JP2013041101A - Electrophotographic photoconductor, method for manufacturing the same, image forming method, image forming apparatus, and process cartridge - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an electrophotographic photoconductor having both of excellent mechanical durability and gas-resistant stability and a method for manufacturing the photoconductor, to provide an image forming apparatus having a long service life, capable of stably outputting an image of high picture quality, in particular, even under the condition of exposure to an oxidative gas at a high concentration, and to provide an image forming method and a process cartridge.SOLUTION: The electrophotographic photoconductor includes at least a photosensitive layer on a conductive support body. The outermost surface layer of the photosensitive layer contains a phthalate compound expressed by general formula (1) and a three-dimensional crosslinked polymer. The three-dimensional crosslinked polymer is formed by polymerization of a compound which is a charge transporting compound including an aromatic ring that has three or more [(tetrahydro-2H-pyran-2-yl)oxy]methyl groups through an elimination reaction of a part of the [(tetrahydro-2H-pyran-2-yl)oxy]methyl groups from the compound.

Description

The present invention relates to an electrophotographic photosensitive member used in an electrophotographic copying machine, a printer, a facsimile machine, or a combination machine thereof, a manufacturing method thereof, an image forming method, an image forming apparatus, and a process cartridge.

  In recent years, organic photoconductors (OPCs) have good performance and are widely used in copiers, facsimiles, laser printers, and composite machines in place of inorganic photoreceptors because of their various advantages. . The reason for this is that organic photoreceptors have a wide light absorption wavelength range, optical characteristics such as the amount of absorption, electrical characteristics such as high sensitivity and stable charging characteristics, a wide range of material selection, It is excellent in ease, low cost, non-toxicity and the like.

  However, since the organic photoreceptor contains a low-molecular charge transport material, an inert polymer, etc. as a main component in the charge transport layer, it is generally soft and depends on a development system or a cleaning system by repeated use over a long period of time in an electrophotographic process. There is a problem that mechanical load is generated and mechanical durability such as wear resistance and damage resistance is inferior. Such wear, damage, etc. of the organic photoreceptor has a problem of deteriorating electrical characteristics such as sensitivity deterioration and chargeability, and generating abnormal images such as image density reduction and background stains. Further, there is a problem that scratches in which wear occurs locally cause streak-like stain images due to poor cleaning.

  Therefore, for the purpose of improving the mechanical durability of the organic photoreceptor, it has been proposed to form a charge transport layer having a three-dimensional crosslinked polymer on the organic photoreceptor (see, for example, Patent Documents 1 to 9).

  Patent Document 1 proposes a charge transport layer having a three-dimensional crosslinked polymer obtained by radical polymerization of a hole transporting compound having two or more chain polymerizable functional groups in the same molecule by ultraviolet irradiation, electron beam irradiation, or the like. Has been. However, a large-scale apparatus that performs ultraviolet irradiation, electron beam irradiation, or the like is required, which is problematic in terms of productivity. Further, there is a problem that the charge transporting compound deteriorates due to ultraviolet irradiation, electron beam irradiation, etc., and the potential characteristics of the photoreceptor deteriorate.

  In Patent Documents 2 to 8, a charge transport layer having a three-dimensional crosslinked polymer using a charge transport compound having a polar group such as a hydroxyl group is proposed, but the polar group such as a hydroxyl group possessed by the charge transport compound is Since it remains in the three-dimensional cross-linked polymer, there is a problem that charging is reduced. In addition, there is a problem that the image density tends to be lowered under a high temperature and high humidity environment, and the image density is likely to be lowered due to exposure of NOx gas or the like generated by the charger.

  Patent Document 9 proposes a charge transport layer having a three-dimensional crosslinked polymer obtained by curing a compound in which a polar group such as a hydroxyl group of a charge transporting compound is blocked and a reactive species such as melamine. In this case, the polar group can be prevented from remaining, but there is a problem that the reaction between the blocked polar group and the reactive species is poor and the mechanical durability is poor.

  As described above, for the purpose of improving the mechanical durability of the organic photoreceptor, it has been intensively studied to form a charge transport layer having a three-dimensional crosslinked polymer on the organic photoreceptor. On the other hand, an organic photoreceptor having a charge transport layer having a three-dimensional cross-linked polymer has a new problem that it is inferior in gas resistance stability.

  The charge transport layer having a three-dimensional cross-linked polymer has large voids and very high gas permeability compared to a normal charge transport layer due to distortion during curing and steric arrangement of intermolecular bonds. all right. For this reason, an oxidizing gas such as NOx gas, which has a great influence on the photoconductor due to long-term use, permeates into the inside from the photoconductor surface, gradually deteriorates the photoconductor characteristics, and causes image deterioration such as a decrease in image density. There is a problem that occurs. Therefore, a method of mixing a plasticizer or the like to fill the voids is well known, but the compatibility is poor and a uniform three-dimensional cross-linked polymer cannot be obtained, so that the curing reaction is inhibited and mechanical durability is increased. There is a problem that is greatly reduced.

  Therefore, an electrophotographic photosensitive member having excellent mechanical durability and gas resistance stability and a method for producing the same, particularly capable of outputting a high-quality image stably even under conditions of exposure to a high concentration of oxidizing gas, and having a long lifetime. Such an image forming apparatus, an image forming method, and a process cartridge have not been provided yet, and the development is strongly demanded at present.

  This invention is made | formed in view of this present condition, and makes it a subject to solve the said various problems in the past and to achieve the following objectives. That is, the present invention provides an electrophotographic photosensitive member having excellent mechanical durability and gas resistance stability, and a method for producing the same, in particular, stable and high-quality image output even under high-concentration oxidizing gas exposure conditions. An object of the present invention is to provide an image forming apparatus, an image forming method, and a process cartridge capable of having a long life.

As a result of intensive studies to achieve the above object, the present inventors have used a charge transporting compound having a specific structure, thereby preventing a curing reaction from being hindered and a three-dimensional crosslinking having a high crosslinking density. It was found that a polymer was formed.
In addition, when such a three-dimensional crosslinked polymer having a high crosslinking density and a specific phthalate compound are mixed, the bulky cyclic hydrocarbon group portion in the phthalate compound is efficiently converted into the three-dimensional crosslinked polymer. An aromatic ring inclusion structure that fills voids in a three-dimensional network structure and has limited molecular mobility due to moderate steric hindrance, and that suppresses mechanical property degradation such as film hardness degradation due to non-crosslinking components to a minimum. It was found that it was formed.
Then, by providing such an aromatic ring inclusion structure on the outermost surface layer of the photosensitive layer of the electrophotographic photosensitive member, it is possible to provide an electrophotographic photosensitive member having both excellent mechanical durability and gas resistance stability. I found out that it would be possible.
In addition, by using such an electrophotographic photosensitive member, an image forming method, an image forming apparatus, and a process cartridge capable of stably outputting high-quality images over a long period even under high-concentration oxidizing gas exposure conditions. As a result, the present invention has been completed.

This invention is based on the said knowledge by the present inventors, and as means for solving the said subject, it is as follows. That is,
<1> An electrophotographic photosensitive member having at least a photosensitive layer on a conductive support, wherein the outermost surface layer of the photosensitive layer is a phthalate compound represented by the following general formula (1) and a three-dimensional cross-linking The three-dimensional crosslinked polymer from a compound having three or more [(tetrahydro-2H-pyran-2-yl) oxy] methyl groups on the aromatic ring of the charge transporting compound; 2H-pyran-2-yl) oxy] An electrophotographic photoreceptor formed by polymerization by a reaction in which a part of a methyl group is cut off and eliminated.
However, in the said General formula (1), R may be the same and may differ and each represents a C5-C10 cyclic hydrocarbon group.
<2> A method for producing an electrophotographic photosensitive member having at least a photosensitive layer on a conductive support, wherein the outermost surface layer of the photosensitive layer is a phthalate compound represented by the following general formula (1): A compound having three or more [(tetrahydro-2H-pyran-2-yl) oxy] methyl groups on the aromatic ring of the charge transporting compound; (Tetrahydro-2H-pyran-2-yl) oxy] A method for producing an electrophotographic photosensitive member characterized by being formed by polymerization through a reaction in which a part of a methyl group is cut off and eliminated.
However, in the said General formula (1), R may be the same and may differ and each represents a C5-C10 cyclic hydrocarbon group.
<3> A charging step for charging the surface of the electrophotographic photosensitive member, an exposure step for exposing the charged surface of the electrophotographic photosensitive member to form an electrostatic latent image, and developing the electrostatic latent image using toner. An image forming method comprising at least a developing step for forming a visible image, a transfer step for transferring the visible image to a recording medium, and a fixing step for fixing the transferred image transferred to the recording medium. The image forming method is characterized in that the electrophotographic photosensitive member is the electrophotographic photosensitive member according to <1>.
<4> An electrophotographic photosensitive member, charging means for charging the surface of the electrophotographic photosensitive member, exposure means for exposing the charged electrophotographic photosensitive member surface to form an electrostatic latent image, and the electrostatic latent image At least development means for developing a visible image by using toner, transfer means for transferring the visible image to a recording medium, and fixing means for fixing the transfer image transferred to the recording medium An image forming apparatus, wherein the electrophotographic photosensitive member is the electrophotographic photosensitive member according to <1>.
<5> A process cartridge that has an electrophotographic photosensitive member and at least one means selected from a charging means, an exposure means, a developing means, a transfer means, a cleaning means, and a charge eliminating means, and is detachable from the image forming apparatus main body. The process cartridge is characterized in that the electrophotographic photosensitive member is the electrophotographic photosensitive member according to <1>.

  According to the present invention, various problems in the prior art can be solved, and an electrophotographic photosensitive member having excellent mechanical durability and gas resistance stability and a method for producing the same, and particularly stable under conditions of exposure to a high concentration of oxidizing gas. Thus, it is possible to provide an image forming apparatus, an image forming method, and a process cartridge that can output a high-quality image and have a long life.

FIG. 1 is a schematic view showing the layer structure of the electrophotographic photosensitive member according to the first embodiment of the present invention. FIG. 2 is a schematic view showing the layer structure of the electrophotographic photosensitive member according to the second embodiment of the present invention. FIG. 3 is a schematic view showing the layer structure of an electrophotographic photosensitive member according to the third embodiment of the present invention. FIG. 4 is a schematic view showing a layer structure of an electrophotographic photosensitive member according to the fourth embodiment of the present invention. FIG. 5 is a schematic view showing the layer structure of an electrophotographic photosensitive member according to the fifth embodiment of the present invention. FIG. 6 is a schematic diagram illustrating an example of the image forming apparatus and the electrophotographic process of the present invention. FIG. 7 is a schematic diagram illustrating an example of a tandem full-color image forming apparatus according to the present invention. FIG. 8 is a schematic diagram for explaining an example of the process cartridge of the present invention. FIG. 9 is a diagram showing a result of an X-ray diffraction spectrum of titanyl phthalocyanine powder produced in the example. FIG. 10 is an infrared absorption spectrum diagram (KBr tablet method) of the compound obtained in Synthesis Example 1, the horizontal axis indicates the wave number (cm ⁻¹ ), and the vertical axis indicates the transmittance (%). FIG. 11 is an infrared absorption spectrum diagram (KBr tablet method) of the compound obtained in Synthesis Example 2. The horizontal axis indicates the wave number (cm ⁻¹ ), and the vertical axis indicates the transmittance (%). FIG. 12 is an infrared absorption spectrum diagram (KBr tablet method) of the compound obtained in Synthesis Example 3. The horizontal axis indicates the wave number (cm ⁻¹ ), and the vertical axis indicates the transmittance (%). FIG. 13 is an infrared absorption spectrum diagram (KBr tablet method) of the compound obtained in Synthesis Example 4, the horizontal axis indicates the wave number (cm ⁻¹ ), and the vertical axis indicates the transmittance (%). FIG. 14 is an infrared absorption spectrum diagram (KBr tablet method) of the compound obtained in Synthesis Example 5, the horizontal axis indicates the wave number (cm ⁻¹ ), and the vertical axis indicates the transmittance (%). FIG. 15 is an infrared absorption spectrum diagram (KBr tablet method) of the compound obtained in Synthesis Example 6. The horizontal axis indicates the wave number (cm ⁻¹ ), and the vertical axis indicates the transmittance (%). FIG. 16 is an infrared absorption spectrum diagram (KBr tablet method) of the compound obtained in Synthesis Example 7, in which the horizontal axis indicates wave number (cm ⁻¹ ) and the vertical axis indicates transmittance (%). FIG. 17 is an infrared absorption spectrum diagram (KBr tablet method) of the compound obtained in Synthesis Example 8, the horizontal axis indicates the wave number (cm ⁻¹ ), and the vertical axis indicates the transmittance (%). FIG. 18 is an infrared absorption spectrum diagram (KBr tablet method) of the compound obtained in Synthesis Example 9, where the horizontal axis indicates wave number (cm ⁻¹ ) and the vertical axis indicates transmittance (%). FIG. 19 is an infrared absorption spectrum diagram (KBr tablet method) of the compound obtained in Synthesis Example 10, in which the horizontal axis indicates wave number (cm ⁻¹ ) and the vertical axis indicates transmittance (%). FIG. 20 is an infrared absorption spectrum diagram (KBr tablet method) of the compound obtained in Synthesis Example 11, the horizontal axis indicates the wave number (cm ⁻¹ ), and the vertical axis indicates the transmittance (%). FIG. 21 is an infrared absorption spectrum diagram (KBr tablet method) of the compound obtained in Synthesis Example 12, in which the horizontal axis indicates wave number (cm ⁻¹ ) and the vertical axis indicates transmittance (%). FIG. 22 is an infrared absorption spectrum diagram (KBr tablet method) of the compound obtained in Synthesis Example 13, with the horizontal axis indicating the wave number (cm ⁻¹ ) and the vertical axis indicating the transmittance (%). FIG. 23 is an infrared absorption spectrum diagram (KBr tablet method) of the compound obtained in Synthesis Example 14, in which the horizontal axis represents wave number (cm ⁻¹ ) and the vertical axis represents transmittance (%). FIG. 24 is a diagram for explaining the micro surface hardness measurement of the outermost surface layer (crosslinked charge transport layer). FIG. 25 is a diagram for explaining the micro surface hardness measurement of the outermost surface layer (crosslinked charge transport layer). FIG. 26 is a diagram for explaining the micro surface hardness measurement of the outermost surface layer (crosslinked charge transport layer).

(Electrophotographic photoreceptor)
The electrophotographic photoreceptor of the present invention comprises at least a photosensitive layer on a conductive support, and further comprises other structures as necessary.

<Conductive support>
The conductive support is not particularly limited as long as it has a volume resistance of 10 ¹⁰ Ω · cm or less, and can be appropriately selected according to the purpose. An endless belt (such as an endless nickel belt or an endless stainless steel belt) disclosed in Japanese Patent Laid-Open No. 52-36016 may be used.

  There is no restriction | limiting in particular as a formation method of the said electroconductive support body, According to the objective, it can select suitably, For example, a metal (aluminum, nickel, chromium, nichrome, copper, gold | metal | money, silver, platinum etc.) or a metal A method in which an oxide (tin oxide, indium oxide, etc.) is deposited or sputtered and coated on a support (film, cylindrical plastic, paper, etc.); metal (aluminum, aluminum alloy, nickel, For example, a method of extruding a plate of stainless steel, etc., performing drawing, etc., and performing surface treatment (cutting, superfinishing, polishing, etc. after forming a blank), and the like.

The conductive support may be provided with a conductive layer on the conductive support.
The method for forming the conductive layer is not particularly limited and may be appropriately selected according to the purpose. For example, the conductive layer and the binder resin may be dispersed or dissolved in a solvent as necessary. A method of forming the applied coating liquid on the conductive support, such as polyvinyl chloride, polypropylene, polyester, polystyrene, polyvinylidene chloride, polyethylene, chlorinated rubber, and Teflon (registered trademark) Examples include a method of forming using a heat-shrinkable tube containing conductive powder.

  There is no restriction | limiting in particular as said electroconductive powder, According to the objective, it can select suitably, For example, metals, such as carbon black, acetylene black, aluminum, nickel, iron, nichrome, copper, zinc, silver, etc. Powders: Conductive tin oxide, metal oxide powders such as ITO, and the like.

  The binder resin used for the conductive layer is not particularly limited and may be appropriately selected depending on the intended purpose. For example, polystyrene resin, styrene-acrylonitrile copolymer, styrene-butadiene copolymer, styrene-anhydrous Maleic acid copolymer, polyester resin, polyvinyl chloride resin, vinyl chloride-vinyl acetate copolymer, polyvinyl acetate resin, polyvinylidene chloride resin, polyarylate resin, phenoxy resin, polycarbonate resin, cellulose acetate resin, ethyl cellulose resin, Examples include polyvinyl butyral resin, polyvinyl formal resin, polyvinyl toluene resin, poly-N-vinyl carbazole, acrylic resin, silicone resin, epoxy resin, melamine resin, urethane resin, phenol resin, alkyd resin, and the like.

  There is no restriction | limiting in particular as a solvent used for the said electroconductive layer, According to the objective, it can select suitably, For example, tetrahydrofuran, a dichloromethane, methyl ethyl ketone, toluene etc. are mentioned.

<Photosensitive layer>
The photosensitive layer includes, for example, at least a charge generation layer, a charge transport layer, and an outermost surface layer (crosslinked charge transport layer) in this order, and further includes other layers as necessary.
The outermost surface layer (crosslinked charge transport layer) has an aromatic ring inclusion structure containing at least a phthalate compound represented by the following general formula (1) and a three-dimensional crosslinked polymer.
In addition, a conventionally well-known thing can be used for the said charge generation layer, the said charge transport layer, and the said other layer.

<< Outermost surface layer (crosslinked charge transport layer) >>
The outermost surface layer is the outermost surface layer of the photosensitive layer and is also referred to as a crosslinkable charge transport layer.
The outermost surface layer has a phthalate compound represented by the following general formula (1) and a three-dimensional crosslinked polymer, and further contains other components as necessary.
The structure in which the phthalate ester compound represented by the general formula (1) is molecularly dispersed in the void of the three-dimensional network structure of the three-dimensional crosslinked polymer is referred to as an aromatic ring inclusion structure. is there.

The water vapor permeability in the outermost surface layer (crosslinked charge transport layer) is not particularly limited and may be appropriately selected depending on the intended purpose, but is 100 g / m ² · day in terms of excellent gas stability. The following is preferable, and 43 g / m ² · day or less is more preferable.

-Phthalate ester compound represented by the general formula (1)-
There is no restriction | limiting in particular as a phthalic acid ester compound represented by the said General formula (1), According to the objective, it can select suitably.
However, in the said General formula (1), R may be the same and may differ and each represents a C5-C10 cyclic hydrocarbon group.

  In the general formula (1), the cyclic hydrocarbon group in R is not particularly limited and may be appropriately selected depending on the intended purpose. For example, an aliphatic cyclic hydrocarbon group which may have an alkyl substituent And an aromatic cyclic hydrocarbon group which may have an alkyl substituent. The alkyl substituent is not particularly limited as long as it is an alkyl substituent that does not exceed the maximum carbon number 10 of the cyclic hydrocarbon group, and can be appropriately selected according to the purpose. Group, propyl group, butyl group and the like.

  In the general formula (1), specific examples of the cyclic hydrocarbon group are not particularly limited and may be appropriately selected depending on the intended purpose. Examples thereof include a cyclopentyl group, a cyclohexyl group, a cycloheptyl group, a cyclooctyl group, and the like. An aliphatic cyclic hydrocarbon group of the above; an aromatic cyclic hydrocarbon group such as a phenyl group or a naphthyl group; a group in which an aliphatic hydrocarbon group such as a benzyl group or a phenethyl group is combined with an aromatic cyclic hydrocarbon group It is done.

The phthalic acid ester compound represented by the general formula (1) is not particularly limited and may be appropriately selected depending on the intended purpose, but is compatible with the specific charge transporting compound used in the present invention. The compound represented by the following general formula (1-1) is preferable from the viewpoint of excellent gas stability and can be dispersed in the three-dimensional crosslinked film of the present invention in a wide content range. A compound represented by the following general formula (1-2) is more preferable in terms of excellent gas stability and mechanical durability.
However, in the general formula (1-1), R ′ may be the same or different, and may have a cycloalkyl group or an alkyl substituent which may have an alkyl substituent. Represents an optionally substituted phenyl group.
However, in the general formula (1-2), R ″ may be the same or different and represents a cyclohexyl group which may have an alkyl substituent.

There is no restriction | limiting in particular as a phthalate ester compound represented by the said General formula (1), According to the objective, it can select suitably, For example, following Structural formula (1-1)-(1-11) And the like. Among these, the compound represented by the following structural formula (1-2) is preferable.
In the structural formula, Me represents a methyl group.

  There is no restriction | limiting in particular as a synthesis method of the phthalic acid ester compound represented by the said General formula (1), According to the objective, it can select suitably, For example, it is a conventionally well-known method from the alcohol body corresponding to phthalic acid. And the like.

-3D cross-linked polymer
The three-dimensional crosslinked polymer is a polymer having a three-dimensional network structure, and is a polymer formed by crosslinking at least a part of the three-dimensional crosslinked polymer by a crosslinking reaction.
The three-dimensional crosslinked polymer is obtained from a compound having three or more [(tetrahydro-2H-pyran-2-yl) oxy] methyl groups on the aromatic ring of the charge transporting compound, from the [(tetrahydro-2H-pyran-2- Yl) oxy] formed by polymerization through a reaction in which part of the methyl group is cut off and eliminated.

--A compound having three or more [(tetrahydro-2H-pyran-2-yl) oxy] methyl groups on the aromatic ring of the charge transporting compound--
The compound having three or more [(tetrahydro-2H-pyran-2-yl) oxy] methyl groups on the aromatic ring of the charge transporting compound is converted into the [(tetrahydro-2H-pyran-2-yl) by the polymerization reaction. Part of the oxy] methyl group is eliminated to form a three-dimensional crosslinked polymer.

  The charge transporting compound used in the compound having three or more [(tetrahydro-2H-pyran-2-yl) oxy] methyl groups on the aromatic ring of the charge transporting compound is not particularly limited, and may be selected depending on the purpose. Examples thereof include compounds having a triarylamine structure, an aminobiphenyl structure, a benzidine structure, an aminostilbene structure, a naphthalenetetracarboxylic acid diimide structure, a benzhydrazine structure, and the like.

  The compound having three or more [(tetrahydro-2H-pyran-2-yl) oxy] methyl groups on the aromatic ring of the charge transporting compound is not particularly limited and may be appropriately selected depending on the purpose. Examples thereof include a compound represented by the following general formula (2), a compound represented by the following general formula (3), and a compound represented by the following general formula (4). These may be used alone or in combination of two or more.

--- Compound represented by formula (2) ---
The compound represented by the following general formula (2) has a high proportion of [(tetrahydro-2H-pyran-2-yl) oxy] methyl group per molecular weight, and thus can form a three-dimensional crosslinked film having a high crosslinking density. Therefore, it is possible to provide a photoconductor with high hardness and scratch resistance.
However, in said general formula (2), Ar < ₇ >, Ar < ₈ > and Ar < ₉ > represent the C6-C18 bivalent aromatic hydrocarbon group which may have an alkyl group as a substituent.

In the general formula (2), examples of the alkyl group in Ar ₇ , Ar ₈ and Ar ₉ include a methyl group, an ethyl group, a propyl group, a butyl group, a pentyl group, a hexyl group, a heptyl group, and an octyl group. Examples include linear or branched aliphatic alkyl groups.
In the general formula (2), examples of the aromatic hydrocarbon having 6 to 18 carbon atoms in Ar ₇ , Ar ₈ and Ar ₉ include, for example, benzene, naphthalene, fluorene, phenanthrene, anthracene, pyrene, biphenyl, terphenyl, Examples include stilbene.

There is no restriction | limiting in particular as a compound represented by the said General formula (2), Although it can select suitably according to the objective, It is represented by the following general formula (2-1) at the point which is excellent in a crosslinking reaction. Compounds are preferred.
However, in said general formula (2-1), R < ₁ >, R < ₂ > and R < ₃ > may be the same and may differ, and represent a hydrogen atom, a methyl group, or an ethyl group, l, n and m represent an integer of 1 to 4.

  The compound represented by the general formula (2-1) is particularly excellent among the compounds represented by the general formula (2), and the mutual polymerization reactivity is particularly good. The presence of [(tetrahydro-2H-pyran-2-yl) oxy] methyl group is still unclear about the polymerization reaction between the [(tetrahydro-2H-pyran-2-yl) oxy] methyl groups. When the aromatic ring to be formed is a benzene ring having a tertiary amino group, the progress is the fastest, and a crosslinked protective layer having a higher crosslinking density can be formed.

There is no restriction | limiting in particular as a compound represented by the said General formula (2), According to the objective, it can select suitably, As a specific example, it represents with following Structural formula (2-1)-(2-11). And the like. In addition, the compounds represented by the following structural formulas (2-1) to (2-8) are also specific examples of the compounds represented by the general formula (2-1).
However, in the structural formulas, Me represents a methyl group, and Et represents an ethyl group.

--- Compound represented by formula (3) ---
The compound represented by the following general formula (3) has four [(tetrahydro-2H-pyran-2-yl) oxy] methyl groups on the aromatic ring of the charge transporting compound, and is non-conjugated linked. A three-dimensional cross-linked film having an appropriate molecular mobility by having the group X ₃ and leaving a part of [(tetrahydro-2H-pyran-2-yl) oxy] methyl group by polymerization reaction It is easy to form, and the finished three-dimensional crosslinked film has a good balance of hardness and elastic properties, and it is possible to form a surface protective layer that is tough and excellent in both scratch resistance and wear resistance. Furthermore, due to the structure of X _3, the molecule has a relatively high oxidation potential and is difficult to oxidize, and is relatively stable when exposed to an oxidizing gas such as ozone gas or NOx gas. It is possible to provide a photoreceptor that is strong against
However, in the general formula (3), X ₃ is an alkylene group having 1 to 4 carbon atoms, an alkylidene group having 2 to 6 carbon atoms, and two alkylidene groups having 2 to 6 carbon atoms bonded via a phenylene group. Represents a divalent group or an oxygen atom, and Ar ₁₀ , Ar ₁₁ , Ar ₁₂ , Ar ₁₃ , Ar ₁₄ and Ar ₁₅ are divalent aromatics having 6 to 18 carbon atoms which may have an alkyl group as a substituent. Represents a group hydrocarbon group.

In the general formula (3), examples of the alkylene group having 1 to 4 carbon atoms for X _3, for example, methylene group, ethylene group, propylene group, etc. linear or branched alkylene group such as butylene group .
In the general formula (3), examples of the alkylidene group having 2 to 6 carbon atoms in X ₃ include 1,1-ethylidene group, 1,1-propylidene group, 2,2-propylidene group, 1,1- A butylidene group, a 2,2-butylidene group, 3,3-pentanylidene, 3,3-hexanylidene and the like can be mentioned.
In the general formula (3), examples of the divalent group in which two alkylidene groups having 2 to 6 carbon atoms are bonded via the phenylene group in X ₃ include the following structures.
In the structural formula, Me represents a methyl group.

There is no restriction | limiting in particular as a compound represented by the said General formula (3), Although it can select suitably according to the objective, It is represented by the following general formula (3-1) at the point which is excellent in a crosslinking reaction. Compounds are preferred.
In the general formula (3-1), _{X 4 is, -CH 2 -, - CH 2} CH 2 -, - C (CH 3) 2 -Ph-C (CH 3) 2 -, - C (CH ₂ ) Represents _5- or -O-, and R ₄ , R ₅ , R ₆ , R ₇ , R ₈ and R ₉ may be the same or different, and may be a hydrogen atom or a methyl group Or an ethyl group, Ph represents a phenylene group, and o, p, q, r, s, and t represent an integer of 1 to 4.

  The compound represented by the general formula (3-1) is particularly excellent among the compounds represented by the general formula (3), and the mutual polymerization reactivity is particularly good. Further, it has the same characteristics as the general formula (3), has a good balance between hardness characteristics and elastic characteristics, is strong in gas resistance, and can form a crosslinked protective layer having a high crosslinking density.

There is no restriction | limiting in particular as a compound represented by the said General formula (3), According to the objective, it can select suitably, As a specific example, it represents with following Structural formula (3-1)-(3-29). And the like. In addition, the compounds represented by the following structural formulas (3-1) to (3-24) are also specific examples of the compounds represented by the general formula (3-1).
However, in the structural formulas, Me represents a methyl group, and Et represents an ethyl group.

--- Compound represented by formula (4) ---
The compound represented by the following general formula (4) has four [(tetrahydro-2H-pyran-2-yl) oxy] methyl groups on the aromatic ring of the charge transporting compound, and is partially due to the polymerization reaction. It is easy to form a three-dimensional crosslinked film leaving [(tetrahydro-2H-pyran-2-yl) oxy] methyl group. In addition, it has a diamine structure via a specific aromatic hydrocarbon structure represented by Y ₁ , enables intramolecular charge transfer, and enables formation of a crosslinked protective layer having high hole mobility. Therefore, it is possible to provide an electrophotographic photosensitive member having a low bright portion potential even when the time from optical writing to developing on the photosensitive member is shortened as in high-speed printing or printing with a small diameter drum.
In the general formula (4), Y ₁ represents benzene, biphenyl, terphenyl, stilbene, distyrylbenzene, or a divalent condensed polycyclic aromatic hydrocarbon group, Ar ₁₆ , Ar ₁₇ , Ar ₁₈ and Ar ₁₉ represent a C 6-18 divalent aromatic hydrocarbon group which may have an alkyl group as a substituent.

In the general formula (4), examples of the condensed polycyclic aromatic hydrocarbon in Y ₁ include naphthalene, phenanthrene, anthracene, and pyrene.

There is no restriction | limiting in particular as a compound represented by the said General formula (4), Although it can select suitably according to the objective, It is represented by the following general formula (4-1) at the point which is excellent in a crosslinking reaction. Compounds are preferred.
However, the general formula (4-1), _{Y 2} represents a benzene, biphenyl, terphenyl, stilbene, or a divalent group of naphthalene. R ₁₀ , R ₁₁ , R ₁₂ and R ₁₃ may be the same or different and each represents a hydrogen atom, a methyl group or an ethyl group, and u, v, w and z are 1 to 1 Represents an integer of 4.

  The compound represented by the general formula (4-1) is particularly excellent among the compounds represented by the general formula (4), and the mutual polymerization reactivity is particularly good. Further, it has the same characteristics as the general formula (4), and it is possible to form a crosslinked protective layer having good potential characteristics and high crosslinking density.

There is no restriction | limiting in particular as a compound represented by the said General formula (4), According to the objective, it can select suitably, As a specific example, it represents with following Structural formula (4-1)-(4-26). And the like. The compounds represented by the following structural formulas (4-3) to (4-5), (4-12) to (4-14), and (4-17) to (4-24) It is also a specific example of the compound represented by (4-1).
However, in the structural formulas, Me represents a methyl group, and Et represents an ethyl group.

--Method for synthesizing a compound having three or more [(tetrahydro-2H-pyran-2-yl) oxy] methyl groups on the aromatic ring of the charge transporting compound--
The compound having three or more [(tetrahydro-2H-pyran-2-yl) oxy] methyl groups on the aromatic ring of the charge transporting compound is a novel compound, and for example, by the following first to second synthesis methods Can be synthesized.

--- First synthesis method ---
Specifically, the first synthesis method includes (1) synthesizing an aldehyde form of a charge transporting compound, (2) synthesizing a methylol compound by reacting the obtained aldehyde compound with a reducing agent, 3) A method of synthesizing a compound having three or more [(tetrahydro-2H-pyran-2-yl) oxy] methyl groups by reacting the obtained methylol compound with 3,4-dihydro-2H-pyran. Etc.

The method for synthesizing the aldehyde form of the charge transporting compound (1) is not particularly limited and may be appropriately selected depending on the purpose. For example, as shown in the following reaction formula, the charge transporting compound is used as a raw material. And a method of synthesizing this by formylation using a conventionally known method (for example, Vilsmeier reaction). Details are described in formylation described in Japanese Patent No. 3934522, and those methods can be used.
The method for formylating three or more aromatic rings of the charge transporting compound is not particularly limited and may be appropriately selected depending on the intended purpose. For example, a method using zinc chloride, phosphorus oxychloride, dimethylformaldehyde or the like Etc.
However, in reaction formula, n represents the integer of 0-2 and m represents the integer of 3-n.

The method for synthesizing the methylol body of the charge transporting compound (2) is not particularly limited and may be appropriately selected depending on the intended purpose. For example, an aldehyde compound as shown in the following reaction formula is used as an intermediate. And a method of synthesizing a methylol compound using a conventionally known reduction method.
There is no restriction | limiting in particular as a reduction method at the time of synthesize | combining the methylol body of the said charge transport compound, Although it can select suitably according to the objective, the reduction method using a sodium borohydride is preferable.
However, in reaction formula, n represents the integer of 0-2 and m represents the integer of 3-n.

The method for synthesizing the compound having three or more (3) [(tetrahydro-2H-pyran-2-yl) oxy] methyl groups is not particularly limited and can be appropriately selected according to the purpose. A methylol compound as shown in the following reaction formula is used as an intermediate, and 3,4-dihydro-2H-pyran is subjected to an addition reaction in the presence of an acid catalyst to produce [(tetrahydro-2H-pyran-2-yl) oxy] methyl. And a method of synthesizing a compound having three or more groups.
However, in reaction formula, n represents the integer of 0-2 and m represents the integer of 3-n.

--- Second synthesis method ---
As the second synthesis method, specifically, (1) an intermediate compound having [(tetrahydro-2H-pyran-2-yl) oxy] methyl group is synthesized, and (2) an amine compound is synthesized using the intermediate compound. Examples thereof include a method of synthesizing a charge transporting compound by a coupling reaction with a compound.

Examples of the synthesis method of the intermediate compound having the (1) [(tetrahydro-2H-pyran-2-yl) oxy] methyl group include a compound having a halogen and a methylol group in an aromatic ring as a raw material, and the methylol group Is synthesized with 3,4-dihydro-2H-pyran in the presence of an acid catalyst to synthesize an intermediate compound having a halogen and a [(tetrahydro-2H-pyran-2-yl) oxy] methyl group.
However, in the formula, X represents a halogen.

(2) The method for synthesizing the [(tetrahydro-2H-pyran-2-yl) oxy] methyl group-containing charge transporting compound has the [(tetrahydro-2H-pyran-2-yl) oxy] methyl group. Examples thereof include a method in which an intermediate compound is coupled with an amine compound to synthesize a charge transporting compound. Depending on the series and number of amines in the amine compound, a large number of [(tetrahydro-2H-pyran-2-yl) oxy] methyl groups can be introduced at one time. In addition, when the halogen is an iodo form, it can be coupled by an Ullmann reaction, and when the halogen is a chloro form or a bromo form, it can be coupled by a Suzuki-Miyaura reaction using a palladium catalyst.

--- Polymerization method ---
Next, the polymerization reaction will be described.
Compounds having three or more [(tetrahydro-2H-pyran-2-yl) oxy] methyl groups on the aromatic ring of the charge transporting compound are heated by adding an acid to the curing catalyst and heating them to each other [(tetrahydro -2H-pyran-2-yl) oxy] methyl groups are cut and eliminated to bond and polymerize to form a three-dimensional network macromolecule. At this time, some [(tetrahydro-2H-pyran-2-yl) oxy] methyl groups remain unreacted. Although the reaction in which a part of this [(tetrahydro-2H-pyran-2-yl) oxy] methyl group is cut and eliminated has not been clarified, it is not a single reaction but a plurality of reactions as shown below. Is a reaction in which the compounds are linked to each other and are linked together.

--- Reaction mode ---
The reaction mode is shown below.
A compound having three or more [(tetrahydro-2H-pyran-2-yl) oxy] methyl groups on the aromatic ring of the charge transporting compound is combined with the following reaction modes 1 to 3 to form complex bonds While taking the form, it is presumed to polymerize into a three-dimensional network to form a macromolecule.
All of these reactions are reactions in which a part of the (tetrahydro-2H-pyran-2-yl) oxy group is cut off and eliminated, and the weight is reduced. Therefore, weight loss is observed when these compositions are heated with an acid catalyst by a TG-DTA thermal analyzer.
Further, when the gas components generated during the heating reaction are analyzed by mass spectrometry gas chromatography (GC-MS), (tetrahydro-2H-pyran-2-yl such as 3,4-dihydro-2H-pyran, 5-hydroxypentanal, etc.) ) A desorption product indicating that a part of the oxy group is broken is detected.

[Reaction mode 1]
In Reaction Mode 1, the tetrahydro-2H-pyran-2-yl group portion of one [(tetrahydro-2H-pyran-2-yl) oxy] methyl group is cut off and eliminated, and the other [(tetrahydro-2H- Pyran-2-yl) oxy] is a reaction that forms a dimethylene ether bond while the (tetrahydro-2H-pyran-2-yl) oxy group portion of the methyl group is cut off and eliminated.
However, Ar represents an arbitrary aromatic ring of the charge transporting compound used in the present invention.

[Reaction mode 2]
Reaction mode 2 forms an ethylene bond while the (tetrahydro-2H-pyran-2-yl) oxy groups of both [(tetrahydro-2H-pyran-2-yl) oxy] methyl groups are cut off and eliminated. It is a reaction.
However, Ar represents an arbitrary aromatic ring of the charge transporting compound used in the present invention.

[Reaction mode 3]
Reaction mode 3 consists in that the (tetrahydro-2H-pyran-2-yl) oxy group of one [(tetrahydro-2H-pyran-2-yl) oxy] methyl group is cut off and eliminated while the other aromatic ring is removed. To form a methylene bond.
However, Ar represents an arbitrary aromatic ring of the charge transporting compound used in the present invention.

-Method for forming three-dimensional crosslinked polymer or aromatic ring inclusion structure-
The formation of the three-dimensional crosslinked polymer may be performed simultaneously with the formation of the aromatic ring inclusion structure.
There is no restriction | limiting in particular as a formation method of the said three-dimensional crosslinked polymer, According to the objective, it can select suitably, For example, [(tetrahydro-2H-pyran-2-yl) is added to the aromatic ring of the said charge transport compound. A coating solution containing a compound having three or more oxy] methyl groups and a curing catalyst is diluted with a solvent or the like as necessary, and the coating solution is applied to the surface of the photoreceptor, followed by drying by heating. And a method of forming by polymerization.

  As a method for forming the aromatic ring inclusion structure, a compound having three or more [(tetrahydro-2H-pyran-2-yl) oxy] methyl groups in the aromatic ring of the charge transporting compound, the curing catalyst, A coating solution containing the phthalate ester compound represented by the general formula (1) is diluted with a solvent or the like as necessary, and the coating solution is applied to the surface of the photoreceptor, followed by heat drying. And a method of forming by polymerization. The three-dimensional crosslinked polymer is formed by the polymerization, and at the same time, the phthalate ester compound represented by the general formula (1) is formed in the voids in the three-dimensional network structure of the three-dimensional crosslinked polymer. An aromatic ring inclusion structure having a certain hardness may be formed by inclusion.

  A mixture of a compound having three or more [(tetrahydro-2H-pyran-2-yl) oxy] methyl groups on the aromatic ring of the charge transporting compound and a phthalate compound represented by the general formula (1) The mixing ratio of the phthalate ester compound represented by the general formula (1) is not particularly limited and may be appropriately selected depending on the intended purpose, but is preferably 5% by mass to 50% by mass, 20 mass%-50 mass% are more preferable at the point of gas stability. When the mixing ratio is less than 5% by mass, the gas resistance stability may be inferior, and when it exceeds 50% by mass, the cross-linking reaction part decreases, and the mechanical durability of the aromatic ring inclusion structure becomes weak. In some cases, defects such as crystallization easily occur and the surface of the photoreceptor becomes clouded.

  The heating temperature for forming the three-dimensional crosslinked polymer or the aromatic ring inclusion structure can be arbitrarily selected depending on the formulation conditions because the reaction rate varies depending on the type and content of the catalyst. -160 degreeC is preferable, 100 degreeC-150 degreeC is more preferable, 135 degreeC-150 degreeC is especially preferable. When the heating temperature is less than 80 ° C., the reaction rate becomes slow and it may not be possible to reach a sufficient crosslinking density over a long period of time. When the heating temperature exceeds 160 ° C., the reaction speeds up, but the crosslink density increases too much, causing a decrease in charge transportability, increasing the bright part potential of the photoreceptor, lowering the sensitivity, and reducing the sensitivity of the electrophotographic photoreceptor. The influence of heating on other layer constituting materials is increased, and the electrophotographic photosensitive member may be deteriorated.

  The heating time for forming the three-dimensional crosslinked polymer or the aromatic ring inclusion structure is preferably 20 minutes to 60 minutes when heated and dried at 135 ° C. to 150 ° C.

-Other ingredients-
There is no restriction | limiting in particular as said other component, According to the objective, it can select suitably, For example, a curing catalyst, a solvent, a leveling agent, antioxidant, a filler, a surface treating agent etc. are mentioned.

--Curing catalyst--
There is no restriction | limiting in particular as said curing catalyst, Although it can select suitably according to the objective, An acidic compound is preferable.

There is no restriction | limiting in particular as said acidic compound, According to the objective, it can select suitably, For example, organic sulfonic acids, such as p-toluenesulfonic acid, naphthalenesulfonic acid, dodecylbenzenesulfonic acid; Organic sulfonic acid derivative; Organic sulfone Examples include acid salts; thermal latent compounds (compounds that develop acidity by applying a certain temperature or higher).
Among these, organic sulfonic acid and organic sulfonic acid derivatives are preferable.

  There is no restriction | limiting in particular as said curing catalyst, What was synthesize | combined suitably may be used and a commercial item may be used. Examples of the commercially available products include thermal latent proton acid catalysts blocked with amines such as NACURE 2500, NACURE 5225, NACURE 5543, NACURE 5925 (all manufactured by King Industries); SI-60 (manufactured by Sanshin Chemical Co., Ltd.); Optomer SP-300 (manufactured by Asahi Denka Co., Ltd.) and the like can be mentioned.

There is no restriction | limiting in particular as content of the said curing catalyst, Although it can select suitably according to the objective, 0.02 mass%-5 mass% are preferable with respect to solid content concentration of a coating liquid.
The content of an acid-only catalyst such as paratoluenesulfonic acid is preferably 0.02% by mass to 0.4% by mass with respect to the solid content concentration of the coating liquid. When the content exceeds 0.4% by mass, the acidity of the coating liquid increases, which may cause corrosion of coating equipment and the like.
The content of the thermal latent compound is preferably 0.2% by mass to 2% by mass with respect to the solid content concentration of the coating liquid. The thermal latent compound does not cause a problem of corrosion at the coating liquid stage and can be increased in content, but if the content exceeds 2% by mass, an amine compound as a blocking agent If the toner remains, it may adversely affect the photoreceptor characteristics such as residual potential.

--Solvent--
The solvent is not particularly limited and may be appropriately selected depending on the intended purpose. Examples thereof include alcohols such as methanol, ethanol, propanol and butanol; ketones such as acetone, methyl ethyl ketone, methyl isobutyl ketone and cyclohexanone; acetic acid Esters such as ethyl and butyl acetate; Ethers such as tetrahydrofuran, methyltetrahydrofuran, dioxane, propyl ether, diethylene glycol dimethyl ether and propylene glycol 1-monomethyl ether-2-acetate; Halogens such as dichloromethane, dichloroethane, trichloroethane and chlorobenzene; benzene And aromatic systems such as toluene and xylene; and cellosolv systems such as methyl cellosolve, ethyl cellosolve, and cellosolve acetate. These may be used alone or in combination of two or more.

  The dilution ratio of the solvent is not particularly limited and is appropriately selected depending on the solubility of the composition, the coating method such as the dip coating method, the spray coating method, the bead coating method, the ring coating method, the target thickness, and the like. be able to.

--Leveling agent--
The leveling agent is not particularly limited and may be appropriately selected depending on the intended purpose. Examples thereof include silicone oils such as dimethyl silicone oil and methyl phenyl silicone oil; polymers or oligomers having a perfluoroalkyl group in the side chain. Etc.
There is no restriction | limiting in particular as content of the said leveling agent, Although it can select suitably according to the objective, 1 mass% or less is preferable with respect to the total solid amount.

--Antioxidant--
The antioxidant can be added for the purpose of preventing a decrease in sensitivity of the electrophotographic photosensitive member against repeated use, an increase in residual potential, and the like.
The antioxidant may be added to each layer such as the cross-linked charge transport layer, the charge transport layer, the charge generation layer, and the other layers.

  There is no restriction | limiting in particular as said antioxidant, According to the objective, it can select suitably, For example, phenolic compounds, paraphenylenediamines, hydroquinones, organic sulfur compounds, organic phosphorus compounds, etc. are mentioned. It is done. These may be used individually by 1 type and may use 2 or more types together.

  The phenolic compounds are not particularly limited and may be appropriately selected depending on the intended purpose. Examples thereof include 2,6-di-t-butyl-p-cresol, butylated hydroxyanisole, 2,6-di -T-butyl-4-ethylphenol, stearyl-β- (3,5-di-t-butyl-4-hydroxyphenyl) propionate, 2,2'-methylene-bis- (4-methyl-6-t- Butylphenol), 2,2'-methylene-bis- (4-ethyl-6-tert-butylphenol), 4,4'-thiobis- (3-methyl-6-tert-butylphenol), 4,4'-butylidenebis- (3-methyl-6-tert-butylphenol), 1,1,3-tris- (2-methyl-4-hydroxy-5-tert-butylphenyl) butane, 1,3,5-trimethyl-2 4,6-tris (3,5-di-t-butyl-4-hydroxybenzyl) benzene, tetrakis- [methylene-3- (3 ′, 5′-di-t-butyl-4′-hydroxyphenyl) propionate Methane, bis [3,3′-bis (4′-hydroxy-3′-t-butylphenyl) butyric acid] cricol ester, tocopherols and the like.

  The paraphenylenediamines are not particularly limited and may be appropriately selected depending on the intended purpose. For example, N-phenyl-N′-isopropyl-p-phenylenediamine, N, N′-di-sec-butyl -P-phenylenediamine, N-phenyl-N-sec-butyl-p-phenylenediamine, N, N'-di-isopropyl-p-phenylenediamine, N, N'-dimethyl-N, N'-di-t -Butyl-p-phenylenediamine and the like.

  There is no restriction | limiting in particular as said hydroquinones, According to the objective, it can select suitably, For example, 2, 5- di- t-octyl hydroquinone, 2, 6- didodecyl hydroquinone, 2-dodecyl hydroquinone, 2- Examples include dodecyl-5-chlorohydroquinone, 2-t-octyl-5-methylhydroquinone, and 2- (2-octadecenyl) -5-methylhydroquinone.

  The organic sulfur compounds are not particularly limited and may be appropriately selected depending on the intended purpose. Examples thereof include dilauryl-3,3′-thiodipropionate and distearyl-3,3′-thiodipropionate. And ditetradecyl-3,3′-thiodipropionate.

  The organic phosphorus compounds are not particularly limited and may be appropriately selected depending on the intended purpose. Examples thereof include triphenylphosphine, tri (nonylphenyl) phosphine, tri (dinonylphenyl) phosphine, tricresylphosphine, And tri (2,4-dibutylphenoxy) phosphine.

There is no restriction | limiting in particular as said antioxidant, You may use what was synthesize | combined suitably, and may use a well-known commercial item as antioxidants, such as rubber | gum, a plastics, and fats and oils.
There is no restriction | limiting in particular as content of the said antioxidant, Although it can select suitably according to the objective, 0.01 mass%-10 mass with respect to the total mass of the layer added with respect to the total solid amount. % By mass is preferable, and 0.01% by mass to 1% by mass is more preferable.

--Filler--
The filler can be added for the purpose of improving the further wear resistance of the coating solution.
There is no restriction | limiting in particular as said filler, According to the objective, it can select suitably, For example, an organic filler material, an inorganic filler material, etc. are mentioned.

There is no restriction | limiting in particular as said organic filler material, According to the objective, it can select suitably, For example, fluororesin powders, such as polytetrafluoroethylene, silicone resin powder, a-carbon powder, etc. are mentioned.
There is no restriction | limiting in particular as said inorganic filler material, According to the objective, it can select suitably, For example, metal powder, such as copper, tin, aluminum, and indium: Silica, tin oxide, zinc oxide, titanium oxide, alumina Zirconium oxide, indium oxide, antimony oxide, bismuth oxide, calcium oxide, antimony-doped tin oxide, tin-doped indium oxide and other metal oxides; tin fluoride, calcium fluoride, aluminum fluoride and other metal oxides Examples thereof include potassium titanate and boron nitride.
Among these, inorganic materials are preferable from the viewpoint of excellent wear resistance, and α-type alumina having a hexagonal close-packed structure is more preferable from the viewpoint of excellent insulation, thermal stability, and wear resistance.

  There is no restriction | limiting in particular as an average primary particle diameter of the said filler, Although it can select suitably according to the objective, 0.01 micrometer-0.5 micrometer are preferable at the point which is excellent in a light transmittance, abrasion resistance, etc. If the average primary particle size is less than 0.01 μm, it may cause a decrease in abrasion resistance, a decrease in dispersibility, and the like. If it exceeds 0.5 μm, the settling property of the filler is promoted, and the toner Filming may occur.

  There is no restriction | limiting in particular as content of the said filler, Although it can select suitably according to the objective, 5 mass%-50 mass% are preferable, and 10 mass%-40 mass% are more preferable. When the content is less than 5% by mass, the wear resistance may be insufficient, and when it exceeds 50% by mass, the transparency may be impaired.

--Surface treatment agent--
The surface treatment agent is added for the purpose of surface treatment of the filler.
By performing the surface treatment of the filler with the surface treatment agent, the dispersibility of the filler is improved. The decrease in the dispersibility of the filler not only increases the residual potential, but also decreases the transparency of the coating film, the occurrence of coating film defects, and further decreases the abrasion resistance. There is a possibility that it will develop into a big problem.

The surface treatment agent is not particularly limited and may be appropriately selected depending on the intended purpose. However, a surface treatment agent capable of maintaining the insulating properties of the filler is preferable, and in terms of filler dispersibility and image blur, a titanate system is preferable. Coupling agent, aluminum coupling agent, zircoaluminate coupling agent, higher fatty acid or a mixture thereof with silane coupling agent; Al ₂ O ₃ , TiO ₂ , ZrO ₂ , silicone, aluminum stearate or these A mixture is more preferred. The treatment with the silane coupling agent is strongly influenced by image blur, but the influence may be suppressed by performing a mixing treatment of the surface treatment agent and the silane coupling agent.

  There is no restriction | limiting in particular as content of the said surface treating agent, It changes with the average primary particle diameters of the filler to be used, It can select suitably according to the objective, However 3 mass%-30 mass% are preferable, and 5 mass% -20 mass% is more preferable. When the content is less than 3% by mass, the filler dispersion effect may not be obtained. When the content exceeds 30% by mass, the residual potential may be significantly increased.

-Formation method of cross-linked charge transport layer (outermost surface layer)-
There is no restriction | limiting in particular as a formation method of the said bridge | crosslinking type charge transport layer (outermost surface layer), According to the objective, it can select suitably, For example, an aromatic ring of a charge transport compound is [(tetrahydro-2H-pyran. -2-yl) oxy] Coating comprising a compound having three or more methyl groups, a curing catalyst, the phthalate compound represented by the general formula (1), and the other components such as the solvent. Examples thereof include a method of forming a liquid using a casting method.
The casting method is not particularly limited and may be appropriately selected depending on the intended purpose. Examples thereof include a dip coating method, a spray coating method, a bead coating method, and a ring coating method.

  It is formed by a polymerization reaction of a compound having three or more [(tetrahydro-2H-pyran-2-yl) oxy] methyl groups on the aromatic ring of the charge transporting compound of the present invention and represented by the general formula (1). The three-dimensional crosslinked film in which the phthalate ester compound is molecularly dispersed is a film having excellent charge transportability among the crosslinked films and has high applicability as a charge transport layer. Compared with charge transportability, it is inferior. Therefore, it is preferable to use a relatively thin film, and when used in such a configuration, a photoreceptor having the most excellent characteristics can be provided.

  There is no restriction | limiting in particular as thickness of the said bridge | crosslinking type charge transport layer, Although it can select suitably according to the objective, 1 micrometer-10 micrometers are preferable, and 3 micrometers-8 micrometers are more preferable. If the thickness is less than 1 μm, it may not be possible to achieve a sufficiently long life. If the thickness exceeds 10 μm, the sensitivity will decrease, the bright part potential will increase, and stable image output will be difficult.

<< Charge transport layer >>
The charge transport layer is a layer intended to hold a charged charge and to couple the charge generated and separated in the charge generation layer by exposure to the charged charge held by movement. In order to achieve the purpose of holding the charged charge, it is required that the electric resistance is high. Further, in order to achieve the purpose of obtaining a high surface potential with the charged charge that has been held, it is required that the dielectric constant is small and the charge mobility is good.

  The charge transport layer preferably includes a charge transport material, preferably includes a binder resin, and further includes other components as necessary.

-Charge transport material-
The charge transport material is not particularly limited and may be appropriately selected depending on the intended purpose. Examples thereof include an electron transport material, a hole transport material, and a polymer charge transport material.

--Electron transport material--
The electron transport material (electron-accepting material) is not particularly limited and may be appropriately selected depending on the intended purpose. For example, chloroanil, bromoanil, tetracyanoethylene, tetracyanoquinodimethane, 2, 4, 7 -Trinitro-9-fluorenone, 2,4,5,7-tetranitro-9-fluorenone, 2,4,5,7-tetranitroxanthone, 2,4,8-trinitrothioxanthone, 2,6,8-trinitro -4H-indeno [1,2-b] thiophene-4-one, 1,3,7-trinitrodibenzothiophene-5,5-dioxide, and the like. These may be used alone or in combination of two or more.

--- Hole transport material--
The hole transport material (electron donating material) is not particularly limited and may be appropriately selected depending on the intended purpose. Examples thereof include oxazole derivatives, oxadiazole derivatives, imidazole derivatives, triphenylamine derivatives, 9- (P-diethylaminostyrylanthracene), 1,1-bis- (4-dibenzylaminophenyl) propane, styrylanthracene, styrylpyrazoline, phenylhydrazones, α-phenylstilbene derivatives, thiazole derivatives, triazole derivatives, phenazine derivatives, Examples include acridine derivatives, benzofuran derivatives, benzimidazole derivatives, thiophene derivatives, and the like. These may be used alone or in combination of two or more.

--- Polymer charge transport material--
The polymer charge transport material is not particularly limited and may be appropriately selected depending on the intended purpose.For example, a polymer having a carbazole ring, a polymer having a hydrazone structure, a polysilylene polymer, or a triarylamine structure may be used. For example, a polymer having an electron donating group, and other polymers.

  The polymer having a carbazole ring is not particularly limited and may be appropriately selected depending on the intended purpose. Examples thereof include poly-N-vinylcarbazole, JP-A-50-82056, and JP-A-54-9632. And the compounds described in JP-A Nos. 54-11737, 4-175337, 4-183719, and 6-234841.

  The polymer having the hydrazone structure is not particularly limited and may be appropriately selected depending on the intended purpose. For example, JP-A-57-78402, JP-A-61-20953, JP-A-61. JP-A-296358, JP-A-1-134456, JP-A-1-179164, JP-A-3-180851, JP-A-3-180852, JP-A-3-50555, JP-A-5-310904. And the compounds described in JP-A-6-234840.

  The polysilylene polymer is not particularly limited and may be appropriately selected depending on the intended purpose. Examples thereof include JP-A 63-285552, JP-A 1-88461, and JP-A 4-264130. Examples thereof include compounds described in JP-A-4-264131, JP-A-4-264132, JP-A-4-264133, and JP-A-4-289867.

  The polymer having a triarylamine structure is not particularly limited and may be appropriately selected depending on the intended purpose. For example, N, N-bis (4-methylphenyl) -4-aminopolystyrene, JP-A-134457, JP-A-2-282264, JP-A-2-304456, JP-A-4-133305, JP-A-4-1330666, JP-A-5-40350, JP-A-5-202135. And the compounds described in Japanese Patent Publication No.

  The polymer having an electron-donating group is not particularly limited and may be appropriately selected depending on the intended purpose. Examples thereof include copolymers with known monomers, block polymers, graft polymers, and stars. For example, a polymer, and a crosslinked polymer having an electron donating group as disclosed in JP-A-3-109406 can also be used.

  Examples of the other polymer include, for example, formaldehyde condensation polymer of nitropyrene, JP-A-51-73888, JP-A-56-150749, JP-A-6-234836, JP-A-6-234837. And the like.

  In addition to the above, the polymer charge transporting material includes, for example, a polycarbonate resin having a triarylamine structure, a polyurethane resin having a triarylamine structure, a polyester resin having a triarylamine structure, and a polyarylamine structure having a polyarylamine structure. And ether resins. Examples of the polymer charge transporting material include JP-A 64-1728, JP-A 64-13061, JP-A 64-19049, JP-A-4-11627, JP-A 4-116627. JP 2225014, JP 4-230767, JP 4-320420, JP 5-232727, JP 7-56374, JP 9-127713, JP 9-222740. And compounds described in JP-A-9-265197, JP-A-9-211877, JP-A-9-30495, and the like.

-Binder resin-
The binder resin is not particularly limited and can be appropriately selected depending on the purpose. For example, polycarbonate resin, polyester resin, methacrylic resin, acrylic resin, polyethylene resin, polyvinyl chloride resin, polyvinyl acetate resin, Polystyrene resin, phenol resin, epoxy resin, polyurethane resin, polyvinylidene chloride resin, alkyd resin, silicone resin, polyvinyl carbazole resin, polyvinyl butyral resin, polyvinyl formal resin, polyacrylate resin, polyacrylamide resin, phenoxy resin, and the like are used. These may be used alone or in combination of two or more.
The charge transport layer may also contain a copolymer of a crosslinkable binder resin and a crosslinkable charge transport material.

-Other ingredients-
There is no restriction | limiting in particular as said other component, According to the objective, it can select suitably, For example, a solvent, a plasticizer, a leveling agent, etc. are mentioned, The above-mentioned antioxidant may be included.

--Solvent--
The solvent is not particularly limited and may be appropriately selected depending on the purpose. The same solvent as the charge generation layer can be used, but a solvent that dissolves the charge transport material and the binder resin satisfactorily. preferable. These may be used singly or in combination of two or more.

--Plasticizer--
The plasticizer is not particularly limited and may be appropriately selected depending on the intended purpose. Examples thereof include plasticizers for general resins such as dibutyl phthalate and dioctyl phthalate.
There is no restriction | limiting in particular as content of the said plasticizer, Although it can select suitably according to the objective, 0 mass part-30 mass parts are preferable with respect to 100 mass parts of said binder resins.

--Leveling agent--
The leveling agent is not particularly limited and may be appropriately selected depending on the intended purpose. Examples thereof include silicone oils such as dimethyl silicone oil and methyl phenyl silicone oil; polymers or oligomers having a perfluoroalkyl group in the side chain. Etc.
There is no restriction | limiting in particular as content of the said leveling agent, Although it can select suitably according to the objective, 0 mass part-1 mass part are preferable with respect to 100 mass parts of said binder resins.

-Method for forming charge transport layer-
The method for forming the charge transport layer is not particularly limited and may be appropriately selected depending on the intended purpose. For example, the charge transport material and the binder resin are dissolved or dispersed in the other components such as the solvent. And a method of forming the coating liquid obtained by coating on the charge generation layer and drying. In addition, the said coating liquid can be apply | coated by the above-mentioned casting method.

  There is no restriction | limiting in particular as thickness of the said charge transport layer, Although it can select suitably according to the objective, 5 micrometers-40 micrometers are preferable, and 10 micrometers-30 micrometers are more preferable.

<< Charge generation layer >>
The charge generation layer includes a charge generation material, preferably includes a binder resin, and further includes other components such as the above-described antioxidant as necessary.

-Charge generation material-
There is no restriction | limiting in particular as said charge generation substance, According to the objective, it can select suitably, For example, an inorganic material, an organic material, etc. are mentioned.

--Inorganic materials--
There is no restriction | limiting in particular as an inorganic material, According to the objective, it can select suitably, For example, crystalline selenium, amorphous-selenium, selenium-tellurium, selenium-tellurium-halogen, selenium-arsenic compound, amorphous silicon ( For example, a dangling bond terminated with a hydrogen atom, a halogen atom or the like; a boron atom, a phosphorus atom or the like doped is preferred.

--- Organic materials--
The organic material is not particularly limited and may be appropriately selected depending on the intended purpose. Examples thereof include phthalocyanine pigments such as metal phthalocyanine and metal-free phthalocyanine; azulenium salt pigments, squaric acid methine pigments, and carbazole skeletons. Azo pigments having a triphenylamine skeleton, azo pigments having a diphenylamine skeleton, azo pigments having a dibenzothiophene skeleton, azo pigments having a fluorenone skeleton, azo pigments having an oxadiazole skeleton, azo having a bisstilbene skeleton Pigment, azo pigment having distyryl oxadiazole skeleton, azo pigment having distyryl carbazole skeleton, perylene pigment, anthraquinone or polycyclic quinone pigment, quinoneimine pigment, diphenylmethane and triphenylmethane face , Benzoquinone and naphthoquinone pigments, cyanine and azomethine pigments, indigoid pigments, and bis-benzimidazole-based pigments. These may be used individually by 1 type and may use 2 or more types together.

-Binder resin-
The binder resin is not particularly limited and can be appropriately selected according to the purpose. For example, polyamide resin, polyurethane resin, epoxy resin, polyketone resin, polycarbonate resin, silicone resin, acrylic resin, polyvinyl butyral resin, Examples thereof include polyvinyl formal resin, polyvinyl ketone resin, polystyrene resin, poly-N-vinyl carbazole resin, polyacrylamide resin and the like. These may be used individually by 1 type and may use 2 or more types together.

  In addition to the above-mentioned binder resin, the binder resin may include a charge transporting polymer material having a charge transport function. For example, (1) an arylamine skeleton, a benzidine skeleton, a hydrazone skeleton, a carbazole skeleton, Polymer materials having a stilbene skeleton, a pyrazoline skeleton, etc., such as polycarbonate, polyester, polyurethane, polyether, polysiloxane, and acrylic resin, and (2) a polymer material having a polysilane skeleton can be used.

  Specific examples of the above (1) include, for example, JP-A-01-001728, JP-A-01-009964, JP-A-01-013061, JP-A-01-019049, JP-A-01-241559. JP, 04-011627, JP 04-175337, JP 04-183719, JP 04-22514, JP 04-230767, JP 04-320420, JP 05-232727, JP 05-310904, JP 06-234836, JP 06-234837, JP 06-234838, JP 06-234839, JP JP 06-234840, JP 06-234841 A, JP 06-23904 JP, JP-A 06-236050, JP-A 06-236051, JP-A 06-295077, JP-A 07-056374, JP 08-176293, JP 08-208820. JP-A-08-21640, JP-A-08-253568, JP-A-08-269183, JP-A-09-062019, JP-A-09-038883, JP-A-09-71642, Special Japanese Laid-Open Patent Application Nos. 09-87376, 09-104746, 09-110974, 09-110976, 09-157378, 09-221544, 09 JP-A No. 227669, JP-A No. 09-235367, JP-A No. 09-2413 No. 9, JP 09-268226 A, JP 09-272735 A, JP 09-302084 A, JP 09-302085 A, JP 09-328539 A, etc. Examples include polymer materials.

  Specific examples of the above (2) include polysilylene weights described in, for example, JP-A 63-285552, JP-A 05-19497, JP-A 05-70595, JP-A 10-73944, and the like. Examples thereof include charge transporting polymer materials such as coalescence.

-Other ingredients-
There is no restriction | limiting in particular as said other component, According to the objective, it can select suitably, For example, a low molecular charge transport material, a solvent, a leveling agent etc. are mentioned, You may include the above-mentioned antioxidant.

--Low molecular charge transport material--
There is no restriction | limiting in particular as said low molecular charge transport material, According to the objective, it can select suitably, For example, an electron transport material, a hole transport material, etc. are mentioned.

  The electron transport material is not particularly limited and may be appropriately selected depending on the intended purpose. For example, chloroanil, bromilyl, tetracyanoethylene, tetracyanoquinodimethane, 2,4,7-trinitro-9-fluorenone 2,4,5,7-tetranitro-9-fluorenone, 2,4,5,7-tetranitroxanthone, 2,4,8-trinitrothioxanthone, 2,6,8-trinitro-4H-indeno [1 , 2-b] thiophen-4-one, 1,3,7-trinitrodibenzothiophene-5,5-dioxide, diphenoquinone derivatives and the like. These may be used individually by 1 type and may use 2 or more types together.

  The hole transport material is not particularly limited and may be appropriately selected depending on the intended purpose. Examples thereof include oxazole derivatives, oxadiazole derivatives, imidazole derivatives, monoarylamine derivatives, diarylamine derivatives, and triarylamine derivatives. , Stilbene derivatives, α-phenylstilbene derivatives, benzidine derivatives, diarylmethane derivatives, triarylmethane derivatives, 9-styrylanthracene derivatives, pyrazoline derivatives, divinylbenzene derivatives, hydrazone derivatives, indene derivatives, butadiene derivatives, pyrene derivatives, etc. Derivatives, enamine derivatives and the like. These may be used individually by 1 type and may use 2 or more types together.

--Solvent--
The solvent is not particularly limited and may be appropriately selected depending on the intended purpose.For example, tetrahydrofuran, dioxane, dioxolane, toluene, dichloromethane, monochlorobenzene, dichloroethane, cyclohexanone, cyclopentanone, anisole, xylene, methyl ethyl ketone, Acetone, ethyl acetate, butyl acetate and the like can be mentioned. These may be used individually by 1 type and may use 2 or more types together.

--Leveling agent--
There is no restriction | limiting in particular as said leveling agent, According to the objective, it can select suitably, For example, silicone oils, such as dimethyl silicone oil and methylphenyl silicone oil, etc. are mentioned. These may be used individually by 1 type and may use 2 or more types together.

-Method for forming charge generation layer-
The method for forming the charge generation layer is not particularly limited and may be appropriately selected depending on the purpose. For example, the charge generation material and the binder resin are dissolved or dispersed in the other components such as the solvent. For example, a method of forming the coating liquid obtained by applying the coating liquid on the conductive support and drying it may be used. In addition, the said coating liquid can be apply | coated by the above-mentioned casting method.

  There is no restriction | limiting in particular as thickness of the said charge generation layer, Although it can select suitably according to the objective, 0.01 micrometer-5 micrometers are preferable, and 0.05 micrometer-2 micrometers are more preferable.

<< Other layers >>
There is no restriction | limiting in particular as said other layer, According to the objective, it can select suitably, For example, an undercoat layer, an intermediate | middle layer, etc. are mentioned.

-Undercoat layer-
The undercoat layer can be provided between the conductive support and the photosensitive layer.
The undercoat layer contains a resin and, if necessary, further contains other components such as the above-mentioned antioxidant, fine powder pigment, and coupling agent.

The resin contained in the undercoat layer is not particularly limited and may be appropriately selected depending on the intended purpose. Examples thereof include water-soluble resins such as polyvinyl alcohol, casein and sodium polyacrylate, copolymer nylon, and methoxymethyl. Examples thereof include alcohol-soluble resins such as nylon fluoride, curable resins that form a three-dimensional network structure, such as polyurethane, melamine resin, phenol resin, alkyd-melamine resin, and epoxy resin.
Among these, a resin having high solvent resistance with respect to a general organic solvent is preferable in that the photosensitive layer is coated on the resin with a solvent.

  The fine powder pigment contained in the undercoat layer is not particularly limited as long as it is a pigment that can prevent moire, reduce residual potential, etc., and can be appropriately selected according to the purpose. Examples thereof include metal oxides such as titanium, silica, alumina, zirconium oxide, tin oxide, and indium oxide.

  There is no restriction | limiting in particular as a coupling agent contained in the said undercoat layer, According to the objective, it can select suitably, For example, a silane coupling agent, a titanium coupling agent, a chromium coupling agent etc. are mentioned.

  There is no restriction | limiting in particular as said undercoat layer, According to the objective, it can select suitably, For example, a single layer may be sufficient and the lamination | stacking of two or more layers may be sufficient as the combination of the said kind.

A method for forming the undercoat layer is not particularly limited, and can be formed by using an appropriate solvent and a coating method as in the above-described photosensitive layer. For example, a method of forming by anodizing Al ₂ O ₃ And an organic material such as polyparaxylylene (parylene); an inorganic material such as SiO ₂ , SnO ₂ , TiO ₂ , ITO, and CeO ₂ ; by a vacuum thin film manufacturing method.

  There is no restriction | limiting in particular as thickness of the said undercoat layer, Although it can select suitably according to the objective, 1 micrometer-5 micrometers are preferable.

-Intermediate layer-
The intermediate layer is intended to suppress mixing of charge transport layer components into the cross-linked charge transport layer or improve adhesion between both layers between the charge transport layer and the cross-linked charge transport layer. Can be provided.

  The intermediate layer is suitably insoluble or sparingly soluble in the crosslinkable charge transport layer coating solution, contains a binder resin, and further contains other components such as the above-mentioned antioxidant as necessary. .

  The binder resin contained in the intermediate layer is not particularly limited and may be appropriately selected depending on the intended purpose. Examples thereof include polyamide, alcohol-soluble nylon, water-soluble polyvinyl butyral, polyvinyl butyral, and polyvinyl alcohol. .

  There is no restriction | limiting in particular as a formation method of the said intermediate | middle layer, According to the objective, it can select suitably, For example, the method of forming using a suitable solvent and a coating method like the above-mentioned photosensitive layer etc. are mentioned.

  There is no restriction | limiting in particular as thickness of the said intermediate | middle layer, Although it can select suitably according to the objective, 0.05 micrometer-2 micrometers are preferable.

  Hereinafter, embodiments of the electrophotographic photosensitive member of the present invention will be described.

<First Embodiment>
The layer structure of the electrophotographic photoreceptor according to the first embodiment will be described with reference to FIG.
FIG. 1 shows a configuration example of the most basic laminated photoconductor, in which a charge generation layer 2 and a charge transport layer 3 are sequentially laminated on a conductive support 1. When used in a negative charge, a hole transporting charge transport material is used for the charge transport layer, and when used in a positive charge, an electron transporting charge transport material is used for the charge transport layer. In this case, the outermost surface layer is the charge transport layer 3.
Therefore, an aromatic ring inclusion structure in which the phthalate ester compound represented by the general formula (1) is molecularly dispersed in the network structure of the three-dimensional crosslinked polymer is applied to the charge transport layer 3.

<Second Embodiment>
The layer structure of the electrophotographic photosensitive member according to the second embodiment will be described with reference to FIG.
FIG. 2 shows a configuration in which an undercoat layer 4 is provided on a laminated photoconductor having a basic configuration, which is the most practical configuration. In this case, the outermost surface layer is the charge transport layer 3.
Therefore, an aromatic ring inclusion structure in which the phthalate ester compound represented by the general formula (1) is molecularly dispersed in the network structure of the three-dimensional crosslinked polymer is applied to the charge transport layer 3.

<Third Embodiment>
The layer structure of the electrophotographic photosensitive member according to the third embodiment will be described with reference to FIG.
FIG. 3 shows a configuration in which a crosslinkable charge transport layer 5 is further provided on the outermost surface as a protective layer.
Therefore, an aromatic ring inclusion structure in which the phthalate compound represented by the general formula 1 is molecularly dispersed in the network structure of the three-dimensional crosslinked polymer is applied to the crosslinked charge transport layer 5. Here, the undercoat layer is not essential, but it plays an important function for prevention of charge leakage and is usually used. In the case of this photoconductor structure, the charge transfer from the charge generation layer to the surface of the photoconductor is shared by the two layers of the charge transport layer 3 and the cross-linked charge transport layer 5, and the main functions can be separated. For example, by combining a charge transport layer having excellent charge transportability with a cross-linked charge transport layer having excellent mechanical durability, it is possible to provide a photoreceptor having excellent charge transportability and excellent mechanical durability.

<Fourth Embodiment>
The layer configuration of the electrophotographic photosensitive member according to the fourth embodiment will be described with reference to FIG.
FIG. 4 shows a configuration in which a photosensitive layer (outermost surface layer) 6 mainly composed of a charge generation material and a charge transport material is provided on the conductive support 1.
Therefore, an aromatic ring inclusion structure in which the phthalate ester compound represented by the general formula (1) is molecularly dispersed in the photosensitive layer (outermost surface layer) 6 in the network structure of the three-dimensional crosslinked polymer. Apply. In this case, it is necessary to contain a charge generating substance in the crosslinked film, and a coating liquid in which the charge generating substance is mixed and dispersed in the coating liquid is prepared, and after the coating, a polymerization reaction is performed by heating and drying. To make a three-dimensional resin.

<Fifth Embodiment>
The layer structure of the electrophotographic photosensitive member according to the fifth embodiment will be described with reference to FIG.
FIG. 5 shows a configuration in which a protective layer 7 is provided on the single-layer photosensitive layer 6.
Therefore, an aromatic ring inclusion structure in which the phthalate ester compound represented by the general formula (1) is molecularly dispersed in the network structure of the three-dimensional crosslinked polymer is applied to the protective layer 7.

(Image forming method and image forming apparatus)
The image forming method of the present invention includes at least a charging step, an exposure step, a development step, and a transfer step, and further includes other steps as necessary. The electrophotographic photosensitive member used in the image forming method is the above-described electrophotographic photosensitive member of the present invention. The charging process and the exposure process may be collectively referred to as an electrostatic latent image forming process.
The image forming apparatus of the present invention includes at least an electrophotographic photosensitive member, a charging unit, an exposure unit, a developing unit, and a transfer unit, and further includes other units as necessary. The electrophotographic photosensitive member used in the image forming apparatus is the above-described electrophotographic photosensitive member of the present invention. The charging unit and the exposure unit may be collectively referred to as an electrostatic latent image forming unit.

<Charging step and charging means>
The charging step can be performed by the charging means and is a step of charging the surface of the electrophotographic photosensitive member.
The charging means is not particularly limited and may be appropriately selected according to the purpose. For example, a known contact charger including a conductive or semiconductive roll, brush, film, rubber blade, etc. And non-contact chargers using corona discharge such as corotron and scorotron (including proximity-type non-contact chargers having a gap of 100 μm or less between the surface of the electrophotographic photosensitive member and the charger).

<Exposure process and exposure means>
The exposure step can be performed by the exposure means, and is a step of exposing the charged electrophotographic photosensitive member surface to form an electrostatic latent image.
The exposure means is not particularly limited as long as the surface of the electrophotographic photosensitive member charged by the charging means can be exposed like an image to be formed, and can be appropriately selected according to the purpose. Examples include various exposure devices such as a copying optical system, a rod lens array system, a laser optical system, a liquid crystal shutter optical system, and an LED optical system, and examples of the light source in the exposure device include a light emitting diode (LED) and a semiconductor laser. (LD), electroluminescence (EL), etc. and the light source etc. which can ensure high brightness | luminance are mentioned. In the present invention, an optical backside system that performs imagewise exposure from the backside of the electrophotographic photosensitive member may be employed.

<Development process and development means>
The developing step can be carried out by the developing means, and is a step of developing the electrostatic latent image with toner to form a visible image.
The developing means is not particularly limited and may be appropriately selected depending on the purpose. For example, as long as development can be performed using the toner or developer, there is no particular limitation, and the developing means is appropriately selected according to the purpose. However, it is preferable to have at least a developing unit that accommodates the developer and can apply the developer to the electrostatic latent image in a contact or non-contact manner. The developing unit may be a dry developing type, a wet developing type, a single color developing unit, or a multicolor developing unit. For example, a developer having a stirrer for charging the developer by frictional stirring and a rotatable magnet roller is preferable. In the developing device, for example, the toner and the carrier are mixed and agitated, and the toner is charged by friction at that time, and held on the surface of the rotating magnet roller in a raised state to form a magnetic brush. . Since the magnet roller is disposed in the vicinity of the electrophotographic photosensitive member, a part of the toner constituting the magnetic brush formed on the surface of the magnet roller is electrically attracted to the electrophotographic photosensitive member. Move to the surface of the body. As a result, the electrostatic latent image is developed with the toner, and a visible image is formed with the toner on the surface of the electrophotographic photosensitive member.

<Transfer process and transfer means>
The transfer step can be performed by the transfer unit, and is a step of transferring the visible image to a recording medium.
The transfer means is a means for transferring the visible image to a recording medium, and uses a method for directly transferring a visible image from the surface of the electrophotographic photosensitive member to a recording medium, and an intermediate transfer member. There is a method in which a visible image is primarily transferred onto the recording medium, and then the visible image is secondarily transferred onto the recording medium. Either aspect can be used satisfactorily, but the former (direct transfer) method with a small number of transfers is preferred when the adverse effect of the transfer is great when the image quality is improved. The transfer can be performed, for example, by charging the electrophotographic photosensitive member with the transfer charger using the visible image, and can be performed by the transfer unit.

<Fixing process and fixing means>
The fixing step can be performed by the fixing unit, and is a step of fixing the transferred image transferred to the recording medium.
The fixing unit is not particularly limited and may be appropriately selected depending on the purpose. However, a known heating and pressing unit is preferable, and the heating and pressing unit includes a combination of a heating roller and a pressing roller, A combination of a heating roller, a pressure roller, and an endless belt can be mentioned. The fixing may be performed, for example, every time the toner of each color is transferred to the recording medium, or may be performed simultaneously in a state where the toner of each color is stacked.

<Other processes and other means>
The other steps and other means are not particularly limited and may be appropriately selected depending on the purpose. For example, the charge removal step and the charge removal unit, the cleaning step and the cleaning unit, the recycling step and the recycling unit, the control step, and the like. A control means etc. are mentioned.

-Static elimination process and static elimination means-
The static elimination step can be performed by the static elimination means, and is a step of performing static elimination by applying a static elimination bias to the electrophotographic photosensitive member.
The neutralization means is not particularly limited, and may be appropriately selected from known neutralizers as long as it can apply a neutralization bias to the electrophotographic photosensitive member. For example, a neutralization lamp is preferably used. Can be mentioned.

-Cleaning process and cleaning means-
The cleaning step can be performed by the cleaning unit, and is a step of removing the toner remaining on the electrophotographic photosensitive member.
The cleaning means is not particularly limited as long as it can remove the electrophotographic toner remaining on the electrophotographic photosensitive member, and can be appropriately selected from known cleaners. For example, a magnetic brush cleaner Suitable examples include electrostatic brush cleaners, magnetic roller cleaners, blade cleaners, brush cleaners, web cleaners, and the like.

-Recycling process and recycling means-
The recycling step can be performed by the recycling unit, and is a step of recycling the toner removed by the cleaning step to the developing unit.
There is no restriction | limiting in particular as said recycling means, A well-known conveyance means etc. are mentioned.

-Control process and control means-
The said control process is a process which can be implemented by the said control means and controls each said process.
The control means is not particularly limited as long as the movement of each means can be controlled, and can be appropriately selected according to the purpose. Examples thereof include devices such as a sequencer and a computer.

  Hereinafter, embodiments of the image forming apparatus of the present invention will be described.

  FIG. 6 is a schematic diagram for explaining the electrophotographic process and the image forming apparatus of the present invention, and the following examples also belong to the category of the present invention.

  As shown in FIG. 6, the photoconductor 10 rotates in the direction of the arrow, and around the photoconductor 10 is a charging member 11, an image exposure member 12, a developing member 13, a transfer member 16, a cleaning member 17, and a charge eliminating member. 18 etc. are arranged. The cleaning member 17 and the charge removal member 18 may be omitted.

  As shown in FIG. 6, the operation of the image forming apparatus is basically as follows. The charging member 11 charges the surface of the photoreceptor 10 almost uniformly. Subsequently, image light writing corresponding to the input signal is performed by the image exposure member 12 to form an electrostatic latent image. Next, the electrostatic latent image is developed by the developing member 13, and a toner image is formed on the surface of the photoreceptor. The formed toner image is transferred onto the transfer paper 15 sent to the transfer site by the transport roller 14 by the transfer member. This toner image is fixed on the transfer paper by a fixing device (not shown). A part of the toner that has not been transferred to the transfer paper is cleaned by the cleaning member 17. Next, the charge remaining on the photoconductor is neutralized by the neutralizing member 18 and proceeds to the next cycle.

  As shown in FIG. 6, the photoconductor 10 has a drum shape, but may have a sheet shape or an endless belt shape. For the charging member 11 and the transfer member 16, in addition to corotron, scorotron, solid state charger (solid state charger), roller-shaped charging members or brush-shaped charging members are used, and all known means can be used. It is.

  On the other hand, light sources such as a fluorescent lamp, a tungsten lamp, a halogen lamp, a mercury lamp, a sodium lamp, a light emitting diode (LED), a semiconductor laser (LD), and an electroluminescence (EL) are used as light sources such as the image exposure member 12 and the charge removal member 18. All things can be used. Among these, a semiconductor laser (LD) and a light emitting diode (LED) are mainly used. Various types of filters such as a sharp cut filter, a band pass filter, a near infrared cut filter, a dichroic filter, an interference filter, and a color temperature conversion filter can be used to irradiate only light in a desired wavelength range.

  The light source or the like is provided with a process such as a transfer process, a charge eliminating process, a cleaning process, or a pre-exposure process using light irradiation, so that the photoconductor 10 is irradiated with light. However, the exposure of the photoconductor 10 in the static elimination step has a large influence of fatigue on the photoconductor 10 and may cause a decrease in charge and an increase in residual potential. Therefore, there is a case where it is possible to eliminate static electricity by applying a reverse bias in the charging process or cleaning process instead of static elimination by exposure, which may be effective from the viewpoint of enhancing the durability of the photoreceptor.

  When the electrophotographic photosensitive member 10 is positively (negatively) charged and image exposure is performed, a positive (negative) electrostatic latent image is formed on the surface of the photosensitive member. A positive image can be obtained by developing this with negative (positive) toner (electrodetection fine particles), and a negative image can be obtained by developing with positive (negative) toner. A known method is applied to the developing unit, and a known method is also used for the charge eliminating unit.

  Among the contaminants that adhere to the surface of the photoconductor, discharge substances generated by charging and external additives contained in the toner are easy to pick up the effects of humidity and cause abnormal images. Paper powder is one of the causative substances, and when they adhere to the photoreceptor, abnormal images are more likely to occur, as well as a tendency to reduce wear resistance and cause uneven wear. Is seen. Therefore, it is more preferable from the viewpoint of high image quality that the photoconductor and the paper are not in direct contact for the above reason.

  The toner developed on the photosensitive member 10 by the developing member 13 is transferred to the transfer paper 15, but not all is transferred, and toner remaining on the photosensitive member 10 is also generated. Such toner is removed from the photoreceptor 10 by the cleaning member 17. As the cleaning member, a known member such as a cleaning blade or a cleaning brush is used. Moreover, both may be used together.

  The photoconductor according to the present invention can be applied to a small-diameter photoconductor because high photosensitivity and high stability are realized. Therefore, as an image forming apparatus or method for using the above photoreceptor more effectively, each developing unit corresponding to a plurality of colors of toner is provided with a plurality of corresponding photoreceptors, thereby performing parallel processing. It is very effectively used in a so-called tandem type image forming apparatus. The tandem image forming apparatus includes at least four color toners of yellow (C), magenta (M), cyan (C), and black (K) required for full-color printing and a developing unit that holds them. Further, by providing at least four photoconductors corresponding to them, full-color printing can be performed at an extremely high speed as compared with a conventional image forming apparatus capable of full-color printing.

  FIG. 7 is a schematic diagram for explaining the tandem-type full-color electrophotographic apparatus of the present invention, and the following modifications also belong to the category of the present invention.

  In FIG. 7, photoconductors (10C (cyan), 10M (magenta), 10Y (yellow), 10K (black)) are drum-like photoconductors 10, and these photoconductors (10C, 10M, 10Y, 10K). ) Rotate in the direction of the arrow in the figure, and at least in that order around the charging member (11C, 11M, 11Y, 11K), the developing member (13C, 13M, 13Y, 13K), the cleaning member (17C, 17M, 17Y). , 17K). From the outside of the photoreceptor 10 between the charging member (11C, 11M, 11Y, 11K) and the developing member (13C, 13M, 13Y, 13K), laser light (12C, 12M, 12Y, 12K) is irradiated, and an electrostatic latent image is formed on the photoconductor (10C, 10M, 10Y, 10K).

  In FIG. 7, four image forming elements (20C, 20M, 20Y, 20K) centering on the photoconductors (10C, 10M, 10Y, 10K) are juxtaposed along the transfer conveyance belt 19 which is a transfer material conveyance unit. Has been. The transfer conveyance belt 19 is a photosensitive member between the developing member (13C, 13M, 13Y, 13K) of each image forming unit (20C, 20M, 20Y, 20K) and the cleaning member (17C, 17M, 17Y, 17K). (10C, 10M, 10Y, and 10K), and a transfer member (16C, 16M, 16Y, and 16K) for applying a transfer bias to the back surface (back surface) of the transfer and transport belt 19 that contacts the back side of the photoconductor 10 side. ) Is arranged. Each of the image forming elements (20C, 20M, 20Y, 20K) is different in toner color inside the developing device, and the other components have the same configuration.

  In the color electrophotographic apparatus having the configuration shown in FIG. 7, the image forming operation is performed as follows. First, in each of the image forming elements (20C, 20M, 20Y, and 20K), the charging member (11C, 11M, 11Y, and 11K) in which the photosensitive member (10C, 10M, 10Y, and 10K) rotates along with the photosensitive member 10 is rotated. ), And then an electrostatic latent image corresponding to each color image to be created by laser light (12C, 12M, 12Y, 12K) by an exposure unit (not shown) arranged outside the photoreceptor 10. Is formed.

  Next, the latent image is developed by a developing member (13C, 13M, 13Y, 13K) to form a toner image. The developing members (13C, 13M, 13Y, and 13K) are developing members that perform development with toners of C (cyan), M (magenta), Y (yellow), and K (black), respectively. 10M, 10Y, and 10K) are overlaid on the transfer belt 19).

  The transfer paper 15 is sent out from the tray by a paper feed roller 21, temporarily stopped by a pair of registration rollers 22, and sent to the transfer member 23 in synchronism with the image formation on the photosensitive member. The toner image held on the transfer belt 19 is transferred onto the transfer paper 15 by an electric field formed from the potential difference between the transfer bias applied to the transfer member 23 and the transfer belt 19. The toner image transferred onto the transfer paper is conveyed, the toner is fixed onto the transfer paper by the fixing member 24, and is discharged to a paper discharge unit (not shown). Further, residual toner that is not transferred by the transfer unit and remains on the photosensitive members (10C, 10M, 10Y, and 10K) is collected by cleaning members (17C, 17M, 17Y, and 17K) provided in the respective units. The

The intermediate transfer system as shown in FIG. 7 is particularly effective for an image forming apparatus capable of full color printing. A plurality of toner images are once formed on an intermediate transfer body and then transferred onto paper at a time, thereby causing color misregistration. This is easy to control and is effective for high image quality.
The intermediate transfer member includes various materials or shapes such as a drum shape and a belt shape. In the present invention, any conventionally known intermediate transfer member can be used. It is effective and useful for achieving high quality or high image quality.

  In the example of FIG. 7, the image forming elements are arranged in the order of Y (yellow), M (magenta), C (cyan), and K (black) from the upstream side to the downstream side in the transfer sheet conveyance direction. However, it is not limited to this order, and the color order is arbitrarily set. Further, when a black-only document is created, it is particularly effective to use the present invention to provide a mechanism that stops the image forming elements (20C, 20M, 20Y) other than black.

  The above-described tandem image forming apparatus can transfer a plurality of toner images at a time, so that high-speed full-color printing is realized. However, since at least four photoconductors are required, an increase in the size of the apparatus is unavoidable, and depending on the amount of toner used, there is a difference in the wear amount of each photoconductor, thereby reproducing the color. There are many problems such as a decrease in performance and occurrence of abnormal images. On the other hand, the photosensitive member according to the present invention can be applied to a small-diameter photosensitive member by realizing high photosensitivity and high stability, and the influence of increase in residual potential, sensitivity deterioration, etc. is reduced. Even if the amount of the photoconductor used is different, the difference in residual potential and sensitivity over time is small, and a full color image having excellent color reproducibility can be obtained even when used repeatedly for a long time.

  The image forming means as described above may be fixedly incorporated in a copying apparatus, a facsimile, or a printer, but may be incorporated in these apparatuses in the form of a process cartridge.

(Process cartridge)
The process cartridge of the present invention has an electrophotographic photosensitive member and at least one means selected from a charging means, an exposure means, a developing means, a transfer means, a cleaning means, and a slow current means, and is detachable from the image forming apparatus. In a certain process cartridge, the electrophotographic photosensitive member is the above-described electrophotographic photosensitive member of the present invention. As a result, it is possible to provide a process cartridge that has high image stability during repeated use and can maintain high image quality with few image defects over a long period of time, and is excellent in environmental stability and gas resistance.

  As shown in FIG. 8, the process cartridge includes a photosensitive member 10 and includes a charging member 11, an image exposure member 12, a developing member 13, a transfer member 16, a cleaning member 17, and a charge eliminating member. One device (part).

EXAMPLES Next, although an Example and a comparative example are given and this invention is demonstrated more concretely, this invention is not restrict | limited to the following Example.
In addition, all "parts" used in an Example represent a mass part.
Further, the abbreviation, p-TolSO ₃ H represents paratoluenesulfonic acid, t-Bu ₃ P represents tri-tert-butylphosphine, t-BuONa represents sodium-tert-butoxide, and Pd (OAc) ₂ represents palladium acetate, and Pd [(t-Bu) ₃ P] ₂ represents bis (tri-t-butoxyphosphine) palladium.

(Synthesis Example 1)
<Synthesis of intermediate material of three-dimensional crosslinked polymer>
Synthesis of 4-[(tetrahydro-2H-pyran-2-yl) oxy] methyl bromobenzene, which is an intermediate of the material of the three-dimensional crosslinked polymer, was performed by the following procedure.
First, 4-bromobenzyl alcohol (50.43 g), 3,4-dihydro-2H-pyran (45.35 g), and tetrahydrofuran (150 mL) were placed in a four-necked flask and stirred at 5 ° C., paratoluene. Sulfonic acid (0.512 g) was dropped to prepare a solution. Subsequently, this solution was stirred at room temperature for 2 hours, extracted with ethyl acetate, dehydrated with magnesium sulfate, and subjected to adsorption treatment with activated clay and silica gel. And the target object was obtained by filtering, wash | cleaning, and concentrating this (yield 72.50g, colorless oily substance). The reaction formula is shown below. FIG. 10 shows an infrared absorption spectrum (KBr tablet method) of the compound obtained in Synthesis Example 1.

(Synthesis Example 2)
<Synthesis of intermediate material of three-dimensional crosslinked polymer>
Synthesis of 3-[(tetrahydro-2H-pyran-2-yl) oxy] methyl bromobenzene, which is an intermediate of the material of the three-dimensional crosslinked polymer, was performed by the following procedure.
First, 3-bromobenzyl alcohol (25.21 g), 3,4-dihydro-2H-pyran (22.50 g), and tetrahydrofuran (50 mL) were placed in a four-necked flask and stirred at 5 ° C., paratoluene. Sulfonic acid (0.259 g) was dropped to prepare a solution. Subsequently, this solution was stirred at room temperature for 1 hour, extracted with ethyl acetate, dehydrated with magnesium sulfate, and adsorbed with activated clay and silica gel. And the target object was obtained by filtering, wash | cleaning, and concentrating this (yield 36.84g, colorless oily substance). The reaction formula is shown below. FIG. 11 shows an infrared absorption spectrum (KBr tablet method) of the compound obtained in Synthesis Example 2.

(Synthesis Example 3)
<Synthesis of Intermediate Methylol Compound>
Synthesis of 4,4′-bis [di (4-hydroxymethylphenyl) amino] diphenylmethane, which is a methylol intermediate, was performed according to the following procedure.
First, an intermediate aldehyde compound (12.30 g) and ethanol (150 mL) were placed in a four-necked flask, stirred at room temperature, and sodium borohydride (3.63 g) was dropped to prepare a solution. Subsequently, this solution was stirred at room temperature for 4 hours, extracted with ethyl acetate, dehydrated with magnesium sulfate, and adsorbed with activated clay and silica gel. Then, this was filtered, washed, and concentrated to obtain an amorphous substance. This was dispersed in n-hexane, filtered, washed, and dried to obtain the desired product (yield 12.0 g, pale yellowish white amorphous). The reaction formula is shown below. FIG. 12 shows an infrared absorption spectrum (KBr tablet method) of the compound obtained in Synthesis Example 3.

(Synthesis Example 4)
<Synthesis of three-dimensional crosslinked polymer material>
The synthesis of [(tetrahydro-2H-pyran-2-yl) oxy] methyl group-containing charge transporting compound (compound represented by the following structural formula (2-4)), which is a material of the three-dimensional crosslinked polymer, The procedure was followed.
First, an intermediate methylol compound (3.4 g), 3,4-dihydro-2H-pyran (4.65 g), and tetrahydrofuran (100 mL) were placed in a four-necked flask and stirred at 5 ° C., paratoluene sulfone. A solution was prepared by dropping acid (58 mg). Subsequently, this solution was stirred at room temperature for 5 hours, extracted with ethyl acetate, dehydrated with magnesium sulfate, and subjected to adsorption treatment with activated clay and silica gel. And this was filtered, washed, and concentrated to obtain a yellow oily substance. This yellow oily substance was purified and purified by a silica gel column (toluene / ethyl acetate = 10/1) (volume ratio) to obtain the desired product (yield 2.7 g, colorless oily substance). The reaction formula is shown below. FIG. 13 shows an infrared absorption spectrum (KBr tablet method) of the compound obtained in Synthesis Example 4.

(Synthesis Example 5)
<Synthesis of three-dimensional crosslinked polymer material>
The synthesis of [(tetrahydro-2H-pyran-2-yl) oxy] methyl group-containing charge transporting compound (compound represented by the following structural formula (3-1)), which is a material of the three-dimensional crosslinked polymer, The procedure was followed.
First, 4,4′-diaminodiphenylmethane (2.99 g), the compound obtained in Synthesis Example 1 (17.896 g), palladium acetate (0.336 g), tertiary butoxy sodium (13.83 g), and o- Xylene (100 mL) was placed in a four-necked flask, stirred at room temperature under an argon gas atmosphere, and tritertial butylphosphine (1.214 g) was added dropwise to prepare a solution. Subsequently, this solution was stirred at 80 ° C. for 1 hour, stirred at reflux for 1 hour, diluted with toluene, dehydrated with magnesium sulfate, and subjected to adsorption treatment with activated clay and silica gel. And this was filtered, washed, and concentrated to obtain a yellow oily substance. This yellow oily substance was purified and isolated on a silica gel column (toluene / ethyl acetate = 20/1) (volume ratio) to obtain the desired product (yield 5.7 g, light yellow amorphous substance). FIG. 14 shows an infrared absorption spectrum (KBr tablet method) of the compound obtained in Synthesis Example 5. The reaction formula is shown below.
This compound could also be synthesized by using the intermediate methylol compound obtained in Synthesis Example 3 and reacting with 3,4-dihydro-2H-pyran in the same manner as in Synthesis Example 4.

(Synthesis Example 6)
<Synthesis of three-dimensional crosslinked polymer material>
The synthesis of [(tetrahydro-2H-pyran-2-yl) oxy] methyl group-containing charge transporting compound (compound represented by the following structural formula (3-8)), which is a material of the three-dimensional crosslinked polymer, The procedure was followed.
First, 4,4′-diaminodiphenyl ether (3.0 g), the compound obtained in Synthesis Example 1 (17.896 g), palladium acetate (0.336 g), tertiary butoxy sodium (13.83 g), and o- Xylene (100 mL) was placed in a four-necked flask, stirred at room temperature under an argon gas atmosphere, and tritertial butylphosphine (1.214 g) was added dropwise to prepare a solution. Next, this solution was stirred at 80 ° C. for 1 hour, stirred at reflux for 1 hour, diluted with toluene, dehydrated with magnesium sulfate, and subjected to adsorption treatment with activated clay and silica gel. And this was filtered, washed, and concentrated to obtain a yellow oily substance. This yellow oily substance was purified and purified by a silica gel column (toluene / ethyl acetate = 10/1) (volume ratio) to obtain the desired product (yield 5.7 g, pale yellow oily substance). The reaction formula is shown below. FIG. 15 shows an infrared absorption spectrum (KBr tablet method) of the compound obtained in Synthesis Example 6.

(Synthesis Example 7)
<Synthesis of three-dimensional crosslinked polymer material>
The synthesis of a [(tetrahydro-2H-pyran-2-yl) oxy] methyl group-containing charge transporting compound (compound represented by the following structural formula (3-13)), which is a material of a three-dimensional crosslinked polymer, The procedure was followed.
First, 4,4′-ethylenedianiline (3.18 g), the compound obtained in Synthesis Example 1 (17.896 g), palladium acetate (0.336 g), sodium tertiary butoxy (13.83 g), and o -Xylene (100 mL) was put into a four-necked flask, stirred at room temperature under an argon gas atmosphere, and tritertiary butylphosphine (1.214 g) was added dropwise to prepare a solution. Subsequently, this solution was stirred at 80 ° C. for 1 hour, stirred at reflux for 1 hour, diluted with toluene, dehydrated with magnesium sulfate, and subjected to adsorption treatment with activated clay and silica gel. And this was filtered, washed, and concentrated to obtain a yellow oily substance. This yellow oily substance was purified and purified by a silica gel column (toluene / ethyl acetate = 20/1) (volume ratio) to obtain the desired product (yield 5.7 g, pale yellow oily substance). The reaction formula is shown below. FIG. 16 shows an infrared absorption spectrum (KBr tablet method) of the compound obtained in Synthesis Example 7.

(Synthesis Example 8)
<Synthesis of three-dimensional crosslinked polymer material>
The synthesis of [(tetrahydro-2H-pyran-2-yl) oxy] methyl group-containing charge transporting compound (compound represented by the following structural formula (3-18)), which is a material of the three-dimensional crosslinked polymer, The procedure was followed.
First, 1,1-bis (4-aminophenyl) cyclohexene (9.323 g), the compound obtained in Synthesis Example 1 (45.55 g), palladium acetate (0.785 g), tarbutoxy sodium (32.289 g) ) And o-xylene (300 mL) were placed in a four-necked flask, stirred at room temperature under an argon gas atmosphere, and tritertiary butylphosphine (2.43 g) was added dropwise to prepare a solution. Next, this solution was stirred at 80 ° C. for 1 hour, stirred at reflux for 2 hours, diluted with toluene, dehydrated with magnesium sulfate, and subjected to adsorption treatment with activated clay and silica gel. And this was filtered, washed, and concentrated to obtain a yellow oily substance. This yellow oily substance was isolated by purification on a silica gel column (toluene / ethyl acetate = 10/1) (volume ratio) to obtain the desired product (yield 11.42 g, yellow amorphous substance). The reaction formula is shown below. FIG. 17 shows an infrared absorption spectrum (KBr tablet method) of the compound obtained in Synthesis Example 8.

(Synthesis Example 9)
<Synthesis of three-dimensional crosslinked polymer material>
The synthesis of the [(tetrahydro-2H-pyran-2-yl) oxy] methyl group-containing charge transporting compound (compound represented by the following structural formula (3-21)), which is a material of the three-dimensional crosslinked polymer, The procedure was followed.
First, α, α′-bis (4-aminophenyl) -1,4-diisopropylbenzene (10.335 g), the compound obtained in Synthesis Example 1 (39.05 g), palladium acetate (0.673 g), Tasha Rubutoxy sodium (27.677 g) and o-xylene (200 mL) were put into a four-necked flask, stirred at room temperature under an argon gas atmosphere, and tritertiary butylphosphine (2.43 g) was added dropwise. A solution was prepared. Next, this solution was stirred at 80 ° C. for 1 hour, stirred at reflux for 2 hours, diluted with toluene, dehydrated with magnesium sulfate, and subjected to adsorption treatment with activated clay and silica gel. And this was filtered, washed, and concentrated to obtain a yellow oily substance. The yellow oily substance was purified and purified on a silica gel column (toluene / ethyl acetate = 10/1) (volume ratio) to obtain the desired product (yield 23.5 g, pale yellow amorphous substance). The reaction formula is shown below. FIG. 18 shows an infrared absorption spectrum (KBr tablet method) of the compound obtained in Synthesis Example 9.

(Synthesis Example 10)
<Synthesis of three-dimensional crosslinked polymer material>
The synthesis of [(tetrahydro-2H-pyran-2-yl) oxy] methyl group-containing charge transporting compound (compound represented by the following structural formula (4-3)), which is a material of the three-dimensional crosslinked polymer, The procedure was followed.
First, 4,4′-diamino-p-terphenyl (1.30 g), the compound obtained in Synthesis Example 1 (6.508 g), tert-butoxy sodium (3.844 g), bis (tri-t-butoxy) Phosphine) palladium (52 mg) and o-xylene (50 mL) were placed in a four-necked flask and stirred at room temperature under an argon gas atmosphere to prepare a solution. Subsequently, this solution was stirred at reflux for 1 hour, diluted with toluene, dehydrated with magnesium sulfate, and subjected to adsorption treatment with activated clay and silica gel. And this was filtered, washed, and concentrated to obtain a yellow oily substance. This yellow oily substance was purified and purified with a silica gel column (toluene / ethyl acetate = 20/1) (volume ratio) to obtain the desired product (yield 1.95 g, pale yellow amorphous substance). The reaction formula is shown below. FIG. 19 shows an infrared absorption spectrum (KBr tablet method) of the compound obtained in Synthesis Example 10.

(Synthesis Example 11)
<Synthesis of three-dimensional crosslinked polymer material>
The synthesis of the [(tetrahydro-2H-pyran-2-yl) oxy] methyl group-containing charge transporting compound (compound represented by the following structural formula (4-5)), which is a material of the three-dimensional crosslinked polymer, The procedure was followed.
First, 1,3-phenylenediamine (0.541 g), the compound obtained in Synthesis Example 1 (6.508 g), tert-butoxy sodium (3.844 g), bis (tri-t-butoxyphosphine) palladium (52 mg) ) And o-xylene (20 mL) were placed in a four-necked flask and stirred at room temperature under an argon gas atmosphere to prepare a solution. Next, this solution was diluted with toluene, dehydrated with magnesium sulfate, and adsorbed with activated clay and silica gel. And this was filtered, washed, and concentrated to obtain a yellow oily substance. The yellow oily substance was purified and purified with a silica gel column (toluene / ethyl acetate = 10/1) (volume ratio) to obtain the desired product (yield 3.02 g, pale yellow amorphous substance). The reaction formula is shown below. FIG. 20 shows an infrared absorption spectrum (KBr tablet method) of the compound obtained in Synthesis Example 11.

(Synthesis Example 12)
<Synthesis of three-dimensional crosslinked polymer material>
The synthesis of [(tetrahydro-2H-pyran-2-yl) oxy] methyl group-containing charge transporting compound (compound represented by the following structural formula (4-12)), which is a material of the three-dimensional crosslinked polymer, The procedure was followed.
First, 4,4′-diaminostilbene dihydrochloride (1.42 g), the compound obtained in Synthesis Example 1 (6.51 g), tert-butoxy sodium (9.61 g), bis (tri-t-butoxyphosphine) ) Palladium (52 mg) and o-xylene (50 mL) were placed in a four-necked flask and stirred at room temperature under an argon gas atmosphere to prepare a solution. Subsequently, this solution was stirred at reflux for 1 hour, diluted with toluene, dehydrated with magnesium sulfate, and subjected to adsorption treatment with activated clay and silica gel. And this was filtered, washed, and concentrated to obtain a yellow oily substance. The yellow oily substance was purified and purified on a silica gel column (toluene / ethyl acetate = 10/1) (volume ratio) to obtain the desired product (yield 1.6 g, pale yellow amorphous substance). The reaction formula is shown below. FIG. 21 shows an infrared absorption spectrum (KBr tablet method) of the compound obtained in Synthesis Example 12.

(Synthesis Example 13)
<Synthesis of three-dimensional crosslinked polymer material>
The synthesis of [(tetrahydro-2H-pyran-2-yl) oxy] methyl group-containing charge transporting compound (compound represented by the following structural formula (4-17)), which is a material of the three-dimensional crosslinked polymer, The procedure was followed.
First, an intermediate methylol compound (1.274 g), 3,4-dihydro-2H-pyran (1.346 g), and tetrahydrofuran (20 mL) were placed in a four-necked flask and stirred at 5 ° C. A solution was prepared by dropwise addition of acid (14 mg). Subsequently, this solution was stirred at room temperature for 4 hours, extracted with ethyl acetate, dehydrated with magnesium sulfate, and adsorbed with activated clay and silica gel. And this was filtered, washed, and concentrated to obtain a yellow oily substance. This yellow oily substance was purified and purified on a silica gel column (toluene / ethyl acetate = 20/1) (volume ratio) to obtain the desired product (yield 1.48 g, yellow oily substance). The reaction formula is shown below. FIG. 22 shows an infrared absorption spectrum (KBr tablet method) of the compound obtained in Synthesis Example 13.

(Synthesis Example 14)
<Synthesis of three-dimensional crosslinked polymer material>
The synthesis of [(tetrahydro-2H-pyran-2-yl) oxy] methyl group-containing charge transporting compound (compound represented by the following structural formula (4-24)), which is a material of the three-dimensional crosslinked polymer, The procedure was followed.
First, 1,5-diaminonaphthalene (0.791 g), the compound obtained in Synthesis Example 1 (6.508 g), tert-butoxy sodium (3.844 g), bis (tri-t-butoxyphosphine) palladium (52 mg) ) And o-xylene (20 mL) were placed in a four-necked flask and stirred at room temperature under an argon gas atmosphere to prepare a solution. Subsequently, this solution was stirred at reflux for 1 hour, diluted with toluene, dehydrated with magnesium sulfate, and subjected to adsorption treatment with activated clay and silica gel. And this was filtered, washed, and concentrated to obtain a yellow oily substance. This yellow oily substance was purified and isolated on a silica gel column (toluene / ethyl acetate = 9/1) (volume ratio) to obtain the desired product (yield 2.56 g, pale yellow amorphous substance). The reaction formula is shown below. FIG. 23 shows an infrared absorption spectrum (KBr tablet method) of the compound obtained in Synthesis Example 14.

  As described above, the method of direct formylation of a charge transporting compound and the coupling reaction between a [(tetrahydro-2H-pyran-2-yl) oxy] methylated halogenated aromatic intermediate compound and an amine compound are performed. By combining them, a charge transporting compound having three or more [[tetrahydro-2H-pyran-2-yl) oxy] methyl groups can be synthesized. For example, the compound represented by the structural formula (3-26) can be obtained by performing the same reaction using the intermediate obtained in Synthesis Example 2 in place of the intermediate obtained in Synthesis Example 1 in Synthesis Example 5. Is obtained.

(Synthesis Example 15)
<Synthesis of titanyl phthalocyanine crystal>
The synthesis of titanyl phthalocyanine crystals was in accordance with Japanese Patent Application Laid-Open No. 2004-83859.
First, 1,3-diiminoisoindoline (292 parts) and sulfolane (1,800 parts) were mixed, and titanium tetrabutoxide (204 parts) was added dropwise under a nitrogen stream to prepare a solution. After completion of the dropping, the solution was gradually heated to 180 ° C., and the reaction was carried out by stirring for 5 hours while keeping the reaction temperature between 170 ° C. and 180 ° C. After completion of the reaction, the reaction product was allowed to cool, and then the precipitate was filtered, washed with chloroform until the powder turned blue, then washed several times with methanol, and further washed several times with hot water at 80 ° C. Thereafter, it was dried to obtain crude titanyl phthalocyanine. This crude titanyl phthalocyanine was dissolved in 20 times the amount of concentrated sulfuric acid and added dropwise to 100 times the amount of ice water with stirring, and the precipitated crystals were filtered. The precipitated crystals are repeatedly washed with ion-exchanged water (pH: 7.0, specific conductivity: 1.0 μS / cm) until the washing solution becomes neutral (pH of ion-exchanged water after washing). The value was 6.8, the specific conductivity was 2.6 μS / cm), and a titanyl phthalocyanine pigment wet cake (water paste) was obtained.

  The obtained wet cake (water paste) (40 parts) was put into tetrahydrofuran (200 parts) and stirred vigorously (2000 rpm) with a homomixer (Kennis, MARKIIf model) at room temperature, and the dark blue color of the paste When the color changed to light blue (20 minutes after the start of stirring), stirring was stopped and filtration under reduced pressure was immediately performed. The crystals obtained on the filtration device were washed with tetrahydrofuran to obtain a wet cake of pigment. This wet cake was dried under reduced pressure (5 mmHg) at 70 ° C. for 2 days to obtain titanyl phthalocyanine crystals (8.5 parts). The solid content concentration of the wet cake was 15% by mass. The crystal conversion solvent was used in a mass ratio of 33 times that of the wet cake.

When the obtained titanyl phthalocyanine powder was subjected to X-ray diffraction spectrum measurement under the following conditions, the Bragg angle 2θ with respect to CuKα ray (wavelength 1.542１．５) was 27.2 ± 0.2 °, and the maximum peak and the minimum angle 7.3. It has a peak at ± 0.2 °, and further has major peaks at 9.4 ± 0.2 °, 9.6 ± 0.2 °, 24.0 ± 0.2 °, and 7.3 It was found to be a titanyl phthalocyanine powder having no peak between the peak at ° and the peak at 9.4 °, and further having no peak at 26.3 °. The result is shown in FIG.
[X-ray diffraction spectrum measurement conditions]
X-ray tube: Cu
Voltage: 50 kV
Current: 30 mA
Scanning speed: 2 ° / min Scanning range: 3 ° -40 °
Time constant: 2 seconds

Example 1
<Manufacture of electrophotographic photoreceptor>
An undercoating layer coating solution having the following composition, a charge generation layer coating solution having the following composition, and a charge transporting layer coating solution having the following composition are sequentially dip coated on a 60 mm diameter surface-polished aluminum cylinder and dried. Thus, an undercoat layer having a thickness of 3.5 μm, a charge generation layer having a thickness of 0.2 μm, and a charge transport layer having a thickness of 22 μm were formed.
On the obtained charge transport layer, a cross-linked charge transport layer coating solution having the following composition is spray-coated, and heated and dried at 135 ° C. for 30 minutes to provide a cross-linked charge transport layer having a thickness of 5.5 μm. An electrophotographic photoreceptor of the invention was produced.

[Composition of undercoat layer coating solution]
-Alkyd resin: 6.0 parts (Beccosol 1307-60-EL, manufactured by DIC Corporation)
Melamine resin: 4.0 parts (Super Becamine G-821-60, manufactured by DIC Corporation)
・ Titanium oxide (CREL, manufactured by Ishihara Sangyo Co., Ltd.) ・ ・ ・ 50.0 parts ・ Methyl ethyl ketone ・ ・ ・ 50.0 parts

[Composition of charge generation layer coating solution]
Polyvinyl butyral (XYHL, manufactured by UCC) ... 0.5 part Cyclohexanone ... 200.0 parts Methyl ethyl ketone ... 80.0 parts-Titanyl phthalocyanine synthesized in Synthesis Example 15 1.5 Part

[Composition of charge transport layer coating solution]
-Bisphenol Z polycarbonate ... 10.0 parts (Panlite TS-2050, manufactured by Teijin Chemicals Ltd.)
・ Tetrahydrofuran solution of 1 mass% silicone oil: 0.2 part (KF50-100CS, manufactured by Shin-Etsu Chemical Co., Ltd.)
Tetrahydrofuran: 100 parts Low molecular charge transport material represented by the following structural formula (A-1): 10.0 parts

[Composition of crosslinking type charge transport layer coating solution]
-Compound represented by Structural Formula (3-1) synthesized in Synthesis Example 5-7.0 parts-Phthalate compound represented by General Formula (1)-3.0 parts (below) Compound represented by Structural Formula (1-11)
・ Acid catalyst (p-toluenesulfonic acid) 0.01 part ・ Tetrahydrofuran (dehydration) 90.0 parts

(Examples 2 to 16)
<Manufacture of electrophotographic photoreceptor>
In Example 1, except that [three-dimensional crosslinked polymer] and [phthalate ester compound represented by general formula (1)] in [crosslinked charge transport layer coating solution] were changed as shown in Table 1. Produced an electrophotographic photoreceptor in the same manner as in Example 1.

(Example 17)
<Manufacture of electrophotographic photoreceptor>
In Example 1, an electrophotographic photosensitive member was produced in the same manner as in Example 1 except that [Crosslinking type charge transport layer coating solution] was changed to the following composition.

[Composition of crosslinking type charge transport layer coating solution]
-Compound represented by Structural Formula (3-1) synthesized in Synthesis Example 5-7.0 parts-Phthalate compound represented by General Formula (1)-3.0 parts (below) Compound represented by Structural Formula (1-5))
・ Acid catalyst (Nacure 2500, manufactured by Enomoto Kasei Co., Ltd.) 0.1 part ・ Tetrahydrofuran (dehydration) 90.0 parts

(Example 18)
<Manufacture of electrophotographic photoreceptor>
In Example 1, an electrophotographic photosensitive member was produced in the same manner as in Example 1 except that [Crosslinking type charge transport layer coating solution] was changed to the following composition.

[Composition of crosslinking type charge transport layer coating solution]
-Compound represented by Structural Formula (3-1) synthesized in Synthesis Example 5-7.0 parts-Phthalate compound represented by General Formula (1)-3.0 parts (said Compound represented by Structural Formula (1-5))
・ Acid catalyst (p-toluenesulfonic acid monohydrate) ・ ・ ・ 0.02 part ・ Tetrahydrofuran (dehydration) ・ ・ ・ 90.0 parts

(Example 19)
<Manufacture of electrophotographic photoreceptor>
In Example 1, an electrophotographic photosensitive member was produced in the same manner as in Example 1 except that [Crosslinking type charge transport layer coating solution] was changed to the following composition.

[Composition of crosslinking type charge transport layer coating solution]
-Compound represented by Structural Formula (3-1) synthesized in Synthesis Example 5-7.0 parts-Phthalate compound represented by General Formula (1)-3.0 parts (said Compound represented by Structural Formula (1-5))
・ Acid catalyst (p-toluenesulfonic acid monohydrate) ・ ・ ・ 0.04 parts ・ Tetrahydrofuran (dehydration) ・ ・ ・ 90.0 parts

(Comparative Example 1)
<Manufacture of electrophotographic photoreceptor>
In Example 1, an electrophotographic photosensitive member was produced in the same manner as in Example 1 except that [Crosslinking type charge transport layer coating solution] was changed to the following composition.

[Composition of crosslinking type charge transport layer coating solution]
Compound represented by structural formula (3-1) synthesized in Synthesis Example 5 10.0 parts Acid catalyst (p-toluenesulfonic acid monohydrate) 0.01 parts Tetrahydrofuran ( Dehydration) 90.0 parts

(Comparative Example 2)
<Manufacture of electrophotographic photoreceptor>
In Example 1, an electrophotographic photosensitive member was produced in the same manner as in Example 1 except that [Crosslinking type charge transport layer coating solution] was changed to the following composition.
However, the compatibility between the methylol intermediate and the phthalate ester compound represented by the general formula (1) (the compound represented by the structural formula (1-11)) is poor, and is represented by the general formula (1). The resulting phthalate ester compound (compound represented by the structural formula (1-11)) was whitened by the phase separation and could not be evaluated as an electrophotographic photosensitive member.

[Composition of crosslinking type charge transport layer coating solution]
-Intermediate methylol compound synthesized in Synthesis Example 3-7.0 parts-Phthalate compound represented by the general formula (1)-3.0 parts (in the structural formula (1-11) Represented compounds)
・ Acid catalyst (p-toluenesulfonic acid) 0.01 part ・ Tetrahydrofuran (dehydration) 90.0 parts

(Comparative Example 3)
<Manufacture of electrophotographic photoreceptor>
In Example 1, an electrophotographic photosensitive member was produced in the same manner as in Example 1 except that [Crosslinking type charge transport layer coating solution] was changed to the following composition.
However, the surface of the obtained electrophotographic photosensitive member is in a liquid state, and the phthalate ester compound represented by the general formula (1) (the compound represented by the structural formula (1-2)) is crystallized. As a result, it could not be evaluated as an electrophotographic photosensitive member.

[Composition of crosslinking type charge transport layer coating solution]
-Charge transport compound represented by the following structural formula (A-2) ... 6.0 parts-Phthalate ester compound represented by the general formula (1) ... 4.0 parts (following structural formula Compound represented by (1-2)
・ Acid catalyst (p-toluenesulfonic acid) 0.01 part ・ Tetrahydrofuran (dehydration) 90.0 parts

(Comparative Example 4)
<Manufacture of electrophotographic photoreceptor>
In Example 1, an electrophotographic photosensitive member was produced in the same manner as in Example 1 except that [Crosslinking type charge transport layer coating solution] was changed to the following composition.
However, the surface of the obtained electrophotographic photosensitive member is sticky, and phase separation of the phthalate compound represented by the general formula (1) (the compound represented by the structural formula (1-2)) is performed. As a result, the electrophotographic photosensitive member could not be evaluated.

[Composition of crosslinking type charge transport layer coating solution]
-Charge transporting compound represented by the following structural formula (A-3) ... 3.0 parts-Phthalate ester compound represented by the general formula (1) ... 6.0 parts (said structural formula Compound represented by (1-2)
・ Resol type phenol resin PL-2211 (manufactured by Gunei Chemical Co., Ltd.) 3.5 parts ・ Acid catalyst (Nacure 2500, manufactured by Enomoto Kasei Co., Ltd.) 0.2 part ・ Isopropanol 15.0 parts・ Methyl ethyl ketone: 5.0 parts

(Comparative Example 5)
<Manufacture of electrophotographic photoreceptor>
In Example 1, the [Crosslinking type charge transport layer coating solution] was changed to the following composition, naturally dried for 20 minutes, then a metal halide lamp: 160 W / cm, irradiation distance: 120 mm, irradiation intensity: 500 mW / cm ^2. , Irradiation time: Example 1 except that light irradiation was performed under the condition of 180 seconds, the coating film was cured, and further dried at 130 ° C. for 30 minutes to provide a 5.5 μm cross-linked charge transport layer. An electrophotographic photoreceptor was produced in the same manner as described above.
However, the surface of the obtained electrophotographic photosensitive member is sticky, and phase separation of the phthalate compound represented by the general formula (1) (the compound represented by the structural formula (1-2)) is performed. And became cloudy, and could not be evaluated as an electrophotographic photosensitive member.

[Composition of crosslinking type charge transport layer coating solution]
-Radical polymerizable charge transporting compound represented by the following structural formula (A-4): 5.0 parts-Multifunctional radical polymerizable monomer: 5.0 parts (trimethylolpropane triacrylate)
(KAYARAD TMPTA, Nippon Kayaku)
(Molecular weight: 296, number of functional groups: trifunctional, molecular weight / number of functional groups = 99)
-Phthalate ester compound represented by the general formula (1) 10.0 parts (compound represented by the structural formula (1-2))
Photopolymerization initiator: 1.0 part (1-hydroxy-cyclohexyl-phenyl-ketone)
(Irgacure 184, manufactured by Ciba Specialty Chemicals)
・ Tetrahydrofuran ... 100.0 parts

(Comparative Example 6)
<Manufacture of electrophotographic photoreceptor>
In Example 1, an electrophotographic photosensitive member was produced in the same manner as in Example 1 except that [Crosslinking type charge transport layer coating solution] was changed to the following composition.
However, the surface of the obtained electrophotographic photosensitive member is sticky, phase separation of the compound represented by the structural formula (1-2) is observed, and it becomes white turbid, and can be evaluated as an electrophotographic photosensitive member. There wasn't.

[Composition of crosslinking type charge transport layer coating solution]
・ Hydroxyl-containing charge transporting compound represented by the following structural formula (A-5) 2.5 parts ・ Phthalate ester compound represented by the general formula (1) 5.0 parts Compound represented by Structural Formula (1-2))
・ Tolylene diisocyanate ・ ・ ・ 2.5 parts ・ Tetrahydrofuran ・ ・ ・ 50.0 parts

(Comparative Example 7)
<Manufacture of electrophotographic photoreceptor>
An electrophotographic photosensitive member was produced in the same manner as in Example 1 except that the crosslinkable charge transport layer was not provided in Example 1.

(Comparative Example 8)
<Manufacture of electrophotographic photoreceptor>
In Example 1, an electrophotographic photosensitive member was produced in the same manner as in Example 1 except that [Crosslinking type charge transport layer coating solution] was changed to the following composition.
However, the surface of the obtained electrophotographic photosensitive member was sticky, and dioctyl phthalate was phase-separated into a liquid state, so that it could not be evaluated as an electrophotographic photosensitive member.

[Composition of crosslinking type charge transport layer coating solution]
-Compound represented by Structural Formula (3-1) synthesized in Synthesis Example 5-6.0 parts-Dioctyl phthalate-4.0 parts-Acid catalyst (p-toluenesulfonic acid)-0 .01 parts ・ Tetrahydrofuran (dehydrated) ・ ・ ・ 90.0 parts

(Comparative Example 9)
<Manufacture of electrophotographic photoreceptor>
In Example 1, an electrophotographic photosensitive member was produced in the same manner as in Example 1 except that [Crosslinking type charge transport layer coating solution] was changed to the following composition.
However, the surface of the obtained electrophotographic photosensitive member was sticky, and dibutyl phthalate was phase-separated into a liquid state, so that it could not be evaluated as an electrophotographic photosensitive member.

[Composition of crosslinking type charge transport layer coating solution]
-Compound represented by Structural Formula (3-1) synthesized in Synthesis Example 5-6.0 parts-Dibutyl phthalate-4.0 parts-Acid catalyst (p-toluenesulfonic acid)-0 .01 parts ・ Tetrahydrofuran (dehydrated) ・ ・ ・ 90.0 parts

(Comparative Example 10)
<Manufacture of electrophotographic photoreceptor>
In Comparative Example 5, an electrophotographic photosensitive member was produced in the same manner as in Comparative Example 5 except that [Coating liquid for crosslinkable charge transport layer] was changed to the following composition.

[Composition of crosslinking type charge transport layer coating solution]
-Radical polymerizable charge transporting compound represented by the structural formula (A-4) ... 10.0 parts-Multifunctional radical polymerizable monomer ... 10.0 parts (trimethylolpropane triacrylate)
(KAYARAD TMPTA, Nippon Kayaku)
(Molecular weight: 296, number of functional groups: trifunctional, molecular weight / number of functional groups = 99)
Photopolymerization initiator: 1.0 part (1-hydroxy-cyclohexyl-phenyl-ketone)
(Irgacure 184, manufactured by Ciba Specialty Chemicals)
・ Tetrahydrofuran ... 100.0 parts

(Comparative Example 11)
<Manufacture of electrophotographic photoreceptor>
In Comparative Example 6, an electrophotographic photosensitive member was produced in the same manner as in Comparative Example 6 except that [Coating liquid for crosslinkable charge transport layer] was changed to the following composition.

[Composition of crosslinking type charge transport layer coating solution]
・ Hydroxyl-containing charge transporting compound represented by the structural formula (A-5) ・ ・ ・ 5.0 parts ・ Tolylene diisocyanate ・ ・ ・ 5.0 parts ・ Tetrahydrofuran ・ ・ ・ 50.0 parts

<Evaluation>
The electrophotographic photoreceptors produced in Examples 1 to 19 and Comparative Examples 1 to 11 were evaluated.
In addition, since the crosslinkable charge transport layers in the electrophotographic photoreceptors of Examples 1 to 19 were all confirmed to be transparent and uniform by visual observation, the three-dimensional network structure has voids in the three-dimensional network structure It was suggested that the phthalate ester compound represented by the general formula (1) was uniformly molecularly dispersed.

<Evaluation of cross-linked charge transport layer>
-Surface hardness measurement of cross-linked charge transport layer-
The mechanical durability of the crosslinkable charge transport layer is evaluated by measuring the Martens hardness (HM) and elastic work rate (We / Wt) of the crosslinkable charge transport layer using the crosslinkable charge transport layer coating solution. did.
The Martens hardness obtained by measuring the micro surface hardness is an index representing the amount of cross-linking formed in a certain volume. The elastic power is a measure showing the relaxation property of the film with respect to the energy applied from the outside, and is correlated with the wear of the photoreceptor in the electrophotographic process. In any direction, it is preferable that both characteristics are large. Even if only the elastic power is large like rubber, there is a problem in practical use.
Using a microhardness measurement system H-100 (manufactured by Fischer), the Vickers indenter was gradually pushed into the sample surface over 30 seconds, and the load was maintained at the maximum load (9.8 mN) for 5 seconds. The load was then gradually reduced over 30 seconds. Various hardness characteristics and elastoplastic deformation characteristics could be evaluated by measuring the indentation depth under each load. The data actually obtained is a curve as shown in FIG. Here, Martens hardness [HM] (unit: N / mm ² ), which is a characteristic value of hardness, was obtained from the indentation depth at the maximum load. Moreover, the elastic characteristic of the sample surface was obtained by reducing the load from the maximum load. Specifically, the work amount of the elastic deformation of the sample surface pushing back the Vickers indenter with respect to the work amount [Wt: equivalent to the area value of the black vertical line area in FIG. The ratio of [We: equivalent to the area value of the black horizontal line region in FIG. 26] was obtained as the elastic power [We / Wt] (unit:%). The results are shown in Table 2.

-Measurement of water vapor permeability of cross-linked charge transport layer-
The gas resistance of the crosslinkable charge transport layer was evaluated by measuring the water vapor permeability of the crosslinkable charge transport layer using the crosslinkable charge transport layer coating solution. Since water vapor has a smaller molecular weight than an oxidizing gas such as NOx, the gas stability against an oxidizing gas such as NOx was evaluated by measuring the permeability of the water vapor.
Since it is difficult to form a self-supporting film of a crosslinkable charge transport layer, a crosslinkable charge transport layer is laminated on a known polymer film having a high water vapor permeability, and the crosslinkable charge transport layer is determined from the water vapor permeability of the entire laminated film. The water vapor permeability was calculated.
First, as a known polymer film, an electrophotography in which a crosslinkable charge transport layer coating solution was produced in Examples and Comparative Examples on an A-type polycarbonate resin film (film thickness 20 μm, water vapor permeability = 265 g / m ² · day). Coating and heating were carried out in the same manner as in the production conditions of the photoreceptor to form a cross-linked charge transport layer having a thickness of 5 μm. Subsequently, this film was set in a water vapor permeability meter (P80, manufactured by PBI Dancer, L80-4000), and the water vapor permeability was measured at a water temperature of 40 ° C. From the measured water vapor permeability, the water vapor permeability Pc ₍₂₀₎ in terms of a film thickness of 20 μm was calculated using the following relational expression. The results are shown in Table 2.

Measured water vapor permeability: P
Water vapor permeability of crosslinked membrane: Pc
Water vapor permeability of type A polycarbonate resin film: Pa
Water vapor permeability in terms of 20 μm thickness of crosslinked film: Pc ₍₂₀₎
Water vapor permeability in terms of 20 μm film thickness of A-type polycarbonate resin film: Pa ₍₂₀₎
Measured film thickness of crosslinked film: dc
Measured film thickness of type A polycarbonate resin film: dz
1 / P = (1 / Pc) + (1 / Pa)
Pc ₍₂₀₎ = P · dc / (20− (P · da / Pa ₍₂₀₎ ))

<Image output evaluation>
-Mechanical durability-
The electrophotographic photosensitive members produced in Examples 1 to 19 and Comparative Examples 1, 7, 10, and 11 are attached to a process cartridge of a digital full-color composite machine (MP C7500 SP, manufactured by Ricoh Co., Ltd.) and attached to the main body to be 600 dpi × Using A4 paper (Ricoh My Recycle Paper GP, manufactured by Ricoh Co., Ltd.) with a resolution of 600 dpi, a continuous 500 image output of each halftone pattern of yellow, magenta, cyan, and black is output 60 sheets per minute. Repeatedly at the printing speed, a total of 50,000 sheets were printed. The mechanical durability was evaluated by evaluating the photoconductor wear amount at this time and the presence or absence of abnormal image output. Further, the initial in-machine bright part potential (VL) at the time of outputting a solid image was measured. The results are shown in Table 2.

-Gas stability-
In addition, the electrophotographic photosensitive member was exposed for 2 days in a high concentration NOx gas exposure device (NO gas 10 ppm / NO ₂ gas 40 ppm), and then 50 images were continuously output in the same manner, and the middle of the 50th sheet. The image density of the band pattern portion (1 by 1 dot black image portion) was measured with a Macbeth densitometer, and the gas resistance stability was evaluated by the dot reproducibility.
The determination was in accordance with the following evaluation criteria. The results are shown in Table 2.
[Evaluation criteria]
Good: Concentration 0.35 or more and less than 0.45 Slightly decreased: Concentration 0.25 or more and less than 0.35 Decrease: Concentration 0.15 or more and less than 0.25 Large decrease: Concentration less than 0.15

  As described above, in Comparative Example 1 in which the phthalate compound represented by the general formula (1) is not used, the water vapor permeability is large and the gas permeability is large, whereas in the examples, the water vapor permeability is all. Was found to be smaller.

  Further, in the examples, Martens hardness (HM) representing mechanical durability and elastic work rate (We / Wt) (both are indexes representing mechanical durability, and the larger HM, the better the scratch resistance. It has been found that the higher the / Wt, the better the wear resistance)) having an HM value of 200 or more necessary for scratch resistance and a τe value of 40 or more necessary for wear resistance.

  It was found that the electrophotographic photosensitive member of the example had a small water vapor permeability compared to the water vapor permeability of the electrophotographic photosensitive member having a cured film such as acrylic or urethane as in Comparative Examples 10-11. . Further, even when trying to molecularly disperse the phthalate ester compound represented by the general formula (1) in an acrylic or urethane cured film, as shown in Comparative Examples 5 to 6, curing failure occurs, and phase separation occurs. As a result, problems such as white turbidity occurred, and it was found that a desired electrophotographic photosensitive member could not be formed.

  Further, a methylol compound or a charge transporting compound having a structure similar to that of a compound having three or more [(tetrahydro-2H-pyran-2-yl) oxy] methyl groups on the aromatic ring of the charge transporting compound of the present invention. In Comparative Examples 2 to 4 using a compound having only two [(tetrahydro-2H-pyran-2-yl) oxy] methyl groups on the aromatic ring or a similar compound, white turbidity due to poor compatibility, insufficient curing Thus, it was found that a desired electrophotographic photoreceptor cannot be formed.

  On the other hand, in Comparative Examples 8 to 9 using dioctyl phthalate or dibutyl phthalate which are compounds similar to the phthalate compound represented by the general formula (1), desired electrons are generated due to generation of droplets by phase separation. It has been found that a photographic photoreceptor cannot be formed.

  As described above, a compound having three or more [(tetrahydro-2H-pyran-2-yl) oxy] methyl groups on the aromatic ring of the charge transporting compound which is a specific compound, and represented by the general formula (1) In combination with a phthalate ester compound, it has been found for the first time that an electrophotographic photoreceptor excellent in mechanical durability and gas stability is obtained.

  In addition, as shown in Comparative Example 7, in an ordinary electrophotographic photoreceptor that does not use a three-dimensional crosslinked polymer for the surface layer, the amount of wear is extremely large, and the electrophotographic photoreceptor of the present invention is extremely durable as compared with the ordinary photoreceptor. It was found to be excellent in performance. In addition, the image output evaluation results show that the electrophotographic photosensitive member of the present invention has both wear resistance and gas resistance stability. By using this electrophotographic photosensitive member, a high concentration oxidizing gas exposure condition is obtained. The following also shows that it is possible to provide an image forming method, an image forming apparatus, and a process cartridge capable of stably outputting a high-quality image.

  As shown in Examples 1 to 3, it was found that the electrophotographic photoreceptor of claim 2 exhibits excellent mechanical properties and low water vapor permeability. Therefore, it was found that both excellent wear resistance and gas stability can be achieved.

  Further, as shown in Examples 4 to 5, the electrophotographic photosensitive member of claim 3 has a particularly low water vapor transmission rate, and is a normal electrophotographic photosensitive member without a cross-linked charge transport layer of Comparative Example 7. It was clearly found that the water vapor permeability was small compared to the other, and the gas stability was excellent.

  Moreover, when Example 4 and Examples 6-10 were compared, it turned out that gas permeability becomes small as the mixing ratio of the phthalate ester compound represented by the general formula (1) increases. Therefore, it was found that when the mixing ratio was about 10% by mass as in Example 8, there was no significant difference compared to the additive-free system of Comparative Example 1.

  Further, as in Example 10, it was found that when the mixing ratio was about 60% by mass, the elastic displacement rate was less than 40%, and it could not be said that the film had a high crosslinking density. Therefore, from these results, it was found that the mixing ratio of the phthalate ester compound represented by the general formula (1) is appropriate when it is in the range of 20% by mass to 50% by mass. It was found that by using this range, the mechanical durability can achieve a low water vapor transmission rate with almost no drop.

  In Example 11, the compound represented by the general formula (2) is added to a compound having three or more [(tetrahydro-2H-pyran-2-yl) oxy] methyl groups on the aromatic ring of the charge transporting compound. It shows the characteristics when used, and because it shows extremely high hardness and elastic displacement rate, it is an electrophotographic photoreceptor that is advantageous for photoreceptor design that emphasizes scratch resistance and abrasion resistance, but water vapor transmission rate Was found to be slightly larger.

  Examples 12 to 15 are represented by the general formula (3) as compounds having three or more [(tetrahydro-2H-pyran-2-yl) oxy] methyl groups on the aromatic ring of the charge transporting compound. It shows the characteristics when using a compound, but the hardness and / or elasticity is somewhat low, but there is no significant decrease, it shows excellent water vapor shielding properties, and both required characteristics are compatible at a high level. I understood it.

  In Example 16, the compound represented by the general formula (4) is added to a compound having three or more [(tetrahydro-2H-pyran-2-yl) oxy] methyl groups on the aromatic ring of the charge transporting compound. The characteristics when used were shown, and it was found that a low bright part potential was exhibited due to the excellent charge transportability as shown by the in-flight bright part potential. From this, it has been found that it is possible to provide an electrophotographic photosensitive member that maintains stable potential characteristics during high-speed printing or printing with a small-diameter drum, and that is excellent in mechanical durability and gas resistance stability.

  Moreover, Examples 17-19 show the characteristic at the time of changing the kind and content of an acid catalyst when the mixing ratio of the phthalate ester compound represented by the general formula (1) is 30% by mass. Therefore, it was found that both high mechanical durability and low water vapor permeability can be achieved in a wide range.

  As described above, according to the present invention, it is possible to design an electrophotographic photosensitive member having excellent mechanical durability and gas resistance stability, which is stable even under a high-concentration oxidizing gas exposure condition. It has been found that it is possible to provide an electrophotographic photosensitive member, an image forming method, an image forming apparatus, and a process cartridge that can output images for a long period of time.

DESCRIPTION OF SYMBOLS 1 Conductive support body 2 Charge generation layer 3 Charge transport layer 4 Undercoat layer 5 Crosslinkable charge transport layer 6 Photosensitive layer (outermost surface layer)
7 Protective Layer 10 Photoconductor 10Y Photoconductor 10M Photoconductor 10C Photoconductor 10K Photoconductor 11 Charging Member 11Y Charging Member 11M Charging Member 11C Charging Member 11K Charging Member 12 Image Exposure Member 12Y Image Exposure Member 12M Image Exposure Member 12C Image Exposure Member 13K Image exposure member 13 Developing member 13Y Developing member 13M Developing member 13C Developing member 13K Developing member 14 Conveying roller 15 Transfer paper 16 Transfer member 16Y Transfer member 16M Transfer member 16C Transfer member 16K Transfer member 17 Cleaning member 17Y Cleaning member 17M Cleaning member 17C Cleaning Member 17K Cleaning member 18 Static elimination member 20Y Image forming element 20M Image forming element 20C Image forming element 20K Image forming element 21 Paper feed roller 22 Registration roller 23 Transfer Material (secondary transfer member)
24 Fixing member

JP 2000-066425 A JP 2000-171990 A JP 2003-186223 A JP 2007-293197 A JP 2008-299327 A Japanese Patent No. 4262661 JP 2006-251771 A JP 2009-229549 A JP 2006-084711 A

Claims (19)

An electrophotographic photoreceptor having at least a photosensitive layer on a conductive support,
The outermost surface layer of the photosensitive layer has a phthalic acid ester compound represented by the following general formula (1) and a three-dimensional crosslinked polymer,
From the compound in which the three-dimensional crosslinked polymer has three or more [(tetrahydro-2H-pyran-2-yl) oxy] methyl groups on the aromatic ring of the charge transporting compound, the [(tetrahydro-2H-pyran-2- I) Oxy] An electrophotographic photosensitive member formed by polymerization through a reaction in which a part of a methyl group is cut off and eliminated.
However, in the said General formula (1), R may be the same and may differ and each represents a C5-C10 cyclic hydrocarbon group. The electrophotographic photoreceptor according to claim 1, wherein the phthalic acid ester compound represented by the general formula (1) is a compound represented by the following general formula (1-1).
However, in the general formula (1-1), R ′ may be the same or different, and may have a cycloalkyl group or an alkyl substituent which may have an alkyl substituent. Represents an optionally substituted phenyl group. The electrophotographic photosensitive member according to claim 1, wherein the phthalate ester compound represented by the general formula (1) is a compound represented by the following general formula (1-2).
However, in the general formula (1-2), R ″ may be the same or different and represents a cyclohexyl group which may have an alkyl substituent.   The photosensitive layer has at least a charge generation layer, a charge transport layer, and a crosslinked charge transport layer in this order, and the crosslinked charge transport layer is the outermost surface layer of the photosensitive layer. The electrophotographic photosensitive member according to any one of the above. 5. The electrophotographic photosensitive member according to claim 1, wherein the water vapor permeability in the outermost surface layer of the photosensitive layer is 100 g / m ² · day or less.   When the three-dimensional crosslinked polymer mixes and heats a compound having three or more [(tetrahydro-2H-pyran-2-yl) oxy] methyl groups on the aromatic ring of the charge transporting compound, and a curing catalyst, The electrophotographic photoreceptor according to claim 1, wherein the electrophotographic photoreceptor is formed by polymerization through a reaction in which a part of the [(tetrahydro-2H-pyran-2-yl) oxy] methyl group is cut off and eliminated.   For the total amount of the compound having three or more [(tetrahydro-2H-pyran-2-yl) oxy] methyl groups on the aromatic ring of the charge transporting compound and the phthalate compound represented by the general formula (1), The electrophotographic photosensitive member according to any one of claims 1 to 6, wherein a content of the phthalic acid ester compound represented by the general formula (1) is 20% by mass to 50% by mass. The compound having three or more [(tetrahydro-2H-pyran-2-yl) oxy] methyl groups on the aromatic ring of the charge transporting compound is a compound represented by the following general formula (2): The electrophotographic photosensitive member according to any one of the above.
However, in said general formula (2), Ar < ₇ >, Ar < ₈ > and Ar < ₉ > represent the C6-C18 bivalent aromatic hydrocarbon group which may have an alkyl group as a substituent. The electrophotographic photosensitive member according to claim 8, wherein the compound represented by the general formula (2) is a compound represented by the following general formula (2-1).
However, in said general formula (2-1), R < ₁ >, R < ₂ > and R < ₃ > may be the same and may differ, and represent a hydrogen atom, a methyl group, or an ethyl group, l, n and m represent an integer of 1 to 4. The compound having three or more [(tetrahydro-2H-pyran-2-yl) oxy] methyl groups on the aromatic ring of the charge transporting compound is a compound represented by the following general formula (3): The electrophotographic photosensitive member according to any one of the above.
However, in the general formula (3), X ₃ is an alkylene group having 1 to 4 carbon atoms, an alkylidene group having 2 to 6 carbon atoms, and two alkylidene groups having 2 to 6 carbon atoms bonded via a phenylene group. Represents a divalent group or an oxygen atom, and Ar ₁₀ , Ar ₁₁ , Ar ₁₂ , Ar ₁₃ , Ar ₁₄ and Ar ₁₅ are divalent aromatics having 6 to 18 carbon atoms which may have an alkyl group as a substituent. Represents a group hydrocarbon group. The electrophotographic photoreceptor according to claim 10, wherein the compound represented by the general formula (3) is a compound represented by the following general formula (3-1).
In the general formula (3-1), _{X 4 is, -CH 2 -, - CH 2} CH 2 -, - C (CH 3) 2 -Ph-C (CH 3) 2 -, - C (CH ₂ ) Represents _5- or -O-, and R ₄ , R ₅ , R ₆ , R ₇ , R ₈ and R ₉ may be the same or different, and may be a hydrogen atom or a methyl group Or an ethyl group, Ph represents a phenylene group, and o, p, q, r, s, and t represent an integer of 1 to 4. The compound having three or more [(tetrahydro-2H-pyran-2-yl) oxy] methyl groups on the aromatic ring of the charge transporting compound is a compound represented by the following general formula (4): The electrophotographic photosensitive member according to any one of the above.
In the general formula (4), Y ₁ represents benzene, biphenyl, terphenyl, stilbene, distyrylbenzene, or a divalent condensed polycyclic aromatic hydrocarbon group, Ar ₁₆ , Ar ₁₇ , Ar ₁₈ and Ar ₁₉ represent a C 6-18 divalent aromatic hydrocarbon group which may have an alkyl group as a substituent. The electrophotographic photosensitive member according to claim 12, wherein the compound represented by the general formula (4) is a compound represented by the following general formula (4-1).
However, the general formula (4-1), _{Y 2} represents a benzene, biphenyl, terphenyl, stilbene, or a divalent group of naphthalene. R ₁₀ , R ₁₁ , R ₁₂ and R ₁₃ may be the same or different and each represents a hydrogen atom, a methyl group or an ethyl group, and u, v, w and z are 1 to 1 Represents an integer of 4. A method for producing an electrophotographic photosensitive member having at least a photosensitive layer on a conductive support,
The outermost surface layer of the photosensitive layer has a phthalic acid ester compound represented by the following general formula (1) and a three-dimensional crosslinked polymer,
From the compound in which the three-dimensional crosslinked polymer has three or more [(tetrahydro-2H-pyran-2-yl) oxy] methyl groups on the aromatic ring of the charge transporting compound, the [(tetrahydro-2H-pyran-2- I) Oxy] A method for producing an electrophotographic photosensitive member, which is formed by polymerization through a reaction in which a part of a methyl group is cut off and eliminated.
However, in the said General formula (1), R may be the same and may differ and each represents a C5-C10 cyclic hydrocarbon group.   A charging process for charging the surface of the electrophotographic photosensitive member, an exposure process for exposing the charged surface of the electrophotographic photosensitive member to form an electrostatic latent image, and developing the electrostatic latent image with toner. An image forming method comprising at least a development step for forming a visual image, a transfer step for transferring the visible image to a recording medium, and a fixing step for fixing the transfer image transferred to the recording medium, An image forming method, wherein the photographic photosensitive member is the electrophotographic photosensitive member according to claim 1.   The image forming method according to claim 15, wherein the electrostatic latent image is written on the photoconductor in the exposure step by a digital method.   An electrophotographic photosensitive member; a charging unit that charges the surface of the electrophotographic photosensitive member; an exposing unit that exposes the surface of the charged electrophotographic photosensitive member to form an electrostatic latent image; and An image forming apparatus comprising at least a developing unit that develops a visible image using the developing unit, a transfer unit that transfers the visible image to a recording medium, and a fixing unit that fixes the transferred image transferred to the recording medium An image forming apparatus, wherein the electrophotographic photosensitive member is the electrophotographic photosensitive member according to claim 1.   18. The image forming apparatus according to claim 17, wherein writing of the electrostatic latent image on the electrophotographic photosensitive member by the exposure unit is a digital method.   A process cartridge having an electrophotographic photosensitive member and at least one means selected from a charging means, an exposure means, a developing means, a transfer means, a cleaning means, and a static elimination means, and is attachable to and detachable from an image forming apparatus main body, 14. A process cartridge, wherein the electrophotographic photosensitive member is the electrophotographic photosensitive member according to claim 1.