JP5598227B2 - Photoconductor, image forming method, image forming apparatus, and process cartridge - Google Patents

Description

  The present invention relates to a photoreceptor, an image forming method, an image forming apparatus, and a process cartridge.

  In recent years, as the electrophotographic process has been speeded up and miniaturized, a photoreceptor having excellent wear resistance and capable of forming a high-quality image even when used for a long time is required.

  Therefore, Patent Document 1 discloses a layer structure in which at least a photosensitive layer and a surface protective layer in which a filler is dispersed in a resin are sequentially formed on a conductive support, and the photosensitive layer and the surface protective layer are continuous. An electrophotographic photosensitive member is disclosed in which the standard deviation σ of the maximum film thickness of the surface protective layer is 1/5 or less of D, where D is the average maximum film thickness of the surface protective layer.

  However, when used in a low temperature and low humidity environment for a long time, there is a problem that the potential of the exposed portion increases.

  In view of the above-described problems of the prior art, the present invention provides a photoreceptor capable of suppressing an increase in potential of an exposed portion even when used for a long time in a low temperature and low humidity environment, an image forming method using the photoreceptor, and the An object of the present invention is to provide an image forming apparatus having a photoconductor and a process cartridge.

  According to the first aspect of the present invention, in the photoreceptor, the general formula is formed on the conductive support.

（式中、Ｒ_１、Ｒ_２、Ｒ_３及びＲ_４は、それぞれ独立に、水素原子、ハロゲン原子、置換基を有してもよい炭素数が１以上６以下のアルキル基、置換基を有してもよい炭素数が１以上６以下のアルコキシ基であり、ｍ及びｎは、それぞれ独立に、０又は１である。）
で表される化合物、電荷発生物質及び第一の樹脂を含む感光層と、フィラー及び第二の樹脂を含む保護層が順次積層されており、
前記感光層と前記保護層が連続した層構造を有し、前記保護層の最大膜厚の平均値及び前記保護層の最大膜厚の標準偏差を、それぞれＤ及びσとすると、式
σ≦Ｄ／５
を満たすことを特徴とする。

(In the formula, R ₁ , R ₂ , R ₃ and R ₄ each independently have a hydrogen atom, a halogen atom, an alkyl group having 1 to 6 carbon atoms which may have a substituent, or a substituent. And may be an alkoxy group having 1 to 6 carbon atoms, and m and n are each independently 0 or 1.)
A photosensitive layer containing a compound represented by: a charge generation material and a first resin, and a protective layer containing a filler and a second resin are sequentially laminated,
When the photosensitive layer and the protective layer have a continuous layer structure, and the average value of the maximum thickness of the protective layer and the standard deviation of the maximum thickness of the protective layer are D and σ, respectively, the formula σ ≦ D / 5
It is characterized by satisfying.

  According to a second aspect of the present invention, in the photosensitive member according to the first aspect, the photosensitive layer includes a charge generation layer containing the charge generation material, the compound represented by the general formula (1), and the first The charge transport layer containing the resin is sequentially laminated.

  According to a third aspect of the present invention, in the photoreceptor according to the first or second aspect, the filler is an inorganic filler.

  According to a fourth aspect of the present invention, in the photoreceptor according to the third aspect, the inorganic filler contains a metal oxide.

  According to a fifth aspect of the present invention, in the photoreceptor according to the fourth aspect, the metal oxide is aluminum oxide.

  The invention according to claim 6 has the general formula

（式中、Ｒ_１、Ｒ_２、Ｒ_３及びＲ_４は、それぞれ独立に、水素原子、ハロゲン原子、置換基を有してもよい炭素数が１以上６以下のアルキル基、置換基を有してもよい炭素数が１以上６以下のアルコキシ基であり、ｍ及びｎは、それぞれ独立に、０又は１である。）
で表される化合物、電荷発生物質及び第一の樹脂を含む感光層が形成された導電性支持体に、フィラー、第二の樹脂及び溶媒を含む塗布液をスプレー塗布して保護層を形成する工程を有し、前記第一の樹脂は、前記溶媒に可溶であり、前記塗布液をスプレー塗布する条件で、前記感光層が形成された導電性支持体に前記塗布液をスプレー塗布した後、前記塗布液をスプレー塗布した環境で６０分間放置した時の塗布膜の質量をＡ、該塗布膜の乾燥質量をＢとすると、式
１．２＜Ａ／Ｂ＜２．０
を満たすことを特徴とする。

(In the formula, R ₁ , R ₂ , R ₃ and R ₄ each independently have a hydrogen atom, a halogen atom, an alkyl group having 1 to 6 carbon atoms which may have a substituent, or a substituent. And may be an alkoxy group having 1 to 6 carbon atoms, and m and n are each independently 0 or 1.)
A coating layer containing a filler, a second resin and a solvent is spray-coated on a conductive support on which a photosensitive layer containing a compound represented by formula (1), a charge generation material and a first resin is formed to form a protective layer. After the first resin is soluble in the solvent and spray-coated with the coating solution on the conductive support on which the photosensitive layer is formed under the condition that the coating solution is spray-coated. When the mass of the coating film when left for 60 minutes in an environment where the coating liquid is spray-coated is A and the dry mass of the coating film is B, the formula 1.2 <A / B <2.0
It is characterized by satisfying.

  According to a seventh aspect of the present invention, in the image forming method, the step of charging the photosensitive member according to any one of the first to fifth aspects, and exposing the charged photosensitive member to form an electrostatic latent image. A step of developing the electrostatic latent image formed on the photoconductor with toner to form a toner image, and a step of transferring the toner image formed on the photoconductor to a recording material. Features.

  According to an eighth aspect of the present invention, in the image forming method according to the seventh aspect, the charged photosensitive member is exposed using a semiconductor laser or a light emitting diode.

  According to a ninth aspect of the present invention, in the image forming apparatus, the photosensitive member according to any one of the first to fifth aspects, a charging unit for charging the photosensitive member, and the charged photosensitive member are exposed. An exposure unit that forms an electrostatic latent image; a developing unit that develops the electrostatic latent image formed on the photoconductor with toner to form a toner image; and a toner image formed on the photoconductor It has the transfer means to transfer to.

  According to a tenth aspect of the present invention, in the image forming apparatus according to the ninth aspect, the exposure means includes a semiconductor laser or a light emitting diode.

  According to an eleventh aspect of the present invention, in the image forming apparatus according to the ninth or tenth aspect, the image forming apparatus is a tandem type including a plurality of the photosensitive member, the charging unit, and the developing unit.

  A twelfth aspect of the present invention is the image forming apparatus according to any one of the ninth to eleventh aspects, further comprising an intermediate transfer member to which toner images formed on the plurality of the photosensitive members are transferred. The transfer unit sequentially transfers and superimposes the toner images formed on the plurality of photosensitive members to the intermediate transfer member, and then transfers the toner images transferred and superimposed on the intermediate transfer member to the recording material. It is characterized by doing.

  According to a thirteenth aspect of the present invention, in the process cartridge, the photosensitive member according to any one of the first to fifth aspects, a charging unit that charges the photosensitive member, and the charged photosensitive member is exposed to electrostatic charge. Exposure means for forming a latent image, development means for developing the electrostatic latent image formed on the photoreceptor with toner to form a toner image, and transfer for transferring the toner image formed on the photoreceptor to a recording material And at least one cleaning means for cleaning the photosensitive member to which the toner image is transferred.

  According to the present invention, a photoreceptor capable of suppressing an increase in potential of an exposed portion even when used in a low temperature and low humidity environment for a long period of time, an image forming method using the photoreceptor, and an image forming apparatus having the photoreceptor. And a process cartridge can be provided.

It is sectional drawing which shows an example of the photoreceptor of this invention. It is sectional drawing explaining the maximum film thickness of a protective layer. FIG. 7 is a cross-sectional view showing a modification of the photoreceptor in FIG. 1. FIG. 4 is a cross-sectional view showing a modification of the photoconductor of FIG. 3. It is a figure which shows an example of the image forming apparatus of this invention. FIG. 6 is a diagram illustrating a modification of the image forming apparatus in FIG. 5. It is a figure which shows an example of the process cartridge of this invention. FIG. 6 is a diagram illustrating a modification of the image forming apparatus in FIG. 5. It is a figure which shows the modification of the image forming apparatus of FIG.

  Next, the form for implementing this invention is demonstrated with drawing.

  FIG. 1 shows an example of the photoreceptor of the present invention. The photoreceptor 10 has a general formula on a conductive support 11.

（式中、Ｒ_１、Ｒ_２、Ｒ_３及びＲ_４は、それぞれ独立に、水素原子、ハロゲン原子、置換基を有してもよい炭素数が１以上６以下のアルキル基、置換基を有してもよい炭素数が１以上６以下のアルコキシ基であり、ｍ及びｎは、それぞれ独立に、０又は１である。）
で表される化合物、電荷発生物質及び第一の樹脂を含む感光層１２と、フィラーＦ及び第二の樹脂を含む保護層１３が順次積層されており、感光層１２と保護層１３が連続した層構造を有し、保護層１３の最大膜厚の平均値及び標準偏差を、それぞれＤ及びσとすると、式
σ≦Ｄ／５
を満たし、式
σ≦Ｄ／７
を満たすことが好ましい。

(In the formula, R ₁ , R ₂ , R ₃ and R ₄ each independently have a hydrogen atom, a halogen atom, an alkyl group having 1 to 6 carbon atoms which may have a substituent, or a substituent. And may be an alkoxy group having 1 to 6 carbon atoms, and m and n are each independently 0 or 1.)
The photosensitive layer 12 containing the compound represented by formula (1), the charge generation material and the first resin, and the protective layer 13 containing the filler F and the second resin are sequentially laminated, and the photosensitive layer 12 and the protective layer 13 are continuous. When the average value and the standard deviation of the maximum film thickness of the protective layer 13 have a layer structure, and D and σ, respectively, the formula σ ≦ D / 5
And the formula σ ≦ D / 7
It is preferable to satisfy.

  At this time, since the photosensitive layer 12 contains the compound represented by the general formula (1), the photoreceptor 10 can suppress an increase in potential of the exposed portion even when used for a long time in a low temperature and low humidity environment.

  Although it does not specifically limit as a compound represented by General formula (1), Compound (1-1)-(1-15) etc. are mentioned.

また、感光層１２と保護層１３が連続した層構造を有するため、感光層１２と保護層１３の境界領域で明確な境界が見られない。感光層１２と保護層１３が連続した層構造を有するためには、第一の樹脂及び第二の樹脂が、同一の溶媒に可溶である必要がある。このような溶媒を含む塗布液を用いて、保護層１３を形成すると、感光層１２の表面に塗布液を塗布した際に、第一の樹脂と第二の樹脂が相溶し、連続した層構造が形成される。これにより、感光層１２と保護層１３の接着性が強くなり、感光体１０を長期間使用した場合に、保護層１３の剥離を抑制できる。また、感光体１０を長期間使用した場合に、感光層１２から保護層１３への電荷輸送が阻害されず、露光部の電位の上昇を抑制できる。さらに、ベタ画像の端部における画像太り及びトナー飛散を抑制できる。

In addition, since the photosensitive layer 12 and the protective layer 13 have a continuous layer structure, no clear boundary is seen in the boundary region between the photosensitive layer 12 and the protective layer 13. In order for the photosensitive layer 12 and the protective layer 13 to have a continuous layer structure, the first resin and the second resin need to be soluble in the same solvent. When the protective layer 13 is formed using a coating solution containing such a solvent, when the coating solution is applied to the surface of the photosensitive layer 12, the first resin and the second resin are compatible, and a continuous layer is formed. A structure is formed. Thereby, the adhesiveness of the photosensitive layer 12 and the protective layer 13 becomes strong, and peeling of the protective layer 13 can be suppressed when the photosensitive member 10 is used for a long period of time. Further, when the photoconductor 10 is used for a long period of time, charge transport from the photosensitive layer 12 to the protective layer 13 is not hindered, and an increase in potential of the exposed portion can be suppressed. Furthermore, image thickening and toner scattering at the edge of a solid image can be suppressed.

Next, the maximum film thickness Dn of the protective layer 13 will be described. The maximum film thickness Dn of the protective layer 13 is obtained from an SEM photograph of a cross section of the photoreceptor 10. Specifically, an arbitrary range having a width of 100 μm was selected in a direction perpendicular to the film thickness direction of the photosensitive layer 12 and the protective layer 13 of the SEM photograph, and was divided into 20 equal parts. The maximum film thicknesses D _{1 to} D ₂₀ are determined from each range. The maximum film thickness Dn is the distance to the filler farthest from the surface of the protective layer 13 (see FIG. 2). Moreover, the maximum film average value D and the standard deviation σ of the thickness of the protective layer _13, obtained from D 1 _{to D 20.}

  At this time, if σ exceeds D / 5, the light incident on the protective layer 13 is scattered by the filler F, so that the charge generated in the photosensitive layer 12 becomes non-uniform, and the generated charge becomes the filler F. Therefore, the charge reaching the protective layer 13 becomes non-uniform. Further, when the photosensitive member 10 is used for a long period of time, the wear rate of the protective layer 13 becomes non-uniform depending on the presence or absence of the filler F, so that image unevenness is likely to appear.

In the present invention, the formula (2/3) D ≦ Dn ≦ (4/3) D
It is preferable to satisfy.

  FIG. 3 shows a modification of the photoreceptor 10. The photosensitive member 20 includes a photosensitive layer 22 in which a charge generation layer 22a including a charge generation material and a charge transport layer 22b including a charge transport material and a first resin are sequentially stacked instead of the single photosensitive layer 12. The structure is the same as that of the photoconductor 10 except that it is formed.

  FIG. 4 shows a modification of the photoconductor 20. The photoconductor 30 has the same configuration as the photoconductor 20 except that an undercoat layer 31 is formed between the conductive support 11 and the charge generation layer 12a.

  An undercoat layer 31 may be formed between the conductive support 11 of the photoreceptor 10 and the photosensitive layer 12.

The conductive support 11 is not particularly limited as long as the volume resistivity is 1 × 10 ¹⁰ Ω · cm or less, but a metal such as aluminum, nickel, chromium, nichrome, copper, gold, silver, or platinum, tin oxide Film or cylindrical plastic or paper coated by vapor deposition or sputtering of metal oxide such as indium oxide; aluminum, aluminum alloy, nickel, stainless steel, etc .; aluminum, aluminum alloy, nickel, stainless steel Examples thereof include a tube subjected to surface treatment such as cutting, superfinishing, polishing, etc. after extruding a plate such as the like and forming a raw tube by a method such as drawing. Further, an endless nickel belt and an endless stainless steel belt disclosed in JP-A-52-36016 can also be used as the conductive support 11.

  In addition, the conductive support 11 may have a conductive layer on the surface in which conductive powder is dispersed in a resin. Although it does not specifically limit as electroconductive powder, Carbon powder, such as carbon black and acetylene black; Metal powder, such as aluminum, nickel, iron, nichrome, copper, zinc, silver; Metal oxide, such as electroconductive tin oxide, ITO A powder etc. are mentioned. The resin is not particularly limited, but polystyrene, styrene-acrylonitrile copolymer, styrene-butadiene copolymer, styrene-maleic anhydride copolymer, polyester, polyvinyl chloride, vinyl chloride-vinyl acetate copolymer. , Polyvinyl acetate, polyvinylidene chloride, polyarylate resin, phenoxy resin, polycarbonate, cellulose acetate resin, ethyl cellulose resin, polyvinyl butyral, polyvinyl formal, polyvinyl toluene, poly (N-vinylcarbazole), acrylic resin, silicone resin, epoxy resin , A thermoplastic resin such as a melamine resin, a urethane resin, a phenol resin, and an alkyd resin, a thermosetting resin, or a photocurable resin. The conductive layer can be formed by applying a coating liquid in which conductive powder and resin are dispersed in a solvent such as tetrahydrofuran, dichloromethane, methyl ethyl ketone, or toluene.

  Further, the conductive support 11 is a heat in which conductive powder is dispersed in a resin such as polyvinyl chloride, polypropylene, polyester, polystyrene, polyvinylidene chloride, polyethylene, chlorinated rubber, Teflon (registered trademark) on a cylindrical substrate. A shrink tube may be provided.

  The charge generation layer 22a can be formed by applying a coating liquid in which a charge generation material is dispersed in a solvent together with a resin, if necessary, on the conductive support 11, and then drying.

  The charge generation material is not particularly limited, but is a monoazo pigment, disazo pigment, trisazo pigment, perylene pigment, perinone pigment, quinacridone pigment, quinone condensed polycyclic compound, squalic acid dye, phthalocyanine pigment, naphthalocyanine. Pigments, azulenium salt dyes, etc., may be used in combination. Of these, azo pigments and phthalocyanine pigments are preferred, and have the general formula

（式中、Ｒ_１及びＲ_２は、それぞれ独立に、水素原子、ハロゲン基、アルキル基、アルコキシ基又はシアノ基であり、Ｃｐ_１及びＣｐ_２は、それぞれ独立に、一般式

(In the formula, R ₁ and R ₂ are each independently a hydrogen atom, a halogen group, an alkyl group, an alkoxy group or a cyano group, and Cp ₁ and Cp ₂ are each independently a general formula.

（式中、Ｒ_３は、水素原子、メチル基、エチル基等のアルキル基、フェニル基等のアリール基であり、Ｒ_４、Ｒ_５、Ｒ_６、Ｒ_７及びＲ_８は、それぞれ独立に、水素原子、ニトロ基、シアノ基、フルオロ基、クロロ基、ブロモ基、ヨード基等のハロゲン基、トリフルオロメチル基、メチル基、エチル基等のアルキル基、メトキシ基、エトキシ基等のアルコキシ基、ジアルキルアミノ基又は水酸基であり、Ｚは、置換若しくは無置換の芳香族炭化水素環又は置換若しくは無置換の芳香族複素環を構成するのに必要な基である。）
で表されるカップラー残基である。）
で表されるアゾ顔料及びＣｕＫαの特性Ｘ線（波長１．５１４Å）に対するブラッグ角２θの回折ピーク（±０．２゜）として、少なくとも２７．２゜に最大回折ピークを有するチタニルフタロシアニンが特に好ましい。

(Wherein R ₃ is a hydrogen atom, an alkyl group such as a methyl group or an ethyl group, or an aryl group such as a phenyl group, and R ₄ , R ₅ , R ₆ , R ₇ and R ₈ are each independently Hydrogen atom, nitro group, cyano group, fluoro group, chloro group, bromo group, iodo group and other halogen groups, trifluoromethyl group, methyl group, ethyl group and other alkyl groups, methoxy group, ethoxy group and other alkoxy groups, (It is a dialkylamino group or a hydroxyl group, and Z is a group necessary for constituting a substituted or unsubstituted aromatic hydrocarbon ring or a substituted or unsubstituted aromatic heterocyclic ring.)
It is a coupler residue represented by these. )
Especially preferred is a titanyl phthalocyanine having a maximum diffraction peak at 27.2 ° as a diffraction peak (± 0.2 °) with a Bragg angle 2θ with respect to the characteristic X-ray (wavelength 1.514Å) of the azo pigment represented by .

  The resin is not particularly limited, but polyamide, polyurethane, epoxy resin, polyketone, polycarbonate, silicone resin, acrylic resin, polyvinyl butyral, polyvinyl formal, polyvinyl ketone, polystyrene, polysulfone, poly (N-vinylcarbazole), polyacrylamide, Examples thereof include polyvinyl benzal, polyester, phenoxy resin, vinyl chloride-vinyl acetate copolymer, polyvinyl acetate, polyphenylene oxide, polyamide, polyvinyl pyridine, cellulose resin, casein, polyvinyl alcohol, polyvinyl pyrrolidone and the like.

  The addition amount of the resin is usually 0 to 500 parts by mass, preferably 10 to 300 parts by mass with respect to 100 parts by mass of the charge generation material.

  Examples of the solvent include, but are not limited to, isopropanol, acetone, methyl ethyl ketone, cyclohexanone, tetrahydrofuran, dioxane, ethyl cellosolve, ethyl acetate, methyl acetate, dichloromethane, dichloroethane, monochlorobenzene, cyclohexane, toluene, xylene, ligroin, and the like. Two or more kinds may be used in combination. Among these, ketone solvents, ester solvents, and ether solvents are preferable.

  A method for applying the coating liquid is not particularly limited, and examples thereof include a dip coating method, a spray coating method, a beat coating method, a nozzle coating method, a spinner coating method, and a ring coating method.

  The film thickness of the charge generation layer 22a is usually 0.01 to 5 μm, preferably 0.1 to 2 μm.

  The charge transport layer 22b is formed by applying a coating solution in which the compound represented by the general formula (1) and the first resin are dissolved or dispersed in a solvent on the charge generation layer 22a and then drying. Can do.

  Although it does not specifically limit as 1st resin, Thermoplastic resins, such as a polystyrene, polyester, a polyate, a polycarbonate, polyvinyl butyral, polyvinyl formal, polyvinyl toluene, poly (N-vinyl carbazole), are mentioned.

  Examples of the solvent include, but are not limited to, tetrahydrofuran, dioxane, toluene, dichloromethane, monochlorobenzene, dichloroethane, cyclohexanone, methyl ethyl ketone, and acetone, and two or more kinds may be used in combination.

  The addition amount of the compound represented by General formula (1) is 20-300 mass parts normally with respect to 100 mass parts of 1st resin, and 40-150 mass parts is preferable.

  The charge transport layer 22b may further contain a charge transport material.

  Examples of charge transport materials include poly (N-vinylcarbazole) and derivatives thereof, poly (γ-carbazolylethyl glutamate) and derivatives thereof, pyrene-formaldehyde condensates and derivatives thereof, polyvinylpyrene, polyvinylphenanthrene, polysilane, and oxazole derivatives. Oxadiazole derivatives, imidazole derivatives, monoarylamine derivatives, diarylamine derivatives, triarylamine derivatives, stilbene derivatives, α-phenylstilbene derivatives, benzidine derivatives, diarylmethane derivatives, triarylmethane derivatives, 9-styrylanthracene derivatives, Hole transport such as pyrazoline derivatives, divinylbenzene derivatives, hydrazone derivatives, indene derivatives, butadiene derivatives, pyrene derivatives, bisstilbene derivatives, enamine derivatives, etc. Sending substances: chloroanil, bromoanil, tetracyanoethylene, tetracyanoquinodimethane, 2,4,7-trinitro-9-fluorenone, 2,4,5,7-tetranitro-9-fluorenone, 2,4,5,7 -Tetranitroxanthone, 2,4,8-trinitrothioxanthone, 2,6,8-trinitro-4H-indeno [1,2-b] thiophen-4-one, 1,3,7-trinitrodibenzothiophene- Electron transport materials such as 5,5-dioxide and benzoquinone derivatives are listed, and two or more kinds may be used in combination.

  A method for applying the coating liquid is not particularly limited, and examples thereof include a dip coating method, a spray coating method, a beat coating method, a nozzle coating method, a spinner coating method, and a ring coating method.

  The thickness of the charge transport layer 22b is preferably 5 to 25 μm in consideration of resolution and responsiveness.

  The photosensitive layer 12 is a coating in which the compound represented by the general formula (1), the charge generation material, and the first resin are dissolved or dispersed in a solvent together with the resin exemplified in the charge generation layer 22a as necessary. After applying the liquid, it can be formed by drying.

  Although it does not specifically limit as a solvent, Tetrahydrofuran, a dioxane, a dichloroethane, a cyclohexane etc. are mentioned, You may use 2 or more types together.

  The addition amount of the charge generation material is usually 5 to 40 parts by mass with respect to 100 parts by mass of the resin. Moreover, the addition amount of the compound represented by General formula (1) is 10-190 mass parts normally with respect to 100 mass parts of resin, and 50-150 mass parts is preferable.

  The method for applying the coating liquid is not particularly limited, and examples thereof include a dip coating method, a spray coating method, a bead coating method, a nozzle coating method, a spinner coating method, and a ring coating method.

  The film thickness of the photosensitive layer 12 is usually 5 to 25 μm.

  The undercoat layer 31 can be formed by applying a coating solution in which a resin is dissolved or dispersed in a solvent on the conductive support 11 and then drying. At this time, metal oxide powders such as titanium oxide, silica, alumina, zirconium oxide, tin oxide, and indium oxide may be added to the coating solution in order to prevent moire and reduce the residual potential.

  The resin contained in the undercoat layer 31 is a solvent contained in the coating solution for the charge generation layer 22a or the photosensitive layer 12 in consideration of applying the coating solution for the charge generation layer 22a or the photosensitive layer 12 on the undercoat layer 31. It is preferable to have resistance to. Examples of such resins include water-soluble resins such as polyvinyl alcohol, casein, and sodium polyacrylate; alcohol-soluble resins such as copolymer nylon and methoxymethylated nylon; polyurethane, melamine resin, phenol resin, alkyd-melamine resin, epoxy Examples thereof include a resin obtained by curing a resin or the like.

  Examples of the solvent include, but are not limited to, tetrahydrofuran, dioxane, toluene, dichloromethane, monochlorobenzene, dichloroethane, cyclohexanone, methyl ethyl ketone, and acetone, and two or more kinds may be used in combination.

  The method for applying the coating liquid is not particularly limited, and examples thereof include a dip coating method, a spray coating method, a bead coating method, a nozzle coating method, a spinner coating method, and a ring coating method.

Examples of the undercoat layer 31 other than these include a silane coupling agent, a titanium coupling agent, and a chromium coupling agent. Also, an aluminum oxide formed by anodizing the conductive support 11 made of aluminum, an organic compound such as polyparaxylylene (parylene); SiO ₂ , SnO ₂ , TiO ₂ , ITO, CeO _2, etc. The thing which vapor-deposited the inorganic compound is mentioned.

  The thickness of the undercoat layer 31 is usually 0.1 to 50 μm, preferably 1 to 5 μm.

  The protective layer 13 can be formed by applying a protective layer coating solution in which a filler and a second resin are dispersed in a solvent on the photosensitive layer 12 or 22 and then drying. Note that the solvent is soluble in the first resin.

  The second resin is not particularly limited, but ABS resin, ACS resin, olefin-vinyl monomer copolymer, chlorinated polyether, allyl resin, phenol resin, polyacetal, polyamide, polyamideimide, polyacrylate, polyallylsulfone , Polybutylene, polybutylene terephthalate, polycarbonate, polyethersulfone, polyethylene, polyethylene terephthalate, polyimide, acrylic resin, polymethylbenten, polypropylene, polyphenylene oxide, polysulfone, polystyrene, AS resin, butadiene-styrene copolymer, polyurethane, polychlorinated Examples thereof include vinyl, polyvinylidene chloride, and epoxy resin, and two or more kinds may be used in combination. Of these, polycarbonate and polyarylate are preferable.

  Although it does not specifically limit as filler F, Organic fillers, such as fluorine resin powders, such as polytetrafluoroethylene, silicone resin powder, and a-carbon powder; Metal powders, such as copper, tin, aluminum, an indium, silica, tin oxide, Examples include zinc oxide, titanium oxide, indium oxide, antimony oxide, bismuth oxide, tin oxide doped with antimony, metal oxide powder such as tin-doped indium oxide, and inorganic fillers such as potassium titanate powder. You may use together. Among these, considering the hardness of the filler F, inorganic fillers are preferable, metal oxide powders are more preferable, and aluminum oxide powders are particularly preferable.

  The average primary particle size of the filler F is preferably 0.01 to 0.5 μm. When the average primary particle size of the filler F is less than 0.01 μm, the wear resistance of the protective layer 13 may be reduced, and when it exceeds 0.5 μm, the light transmittance may be reduced.

  Content of the filler F in the protective layer 13 is 1-50 mass% normally, and 5-30 mass% is preferable. When the content of the filler F is less than 1% by mass, the wear resistance of the protective layer 13 may be reduced. When the content exceeds 50% by mass, the residual potential is increased or the light transmittance of the protective layer 13 is increased. May decrease.

  The average particle size of the filler F in the coating solution for the protective layer is usually 0.01 to 1 μm, preferably 0.01 to 0.5 μm. If the average particle size of the filler F in the coating solution for the protective layer is less than 0.01 μm, the wear resistance of the protective layer 13 may decrease, and if it exceeds 1 μm, the light transmittance may decrease. is there.

  In consideration of dispersibility, the filler F is preferably surface-treated with a surface treatment agent. Although it does not specifically limit as a surface treating agent, Since the insulating property of a filler can be maintained, a titanate coupling agent, an aluminum coupling agent, a zircoaluminate coupling agent, a higher fatty acid, etc. are mentioned. Further, these surface treatment agents and silane coupling agents may be used in combination. Examples of the surface treatment agent other than these include aluminum oxide, titanium oxide, zirconium oxide, silicone resin, aluminum stearate and the like, and two or more kinds may be used in combination.

  The surface treatment amount of the filler F varies depending on the average primary particle size, but is usually 3 to 30% by mass, and preferably 5 to 20% by mass. If the surface treatment amount is less than 3% by mass, the effect of improving the dispersibility of the filler F may not be obtained, and if it exceeds 30% by mass, the residual potential may increase.

  The protective layer 13 may further include a charge transport material exemplified for the charge transport layer 22b in order to reduce the residual potential or improve the responsiveness. The charge transport material in the protective layer 13 may have a concentration gradient. At this time, in order to improve the wear resistance of the protective layer 13, it is preferable to reduce the concentration of the charge transport material on the surface side.

  The film thickness of the protective layer 13 is usually 0.1 to 10 μm, preferably 1 to 8 μm.

In the present invention, after the protective layer coating solution is spray-coated on the conductive support 11 on which the photosensitive layer 12 or 22 is formed under the condition that the protective layer coating solution is spray-coated on the photosensitive layer 12 or 22, Assuming that the mass of the coating film when left for 60 minutes in an environment where the coating solution for the protective layer is spray-coated is A and the dry mass of the coating film is B, the formula 1.2 <A / B <2.0
Meet. In addition, the dry mass of a coating film means the mass whose content of the solvent in a coating film is 1000 ppm or less. Examples of the environment in which the protective layer coating solution is spray-coated include temperature, exhaust air amount, and the like, and when the conductive support 11 is in a drum shape, the rotational speed of the conductive support 11 is also included.

  When A / B is 1.2 or less, the atomization state when spraying the coating liquid for protective layer becomes unstable, and part of the coating liquid for protective layer solidifies during atomization. There is. On the other hand, when A / B is 2.0 or more, the solvent contained in the coating solution for the protective layer excessively dissolves or swells the first resin contained in the charge transport layer 22b or the photosensitive layer 12, and σ is D / 5 may be exceeded.

  Next, a method for measuring A and B will be described. First, the mass (M1) of the conductive support 11 on which the photosensitive layer 12 or 22 is formed is measured. Next, a protective layer coating solution is spray-coated on the conductive support 11 on which the photosensitive layer 12 or 22 is formed. And it is left to stand for 60 minutes in the environment which applied the coating liquid for protective layers by spraying, and the mass (M2) of the electroconductive support body 11 in which the coating film was formed is measured. Furthermore, the coating film is dried, and the mass (M3) of the conductive support 11 on which the coating film is formed is measured. At this time, A and B become M2-M1 and M3-M1, respectively.

  The solvent contained in the protective layer coating solution is preferably a mixed solvent of a solvent having a boiling point of 50 to 80 ° C and a solvent having a boiling point of 130 to 160 ° C. Since the protective layer coating solution contains a solvent having a boiling point of 50 to 80 ° C., A / B can be made smaller than 2.0, and the solvent having a boiling point of 130 to 160 ° C. Therefore, A / B can be made larger than 1.2.

  Examples of the solvent having a boiling point of 50 to 80 ° C. include tetrahydrofuran and dioxolane, and examples of the solvent having a boiling point of 130 to 160 ° C. include cyclohexanone, cyclopentanone, and methylphenyl ether.

  Usually, the left conductive support 11 is heated and dried, but is preferably dried at 130 to 160 ° C. for 10 to 60 minutes. When the drying temperature is less than 130 ° C. or when the drying time is less than 10 minutes, the content of the solvent in the protective layer 13 may exceed 1000 ppm. On the other hand, when the drying temperature exceeds 160 ° C. or when the drying time exceeds 60 minutes, the crystallinity and crystal system of the charge generation material may change.

  The solid concentration of the protective layer coating solution is preferably 3 to 6% by mass. When the solid content concentration is less than 3% by mass, the solvent contained in the protective layer coating solution excessively dissolves or swells the first resin contained in the charge transport layer 22b or the photosensitive layer 12, and σ is D / 5. May be exceeded. On the other hand, when the solid content concentration exceeds 6% by mass, the atomization state when the protective layer coating solution is spray-coated becomes unstable, and a part of the protective layer coating solution is solidified during the atomization. Sometimes.

  The diameter of the spray gun is preferably 0.5 to 0.8 mm. Thereby, the atomization state when spraying the coating liquid for protective layers can be controlled.

  The discharge amount of the spray gun is preferably 5 to 25 cc / min. If the discharge rate is less than 5 cc / min, the productivity may be reduced, and if it exceeds 25 cc / min, the solvent contained in the protective layer coating solution contains the first in the charge transport layer 22b or the photosensitive layer 12. May be excessively dissolved or swollen, and σ may exceed D / 5.

The discharge pressure of the spray gun is preferably 1.0 to 3.0 kg / cm ² . When the discharge pressure is less than 1.0 kg / cm ² , when the coating liquid for the protective layer is spray-coated, the droplets may become non-uniform, and when it exceeds 3.0 kg / cm ² , the coating for the protective layer is applied. When spraying the liquid, the droplets may bounce off.

  The distance between the spray gun and the conductive support 11 on which the photosensitive layer 12 or 22 is formed is preferably 3 to 15 cm. If this distance is less than 3 cm, the atomization state when the protective layer coating solution is spray applied may become unstable, and if it exceeds 15 cm, the adhesion efficiency of the protective layer coating solution may decrease. is there.

  When the conductive support 11 is in the form of a drum, the rotation speed of the conductive support 11 is preferably 120 to 640 rpm, and the gun feed rate is preferably 5 to 40 mm / second. Thereby, it can suppress that the spiral abnormal structure generate | occur | produces in the electroconductive support body 11 in which the photosensitive layer 12 or 22 was formed.

  The film thickness of the protective layer 13 per gun feed is preferably 0.5 to 2.0 μm. When the film thickness of the protective layer 13 per one gun feed is less than 0.5 μm, the productivity may be reduced. When the film thickness exceeds 2.0 μm, the solvent contained in the protective layer coating solution is used as the charge transport layer. 22b or the first resin contained in the photosensitive layer 12 may be excessively dissolved or swollen, and σ may exceed D / 5. In addition, the film thickness of the coating film per one gun feed is a value obtained by dividing the thickness of the protective layer 13 by the number of times the spray gun is fed.

  The method for applying the protective layer coating solution is not limited to the spray coating method, and examples thereof include a dip coating method, a bead coating method, a nozzle coating method, a spinner coating method, and a ring coating method.

  In the present invention, the coating solution for the photosensitive layer 12, the charge generation layer 22a, the charge transport layer 22b, the protective layer 13, and the undercoat layer 31 includes an antioxidant, an ultraviolet absorber, a radical scavenger, a softener, a curing agent, A crosslinking agent, dispersion stabilizer, anti-settling agent, anti-color separation agent, leveling agent, antifoaming agent, thickening agent, matting agent and the like may further be included. Among them, the durability of the photoreceptor can be further improved by combining an antioxidant and an ultraviolet absorber with the compound represented by the general formula (1). For this reason, it is preferable that the photosensitive layer 12 or 22 further includes a phenol-based antioxidant, an amine-based antioxidant, a sulfur-based antioxidant, and a benzotriazole-based ultraviolet absorber.

  The phenolic antioxidant is not particularly limited, but 2,6-di-tert-butylphenol, 2,6-di-tert-4-methoxyphenol, 2-tert-butyl-4-methoxyphenol, 2,4 -Dimethyl-6-tert-butylphenol, 2,6-di-tert-butyl-4-methylphenol, butylated hydroxyanisole, stearyl propionate-β- (3,5-di-tert-butyl-4-hydroxyphenyl ), Α-tocopherol, β-tocopherol, n-octadecyl-3- (3 ′, 5′-di-tert-butyl-4′-hydroxyphenyl) propionate, and the like; 2,2′- Methylene bis (6-tert-butyl-4-methylphenol), 4,4′-butylidene bis (3-methyl 6-tert-butylphenol), 4,4′-thiobis (6-tert-butyl-3-methylphenol), 1,1,3-tris (2-methyl-4-hydroxy-5-tert-butylphenyl) ) Butane, 1,3,5-trimethyl-2,4,6-tris (3,5-di-tert-butyl-4-hydroxybenzyl) benzene, tetrakis [methylene-3 (3,5-di-tert- (Butyl-4-hydroxyphenyl) propionate] polyphenol antioxidants such as methane and the like, and two or more kinds may be used in combination.

  The amine antioxidant is not particularly limited, but N-phenyl-1-naphthylamine, N-phenyl-N′-isopropyl-p-phenylenediamine, N, N-diethyl-p-phenylenediamine, N-phenyl- N'-ethyl-2-methyl-p-phenylenediamine, N-ethyl-N-hydroxyethyl-p-phenylenediamine, alkylated diphenylamine, N, N'-diphenyl-p-phenylenediamine, N, N'-diallyl -P-phenylenediamine, N-phenyl-1,3-dimethylbutyl-p-phenylenediamine, 4,4'-dioctyldiphenylamine, 4,4'-dioctyldiphenylamine, 6-ethoxy-2,2,4-trimethyl- 1,2-dihydroquinoline, 2,2,4-trimethyl-1,2-dihydroquinoline, - phenyl -β- naphthylamine, N, N'-di-2-naphthyl -p- phenylenediamine and the like, may be used in combination.

The sulfur-based antioxidant is not particularly limited, but dilauryl 3,3-thiodipropionate, ditridecyl 3,3-thiodipropionate, dimyristyl 3,3-thiodipropionate, 3,3-thiodipropion. distearyl, 3,3 thiopropionic lauryl stearyl, bis [2-methyl -4- (3-n- alkyl _(C 12 _{~C 14))} thio-propionate) -5-t-butylphenyl] sulfide , Pentaerythritol tetra (β-laurylthiopropionate), 2-mercaptobenzimidazole, 2-mercapto-6-methylbenzimidazole, and the like.

  Although it does not specifically limit as a benzotriazole type ultraviolet absorber, 2- (5-methyl-2-hydroxyphenyl) benzotriazole, 2- [2-hydroxy-3,5-bis (α, α-dimethylbenzyl) phenyl ] -2H-benzotriazole, 2- (3,5-di-tert-butyl-2-hydroxyphenyl) benzotriazole, 2- (3-tert-butyl-5-methyl-2-hydroxyphenyl) -5-chloro Benzotriazole, 2- (3,5-di-tert-butyl-2-hydroxyphenyl) -5-chlorobenzotriazole, 2- (3,5-di-tert-amyl-2-hydroxyphenyl) benzotriazole, 2 -(2'-hydroxy-5'-tert-octylphenyl) benzotriazole, etc. It may be use.

  FIG. 5 shows an example of the image forming apparatus of the present invention. In the image forming apparatus 100, the photoconductor 101 has a drum shape. The photoreceptor 101 is neutralized using the neutralizing lamp 102 and then charged positively (or negatively) using the charger 103. Next, the charged photosensitive member 101 is irradiated with light L using an exposure device (not shown), and a positive (or negative) electrostatic latent image is formed. The latent image is developed with toner to form a toner image. At this time, when developing with negative (or positive) toner, a positive image is formed, and when developing with positive (or negative) toner, a negative image is formed. Further, the toner image formed on the photosensitive member 101 is charged using the pre-transfer charger 106 and then transferred to the transfer paper P supplied from the registration roller 107 using the transfer charger 108. The transfer paper P onto which the toner image has been transferred is charged using the separation charger 109 and then separated from the photoconductor 101 using the separation claw 110. On the other hand, the toner remaining on the photoconductor 101 is charged using the pre-cleaning charger 111 and then removed from the photoconductor 101 using the cleaning brush 112 and the cleaning blade 113. Although it does not specifically limit as the cleaning brush 112, A fur brush, a mag fur brush, etc. can be used.

  As the charger 103, the pre-transfer charger 106, the transfer charger 108, the separation charger 109, and the pre-cleaning charger 111, a corotron, a scorotron, a solid charger (solid state charger), a charging roller, or the like may be used. it can. Further, as a light source of the static elimination lamp 102 and the exposure device (not shown), a fluorescent lamp, a tungsten lamp, a halogen lamp, a mercury lamp, a sodium lamp, a light emitting diode (LED), a semiconductor laser (LD), an electroluminescence (EL), etc. Can be used. At this time, a sharp cut filter, a band pass filter, a near infrared cut filter, a dichroic filter, an interference filter, a color temperature conversion filter, or the like may be used to irradiate only light in a desired wavelength range.

  FIG. 6 shows a modification of the image forming apparatus 100. In the image forming apparatus 200, the photoconductor 201 has an endless belt shape and is driven using drive rollers 201a and 201b. The photoconductor 201 is neutralized using a static elimination lamp 202 and then charged using a charger 203. Next, the exposure device 204 is used to irradiate the charged photosensitive member 201 with light to form an electrostatic latent image, and then the developing device (not shown) is used to develop the electrostatic latent image with toner. A toner image is formed. Further, the toner image formed on the photoconductor 201 is transferred onto a transfer paper (not shown) using the transfer charger 205. On the other hand, the toner remaining on the photosensitive member 201 is exposed using the pre-cleaning exposure device 206 and then removed from the photosensitive member 201 using the cleaning brush 207. At this time, the pre-cleaning exposure device 206 is disposed on the conductive support side of the photoconductor 201, and the conductive support has translucency.

  As the charger 203 and the transfer charger 205, a corotron, a scorotron, a solid charger (solid state charger), a charging roller, or the like can be used. Further, as a light source of the static elimination lamp 202, the exposure unit 204, and the pre-cleaning exposure unit 206, a fluorescent lamp, a tungsten lamp, a halogen lamp, a mercury lamp, a sodium lamp, a light emitting diode (LED), a semiconductor laser (LD), and an electroluminescence (EL) ) Etc. can be used. At this time, a sharp cut filter, a band pass filter, a near infrared cut filter, a dichroic filter, an interference filter, a color temperature conversion filter, or the like may be used to irradiate only light in a desired wavelength range.

  Note that the pre-cleaning exposure device 206 may be disposed on the photosensitive layer side of the photosensitive member 201. Further, the static elimination lamp 202 and the exposure unit 204 may be disposed on the conductive support side of the photoconductor 201. Further, the charged photoreceptor 201 may be pre-exposed before exposure, or may be exposed before the toner image formed on the photoreceptor 201 is transferred.

  Such an image forming apparatus may be fixedly incorporated in a copying apparatus, a facsimile, or a printer. At this time, the image forming apparatus may have a process cartridge that is detachable from the main body of the image forming apparatus.

  FIG. 7 shows an example of the process cartridge of the present invention. The process cartridge 300 includes a drum-shaped photoreceptor 301, a charger 302, an exposure device 303, a developing device 304, and a cleaning brush 305.

  FIG. 8 shows a full-color image forming apparatus 400 as a modification of the image forming apparatus 100. The drum-shaped photosensitive member 401 is driven to rotate counterclockwise in the drawing while being neutralized using the neutralizing lamp 402 and then charged using the charger 403. Next, using an exposure device (not shown), the charged photoconductor 401 is irradiated with light L to form an electrostatic latent image. At this time, a single-color electrostatic latent image is formed based on single-color image information obtained by decomposing a full-color image into each color information of yellow, magenta, cyan, and black. For this reason, a revolver developing unit 404 is provided. The revolver developing unit 404 includes a yellow developing unit 404Y, a magenta developing unit 404M, a cyan developing unit 404C, and a black developing unit 404B in a drum-shaped housing. By rotating the casing, each color developing unit 404 is developed. The apparatus is sequentially moved to a development position facing the photosensitive member 401. In this way, after yellow, magenta, cyan, and black electrostatic latent images are sequentially formed on the photoreceptor 401, the revolver developing unit 404 is used to sequentially develop the toner images of the respective colors. It is formed. The toner images of the respective colors formed on the photoconductor 401 are sequentially transferred and superimposed on the intermediate transfer belt 405 by the bias of the intermediate transfer bias roller 405a at the intermediate transfer nip where the photoconductor 401 and the intermediate transfer belt 405 are in contact with each other. A full color toner image is formed. At this time, the intermediate transfer belt 405 is stretched by an intermediate transfer bias roller 405a, a backup roller 405b, a belt driving roller 405c, and a stretching roller 405d. The belt driving roller 405c is rotated clockwise in the drawing. It is moved endlessly. Note that the toner remaining on the photosensitive member 401 is removed by using the cleaning unit 406. The cleaning unit 406 removes toner using a cleaning roller 406a to which a cleaning bias is applied.

  On the other hand, the registration roller 407 has an intermediate transfer belt 405 and a transfer belt 408 at a timing when the transfer paper P conveyed from a paper feed cassette (not shown) is superimposed on the full color toner image formed on the intermediate transfer belt 405. Are conveyed to the secondary transfer nip where they come into contact. The full-color toner image formed on the intermediate transfer belt 405 is transferred to the transfer paper P by the bias of the bias roller 408a at the secondary transfer nip. At this time, the transfer belt 408 is stretched by a belt driving roller 408b and stretching rollers 408c and 408d, and is endlessly moved counterclockwise in the drawing by the rotational driving of the belt driving roller 408b.

  The transfer paper P on which the full-color toner image is transferred is conveyed to the conveyance belt 409 using the transfer belt 408. The conveyance belt 409 conveys the transfer paper P into the fixing device 410. The fixing device 410 conveys the transfer paper P while sandwiching the transfer paper P in the fixing nip where the heating roller 410a and the backup roller 410b are in contact, and the full color toner image is fixed on the transfer paper P.

  Note that a bias for attracting the transfer paper P is applied to the transfer belt 408 and the conveyance belt 409. In addition, a charger (not shown) for discharging the transfer paper P and three chargers (not shown) for discharging the intermediate transfer belt 405, the transfer belt 409, and the conveying belt 409 are provided. Further, the intermediate transfer belt 405 includes a cleaning unit (not shown) having the same configuration as the cleaning unit 406, and the toner remaining on the intermediate transfer belt 405 is removed.

  As the charger 403, the charger for removing the transfer paper P, and the three chargers for removing the intermediate transfer belt 405, the transfer belt 409, and the conveying belt 409, a corotron, a scorotron, and a solid state charger (solid state charger). A charging roller or the like can be used. Further, as the light source of the static elimination lamp 402 and the exposure device, a fluorescent lamp, a tungsten lamp, a halogen lamp, a mercury lamp, a sodium lamp, a light emitting diode (LED), a semiconductor laser (LD), an electroluminescence (EL), or the like can be used. . At this time, a sharp cut filter, a band pass filter, a near infrared cut filter, a dichroic filter, an interference filter, a color temperature conversion filter, or the like may be used to irradiate only light in a desired wavelength range.

  FIG. 9 shows a tandem image forming apparatus 500 as a modification of the image forming apparatus 400. The image forming apparatus 500 has substantially the same configuration as the image forming apparatus 400 except that the image forming apparatus 500 includes a photosensitive member 401 for each color, a static elimination lamp 402, a charger 403, a developing unit 504, and a cleaning unit 405.

  EXAMPLES Hereinafter, although an Example demonstrates this invention, this invention is not limited to an Example. In addition, a part means a mass part.

[Example 1]
3 parts alkyd resin Beccosol 1307-60-EL (manufactured by Dainippon Ink and Chemicals), 2 parts melamine resin Super Becamine G-821-60 (manufactured by Dainippon Ink and Chemicals), titanium oxide CR-EL (Ishihara Sangyo) An undercoat layer coating solution consisting of 20 parts and 100 parts of methyl ethyl ketone was obtained.

  As a diffraction peak (± 0.2 °) with a Bragg angle 2θ with respect to the characteristic X-ray (wavelength 1.514 mm) of CuKα, 1.5 parts of titanyl phthalocyanine having a maximum diffraction peak at 27.2 °, polyvinyl butyral XYHL (UCC) A coating solution for a charge generation layer comprising 1 part and 120 parts of tetrahydrofuran was obtained.

  A coating solution for a charge transport layer comprising 1 part of bisphenol Z-type polycarbonate, 1 part of compound (1-2) and 10 parts of tetrahydrofuran was obtained.

  Chemical formula

で表される電荷輸送物質（Ａ）３部、ビスフェノールＺ型ポリカーボネート４部、シリカ粒子ＫＭＰＸ１００（信越化学工業社製）３部、テトラヒドロフラン１５０部及びシクロヘキサノン６０部からなる保護層用塗布液を得た。

A coating solution for a protective layer comprising 3 parts of a charge transport material (A) represented by the formula, 4 parts of bisphenol Z-type polycarbonate, 3 parts of silica particles KMPX100 (manufactured by Shin-Etsu Chemical Co., Ltd.), 150 parts of tetrahydrofuran and 60 parts of cyclohexanone was obtained. .

  An undercoat layer coating solution was dip-coated on an aluminum conductive support having an outer diameter of 30 mm and a length of 340 mm, followed by drying by heating to form an undercoat layer having a thickness of 3.5 μm.

  The charge generation layer coating solution was dip-coated on the conductive support on which the undercoat layer was formed, and then dried by heating to form a charge generation layer having a thickness of 0.2 μm.

  The charge transport layer coating solution was dip-coated on the conductive support on which the charge generation layer was formed, and then dried by heating to form a charge transport layer having a thickness of 20 μm.

  Using a spray gun A-100 (manufactured by Meiji Kikai Co., Ltd.) while rotating the conductive support on which the charge transport layer is formed, the coating solution for the protective layer is applied under the following coating conditions, and at 130 ° C. for 20 minutes. It dried and formed the protective layer and obtained the photoreceptor.

Application conditions Discharge rate: 16cc / min
Discharge pressure: 3.0 kg / cm ²
The rotational speed of the conductive support on which the charge transport layer is formed: 120 rpm
Gun feed rate: 17mm / s
Distance between conductive support with charge transport layer and spray gun: 5cm
Number of applications: 3 [Example 2]
A protective layer coating solution comprising 3 parts of a charge transport material (A), 4 parts of bisphenol Z-type polycarbonate, 3 parts of alumina particles AA03 (Sumitomo Chemical Co., Ltd.), 150 parts of tetrahydrofuran and 60 parts of cyclohexanone was obtained.

  A photoconductor was obtained in the same manner as in Example 1 except that the obtained protective layer coating solution was used.

[Example 3]
A photoconductor was obtained in the same manner as in Example 2 except that, among the coating conditions, the discharge rate was changed to 18 cc / min, the discharge pressure was changed to 2.5 kg / cm ² , and the gun feed rate was changed to 14 mm / s.

[Example 4]
A photoconductor was obtained in the same manner as in Example 2 except that, among the coating conditions, the discharge rate was changed to 12.5 cc / min and the number of coatings was changed to four.

[Example 5]
A photoconductor was obtained in the same manner as in Example 2 except that, among the application conditions, the discharge rate was changed to 9 cc / min, the gun feed rate was changed to 16 mm / s, and the number of times of application was changed to 5.

[Example 6]
A photoconductor was obtained in the same manner as in Example 2 except that the compound (1-1) was used instead of the compound (1-2).

[Examples 7 to 19]
A photoconductor was obtained in the same manner as in Example 2 except that the compounds (1-3) to (1-15) were used instead of the compound (1-2).

[Comparative Example 1]
A photoconductor was obtained in the same manner as in Example 2 except that the charge transport material (A) was used instead of the compound (1-2).

[Comparative Example 2]
Instead of compound (1-2), the chemical formula

で表される電荷輸送物質を用いた以外は、実施例２と同様にして、感光体を得た。

A photoconductor was obtained in the same manner as in Example 2 except that the charge transport material represented by

[Comparative Example 3]
Instead of compound (1-2), the chemical formula

で表される電荷輸送物質を用いた以外は、実施例２と同様にして、感光体を得た。

A photoconductor was obtained in the same manner as in Example 2 except that the charge transport material represented by

[Comparative Example 4]
Among the coating conditions, the discharge amount is 26 cc / min, the discharge pressure is 2.5 kg / cm ² , the rotational speed of the conductive support on which the charge transport layer is formed is 150 rpm, the gun feed rate is 10 mm / s, and the number of coatings is A photoconductor was obtained in the same manner as in Example 1 except that the change was made once.

[Comparative Example 5]
Among the coating conditions, the discharge rate is 24 cc / min, the discharge pressure is 2.0 kg / cm ² , the rotational speed of the conductive support on which the charge transport layer is formed is 250 rpm, the gun feed rate is 10 mm / s, and the number of coatings is A photoconductor was obtained in the same manner as in Example 2 except that the change was made once.

[Comparative Example 6]
A protective layer coating solution comprising 3 parts of a charge transport material (A), 4 parts of bisphenol Z-type polycarbonate, 3 parts of silica particles KMPX100 (manufactured by Shin-Etsu Chemical Co., Ltd.) and 90 parts of tetrahydrofuran was obtained.

  A photoconductor was obtained in the same manner as in Example 1 except that the obtained coating liquid for protective layer was applied at a coating speed of 3.0 mm / s using a ring coating method.

[Comparative Example 7]
A protective layer coating solution comprising 3 parts of a charge transport material (A), 4 parts of bisphenol Z-type polycarbonate, 3 parts of alumina particles AA03 (manufactured by Sumitomo Chemical Co., Ltd.) and 80 parts of tetrahydrofuran was obtained.

  A photoconductor was obtained in the same manner as in Example 1 except that the obtained coating solution for a protective layer was coated at a coating speed of 2.4 mm / s using a ring coating method.

[Comparative Example 8]
A coating solution for a charge transport layer comprising 1 part of bisphenol Z-type polycarbonate, 1 part of compound (1-2) and 12 parts of dichloromethane was obtained.

  A photoconductor was obtained in the same manner as in Example 1 except that the charge transport layer having a thickness of 22 μm was formed using the obtained charge transport layer coating solution.

[Comparative Example 9]
A photoconductor was obtained in the same manner as in Example 1 except that the protective layer was not formed and the thickness of the charge transport layer was 28 μm.

[Layer structure of photosensitive layer and protective layer]
Using the microtome, the photoconductors of Examples and Comparative Examples were cut in the film thickness direction of the photosensitive layer and the protective layer, and then enlarged to 2000 times using a scanning electron microscope (SEM), and the SEM of the cut surface was obtained. A photograph was taken, and the average value D and the standard deviation σ of the maximum film thickness of the protective layer were determined. The evaluation results are shown in Table 1. In addition, the case where σ ≦ D / 7 was evaluated as ◎, the case where D / 7 <σ ≦ D / 5 was evaluated as ◯, and the case where D / 5 <σ was determined as ×.

[A / B]
While rotating the conductive support on which the undercoat layer, the charge generation layer, and the charge transport layer are formed, the protective layer coating solution is applied under the coating conditions of the examples and comparative examples, and then the protective layer coating solution is applied. A / B was determined by leaving it to stand for 60 minutes in the above environment and drying by heating.

  Table 1 shows the layer structure of the photosensitive layer and the protective layer and the evaluation results of A / B.

なお、比較例４、５の感光体は、表面がスパイラル状であった。また、比較例８の感光体は、感光層と保護層が不連続な層構造を有していた。

The photoreceptors of Comparative Examples 4 and 5 had a spiral surface. The photoreceptor of Comparative Example 8 had a layer structure in which the photosensitive layer and the protective layer were discontinuous.

[Image formation]
The photoconductors of Examples and Comparative Examples are mounted on a black station of a digital full-color copying machine IpsioCX8200 (manufactured by Ricoh) and tested for 100,000 sheets in an environment of 22 ° C. and 50% RH (A4 landscape, continuous). Pass through, image area 7%), initial halftone when passing 50,000 sheets, 100,000 sheets, edge of solid image, potential of exposed area when forming solid image, 50,000 sheets, 10 The amount of wear when passing 10,000 sheets was evaluated. The evaluation of the potential of the exposed portion when forming a solid image was also performed in a low temperature and low humidity environment of 10 ° C. and 15% RH.

  The edge of the halftone and solid image is a test chart NO. 3 was used to output an image and evaluated by visual observation and observation with an optical microscope. Note that halftones were judged as ◎ when very good, ○ when slightly rough, △ when generally rough, and × when there was image unevenness. Further, the edge of the solid image was judged as “Good” as “Good”, “A” when slightly thickened at the edge, and “C” when dust was seen.

  The potential of the exposed portion was measured using a surface potential meter Model 344 (manufactured by Trek).

  The amount of wear was determined by measuring the average thickness of 20 photoconductors using a Fisherscope eddy current film thickness meter MMS to determine the amount of decrease in thickness relative to the initial value.

  Tables 2 and 3 show the evaluation results of image formation.

なお、比較例８の感光体は、２万枚通紙時に、保護層が剥離したため、通紙試験を中止した。また、比較例９の感光体は、８万枚通紙時に、摩耗量が大きいため、通紙試験を中止した。

In addition, since the protective layer peeled off the photosensitive member of Comparative Example 8 when 20,000 sheets were passed, the sheet passing test was stopped. Further, the photosensitive member of Comparative Example 9 had a large wear amount when 80,000 sheets were passed, so the paper passing test was stopped.

  From Table 2, it can be seen that the photoconductors of the examples can form images with excellent halftone and solid image edges at the initial time when 50,000 sheets are passed and when 100,000 sheets are passed. Further, from Table 3, the photoreceptors of the examples reduce the potential of the initial exposure part in both the normal environment and the low-temperature and low-humidity environment, and the exposure part when passing 50,000 sheets and 100,000 sheets. It can be seen that the increase in the potential can be suppressed.

10, 20, 30 Photoconductor 11 Conductive support 12, 22 Photosensitive layer 22a Charge generation layer 22b Charge transport layer 13 Protective layer 31 Undercoat layer F Filler

JP 2002-341571 A

Claims (13)

On the conductive support, the general formula

(In the formula, R ₁ , R ₂ , R ₃ and R ₄ each independently have a hydrogen atom, a halogen atom, an alkyl group having 1 to 6 carbon atoms which may have a substituent, or a substituent. And may be an alkoxy group having 1 to 6 carbon atoms, and m and n are each independently 0 or 1.)
A photosensitive layer containing a compound represented by: a charge generation material and a first resin, and a protective layer containing a filler and a second resin are sequentially laminated,
When the photosensitive layer and the protective layer have a continuous layer structure, and the average value of the maximum thickness of the protective layer and the standard deviation of the maximum thickness of the protective layer are D and σ, respectively, the formula σ ≦ D / 5
A photoconductor characterized by satisfying:   The photosensitive layer includes a charge generation layer containing the charge generation material, and a charge transport layer containing the compound represented by the general formula (1) and the first resin, which are sequentially laminated. Item 2. The photoreceptor according to Item 1.   The photoconductor according to claim 1, wherein the filler is an inorganic filler.   The photoreceptor according to claim 3, wherein the inorganic filler includes a metal oxide.   The photoconductor according to claim 4, wherein the metal oxide is aluminum oxide. General formula

(In the formula, R ₁ , R ₂ , R ₃ and R ₄ each independently have a hydrogen atom, a halogen atom, an alkyl group having 1 to 6 carbon atoms which may have a substituent, or a substituent. And may be an alkoxy group having 1 to 6 carbon atoms, and m and n are each independently 0 or 1.)
A coating layer containing a filler, a second resin and a solvent is spray-coated on a conductive support on which a photosensitive layer containing a compound represented by formula (1), a charge generation material and a first resin is formed to form a protective layer. Having a process,
The first resin is soluble in the solvent;
The mass of the coating film when the coating solution is spray-coated on the conductive support on which the photosensitive layer is formed under the condition of spray-coating the coating solution and then left for 60 minutes in an environment where the coating solution is spray-coated. Is A and the dry mass of the coating film is B, the formula 1.2 <A / B <2.0
A method for producing a photoreceptor, characterized in that: Charging the photoreceptor according to any one of claims 1 to 5,
Exposing the charged photoreceptor to form an electrostatic latent image;
Developing an electrostatic latent image formed on the photoreceptor with toner to form a toner image;
An image forming method comprising a step of transferring a toner image formed on the photoreceptor to a recording material.   The image forming method according to claim 7, wherein the charged photoconductor is exposed using a semiconductor laser or a light emitting diode. A photoreceptor according to any one of claims 1 to 5;
Charging means for charging the photoreceptor;
Exposure means for exposing the charged photoreceptor to form an electrostatic latent image;
Developing means for developing the electrostatic latent image formed on the photoreceptor with toner to form a toner image;
An image forming apparatus comprising transfer means for transferring a toner image formed on the photoreceptor to a recording material.   The image forming apparatus according to claim 9, wherein the exposure unit includes a semiconductor laser or a light emitting diode.   11. The image forming apparatus according to claim 9, wherein the image forming apparatus is a tandem type including a plurality of the photoconductor, the charging unit, and the developing unit. An intermediate transfer member to which toner images formed on the plurality of photosensitive members are transferred;
The transfer unit sequentially transfers and superimposes the toner images formed on the plurality of photosensitive members to the intermediate transfer member, and then transfers the toner images transferred and superimposed on the intermediate transfer member to the recording material. The image forming apparatus according to claim 9, wherein the image forming apparatus is an image forming apparatus. A photoreceptor according to any one of claims 1 to 5;
Charging means for charging the photoreceptor, exposure means for exposing the charged photoreceptor to form an electrostatic latent image, and developing the electrostatic latent image formed on the photoreceptor with toner to form a toner image A process cartridge comprising at least one of developing means, transfer means for transferring a toner image formed on the photoreceptor to a recording material, and cleaning means for cleaning the photoreceptor on which the toner image is transferred.

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