JP4335850B2 - Electrophotographic photosensitive member and image forming apparatus having the same - Google Patents

Description

  The present invention relates to an electrophotographic photosensitive member used for image formation by an electrophotographic method and an image forming apparatus including the same.

  2. Description of the Related Art An electrophotographic image forming apparatus that forms an image using electrophotographic technology is widely used as a copying machine, a printer, a facsimile machine, or the like. In an electrophotographic image forming apparatus, an image is formed through an electrophotographic process using a photoconductive electrophotographic photosensitive member (hereinafter also simply referred to as a photosensitive member). The electrophotographic process is one of information recording means using the photoconductive phenomenon of the photoreceptor, and is performed as follows.

  First, the photosensitive member is placed in a dark place, and the surface of the photosensitive member is uniformly charged by a charging unit, and then exposure corresponding to image information is performed to selectively discharge the surface charge of the exposed portion. As a result, the surface charge remains only in the non-exposed portion of the photoreceptor, and a difference occurs between the surface charge in the exposed portion and the surface charge in the non-exposed portion, and an electrostatic latent image is formed. Next, colored fine particles called toner are adhered to the formed electrostatic latent image by electrostatic attraction or the like to form a visible toner image. The formed toner image is transferred onto a transfer material such as paper and fixed as necessary to form an image.

  The photoreceptor used in the electrophotographic technology for forming an image through the series of electrophotographic processes described above has excellent electrical characteristics as a basic characteristic, for example, excellent charge holding ability, and discharge of charge in the dark. It is required to have a small amount of light, to have excellent photosensitivity, and to quickly discharge charges by light irradiation. In addition, the above-described electrical characteristics are stable even during repeated use so that a homogeneous image can be formed on the photoreceptor for a long period of time, and the stability of the electrical characteristics (hereinafter, also simply referred to as characteristic stability). ) Is also required.

In recent years, electrophotographic technology has been used not only in the field of copying machines, but also in fields such as printing plate materials, slide films, and microfilms that previously used silver salt photographic technology. Light Emitting Diode (abbreviation LED) or cathode ray tube (
Cathode Ray Tube (abbreviated as CRT) is also applied to a high-speed printer using a light source. With the expansion of the application range of electrophotographic technology, the demand for electrophotographic photoreceptors is becoming advanced and wide.

  The electrophotographic photoreceptor has a configuration in which a photosensitive layer containing a photoconductive material is laminated on a conductive support. As an electrophotographic photoreceptor, an inorganic photoreceptor having a photosensitive layer mainly composed of an inorganic photoconductive material such as selenium, zinc oxide or cadmium sulfide has been widely used. Although the inorganic photoreceptor has some basic characteristics as a photoreceptor, it has drawbacks such as difficulty in forming a photosensitive layer, poor plasticity, and high manufacturing cost. 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. Organic photoconductive materials have been widely researched and developed in recent years, and are not only used for electrostatic recording elements such as electrophotographic photoreceptors, but also applied to sensors or organic electroluminescent (EL) elements. Being started.

  Organic photoconductors using organic photoconductive materials have good film-forming properties, excellent flexibility, light weight, good transparency, and a wide wavelength range by appropriate sensitization methods. However, it has been developed as a mainstay of electrophotographic photosensitive members because it has an advantage that a photosensitive member exhibiting good sensitivity can be easily designed.

  Recently, a function-separated electrophotographic photosensitive member in which a charge generation function and a charge transport function are assigned to different substances has been developed. In the function-separated type photoreceptor, since the charge generation material responsible for the charge generation function and the charge transport material responsible for the charge transport function are separate materials, it is easy to select materials used for the charge generation material and the charge transport material, It is widely used because it has an advantage that an electrophotographic photoreceptor having arbitrary characteristics can be produced relatively easily. Although early organic photoreceptors had drawbacks in sensitivity and durability, these drawbacks have been significantly improved by the development of a function-separated electrophotographic photoreceptor.

  The function-separated type photoreceptor includes a single-layer type photoreceptor having a photosensitive layer in which a charge generation material and a charge transport material are co-dispersed in a binder resin called a binder resin, and the charge generation material is dispersed. The photoconductive layer is roughly classified into a multilayer type photoreceptor having a photosensitive layer formed by laminating a charge generation layer and a charge transport layer in which a charge transport material is dispersed.

  As the layered photoreceptor, a positive two-layer photoreceptor in which a charge transport layer is provided on the surface portion side of the photoreceptor and a charge generation layer is provided on the conductive support side is frequently used. The positive two-layer type photoreceptor has a charge transport layer laminated on the charge generation layer, and the charge transport layer usually has only a hole transport function, so that it has sensitivity in a negatively charged state and is negatively charged. Mainly used below. In addition, as a layered photoreceptor that can be used under positive charging, a reverse two-layer photoreceptor in which a charge transport layer is provided on the conductive support side and a charge generation layer is provided on the surface side of the photoreceptor is also developed. It has been broken.

  However, conventional photoreceptors have insufficient characteristic stability, and repeated use causes fatigue degradation such as a decrease in charging potential, an increase in residual potential, and a decrease in surface potential, resulting in a decrease in resolution, white spots, and white spots. It has the disadvantage of causing image defects such as black belts. Here, the white spot is a phenomenon in which a portion where the toner is not attached is generated in a portion where the toner is to be attached. Further, the black belt is a phenomenon in which a portion where the toner adheres in a strip shape occurs between the portion where the toner should adhere and the other portion.

  The cause of fatigue deterioration of the photoreceptor is that ozone discharged from a corona discharge charger (hereinafter referred to as a corona discharge charger) used as a charging means in the charging process and the released ozone is nitrogen in the air. It is conceivable that an oxidizing gas such as nitrogen oxide generated by the reaction with the material oxidizes the material constituting the surface of the photoreceptor and the photosensitive layer, and damages the photoreceptor such as a decrease in surface resistance.

  As an attempt to solve the problem of fatigue deterioration of the photoreceptor from the viewpoint of the apparatus, it has been proposed to provide an exhaust system in the image forming apparatus and efficiently exhaust the oxidizing gas around the corona discharge charger. However, providing the exhaust system in the image forming apparatus causes a problem that the apparatus configuration becomes complicated.

  Attempts have also been made to suppress fatigue deterioration of the photoreceptor by improving the gas barrier properties of the photosensitive layer and making it difficult for the oxidizing gas to permeate. However, a photosensitive layer having sufficient gas barrier properties has not been realized.

  Further, in order to improve the resistance of the photoreceptor to the oxidizing gas (hereinafter referred to as “oxidizing gas resistance”) itself, attempts have been made to add an antioxidant, a stabilizer, or the like to the photosensitive layer. For example, it has been proposed to add a hindered phenol-based antioxidant such as a compound having a triazine ring and a hindered phenol skeleton to the photosensitive layer (see Patent Document 1).

  In another prior art, it is proposed to add a hindered phenolic antioxidant, a phosphite antioxidant, an amine antioxidant or the like as an additive to a photosensitive layer containing a specific arylamine compound. (See Patent Document 2). In another prior art, it has been proposed to add a compound having a hindered amine skeleton and an amine compound having a specific structure such as tribenzylamine to the photosensitive layer (see Patent Document 3).

  Here, the compound having a hindered phenol skeleton is a phenol compound having a bulky substituent such as a branched alkyl group, a cycloalkyl group, an aryl group, or a heterocyclic group at the position adjacent to the phenolic hydroxyl group. It is. The compound having a hindered amine skeleton is an amine compound in which a hydrogen atom of an amino group is substituted with a bulky substituent such as a branched alkyl group, a cycloalkyl group, an aryl group, or a heterocyclic group.

JP 62-105151 A JP-A-8-292587 Japanese Patent Laid-Open No. 10-282696

  In the technique disclosed in Patent Document 1 described above, attempts are made to suppress fatigue deterioration of the photoreceptor by adding a hindered phenol-based antioxidant to the photosensitive layer, but halftone (halftone; (Abbreviation HF) There is a problem that image degradation such as a black belt occurs. This is because the photosensitive member is not sufficiently resistant to oxidation gas, and the material constituting the photosensitive layer is altered by the oxidizing gas such as ozone remaining around the corona discharge charger when the image forming apparatus is stopped. This is thought to be due to changes in the charging characteristics of the body. Here, the HF black belt refers to a photoconductor disposed close to the charger when the halftone image is formed again after the image forming apparatus is stopped for a certain period of time after image formation. This is a phenomenon in which a portion where the toner adheres in a band shape is generated at a portion of the recording material corresponding to a portion where the toner image is transferred from the portion. A halftone image is an image in which the gradation of an image is expressed by gradation using black and white dots.

  Further, when an antioxidant disclosed in Patent Documents 1 to 3 is added to the photosensitive layer, an electrophotographic process for performing charging, exposure, static elimination, etc. occurs due to a decrease in sensitivity and a decrease in response due to a change in photosensitive wavelength. There is also a problem that the charging potential decreases and the residual potential increases while the process is repeated.

  Thus, in the prior art, a photoreceptor that satisfies both good electrical characteristics and stability thereof has not been realized.

  An object of the present invention is an electrophotographic film having excellent electrical characteristics such as charging property, sensitivity and responsiveness, excellent oxidation-resistant gas resistance, and excellent property stability that does not deteriorate the above-mentioned good electrical property even when used repeatedly. It is an object to provide a photoreceptor and an image forming apparatus including the same.

  As a result of researches to solve the above-mentioned problems, the present inventors have added a specific amine compound to the undercoat layer provided between the conductive support constituting the electrophotographic photoreceptor and the photosensitive layer. However, it exhibits a strong inhibitory effect on the oxidation of the photosensitive layer by oxidizing gases such as ozone, while maintaining good electrical characteristics such as chargeability, sensitivity, and responsiveness, while maintaining the oxidation resistance of the electrophotographic photoreceptor. The present inventors have found that the gas property can be improved and completed the present invention.

That is, the present invention is an electrophotographic photosensitive member having a conductive support made of a conductive material, and a photosensitive layer provided on the conductive support and containing a charge generation material and a charge transport material,
An undercoat layer provided between the conductive support and the photosensitive layer and containing an amine compound represented by the following general formula (1);
In the general formula (1), R ¹ , R ² and R ³ are each an aralkyl group which may have a substituent,
The photosensitive layer comprises a charge generation layer provided on the undercoat layer, and a charge transport layer provided on the charge generation layer,
The charge generation layer is composed of a charge generation material and a binder resin,
The charge generation material is a titanyl phthalocyanine compound represented by the following general formula (2):
The charge transport layer is composed of a charge transport material and a binder resin,
The charge transporting material is an electrophotographic photosensitive member characterized by being an enamine compound represented by the following general formula (3) .

(In the formula, R ¹ , R ² and R ³ each represents an aralkyl group which may have a substituent.)

  In the present invention, the amine compound represented by the general formula (1) is an amine compound represented by the following structural formula (1a).

  The present invention is also characterized in that the content of the amine compound represented by the general formula (1) is 0.1% by weight or more and 30% by weight or less of the total solid content of the undercoat layer.

  The present invention is also characterized in that the content of the amine compound represented by the general formula (1) is 1% by weight or more and 10% by weight or less of the total solid content of the undercoat layer.

The present invention also provides the electrophotographic photoreceptor of the present invention,
Charging means for charging the electrophotographic photoreceptor;
Exposure means for exposing the charged electrophotographic photosensitive member;
An image forming apparatus comprising: a developing unit that develops an electrostatic latent image formed by exposure.

According to the present invention, an electrophotographic photosensitive member (hereinafter, simply also photosensitive body referred to) containing the amine compound represented by the general formula (1) between the electroconductive support and the sensitive optical layer of subbing A layer is provided. In the general formula (1), R ¹ , R ² and R ³ are each an aralkyl group which may have a substituent, the photosensitive layer is composed of a charge generation layer and a charge transport layer, The charge transport material is composed of a titanyl phthalocyanine compound represented by the general formula (2) and a binder resin, and the charge transport layer is composed of an enamine compound and a binder resin represented by the general formula (3) which are charge transport materials. As a result, it is possible to impart oxidation resistance gas resistance such as ozone resistance and nitrogen oxide resistance to the photoreceptor without deteriorating electrical characteristics such as chargeability, sensitivity and responsiveness. Thus, strip conductive, excellent in electric characteristics such as sensitivity and responsiveness, high oxidation resistance and gas resistance, the electrophotographic photosensitive member be repeatedly used superior properties stability good electrical characteristics described above is not reduced Can be realized.
Further, since the charge generating material is a titanyl phthalocyanine compound represented by the general formula (2), an undercoat layer containing an amine compound represented by the general formula (1) is provided between the conductive support and the photosensitive layer. It is possible to further suppress the deterioration of the electric characteristics due to the provision, and to improve the electric characteristics such as the chargeability, sensitivity and responsiveness of the photoreceptor. Since Also electrostatic charge transport material is a enamine compound represented by a general formula (3), subbing containing amine compound represented by the general formula (1) between the electroconductive support and the photosensitive layer It is possible to further suppress the deterioration of the electric characteristics due to the provision of the layer, and to further improve the electric characteristics such as charging property, sensitivity and responsiveness of the photoreceptor. In particular, since the charge generation material is a titanyl phthalocyanine compound represented by the general formula (2) and the charge transport material is an enamine compound represented by the general formula (3), sensitivity characteristics, charging characteristics, and image reproducibility are improved. A particularly excellent photoreceptor can be realized.

According to the present invention, Among the general formula (1) an amine compound represented by the amine compound represented by the structural formula (1a) are particularly preferred. This amine compound exhibits a particularly excellent suppression effect against fatigue deterioration of the photoreceptor due to the oxidizing gas. Therefore, by adding this amine compound to the undercoat layer, a highly reliable electrophotographic photoreceptor excellent in oxidation-resistant gas property and showing stable electric characteristics during repeated use is realized.

  According to the invention, the content of the amine compound represented by the general formula (1) contained in the undercoat layer is 0.1 wt% or more and 30 wt% or less of the total solid content of the undercoat layer. Preferably, it is 1% by weight or more and 10% by weight or less of the total solid content of the undercoat layer. By selecting the content of the amine compound represented by the general formula (1) within the above range, it is possible to realize an electrophotographic photosensitive member particularly excellent in oxidation resistance gas resistance. Further, the undercoat layer containing the amine compound represented by the general formula (1) has a small contribution to charge generation and charge transport in the electrophotographic photoreceptor of the present invention. Therefore, in the electrophotographic photoreceptor of the present invention, The content of the amine compound represented by the general formula (1) can be selected within the above range without deteriorating electric characteristics such as chargeability, sensitivity and responsiveness. Therefore, an electrophotographic photosensitive member that has good electrical characteristics such as chargeability, sensitivity and responsiveness, is particularly excellent in oxidation-resistant gas resistance, and exhibits good electrical characteristics even in the initial stage of use even after repeated use. Realized.

  Further, according to the present invention, the electrophotographic photosensitive member of the image forming apparatus is excellent in electric characteristics such as charging property, sensitivity and responsiveness, in addition to excellent oxidation resistance gas resistance, and the above-mentioned good even when used repeatedly. The electrophotographic photosensitive member of the present invention is used which has excellent characteristic stability without deteriorating electrical characteristics. As a result, it is possible to realize an image forming apparatus having high durability and capable of stably forming a high-quality image with high resolution and no image defects over a long period of time.

  FIG. 1 is a partial cross-sectional view showing a simplified configuration of an electrophotographic photosensitive member 1 according to a first embodiment of the present invention. The electrophotographic photoreceptor 1 is a sheet-like conductive support 11 made of a conductive material, an undercoat layer 12 laminated on the conductive support 11, and a layer laminated on the undercoat layer 12. A charge generation layer 13 containing a charge generation material, and a charge transport layer 14 which is further laminated on the charge generation layer 13 and contains a charge transport material. The photoreceptor 1 is a laminated photoreceptor, and the charge generation layer 13 and the charge transport layer 14 constitute a photosensitive layer 15.

  The conductive support 11 serves as an electrode for the photoreceptor 1 and also functions as a support member for the other layers 12, 13, and 14. The shape of the conductive support 11 is not limited to a sheet shape, and may be a cylindrical shape, a columnar shape, a plate shape, a film shape, a belt shape, or the like.

The conductive material constituting the conductive support 11 includes (a) a metal material such as aluminum, stainless steel, copper and nickel, and (b) a surface of an insulating material such as a polyester film, a phenol resin pipe, and a paper tube. Examples thereof include those provided with a conductive layer made of aluminum, copper, palladium, tin oxide, indium oxide, or the like. The conductive support 11 preferably has conductivity with a volume resistance of 10 ¹⁰ Ω · cm or less. The surface of the conductive support 11 may be oxidized for the purpose of adjusting the volume resistance described above.

  The undercoat layer 12 provided on the conductive support 11 includes an amine compound represented by the following general formula (1) and a binding material that binds the amine compound represented by the general formula (1). Can be configured.

In Formula (1), reference numeral R ^1, R ² and ^{R 3} are both indicates aralkyl group may have a substituent.

In the general formula (1), examples of the aralkyl group represented by the symbols R ¹ , R ^2, and R ³ include aryl such as benzyl group, phenethyl group, 1-naphthylmethyl group, and 2- (1-naphthyl) ethyl group. Examples of the moiety include a phenyl group, a naphthyl group, an anthryl group, a pyrenyl group, a biphenylyl group, and a terphenyl group, preferably a monocyclic or bicyclic aryl group, and particularly preferably an aralkyl group that is a phenyl group. Among these, an aralkyl group having 1 to 4 carbon atoms in the alkyl portion is preferable, and a benzyl group and a phenethyl group are particularly preferable.

In the general formula (1), as the code R ^1, R ² and R ³ with the indicated substituent that may be possessed by luer aralkyl group, a methyl group, an ethyl group, an alkyl group such as propyl group, preferably Alkoxy groups such as alkyl groups having 1 to 4 carbon atoms, methoxy groups, ethoxy groups, and propoxy groups, preferably alkoxy groups having 1 to 4 carbon atoms, halogen atoms such as fluorine atoms, chlorine atoms, bromine atoms, and thienyl groups , Heterocyclic groups such as furyl groups, aryl groups such as phenyl groups and naphthyl groups, aralkyl groups such as benzyl groups and phenethyl groups, cycloalkyl groups such as cyclohexyl groups, hydroxyl groups, carboxyl groups, cyano groups, nitro groups, amino groups Monosubstituted or disubstituted substituted amino groups and the like. Among these, as the code R ¹ and R ² with the indicated substituent that may be possessed by luer aralkyl group, preferably an alkyl group having 1 to 4 carbon atoms.

  The amine compound represented by the general formula (1) functions as an antioxidant. An antioxidant such as an amine compound represented by the general formula (1) prevents the photosensitive layer from being oxidized by an oxidizing gas such as ozone and nitrogen oxide generated in the charging process, and suppresses fatigue deterioration of the photoreceptor. Therefore, it is usually added to each layer of the photosensitive layer, that is, the charge transport layer and / or the charge generation layer. However, when an antioxidant is added to the charge transport layer, electrical characteristics such as chargeability, sensitivity, and responsiveness are deteriorated, resulting in a problem that electrical characteristics sufficient for practical use cannot be obtained from the beginning of use. In addition, since the charge generation layer is as thin as about 0.05 to 5 μm, for example, there is a limit to the amount of antioxidant added. If a large amount of antioxidant is added, the generation of charge by the charge generation material is inhibited, and the sensitivity is increased. May decrease.

  In contrast, in the present embodiment, an undercoat layer 12 is provided between the conductive support 11 and the photosensitive layer 15, and an amine compound represented by the general formula (1) is added to the undercoat layer 12. ing. The undercoat layer 12 functions as a barrier layer that suppresses the flow of charges from the conductive support 11 to the photosensitive layer 15, and contributes little to charge transport and charge generation in the photoreceptor 1. For this reason, in this Embodiment, compared with the case where the amine compound represented by General formula (1) is added to the photosensitive layer 15, electrical characteristics, such as charging property, a sensitivity, and a response, can be made favorable. Further, by adding the amine compound represented by the general formula (1) to the undercoat layer 12, the material constituting the photosensitive layer 15 can be selected from a wide range, and therefore a photoconductor having arbitrary characteristics. 1 can be easily manufactured, and production efficiency can be improved. In addition, manufacturing costs can be reduced.

  However, since the undercoat layer 12 is a lower layer of the photosensitive layer 15 and is not a layer exposed to the oxidizing gas, even if an antioxidant is added to the undercoating layer 12, fatigue deterioration of the photoreceptor 1 due to the oxidizing gas. May not be sufficiently suppressed. However, the amine compound represented by the general formula (1) used as the antioxidant in this embodiment is added to the photosensitive layer 15 when added to the undercoat layer 12 as in this embodiment. As compared with the case of the above, it is possible to exhibit an excellent suppression effect against fatigue deterioration of the photoreceptor 1 due to the oxidizing gas. In other words, in the present embodiment, it is possible to impart oxidation resistance gas resistance such as ozone resistance and nitrogen oxide resistance to the photoreceptor 1 without deteriorating electrical characteristics such as chargeability, sensitivity, and responsiveness. .

  Therefore, by including the amine compound represented by the general formula (1) in the undercoat layer 12 as in the present embodiment, the electrical properties such as charging property, sensitivity and responsiveness are excellent, and the oxidation resistant gas. Thus, it is possible to realize the photosensitive member 1 that is excellent in property stability and has excellent property stability that does not deteriorate the above-described good electrical property even when used repeatedly. That is, the photosensitive member 1 of the present embodiment has an advantage that it is not easily affected by an oxidizing gas such as ozone and nitrogen oxide generated from a charger such as a corona discharge charger, and is effective even after repeated use. It has sufficient electrical properties for use. By using such a photoreceptor 1 of this embodiment, a high-quality image with high resolution and no image defects due to active species such as ozone and nitrogen oxide generated in the charging process can be stabilized over a long period of time. Can be provided. The undercoat layer 12 also serves as an adhesive layer between the conductive support 11 and the photosensitive layer 15, so that the conductive support for the photosensitive layer 15 is provided by providing the undercoat layer 12 as in the present embodiment. The peeling from the body 11 can be suppressed, and the mechanical durability of the photoreceptor 1 can be improved.

Among the amine compounds represented by the general formula (1), as a particularly excellent compound from the viewpoint of suppressing fatigue deterioration of the photoreceptor 1, R ¹ , R ² and R ³ in the general formula (1) are , include amine compounds are good ear aralkyl group which may have a substituent, among which, in the general formula (1), at least any one of R ^1, R ² and R ³ substituents An amine compound which is an aralkyl group which may have a group is preferred. Among these, in the general formula (1), an amine compound in which R ¹ , R ^2, and R ³ are each an aralkyl group that may have a substituent is preferable. 1 and no. 4 is more preferable, and Exemplified Compound No. 4 Particularly preferred is an amine compound represented by the following structural formula (1a), which is 1.

  These amine compounds exhibit a particularly excellent suppression effect against fatigue deterioration of the photoreceptor 1 due to the oxidizing gas. Therefore, by using these amine compounds, it is possible to realize a highly reliable photoreceptor 1 that is particularly excellent in oxidation resistance gas resistance and exhibits stable electrical characteristics during repeated use.

Specific examples of the amine compound represented by the general formula (1) include, for example, exemplified compound No. 1 shown in the following Table 1. 1 and no . Although 4 can be exemplified, the amine compound represented by the general formula (1) is not limited thereto.

The amine compound represented by the general formula (1) is exemplified by the exemplified compound No. 1 shown in Table 1 above. 1 and no . 4 or Ranaru one selected from group may be used singly or two or more kinds may be used in combination.

  The amount of the amine compound represented by the general formula (1), that is, the content of the amine compound represented by the general formula (1) in the undercoat layer 12 is 0.1 weight of the total solid content of the undercoat layer 12. % Or more and 30% by weight or less, and more preferably 1% by weight or more and 10% by weight or less of the total solid content of the undercoat layer 12. By selecting the amount of the amine compound represented by the general formula (1) within the above range, it is possible to realize the photoreceptor 1 that is particularly excellent in oxidation resistance gas resistance.

  The amount of the amine compound represented by the general formula (1) is such that, for example, when the amine compound represented by the general formula (1) is added to the charge generation layer, the generation of charges by the charge generation material is not inhibited. Need to choose. Further, since the charge generation layer is thin as described above, a large amount of the amine compound represented by the general formula (1) cannot be added. However, in this embodiment, the undercoat layer 12 containing the amine compound represented by the general formula (1) has a thickness of, for example, about 0.1 to 10 μm, and charge generation and charge in the photoconductor 1. Since the contribution to transportation is small, in this embodiment, the content of the amine compound represented by the general formula (1) is selected within the above range without deteriorating the electrical characteristics such as chargeability, sensitivity, and responsiveness. can do.

  Therefore, by selecting the content of the amine compound represented by the general formula (1) within the above range, the electrical characteristics such as charging property, sensitivity and responsiveness are good, and the oxidation resistance gas property is particularly excellent. Even if it is used repeatedly, the photoreceptor 1 showing good electrical characteristics as in the beginning of use is realized. When the amount of the amine compound represented by the general formula (1) is less than 0.1% by weight of the total solid content of the undercoat layer 12, the oxidation resistance gas resistance of the photoreceptor 1 can be sufficiently obtained. There is no possibility. When the amount of the amine compound represented by the general formula (1) exceeds 30% by weight of the total solid content of the undercoat layer 12, the electrical characteristics such as the chargeability, sensitivity and responsiveness of the photoreceptor 1 are deteriorated. Repeated use may cause a significant decrease in charging potential and a significant increase in residual potential.

  Examples of the binding material contained in the undercoat layer 12 and binding the amine compound represented by the general formula (1) include resins such as polyamide, polyurethane, polyvinyl alcohol, polyvinyl pyrrolidone, and polyacrylamide, cellulose, Examples thereof include celluloses such as nitrocellulose, gelatin, starch, and casein. Among these, the polyamide resin is preferably used because it is excellent in compatibility with the amine compound represented by the general formula (1) and is excellent in adhesiveness with the conductive support 11. Among polyamide resins, alcohol-soluble nylon resins are particularly preferably used. As alcohol-soluble nylon resins, for example, modified nylon resins such as N-methoxymethylated nylon, 6-nylon, 6,6-nylon, 6,10-nylon, 11-nylon, 12-nylon, and the like were copolymerized. Examples thereof include copolymer nylon resins.

  In the undercoat layer 12, conductive particles such as titanium oxide, tin oxide, and aluminum oxide may be dispersed in order to adjust the volume resistance value of the undercoat layer 12. By adding conductive particles to the undercoat layer 12, the volume resistance value of the undercoat layer 12 can be adjusted and the responsiveness of the photoreceptor 1 can be improved. In the undercoat layer 12, various additives generally used in this field may be further dispersed.

  The undercoat layer 12 is, for example, added to an appropriate solvent, for example, an amine compound represented by the general formula (1) and the above binding material, and if necessary, various additives such as the above conductive particles. It can be formed by dissolving and / or dispersing to prepare a coating solution for the undercoat layer and coating the coating solution on the surface of the conductive support 11. Examples of the coating method for the coating solution for the undercoat layer include a spray method, a bar coating method, a roll coating method, a blade method, a ring method, and a dip coating method.

  As the solvent for the coating solution for the undercoat layer, water, various organic solvents, or a mixed solvent thereof is used. Among them, single solvents such as water, alcohols such as methanol, ethanol and butanol, water and alcohols, two or more alcohols, alcohols, ketones such as acetone, ethers such as dioxolane, dichloroethane, chloroform A mixed solvent such as an alcohol-based mixed solvent mixed with halogenated hydrocarbons such as trichloroethane is preferably used.

  The thickness of the undercoat layer 12 is preferably 0.1 μm or more and 10 μm or less. When the thickness of the undercoat layer 12 is smaller than 0.1 μm, there is a possibility that fatigue deterioration of the photoreceptor 1 cannot be sufficiently suppressed. In addition, charges may flow from the conductive support 11 to the photosensitive layer 15 and the charge holding ability of the photoreceptor 1 may be reduced. When the thickness of the undercoat layer 12 exceeds 10 μm, the responsiveness of the photoreceptor 1 may be lowered.

  The charge generation layer 13 provided on the undercoat layer 12 can be configured to include a charge generation material. The charge generating substance is not particularly limited as long as it absorbs light such as visible light and generates free charge, and known substances can be used, and examples thereof include inorganic pigments, organic pigments, and organic dyes. Inorganic pigments include selenium and its alloys, arsenic-selenium, cadmium sulfide, zinc oxide, amorphous silicon, and other inorganic photoconductors. Examples of organic pigments include phthalocyanine compounds, azo compounds, quinacridone compounds, polycyclic quinone compounds, and perylene compounds. Examples of organic dyes include thiapyrylium salts and squarylium salts.

  Among these, organic photoconductive compounds such as organic pigments and organic dyes are preferably used. Further, among organic photoconductive compounds, phthalocyanine compounds are preferable, and titanyl phthalocyanine compounds represented by the following general formula (2) are particularly preferable.

In the general formula (2), X ¹ , X ² , X ³ and X ⁴ each represent a hydrogen atom, a halogen atom, an alkyl group or an alkoxy group, and n, m, l and k are each 1 to 4 Indicates an integer.

In the general formula (2), examples of the halogen atom represented by the symbols X ¹ , X ² , X ³ and X ⁴ include a fluorine atom, a chlorine atom and a bromine atom. Examples of the alkyl group represented by the symbols X ¹ , X ² , X ³ and X ⁴ include a linear alkyl group such as a methyl group, an ethyl group, an n-propyl group, an n-butyl group and an n-hexyl group, and an isopropyl group. , Branched chain alkyl groups such as t-butyl group and neopentyl group, cycloalkyl groups such as cyclopentyl group, cyclohexyl group and cycloheptyl group. Among these, alkyl groups having 1 to 4 carbon atoms are preferable. . Examples of the alkoxy group represented by the symbols X ¹ , X ² , X ³ and X ⁴ include linear alkoxy groups such as methoxy group, ethoxy group, n-propoxy group and n-hexanoxy group, isopropoxy group and isohexanoxy group The branched chain alkoxy group of these is mentioned, Among these, a C1-C4 alkoxy group is preferable.

  By using a phthalocyanine compound, preferably a titanyl phthalocyanine compound represented by the general formula (2), an amine compound represented by the general formula (1) is contained between the conductive support 11 and the photosensitive layer 15. It is possible to further suppress the deterioration of the electrical characteristics due to the provision of the undercoat layer 12 and to improve the electrical characteristics such as the charging property, sensitivity and responsiveness of the photoreceptor 1. In particular, by using a phthalocyanine compound, preferably a titanyl phthalocyanine compound represented by the general formula (2), in combination with an enamine compound represented by the general formula (3) described later, sensitivity characteristics, charging characteristics and image reproduction are achieved. Thus, it is possible to realize a photoreceptor 1 that is particularly excellent in properties.

The titanyl phthalocyanine compound represented by the general formula (2) is, for example, Moser.
And “Phthalocyanine” by Thomas
The compound can be produced by a conventionally known production method such as the method described in “Compounds”). For example, among the titanyl phthalocyanine compounds represented by the general formula (2), in the general formula (2), X ¹ , X ² , X ³ and X ⁴ are each a hydrogen atom, and n, m, l and k are Each titanyl phthalocyanine which is 4 is obtained by synthesizing dichlorotitanium phthalocyanine by heating and melting phthalonitrile and titanium tetrachloride or by reacting in a suitable solvent such as α-chloronaphthalene. It can be produced by hydrolyzing phthalocyanine with a base or water. In addition, titanyl phthalocyanine can be produced by reacting isoindoline with titanium tetraalkoxide such as tetrabutoxytitanium in a suitable solvent such as N-methylpyrrolidone.

One type of charge generation material may be used alone, or two or more types may be used in combination.
Various additives such as a chemical sensitizer or an optical sensitizer may be added to the charge generation layer 13 in addition to the above-described pigments and dyes used as the charge generation material. Examples of the chemical sensitizer include cyano compounds such as tetracyanoethylene and 7,7,8,8-tetracyanoquinodimethane, quinones such as anthraquinone and p-benzoquinone, and 2,4,7-trinitrofluorenone. , 2,4,5,7-tetranitrofluorenone and other electron accepting substances such as nitro compounds can be used. As the optical sensitizer, a dye such as a xanthene dye, a thiazine dye, or a triphenylmethane dye can be used.

The charge generation layer 13 can be formed by vacuum evaporation, sputtering, chemical vapor deposition (Chemical
Vapor Deposition (abbreviation: CVD) method such as vapor deposition method or coating method can be applied. When using a coating method, the above-described charge generating material is pulverized by a ball mill, sand grinder, paint shaker, ultrasonic disperser, etc., and dispersed in an appropriate solvent, and a binder resin called a binder resin is used as necessary. A charge generating layer coating solution is prepared by adding a resin having adhesion, and this coating solution is applied to the surface of the undercoat layer 12 by a known coating method, and dried or cured to form a film. Layer 13 can be formed.

  Examples of the binder resin used for the charge generation layer 13 include polyarylate, polyvinyl butyral, polycarbonate, polyester, polystyrene, polyvinyl chloride, phenoxy resin, epoxy resin, silicone resin, and polyacrylate.

  Solvents used in the coating solution for the charge generation layer include alcohols such as isopropyl alcohol, ketones such as cyclohexanone, acetone and methyl ethyl ketone, hydrocarbons such as cyclohexane, aromatic hydrocarbons such as toluene and xylene, tetrahydrofuran, Ethers such as dioxane, dioxolane, ethyl cellosolve, ethylene glycol dimethyl ether, esters such as ethyl acetate and methyl acetate, halogenated hydrocarbons such as dichloromethane, dichloroethane and monochlorobenzene, N, N-dimethylformamide, N, N- Amides such as dimethylacetamide are exemplified. One of these solvents may be used alone, or two or more thereof may be mixed and used as a mixed solvent.

  Among the above-mentioned solvents, in consideration of suppressing the decrease in the sensitivity of the photoreceptor 1 based on the crystal transition during the pulverization and / or milling of the charge generation material and the alteration of the charge generation material in the coating solution. It is preferable to use one or more of cyclohexanone, 1,2-dimethoxyethane, methyl ethyl ketone, and tetrahydroquinone, which do not easily cause crystal transition and alteration of the charge generating substance.

  When the conductive support 11 is in the form of a sheet, the charge generation layer coating solution can be applied to the surface of the undercoat layer 12 using a baker applicator, bar coater, casting, spin coater, or the like. When the conductive support 11 is cylindrical or columnar, the charge generation layer coating solution can be applied by a spray method, a vertical ring method, a dip coating method, or the like.

  The layer thickness of the charge generation layer 13 is preferably 0.05 μm or more and 5 μm or less, and more preferably 0.1 μm or more and 1 μm or less. If the layer thickness of the charge generation layer 13 is less than 0.05 μm, the light absorption efficiency is lowered, and the sensitivity of the photoreceptor 1 may be lowered. If the thickness of the charge generation layer 13 exceeds 5 μm, the charge transfer inside the charge generation layer 13 becomes a rate-determining step in the process of erasing the charge on the surface of the photosensitive layer 15, and the sensitivity of the photoreceptor 1 may be lowered.

The charge transport layer 14 provided on the charge generation layer 13 can include a charge transport material and a binder resin that binds the charge transport material. The charge transport material is not particularly limited as long as it has the ability to accept the charge generated by the charge generation material contained in the charge generation layer 13 and transport it, and a known material can be used, for example, poly-N -Vinylcarbazole and derivatives thereof, poly-g-carbazolylethyl glutamate and derivatives thereof, polyvinylpyrene, polyvinylphenanthrene, oxazole derivatives, oxadiazole derivatives, imidazole derivatives, 9- (p-diethylaminostyryl) anthracene, 1,1 -Bis (4-dibenzylaminophenyl) propane, styrylanthracene, styrylpyrazoline, pyrazoline derivatives, phenylhydrazones, hydrazone derivatives, triphenylamine compounds, tetraphenyldiamine compounds, stilbene compounds, 3-methyl Azine compounds having a 2-benzothiazoline ring, such as an electron-donating substance such as enamine compounds.
Among these, enamine compounds represented by the following general formula (3) are preferable.

In the general formula (3), R ⁴ , R ⁵ , R ⁶ and R ⁷ each represent a hydrogen atom, an alkoxy group which may have a substituent or an alkyl group which may have a substituent, and R ⁸ and R ⁹ each represent a hydrogen atom, an aryl group that may have a substituent, or an alkyl group that may have a substituent. However, the benzene ring and naphthalene ring to which R ^{4 to} R ⁷ are bonded may have other substituents in addition to R ^{4 to} R ⁷ .

In the general formula (3), examples of the alkoxy group represented by the symbols R ⁴ , R ⁵ , R ⁶ and R ⁷ include linear alkoxy groups such as methoxy group, ethoxy group and n-propoxy group, isopropoxy group, etc. The branched chain alkoxy group of these is mentioned, Among these, a C1-C4 alkoxy group is preferable.

In the general formula (3), examples of the alkyl group represented by the symbols R ⁴ , R ⁵ , R ⁶ , R ⁷ , R ⁸ and R ⁹ include a methyl group, an ethyl group, an n-propyl group, an n-butyl group, Examples include linear alkyl groups such as n-hexyl group, branched alkyl groups such as isopropyl group, t-butyl group and neopentyl group, cycloalkyl groups such as cyclopentyl group, cyclohexyl group and cycloheptyl group. Among these, an alkyl group having 1 to 4 carbon atoms is preferable.

In the general formula (3), examples of the aryl group represented by the symbols R ⁸ and R ⁹ include a phenyl group, a naphthyl group, an anthryl group, a pyrenyl group, a biphenylyl group, and a terphenyl group. A monocyclic or bicyclic aryl group such as a group, a naphthyl group or a biphenylyl group is preferred, and a phenyl group is particularly preferred.

In the general formula (3), the substituent that the alkoxy group, alkyl group, and aryl group represented by the symbols R ^{4 to} R ⁹ may have is an alkyl group such as a methyl group, an ethyl group, or a propyl group, preferably Is an alkoxy group such as an alkyl group having 1 to 4 carbon atoms, a methoxy group, an ethoxy group or a propoxy group, preferably an alkoxy group having 1 to 4 carbon atoms, a halogen atom such as a fluorine atom, a chlorine atom or a bromine atom, or thienyl. Groups, heterocyclic groups such as furyl groups, aryl groups such as phenyl groups and naphthyl groups, aralkyl groups such as benzyl groups and phenethyl groups, and cycloalkyl groups such as cyclohexyl groups.

In Formula (3), the benzene ring and naphthalene ring may other substituents have besides R ⁴ ~R ⁷ R ⁴ ~R ⁷ are attached, dimethylamino group, diethylamino group, diisopropylamino A dialkylamino group such as a symmetric dialkylamino group such as a group, an asymmetric dialkylamino group such as an ethylmethylamino group, an isopropylethylamino group, preferably a symmetric or asymmetrical dialkylamino group having 2 to 8 carbon atoms, a methoxy group, ethoxy Group, an alkoxy group such as propoxy group, preferably an alkoxy group having 1 to 4 carbon atoms, an aryl group such as phenyl group and naphthyl group, a halogen atom such as fluorine atom, chlorine atom and bromine atom.

  By using the enamine compound represented by the general formula (3), the undercoat layer 12 containing the amine compound represented by the general formula (1) is provided between the conductive support 11 and the photosensitive layer 15. The electrical characteristics such as charging property, sensitivity and responsiveness of the photoreceptor 1 can be further improved. In particular, the sensitivity is obtained by using the enamine compound represented by the general formula (3) as the charge transport material and the above-mentioned phthalocyanine compound, preferably the titanyl phthalocyanine compound represented by the general formula (2) as the charge generation material. It is possible to realize the photoreceptor 1 that is particularly excellent in characteristics, charging characteristics, and image reproducibility.

  The enamine compound represented by the general formula (3) is obtained by, for example, dehydrating and condensing a secondary amine compound and a carbonyl compound to produce an enamine intermediate, followed by formylation by the Vilsmeier reaction or acyl by Friedel-Craft reaction. It can be produced by introducing a carbonyl group by oxidization or the like and introducing a double bond moiety to the resulting enamine-carbonyl intermediate by Wittig-Horner reaction or the like.

One type of charge transport material may be used alone, or two or more types may be used in combination.
The content of the charge transport material contained in the charge transport layer 14 is preferably 30 wt% or more and 80 wt% or less of the total solid content of the charge transport layer 14. If the content of the charge transport material is less than 30% by weight of the total solid content of the charge transport layer 14, sufficient sensitivity and responsiveness in practical use may not be obtained. When the content of the charge transport material exceeds 80% by weight of the total solid content of the charge transport layer 14, the content of the binder resin contained in the charge transport layer 14 is relatively lowered, so that the resistance of the charge transport layer 14 is improved. There is a possibility that the printability is lowered and the mechanical durability of the photoreceptor 1 cannot be sufficiently obtained.

As the binder resin contained in the charge transport layer 14 and binding the charge transport material, those having excellent compatibility with the charge transport material can be used. For example, polycarbonate and copolymer polycarbonate, polyarylate, polyvinyl butyral, Examples include polyamide, polyester, epoxy resin, polyurethane, polyketone, polyvinyl ketone, polystyrene, polyacrylamide, phenol resin, phenoxy resin and polysulfone resin, and copolymer resins thereof. Among these, resins such as polystyrene, polycarbonate and copolymer polycarbonate, polyarylate, and polyester have a volume resistivity of 10 ¹³ Ω or more and excellent electrical insulation properties, and also have film formability and potential characteristics. Since it is excellent, it is preferably used. Binder resin may be used individually by 1 type, and 2 or more types may be used together.

  The charge transport layer 14 may contain various additives such as a chemical sensitizer and an optical sensitizer in addition to the charge transport material and the binder resin. By including a chemical sensitizer, an optical sensitizer, or the like in the charge transport layer 14, the sensitivity of the photoreceptor 1 can be improved, and an increase in residual potential and fatigue deterioration during repeated use can be further suppressed. Examples of chemical sensitizers include acid anhydrides such as succinic anhydride, maleic anhydride, phthalic anhydride, 4-chloronaphthalic anhydride, cyano compounds such as tetracyanoethylene and terephthalmalondinitrile, 4-nitrobenzaldehyde, and the like. Electron acceptability of aldehydes, anthraquinones, anthraquinones such as 1-nitroanthraquinone, polycyclic or heterocyclic nitro compounds such as 2,4,7-trinitrofluorenone and 2,4,5,7-tetranitrofluorenone Substances can be used. Examples of the optical sensitizer include dyes such as xanthene dyes, thiazine dyes, and triphenylmethane dyes, organic photoconductive compounds such as quinoline pigments, and copper phthalocyanine.

  The charge transport layer 14 can be formed in the same manner as when the charge generation layer 13 is formed by coating. For example, the above charge transport material and binder resin, and, if necessary, various additives such as the above-described chemical sensitizer and optical sensitizer are dissolved and / or dispersed in a suitable solvent to form a coating solution for the charge transport layer. The charge transport layer 14 can be formed by applying the coating liquid onto the surface of the charge generation layer 13 and drying it.

  Solvents used in the coating solution for the charge transport layer include alcohols such as methanol and ethanol, ketones such as acetone, methyl ethyl ketone and cyclohexanone, ethers such as ethyl ether, tetrahydrofuran, dioxane and dioxolane, chloroform, dichloromethane and dichloroethane. And aliphatic hydrocarbons such as benzene, chlorobenzene, and toluene. One of these solvents may be used alone, or two or more thereof may be mixed and used.

  The layer thickness of the charge transport layer 14 is preferably 10 μm or more and 50 μm or less, and more preferably 15 μm or more and 40 μm or less. If the layer thickness of the charge transport layer 14 is less than 10 μm, the charge holding ability of the surface of the photoreceptor 1 may be lowered. If the layer thickness of the charge transport layer 14 exceeds 50 μm, the resolution of the photoreceptor 1 may be reduced.

  The photosensitive layer 15 is configured by laminating a charge generation layer 13 and a charge transport layer 14. In this way, by assigning the charge generation function and the charge transport function to separate layers, it becomes possible to select the optimum material for each of the charge generation function and the charge transport function as the material constituting each layer. It is possible to obtain a photoreceptor 1 having particularly good sensitivity characteristics, charging characteristics, and image reproducibility.

  The electrostatic latent image forming operation in the photoreceptor 1 will be briefly described below. The photosensitive layer 15 provided on the photoreceptor 1 is charged uniformly, for example, negatively by a charger or the like, and when the charge generation layer 13 is irradiated with light having an absorption wavelength in the charged state, the charge generation layer 13 Electron and hole charges are generated. The holes are transported to the surface of the photoreceptor 1 by the charge transport material contained in the charge transport layer 14 to neutralize the negative charge on the surface, and the electrons in the charge generation layer 13 are electrically conductive support in which a positive charge is induced. Move to the side of the body 11 to neutralize the positive charge. In this way, there is a difference between the charge amount of the exposed part and the charge amount of the unexposed part, and an electrostatic latent image is formed on the photosensitive layer 15.

  As described above, in the present embodiment, the photosensitive layer 15 is formed by laminating the charge generation layer 13 and the charge transport layer 14 on the undercoat layer 12 in this order. The photosensitive layer 15 is not limited to the above configuration. For example, the photosensitive layer 15 may have a configuration in which the charge transport layer 14 and the charge generation layer 13 are stacked on the undercoat layer 12 in this order.

Figure 2 is a partial cross-sectional view schematically showing the structure of the electronic photosensitive member 2. Photoreceptor 2 of this shape state is similar to the photosensitive member 1 of the first embodiment shown in FIG. 1, corresponding portions will be omitted with denoted by the same reference numerals. What should be noted in the photoreceptor 2 is that a photosensitive layer 16 composed of a single layer containing both a charge generation material and a charge transport material is provided on the undercoat layer 12. That is, the photosensitive member 2 of the present form status is a single-layer type photosensitive material.

Single-layer type photosensitive material 2 of this shape state is suitable as a photosensitive material for positive charging type image forming apparatus with less ozone generation. The single-layer type photosensitive material 2 of this shape state, since the layer to be coated on the undercoat layer 12 is only one layer of the photosensitive layer 16, a charge generation layer on the undercoat layer 12 13 and the charge transport layer 14 The manufacturing cost and the yield are superior to those of the multilayer photoreceptor 1 of the first embodiment in which is laminated.

Also in this shape state, the undercoat layer 12, an amine compound represented by the above general formula (1) is contained. Accordingly, the photoreceptor 2 of the form status, like the photosensitive member 1 of the first embodiment, charging property, excellent in electric characteristics such as sensitivity and responsiveness, high oxidation gas resistance, is repeatedly used However, the above-described good electrical characteristics do not deteriorate, and the electrical characteristics are sufficient for practical use even after repeated use.

  The photosensitive layer 16 is formed by dispersing the aforementioned charge generation material and charge transport material in a binder resin. The photosensitive layer 16 uses the same charge generating material, charge transporting material, and binder resin as those used in the photoreceptor 1 of the first embodiment, and the charge generating layer 13 or the charge transporting layer in the first embodiment. 14 can be formed in the same manner. For example, the charge generation material and the charge transport material are dispersed in a solution in which the binder resin is dissolved, or the charge generation material is dispersed in the form of pigment particles in the binder resin containing the charge transport material. The coating layer is applied to the surface of the undercoat layer 12 by the same coating method as in the case of forming the charge generation layer 13 in the first embodiment, and dried to form a single photosensitive layer 16. Can be formed.

  The electrostatic latent image forming operation on the photosensitive member 2 will be briefly described below. The photosensitive layer 16 provided on the photosensitive member 2 is charged positively and uniformly, for example, with a charger or the like. When the charge generating material is irradiated with light having an absorption wavelength in the charged state, the photosensitive layer 16 is in the vicinity of the surface of the photosensitive layer 16. Electron and hole charges are generated. The electrons neutralize the positive charge on the surface of the photosensitive layer 16, and the holes are transported by the charge transport material to the side of the conductive support 11 on which the negative charge is induced, and the negative charge induced on the conductive support 11. Neutralize charge. In this way, there is a difference between the charge amount of the exposed part and the charge amount of the unexposed part, and an electrostatic latent image is formed on the photosensitive layer 16.

Next, the image forming apparatus of the present invention provided with the electrophotographic photosensitive member of the present invention will be described. FIG. 3 is an arrangement side view showing a simplified configuration of the image forming apparatus 100 according to the second embodiment of the present invention. An image forming apparatus 100 shown in FIG. 3 has a cylindrical photoconductor 10 having the same layer structure as the photoconductor 1 of the first embodiment shown in FIG. 1 as the electrophotographic photoconductor of the present invention. . The configuration of the image forming apparatus 100 and the image forming operation will be described below with reference to FIG.

  The image forming apparatus 100 includes the above-described photoconductor 10 that is rotatably supported by an apparatus main body (not shown), and a drive unit (not shown) that rotates the photoconductor 10 around the rotation axis 44 in the direction of an arrow 41. The drive means includes, for example, a motor as a power source, and transmits the power from the motor to a support body constituting the core of the photoconductor 10 via a gear (not shown), thereby rotating the photoconductor 10 at a predetermined peripheral speed. Let

  Around the photosensitive member 10, 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 photosensitive member 10 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 10 to a predetermined negative or positive potential. The charger 32 is a non-contact charging means such as a corona discharge charger.

  The exposure unit 30 includes, for example, a semiconductor laser as a light source, and exposes the surface 43 of the charged photoconductor 10 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 unit 33 is a developing unit that develops the electrostatic latent image formed on the surface 43 of the photoconductor 10 with a developer to form a visible toner image, and is provided facing the photoconductor 10. A developing roller 33a that supplies toner to the surface 43 of the photoconductor 10, and a developing roller 33a that rotatably supports a rotation axis parallel to the rotation axis 44 of the photoconductor 10 and a developer containing toner in the internal space 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 10 from the surface 43 of the photoconductor 10 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 43 of the photoconductor 10 after the toner image is transferred. The cleaner 36 is pressed against the photoconductor surface 43 and remains on the surface 43 of the photoconductor 10 after the transfer operation by the transfer unit 34. A cleaning blade 36a that peels foreign matter such as toner and paper dust from the surface 43 and a recovery casing 36b that contains foreign matter such as toner peeled by the cleaning blade 36a are provided. All of the toner that forms a toner image on the surface 43 of the photoreceptor 1 is not transferred onto the recording paper 51 and may slightly remain on the surface 43 of the photoreceptor 1. The toner remaining on the photosensitive member surface 43 is called residual toner, and the presence of the residual toner causes deterioration of the quality of the formed image. Therefore, the cleaning blade 36a pressed against the photosensitive member surface 43 causes paper to be removed. It is removed and cleaned from the surface 43 of the photoconductor 10 together with other foreign matters such as powder.

  In addition, a fixing unit 35 that is a fixing unit that fixes the transferred toner image is provided in a direction in which the recording paper 51 is conveyed after passing between the photosensitive member 10 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 10 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 10. 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 10. The light 31 from the light source is repeatedly scanned in the longitudinal direction of the photoconductor 10, which is the main scanning direction, based on the image information. By rotating the photoconductor 10 and repeatedly scanning the light 31 from the light source based on the image information, the surface 43 of the photoconductor 10 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 to the photoconductor 10, the recording paper 51 is supplied to the transfer position between the transfer device 34 and the photoconductor 10 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 10 from the image formation point of the light 31 from the light source to the surface 43 of the photoconductor 10 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 10. When the recording paper 51 is supplied between the photoconductor 10 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 10. 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 10 that rotates further in the direction of the arrow 41 is scraped and cleaned by the cleaning blade 36 a provided on the cleaner 36. The surface 43 of the photoconductor 10 from which foreign matters such as toner have been removed in this way is removed of electric charge by light from the charge eliminating lamp. As a result, the electrostatic latent image on the surface 43 of the photoreceptor 10 disappears. Thereafter, the photosensitive member 10 is further rotated and a series of operations starting from charging of the photosensitive member 10 is repeated. As described above, images are continuously formed.

  The photoreceptor 10 provided in the image forming apparatus 100 contains an amine compound represented by the general formula (1) in an undercoat layer, and is excellent in electrical characteristics such as chargeability, sensitivity, and responsiveness, and oxidation resistance. It has the advantage that it is excellent in reactive gas properties and is not easily affected by oxidizing gases such as ozone and nitrogen oxides generated from a charger 32 such as a corona discharge charger. For this reason, the photoreceptor 10 does not deteriorate the above-described good electrical characteristics even when used repeatedly, and has sufficient electrical characteristics for practical use even after repeated use. Therefore, it is possible to realize the image forming apparatus 100 with high resolution and excellent durability that can stably form a high-quality image without image defects over a long period of time.

As described above, the photoconductor 10 provided in the image forming apparatus 100 of the present embodiment has the same layer configuration as the photoconductor 1 of the first embodiment shown in FIG. Photoreceptor 10 is not limited to the above configuration, for example, it may have the same layer structure as shown to sense the light body 2 in FIG. 2 described above.

  The image forming apparatus according to the present invention is not limited to the configuration of the image forming apparatus 100 shown in FIG. 3 described above, and may be different as long as the photosensitive member according to the present invention can be used. It may be a configuration.

  For example, in the image forming apparatus 100 of the present embodiment, the charger 32 is a non-contact charging unit, but is not limited thereto, and may be a contact charging unit such as a charging roller. . The transfer unit 34 is a non-contact type transfer unit that performs transfer without using a pressing force, but is not limited thereto, and is a contact type transfer unit that performs transfer using a pressing force. Also good. As the contact-type transfer means, for example, a transfer roller is provided, and the transfer roller is pressed against the photoconductor 10 from the surface opposite to the contact surface of the recording paper 51 with the surface 43 of the photoconductor 10. In the state in which the recording paper 51 and the recording paper 51 are in pressure contact, a toner image can be transferred onto the recording paper 51 by applying a voltage to the transfer roller.

EXAMPLES Hereinafter, although an Example , a reference example, and a comparative example are given and this invention is demonstrated further in detail, this invention is not limited to the following description content.

[Production example]
In the following Examples , Reference Examples and Comparative Examples, an enamine compound represented by the following structural formula (3a) was used as a charge transport material.

Hereinafter, a method for producing the enamine compound represented by the structural formula (3a) will be described.
[Production of Enamine Compound Represented by Structural Formula (3a)]
(Production Example 1-1) Production of enamine intermediate To 100 mL of toluene, 4.9 g (1.0 molar equivalent) of N- (p-methoxyphenyl) -α-naphthylamine represented by the following structural formula (4); Water by-produced by adding 4.1 g (1.05 molar equivalent) of diphenylacetaldehyde represented by the following structural formula (5) and 46 mg (0.01 molar equivalent) of DL-10-camphorsulfonic acid and heating. The reaction was carried out for 6 hours while azeotroping with toluene and removing it from the system. After completion of the reaction, the reaction solution was concentrated to about one-tenth (1/10) and gradually dropped into 100 mL of hexane, which was vigorously stirred, to form crystals. The produced crystal was separated by filtration and washed with cold ethanol to obtain 7.9 g of a pale yellow powdery compound.

The obtained compound was subjected to liquid chromatography-mass spectrometry (Liquid Chromatography-
As a result of analysis by Mass Spectrometry (abbreviation LC-MS), it corresponds to a molecular ion [M + H] ⁺ in which a proton is added to an enamine intermediate represented by the following structural formula (6) (calculated molecular weight: 427.20). Since a peak was observed at 428.5, it was confirmed that the obtained compound was an enamine intermediate represented by the following structural formula (6) (yield: 94%). Moreover, the analysis result of LC-MS showed that the purity of the obtained enamine intermediate was 94%.

  As described above, N- (p-methoxyphenyl) -α-naphthylamine represented by the structural formula (4) which is a secondary amine compound and diphenyl represented by the structural formula (5) which is an aldehyde compound. By performing a dehydration condensation reaction with acetaldehyde, the enamine intermediate represented by the structural formula (6) was obtained in a high yield.

(Production Example 1-2) Production of enamine-aldehyde intermediate In 100 mL of anhydrous N, N-dimethylformamide (DMF), 3.4 g (1.2 molar equivalents) of phosphorus oxychloride was gradually added under ice cooling. Stir for about 30 minutes to prepare a Filsmeier reagent. To this solution, 7.9 g (1.0 molar equivalent) of the enamine intermediate represented by the structural formula (6) obtained in Production Example 1-1 was gradually added under ice cooling. Thereafter, the mixture was gradually heated to raise the reaction temperature to 80 ° C. and stirred for 3 hours while heating to maintain 80 ° C. After completion of the reaction, the reaction solution was allowed to cool and gradually added to 800 mL of a cooled 4N (4N) -sodium hydroxide aqueous solution to cause precipitation. The resulting precipitate was separated by filtration, sufficiently washed with water, and then recrystallized with a mixed solvent of ethanol and ethyl acetate to obtain 7.2 g of a yellow powdery compound.

As a result of analyzing the obtained compound by LC-MS, it was found that an enamine-aldehyde intermediate represented by the following structural formula (7) (calculated molecular weight: 455.19) has a molecular ion [M + H] ⁺ added with a proton. Since the corresponding peak was observed at 456.5, it was confirmed that the obtained compound was an enamine-aldehyde intermediate represented by the following structural formula (7) (yield: 85%). Moreover, the analysis result of LC-MS showed that the purity of the obtained enamine-aldehyde intermediate was 85%.

  As described above, the enamine-aldehyde intermediate represented by the structural formula (7) is increased by subjecting the enamine intermediate represented by the structural formula (6) to formylation by the Filsmeier reaction. The yield could be obtained.

(Production Example 1-3) Production of Enamine Compound Represented by Structural Formula (3a) 7.0 g of enamine-aldehyde intermediate represented by the structural formula (7) obtained in Production Example 1-2 (1. 0 mol equivalent) and 4.7 g (1.2 mol equivalent) of diethylcinnamylphosphonate represented by the following structural formula (8) are dissolved in 80 mL of anhydrous DMF, and 2.15 g of potassium t-butoxide is added to the solution. (1.25 molar equivalent) was gradually added at room temperature, followed by heating to 50 ° C. and stirring for 5 hours while heating to maintain 50 ° C. The reaction mixture was allowed to cool and then poured into excess methanol. The precipitate was collected and dissolved in toluene to obtain a toluene solution. The toluene solution was transferred to a separatory funnel and washed with water. Then, the organic layer was taken out, and the taken out organic layer was dried over magnesium sulfate. After drying, the organic layer from which the solid was removed was concentrated and subjected to silica gel column chromatography to obtain 7.9 g of yellow crystals.

As a result of analyzing the obtained crystal by LC-MS, a peak corresponding to a molecular ion [M + H] ⁺ in which a proton was added to the enamine compound represented by the structural formula (3a) (calculated molecular weight: 555.26). Was observed at 556.7. Further, when the nuclear magnetic resonance (Nuclear Magnetic Resonance; abbreviated NMR) spectrum of the obtained crystal in deuterated chloroform (chemical formula: CDCl ₃ ) was measured, the structure of the enamine compound represented by the structural formula (3a) was supported. A spectrum was obtained. From the LC-MS analysis results and NMR spectrum measurement results, it was confirmed that the obtained crystal was an enamine compound represented by the structural formula (3a) (yield: 92%). Further, from the analysis result of LC-MS, it was found that the purity of the obtained enamine compound represented by the structural formula (3a) was 99%.

  As described above, the Wittig--enamine-aldehyde intermediate represented by the structural formula (7) and the diethylcinnamylphosphonate represented by the structural formula (8) which is a Wittig reagent. By performing the Horner reaction, the enamine compound represented by the structural formula (3a) was obtained in a high yield.

[Example]
Hereinafter, an undercoat layer and a photosensitive layer were formed under various conditions on an aluminum cylindrical conductive support having an outer diameter of 30 mm and a length in the longitudinal direction of 346 mm, and were prepared as examples , reference examples, and comparative examples. Explain the body. In the following, in each condition, a photoconductor (hereinafter referred to as an evaluation device evaluation photoconductor) used for evaluation of an oxidation-resistant gas property by an evaluation device described later and a photoconductor used for evaluation of an oxidation-resistant gas property by an actual device. Two types of photoconductors (hereinafter referred to as actual device evaluation photoconductors) were produced.

Example 1
[Production of photoconductor for evaluation device evaluation]
3 parts by weight of titanium oxide (trade name: TTO-D1 (dendritic rutile type surface-treated with Al ₂ O ₃ and ZrO ₂ , titanium component 85%), manufactured by Ishihara Sangyo Co., Ltd.) and alcohol-soluble nylon resin (product) Name: CM8000, manufactured by Toray Industries, Inc.) 3 parts by weight, and exemplified compound No. 1 shown in Table 1 above as an antioxidant. 1 part of an amine compound, tribenzylamine (0.3 parts by weight) (4.8% by weight of the total solid content of the undercoat layer) in a mixed solvent of 60 parts by weight of methanol and 40 parts by weight of 1,3-dioxolane In addition, a coating solution for undercoat layer was prepared by dispersing for 10 hours with a paint shaker. The coating solution was filled in the coating tank, the conductive support was dipped, pulled up, and naturally dried to form an undercoat layer having a layer thickness of 0.9 μm.

Next, 10 parts by weight of polyvinyl butyral resin (trade name: S-LEC BL-2, manufactured by Sekisui Chemical Co., Ltd.), 1400 parts by weight of 1,3-dioxolane, and titanyl phthalocyanine (in the general formula (2), X ¹ , X ² , X ³ and X ⁴ are each a hydrogen atom, and n, m, l and k are each 4) and 15 parts by weight are dispersed in a ball mill for 72 hours to produce a charge generation layer A coating solution was prepared. This coating solution was applied onto the previously formed undercoat layer by the same dip coating method as that for the undercoat layer, and then naturally dried to form a charge generation layer having a layer thickness of 0.2 μm.

  Next, 100 parts by weight of the enamine compound represented by the structural formula (3a) produced in the above production example as a charge transport material, and polycarbonate resins J-500, G-400, GH-503 (trade names) as binder resins. 48 parts by weight, 32 parts by weight, 32 parts by weight and 48 parts by weight of TS2020 (trade name, manufactured by Teijin Chemicals), respectively, and dissolved in 980 parts by weight of tetrahydrofuran Thus, a coating solution for a charge transport layer was prepared. This coating solution was applied onto the charge generation layer previously formed by the same dip coating method as that for the undercoat layer, and dried at a temperature of 130 ° C. for 1 hour to form a charge transport layer having a layer thickness of 15 μm. In this manner, a photoconductor for evaluation apparatus evaluation of Example 1 was produced.

[Production of photoconductor for actual machine evaluation]
A photoconductor for actual device evaluation of Example 1 was prepared in the same manner as the photoconductor for evaluation apparatus evaluation, except that the charge transport layer was formed so that the thickness of the charge transport layer was 28 μm.

(Example 2)
In forming the undercoat layer, Exemplified Compound No. Except for changing the blending amount of the amine compound 1 to 0.7 parts by weight (10% by weight of the total solid content of the undercoat layer), in the same manner as in Example 1, the evaluation device evaluation photosensitivity of Example 2 Body and a photoconductor for actual machine evaluation were prepared.

(Example 3)
In forming the undercoat layer, Exemplified Compound No. Except for changing the blending amount of the amine compound 1 to 0.9 parts by weight (13% by weight of the total solid content of the undercoat layer), in the same manner as in Example 1, the evaluation device evaluation photosensitivity of Example 3 Body and a photoconductor for actual machine evaluation were prepared.

(Example 4)
In forming the undercoat layer, Exemplified Compound No. Evaluation apparatus evaluation of Example 4 in the same manner as in Example 1 except that the compounding amount of 1 amine compound was changed to 0.006 parts by weight (0.1% by weight of the total solid content of the undercoat layer). Photoconductors and actual photoconductors were prepared.

( Reference Example 1 )
In forming the undercoat layer, Exemplified Compound No. In place of the amine compound of Example 1, Exemplified Compound Nos. A photoconductor for evaluation apparatus evaluation and a photoconductor for actual machine evaluation of Reference Example 1 were prepared in the same manner as in Example 1 except that the amine compound having a phenylamine structure as the amine compound 2 was used.

( Reference Example 2 )
In forming the undercoat layer, Exemplified Compound No. In place of the amine compound of Example 1, Exemplified Compound Nos. Except for using the amine compound having a diaralkylamine structure, which is the amine compound No. 3, a photoconductor for evaluation apparatus evaluation and a photoconductor for actual machine evaluation of Reference Example 2 were prepared in the same manner as in Example 1.

(Example 5 )
In forming the undercoat layer, Exemplified Compound No. In place of the amine compound of Example 1, Exemplified Compound Nos. Except for using triphenethylamine, which is an amine compound of No. 4, a photoconductor for evaluation device evaluation and a photoconductor for actual device evaluation of Example 5 were prepared in the same manner as in Example 1, respectively.

( Reference Example 3 )
In forming the undercoat layer, Exemplified Compound No. In place of the amine compound of Example 1, Exemplified Compound Nos. The evaluation device evaluation photoconductor and the actual device evaluation photoconductor of Reference Example 3 were prepared in the same manner as in Example 1 except that an amine compound having an aralkylamine-arylamine structure, which is an amine compound of No. 5, was used. .

( Reference Example 4 )
In forming the undercoat layer, Exemplified Compound No. In place of the amine compound of Example 1, Exemplified Compound Nos. Except for using the amine compound having a diaralkylamine-arylamine structure, which is an amine compound of No. 6, a photoconductor for evaluation apparatus evaluation and a photoconductor for actual machine evaluation of Reference Example 4 were prepared in the same manner as in Example 1. did.

(Reference Example 5 )
In forming the undercoat layer, Exemplified Compound No. In place of the amine compound of Example 1, Exemplified Compound Nos. A photoconductor for evaluation device evaluation and a photoconductor for actual device evaluation of Reference Example 5 were prepared in the same manner as in Example 1 except that the amine compound having a diaralkylamine structure, which is the amine compound of No. 7, was used.

(Reference Example 6 )
In forming the undercoat layer, Exemplified Compound No. In place of the amine compound of Example 1, Exemplified Compound Nos. A photoconductor for evaluation device evaluation and a photoconductor for actual device evaluation in Reference Example 6 were prepared in the same manner as in Example 1 except that the amine compound having a diaralkylamine structure, which is the amine compound of No. 8, was used.

(Example 6 )
In forming the undercoat layer, Exemplified Compound No. Except that the amount of the amine compound 1 is changed to 2.8 parts by weight (32% by weight of the total solid content of the undercoat layer), the evaluation device evaluation photosensitive material of Example 6 is performed in the same manner as in Example 1. Body and a photoconductor for actual machine evaluation were prepared.

(Example 7 )
In forming the undercoat layer, Exemplified Compound No. Evaluation apparatus evaluation of Example 7 in the same manner as in Example 1 except that the compounding amount of 1 amine compound is changed to 0.0048 parts by weight (0.08% by weight of the total solid content of the undercoat layer). Photoconductors and actual photoconductors were prepared.

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

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

(Comparative Example 3)
In forming the undercoat layer, Exemplified Compound No. In the formation of the charge generation layer without using the amine compound of No. 1, the exemplified compound No. 1 was added to the charge generation layer coating solution. Except for adding 7.5 parts by weight of the amine compound No. 1, a photoconductor for evaluation device evaluation and a photoconductor for actual device evaluation of Comparative Example 3 were prepared in the same manner as in Example 1, respectively.

(Comparative Example 4)
In forming the undercoat layer, Exemplified Compound No. Other than adding 5 parts by weight of a hindered phenolic antioxidant Sumitizer BHT (trade name, manufactured by Sumitomo Chemical Co., Ltd.) to the charge transport layer coating solution when forming the charge transport layer without using the amine compound 1 In the same manner as in Example 1, the evaluation device evaluation photoconductor and the actual device evaluation photoconductor of Comparative Example 4 were respectively produced.

(Comparative Example 5)
In forming the undercoat layer, Exemplified Compound No. In the same manner as in Example 1, except that a hindered amine antioxidant represented by the following structural formula (9) is used in place of the amine compound of 1, the evaluation apparatus evaluation photoreceptor of Comparative Example 5 and actual machine evaluation are used. Each photosensitive member was prepared.

For each of the photoreceptors of Examples 1 to 7, Reference Examples 1 to 6, and Comparative Examples 1 to 5 produced as described above, (a) oxidation resistance gas resistance and (b) electrical characteristics were as follows. The stability was evaluated, and (c) the overall performance of the photoreceptor was determined.

(A) Oxidation resistant gas resistance [Evaluation by evaluation equipment]
Each evaluation apparatus evaluation photoreceptor of Examples 1-7, Reference Examples 1-6 and Comparative Examples 1-5 (layer thickness of charge transport layer: 15 μm) was mounted on a test copying machine, and the temperature was 25 ° C., relative In a normal temperature / normal humidity (N / N) environment with a humidity of 50%, the surface potential V ₁ (V) of the photoreceptor immediately after charging and the surface potential V of the photoreceptor after 3 seconds from charging. ₂ (V) was measured. The test copier measures the surface potential of the photoconductor during the image forming process inside a commercially available copier AR-F330 (trade name, manufactured by Sharp Corporation) equipped with a corona discharge charger as the charging means for the photoconductor. What provided the surface electrometer (brand name: CATE751, the Gentec company make) so that it could do was used. The measured surface potential V ₁ (V) immediately after charging and the surface potential V ₂ (V) after 3 seconds from charging are substituted into the following formula (I) to calculate the charge retention ratio DD (%). was the initial charge retention rate DD _0.

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

A value obtained by subtracting the charge retention ratio DD ₀₂ after ozone exposure from the charge retention ratio before exposure to ozone, ie, the initial charge retention ratio DD ₀ , is obtained as a charge retention ratio change amount ΔDD (= DD ₀ -DD ₀₂ ), and oxidation resistance It was used as an evaluation index for gas.

[Evaluation with actual machine]
Examples 1 to 7, Reference Examples 1 to 6 and Comparative Examples 1 to 5 are commercially available with a corona discharge charger as a charging means for each of the actual device evaluation photoreceptors (layer thickness of the charge transport layer: 28 μm). Mounted on each copier AR-F330 (trade name, manufactured by Sharp Corporation), a test image of a predetermined pattern is recorded on a recording sheet in a normal temperature / normal humidity (N / N) environment at a temperature of 25 ° C. and a relative humidity of 50%. 50,000 photos were taken. The operation of the copying machine was stopped for 1 hour after the end of the 50,000 actual shots, and then a halftone image was copied on the recording paper, which was used as the first evaluation image. Next, a test image of a predetermined pattern is photographed on 50,000 sheets of recording paper again in an N / N environment at a temperature of 25 ° C. and a relative humidity of 50%. Then, a halftone image was copied on the recording paper, and this was used as a second evaluation image.

  The formed first evaluation image and second evaluation image were visually observed, and the toner image was transferred from the portion of the photoconductor that was placed close to the corona discharge charger when the operation of the copying machine was stopped. The image quality of the portion of the recording paper corresponding to the portion was determined by the degree of occurrence of image defects such as white spots and black belts, and used as an evaluation index for oxidation resistance gas resistance. The criteria for determining the image quality are as follows.

A: Excellent. No image defect occurs in any of the first evaluation image and the second evaluation image.
○: Good. Although some image defects have occurred in one or both of the first evaluation image and the second evaluation image, it is negligible.
Δ: Yes. Although some image defects have occurred in one or both of the first evaluation image and the second evaluation image, there is no problem in practical use.
×: Impossible. Many image defects occur in one or both of the first evaluation image and the second evaluation image, and the image cannot be actually used.

  The value of the charge retention rate change ΔDD and the image quality determination result were combined to evaluate the oxidation resistance gas resistance of the photoreceptor. The evaluation criteria for the oxidation-resistant gas resistance are as follows.

A: Excellent. ΔDD is less than 3.0% and image quality is excellent (（).
○: Good. ΔDD is 3.0% or more and less than 7.0% and image quality is excellent (（), or ΔDD is less than 7.0% and image quality is good (◯).
Δ: No problem in actual use. ΔDD is less than 7.0% and image quality is acceptable (Δ).
X: Defect. ΔDD is 7.0% or more, or image quality is not possible (×).

(B) Stability of electrical characteristics The photoconductors for actual machine evaluation of Examples 1 to 7, Reference Examples 1 to 6 and Comparative Examples 1 to 5 (layer thickness of the charge transport layer: 28 μm) are mounted on a test copying machine, respectively. In a low temperature / low humidity (L / L) environment with a temperature of 5 ° C. and a relative humidity of 20%, and a high temperature / high humidity (H / H) with a temperature of 35 ° C. and a relative humidity of 85%. Humidity) In each environment, the stability of the electrical characteristics was evaluated as follows. The test copier measures the surface potential of the photoconductor during the image forming process inside a commercially available copier AR-F330 (trade name, manufactured by Sharp Corporation) equipped with a corona discharge charger as the charging means for the photoconductor. What provided the surface electrometer (brand name: CATE751, the Gentec company make) so that it could do was used. The copying machine AR-F330 is a negatively charged image forming apparatus that performs electrophotographic process by negatively charging the surface of the photoreceptor.

Using the test copying machine on which the photoreceptors of Examples 1 to 7, Reference Examples 1 to 6 and Comparative Examples 1 to 5 are mounted, the surface potential of the photoreceptor immediately after the charging operation by the charger is set to the charging potential V0 (V ) as were measured and the charge potential V0 ₁ early. The measured surface potential of the photosensitive member immediately after subjected to exposure by a laser beam as a residual potential Vr (V), which was used as the initial residual potential Vr _1.

Then, after copying successively the test image of a predetermined pattern on the recording paper 30 million copies, the initial and in the same manner by measuring the charge potential V0 and residual potential Vr, the charge potential V0 ₂ and after repeated use of these The residual potential Vr ₂ after repeated use was set. The absolute value of the difference between the initial charging potential V0 ₁ and the charging potential V0 ₂ after repeated use was determined as a charging potential change amount ΔV0 (= | V0 ₁ −V0 ₂ |). Further, the absolute value of the difference between the initial residual potential Vr ₁ and the residual potential Vr ₂ after repeated use was determined as a residual potential change amount ΔVr (= | Vr ₁ −Vr ₂ |). The stability of the electrical characteristics was evaluated using the charging potential change amount ΔV0 and the residual potential change amount ΔVr as evaluation indexes.

The evaluation criteria for the stability of the electrical characteristics under the L / L environment are as follows.
A: Excellent. ΔV0 is 35V or less and ΔVr is 55V or less.
○: Good. ΔV0 is 35V or less and ΔVr is more than 55V and 80V or less, or ΔV0 is more than 35V and 75V or less and ΔVr is 55V or less.
Δ: No problem in actual use. ΔV0 exceeds 35V and 75V or less, and ΔVr exceeds 55V and 80V or less.
X: Defect. ΔV0 exceeds 75V or ΔVr exceeds 80V.

The evaluation criteria for the stability of the electrical characteristics in the H / H environment are as follows.
A: Excellent. ΔV0 is 15V or less and ΔVr is 105V or less.
○: Good. ΔV0 is 15V or less and ΔVr exceeds 105V and 125V or less, or ΔV0 exceeds 15V and 30V or less and ΔVr is 105V or less.
Δ: No problem in actual use. ΔV0 exceeds 15V and 30V or less, and ΔVr exceeds 105V and 125V or less.
X: Defect. ΔV0 exceeds 30V, or ΔVr exceeds 125V.

  In addition, the evaluation result in the L / L environment and the evaluation result in the H / H environment were combined to perform a comprehensive evaluation of the stability of the electrical characteristics. The evaluation criteria for the comprehensive evaluation of the stability of the electrical characteristics are as follows.

A: Excellent. Excellent in both L / L and H / H environments (（).
○: Good. Either the L / L environment or the 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 the L / L environment or the H / H environment (Δ), and the other is not defective (x).
X: Defect. Either or both of the L / L environment and the H / H environment are defective (x).

(C) Comprehensive Judgment of Photoreceptor Performance A comprehensive judgment of the photoconductor performance was made by combining the evaluation result of the oxidation-resistant gas property and the comprehensive evaluation result of the stability of the electric characteristics. The criteria for comprehensive judgment are as follows.

A: Excellent. Excellent resistance to oxidation gas and electrical properties (◎).
○: Good. Either oxidation-resistant gas resistance or electrical property stability is good (◯), and the other is excellent (◎) or good (）).
Δ: No problem in actual use. Either oxidation-resistant gas resistance or electrical property stability is not a problem in actual use (Δ), and the other is not defective (x).
X: Defect. Either or both of oxidation-resistant gas resistance and electrical property stability are poor (x).

The above evaluation results are shown in Table 2. In Table 2, the undercoat layer is abbreviated as UC (Under Coat) layer, the charge transport layer is abbreviated as CT (Charge Transport) layer, and the charge generation layer is denoted as CG (Charge).
Generation) layer.

Examples 1 7 and Comparison with Comparative Example 1 and Reference Examples 1 to 6, carried amine compound represented by the general formula (1) in the undercoat layer was added Example 1 to 7 and Reference Examples 1 to 6 This photoreceptor is superior in oxidation-resistant gas resistance and stability of electric characteristics as compared with the photoreceptor of Comparative Example 1 in which the amine compound represented by the general formula (1) is not added to the undercoat layer, and is used repeatedly. However, it has been found that it exhibits good electrical characteristics.

From comparison between Examples 1 to 7 and Reference Examples 1 to 6 and Comparative Examples 2 and 3, Comparative Examples 2 and 3 in which the amine compound represented by the general formula (1) was added to the charge transport layer or the charge generation layer Although the photosensitive member of No. 1 has a relatively good oxidation resistance gas resistance, the photosensitive member in Examples 1 to 7 and Reference Examples 1 to 6 can be used in both the L / L environment and the H / H environment. It was found that the charge potential change amount ΔV0 due to repeated use was large and the chargeability stability was poor, and the residual potential change amount ΔVr was large and the response stability was poor.

From the comparison between Examples 1 to 7 and Reference Examples 1 to 6 and Comparative Example 4, the photoconductor of Comparative Example 4 in which Sumilizer BHT, which is a hindered phenol-based antioxidant, was added to the charge transport layer as an antioxidant. Compared to the photoreceptors of Examples 1 to 7 and Reference Examples 1 to 6 , the charge retention rate change ΔDD is large, the image quality cannot be evaluated (x), and the oxidation resistance gas property is insufficient. I understood.

From the comparison between Examples 1 to 7 and Reference Examples 1 to 6 and Comparative Example 5, the hindered amine antioxidant represented by the structural formula (9) not corresponding to the amine compound represented by the general formula (1) was used. The photoconductor of Comparative Example 5 used has a larger charge retention rate change ΔDD than the photoconductors of Examples 1 to 7 and Reference Examples 1 to 6 , and the image quality cannot be evaluated (x). It was found that the gas nature is insufficient. The photoreceptor of Comparative Example 5 has a charge potential change amount ΔV0 due to repeated use in both the L / L environment and the H / H environment as compared with the photoreceptors of Examples 1 to 7 and Reference Examples 1 to 6. It was found that the stability of the charging property was greatly inferior.

From comparison between Examples 1 to 5 and Reference Examples 1 to 6 and Example 6 , the content of the amine compound represented by the general formula (1) in the undercoat layer is 0.1 to 30% by weight of the total solid content. photoreceptor are within the scope of examples 1-5 and reference examples 1-6, example content of the amine compound represented by the general formula (1) in the undercoat layer is outside the larger the range 6 Compared with other photoreceptors, in both L / L and H / H environments, the charge potential change amount ΔV0 due to repeated use is small and the chargeability is stable, and the residual potential change amount ΔVr is small and responds. It was found that the stability of the property is excellent. Further, from comparison between Examples 1 , 2, 5 and Reference Examples 1-6 and Example 3, Example 1 in which the content of the amine compound is in the range of 1 to 10% by weight of the total solid content of the undercoat layer. , 2 , 5 and the photoconductors of Reference Examples 1 to 6 are compared with the photoconductor of Example 3 in which the amine compound content exceeds 10% by weight of the total solid content of the undercoat layer and in the L / L environment and H In both the / H environments, it was found that the charge potential change amount ΔV0 due to repeated use is small and excellent in chargeability stability, and the residual potential change amount ΔVr is small and excellent in response stability.

Further, from comparison between Examples 1 to 5 and Reference Examples 1 to 6 and Example 7 , the content of the amine compound represented by the general formula (1) in the undercoat layer is 0.1 to 30% by weight of the total solid content. % Of the photoconductors of Examples 1 to 5 and Reference Examples 1 to 6 in which the content of the amine compound represented by the general formula (1) in the undercoat layer is 0.1 to 30 of the total solid content. Compared with the photoconductor of Example 7 that deviates from the range of wt%, the amount of change in charge retention ΔDD is small, and the evaluation of image quality is excellent (良) or good (◯), and the resistance to oxidation gas is improved. It turns out that it is excellent. Further, from comparison between Examples 1 , 2, 5 and Reference Examples 1-6 and Example 4, Examples 1 , 2 , 5 in which the content of the amine compound is in the range of 1 to 10% by weight of the total solid content The photoreceptors of Reference Examples 1 to 6 are more excellent in oxidation resistance gas resistance than the photoreceptor of Example 4 in which the amine compound content is less than 1% by weight of the total solid content of the undercoat layer. I understand.

From the comparison between Example 1 and Example 5 and Reference Examples 1 to 6 , among the amine compounds represented by the general formula (1), the amine compound having a tribenzylamine structure represented by the structural formula (1a) It can be seen that a photoconductor that is particularly excellent in oxidation resistance gas resistance and electrical property stability can be obtained by using.

  As described above, by containing the amine compound represented by the general formula (1) in the undercoat layer, it is excellent in electrical characteristics such as chargeability and responsiveness, and is excellent in oxidation-resistant gas property and used repeatedly. However, it was possible to obtain an electrophotographic photoreceptor excellent in property stability in which the above-described good electrical properties were not deteriorated.

1 is a partial cross-sectional view showing a simplified configuration of an electrophotographic photosensitive member 1 according to a first embodiment of the present invention. It is a partial cross-sectional view schematically showing the structure of the electronic photosensitive member 2. FIG. 5 is a side view of a layout showing a simplified configuration of an image forming apparatus 100 according to a second embodiment of the present invention.

Explanation of symbols

1, 2, 10 Electrophotographic photoreceptor 11 Conductive support 12 Undercoat layer 13 Charge generation layer 14 Charge transport layer 15, 16 Photosensitive layer 30 Exposure means 32 Charger 33 Developer 34 Transfer device 35 Fixer 36 Cleaner 100 Image Forming equipment

Claims (5)

An electrophotographic photosensitive member comprising a conductive support made of a conductive material, and a photosensitive layer provided on the conductive support and containing a charge generation material and a charge transport material,
An undercoat layer provided between the conductive support and the photosensitive layer and containing an amine compound represented by the following general formula (1);
In the general formula (1), R ¹ , R ² and R ³ are each an aralkyl group which may have a substituent,
The photosensitive layer comprises a charge generation layer provided on the undercoat layer, and a charge transport layer provided on the charge generation layer,
The charge generation layer is composed of a charge generation material and a binder resin,
The charge generation material is a titanyl phthalocyanine compound represented by the following general formula (2):
The charge transport layer is composed of a charge transport material and a binder resin,
The electrophotographic photoreceptor, wherein the charge transport material is an enamine compound represented by the following general formula (3).

(In the formula, R ¹ , R ² and R ³ each represents an aralkyl group which may have a substituent .)

(In the formula, X ¹ , X ² , X ³ and X ⁴ each represent a hydrogen atom, a halogen atom, an alkyl group or an alkoxy group, and n, m, l and k each represent an integer of 1 to 4. )

(Wherein R ⁴ , R ⁵ , R ⁶ and R ⁷ each represent a hydrogen atom, an alkoxy group which may have a substituent or an alkyl group which may have a substituent, and R ⁸ and R ⁹ Each represents a hydrogen atom, an aryl group which may have a substituent, or an alkyl group which may have a substituent, provided that the benzene ring and naphthalene ring to which R ^{4 to} R ⁷ are bonded are R ⁴ to besides R ⁷ may have other substituents.) The electrophotographic photosensitive member according to claim 1, wherein the amine compound represented by the general formula (1) is an amine compound represented by the following structural formula (1a).

  3. The electron according to claim 1, wherein the content of the amine compound represented by the general formula (1) is 0.1 wt% or more and 30 wt% or less of the total solid content of the undercoat layer. Photoconductor.   The electrophotographic photosensitive member according to claim 3, wherein the content of the amine compound represented by the general formula (1) is 1% by weight or more and 10% by weight or less of the total solid content of the undercoat layer. An electrophotographic photoreceptor according to any one of claims 1 to 4,
Charging means for charging the electrophotographic photoreceptor;
Exposure means for exposing the charged electrophotographic photosensitive member;
An image forming apparatus comprising: a developing unit that develops an electrostatic latent image formed by exposure.

Images