JP4982276B2 - Electrophotographic photoreceptor containing diamine compound and image forming apparatus having the same - Google Patents

Description

  The present invention relates to an electrophotographic photosensitive member 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 is gradually being developed as the main force of the photoconductor because it has an advantage that a photoconductor exhibiting 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 an oxidizing gas such as ozone and nitrogen oxide released from a corona discharge charger, which is one of non-contact charging methods, causes significant damage to the photosensitive layer. The non-contact charging method does not contact the photoconductor, so that the surface of the photoconductor is not easily worn or scratched by rubbing, is excellent in mechanical durability, and the photoconductor is introduced when an image forming process using the non-contact charging method is introduced. Although it can be expected to have a long life, ozone is generated more than the contact charging method, and there is a disadvantage that the photoreceptor is significantly deteriorated by an oxidizing gas. 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.
However, in the proposal that incorporates measures to efficiently exhaust and replace the gas around the corona charger and avoid the direct influence of the gas on the photoconductor, an image forming apparatus is used to exhaust the oxidizing gas. It is necessary to provide a new exhaust system inside, and there is a problem that the entire process and the process become complicated.

  Further, as a proposal for preventing deterioration by adding an antioxidant or a stabilizer to the photosensitive layer, for example, JP-A-62-105151 (Patent Document 1) has a triazine ring and a hindered phenol skeleton in the molecule. Addition of an antioxidant to the photosensitive layer, Japanese Patent Application Laid-Open No. 63-18355 (Patent Document 2) discloses adding a specific hindered amine 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

  That is, the conventional technology has not yet achieved a sufficient ozone resistance effect (an effect of suppressing fatigue deterioration), and the addition of such an antioxidant or the like has no effect on sensitivity and residual potential. At present, there are still unsatisfactory practical problems such as deterioration of electrophotographic characteristics. Therefore, a new material proposal that improves ozone resistance and has no harmful effect on electrophotographic characteristics is awaited.

  Therefore, the present invention is excellent in electrical characteristics such as chargeability, sensitivity, and responsiveness, and is excellent in oxidation gas resistance such as ozone resistance and nitrogen oxide resistance. It is an object of the present invention to provide an electrophotographic photoreceptor excellent in electrical durability in which characteristics are not deteriorated and an image forming apparatus provided with the same.

  As a result of intensive research, the present inventors have found that a specific diamine compound is surprisingly excellent in ozone resistance and has no adverse effects on electrophotographic characteristics. The present invention was found to be extremely useful for the image forming apparatus, and the present invention was completed.

  Thus, according to the present invention, a multilayer photosensitive film in which a charge generation layer containing a charge generation material and a charge transport layer containing a charge transport material are laminated in this order on a conductive support made of a conductive material. An electrophotographic photosensitive member in which layers are laminated, wherein the charge transport layer of the multilayer photosensitive layer contains an oxidation-resistant gas additive, and the charge generation layer of the multilayer photosensitive layer has a 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.
Note that. The numbering of the substituents in the chemical formulas described in this specification includes the upper left and upper right letters, which are the same. For example, “ ¹ Ar” and “Ar ¹ ” represent the same substituent.

  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.

According to the present invention, an electron having a conductive support made of a conductive material, and a photosensitive layer formed by laminating a charge generation layer containing a charge generation material and a charge transport layer containing a charge transport material. In the photographic photoreceptor, the charge transport layer contains an ozone-resistant additive, and the charge generation layer contains a diamine compound represented by the general formula (1).
By containing the diamine compound in the charge generation layer, the diamine compound can supplement the oxidizing gas such as ozone and nitrogen oxide, and can effectively suppress the adsorption of the oxidizing gas to the charge generating material. Oxidation-resistant gas properties such as ozone resistance and nitrogen oxide resistance of the photoreceptor can be improved. In the photoreceptor of the present invention, even when it is repeatedly used, ozone resistance, nitrogen oxide resistance, etc., without causing a decrease in charging potential, an increase in residual potential, a decrease in sensitivity, a decrease in resolution due to a decrease in surface resistance, etc. It is possible to realize a photoconductor excellent in oxidation-resistant gas resistance and having suppressed fatigue deterioration.

  In addition, according to the present invention, the electrophotographic photosensitive member of the image forming apparatus is excellent in electrical characteristics such as charging property, sensitivity and responsiveness, and also in oxidation-resistant gas property, even if it is used repeatedly. The electrophotographic photosensitive member of the present invention having excellent electrical durability that does not deteriorate good electrical properties is used. Thus, a highly reliable image forming apparatus capable of providing a stable and high quality image can be realized.

  Furthermore, according to the present invention, since the electrophotographic photosensitive member of the present invention having very excellent oxidation resistance gas resistance is used for the electrophotographic photosensitive member of the image forming apparatus, the photosensitive member in the image forming apparatus is charged. As a charging means, it can be used in combination with a non-contact charging method that releases more oxidizing gas than a contact charging method. Since the non-contact charging method does not directly contact the photoconductor, the photoconductor surface is not easily worn or scratched by rubbing, has excellent mechanical durability, and can extend the life of the photoconductor. Thus, it is possible to realize a highly reliable image forming apparatus that can provide a stable and high-quality image over a long period of time.

  The photoreceptor of the present invention is a laminated photosensitive layer in which a charge generation layer containing a charge generation material and a charge transport layer containing a charge transport material are laminated in this order on a conductive support made of a conductive material. In which the charge transport layer of the multilayer photosensitive layer contains an oxidation-resistant gas additive, and the charge generation layer of the multilayer photosensitive layer is represented by the general formula (1). It contains a diamine compound.

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 , Y ⁴ , Y ⁵ and Y ⁶ 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, a 4,4-dimethylcyclohexylidenyl group, a cyclopentylidene group, and the like.

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 propylene group, and a 2,2-dimethylpropylene 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

  Among the diamine compounds of the present invention shown in Tables 1-1 to 1-4, Exemplified Compound Nos. 1, 3, 7, 13, 21, 28, 37, 49, 52 and 56 are preferred. 1, 3, 13 and 28 are particularly preferred. 1 (the following structural formula (I)) is more preferable.

  The diamine compound of the present invention can be produced by the method shown in the following reaction formula. That is, the secondary amine compound represented by the general formula (4) and the general formula (5) and the dihalogen compound represented by the general formula (6) are heated in the presence of an organic amine base for easy collection. The target product can be produced with high purity and high efficiency.

（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.

By containing the diamine compound of the present invention in the charge generation layer of the photoreceptor, it is possible to impart oxidation resistance gas resistance such as ozone resistance and nitrogen oxide resistance to the photoreceptor. This is because the diamine compound of the present invention supplements oxidizing gases such as ozone, nitrogen oxides, chlorine oxides and sulfur oxides, and is effective in adsorbing oxidizing gases to charge generating materials contained in the charge generating layer. This is presumably because it can be suppressed.
Therefore, the photoreceptor containing the diamine compound of the present invention in the charge generation layer of the photosensitive layer has excellent electrophotographic characteristics, is not easily influenced by ozone and nitrogen oxide generated from the system, and is stable even after repeated use. It has excellent characteristics and 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.
That is, FIGS. 1 to 4 show a multilayer photosensitive body (hereinafter referred to as “functional separation type photosensitive layer”) in which the photosensitive layer is a multilayer photosensitive layer composed of a charge generation layer and a charge transport layer (hereinafter also referred to as “function separation type photosensitive 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.

In the photoreceptor 1 of FIG. 1, a laminated photoconductive layer 14 that is a photosensitive layer 10 in which a charge generation layer 12 and a charge transport layer 13 are laminated in this order is formed on the surface of a conductive support 11. Yes.
2 includes an intermediate layer 15, a stacked photoconductive layer 14 in which a charge generation layer 12 and a charge transport layer 13 are stacked in this order on the surface of a conductive support 11. Is formed.
In the photoreceptor 3 of FIG. 3, a laminated photoconductive layer 14 in which a charge generation layer 12 and a charge transport layer 13 are laminated in this order on a surface of a conductive support 11, and a surface protective layer 21 in this order. It is formed with.
4 includes an intermediate layer 15, a stacked photoconductive layer 14 in which a charge generation layer 12 and a charge transport layer 13 are stacked in this order on the surface of a conductive support 11, and a surface protective layer. 21 are formed in this order.

[Conductive support 11 (element tube for photoreceptor)]
The constituent material of the conductive support 11 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 4, and may be a cylindrical shape, a columnar shape, an endless belt shape, or the like.
If necessary, the surface of the conductive support is subjected to irregular reflection treatment such as anodizing film treatment, surface treatment with chemicals, hot water, coloring treatment, and surface roughening within a range that does not affect the image quality. May be given.

  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.

[Laminated Photoconductive Layer 14]
The laminated photosensitive layer is composed of a charge generation layer 12 and a charge transport layer 13. As described above, by assigning the charge generation function and the charge transport function to separate layers, the optimum material constituting each layer can be independently selected.

[Charge generation layer 12]
The charge generation layer 12 contains a charge generation material, the diamine compound of the present invention, and optionally a binder resin.

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 the phthalocyanine pigment has high charge generation efficiency and charge injection efficiency, it generates a large amount of charge by absorbing light, and the charge of the charge transport layer 13 is not accumulated in the molecule. Since charges are efficiently injected into the transport material and smoothly transported, a highly sensitive and high resolution photoreceptor can be obtained.
The oxotitanium phthalocyanine may be one in which the hydrogen atom of the benzene ring contained in the phthalocyanine group is substituted with a halogen atom such as a chlorine atom or a fluorine atom, a substituent such as a nitro group, a cyano group, or a sulfonic acid group, Alternatively, a ligand coordinated to the central metal may be used.

  The charge generation layer may contain an appropriate amount of one or more of a chemical sensitizer and an optical sensitizer within a range that does not impair the preferable characteristics of the present invention. These sensitizers improve the sensitivity of the photoreceptor, suppress an increase in residual potential and fatigue due to repeated use, and improve electrical durability. These sensitizers may be contained in the charge transport layer described later, or may be contained in both the charge generation layer and the charge transport layer.

  Examples of chemical sensitizers include acid anhydrides such as succinic anhydride, maleic anhydride, phthalic anhydride, and 4-chloronaphthalic anhydride; cyano compounds such as tetracyanoethylene and terephthalmalondinitrile, 4-nitrobenzaldehyde, and the like. Aldehydes; anthraquinones such as anthraquinone and 1-nitroanthraquinone; polycyclic or heterocyclic nitro compounds such as 2,4,7-trinitrofluorenone and 2,4,5,7-tetranitrofluorenone; diphenoquinone compounds Examples thereof include electron-withdrawing materials and those obtained by polymerizing these electron-withdrawing materials.

  Examples of the optical sensitizer include xanthene dyes, quinoline pigments, organic photoconductive compounds such as copper phthalocyanine, triphenylmethane dyes represented by methyl violet, crystal violet, knight blue and victoria blue; erythrosin, Acridine dyes typified by rhodamine B, rhodamine 3R, acridine orange and frapeosin; thiazine dyes typified by methylene blue and methylene green; oxazine dyes typified by capri blue and meldra blue; cyanine dyes; styryl dye; Examples include pyrylium salt dyes and thiopyrylium salt dyes.

  As the binder resin, for example, a resin having a binding property used in the field can be used for the purpose of improving the mechanical strength, durability, and the like of the charge generation layer 12, and the phase difference with the diamine compound of the present invention can be used. Those having excellent solubility 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.

The ratio of the charge generating material to the diamine compound of the present invention is not particularly limited, but when the weight G of the charge generating material and the weight J of the diamine compound are used, the ratio G / J is 100 / 0.01 or more and 100 /20.0 or less is preferable, and 100 / 0.1 or more and 100 / 10.0 or less is particularly preferable.
When the amount of the diamine compound of the present invention is less than 0.01 parts by weight based on 100 parts by weight of the charge generating substance, sufficient resistance to oxidizing gases such as ozone and nitrogen oxides cannot be obtained, and the image quality is deteriorated when repeatedly used. There is a risk that the charging potential will decrease.
On the other hand, when the used amount of the diamine compound of the present invention exceeds 20.0 parts by weight based on 100 parts by weight of the charge generating material, the sensitivity and responsiveness are lowered, and there is a possibility that the residual potential is increased during repeated use.

The use ratio of the charge generation material and the binder resin is not particularly limited, but when the weight G of the charge generation material and the weight B of the binder resin are used, the ratio G / B is 10/100 or more and 99/100 or less. Is preferred.
When the ratio G / B is less than 10/100, the sensitivity of the photoreceptor may be lowered.
On the other hand, if the ratio G / B exceeds 99/100, the film strength of the charge generation layer may be reduced, the dispersibility of the charge generation material is reduced, and coarse particles are increased. The surface charge of the image is reduced by exposure, and there is a possibility that image fogging, in particular, fogging of an image called a black spot where a toner adheres to a white background and a minute black spot is formed.

The charge generation layer 12 can be formed by a known dry method and wet method.
Examples of the dry method include a method of vacuum-depositing the charge generating material and the diamine compound of the present invention on the conductive support 11.
As the wet method, for example, a charge generation layer forming coating solution is prepared by dissolving or dispersing the charge generation material, the diamine compound of the present invention, and, if necessary, a binder resin in a suitable organic solvent. The method of apply | coating to the surface of the electroconductive support body 11 or the surface of the intermediate | middle layer 15 formed on the electroconductive support body 11, then drying and removing the organic solvent is mentioned.

  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 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 method for applying the charge generation layer forming coating solution include roll coating, spray coating, blade coating, ring coating, and dip coating.
The dip coating method is a method of forming a layer on the conductive support 11 by immersing the conductive support 11 in a coating tank filled with a coating solution, and then pulling it up at a constant speed or a sequentially changing speed. . Since this method is relatively simple and excellent in terms of productivity and cost, it is widely used for producing an electrophotographic photosensitive member. In addition, you may provide the coating liquid dispersion | distribution apparatus represented by the ultrasonic generator in the apparatus used for the dip coating method in order to stabilize the dispersibility of a coating liquid.

The charge generation layer 12 is one kind selected from a hole transport material, an electron transport material, an antioxidant, a dispersion stabilizer, a sensitizer, a leveling agent, a plasticizer, fine particles of an inorganic compound or an organic compound, if necessary. Alternatively, two or more kinds may be included in appropriate amounts.
Plasticizers or leveling agents can improve film formability, flexibility, and surface smoothness.
Examples of the plasticizer include dibasic acid esters such as phthalate esters, fatty acid esters, phosphate esters, chlorinated paraffins, and epoxy type plasticizers.
As a leveling agent, a silicone type leveling agent etc. can be mentioned, for example.
Fine particles of an inorganic compound or an organic compound can enhance mechanical strength and improve electrical characteristics.

  The thickness of the charge generation layer 12 is not particularly limited, but is preferably 0.05 to 5 μm, 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 13]
The charge transport layer 13 contains a charge transport material, a binder resin, and an oxidation-resistant gas additive.
As the oxidation-resistant gas additive contained in the charge transport layer, the diamine compound (1) according to the present invention, other antioxidants, and the like can be used.

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.

As the binder resin, one or more of the same binder resins as those contained in the charge generation layer 12 can be used. In particular, polystyrene, polycarbonate, polyarylate, or polyphenylene oxide is preferably used because it has a volume resistivity of 10 ¹³ Ω · cm or more, excellent electrical insulation, and excellent film properties and potential characteristics. It is done.

The use ratio of the charge transport material and the binder resin is not particularly limited, but the ratio T / B is 10/30 or more and 10/12 or less when the weight T of the charge transport material and the weight B of the binder resin are used. Is preferred.
If the ratio T / B is less than 10/30, the sensitivity of the photoreceptor may be lowered.
On the other hand, if the ratio T / B exceeds 10/12, the film strength of the charge generation layer may be reduced, the dispersibility of the charge generation material is reduced, and coarse particles are increased. The surface charge of the image is reduced by exposure, and there is a possibility that image fogging, in particular, fogging of an image called a black spot where a toner adheres to a white background and a minute black spot is formed.

Further, when the charge transport layer is formed by the dip coating method, if the ratio T / B is less than 10/30, the viscosity of the coating solution increases, the coating speed decreases, and the productivity may be remarkably deteriorated. . Furthermore, if the amount of the solvent in the coating solution is increased in order to suppress an increase in the viscosity of the coating solution, a brushing phenomenon may occur, and the formed charge transport layer may become cloudy.
On the other hand, when the ratio T / B exceeds 10/12, the printing durability of the photosensitive layer decreases, the amount of film loss due to repeated use increases, and the chargeability of the photosensitive member may decrease.

  In addition to the two essential components, the charge transport layer may contain the same additive as that contained in the charge generation layer 12 as necessary.

The charge transport layer 13 is prepared by dissolving or dispersing a charge transport material, a binder resin and, if necessary, other additives in an appropriate organic solvent to prepare a coating solution for forming a charge transport layer. It can be formed by applying to the surface of 12 and then drying to remove the organic solvent. More specifically, for example, a charge transport layer forming coating solution is prepared by dissolving or dispersing a charge transport substance and, if necessary, other additives in a resin solution obtained by dissolving a binder resin in an organic solvent. Prepare.
Other steps and conditions are in accordance with the formation of the charge generation layer 12.

  The thickness of the charge transport layer 13 is not particularly limited, but is preferably 5 to 50 μm, 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 21]
The surface protective layer 21 has a function of improving the durability of the photoreceptor, is made of a resin, and may contain a charge transport material in order to improve the responsiveness of the photoreceptor.
As the resin, one or more of the same binder resins as those contained in the charge generation layer 12 can be used.
As the charge transport material, one or more of the same charge transport materials as those contained in the charge transport layer 13 can be used.

For example, the surface protective layer 21 is prepared by dissolving or dispersing a charge transport material and a binder resin in an appropriate organic solvent to prepare a coating solution for forming a surface protective layer. It can be formed by applying to the surface of the layer 14 and removing the organic solvent by drying. As the organic solvent used here, the same organic solvent used for forming the photosensitive layer can be used.
Other steps and conditions are in accordance with the formation of the charge generation layer 12.
As the organic solvent, one or more of the same solvents as those used for preparing the coating liquid for forming the charge generation layer 12 can be used.

The film thickness of the surface protective layer 21 is not particularly limited, but is preferably 0.1 to 10 μm, and particularly preferably 1 to 8 μm.
When the photoconductor is mounted and used in an image forming apparatus, ozone and nitrogen oxides generated from a corona discharger adhere to the photoconductor surface, and an image flows in the direction of the image forming surface of the transfer material. In other words, so-called image flow may occur. In order to prevent this image flow, the photosensitive layer is configured to be worn at a speed equal to or higher than a certain speed. For this reason, when considering long-term repeated use, the film thickness of the surface protective layer 21 is preferably 0.1 μm or more. If the thickness of the surface protective layer is less than 0.1 μm, the surface protective layer may disappear in a short period of time and the life of the photoreceptor may be shortened. On the other hand, if the film thickness of the surface protective layer exceeds 10 μm, there is a risk that the residual potential increases due to repeated use and the resolution decreases such as a decrease in fine dot reproducibility.

[Intermediate layer 15]
The photoreceptor of the present invention preferably has an intermediate layer 15 between the conductive support 11 and the laminated photosensitive layer.
The intermediate layer 15 has a function of preventing charge injection from the conductive support to the laminated photosensitive layer. That is, a decrease in chargeability of the laminated photosensitive layer is suppressed, a decrease in surface charge other than a portion to be erased by exposure is suppressed, and 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 intermediate layer 15 that covers the surface of the conductive support 11 with the intermediate layer 15 reduces the degree of unevenness that is a defect on the surface of the conductive support 11 and makes the surface uniform, thereby forming a laminated photosensitive layer. The film property can be improved and the adhesion between the conductive support 11 and the laminated photosensitive layer can be improved.

  The intermediate layer 15 is prepared by, for example, preparing a coating solution for forming an intermediate layer by dissolving a resin material in an appropriate solvent, applying the coating solution to the surface of the conductive support 11, and removing the organic solvent by drying. Can be formed.

Examples of the resin material include natural polymer materials such as casein, gelatin, polyvinyl alcohol, and ethyl cellulose in addition to the same binder resin as that contained in the charge generation layer, and one or more of these materials are used. it can. Among these resins, polyamide resins are preferable, and alcohol-soluble nylon resins are particularly preferable.
Examples of alcohol-soluble nylon resins include copolymerized nylons obtained by copolymerizing 6-nylon, 6,6-nylon, 6,10-nylon, 11-nylon, 12-nylon, and the like; N-alkoxymethyl-modified nylon and N- Examples thereof include a resin obtained by chemically modifying nylon such as alkoxyethyl-modified nylon.

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 steps and conditions are in accordance with the formation of the charge generation layer 12.

Moreover, the coating liquid for intermediate | middle layer formation may contain the metal oxide particle.
The metal oxide particles can easily adjust the volume resistance value of the intermediate layer, can further suppress the injection of charges into the laminated photosensitive layer, and can maintain the electrical characteristics of the photoreceptor in various environments.
Examples of the metal oxide particles include titanium oxide, aluminum oxide, aluminum hydroxide, and tin oxide.
When the total content of the resin material and the metal oxide particles in the coating liquid for forming the intermediate layer is C and the content of the solvent is D, the weight ratio (C / D) of both is 1/99 to 40/60. Is preferable, and 2/98 to 30/70 is particularly preferable.
The weight ratio (E / F) of the resin material content (E) and the metal oxide particle content (F) is preferably 1/99 to 90/10, and preferably 5/95 to 70/30. Particularly preferred.

Although the film thickness of the intermediate | middle layer 15 is not specifically limited, 0.01-20 micrometers is preferable and 0.1-10 micrometers is especially preferable. If the thickness of the intermediate layer is less than 0.01 μm, the intermediate layer substantially does not function, and there is a possibility that a uniform surface cannot be obtained by covering the defects of the conductive support 11. If it exceeds 20 μm, it is difficult to form a uniform intermediate layer, and the sensitivity of the photoreceptor may be lowered.
In addition, when the constituent material of the electroconductive support 11 is aluminum, a layer containing alumite (alumite layer) can be formed to form an intermediate layer.

  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.
An image forming apparatus 100 shown in FIG. 5 mounts, for example, a cylindrical photoconductor 7 having the same layer configuration as that of the photoconductor 1 shown in FIG.
The image forming apparatus 100 is rotatably supported by an apparatus main body (not shown), and is rotationally driven around the rotation axis 44 in the direction of an arrow 41 by a driving means (not shown). For example, the driving means includes a motor as a power source, and transmits the power from the motor to a support body constituting the core of the photoconductor 7 via a gear (not shown), thereby rotating the photoconductor 7 at a predetermined peripheral speed. Drive.
Around the photoconductor 7, a charger 32, an exposure unit 30, a developing device 33, a transfer device 34, and a cleaner 36 are downstream from the upstream side in the rotation direction of the photoconductor 7 indicated by an arrow 41. In this order towards the side. The cleaner 36 is provided together with a static elimination lamp (not shown).

The charger 32 is a charging unit that charges the surface 43 of the photoreceptor 7 to a predetermined potential, and is a non-contact charging method such as a corona discharge charger. As an example of the charging means, there is a contact charging method such as a charging roller in addition to the non-contact charging method, but the contact charging method emits less oxidizing gas than the non-contact charging method, but the photoconductor Since it is in direct contact with the surface, the surface of the photoreceptor is easily worn or scratched by rubbing, and is inferior in mechanical durability. Since the photoconductor of the present invention in which the diamine compound represented by the general formula (1) is added to the charge generation layer 12 is very excellent in oxidation resistance gas resistance, charging that charges the photoconductor in the image forming apparatus is possible. As a means, it can be used in combination with a non-contact charging method that releases more oxidizing gas than a contact charging method.
Since the non-contact charging method does not directly contact the photoconductor, the photoconductor surface is not easily worn or scratched by rubbing, has excellent mechanical durability, and can extend the life of the photoconductor.

  The exposure unit 30 includes, for example, a semiconductor laser as a light source, and exposes the surface 43 of the charged photoconductor 7 with light 31 such as a laser beam output according to image information from the light source. An electrostatic latent image is formed on the surface 43 of the substrate.

  The developing device 33 is a developing unit that develops the electrostatic latent image formed on the surface 43 of the photoconductor 7 with a developer to form a visible toner image, and is provided facing the photoconductor 7. A developing roller 33a for supplying toner to the surface 43 of the photosensitive member 7, and a developing roller 33a that supports the developing roller 33a so as to be rotatable about a rotational axis parallel to the rotational axis 44 of the photosensitive member 7, and a developer containing toner in the internal space thereof. And a casing 33b for housing.

  The transfer unit 34 is a transfer unit that transfers the toner image formed on the surface 43 of the photoconductor 7 from the surface 43 of the photoconductor 7 onto the recording paper 51 that is a transfer material. The transfer unit 34 includes a charging unit such as a corona discharge charger, and is a non-contact type transfer unit that transfers a toner image onto the recording paper 51 by applying a charge having a polarity opposite to that of the toner to the recording paper 51. .

The cleaner 36 is a cleaning unit that cleans the surface of the photoconductor 7 after the toner image is transferred. The toner 36 is pressed against the photoconductor surface 43 and remains on the surface 43 of the photoconductor 7 after the transfer operation by the transfer unit 34. A cleaning blade 36a for separating the toner from the surface 43, and a recovery casing 36b for storing the toner peeled by the cleaning blade 36a.
In addition, a fixing unit 35 that is a fixing unit that fixes the transferred toner image is provided in the direction in which the recording paper 51 is conveyed after passing between the photosensitive member 7 and the transfer unit 34. The fixing device 35 includes a heating roller 35a having a heating unit (not shown), and a pressure roller 35b provided to face the heating roller 35a and pressed by the heating roller 35a to form a contact portion.

An image forming operation by the image forming apparatus 100 will be described.
First, in response to an instruction from a control unit (not shown), the photosensitive member 7 is rotationally driven in the direction of the arrow 41 by the driving unit, and is upstream of the image forming point of the light 31 from the exposure unit 30 in the rotational direction of the photosensitive member 7. The surface 43 is uniformly charged to a predetermined positive or negative potential by the charger 32 provided on the side.

  Next, in response to an instruction from the control unit, light 31 is irradiated from the exposure unit 30 to the charged surface 43 of the photoreceptor 7. The light 31 from the light source is repeatedly scanned in the longitudinal direction of the photoconductor 7 which is the main scanning direction based on the image information. By rotating the photosensitive member 7 and repeatedly scanning the light 31 from the light source based on the image information, the surface 43 of the photosensitive member 7 can be exposed according to the image information. By this exposure, the surface charge of the portion irradiated with the light 31 is reduced, and a difference occurs between the surface potential of the portion irradiated with the light 31 and the surface potential of the portion not irradiated with the light 31. An electrostatic latent image is formed on the surface 43. In synchronism with the exposure of the photoconductor 7, the recording paper 51 is supplied to the transfer position between the transfer device 34 and the photoconductor 7 from the direction of the arrow 42 by a conveying unit (not shown).

  Next, toner is applied from the developing roller 33a of the developing unit 33 provided on the downstream side in the rotation direction of the photoconductor 7 from the image formation point of the light 31 from the light source to the surface 43 of the photoconductor 7 on which the electrostatic latent image is formed. Is supplied. As a result, the electrostatic latent image is developed, and a visible toner image is formed on the surface 43 of the photoreceptor 7. When the recording paper 51 is supplied between the photoconductor 7 and the transfer device 34, the transfer device 34 applies a charge having a polarity opposite to that of the toner to the recording paper 51, thereby forming the surface 43 of the photoconductor 7. The toner image is transferred onto the recording paper 51.

  The recording paper 51 to which the toner image has been transferred is conveyed to the fixing device 35 by the conveying means, and is heated and pressurized when passing through the contact portion between the heating roller 35a and the pressure roller 35b of the fixing device 35. As a result, the toner image on the recording paper 51 is fixed on the recording paper 51 and becomes a robust image. The recording paper 51 on which the image is formed in this way is discharged to the outside of the image forming apparatus 100 by the conveying means.

  On the other hand, after the toner image is transferred to the recording paper 51, the photoreceptor 7 that further rotates in the direction of the arrow 41 is cleaned by the surface 43 being scraped by a cleaning blade 36 a provided in the cleaner 36. The charge is removed from the surface 43 of the photoreceptor 7 from which the toner has been removed in this manner by the light from the charge eliminating lamp. As a result, the electrostatic latent image on the surface 43 of the photoreceptor 7 disappears. Thereafter, the photoconductor 7 is further rotated and a series of operations starting from charging of the photoconductor 7 is repeated again. As described above, images are continuously formed.

As described above, the photoconductor 7 provided in the image forming apparatus 100 contains the diamine compound represented by the general formula (1) in the charge generation layer 12 and has electrical characteristics such as chargeability, sensitivity, and responsiveness. In addition to being excellent, it has excellent oxidation resistance gas resistance, and even if it is used repeatedly, the above-mentioned good electrical characteristics are not deteriorated, and it has excellent electrical durability. Therefore, a highly reliable image forming apparatus 100 that can stably form a high-quality image over a long period of time is realized.
The image forming apparatus of the present invention is not limited to the configuration of the image forming apparatus 100 shown in FIG. 5 described above, and is different as long as the photoconductor according to the present invention can be used. It may be a configuration.

In the image forming apparatus 100 according to the present embodiment, the transfer unit 34 is a non-contact type transfer unit that performs transfer without using a pressing force. However, the transfer device 34 is not limited thereto, and the transfer is performed using the pressing force. It may be a contact type transfer means. As the contact-type transfer means, for example, a transfer roller is provided, and the transfer roller is pressed against the photoconductor 7 from the surface opposite to the contact surface with the surface 43 of the photoconductor 7 of the recording paper 51, and the photoconductor 7 and the recording paper 51 can be used such that a toner image is transferred onto the recording paper 51 by applying a voltage to the transfer roller while the recording paper 51 is in pressure contact.
Since the image forming apparatus 100 according to the present invention includes the photoreceptor 7 having the charge generation layer 12 in which the diamine compound of the present invention is uniformly dispersed, a high-quality image free from image defects such as black spots can be formed. .

The present invention will be specifically described below with reference to synthesis examples, production examples, comparative production examples, examples, and comparative examples, but the present invention is not limited to these synthesis examples, production examples, and examples.
In addition, the chemical structure, molecular weight, and elemental analysis of the compound obtained by the synthesis 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.

(Synthesis Example 1)
In the above reaction formula, dibenzylamine as the secondary amine compound represented by the general formulas (4) and (5), and 4,4′-bis (chloromethyl) as the dihalogen compound represented by the general formula (6). According to the following reaction formula using biphenyl, Exemplified Compound No. 1 (Structural Formula (I)) was synthesized.

[Production of Amine-Bisaldehyde Intermediate]
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 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%.

(Synthesis Examples 2 to 10)
In Synthesis Example 1, the same operation was carried out using the secondary amine compounds represented by the general formulas (4) and (5) and the respective raw material compounds shown in Table 2 as the dihalogen compound represented by the general formula (6). Exemplified Compound No. 3, 7, 13, 21, 28, 37, 49, 52 and 56 were produced, respectively. In Table 2, Exemplified Compound No. 1 raw material compounds are also shown.

  In addition, Table 3 shows the elemental analysis values, the calculated molecular weights, and the actually measured values [M + H] obtained by LC-MS of the respective exemplary compounds obtained in Synthesis Examples 1 to 10.

(Production Example 1)
Exemplified Compound No. 1 which is a diamine compound according to the present invention produced in Synthesis Example 1 as follows. A photoreceptor having 1 in the charge generation layer was prepared. Two types of photoconductors were used: a photoconductor (evaluation device photoconductor) used for evaluation by an evaluation device, which will be described later, and a photoconductor used for evaluation using an actual machine (referred to as an actual photoconductor).
As the conductive support, an aluminum cylindrical conductive support having an outer diameter of 30 mm and a length in the longitudinal direction of 357 mm was used.

  7 parts by weight of titanium oxide (trade name: Taibake TTO55A, manufactured by Ishihara Sangyo Co., Ltd.) and 13 parts by weight of copolymer nylon resin (trade name: Amilan CM8000, manufactured by Toray Industries, Inc.), 159 parts by weight of methanol and 1,3-dioxolane In addition to the mixed solvent with 106 parts by weight, the coating solution for the intermediate layer was prepared by dispersion treatment with a paint shaker. The coating solution was filled in the coating tank, and the conductive support was immersed in the coating tank, then pulled up and dried naturally to form an intermediate layer having a thickness of 0.9 μm.

  Next, as a charge generation material, 2 parts by weight of titanyl phthalocyanine represented by the following structural formula (7) (for example, prepared by the method described in Japanese Patent No. 3569422), polyvinyl butyral resin (trade name: S-LEC BM-2) Sekisui Chemical Co., Ltd.) 1 part by weight and Exemplified Compound No. synthesized in Synthesis Example 1 0.06 part by weight of the diamine compound 1 was mixed with 97 parts by weight of methyl ethyl ketone and dispersed with a paint shaker to prepare a coating solution for forming a charge generation layer. This charge generation layer forming coating solution was applied to the surface of the previously provided intermediate layer in the same manner as the above intermediate layer and naturally dried to form a charge generation layer having a thickness of 0.4 μm.

  Next, as a charge transport material, 100 parts by weight of a charge transport material represented by the following structural formula (8) and 160 parts by weight of a polycarbonate resin (trade name: Iupilon Z400, manufactured by Mitsubishi Gas Chemical Co., Ltd.) and a hindered phenol antioxidant (Product name: Sumilizer BHT, manufactured by Sumitomo Chemical Co., Ltd.) 3 parts by weight were mixed, and the resulting mixture was dissolved in 980 parts by weight of tetrahydrofuran to prepare a coating solution for forming a charge transport layer. This charge transport layer forming coating solution is applied to the surface of the charge generation layer previously provided in the same manner as the intermediate layer and dried at a temperature of 130 ° C. so that the film thicknesses become 15 μm and 26 μm, respectively. Two types of charge transport layers having different film thicknesses were formed. In this way, a laminated photoreceptor according to the present invention having a laminated structure in which an intermediate layer, a charge generation layer, and a charge transport layer are sequentially laminated on the conductive support shown in FIG. 2 was produced.

(Production Examples 2 and 3)
In forming the charge generation layer, Exemplified Compound No. 1 which is a diamine compound according to the present invention is used. A laminated photoreceptor according to the present invention was produced in the same manner as in Production Example 1, except that 0.06 part by weight of 1 was changed to 0.002 part by weight and 0.2 part by weight.

(Production Examples 4 to 6)
In forming the charge generation layer, Exemplified Compound No. 1 which is a diamine compound according to the present invention is used. In place of Exemplified Compound No. 1 A laminated photoreceptor according to the present invention was produced in the same manner as in Production Example 1 except that 3, 13, and 28 were used.

(Production Examples 7 to 10)
In forming the charge generation layer, Exemplified Compound No. 1 which is a diamine compound according to the present invention is used. 1 in the same manner as in Production Example 1 except that 0.06 parts by weight of 1 was changed to 0.0002 parts by weight, 0.4 parts by weight, 0.00016 parts by weight and 0.44 parts by weight. A photoconductor was prepared.

(Production Example 11)
A laminated photoreceptor according to the present invention having a laminated structure in which a charge generation layer and a charge transport layer are sequentially laminated on a conductive support shown in FIG. 1 in the same manner as in Production Example 1 except that no intermediate layer is formed. Produced.
(Production Example 12)
In the formation of the charge transport layer, instead of the hindered phenol-based antioxidant and the Sumilizer BHT (trade name, manufactured by Sumitomo Chemical Co., Ltd.), Exemplified Compound No. A photoconductor of Preparation Example 12 was prepared in the same manner as Preparation Example 1 except that No. 1 was used.

(Comparative Production Example 1)
In forming the charge generation layer, Exemplified Compound No. 1 which is a diamine compound according to the present invention is used. A laminated photoreceptor was produced in the same manner as in Production Example 1 except that No. 1 was used.

(Comparative Production Example 2)
In forming the charge generation layer, Exemplified Compound No. 1 which is a diamine compound according to the present invention is used. A laminated photoreceptor was produced in the same manner as in Production Example 1 except that a hindered amine antioxidant represented by the following structural formula (9) was used instead of 1.

(Comparative Production Example 3)
In forming the charge generation layer, Exemplified Compound No. 1 which is a diamine compound according to the present invention is used. A laminated type photoreceptor was produced in the same manner as in Production Example 1 except that a hindered phenolic antioxidant (trade name: Sumilizer BHT, manufactured by Sumitomo Chemical Co., Ltd.) was used instead of 1.

(Examples 1-11, 13 and Comparative Examples 1-3)
About the photoconductor for evaluation devices and the photoconductor for actual devices of Production Examples 1 to 12 and Comparative Production Examples 1 to 3 produced as described above, (a) oxidation resistance gas resistance and (b) as follows. The electrical property stability (electrical durability) was evaluated, and (c) the overall performance of the photoreceptor was determined.

(A) Oxidation-resistant gas resistance [evaluation by an evaluation apparatus]
Each of the photoconductors for evaluation devices (film thickness of the charge transport layer: 15 μm) of Production Examples 1 to 12 and Comparative Production Examples 1 to 3 is mounted on an evaluation device (trade name: CYNTHIA 59, manufactured by Gentec Corporation), respectively. In a normal temperature / normal humidity (N / N) environment at a temperature of 25 ° C. and a relative humidity of 50%, the surface potential V ₁ (V) of the photoconductor immediately after charging and photosensitivity after elapse of 3 seconds from charging. The body surface potential V ₂ (V) was measured. 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 8.0 ppm (ozone concentration meter MODEL1200 (trade name) manufactured by Directec Co., Ltd.). Exposure to ozone for 24 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.

[Evaluation using actual equipment]
Each of the photoconductors for production machines (layer thickness of the charge transport layer: 26 μm) of Production Examples 1 to 12 and Comparative Production Examples 1 to 3 was mounted on a test copying machine (model: MX-2300, manufactured by Sharp Corporation), respectively. In a room temperature / normal humidity (N / N) environment at a temperature of 25 ° C. and a relative humidity of 50%, a test image having a predetermined pattern was photographed on 40,000 sheets of recording paper. The operation of the copying machine was stopped for 1 hour from the time when 40,000 shots were completed, and then a halftone image was copied on a recording sheet, which was used as a first evaluation image. Next, a test image of a predetermined pattern is photographed on 40,000 sheets of recording paper again in an N / N environment at a temperature of 25 ° C. and a relative humidity of 50%, and the copying machine operates for one hour from the point when 40,000 sheets are photographed. Then, a halftone image was copied on the recording paper, and this was used as a second evaluation image. Furthermore, a test image of a predetermined pattern is taken on 40,000 sheets of recording paper again in an N / N environment at a temperature of 25 ° C. and a relative humidity of 50%. Was stopped, a halftone image was copied on a recording sheet, and this was used as a third evaluation image.

  The first evaluation image, the second evaluation image, and the third evaluation image that are formed are visually observed, and a toner image is generated from a portion of the photoconductor that is disposed close to the charger when the operation of the copying machine is stopped. The image quality of the portion of the recording paper corresponding to the portion to which the image was transferred was determined based on the degree of occurrence of image defects such as white spots and black bands, and used as an evaluation index of oxidation resistance gas resistance. The criteria for determining the image quality are as follows.

Judgment A: No image defect has occurred. O: Some image defect has occurred but can be ignored. Δ: Some image defect has occurred, but there is no problem in actual use. Yes ×: Many image defects occur and cannot be used

Comprehensive determination of first to third evaluation images A: The first evaluation image and the second evaluation image are determinations ◎, and the third evaluation image is greater than or equal to the determination O: O: First evaluation image, first Both of the second evaluation image and the third evaluation image are equal to or more than determination Δ. Δ: At least one of the first evaluation image, the second evaluation image, and the third evaluation image has a determination Δ, and determination × No: x: At least one of the first evaluation image, the second evaluation image, and the third evaluation image has a determination x

The oxidation resistance gas resistance of the photoconductor was evaluated by combining the value of the charge retention rate change ΔDD and the overall determination of the first to third evaluation images. The evaluation criteria for the oxidation-resistant gas resistance are as follows.
◎: Excellent (ΔDD is less than 3.0% and image quality is excellent (◎))
○: Good (ΔDD is 3.0% or more and less than 10.0% and image quality is excellent (◎), or ΔDD is less than 10.0% and image quality is good (◯))
Δ: No problem in actual use (ΔDD is less than 10.0% and image quality is acceptable (Δ))
×: Defect (ΔDD is 10.0% or more, or image quality is not possible (×))

(B) Electrical characteristics and stability (electrical durability)
Each of the photoconductors for production machines (layer thickness of the charge transport layer: 26 μm) of Production Examples 1 to 12 and Comparative Production Examples 1 to 3 was mounted on a test copying machine (model: MX-2300, manufactured by Sharp Corporation), respectively. High temperature / high humidity (H / H) in a low temperature / low humidity (L / L) environment with a temperature of 5 ° C and a relative humidity of 20% and a temperature of 35 ° C and a relative humidity of 85%. In each environment, the electrical property stability (electrical durability) was evaluated as follows. The test copying machine is a negatively charged image forming apparatus that performs the electrophotographic process by negatively charging the surface of the photoconductor, and has a surface potential so that the surface potential of the photoconductor can be measured during the image forming process. A total (trade name: model 344, manufactured by Trek) was provided.

The surface potential of the photosensitive member immediately after the charging operation by the charger is measured as charge potential V0 (V), which was used as a charge potential V0 ₁ early. The measured surface potential of the photosensitive member immediately after subjected to exposure by laser light as the exposure potential VL (V), which was used as the initial exposure potential VL _1.
Then, after copying successively the test image of a predetermined pattern on the recording paper 100,000 sheets, the initial and in the same manner by measuring the charge potential V0 and exposure potential VL, charge potential V0 ₂ and after repeated use of these was the exposure potential VL ₂ after repeated use. 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 exposure potential VL ₁ and the exposure potential VL ₂ after repeated use was determined as an exposure potential change amount ΔVL (= | VL ₁ −VL ₂ |). Electrical characteristic stability (electric durability) was evaluated using the charging potential change amount ΔV0 and the exposure potential change amount ΔVL as evaluation indexes.

(Evaluation criteria for electrical property stability (electric durability) under L / L environment are as follows)
A: Excellent (ΔV0 is 25V or less and ΔVL is 30V or less)
○: Good (ΔV0 is 25V or less and ΔVL exceeds 30V and 60V or less, or ΔV0 exceeds 25V and 40V or less and ΔVL is 30V or less)
Δ: No problem in actual use (ΔV0 exceeds 25V and 40V or less, and ΔVL exceeds 30V and 60V or less)
X: Defect (ΔV0 exceeds 40V or ΔVL exceeds 60V)

Evaluation criteria for electrical property stability (electrical durability) under H / H environment are as follows.
A: Excellent (ΔV0 is 20V or less and ΔVL is 45V or less)
○: Good (ΔV0 is 20V or less and ΔVL exceeds 45V and 75V or less, or ΔV0 exceeds 20V and 35V or less and ΔVL is 45V or less)
Δ: No problem in actual use (ΔV0 exceeds 20V and 35V or less, and ΔVL exceeds 45V and 75V or less)
X: Defect (ΔV0 exceeds 35V or ΔVL exceeds 75V)

In addition, the evaluation result under the L / L environment and the evaluation result under the H / H environment were combined to make a comprehensive evaluation of the electrical property stability (electric durability). Evaluation criteria for comprehensive evaluation of electrical property stability (electric durability) are as follows.
A: Excellent (L / L environment and H / H environment are both excellent (A))
○: Good (L / L environment or H / H environment is good (◯) and the other is excellent (◎) or good (○))
Δ: No problem in actual use (There is no problem in actual use in either L / L environment or H / H environment (△) and the other is not defective (x))
X: Defect) Either one or both of L / L environment and H / H environment is defective (X))

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

(Example 12)
A photocopier (model: MX-) in which the photoconductor of Production Example 1 was modified to include a roller charger, which is one of contact charging methods, instead of the corona discharge charger, which is a photoconductor charging means of an actual test machine. 2300 (manufactured by Sharp Corporation), and (a) oxidation-resistant gas resistance and (b) electrical property stability (electrical durability) and (c) photoreceptor performance are comprehensively determined in the same manner as described above. It was. However, in the actual image taken by the actual machine at the time of evaluation, since the charger directly contacts the photoconductor, the film was significantly scraped and the actual image had to be interrupted. For this reason, the evaluation could not be continued.

The photoreceptors of Examples 1 to 8 and 13 containing the diamine compound represented by the general formula (1) in the charge generation layer are more resistant to oxidation gas than the photoreceptor of Comparative Example 1 which does not contain the diamine compound. In addition, it can be seen that it has excellent electrical property stability (electrical durability) and exhibits good electrical properties even when used repeatedly.
Therefore, by adding the diamine compound represented by the general formula (1) to the charge generation layer, the photoreceptor is protected from oxidizing gas such as ozone and nitrogen oxide released from the charger. It turns out that fatigue deterioration can be suppressed. It can also be seen that the addition of the diamine compound does not adversely affect the electrical characteristics such as chargeability, sensitivity, and responsiveness.

  In addition, the photoconductor of Comparative Example 1 containing a hindered phenol antioxidant (BHT) only in the charge transport layer has deteriorated in evaluation of oxidation resistance gas property and image quality with the passage of time. Recognize. Therefore, when a hindered phenol-based antioxidant (BHT) is added only to the charge transport layer, the oxidizing gas permeates the charge transport layer by exposure to the oxidizing gas for a long time, and the charge generation layer This suggests the possibility of deactivating the charge generation material.

The photoconductors of Examples 1 to 8 containing the diamine compound represented by the general formula (1) in the charge generation layer generate a hindered amine antioxidant or a hindered phenol antioxidant (BHT) as an antioxidant. It can be seen that the evaluation of the image quality is better than the photoreceptors of Comparative Examples 2 and 3 contained in the layer.
From this, it can be seen that the diamine compound represented by the general formula (1) is excellent in suppressing the fatigue deterioration of the photoreceptor due to the oxidizing gas.

  Further, in the photoreceptors of Comparative Examples 2 and 3 in which a hindered amine antioxidant or a hindered phenol antioxidant (BHT) is added to the charge generation layer, the diamine compound represented by the general formula (1) is added to the charge generation layer. Compared to the added photoreceptors of Examples 1 to 8, the initial exposure potential ΔVL and the exposure potential change ΔVL due to repeated use were large. From this, the addition of hindered amine antioxidants and hindered phenol antioxidants (BHT) to the charge generation layer is more sensitive to photoconductors exposed to oxidizing gas than diamine compounds represented by the general formula (1). Addition of the hindered amine antioxidant or hindered phenolic antioxidant (BHT) to the charge generation layer has an adverse effect on the charge generation material, and the responsiveness is small. It can be seen that electrical characteristics such as sensitivity and electrical characteristic stability (electrical durability) are deteriorated.

Comparing the photoconductor of Example 1 with the photoconductor of Example 11 having no intermediate layer, it can be seen that the latter photoconductor has a low initial charging potential V0 ₁ and a low image quality evaluation. Therefore, in the latter photoreceptor, charges are injected from the conductive support to the photosensitive layer, the chargeability of the photoreceptor is reduced, surface charges other than the exposed areas are reduced, and the image is defective. It can be seen that

  The photoconductors of Examples 1 to 3, 7 and 8 containing the diamine compound represented by the general formula (1) in the charge generation layer in a ratio of 0.01 to 20 parts by weight with respect to 100 parts by weight of the charge generation material, It can be seen that the evaluation of the image quality is good as compared with the photoreceptor of Example 9 containing the diamine compound in a proportion of less than 0.01 part by weight with respect to 100 parts by weight of the charge generating material.

  Furthermore, the photoconductors of Examples 1 to 3 in which the charge generation layer contains the diamine compound represented by the general formula (1) at a ratio of 0.1 to 10 parts by weight with respect to 100 parts by weight of the charge generation material is the diamine. It can be seen that the compound is superior in oxidation gas resistance as compared with the photoreceptor of Example 7 containing the compound in a proportion of less than 0.1 part by weight with respect to 100 parts by weight of the charge generating material.

In addition, the photoconductors of Examples 1 to 3, 7 and 8 in which the charge generation layer contains the diamine compound represented by the general formula (1) in a ratio of 0.01 to 20 parts by weight with respect to 100 parts by weight of the charge generation material. Compared with the photoreceptor of Example 10 containing the diamine compound in a proportion exceeding 20 parts by weight with respect to 100 parts by weight of the charge generating material, the initial exposure potential VL ₁ is small, and the charging potential by repeated use is The change amount ΔV0 and the exposure potential change amount ΔVL are small, and it can be seen that the electrical characteristics of responsiveness and sensitivity and its stability (electrical durability) are excellent.

  Furthermore, the photoconductors of Examples 1 to 3 in which the charge generation layer contains the diamine compound represented by the general formula (1) at a ratio of 0.1 to 10 parts by weight with respect to 100 parts by weight of the charge generation material is the diamine. Compared to the photoreceptor of Example 8 containing the compound in a proportion exceeding 10 parts by weight with respect to 100 parts by weight of the charge generating material, the responsiveness, the electrical characteristics of the sensitivity and its stability (electric durability) are excellent. I understand that.

  From the above, the ratio G / J between the weight G of the charge generating substance and the weight J of the diamine compound represented by the general formula (1) is preferably 100 / 0.01 or more and 100 / 20.0 or less, It can be seen that 0.1 to 100 / 10.0 is more preferable.

  From a comparison between Example 1 and Example 12, the photoconductor containing the diamine compound represented by the general formula (1) in the charge generation layer has a non-contact charging method in which the generation amount of oxidizing gas is larger than that in the contact charging method. It can be seen that even in the environment, it exhibits excellent oxidation resistance gas resistance. That is, the photoconductor of the present invention can be used together with an image forming apparatus having non-contact charging as a charging means. It can be seen that it is a long-life photoreceptor that is difficult to stick and has excellent mechanical durability.

  As described above, by containing the diamine compound of the present invention represented by the general formula (1) in the charge generation layer, the electrical characteristics such as charging property, sensitivity and responsiveness are excellent, and ozone gas resistance and nitrogen resistance are excellent. It was possible to obtain a long-life electrophotographic photosensitive member excellent in oxidation resistance gas resistance such as oxide property, and excellent in electric durability in which the above-mentioned good electric characteristics were not deteriorated even when used repeatedly.

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. 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

1, 2, 3, 4, 7 Electrophotographic photoreceptor 10, 16, 18, 19 Photosensitive layer 11 Conductive support 12 Charge generation layer 13 Charge transport layer 14 Multilayer photoconductive layer 15 Intermediate layer 21 Surface protective layer 100 Image Forming device 44 Rotating axis 41, 42 Arrow 32 Charging means (charger)
33 Developing means (developer)
33a Developing roller 33b Casing 34 Transfer device 36 Cleaner 36a Cleaning blade 36b Recovery casing 30 Exposure means 31 Light 51 Recording paper 35 Fixing device 35a Heating roller 35b Pressure roller 43 Surface of electrophotographic photosensitive member

Claims (8)

An electrophotographic film in which a multilayer photosensitive layer in which a charge generation layer containing a charge generation material and a charge transport layer containing a charge transport material are laminated in this order on a conductive support made of a conductive material is laminated. A photosensitive member, wherein the charge transport layer of the multilayer photosensitive layer contains an oxidation-resistant gas additive, and the charge generation layer of the multilayer photosensitive 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)
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 2, which is represented by: The diamine compound has the structural formula (I):

The electrophotographic photosensitive member according to claim 3, which is represented by:   The electron according to any one of claims 1 to 4, wherein a ratio G / J of a weight G of the charge generation material to a weight J of the diamine compound is 100 / 0.01 or more and 100 / 20.0 or less. Photoconductor.   The electrophotographic photosensitive member according to claim 1, further comprising an intermediate layer between the conductive support and the laminated photosensitive 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 non-contact charging method.

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