JP4982284B2 - Electrophotographic photoreceptor containing diamine compound and image forming apparatus having the same - Google Patents

Description

  The present invention relates to an electrophotographic photoreceptor containing a diamine compound and an image forming apparatus including the same.

2. Description of the Related Art An electrophotographic image forming apparatus (hereinafter also referred to as “electrophotographic apparatus”) that forms an image using electrophotographic technology is widely used in copying machines, printers, facsimile apparatuses, and the like.
In an electrophotographic apparatus, an image is formed through the following electrophotographic process. First, a photosensitive layer of an electrophotographic photosensitive member (hereinafter also referred to as “photosensitive member”) provided in the apparatus is charged and then exposed to form an electrostatic latent image. The formed electrostatic latent image is developed to form a toner image, and the formed toner image is transferred onto a transfer material such as recording paper and fixed to form a desired image on the transfer material.

  In recent years, electrophotographic technology has been used not only in the field of copying machines but also in the fields of printing plate materials, slide films, microfilms, and the like in which silver salt photographic technology has been conventionally used. For example, it is also applied to a high-speed printer using a laser, a light emitting diode (abbreviated as LED), a cathode ray tube (abbreviated as CRT), or the like as a light source. With the expansion of the application range of electrophotographic technology, the demand for photoreceptors is becoming advanced and wide.

Conventionally, inorganic photoreceptors having a photosensitive layer mainly composed of an inorganic photoconductive material such as selenium, zinc oxide or cadmium sulfide have been widely used as the photoreceptor.
Inorganic photoconductors have some basic characteristics as photoconductors, but have disadvantages such as difficulty in forming a photosensitive layer, poor plasticity, and high production costs. In addition, inorganic photoconductive materials are generally highly toxic and have significant limitations in manufacturing and handling.
As described above, since the inorganic photoconductive material and the inorganic photoreceptor using the inorganic photoconductive material have many drawbacks, research and development of the organic photoconductive material has been advanced.

In recent years, organic photoconductive materials have been widely researched and developed, and are not only used for electrostatic recording elements such as photoreceptors, but also have begun to be applied to sensor elements, organic electroluminescent (EL) elements, and the like. Yes.
Organic photoconductors using organic photoconductive materials have good film-forming properties, excellent flexibility, light weight, good transparency, and a wide wavelength range by appropriate sensitization methods. However, it has been gradually developed as the main force of the photoconductor because it has an advantage that a photoconductor showing good sensitivity can be easily designed.

  Organic photoreceptors initially had drawbacks in sensitivity and durability, but these drawbacks were the development of function-separated photoreceptors in which the charge generation function and charge transport function were shared by different substances. Is significantly improved. In addition to the above-mentioned advantages of the organic photoconductor, this function-separated type photoconductor also has the advantage that a wide range of materials can be selected for the photosensitive layer and a photoconductor having arbitrary characteristics can be produced relatively easily. Have.

  Such an organic photoreceptor has a single-layer structure in which both a charge generation material and a charge transport material (also referred to as “charge transfer material”) are dispersed in a binder resin on a support, and a charge on the support. Various configurations such as a stacked structure or a reverse two-layer stacked structure in which a charge generation layer in which a generated material is dispersed in a binder resin and a charge transport layer in which a charge transport material is dispersed in a binder resin are formed in this order or in reverse order Has been proposed. Among these, the functionally separated type photoconductor, in which a charge transport layer is laminated on the charge generation layer as the photosensitive layer, is excellent in electrophotographic characteristics and durability, and various characteristics of the photoconductor can be designed with a high degree of freedom in material selection. It is widely used because it can be done.

The charge generating materials used in these functionally separated photoreceptors include various materials such as phthalocyanine pigments, squarylium dyes, azo pigments, perylene pigments, polycyclic quinone pigments, cyanine dyes, squaric acid dyes, and pyrylium salt dyes. Various materials that have been studied and have high light resistance and high charge generation ability have been proposed.
As charge transport materials, various compounds such as pyrazoline compounds, hydrazone compounds, triphenylamine compounds, stilbene compounds, enamine compounds are known.

  Various performances such as higher speed, durability, and sensitivity stability are required for the photoreceptor having the configuration proposed or studied in this way. In particular, in response to reversal development type electrophotographic apparatuses such as recent digital copying machines and laser printers, high sensitivity corresponding to high speed as photoconductor characteristics and durability by improving wear resistance and sensitivity stability = Coexistence with long life is required. In addition, higher image reliability and repetitive stability are required for photoreceptors used in laser printers and the like.

However, it has been considered that one of the major disadvantages of these photoreceptors is that their durability is generally lower than that of inorganic photoreceptors. Durability is broadly divided into durability of electrophotographic physical properties such as sensitivity, residual potential, charging ability, and image blur, and mechanical durability such as abrasion and scratches on the surface of the photoreceptor due to rubbing. The main cause of the decrease in durability of electrophotographic physical properties is that ozone, NO _x (nitrogen oxide), etc. generated by corona discharge or deterioration of the charge transport material contained in the photoreceptor surface layer due to light irradiation. Are known. Many charge transport materials composed of various skeletons that have been proposed are also being improved considerably in terms of durability, but they are still not sufficient.

In addition, the photoreceptor is used repeatedly in the system, and always requires constant and stable electrophotographic characteristics. With respect to such stability and durability, the present situation is that a sufficient product has not been obtained in any configuration.
That is, the potential decreases, the residual potential increases, the sensitivity changes, and the like with repeated use, and the copy quality is lowered and cannot be used. All of these causes of degradation have not been elucidated, but there are several possible causes.

  For example, it has been found that oxidative gases such as ozone and nitrogen oxides emitted from a corona discharge charger cause significant damage to the photosensitive layer. These oxidizing gases chemically change the material in the photosensitive layer and cause various characteristic changes. For example, a decrease in charging potential, an increase in residual potential, and a decrease in resolving power due to a decrease in surface resistance. As a result, image blurring such as white spots and black bands occur on the output image, which significantly reduces image quality, It shortens the life of the body. For such a phenomenon, proposals to incorporate measures to efficiently exhaust and replace the gas around the corona charger to avoid direct gas influence on the photoreceptor, and antioxidants and stabilizers in the photosensitive layer There is also a proposal to prevent deterioration by adding.

  For example, JP-A-62-105151 (Patent Document 1) discloses that an antioxidant having a triazine ring and a hindered phenol skeleton in the molecule is added to the photosensitive layer, and JP-A-63-18355 ( Patent Document 2) discloses that a specific hindered amine is added to the photosensitive layer. JP-A 63-4238 (Patent Document 3), JP-A 63-216055 (Patent Document 4) and JP-A-3-172852 (Patent Document 5) disclose trialkylamines, aromatics. Japanese Patent Application Laid-Open No. 5-158258 (Patent Document 6) discloses adding an amine dimer to a photosensitive layer. However, these are still not sufficient. .

JP 62-105151 A JP-A-63-18355 Japanese Unexamined Patent Publication No. 63-4238 Japanese Patent Laid-Open No. 63-216055 JP-A-3-172852 JP-A-5-158258

  In other words, such a conventional technique has not yet achieved a sufficient effect of oxidizing gas resistance, and addition of such an antioxidant deteriorates electrophotographic characteristics such as sensitivity and residual potential. In reality, there are still problems that are insufficient for practical use. Therefore, there is a need for a new material proposal that improves the resistance to oxidation gas and has no adverse effect on electrophotographic characteristics.

  Therefore, the present invention provides a novel diamine compound that can be used to provide a photoreceptor excellent in oxidation-resistant gas resistance and having no adverse effects on other characteristics, and an image forming apparatus including the same. The task is to do.

  As a result of intensive studies, the present inventors have unexpectedly added a specific diamine compound to the undercoat layer provided between the conductive support constituting the photoreceptor and the photosensitive layer. It exerts a strong inhibitory effect on the oxidation of the photosensitive layer by oxidizing gases such as ozone, and maintains the electrical characteristics such as chargeability, sensitivity and responsiveness, while maintaining the oxidation resistance of the electrophotographic photoreceptor. The present inventors have found that it can be improved and have completed the present invention.

Thus, according to the present invention, on a conductive support made of a conductive material, an undercoat layer, a monolayer type photosensitive layer containing a charge generation material and a charge transport material, or a charge containing a charge generation material. A photoconductor in which a generation layer and a charge transport layer containing a charge transport material are stacked in this order are stacked in this order, and the single layer type photosensitive layer or the stacked type photosensitive layer. The charge transport layer of the layer contains an oxidation-resistant gas additive, and the subbing layer comprises:
General formula (1):

[Where:
Ar ¹ , Ar ² , Ar ³ and Ar ⁴ are the same or different and each may have an aryl group which may have a substituent, a cycloalkyl group which may have a substituent, or a hetero which may have a substituent. A monovalent heterocyclic residue optionally having an atom-containing cycloalkyl group or a substituent;
Y ¹ , Y ² , Y ³ , Y ⁴ , Y ⁵ and Y ⁶ are the same or different and are a chain alkylene group which may have a substituent;
Z is i) —Ar ⁵ —Ar ⁶ — or ii) —Ar ⁵ —W—Ar ⁶ — (wherein Ar ⁵ and Ar ⁶ are the same or different and may have a substituent) Or a divalent heterocyclic residue which may have a substituent; W is a cycloalkylidene group which may have a substituent, or a chain or branched alkylene group which may have a substituent An oxygen atom or a sulfur atom)
A photoconductor comprising a diamine compound represented by the formula: is provided.

According to the present invention, the above-mentioned photoconductor, a charging unit for charging the photoconductor, an exposure unit for exposing the charged photoconductor, and an electrostatic latent image formed by the exposure are provided. An image forming apparatus including a developing unit for developing is provided.
The numbering of substituents in the chemical formulas described in this specification includes upper left and upper right letters, but these are the same. For example, “ ¹ Ar” and “Ar ¹ ” represent the same substituent.

By including any of the diamine compounds of the present invention in the undercoat layer, it is possible to provide a photoreceptor that is excellent in oxidation-resistant gas resistance and at the same time excellent in durability and environmental stability.
In particular, the photoreceptor of the present invention exhibits the above effect even in an oxidizing gas concentration atmosphere such as ozone that reaches the undercoat layer.
Further, even when the photoreceptor of the present invention is used in a high-speed electrophotographic process, it can provide a high-quality image due to its excellent oxidation-resistant gas resistance effect.
Therefore, by using the photoconductor according to the present invention, it is possible to form a high-quality image excellent in oxidation resistance gas resistance even if it is repeatedly used over a long period of time.

In addition, since the photoreceptor according to the present invention contains the diamine compound according to the present invention in the surface protective layer, it is excellent in the effect of oxidation-resistant gas, and is excellent in terms of the resting memory phenomenon of the photoreceptor due to the longer life of the photoreceptor. ing.
Therefore, the image forming apparatus according to the present invention can stably form a high-quality image free from image defects over a long period of time under various environments.
Further, since the photoconductor according to the present invention can provide a high-quality image even in a high-speed electrophotographic process, the image forming apparatus according to the present invention can increase the image forming speed.

  The photoreceptor of the present invention is a single-layer type photosensitive layer containing a charge generating material and a charge transport material on a conductive support made of a conductive material, or a charge generation layer and a charge transport material containing a charge generation material. A photosensitive layer formed by laminating a charge-transporting layer containing a photoconductive layer and a surface protective layer in this order, the monolayer-type photosensitive layer or the multi-layered photosensitive layer. The charge transport layer contains an oxidation-resistant gas additive, and the surface protective layer contains a diamine compound represented by the general formula (1).

Among such diamine compounds of the general formula (1), points such as chemical stability such as decomposition or alteration as chemical substances, easy availability of raw materials, ease of production and high yield, and production cost A diamine compound in which Y ¹ , Y ² , Y ³ and Y ⁴ in the general formula (1) are chain alkylene groups, that is, the sub-formula (2):

（式中、Ａｒ¹、Ａｒ²、Ａｒ³、Ａｒ⁴、Ｙ⁵、Ｙ⁶およびＺは、一般式（１）と同義であり；ｎ、ｍ、ｌおよびｐは、同一または異なって１〜３の整数である）のジアミン化合物が好ましく、一般式（１）のＹ¹、Ｙ²、Ｙ³、Ｙ⁴、Ｙ⁵およびＹ⁶が鎖状のメチレン基であるジアミン化合物、すなわち副式（３）：

(In the formula, Ar ¹ , Ar ² , Ar ³ , Ar ⁴ , Y ⁵ , Y ⁶ and Z are as defined in the general formula (1); n, m, l and p are the same or different and A diamine compound in which Y ¹ , Y ² , Y ³ , Y ⁴ , Y ⁵ and Y ^{6 in} the general formula (1) are chain methylene groups, that is, the sub-formula ( 3):

（式中、Ａｒ¹、Ａｒ²、Ａｒ³、Ａｒ⁴、Ａｒ⁵およびＡｒ⁶は、一般式（１）と同義である）
で示されるジアミン化合物が特に好ましい。

(In the formula, Ar ¹ , Ar ² , Ar ³ , Ar ⁴ , Ar ⁵ and Ar ⁶ have the same meanings as those in the general formula (1)).
A diamine compound represented by is particularly preferred.

The substituents in the general formula (1), sub formula (2) and sub formula (3) will be described.
Examples of the aryl group that may have a substituent of Ar ¹ , Ar ² , Ar ^3, and Ar ⁴ include, for example, an alkyl group having 1 to 4 carbon atoms, an alkoxy group having 1 to 4 carbon atoms, and 2 to 6 carbon atoms. Examples thereof include an aryl group optionally substituted with a dialkylamino group or a halogen atom.
Specifically, phenyl group, o-tolyl group, 2,4-xylyl group, 4-methoxyphenyl group, 3-methoxy-4-methylphenyl group, t-butylphenyl group, 4-diethylaminophenyl group, 4- A chlorophenyl group, a 4-fluorophenyl group, a 1-naphthyl group, a 2-naphthyl group, etc. are mentioned. Among these, a phenyl group, an o-tolyl group, a 4-methoxyphenyl group, a 1-naphthyl group, a 2-naphthyl group Is particularly preferred.

Examples of the cycloalkyl group which may have a substituent of Ar ¹ , Ar ² , Ar ³ and Ar ⁴ include a cycloalkyl group which may be substituted with an alkyl group having 1 to 4 carbon atoms.
Specific examples include a cyclohexyl group, a cyclopentyl group, a 4,4-dimethylcyclohexyl group, and among these, a cyclohexyl group is particularly preferable.

Examples of the hetero atom-containing cycloalkyl group which may have a substituent for Ar ¹ , Ar ² , Ar ³ and Ar ⁴ include a tetrahydrofuryl group and a tetramethyltetrahydrofuryl group.

As the monovalent heterocyclic residue which may have a substituent of Ar ¹ , Ar ² , Ar ³ and Ar ⁴ , for example, a monovalent complex which may be substituted with an alkyl group having 1 to 4 carbon atoms. A ring residue is mentioned.
Specific examples include a furyl group, a 4-methylfuryl group, a benzofuryl group, and a benzothiophenyl group. Among these, a furyl group and a benzofuryl group are particularly preferable.

The chain alkylene group which may have a substituent of Y ¹ , Y ² , Y ³ , Y ⁴ , Y ⁵ and Y ⁶ may be substituted with, for example, an alkyl group having 1 to 4 carbon atoms. An alkylene group is mentioned.
Specific examples include a methylene group, an ethylene group, a propylene group, and a 2,2-dimethylpropylene group. Among these, a methylene group and an ethylene group are particularly preferable.

Examples of the arylene group which may have a substituent for Ar ⁵ and Ar ⁶ in Z include an arylene group which may be substituted with an alkyl group having 1 to 4 carbon atoms or an alkoxy group having 1 to 4 carbon atoms. It is done.
Specific examples include p-phenylene group, m-phenylene group, methyl-p-phenylene group, methoxy-p-phenylene group, 1,4-naphthylene group, benzoxazolen group, biphenylylene group, and the like. Among them, p-phenylene group, m-phenylene group, methyl-p-phenylene group, methoxy-p-phenylene group and 1,4-naphthylene group are preferable, and p-phenylene group and 1,4-naphthylene group are particularly preferable. .

Examples of the divalent heterocyclic residue optionally having a substituent for Ar ⁵ and Ar ⁶ in Z include a 1,4-furandiyl group, a 1,4-thiophenediyl group, and a 2,5-benzofurandyl group. 2,5-benzoxazolediyl group and N-ethylcarbazole-3,6-diyl group.

Examples of the cycloalkylidene group which may have a substituent of W in Z include a cycloalkylidene group which may be substituted with an alkyl group having 1 to 4 carbon atoms.
Specific examples include a cyclopentylidene group, a cyclohexylidene group, and a 4,4-dimethylcyclohexylidenyl group.

Examples of the chain or branched alkylene group which may have a substituent include an alkylene group which may be substituted with an alkyl group having 1 to 4 carbon atoms.
Specific examples include a methylene group, an ethylene group, a trimethylene group, and a 2,2-dimethyltrimethylene group. Among these, a methylene group and an ethylene group are particularly preferable.

Specific examples of the diamine compound of the present invention are shown in Table 1.
In Tables 1-1 to 1-4, the substituents are represented by the following abbreviations.
-Me-: methylene group -Et-: ethylene group -Tr-: trimethylene group -Dm-: 2,2-dimethyltrimethylene group

で示されるジアミン化合物が特に好ましい。 Among these diamine compounds, the structural formula (I):

A diamine compound represented by is particularly preferred.

  The diamine compound of the present invention can be produced by the method shown in the following reaction scheme. That is, by heating the amine compound represented by the general formula (4) and the general formula (5) and the dihalogen compound represented by the general formula (6) in the presence of an organic amine base, the yield can be easily increased. The target product can be produced with high purity.

（式中、Ａｒ¹、Ａｒ²、Ａｒ³、Ａｒ⁴、Ｙ¹、Ｙ²、Ｙ³、Ｙ⁴、Ｙ⁵、Ｙ⁹およびＺは、一般式（１）と同義であり；Ｘ¹およびＸ²はハロゲン原子を示す）
反応式におけるＸ¹およびＸ²のハロゲン原子としては、塩素原子、臭素原子、ヨウ素原子が挙げられ、これらの中でも、塩素原子、臭素原子が特に好ましい。 [Reaction formula]

(In the formula, Ar ¹ , Ar ² , Ar ³ , Ar ⁴ , Y ¹ , Y ² , Y ³ , Y ⁴ , Y ⁵ , Y ⁹ and Z have the same meanings as in the general formula (1); X ¹ and X ² represents a halogen atom)
Examples of the halogen atom of X ¹ and X ² in the reaction formula include a chlorine atom, a bromine atom, and an iodine atom, and among these, a chlorine atom and a bromine atom are particularly preferable.

The reaction of the above reaction formula can be carried out, for example, as follows.
The secondary amine compounds (4) and (5) and the dihalogen compound (6) are dissolved or dispersed in a solvent, an organic amine base is added thereto, and the mixture is heated and stirred. After completion of the reaction, the precipitate is filtered off and recrystallized in ethanol, methanol, ethyl acetate or the like alone or in a mixed solvent system, whereby the target product can be obtained easily and with high purity in high yield.

The solvent is not particularly limited as long as it is inert to the above reaction and can dissolve or disperse the reaction substrate and the organic amine base. Specifically, aromatic hydrocarbons such as toluene and xylene; ethers such as diethyl ether, tetrahydrofuran, ethylene glycol dimethyl ether and 1,4-dioxane; amides such as N, N-dimethylformamide; dimethyl sulfoxide and the like Examples thereof include sulfoxides, and these can be used alone or as a mixed solvent.
The amount of the solvent used is not particularly limited, and the amount by which the reaction smoothly proceeds may be appropriately set according to the reaction conditions such as the amount of the reaction substrate used, the reaction temperature, and the reaction time.
Examples of the organic amine base include N, N-diisopropylethylamine, N, N-dimethylaminopyridine, 1,4-diazabicycloundecene and the like.

The ratio of the secondary amine compounds (4) and (5) to the dihalogen compound (6) is not particularly limited.
For example, when a symmetric compound is obtained (when either one of the secondary amine compounds (4) and (5) is used), 1 equivalent of the dihalogen compound (6) in consideration of the efficiency of the reaction. The secondary amine compound is preferably used in an amount of about 2.0 to 2.3 equivalents.
In addition, when obtaining an asymmetric compound (when using both the secondary amine compounds (4) and (5)), the reaction efficiency and the like are taken into consideration with respect to 1 equivalent of the dihalogen compound (6). Each secondary amine compound is preferably used in an amount of about 1.0 to 1.2 equivalents (the total of the secondary amine compounds (4) and (5) is about 2.0 to 2.4 equivalents).

The use ratio of the dihalogen compound (6) and the organic amine base is not particularly limited, but considering the reaction efficiency and the like, the organic amine base is used in an amount of 2. with respect to 1 equivalent of the dihalogen compound (6). It is preferable to use about 05 to 5.0 equivalents.
The heating temperature and reaction time are not particularly limited, but it is preferable to react at 60 to 120 ° C. for 2 to 8 hours, depending on the solvent used in consideration of the efficiency of the reaction.

  The diamine compound of the present invention is excellent in oxidation resistance gas resistance. Therefore, the photoreceptor containing the diamine compound of the present invention in the undercoat layer has excellent electrophotographic characteristics, is hardly affected by ozone and nitrogen oxides generated from the system, and has stable characteristics even after repeated use. It has image quality and can achieve extremely high durability.

Next, the configuration of the photoreceptor of the present invention will be specifically described.
1 to 4 are schematic cross-sectional views showing the configuration of the main part of the photoreceptor of the present invention.
FIGS. 1 and 2 are schematic cross-sectional views showing the configuration of the main part of a single-layer type photoreceptor that is a single-layer type photosensitive layer having a single photosensitive layer.
3 and 4 show a multilayer photosensitive body (hereinafter referred to as “function-separated type photosensitive layer”) in which the photosensitive layer is a layered photosensitive layer (hereinafter also referred to as “function-separated type photosensitive layer”) composed of a charge generation layer and a charge transport layer. FIG. 2 is a schematic cross-sectional view illustrating a configuration of a main part of the body. The photoreceptor of the present invention may have a reverse two-layered laminated structure in which a charge generating layer and a charge transporting layer are formed in reverse order, but the laminated type is preferred.

1 has an undercoat layer 6 and a single-layer type photosensitive layer 2 formed in this order on the surface of a conductive support 1.
2, the undercoat layer 6, the single-layer type photosensitive layer 2, and the surface protective layer 5 are formed on the surface of the conductive support 1 in this order.
The photoreceptor 17 in FIG. 3 has an undercoat layer 6, and a laminated photosensitive layer 7 in which the charge generation layer 3 and the charge transport layer 4 are laminated in this order on the surface of the conductive support 1. Is formed.
4 includes an undercoat layer 6, a stacked photosensitive layer 7 in which the charge generation layer 3 and the charge transport layer 4 are stacked in this order on the surface of the conductive support 1, and a surface protective layer. 5 are formed in this order.

[Conductive support 1 (photosensitive element tube)]
The constituent material of the conductive support is not particularly limited as long as it is a material used in this field.
Specifically, metallic materials such as aluminum, aluminum alloys, copper, zinc, stainless steel, titanium: substrate surface made of polymer materials such as polyethylene terephthalate, polyamide, polyester, polyoxymethylene, polystyrene, hard paper, glass, etc. And metal foil laminated, metal material deposited, conductive polymer, tin oxide, indium oxide or other conductive compound layer deposited or applied.

The shape of the conductive support is not limited to a sheet shape as shown in FIGS. 1 to 8, and may be a cylindrical shape, a columnar shape, an endless belt shape, or the like.
If necessary, the surface of the conductive support 1 is irregularly reflected within a range that does not affect the image quality, such as anodized film treatment, surface treatment with chemicals, hot water, coloring treatment, or roughening the surface. It may be processed.

  The irregular reflection treatment is particularly effective when the photoreceptor according to the present invention is used in an electrophotographic process using a laser as an exposure light source. That is, in the electrophotographic process using a laser as an exposure light source, the wavelength of the laser beam is uniform, so the laser beam reflected on the surface of the photoconductor and the laser beam reflected inside the photoconductor cause interference, Interference fringes due to this interference may appear in the image and cause image defects. Therefore, by performing irregular reflection processing on the surface of the conductive support, it is possible to prevent image defects due to interference of laser light having a uniform wavelength.

[Single-layer type photosensitive layer 2]
The single-layer type photosensitive layer contains a charge generation material, a charge transport material, an oxidation-resistant gas additive, and a binder resin.
A single-layer type photoreceptor having a single-layer type photosensitive layer is suitable as a photoreceptor for a positively charged image forming apparatus that generates less ozone, and has a lower manufacturing cost and a step than a multilayer photoreceptor having a multilayer-type photosensitive layer. It is excellent in Toru.

The charge generation material has an ability to generate charges by absorbing light.
As the charge generation material, a compound used in this field can be used.
Specifically, azo pigments (monoazo pigments, bisazo pigments, trisazo pigments, etc.), indigo pigments (indigo, thioindigo, etc.), perylene pigments (perylene imide, perylene acid anhydride, etc.), polycyclic quinone pigments Pigments (anthraquinone, pyrenequinone, etc.), phthalocyanine pigments (metal phthalocyanine, X-type metal-free phthalocyanine, etc.), organic pigments or dyes such as squarylium dyes, pyrylium salts, thiopyrylium salts, triphenylmethane dyes, selenium, amorphous Examples thereof include inorganic materials such as silicon. These charge generating materials can be used alone or in combination of two or more.

Among these charge generation materials, phthalocyanine pigments such as metal phthalocyanine and X-type metal-free phthalocyanine are preferable, and oxotitanium phthalocyanine is particularly preferable.
Since phthalocyanine pigments have high charge generation efficiency and charge injection efficiency, they generate a large amount of charge by absorbing light, and in the single layer type photosensitive layer without accumulating the generated charge in the molecule. Since charges are efficiently injected into the contained charge transport material and smoothly transported, a highly sensitive and high resolution photoreceptor can be obtained. This effect is the same for the laminated type photoconductor described later.

Charge generating materials can be used in combination with sensitizing dyes.
Examples of such sensitizing dyes include triphenylmethane dyes typified by methyl violet, crystal violet, knight blue and victoria blue; acridines typified by erythrosine, rhodamine B, rhodamine 3R, acridine orange and frappeosin. Dyes; thiazine dyes typified by methylene blue and methylene green; oxazine dyes typified by capri blue and meldra blue; cyanine dyes; styryl dyes; pyrylium salt dyes and thiopyrylium salt dyes.

The charge transport material has an ability to accept and transport charges generated by the charge generation material, and includes a hole transport material and an electron transport material.
As the hole transport material, a compound used in this field can be used.
Specifically, carbazole derivatives, pyrene derivatives, oxazole derivatives, oxadiazole derivatives, thiazole derivatives, thiadiazole derivatives, triazole derivatives, imidazole derivatives, imidazolone derivatives, imidazolidine derivatives, bisimidazolidine derivatives, styryl compounds, hydrazone compounds, many Ring aromatic compounds, indole derivatives, pyrazoline derivatives, oxazolone derivatives, benzimidazole derivatives, quinazoline derivatives, benzofuran derivatives, acridine derivatives, phenazine derivatives, aminostilbene derivatives, triarylamine derivatives, triarylmethane derivatives, phenylenediamine derivatives, stilbene derivatives , Enamine derivatives, benzidine derivatives, polymers having groups derived from these compounds in the main chain or side chain (Polymers) -N- vinylcarbazole, poly-1-vinylpyrene, ethylcarbazole - formaldehyde resins, triphenylmethane polymers, poly-9-vinyl anthracene, etc.), etc. polysilane and the like.

Moreover, as an electron transport substance, the compound used in the said field | area can be used.
Specifically, organic compounds such as benzoquinone derivatives, tetracyanoethylene derivatives, tetracyanoquinodimethane derivatives, fluorenone derivatives, xanthone derivatives, phenanthraquinone derivatives, phthalic anhydride derivatives, diphenoquinone derivatives, amorphous silicon, amorphous selenium, Examples include inorganic materials such as tellurium, selenium-tellurium alloy, cadmium sulfide, antimony sulfide, zinc oxide, and zinc sulfide. These charge transport materials can be used alone or in combination of two or more.

  As the binder resin, for example, a resin having a binding property used in this field can be used for the purpose of improving the mechanical strength, durability, etc. of the single-layer type photosensitive layer, and the diamine compound of the present invention can be used. Those having excellent compatibility are preferred.

  Specifically, vinyl resins such as polymethyl methacrylate, polystyrene, polyvinyl chloride, polycarbonate, polyester, polyester carbonate, polysulfone, polyarylate, polyamide, methacrylic resin, acrylic resin, polyether, polyacrylamide, polyphenylene oxide, etc. Thermoplastic resin: Thermosetting resin such as phenoxy resin, epoxy resin, silicone resin, polyurethane, phenol resin, alkyd resin, melamine resin, phenoxy resin, polyvinyl butyral, polyvinyl formal, partially cross-linked products of these resins, these resins Copolymer resins containing two or more of the structural units contained in (vinyl chloride-vinyl acetate copolymer resin, vinyl chloride-vinyl acetate-maleic anhydride copolymer resin, acrylo Tolyl - insulating resin such as styrene copolymer resin). These binder resins can be used alone or in combination of two or more.

Among these resins, polystyrene, polycarbonate, polyarylate, and polyphenylene oxide are particularly excellent in compatibility with the diamine compound of the present invention, and further have a volume resistance of 10 ¹³ Ω or more, excellent electrical insulation, and composition. Polycarbonate is particularly preferred because it is excellent in film properties, potential characteristics, and the like.

In addition, the single-layer type photosensitive layer contains an additive such as an antioxidant (oxidation-resistant gas additive) used in this field. Such an additive is preferable because the stability as a coating solution for forming a photosensitive layer is increased and the life of the solution is extended, and the photoreceptor produced with the coating solution is also reduced in oxidizing impurities and improved in durability.
Examples of the antioxidant include hindered phenol derivatives and hindered amine derivatives.

The use ratio of the antioxidant is not particularly limited, but the ratio A / TB between the weight A of the antioxidant and the total weight TB of the charge transport material and the binder resin is the weight J of the diamine compound in the surface protective layer described later. And the ratio J / B of the weight B of the binder resin is preferably lower.
The amount of the antioxidant used is more preferably 0.1 to 10 parts by weight with respect to 100 parts by weight of the charge transport material. When the amount of the antioxidant used is less than 0.1 parts by weight, the effect of improving the stability of the coating solution for forming a photosensitive layer described later and the durability of the photoreceptor may be insufficient. On the other hand, if the ratio A / TB is higher than the ratio J / B or exceeds 10 parts by weight, the electrical characteristics of the photoreceptor may be adversely affected.

  The single-layer type photosensitive layer 2 is formed by dissolving or dispersing a charge generating substance, a charge transporting substance, an oxidation-resistant gas additive and a binder resin, and other additives as required in an appropriate organic solvent. A coating solution is prepared, and this coating solution is applied to the surface of the conductive support 1 or to the surface of the undercoat layer 6 formed on the conductive support 1, and then dried to remove the organic solvent. Can be formed. More specifically, for example, a coating solution for forming a single-layer photosensitive layer is prepared by dissolving or dispersing a constituent material in a resin solution obtained by dissolving a binder resin in an organic solvent.

  Examples of the organic solvent include aromatic hydrocarbons such as benzene, toluene, xylene, mesitylene, tetralin, diphenylmethane, dimethoxybenzene, and dichlorobenzene; halogenated hydrocarbons such as dichloromethane, dichloroethane, and tetrachloropropane; tetrahydrofuran (THF) , Ethers such as dioxane, dibenzyl ether, dimethoxymethyl ether and 1,2-dimethoxyethane; ketones such as methyl ethyl ketone, cyclohexanone, acetophenone and isophorone; esters such as methyl benzoate, ethyl acetate and butyl acetate, diphenyl sulfide Sulfur-containing solvents such as: Fluorinated solvents such as hexafluoroisopropanol; non-protons such as N, N-dimethylformamide and N, N-dimethylacetamide Such as a polar solvent and the like, which may be used alone or as a mixed solvent. A mixed solvent obtained by adding alcohols, acetonitrile, or methyl ethyl ketone to such a solvent can also be used.

Prior to dissolving or dispersing the constituent materials in the resin solution, the charge generating material and other additives may be pre-ground.
The preliminary pulverization can be performed using, for example, a general pulverizer such as a ball mill, a sand mill, an attritor, a vibration mill, or an ultrasonic disperser.
The dissolution or dispersion of the constituent materials in the resin solution can be performed using, for example, a general disperser such as a paint shaker, a ball mill, or a sand mill. At this time, it is preferable to appropriately set the dispersion condition so that impurities are generated from the container and the members constituting the disperser due to wear and the like and are not mixed into the coating liquid.
Examples of the coating method of the single layer type photosensitive layer forming coating solution include roll coating, spray coating, blade coating, ring coating, and dip coating.

  Although the film thickness of a single layer type photosensitive layer is not specifically limited, 5-100 micrometers is preferable and 10-50 micrometers is especially preferable. If the film thickness of the single-layer type photosensitive layer is less than 5 μm, the charge holding ability on the surface of the photoreceptor may be lowered. Conversely, if the film thickness of the single-layer type photosensitive layer exceeds 100 μm, the productivity of the photoreceptor is reduced. There is a risk.

[Laminated Photosensitive Layer 7]
The laminated photosensitive layer is composed of a charge generation layer 3 and a charge transport layer 4.

[Charge generation layer 3]
The charge generation layer 3 contains a charge generation material and a binder resin.
As the charge generation material, one or more of the same charge generation materials as those contained in the single-layer type photosensitive layer can be used.
As the binder resin, one or more of the same binder resins as those contained in the single-layer type photosensitive layer can be used.
The use ratio of the charge generation material and the binder resin is not particularly limited. Preferably, the charge generation material is contained in an amount of 10 to 99% by weight in the total amount of the charge generation material and the binder resin, and the balance is the binder resin. It is.
If the ratio of the charge generation material is less than 10% by weight, the sensitivity may be lowered. Conversely, if the ratio of the charge generation material exceeds 99% by weight, not only the film strength of the charge generation layer is decreased, but also the charge generation. This is called a black spot where the dispersibility of the substance decreases and the coarse particles increase, the surface charge other than that which should be erased by exposure decreases, and image defects, especially toner adheres to the white background and minute black spots are formed. There is a possibility that a lot of fogging of the image occurs.

  In addition to the two essential components, the charge generation layer may be one or more selected from a hole transport material, an electron transport material, an antioxidant, a dispersion stabilizer, a sensitizer, and the like, if necessary. Each may contain an appropriate amount. As a result, the potential characteristics are improved, the stability of the coating solution for forming a charge generation layer, which will be described later, is increased, fatigue deterioration during repeated use of the photoreceptor is reduced, and durability can be improved.

The charge generation layer 3 is prepared by dissolving or dispersing a charge generation material, a binder resin and, if necessary, other additives in an appropriate organic solvent to prepare a coating solution for forming a charge generation layer. It can be formed by applying to the surface of the body 1 or the surface of the undercoat layer 6 formed on the conductive support 1, and then drying to remove the organic solvent. More specifically, for example, a charge generating layer forming coating solution is prepared by dissolving or dispersing a charge generating substance and other additives as required in a resin solution obtained by dissolving a binder resin in an organic solvent. To do.
Other processes and conditions are in accordance with the formation of the single-layer type photosensitive layer.
The organic solvent can use 1 type (s) or 2 or more types of the same solvent as what is used for preparation of the coating liquid for formation of a single layer type photosensitive layer.

  The thickness of the charge generation layer 3 is not particularly limited, but is preferably 0.05 to 5 μm, and particularly preferably 0.1 to 1 μm. This is because if the film thickness of the charge generation layer is less than 0.05 μm, the efficiency of light absorption may be reduced and the sensitivity may decrease. Conversely, if the film thickness of the charge generation layer exceeds 5 μm, In this case, the charge transport in this process becomes a rate-determining step in the process of erasing the charge on the surface of the photoreceptor, and the sensitivity may be lowered.

[Charge transport layer 4]
The charge transport layer 4 contains a charge transport material, an oxidation-resistant gas additive, and a binder resin.
As the charge transport material, one or more of the same charge transport materials as those contained in the single-layer type photosensitive layer can be used.
As the binder resin, one or more of the same binder resins as those contained in the single-layer type photosensitive layer can be used.
As the oxidation-resistant gas additive, one or more of the same antioxidants as those contained in the single-layer type photosensitive layer can be used.
The use ratio of the charge generation material and the binder resin is the same as that of the single-layer type photosensitive layer.
The charge transport layer may contain the same additives as those contained in the single-layer type photosensitive layer, if necessary, in addition to the three essential components.

The charge transport layer 4 is prepared by dissolving or dispersing a charge transport material, an oxidation-resistant gas additive, a binder resin and other additives as required in an appropriate organic solvent to prepare a coating solution for forming a charge transport layer. The coating liquid can be applied to the surface of the charge generation layer 3 and then dried to remove the organic solvent. More specifically, for example, the charge transport layer is prepared by dissolving or dispersing the charge transport material, the diamine compound of the present invention and, if necessary, other additives in a resin solution obtained by dissolving a binder resin in an organic solvent. A forming coating solution is prepared.
Other processes and conditions are in accordance with the formation of the single-layer type photosensitive layer.

  The thickness of the charge transport layer 4 is not particularly limited, but is preferably 5 to 50 μm, and particularly preferably 10 to 40 μm. If the thickness of the charge transport layer is less than 5 μm, the charge holding ability on the surface of the photoreceptor may be lowered. Conversely, if the thickness of the charge transport layer exceeds 50 μm, the resolution of the photoreceptor may be lowered.

[Surface protective layer 5]
The surface protective layer 5 has a function of improving the durability of the photoreceptor and contains a binder resin.
As the binder resin, one or more of the same binder resins as those contained in the single-layer type photosensitive layer can be used.
In addition to the two essential components, the surface protective layer can contain additives such as charge transport materials, antioxidants and fillers similar to those contained in the single-layer type photosensitive layer, if necessary. .
As the charge transport material, one or more of the same charge transport materials as those contained in the single-layer type photosensitive layer can be used.

The surface protective layer 5 is prepared by, for example, preparing a coating solution for forming a surface protective layer by dissolving or dispersing a binder resin or the like in an appropriate organic solvent, and applying the coating solution for forming the surface protective layer to the single-layer photosensitive layer 2 or the laminated layer. It can be formed by applying to the surface of the mold photosensitive layer 7 and removing the organic solvent by drying. As the organic solvent used here, the same organic solvent used for forming the photosensitive layer 2 can be used.
Other processes and conditions are in accordance with the formation of the single-layer type photosensitive layer.
The organic solvent can use 1 type (s) or 2 or more types of the same solvent as what is used for preparation of the coating liquid for formation of a single layer type photosensitive layer.

  The thickness of the surface protective layer 5 is not particularly limited, but is preferably 0.5 to 10 μm, and particularly preferably 1 to 5 μm. If the thickness of the surface protective layer 5 is less than 0.5 μm, the surface resistance of the photoreceptor is inferior and the durability may be insufficient. Conversely, if it exceeds 10 μm, the resolution of the photoreceptor may be reduced. There is.

[Undercoat layer (intermediate layer) 6]
The undercoat layer (also referred to as “intermediate layer”) has a function of preventing the injection of charges from the conductive support to the single-layer type photosensitive layer or the multilayer type photosensitive layer. That is, the decrease in chargeability of the single-layer type photosensitive layer or the multilayer type photosensitive layer is suppressed, the decrease in surface charge other than the portion to be erased by exposure is suppressed, and the occurrence of image defects such as fog is prevented. In particular, during image formation by the reversal development process, it is possible to prevent the occurrence of image fogging called black spots in which minute black dots made of toner are formed on a white background portion.
In addition, the undercoat layer reduces the degree of unevenness, which is a defect on the surface of the conductive support, and makes the surface uniform, improving the film formability of the single-layer type photosensitive layer or the multilayer type photosensitive layer, and the conductive support. And the adhesion between the single layer type photosensitive layer and the multilayer type photosensitive layer can be improved.

The diamine compound of the present invention contained in the undercoat layer functions as an antioxidant.
Antioxidants usually prevent the photosensitive layer from being oxidized by oxidizing gases such as ozone and nitrogen oxides generated in the charging process, and suppress fatigue deterioration of the photoreceptor. Added to the layer and / or the charge generation layer. However, when an antioxidant is added to the charge transport layer, electrical characteristics such as chargeability, sensitivity, and responsiveness are deteriorated, resulting in a problem that electrical characteristics sufficient for practical use cannot be obtained from the beginning of use. In addition, since the charge generation layer is as thin as about 0.05 to 5 μm, there is a limit to the amount of addition of the antioxidant, and when a large amount of antioxidant is added, the generation of charges by the charge generation material is inhibited and the sensitivity is increased. May decrease.

In the photoreceptor of the present invention, an undercoat layer is provided between a conductive support and a single layer type or a laminate type photosensitive layer, and the undercoat layer 12 contains the diamine compound of the present invention. The undercoat layer functions as a barrier layer that suppresses the flow of charges from the conductive support to the photosensitive layer, and contributes little to charge transport and charge generation in the photoreceptor. For this reason, compared with the case where the diamine compound of this invention is added to a photosensitive layer, electrical characteristics, such as charging property, a sensitivity, and a response, can be made favorable.
Further, by adding the diamine compound of the present invention to the undercoat layer, it is possible to select a material constituting the photosensitive layer from a wide range, so that a photoreceptor having arbitrary characteristics can be easily produced. , Production efficiency can be improved. In addition, manufacturing costs can be reduced.

Since the undercoat layer is a layer below the photosensitive layer and is not exposed to an oxidizing gas, even if an antioxidant is added to the undercoat layer, the fatigue deterioration of the photoreceptor due to the oxidizing gas may not be sufficiently suppressed. There is sex. However, when the diamine compound of the present invention is added to the undercoat layer, it can exhibit an excellent inhibitory effect on fatigue deterioration of the photoreceptor due to the oxidizing gas, compared to when it is added to the photosensitive layer. it can. That is, in the present invention, it is possible to impart oxidation resistance gas resistance such as ozone resistance and nitrogen oxide resistance to the photoreceptor without deteriorating electrical characteristics such as chargeability, sensitivity and responsiveness.
That is, the photoconductor of the present invention has an advantage that it is not easily affected by oxidizing gas such as ozone and nitrogen oxides generated from a charger such as a corona discharge charger, and is sufficient for practical use even after repeated use. Have excellent electrical characteristics. Therefore, by using the photoreceptor of the present invention, it is possible to stably provide a high-quality image over a long period of time with high resolution and no image defects due to active species such as ozone and nitrogen oxide generated in the charging process. Can do. In addition, the undercoat layer also serves as an adhesive layer between the conductive support and the photosensitive layer, so that the peeling of the photosensitive layer from the conductive support can be suppressed, and the mechanical durability of the photoreceptor can be improved. it can.

The content of the diamine compound in the undercoat layer is preferably from 0.1% by weight to 30% by weight, and particularly preferably from 1% by weight to 10% by weight, based on the total solid content of the undercoat layer.
The content of the diamine compound in the undercoat layer needs to be selected to such an extent that the generation of charges by the charge generating substance is not inhibited. Further, since the charge generation layer is thin as described above, a large amount of the diamine compound cannot be added. However, in the present invention, the thickness of the undercoat layer containing the diamine compound is, for example, about 0.1 to 10 μm, and the contribution to charge generation and charge transport in the photoreceptor is small. The content of the diamine compound can be selected within the above range without deteriorating electrical characteristics such as property, sensitivity and responsiveness.

Therefore, by selecting the content of the diamine compound within the above range, the electrical characteristics such as charging property, sensitivity and responsiveness are good and the oxidation resistance gas property is particularly excellent. Thus, a photoconductor showing good electrical characteristics can be realized.
If the content of the diamine compound is less than 0.1% by weight of the total solid content of the undercoat layer, the oxidation resistance gas resistance of the photoreceptor may not be sufficiently obtained. In addition, if the content of the diamine compound exceeds 30% by weight of the total solid content of the undercoat layer, the electrical properties such as the chargeability, sensitivity and responsiveness of the photoreceptor are reduced, and the charging potential is greatly reduced by repeated use. In addition, there is a risk of a significant increase in residual potential.

The undercoat layer is prepared by, for example, preparing a coating solution for forming an undercoat layer by dissolving the diamine compound of the present invention, the resin material and other components in a suitable solvent, and applying this coating solution to the surface of the conductive support. It can be formed by applying and removing the organic solvent by drying.
Examples of the solvent for dissolving or dispersing the resin material include water, alcohols such as methanol, ethanol and butanol, glymes such as methyl carbitol and butyl carbitol, and mixed solvents in which two or more of these solvents are mixed. Can be mentioned.
Other processes and conditions are in accordance with the formation of the single-layer type photosensitive layer.

Examples of the resin material include natural polymeric materials such as casein, gelatin, polyvinyl alcohol, and ethyl cellulose in addition to the same binder resin as that contained in the single-layer type photosensitive layer, and one or more of these may be used. Can be used.
Among these, a polyamide resin is preferable and an alcohol-soluble nylon resin is particularly preferable because it is excellent in compatibility with the diamine compound and is excellent in adhesiveness with the conductive support. As alcohol-soluble nylon resins, for example, modified nylon resins such as N-methoxymethylated nylon, 6-nylon, 6,6-nylon, 6,10-nylon, 11-nylon, 12-nylon and the like were copolymerized. Examples thereof include copolymer nylon resins.

The undercoat layer forming coating solution may contain metal oxide particles.
The metal oxide particles can easily adjust the volume resistance value of the undercoat layer, can further suppress the injection of charge into the single-layer type photosensitive layer or the multilayer type photosensitive layer, and can also improve the electrical characteristics of the photoreceptor in various environments. Can be maintained.
Examples of the metal oxide particles include titanium oxide, aluminum oxide, aluminum hydroxide, and tin oxide.
The content of the metal oxide particles and the resin material in the undercoat layer is about 7 to 15% by weight of the total solid content of the undercoat layer.

  Although the film thickness of an undercoat layer is not specifically limited, 0.1-10 micrometers is preferable. If the thickness of the undercoat layer is less than 0.1 μm, fatigue deterioration of the photoconductor may not be sufficiently suppressed, and electric charge flows from the conductive support to the photoconductive layer, and the charge holding ability of the photoconductor. May decrease. Moreover, it may not substantially function as an undercoat layer, and there is a possibility that a uniform surface cannot be obtained by covering defects of the conductive support. On the other hand, if the thickness of the undercoat layer exceeds 10 μm, it is difficult to form a uniform undercoat layer, and the sensitivity of the photoreceptor may be lowered.

  An image forming apparatus according to the present invention includes a photosensitive member according to the present invention, a charging unit that charges the photosensitive member, an exposure unit that exposes the charged photosensitive member, and an electrostatic latent image formed by exposure. And developing means for developing.

The image forming apparatus of the present invention will be described with reference to the drawings, but is not limited to the following description.
FIG. 5 is a schematic side view showing the configuration of the image forming apparatus of the present invention.
The image forming apparatus 20 in FIG. 5 includes a photoreceptor 21 of the present invention (for example, any one of the photoreceptors 13, 14, 17 and 18 in FIGS. 1 to 4), a charging unit (charger) 24, and exposure. The image forming apparatus includes a unit 28, a developing unit (developing unit) 25, a transfer unit 26, a cleaner 27, and a fixing unit 31. Reference numeral 30 indicates a transfer sheet.

  The photosensitive member 21 is rotatably supported by the main body of the image forming apparatus 20 (not shown), and is driven to rotate in the direction of the arrow 23 around the rotation axis 22 by a driving unit (not shown). The drive means includes, for example, an electric motor and a reduction gear, and transmits the driving force to a conductive support constituting the core of the photoconductor 21, thereby rotating the photoconductor 21 at a predetermined peripheral speed. . The charger 24, the exposure unit 28, the developing unit 25, the transfer unit 26, and the cleaner 27 are arranged in this order along the outer peripheral surface of the photoconductor 21 from the upstream side in the rotation direction of the photoconductor 21 indicated by the arrow 23. It is provided toward the side.

The charger 24 is a charging unit that charges the outer peripheral surface of the photoconductor 21 to a predetermined potential. In the present embodiment, the charger 24 is realized by a contact-type charging roller 24a and a bias power source 24b that applies a voltage to the charging roller 24a.
Although a charger wire can be used as the charging means, in a charging roller that requires high wear resistance on the surface of the photoconductor, the photoconductor on which the surface protective layer according to the present invention is formed exhibits a great effect by improving durability.
Therefore, in the image forming apparatus of the present invention, the charging unit is preferably a contact charging unit.

  The exposure unit 28 includes, for example, a semiconductor laser as a light source, and is charged by irradiating light 28 a such as a laser beam output from the light source between the charger 24 and the developing unit 25 of the photosensitive member 21. The outer peripheral surface of the photoconductor 21 is exposed according to image information. The light 28a is repeatedly scanned in the main scanning direction in the direction in which the rotation axis 22 of the photoconductor 21 extends, and accordingly, electrostatic latent images are sequentially formed on the surface of the photoconductor 21.

  The developing unit 25 is a developing unit that develops an electrostatic latent image formed on the surface of the photoreceptor 21 by exposure with a developer. The developing unit 25 is provided facing the photoreceptor 21, and applies toner to the outer peripheral surface of the photoreceptor 21. A developing roller 25a to be supplied and a casing 25b for supporting the developing roller 25a so as to be rotatable around a rotation axis parallel to the rotation axis 22 of the photosensitive member 21 and containing a developer containing toner in the internal space thereof.

  The transfer device 26 supplies a toner image, which is a visible image formed on the outer peripheral surface of the photoconductor 21 by development, between the photoconductor 21 and the transfer device 26 from the direction of the arrow 29 by a conveying unit (not shown). It is a transfer means for transferring onto the transfer paper 30 as a recording medium. The transfer unit 26 is, for example, a non-contact type transfer unit that includes a charging unit and transfers the toner image onto the transfer paper 30 by applying a charge having a polarity opposite to that of the toner to the transfer paper 30.

  The cleaner 27 is a cleaning unit that removes and collects toner remaining on the outer peripheral surface of the photoconductor 21 after the transfer operation by the transfer device 26, and includes a cleaning blade 27 a that peels off toner remaining on the outer peripheral surface of the photoconductor 21, and a cleaning device. A recovery casing 27b for storing the toner separated by the blade 27a. The cleaner 27 is provided together with a charge eliminating lamp (not shown).

  Further, the image forming apparatus 20 is provided with a fixing device 31 as fixing means for fixing the transferred image on the downstream side where the transfer paper 30 that has passed between the photoreceptor 21 and the transfer device 26 is conveyed. . The fixing device 31 includes a heating roller 31a having a heating unit (not shown), and a pressure roller 31b that is provided to face the heating roller 31a and is pressed by the heating roller 31a to form a contact portion.

  The image forming operation by the image forming apparatus 20 is performed as follows. First, when the photosensitive member 21 is rotationally driven in the direction of the arrow 23 by the driving means, the photosensitive member 24 is provided by the charger 24 provided on the upstream side in the rotational direction of the photosensitive member 21 with respect to the imaging point of the light 28a by the exposure means 28. The surface of 21 is uniformly charged to a predetermined positive or negative potential.

Next, light 28 a corresponding to image information is irradiated from the exposure unit 28 to the surface of the photoconductor 21. With this exposure, the surface charge of the portion irradiated with the light 28a is removed from the photosensitive member 21, and a difference occurs between the surface potential of the portion irradiated with the light 28a and the surface potential of the portion not irradiated with the light 28a. An electrostatic latent image is formed.
Toner is supplied to the surface of the photosensitive member 21 on which the electrostatic latent image is formed from a developing unit 25 provided on the downstream side in the rotation direction of the photosensitive member 21 with respect to the image forming point of the light 28a by the exposure means 28, and electrostatic latent The image is developed to form a toner image.

In synchronization with the exposure of the photosensitive member 21, the transfer paper 30 is supplied between the photosensitive member 21 and the transfer device 26. The transfer device 26 applies a charge having a polarity opposite to that of the toner to the supplied transfer paper 30, and the toner image formed on the surface of the photoreceptor 21 is transferred onto the transfer paper 30.
The transfer paper 30 onto which the toner image has been transferred is conveyed to a fixing device 31 by a conveying means, and is heated and pressurized when passing through a contact portion between a heating roller 31a and a pressure roller 31b of the fixing device 31, and toner The image is fixed on the transfer paper 30 and becomes a robust image. The transfer paper 30 on which the image is formed in this way is discharged to the outside of the image forming apparatus 20 by the conveying means.

On the other hand, the toner remaining on the surface of the photoconductor 21 even after the transfer of the toner image by the transfer unit 26 is separated from the surface of the photoconductor 21 by the cleaner 27 and collected. The charge on the surface of the photoconductor 21 from which the toner has been removed in this manner is removed by the light from the static elimination lamp, and the electrostatic latent image on the surface of the photoconductor 21 disappears. Thereafter, the photosensitive member 21 is further driven to rotate, and a series of operations starting from charging again is repeated to continuously form images.
Since the image forming apparatus 20 according to the present invention includes the photoreceptor 21 having the photosensitive layer in which the diamine compound of the present invention is uniformly dispersed, it is possible to form a high quality image free from image defects such as black spots.

The present invention will be specifically described below with reference to production examples (including comparison), examples and comparative examples, but the present invention is not limited to these production examples (excluding comparison) and examples.
In addition, the chemical structure, molecular weight, and elemental analysis of the compound obtained by the manufacture example were measured with the following apparatuses and conditions.

(Chemical structure)
Nuclear magnetic resonance apparatus: NMR (Bruker Biospin, model: DPX-200)
Sample preparation About 4mg / 0.4m (CDCl3)
Measurement mode ¹ H (normal), ¹³ C (normal, DPET-135)

(Molecular weight)
Molecular weight measuring device: LC-MS (manufactured by Thermoquest,
(Finegan LCQ Deca Mass Spectrometer System)
LC column GL-Sciences Inertsil ODS-3 2.1 × 100mm
Column temperature 40 ° C
Eluent methanol: water = 90: 10
Sample injection volume 5 μl
Detector UV254nm and MS ESI

(Elemental analysis)
Elemental analysis device: Perkin Aelmer, Elemental Analysis 2400
Sample amount: Weigh accurately about 2 mg Gas flow rate (ml / min): He = 1.5, O ₂ = 1.1, N ₂ = 4.3
Combustion tube temperature setting: 925 ° C
Reduction tube temperature setting: 640 ° C
In addition, the elemental analysis was analyzed by the simultaneous determination method of carbon (C), hydrogen (H) and nitrogen (N) by the differential thermal conductivity method.

(Production Example 1)
According to the following reaction formula, Exemplified Compound No. 1 (Structural Formula (I)) was produced.

[Production of Amine-Bisaldehyde Intermediate (7aa)]
In 50 ml of anhydrous 1,4-dioxane, 6.06 g (1.0 equivalent) of 4,4′-bis (chloromethyl) biphenyl and 10.0 g (2.1 equivalent) of dibenzylamine were added, and iced on an ice bath. Cooled under cold. To this solution, 6.86 g (2.2 equivalents) of N, N-diisopropylethylamine was gradually added. Then, it heated gradually, raised reaction temperature to 100-110 degreeC, and stirred for 4 hours, heating so that 100-110 degreeC might be maintained. After completion of the reaction, the reaction solution is allowed to cool, and the resulting precipitate is collected by filtration, washed thoroughly with water, and re-reused with a mixed solvent of ethanol and ethyl acetate (ethanol: ethyl acetate = 8: 2 to 7: 3). By performing crystallization, 12.1 g of a white powdery compound was obtained.

As a result of chemical analysis of the obtained white powdery compound,
Nuclear magnetic resonance equipment: NMR
¹ H-NMR spectrum (normal) showed δ (ppm) = 3.58 (S.12H) 7.07 to 7.84 (m.28H).
The ¹³ C-NMR spectrum (usually DPET-135) has δ = 57.80 (CH ₂ , signal intensity 2), 58.07 (CH 2, signal intensity 4), 126.94 (CH, signal intensity 4). ), 128.32 (CH, signal intensity 8), 128.72 (CH, signal intensity 4), 128.83 (CH, signal intensity 4), 128.85 (CH, signal intensity 8), 138.29 ( C, signal intensity 2), 139.25 (C, signal intensity 4), and 139.28 (C, signal intensity 2) were shown.
Furthermore, the molecular weight measuring device: LC-MS is exemplified by Compound No. A peak corresponding to a molecular ion [M + H] ⁺ in which a proton is added to 1 (calculated molecular weight: 572.30) was observed at 573.2.

The elemental analysis values of the white powdery compound were as follows.
<Exemplary Compound No. Elemental analysis value of 1>
Theoretical value C: 88.07%, H: 7.04%, N: 4.89%
Actual value C: 87.25%, H: 6.88%, N: 4.42%
As described above, from the results of analysis such as NMR, LC-MS, and elemental analysis, the obtained white powdery compound was found to be Compound No. 1 diamine compound (yield: 87.5%). Moreover, from the analysis result of HPLC at the time of LC-MS measurement, the obtained exemplary compound No. The purity of 1 was 99.0%.

(Production Examples 2 to 4)
Exemplified compounds were prepared in the same manner as in Production Example 1 using the amine compounds represented by the general formulas (4) and (5) and the starting compounds shown in Table 2 as the dihalogen compounds represented by the general formula (6). No. 3, 7 and 28 were produced respectively. In Table 2, Exemplified Compound No. 1 raw material compounds are also shown.

  In addition, Table 3 shows elemental analysis values, calculated molecular weight values, and actual measurement values [M + H] obtained by LC-MS of the respective exemplary compounds obtained in Production Examples 1 to 4 above.

(Production Example 5) (Production Example by Reaction Treatment in Aqueous System Using Synthetic Comparative Diamine Compound and Inorganic Base)
According to the synthesis example described in JP-A-5-158258, a diamine compound represented by the following chemical structural formula (7), which is the exemplified compound (No. 10) described below (hereinafter referred to as “diamine compound synthesized by comparative production example”). To obtain 6.2 g.

The elemental analysis values of the diamine compound synthesized by the obtained comparative production example were as follows.
<Elemental analysis value of diamine compound synthesized by comparative production example>
Theoretical value C: 85.67%, H: 7.67%, N: 6.66%
Actual measurement C: 84.21%, H: 6.38%, N: 5.87%
In addition, as a result of analyzing the diamine compound synthesized by the obtained comparative production example by LC-MS, a molecule in which a proton was added to the target compound (calculated molecular weight: 420.26) represented by the above chemical structural formula. A peak corresponding to the ion [M + H] ⁺ was observed at 421.5.
From the results of elemental analysis and LC-MS analysis, it was found that the obtained compound was a diamine compound of the exemplified compound (No. 10) described in JP-A No. 5-158258. Moreover, the purity of the obtained diamine compound was 96.3% from the analysis result of HPLC at the time of LC-MS measurement.

Example 1
Exemplified compound No. which is the diamine compound of the present invention is as follows. A photoconductor containing 1 in the undercoat layer was prepared. As the conductive support, a polyethylene terephthalate (abbreviated as PET) film having a thickness of 100 μm deposited with aluminum (hereinafter referred to as “aluminum-deposited PET film”) was used.

3 parts by weight of titanium oxide (trade name: TTO-D1 (dendritic rutile type surface-treated with Al ₂ O ₃ and ZrO ₂ , titanium component 85%), manufactured by Ishihara Sangyo Co., Ltd.) and alcohol-soluble nylon resin (product) Name: CM8000, manufactured by Toray Industries, Inc.) 3 parts by weight and the exemplified compound No. 1 prepared in Preparation Example 1 as an antioxidant. 1 part of the diamine compound 1 (4.8% by weight of the total solid content of the undercoat layer) is added to a mixed solvent of 60 parts by weight of methanol and 40 parts by weight of 1,3-dioxolane, and paint shaker is added. The coating solution for undercoat layer was prepared by dispersing for 10 hours. The coating solution was filled in the coating tank, the conductive support was dipped, pulled up, and naturally dried to form an undercoat layer having a layer thickness of 0.9 μm.

Next, 15 parts by weight of titanyl phthalocyanine having the following structural formula as a charge generating substance, 10 parts by weight of polyvinyl butyral resin (trade name: S-LEC BL-2, manufactured by Sekisui Chemical Co., Ltd.) as a binder resin, and 1,3- A charge generation layer coating solution was prepared by dispersing 1400 parts by weight of dioxolane in a ball mill for 72 hours. This coating solution was applied onto the previously formed undercoat layer by the same dip coating method as that for the undercoat layer, and then naturally dried to form a charge generation layer having a layer thickness of 0.2 μm.

Next, 100 parts by weight of an enamine compound having the following structural formula as a charge transport material, polycarbonate resin (trade names: J-500, G-400, GH-503 (more than three types, manufactured by Idemitsu Kosan Co., Ltd.)) as a binder resin and Trade name: TS2020 (trade name, manufactured by Teijin Chemicals Ltd.) 48 parts by weight, 32 parts by weight, 32 parts by weight and 48 parts by weight, hindered phenol antioxidants (trade names: Sumilizer BHT, Sumitomo Chemical Co., Ltd.) 3 parts by weight) were mixed and dissolved in 980 parts by weight of tetrahydrofuran to prepare a charge transport layer coating solution. This coating solution was applied onto the charge generation layer previously formed by the same dip coating method as that for the undercoat layer, and dried at a temperature of 130 ° C. for 1 hour to form a charge transport layer having a layer thickness of 15 μm. In this manner, a photoconductor for evaluation apparatus evaluation of Example 1 was produced.
Further, in the formation of the charge transport layer, the actual device evaluation photoconductor of Example 1 was prepared in the same manner as the evaluation device evaluation photoconductor described above except that the charge transport layer was formed so as to have a film thickness of 28 μm. Produced.

(Example 2)
In forming the undercoat layer, Exemplified Compound No. In the same manner as in Example 1, except that 0.7 parts by weight of the diamine compound 1 (10% by weight of the total solid content of the undercoat layer) was used, the evaluation device evaluation photoreceptor of Example 2 and the actual device evaluation A photoconductor was prepared.

Example 3
In forming the undercoat layer, Exemplified Compound No. Example 3 evaluation device evaluation photoreceptor and actual device evaluation in the same manner as Example 1, except that 0.9 part by weight of diamine compound 1 (13% by weight of the total solid content of the undercoat layer) was used. A photoconductor was prepared.

Example 4
In forming the undercoat layer, Exemplified Compound No. The evaluation apparatus evaluation photoreceptor of Example 4 and the actual machine are the same as Example 1 except that 0.006 part by weight of the diamine compound 1 (0.1% by weight of the total solid content of the undercoat layer) is used. A photoconductor for evaluation was produced.

(Examples 5-7)
In forming the undercoat layer, Exemplified Compound No. In place of Exemplified Compound No. 1 Except that the diamine compounds 3, 7, and 28 were used, the evaluation device evaluation photoconductor and the actual device evaluation photoconductor of Examples 5 to 7 were produced in the same manner as in Example 1.

(Example 8)
In forming the undercoat layer, Exemplified Compound No. In the same manner as in Example 1, except that 2.8 parts by weight of the diamine compound 1 (32% by weight of the total solid content of the undercoat layer) was used, the evaluation device evaluation photoreceptor of Example 8 and the actual device evaluation A photoconductor was prepared.

Example 9
In forming the undercoat layer, Exemplified Compound No. In the same manner as in Example 1, except that 0.0048 part by weight of the diamine compound 1 (0.08% by weight of the total solid content of the undercoat layer) was used, the evaluation apparatus evaluation photoreceptor of Example 9 and the actual machine A photoconductor for evaluation was produced.

(Comparative Example 1)
In forming the undercoat layer, Exemplified Compound No. A photoconductor for evaluation device evaluation and a photoconductor for actual device evaluation of Comparative Example 1 were produced in the same manner as in Example 1 except that 1 diamine compound was not used.

(Comparative Example 2)
In forming the undercoat layer, Exemplified Compound No. In the same manner as in Example 1 except that 5 parts by weight of tribenzylamine having the following structural formula was added to the charge transport layer coating solution when forming the charge transport layer without using the diamine compound of Example 1. A photoconductor for evaluation device evaluation and a photoconductor for actual device evaluation were prepared.

(Comparative Example 3)
In forming the undercoat layer, Exemplified Compound No. Evaluation of Comparative Example 3 was conducted in the same manner as in Example 1 except that 5 parts by weight of triphenylamine having the following structural formula was added to the charge transport layer coating solution when forming the charge transport layer without using the amine compound of 1. An apparatus evaluation photoreceptor and an actual apparatus evaluation photoreceptor were prepared.

(Comparative Example 4)
In forming the undercoat layer, Exemplified Compound No. In place of 1, a diamine compound (7) synthesized by a comparative production example (a compound described in JP-A-5-158258) was used in the same manner as in Example 1 for evaluating the evaluation device of Comparative Example 4. A photoconductor and a photoconductor for actual device evaluation were prepared.

  For each of the photoreceptors of Examples 1 to 9 and Comparative Examples 1 to 4 manufactured as described above, (a) oxidation resistance gas gas resistance and (b) stability of electrical characteristics were evaluated as follows. Further, (c) comprehensive determination of the photoreceptor performance was performed.

(A) Oxidation-resistant gas and gas properties [Evaluation by evaluation equipment]
Each evaluation apparatus evaluation photoreceptor of Examples 1 to 9 and Comparative Examples 1 to 4 (layer thickness of the charge transport layer: 15 μm) is mounted on a test copying machine, and the temperature is 35 ° C. and the relative humidity is 85%. In a normal temperature / normal humidity (N / N) environment, the surface potential V ₁ (V) of the photoconductor immediately after charging and the surface potential V ₂ (V) of the photoconductor 3 seconds after charging are measured. did. The test copier measures the surface potential of the photoconductor during the image forming process inside a commercially available copier AR-F330 (trade name, manufactured by Sharp Corporation) equipped with a corona discharge charger as the charging means for the photoconductor. What provided the surface electrometer (brand name: CATE751, the Gentec company make) so that it could do was used. The measured surface potential V ₁ (V) immediately after charging and the surface potential V ₂ (V) after 3 seconds from charging are substituted into the following formula (I) to calculate the charge retention ratio DD (%). was the initial charge retention rate DD _0.

Next, using an ozone generation / control device (trade name: OES-10A, manufactured by Directec Co., Ltd.), each photoconductor has an ozone concentration of about 7.5 ppm (the ozone concentration meter MODEL1200 (trade name) manufactured by Directec Co., Ltd.). Exposure to ozone for 20 hours in a sealed container adjusted to (confirmation). After exposure to ozone, each photoconductor was left in a room temperature / normal humidity (N / N) environment at a temperature of 25 ° C. and a relative humidity of 50% for 2 hours, and then the charge retention ratio DD (% ) And obtained as the charge retention ratio DD ₀₂ after ozone exposure.
The value obtained by subtracting the charge retention ratio DD ₀₂ after ozone exposure from the charge retention ratio before exposure to ozone, that is, the initial charge retention ratio DD ₀ , is obtained as a charge retention ratio change amount ΔDD (= DD ₀ -DD ₀₂ ). Was used as an evaluation index.

The value of the charge retention rate change ΔDD before and after the above ozone exposure and the oxidation resistance gas resistance of the photoreceptor were evaluated. The evaluation criteria for the oxidation-resistant gas resistance are as follows.
A: Excellent (ΔDD is less than 5.0% and image quality is excellent (A))
○: Good (ΔDD is 4.0% or more and less than 5.5%)
Δ: No problem in actual use (ΔDD is 5.5% or more and less than 10.0%)
X: Defect (ΔDD is 10.0% or more)

(B) Stability of electrical characteristics Each of the actual machine evaluation photoreceptors of Examples 1 to 9 and Comparative Examples 1 to 4 (layer thickness of the charge transport layer: 28 μm) was mounted on a test copying machine, and the temperature was 35 ° C. In a high temperature / high humidity (H / H) environment with a relative humidity of 85%, the stability of electrical characteristics was evaluated as follows. In the test copying machine, the surface potential of the photosensitive member in the image forming process is set inside a commercially available copying machine (trade name: AR-F330, manufactured by Sharp Corporation) equipped with a corona discharge charger as charging means for the photosensitive member. What provided the surface electrometer (brand name: CATE751, the Gentec company make) so that it could measure was used. The copying machine AR-F330 is a negatively charged image forming apparatus that performs electrophotographic process by negatively charging the surface of the photoreceptor.

Using the test copying machine on which each of the photoconductors of Examples 1 to 9 and Comparative Examples 1 to 4 is mounted, the surface potential of the photoconductor immediately after the charging operation by the charger is measured as a charging potential V0 (V). It was the charging potential V0 ₁ early. The measured surface potential of the photosensitive member immediately after subjected to exposure by a laser beam as a residual potential Vr (V), which was used as the initial residual potential Vr _1.
Then, after copying successively the test image of a predetermined pattern on the recording paper 30 million copies, the initial and in the same manner by measuring the charge potential V0 and residual potential Vr, the charge potential V0 ₂ and after repeated use of these The residual potential Vr ₂ after repeated use was set. The absolute value of the difference between the initial charging potential V0 ₁ and the charging potential V0 ₂ after repeated use was determined as a charging potential change amount ΔV0 (= | V0 ₁ −V0 ₂ |). Further, the absolute value of the difference between the initial residual potential Vr ₁ and the residual potential Vr ₂ after repeated use was determined as a residual potential change amount ΔVr (= | Vr ₁ −Vr ₂ |). The stability of the electrical characteristics was evaluated using the charging potential change amount ΔV0 and the residual potential change amount ΔVr as evaluation indexes.

The evaluation criteria for the stability of the electrical characteristics are as follows.
A: Excellent (ΔVr is less than 80V)
○: Good (ΔVr is 80V or less and less than 105V)
Δ: No problem in actual use (ΔVr is 105V or more and less than 125V)
X: Defect (ΔVr is 125V or more)

(C) Comprehensive Judgment of Photoreceptor Performance A comprehensive judgment of the photoconductor performance was made by combining the evaluation result of the oxidation-resistant gas property and the comprehensive evaluation result of the stability of the electric characteristics. (The criteria for comprehensive judgment are as follows)
◎: Excellent (Oxidation-resistant gas resistance and electrical property stability are both excellent (◎))
○: Good (Oxidation-resistant gas resistance or electrical property stability is good (○) and the other is excellent (◎) or good (○))
△: No problem in actual use (Oxidation-resistant gas property or electrical property stability is no problem in actual use (△) and the other is not defective (x))
X: Defect (either or both of oxidation-resistant gas resistance and electrical property stability are unsatisfactory (x))
The above evaluation results are shown in Table 4. In Table 4, the undercoat layer is abbreviated as a UC (Under Coat) layer.

  From comparison between Examples 1 to 9 and Comparative Example 1, the photoreceptors of Examples 1 to 9 containing the diamine compound of the present invention in the undercoat layer compared to the photoreceptor of Comparative Example 1 not containing, It can be seen that it is excellent in oxidation resistance gas resistance and electrical property stability, and exhibits good electrical properties even when used repeatedly.

  From comparison between Examples 1-9 and Comparative Examples 2-4, tribenzylamine, triphenylamine as antioxidants, diamine compound (7) synthesized by Comparative Production Example (described in JP-A-5-158258) The photoconductors of Comparative Examples 2 to 4 to which (compound) was added had a large amount of change in charge retention ΔDD due to ozone exposure and insufficient oxidation-resistant gas properties compared to the photoconductors of Examples 1 to 9. I understand that. Further, it can be seen that the photoreceptors of Comparative Examples 3 and 4 have a large increase in residual potential (ΔVr) when repeatedly used, and are excellent in stability of responsiveness.

From the comparison between Examples 1 to 7 and Example 8, the photosensitivity of Examples 1 to 7 in which the content of the diamine compound of the present invention is in the range of 0.1 to 30% by weight of the total solid content of the undercoat layer. As compared with the photoconductor of Example 8 that deviates from the larger range, it is found that the residual potential change ΔVr due to repeated use is small and the response stability is excellent.
From comparison between Examples 1 and 2 and Example 3, the photoreceptors of Examples 1 and 2 in which the content of the diamine compound of the present invention is in the range of 1 to 10% by weight of the total solid content of the undercoat layer are as follows. It can be seen that the residual potential change ΔVr is small and the response stability is excellent.

  From the comparison between Examples 1 to 8 and Example 9, the photosensitivity of Examples 1 to 8 in which the content of the diamine compound of the present invention is in the range of 0.1 to 30% by weight of the total solid content of the undercoat layer. It can be seen that the body has a smaller amount of change in charge retention ΔDD due to exposure to ozone and superior oxidation-resistant gas properties compared to the photoreceptor of Example 9 that deviates from the range.

  From a comparison between Examples 1 and 2 and Example 4, the photoreceptors of Examples 1 and 2 in which the content of the diamine compound of the present invention is in the range of 1 to 10% by weight of the total solid content of the undercoat layer are as follows. It can be seen that the oxidation resistance gas resistance is more excellent as compared with the photoreceptor of Example 4 whose content is less than 1% by weight of the total solid content of the undercoat layer.

  From the comparison between Example 1 and Examples 5 to 7, among the amine compounds of the present invention represented by the general formula (1), an amine compound having a tribenzylamine structure represented by the structural formula (I) was obtained. It can be seen that a photoconductor that is particularly excellent in both oxidation resistance gas resistance and responsive stability can be obtained.

  As described above, by including the diamine compound of the present invention in the undercoat layer, it is excellent in electrical characteristics such as chargeability and responsiveness, is excellent in oxidation-resistant gas resistance, and is good as described above even when used repeatedly. An electrophotographic photoreceptor excellent in property stability in which the electrical properties do not deteriorate can be obtained.

FIG. 2 is a schematic cross-sectional view illustrating a configuration of a main part of a single layer type photoreceptor of the present invention. FIG. 2 is a schematic cross-sectional view illustrating a configuration of a main part of a single layer type photoreceptor of the present invention. FIG. 2 is a schematic cross-sectional view illustrating a configuration of a main part of the multilayer photoconductor of the present invention. FIG. 2 is a schematic cross-sectional view illustrating a configuration of a main part of the multilayer photoconductor of the present invention. 1 is a schematic side view illustrating a configuration of an image forming apparatus of the present invention.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Conductive support body 2 Single layer type photosensitive layer 3 Charge generation layer 4 Charge transport layer 5 Surface protective layer 6 Undercoat layer (intermediate layer)
7 Laminated Photosensitive Layer 13, 14, 17, 18 Photoconductor

20 Image forming apparatus 22 Axis of rotation 23, 29 Arrow 24 Charging means (charger)
24a Charging roller 24b Bias power supply 25 Developing means (developer)
25a Developing roller 25b Casing 26 Transfer device 27 Cleaner 27a Cleaning blade 27b Recovery casing 28 Exposure means 28a Light 30 Transfer paper 31 Fixing device 31a Heating roller 31b Pressure roller

Claims (8)

Containing a subbing layer and a single-layer photosensitive layer containing a charge generation material and a charge transport material, or a charge generation layer containing a charge generation material and a charge transport material on a conductive support made of a conductive material An electrophotographic photosensitive member in which a charge-transporting layer is laminated in this order, and the single-layer photosensitive layer or the charge-transporting layer of the laminated photosensitive layer is Containing an oxidation-resistant gas additive, and the undercoat layer is
General formula (1):

[Where:
Ar ¹ , Ar ² , Ar ³ and Ar ⁴ are the same or different and each may have an aryl group which may have a substituent, a cycloalkyl group which may have a substituent, or a hetero which may have a substituent. A monovalent heterocyclic residue optionally having an atom-containing cycloalkyl group or a substituent;
Y ¹ , Y ² , Y ³ , Y ⁴ , Y ⁵ and Y ⁶ are the same or different and are a chain alkylene group which may have a substituent;
Z is i) —Ar ⁵ —Ar ⁶ — or ii) —Ar ⁵ —W—Ar ⁶ — (wherein Ar ⁵ and Ar ⁶ are the same or different and may have a substituent) Or a divalent heterocyclic residue which may have a substituent; W is a cycloalkylidene group which may have a substituent, or a chain or branched alkylene group which may have a substituent An oxygen atom or a sulfur atom)
An electrophotographic photoreceptor comprising a diamine compound represented by the formula: The diamine compound is a sub-formula (2):

(In the formula, Ar ¹ , Ar ² , Ar ³ , Ar ⁴ , Y ⁵ , Y ⁶ and Z are as defined in the general formula (1); (It is an integer of 3)
The electrophotographic photosensitive member according to claim 1, which is represented by: The diamine compound is a sub-formula (3):

(In the formula, Ar ¹ , Ar ² , Ar ³ , Ar ⁴ , Ar ⁵ and Ar ⁶ have the same meanings as those in the general formula (1)).
The electrophotographic photosensitive member according to claim 1, which is represented by: The diamine compound has the structural formula (I):

The electrophotographic photosensitive member according to claim 1, which is represented by:   5. The electrophotographic photosensitive member according to claim 1, wherein the content of the diamine compound is 0.1 wt% or more and 30 wt% or less of the total solid content of the undercoat layer.   The electrophotographic photosensitive member according to claim 5, wherein the content of the diamine compound is 1 wt% or more and 10 wt% or less of the total solid content of the undercoat layer.   An electrophotographic photosensitive member according to any one of claims 1 to 6, a charging unit for charging the electrophotographic photosensitive member, an exposure unit for exposing the charged electrophotographic photosensitive member, and exposure An image forming apparatus comprising: a developing unit that develops the electrostatic latent image formed by the step.   The image forming apparatus according to claim 7, wherein the charging unit is a contact charging unit.

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