JP2001142246A - Electrophotographic image forming method and electrophotographic image forming device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an electrophotographic image forming method and an electrophotographic image forming device in which cleaning performance is retained over a long period of time, image defects are not caused and the service life of a cleaning blade is prolonged. SOLUTION: In the electrophotographic image forming method including at least a step for developing an electrostatic charge image on an electrophotographic photoreceptor with a toner-containing a developer and a step for removing the toner on the photoreceptor by blade cleaning, the surface roughness of the photoreceptor in 15 mm standard length is in the range of 0.01-2.5 μm as ten-point average roughness Rz and the fixing ratio Fd of an additive on the toner matrix represented by equation 1 is 10-90%. Equation 1 Fd=[1- Sw1-Sw2)/Sw3}]×100 Sw1: the specific surface area (m2/g) of the toner fixed with the additive Sw2: the specific surface area (m2/g) of the toner untreated with the additive Sw3: the specific surface area (m2/g) of the additive.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an electrophotographic image forming method and an electrophotographic image forming apparatus using the image forming method.

[0002]

2. Description of the Related Art In recent years, the Carlson method is often used in electrophotographic image forming methods. Generally, in the electrophotographic image forming method of the Carlson method, after the photosensitive member is uniformly charged, the charge is erased imagewise by exposure,
An electrostatic latent image is formed. Next, after being transferred to paper or the like, the photoreceptor is subjected to a process in which the toner remaining on the photoreceptor is removed by blade cleaning or the like.

As described above, the electrophotographic photosensitive member and the cleaning blade are always in contact with each other, and the surfaces thereof are subjected to a mechanical external force. Therefore, both the photosensitive member and the cleaning blade have been required to have durability. Especially for photoreceptors,
As to the durability against scratches and film peeling due to abrasion and scratches on the surface of the photoreceptor due to rubbing, mixing of foreign matters, and impact during paper jam processing, a strength as high as that of the inorganic photoreceptor is strongly required. In addition, a cleaning blade that is always in contact with the photoconductor has been required to maintain toner cleaning properties for a long period of time without causing toner to pass through or fusing the toner to the surface of the photoconductor (toner filming).

[0004] In order to satisfy the various characteristics required as described above, various studies have been made so far.

For example, with regard to the mechanical durability of the photoreceptor, by using bisphenol Z-type polycarbonate as a binder (binder resin) on the surface of the organic photoreceptor, the surface abrasion characteristics and toner filming characteristics are improved. It has been reported. Also, with respect to the cleaning blade, an attempt has been made to improve the durability by using polyurethane as the material of the cleaning blade and optimizing the hardness, the rebound resilience, and the like.

However, a photoreceptor using a bisphenol Z-type polycarbonate binder still lacks abrasion resistance and does not have sufficient durability. In addition, when used in combination with a cleaning blade made of polyurethane or the like, the edge of the cleaning blade is worn by friction with the photoreceptor or the toner due to repeated use for a long period of time, and a cleaning defect occurs in which the toner slips through the cleaning blade. This cleaning failure tends to occur particularly in a high-temperature and high-humidity environment, and the wear of the cleaning blade has determined the blade life. In addition, in the image forming method in which the toner is recycled, the external additive on the toner surface is buried or detached, so that the transfer efficiency of the toner is reduced. As a result, there has been a defect that image defects such as white spots and the like, and that toner filming on the photosensitive member occurs. For this reason, there has been a demand for an electrophotographic image forming method capable of not only having a highly durable photoreceptor but also having a cleaning failure for a long time and a long durability of a cleaning blade.

[0007]

SUMMARY OF THE INVENTION An object of the present invention is to solve the above-mentioned problems and maintain cleaning performance for a long period of time.
An electrophotographic image forming method and an electrophotographic image forming apparatus which are free from image defects and can prolong the service life of a cleaning blade. An electrophotograph which does not cause image defects even in an electrophotographic image forming method in which toner is recycled. An object of the present invention is to provide an image forming method and an electrophotographic image forming apparatus.

[0008]

The object of the present invention is achieved by the following constitution.

1. An electrophotographic image forming method comprising: a step of developing at least an electrostatic charge image on the electrophotographic photosensitive member with a developer containing a toner; and a step of cleaning the toner on the electrophotographic photosensitive member using blade cleaning. The surface roughness of the electrophotographic photosensitive member at a reference length of 15 mm is 0.01 to 2.5 μm as a ten-point average roughness Rz.
Wherein the external additive fixing rate Fd with respect to the toner matrix represented by the following formula (1) is 10 to 90%. Formula (1) External additive fixation rate Fd = [1-｛(Sw ₁ -Sw ₂ ) / S
_{w 3}] × 100 Sw 1} : BET specific surface area of the toner external additive was immobilized _{^{(m 2 / g) Sw 2}} : external additive untreated BET specific surface area of toner (m ² /
g) Sw ₃ : BET specific surface area of external additive (m ² / g).

[0010] 2. The ten-point average roughness Rz is 0.2-1.
2. The electrophotographic image forming method according to the above item 1, wherein the thickness is within a range of 5 μm.

3. 3. The electrophotographic image forming method according to the above 1 or 2, wherein the surface layer of the electrophotographic photosensitive member contains a siloxane-based resin having a crosslinked structure.

4. 4. The electrophotographic image forming method according to any one of the above items 1 to 3, wherein the surface layer of the electrophotographic photoreceptor contains a siloxane-based resin having a structural unit having charge transport performance.

5. Any one of the above items 1 to 4, wherein the layer constitution of the electrophotographic photosensitive member is an intermediate layer, a photosensitive layer, and a surface layer containing a siloxane-based resin having the crosslinked structure on a conductive support in this order. 2. The electrophotographic image forming method according to claim 1.

6. 6. The electrophotographic image forming apparatus according to any one of 1 to 5 above, wherein the toner has a saturated water content in an environment of 30 ° C. and 80 RH% within a range of 0.1 to 2.0% by mass. Method.

[0015] 7. Developing at least an electrostatic charge image on the electrophotographic photoreceptor with a developer containing toner, cleaning the electrophotographic photoreceptor using blade cleaning, and developing the toner collected in the cleaning step. In an electrophotographic image forming method having a toner recycling step of returning to a developer for reuse, the surface roughness of the electrophotographic photosensitive member at a reference length of 15 mm is 0.01 to 2.5 μm as a ten-point average roughness Rz. Wherein the external additive fixing rate Fd with respect to the toner matrix represented by the formula (1) is 10 to 90%.

8. In an electrophotographic image forming apparatus having at least means for developing an electrostatic image on an electrophotographic photosensitive member with a developer containing toner, and means for cleaning the toner on the electrophotographic photosensitive member using blade cleaning, The surface roughness of the electrophotographic photosensitive member at a reference length of 15 mm is 0.01 to 2.5 μm as a ten-point average roughness Rz.
Wherein the external additive fixing rate Fd with respect to the toner matrix represented by the formula (1) is 10 to 90%.

9. Means for developing at least an electrostatic charge image on the electrophotographic photosensitive member with a developer containing toner, means for cleaning the electrophotographic photosensitive member using blade cleaning, and means for developing the toner collected by the cleaning means In an electrophotographic image forming apparatus having a toner recycling unit for returning to a developer and reusing the same, the surface roughness of the electrophotographic photosensitive member at a reference length of 15 mm is 0.01 to 2.5 μm as a ten-point average roughness Rz. Wherein the external additive fixing rate Fd with respect to the toner matrix represented by the formula (1) is 10 to 90%.

The present inventors control the surface roughness of the photoreceptor; the ten-point average roughness Rz within the range of 0.01 to 2.5 μm, and furthermore, the ratio Fd of the external additive fixed on the toner resin surface. 1
It has been found that by keeping the content within the appropriate range of 0 to 90%, good cleaning properties over a long period of time can be obtained, and the durability of the cleaning blade can be extended without impairing the image quality or the durability of the photosensitive member.

The surface roughness of the photoreceptor greatly affects the area to which the toner adheres, and hence the scraping force for cleaning the toner. Surface roughness; ten-point average roughness Rz is 0.01
If it is smaller, the contact area with the cleaning blade becomes large, the blade is easily turned over, and the long-term cleaning stability cannot be obtained. Also, Rz is 2.5
Even if it exceeds, toner filming is likely to occur, which is not suitable for long-term use.

Further, in order to stabilize the cleaning property of the toner, it is necessary to develop a technique for reducing the van der Waals force between the toner and the photosensitive member to facilitate the cleaning. This is achieved by fixing an external additive on the surface of the toner resin and forming a minute space between the external additive and the photosensitive member. That is, the external additive fixation rate on the toner resin surface is 10 to 9
By setting it to 0%, the toner can be more stably cleaned from the surface of the photoconductor. Here, if the amount of the external additive fixed exceeds 90, the amount of the external additive on the toner resin surface becomes excessive, and as a result, aggregation between toners occurs, making cleaning difficult. If the amount of the external additive fixed on the surface of the toner resin is less than 10%, the external additive is liable to be detached, and a stable cleaning property can be obtained in an image forming method for long-term repeated use or toner recycling. Can not. Therefore, the surface roughness of the photoreceptor and the fixation rate of the external additive fixed on the surface of the used toner resin are set to 10 to 10%.
By adjusting the ratio to 90%, more preferably 40 to 90%, it becomes possible to form an electrophotographic image that can simultaneously satisfy long-term cleaning properties, image quality, photoreceptor durability, and blade durability.

In particular, in an image forming method in which toner used once for forming an image is collected in a cleaning step and the toner is recycled for reuse, the surface roughness of the photoreceptor and the appropriateness of the fixation rate of the external additive of the toner are determined. Modification has a remarkable effect on the long-term stability of performance such as the cleaning property and image quality.

<< Method of Controlling Surface Roughness of Photoconductor; Ten-Point Average Roughness Rz Within a Range of 0.01 to 2.5 μm >> 01-2.5
As a method of controlling the thickness within the range of μm, it is effective to appropriately reduce the surface roughness of the conductive support constituting the photosensitive member.

The material of the conductive support used in the present invention is mainly aluminum, copper, brass, steel,
A belt-shaped or drum-shaped metal material such as stainless steel or another plastic material is used. Among them, aluminum excellent in cost, workability and the like is preferably used, and a thin-walled cylindrical aluminum tube usually formed by extrusion or drawing is often used.

The conductive support used in the present invention preferably has a roughened surface having a ten-point average surface roughness Rz of more than 0.01 μm and not more than 2.5 μm. More preferably, it is 0.2 μm or more and 1.5 μm or less. The surface roughness can be adjusted by coating an intermediate layer or a photosensitive layer described below on a support having such a surface roughness.

As described above, the method of roughening the surface of the support includes a method of shaving the surface of the support with a cutting tool or the like, and a method of colliding fine particles with the surface of the support.
Sand blasting method, processing method using an ice particle cleaning apparatus described in JP-A-4-204538, JP-A-9-204538
There is a honing method described in 236937.
Also, an anodizing method, an alumite treatment method, a buffing method, a method using a laser ablation method described in JP-A-4-233546, a method using a polishing tape described in JP-A-8-1502, No.-1510, a method of roller burnishing, and the like. However, the method of roughening the surface of the support is not limited thereto.

As another method of roughening the surface of the photoconductor, a method of adding fine particles of 0.1 to 5 μm to the surface layer of the photoconductor can be considered. For example, the surface roughness of the photoreceptor can be adjusted to the above range by dispersing the inorganic fine particles subjected to the hydrophobizing treatment in the surface layer of the photoreceptor as described in JP-A-8-248663. is there. As a method of hydrophobizing the inorganic fine particles, a method of treating with a hydrophobizing agent such as a titanium coupling agent, a silane coupling agent, a polymer fatty acid or a metal salt thereof can be used.

Definition and Measurement Method of Ten-Point Average The ten-point average surface roughness Rz is the length L (15 in the present invention).
mm) is the difference between the average height of the five peaks and the average height of the five valleys.

In the present invention, the ten-point average roughness Rz is measured by using a surface roughness meter (Surforder SE- manufactured by Kosaka Laboratory Co., Ltd.).
30H). However, any other measuring device that produces the same result within the error range may be used.

<< Toner having an external additive fixation rate Fd of 10 to 90% >> Next, the toner used in the present invention has an external additive fixation rate Fd of 10 to 9 with respect to the toner matrix represented by the following formula (1).
0%. Formula (1) External additive fixation rate Fd = [1-｛(Sw ₁ -Sw ₂ ) / S
_{w 3}] × 100 Sw 1} : BET specific surface area of the toner external additive was immobilized _{^{(m 2 / g) Sw 2}} : external additive untreated BET specific surface area of toner (m ² /
g) Sw ₃ : BET specific surface area of external additive (m ² / g). The above toner can be produced by the method described below.

The toner used in the present invention is formed into colored particles (also referred to as a toner base or a toner not treated with an external additive) containing a binder resin, a colorant, and, if necessary, other additives. This is a toner in which external additive fine particles are externally added and fixed.

The external additives used in the present invention are roughly classified into inorganic fine particles and organic fine particles. The particle diameter of these fine particles is 1 to 2000 nm in number average particle diameter,
nm is preferably used. When the number average particle diameter of the external additive is larger than 2000 nm, the external additive is likely to be detached from the toner, and when it is smaller than 1 nm, the effect of the external additive as a fluidity improving agent is small.

As the inorganic fine particles, various inorganic oxides, nitrides, borides and the like are preferably used. For example,
Silica, alumina, titania, zirconia, barium titanate, aluminum titanate, strontium titanate, magnesium titanate, cerium oxide, zinc oxide,
Examples thereof include chromium oxide, cerium oxide, antimony oxide, tungsten oxide, tin oxide, tellurium oxide, manganese oxide, boron oxide, silicon carbide, boron carbide, titanium carbide, silicon nitride, titanium nitride, and boron nitride.

Further, the above-mentioned inorganic fine particles may be subjected to a hydrophobic treatment. When performing the hydrophobizing treatment, it is preferable to perform hydrophobizing treatment with a so-called coupling agent such as various titanium coupling agents and silane coupling agents, and further, higher fatty acids such as aluminum stearate, zinc stearate, and calcium stearate. Those subjected to a hydrophobic treatment with a metal salt are also preferably used.

On the other hand, the composition of the organic fine particles is not particularly limited. Generally, vinyl-based organic fine particles are preferable. The reason for this is that it can be easily produced by a production method such as an emulsion polymerization method or a suspension polymerization method. Specifically, styrene, o-methylstyrene, m-methylstyrene, p-methylstyrene, α
-Methylstyrene, p-chlorostyrene, 3,4-dichlorostyrene, p-phenylstyrene, p-ethylstyrene, 2,4-dimethylstyrene, pt-butylstyrene, pn-hexylstyrene, p- Styrene or styrene derivatives such as n-octylstyrene, pn-nonylstyrene, pn-decylstyrene, pn-dodecylstyrene, methyl methacrylate, ethyl methacrylate, n-butyl methacrylate, isopropyl methacrylate Methacrylic acid such as isobutyl methacrylate, t-butyl methacrylate, n-octyl methacrylate, 2-ethylhexyl methacrylate, stearyl methacrylate, lauryl methacrylate, phenyl methacrylate, diethylaminoethyl methacrylate, and dimethylaminoethyl methacrylate Ter derivatives, methyl acrylate, ethyl acrylate, isopropyl acrylate, n-butyl acrylate, t-butyl acrylate, isobutyl acrylate, n-octyl acrylate, 2-ethylhexyl acrylate, stearyl acrylate, lauryl acrylate Acrylic ester derivatives such as phenyl acrylate, dimethylaminoethyl acrylate, diethylaminoethyl acrylate, and the like can be cited as materials constituting the organic fine particles. These can be used alone or in combination.

Further, other materials for composing the vinyl resin fine particles include olefins such as ethylene / propylene / isobutylene; halogen-based vinyls such as vinyl chloride / vinylidene chloride / vinyl bromide / vinyl fluoride; Vinyl esters such as vinyl propionate / vinyl acetate / vinyl benzoate; vinyl ethers such as vinyl methyl ether / vinyl ethyl ether; vinyl ketones such as vinyl methyl ketone / vinyl ethyl ketone / vinyl hexyl ketone; N-vinyl carbazole / N -N-vinyl compounds such as vinylindole and N-vinylpyrrolidone; vinyl compounds such as vinylnaphthalene and vinylpyridine; acrylonitrile / methacrylonitrile / acrylamide / N-butylacrylamide / N, N-dibutylacrylamide Is acrylic acid or methacrylic acid derivatives such as methacrylamide · N-butyl methacrylamide · N-octadecyl acrylamide. These vinyl monomers can be used alone or in combination.

Further, the resin fine particles need to be stable even when a developer is used for a long period of time. For this purpose, it is preferable that the resin fine particles themselves are cross-linked by various cross-linking agents and used as a material having high hardness. Examples of the crosslinking agent include divinylbenzene / ethylene glycol diacrylate / diethylene glycol diacrylate / triethylene glycol diacrylate / ethylene glycol dimethacrylate / diethylene glycol dimethacrylate / triethylene glycol dimethacrylate. The amount of the crosslinking agent used is appropriately adjusted depending on the required degree of crosslinking, and is preferably used in an amount of 0.1 to 5% by mass based on the vinyl monomer. If the amount of the cross-linking agent is excessive, the hardness increases, but the brittleness becomes brittle, and on the contrary, there is a problem that the durability decreases. If the amount of the cross-linking agent is too small, the effect of the cross-linking agent cannot be exerted.

The resin fine particles can be produced by an emulsion polymerization method or a suspension polymerization method. The emulsion polymerization method is a method in which the above-mentioned monomer is added to water containing a surfactant and emulsified, followed by polymerization. As the surfactant, sodium dodecylbenzenesulfonate, polyvinyl alcohol, an ethylene oxide adduct, Any substance that is used as a surfactant such as alcohol sodium sulfate can be used and is not particularly limited. Further, the use of a reactive emulsifier, a hydrophilic monomer, for example, polymerization with a persulfate initiator such as vinyl acetate or methyl acrylate, a method of copolymerizing a water-soluble monomer, a water-soluble resin, So-called non-emulsion polymerization methods such as a method using an oligomer, a method using a decomposable emulsifier, and a method using a cross-linkable emulsifier are also suitable. Examples of the reactive emulsifier include sulfonic acid salts of acrylic acid amide and salts of maleic acid derivatives. The non-emulsion polymerization method is not affected by the residual emulsifier, and is suitable when organic fine particles are used alone.

Polymerization initiators required for synthesizing resin fine particles include peroxides such as benzoyl peroxide and lauryl peroxide, and azo-based polymerization initiators such as azobisisobutyronitrile and azobisisovaleronitrile. Agents. The addition amount of these is preferably 0.1 to 2% by mass based on the monomer. If the amount is less than this, the polymerization reaction becomes insufficient, and the problem of residual monomer itself occurs. Further, when the amount is too large, a decomposition product of the polymerization initiator remains and affects the chargeability, and furthermore, the polymerization reaction is too early to cause a problem that the molecular weight becomes small. Further, in an emulsion polymerization method or the like, potassium persulfate, sodium thiosulfate, or the like can be used as a polymerization initiator.

The above-mentioned inorganic fine particles and organic fine particles may be used in combination. The addition amount of the fine particles is preferably about 0.1 to 5.0% by mass based on the toner. If the addition amount is too small, the effect of improving the fluidity is small. If the addition amount is too large, there is a possibility that scratches on the photoreceptor due to release of the added fine particles and a problem of poor conveyance of the developer may occur.

Further, depending on the purpose, two or more kinds of external additives may be used simultaneously. The method for measuring the number average particle diameter of the fine particles was observed using a transmission electron microscope, and displayed using a value measured by image analysis.

In the present invention, as a method of fixing the fine particles to the toner surface, it is preferable to stir and mix the toner and the external additive and to uniformly fix the external additive to the toner surface while applying a mechanical impact force. . As a specific mixing device,
A Henschel mixer, a V-type mixer, a Lodige mixer, a Nauter mixer, a W cone mixer, a vibratory mill and the like can be used. Above all, the Henschel mixer can be suitably used in view of the fact that the mixing and fixing of the external additives can be performed by the same apparatus, and that the mixing and stirring can be easily performed and the external heating can be easily performed.

As the mixing conditions at the time of the above-mentioned fixing treatment, it is desirable that the stirring is performed at a peripheral speed of the tip of the stirring blade of 5 to 50 m / s. More preferably, 10 to 40 m / s
Is desirably processed. In addition, if necessary in the fixing process, the temperature may be adjusted to a required temperature from outside using hot water or the like.

The method for measuring the temperature is to measure the temperature of the portion where the toner flows while the toner is being stirred and mixed. Further, it is preferable that cold water is circulated after the fixing treatment to perform the cooling and crushing steps.

As a method of controlling the degree of immobilization of the fine particles on the surface of the colored particles, the colored particles and the fine particles are stirred and mixed under a temperature condition of Tg−20 ≦ (stirring / mixing temperature) ≦ Tg + 20 to reduce the mechanical impact force. By adjusting the time during the application, the fine particle external additive can be uniformly attached to the surface of the colored particles.

As used herein, Tg refers to the glass transition temperature of the toner or the binder resin constituting the toner. The glass transition temperature was measured using a DSC7 differential scanning calorimeter (manufactured by PerkinElmer). Measurement method is 10 ° C
/ Min at 0 ° C to 200 ° C, then 10 ° C
After cooling from 200 ° C. to 0 ° C. at / min to eliminate the previous history, the temperature was raised from 0 ° C. to 200 ° C. at 10 ° C./min, and the endothermic peak temperature of the second heat was determined and defined as Tg. When there were a plurality of endothermic peaks, the temperature of the main endothermic peak was defined as Tg.

The Tg of the toner or the binder resin constituting the toner is preferably from 40 to 70 ° C. 40
If the temperature is lower than ℃, the storage stability of the toner is poor and the toner is aggregated. If it is higher than 70 ° C., it is not preferable from the viewpoint of fixing property and productivity.

The toner of the present invention preferably has a saturated water content in an environment of 30 ° C. and 80 RH% within a range of 0.1 to 2.0% by weight. The water content of the toner can be sufficiently dried at the same time as the fixation of the fine particles by heating the toner near the Tg in the step of fixing the fine particle external additive. 30 ° C, 80
In order to reduce the hygroscopicity of the toner under high-temperature and high-humidity conditions such as RH% environment, saturation is achieved by using a surface-treated external additive having low hygroscopicity or resin fine particles. It is effective to control the amount of water. The saturated water content in an environment of 30 ° C. and 80 RH% is set to 0.1.
To reduce it to less than 1% by weight would be too costly. On the other hand, if it exceeds 2.0% by weight, the storage stability of the toner is poor and the toner is aggregated.

The water content is measured by the Karl Fischer method. In the present invention, the water content is measured using a Hiranuma automatic trace moisture analyzer AQS-724. The measurement conditions in the present invention were a vaporization temperature of 110 ° C. and a vaporization time of 25 seconds.

The toner used in the present invention has a volume average particle diameter of usually 1 to 30 μm, preferably 5 to 1 μm.
5 μm.

The binder resin constituting the colored particles is not particularly limited, and various conventionally known resins can be used. For example, a styrene resin, an acrylic resin, a styrene / acrylic resin, a polyester resin, and the like can be given. Here, the glass transition temperature of the resin is 45 to 70 ° C., preferably 52 to 65 ° C., for improving the fixing property and the blocking property.
° C. When this temperature is low, the fine particles are fixed well, but the blocking property is reduced, and the so-called aggregation inside the developing device and the problem of fusion of the toner to the carrier occur. On the other hand, when the glass transition temperature is high, the problem of blocking does not occur, but the problem that the adhesiveness to paper is reduced and the fixability is reduced is generated.

The coloring agent is not particularly limited, and known coloring agents can be used. For example, carbon black / nigrosine dye or the like can be preferably used.

In the case of a one-component toner, magnetic fine particles such as magnetite may be used as a coloring agent.

Examples of other additives include charge control agents such as salicylic acid derivatives and azo metal complexes, and fixability improvers such as low molecular weight polyolefin and carnauba wax.

When the toner of the present invention is used as a two-component developer, the toner and a carrier are required. As the carrier, magnetic particles having a volume average particle diameter of 20 to 200 μm, preferably 30 to 100 μm are used. Used.

The monomers constituting the olefin resin include ethylene, propylene, 1-butene, isobutylene, 1-octene, 1-pentene, 2-methyl-1-butene, 1-hexene, 1-nonene, -Aliphatic unsaturated hydrocarbon monomers such as decene are preferred. Further, resins or copolymers obtained from other vinyl monomers can also be used. Preferably, polyethylene using ethylene as a monomer is good. Ferrite, magnetite, iron powder, and the like can be given as materials for these magnetic materials.

The surface of the carrier used in the present invention is preferably coated with a resin capable of forming a low surface energy layer. For example, a carrier coated with a silicone resin, a fluorine resin, or a polyolefin resin is preferable.
The coating amount is 1 to 20% by mass, preferably 2.5 to 8% by mass based on the magnetic particles. If the amount is less than 1% by mass, a uniform film of the coating layer may not be formed, and the excellent characteristics of the resin-coated carrier may not be exhibited. Also, 20
If the amount is more than 10% by mass, the film thickness becomes too large, the fluidity of the carrier is deteriorated, the charging rise is deteriorated, and fog and toner scattering may occur.

The method for producing the carrier used in the present invention includes various generally known coating methods, for example, a method of dissolving a polyolefin in an appropriate solvent and spray-coating the surface of the magnetic particles, A method of mechanically fixing a resin material while adhering a polyolefin powder to the resin material while heating the resin material to a temperature equal to or higher than the melting point if necessary.
Any of the surface polymerization coating method described in 106808 and the like may be used.

In order to effectively improve the long-term cleaning property, image quality, photoreceptor durability and blade durability of the present invention, the surface layer of the electrophotographic photoreceptor used in the present invention has a crosslinked structure. It becomes more remarkable by forming a layer containing a siloxane-based resin having The surface layer containing a siloxane-based resin having a cross-linked structure as a main component has a high surface hardness and excellent elasticity. Therefore, even if a toner to which a relatively large amount of the external additive is fixed as described above is used, the blade can be used. Less photoreceptor surface shaving due to cleaning
The surface shape formed after application and drying of the electrophotographic photoreceptor surface layer is maintained for a long time, and stable cleaning properties are maintained for a long time.

A photoreceptor having a surface layer containing a siloxane-based resin having a crosslinked structure can be formed by the method described below.

<< Photoreceptor Having Surface Layer Containing Siloxane Resin >> The surface layer containing siloxane resin is typically a coating composition using an organosilicon compound represented by the following general formula (1) as a raw material. Is formed by coating and drying. These raw materials form a condensate (oligomer) of an organosilicon compound in a hydrophilic solvent by hydrolysis and a subsequent condensation reaction. By coating and drying these coating compositions, a resin layer containing a siloxane-based resin having a three-dimensional network structure can be formed.

Formula (1) (R) _n -Si- (X) _{4-n In the} formula, R represents an organic group in which carbon is directly bonded to a silicon atom, and X represents a hydroxyl group or a hydrolyzable group. And n is 0 to
Represents an integer of 3.

In the organosilicon compound represented by the general formula (1), examples of the organic group in which carbon represented by R is directly bonded to silicon include alkyl groups such as methyl, ethyl, propyl and butyl, phenyl and tolyl. , Naphthyl, aryl groups such as biphenyl, γ-glycidoxypropyl, β-
Epoxy-containing groups such as (3,4-epoxycyclohexyl) ethyl, (meth) acryloyl groups such as γ-acryloxypropyl and γ-methacryloxypropyl, γ-hydroxypropyl and 2,3-dihydroxypropyloxypropyl Hydroxyl groups, vinyl, vinyl-containing groups such as propenyl, mercapto-containing groups such as γ-mercaptopropyl, γ-
Amino-containing groups such as aminopropyl and N-β (aminoethyl) -γ-aminopropyl; γ-chloropropyl;
Examples include a halogen-containing group such as 1,1-trifluorofluoropropyl, nonafluorohexyl, and perfluorooctylethyl, and other nitro and cyano-substituted alkyl groups. Particularly, an alkyl group such as methyl, ethyl, propyl, and butyl is preferable. Examples of the hydrolyzable group for X include an alkoxy group such as methoxy and ethoxy, a halogen group, and an acyloxy group. Particularly, an alkoxy group having 6 or less carbon atoms is preferable.

The organosilicon compounds represented by the general formula (1) may be used alone or in combination of two or more. However, it is preferable that at least one of the organosilicon compounds represented by the general formula (1) used is an organosilicon compound in which n is 0 or 1.

When n is 2 or more in the specific compound of the organosilicon compound represented by the general formula (1), a plurality of Rs may be the same or different. Similarly, when n is 2 or less, a plurality of Xs may be the same or different. When two or more organosilicon compounds represented by the general formula (1) are used, R and X may be the same or different between the respective compounds.

The surface layer is preferably formed by adding colloidal silica to a composition containing the above-mentioned organosilicon compound or a hydrolytic condensate thereof. Colloidal silica is silicon dioxide particles dispersed in a colloidal form in a dispersion medium. Colloidal silica may be added at any stage of adjusting the composition of the coating solution. Colloidal silica may be added in the form of an aqueous or alcoholic sol,
The aerosol formed in the gas phase may be directly dispersed in the coating solution of the present invention.

In addition, metal oxides such as titania and alumina may be added in the form of sol or fine particles.

The colloidal silica or the tetrafunctional (n = 0) or trifunctional (n = 1) organosilicon compound imparts rigidity to the resin layer film of the present invention by forming a crosslinked structure or the like. When the ratio of the bifunctional organosilicon compound (n = 2) increases, the rubber elasticity increases and the hydrophobicity increases. The monofunctional organosilicon compound (n = 3) does not become a polymer but reacts with unreacted residual SiOH groups. Work to increase the hydrophobicity.

The surface layer is formed by the following general formula (I) in a siloxane-based resin formed from the above-mentioned organosilicon compound having a hydroxyl group or a hydrolyzable group or a condensate formed from an organosilicon compound having a hydroxyl group or a hydrolyzable group. It is more preferable that the compound shown in 2) is a resin layer contained by a condensation reaction with the organosilicon compound or the condensate. General formula (2) B- (R ₁ -ZH) _m (wherein B represents a monovalent or polyvalent group containing a charge-transporting compound structure, and R ₁ represents a single bond or a divalent alkylene group. , Z represents an oxygen atom, a sulfur atom or NH;
The compound represented by the general formula (2) may be incorporated into the siloxane-based resin layer by a condensation reaction with a hydroxyl group on the surface of colloidal silica.

In the present invention, a siloxane-based ceramic resin layer formed by adding a metal hydroxide other than colloidal silica (for example, a hydrolyzate of each alkoxide of aluminum, titanium and zirconium) may be used.

In the general formula (2), B is a charge-transporting compound structure
And a monovalent or higher group. Where B is a charge transport compound
Including the compound structure means that (R) in the general formula (2)₁-ZH)_mBase
Whether the compound structure except for has charge transport performance, or
Is (R) in the general formula (2). ₁-ZH) group by a hydrogen atom
The substituted general formula (BH_m) Has charge transport performance
Means to do.

The above-mentioned charge transporting compound is a compound exhibiting the property of having electron or hole drift mobility. Another definition is Time-Of-Flight.
It can be defined as a compound capable of obtaining a detection current due to charge transport by a known method capable of detecting charge transport performance such as a method.

The total amount (H) of the organosilicon compound having a hydroxyl group or a hydrolyzable group, and the condensate formed from the organosilicon compound having a hydroxyl group or a hydrolyzable group, and the compound of the formula (2) The composition ratio in the composition (I) is preferably 100: 3 to 50: 100, more preferably 100: 10 to 50:10 by mass ratio.
It is between 0.

In the present invention, colloidal silica or another metal oxide may be added. However, when colloidal silica or another metal oxide (J) is added, the above (H) + (I) component is added. (J) is 1 for 100 parts of the total mass of
It is preferable to use 〜30 parts by mass.

When the component (H) is used within the above range, the resin layer of the present invention has high hardness and elasticity. Excess or deficiency of the colloidal silica component (J) has the same tendency as the component (H). On the other hand, when the component (I) is used within the above range, the electrophotographic characteristics such as sensitivity and residual charge characteristics are good, and the hardness of the resin layer is high.

For forming the siloxane-based resin layer as the surface layer, it is preferable to use a condensation catalyst in order to promote a condensation reaction. The condensation catalyst used here may be a catalyst that has at least one of a catalyst that acts in contact with the condensation reaction and a catalyst that acts to shift the reaction equilibrium of the condensation reaction to the production system.

As a specific condensation catalyst, a known catalyst such as an acid, a metal oxide, a metal salt and an alkylaminosilane compound which has been conventionally used for a silicon hard coat material can be used. For example, organic carboxylic acids, nitrous acid,
Alkali metal salts of sulfurous acid, aluminate, carbonic acid and thiocyanic acid, organic amine salts (tetramethylammonium hydroxide, tetramethylammonium acetate), tin organic acid salts (stannas octoate, dibutyltin diacetate, dibutyltin dilaurate, dibutyl) Timmercaptide, dibutyltin thiocarboxylate, dibutyltin malate and the like.

In the general formula (2), the group having a charge transporting compound structure represented by B includes a hole transport type and an electron transport type. The hole transport type is oxazole, oxadiazole, thiazole, triazole, imidazole, imidazolone, imidazoline, bisimidazolidine, styryl, hydrazone, benzidine, pyrazoline, triarylamine, oxazolone, benzothiazole, benzimidazole, quinazoline, benzofuran, acridine And groups containing structural units such as phenazine and the like, and groups derived from derivatives thereof. On the other hand, the electron transport type includes succinic anhydride, maleic anhydride, phthalic anhydride, pyromellitic anhydride, melitic anhydride, tetratocyanoethylene, tetratocyanoquinodimethane, nitrobenzene, dinitrobenzene, trinitrobenzene, tetranitrobenzene, and nitrobenzene. Benzonitrile, picryl chloride,
Quinone chlorimide, chloranil, bromanyl, benzoquinone, naphthoquinone, diphenoquinone, tropoquinone, anthraquinone, 1-chloroanthraquinone, dinitroanthraquinone, 4-nitrobenzophenone, 4,
4'-dinitrobenzophenone, 4-nitrobenzalmalone dinitrile, α-cyano-β- (p-cyanophenyl) -2- (p-chlorophenyl) ethylene, 2,7-
Dinitrofluorenone, 2,4,7-trinitrofluorenone, 2,4,5,7-tetranitrofluorenone,
9-fluoronylidenedicyanomethylenemalonitrile,
Polynitro-9-fluoronylidenedicyanomethylenemalonitrile, picric acid, o-nitrobenzoic acid, p-nitrobenzoic acid, 3,5-dinitrobenzoic acid, perfluorobenzoic acid, 5-nitrosalicylic acid, 3,5-dinitro Examples include groups containing chemical structural units such as salicylic acid, phthalic acid and melitic acid, and groups derived from derivatives thereof, but are not limited to these structures.

The typical examples of the compounds represented by the general formula (2) are shown below. Examples of compounds in which Z is an oxygen atom in the general formula (2) are shown below.

[0079]

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[0080]

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[0081]

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[0082]

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[0083]

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[0084]

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Next, examples of the compound in which Z is an NH group in the general formula (2) are shown below.

[0086]

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Next, in the general formula (2), examples of compounds in which Z is a mercapto group (SH) are shown below.

[0088]

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The layer constitution of the photoreceptor of the present invention is not particularly limited. In the case of a negatively charged photoreceptor, an undercoat layer (UCL) is provided on a conductive support, and a charge generation layer of a photosensitive layer functionally separated therefrom. (CGL) and a charge transport layer (CTL layer) are preferably provided in this order, and the resin layer of the present invention is preferably applied.
The positively charged photoreceptor preferably has a configuration in which the order of the charge generation layer (CGL) and the charge transport layer (CTL layer) is reversed in the negatively charged photoreceptor layer configuration. A single-layer photoreceptor employs a structure in which a photosensitive layer (charge generation + charge transport) is provided on an undercoat layer (UCL) on a conductive support, and a resin layer of the present invention is provided thereon. Is also good.

Further, the resin layer of the present invention may have a structure which also serves as the photosensitive layer. That is, the charge transport layer or the charge generation layer of the function-separated photoreceptor can be used as the resin layer of the present invention. Further, the photosensitive layer of the photosensitive member having a single-layer structure may be used as the resin layer of the present invention.

The resin layer of the present invention is most preferably formed as a surface layer of a photoreceptor in order to take advantage of the characteristics of the resin layer, but at the time of starting image formation when the photoreceptor is incorporated in an electrophotographic image forming apparatus. A surface layer may be further provided on the resin layer for the purpose of improving the slip characteristics and the like of the resin layer.

Known techniques can be used for the charge generation layer (CGL), the charge transport layer (CTL layer), and the photosensitive layer of the single-layer photosensitive member. For example, a phthalocyanine pigment, an azo pigment, a perylene pigment, an azulenium pigment, or the like can be used as the charge generation material (CGM). Triphenylamine derivatives as charge transport materials,
A hydrazone compound, a styryl compound, a benzidine compound, a butadiene compound, or the like can be used. These charge transport materials are usually dissolved in a suitable binder resin to form a layer.

In the photosensitive member of the present invention, when the resin layer of the present invention is not used as a photosensitive layer, the photosensitive layer includes a charge generation layer (CGL), a charge transport layer (CTL layer), and a photosensitive layer having a single-layer structure. The following resins can be used as the binder resin for the layer. For example, polystyrene, acrylic resin, methacrylic resin, vinyl chloride resin, vinyl acetate resin, polyvinyl butyral resin, epoxy resin, polyurethane resin,
Phenolic resin, polyester resin, alkyd resin,
A polycarbonate resin, a silicon resin, a melamine resin, and a copolymer resin containing two or more of repeating units of these resins. In addition to these insulating resins, poly-
A high-molecular organic semiconductor such as N-vinylcarbazole may be used.

The ratio of the binder resin to the charge generating substance is preferably 20 to 600 parts by mass with respect to 100 parts by mass of the binder resin in the charge generating layer or the photosensitive layer of the single-layer photosensitive member. The ratio of the binder resin to the charge transporting material is preferably 10 to 200 parts by mass with respect to 100 parts by mass of the binder resin in the charge transporting layer or the photosensitive layer of the single-layer photosensitive member.

The thickness of each layer of the photoreceptor in the present invention is 0.01 to 10 μm for the charge generation layer, and 1 to 4 for the charge transport layer.
0 μm is preferred. In the case of a photosensitive layer of a single-layer photosensitive member, the thickness is preferably 1 to 40 μm. Each of the resin layers provided on the photosensitive layer preferably has a thickness of 0.1 to 5 μm.

The undercoat layer (UC) used in the photoreceptor of the present invention
L) is provided between the support and the photosensitive layer to improve the adhesion between the conductive support and the photosensitive layer or to prevent charge injection from the support. Examples of the material include polyamide resins, vinyl chloride resins, vinyl acetate resins, and copolymer resins containing two or more of the repeating units of these resins. Further, a curable metal resin compound obtained by thermally curing an organic metal compound such as a silane coupling agent and a titanium coupling agent may be used. The thickness of the intermediate layer is preferably from 0.01 to 10 μm.

By adding an antioxidant to the surface layer, it is possible to effectively prevent the occurrence of fog and image blurring at high temperature and high humidity.

[0098] Here, the antioxidant is a typical antioxidant which reacts with an autoxidizable substance present in the electrophotographic photoreceptor or on the surface of the photoreceptor under the conditions of light, heat, discharge and the like. It is a substance having the property of preventing or suppressing the action. Specifically, the following compounds may be mentioned. (1) Radical chain inhibitor • Phenolic antioxidant (hindered phenol) • Amine antioxidant (hindered amine, diallyldiamine, diallylamine) • Hydroquinone antioxidant (2) Peroxide decomposer -Sulfur-based antioxidants (thioethers)-Phosphoric acid-based antioxidants (phosphites) Among the above-mentioned antioxidants, the radical chain inhibitor (1) is preferred, and particularly, hindered phenol-based or hindered amine-based oxidation. Inhibitors are preferred. Further, two or more kinds may be used in combination, for example, a combination of the hindered phenol antioxidant (1) and the thioether antioxidant (2) may be used. Further, a molecule containing the above structural unit, for example, a hindered phenol structural unit and a hindered amine structural unit in a molecule may be used.

Among the above antioxidants, hindered phenol-based and hindered amine-based antioxidants are particularly effective in preventing fogging and image blurring at high temperature and high humidity.

The content of the hindered phenol or hindered amine antioxidant in the resin layer is 0.01 to 2
0% by mass is preferred. When the content is less than 0.01% by mass, there is no effect on fogging and image blur at high temperature and high humidity, and when the content is more than 20% by mass, the charge transport ability in the resin layer is reduced, and the residual potential tends to increase, In addition, a decrease in film strength occurs.

The antioxidant may be contained in the lower charge generation layer, charge transport layer, intermediate layer, and the like, if necessary. The amount of the antioxidant added to these layers is preferably 0.01 to 20% by mass with respect to each layer.

Here, hindered phenol refers to compounds having a branched alkyl group at an ortho position to the hydroxyl group of the phenol compound and derivatives thereof (however, the hydroxyl group may be modified to alkoxy).

A hindered amine compound is a compound having a bulky organic group near an N atom. As the bulky organic group, there is a branched alkyl group, and for example, a t-butyl group is preferable. For example, compounds having an organic group represented by the following structural formula are preferable.

[0104]

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(Wherein R ₁₃ represents a hydrogen atom or a monovalent organic group, R ₁₄ , R ₁₅ , R ₁₆ and R ₁₇ represent an alkyl group, and R ₁₈ represents a hydrogen atom, a hydroxyl group or a monovalent organic group. Examples of the antioxidant having a hindered phenol partial structure include, for example, JP-A-1-118137 (P7 to P14).
The compounds described above are included, but the present invention is not limited thereto.

Examples of the antioxidant having a hindered amine partial structure include, for example, JP-A-1-118138 (P7-
The compounds described in P9) may also be mentioned, but the present invention is not limited thereto.

As the organic phosphorus compound, for example, the following compounds are representative of the compounds represented by the general formula RO-P (OR) -OR. Here, R represents a hydrogen atom, a substituted or unsubstituted alkyl group, alkenyl group or aryl group.

Examples of the organic sulfur compounds include, for example, the following compounds represented by the general formula RSR. Here, R represents a hydrogen atom, a substituted or unsubstituted alkyl group, alkenyl group or aryl group.

The following are examples of typical antioxidant compounds.

[0110]

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[0111]

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[0112]

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[0113]

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The following compounds are commercially available antioxidants, such as “Irganox 1076” and “Irganox 1” as hindered phenol compounds.
010 "," Ilganox 1098 "," Ilganox 245 "," Ilganox 1330 "," Ilganox 3114 "," Ilganox 1076 ",
"3,5-di-t-butyl-4-hydroxybiphenyl" and "Sanol LS262
6 "," Sanol LS765 "," Sanol LS262 "
6, "Sanol LS770", "Sanol LS74"
4, "Tinuvin 144", "Tinuvin 622LD",
"Mark LA57", "Mark LA67", "Mark L
A62 "," Mark LA68 ", and" Mark LA63 ".
S "and" SUMILIZER TP-D ". Examples of the phosphite series include" Mark 2112 "and" Mark PEP-D ".
8 "," Mark PEP-24G "," Mark PEP-3 "
6 "," Mark 329K ", and" Mark HP-10 ".

In order to form a layer containing the siloxane-based resin of the present invention, the siloxane-based resin composition is usually dissolved in a solvent and applied. Methanol as a solvent,
Alcohols such as ethanol, propanol, butanol, methyl cellosolve and ethyl cellosolve and derivatives thereof; ketones such as methyl ethyl ketone and acetone; esters such as ethyl acetate and butyl acetate are used.

The siloxane-based resin of the present invention is preferably dried by heating. The heating promotes the crosslinking / curing reaction of the siloxane-based resin layer. The conditions for the crosslinking and curing vary depending on the type of solvent used and the presence or absence of a catalyst.
Heating for 10 minutes to 5 hours in the range of ~ 160 ° C is preferable,
More preferably, heating in the range of 90 to 120 ° C. for 30 minutes to 2 hours is preferable.

Solvents used for dispersing and dissolving the charge generating substance and the charge transporting substance include hydrocarbons such as toluene and xylene; halogenated hydrocarbons such as methylene chloride and 1,2-dichloroethane; methyl ethyl ketone and cyclohexanone. Ketones; esters such as ethyl acetate and butyl acetate; alcohols such as methanol, ethanol, methyl cellosolve and ethyl cellosolve and derivatives thereof; tetrahydrofuran, 1,4-dioxane and 1,3
Ethers such as dioxolane; amines such as pyridine and diethylamine; amides such as N, N-dimethylformamide; other fatty acids and phenols; one or two of sulfur and phosphorus compounds such as carbon disulfide and triethyl phosphate; More than one species can be used.

As a coating method for producing the electrophotographic photoreceptor having the surface layer, dip coating, spray coating, circular amount control type coating and the like of a coating solution can be used. In particular, in the coating process on the surface layer side of the photosensitive layer, spray coating or circular amount control type coating (a typical example is a circular slide hopper) is used to dissolve the lower layer film as much as possible and to achieve uniform coating process. Is preferred. The spray coating is described in JP-A-3-90250 and JP-A-3-269238, and the details of the circular amount control type coating are described in JP-A-58-189061.

<Step of Cleaning with Blade> Using an apparatus provided with a blade-shaped cleaning member arranged in pressure contact with the photoconductor, the toner remaining on the photoconductor without being transferred is cleaned. The pressure of the cleaning member against the photoreceptor is preferably 5 to 50 g / cm from the viewpoint of improving the cleaning performance. Prior to the cleaning step, it is preferable to add a charge elimination step for eliminating the charge on the surface of the photoconductor in order to facilitate the cleaning.
This static elimination step is performed by, for example, a static eliminator that generates an AC corona discharge.

As the cleaning blade used in the present invention, silicon rubber, urethane rubber, or the like is used, but one made of urethane rubber is most preferable. Among them, polyurethane rubber having a rebound resilience of 20 to 80 (under conditions of 20 ° C. and 50 ± 5% RH) is preferable. If the rebound resilience is less than 20, the cleaning property is not sufficient, and if it exceeds 80%, blade scraping is liable to occur (urethane rubber physical property values conform to JIS-K6301).

FIG. 1 is a sectional view of an electrophotographic image forming apparatus as an example of the image forming apparatus of the present invention.

In FIG. 1, reference numeral 50 denotes a photosensitive drum (photosensitive member) serving as an image carrier, and an organic photosensitive layer is coated on the drum.
A photoreceptor coated with the resin layer of the present invention thereon is grounded and driven to rotate clockwise. Reference numeral 52 denotes a scorotron charger, which applies uniform charge to the peripheral surface of the photosensitive drum 50 by corona discharge. Prior to the charging by the charger 52, in order to eliminate the history of the photoconductor in the previous image formation, exposure by the exposure unit 51 using a light emitting diode or the like may be performed to eliminate the charge on the peripheral surface of the photoconductor.

After the photosensitive member is uniformly charged, the image exposure device 53 performs image exposure based on the image signal. The image exposure device 53 in this figure uses a laser diode (not shown) as an exposure light source. The light on the photosensitive drum is scanned by the light whose optical path is bent by the reflection mirror 542 via the rotating polygon mirror 531 and the fθ lens and the like, and an electrostatic latent image is formed.

Next, the electrostatic latent image is developed by the developing device 54. A developing device 54 having a built-in developer composed of toner and carrier is provided around the periphery of the photosensitive drum 50.
The developing is performed by a developing sleeve 541 that has a built-in magnet and rotates while holding the developer. The developer is, for example, a carrier in which an insulating resin is coated around the above-described ferrite as a core, a colorant such as carbon black, a charge control agent, and a low molecular weight polyolefin of the present invention using the above-mentioned styrene acrylic resin as a main material. The toner is a toner in which silica, titanium oxide, or the like is externally added to colored particles made of, and the developer is regulated to a layer thickness of 100 to 600 μm on the developing sleeve 541 by the layer forming means, and is conveyed to the developing area. , And development is performed. At this time, development is usually performed by applying a DC bias voltage between the photosensitive drum 50 and the developing sleeve 541 and, if necessary, an AC bias voltage. The developer is developed in a state of contact or non-contact with the photoconductor.

After the image is formed, the recording paper P is fed to the transfer area by the rotation of the paper feed roller 57 at the time when the transfer timing is adjusted.

In the transfer area, a transfer roller (transfer device) is mounted on the peripheral surface of the photosensitive drum 50 in synchronization with the transfer timing.
58 is pressed and transferred while sandwiching the fed recording paper P.

Next, the recording paper P is neutralized by a separation brush (separator) 59 which is brought into pressure contact with the transfer roller almost at the same time. After the toner is welded by heating and pressing the 601 and the pressure roller 602, the toner is discharged to the outside of the apparatus via the discharge roller 61. The transfer roller 58 and the separation brush 59 are provided on the recording paper P.
After passing through, the photosensitive drum 50 is retracted and separated from the peripheral surface thereof to prepare for the formation of the next toner image.

On the other hand, the photosensitive drum 50 from which the recording paper P has been separated removes and cleans the residual toner by pressing the blade 621 of the cleaning unit 62, and receives the charge removal by the exposure unit 51 and the charge by the charger 52 again. The next image forming process is started.

Reference numeral 70 denotes a detachable process cartridge in which a photosensitive member, a charging device, a transfer device / separator, and a cleaning device are integrated.

An electrophotographic image forming apparatus is constructed by integrally combining the above-described photoreceptor, a developing device, a cleaning device, and other components as a process cartridge, and this unit is configured to be detachable from the apparatus main body. You may.
Also, a process cartridge is formed by integrally supporting at least one of a charger, an image exposing unit, a developing unit, a transfer or separating unit, and a cleaning unit together with a photoreceptor. It may be configured to be detachable using a guide means such as a rail of the apparatus body.

The process cartridge generally includes an integral type cartridge and a separate type cartridge described below. The integral type cartridge is configured such that at least one of a charger, an image exposing unit, a developing unit, a transfer or separating unit, and a cleaning unit is integrally formed with a photoconductor, and is detachable from an apparatus main body. Are a charging device, an image exposure device, a developing device, a transfer or separation device, and a cleaning device which are configured separately from the photoreceptor, but have a configuration detachable from the apparatus main body and are incorporated in the apparatus main body. When integrated, it is integrated with the photoconductor. The process cartridge in the present invention includes both types of cartridges.

The method for recycling the toner is not particularly limited. For example, the toner collected by the cleaning unit is transported by a transport conveyor or a transport screw to a toner hopper for replenishment, a developing device, or a replenishing toner. A method of mixing and supplying the mixture to the developing device depending on the chamber can be given. Preferably, a method of directly returning the toner to the developing device or a method of mixing the replenishment toner and the recycled toner in the intermediate chamber and supplying the mixed toner can be used.

Next, FIG. 2 shows an example of a perspective configuration diagram of a toner recycling member. In this method, the recycled toner is directly returned to the developing device.

The untransferred toner collected by the cleaning blade 4 is collected in a toner recycling pipe 5 by a conveying screw in the cleaning device 3 and is returned to the developing device 2 from a receiving port 6 of the recycling pipe and used again as a developer. Is done.

FIG. 2 is also a perspective view of a process cartridge detachably mounted on the image forming apparatus of the present invention. This figure 2
Although the photoconductor unit and the developer unit are separated from each other in order to make the perspective structure easy to understand, they can be removably mounted on the image forming apparatus as an integrated unit. In this case, the photosensitive drum 1, the developing device 2, the cleaning device 3, and the recycle member (toner recycle pipe 5) are integrated to form a process cartridge.

Further, the image forming apparatus may have a form in which a process cartridge including a photosensitive drum and at least one of a charging device, a developing device, a cleaning device, and a recycling member is mounted.

Next, the transfer paper is typically plain paper, but is not particularly limited as long as it can transfer an unfixed image after development, and of course includes a PET base for OHP.

In the image exposure, when the electrophotographic image forming apparatus is used as a copying machine or a printer, the reflected light or transmitted light from the original is irradiated on the photosensitive member, or the original is read by a sensor and converted into a signal. Scanning of a laser beam, driving of an LED array, or driving of a liquid crystal shutter array according to a signal is performed by irradiating light to a photoconductor.

When used as a facsimile printer, the image exposure unit 53 performs exposure for printing received data.

The electrophotographic photosensitive member of the present invention is applicable to general electrophotographic devices such as copiers, laser printers, LED printers, and liquid crystal shutter printers. It can be widely applied to devices such as light printing, plate making, and facsimile.

[0141]

EXAMPLES Hereinafter, the present invention will be described in detail with reference to examples, but embodiments of the present invention are not limited thereto. In the description, “parts” means “parts by mass”.

[Preparation of Photoconductor 1] Photoconductor 1 was prepared as follows.

<Intermediate Layer> Titanium chelate compound (TC-750, manufactured by Matsumoto Pharmaceutical Co., Ltd.) 30 g Silane coupling agent (KBM-503, manufactured by Shin-Etsu Chemical Co., Ltd.) 17 g 2-propanol 150 ml And a dry film thickness of 0.
It was applied so as to have a thickness of 5 μm.

<Charge Generating Layer> Y-type titanyl phthalocyanine 60 g Silicon-modified butyral resin (X-40-1211: manufactured by Shin-Etsu Chemical Co., Ltd.) 700 g 2-butanone 2000 ml was mixed and dispersed using a sand mill for 10 hours. Was prepared. This coating solution was applied onto the intermediate layer by a dip coating method to form a charge generation layer having a dry film thickness of 0.2 μm.

<Charge Transporting Layer> 200 g of a charge transporting substance (4-methoxy-4 '-(4-methyl-α-phenylstyryl) triphenylamine) 300 g of polycarbonate (TS2050: manufactured by Teijin Chemicals Ltd.) 300 g of dichloromethane were mixed. After dissolution, a charge transport layer coating solution was prepared. This coating solution was applied on the charge generation layer by a dip coating method to form a charge transport layer having a dry film thickness of 20 μm.

[Preparation of Photoreceptor 2] Photoreceptor 2 was prepared in the same manner as in Photoreceptor 1 except that the surface of the aluminum drum substrate of Example 1 was cut to a surface roughness of 0.3 μm.

[Preparation of Photoconductor 3] In the same manner as in Photoconductor 1, the components up to the charge transport layer were prepared.

<Resin Layer> Methyltrimethoxysilane 150 g Phenyltrimethoxysilane 30 g Antioxidant (Exemplary Compound 1-8) 1 g 2-propanol 225 g 2% acetic acid 106 g trisacetylacetonatoaluminum 4 g colloidal silica (30% methanol solution: (Nissan Chemical Co., Ltd.) was mixed to prepare a coating solution for a resin layer. A 2.5 μm-dry resin layer is formed on the charge transport layer by a circular-amount-regulating coating device on the charge transporting layer, and is cured by heating at 110 ° C. for 1 hour to form a siloxane-based resin layer having a crosslinked structure. The photosensitive member 3 was formed.

[Preparation of Photoreceptor 4] In the same manner as for Photoreceptor 1, the components up to the charge transport layer were prepared.

<Resin Layer> Methyltrimethoxysilane 100 g γ-glycidoxypropyltrimethoxysilane 30 g Exemplified compound (T-1) 75 g Antioxidant (Exemplified compound 2-1) 1 g Methyl ethyl ketone 225 g 3% acetic acid 30 g Trisacetylacetoacetate 3 g of sodium aluminum and 79 g of colloidal silica (30% methanol solution: manufactured by Nissan Chemical Industries, Ltd.) were mixed to prepare a coating solution for a resin layer. A 2.5 μm-dry resin layer is formed on the charge transport layer by a circular-amount-regulating coating device on the charge transporting layer, and is cured by heating at 110 ° C. for 1 hour to form a siloxane-based resin layer having a crosslinked structure. The photosensitive member 4 was formed.

[Preparation of Photoconductor 5] Photoconductor 5 was prepared in the same manner as photoconductor 1 except that the undercoat layer was removed.

[Preparation of Photoreceptor 6] In the same manner as in Photoreceptor 1, the components up to the charge transport layer were prepared.

<Resin Layer> Methyltrimethoxysilane 100 g Dimethyldimethoxysilane 53 g Exemplary Compound (T-1) 45 g Antioxidant (Exemplary Compound 2-1) 1 g 2-propanol 225 g 3% acetic acid 30 g Trisacetylacetonatoaluminum 3 g Colloidal A coating liquid for a resin layer was prepared by mixing 81 g of silica (30% methanol solution: manufactured by Nissan Chemical Industries, Ltd.). A 2.5 μm-dry resin layer is formed on the charge transport layer by a circular-amount-regulating coating device on the charge transporting layer, and is cured by heating at 110 ° C. for 1 hour to form a siloxane-based resin layer having a crosslinked structure. The photosensitive member 6 was formed.

[Preparation of Photoreceptor 7] Photoreceptor 7 was prepared in the same manner as photoreceptor 1 except that the aluminum drum substrate used in the preparation of photoreceptor 1 was mirror-finished.

Surface roughness of photoreceptors 1 to 7: ten-point average roughness R
z is measured with a surface roughness meter (Surfcode manufactured by Kosaka Laboratory Co., Ltd.)
r SE-30H). Table 1 shows the measured values.

Measurement conditions Measurement speed: 0.1 mm / s Measurement distance: 15 mm Stylus: 2 μm

[0157]

[Table 1]

Next, the toner used in this example was produced as follows. [Preparation of Toner 1] 100 parts of styrene acrylic resin having a mass ratio of styrene: butyl acrylate: butyl methacrylate = 75: 20: 5, carbon black 10
Parts, low molecular weight polypropylene (number average molecular weight = 3500)
After 4 parts were melted and kneaded, fine pulverization was performed using a mechanical pulverizer, and classification was performed to obtain colored particles having a volume average particle size of 4.2 μm. 1.2% by mass of hydrophobic silica (hydrophobicity = 75 / number average primary particle size = 12 nm) is added to the colored particles, and mixed for 10 minutes with a Henschel mixer (peripheral speed of the stirring blade: 40 m / s). : Normal temperature), negatively chargeable toner 1
I got

[Preparation of Toner 2] Negatively chargeable toner 2 was obtained in the same manner as in preparation of toner 1, except that the peripheral speed of the Henschel mixer was set to 20 m / s. The fixation ratio of this toner was 25%.

[Preparation of Toner 3] 100 parts of a polyester resin having an acid value of 45, 10 parts of carbon black, and 4 parts of a low molecular weight polypropylene (number average molecular weight = 3500) were melted and kneaded. Used, pulverized, and classified to obtain colored particles having a volume average particle size of 10.4 μm. Hydrophobic silica (degree of hydrophobicity =
1.2% by mass (75 / number average primary particle diameter = 12 nm) was added and mixed for 10 minutes with a Henschel mixer (peripheral speed of the stirring blade: 40 m / s: at room temperature) to obtain negatively chargeable toner 3. The fixation ratio of this toner was 41%.

[Preparation of Toner 4] A negatively chargeable toner 4 was obtained in the same manner as in preparation of Toner 1, except that the peripheral speed of the Henschel mixer was changed to 5 m / s. The fixation ratio of this toner D was 5%.

[Preparation of Toner 5] Negatively charged toner 5 was prepared in the same manner as in preparation of toner 1, except that the peripheral speed of the Henschel mixer was changed to 50 m / s. The fixation ratio of this toner was 92%.

The external additive fixing rate of the above toner, 30 ° C., 80
Table 2 shows the measurement results of the saturated water content (% by mass) at RH%.
Shown in

In this example, the BET specific surface area for the measurement of the external additive fixation rate was measured by Flowso manufactured by Shimadzu Corporation.
rb2300 "using the BET one-point method.

Subsequently, a ferrite carrier coated with a silicone resin and having a volume average particle diameter of 45 μm was mixed with each of the toners described above, and a developer having a toner concentration of 6% was prepared and used for evaluation. These developers are referred to as developers 1 to 5, respectively, corresponding to the toner.

[0166]

[Table 2]

<< Evaluation >> The combinations of the photoreceptor and the developer (toner) shown in Table 3 were used with a digital copying machine ko manufactured by Konica Corporation.
Nica 7050 (Laser exposure, reversal development, nail separation,
(With a blade cleaning process and a toner recycling process), mounted on an evaluator with an appropriate amount of exposure, set the initial charging potential to -750 V, and operated at room temperature and humidity (20 ° C., 60% RH). After continuous copying of 10,000 sheets, evaluation of continuous copying of 50,000 sheets was performed in a high-temperature and high-humidity environment (30 ° C., 80% RH). 1. Image Evaluation For image evaluation, a character image having a blackening ratio of 7% was copied at A4, and a halftone, solid white image and solid black image were evaluated every 1000 sheets. The image density was measured as the absolute reflection density of a solid black image using RD-918 manufactured by Macbeth. Fog was visually confirmed using a solid white image.

Image density ◎: Good at 1.2 or higher ：: 0.8 to less than 1.2, no practical problem x: Less than 0.8, practical problem Fog ：: 5 or less per 100,000 sheets O: Occurrence of 6 to 20 sheets out of 100,000 sheets (a level that is practically acceptable) ×: Occurrence of 20 or more sheets out of 100,000 sheets Evaluation of cleaning performance The presence or absence of blade turn-up and slip-through due to poor cleaning were visually evaluated.

Blade turning ◎: No blade turning occurs in 100,000 sheets ○: No blade turning occurs in 100,000 sheets, but abnormal noise occurs when photoconductor is installed (no problem in practical use) ×: Blade turning in 100,000 sheets Occurrence of 1 or more times Slip-through ◎: No slip-through occurs in 100,000 sheets ○: Slip-through of 1 to 5 sheets occurs in 100,000 sheets (no problem in practical use) ×: 6-sheets or more occur in 100,000 sheets 3. Photoreceptor film thickness loss evaluation Photoreceptor film thickness when not used-100,000th sheet photoreceptor film thickness * Film thickness measurement method The average value is defined as the thickness of the photosensitive layer. The film thickness measuring device is an eddy current type film thickness measuring device EDDY560C (HELMUT
FISCER GMBTE CO), and the difference between the thicknesses of the photosensitive layers before and after the actual printing test is defined as the thickness loss. 4. Evaluation of Cleaning Blade Depletion Amount of Depletion at Edge of Cleaning Blade Measuring Method of Cleaning Blade Edge Depletion FIG. 3 is a schematic diagram illustrating a method of measuring a cleaning blade edge depletion. As shown in FIG. 3, the edge wear amount 44 of the cleaning blade is measured from an image obtained by enlarging the edge portion using an optical or laser microscope.

In FIG. 3, reference numeral 41 denotes a photosensitive drum, reference numeral 42 denotes a cleaning blade, reference numeral 43 denotes a blade supporting plate, and reference numeral 44 denotes an edge wear amount.

Table 3 shows the results of the above evaluation.

[0172]

[Table 3]

As is clear from Table 3, the electrophotographic image forming method of the present invention, which was manufactured while keeping the surface roughness of the photoreceptor and the fixation ratio of the toner to the external additives, was within an appropriate range.
There is no blade turn-up and the image quality after long-term continuous copying of 100,000 sheets is good without cleaning problems such as slip-through. Further, the wear of the photosensitive member and the cleaning blade is small, and the durability can be extended by the present invention. However, those out of the range of the present invention (comparative examples) cause image failure, cleaning failure due to turning over of the blade, and wear of the photoconductor and cleaning blade due to continuous copying, and the effect of the present invention is remarkable. It is shown.

[0174]

According to the above embodiments, by using the electrophotographic image forming method or the electrophotographic image forming apparatus in which the photoreceptor and the developer of the present invention are combined, it is possible to maintain the cleaning performance for a long time and reduce the image defect. It is clear that the cleaning blade can have a longer life.

[Brief description of the drawings]

FIG. 1 is a cross-sectional view of an electrophotographic image forming apparatus as an example of an image forming apparatus of the present invention.

FIG. 2 is a perspective configuration diagram of a toner recycling member.

FIG. 3 is a schematic diagram for explaining a method of measuring a cleaning blade edge wear amount.

[Explanation of symbols]

 REFERENCE SIGNS LIST 1 photoconductor drum 2 developing device 3 cleaning device 4 cleaning blade 5 toner recycle pipe 6 recycle pipe receptacle 41 photoconductor drum 42 cleaning blade 43 blade support plate 44 edge depletion amount 50 photoconductor drum (or photoconductor) 51 exposure unit 52 Charger 53 Image Exposure Device 54 Developing Device 57 Feed Roller 58 Transfer Roller (Transfer Device) 59 Separation Brush (Separator) 60 Fixing Device 61 Discharge Roller 62 Cleaning Device 70 Process Cartridge

Continued on the front page F term (reference) 2H005 AA08 AB10 DA07 EA07 EA10 2H034 AA00 BF00 BF03 CB00 CB01 2H068 AA03 AA09 AA41 BB32 BB57 FC08 FC15

Claims (9)

[Claims] 1. An electrophotographic image comprising: a step of developing at least an electrostatic charge image on an electrophotographic photosensitive member with a developer containing toner; and a step of cleaning the toner on the electrophotographic photosensitive member by blade cleaning. In the forming method, the toner represented by the following formula (1), wherein the surface roughness of the electrophotographic photosensitive member at a reference length of 15 mm is in a range of 0.01 to 2.5 μm in ten-point average roughness Rz. An electrophotographic image forming method, wherein an external additive fixation rate Fd to a base is 10 to 90%. Formula (1) External additive fixation rate Fd = [1-｛(Sw ₁ -Sw ₂ ) / S
_{w 3}] × 100 Sw 1} : BET specific surface area of the toner external additive was immobilized _{^{(m 2 / g) Sw 2}} : external additive untreated BET specific surface area of toner (m ² /
g) Sw ₃ : BET specific surface area of external additive (m ² / g) 2. The ten-point average roughness Rz is 0.2 to 1.5.
2. The electrophotographic image forming method according to claim 1, wherein the thickness is within a range of μm. 3. The electrophotographic image forming method according to claim 1, wherein the surface layer of the electrophotographic photosensitive member contains a siloxane-based resin having a crosslinked structure. 4. The electrophotographic image according to claim 1, wherein the surface layer of the electrophotographic photosensitive member contains a siloxane-based resin having a structural unit having charge transporting performance. Forming method. 5. The electrophotographic photoreceptor according to claim 1, wherein the layer structure of the electrophotographic photoreceptor is such that an intermediate layer, a photosensitive layer, and a surface layer containing a siloxane-based resin having the crosslinked structure are formed on a conductive support. Item 5. The electrophotographic image forming method according to any one of Items 1 to 4. 6. The toner according to claim 1, wherein the saturated water content of the toner in an environment of 30 ° C. and 80 RH% is within a range of 0.1 to 2.0% by mass. The electrophotographic image forming method according to the above. 7. A step of developing at least an electrostatic charge image on the electrophotographic photoreceptor with a developer containing a toner, a step of cleaning the electrophotographic photoreceptor using blade cleaning, and a step recovered by the cleaning step. In an electrophotographic image forming method having a toner recycling step in which a toner is returned to a developer in a developing step and reused, the surface roughness of the electrophotographic photosensitive member at a reference length of 15 mm is 0.1 point average roughness Rz. In the range of 01 to 2.5 μm,
An electrophotographic image forming method, wherein the external additive fixing rate Fd with respect to the toner matrix represented by the formula (1) is 10 to 90%. 8. An electrophotographic image comprising: means for developing at least an electrostatic charge image on an electrophotographic photosensitive member with a developer containing toner; and means for cleaning the toner on the electrophotographic photosensitive member by blade cleaning. In the forming apparatus, the toner represented by the formula (1), wherein the surface roughness of the electrophotographic photosensitive member at a reference length of 15 mm is in a range of 0.01 to 2.5 μm in ten-point average roughness Rz. An electrophotographic image forming apparatus, wherein the external additive fixing rate Fd to the base is 10 to 90%. 9. A means for developing at least an electrostatic charge image on an electrophotographic photosensitive member with a developer containing a toner, a means for cleaning the electrophotographic photosensitive member using blade cleaning, and a means for recovering the electrophotographic photosensitive member recovered by the cleaning means. In an electrophotographic image forming apparatus having a toner recycling unit for returning a toner to a developer of a developing unit and reusing the toner, the surface roughness of the electrophotographic photoreceptor at a reference length of 15 mm is 0.1 point average roughness Rz. In the range of 01 to 2.5 μm,
An electrophotographic image forming apparatus, wherein the external additive fixation rate Fd with respect to the toner matrix represented by the formula (1) is 10 to 90%.