JP2007212597A - Electrophotographic photosensitive member, image forming method and image forming device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a tough electrophotographic photosensitive member having high sensitivity, excellent in electrophotographic characteristics such as charging property and residual potential, and less liable to deterioration by mechanical stress. <P>SOLUTION: The electrophotographic photosensitive member has a photosensitive layer on a conductive support, wherein the photosensitive layer contains a polycarbonate resin comprising a repeating structure represented by formula (1) and a compound represented by formula (2). In the formula (1), R<SP>1</SP>represents H or alkyl; R<SP>2</SP>and R<SP>3</SP>each represent alkyl; and m and n each represent an integer of 1-4. In the formula (2), Y represents optionally substituted alkylene, substituents may bond to each other to form a ring; Ar<SP>1</SP>and Ar<SP>2</SP>each independently represent optionally substituted alkylene or optionally substituted arylene; and Ar<SP>3</SP>-Ar<SP>6</SP>each independently represent optionally substituted alkyl or optionally substituted aryl. <P>COPYRIGHT: (C)2007,JPO&INPIT

Description

  The present invention relates to an electrophotographic photoreceptor using a combination of specific materials. In particular, it is an electrophotographic photosensitive member used for laser printers, copiers, fax machines, etc., and it is an electrophotographic photosensitive member that is resistant to damage even after repeated use, and has excellent durability. In particular, the present invention relates to a high-performance electrophotographic photosensitive that can be suitably used for exposure with monochromatic light of 380 to 500 nm.

  In recent years, electrophotographic technology has been widely used and applied not only in the field of copying machines but also in the field of various printers because of its immediacy and high-quality images. In recent years, electrophotographic photoreceptors, which are the core of electrophotographic technology, are electronic materials that use organic photoconductive materials that have advantages such as non-polluting, easy film formation, and easy manufacturing. Photoconductors have been developed.

  As electrophotographic photoreceptors using organic photoconductive materials, so-called dispersion type photoreceptors in which photoconductive fine powder is dispersed in a binder resin, laminated photoreceptors in which a charge generation layer and a charge transport layer are laminated are available. Are known. In addition, in the laminated type photoreceptor, there are a forward laminated type photoreceptor in which the charge generation layer and the charge transport layer are laminated in this order on the conductive substrate, and a reverse laminated type photoreceptor in which the charge transport layer and the charge generation layer are laminated in this order. Are known. The multi-layer photoreceptor can provide a highly sensitive electrophotographic photoreceptor by combining a highly efficient charge generating substance and charge transporting substance, and a highly safe electrophotographic photoreceptor having a wide material selection range. In addition, since it is highly productive and relatively advantageous in terms of cost, it has been developed and put into practical use as the mainstream of electrophotographic photoreceptors.

  The electrophotographic photosensitive member is repeatedly used in an electrophotographic process, that is, a cycle such as charging, exposure, development, transfer, cleaning, and static elimination. The electrophotographic photoreceptor is repeatedly used and deteriorates due to various stresses. As such deterioration, for example, strong oxidative ozone and NOx generated from the charger give chemical damage to the photosensitive layer, or carriers (current) generated by image exposure flow in the photosensitive layer. There are chemical and electrical degradations caused by the composition of the photosensitive layer being decomposed by static electricity, static elimination light, or external light. In order to suppress these degradations, studies have been made on charge generation materials, charge transport materials, additives, and the like.

  Further, as deterioration different from the above electrical factors, in order to charge the electrophotographic photosensitive member, a charging roller or charging brush in contact with the photosensitive member, a cleaning blade for removing excess toner, and an image are transferred. There is a mechanical deterioration due to a transfer roller for the purpose, and an artificial deterioration due to contact or scratches during assembly or maintenance of the image forming apparatus. As a method for minimizing such deterioration, introduction of an overcoat layer and examination of a binder resin have been performed on electrophotographic photoreceptors.

On the other hand, as an exposure light for an electrophotographic photosensitive member, an electrophotographic apparatus using monochromatic light typified by an LED or a laser as exposure light is known. In such an electrophotographic apparatus, those using a relatively long wavelength laser having a wavelength of about 600 to 800 nm as the exposure light are mainly used.
In recent years, there has been a strong demand for higher resolution of output images, and a reduction in the wavelength of exposure light is being studied. If the wavelength of the exposure light is shortened, it becomes difficult to be affected by the curvature of field of the scanning lens, so that it is relatively easy to make the small-diameter laser spot uniform, and it is effective for increasing the resolution. With the advancement of technology, the application of light sources with a wavelength of around 400 nm has also begun,
Recently, a demand for a practical electrophotographic photosensitive member corresponding to a short wavelength light exposure technique of m to 500 nm is also increasing. Various electrophotographic photoconductors suitable for the electrophotographic photoconductor exposed with a short wavelength light source have been proposed (see, for example, Patent Document 1 and Patent Document 2).

  Among these, those represented by the general formula (1) are known to give an electrophotographic photosensitive member having particularly good electrical characteristics. However, these compounds have the property that they are very easily peeled off when formed into an electrophotographic photoreceptor. When an electrophotographic photosensitive member having such properties is mounted on a copier or printer machine, film peeling occurs due to stimulation of a contact charging roller or frictional stress of a magnetic brush or a cleaning blade, resulting in image defects. It will be. Alternatively, if the film strength partially weakens due to slight contact during assembly of the image forming apparatus, peeling easily occurs from that part. The reason why these charge transport materials are likely to cause film peeling is unknown, but the compatibility with the binder resin and the shrinkage ratio after the coating film, or the hydrophilic / The influence of the compatibility with the charge generation layer due to the hydrophobic nature is considered.

  In addition, when short wavelength light is used as exposure light, unlike electrophotographic photoreceptors adapted to long wavelength light as conventionally used, electrical characteristics represented by sensitivity to short wavelength light are present. It is necessary to use an excellent electrophotographic photoreceptor. In an electrophotographic apparatus using a long-wavelength laser, a phthalocyanine compound that is sensitive to long-wavelength light is mainly used as a charge generation material, and the phthalocyanine compound is known to have sensitivity to light of 380 nm to 500 nm. Yes. On the other hand, one of the materials currently being studied as a charge generation material for a short-wavelength light source is an azo compound, and an azo compound having various structures emits a semiconductor laser that emits light having a wavelength of 380 to 500 nm. It has been proposed as a charge generating material for an electrophotographic photoreceptor of an electrophotographic apparatus (see, for example, Patent Document 3).

Various charge transport materials suitable for electrophotographic photoreceptors that are exposed with a light source having a short wavelength have been proposed (see, for example, Patent Document 4 and Patent Document 5).
JP 2002-40687 A JP 2005-24929 A JP 2000-250238 A JP 2000-105475 A JP 2001-350282 A

  The present invention has been made in view of the above circumstances, and is a strong electrophotographic photoreceptor having high sensitivity, excellent electrophotographic characteristics such as chargeability and residual potential, and little deterioration due to mechanical stress, An object of the present invention is to provide an electrophotographic photosensitive member having a particularly high sensitivity to light having a wavelength of 380 nm to 500 nm. Further, it is intended to provide a high-performance image forming apparatus capable of forming a good image even when exposure is performed with light having a wavelength of 380 to 500 nm.

As a result of intensive studies on the electrophotographic photoreceptor that can solve the above-mentioned problems, the present inventors have found that the electrophotographic photoreceptor has a photosensitive layer containing a specific arylamine compound and a polycarbonate resin having a specific repeating structure. Has been found to be suitable, leading to the present invention.
That is, the first gist of the present invention is an electrophotographic photosensitive member having a photosensitive layer on a conductive support, and a polycarbonate resin having a repeating structure represented by the following general formula (1) in the photosensitive layer: And an electrophotographic photoreceptor comprising a compound represented by the following general formula (2).

(In Formula (1), R ¹ represents a hydrogen atom or an alkyl group, R ² and R ³ represent an alkyl group, and m and n represent an integer of 1 to 4.)

(Y in formula (2) Represents an alkylene group which may have a substituent, the substituents may be bonded to each other to form a ring, and Ar ¹ and Ar ² are each independently an alkylene which may have a substituent. Represents an arylene group which may have a group or a substituent, and Ar ^{3 to} Ar ⁶ may each independently have an alkyl group which may have a substituent or a substituent. Represents an aryl group. )
The second gist of the present invention resides in an electrophotographic photoreceptor, wherein the photosensitive layer contains the compounds represented by the formulas (1) and (2) and an azo pigment.

The third gist of the present invention resides in an electrophotographic photosensitive member characterized by forming an image by exposing the electrophotographic photosensitive member according to the present invention to monochromatic light having a wavelength of 380 to 500 nm.
The fourth gist of the present invention is an electrophotographic photosensitive member according to the present invention, a charging device for charging the electrophotographic photosensitive member, and an exposure device for exposing the charged electrophotographic photosensitive member to form an electrostatic latent image. And a developing device that develops the electrostatic latent image formed on the electrophotographic photosensitive member, wherein the charging device charges the electrophotographic photosensitive member when charging the electrophotographic photosensitive member. A fifth gist of the present invention resides in an image forming apparatus, wherein the image forming apparatus is located in contact with a photoconductor, and a charging device for charging the electrophotographic photoconductor according to the present invention. An exposure apparatus for exposing the charged electrophotographic photosensitive member with monochromatic light in the range of 380 to 500 nm to form an electrostatic latent image, and a developing device for developing the electrostatic latent image formed on the electrophotographic photosensitive member And an image forming apparatus.

  According to the present invention, the electrophotographic photosensitive member has high durability, low residual potential, excellent electrical characteristics, and is resistant to damage to the photosensitive layer film of the electrophotographic photosensitive member due to mechanical stress in the image forming apparatus. The body can be provided. Also, to provide an electrophotographic photosensitive member having high sensitivity in a region of 380 to 500 nm, particularly suitable for exposure means using a semiconductor laser or LED emitting monochromatic light in the region, and an image forming apparatus having the exposure means. Can do.

Hereinafter, embodiments of the present invention will be described in detail. However, the description of the constituent elements described below is a representative example of the embodiments of the present invention, and is appropriately modified and implemented without departing from the spirit of the present invention. can do.
The photosensitive layer of the electrophotographic photoreceptor according to the present invention contains a polycarbonate resin having a repeating structure represented by the following formula (1) and a compound represented by the following formula (2).

(In Formula (1), R ¹ represents a hydrogen atom or an alkyl group, R ² and R ³ represent an alkyl group, and m and n represent an integer of 1 to 4.)

(Y in formula (2) Represents an alkylene group which may have a substituent, the substituents may be bonded to each other to form a ring, and Ar ¹ and Ar ² are each independently an alkylene which may have a substituent. Represents an arylene group which may have a group or a substituent, and Ar ^{3 to} Ar ⁶ may each independently have an alkyl group which may have a substituent or a substituent. Represents an aryl group. )
<Polycarbonate resin>
The electrophotographic photosensitive member of the present invention contains a polycarbonate resin composed of a repeating structural unit represented by the following formula (1) as a binder resin.

In the formula (1), R ¹ represents a hydrogen atom or an alkyl group, preferably a hydrogen atom or an alkyl group having 1 to 5 carbon atoms, more preferably a hydrogen atom or an alkyl group having 3 or less carbon atoms, particularly hydrogen. An atom or a methyl group is preferred. R ² and R ³ represent an alkyl group, preferably an alkyl group having 1 to 5 carbon atoms, more preferably an alkyl group having 3 or less carbon atoms, and particularly preferably a methyl group. m and n represent an integer of 1 to 4, preferably 2 or less, and particularly preferably 1. When m and n are 2 or more, a plurality of R ² and R ³ may be different from each other. R ² and R ³ can be bonded to any position with respect to the benzene ring in the formula (1), but the oxygen atom bonded to each benzene ring has an o-position (ortho- In this case, it is particularly preferable that m and n are both 1.

  Specific examples of the polycarbonate resin according to the present invention include polycarbonate resins composed of the following repeating structural units, but the polycarbonate resin according to the present invention is not limited to these polycarbonate resins.

For example, in the formula (1), R ¹ , R ² and R ³ are each a methyl group, and the resin 1 having a repeating structure is synthesized by the production method described in JP-A-63-148263. However, it is not limited to this manufacturing method.
When the viscosity average molecular weight of the polycarbonate resin of the general formula (1) is too low, the mechanical strength is insufficient, and is usually 10,000 or more, preferably 20,000 or more, particularly 30,000 or more. In addition, if the viscosity average molecular weight is too high, the viscosity of the coating solution for forming the photosensitive layer may be increased and the productivity may be lowered. Therefore, it is usually 150,000 or less, preferably 100,000 or less, particularly Used at 50,000 or less. The viscosity average molecular weight in this case can be measured as follows. That is, the polycarbonate resin is dissolved in dichloromethane to prepare a solution having a concentration C of 6.00 g / L. Using an Ubbelohde capillary viscometer with a solvent (dichloromethane) flow time t ₀ of 136.16 seconds, 20.0 ° C.
The flow time t of the sample solution is measured in a constant temperature water bath set to. The viscosity average molecular weight Mv is calculated according to the following formula.

a = 0.438 × η _sp +1 η _sp = t / t ₀ −1
b = 100 × η _sp / C C = 6.00 (g / L)
η = b / a
Mv = 3207 × η ^1.205

  The photosensitive layer of the present invention contains a polycarbonate resin having a repeating structure represented by the formula (1), but the polycarbonate resin having a repeating structure represented by the formula (1) is substantially a formula (1). As long as it consists of the repeating structure represented by this, you may have another repeating structure in the range which does not deviate from the meaning of this invention.

  Moreover, although the photosensitive layer of this invention contains the polycarbonate resin which consists of a repeating structure represented by Formula (1) based on this invention, you may contain another binder resin. Other resins used in combination include vinyl polymers such as polymethyl methacrylate, polystyrene, and polyvinyl chloride, and copolymers thereof, thermoplastic resins such as polycarbonate, polyester, polysulfone, phenoxy, epoxy, and silicone resins, and various resins. And thermosetting resin. Among these resins, polycarbonate resin or polyester resin is preferable.

  When the layer containing a polycarbonate resin having a repeating structure represented by the formula (1) contains a binder resin other than the resin, it is contained in the layer in order to maintain the strength of the electrophotographic photosensitive member of the present invention. The polycarbonate resin having a repeating structure represented by the formula (1) is preferably 50% by weight or more, more preferably 80% by weight or more, and particularly preferably the binder resin. Only a polycarbonate resin having a repeating structure represented by the formula (1) is used, and no binder resin other than the resin is contained.

<Compound represented by Formula (2)>
The electrophotographic photoreceptor of the present invention contains a compound represented by the following formula (2).

Y in formula (2) Represents an alkylene group which may have a substituent, the substituents may be bonded to each other to form a ring, and Ar ¹ and Ar ² are each independently an alkylene which may have a substituent. Represents an arylene group which may have a group or a substituent, and Ar ^{3 to} Ar ⁶ may each independently have an alkyl group which may have a substituent or a substituent. Represents an aryl group.

Y Represents an alkylene group which may have a substituent, and the substituents may be bonded to each other to form a ring such that the Y part is cyclohexylidene. The alkylene group is preferably an alkylene group having 5 or less carbon atoms, more preferably 3 or less carbon atoms, particularly a methylene group. Examples of the substituent that the alkylene group that may have a substituent represented by Y include an alkyl group, an alkoxy group, an aryl group, and a halogen atom. The number of carbon atoms of the entire substituent is preferably 50 or less, more preferably 20 or less, still more preferably 12 or less, and particularly preferably 6 or less. Y is particularly preferably a group represented by the following formula (3).

In the above formula (3), R ⁴ and R ⁵ each independently represents a hydrogen atom, an alkyl group which may have a substituent, or an aryl group which may have a substituent. When R ⁴ is a hydrogen atom, R ⁵ represents a hydrogen atom or an alkyl group which may have a substituent. When R ⁴ is an alkyl group, R ⁵ has a hydrogen atom or a substituent. Represents an alkyl group which may have a substituent or an aryl group which may have a substituent, and when R ⁴ is an aryl group, R ⁵ has an alkyl group which may have a substituent or a substituent. Represents an aryl group which may be substituted.

  Examples of the alkyl group include a methyl group, an ethyl group, a propyl group, a butyl group, a hexyl group, an isopropyl group, and the like, and may have a straight chain or branched structure. Aryl groups include phenyl, tolyl, xylyl, biphenyl, naphthyl, anthryl, phenanthryl, thiophenyl, furanyl, pyrenyl, and other hydrocarbon aryl groups and heterocyclic aryl groups. It is done. These alkyl groups and aryl groups may further have a substituent, and examples of the substituent include an alkyl group such as a methyl group and a halogen atom such as a fluorine atom.

Among the above, R ⁴ in the formula (3) is preferably a group having at least one chiral center, and the group having a chiral center is represented by the following formula (4) in which the chiral center is a carbon atom. More preferably, it is a group represented.

In formula (4), R ⁶ , R ⁷ , and R ⁸ each independently represent a hydrogen atom, an alkyl group that may have a substituent, or an alkenyl group that may have a substituent. , R ^{6 to} R
⁸ are different from each other. R ⁶ , R ⁷ , and R ⁸ are not particularly limited as long as the three are different from each other and are not groups that deteriorate electrical characteristics such as a carbonyl group, an alkoxycarbonyl group, and a nitro group. For example, a hydrogen atom, an alkyl group that may have a substituent, an alkenyl group that may have a substituent, an alkynyl group that may have a substituent, and a substituent Preferred aryl groups and the like. Among them, a hydrogen atom, an alkyl group which may have a substituent, or an alkenyl group which may have a substituent is preferable, and a hydrogen atom or a substituent may be Particularly preferred is an alkyl group which may be present. The alkyl group preferably has 1 to 17 carbon atoms, and particularly preferably 1 to 5 carbon atoms. Examples of the substituent such as an alkyl group, alkenyl group, alkynyl group, and aryl group include, for example, a hydroxyl group, an alkyl group such as an optionally substituted methyl group, ethyl group, and propyl group, and An aryl group such as an optionally substituted phenyl group and naphthyl group, an arylthio group such as an optionally substituted phenylthio group, and the like. Examples of the substituent include a methyl group. And alkyl groups such as fluorine atoms and halogen atoms such as fluorine atoms.

In the above, R ⁴ in the general formula (3) is an alkyl group in which two of R ⁶ , R ⁷ and R ^{8 in} the general formula (4) may have a substituent. Particularly preferably one is a hydrogen atom.
Further, when R ⁴ in the formula (3) is represented by the formula (4), R ⁵ is a hydrogen atom, an alkyl group which may have a substituent, and an aryl group having a substituent. A hydrogen atom or an alkyl group which may have a substituent is preferable, and a hydrogen atom is particularly preferable. Examples of the substituent for the alkyl group and aryl group include the same substituents as those described above for R ⁴ .

Ar ¹ and Ar ² each independently represent an alkylene group which may have a substituent, or an arylene group which may have a substituent, but Ar ¹ and Ar ² may be the same Among the alkylene groups which may be different and may have a substituent, and the arylene group which may have a substituent, the arylene group which may have a substituent is A phenylene group is more preferable, and a 1,4-phenylene group is particularly preferable. In addition, examples of the substituent for the alkylene group and the arylene group include the same substituents as those described above for R ⁴ .

Ar ^{3 to} Ar ⁶ each independently represents an alkyl group which may have a substituent, or an aryl group which may have a substituent, but an aryl group which may have a substituent It is preferable that all four of Ar ^{3 to} Ar ⁶ are aryl groups which may have a substituent. Examples of the aryl group include a phenyl group and a naphthyl group, and examples of the substituent include those similar to the substituents shown for Ar ¹ and Ar ² above. Among them, an alkyl group is preferable, A tolyl group and a xylyl group having a substituted methyl group in at least one position selected from the 3-position and the 4-position with respect to the carbon atom bonded to the nitrogen atom are particularly preferred. Preferred specific examples of the arylamine compound of the present invention represented by the above formula (2) are shown below.

These arylamine compounds are, for example, Ar ¹ and Ar ³ in the formula (2).
And a tertiary amine compound having Ar ⁴ as a substituent, and a tertiary amine compound having Ar ² , Ar ⁵ , and Ar ⁶ as a substituent, and a carbonyl having R ⁴ and R ⁵ in the formula (3) A method of subjecting a compound to an acid condensation reaction, or a secondary amine compound having Ar ¹ and Ar ³ in the formula (2) as substituents, and Ar ²
And a secondary amine compound having Ar ⁵ as a substituent and a carbonyl compound having R ⁴ and R ⁵ in the formula (3) are subjected to an acid condensation reaction, and then a halogen compound having Ar ⁴ and Ar ⁶ by a coupling reaction with a halogen compound having ⁶ or the like.

The coupling reaction at that time is Ullmann (Ullmann) using a copper catalyst or an iron catalyst.
) The reaction may be performed, or may be performed by a method using a palladium catalyst. However, considering the electrical characteristics when the arylamine compound of the present invention is used in an electrophotographic photoreceptor, it is preferable to use a method using a palladium catalyst, and the ligand of the palladium catalyst is preferably a phosphorus derivative. In addition, in the above reaction, it is preferable to discharge water, acid, alcohol, and the like generated out of the system at an early stage, and for example, it is particularly preferable to perform the reaction under a nitrogen flow. In this case, the nitrogen flow rate is preferably 0.0001 to 5% by volume / minute of the reaction vessel, particularly preferably 0.001 to 3% by volume / minute.

  The compound represented by Formula (2) may be used alone or in combination. If desired, the compound represented by the formula (2) can be used in combination with another charge transport material. The amount of the charge transport material used in combination is not particularly limited, but in order to obtain the effects of the present invention sufficiently, the weight ratio of the compound represented by the formula (2) to the total weight of all the charge transport materials contained in the photosensitive layer is 20% or more, more preferably 30% or more, still more preferably 50% or more, and particularly preferably 60% or more.

<Charge generating material>
Examples of the charge generation material include inorganic photoconductive materials such as selenium and its alloys, cadmium sulfide, and organic photoconductive materials such as organic pigments. Organic photoconductive materials are preferable, and organic pigments are particularly preferable. . Examples of organic pigments include phthalocyanine pigments, azo pigments, dithioketopyrrolopyrrole pigments, squalene (squarylium) pigments, quinacridone pigments, indigo pigments, perylene pigments, polycyclic quinone pigments, anthanthrone pigments, and benzimidazole pigments. . Among these, phthalocyanine pigments or azo pigments are particularly preferable. The phthalocyanine pigment provides a highly sensitive photoconductor for a relatively long wavelength laser beam, and the azo pigment has a sufficient sensitivity for white light and a relatively short wavelength laser beam. , Each is excellent.

  Specific examples of the phthalocyanine pigment include metal-free phthalocyanine, copper, indium, gallium, tin, titanium, zinc, vanadium, silicon, germanium, aluminum and other oxides, halides, hydroxides, alkoxides, and the like. Examples include coordinated phthalocyanines having crystal forms and phthalocyanine dimers using oxygen atoms as bridging atoms. In particular, titanyl phthalocyanines (also known as oxytitanium) such as X-type, τ-type metal-free phthalocyanine, A-type (also known as β-type), B-type (also known as α-type), and D-type (also known as Y-type), which are highly sensitive crystal types Phthalocyanine), vanadyl phthalocyanine, chloroindium phthalocyanine, hydroxyindium phthalocyanine, chlorogallium phthalocyanine such as type II, hydroxygallium phthalocyanine such as type V, μ-oxo-gallium phthalocyanine dimer such as type G and type I, type II, etc. The [mu] -oxo-aluminum phthalocyanine dimer is preferred.

Among these phthalocyanines, A-type (also known as β-type), B-type (also known as α-type), and powder X-ray diffraction angle 2θ (± 0.2 °) are 27.1 ° or 27.3 °. D-type (Y-type) titanyl phthalocyanine, II-type chlorogallium phthalocyanine, V-type and 28.1 ° have the strongest peaks, and 26.2 ° have peaks Particularly preferred is hydroxygallium phthalocyanine, which has a clear peak at 28.1 ° and a half width W of 25.9 ° is 0.1 ° ≦ W ≦ 0.4 °.

  As the azo pigment, any azo pigment can be used as long as it can be used for an electrophotographic photoreceptor, and examples thereof include a monoazo pigment, a bisazo pigment, and a trisazo pigment. Among these, those having a plurality of azo bonds are preferable, and among them, bisazo pigments or trisazo pigments are more preferably used. In the case of an azo pigment having a plurality of azo bonds, the coupler components may be the same or different, and more preferably different couplers are used. Specific examples of the azo compound suitably used in the electrophotographic photoreceptor of the present invention are shown below, but the charge generating material used in the present invention is not limited to the following azo pigments.

Among the azo compounds, those represented by azo 1, azo 2, and azo 3 are particularly preferable.
When an organic pigment is used as the charge generation material, one kind may be used alone, or two or more kinds of pigments may be mixed and used, preferably azo pigments, phthalocyanine pigments, or azo pigments And phthalocyanine pigments are used in combination. When organic pigments are used as the charge generating substance, usually, fine particles of these organic pigments are used in the form of a dispersion layer bound with various binder resins.

<Electrophotographic photoreceptor>
The electrophotographic photoreceptor of the present invention will be described below.
The photosensitive layer of the electrophotographic photosensitive member is provided on the conductive support, and when it has an undercoat layer, it is provided on the undercoat layer. As the type of the photosensitive layer, the charge generation material and the charge transport material are present in the same layer and are dispersed in a binder resin, a so-called single-layer type photoreceptor, and charge generation in which the charge generation material is dispersed in a binder resin. A so-called laminated type photoreceptor having a multilayer structure in which a layer and a charge transport material are separated into two functions of a charge transport layer in which a charge transport material is dispersed in a binder resin can be mentioned, but any structure may be used. Further, an overcoat layer may be provided on the photosensitive layer for the purpose of improving the chargeability and improving the wear resistance.

As the laminated type photosensitive layer, a charge generation layer and a charge transport layer are laminated in this order from the conductive support side, and a reverse lamination layer in which a charge transport layer and a charge generation layer are laminated in reverse order. Any one of them can be used, but a sequentially laminated photosensitive layer that can exhibit the most balanced photoconductivity is preferable.
The polycarbonate resin represented by the formula (1) and the compound represented by the formula (2) used in the electrophotographic photoreceptor of the present invention are contained in any layer formed on the conductive support. However, the compounds of the formula (1) and the formula (2) are usually contained in the charge transport layer of the single layer type photosensitive layer or the multilayer type photosensitive layer. In particular, it is preferable to be contained in the charge transport layer of the laminated photosensitive layer since a high effect on the electrical characteristics can be obtained.

<Conductive support>
As the conductive support used for the electrophotographic photosensitive member, for example, a metal material such as aluminum, aluminum alloy, stainless steel, copper, nickel, or conductive powder such as metal, carbon, tin oxide is added to make the conductive support. Mainly used are resin, glass, paper, or the like obtained by depositing or applying the applied resin material or conductive material such as aluminum, nickel, ITO (indium tin oxide) on the surface. As a form, a drum shape, a sheet shape, a belt shape or the like is used. For conductive support of metallic materials, for control of conductivity and surface properties, and for defect coating. A conductive material having an appropriate resistance value may be applied.

When a metal material such as an aluminum alloy is used as the conductive support, it may be used after an anodized film is applied. When an anodized film is applied, it is desirable to perform a sealing treatment by a known method.
For example, an anodic oxidation film is formed by anodizing in an acidic bath such as chromic acid, sulfuric acid, oxalic acid, boric acid, sulfamic acid, etc. give. In the case of anodic oxidation in sulfuric acid, the sulfuric acid concentration is 100 to 300 g / l, the dissolved aluminum concentration is 2 to 15 g / l, the liquid temperature is 15 to 30 ° C., the electrolysis voltage is 10 to 20 V, and the current density is 0.5 to Although it is preferable to set within the range of ² A / dm ² , it is not limited to the above conditions.

It is preferable to perform a sealing treatment on the anodic oxide film thus formed. The sealing treatment may be performed by a known method. For example, it is immersed in an aqueous solution containing nickel fluoride as a main component, or immersed in an aqueous solution containing nickel acetate as a main component. A high temperature sealing treatment is preferably performed.
The concentration of the nickel fluoride aqueous solution used in the case of the low-temperature sealing treatment can be appropriately selected, but more preferable results can be obtained when it is used in the range of 3 to 6 g / l. Moreover, in order to advance a sealing process smoothly, as processing temperature, it is 25-40 degreeC, Preferably it is 30-35 degreeC, Moreover, nickel fluoride aqueous solution pH is 4.5-6.5, Preferably it is 5 It is better to process in the range of .5 to 6.0. As the pH adjuster, oxalic acid, boric acid, formic acid, acetic acid, sodium hydroxide, sodium acetate, aqueous ammonia and the like can be used. The treatment time is preferably in the range of 1 to 3 minutes per 1 μm of film thickness. In order to further improve the physical properties of the film, cobalt fluoride, cobalt acetate, nickel sulfate, a surfactant or the like may be added to the nickel fluoride aqueous solution. Subsequently, it is washed with water and dried to finish the low temperature sealing treatment. As the sealing agent in the case of the high temperature sealing treatment, an aqueous solution of a metal salt such as nickel acetate, cobalt acetate, lead acetate, nickel acetate-cobalt, barium nitrate can be used, and it is particularly preferable to use nickel acetate. . The concentration in the case of using an aqueous nickel acetate solution is preferably 5 to 20 g / l. The treatment temperature is 80 to 100 ° C., preferably 90 to 98 ° C., and the pH of the nickel acetate aqueous solution is preferably 5.0 to 6.0. Here, ammonia water, sodium acetate, or the like can be used as the pH adjuster. The treatment time is 10 minutes or longer, preferably 20 minutes or longer. In this case as well, sodium acetate, organic carboxylic acid, anionic and nonionic surfactants may be added to the nickel acetate aqueous solution in order to improve the film properties. Subsequently, it is washed with water and dried to finish the high temperature sealing treatment. When the average film thickness is thick, stronger sealing conditions are required due to the higher concentration of the sealing liquid and high temperature / long-time treatment. Accordingly, productivity is deteriorated and surface defects such as spots, dirt, and dusting are likely to occur on the coating surface. From such a point, it is preferable that the average film thickness of the anodic oxide coating is usually 20 μm or less, particularly 7 μm or less.

  The support surface may be smooth, or may be roughened by using a special cutting method or polishing. Further, it may be roughened by mixing particles having an appropriate particle diameter with the material constituting the support. In order to reduce the cost, it is possible to use the drawing tube as it is without cutting. Especially when using non-cutting aluminum supports such as drawing, impact processing, ironing, etc., the process eliminates dirt, foreign matter, etc. on the surface, small scratches, etc., and a uniform and clean support can be obtained. Therefore, it is preferable.

<Underlayer>
An undercoat layer may be provided between the conductive support and the photosensitive layer described later for improving adhesion and blocking properties. As the undercoat layer, a resin, a resin in which particles such as a metal oxide are dispersed, or the like is used.
Examples of metal oxide particles used for the undercoat layer include metal oxide particles containing one metal element such as titanium oxide, aluminum oxide, silicon oxide, zirconium oxide, zinc oxide, iron oxide, calcium titanate, titanium Examples thereof include metal oxide particles containing a plurality of metal elements such as strontium acid and barium titanate. One kind of these particles may be used alone, or a plurality of kinds of particles may be mixed and used. Among these metal oxide particles, titanium oxide and aluminum oxide are preferable, and titanium oxide is particularly preferable. The surface of the titanium oxide particles may be treated with an inorganic substance such as tin oxide, aluminum oxide, antimony oxide, zirconium oxide, or silicon oxide, or an organic substance such as stearic acid, polyol, or silicon. As the crystal form of the titanium oxide particles, any of rutile, anatase, brookite, and amorphous can be used. Moreover, the thing of the several crystal state may be contained.

Various metal oxide particle diameters can be used. Among them, the average primary particle diameter is usually 1 nm or more, preferably 10 nm, from the viewpoint of electrical characteristics and the stability of the coating liquid for forming the undercoat layer. As described above, it is usually 100 nm or less, preferably 50 nm or less.
The undercoat layer is preferably formed in a form in which metal oxide particles are dispersed in a binder resin. As binder resin used for the undercoat layer, epoxy resin, polyethylene resin, polypropylene resin, acrylic resin, methacrylic resin, polyamide resin, vinyl chloride resin, vinyl chloride resin, vinyl acetate resin, phenol resin, polycarbonate resin, polyurethane resin, Polyimide resin, vinylidene chloride resin, polyvinyl acetal resin, vinyl chloride-vinyl acetate copolymer, polyvinyl alcohol resin, polyurethane resin, polyacrylic acid resin, polyacrylamide resin, polyvinyl pyrrolidone resin, polyvinyl pyridine resin, water-soluble polyester resin, nitro Cellulose ester resins such as cellulose, cellulose ether resins, casein, gelatin, polyglutamic acid, starch, starch acetate, amino starch, zirconium chelate Compounds, organic zirconium compounds such as zirconium alkoxide compounds, titanyl chelate compounds, organic titanyl compounds such as titanyl alkoxide compound, a known binder resin such as a silane coupling agent and the like. These may be used alone or in combination of two or more in any combination and ratio. Moreover, you may use with the hardening | curing form with the hardening | curing agent. Of these, alcohol-soluble copolymerized polyamides, modified polyamides, and the like are preferable because they exhibit good dispersibility and coatability.

The use ratio of the inorganic particles to the binder resin used in the undercoat layer can be arbitrarily selected, but is usually in the range of 10% by weight or more and 500% by weight or less from the viewpoint of dispersion stability and coatability. Is preferably used.
The thickness of the undercoat layer can be selected arbitrarily, but is usually preferably in the range of 0.1 μm or more and 20 μm or less from the viewpoint of improving the photoreceptor characteristics and coating properties.
A known antioxidant or the like may be mixed in the undercoat layer. For the purpose of preventing image defects, pigment particles, resin particles and the like may be contained and used.

<Charge generating material>
The photosensitive layer formed on the conductive support may have a single layer structure in which the charge generation material and the charge transport material are present in the same layer and are dispersed in the binder resin, or the charge generation material may be It may be any one having a laminated structure in which a charge generating layer dispersed in a binder and a charge transporting substance in which a charge transporting substance is dissolved or dispersed in a binder resin are functionally separated. When the photosensitive layer has a laminated structure, the charge generation layer is composed of a charge generation material containing at least one of charge generation materials typified by azo pigments and phthalocyanines and a binder resin.

The charge generation layer in the functional separation type photoconductor is prepared by dispersing a charge generation material containing at least one pigment in a solution in which a binder resin is dissolved in an organic solvent, and adjusting the coating solution to support the conductive layer. It is formed by coating on a body and binding fine particles of a charge generating substance and various binder resins.
Examples of the binder resin used for the charge generation layer in the function-separated photoreceptor include polyvinyl butyral resin, polyvinyl formal resin, partially acetalized polyvinyl butyral resin in which a part of butyral is modified with formal, acetal, etc. Polyvinyl acetal resin, polyarylate resin, polycarbonate resin, polyester resin, modified ether polyester resin, phenoxy resin, polyvinyl chloride resin, polyvinylidene chloride resin, polyvinyl acetate resin, polystyrene resin, acrylic resin, methacrylic resin, polyacrylamide Resin, polyamide resin, polyvinyl pyridine resin, cellulose resin, polyurethane resin, epoxy resin, silicone resin, polyvinyl alcohol resin, polyvinyl pyrrolidone resin, casein, chloride Vinyl chloride-vinyl acetate, such as nyl-vinyl acetate copolymer, hydroxy-modified vinyl chloride-vinyl acetate copolymer, carboxyl-modified vinyl chloride-vinyl acetate copolymer, vinyl chloride-vinyl acetate-maleic anhydride copolymer Copolymers, styrene-butadiene copolymers, vinylidene chloride-acrylonitrile copolymers, styrene-alkyd resins, silicon-alkyd resins, insulating resins such as phenol-formaldehyde resins, poly-N-vinylcarbazole, polyvinylanthracene, It can be selected from organic photoconductive polymers such as polyvinyl perylene, but is not limited to these polymers. These binder resins may be used alone or in combination of two or more.

Solvents and dispersion media used to dissolve the binder resin and prepare the coating solution include, for example, saturated aliphatic solvents such as pentane, hexane, octane, and nonane, aromatic solvents such as toluene, xylene, and anisole, chlorobenzene Halogenated aromatic solvents such as dichlorobenzene and chloronaphthalene, amide solvents such as dimethylformamide and N-methyl-2-pyrrolidone, alcohol solvents such as methanol, ethanol, isopropanol, n-butanol and benzyl alcohol, glycerin Aliphatic polyhydric alcohols such as polyethylene glycol, chain solvents such as acetone, cyclohexanone and methyl ethyl ketone, and cyclic ketone solvents, ester solvents such as methyl formate, ethyl acetate and n-butyl acetate, methylene chloride, chloroform, 1 , 2-Dichloroe Halogenated hydrocarbon solvents such as ethylene, chain ether such as diethyl ether, dimethoxyethane, tetrahydrofuran, 1,4-dioxane, methyl cellosolve, ethyl cellosolve, and cyclic ether solvents, acetonitrile, dimethyl sulfoxide, sulfolane, hexa Examples include aprotic polar solvents such as methyl phosphoric acid triamide, nitrogen-containing compounds such as n-butylamine, isopropanolamine, diethylamine, triethanolamine, ethylenediamine, triethylenediamine, and triethylamine, mineral oil such as ligroin, and water, which will be described later. Those which do not dissolve the undercoat layer are preferably used. These can be used alone or in combination of two or more.

  In the charge generation layer of the function-separated type photoreceptor, the compounding ratio (weight) of the binder resin and the charge generation material is 10 to 1000 parts by weight, preferably 30 to 500 parts by weight with respect to 100 parts by weight of the binder resin. The film thickness is usually 0.1 μm to 4 μm, preferably 0.15 μm to 0.6 μm. If the ratio of the charge generation material is too high, the stability of the coating solution is lowered due to problems such as aggregation of the charge generation material. On the other hand, if it is too low, the sensitivity as a photoreceptor is reduced. Things are preferable. As a method for dispersing the charge generation material, a known dispersion method such as a ball mill dispersion method, an attritor dispersion method, or a sand mill dispersion method can be used. In this case, it is effective to refine the particles to a particle size of 0.5 μm or less, preferably 0.3 μm or less, more preferably 0.15 μm or less.

<Charge transport material>
The charge transport layer of the multilayer photoreceptor contains the compound represented by the formula (2) according to the present invention and usually contains other components used as necessary. Specifically, such a charge transport layer is prepared by, for example, preparing a coating solution by dissolving or dispersing the charge transport material of the present invention and a binder resin in a solvent. It can be obtained by coating and drying on a charge generation layer, or in the case of a reverse lamination type photosensitive layer, on a conductive support (or on an undercoat layer when an undercoat layer is provided).

  The charge transport material contained in the photosensitive layer according to the invention may be used alone or in combination of two or more in any combination. Usually, the compound represented by the formula (2) according to the present invention functions as a charge transport material, but may be used in combination with a known charge transport material other than the compound represented by the formula (2). . Examples of charge transport materials to be combined include aromatic nitro compounds such as 2,4,7-trinitrofluorenone, cyano compounds such as tetracyanoquinodimethane, electron withdrawing materials such as quinone compounds such as diphenoquinone, carbazole derivatives, Indole derivatives, imidazole derivatives, oxazole derivatives, pyrazole derivatives, thiadiazole derivatives, heterocyclic compounds such as benzofuran derivatives, aniline derivatives, hydrazone derivatives, aromatic amine derivatives, stilbene derivatives, butadiene derivatives, enamine derivatives and multiple types of these compounds Examples thereof include an electron donating substance such as a polymer having a bond or a group composed of these compounds in the main chain or side chain. Among these, carbazole derivatives, aromatic amine derivatives, stilbene derivatives, butadiene derivatives, enamine derivatives, and those in which a plurality of these compounds are bonded are preferable.

<Binder resin>
The photosensitive layer may be a vapor-deposited film, but is usually formed by binding raw materials such as a charge generation material and a charge transport material of the present invention with a binder resin, and the polycarbonate resin according to the present invention is a binder resin. Used as In the case of a photosensitive layer in which a plurality of layers are laminated, the polycarbonate resin according to the present invention may be used in any of the layers, but is usually a charge transport layer of a laminated photosensitive layer or a single layer type photoreceptor. Used for photosensitive layer. As the binder resin, in addition to the polycarbonate according to the present invention, any binder resin can be used in combination as long as it is usually applicable to an electrophotographic photoreceptor. In order to express the effect of the present invention, the polycarbonate resin according to the present invention is not necessarily included in the outermost layer, and may be included in any layer.

  The ratio of the binder resin and charge transport material used in the charge transport layer of the multilayer photoreceptor and the photosensitive layer of the single photoreceptor is usually 100 parts by weight of the binder resin in both the single layer and multilayer. The charge transport material is 20 parts by weight or more, preferably 30 parts by weight or more from the viewpoint of reducing residual potential, and more preferably 40 parts by weight or more from the viewpoint of stability during repeated use and charge mobility. On the other hand, from the viewpoint of thermal stability of the photosensitive layer, it is usually 150 parts by weight or less, preferably 120 parts by weight or less from the viewpoint of compatibility between the charge transport material and the binder resin, and from the viewpoint of printing durability. The amount is more preferably 100 parts by weight or less, and particularly preferably 80 parts by weight or less from the viewpoint of scratch resistance.

  In the case of a single-layer type photoreceptor, the charge generating substance is further dispersed in the charge transport medium having the above-described blending ratio. In this case, the particle size of the charge generating material needs to be sufficiently small, preferably 1 μm or less, more preferably 0.5 μm or less. If the amount of the charge generating material dispersed in the photosensitive layer is too small, sufficient sensitivity cannot be obtained. If the amount is too large, there is an adverse effect of reduced chargeability and reduced sensitivity, for example, preferably 0.1 to 50% by weight. It is used in the range, preferably in the range of 1 to 20% by weight.

The film thickness of the photosensitive layer of the single-layer type photoreceptor is usually 5 to 100 μm, preferably 10 to 50 μm. The film thickness of the charge transport layer of the forward laminated photoreceptor is usually 5 to 50 μm. Although used, it is preferably 10 to 45 μm from the viewpoint of long life and image stability, and more preferably 10 to 30 μm from the viewpoint of high resolution.
The photosensitive layer has well-known antioxidants, plasticizers, ultraviolet absorbers, electron-withdrawing compounds to improve film-forming properties, flexibility, coating properties, stain resistance, gas resistance, light resistance, etc. In addition, additives such as a leveling agent and a visible light shielding agent may be contained. In addition, the photosensitive layer may contain various additives such as a leveling agent, an antioxidant, and a sensitizer for improving the coating property as necessary. Examples of the antioxidant include hindered phenol compounds and hindered amine compounds. Examples of dyes and pigments include various pigment compounds and azo compounds. Examples of surfactants include silicone oil and fluorine-based oil.

A protective layer may be provided on the outermost surface layer of the photosensitive member for the purpose of preventing the photosensitive layer from being worn out or preventing or reducing the deterioration of the photosensitive layer due to a discharge substance generated from a charger or the like. The protective layer is formed by containing a conductive material in an appropriate binder resin, or charge transporting ability such as a triphenylamine skeleton as described in JP-A-9-190004 and JP-A-10-252377. The copolymer using the compound which has can be used. Examples of the conductive material include aromatic amino compounds such as TPD (N, N′-diphenyl-N, N′-bis- (m-tolyl) benzidine), antimony oxide, indium oxide, tin oxide, titanium oxide, and tin oxide. -Metal oxides such as antimony oxide, aluminum oxide, and zinc oxide can be used, but are not limited thereto. As the binder resin used for the protective layer, known resins such as polyamide resin, polyurethane resin, polyester resin, epoxy resin, polyketone resin, polycarbonate resin, polyvinyl ketone resin, polystyrene resin, polyacrylamide resin, and siloxane resin can be used. Also, a skeleton having a triphenylamine skeleton having a charge transporting ability as described in JP-A-9-190004 and JP-A-10-252377 and a copolymer of the above resin can be used. The protective layer has an electric resistance of 10 ⁹ to 10 ¹⁴ Ω · cm.
It is preferable to configure so that. When the electrical resistance is higher than 10 ¹⁴ Ω · cm, the residual potential is increased, resulting in an image with much fog. On the other hand, when the electric resistance is lower than 10 ⁹ Ω · cm, the image is blurred and the resolution is lowered. In addition, the protective layer must be configured so as not to substantially impede transmission of light irradiated for image exposure.

  In addition, fluorine resin, silicone resin, polyethylene resin, polystyrene resin, etc. are used for the surface layer for the purpose of reducing frictional resistance and abrasion on the surface of the photoconductor and increasing the transfer efficiency of the toner from the photoconductor to the transfer belt and paper. May be included. Moreover, the particle | grains which consist of these resin, and the particle | grains of an inorganic compound may be included.

<Layer formation method>
Each layer constituting the photoreceptor is formed by sequentially applying a coating solution containing the material constituting each layer on the support using a known coating method and repeating the coating and drying process for each layer. The
The coating solution for forming a layer is used in the case of a charge transport layer of a single layer type photoreceptor or a multilayer type photoreceptor, and the solid content is usually used in the range of 5 to 40% by weight, but 10 to 35% by weight. It is preferable to use in the range. Moreover, although the viscosity of this coating liquid is normally used in the range of 10-500 mPa * s, it is preferable to set it as the range of 50-400 mPa * s.
In the case of the charge generating layer of the multilayer photoreceptor, the solid content is usually used in the range of 0.1 to 15% by weight, but more preferably in the range of 1 to 10%. Although the viscosity of a coating liquid is normally used in the range of 0.01-20 mPa * s, it is more preferable to be used in the range of 0.1-10 mPa * s.

Examples of the application method of the coating liquid include dip coating, spray coating, spinner coating, bead coating, wire bar coating, blade coating, roller coating, air knife coating, and curtain coating. Other known coating methods can also be used.
The coating solution is preferably dried by touching at room temperature and then heating and drying in a temperature range of 30 to 200 ° C. for 1 minute to 2 hours with no air or air. The heating temperature may be constant or may be changed while drying.

  The electrophotographic photoreceptor thus obtained can be used as a highly durable photoreceptor having high sensitivity, low residual potential, and little deterioration due to repeated use. Further, since the sensitivity in the region of 380 to 500 nm is high, it is particularly suitable for a photoconductor for an electrophotographic apparatus having an exposure means using a semiconductor laser or LED in this region.

<Image forming apparatus>
Next, an embodiment of an image forming apparatus using the electrophotographic photosensitive member of the present invention (an image forming apparatus of the present invention) will be described with reference to FIG. However, the embodiment is not limited to the following description, and can be arbitrarily modified without departing from the gist of the present invention.

As shown in FIG. 1, the image forming apparatus includes an electrophotographic photosensitive member 1, a charging device 2, an exposure device 3, and a developing device 4, and further, a transfer device 5, a cleaning device 6 and a fixing device as necessary. A device 7 is provided.
The electrophotographic photoreceptor 1 is not particularly limited as long as it is the above-described electrophotographic photoreceptor of the present invention, but in FIG. 1, as an example, a drum in which the above-described photosensitive layer is formed on the surface of a cylindrical conductive support. The photoconductor is shown. A charging device 2, an exposure device 3, a developing device 4, a transfer device 5 and a cleaning device 6 are arranged along the outer peripheral surface of the electrophotographic photosensitive member 1, respectively.

The charging device 2 charges the electrophotographic photosensitive member 1 and uniformly charges the surface of the electrophotographic photosensitive member 1 to a predetermined potential. Examples of the charging device include a corona charging device such as a corotron and a scorotron, a direct charging device (contact type charging device) that charges a direct charging member to which a voltage is applied by contacting the photosensitive member surface, and a contact type charging device such as a charging brush. Often used. Examples of the direct charging means include a contact charger such as a charging roller and a charging brush. In FIG. 1, a roller type charging device (charging roller) is shown as an example of the charging device 2. As the direct charging means, either charging with air discharge or injection charging without air discharge is possible. It is also possible to use an NC roller charging method in which charging is performed in a state where a photosensitive sheet and a charging roller are kept in a non-contact state at a stable charging distance by winding a resin sheet or the like around the charging roller. In addition, as a voltage applied at the time of charging, in the case of only a direct current voltage, an alternating current can be superimposed on a direct current.

  The type of the exposure apparatus 3 is not particularly limited as long as it can expose the electrophotographic photoreceptor 1 to form an electrostatic latent image on the photosensitive surface of the electrophotographic photoreceptor 1. Specific examples include halogen lamps, fluorescent lamps, lasers such as semiconductor lasers and He—Ne lasers, LEDs, and the like. Further, exposure may be performed by a photoreceptor internal exposure method. As the digital electrophotographic system, it is preferable to use a laser, an LED, an optical shutter array, or the like. The light used for the exposure is arbitrary. For example, the exposure may be performed using monochromatic light with a wavelength of 780 nm, monochromatic light with a wavelength slightly shorter than 600 nm to 700 nm, or monochromatic light with a short wavelength of 380 nm to 500 nm. . The electrophotographic photoreceptor according to the present invention has excellent performance particularly when exposed to monochromatic light having a wavelength of 380 nm to 500 nm.

  The type of the developing device 4 is not particularly limited, and an arbitrary device such as a dry development method such as cascade development, one-component insulating toner development, one-component conductive toner development, or two-component magnetic brush development, or a wet development method is used. be able to. In FIG. 1, the developing device 4 includes a developing tank 41, an agitator 42, a supply roller 43, a developing roller 44, and a regulating member 45, and has a configuration in which the toner T is stored inside the developing tank 41. . Further, a replenishing device (not shown) for replenishing the toner T may be attached to the developing device 4 as necessary. The replenishing device is configured to be able to replenish toner T from a container such as a bottle or a cartridge. The development method may be either a contact method or a non-contact method. As the toner to be used, in addition to the pulverized toner, chemical toners such as suspension granulation, suspension polymerization, and emulsion polymerization aggregation method can be used. In particular, in the case of chemical toners, those having a small particle size of about 4 to 8 μm are used, and those having a shape close to a sphere, and those outside the potato and rugby ball shape can also be used. The polymerized toner is excellent in charging uniformity and transferability and is suitably used for high image quality.

The supply roller 43 is formed from a conductive sponge or the like. The developing roller 44 is made of a metal roll such as iron, stainless steel, aluminum, or nickel, or a resin roll obtained by coating such a metal roll with a silicon resin, a urethane resin, a fluororesin, or the like. The surface of the developing roller 44 may be smoothed or roughened as necessary.
The developing roller 44 is disposed between the electrophotographic photoreceptor 1 and the supply roller 43, and is in contact with the electrophotographic photoreceptor 1 and the supply roller 43, respectively. The supply roller 43 and the developing roller 44 are rotated by a rotation drive mechanism (not shown). The supply roller 43 carries the stored toner T and supplies it to the developing roller 44. The developing roller 44 carries the toner T supplied by the supply roller 43 and contacts the surface of the electrophotographic photoreceptor 1.

  The regulating member 45 is formed of a resin blade such as silicon resin or urethane resin, a metal blade such as stainless steel, aluminum, copper, brass, phosphor bronze, or a blade obtained by coating such a metal blade with resin. The regulating member 45 abuts on the developing roller 44 and is pressed with a predetermined force against the developing roller 44 by a spring or the like (a general blade linear pressure is 5 to 500 g / cm). If necessary, the regulating member 45 may be provided with a function of imparting charging to the toner T by frictional charging with the toner T.

The agitator 42 is rotated by a rotation driving mechanism, and agitates the toner T and conveys the toner T to the supply roller 43 side. A plurality of agitators 42 may be provided with different blade shapes and sizes.
The type of the transfer device 5 is not particularly limited, and an apparatus using an arbitrary system such as an electrostatic transfer method such as corona transfer, roller transfer, or belt transfer, a pressure transfer method, or an adhesive transfer method can be used. . Here, it is assumed that the transfer device 5 includes a transfer charger, a transfer roller, a transfer belt, and the like disposed so as to face the electrophotographic photoreceptor 1. The transfer device 5 applies a predetermined voltage value (transfer voltage) having a polarity opposite to the charging potential of the toner T, and transfers the toner image formed on the electrophotographic photosensitive member 1 to a recording paper (paper, medium) P. Is. The present invention exhibits a greater effect when the transfer voltage is large.

  There is no restriction | limiting in particular about the cleaning apparatus 6, Arbitrary cleaning apparatuses, such as a brush cleaner, a magnetic brush cleaner, an electrostatic brush cleaner, a magnetic roller cleaner, a blade cleaner, can be used. The cleaning device 6 is for scraping off residual toner adhering to the photoreceptor 1 with a cleaning member and collecting the residual toner. However, when there is little or almost no toner remaining on the surface of the photoreceptor, the cleaning device 6 may be omitted.

  The fixing device 7 includes an upper fixing member (fixing roller) 71 and a lower fixing member (fixing roller) 72, and a heating device 73 is provided inside the fixing member 71 or 72. FIG. 1 shows an example in which a heating device 73 is provided inside the upper fixing member 71. As the upper and lower fixing members 71 and 72, known heat fixing members such as a fixing roll in which a metal base tube such as stainless steel or aluminum is coated with silicon rubber, a fixing roll coated with a fluororesin, or a fixing sheet are used. be able to. Further, each of the fixing members 71 and 72 may be configured to supply a release agent such as silicone oil in order to improve releasability, or may be configured to forcibly apply pressure to each other by a spring or the like.

When the toner transferred onto the recording paper P passes between the upper fixing member 71 and the lower fixing member 72 heated to a predetermined temperature, the toner is heated to a molten state and cooled after passing through the recording paper. Toner is fixed on P.
There is no particular limitation on the type of the fixing device, and fixing by any method such as those used here, heat roller fixing, flash fixing, oven fixing, pressure fixing, IH fixing, belt fixing, IHF fixing, and the like. A device can be provided. Any of these known methods can be used, and these fixing methods may be used singly or in combination of a plurality of fixing methods.

In the electrophotographic apparatus configured as described above, an image is recorded as follows. That is, first, the surface (photosensitive surface) of the photoreceptor 1 is charged to a predetermined potential (for example, −600 V) by the charging device 2. At this time, charging may be performed by a DC voltage, or charging may be performed by superimposing an AC voltage on the DC voltage.
Subsequently, the photosensitive surface of the charged photoreceptor 1 is exposed by the exposure device 3 according to the image to be recorded, and an electrostatic latent image is formed on the photosensitive surface. The developing device 4 develops the electrostatic latent image formed on the photosensitive surface of the photoreceptor 1.

The developing device 4 thins the toner T supplied by the supply roller 43 with a regulating member (developing blade) 45 and has a predetermined polarity (here, the same polarity as the charging potential of the photosensitive member 1) and the negative polarity. ) And is carried while being carried on the developing roller 44 and brought into contact with the surface of the photoreceptor 1.
When the charged toner T carried on the developing roller 44 comes into contact with the surface of the photoreceptor 1, a toner image corresponding to the electrostatic latent image is formed on the photosensitive surface of the photoreceptor 1. This toner image is transferred onto the recording paper P by the transfer device 5. Thereafter, the toner remaining on the photosensitive surface of the photoreceptor 1 without being transferred is removed by the cleaning device 6.

After the transfer of the toner image onto the recording paper P, the final image is obtained by passing the fixing device 7 and thermally fixing the toner image onto the recording paper P.
In addition to the above-described configuration, the image forming apparatus may have a configuration capable of performing, for example, a static elimination process. The neutralization step is a step of neutralizing the electrophotographic photosensitive member by exposing the electrophotographic photosensitive member, and a fluorescent lamp, an LED, or the like is used as the neutralizing device. In addition, the light used in the static elimination process is often light having an exposure energy that is at least three times that of the exposure light.

The image forming apparatus may be further modified. For example, the image forming apparatus may be configured to perform a pre-exposure process, an auxiliary charging process, or the like, or may be configured to perform offset printing. A full-color tandem system configuration using toner may be used.
The electrophotographic photosensitive member 1 is combined with one or more of the charging device 2, the exposure device 3, the developing device 4, the transfer device 5, the cleaning device 6, and the fixing device 7 to form an integrated cartridge ( The electrophotographic photosensitive member cartridge may be configured to be detachable from a main body of an electrophotographic apparatus such as a copying machine or a laser beam printer. For example, at least one of the charging unit 3, the developing unit 4, and the cleaning unit 6 can be integrally supported together with the drum-shaped photoreceptor 1 to form a cartridge. In this case, for example, when the electrophotographic photosensitive member 1 and other members are deteriorated, the electrophotographic photosensitive member cartridge is removed from the main body of the image forming apparatus, and another new electrophotographic photosensitive member cartridge is mounted on the main body of the image forming apparatus. This facilitates maintenance and management of the image forming apparatus.

Hereinafter, the present invention will be described by way of examples. The examples are given for the purpose of illustrating the present invention in detail, and are not limited to the examples unless they are contrary to the gist of the present invention. In Examples and Comparative Examples, the part means “part by weight”.
Example 1
A film obtained by depositing aluminum on a 75 μm thick polyester film was used as a support, and the film thickness after drying the following charge generation layer coating solution 1 was 0.4 g / m ² (about 0.4 g).
μm) was applied with a wire bar and dried to form a charge generation layer. The following charge transport layer coating solution was applied thereon with an applicator and dried at room temperature for 30 minutes and then at 125 ° C. for 20 minutes to produce a photoreceptor A having a charge transfer layer with a thickness of 25 μm.

Charge generation layer coating solution 1:
To 1.5 parts of the azo compound represented by the following formula (5) synthesized by the method described in JP-A-9-281733, 30 parts of 1,2-dimethoxyethane is added and pulverized with a sand grind mill for 6 hours. Atomization and dispersion treatment was performed. Subsequently, 0.75 part of polyvinyl butyral (manufactured by Denki Kagaku Kogyo Co., Ltd., trade name “Denkabutyral” # 6000C) and 0.75 part of phenoxy resin (product of Union Carbide, PKHH) were added to 1,2-dimethoxyethane 28. The resulting mixture was mixed with a binder solution dissolved in 5 parts, and finally, 13.5 parts of an arbitrary mixture of 1,2-dimethoxyethane and 4-methoxy-4-methyl-2-pentanone was added to obtain a solid concentration of 4.0. A charge generation layer coating solution of wt% was prepared.

Charge transport layer coating solution:
40 parts of a compound represented by the following formula (6) (charge transporting substance 1), 30 parts of a compound represented by the following formula (7) (charge transporting substance 2), and a polycarbonate resin (PC1) represented by the following formula (8) , Viscosity average molecular weight 30,000) and 0.05 part of silicone oil (trade name KF96 manufactured by Shin-Etsu Chemical Co., Ltd.) are dissolved in 480 parts of tetrahydrofuran and 120 parts of toluene to prepare a charge transport layer coating solution A. did.

Example 2
In Example 1, 35 parts of the compound of the following formula (9) (charge transport material 2) and 35 parts of the compound of the formula (6) were mixed instead of the compounds represented by the formulas (6) and (7). A photoconductor B was produced in the same manner as in Example 1 except that it was used.

Example 3
In Example 2, instead of the polycarbonate resin (PC1) represented by the formula (8), all except that the polycarbonate resin (PC2, viscosity average molecular weight 30,000) represented by the following formula (10) was used. In the same manner as in Example 2, a photoreceptor C was produced.

Example 4
In Example 1, in the same manner as in Example 1 except that 70 parts of the compound of formula (11) (charge transport material 4) was used instead of the compound represented by formulas (6) and (7). Photoconductor D was manufactured.

Example 5
In Example 3, instead of using a mixture of the compound represented by the formula (6) and the compound represented by the formula (9), 70 parts of the compound of the formula (11) (charge transport material 4) was used. A photoconductor E was manufactured in the same manner as in Example 3 except for the above.
Example 6
In Example 4, in place of the charge generation layer coating solution 1 instead of the charge generation layer coating solution 1, a photoconductor F was prepared in the same manner as in Example 4 except that the charge generation layer coating solution 2 prepared by the following method was used. Manufactured.

Charge generation layer coating solution 2
Bragg angles (2θ ± 0.2 °) 7.3 °, 9.5 °, 11.6 °, 14.2 °, 18.0 for CuKα characteristic X-rays (wavelength 1.541 mm) as shown in FIG. 20 parts of oxytitanium phthalocyanine (phthalocyanine 1) having main diffraction peaks at °, 24.3 ° and 27.2 ° and 280 parts of 1,2-dimethoxyethane are mixed and pulverized in a sand grind mill for 2 hours for atomization Distributed processing was performed. Subsequently, 253 parts of 1,2-dimethoxyethane was added to polyvinyl butyral (trade name “Denkabutyral” # 6000C, manufactured by Denki Kagaku Kogyo Co., Ltd.), and 4-methoxy-4-methyl-2-butylene. A charge generation layer coating solution 2 was prepared by mixing a binder solution obtained by dissolving pentanone in 85 parts of a mixed solution and 230 parts of 1,2-dimethoxyethane.

Example 7
In Example 6, instead of the polycarbonate resin (PC1) represented by Formula (8), the same procedure as in Example 6 was used except that the polycarbonate resin (PC2) represented by Formula (10) was used. Photoconductor G was manufactured.
Comparative Example 1
In Example 1, all except having used the polycarbonate resin (PC3, viscosity average molecular weight 30,000) represented by following formula (12) instead of the polycarbonate resin (PC1) represented by Formula (8). In the same manner as in Example 1, a photoreceptor H was produced.

Comparative Example 2
In Comparative Example 1, everything was the same as Comparative Example 1 except that 70 parts of the compound of formula (11) (charge transport material 4) was used instead of the compounds represented by formulas (6) and (7). Photoconductor I was manufactured.
Comparative Example 3
A photoconductor J was produced in the same manner as in Comparative Example 1 except that the charge generation layer coating solution 2 was used instead of the charge generation layer coating solution 1 in Comparative Example 1.
Table 1 below shows the photoreceptors produced in the examples.

Each of the obtained photoreceptors A to J is attached to an electrophotographic characteristic evaluation apparatus (manufactured by Mitsubishi Chemical Corporation) manufactured according to the Electrophotographic Society of Japan measurement standard, and electrical characteristics due to charging, exposure, potential measurement, and static elimination cycles. Was evaluated.
Each photoconductor was attached to an aluminum drum having an outer diameter of 80 mm, and the aluminum drum and the aluminum vapor deposition layer of the photoconductor were electrically connected to each other and rotated at a constant speed of 30 rpm. In an environment where the temperature is 25 ° C. and the humidity is 50%, the photosensitive member is charged so that the initial surface potential is −700 V, and the exposure is performed using a halogen lamp light converted to a monochromatic light of 400 nm by an interference filter. Was an exposure amount (hereinafter sometimes referred to as sensitivity) of −350 V and a surface potential (hereinafter referred to as VL) when exposed at a light amount of 1.0 μJ / cm ² . The sensitivity is an exposure amount necessary for the surface potential to be ½ of the initial potential, and the smaller the numerical value, the higher the sensitivity. Further, VL is a potential after exposure, and a smaller value is excellent in electrical characteristics. The time from exposure to potential measurement was 389 milliseconds. The residual potential (hereinafter referred to as Vr) after the neutralizing light irradiation was measured using 75 lux white light as the neutralizing light. The results are shown in Table 2 below.

  Next, these drums were subjected to a cross cut test of 1 mm square and 100 mm in accordance with JIS K5400 to evaluate the adhesive strength of the photosensitive layer. The results were evaluated in 4 grades from 0 (bad) to 3 (good). The obtained results are shown in Table 2.

  Both the examples and the comparative examples showed a high sensitivity and a low bright part potential when exposed to monochromatic light of 400 nm, but in the comparative photoreceptor using a binder resin outside the scope of the present invention, Since the adhesive strength is low, the photosensitive layer is expected to be damaged by contact with various members in the image forming apparatus. In particular, the photoreceptors H and I of Comparative Examples 1 and 2 in which a charge transport layer is formed on a charge generation layer using an azo pigment as a charge generation material have low adhesive strength, and charge using an azo pigment as a charge generation material It was found that the effect of the present invention is high when a charge transport layer is formed on the generation layer.

Example 8
The surface of a cylinder made of an aluminum alloy having an outer diameter of 30 mm, a length of 351 mm, and a wall thickness of 1.0 mm, which has a mirror-finished surface, is anodized and then sealed with a sealant mainly composed of nickel acetate. As a result, an anodic oxide coating (alumite coating) of about 6 μm was formed. Next, an anodized aluminum cylinder was dip-coated on the charge generation layer coating solution 3 prepared by the following method to prepare a charge generation layer so that the film thickness after drying was 0.6 μm. On this charge generation layer, a charge transport layer coating solution 2 prepared by the following method is dip-coated so that the film thickness after drying is 18 μm to form a charge transport layer, and a photosensitive layer having a laminated photosensitive layer. Body drum K was obtained.

Charge generation layer coating solution 3:
20 parts of the azo compound represented by the above formula (5) and 280 parts of 1,2-dimethoxyethane were mixed and pulverized with a sand grind mill for 4 hours for atomization dispersion treatment. Subsequently, 10 parts of polyvinyl butyral (trade name “Denkabutyral” # 6000C, manufactured by Denki Kagaku Kogyo Co., Ltd.) were added to 250 parts of 1,2-dimethoxyethane and 4-methoxy-4-methyl-2. -The charge generation layer coating solution 3 was prepared by mixing a binder solution obtained by dissolving pentanone in 85 parts of a mixture and 230 parts of 1,2-dimethoxyethane.

Charge transport layer coating solution 2:
70 parts of the charge generation material 4 represented by the above formula (11), 100 parts of the polycarbonate resin (PC1) represented by the above formula (8), 8 parts of the antioxidant having the following structure, and silicone as the leveling agent 0.05 parts of oil (trade name: KF96 manufactured by Shin-Etsu Chemical Co., Ltd.) was dissolved in 640 parts of a mixed solvent of tetrahydrofuran / toluene = 8/2 (mixed weight ratio) to prepare the charge transport layer coating solution 2.

Comparative Example 4
In Example 8, the photosensitive drum L was obtained in the same manner except that the polycarbonate resin (PC3) represented by the above formula (12) was used instead of PC1 as the binder resin for the charge transport layer coating solution. It was.
Next, the photosensitive drum K of the example was mounted on a black drum cartridge of a commercially available tandem type color printer (Microline 3050c manufactured by Oki Data Co.) that is compatible with A3 printing, and mounted on the printer. This printer has red LED exposure, but for the purpose of evaluating the peel strength of the photosensitive layer, a live-action evaluation was performed. Although 10,000 sheets of a 5% printed text document consisting only of black were printed (actually, the red LED light was not printed because it was not sensitive), no problems such as peeling of the photosensitive layer occurred.

On the other hand, when a similar test was performed on the photosensitive drum L of the comparative example, the photosensitive layer was peeled off from the end of the roller charger that was in contact, the electrophotographic photosensitive member was destroyed, and the image forming apparatus was stopped. .
From the above results, in the electrophotographic photosensitive member having a photosensitive layer containing the compound having the structure of the formula (2) according to the present invention, the layer is bonded with a polycarbonate resin having a repeating structure represented by the formula (1). It has been found that it has a particularly excellent mechanical strength when worn, and is particularly preferable when exposed to monochromatic light having a wavelength of 380 to 500 nm.

1 is a schematic diagram illustrating a main configuration of an embodiment of an image forming apparatus of the present invention. 2 is a powder X-ray diffraction pattern of oxytitanium phthalocyanine used in Example 1. FIG.

Explanation of symbols

1 Photoconductor 2 Charging device (charging roller)
DESCRIPTION OF SYMBOLS 3 Exposure apparatus 4 Developing apparatus 5 Transfer apparatus 6 Cleaning apparatus 7 Fixing apparatus 41 Developing tank 42 Agitator 43 Supply roller 44 Developing roller 45 Control member 71 Upper fixing member (fixing roller)
72 Lower fixing member (fixing roller)
73 Heating device T Toner P Recording paper

Claims (8)

In an electrophotographic photosensitive member having a photosensitive layer on a conductive support, the photosensitive layer comprises a polycarbonate resin having a repeating structure represented by the following formula (1) and a compound represented by the following formula (2). An electrophotographic photosensitive member, comprising:

(In Formula (1), R ¹ represents a hydrogen atom or an alkyl group, R ² and R ³ represent an alkyl group, and m and n represent an integer of 1 to 4.)

(Y in formula (2) Represents an alkylene group which may have a substituent, the substituents may be bonded to each other to form a ring, and Ar ¹ and Ar ² are each independently an alkylene which may have a substituent. Represents an arylene group which may have a group or a substituent, and Ar ^{3 to} Ar ⁶ may each independently have an alkyl group which may have a substituent or a substituent. Represents an aryl group. ) 2. The weight ratio of the compound represented by the formula (2) contained in the photosensitive layer to the total charge transporting substance contained in the photosensitive layer is 20% or more. The electrophotographic photosensitive member described. The electrophotographic photoreceptor according to claim 1, wherein Y in the formula (2) is a group represented by the following formula (3).

(In formula (3), R ⁴ and R ⁵ each independently represents a hydrogen atom, an alkyl group which may have a substituent, or an aryl group which may have a substituent.) The electrophotographic photoreceptor according to claim 3, wherein R ⁴ in the formula (3) is a group having at least one chiral center. The electrophotographic photoreceptor according to claim 4, wherein R ⁴ in the formula (3) is a group represented by the following formula (4) having a chiral center as a carbon atom.

(In the formula (4), R ⁶ ~R ⁸ each independently represent a hydrogen atom, an optionally substituted alkyl group, or may have a substituent group alkenyl group,, R ⁶ ~R ⁸ are different from each other.) The electrophotographic photosensitive member according to claim 1, wherein the photosensitive layer contains an azo pigment. The electrophotographic photosensitive member according to claim 1, a charging device that charges the electrophotographic photosensitive member, and an exposure device that exposes the charged electrophotographic photosensitive member to form an electrostatic latent image. And a developing device that develops the electrostatic latent image formed on the electrophotographic photosensitive member, wherein the charging device charges the electrophotographic photosensitive member when charging the electrophotographic photosensitive member. An image forming apparatus, wherein the image forming apparatus is disposed in contact with a photosensitive member. The electrophotographic photosensitive member according to any one of claims 1 to 6, a charging device for charging the electrophotographic photosensitive member, and the charged electrophotographic photosensitive member are exposed to monochromatic light in a range of 380 to 500 nm. An image forming apparatus comprising: an exposure device that forms an electrostatic latent image; and a developing device that develops the electrostatic latent image formed on the electrophotographic photosensitive member.

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