JP5493349B2 - Image forming apparatus and process cartridge - Google Patents

Description

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

  An electrophotographic image forming apparatus generally has the following configuration and process. That is, the surface of the image carrier is charged to a predetermined polarity and potential by a charging means, and the electrostatic latent image is formed by selectively removing the charged image carrier surface by image exposure or the like. Thereafter, toner is attached to the electrostatic latent image by the developing unit to develop the latent image as a toner image, and the toner image is transferred to a transfer medium by the transfer unit, and discharged as an image formed product.

The image carrier is known to have a photosensitive layer and a surface layer on a substrate. As a material system for forming the surface layer, for example, Patent Document 1 in which conductive powder is dispersed in a phenol resin is used. Proposed. Patent Document 2 proposes a chain polymerizable material. Further, Patent Document 3 proposes an image forming apparatus using an image carrier containing a charge transporting material in a surface layer.
Japanese Patent No. 3287678 JP 2005-234546 A JP 2006-85033 A

  An object of the present invention includes a crosslinked product of a guanamine compound and / or a melamine compound and a charge transporting material having a specific functional group, and does not consider the content of the charge transporting material with respect to the total solid content of the surface layer. Compared to the case, the mechanical strength is improved while maintaining good electrical characteristics, and further, the deterioration of image quality is suppressed as compared with the case where no lubricant is applied.

The above problem is solved by the following means. That is,
The invention according to claim 1
A photosensitive layer, and at least one selected from a guanamine compound and a melamine compound and a substituent selected from —OH, —OCH ₃ , —NH ₂ , —SH, and —COOH on the substrate in this order from the substrate side A surface layer containing at least one charge transport material having at least one and containing 80% by mass or more of the charge transport material constituting the cross-linked material with respect to the total solid content in the layer; And an image carrier in which a lubricant is applied on the surface layer,
Charging means for charging the image carrier;
Latent image forming means for forming an electrostatic latent image on the charged image carrier;
Developing means for developing the electrostatic latent image formed on the image carrier with toner to form a toner image;
Transfer means for transferring the toner image to a transfer object ,
The lubricant is zinc stearate;
In the image forming apparatus, the coverage of zinc on the surface of the image carrier is in the range of the following formula (1) .
Formula (1) 60% ≦ Zinc coverage by XPS analysis ≦ 100%

The invention according to claim 2
A photosensitive layer, and at least one selected from a guanamine compound and a melamine compound and a substituent selected from —OH, —OCH ₃ , —NH ₂ , —SH, and —COOH on the substrate in this order from the substrate side A surface layer containing at least one charge transport material having at least one and containing 80% by mass or more of the charge transport material constituting the cross-linked material with respect to the total solid content in the layer; And at least an image carrier provided with a lubricant on the surface layer ,
The lubricant is zinc stearate;
In the process cartridge, the zinc coverage on the surface of the image carrier is in the range of the following formula (1) .
Formula (1) 60% ≦ Zinc coverage by XPS analysis ≦ 100%

  According to the invention of claim 1, it contains a cross-linked product of a guanamine compound and / or a melamine compound and a charge transporting material having a specific functional group, and contains the charge transporting material with respect to the total solid content of the surface layer Compared with the case where the amount is not taken into consideration, the mechanical strength is improved while maintaining the electric characteristics well, and further, the deterioration of the image quality is suppressed as compared with the case where the lubricant is not applied.

Further, according to the invention of claim 1, compared with the case without consideration of the coverage of the zinc at the surface of the image carrier, the deterioration of the image carrier can be suppressed.

According to the invention which concerns on Claim 2 , while containing the crosslinked material of the guanamine compound and / or melamine compound and the charge transport material which has a specific functional group, inclusion of the charge transport material with respect to the total solid of a surface layer Compared with the case where the amount is not taken into consideration, the mechanical strength is improved while maintaining the electric characteristics well, and further, the deterioration of the image quality is suppressed as compared with the case where the lubricant is not applied.

Further, according to the invention of claim 2, compared with the case without consideration of the coverage of the zinc at the surface of the image carrier, the deterioration of the image carrier can be suppressed.

<Image forming apparatus and process cartridge>
In the image forming apparatus according to this embodiment, at least one selected from a photosensitive layer, a guanamine compound, and a melamine compound, and —OH, —OCH ₃ , —NH ₂ , —SH on the substrate in this order from the substrate side. And a cross-linked product with at least one kind of charge transporting material having at least one substituent selected from —COOH, and the charge transporting material forming the cross-linking product is included in the total solid content in the layer. An image carrier having a surface layer containing 80% by mass or more and having a lubricant applied to the surface layer, a charging means for charging the image carrier, and an electrostatic latent image on the charged image carrier A latent image forming unit that forms a toner image by developing an electrostatic latent image formed on the image holding member with toner, and a transfer unit that transfers the toner image to a transfer target; Said lubrication The agent is zinc stearate, and the zinc coverage on the surface of the image carrier is in the range of the following formula (1) .
Formula (1) 60% ≦ Zinc coverage by XPS analysis ≦ 100%

In addition, the process cartridge according to the present embodiment includes a photosensitive layer, at least one selected from a guanamine compound and a melamine compound, and —OH, —OCH ₃ , —NH ₂ , —SH on the substrate in this order from the substrate side. And a cross-linked product with at least one kind of charge transporting material having at least one substituent selected from —COOH, and the charge transporting material forming the cross-linking product is included in the total solid content in the layer. A surface layer containing 80% by mass or more, and at least an image carrier having a lubricant applied thereto , wherein the lubricant is zinc stearate, and the surface of the image carrier is coated with zinc. The rate is in the range of the following formula (1) .
Formula (1) 60% ≦ Zinc coverage by XPS analysis ≦ 100%

In the present embodiment, in the surface layer of the image carrier, a cross-linking site (cross-linking site) can be polyfunctionalized by a guanamine compound and / or a melamine compound and a charge transporting material having a specific functional group. It is presumed that the mechanical strength is increased. In addition, since the amount of charge transporting material in the total solid content of the surface layer is larger than that of the conventional surface layer, the electrical characteristics (sensitivity) can be maintained well while maintaining this highly crosslinked state. Inferred.
In the present embodiment, the lubricant is applied to the surface of the image carrier and the surface is coated with the lubricant, so that the wear of the surface layer on the image carrier is first suppressed by the lubricating effect of the lubricant itself. Furthermore, image quality deterioration due to chemical changes in the charge transport material is suppressed.

Here, when the content of the charge transporting material that forms a cross-linked product with respect to the total solid content of the surface layer is 80% by mass or more, the surface of the image carrier is coated with a lubricant to improve the image quality. The mechanism to do this is not clear, but is presumed as follows.
Discharge products generated by the charging means adhere to the surface of the image carrier. At this time, the charge transporting material is radicalized by the highly oxidative discharge product and the resistance decreases. For this reason, charged charges flow in the direction of the surface to cause a decrease in density, or flow in the direction of the bulk to cause an increase in density. In particular, when the surface layer contains a large amount of charge transporting material, that is, when the content of the charge transporting material is 80% by mass or more based on the total solid content of the surface layer, the discharge product on the surface of the image carrier. The image quality deteriorates because there are more opportunities for the charge transporting material to react with each other, and there are many crosslinks between the charge transporting materials and the effect of radicalization is easily transmitted to the internal bulk direction. Presumed to be.
On the other hand, the lubricant is applied to the surface layer of the image carrier as in the present embodiment and the surface is coated with the lubricant, so that the charge transport material and the discharge product are lubricated at the interface of the surface layer. It is estimated that the radicalization of the charge transporting material is suppressed by the coating layer due to the above, and the occurrence of image quality defects due to the decrease in resistance is suppressed.

In addition, the content of the charge transporting material forming a cross-linked product with respect to the total solid content of the surface layer is preferably 90% by mass or more, and particularly preferably 95% by mass or more.
Here, the content of the charge transport material that forms a cross-linked product with respect to the total solid content of the surface layer is regarded as the same as the content of the charge transport material that forms a cross-linked product with respect to the total solid content in the surface layer coating solution.

Further, in the image forming apparatus or process cartridge according to the present embodiment, the lubricant is zinc stearate, zinc coverage on the surface of the image carrier is area by der the following formula (1).
Formula (1) 60% ≦ Zinc coverage by XPS analysis ≦ 100%

  Here, in defining the zinc coverage on the surface of the image carrier, in this embodiment, quantification was performed from XPS analysis. XPS analysis is effective for elemental analysis of the extreme surface, but is measured in the form of the element ratio of zinc to all elements, so that the ratio value saturates as the coating amount increases. The value of the ratio of zinc to all elements at the time of saturation is defined as 100% coverage. On the other hand, the analytical value of the surface of the image carrier when no stearic acid is applied (the ratio of the ratio of zinc to all elements) is 0%. The coverage was determined as follows.

By defining the zinc coverage on the surface of the image carrier, the effective coating amount of zinc stearate as a lubricant is controlled. Further, when the amount of zinc on the surface of the image carrier is defined by the coverage, as described above, the intensity of the peak related to zinc in the XPS analysis increases as the amount of zinc stearate applied increases. Although it is saturated at a certain amount, this state is treated as an absolute quantitative value that is not affected by the state of the ground by providing zinc stearate as a guide for covering the surface of the image carrier 100%.
By defining the coverage of the lubricant on the surface of the image carrier, deterioration of the image carrier is suppressed, and in the case of having a cleaning unit (cleaning unit) for cleaning the surface of the image carrier, Deterioration is suppressed. As a result, good image quality is formed over a long period of time.

  When the zinc coverage by XPS analysis is less than 60%, the friction between the cleaning means such as a cleaning blade and the surface of the image carrier increases, and the lubricant is used against wear or scratches on the surface of the image carrier or deterioration of the cleaning means. May not be able to exert the effect.

Below, the measuring method of the zinc coverage by XPS analysis is described.
In this embodiment, the zinc coverage by XPS analysis was determined based on the value of the ratio of zinc to all elements measured by JPS-9010 (manufactured by JEOL Ltd.). Since the XPS analysis is an analysis of the extreme surface of the image carrier, the value of the ratio of zinc to all elements is saturated as the coating amount of zinc stearate increases. The coverage of zinc on the surface of the image carrier was determined by setting the ratio of the ratio of saturated zinc to all elements as 100%. The values described in this specification are measured by the method.

Note that the minimum coating amount of zinc stearate at which the zinc coverage by XPS analysis is 100% can be determined as follows.
When the analysis value of the surface of the image carrier when no zinc stearate is applied is 0%, the ratio of zinc to all elements by XPS analysis is plotted against the amount of zinc stearate applied to the surface of the image carrier. As the coating amount increases, the ratio of zinc to all elements increases. However, when the coating amount exceeds a certain amount, the ratio of zinc to all elements saturates and shows a constant value. The coating amount at the inflection point that is apparent from the plot is the minimum coating amount of zinc stearate at which the coverage is 100%.

  The zinc coverage on the surface of the image carrier is preferably 70% ≦ zinc coverage by XPS analysis ≦ 100%, and 80% ≦ zinc coverage by XPS analysis ≦ 100%. Particularly preferred.

[Method of applying lubricant to the surface of the image carrier]
In the image forming apparatus and the process cartridge according to the present embodiment, a certain amount of lubricant (for example, zinc stearate) is applied to the surface of the image carrier. The application method is not particularly limited, and examples thereof include a method in which a developer containing at least a toner and a lubricant is used and the lubricant is applied to the surface of the image carrier during development.
For example, when zinc stearate is added as a lubricant to the developer, the amount of zinc stearate added to the toner is preferably 0.1% by mass to 0.4% by mass, more preferably 0.1% by mass to 0%. .2% by mass or less.

Other examples of the method for applying the lubricant to the surface of the image carrier include a method using a means for applying a lubricant to the surface of the image carrier.
Examples of the application means include a melt-formed solid lubricant bar (for example, zinc stearate bar), a cylindrical brush that rotates in contact with the solid lubricant bar and contacts the image carrier. And a lubricant application device having the following.
The cylindrical brush of the lubricant application device holds the lubricant on the surface thereof by rotating in contact with the solid lubricant bar. The lubricant held on the surface of the cylindrical brush is carried to the contact portion between the cylindrical brush and the image holding body as the cylindrical brush rotates, and is applied to the surface of the image holding body there.

If the amount of lubricant applied by the lubricant applying device is, for example, when using a zinc stearate bar as a solid lubricant bar, the initial load on the cylindrical brush of the zinc stearate bar and the cylindrical brush are used. It is controlled by adjusting the surface fiber density, fiber length, fiber thickness, fiber material, and the like.
The initial load of the zinc stearate bar on the cylindrical brush is preferably 12 gf or more and 60 gf or less (118 mN or more and 588 mN or less), more preferably 15 gf or more and 40 gf or less (147 mN or more and 392 mN or less).

Fiber density of the cylindrical brush surface, 15 × 10 ³ present / inch ² or more 120 × 10 ³ present / inch ² or less (23.4 present / mm ² or more 186 present / mm ² or less), more preferably 20 X10 ³ pieces / inch ² or more and 60 × 10 ³ pieces / inch ² or less (31.0 pieces / mm ² or more and 93.0 pieces / mm ² or less).
The fiber length on the surface of the cylindrical brush (not including the thickness of the brushed adhesive layer) is preferably 2.5 mm or more and 7 mm or less, and more preferably 3 mm or more and 6.5 mm or less.
The fiber thickness on the surface of the cylindrical brush is preferably 2 denier or more and 10 denier or less, and more preferably 3 denier or more and 10 denier or less.
As the material of the fiber of the cylindrical brush, nylon, acrylic or polypropylene is preferable, and among these, nylon is particularly preferable because of excellent long-term stability.

  The amount of lubricant applied to the surface of the image carrier by the lubricant application device is a cylindrical or belt-like image carrier that can rotate the image carrier, particularly when zinc stearate is used as the lubricant. In this case, it is preferably 2 μg or more and 30 μg or less, more preferably 3 μg or more and 10 μg or less, and particularly preferably 4 μg or more and 8 μg or less.

The cleaning means used in the present embodiment is not particularly limited, and for example, a rubber cleaning blade or the like can be used.
The cleaning angle α and the blade linear pressure of the cleaning blade used as the cleaning means are preferably in the following ranges.

12 ° ≦ α ≦ (−3.9 × blade linear pressure + 27.85) ° and 1.9 gf / mm (18.6 N / m) ≦ blade linear pressure ≦ 3.0 gf / mm (29.4 N / m)

Here, the cleaning angle α will be described with reference to the drawings.
FIG. 5 is a schematic enlarged cross-sectional view showing a state where the cleaning blade 22 is in contact with the surface of the image carrier 21. The cleaning blade 22 held by the holding member 23 so that the free length is L is θ on the surface of the image holding body 21 so that the contact angle with the tangent to the surface of the image holding body 21 is θ and the biting amount is d. It is in a pressed state. In this case, the cleaning angle α is expressed by Expression (2). The unit is degree.

α = θ−tan ⁻¹ (1.5 × d / L) × 180 / π Formula (2)

As the material of the cleaning blade, urethane rubber, silicon rubber, polyimide-modified silicon rubber, fluorine rubber, or the like is used. Among these, urethane rubber is preferable.
The hardness of the cleaning blade is preferably from 60 to 100, particularly preferably from 80 to 90, as measured at room temperature (20 ° C.). Here, the hardness of the cleaning blade refers to a value defined in JIS-K6301.

  Hereinafter, this embodiment will be described in detail with reference to the drawings. In the drawings, the same or corresponding parts are denoted by the same reference numerals, and redundant description is omitted.

(Image carrier)
FIG. 1 is a schematic cross-sectional view showing a preferred embodiment of an image carrier according to this embodiment. 2 to 3 are schematic cross-sectional views illustrating image carriers according to other embodiments.

  In the image carrier 7 shown in FIG. 1, an undercoat layer 1 is provided on a conductive substrate 4, and a photosensitive layer on which a charge generation layer 2, a charge transport layer 3, and a surface layer 5 are sequentially formed is provided. ing.

  The image carrier 7 shown in FIG. 2 is provided with a photosensitive layer in which the functions are separated into the charge generation layer 2 and the charge transport layer 3 like the image carrier 7 shown in FIG. Further, the image carrier 7 shown in FIG. 3 contains the charge generation material and the charge transport material in the same layer (single-layer type photosensitive layer 6 (charge generation / charge transport layer)).

  In the image carrier 7 shown in FIG. 2, an undercoat layer 1 is provided on a conductive substrate 4, and a photosensitive layer on which a charge transport layer 3, a charge generation layer 2, and a surface layer 5 are sequentially formed is provided. It has been. In the image carrier 7 shown in FIG. 3, the undercoat layer 1 is provided on the conductive substrate 4, and the photosensitive layer in which the single-layer type photosensitive layer 6 and the surface layer 5 are sequentially formed thereon is provided. ing.

  Note that the undercoat layer may or may not be provided in the image carrier shown in FIGS.

  Hereinafter, each element will be described based on the image carrier 7 shown in FIG. 1 as a representative example.

<Conductive substrate>
Examples of the conductive substrate 4 include a metal plate, a metal drum, and a metal belt formed using a metal or an alloy such as aluminum, copper, zinc, stainless steel, chromium, nickel, molybdenum, vanadium, indium, gold, and platinum. Or a paper, a plastic film, a belt, or the like on which a conductive compound such as a conductive polymer or indium oxide, or a metal or alloy such as aluminum, palladium, or gold is applied, vapor-deposited, or laminated. Here, “conductive” means that the volume resistivity is less than 10 ¹³ Ωcm.

  When the image carrier 7 is used in a laser printer, the surface of the conductive substrate 4 has a center line average roughness Ra of 0.04 μm or more and 0.0.mu.m in order to prevent interference fringes generated when laser light is irradiated. It is desirable to roughen the surface to 5 μm or less.

  Surface roughening methods include wet honing by suspending an abrasive in water and spraying it on the support, or centerless grinding and anodization in which the support is brought into contact with a rotating grindstone and continuously ground. Processing is desirable.

  As another roughening method, a conductive or semiconductive powder is dispersed in a resin without roughening the surface of the conductive substrate 4 to form a layer on the support surface. A method of roughening with particles dispersed in the layer is also desirably used.

  Here, the roughening treatment by anodic oxidation is to form an oxide film on the aluminum surface by anodizing in an electrolyte solution using aluminum as an anode. Examples of the electrolyte solution include a sulfuric acid solution and an oxalic acid solution. However, the porous anodic oxide film formed by anodic oxidation is chemically active as it is, easily contaminated, and has a large resistance fluctuation due to the environment. Therefore, the pores in the anodized film are sealed with pressurized water vapor or boiling water (a metal salt such as nickel may be added) by volume expansion due to a hydration reaction, and a sealing process is performed to change to a more stable hydrated oxide. It is desirable.

  The thickness of the anodic oxide film is desirably 0.3 μm or more and 15 μm or less.

  Further, the conductive substrate 4 may be subjected to treatment with an acidic aqueous solution or boehmite treatment. The treatment with an acidic treatment solution containing phosphoric acid, chromic acid and hydrofluoric acid is carried out as follows. First, an acidic treatment liquid is prepared. The mixing ratio of phosphoric acid, chromic acid and hydrofluoric acid in the acidic treatment liquid is such that phosphoric acid is in the range of 10% by mass to 11% by mass, chromic acid is in the range of 3% by mass to 5% by mass, and hydrofluoric acid is 0.00%. The concentration of these acids is preferably in the range of 13.5 mass% to 18 mass%. The treatment temperature is desirably 42 ° C. or higher and 48 ° C. or lower. The film thickness is preferably from 0.3 μm to 15 μm.

  The boehmite treatment is performed by immersing in pure water of 90 ° C. or more and 100 ° C. or less for 5 minutes or more and 60 minutes or less, or by contacting with heated steam of 90 ° C. or more and 120 ° C. or less for 5 minutes or more and 60 minutes or less. The film thickness is preferably 0.1 μm or more and 5 μm or less. This is further anodized using an electrolyte solution with lower film solubility than other types such as adipic acid, boric acid, borate, phosphate, phthalate, maleate, benzoate, tartrate, citrate, etc. It may be processed.

<Underlayer>
The undercoat layer 1 is configured by containing inorganic particles in a binder resin, for example.
As the inorganic particles, those having a powder resistance (volume resistivity) of 10 ² Ω · cm to 10 ¹¹ Ω · cm are desirably used.

  Among these, inorganic particles (conductive metal oxide) such as tin oxide, titanium oxide, zinc oxide and zirconium oxide are preferably used as the inorganic particles having the above resistance value, and zinc oxide is particularly preferably used.

  In addition, the inorganic particles may be subjected to a surface treatment, or may be used as a mixture of two or more types such as those having different surface treatments or particles having different particle diameters. The volume average particle size of the inorganic particles is desirably in the range of 50 nm to 2000 nm (desirably 6 nm to 1000 nm).

As the inorganic particles, those having a specific surface area of 10 m ² / g or more by the BET method are desirably used.

  Further, by incorporating inorganic particles and an acceptor compound, a product having excellent electrical properties for a long period of time and carrier blockability can be obtained. As the acceptor compound, any compound can be used as long as the desired characteristics can be obtained. However, quinone compounds such as chloranil and bromoanil, tetracyanoquinodimethane compounds, 2,4,7-trinitrofluorenone, Fluorenone compounds such as 2,4,5,7-tetranitro-9-fluorenone, 2- (4-biphenyl) -5- (4-tert-butylphenyl) -1,3,4-oxadiazole, and 2,5 Oxadiazole compounds such as -bis (4-naphthyl) -1,3,4-oxadiazole, 2,5-bis (4-diethylaminophenyl) 1,3,4-oxadiazole, xanthone compounds, Desirable are electron transport materials such as thiophene compounds and diphenoquinone compounds such as 3,3 ′, 5,5′tetra-t-butyldiphenoquinone. In particular compounds having an anthraquinone structure are preferable. Furthermore, acceptor compounds having an anthraquinone structure such as hydroxyanthraquinone compounds, aminoanthraquinone compounds, aminohydroxyanthraquinone compounds, and the like are desirably used, and specific examples include anthraquinone, alizarin, quinizarin, anthralfin, and purpurin.

  The content of these acceptor compounds may be arbitrarily set as long as desired characteristics are obtained, but is desirably 0.01% by mass or more and 20% by mass or less with respect to the inorganic particles. Furthermore, 0.05 mass% or more and 10 mass% or less are desirable.

  The acceptor compound may be added only when the undercoat layer is applied, or may be previously attached to the surface of the inorganic particles. Examples of the method for imparting the acceptor compound to the surface of the inorganic particles include a dry method or a wet method.

  When surface treatment is performed by a dry method, dispersion is caused by dropping an acceptor compound dissolved in an organic solvent directly or with dry air or nitrogen gas while stirring inorganic particles with a mixer having a large shearing force. Processed without occurring. The addition or spraying is preferably performed at a temperature below the boiling point of the solvent. When spraying at a temperature equal to or higher than the boiling point of the solvent, the solvent evaporates before stirring without causing variation, and the acceptor compound is locally concentrated, which makes it difficult to perform processing without variation. After addition or spraying, baking may be performed at 100 ° C. or higher. Baking is carried out in an arbitrary range as long as the temperature and time allow the desired electrophotographic characteristics to be obtained.

  As a wet method, the inorganic particles are dispersed in a solvent using stirring, ultrasonic waves, a sand mill, an attritor, a ball mill, etc., added with an acceptor compound, stirred or dispersed, and then the solvent is removed without causing variations. It is processed. The solvent removal method is distilled off by filtration or distillation. After removing the solvent, baking may be performed at 100 ° C. or higher. Baking is carried out in an arbitrary range as long as the temperature and time allow the desired electrophotographic characteristics to be obtained. In the wet method, water containing inorganic particles can also be removed before adding the surface treatment agent. For example, a method of removing with stirring and heating in a solvent used for the surface treatment, a method of removing by azeotropic distillation with the solvent May be used.

  In addition, the inorganic particles may be subjected to a surface treatment before the acceptor compound is provided. The surface treatment agent is not particularly limited as long as it has desired characteristics and is selected from known materials. For example, a silane coupling agent, a titanate coupling agent, an aluminum coupling agent, a surfactant, and the like can be given. In particular, silane coupling agents are desirably used because they provide good electrophotographic properties. Further, a silane coupling agent having an amino group is desirably used because it gives the undercoat layer 1 good blocking properties.

  Any silane coupling agent having an amino group may be used as long as the desired image carrier characteristics can be obtained. Specific examples include γ-aminopropyltriethoxysilane, N-β- ( Aminoethyl) -γ-aminopropyltrimethoxysilane, N-β- (aminoethyl) -γ-aminopropylmethyldimethoxysilane, N, N-bis (β-hydroxyethyl) -γ-aminopropyltriethoxysilane, etc. Although it is mentioned, it is not limited to these.

  Two or more silane coupling agents may be mixed and used. Examples of the silane coupling agent that may be used in combination with the silane coupling agent having an amino group include vinyltrimethoxysilane, γ-methacryloxypropyl-tris (β-methoxyethoxy) silane, β- (3, 4-epoxycyclohexyl) ethyltrimethoxysilane, γ-glycidoxypropyltrimethoxysilane, vinyltriacetoxysilane, γ-mercaptopropyltrimethoxysilane, γ-aminopropyltriethoxysilane, N-β- (aminoethyl)- γ-aminopropyltrimethoxysilane, N-β- (aminoethyl) -γ-aminopropylmethyldimethoxysilane, N, N-bis (β-hydroxyethyl) -γ-aminopropyltriethoxysilane, γ-chloropropyltri Examples include methoxysilane, etc. Not intended to be constant.

  As the surface treatment method, any known method can be used, but a dry method or a wet method is preferably used. Moreover, you may perform both surface treatment by acceptor provision and a coupling agent.

  The amount of the silane coupling agent with respect to the inorganic particles in the undercoat layer 1 is arbitrarily set as long as the desired electrophotographic characteristics can be obtained, but 0.5% by mass or more and 10% by mass or less with respect to the inorganic particles. Is desirable.

  As the binder resin contained in the undercoat layer 1, any known resin can be used as long as it can form a good film and can obtain desired characteristics. For example, polyvinyl butyral, etc. Acetal resin, polyvinyl alcohol resin, casein, polyamide resin, cellulose resin, gelatin, polyurethane resin, polyester resin, methacrylic resin, acrylic resin, polyvinyl chloride resin, polyvinyl acetate resin, vinyl chloride-vinyl acetate-maleic anhydride resin, Known polymer resin compounds such as silicone resins, silicone-alkyd resins, phenol resins, phenol-formaldehyde resins, melamine resins, urethane resins, charge transport resins having a charge transport group, and conductive resins such as polyaniline, etc. Used. Among these, resins that are insoluble in the upper coating solvent are preferably used, and phenol resins, phenol-formaldehyde resins, melamine resins, urethane resins, epoxy resins, and the like are particularly preferable. When these are used in combination of two or more, the mixing ratio is set as necessary.

  The ratio of the metal oxide to which the acceptor property is imparted in the coating liquid for forming the undercoat layer and the binder resin, or the inorganic particles and the binder resin is arbitrarily set within a range in which desired image carrier characteristics can be obtained.

  Various additives may be used in the undercoat layer 1 in order to improve electrical characteristics, environmental stability, and image quality. As additives, known materials such as polycyclic condensation type, azo type electron transporting pigments, zirconium chelate compounds, titanium chelate compounds, aluminum chelate compounds, titanium alkoxide compounds, organic titanium compounds, silane coupling agents and the like are used. It is done. The silane coupling agent is used for the surface treatment of the metal oxide, but may be further added to the coating solution as an additive. Specific examples of the silane coupling agent used here include vinyltrimethoxysilane, γ-methacryloxypropyl-tris (β-methoxyethoxy) silane, β- (3,4-epoxycyclohexyl) ethyltrimethoxysilane, γ- Glycidoxypropyltrimethoxysilane, vinyltriacetoxysilane, γ-mercaptopropyltrimethoxysilane, γ-aminopropyltriethoxysilane, N-β- (aminoethyl) -γ-aminopropyltrimethoxysilane, N-β- (Aminoethyl) -γ-aminopropylmethyldimethoxysilane, N, N-bis (β-hydroxyethyl) -γ-aminopropyltriethoxysilane, γ-chloropropyltrimethoxysilane and the like. Examples of zirconium chelate compounds include zirconium butoxide, zirconium zirconium acetoacetate, zirconium triethanolamine, acetylacetonate zirconium butoxide, ethyl zirconium acetoacetate, zirconium acetate, zirconium oxalate, zirconium lactate, zirconium phosphonate, zirconium octoate, naphthene. Zirconate, zirconium laurate, zirconium stearate, zirconium isostearate, methacrylate zirconium butoxide, stearate zirconium butoxide, isostearate zirconium butoxide and the like.

  Examples of titanium chelate compounds include tetraisopropyl titanate, tetranormal butyl titanate, butyl titanate dimer, tetra (2-ethylhexyl) titanate, titanium acetylacetonate, polytitanium acetylacetonate, titanium octylene glycolate, titanium lactate ammonium salt, Examples thereof include titanium lactate, titanium lactate ethyl ester, titanium triethanolamate, and polyhydroxytitanium stearate.

  Examples of the aluminum chelate compound include aluminum isopropylate, monobutoxy aluminum diisopropylate, aluminum butyrate, ethyl acetoacetate aluminum diisopropylate, aluminum tris (ethyl acetoacetate) and the like.

  These compounds may be used alone or as a mixture or polycondensate of a plurality of compounds.

  The solvent for preparing the coating solution for forming the undercoat layer is arbitrarily selected from known organic solvents such as alcohols, aromatics, halogenated hydrocarbons, ketones, ketone alcohols, ethers, esters, etc. Selected. Examples of the solvent include methanol, ethanol, n-propanol, iso-propanol, n-butanol, benzyl alcohol, methyl cellosolve, ethyl cellosolve, acetone, methyl ethyl ketone, cyclohexanone, methyl acetate, ethyl acetate, n-butyl acetate, Usual organic solvents such as dioxane, tetrahydrofuran, methylene chloride, chloroform, chlorobenzene and toluene are used.

  Moreover, you may use the solvent used for these dispersion | distribution individually or in mixture of 2 or more types. When mixing, any solvent can be used as long as it can dissolve the binder resin as the mixed solvent.

  As a dispersion method, known methods such as a roll mill, a ball mill, a vibrating ball mill, an attritor, a sand mill, a colloid mill, and a paint shaker are used. Further, as the coating method used when the undercoat layer 1 is provided, conventional methods such as blade coating method, wire bar coating method, spray coating method, dip coating method, bead coating method, air knife coating method, curtain coating method, etc. Is used.

  The undercoat layer 1 is formed on the conductive substrate 4 using the undercoat layer-forming coating solution thus obtained.

The undercoat layer 1 preferably has a Vickers hardness of 35 or more.
Furthermore, the undercoat layer 1 may be set to any thickness as long as desired characteristics can be obtained, but the thickness is preferably 15 μm or more, and more preferably 15 μm or more and 50 μm or less. desirable.

  Further, the surface roughness (ten-point average roughness Ra) of the undercoat layer 1 is ½λ from ¼n (n is the refractive index of the upper layer) of the exposure laser wavelength λ used to prevent moire images. It is preferable to adjust by. In order to adjust the surface roughness, particles such as a resin may be added to the undercoat layer. As the resin particles, silicone resin particles, cross-linked polymethyl methacrylate resin particles and the like are used.

  Here, the undercoat layer 1 contains a binder resin and a conductive metal oxide, and has a light transmittance of 40% or less (desirably 10% or more and 35% or less, more desirably) with respect to light having a wavelength of 950 nm at a thickness of 20 μm. 15% or more and 30% or less).

  The light transmittance of the undercoat layer 1 is measured as follows. The undercoat layer-forming coating solution is applied on a glass plate so that the thickness after drying is 20 μm, and after drying, the light transmittance of the film at a wavelength of 950 nm is measured using a spectrophotometer. For the light transmittance by the photometer, an apparatus name “Spectrophotometer (U-2000)” manufactured by Hitachi, Ltd. is used as a spectrophotometer.

  The light transmittance of the undercoat layer 1 can be controlled by adjusting the dispersion time during dispersion using the roll mill, ball mill, vibration ball mill, attritor, sand mill, colloid mill, paint shaker, or the like. The dispersion time is not particularly limited, but is preferably any time from 5 minutes to 1000 hours, and more preferably from 30 minutes to 10 hours.

  Further, the undercoat layer 1 may be polished for adjusting the surface roughness. As a polishing method, buffing, sandblasting, wet honing, grinding, or the like is used.

  The applied layer is dried to obtain the undercoat layer 1. Usually, the drying is performed at a temperature at which the solvent can be evaporated to form a film.

<Charge generation layer>
The charge generation layer 2 is a layer containing a charge generation material and a binder resin.
Examples of the charge generation material include azo pigments such as bisazo and trisazo, condensed aromatic pigments such as dibromoanthanthrone, perylene pigments, pyrrolopyrrole pigments, phthalocyanine pigments, zinc oxide, and trigonal selenium. Among these, for near-infrared laser exposure, a metal or metal-free phthalocyanine pigment is desirable, and in particular, hydroxygallium phthalocyanine disclosed in JP-A-5-263007, JP-A-5-279591, etc. Chlorogallium phthalocyanine disclosed in JP-A-5-98181, dichlorotin phthalocyanine disclosed in JP-A-5-140472, JP-A-5-140473, etc., JP-A-4-189873, More preferred is titanyl phthalocyanine disclosed in JP-A-5-43823. For near-ultraviolet laser exposure, condensed aromatic pigments such as dibromoanthanthrone, thioindigo pigments, porphyrazine compounds, zinc oxide, and trigonal selenium are more desirable. As the charge generation material, an inorganic pigment is desirable when a light source having an exposure wavelength of 380 nm to 500 nm is used, and a metal or metal-free phthalocyanine pigment is desirable when a light source having an exposure wavelength of 700 nm to 800 nm is used.

  As the charge generation material, it is desirable to use a hydroxygallium phthalocyanine pigment having a maximum peak wavelength in a range of 810 nm to 839 nm in a spectral absorption spectrum in a wavelength range of 600 nm to 900 nm. This hydroxygallium phthalocyanine pigment is different from the conventional V-type hydroxygallium phthalocyanine pigment, and is desirable because it provides better dispersibility. Thus, by shifting the maximum peak wavelength of the spectral absorption spectrum to a shorter wavelength side than the conventional V-type hydroxygallium phthalocyanine pigment, it becomes a fine hydroxygallium phthalocyanine pigment in which the crystal arrangement of the pigment particles is suitably controlled, When used as a material for an image carrier, excellent dispersibility and sufficient sensitivity, chargeability, and dark decay characteristics can be obtained.

The hydroxygallium phthalocyanine pigment having the maximum peak wavelength in the range of 810 nm to 839 nm is preferably in a specific range for the average particle size and in a specific range for the BET specific surface area. Specifically, the average particle size is desirably 0.20 μm or less, more desirably 0.01 μm or more and 0.15 μm or less, while the BET specific surface area is desirably 45 m ² / g or more. 50 m ² / g or more is more desirable, and 55 m ² / g or more and 120 m ² / g or less is particularly desirable. The average particle size is a volume average particle size (d50 average particle size) measured by a laser diffraction / scattering particle size distribution analyzer (LA-700, manufactured by Horiba, Ltd.). Moreover, it is the value measured by the nitrogen substitution method using the BET-type specific surface area measuring device (Shimadzu Corporation make: Flow soap II2300).

  The maximum particle diameter (maximum primary particle diameter) of the hydroxygallium phthalocyanine pigment is desirably 1.2 μm or less, more desirably 1.0 μm or less, and more desirably 0.3 μm or less. is there.

Furthermore, the hydroxygallium phthalocyanine pigment has an average particle size of 0.2 μm or less and a maximum particle size of 1. from the viewpoint of more reliably suppressing density unevenness caused by exposure of the image carrier to a fluorescent lamp or the like. It is desirable that it is 2 μm or less and the specific surface area value is 45 m ² / g or more.

  In addition, the hydroxygallium phthalocyanine pigment described above has Bragg angles (2θ ± 0.2 °) of 7.5 °, 9.9 °, 12.5 °, and 16.5 in an X-ray diffraction spectrum using CuKα characteristic X-rays. It is desirable to have diffraction peaks at 3 °, 18.6 °, 25.1 ° and 28.3 °.

  The hydroxygallium phthalocyanine pigment preferably has a thermal weight reduction rate of 2.0% or more and 4.0% or less when heated from 25 ° C. to 400 ° C., and preferably 2.5% or more and 3.8%. % Or less is more desirable. The thermal weight reduction rate is measured by a thermobalance or the like.

The binder resin used for the charge generation layer 2 is selected from a wide range of insulating resins, and selected from organic photoconductive polymers such as poly-N-vinylcarbazole, polyvinylanthracene, polyvinylpyrene, and polysilane. Also good. Desirable binder resins include polyvinyl butyral resins, polyarylate resins (polycondensates of bisphenols and aromatic divalent carboxylic acids, etc.), polycarbonate resins, polyester resins, phenoxy resins, vinyl chloride-vinyl acetate copolymers, polyamides. Resins, acrylic resins, polyacrylamide resins, polyvinyl pyridine resins, cellulose resins, urethane resins, epoxy resins, caseins, polyvinyl alcohol resins, polyvinyl pyrrolidone resins, and the like. These binder resins are used alone or in combination of two or more. The blending ratio of the charge generation material and the binder resin is preferably in the range of 10: 1 to 1:10 by mass ratio. Here, “insulating” means that the volume resistivity is 10 ¹³ Ωcm or more.

  The charge generation layer 2 is formed using a coating liquid in which the charge generation material and the binder resin are dispersed in a predetermined solvent.

  Solvents used for dispersion include methanol, ethanol, n-propanol, n-butanol, benzyl alcohol, methyl cellosolve, ethyl cellosolve, acetone, methyl ethyl ketone, cyclohexanone, methyl acetate, n-butyl acetate, dioxane, tetrahydrofuran, and methylene chloride. , Chloroform, chlorobenzene, toluene and the like. These may be used alone or in admixture of two or more.

  Further, as a method for dispersing the charge generating material and the binder resin in the solvent, usual methods such as a ball mill dispersion method, an attritor dispersion method, and a sand mill dispersion method are used. By these dispersion methods, changes in the crystal form of the charge generation material due to dispersion are prevented. Further, at the time of dispersion, it is effective that the average particle size of the charge generating material is 0.5 μm or less, desirably 0.3 μm or less, and more desirably 0.15 μm or less.

  Further, when forming the charge generation layer 2, a usual method such as a blade coating method, a Mayer bar coating method, a spray coating method, a dip coating method, a bead coating method, an air knife coating method or a curtain coating method is used. .

  The film thickness of the charge generation layer 2 obtained in this way is desirably 0.1 μm or more and 5.0 μm or less, and more desirably 0.2 μm or more and 2.0 μm or less.

<Charge transport layer>
The charge transport layer 3 is formed containing a charge transport material and a binder resin, or containing a polymer charge transport material.
Examples of charge transport materials include quinone compounds such as p-benzoquinone, chloranil, bromanyl and anthraquinone, tetracyanoquinodimethane compounds, fluorenone compounds such as 2,4,7-trinitrofluorenone, xanthone compounds, and benzophenone compounds. Compounds, electron transport compounds such as cyanovinyl compounds, ethylene compounds, triarylamine compounds, benzidine compounds, arylalkane compounds, aryl-substituted ethylene compounds, stilbene compounds, anthracene compounds, hydrazone compounds, etc. Examples thereof include hole transporting compounds. These charge transport materials may be used alone or in combination of two or more, but are not limited thereto.

  As the charge transport material, from the viewpoint of charge mobility, a triarylamine derivative represented by the following structural formula (a-1) and a benzidine derivative represented by the following structural formula (a-2) are desirable.

(In Structural Formula (a-1), R ⁸ represents a hydrogen atom or a methyl group. N represents 1 or 2. Ar ⁶ and Ar ⁷ are each independently a substituted or unsubstituted aryl group, —C _6. H ₄ —C (R ⁹ ) ═C (R ¹⁰ ) (R ¹¹ ), or —C ₆ H ₄ —CH═CH—CH═C (R ¹² ) (R ¹³ ), wherein R ^{9 to} R ¹³ are Each independently represents a hydrogen atom, a substituted or unsubstituted alkyl group, or a substituted or unsubstituted aryl group, including a halogen atom, an alkyl group having 1 to 5 carbon atoms, and an alkoxy group having 1 to 5 carbon atoms; A substituted amino group substituted with a group or an alkyl group having 1 to 3 carbon atoms.)

(In Structural Formula (a-2), R ¹⁴ and R ^{14 ′} may be the same or different and each independently represents a hydrogen atom, a halogen atom, an alkyl group having 1 to 5 carbon atoms, or 1 to 5 carbon atoms. R ¹⁵ , R ^{15 ′} , R ¹⁶ and R ^{16 ′} may be the same or different and each independently represents a hydrogen atom, a halogen atom, an alkyl group having 1 to 5 carbon atoms, or 1 carbon atom. Or more, an alkoxy group having 5 or less, an amino group substituted with an alkyl group having 1 to 2 carbon atoms, a substituted or unsubstituted aryl group, -C (R ¹⁷ ) = C (R ¹⁸ ) (R ¹⁹ ), or- CH = CH—CH═C (R ²⁰ ) (R ²¹ ), wherein R ^{17 to} R ²¹ each independently represents a hydrogen atom, a substituted or unsubstituted alkyl group, or a substituted or unsubstituted aryl group. And n are independent of each other 0 or 2 show the following integer.)

Here, among the triarylamine derivatives represented by the structural formula (a-1) and the benzidine derivatives represented by the structural formula (a-2), in particular, “—C ₆ H ₄ —CH═CH—CH ═C (R ¹² ) (R ¹³ ) ”and a benzidine derivative having“ —CH═CH—CH═C (R ²⁰ ) (R ²¹ ) ”have charge mobility, surface layer and It is excellent and desirable from the standpoints of adhesiveness and afterimage (hereinafter sometimes referred to as “ghost”) caused by the history of the previous image remaining.

  The binder resin used for the charge transport layer 3 is polycarbonate resin, polyester resin, polyarylate resin, methacrylic resin, acrylic resin, polyvinyl chloride resin, polyvinylidene chloride resin, polystyrene resin, polyvinyl acetate resin, styrene-butadiene copolymer. , Vinylidene chloride-acrylonitrile copolymer, vinyl chloride-vinyl acetate copolymer, vinyl chloride-vinyl acetate-maleic anhydride copolymer, silicone resin, silicone alkyd resin, phenol-formaldehyde resin, styrene-alkyd resin, poly- N-vinyl carbazole, polysilane, etc. are mentioned. Further, as described above, polymer charge transport materials such as polyester polymer charge transport materials disclosed in JP-A-8-176293 and JP-A-8-208820 may be used. These binder resins are used alone or in combination of two or more. The blending ratio of the charge transporting material and the binder resin is desirably 10: 1 to 1: 5 by mass ratio.

  In particular, the binder resin is not particularly limited, but at least one of a polycarbonate resin having a viscosity average molecular weight of 50,000 to 80,000 and a polyarylate resin having a viscosity average molecular weight of 50,000 to 80,000 can be easily obtained. desirable.

  Further, a polymer charge transporting material may be used as the charge transporting material. As the polymer charge transporting material, known materials having charge transporting properties such as poly-N-vinylcarbazole and polysilane are used. In particular, polyester-based polymer charge transport materials disclosed in JP-A-8-176293, JP-A-8-208820 and the like have a higher charge transportability than other types and are particularly desirable. It is. The polymer charge transporting material can be formed by itself, but may be formed by mixing with a binder resin described later.

  The charge transport layer 3 is formed using a charge transport layer forming coating solution containing the above-described constituent materials. Solvents used in the coating solution for forming the charge transport layer include aromatic hydrocarbons such as benzene, toluene, xylene and chlorobenzene, ketones such as acetone and 2-butanone, and halogenation such as methylene chloride, chloroform and ethylene chloride. Ordinary organic solvents such as aliphatic hydrocarbons, cyclic ethers such as tetrahydrofuran and ethyl ether, or straight chain ethers may be used alone or in admixture of two or more. Moreover, a well-known method is used as a dispersion method of each said constituent material.

  The coating method for applying the charge transport layer forming coating solution onto the charge generation layer 2 includes blade coating method, Mayer bar coating method, spray coating method, dip coating method, bead coating method, air knife coating method, A usual method such as a curtain coating method is used.

  The film thickness of the charge transport layer 3 is desirably 5 μm or more and 50 μm or less, and more desirably 10 μm or more and 30 μm or less.

<Surface layer>
The surface layer 5 is the outermost surface layer in the image carrier 7, and is a layer provided to give resistance to abrasion and scratches on the outermost surface and to increase toner transfer efficiency.

The surface layer 5 has a charge transport property having at least one selected from a guanamine compound and a melamine compound and at least one substituent selected from —OH, —OCH ₃ , —NH ₂ , —SH, and —COOH. It comprises a cross-linked product using a coating solution containing at least one material.

First, the guanamine compound will be described.
The guanamine compound is a compound having a guanamine skeleton (structure), and examples thereof include acetoguanamine, benzoguanamine, formoguanamine, steroguanamine, spiroguanamine, and cyclohexylguanamine.

  The guanamine compound is particularly preferably at least one of a compound represented by the following general formula (A) and a multimer thereof. Here, the multimer is an oligomer polymerized using the compound represented by the general formula (A) as a structural unit, and the degree of polymerization thereof is, for example, 2 or more and 200 or less (preferably 2 or more and 100 or less). In addition, the compound shown by general formula (A) may be used individually by 1 type, but may use 2 or more types together. In particular, when the compound represented by the general formula (A) is used as a mixture of two or more kinds, or used as a multimer (oligomer) having the structural unit as a structural unit, the solubility in a solvent is improved.

In General Formula (A), R ₁ is a linear or branched alkyl group having 1 to 10 carbon atoms, a substituted or unsubstituted phenyl group having 6 to 10 carbon atoms, or 4 to 10 carbon atoms. The following substituted or unsubstituted alicyclic hydrocarbon groups are shown. R _{2 to} R ₅ each independently represent hydrogen, —CH ₂ —OH, or —CH ₂ —O—R ₆ . R ₆ represents hydrogen or a linear or branched alkyl group having 1 to 10 carbon atoms.

In general formula (A), the alkyl group represented by R ₁ has 1 to 10 carbon atoms, preferably 1 to 8 carbon atoms, more preferably 1 to 5 carbon atoms. . The alkyl group may be linear or branched.

In general formula (A), the phenyl group represented by R ₁ has 6 to 10 carbon atoms, and more preferably 6 to 8 carbon atoms. Examples of the substituent substituted with the phenyl group include a methyl group, an ethyl group, and a propyl group.

In general formula (A), the alicyclic hydrocarbon group representing R ₁ has 4 to 10 carbon atoms, and more preferably 5 to 8 carbon atoms. Examples of the substituent substituted with the alicyclic hydrocarbon group include a methyl group, an ethyl group, and a propyl group.

In the general formula (A), in “—CH ₂ —O—R ₆ ” representing R _{2 to} R ₅ , the alkyl group representing R ₆ has 1 to 10 carbon atoms, and desirably has carbon atoms. 1 to 8 and more preferably 1 to 6 carbon atoms. The alkyl group may be linear or branched. Desirably, a methyl group, an ethyl group, a butyl group, etc. are mentioned.

As the compound represented by the general formula (A), it is particularly desirable that R ₁ represents a substituted or unsubstituted phenyl group having 6 to 10 carbon atoms, and R _{2 to} R ₅ are each independently —CH ₂ —O. It is a compound represented by —R ₆ . R ₆ is preferably selected from a methyl group and an n-butyl group.

  The compound represented by the general formula (A) is synthesized by, for example, a known method using guanamine and formaldehyde (for example, Experimental Chemistry Course 4th Edition, Volume 28, page 430).

  Specific examples of the compound represented by the general formula (A) are shown below, but are not limited thereto. Moreover, although the following specific examples show the thing of a monomer, the multimer (oligomer) which uses these as a structural unit may be sufficient.

  Commercially available products of the compound represented by the general formula (A) include, for example, “Superbecamine (R) L-148-55, Superbecamine (R) 13-535, Superbecamine (R) L-145- 60, Superbecamine (R) TD-126 "manufactured by Dainippon Ink Co., Ltd.," Nicarac BL-60, Nicarac BX-4000 "manufactured by Nippon Carbide, and the like.

  In addition, the compound represented by the general formula (A) (including multimers) can be used in a suitable solvent such as toluene, xylene, ethyl acetate, etc., in order to remove the influence of residual catalyst after synthesis or after purchasing a commercial product. It may be dissolved and washed with distilled water, ion exchange water or the like, or may be removed by treatment with an ion exchange resin.

Next, the melamine compound will be described.
The melamine compound is a melamine skeleton (structure), and is preferably at least one of a compound represented by the following general formula (B) and a multimer thereof. Here, the multimer is an oligomer obtained by polymerizing the compound represented by the general formula (B) as a structural unit as in the general formula (A), and the degree of polymerization thereof is, for example, 2 or more and 200 or less (preferably 2 or more and 100). The following). In addition, the compound represented by the general formula (B) or a multimer thereof may be used alone or in combination of two or more. Moreover, you may use together with the compound shown by the said general formula (A), or its multimer. In particular, when the compound represented by the general formula (B) is used as a mixture of two or more kinds or used as a multimer (oligomer) having the structural unit as a structural unit, the solubility in a solvent is improved.

In general formula (B), R ^{6 to} R ¹¹ each independently represent a hydrogen atom, —CH ₂ —OH, —CH ₂ —O—R ¹² , and R ¹² is branched from 1 to 5 carbon atoms. Or a good alkyl group. Examples of the alkyl group include a methyl group, an ethyl group, and a butyl group.

  The compound represented by the general formula (B) is synthesized by, for example, a known method using melamine and formaldehyde (for example, synthesized as in the melamine resin of Experimental Chemistry Course 4th edition, Volume 28, page 430). The

  Specific examples of the compound represented by the general formula (B) are shown below, but are not limited thereto. Moreover, although the following specific examples show the thing of a monomer, the multimer (oligomer) which uses these as a structural unit may be sufficient.

  As a commercial item of the compound represented by the general formula (B), for example, Super Melami No. 90 (Nippon Yushi Co., Ltd.), Super Becamine (R) TD-139-60 (Dainippon Ink Co., Ltd.), Uban 2020 (Mitsui Chemicals), Smitex Resin M-3 (Sumitomo Chemical), Nicarak MW-30 (Made by Nippon Carbide).

  In addition, the compound represented by the general formula (B) (including multimers) can be used in a suitable solvent such as toluene, xylene, ethyl acetate, etc., in order to remove the influence of residual catalyst after synthesis or after purchasing a commercial product. It may be dissolved and washed with distilled water, ion exchange water or the like, or may be removed by treatment with an ion exchange resin.

Next, a specific charge transport material will be described. As the specific charge transporting material, for example, a material having at least one substituent selected from —OH, —OCH ₃ , —NH ₂ , —SH, and —COOH is preferably exemplified. In particular, the specific charge transporting material preferably has at least two (or three) substituents selected from —OH, —OCH ₃ , —NH ₂ , —SH, and —COOH. It is done. As described above, the reactive functional group (substituent) increases in a specific charge transporting material, thereby increasing the crosslinking density and obtaining a stronger crosslinked film. In particular, an image carrier when using a blade cleaner. , And the damage to the blade and the wear of the image carrier are suppressed. Although the details are unknown, since a cured film having a high crosslinking density can be obtained by increasing the number of reactive functional groups, the molecular motion of the extreme surface of the image carrier is suppressed, so that It is presumed that the interaction is weakened.

The specific charge transporting material is preferably a compound represented by the following general formula (I).
_{F - ((- R 1 -X} ) n1 R 2 -Y) n2 (I)

In general formula (I), F is an organic group derived from a compound having a hole transporting ability, R ₁ and R ₂ are each independently a linear or branched alkylene group having 1 to 5 carbon atoms. N1 represents 0 or 1, and n2 represents an integer of 1 or more and 4 or less. X represents an oxygen, NH, or sulfur atom, and Y represents —OH, —OCH ₃ , —NH ₂ , —SH, or —COOH.

  In general formula (I), an arylamine derivative is preferably used as the compound having a hole transporting ability in an organic group derived from a compound having a hole transporting ability represented by F. Preferred examples of the arylamine derivative include a triphenylamine derivative and a tetraphenylbenzidine derivative.

  The compound represented by the general formula (I) is preferably a compound represented by the following general formula (II). The compound represented by the general formula (II) is particularly excellent in charge mobility, stability against oxidation and the like.

In general formula (II), Ar ^{1 to} Ar ⁴ may be the same or different and each independently represents a substituted or unsubstituted aryl group, and Ar ⁵ represents a substituted or unsubstituted aryl group or a substituted or unsubstituted group. D represents — (— R ₁ —X) _n1 R ₂ —Y, c represents 0 or 1 independently, k represents 0 or 1, and the total number of D is 1 or more and 4 It is as follows. R ₁ and R ₂ each independently represents a linear or branched alkylene group having 1 to 5 carbon atoms, n1 represents 0 or 1, X represents an oxygen, NH, or sulfur atom. , Y represents —OH, —OCH ₃ , —NH ₂ , —SH, or —COOH.

In the general formula (II), “— (— R ₁ —X) _{n 1} R ₂ —Y” representing D is as described in the general formula (I), and R ₁ and R ₂ are each independently a carbon number. 1 or more and 5 or less linear or branched alkylene group. N1 is preferably 1. X is preferably oxygen. Y is preferably a hydroxyl group.
The total number of D in the general formula (II) corresponds to n2 in the general formula (I), preferably 2 or more and 4 or less, and more preferably 3 or more and 4 or less. That is, in the general formula (I) and the general formula (II), when the molecular weight is desirably 2 or more and 4 or less, more desirably 3 or more and 4 or less in one molecule, the crosslinking density increases and a crosslinked film with higher strength can be obtained. In particular, the rotational torque of the image carrier when using a blade cleaner is reduced, and damage to the blade is suppressed and wear of the image carrier is suppressed. The details are unknown, but by increasing the number of reactive functional groups, a cured film with a high crosslinking density can be obtained, and the molecular motion on the extreme surface of the image carrier is suppressed to interact with the blade member surface molecules. Is presumed to be weakened.

In general formula (II), Ar _{1 to} Ar ₄ are preferably any of the following formulas (1) to (7). Incidentally, the following equation (1) to (7) can be coupled to each Ar ₁ to Ar ₄ - shown with _{"(D) C".}

In formulas (1) to (7), R ⁹ is a phenyl substituted with a hydrogen atom, an alkyl group having 1 to 4 carbon atoms, an alkyl group having 1 to 4 carbon atoms, or an alkoxy group having 1 to 4 carbon atoms. Represents one selected from the group consisting of a group, an unsubstituted phenyl group, and an aralkyl group having 7 to 10 carbon atoms, wherein R ^{10 to} R ¹² are a hydrogen atom, an alkyl group having 1 to 4 carbon atoms, and a carbon number, respectively. One selected from the group consisting of an alkoxy group having 1 to 4 carbon atoms, a phenyl group substituted with an alkoxy group having 1 to 4 carbon atoms, an unsubstituted phenyl group, an aralkyl group having 7 to 10 carbon atoms, and a halogen atom Ar represents a substituted or unsubstituted arylene group, D and c have the same meanings as “D” and “c” in formula (II), s represents 0 or 1, and t represents 1 or more 3 or less It represents an integer. ]

  Here, as Ar in Formula (7), what is represented by following formula (8) or (9) is desirable.

[In formulas (8) and (9), R ¹³ and R ¹⁴ are each a hydrogen atom, an alkyl group having 1 to 4 carbon atoms, an alkoxy group having 1 to 4 carbon atoms, or an alkoxy group having 1 to 4 carbon atoms. 1 represents one selected from the group consisting of a phenyl group substituted with, an unsubstituted phenyl group, an aralkyl group having 7 to 10 carbon atoms and a halogen atom, and t represents an integer of 1 to 3. ]

  Further, Z ′ in the formula (7) is preferably represented by any one of the following formulas (10) to (17).

[In the formulas (10) to (17), R ¹⁵ and R ¹⁶ are each a hydrogen atom, an alkyl group having 1 to 4 carbon atoms, an alkoxy group having 1 to 4 carbon atoms, or an alkoxy group having 1 to 4 carbon atoms. 1 represents one selected from the group consisting of a phenyl group substituted with, an unsubstituted phenyl group, an aralkyl group having 7 to 10 carbon atoms, and a halogen atom, W represents a divalent group, q and r each represent Represents an integer of 1 to 10, and t represents an integer of 1 to 3. ]

  W in the formulas (16) to (17) is preferably any one of divalent groups represented by the following (18) to (26). However, in formula (25), u represents an integer of 0 or more and 3 or less.

In general formula (II), Ar ⁵ is the aryl group of the above (1) to (7) exemplified in the description of Ar ^{1 to} Ar ⁴ when k is 0, and when k is 1, An arylene group obtained by removing a hydrogen atom from the aryl groups of the above (1) to (7).

  Specific examples of the compound represented by the general formula (I) include compounds I-1 to I-34 shown below. In addition, the compound shown by the said general formula (I) is not limited at all by these.

  Here, the solid content concentration in at least one coating liquid selected from a guanamine compound (a compound represented by the general formula (A)) and a melamine compound (a compound represented by the general formula (B)) is 0.1 mass. % To 20% by mass, more preferably 1% to 3% by mass.

  On the other hand, the solid content concentration in the at least one coating solution of the specific charge transporting material is 80% by mass or more, and desirably 95% by mass or more. The upper limit of the solid content concentration is at least one selected from a guanamine compound (a compound represented by the general formula (A)) and a melamine compound (a compound represented by the general formula (B)), and other additives. Is not limited as long as it functions effectively.

Hereinafter, the surface layer 5 will be described in more detail.
The surface layer 5 includes at least one selected from a guanamine compound (compound represented by the general formula (A)) and a melamine compound (compound represented by the general formula (B)) and a specific charge transporting material (general formula). A phenol resin, a melamine resin, a urea resin, an alkyd resin, or the like may be mixed and used together with a crosslinked product with the compound (I). Further, in order to improve the strength, a compound having more functional groups in one molecule such as spiroacetal guanamine resin (for example, “CTU-guanamine” (Ajinomoto Fine Techno Co., Ltd.)) is used as the material in the crosslinked product. Copolymerization is also effective.

  In addition, other heat such as phenol resin, melamine resin, and benzoguanamine resin is added to the surface layer 5 for the purpose of effectively suppressing oxidation by the discharge generated gas by adding it so that the discharge generated gas is not excessively adsorbed. A curable resin may be mixed and used.

  Further, it is preferable to add a surfactant to the surface layer 5, and the surfactant to be used is particularly a surfactant that contains at least one type of structure among a fluorine atom, an alkylene oxide structure, and a silicone structure. Although there is no limitation, those having a plurality of the above structures have high affinity and compatibility with the charge transporting organic compound, improve the film-forming property of the surface layer coating solution, and suppress wrinkles and unevenness of the surface layer 5 Therefore, it is preferable.

  Various types of surfactants having a fluorine atom can be mentioned. Specific examples of the surfactant having a fluorine atom and an acrylic structure include Polyflow KL600 (manufactured by Kyoeisha Chemical Co., Ltd.), F-top EF-351, EF-352, EF-801, EF-802, EF-601 (above, JEMCO Manufactured). The surfactant having an acrylic structure mainly includes those obtained by polymerizing or copolymerizing monomers such as acrylic or methacrylic compounds.

Specific examples of the surfactant having a perfluoroalkyl group as a fluorine atom include perfluoroalkyl sulfonic acids (for example, perfluorobutane sulfonic acid, perfluorooctane sulfonic acid), and perfluoroalkyl carboxylic acids (for example, , Perfluorobutanecarboxylic acid, perfluorooctanecarboxylic acid, etc.) and perfluoroalkyl group-containing phosphates. Perfluoroalkylsulfonic acids and perfluoroalkylcarboxylic acids may be salts thereof and amide-modified products thereof.
Examples of commercially available perfluoroalkyl sulfonic acids include MegaFuck F-114 (manufactured by Dainippon Ink & Chemicals, Inc.), F-top EF-101, EF102, EF-103, EF-104, EF-105, and EF-. 112, EF-121, EF-122A, EF-122B, EF-122C, EF-123A (manufactured by JEMCO), AK, 501 (manufactured by Neos) and the like.

Examples of commercially available perfluoroalkyl carboxylic acids include Megafac F-410 (manufactured by Dainippon Ink & Chemicals, Inc.), Ftop EF-201, EF-204 (and above, manufactured by JEMCO).
As commercial products of perfluoroalkyl group-containing phosphates, MegaFac F-493, F-494 (above, manufactured by Dainippon Ink & Chemicals, Inc.) F-top EF-123A, EF-123B, EF-125M, EF -132 (manufactured by JEMCO).
Examples of the surfactant having an alkylene oxide structure include polyethylene glycol, polyether antifoaming agent, and polyether-modified silicone oil. The polyethylene glycol preferably has a number average molecular weight of 2000 or less, and the polyethylene glycol having a number average molecular weight of 2000 or less includes polyethylene glycol 2000 (number average molecular weight 2000), polyethylene glycol 600 (number average molecular weight 600), polyethylene glycol 400. (Number average molecular weight 400), polyethylene glycol 200 (number average molecular weight 200) and the like.

Moreover, as a polyether antifoamer, PE-M, PE-L (above, Wako Pure Chemical Industries Ltd. make), antifoam No. 1, antifoam No. 5 (above, manufactured by Kao Corporation).
Examples of the surfactant having a silicone structure include dimethyl silicone, methylphenyl silicone, diphenyl silicone, and general silicone oils thereof.

  Furthermore, surfactants having both a fluorine atom and an alkylene oxide structure include those having an alkylene oxide structure or a polyalkylene structure in the side chain, and the end of the alkylene oxide or polyalkylene oxide structure substituted with a substituent containing fluorine. And the like. Specific examples of the surfactant having an alkylene oxide structure include, for example, Megafac F-443, F-444, F-445, and F-446 (above, Dainippon Ink & Chemicals, Inc.), POLY FOX PF636. , PF6320, PF6520, PF656 (above, manufactured by Kitamura Chemical Co., Ltd.).

  As surfactants having both an alkylene oxide structure and a silicone structure, KF351 (A), KF352 (A), KF353 (A), KF354 (A), KF355 (A), KF615 (A), KF618, KF945 (A), KF6004 (above, manufactured by Shin-Etsu Chemical Co., Ltd.), TSF4440, TSF4445, TSF4450, TSF4446, TSF4452, TSF4453, TSF4460 (above, manufactured by GE Toshiba Silicon), BYK-300, 302, 306, 307, 310, 315, 320, 322, 323, 325, 330, 331, 333, 337, 341, 344, 345, 346, 347, 348, 370, 375, 377, 378, UV3500, UV3510, UV3570, etc. (above, Big Chemie Ja Emissions Co., Ltd.) and the like.

  The content of the surfactant is desirably 0.01% by mass or more and 1% by mass or less, and more desirably 0.02% by mass or more and 0.5% by mass or less with respect to the total solid content of the surface layer 7.

  Further, the surface layer 5 may be used in combination with another coupling agent or a fluorine compound for the purpose of adjusting the film formability, flexibility, lubricity, and adhesiveness of the film. As this compound, various silane coupling agents and commercially available silicone hard coat agents are used.

  As the silane coupling agent, vinyltrichlorosilane, vinyltrimethoxysilane, vinyltriethoxysilane, γ-glycidoxypropylmethyldiethoxysilane, γ-glycidoxypropyltrimethoxysilane, γ-aminopropyltriethoxysilane, γ-aminopropyltrimethoxysilane, γ-aminopropylmethyldimethoxysilane, N-β (aminoethyl) γ-aminopropyltriethoxysilane, tetramethoxysilane, methyltrimethoxysilane, dimethyldimethoxysilane, and the like are used. As a commercially available hard coat agent, KP-85, X-40-9740, X-8239 (manufactured by Shin-Etsu Silicone), AY42-440, AY42-441, AY49-208 (manufactured by Toray Dow Corning) Etc. are used. In order to impart water repellency and the like, (tridecafluoro-1,1,2,2-tetrahydrooctyl) triethoxysilane, (3,3,3-trifluoropropyl) trimethoxysilane, 3- (hepta) Fluoroisopropoxy) propyltriethoxysilane, 1H, 1H, 2H, 2H-perfluoroalkyltriethoxysilane, 1H, 1H, 2H, 2H-perfluorodecyltriethoxysilane, 1H, 1H, 2H, 2H-perfluorooctyl Fluorine-containing compounds such as triethoxysilane may be added. Although the silane coupling agent is used in an arbitrary amount, the amount of the fluorine-containing compound is desirably 0.25 times or less by mass with respect to the compound not containing fluorine.

  Further, a resin that dissolves in alcohol may be added for the purpose of discharge gas resistance, mechanical strength, scratch resistance, particle dispersibility, viscosity control, torque reduction, wear amount control, pot life extension, and the like of the surface layer 5.

  Here, the alcohol-soluble resin means a resin that can be dissolved by 1 mass% or more in an alcohol having 5 or less carbon atoms. Examples of resins that are soluble in alcohol solvents include polyvinyl acetal resins such as polyvinyl butyral resin, polyvinyl formal resin, and partially acetalized polyvinyl acetal resin in which a part of butyral is modified with formal or acetoacetal (for example, manufactured by Sekisui Chemical Co., Ltd.) ESREC B, K, etc.), polyamide resin, cellulose resin, polyvinylphenol resin and the like. In particular, polyvinyl acetal resin and polyvinyl phenol resin are desirable in terms of electrical characteristics. The resin preferably has a weight average molecular weight of 2,000 to 100,000, and more preferably 5,000 to 50,000. Moreover, the addition amount of the resin is preferably 1% by mass or more and 10% by mass or less, more preferably 1% by mass or more and 5% by mass or less based on the total amount of the total solid content of the surface layer 5.

  It is desirable to add an antioxidant to the surface layer 5 for the purpose of preventing deterioration due to an oxidizing gas such as ozone generated in the charging device. When the mechanical strength of the surface of the image carrier is increased and the image carrier has a long life, the image carrier is brought into contact with the oxidizing gas for a long time. Antioxidants are preferably hindered phenols or hindered amines, organic sulfur antioxidants, phosphite antioxidants, dithiocarbamate antioxidants, thiourea antioxidants, benzimidazole antioxidants. , Etc., may be used. The addition amount of the antioxidant is preferably 10% by mass or less, more preferably 5% by mass or less, based on the total amount of the total solid content of the surface layer 5.

  Examples of the hindered phenol antioxidant include 2,6-di-t-butyl-4-methylphenol, 2,5-di-t-butylhydroquinone, N, N′-hexamethylene bis (3,5-di). -T-butyl-4-hydroxyhydrocinnamide, 3,5-di-t-butyl-4-hydroxy-benzylphosphonate-diethyl ester, 2,4-bis [(octylthio) methyl] -o-cresol, 2,6-di-t-butyl-4-ethylphenol, 2,2'-methylenebis (4-methyl-6-t-butylphenol), 2,2'-methylenebis (4-ethyl-6-t-butylphenol) 4,4'-butylidenebis (3-methyl-6-t-butylphenol), 2,5-di-t-amylhydroquinone, 2-t-butyl-6- (3-butyl-2- Dorokishi-5-methylbenzyl) -4-methylphenyl acrylate, 4,4'-butylidene bis (3-methyl -6-t-butylphenol) and the like.

  Furthermore, various particles may be added to the surface layer 5 for the purpose of lowering the residual potential or improving the strength. An example of the particles is silicon-containing particles. Silicon-containing particles are particles containing silicon as a constituent element, and specific examples include colloidal silica and silicone particles. The colloidal silica used as the silicon-containing particles is obtained by dispersing silica having an average particle diameter of 1 nm or more and 100 nm or less, preferably 10 nm or more and 30 nm or less in an organic solvent such as an acidic or alkaline aqueous dispersion, alcohol, ketone, or ester. A commercially available product may be used. The solid content of the colloidal silica in the surface layer 5 is not particularly limited, but is preferably 10 based on the total solid content of the surface layer 5 in terms of film forming properties, electrical characteristics, and strength. It is not more than mass%, more desirably not more than 5 mass%.

  The silicone particles used as the silicon-containing particles are selected from silicone resin particles, silicone rubber particles, and silicone surface-treated silica particles, and those commercially available are generally used. These silicone particles are spherical, and the average particle size is desirably 1 nm or more and 500 nm or less, and more desirably 10 nm or more and 100 nm or less. The content of the silicone particles in the surface layer 5 is desirably 10% by mass or less, more desirably 5% by mass or less, based on the total amount of the total solid content of the surface layer 5.

Other particles include fluorine-based particles such as ethylene tetrafluoride, ethylene trifluoride, propylene hexafluoride, vinyl fluoride, vinylidene fluoride, and “8th Polymer Material Forum Lecture Proceedings p89”. As shown, particles made of a resin obtained by copolymerizing a fluororesin and a monomer having a hydroxyl group, ZnO—Al ₂ O ₃ , SnO ₂ —Sb ₂ O ₃ , In ₂ O ₃ —SnO ₂ , ZnO ₂ —TiO ₂ , ZnO Examples thereof include semiconductive metal oxides such as —TiO ₂ , MgO—Al ₂ O ₃ , FeO—TiO ₂ , TiO ₂ , SnO ₂ , In ₂ O ₃ , ZnO, and MgO. For the same purpose, an oil such as silicone oil may be added. Silicone oils include silicone oils such as dimethylpolysiloxane, diphenylpolysiloxane, and phenylmethylsiloxane; amino-modified polysiloxane, epoxy-modified polysiloxane, carboxyl-modified polysiloxane, carbinol-modified polysiloxane, methacryl-modified polysiloxane, mercapto-modified poly Reactive silicone oils such as siloxane and phenol-modified polysiloxane; cyclic dimethylcyclosiloxanes such as hexamethylcyclotrisiloxane, octamethylcyclotetrasiloxane, decamethylcyclopentasiloxane and dodecamethylcyclohexasiloxane; 1,3,5- Trimethyl-1.3.5-triphenylcyclotrisiloxane, 1,3,5,7-tetramethyl-1,3,5,7-tetraphenylcyclo Cyclic methylphenylcyclosiloxanes such as trasiloxane, 1,3,5,7,9-pentamethyl-1,3,5,7,9-pentaphenylcyclopentasiloxane; cyclic phenylcyclosiloxanes such as hexaphenylcyclotrisiloxane Fluorine-containing cyclosiloxanes such as (3,3,3-trifluoropropyl) methylcyclotrisiloxane; hydrosilyl group-containing cyclosiloxanes such as methylhydrosiloxane mixtures, pentamethylcyclopentasiloxane, and phenylhydrocyclosiloxane; penta And vinyl group-containing cyclosiloxanes such as vinylpentamethylcyclopentasiloxane.

  Further, metal, metal oxide, carbon black, or the like may be added to the surface layer 5. Examples of the metal include aluminum, zinc, copper, chromium, nickel, silver and stainless steel, or those obtained by depositing these metals on the surface of plastic particles. Examples of the metal oxide include zinc oxide, titanium oxide, tin oxide, antimony oxide, indium oxide, bismuth oxide, indium oxide doped with tin, tin oxide doped with antimony and tantalum, and zirconium oxide doped with antimony. . These may be used alone or in combination of two or more. When two or more types are used in combination, they may be simply mixed, or may be in the form of a solid solution or fusion. The average particle diameter of the conductive particles is preferably 0.3 μm or less, particularly 0.1 μm or less in terms of the transparency of the surface layer.

  A curing catalyst is used for the surface layer 5 in order to promote curing of a guanamine compound (a compound represented by the general formula (A)), a melamine compound (a compound represented by the general formula (B)) and a charge transporting material. May be. An acid catalyst is preferably used as the curing catalyst. Acid-based catalysts include acetic acid, chloroacetic acid, trichloroacetic acid, trifluoroacetic acid, oxalic acid, maleic acid, malonic acid, lactic acid and other aliphatic carboxylic acids, benzoic acid, phthalic acid, terephthalic acid, trimellitic acid, etc. Aromatic carboxylic acids, methane sulfonic acids, dodecyl sulfonic acids, benzene sulfonic acids, aliphatics such as dodecyl benzene sulfonic acids, naphthalene sulfonic acids, and aromatic sulfonic acids are used, but sulfur-containing materials should be used. desirable.

  By using a sulfur-containing material as a curing catalyst, the sulfur-containing material is converted into a guanamine compound (a compound represented by the general formula (A)), a melamine compound (a compound represented by the general formula (B)) or a charge transporting material. The mechanical strength of the surface layer 5 obtained by exhibiting an excellent function as a curing catalyst is improved by promoting the curing reaction. Furthermore, when the compound represented by the general formula (I) (including the general formula (II)) is used as the charge transport material, the sulfur-containing material exhibits an excellent function as a dopant for these charge transport materials. In addition, the electrical characteristics of the obtained functional layer are further improved. As a result, when the image carrier is formed, all of mechanical strength, film formability and electrical characteristics are achieved at a high level.

  The sulfur-containing material as a curing catalyst is desirably at room temperature (for example, 25 ° C.) or exhibits acidity after heating, and at least one of organic sulfonic acid and its derivatives is most preferable from the viewpoint of adhesiveness, ghost, and electrical characteristics. desirable. The presence of these catalysts in the surface layer 5 is easily confirmed by XPS or the like.

  Examples of the organic sulfonic acid and / or a derivative thereof include p-toluenesulfonic acid, dinonylnaphthalenesulfonic acid (DNNSA), dinonylnaphthalenedisulfonic acid (DNNDSA), dodecylbenzenesulfonic acid, and phenolsulfonic acid. Among these, paratoluenesulfonic acid and dodecylbenzenesulfonic acid are desirable from the viewpoint of catalytic ability and film formability. Further, an organic sulfonate may be used as long as it can be dissociated to some extent in the curable resin composition.

  In addition, by using a so-called thermal latent catalyst that increases the catalytic ability when a temperature above a certain level is applied, the catalytic ability is low at the liquid storage temperature and the catalytic ability is high at the time of curing. And storage stability.

  As a heat latent catalyst, for example, a microcapsule in which an organic sulfone compound or the like is encapsulated in a polymer form, an adsorbed acid or the like on a pore compound such as zeolite, and a proton acid and / or proton acid derivative is blocked with a base Thermal latent proton acid catalyst, proton acid and / or proton acid derivative esterified with primary or secondary alcohol, proton acid and / or proton acid derivative blocked with vinyl ethers and / or vinyl thioethers And boron trifluoride monoethylamine complex, boron trifluoride pyridine complex, and the like.

  Of these, a protonic acid and / or a protonic acid derivative blocked with a base is desirable.

  As the protonic acid of the heat latent protonic acid catalyst, sulfuric acid, hydrochloric acid, acetic acid, formic acid, nitric acid, phosphoric acid, sulfonic acid, monocarboxylic acid, polycarboxylic acids, propionic acid, oxalic acid, benzoic acid, acrylic acid, methacrylic acid, Itaconic acid, phthalic acid, maleic acid, benzenesulfonic acid, o, m, p-toluenesulfonic acid, styrenesulfonic acid, dinonylnaphthalenesulfonic acid, dinonylnaphthalenedisulfonic acid, decylbenzenesulfonic acid, undecylbenzenesulfonic acid, Examples include tridecylbenzenesulfonic acid, tetradecylbenzenesulfonic acid, dodecylbenzenesulfonic acid and the like. In addition, as protonic acid derivatives, neutralized products such as alkali metal salts of alkaline acids or alkaline earth metal circles such as sulfonic acid and phosphoric acid, and polymer compounds in which a protonic acid skeleton is introduced into the polymer chain (polyvinylsulfone) Acid, etc.). Examples of the base that blocks the protonic acid include amines.

  Amines are classified as primary, secondary or tertiary amines. There is no restriction in particular and any of them may be used.

  Examples of the primary amine include methylamine, ethylamine, propylamine, isopropylamine, n-butylamine, isobutylamine, t-butylamine, hexylamine, 2-ethylhexylamine, secondary butylamine, allylamine, and methylhexylamine.

  As secondary amines, dimethylamine, diethylamine, di-n-propylamine, diisopropylamine, di-n-butylamine, diisobutylamine, di-t-butylamine, dihexylamine, di (2-ethylhexyl) amine, N-isopropyl N-isobutylamine , Di (2-ethylhexyl) amine, disecondary butylamine, diallylamine, N-methylhexylamine, 3-pipecoline, 4-pipecoline, 2,4-lupetidine, 2,6-lupetidine, 3,5-lupetidine, morpholine, N -Methylbenzylamine and the like.

  As tertiary amines, trimethylamine, triethylamine, tri-n-propylamine, triisopropylamine, tri-n-butylamine, triisobutylamine, tri-t-butylamine, trihexylamine, tri (2-ethylhexyl) amine, N-methylmorpholine, N, N-dimethylallylamine, N-methyldiallylamine, triallylamine, N, N-dimethylallylamine, N, N, N ′, N′-tetramethyl-1,2-diaminoethane, N, N, N ′, N '-Tetramethyl-1,3-diaminopropane, N, N, N', N'-tetraallyl-1,4-diaminobutane, N-methylpiperidine, pyridine, 4-ethylpyridine, N-propyldiallylamine, 3- Dimethylaminopropanol, 2-ethylpyrazine, 2,3-di Tilpyrazine, 2,5-dimethylpyrazine, 2,4-lutidine, 2,5-lutidine, 3,4-lutidine, 3,5-lutidine, 2,4,6-collidine, 2-methyl-4-ethylpyridine, 2-methyl-5-ethylpyridine, N, N, N ′, N′-tetramethylhexamethylenediamine, N-ethyl-3-hydroxypiperidine, 3-methyl-4-ethylpyridine, 3-ethyl-4-methyl Pyridine, 4- (5-nonyl) pyridine, imidazole, N-methylpiperazine and the like can be mentioned.

  Commercially available products include “NACURE2501” (toluenesulfonic acid dissociation, methanol / isopropanol solvent, pH 6.0 to pH 7.2, dissociation temperature 80 ° C.), “NACURE2107” (p-toluenesulfonic acid dissociation, manufactured by King Industries, Inc. Isopropanol solvent, pH 8.0 to pH 9.0, dissociation temperature 90 ° C.) “NACURE 2500” (p-toluenesulfonic acid dissociation, isopropanol solvent, pH 6.0 to pH 7.0, dissociation temperature 65 ° C.), “NACURE 2530” (P-toluenesulfonic acid dissociation, methanol / isopropanol solvent, pH 5.7 to pH 6.5, dissociation temperature 65 ° C.), “NACURE2547” (p-toluenesulfonic acid dissociation, aqueous solution, pH 8.0 to pH 9.0, Dissociation temperature 107 ), “NACURE2558” (p-toluenesulfonic acid dissociation, ethylene glycol solvent, pH 3.5 to pH4.5, dissociation temperature 80 ° C.), “NACUREXP-357” (p-toluenesulfonic acid dissociation, methanol solvent, pH 2. 0 to pH 4.0, dissociation temperature 65 ° C.) “NACUREXP-386” (p-toluenesulfonic acid dissociation, aqueous solution, pH 6.1 to pH 6.4, dissociation temperature 80 ° C.), “NACUREX C-2211” (p -Toluenesulfonic acid dissociation, pH 7.2 to pH 8.5, dissociation temperature 80 ° C.), “NACURE 5225” (dodecylbenzenesulfonic acid dissociation, isopropanol solvent, pH 6.0 to pH 7.0, dissociation temperature 120 ° C.), “ NACURE 5414 "(dodecylbenzenesulfonic acid dissociation, key Ren solvent, dissociation temperature 120 ° C.), “NACURE 5528” (dodecylbenzenesulfonic acid dissociation, isopropanol solvent, pH 7.0 to pH 8.0, dissociation temperature 120 ° C.), “NACURE 5925” (dodecylbenzenesulfonic acid dissociation, pH 7.0) PH 7.5 or less, dissociation temperature 130 ° C., “NACURE 1323” (disinyl naphthalene sulfonic acid dissociation, xylene solvent, pH 6.8 to pH 7.5, dissociation temperature 150 ° C.), “NACURE 1419” (dinonyl naphthalene sulfonic acid Dissociation, xylene / methyl isobutyl ketone solvent, dissociation temperature 150 ° C.), “NACURE1557” (dinonylnaphthalenesulfonic acid dissociation, butanol / 2-butoxyethanol solvent, pH 6.5 to pH 7.5, dissociation temperature 150 ° C.), “ NA CUREX 49-110 ”(dinonyl naphthalene disulfonic acid dissociation, isobutanol / isopropanol solvent, pH 6.5 to pH 7.5, dissociation temperature 90 ° C.),“ NACURE 3525 ”(dinonyl naphthalene disulfonic acid dissociation, isobutanol / isopropanol solvent, pH 7.0 to pH 8.5, dissociation temperature 120 ° C., “NACUREXP-383” (dinonyl naphthalene disulfonic acid dissociation, xylene solvent, dissociation temperature 120 ° C.), “NACURE 3327” (dinonyl naphthalene disulfonic acid dissociation, isobutanol / Isopropanol solvent, pH 6.5 to pH 7.5, dissociation temperature 150 ° C.), “NACURE4167” (phosphoric acid dissociation, isopropanol / isobutanol solvent, pH 6.8 to pH 7.3, dissociation temperature 80 ), “NACUREXP-297” (phosphoric acid dissociation, water / isopropanol solvent, pH 6.5 to pH 7.5, dissociation temperature 90 ° C., “NACURE 4575” (phosphoric acid dissociation, pH 7.0 to pH 8.0, dissociation temperature) 110 ° C.).

  These thermal latent catalysts may be used alone or in combination of two or more.

  Here, the compounding amount of the catalyst is at least one amount selected from the guanamine compound (compound represented by the general formula (A)) and the melamine compound (compound represented by the general formula (B)) (in the coating solution). The solid content concentration is preferably in the range of 0.1% by mass to 50% by mass, and more preferably 10% by mass to 30% by mass.

  The surface layer 5 having the above structure comprises at least one selected from the guanamine compound (compound represented by the general formula (A)) and the melamine compound (compound represented by the general formula (B)) and the specific charge transport. It forms using the coating liquid for film formation containing at least 1 sort (s) of a conductive material. In the coating liquid for film formation, the constituent components of the surface layer 5 are added as necessary.

  The coating solution for film formation is prepared in the absence of a solvent or, if necessary, alcohols such as methanol, ethanol, propanol and butanol; ketones such as acetone and methyl ethyl ketone; ethers such as tetrahydrofuran, diethyl ether and dioxane. You may carry out using solvents, such as. Such solvents can be used singly or in combination of two or more, and preferably have a boiling point of 100 ° C. or lower. As the solvent, it is particularly preferable to use a solvent having at least one hydroxyl group (for example, alcohol).

  The amount of the solvent is arbitrarily set, but if it is too small, the guanamine compound (the compound represented by the general formula (A)) and the melamine compound (the compound represented by the general formula (B)) are likely to precipitate. 0.5 parts by mass or more and 30 parts by mass or less, preferably 1 part by mass of at least one selected from a compound represented by the general formula (A) and a melamine compound (compound represented by the general formula (B)) 1 to 20 parts by mass is used.

  In addition, when the coating liquid is obtained by reacting the above components, it may be simply mixed and dissolved, but it is room temperature (for example, 25 ° C.) to 100 ° C., preferably 30 ° C. to 80 ° C. for 10 minutes to 100 Heating may be performed for a time or less, preferably 1 hour or more and 50 hours or less. It is also desirable to irradiate ultrasonic waves at this time. Thereby, it is likely that a partial reaction proceeds, and it is easy to obtain a film having no coating film defects and little variation in film thickness.

  Then, a coating solution for forming a film is formed on the charge transport layer 3 by a usual method such as a blade coating method, a Mayer bar coating method, a spray coating method, a dip coating method, a bead coating method, an air knife coating method, or a curtain coating method. The surface layer 5 is obtained by curing by applying at a temperature of, for example, 100 ° C. or more and 170 or less if necessary.

  The coating liquid for forming a film is used for, for example, an antistatic film on a fluorescent coloring paint, a glass surface, a plastic surface, etc., in addition to the use as an image carrier. When this coating liquid for forming a film is used, a film having excellent adhesion to the lower layer is formed, and performance deterioration due to repeated use over a long period is suppressed.

  Here, the image carrier is described as an example of the function separation type, but the content of the charge generation material in the single-layer type photosensitive layer 6 (charge generation / charge transport layer) is 10 mass% or more and 85 mass%. Hereinafter, it is desirably 20% by mass or more and 50% by mass or less. The content of the charge transporting material is preferably 5% by mass or more and 50% by mass or less. The formation method of the single-layer type photosensitive layer 6 (charge generation / charge transport layer) is performed according to the formation method of the charge generation layer 2 and the charge transport layer 3. The film thickness of the single-layer type photosensitive layer (charge generation / charge transport layer) 6 is preferably 5 μm or more and 50 μm or less, and more preferably 10 μm or more and 40 μm or less.

  In the embodiment, at least one selected from a guanamine compound (a compound represented by the general formula (A)) and a melamine compound (a compound represented by the general formula (B)) and a specific charge transporting material (general Although the form using the cross-linked product with the compound represented by the formula (I) for the surface layer 5 has been described, in the case of a layer configuration without the surface layer 5, for example, it is used for the charge transport layer located in the outermost surface layer May be.

(Image forming device / process cartridge)
FIG. 4 is a schematic configuration diagram showing an image forming apparatus according to the present embodiment provided with an application unit that applies a lubricant to the surface of the image carrier. As shown in FIG. 4, the image forming apparatus 100 includes a process cartridge 300 including an image carrier 7, an exposure device 9, a transfer device 40, and an intermediate transfer member 50. In the image forming apparatus 100, the exposure device 9 is disposed at a position where the image carrier 7 can be exposed from the opening of the process cartridge 300, and the transfer device 40 is attached to the image carrier 7 via the intermediate transfer member 50. The intermediate transfer member 50 is disposed so as to be in contact with the image carrier 7.

  The process cartridge 300 in FIG. 4 integrally supports the image carrier 7, the charging device 8, the developing device 11, and the cleaning device 13 in a housing. In the cleaning device 13, a zinc stearate bar (lubricant) 14 is disposed in contact with a fibrous member (brush) 132. Note that a flicker bar for removing residual toner attached to the surface of the fibrous member 132 may be provided on the surface of the fibrous member 132. Zinc stearate is applied to the surface of the image carrier 7 by the fibrous member 132, and the zinc coverage on the surface of the image carrier 7 is controlled within the above-described range. Zinc stearate is applied to the surface of the image carrier 7 by a fibrous member 132 disposed in contact with the zinc stearate bar 14. The cleaning device 13 includes a cleaning blade (cleaning member), and the cleaning blade 131 is disposed so as to contact the surface of the image carrier 7. A lubricant film made of zinc stearate is formed on the surface of the image carrier 7 by the cleaning blade 131 disposed in contact with the image carrier 7.

  Note that the lubricant (for example, zinc stearate) may be applied to the surface of the image carrier 7 by developing the electrostatic latent image using a developer containing a lubricant. In the present embodiment, the method of applying the lubricant to the surface of the image carrier 7 is not particularly limited, and has a zinc stearate bar (lubricant) 14 and a fibrous member 132 as shown in FIG. It may be based on a coating means or may be based on a method using a developer containing a lubricant. Furthermore, you may use both together.

  As the charging device 8, for example, a contact type charger using a conductive or semiconductive charging roller, a charging brush, a charging film, a charging rubber blade, a charging tube or the like is used. Further, a non-contact type roller charger, a known charger such as a scorotron charger using a corona discharge or a corotron charger may be used.

  Although not shown, for the purpose of improving the stability of the image, an image carrier heating member for increasing the temperature of the image carrier 7 and reducing the relative temperature may be provided around the image carrier 7. Good.

  Examples of the exposure device 9 include optical system devices that expose the surface of the image carrier 7 with light such as semiconductor laser light, LED light, and liquid crystal shutter light in a desired image manner. The wavelength of the light source is in the spectral sensitivity region of the image carrier. As the wavelength of the semiconductor laser, near infrared having an oscillation wavelength around 780 nm is the mainstream. However, the present invention is not limited to this wavelength, and a laser having an oscillation wavelength of 600 nm or a laser having an oscillation wavelength of 400 nm to 450 nm as a blue laser may be used. For color image formation, a surface-emitting laser light source capable of multi-beam output is also effective.

  As the developing device 11, for example, a general developing device that performs development by bringing a magnetic or non-magnetic one-component developer or two-component developer into contact or non-contact with each other may be used. The developing device is not particularly limited as long as it has the functions described above, and is selected according to the purpose. For example, a known developing device having a function of attaching the one-component developer or the two-component developer to the image carrier 7 using a brush, a roller, or the like can be used. Among these, those using a developing roller holding the developer on the surface are desirable.

Hereinafter, the toner used in the developing device 11 will be described.
The toner used in the image forming apparatus of the present embodiment has an average shape factor ((ML ² / A) × (π / 4) × 100, where ML is a value from the viewpoint of obtaining high developability and transferability and high image quality. The maximum length of the particle is represented, and A represents the projected area of the particle) is preferably from 100 to 150, more preferably from 105 to 145, and even more preferably from 110 to 140. Further, the toner preferably has a volume average particle diameter of 3 μm or more and 12 μm or less, more preferably 3.5 μm or more and 10 μm or less, and further preferably 4 μm or more and 9 μm or less.

  The toner is not particularly limited by the production method. For example, a kneading and pulverizing method in which a binder resin, a colorant and a release agent, and a charge control agent and the like are added, if necessary, kneading and pulverizing; kneading and pulverizing; A method of changing the shape of particles obtained by the method by mechanical impact force or thermal energy; a dispersion monomer formed by emulsion polymerization of a polymerizable monomer of a binder resin, a colorant and a release agent An emulsion polymerization aggregation method for obtaining toner particles by mixing with a dispersion of a charge control agent or the like, if necessary, and aggregating and heating and fusing; a polymerizable monomer for obtaining a binder resin, a colorant and Suspension polymerization method in which a release agent and, if necessary, a solution such as a charge control agent are suspended in an aqueous solvent for polymerization; a binder resin, a colorant and a release agent, and a charge control agent as required Tona manufactured by dissolution suspension method, etc., in which the solution is suspended in an aqueous solvent and granulated There will be used.

  Further, a known method such as a production method in which the toner obtained by the above method is used as a core, and agglomerated particles are further adhered and heat-fused to give a core-shell structure is used. The toner production method is preferably a suspension polymerization method, an emulsion polymerization aggregation method, or a dissolution suspension method in which an aqueous solvent is used from the viewpoint of shape control and particle size distribution control, and an emulsion polymerization aggregation method is particularly desirable.

  The toner base particles are composed of a binder resin, a colorant, and a release agent, and include silica and a charge control agent if necessary.

  Binder resins used for toner base particles include styrenes such as styrene and chlorostyrene, monoolefins such as ethylene, propylene, butylene and isoprene, vinyl acetate, vinyl propionate, vinyl benzoate, vinyl butyrate, etc. Α-methylene aliphatics such as vinyl esters, methyl acrylate, ethyl acrylate, butyl acrylate, dodecyl acrylate, octyl acrylate, phenyl acrylate, methyl methacrylate, ethyl methacrylate, butyl methacrylate, dodecyl methacrylate Homopolymers and copolymers of monocarboxylic acid esters, vinyl ethers such as vinyl methyl ether, vinyl ethyl ether and vinyl butyl ether, vinyl ketones such as vinyl methyl ketone, vinyl hexyl ketone and vinyl isopropenyl ketone , Polyester resins by copolymerization of dicarboxylic acids and diols.

  Particularly representative binder resins include polystyrene, styrene-alkyl acrylate copolymer, styrene-alkyl methacrylate copolymer, styrene-acrylonitrile copolymer, styrene-butadiene copolymer, styrene-maleic anhydride copolymer. A polymer, polyethylene, a polypropylene, a polyester resin etc. are mentioned. Further, polyurethane, epoxy resin, silicone resin, polyamide, modified rosin, paraffin wax and the like can be mentioned.

  In addition, as colorants, magnetic powders such as magnetite and ferrite, carbon black, aniline blue, caryl blue, chrome yellow, ultramarine blue, Dupont oil red, quinoline yellow, methylene blue chloride, phthalocyanine blue, malachite green oxalate, Lamp Black, Rose Bengal, C.I. I. Pigment red 48: 1, C.I. I. Pigment red 122, C.I. I. Pigment red 57: 1, C.I. I. Pigment yellow 97, C.I. I. Pigment yellow 17, C.I. I. Pigment blue 15: 1, C.I. I. Pigment Blue 15: 3 is exemplified as a representative example.

  Typical examples of the release agent include low molecular weight polyethylene, low molecular weight polypropylene, Fischer tropical wax, montan wax, carnauba wax, rice wax, and candelilla wax.

  As the charge control agent, known ones are used, and azo metal complex compounds, metal complex compounds of salicylic acid, and resin type charge control agents containing polar groups are used. When toner is produced by a wet process, it is desirable to use a material that is difficult to dissolve in water in terms of controlling ionic strength and reducing wastewater contamination. The toner may be either a magnetic toner containing a magnetic material or a non-magnetic toner containing no magnetic material.

  The toner used in the developing device 11 is manufactured by mixing the toner base particles and the external additive with a Henschel mixer or a V blender. Further, when the toner base particles are produced by a wet method, they may be externally added by a wet method.

  Lubricating particles may be added to the toner used in the developing device 11. Lubricating particles include solid lubricants such as graphite, molybdenum disulfide, talc, fatty acids and fatty acid metal salts, low molecular weight polyolefins such as polypropylene, polyethylene and polybutene, silicones having a softening point upon heating, oleic amides , Erucic acid amide, ricinoleic acid amide, stearic acid amide and other aliphatic amides, carnauba wax, rice wax, candelilla wax, tree wax, jojoba oil and other plant waxes, beeswax animal wax, montan wax, ozokerite , Ceresin, paraffin wax, microcrystalline wax, minerals such as Fischer-Tropsch wax, petroleum wax, and modified products thereof. These are used individually by 1 type or in combination of 2 or more types. However, the average particle size is preferably in the range of 0.1 μm or more and 10 μm or less, and those having the above chemical structure may be pulverized to make the particle sizes uniform. The amount added to the toner is desirably in the range of 0.05% by mass to 2.0% by mass, and more desirably in the range of 0.1% by mass to 1.5% by mass.

  To the toner used in the developing device 11, inorganic particles, organic particles, composite particles obtained by attaching inorganic particles to the organic particles, and the like may be added for the purpose of removing the deposits and deteriorated substances on the surface of the image carrier.

  Inorganic particles include silica, alumina, titania, zirconia, barium titanate, aluminum titanate, strontium titanate, magnesium titanate, zinc oxide, chromium oxide, cerium oxide, antimony oxide, tungsten oxide, tin oxide, tellurium oxide, Various inorganic oxides such as manganese oxide, boron oxide, silicon carbide, boron carbide, titanium carbide, silicon nitride, titanium nitride, and boron nitride, nitrides, borides, and the like are preferably used.

  In addition, the inorganic particles may be mixed with titanium coupling agents such as tetrabutyl titanate, tetraoctyl titanate, isopropyl triisostearoyl titanate, isopropyl tridecylbenzene sulfonyl titanate, bis (dioctyl pyrophosphate) oxyacetate titanate, γ- (2- Aminoethyl) aminopropyltrimethoxysilane, γ- (2-aminoethyl) aminopropylmethyldimethoxysilane, γ-methacryloxypropyltrimethoxysilane, N-β- (N-vinylbenzylaminoethyl) γ-aminopropyltrimethoxy Silane hydrochloride, hexamethyldisilazane, methyltrimethoxysilane, butyltrimethoxysilane, isobutyltrimethoxysilane, hexyltrimethoxysilane, octyltrimethoxysilane The treatment may be performed with a silane coupling agent such as run, decyltrimethoxysilane, dodecyltrimethoxysilane, phenyltrimethoxysilane, o-methylphenyltrimethoxysilane, and p-methylphenyltrimethoxysilane. In addition, those hydrophobized with higher fatty acid metal salts such as silicone oil, aluminum stearate, zinc stearate, calcium stearate and the like are also desirably used.

  Examples of the organic particles include styrene resin particles, styrene acrylic resin particles, polyester resin particles, and urethane resin particles.

  The particle diameter is preferably 5 nm to 1000 nm, more preferably 5 nm to 800 nm, and even more preferably 5 nm to 700 nm in terms of number average particle diameter. Moreover, it is desirable that the sum of the addition amounts of the above-described particles and the lubricating particles is 0.6% by mass or more.

  As the other inorganic oxide added to the toner, it is desirable to use a small-diameter inorganic oxide having a primary particle size of 40 nm or less, and further add a larger-diameter inorganic oxide. Known inorganic oxide particles are used, but it is desirable to use silica and titanium oxide in combination.

  Moreover, it is preferable to surface-treat about small diameter inorganic particles. Furthermore, it is also desirable to add carbonates such as calcium carbonate and magnesium carbonate and inorganic minerals such as hydrotalcite.

  In addition, the color toner for electrophotography is used by mixing with a carrier. As the carrier, iron powder, glass beads, ferrite powder, nickel powder, or those coated with a resin are used. The mixing ratio with the carrier is set.

  As the transfer device 40, for example, a contact transfer charger using a belt, a roller, a film, a rubber blade, etc., or a known transfer charger such as a scorotron transfer charger using a corona discharge or a corotron transfer charger. Can be mentioned.

  As the intermediate transfer member 50, a belt-like member (intermediate transfer belt) made of polyimide, polyamideimide, polycarbonate, polyarylate, polyester, rubber or the like having semiconductivity is used. Further, as the form of the intermediate transfer member 50, a drum-like one is used in addition to the belt shape.

  In addition to the above-described devices, the image forming apparatus 100 may include, for example, an optical static elimination device that performs optical static elimination on the image carrier 7.

In the image forming apparatus (process cartridge) according to the present embodiment, the developing device (developing unit) is a developer holding member that moves (rotates) in the opposite direction to the moving direction (rotating direction) of the image holding member. It is desirable to have a certain developing roller. Here, the developing roller has a cylindrical developing sleeve that holds developer on the surface, and the developing device has a configuration that includes a regulating member that regulates the amount of developer supplied to the developing sleeve. Can be mentioned. By moving (rotating) the developing roller of the developing device in a direction opposite to the rotation direction of the image holding member, the surface of the image holding member is rubbed with toner remaining in a region sandwiched between the developing roller and the image holding member. . And this rubbing, at least one selected from a guanamine compound (compound represented by the general formula (A)) and a melamine compound (compound represented by the general formula (B)) and a specific charge transporting material (particularly As described above, the discharge product adhered to the surface of the image carrier (especially, the deposit removal property enhanced by the cross-linked product with a material capable of obtaining a cured film having a high cross-linking density by increasing the number of reactive functional groups) It is considered that the scraping property of the low resistance substance due to ozone and NOx is improved, and the deposition of the discharge product is suppressed for a very long time. As a result, the occurrence of image quality defects peculiar to a highly wear-resistant image carrier such as resolution reduction, streaks, and image blurring is suppressed, and it is presumed that higher image quality and longer life have been achieved at a higher level. Moreover, it is considered that excellent slipperiness of the surface of the image carrier is maintained for a long time by suppressing the accumulation of discharge products. As a result, the cleaning blade can be prevented from turning over or generating abnormal noise, and a high level of cleaning performance can be maintained for a long time.
In the image forming apparatus of the present embodiment, the distance between the developing sleeve and the image carrier is preferably 200 μm or more and 600 μm or less, and more preferably 300 μm or more, from the viewpoint of suppressing the accumulation of discharge products over a longer period. More preferably, it is 500 μm or less. From the same viewpoint, the distance between the developing sleeve and the regulating blade, which is a regulating member that regulates the developer amount, is desirably 300 μm or more and 1000 μm or less, and more desirably 400 μm or more and 750 μm or less.
Furthermore, from the viewpoint of suppressing the accumulation of discharge products over a longer period, the absolute value of the moving speed of the developing roll surface is 1.5 times or more the absolute value (process speed) of the moving speed of the image carrier surface. It is desirable that the ratio be not more than 5 times, and it is more desirable that the ratio be not less than 1.7 times and not more than 2.0 times.

  Further, in the image forming apparatus (process cartridge) according to the present embodiment, the developing device (developing unit) includes a developer holding body having a magnetic material, and is a two-component developer containing a magnetic carrier and toner. It is desirable to develop an image.

Hereinafter, the present invention will be described more specifically with reference to examples, but the present invention is not limited thereto. Examples 1, 7 and 8 shown below are shown as reference examples for the present invention.

<Guanamine resin-A1 (AG-1)>
(A) A superbecamine (R) L-148-55 having a structure of -15 (butylated benzoguanamine resin: manufactured by Dainippon Ink Co., Ltd.) is dissolved in 500 parts by mass of toluene, and 400 ml of distilled water is used for each. And washed 4 times with water. The conductivity of the final wash water was 8 μS / cm. The solvent was distilled off from the solution under reduced pressure to obtain 250 parts by weight of a candy-like resin. This is designated as guanamine resin-A1. Here, the electrical conductivity was measured at room temperature (20 ° C.) using washing water with a direct conductivity meter (Conductivity Meter DS-12: manufactured by HORIBA, Ltd.).

<Melamine resin-A1 (AM-1)>
(U) 20SE60 (n-butylated melamine resin: manufactured by Mitsui Cytec Co., Ltd., solid content 60 mass%, solvent xylene / n-butanol) having the structure of (B) -3 is referred to as melamine resin-A1.

<Preparation of electrophotographic photoreceptor A>
An electrophotographic photoreceptor A was produced as follows.

(Preparation of undercoat layer)
Zinc oxide: (average particle diameter 70 nm: manufactured by Teica: specific surface area value 15 m ² / g) 100 parts by mass is stirred and mixed with 500 parts by mass of tetrahydrofuran, and a silane coupling agent (KBM503: manufactured by Shin-Etsu Chemical Co., Ltd.) 1.3 parts by mass Part was added and stirred for 2 hours. Thereafter, toluene was distilled off under reduced pressure and baked at 120 ° C. for 3 hours to obtain a silane coupling agent surface-treated zinc oxide.
110 parts by mass of the surface-treated zinc oxide was stirred and mixed with 500 parts by mass of tetrahydrofuran, a solution prepared by dissolving 0.6 parts by mass of alizarin in 50 parts by mass of tetrahydrofuran was added, and the mixture was stirred at 50 ° C. for 5 hours. did. Then, the zinc oxide to which alizarin was imparted by filtration under reduced pressure was filtered off, and further dried at 60 ° C. under reduced pressure to obtain alizarin imparted zinc oxide.

  60 parts by mass of this alizarin-provided zinc oxide and a curing agent (blocked isocyanate Sumijoule 3175, manufactured by Sumitomo Bayern Urethane Co., Ltd.): 13.5 parts by mass and 15 parts by mass of butyral resin (ESREC BM-1, manufactured by Sekisui Chemical Co., Ltd.) 38 parts by mass of the solution dissolved in 85 parts by mass and 25 parts by mass of methyl ethyl ketone were mixed, and dispersed for 2 hours with a sand mill using 1 mmφ glass beads to obtain a dispersion.

  Dioctyltin dilaurate: 0.005 parts by mass and silicone resin particles (Tospearl 145, manufactured by GE Toshiba Silicone): 40 parts by mass were added as catalysts to the resulting dispersion to obtain an undercoat layer coating solution. This coating solution was applied on an aluminum substrate having a diameter of 60 mm, a length of 357 mm, and a thickness of 1 mm by a dip coating method, followed by drying and curing at 170 ° C. for 40 minutes to obtain an undercoat layer having a thickness of 19 μm.

(Preparation of charge generation layer)
Bragg angles (2θ ± 0.2 °) of X-ray diffraction spectrum using Cukα characteristic X-ray as a charge generating material are at least 7.3 °, 16.0 °, 24.9 °, 28.0 ° A mixture consisting of 15 parts by mass of hydroxygallium phthalocyanine having a diffraction peak, 10 parts by mass of vinyl chloride / vinyl acetate copolymer resin (VMCH, manufactured by Nihon Unicar) as a binder resin, and 200 parts by mass of n-butyl acetate, The glass beads having a diameter of 1 mmφ were dispersed for 4 hours by a sand mill. To the obtained dispersion, 175 parts by mass of n-butyl acetate and 180 parts by mass of methyl ethyl ketone were added and stirred to obtain a coating solution for a charge generation layer. This charge generation layer coating solution was dip coated on the undercoat layer and dried at room temperature (25 ° C.) to form a charge generation layer having a thickness of 0.2 μm.

(Preparation of charge transport layer)
N, N′-diphenyl-N, N′-bis (3-methylphenyl)-[1,1 ′] biphenyl-4,4′-diamine 45 parts by mass and bisphenol Z polycarbonate resin (viscosity average molecular weight: 50,000) 55 parts by mass was added to 800 parts by mass of chlorobenzene and dissolved to obtain a charge transport layer coating solution. This coating solution was applied onto the charge generation layer and dried at 130 ° C. for 45 minutes to form a charge transport layer having a thickness of 20 μm.

(Preparation of surface layer)
Guanamin resin-A1 (AG-1): 19.8 parts by mass and 80 parts by mass of the compound represented by (I-8) above, 0.2 parts by mass of dodecylbenzenesulfonic acid, 8 parts by mass of 1-methoxy-2-propanol Was added to prepare a coating solution for the surface layer. This coating solution is applied onto the charge transport layer by a dip coating method, air-dried at room temperature (20 ° C.) for 30 minutes, and then cured by heating at 150 ° C. for 1 hour to form a surface layer having a thickness of 6 μm. Thus, a photoreceptor A was produced.

<Preparation of electrophotographic photoreceptor B>
Further, the photoconductor was prepared by the method described in the preparation of the electrophotographic photoconductor A, except that the compounding ratio of the compound represented by guanamine resin-A1 (AG-1) and the above (I-8) was changed as follows. B was produced.
Photoconductor B: 39.8 parts by mass of guanamine resin
60 parts by mass of the compound represented by (I-8)

<Preparation of electrophotographic photoreceptor C>
Melamine resin-A1 (AM-1): 2.8 parts by mass and 97 parts by mass of the compound represented by (I-16) above, 0.2 parts by mass of dodecylbenzenesulfonic acid, 1-methoxy-2-propanol 8 A coating solution for the surface layer was prepared by adding parts by mass. Photoreceptor C was produced by the method described in the production of electrophotographic photoreceptor A, except that the coating solution used for the production of the surface layer was changed to that described above.

<Preparation of electrophotographic photoreceptor D>
Melamine resin-A1 (AM-1): 9.8 parts by mass and 90 parts by mass of the compound represented by (I-16) above, 0.2 parts by mass of dodecylbenzenesulfonic acid, 1-methoxy-2-propanol 8 A coating solution for the surface layer was prepared by adding parts by mass. Photoreceptor D was produced by the method described in Production of electrophotographic photoreceptor A, except that the coating solution used for producing the surface layer was changed to the above.

<Preparation of electrophotographic photoreceptor E>
In addition, guanamine resin-A1 (AG-1): 19.8 parts by mass and 80 parts by mass of the compound represented by the above (I-13), 0.2 part by mass of dodecylbenzenesulfonic acid, 1-methoxy-2-propanol 8 A coating solution for the surface layer was prepared by adding parts by mass. Photoreceptor E was produced by the method described in the production of electrophotographic photoreceptor A, except that the coating solution used for the production of the surface layer was changed to that described above.

<Preparation of electrophotographic photoreceptor F>
Guanamine resin-A1 (AG-1): 19.8 parts by mass and 80 parts by mass of the compound represented by (I-14) above, 0.2 parts by mass of dodecylbenzenesulfonic acid, 1-methoxy-2-propanol 8 A coating solution for the surface layer was prepared by adding parts by mass. Photoreceptor F was produced by the method described in the production of electrophotographic photoreceptor A, except that the coating solution used for the production of the surface layer was changed to that described above.

[Examples 1-8 and Comparative Examples 1-2]
An image forming apparatus (having the configuration shown in FIG. 4) Docu Center C75550 I manufactured by FUJI XEROX was used as an image carrier as a photoreceptor (photoreceptors A to F) shown in Table 1 below. Further, by changing the initial load of the zinc stearate bar, the “zinc coverage on the surface of the image carrier” was controlled to the values shown in Table 1 below.
The following evaluation tests were conducted using this image forming apparatus.

-Image density-
The initial image density at high temperature and high humidity (28 ° C., 80% RH) and low temperature and low humidity (10 ° C., 20% RH) was measured by the following method.
An image of 100% Cin was output, and the image density D was measured with a spectral densitometer (X-Rite 938). The evaluation criteria are as follows. The evaluation results are shown in Table 1.
○: D ≧ 1.2
X: D <1.2

-Image unevenness-
Further, the degree of occurrence of image unevenness immediately after output of 5000 sheets and image unevenness after leaving for 8 hours was determined by sensory evaluation according to the following evaluation criteria. The evaluation results are shown in Table 1.
・ Image immediately after outputting 5000 sheets:
◎ No density unevenness at the image carrier pitch ○ Very slight density unevenness at the image carrier pitch (no problem in actual use)
× Density unevenness at the image carrier pitch (problems in actual use)
・ Image after leaving for 8 hours:
◎ No density unevenness at the image carrier pitch ○ Very slight density unevenness at the image carrier pitch (no problem in actual use)
× Density unevenness at the image carrier pitch (problems in actual use)

It is a schematic fragmentary sectional view which shows the image holding body which concerns on embodiment. It is a schematic fragmentary sectional view which shows the image holding body which concerns on embodiment. It is a schematic fragmentary sectional view which shows the image holding body which concerns on embodiment. 1 is a schematic configuration diagram illustrating an image forming apparatus according to an embodiment. FIG. 3 is a schematic enlarged cross-sectional view showing a state where the cleaning blade is in contact with the surface of the image carrier.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Undercoat layer 2 Charge generation layer 3 Charge transport layer 4 Conductive substrate 5 Surface layer 6 Single layer type photosensitive layer 7 Image holding body 8 Charging device 9 Exposure device 11 Development device 13 Cleaning device 14 Zinc stearate bar (lubricant)
21 Image holding member 22 Cleaning blade 23 Holding member 40 Transfer device 50 Intermediate transfer member 100 Image forming device 132 Fibrous member (roll shape)

Claims (2)

A photosensitive layer, and at least one selected from a guanamine compound and a melamine compound and a substituent selected from —OH, —OCH ₃ , —NH ₂ , —SH, and —COOH on the substrate in this order from the substrate side A surface layer containing at least one charge transport material having at least one and containing 80% by mass or more of the charge transport material constituting the cross-linked material with respect to the total solid content in the layer; And an image carrier in which a lubricant is applied on the surface layer,
Charging means for charging the image carrier;
Latent image forming means for forming an electrostatic latent image on the charged image carrier;
Developing means for developing the electrostatic latent image formed on the image carrier with toner to form a toner image;
Transfer means for transferring the toner image to a transfer object ,
The lubricant is zinc stearate;
An image forming apparatus in which the zinc coverage on the surface of the image carrier is in the range of the following formula (1) .
Formula (1) 60% ≦ Zinc coverage by XPS analysis ≦ 100% A photosensitive layer, and at least one selected from a guanamine compound and a melamine compound and a substituent selected from —OH, —OCH ₃ , —NH ₂ , —SH, and —COOH on the substrate in this order from the substrate side A surface layer containing at least one charge transport material having at least one and containing 80% by mass or more of the charge transport material constituting the cross-linked material with respect to the total solid content in the layer; And at least an image carrier provided with a lubricant on the surface layer ,
The lubricant is zinc stearate;
A process cartridge in which the zinc coverage on the surface of the image carrier is in the range of the following formula (1)
Formula (1) 60% ≦ Zinc coverage by XPS analysis ≦ 100%