JP2010276851A - Method of manufacturing electrophotographic photoreceptor - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a method of manufacturing an electrophotographic photoreceptor that is less apt to cause photograph memory, even if a charge-transport layer is made to contain siloxane-containing polymer. <P>SOLUTION: This method of manufacturing the electrophotographic photoreceptor has a charge-transport layer forming process of forming the charge-transport layer, by applying a coating liquid for the charge-transport layer on the surface of a charge-generating layer and drying it. The coating liquid for the charge-transport layer contains the siloxane-containing polymer. For the temperature of the surface of the charge-generating layer and the temperature of the coating liquid for the charge-transport layer, when the coating liquid for the charge-transport layer is applied to the surface of the charge-generating layer in the charge-transport layer forming process, the relation: 5(°C)≤(temperature of surface of charge generating layer)-(temperature of coating liquid for charge-transport layer)≤15(°C)(temperature of surface of charge generating layer)≥30(°C) is established. <P>COPYRIGHT: (C)2011,JPO&INPIT

Description

  The present invention relates to a method for producing an electrophotographic photoreceptor.

  The electrophotographic photosensitive member is required to have sensitivity, electrical characteristics, mechanical characteristics, and optical characteristics according to the applied electrophotographic process. Further, the output image is required to have no image defect.

  In particular, since electrical and mechanical external forces such as charging, exposure, development, transfer, and cleaning are directly applied to the surface of an electrophotographic photosensitive member that is repeatedly used, durability against them is required.

  Examples of a method for improving the durability of the electrophotographic photosensitive member against mechanical external force include a method for improving the lubricity of the surface of the electrophotographic photosensitive member.

  As a method for improving the lubricity of the surface of the electrophotographic photosensitive member, Patent Document 1 discloses a technique in which silicone oil is contained as a lubricant in the surface layer of the electrophotographic photosensitive member. Patent Document 2 discloses a technique using a polycarbonate having a siloxane chain at the terminal. In particular, according to the technique disclosed in Patent Document 2, it is possible to obtain an electrophotographic photoreceptor having high lubricity and small potential fluctuation due to repeated use.

  Electrophotographic photoreceptors also have a phenomenon in which the potential fluctuates due to repeated use, or a phenomenon in which a carrier stays in a portion irradiated with intense light and causes a potential difference from a portion not irradiated with light (hereinafter referred to as “photo memory”). Electrical characteristics that are difficult to occur) are also required.

  Patent Document 3 discloses an electrophotographic photoreceptor in which the temperature of a material to be coated is set higher than the temperature of the coating solution for the charge transport layer, thereby controlling the ionization potential of the charge transport layer and improving the potential fluctuation due to repeated use. A method of obtaining has been proposed.

  Further, as one of the causes of image defects, it is also known that unevenness occurs in an output image due to coating unevenness at the time of manufacturing an electrophotographic photosensitive member.

  Patent Document 4 proposes a method for forming a uniform charge generation layer by applying a dipping method by heating the substrate and then dipping it in a coating solution.

Japanese Patent Laid-Open No. 7-013368 JP 2007-199688 A JP 2004-004289 A JP 2003-345042 A

  However, in the electrophotographic photosensitive member described in Patent Document 1, photo memory may be easily generated. Further, the electrophotographic photosensitive member described in Patent Document 2 has room for improvement in the generation of photo memory. Moreover, in patent documents 1-4, there is no specific description regarding the uniformity in the interface of a charge transport layer and a charge generation layer.

  An object of the present invention is to provide a method for producing an electrophotographic photosensitive member that hardly causes photo memory even when a siloxane-containing polymer is contained in a charge transport layer.

The present invention is a method for producing an electrophotographic photosensitive member having a charge transport layer forming step of forming a charge transport layer by applying a charge transport layer coating solution on the surface of the charge generation layer and drying the coating solution,
The charge transport layer coating solution contains a siloxane-containing polymer,
In the charge transport layer forming step, the temperature of the surface of the charge generation layer and the temperature of the charge transport layer coating solution when the charge transport layer coating solution is applied to the surface of the charge generation layer have the following relationship: An electrophotographic photosensitive member manufacturing method characterized by satisfying the above.
5 (° C.) ≦ (temperature of charge generation layer surface) − (temperature of charge transport layer coating solution) ≦ 15 (° C.)
(Temperature of surface of charge generation layer) ≧ 30 (° C.)

  According to the present invention, it is possible to produce an electrophotographic photosensitive member that hardly causes a photo memory even when a siloxane-containing polymer is contained in the charge transport layer.

It is a figure which shows an example of a dip coating apparatus.

  The inventors of the present invention have studied a photomemory of an electrophotographic photosensitive member containing a siloxane-containing polymer in the charge transport layer, paying attention to the formation conditions of the charge transport layer. As a result, when the charge transport layer coating solution is applied to the surface of the charge generation layer in the charge transport layer forming step, the temperature of the charge generation layer surface and the temperature of the charge transport layer coating solution satisfy a certain relationship. The present inventors have found that it is effective in reducing photo memory, and have reached the present invention.

  Although the details of the reason why the effect of reducing the photo memory can be obtained by the present invention are not clear, the present inventors consider as follows.

  That is, when a siloxane-containing polymer is contained in the charge transport layer, the retention of carriers that causes photo memory is considered to be due to micro-uniformity at the interface between the charge generation layer and the charge transport layer. Since the siloxane-containing polymer has a structure with high mobility, it is presumed that the uniformity can be easily controlled by temperature conditions and the like. In the present invention, when the charge transport layer coating solution is applied to the surface of the charge generation layer in the charge transport layer formation step, the temperature of the charge generation layer surface and the temperature of the charge transport layer coating solution have a specific relationship. Set as follows. Thereby, it is presumed that the siloxane-containing polymer moves in a uniform state to the interface between the charge generation layer and the charge transport layer, and as a result, the photomemory is suppressed.

  In the present invention, it is preferable from the viewpoint of reducing photomemory that a charge transport layer coating solution is applied to the surface of the charge generation layer and then dried in an environment of 30 ° C. or more and 60 ° C. or less for 30 seconds or more. This is thought to be due to the fact that the siloxane-containing polymer is uniformly homogenized by drying at a temperature of 60 ° C. or lower, and the interface between the charge generation layer and the charge transport layer shifts to a more stable state. On the other hand, when the drying temperature is lower than 30 ° C., the siloxane polymer is not easily homogenized, and it is difficult to shift to a more stable state over time.

[Siloxane-containing polymer]
Examples of the siloxane-containing polymer used in the present invention include silicone oil, siloxane-modified polycarbonate, and siloxane-modified polyarylate.

  A well-known thing can be used as a silicone oil, For example, a methylphenyl silicone oil, a methyl hydrogen silicone oil, a dimethyl silicone oil etc. are mentioned. Among these, dimethyl silicone oil is preferable because the effects of the present invention are easily obtained. These can be used alone or as a mixture or copolymer of two or more.

  Examples of the siloxane-modified polycarbonate and siloxane-modified polyarylate include those having a siloxane skeleton at the main chain or terminal of a known polycarbonate or polyarylate. Among these, a siloxane-modified polycarbonate having a repeating structural unit represented by the following general formula (1) and a repeating structural unit represented by the following general formula (2) is preferable because the effects of the present invention can be easily obtained.

In the general formula (1), X represents — (CR ⁵ R ⁶ ) —, a substituted or unsubstituted cycloalkylidene group, a substituted or unsubstituted α, ω-alkylene group, a single bond, —O—, —S. -, - SO- or -SO ₂ - it shows a. R ^{1 to} R ⁴ each independently represent a hydrogen atom, a halogen atom, a substituted or unsubstituted alkyl group or a substituted or unsubstituted aryl group. R ⁵ and R ⁶ each independently represent a hydrogen atom, a trifluoromethyl group, a substituted or unsubstituted alkyl group, or a substituted or unsubstituted aryl group.

  Examples of the alkyl group include a methyl group, an ethyl group, a propyl group, a cyclohexyl group, and a cycloheptyl group. Examples of the aryl group include a phenyl group, a naphthyl group, and an anthryl group. Examples of the cycloalkylidene group include a cyclohexylidene group, a cycloheptylidene group, and a fluorenylidene group. Examples of the α, ω-alkylene group include a 1,2-ethylene group, a 1,3-propylene group, and a 1,4-butylene group. Examples of the halogen atom include a fluorine atom, a chlorine atom, and a bromine atom. The single bond means that the benzene rings on both sides of X are directly bonded.

In the general formula (2), R ²¹ and R ²² each independently represent a hydrogen atom, a halogen atom, an alkoxy group, a nitro group, a substituted or unsubstituted alkyl group, or a substituted or unsubstituted aryl group. R ²³ and R ²⁴ each independently represent a hydrogen atom, an alkyl group or an aryl group. R ^{25 to} R ²⁹ each independently represent a hydrogen atom, a halogen atom, a substituted or unsubstituted alkyl group or a substituted or unsubstituted aryl group. a represents a positive integer of 1 or more and 30 or less. m represents a positive integer of 1 to 500.

  Examples of the alkyl group include a methyl group, an ethyl group, and a propyl group. Examples of the aryl group include a phenyl group, a naphthyl group, and an anthryl group. Examples of the halogen atom include a fluorine atom, a chlorine atom, and a bromine atom. Examples of the alkoxy group include a methoxy group, an ethoxy group, and a propoxy group.

  Further, the siloxane-modified polycarbonate having the repeating structural unit represented by the general formula (1) and the repeating structural unit represented by the general formula (2) can be used alone. Alternatively, it can be used as a mixture or copolymer with silicone oil, siloxane-modified polycarbonate or siloxane-modified polyarylate.

  The siloxane-modified polycarbonate having the repeating structural unit represented by the general formula (1) and the repeating structural unit represented by the general formula (2) is represented by the compound represented by the following general formula (3) and the following general formula (4). The compounds shown can be synthesized by polymerizing with the action of phosgene in the presence of alkali.

In the general formula (3), X represents — (CR ⁵ R ⁶ ) —, a substituted or unsubstituted cycloalkylidene group, a substituted or unsubstituted α, ω-alkylene group, a single bond, —O—, —S. -, - SO- or -SO ₂ - it shows a. R ^{1 to} R ⁴ each independently represent a hydrogen atom, a halogen atom, a substituted or unsubstituted alkyl group or a substituted or unsubstituted aryl group. R ⁵ and R ⁶ each independently represent a hydrogen atom, a trifluoromethyl group, a substituted or unsubstituted alkyl group, or a substituted or unsubstituted aryl group. X and ^R 1 to R ⁶ in the general formula (3) corresponds to the X and ^R 1 to R ⁶ in the general formula (1).

In the general formula (4), R ²¹ and R ²² each independently represent a hydrogen atom, a halogen atom, an alkoxy group, a nitro group, a substituted or unsubstituted alkyl group, or a substituted or unsubstituted aryl group. R ²³ and R ²⁴ each independently represent a hydrogen atom, an alkyl group or an aryl group. R ^{25 to} R ²⁹ each independently represent a hydrogen atom, a halogen atom, a substituted or unsubstituted alkyl group or a substituted or unsubstituted aryl group. a represents a positive integer of 1 or more and 30 or less. m represents a positive integer of 1 to 500. ^R 21 ^{to R 29,} m and a in the general formula (4) corresponds to the ^R 21 ^{to R 29,} m and a in the general formula (2).

  Preferred specific examples of the compound represented by the general formula (3) are shown below. Two or more of these may be mixed and used for polymerization.

  Preferred specific examples of the compound represented by the general formula (4) are shown below. Two or more of these may be mixed and used for polymerization.

  From the compound represented by the general formula (3) and the compound represented by the general formula (4), it has a repeating structural unit represented by the general formula (1) and a repeating structural unit represented by the general formula (2). When synthesizing siloxane-modified polycarbonate, the reaction may not proceed completely. If the reaction does not proceed completely, the phenolic OH group remains unsealed in the siloxane-modified polycarbonate, or the unreacted compound represented by the general formula (3) and / or the general formula (4) The compound shown by may remain. The remaining unreacted compound represented by the general formula (3) and / or the compound represented by the general formula (4) has a phenolic OH group. Since the residual phenolic OH group (hereinafter referred to as “residual phenolic OH”) has a strong polarity, it attracts the siloxane structure and causes micro-uniformity at the interface between the charge generation layer and the charge transport layer. There is a case. Therefore, the amount of residual phenolic OH in the siloxane-modified polycarbonate is preferably 100 ppm or less.

  Also, from the viewpoint of productivity, if the amount of residual phenolic OH in the siloxane-modified polycarbonate is set to 3 ppm or less, it is difficult to increase the production scale and it is not suitable for mass production. Therefore, the amount of residual phenolic OH is more preferably 3 to 100 ppm.

  In the present invention, the amount of residual phenolic OH in the siloxane-modified polycarbonate can be measured by an absorptiometric method.

[Configuration of electrophotographic photoreceptor]
Next, the structure of the electrophotographic photosensitive member manufactured by the manufacturing method of the present invention will be described.

  As an electrophotographic photoreceptor, one having a support and a photosensitive layer formed on the support is generally used. The electrophotographic photoreceptor produced by the production method of the present invention is a laminate type in which a charge generation layer containing a charge generation material and a charge transport layer containing a charge transport material are laminated in this order as the photosensitive layer ( (Functional separation type) photosensitive layer. The charge transport layer is a surface layer of the electrophotographic photosensitive member.

  As a support body, what is necessary is just to have electroconductivity (conductive support body). Specifically, aluminum, copper, chromium, nickel, zinc, stainless steel, etc. molded into a drum or sheet, aluminum, copper or other metal foil laminated on a plastic film, aluminum, indium oxide And tin oxide deposited on a plastic film.

  Further, the surface of the support may be subjected to cutting treatment, surface roughening treatment (honing treatment or blasting treatment), alumite treatment, etc. for the purpose of preventing interference fringes due to scattering of laser light. Alternatively, chemical treatment may be performed with a solution obtained by dissolving a metal salt compound or a fluorine compound metal salt in an acidic aqueous solution containing alkali phosphate, phosphoric acid, or tannic acid as a main component.

  The honing process is roughly classified into a dry honing process and a wet honing process. The wet honing treatment is a method in which a powdery abrasive is suspended in a liquid such as water and sprayed onto the surface of the support at high speed to roughen the surface of the support. The surface roughness can be controlled by spraying pressure, speed, amount of abrasive, type, shape, size, hardness, specific gravity, suspension temperature, and the like. The dry honing treatment is a method in which an abrasive is sprayed onto the surface of the support at high speed with air to roughen the surface of the support, and the surface roughness can be controlled in the same manner as the wet honing treatment. Examples of the abrasive used for the honing treatment include particles such as silicon carbide particles, alumina particles, iron particles, and glass beads.

  On the support, a conductive layer may be provided for the purpose of preventing interference fringes due to scattering of laser light or covering a scratch on the support. This can be formed by dispersing conductive particles such as carbon black, metal particles, and metal oxide particles in a binder resin. The thickness of the conductive layer is preferably 5 μm or more and 40 μm or less, and more preferably 10 μm or more and 30 μm or less.

  Further, an intermediate layer having an adhesive function may be provided on the support or the conductive layer. Examples of the material for the intermediate layer include polyamide, polyvinyl alcohol, polyethylene oxide, ethyl cellulose, casein, polyurethane, and polyether urethane. An intermediate layer can be formed by applying a coating solution for an intermediate layer obtained by dissolving them in a suitable solvent on a support or a conductive layer and drying it. The thickness of the intermediate layer is preferably 0.05 μm or more and 5.00 μm or less, and more preferably 0.30 μm or more and 1.00 μm or less.

  A charge generation layer is formed on the support, the conductive layer, or the intermediate layer. The charge generation layer can be formed by applying a charge generation layer coating solution prepared by dispersing a charge generation material together with a binder resin and a solvent in an amount of 0.3 to 4 times, and drying the coating solution. . Examples of the dispersion process include a process using a device such as a homogenizer, an ultrasonic disperser, a ball mill, a vibrating ball mill, a sand mill, an attritor, a roll mill, and a liquid collision type high-speed disperser. The thickness of the charge generation layer is preferably 5.0 μm or less, and more preferably 0.1 μm or more and 2.0 μm or less.

  Examples of the charge generating substance include pigments such as phthalocyanine (metal phthalocyanine, metal-free phthalocyanine), anthanthrone, dibenzpyrenequinone, cyanine, azo (trisazo, disazo, monoazo), indigo, quinacrine, and the like.

  A charge transport layer is formed on the charge generation layer.

In the charge transport layer forming step in the present invention, first, a charge transport layer coating solution containing a siloxane-containing polymer and, if necessary, a charge transport material, a binder resin, and a solvent is prepared. The charge transport layer coating liquid is maintained at a temperature of 30 ° C. or higher, and the charge transport layer coating liquid is maintained at a temperature 5 ° C. to 15 ° C. lower than the temperature of the charge generation layer surface. Is applied to the surface of the charge generation layer. That is, when the charge transport layer coating solution is applied to the surface of the charge generation layer, the temperature of the charge generation layer surface and the temperature of the charge transport layer coating solution satisfy the following relationship.
5 (° C.) ≦ (temperature of charge generation layer surface) − (temperature of charge transport layer coating solution) ≦ 15 (° C.)
(Temperature of surface of charge generation layer) ≧ 30 (° C.)
Thereafter, the charge transport layer is formed by drying the charge transport layer coating solution applied to the surface of the charge generation layer.

  Examples of the coating method for the charge transport layer coating solution include a dip coating method, a spin coating method, a spray coating method, a bar coating method, and an electrostatic coating method. In the case of the present invention, the dip coating method is preferred because the temperature of the coating solution for the charge transport layer is easily controlled.

  Examples of the charge transport material include triarylamine compounds, hydrazone compounds, styryl compounds, stilbene compounds, pyrazoline compounds, oxazole compounds, thiazole compounds, and triarylmethane compounds. These may use only 1 type and may use 2 or more types.

  Examples of the binder resin used for the charge transport layer include acrylic resin, acrylonitrile resin, aryl resin, alkyd resin, epoxy resin, nylon, phenol resin, phenoxy resin, butyral resin, polyacrylamide, polyacetal, polyamideimide, polyamide, Examples include polyallyl ether, polyarylate, polyimide, polyurethane, polyester, polyethylene, polycarbonate, polystyrene, polystyrene, polysulfone, polyvinyl butyral, polyphenylene oxide, polybutadiene, polypropylene, methacrylic resin, urea resin, vinyl chloride resin, and vinyl acetate resin. . Among these, polyarylate and polycarbonate are preferable. These can be used alone or as a mixture or copolymer of two or more.

  The ratio between the charge transport material and the binder resin is preferably in the range of 2: 1 to 1: 2 (mass ratio).

  Moreover, you may add antioxidant, a heat stabilizer, a ultraviolet absorber, a plasticizer, etc. to a charge transport layer as needed. Furthermore, you may use lubricants and particle | grains other than a siloxane containing polymer as needed. Examples of the lubricant include solid lubricants such as zinc stearate, aliphatic oils having a fluorinated alkyl group, and varnishes. Examples of the particles include fluorine atom-containing resin particles (polytetrafluoroethylene particles, etc.), resin particles such as polystyrene particles, metal oxide particles such as silica particles, alumina particles, tin oxide particles, and the surface of these particles. Examples of such particles include treated particles.

  The film thickness of the charge transport layer is preferably 1 μm or more and 35 μm or less, and more preferably 5 μm or more and 30 μm or less.

  In the step of forming each layer of the electrophotographic photoreceptor, examples of the solvent to be used include chlorobenzene, tetrahydrofuran, 1,4-dioxane, toluene, xylene and the like. These may be used alone or in combination.

  EXAMPLES Hereinafter, although this invention is demonstrated in detail according to an Example, this invention is not limited to these. In the examples, “part” means “part by mass”.

[Example 1]
(Preparation of electrophotographic photoreceptor)
Support The aluminum cylinder having a diameter of 30 mm and a length of 260 mm was used as a support.

Conductive layer forming step 50 parts of titanium oxide particles coated with tin oxide containing 10% by mass of antimony oxide, 25 parts of resol type phenol resin, 30 parts of methoxypropanol, 20 parts of methanol and silicone oil (polydimethylsiloxane polyoxyalkylene co-polymer) A coating solution for a conductive layer was prepared by dispersing 0.002 part of a polymer, weight average molecular weight 3000) in a sand mill apparatus using glass beads having a diameter of 1 mm for 2 hours. This conductive layer coating solution was dip-coated on a support and cured at 140 ° C. for 20 minutes to form a conductive layer having a thickness of 20 μm.

Intermediate layer forming step An intermediate layer coating solution was prepared by dissolving 5 parts of N-methoxymethylated 6 nylon in 95 parts of methanol. This intermediate layer coating solution was dip coated on the conductive layer and dried at 100 ° C. for 20 minutes to form an intermediate layer having a thickness of 0.8 μm.

Charge generation layer forming step: Oxytitanium phthalocyanine crystal having strong peaks at 9.0 °, 14.2 °, 23.9 ° and 27.1 ° with a Bragg angle 2θ ± 0.2 ° in CuKα characteristic X-ray diffraction (Charge generating material) 4 parts, polyvinyl butyral (trade name: ESREC BM2, manufactured by Sekisui Chemical Co., Ltd.) 2 parts and 60 parts of cyclohexanone were dispersed in a sand mill using glass beads having a diameter of 1 mm for 4 hours. A coating solution for charge generation layer was prepared by adding 100 parts of ethyl acetate. The charge generation layer coating solution was dip coated on the intermediate layer and dried at 100 ° C. for 10 minutes to form a charge generation layer having a thickness of 0.3 μm.

-Charge transport layer forming step 5 parts of a compound (charge transport material) represented by the following structural formula (CT-1),

  3 parts of a compound (charge transport material) represented by the following structural formula (CT-2),

  10 parts of a polycarbonate having a repeating structural unit represented by the following structural formula (CTB-1) (weight average molecular weight: 110000), and

  Siloxane-modified polycarbonate having a repeating structural unit represented by the following structural formula (CTB-2) and a terminal structure represented by the following structural formula (CTB-2 ′) (weight average molecular weight: 55000, residual phenolic OH amount: 70 ppm) 0.8 parts

(0.95 and 0.05 in the formula are copolymerization ratios)

Was dissolved in a mixed solvent of 55 parts of monochlorobenzene and 15 parts of dimethoxymethane to prepare a charge transport layer coating solution.

  This charge transport layer coating solution was added to the coating solution circulating device 3 of the dip coating device shown in FIG. 1, and the temperature of the charge transport layer coating solution was adjusted to 25 ° C. In FIG. 1, reference numeral 1 denotes an object to be applied, 2 an application tank for immersing the object to be applied 1 and applying a coating liquid to the surface of the object to be applied 1, and 3 an application to the application tank 2. This is a coating liquid circulation device for supplying a liquid and for collecting the coating liquid overflowed in the coating tank 2. The arrow indicates the flow of the coating solution.

  Next, after adjusting the temperature of the surface of the charge generation layer of the object to be coated (formed up to the charge generation layer) to 35 ° C., the coating solution for the charge transport layer is immersed in the surface of the charge generation layer It applied by the application method. Then, after performing touch drying for 60 seconds in an environment of 30 ° C., drying was performed at 110 ° C. for 1 hour, thereby forming a charge transport layer having a thickness of 15 μm.

  Thus, an electrophotographic photosensitive member having a conductive layer, an intermediate layer, a charge generation layer, and a charge transport layer on a support, and the charge transport layer being a surface layer was produced.

  The produced electrophotographic photosensitive member was mounted on the following evaluation apparatus, and photo memory was evaluated. The evaluation with the evaluation apparatus was performed in a normal temperature and normal humidity (23 ° C./50% RH) environment. The electrophotographic apparatus used as the evaluation apparatus is a modified machine of a color laser printer (trade name: Color Laser Jet 4600) manufactured by Hewlett-Packard Company. The process speed was set to 160 mm / sec, and only a DC voltage was applied to the charging roller that was charged in contact with the electrophotographic photosensitive member.

  In the evaluation apparatus, 3000 lux white light was irradiated to a part of the produced electrophotographic photosensitive member for 5 minutes. Thereafter, the bright portion potential of the portion irradiated with light and the bright portion potential of the portion not irradiated with light were measured, and the difference between them was calculated to evaluate the photomemory.

  The surface potential of the electrophotographic photosensitive member was measured by attaching an electrometer (trade name: Model 344, manufactured by Trek Japan Co., Ltd.) at the position of the developing unit of the evaluation apparatus. The evaluation results are shown in Table 1.

[Examples 2 to 13]
Table 1 shows the temperature of the surface of the charge generation layer when applying the charge transport layer coating solution in the charge transport layer forming step, the touch drying temperature and time after coating, and the amount of residual phenolic OH of the siloxane-containing polycarbonate used. An electrophotographic photosensitive member was prepared and evaluated in the same manner as in Example 1 except that the above conditions were satisfied. The evaluation results are shown in Table 1.

[Example 14]
A siloxane-containing polymer is a siloxane-modified polycarbonate having a repeating structural unit represented by the following structural formula (CTB-3) and a terminal structure represented by the above structural formula (CTB-2 ′) (weight average molecular weight: 55000, residual phenol). OH content: 70 ppm)

(0.5 and 0.5 in the formula are copolymerization ratios)
An electrophotographic photosensitive member was prepared and evaluated in the same manner as in Example 1 except that the above was changed. The evaluation results are shown in Table 1.

[Example 15]
Except that 0.08 part of dimethyl silicone oil (trade name: KF-96, manufactured by Shin-Etsu Chemical Co., Ltd.) as a siloxane-containing polymer was further added to the coating solution for the charge transport layer, the same as in Example 1. An electrophotographic photoreceptor was prepared and evaluated. The evaluation results are shown in Table 1.

[Comparative Example 1]
In the charge transport layer forming step, an electrophotographic photoreceptor was prepared and evaluated in the same manner as in Example 1 except that the surface temperature of the charge generation layer when applying the charge transport layer coating solution was 25 ° C. . The evaluation results are shown in Table 1.

[Comparative Example 2]
In the charge transport layer forming step, an electrophotographic photoreceptor was prepared and evaluated in the same manner as in Example 1 except that the surface temperature of the charge generation layer when applying the charge transport layer coating solution was 45 ° C. . The evaluation results are shown in Table 1.

[Comparative Example 3]
In the charge transport layer forming step, an electrophotographic photosensitive member was prepared and evaluated in the same manner as in Comparative Example 1 except that the temperature of the charge transport layer coating solution when applying the charge transport layer coating solution was 20 ° C. did. The evaluation results are shown in Table 1.

[Comparative Example 4]
In the charge transport layer forming step, an electrophotographic photosensitive member was prepared and evaluated in the same manner as in Example 3 except that the temperature of the charge transport layer coating solution when applying the charge transport layer coating solution was 30 ° C. did. The evaluation results are shown in Table 1.

[Example 16]
(Preparation of electrophotographic photoreceptor)
The charge generation layer was formed in the same manner as in Example 1.

Charge transport layer forming step 5 parts of the compound (charge transport material) represented by the structural formula (CT-1), 3 parts of the compound (charge transport material) represented by the structural formula (CT-2), the structural formula ( 10 parts of polycarbonate (weight average molecular weight: 110000) having a repeating structural unit represented by CTB-1) and 0.8 part of dimethyl silicone oil (trade name: KF-96, manufactured by Shin-Etsu Chemical Co., Ltd.) A charge transport layer coating solution was prepared by dissolving in a mixed solvent of 55 parts of monochlorobenzene and 15 parts of dimethoxymethane.

  This charge transport layer coating solution was added to the coating solution circulating device 3 of the dip coating device shown in FIG. 1, and the temperature of the charge transport layer coating solution was adjusted to 25 ° C.

  Next, after adjusting the surface of the charge generation layer of the object to be coated (formed up to the charge generation layer) to 35 ° C., the charge transport layer coating solution is immersed in the surface of the charge generation layer It applied by the application method. Then, after performing touch drying for 60 seconds in an environment of 30 ° C., drying was performed at 110 ° C. for 1 hour, thereby forming a charge transport layer having a thickness of 15 μm.

  Thus, an electrophotographic photosensitive member having a conductive layer, an intermediate layer, a charge generation layer, and a charge transport layer on a support, and the charge transport layer being a surface layer was produced.

  The produced electrophotographic photoreceptor was evaluated in the same manner as in Example 1. The evaluation results are shown in Table 2.

[Examples 17 to 24]
In the charge transport layer forming step, the same conditions as in Example 16 except that the surface temperature of the charge generation layer when applying the charge transport layer coating solution, the touch drying temperature and time after coating were set as shown in Table 2. Thus, an electrophotographic photoreceptor was prepared and evaluated. The evaluation results are shown in Table 2.

[Example 25]
An electrophotographic photoreceptor was prepared and evaluated in the same manner as in Example 16 except that the siloxane-containing polymer was changed to methyl hydrogen silicone oil (trade name: KF-99, manufactured by Shin-Etsu Chemical Co., Ltd.). . The evaluation results are shown in Table 2.

[Comparative Example 5]
In the charge transport layer forming step, an electrophotographic photoreceptor was prepared and evaluated in the same manner as in Example 16 except that the temperature of the surface of the charge generation layer when applying the charge transport layer coating solution was 25 ° C. . The evaluation results are shown in Table 2.

[Comparative Example 6]
In the charge transport layer forming step, an electrophotographic photoreceptor was prepared and evaluated in the same manner as in Example 16 except that the temperature of the surface of the charge generation layer when applying the charge transport layer coating solution was 45 ° C. . The evaluation results are shown in Table 2.

[Comparative Example 7]
In the charge transport layer forming step, an electrophotographic photosensitive member was prepared and evaluated in the same manner as in Comparative Example 5 except that the temperature of the charge transport layer coating solution when applying the charge transport layer coating solution was 20 ° C. did. The evaluation results are shown in Table 2.

[Comparative Example 8]
In the charge transport layer forming step, an electrophotographic photosensitive member was produced and evaluated in the same manner as in Example 18 except that the temperature of the charge transport layer coating solution when applying the charge transport layer coating solution was 30 ° C. did. The evaluation results are shown in Table 2.

[Comparative Example 9]
The charge generation layer was formed in the same manner as in Example 1.

Charge transport layer forming step 1,1-bis (p-diethylaminophenyl) -4,4-diphenyl-1,3-butadiene (manufactured by Annan Co., Ltd., trade name T-405), and polycarbonate (commodity) Name: 5 parts of Iupilon Z-300, manufactured by Mitsubishi Gas Chemical Co., Ltd. was dissolved in 45 parts of methylene chloride. By adding 0.1% by mass of dimethyl silicone oil (trade name: KF-96, manufactured by Shin-Etsu Chemical Co., Ltd.) to the solid content of the above, a coating solution for a charge transport layer is prepared. did.

  This charge transport layer coating solution was dipped onto the surface of the charge generation layer in the same manner as in Comparative Example 5 and dried at 110 ° C. for 1 hour to form a charge transport layer having a thickness of 20 μm.

  Thus, an electrophotographic photosensitive member having a conductive layer, an intermediate layer, a charge generation layer, and a charge transport layer on a support, and the charge transport layer being a surface layer was produced.

  The produced electrophotographic photoreceptor was evaluated in the same manner as in Example 1. The evaluation results are shown in Table 2.

[Reference Example 1]
An electrophotographic photosensitive member was prepared and evaluated in the same manner as in Example 16 except that dimethyl silicone oil as a siloxane-containing polymer was not used. The evaluation results are shown in Table 2.

[Reference Example 2]
An electrophotographic photoreceptor was prepared and evaluated in the same manner as in Comparative Example 5 except that dimethyl silicone oil as a siloxane-containing polymer was not used. The evaluation results are shown in Table 2.

  In Tables 1 and 2, the temperature of the charge transport layer coating solution and the surface temperature of the charge generation layer are the temperatures at which the charge transport layer coating solution is applied to the surface of the charge generation layer in the charge transport layer forming step. is there.

DESCRIPTION OF SYMBOLS 1 To-be-coated body 2 Coating tank 3 Coating liquid circulation apparatus

Claims (7)

A method for producing an electrophotographic photoreceptor having a charge transport layer forming step of forming a charge transport layer by applying a charge transport layer coating liquid on the surface of the charge generation layer and drying the coating solution,
The charge transport layer coating solution contains a siloxane-containing polymer,
In the charge transport layer forming step, the temperature of the surface of the charge generation layer and the temperature of the charge transport layer coating solution when the charge transport layer coating solution is applied to the surface of the charge generation layer have the following relationship: A method for producing an electrophotographic photoreceptor, characterized by satisfying:
5 (° C.) ≦ (temperature of charge generation layer surface) − (temperature of charge transport layer coating solution) ≦ 15 (° C.)
(Temperature of surface of charge generation layer) ≧ 30 (° C.)   2. The electrophotographic photosensitive member according to claim 1, wherein in the charge transport layer forming step, the charge transport layer coating liquid is applied to the surface of the charge generation layer and then dried in an environment of 30 ° C. or more and 60 ° C. or less for 30 seconds or more. Manufacturing method.   The method for producing an electrophotographic photosensitive member according to claim 1, wherein the siloxane-containing polymer is silicone oil, siloxane-modified polycarbonate, or siloxane-modified polyarylate.   The method for producing an electrophotographic photosensitive member according to claim 3, wherein the siloxane-containing polymer is a siloxane-modified polycarbonate, and the amount of residual phenolic OH in the siloxane-modified polycarbonate is 100 ppm or less.   The method for producing an electrophotographic photosensitive member according to claim 3, wherein the silicone oil is dimethyl silicone oil. The siloxane-containing polymer is a siloxane-modified polycarbonate, and the amount of residual phenolic OH in the siloxane-modified polycarbonate is 100 ppm or less,
2. The electrophotographic photosensitive member according to claim 1, wherein in the charge transport layer forming step, the charge transport layer coating liquid is applied to the surface of the charge generation layer and then dried in an environment of 30 ° C. or more and 60 ° C. or less for 30 seconds or more. Manufacturing method. The electrophotography according to claim 3, 4 or 6, wherein the siloxane-modified polycarbonate is a siloxane-modified polycarbonate having a repeating structural unit represented by the following general formula (1) and a repeating structural unit represented by the following general formula (2). A method for producing a photoreceptor.

(In the general formula (1), X represents — (CR ⁵ R ⁶ ) —, a substituted or unsubstituted cycloalkylidene group, a substituted or unsubstituted α, ω-alkylene group, a single bond, —O—, — S—, —SO— or —SO ₂ —, wherein R ^{1 to} R ⁴ each independently represents a hydrogen atom, a halogen atom, a substituted or unsubstituted alkyl group or a substituted or unsubstituted aryl group. ⁵ and R ⁶ each independently represent a hydrogen atom, a trifluoromethyl group, a substituted or unsubstituted alkyl group or a substituted or unsubstituted aryl group.

(In the general formula (2), R ²¹ and R ²² each independently represent a hydrogen atom, a halogen atom, an alkoxy group, a nitro group, a substituted or unsubstituted alkyl group, or a substituted or unsubstituted aryl group. R ²³ and R ²⁴ each independently represents a hydrogen atom, an alkyl group or an aryl group, and R ^{25 to} R ²⁹ each independently represent a hydrogen atom, a halogen atom, a substituted or unsubstituted alkyl group or a substituted or unsubstituted group. A represents a substituted aryl group, a represents a positive integer of 1 to 30, and m represents a positive integer of 1 to 500.

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