion coating liquid can be produced by using a medialess type dispersion apparatus that uses a very strong shearing force generated by passing the dispersion liquid through a micro gap at an ultrahigh pressure. It becomes possible.
Examples of the coating method for the coating solution for the undercoat layer include a spray method, a bar coating method, a roll coating method, a blade method, a ring method, and a dip coating method.

Among these coating methods, in particular, the dip coating method is a method of forming a layer on the surface of the substrate by immersing the substrate in a coating tank filled with a coating solution and then pulling it up at a constant speed or a speed that changes sequentially. Since it is relatively simple and excellent in terms of productivity and cost, it is widely used in the production of electrophotographic photosensitive members.
The film thickness of the undercoat layer 18 is preferably 0.01 to 20 μm, more preferably 0.05 to 10 μm.

If the thickness of the undercoat layer 18 is less than 0.01 μm, the unevenness of the conductive substrate 11 cannot be covered and uniform surface properties cannot be obtained. This is not preferable because the injection of charges from the photosensitive substrate 11 to the photosensitive layer 14 cannot be prevented and the chargeability of the photosensitive layer 14 is lowered.
If the thickness of the undercoat layer 18 is greater than 20 μm, it becomes difficult to form the undercoat layer 18 by a dip coating method, and the photosensitive layer 14 cannot be uniformly formed on the undercoat layer 18. This is not preferable because the sensitivity of is reduced.

Charge generation layer 15
The charge generation layer 15 contains, as a main component, the charge generation material 12 that generates charges by absorbing light.
Examples of the charge generation material 12 include azo pigments such as monoazo pigments, bisazo pigments, and trisazo pigments; indigo pigments such as indigo and thioindigo; perylene pigments such as peryleneimide and perylene anhydride; anthraquinone and pyrenequinone Polycyclic quinone pigments such as: metal phthalocyanines such as oxotitanium phthalocyanine compounds and phthalocyanine compounds such as metal-free phthalocyanines; organic photoconductive materials such as squarylium dyes, pyrylium salts and thiopyrylium salts, triphenylmethane dyes; and selenium And inorganic photoconductive materials such as amorphous silicon.

One of these charge generation materials 12 may be used alone, or two or more of these charge generation materials 12 may be used in combination.
Among these charge generation materials 12, it is preferable to use phthalocyanine compounds, particularly oxotitanium phthalocyanine compounds.
The oxotitanium phthalocyanine compound used in the present invention is oxotitanium phthalocyanine and its derivatives. As the oxotitanium phthalocyanine derivative, for example, a hydrogen atom of an aromatic ring contained in a phthalocyanine group of oxotitanium phthalocyanine is substituted with a halogen atom such as a chlorine atom or a fluorine atom, a substituent such as a nitro group, a cyano group or a sulfonic acid group. And those in which a ligand such as a chlorine atom is coordinated to a titanium atom which is a central metal of oxotitanium phthalocyanine.

The oxotitanium phthalocyanine compound preferably has a specific crystal structure. Of the oxotitanium phthalocyanine compounds, the X-ray diffraction spectrum for Cu-Kα characteristic X-ray (wavelength: 1.54 Å) is preferably diffracted at a Bragg angle 2θ (error: ± 0.2 °) 27.2 °. The thing which has the crystal structure which shows a peak is mentioned. Here, the Bragg angle 2θ is an angle formed by incident X-rays and diffracted X-rays, and represents a so-called diffraction angle.
Use of such an oxotitanium phthalocyanine compound as the charge generation material 12 is particularly preferable because a photoconductor further excellent in sensitivity and resolution can be realized.

  That is, since the oxotitanium phthalocyanine compound is excellent in charge generation capability and charge injection capability, it generates a large amount of charge by absorbing light, and does not accumulate the generated charge in the charge transport layer 16. Can be injected efficiently.

The oxotitanium phthalocyanine compound can be produced according to a conventionally known production method such as, for example, a method described in Phthhalocyanine Compounds by Moser and Thomas, Reinhold Publishing Corp., New York, 1963.
For example, oxotitanium phthalocyanine synthesizes dichlorotitanium phthalocyanine by melting and melting phthalonitrile and titanium tetrachloride in a suitable solvent such as α-chloronaphthalene, followed by base or water. It can be produced by hydrolysis. Alternatively, oxotitanium phthalocyanine can also be produced by reacting isoindoline with titanium tetraalkoxide such as tetrabutoxytitanium in a suitable solvent such as N-methylpyrrolidone.

As a method for forming the charge generation layer 15, the charge generation material 12 is vacuum-deposited on the surface of the conductive substrate 11, or the charge generation layer 12 is obtained by dispersing the charge generation material 12 in a suitable solvent. For example, a method of applying a coating solution to the surface of the conductive substrate 11 is used.
Among these, the charge generation material 12 is dispersed by a conventionally known method in a binder resin solution obtained by mixing a binder resin as a binder in a solvent to prepare a coating solution for a charge generation layer. A method of applying the obtained coating solution to the surface of the conductive substrate 11 is preferably used. Hereinafter, this method will be described.

  Examples of the binder resin used for the charge generation layer 15 include polyester resin, polystyrene resin, polyurethane resin, phenol resin, alkyd resin, melamine resin, epoxy resin, silicone resin, acrylic resin, methacrylic resin, polycarbonate resin, and polyarylate resin. And resins such as phenoxy resin, polyvinyl butyral resin, polyvinyl chloride resin and polyvinyl formal resin, and copolymer resins containing two or more of the repeating units constituting these resins.

Specific examples of the copolymer resin include insulating resins such as vinyl chloride-vinyl acetate copolymer resin, vinyl chloride-vinyl acetate-maleic anhydride copolymer resin, and acrylonitrile-styrene copolymer resin. be able to.
The binder resin is not limited to these, and a commonly used resin can be used as the binder resin. One kind of these resins may be used alone, or two or more kinds thereof may be mixed and used.

  Examples of the solvent of the coating solution for the charge generation layer include halogenated hydrocarbons such as dichloromethane or dichloroethane, alcohols such as methanol and ethanol, ketones such as acetone, methyl ethyl ketone and cyclohexanone, esters such as ethyl acetate and butyl acetate, Ethers such as tetrahydrofuran or dioxane, alkyl ethers of ethylene glycol such as 1,2-dimethoxyethane, aromatic hydrocarbons such as benzene, toluene or xylene, or N, N-dimethylformamide or N, N-dimethylacetamide An aprotic polar solvent such as is used.

Among the above solvents, non-halogen organic solvents are preferably used in consideration of the global environment. As for said solvent, 1 type may be used independently and may be used as 2 or more types of mixed solvents.
In the charge generation layer 15 configured to include the charge generation material 12 and the binder resin, the ratio W1 / W2 between the weight W1 of the charge generation material 12 and the weight W2 of the binder resin is 10/100 to 400/100. It is preferable that

When the ratio W1 / W2 is less than 10/100, the sensitivity of the photoreceptor 1 is likely to be lowered.
Conversely, when the ratio W1 / W2 exceeds 400/100, not only the film strength of the charge generation layer 15 is decreased, but also the dispersibility of the charge generation material 12 is decreased and coarse particles are increased. The surface charge other than the portion to be erased decreases, and the image defect, particularly the fogging of the image called black spots where toner adheres to a white background and minute black spots are formed increases.
Therefore, a suitable range of the ratio W1 / W2 is 10/100 to 400/100.

Examples of the coating method for the charge generation layer coating liquid include a spray method, a bar coating method, a roll coating method, a blade method, a ring method, and a dip coating method.
Among these coating methods, the dip coating method described in the undercoat layer coating method is particularly preferable.
The film thickness of the charge generation layer 15 is preferably 0.05 to 5 μm, more preferably 0.1 to 1 μm.

If the film thickness of the charge generation layer 15 is less than 0.05 μm, the charge generation efficiency due to light absorption decreases, and the sensitivity of the photoreceptor 1 decreases.
On the contrary, if the film thickness of the charge generation layer 15 exceeds 5 μm, the light absorption efficiency is lowered, and the charge transfer inside the charge generation layer 15 becomes a rate-limiting step in the process of erasing the surface charge of the photosensitive layer 14. As a result, the sensitivity of the photoreceptor 1 is lowered.
Therefore, a preferable range of the film thickness of the charge generation layer 15 is 0.05 to 5 μm.

Charge transport layer 16
A charge transport layer 16 is provided on the charge generation layer 15. The charge transport layer 16 accepts the charge generated by the charge generation material 12 contained in the charge generation layer 15 and transports the charge transport material 13, the binder 17 binding the charge transport material 13, and the fluororesin fine particles or silica. Filler fine particles 19 composed of at least one of the fine particles and a compound of the general formula (A).

  Examples of the charge transport material 13 include carbazole derivatives, oxazole derivatives, oxadiazole derivatives, thiazole derivatives, thiadiazole derivatives, triazole derivatives, imidazole derivatives, imidazolone derivatives, imidazolidine derivatives, bisimidazolidine derivatives, styryl compounds, hydrazone compounds, Polycyclic aromatic compounds, indole derivatives, pyrazoline derivatives, oxazolone derivatives, benzimidazole derivatives, quinazoline derivatives, benzofuran derivatives, acridine derivatives, phenazine derivatives, aminostilbene derivatives, triarylamine derivatives, triarylmethane derivatives, phenylenediamine derivatives, stilbene Derivatives and benzidine derivatives can be mentioned.

However, in the present invention, in the case of the charge transport layer 16 in which filler fine particles are dispersed, it is particularly preferable to use the bistriphenylamine compound of the general formula (B) as the charge transport material. This is because when the fine particles are dispersed, the charge transporting material is likely to be deteriorated and the electric characteristics are deteriorated. However, when the fine particles are dispersed in combination with the tetraarylenamine compound represented by the general formula (A), This is because the electrical characteristics of the bistriphenylamine compound of the general formula (B) are very little deteriorated without causing adverse effects of the silica fine particles.
As the binder resin constituting the charge transport layer 16, a resin mainly composed of polycarbonate or polyarylate, which is well known in the art, is suitably selected for reasons such as excellent transparency and printing durability.

The charge transport material 13 is preferably contained in the charge transport layer in an amount of 30.0 to 45.0% by weight. Furthermore, it is more preferable that 33.0 to 40.0% by weight is contained in the charge transport layer.
The charge transport layer 16 contains filler fine particles 19 made of at least one of the above-mentioned fluororesin fine particles or silica fine particles for the purpose of improving the wear resistance and the like.
The filler fine particles 19 are preferably contained in the charge transport layer in an amount of 1.0 to 20.0% by weight. Furthermore, it is more preferable to contain 5.0 to 15.0 weight% in a charge transport layer.

  Fluorine resin fine particles include tetrafluoroethylene resin (PTFE) fine particles, trifluorinated ethylene chloride resin fine particles, hexafluoropropylene resin fine particles, vinyl fluoride resin fine particles, vinylidene fluoride resin fine particles, difluorinated dichloride ethylene resin. Fluorine-based fine particles and copolymer resin fine particles containing these units, tetrafluoroethylene / perfluoroalkyl vinyl ether copolymer (PFA) resin fine particles, tetrafluoroethylene / hexafluoropropylene copolymer (FEP) resin fine particles, etc. Examples thereof include resin fine particles.

In particular, from the viewpoint of dispersibility and dispersion stability, tetrafluoroethylene resin (PTFE) fine particles are preferable.
As specific fluororesin fine particles, as commercial products of tetrafluoroethylene resin, product names of Daikin Industries, Ltd .: Lubron L-2, L-5, L-5F; Product names of Kitamura Co., Ltd .: KTL-500F , KTL-1N, KTL-2N; Product name of Asahi Glass Co., Ltd .: FLUON PTFE L173J; Product name of Techno Chemical Co., Ltd .: microdispers-200; Product name of Soken Chemical Co., Ltd .: MP-300; Company product name: TLP-10F-1.

Further, examples of the fine particles of tetrafluoroethylene / perfluoroalkyl vinyl ether copolymer (PFA) resin include product name: MP-101 of Mitsui / DuPont Fluorochemical Co., Ltd.
Examples of the fine particles of tetrafluoroethylene / hexafluoropropylene copolymer (FEP) resin include Mitsui-DuPont Fluorochemical Co., Ltd. product name: 120-JR.
The fluororesin fine particles preferably have an average primary particle diameter of 0.02 to 5 μm.
When the average primary particle diameter of the fluororesin fine particles is less than 0.02 μm, the fine particles are agglomerated and extremely difficult to disperse, and the dispersion stability may be lowered. On the other hand, when the average primary particle diameter of the fluororesin fine particles exceeds 5 μm, image quality defects are likely to occur.

The average primary particle diameter of the more preferable fluororesin fine particles is 0.1 to 3 μm.
In the present invention, the average primary particle size is diluted with the same solvent as the dispersion liquid in which the fine particles are dispersed using, for example, a laser diffraction / scattering particle size analyzer (manufactured by Nikkiso Co., Ltd., model: Microtrack MT3000II). The value measured with the measured solution.
Silica fine particles may be surface-treated with an inorganic substance or an organic substance for the purpose of improving dispersibility, modifying surface properties, and the like. In general, the water repellent treatment of silica fine particles includes a treatment with a silane coupling agent, a treatment with a fluorine-based silane coupling agent, a higher fatty acid treatment or a copolymerization treatment between polymer materials, and inorganic treatment includes alumina, Examples include zirconia, tin oxide, and silica treatment.

If the average primary particle size of the silica fine particles is too large, the friction coefficient increases and the light transmittance may be reduced. On the other hand, if the average primary particle size is too small, the wear resistance may be deteriorated. It is preferably 1.0 μm, more preferably 0.1 to 0.5 μm.
As specific silica fine particles, product names of Nippon Aerosil Co., Ltd .: R972, R974, NY50, RX50; product names of Cabot Japan Co., Ltd .: TS610, TS612, TS620, TS630; product name of Shin-Etsu Chemical Co., Ltd .: X -24-9163A; Product name of Admatechs Corporation: SO-E1, SO-E2, SE100-GDT, SE100-SPT.

Further, a dispersant may be added in order to improve the dispersibility and dispersibility stability of the filler fine particles composed of fluororesin fine particles and / or silica fine particles. More specifically, Surflon S-611, Surflon S-385 (manufactured by AGC Seimi Chemical Co., Ltd.), Megafuck EXP, TF-1507, Megafuck EXP, TF-1535 (manufactured by Dainippon Ink, Inc.), FC-4430, FC-4432 (manufactured by 3M) and GF400 (manufactured by Toa Gosei Co., Ltd.) can be mentioned.
For dispersing the filler fine particles, a known disperser such as a homogenizer or a high-pressure collision type can be used.

In particular, a high-pressure collision type disperser is preferable from the viewpoint of reducing damage to fine particles.
Examples of the high-pressure collision type disperser include a high-pressure jet type emulsifying disperser. This high-pressure injection type emulsifying disperser presses a processing liquid (slurry, emulsified liquid or dispersion) with a high-pressure plunger pump, etc., into a fine flow path, and injects it at a high pressure from the discharge port by adjusting a special valve in the discharge section. -It means a wet atomization device that emulsifies, disperses, and treats a surface without causing damage to fine particles by colliding.

  Therefore, the high-pressure jet disperser is used for emulsifying / dispersing or pulverizing the object to be dispersed due to the collision between the high-pressure jet liquids and the collision between the high-pressure jet liquid and the wall of the device by adjusting the pressure when jetting from the discharge port. Is done. Therefore, the above-described high-pressure jet disperser includes a high-pressure pump, a jig having a plurality of small-diameter orifices connected to the high-pressure pump, and processing so that the liquids collide when the liquid is discharged from the orifices. It is possible to use an apparatus constituted by the prepared jig.

As such an apparatus, Starburst of Sugino Machine Co., Ltd., NanoVita of Yoshida Machine Industry Co., Ltd., and Microfluidizer of Microfluidics can be used.
Note that it is desirable to attach a cooling device to the dispersion circuit because the heat generated by the liquid collision tends to accumulate as the number of collision passes increases.

The high pressure referred to in the present invention preferably means 10 to 300 MPa, which is roughly determined by the discharge amount, discharge pressure, orifice diameter and length of the high-pressure pump, as well as the viscosity of the solvent and the material to be dispersed.
When the treatment pressure is lower than 10 MPa, the collision energy between the liquids is insufficient, and the desired particle size cannot be dispersed.
On the other hand, when the treatment pressure is higher than 300 MPa, the collision energy between the liquids is too high, and there is a risk of deterioration of the dispersion and explosion of the dispersion. A more preferable processing pressure is 50 to 150 MPa.

In addition, various additives may be added to the charge transport layer 16 as necessary. That is, a plasticizer or a leveling agent may be added in order to improve the film formability, flexibility, or surface smoothness.
Examples of the plasticizer include dibasic acid esters such as phthalate esters, fatty acid esters, phosphate esters, chlorinated paraffins, and epoxy type plasticizers.
Moreover, as said leveling agent, a silicone type leveling agent etc. can be mentioned, for example.

  The charge transport layer 16 is formed in the same manner as in the case where the charge generation layer 15 is formed by coating, for example, in a suitable solvent, the charge transport material 13, the binder resin 17, the filler fine particles and, if necessary, the additive The charge transport layer coating solution is prepared by dissolving or dispersing the agent, and the resulting coating solution is applied onto the charge generation layer 15 and dried.

Examples of the solvent for the charge transport layer coating solution include aromatic hydrocarbons such as benzene, toluene, xylene and monochlorobenzene, halogenated hydrocarbons such as dichloromethane and dichloroethane, ethers such as tetrahydrofuran, dioxane and dimethoxymethyl ether, and Examples include aprotic polar solvents such as N, N-dimethylformamide. These solvents may be used alone or in combination of two or more.
Further, if necessary, a solvent such as alcohols, acetonitrile or methyl ethyl ketone can be further added to the above solvent.
Among these solvents, non-halogen organic solvents are preferably used in consideration of the global environment.

  Examples of the coating method for the charge transport layer coating solution include a spray method, a bar coating method, a roll coating method, a blade method, a ring method, and a dip coating method. Among these coating methods, the dip coating method is particularly excellent in various respects as described above, and can be used when the charge transport layer 16 is formed.

The thickness of each charge transport layer 16 is preferably 5 to 40 μm, more preferably 10 to 30 μm.
If the film thickness of the charge transport layer 16 is less than 5 μm, the charge retention ability is lowered, and it becomes difficult to obtain a clear image.
On the other hand, when the thickness of the charge transport layer 16 exceeds 40 μm, the resolution of the photoreceptor 1 is lowered.
Therefore, the thickness of the charge transport layer 16 is preferably in the range of 5 to 40 μm.

Further, an antioxidant or an ultraviolet absorber may be added to each of the layers 15 and 16 of the photosensitive layer 14. In particular, it is preferable to add an antioxidant or an ultraviolet absorber to the charge transport layer 16, and the stability of the coating solution when forming each layer by coating can be improved.
Furthermore, it is particularly preferable to add an antioxidant to the charge transport layer 16. By adding this antioxidant to the charge transport layer, deterioration of the photosensitive layer with respect to an oxidizing gas such as ozone or nitrogen oxide can be reduced.

  Examples of the antioxidant include phenol compounds, hydroquinone compounds, tocopherol compounds, and amine compounds. Among these, a hindered phenol derivative or a hindered amine derivative, or a mixture thereof is preferably used.

Embodiment 2
FIG. 2 is a schematic cross-sectional view showing the configuration of the image forming apparatus according to the present invention.
An image forming apparatus 30 shown in FIG. 2 is a laser printer equipped with the photoreceptor 1 according to the first embodiment of the present invention.
Hereinafter, the configuration of the laser printer 30 and the image forming operation will be described with reference to FIG.
Note that the laser printer 30 shown in FIG. 2 is an exemplification of the present invention, and the image forming apparatus of the present invention is not limited at all by the following description.

A laser printer 30 as an image forming apparatus includes a photosensitive member 1, a semiconductor laser 31, a rotary polygon mirror 32, an imaging lens 34, a mirror 35, a corona charger 36 as a charging unit, a developing unit 37 as a developing unit, and transfer paper. A cassette 38, a paper feed roller 39, a registration roller 40, a transfer charger 41 as a transfer means, a separation charger 42, a transport belt 43, a fixing device 44, a paper discharge tray 45, and a cleaner 46 as a cleaning means.
The semiconductor laser 31, the rotary polygon mirror 32, the imaging lens 34, and the mirror 35 constitute an exposure unit 49.

  The photoreceptor 1 is mounted on the laser printer 30 so as to be rotatable in the direction of an arrow 47 by a driving unit (not shown). A laser beam 33 emitted from the semiconductor laser 31 is repeatedly scanned in the longitudinal direction (main scanning direction) with respect to the surface of the photoreceptor 1 by the rotary polygon mirror 32. The imaging lens 34 has f-θ characteristics, and the laser beam 33 is reflected by the mirror 35 to form an image on the surface of the photosensitive member 1 for exposure. By scanning the laser beam 33 as described above to form an image while rotating the photoconductor 1, an electrostatic latent image corresponding to image information is formed on the surface of the photoconductor 1.

The corona charger 36, the developing device 37, the transfer charger 41, the separation charger 42 and the cleaner 46 are provided in this order from the upstream side to the downstream side in the rotation direction of the photosensitive member 1 indicated by an arrow 47.
The corona charger 36 is provided on the upstream side of the image forming point of the laser beam 33 in the rotation direction of the photoconductor 1 and uniformly charges the surface of the photoconductor 1. Therefore, the laser beam 33 exposes the surface of the photosensitive member 1 that is uniformly charged, and a difference occurs between the charged amount of the portion exposed by the laser beam 33 and the charged amount of the portion not exposed. Electrostatic latent image is formed.

  The developing device 37 is provided on the downstream side in the rotation direction of the photosensitive member 1 with respect to the image forming point of the laser beam 33, supplies toner to the electrostatic latent image formed on the surface of the photosensitive member 1, and converts the electrostatic latent image into toner. Develop as an image. The transfer paper 48 accommodated in the transfer paper cassette 38 is taken out one by one by the paper feed roller 39 and is given to the transfer charger 41 by the registration roller 40 in synchronism with the exposure of the photoreceptor 1. The toner image is transferred onto the transfer paper 48 by the transfer charger 41. A separation charger 42 provided in the vicinity of the transfer charger 41 discharges the transfer paper onto which the toner image has been transferred and separates it from the photoreceptor 1.

  The transfer paper 48 separated from the photoreceptor 1 is conveyed to the fixing device 44 by the conveying belt 43, and the toner image is fixed by the fixing device 44. The transfer paper 48 on which the image is formed in this manner is discharged toward the paper discharge tray 45. In addition, after the transfer paper 48 is separated by the separation charger 42, the photoreceptor 1 that continues to rotate further cleans foreign matters such as toner and paper dust remaining on the surface by the cleaner 46. The photoreceptor 1 whose surface has been cleaned by the cleaner 46 is neutralized by a static eliminator (static elimination lamp) 50 provided together with the cleaner 46, and is further rotated to start a series of image forming operations starting from the charging of the photoreceptor 1. Is repeated.

Therefore, according to the present invention, there is provided an image forming apparatus comprising the electrophotographic photosensitive member according to the present invention, a charging unit, an exposure unit, a developing unit, a transfer unit, and a fixing unit.
The image forming apparatus of the present invention is not limited to the configuration of the image forming apparatus shown in FIG. 2, and any electrophotographic forming process can be used regardless of whether it is monochrome or color as long as it can use the above photoreceptor. Can be suitably used for various printers, copiers, facsimiles, multi-function machines, and the like using the printer.

  The image forming apparatus of the present invention is not limited to the above-described embodiment, and various modifications and changes can be made without departing from the spirit of the present invention. Other forms are described in this specification. And can be easily understood from the description of the drawings.

  EXAMPLES Hereinafter, although this invention is demonstrated further in detail using an Example, this invention is not limited to the following description content.

Example 1
Preparation of undercoat layer 3 parts by weight of titanium oxide (trade name: Tybak TTO-D-1, manufactured by Ishihara Sangyo Co., Ltd.) and 2 parts by weight of commercially available polyamide resin (trade name: Amilan CM8000, manufactured by Toray Industries, Inc.) In addition to 25 parts by weight of alcohol, dispersion treatment was carried out for 8 hours with a paint shaker to prepare 3 kg of an undercoat layer-forming coating solution. The obtained coating solution for the undercoat layer was filled in a coating tank, and an aluminum drum-like support having a diameter of 30 mm and a length of 357 mm was immersed as a conductive support and then pulled up to form an undercoat layer having a thickness of 1 μm. .

Preparation of Charge Generation Layer Next, titanyl phthalocyanine 1 having an X-ray diffraction spectrum in which the Bragg angle (2θ ± 0.2 °) of CuKα1.541Å as the charge generation material 12 exhibits a main peak at 27.2 ° 1 part by weight of butyral resin (trade name: ESREC BM-2, manufactured by Sekisui Chemical Co., Ltd.) as a binder and 98 parts by weight of methyl ethyl ketone are mixed and dispersed in a paint shaker for 8 hours to form a charge generation layer. A coating solution of 3 kg was prepared.
The obtained coating solution for forming the charge generation layer is applied to the surface of the undercoat layer previously provided in the same manner as in the formation of the undercoat layer, and then naturally dried to form a charge generation layer having a thickness of 0.3 μm. did.

Preparation of charge transport layer Compound B-1: D2448 manufactured by Tokyo Chemical Industry Co., Ltd. as charge transport material 100 parts by weight, polycarbonate resin (TS2050: manufactured by Teijin Chemicals) 140 parts by weight, PTFE fine particles (Lublon L-2: Daikin Industries Ltd.) (Company) 27 parts by weight, Compound A-1 5 parts by weight, dispersant (GF400: manufactured by Toa Gosei Co., Ltd.) 0.5 parts by weight were mixed, and a suspension having a solid content of 21% by weight was prepared using tetrahydrofuran as a solvent. Then, a wet emulsification dispersion apparatus Microfluidizer M-110P apparatus was used, and a 5-pass operation was performed under the conditions of a set pressure: 100 MPa to prepare 3 kg of a charge transport layer forming coating solution. This charge transport layer forming coating solution was applied to the surface of the charge generation layer previously provided by an immersion method and dried at 130 ° C. for 1 hour to form a charge transport layer having a thickness of 28 μm. In this way, the multilayer photoreceptor shown in FIG. 1 was produced.

Example 2
A laminated photoreceptor was obtained in the same manner as in Example 1 except that the compound A-1 was changed to the compound A-43.

Example 3
A laminated photoreceptor was obtained in the same manner as in Example 1 except that the compound A-1 was changed to the compound A-111.

Example 4
A laminated photoreceptor was obtained in the same manner as in Example 1 except that 5 parts by weight of Compound A-1 was changed to 1 part by weight.

Example 5
A laminated photoreceptor was obtained in the same manner as in Example 1 except that 5 parts by weight of Compound A-1 was changed to 15 parts by weight.

Example 6
Except for changing 27 parts by weight of PTFE fine particles (Lublon L-2: manufactured by Daikin Industries) to 2.5 parts by weight and 0.5 parts by weight of a dispersant (GF400: manufactured by Toagosei Co., Ltd.) to 0.05 parts by weight, A laminated photoreceptor was obtained in the same manner as in Example 1.

Example 7
Except that 27 parts by weight of PTFE fine particles (Lublon L-2: manufactured by Daikin Industries) was 61 parts by weight and 0.5 parts by weight of a dispersant (GF400: manufactured by Toa Gosei Co., Ltd.) was 1.2 parts by weight. In the same manner as in Example 1, a multilayer photoreceptor was obtained.

Example 8
A laminated photoreceptor was obtained in the same manner as in Example 1 except that the PTFE fine particles (Lublon L-2: manufactured by Daikin Industries, Ltd.) were changed to PTFE fine particles (KTL-1N: Kitamura Co., Ltd.).

Example 9
A laminated photoreceptor was obtained in the same manner as in Example 1 except that PTFE fine particles (Lublon L-2: manufactured by Daikin Industries, Ltd.) were changed to PFA fine particles (MP-101: Mitsui / DuPont Fluorochemical Co., Ltd.).

Example 10
A laminated photoreceptor was obtained in the same manner as in Example 1 except that the PTFE fine particles (Lublon L-2: manufactured by Daikin Industries) were changed to silica fine particles (SO-E2: manufactured by Admatex).

Example 11
A laminated photoreceptor was obtained in the same manner as in Example 1 except that the PTFE fine particles (Lublon L-2: manufactured by Daikin Industries) were changed to silica fine particles (TS610: manufactured by Cabot Specialty Chemicals).

Example 12
A laminated photoreceptor was obtained in the same manner as in Example 1 except that Compound B-1 as the charge transport material was changed to Compound B-2.

Example 13
A laminated photoreceptor was obtained in the same manner as in Example 1 except that Compound B-1 as the charge transport material was changed to Compound B-10.

Example 14
A laminated photoreceptor was obtained in the same manner as in Example 1 except that Compound B-1 as the charge transport material was changed to Compound B-51.

Example 15
Example 1 except that 140 parts by weight of polycarbonate resin (TS2050: manufactured by Teijin Chemicals Ltd.) was 190 parts by weight, and 27 parts by weight of PTFE fine particles (Lublon L-2: manufactured by Daikin Industries) was 33 parts by weight. As a result, a multilayer photoreceptor was obtained.

Example 16
Example 1 except that 140 parts by weight of polycarbonate resin (TS2050: manufactured by Teijin Chemicals Ltd.) was 100 parts by weight and 27 parts by weight of PTFE fine particles (Lublon L-2: manufactured by Daikin Industries) was 23 parts by weight. As a result, a multilayer photoreceptor was obtained.

Comparative Example 1
A photoconductor was prepared in the same manner as in Example 1 except that Compound A-1 was not added to the charge transport layer.

Comparative Example 2
A laminated photoreceptor was obtained in the same manner as in Example 1 except that 5 parts by weight of Compound A-1 was changed to 20 parts by weight.

Comparative Example 3
A laminated photoreceptor was obtained in the same manner as in Example 1 except that Compound B-1 as the charge transport material was changed to Compound A-1.

Comparative Example 4
Except that 27 parts by weight of PTFE fine particles (Lublon L-2: manufactured by Daikin Industries) were changed to 82 parts by weight and 0.5 parts by weight of a dispersant (GF400: manufactured by Toagosei Co., Ltd.) were changed to 1.64 parts by weight. In the same manner as in Example 1, a multilayer photoreceptor was obtained.

Comparative Example 5
A photoconductor was prepared in the same manner as in Example 1 except that PTFE fine particles (Lublon L-2: manufactured by Daikin Industries, Ltd.) were not added.

Comparative Example 6
Lamination was carried out in the same manner as in Example 1 except that Compound B-1 as a charge transport material was changed to 4- (2,2-diphenylethyl) -4 ′, 4 ″ -dimethyl-triphenylamine (manufactured by Takasago International Corporation). A type photoreceptor was obtained.

Comparative Example 7
Example 1 except that 140 parts by weight of polycarbonate resin (TS2050: manufactured by Teijin Chemicals Ltd.) was changed to 210 parts by weight and 27 parts by weight of PTFE fine particles (Lublon L-2: manufactured by Daikin Industries, Ltd.) was changed to 35 parts by weight. As a result, a multilayer photoreceptor was obtained.

Comparative Example 8
Example 1 except that 140 parts by weight of polycarbonate resin (TS2050: manufactured by Teijin Chemicals Ltd.) was changed to 90 parts by weight and 27 parts by weight of PTFE fine particles (Lublon L-2: manufactured by Daikin Industries, Ltd.) was changed to 21 parts by weight. As a result, a multilayer photoreceptor was obtained.

  The charge transport materials, filler fine particles, and tetraaryl enamine compounds used in Examples 1 to 16 and Comparative Examples 1 to 8 are summarized in Table 3 below.

Evaluation The photoreceptors obtained in Examples 1 to 16 and Comparative Examples 1 to 8 are mounted on a test copying machine in which a digital copying machine (trade name: MX-5141FN, manufactured by Sharp Corporation) is modified, and an image forming process is performed. A surface potential meter (manufactured by TREC JAPAN, model 344) was provided so as to measure the surface potential of the photoconductor in each of the photoconductors, and electrical characteristics evaluation, image evaluation, film slip evaluation and cleaning evaluation of each photoconductor were performed.
The light source used was a laser beam having a wavelength of 780 nm.

1. Evaluation of electrical characteristics Photosensitive body when this copying machine is not exposed to laser light in a normal temperature / normal humidity (N / N) environment at a temperature of 25 ° C. and a relative humidity of 50%. Was adjusted to -600V. In this state, the initial surface potential of the photoreceptor when exposed by laser light (0.4 μJ / cm ² ) was measured as the exposure potential VL (V).
The sensitivity was evaluated from the obtained VL according to the following criteria. The smaller the absolute value of the exposure potential VL, the higher the sensitivity.

Criteria G (good): | VL | <110V
NB (not bad): 110V ≦ | VL | <130V
B (bad): 130V ≦ | VL |

2. Film slick evaluation Changes in the film thickness of the photoconductor before and after the actual shooting of 100k sheets were measured using an eddy current film thickness meter (Fischer), and film slicking per 100k rotation of the photoconductor on the copying machine. Converted to quantity.
G: Membrane slippage <0.6 μm / 100 k rotation NB: 0.6 μm / 100 k rotation ≦ Membrane slippage <0.9 μm / 100 k rotation B: Membrane slippage ≧ 0.9 μm / 100 k rotation

3. Light exposure evaluation Except for a part of the surface of the photoreceptor with black paper, adjust the light intensity of the white fluorescent lamp to 400Lux on the unmasked part, irradiate it for 5 minutes, and then leave it for 5 minutes. The tone image was confirmed. The image was evaluated based on the following evaluation criteria.
G: There is no difference between the irradiated part and the non-irradiated part.
NB: A slight difference is observed between the irradiated part and the non-irradiated part (no problem in actual use).
B: A large difference is observed between the irradiated part and the non-irradiated part (there is a problem in actual use).

4). Comprehensive determination Based on the determination results 2 to 4 described above, a determination was made based on the following criteria, and a comprehensive determination was made.
G: All over G: Good for long life and high image quality.
NB: There is only one NB, and the others are G: Levels that can be actually used for long life and high image quality.
B: One or more Bs.

  Table 4 below shows the evaluation results for each item in the photoreceptors produced in Examples 1 to 16 and Comparative Examples 1 to 8.

From the results shown in Table 4 above, the following was found.
(1) The photoreceptors according to Examples 1 to 16 contain 1 to 15 parts by weight of the compound of the general formula (A) with respect to the charge transport material in the charge transport layer containing the fluororesin fine particles or the silica fine particles. It was found that electrical characteristics and printing durability were excellent, and light resistance was also good.
(2) It was found that the photoconductor according to Comparative Example 1 that does not contain the compound of the general formula (A) is problematic due to light exposure by external light.

(3) It was found that the photoreceptor of Comparative Example 2 to which 20% of the compound of the general formula (A) was added had a large problem of deterioration of electrical characteristics.
(4) It was found that the photoreceptor according to Comparative Example 3 using the compound of the general formula (A) as the charge transport material is further problematic in that the electrical characteristics are further deteriorated more than the photoreceptor according to Comparative Example 2. This is considered that the compound of the general formula (A) was deteriorated by being dispersed together with the fluororesin fine particles.

(5) It was found that the photoconductor according to Comparative Example 5 in which the charge transport layer did not contain any fine particles had a very large amount of film slip and a short life. In addition, it was found that the photoreceptor of Comparative Example 4 to which 25% of fine particles were added had a serious problem of deterioration of electrical characteristics.
(6) The photoconductor according to Comparative Example 6 using a charge transport material other than the bistriphenylamine compound of the general formula (B) as the charge transport material has a higher electrical property than when the compound of the general formula (B) is used. Deterioration was seen.

  According to the present invention, the inclusion of fluorine or silica fine particles and a specific compound in the charge transport layer of the multilayer electrophotographic photosensitive member is resistant to light exposure by external light, has high wear resistance, and has a long-lasting electrical property. A stable electrophotographic photosensitive member and an image forming apparatus including the photosensitive member are provided.

DESCRIPTION OF SYMBOLS 1 Electrophotographic photoreceptor 11 Conductive substrate 12 Charge generation material 13 Charge transport material 14 Photosensitive layer 15 Charge generation layer 16 Charge transport layer 17 Binder (binder resin)
18 Undercoat layer 19 Filler fine particles 30 Laser printer (image forming apparatus)
DESCRIPTION OF SYMBOLS 31 Semiconductor laser 32 Rotating polygon mirror 34 Imaging lens 35 Mirror 36 Corona charger 37 Developing device 38 Transfer paper cassette 39 Paper feed roller 40 Registration roller 41 Transfer charger 42 Separation charger 43 Conveyor belt 44 Fixing device 45 Paper discharge tray 46 Cleaner 47 Arrow 48 Transfer paper 49 Exposure means 50 Static eliminator

Claims (5)

On the conductive support, a charge generation layer containing a charge generation material via an undercoat layer, and a charge transport layer containing a charge transport material, a binder and filler fine particles comprising at least one of fluororesin fine particles or silica fine particles are provided. An electrophotographic photosensitive member laminated in order,
The charge transport layer has the following general formula (A):
(Where
a represents a hydrogen atom, a halogen atom, or an alkyl group, alkoxy group, dialkylamino group or aryl group which may have a substituent;
e is an integer of 1 to 6, and when e is 2 or more, a plurality of a may be the same or different and may be bonded to each other to form a ring structure;
b, c and d are the same or different from each other, and each represents an alkyl group, an alkoxy group, a dialkylamino group, an aryl group, an aryloxy group or an arylthio group, which may have a hydrogen atom, a halogen atom, or a substituent. And
f, g and h are the same or different from each other, and are integers of 1 to 5, and when f, g or h is 2 or more, each of a plurality of b, c or d may be the same or different from each other. Or each of b, c or d bonded to adjacent carbon atoms of the benzene ring may be bonded together to form a ring structure;
Ar ¹ and Ar ² are the same as or different from each other, and represent a hydrogen atom or an optionally substituted alkyl group, aryl group, aralkyl group or heterocyclic group, provided that Ar ¹ and Ar ² are At the same time, it cannot be a hydrogen atom, and Ar ¹ and Ar ² may be bonded to each other via an atom or an atomic group to form a ring structure)
Containing 1 to 15% by weight of the tetraaryl enamine compound represented by
The charge transport material has the following general formula (B):
(In the formula, R ₁ and R ₂ are the same or different from each other and represent a hydrogen atom, a halogen atom, an alkyl group or an alkoxy group, and R ₃ , R ₄ , R ₅ and R ₆ are the same or different from each other. Represents a hydrogen atom, an alkyl group or an alkoxy group, and i, j, k and l are 1 or 2)
And is contained in an amount of 30.0 to 45.0% by weight in the charge transport layer,
The filler fine particles are contained in the charge transport layer in an amount of 1.0 to 20.0% by weight ,
The binder, the filler fine particles, the tetraaryl enamine compound represented by the general formula (A) and the bistriphenylamine compound represented by the general formula (B) as a charge transport material are all contained in the same charge transport layer. An electrophotographic photosensitive member characterized by comprising: In the general formula (A), the following partial structure:
But the following:
And the following substructure:
But independently of each other:
And the following substructure:
But the following:
Wherein Ar ¹ or Ar ² is the following substituent:
Or said Ar ² or Ar ¹ is the following substituent:
Or said Ar ¹ and Ar ² together are the following substituents:
The electrophotographic photosensitive member according to claim 1, which means In the general formula (B), R ₁ and R ₂ are the same as or different from each other and represent a hydrogen atom, a C ₁ -C ₄ alkyl group, or a C ₁ -C ₄ alkoxy group, and R ₃ , R ₄ , R ₅ and R ₆ are the same or different from each other and each represents a hydrogen atom, a 2-, 3- or 4-C ₁ -C ₄ alkyl group, or a 2-, 3- or 4-C ₁ -C ₄ alkoxy group. The electrophotographic photosensitive member according to claim 1, wherein i, j, k and l are 1 or 2. 4.   The electrophotographic photosensitive member according to claim 1, wherein the fluororesin fine particles are tetrafluoroethylene resin fine particles.   5. The electrophotographic photosensitive member according to claim 1, charging means for charging the electrophotographic photosensitive member, and exposure of the charged electrophotographic photosensitive member to form an electrostatic latent image. An exposure unit; a developing unit that develops the electrostatic latent image with toner to form a toner image; a transfer unit that transfers the toner image onto a recording material; and the transferred toner image on the recording material. An image forming apparatus including fixing means for fixing.