JP2002196645A - Image forming device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To form an image of high image quality by solving the problem of being prone to the generation of a cleaning failure when small-particle toner is utilized with the target of high image quality. SOLUTION: In the device, a cleaning roll having bias voltage applied to separate electrified toner from a photoreceptor is provided on the upstream side of a cleaning blade, and the photoreceptor having a surface roughness Rz of 0.1 μm to 2.5 μm in an average of ten points is utilized.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an image forming apparatus for forming an image on a recording material by an electrophotographic method, and more particularly, to an improvement in a cleaning technique of a photosensitive member.

[0002]

2. Description of the Related Art In recent years, in an electrophotographic image forming apparatus, the particle size of toner has been reduced from the viewpoint of high image quality. The use of a small particle size toner achieves high image quality by improving the resolution and improving the fine gradation expression power. However, in the image forming process using the small particle size toner, the small particle size toner is unique. Problem arises. One of the problems in the cleaning is that the adhesion of the toner to the photoreceptor is apparently increased due to the reduction in the particle size of the toner, which makes the cleaning difficult. In particular, toner produced by the granulation polymerization method, which is an effective method for producing small particle size toner, has a small particle size and also has a particle shape close to a spherical shape. In a cleaning process for cleaning the body, a so-called “slippage” in which toner passes between the photosensitive member and the edge of the cleaning blade occurs, and cleaning tends to be defective.

As a countermeasure against such defective cleaning, Japanese Patent Application Laid-Open No. 3-189675 proposes a cleaning method in which an electrostatic toner removing action is added to a mechanical toner removing action by a cleaning blade. In the cleaning method disclosed in the above publication, a brush roller to which a bias voltage is applied is provided upstream of a cleaning blade.

[0004]

However, it has been found that the cleaning method described in the above publication has the following problems.

(1) Since most of the toner is removed from the photoreceptor by the brush roller disposed on the upstream side,
The amount of toner adhering to the surface of the photoconductor contacting the cleaning blade is small. In the cleaning action by the cleaning blade, the toner acts as a lubricant between the surface of the photoconductor and the cleaning blade. However, since the toner as the lubricant is removed by the brush roller, the frictional force increases, and "Blade turnover" in which the cleaning blade stops sliding smoothly against the body and the cleaning edge reverses
The phenomenon occurs.

A first aspect of the present invention is to provide an image forming apparatus which can solve the above-mentioned problems in the conventional cleaning technique, has a cleaning means having excellent cleaning performance, and can form a high quality image. The purpose is to:

(2) Japanese Patent Application No. Hei 11-189675 discloses a cleaning method which is an improvement of the method disclosed in Japanese Patent Application Laid-Open No. 3-189675.
No. 272003 proposes a cleaning method in which a cleaning roller to which a voltage is applied is disposed upstream of a cleaning blade.

[0008] A good cleaning effect can be obtained by this method. However, it has been found that there is room for further improvement in order to further improve the cleaning performance and make it usable for a longer period of time. That is, it has been found that in the cleaning method in which the cleaning roller is disposed on the upstream side of the cleaning blade, it may be difficult to maintain good cleaning performance for a long period of time.

[0009] This phenomenon is considered to be due to wear of the cleaning roller. That is, as shown in FIG. 1A, when fine irregularities are generated on the surface of the cleaning roller CL due to wear, the surface of the photoconductor PH and the cleaning roller CL are removed.
Have different values depending on the position, such as a, b, and c. As a result, the electrostatic force that separates the toner adhering on the photoreceptor PH from the photoreceptor PH varies depending on the position, and the toner is not cleaned and the electrostatic force shown in FIG.
As shown in (2), the toner T remains on the photoconductor PH.

In addition, due to the action of the frictional force between the photosensitive member and the cleaning roller, the moving speed of the two at the contact portion becomes unstable, and as a result, the electric field formed between the two becomes unstable, resulting in poor cleaning. More likely to occur.

Further, the toner once transferred to the cleaning roller by the electrostatic force may be transferred again to the photosensitive member to cause a cleaning failure.

A second aspect of the present invention is to provide an image forming apparatus which can solve the above-mentioned problem in the conventional cleaning technique, has a cleaning means having excellent cleaning performance, and can form a high quality image. The purpose is to:

[0013]

The object of the present invention is as follows.
This is achieved by any of the following inventions.

1. A photoconductor, a latent image forming unit that forms an electrostatic latent image on the photoconductor, a developing unit that develops the electrostatic latent image on the photoconductor to form a toner image on the photoconductor, In an image forming apparatus having a transfer unit that transfers a toner image to a recording material and a cleaning unit that cleans the photoconductor after the transfer, the cleaning unit includes a conductive or semiconductive elastic member that contacts a surface of the photoconductor. A cleaning roller, which is disposed downstream of the cleaning roller in the direction of movement of the photoconductor and is in contact with the surface of the photoconductor, and charging of toner that has contributed to toner image formation during development by the developing unit. A constant current power supply for applying a bias voltage having a polarity opposite to the polarity to the cleaning roller, and a removing unit for removing toner from the cleaning roller And the photosensitive member having a surface roughness Rz of 0.1μm~2.5μm
An image forming apparatus.

2. The image forming apparatus according to claim 1, wherein the constant current power supply outputs a constant current of 1 μA to 50 μA.

3. The cleaning roller is 10 ² Ω
3. The image forming apparatus according to 1 or 2, wherein the image forming apparatus has a surface resistivity of / 10 to 10 ¹⁰ Ω / □.

4. 4. The image forming apparatus according to claim 1, wherein the cleaning roller is made of an elastic body. 5.

5. The image forming apparatus according to any one of claims 1 to 4, wherein the cleaning roller includes a foam material and a resin film covering the foam material.

6. A recycle unit for supplying the toner collected by the cleaning unit to the developing unit and reusing the toner;
Item 10. The image forming apparatus according to item 1.

[7] FIG. 7. The image forming apparatus according to claim 1, wherein the removing unit includes a blade.

8. 8. The image forming apparatus according to claim 1, wherein a plurality of said removing units are provided.

9. 9. The image forming apparatus according to any one of items 1 to 8, wherein the photoconductor has a surface layer containing a siloxane-based resin having a crosslinked structure.

10. The image forming apparatus according to any one of Items 1 to 9, wherein the photoconductor has a surface layer containing a siloxane-based resin having a structural unit having charge transport performance.

11. The photoreceptor includes a conductive support, an intermediate layer, a photosensitive layer, and a surface layer containing a siloxane-based resin having a crosslinked structure, and has a structure in which the above-described various layers are stacked in the above-described order. The image forming apparatus according to any one of the above items 1 to 10.

12. The cleaning blade has a.
12. The image forming apparatus according to any one of items 1 to 11, wherein cleaning is performed by contacting the photoconductor with a counter method with a load of 1 g / cm to 30 g / cm.

13. The cleaning blade is at 0 °
Wherein the cleaning is performed by contacting the photosensitive member with a counter method at a contact angle θ of 40 °.
13. The image forming apparatus according to any one of claims 12 to 12.

14. The cleaning blade has 20
14. The image forming apparatus according to any one of the items 1 to 13, wherein the image forming apparatus is made of an elastic body having a hardness in a range of ° to 90 °.

15. The developing means has a volume average particle size of 3
The image forming apparatus according to any one of the above items 1 to 14, wherein the development is performed using a toner having a size of μm to 8.5 μm.

16. A photoconductor, a latent image forming unit that forms an electrostatic latent image on the photoconductor, a developing unit that develops the electrostatic latent image on the photoconductor to form a toner image on the photoconductor, In an image forming apparatus including a transfer unit that transfers a toner image to a recording material and a cleaning unit that cleans the photoconductor after the transfer, the cleaning unit includes:
A cleaning roller having a conductive or semiconductive elastic body that contacts the surface of the photoconductor, a cleaning blade that is disposed downstream of the cleaning roller in the moving direction of the photoconductor, and contacts the surface of the photoconductor; In the development by the developing unit, a constant current power supply that applies a bias voltage having a polarity opposite to the charging polarity of the toner that has contributed to the toner image formation to the cleaning roller, and a removing unit that removes collected toner from the cleaning roller; The image forming apparatus according to claim 1, wherein the photoconductor has a surface having a contact angle with pure water of 90 degrees or more.

17. The constant current power supply is 1 μA to 50 μA
The image forming apparatus according to the above item 16, wherein the current is outputted.

18. The cleaning roller is 10 ²
18. The image forming apparatus as described in 16 or 17, wherein the image forming apparatus has a surface resistivity of Ω / □ to 10 ¹⁰ Ω / □.

19. Any one of the above items 16 to 18, wherein the cleaning roller is made of an elastic material.
Item 10. The image forming apparatus according to item 1.

20. The image forming apparatus according to any one of claims 16 to 19, wherein the cleaning roller includes a foam material and a resin film covering the foam material.

21. 21. The image forming apparatus according to any one of 16 to 20, further comprising a recycling unit that supplies the toner collected by the cleaning unit to the developing unit and reuses the toner.

22. 22. The image forming apparatus according to any one of 16 to 21, wherein the removing unit includes a blade.

23. 23. The image forming apparatus according to any one of the items 16 to 22, wherein a plurality of the removing units are provided.

24. The cleaning blade has a.
24. The image forming apparatus according to any one of 16 to 23, wherein cleaning is performed by contacting the photoconductor with a counter method with a load of 1 g / cm to 30 g / cm.

25. The cleaning blade is at 0 °
25. The image forming apparatus according to any one of the items 16 to 24, wherein the cleaning is performed by contacting the photosensitive member with a contact angle of about 40 [deg.].

26. The cleaning blade has 20
26. The image forming apparatus according to any one of the items 16 to 25, wherein the image forming apparatus is made of an elastic body having a hardness in a range of ° to 90 °.

27. The developing means has a volume average particle size of 3
27. The image forming apparatus according to any one of the above items 16 to 26, wherein development is performed using a toner having a size of μm to 8.5 μm.

[0041]

DESCRIPTION OF THE PREFERRED EMBODIMENTS (1) First Embodiment of the Invention (Embodiments of the Inventions According to Claims 1 to 15) Image Forming Apparatus FIG. 2 shows an image forming apparatus according to a first embodiment of the present invention. Show. In the figure, reference numeral 1 denotes a photoconductor.

As the photoreceptor 1, an organic photoreceptor having a photosensitive layer in which an organic photoconductor is dispersed in a resin is preferable from the viewpoint of environment and cost. A photoreceptor whose performance is maintained is used.

The photosensitive member 1 is not limited to the illustrated drum-shaped photosensitive member, but may be a belt-shaped photosensitive member.
A charging unit 2 charges the photoconductor 1 and forms a uniform potential on the photoconductor 1. As the charging unit, a scorotron charger having a control grid and a discharge electrode or a contact charging type charger using a roller to which a voltage is applied is preferable.

Reference numeral 3 denotes an exposing means for exposing the photosensitive member 1.
The exposure means is preferably a scanning exposure apparatus having a laser diode as a light source and having a scanning optical system composed of a polygon mirror, a lens and a mirror, or a scanning optical apparatus having a light emitting diode array and an image forming optical fiber. The exposure unit 3 performs dot exposure on the photoconductor 1 according to the image data.

Reference numeral 4 denotes a developing means, which contains a one-component developer or a two-component developer, and conveys the developer to a development area by a developing sleeve 41 as a developer conveying means, and forms an electrostatic latent image on the photoreceptor 1. The image is developed to form a toner image on the photoconductor 1. A DC developing bias having the same polarity as the charging polarity of the charging means 2 or a developing bias in which a DC voltage having the same polarity as the charging polarity of the charging means 2 is superimposed on the developing sleeve 41 is applied to the developing sleeve 41. Reversal development in which toner is adhered to the portion is performed. The developing means 4 is not limited to reversal development. Of course, developing means for performing regular development using toner charged to the opposite polarity to the polarity of the electrostatic latent image can also be used.

Reference numeral 5 denotes a transfer unit including a corona charger. The transfer unit 5 charges the recording paper P with a polarity opposite to that of the toner on the photoconductor 1, and transfers the toner image to the recording paper P.

Numeral 6 denotes a separating means composed of a corona charger, which performs AC corona charging on the recording paper P to remove the charge from the recording paper P and separate it from the photoreceptor 1.

Reference numeral 7 denotes a fixing unit which fixes a toner image on the recording paper P by a heating roller 71 having a built-in heat source such as a halogen lamp, and a pressure roller 72 pressed against the heating roller 71.

Reference numeral 8 denotes a cleaning unit. Untransferred toner and untransferred toner adhere to the photoreceptor 1 after the transfer, and it is necessary to clean the photoreceptor 1 in order to perform the next image formation. The cleaning means 8 includes a cleaning blade 8 made of an elastic blade such as urethane rubber.
1 and a cleaning roller 82. The cleaning blade 81 is supported by a fixed blade holder 83, and the leading edge of the cleaning blade 81 is pressed against the photoconductor 1 with a substantially constant pressure due to the elasticity of the blade. As the blade holder 83, a blade holder that is rotatable about an axis and applies a constant pressing force to the cleaning blade 81 by a spring or gravity is also usable. The tip of the cleaning blade 81 contacts the photoreceptor 1 such that the tip and the surface of the photoreceptor 1 form an acute angle θ on the cleaned side, that is, the counter method.

Reference numeral 9 denotes a recycling unit which conveys the toner collected by the cleaning blade 81 and the cleaning roller 82 to the developing unit 4 and throws it into the developing unit 4 for reuse.

A bias voltage is applied to the cleaning roller 82 by a constant current power supply 84, and the toner on the photosensitive member 1 is electrostatically attracted to the cleaning roller 82. The polarity of the bias voltage contributes to the development in the developing unit 4 and is opposite to the polarity of the toner forming the toner image. As shown in FIG. 3, a scraper 89 as a removing means contacts the cleaning roller 82 in a counter manner, and removes the toner collected from the photoconductor 1 and adhered to the cleaning roller 82.

Next, the main configuration of the present embodiment will be described. Photoconductor First, the photoconductor 1 of FIG. 2 (hereinafter, referred to as the present photoconductor) used in the embodiment of the present invention will be described in detail.

The surface roughness of the photoreceptor greatly affects the area to which the toner adheres, and thus the scraping force for cleaning the toner.

As the present photoreceptor, a photoreceptor having a surface roughness Rz within a range of 0.1 μm to 2.5 μm at a reference length of 15 mm is used.

As described above, since the surface of the present photoreceptor is appropriately roughened, that is, having the above-mentioned surface roughness Rz, even when no toner is interposed between the photoreceptor and the cleaning blade, both of them can be used. Avoiding close contact,
The blade is prevented from being turned up due to the high frictional force between the two.

If the surface roughness Rz is less than 0.1 μm, the surface of the photoconductor is too smooth, the frictional force between the photoconductor and the cleaning blade is increased, and the blade is easily turned up.

If the surface roughness Rz is larger than 2.5 μm, the surface of the photosensitive member is excessively roughened, and the cleaning power of the cleaning blade is reduced and the amount of wear of the blade is increased. Cleaning defects such as black stripes and white stripes are likely to occur.

<< Method of Controlling Surface Roughness of Photoconductor; Ten-Point Average Roughness Rz Within a Range of 0.1 μm to 2.5 μm >> Next, a method of controlling the surface roughness of the photoconductor to a desired value Will be described.

As a method for controlling the ten-point average roughness Rz within the range of 0.1 μm to 2.5 μm, the surface roughness of the conductive support constituting the photoreceptor is appropriately roughened. It is effective.

As the material of the conductive support used in the present embodiment, a metal material such as aluminum, copper, brass, steel, stainless steel or the like, or a plastic material formed into a belt or a drum is used. Can be 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 embodiment has a roughened surface having a ten-point average surface roughness Rz of 0.1 μm.
Larger ones, not exceeding 2.5 μm, are preferred. 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, methods for roughening the surface of the support include 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 for roughening the surface of the photoreceptor, a method of adding fine particles of 0.1 μm to 5 μm to the surface layer of the photoreceptor can be considered. For example, Japanese Patent Application Laid-Open No. H8-248663
The surface roughness of the photoreceptor can be adjusted to the above range by dispersing the hydrophobic fine particles into the surface layer of the photoreceptor as described in (1). 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 Surface Roughness Rz The surface roughness Rz used in this embodiment is 1
The ten-point average roughness over a length L of 5 mm, that is, the difference between the average height of the top five peaks and the average low of the bottom five valleys.

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

In order to effectively improve the long-term cleaning property, image quality, photoreceptor durability and blade durability, the surface layer of the electrophotographic photoreceptor used in the present embodiment has a crosslinked structure. It becomes more remarkable by forming a layer containing a siloxane-based resin. 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, so that the surface of the photoconductor is not abraded by blade cleaning, and the surface layer of the electrophotographic photoconductor is applied. The surface shape formed after drying is maintained for a long time, and stable cleaning properties are maintained for a long time.

The photoreceptor according to the present embodiment (the present photoreceptor) having the surface layer containing the siloxane-based resin having the crosslinked structure can be formed by the method described below.

<< Photosensitive Member 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. It is formed by applying and drying an object. 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), the organic group in which carbon represented by R is directly bonded to silicon includes 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 compound 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 its hydrolytic condensate. 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, a metal oxide 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 gives the resin layer film of the present invention rigidity 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;
Represents an integer of 4. 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 photoreceptor, 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 excluding
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 photoreceptor, colloidal silica or another metal oxide may be added, but when colloidal silica or another metal oxide (J) is added, the above (H) + (I) (J) is 1 for 100 parts of the total mass of the components.
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), as the group having the charge transporting compound structure represented by B, there are 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, as the electron transport type, succinic anhydride, maleic anhydride, phthalic anhydride, pyromellitic anhydride, melitic anhydride, tetratocyanoethylene, tetratocyanoquinodimethane, nitrobenzene, dinitrobenzene, trinitrobenzene, tetranitrobenzene, 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 formula (2) are shown below. Examples of compounds in which Z is an oxygen atom in the general formula (2) are shown below.

[0087]

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[0088]

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[0089]

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[0090]

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[0091]

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[0092]

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

[0094]

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

[0096]

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Although the layer constitution of the present photoreceptor is not particularly limited,
In a negatively charged photoreceptor, an undercoat layer (U
CL) and a charge generation layer (C
GL) and a charge transport layer (CTL layer) in that order, and then 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. The photoreceptor having a single-layer structure employs a constitution 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. May be.

Further, the resin layer of the present photoreceptor may be configured to also serve as the photosensitive layer. That is, the charge transport layer or the charge generation layer of the functional separation 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 photoreceptor is most preferably formed as a surface layer of the present photoreceptor in order to take advantage of the characteristics of the resin layer. A surface layer may be further provided on the resin layer for the purpose of improving the slip characteristics at the start.

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 azurenium 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.

The photosensitive layer when the resin layer is not used as the photosensitive layer in the present photoreceptor: the charge generation layer (CGL), the charge transport layer (CTL layer) and the photosensitive layer of the single-layered photoreceptor are as follows. Resin can be used as the binder resin. 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, polycarbonate resin, silicone resin, melamine resin, and these resins A copolymer resin containing two or more of the repeating units.
In addition to these insulating resins, polymer organic semiconductors such as poly-N-vinyl carbazole may be used.

The ratio of the binder resin to the charge generating substance is preferably 20 to 600 parts by weight based on 100 parts by weight of the binder resin in the charge generating layer or the photosensitive layer of the single-layered 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 present photoreceptor is preferably 0.01 to 10 μm for the charge generation layer and 1 to 40 μm for the charge transport layer. In the case of the photosensitive layer of a single-layer photosensitive member, 1 to 40 μm
m is preferred. Each of the resin layers provided on the photosensitive layer preferably has a thickness of 0.1 to 5 μm.

The undercoat layer (UCL) used in the present photoreceptor is used to improve the adhesion between the conductive support and the photosensitive layer or to prevent charge injection from the support. Provided between the photosensitive layers, examples of the material of the undercoat layer include polyamide resins, vinyl chloride resins, vinyl acetate resins, and copolymer resins containing two or more of the repeating units of these resins. Can be 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.

Further, 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.

Here, the antioxidant is a typical antioxidant that reacts with an autoxidizable substance present in or on an electrophotographic 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, the hindered phenol means 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).

The 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.

[0112]

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(In the formula, 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, there are the following 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.

As the organic sulfur compounds, for example, there are 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.

[0118]

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[0119]

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[0120]

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[0121]

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The following compounds are commercially available antioxidants, for example, "Irganox 1076" and "Irganox 1" as hindered phenols.
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 a siloxane-based resin in the present photoreceptor, a siloxane-based resin composition is usually dissolved in a solvent and applied. As the solvent, alcohols such as methanol, ethanol, propanol, butanol, methylcellosolve and ethylcellosolve and derivatives thereof; ketones such as methyl ethyl ketone and acetone; esters such as ethyl acetate and butyl acetate are used.

It is preferable that the siloxane resin in the present photoreceptor is 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, but heating is preferably performed at about 60 to 160 ° C for 10 minutes to 5 hours, and more preferably at 90 to 120 ° C for 30 minutes to 2 hours. Is preferred.

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 and circular amount control type coating (a circular slide hopper is a typical example) are used in order to minimize dissolution of the lower layer film and to achieve uniform coating processing. 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.

Cleaning Roller The cleaning roller 82 is preferably a conductive or semiconductive and elastic cleaning roller.

A voltage having a polarity opposite to that of the toner involved in the development is applied to the cleaning roller 82 by the power supply 84. That is, when the development is performed with the negatively charged toner and the negatively charged toner forms a toner image, a positive bias voltage is applied to the cleaning roller 82 from the power supply 84.

As the cleaning roller, a rubber elastic body is used. As a material of such an elastic body, rubber such as conventionally known silicone rubber or urethane rubber, a foam, or a foam covered with a resin film is preferable.

The surface resistivity of the cleaning roller (Ω /
□) is room temperature and normal humidity (temperature 26 ° C., relative humidity 50%)
High Leicester IP (MPC-HT25) manufactured by Mitsubishi Yuka
0), values measured using an HA probe at an applied voltage of 10 V and a measurement time of 10 seconds.

The thickness of the conductive or semiconductive elastic layer depends on the surface resistivity and hardness of the material.
It is desirable to set the distance between 5 mm and 50 mm from the viewpoint of securing an appropriate resistance value and nip width. The volume resistivity of the roller material is preferably in the range of 10 ² Ωcm to ^{10 10} Ωcm.

The cleaning roller is conductive or semiconductive and preferably has a surface resistivity in the range of 10 ² Ω / □ to 10 ¹⁰ Ω / □. If the resistivity is lower than 10 ² Ω / □, banding or the like due to electric discharge is likely to occur. On the other hand, if it is higher than 10 ¹⁰ Ω / □, the potential difference between the photoconductor and the photoreceptor becomes low, and cleaning failure easily occurs.

It is preferable that the cleaning roller rotates so that the contact portion moves in the same direction as the surface of the photosensitive member. When the contact portion moves in the opposite direction, if excess toner is present on the surface of the image bearing member, the toner removed by the cleaning roller may spill out and stain the recording paper or the apparatus.

When the photosensitive member and the cleaning roller move in the same direction as described above, the surface speed ratio of the two is preferably in the range of 0.5: 1 to 2: 1. Outside this range, the speed difference between the two becomes large,
When foreign matter such as recording paper is caught between the photoconductor and the cleaning roller, the photoconductor may be damaged.

The cleaning roller has a hardness of 5 ° to 60 °.
Is preferable, and a range of 10 ° to 50 ° is particularly preferable. If the hardness is less than 5 °, the durability is insufficient, and the hardness is 60.
When the angle exceeds °, it becomes difficult to secure a contact width between the photoconductor and the cleaning roller required for cleaning, and in addition, the surface of the photoconductor is easily damaged. In addition,
The hardness of the cleaning roller is a value obtained by measuring the elastic body formed on the roller with an Asker C hardness meter (load: 300 gf).

The contact width between the photosensitive member and the cleaning roller is preferably 0.2 mm to 5 mm, more preferably 0.5 mm to 3 m.
The range of m is particularly preferred. When the contact width is less than 0.2 mm, the cleaning force is insufficient, and when the contact width is more than 5 mm, the photosensitive member is liable to be scratched by rubbing.

Bias Voltage A bias voltage is applied to the cleaning roller 82 from a power supply 84. The bias voltage is a voltage at which the toner adhering to the photoreceptor 1 is electrostatically attracted to the cleaning roller 82 and removed therefrom, and has a polarity opposite to the charging polarity of the toner. In the present embodiment using the negatively charged toner, the bias voltage is positive. As the power supply 84 for applying the bias voltage, a constant current power supply is used.

The constant current power source referred to here is a power source configured to control the output voltage according to the resistance between the cleaning roller and the photosensitive member so that a constant current value is always output.

An electrostatic charge is present on the photoreceptor 1 after the transfer,
Although the potential on the photoconductor 1 is not uniform, when a bias voltage is applied to the cleaning roller 82 from a constant current power supply to attract the toner electrostatically to the cleaning roller 82, the potential on the photoconductor 1 depends on the potential. An almost constant electric field that is not generated is formed between the surface of the photoconductor 1 and the surface of the cleaning roller 82, so that a uniform cleaning effect is obtained and an excellent cleaning effect is achieved. In addition, since a large potential difference does not locally occur, discharge is unlikely to occur.

The applied current value is 1 μA to 50 μm in absolute value.
The range of A is preferable. If it is smaller than 1 μA, the cleaning effect may be insufficient, and if it is larger than 50 μA, discharge or the like is likely to occur. This value varies depending on the type of the photoconductor and the resistance value of the cleaning roller.
An organic photoreceptor having a photosensitive layer of 0 μm and a surface resistivity of 1
When a cleaning roller having a resistance of 0 ² Ω / □ to 10 ¹⁰ Ω / □ is used, a range of 5 μA to 40 μA is preferable.

Removing Means As shown in FIG. 3, it is preferable to remove a removed material such as toner transferred from the photosensitive member 1 to the cleaning roller 82 by bringing a scraper 89 as a removing means into contact with the cleaning roller 82.

As the scraper 89, an elastic plate such as a phosphor bronze plate, a polyethylene terephthalate plate, a polycarbonate plate or the like is used, and the trailing end forms an acute angle on the non-cleaning side of the cleaning roller 82, or the cleaning end of the cleaning roller 82 ends. The cleaning roller 82 may be brought into contact with the cleaning roller 82 by any method of a counter method in which an acute angle is formed on the cleaning side.

As the removing means, a roller or a brush can be used in addition to the scraper. The toner collected by the scraper 89 is supplied to the developing unit 4 by the recycling unit 9 together with the toner collected by the cleaning blade 81, and is reused. A plurality of removing means such as a scraper 89 may be provided. When the bias voltage is increased to increase the cleaning force of the cleaning roller 82, the toner is electrostatically strongly adhered to the cleaning roller 82, and thus it is preferable to collect the toner with a plurality of scrapers.

Cleaning Blade The cleaning blade 81 is of a counter type in which an acute contact angle θ is formed on the cleaned side of the photoconductor 1 as shown in FIG. In contact, the toner is scraped off the photoreceptor 1.

The load of the cleaning blade at the leading edge of the cleaning blade is 0.1 g / cm to 30 g / cm.
Is preferable, and a value in the range of 1 g / cm to 25 g / cm is particularly preferable.

When the load is smaller than 0.1 g / cm,
The cleaning power is insufficient, the cleaning is incomplete, and the image is easily stained. If the load is greater than 30 g / cm, the surface of the photoreceptor will be greatly worn, and if the photoreceptor is used for a long period of time, the image will be blurred. The load may be measured by pressing the leading edge of the cleaning blade against the balance, or by electrically arranging a sensor such as a load cell at a pressure contact portion between the photosensitive member and the leading edge of the cleaning blade. A method or the like is used.

The contact angle θ of the tip of the cleaning blade to the photoreceptor is a value within the range of 0 ° to 40 °, particularly 0 °.
A value in the range of ２５25 ° is desirable. If the contact angle is greater than 40 °, the blade edge is likely to be turned, that is, the leading edge of the cleaning blade reverses following the photoconductor. On the other hand, when the angle is smaller than 0 °, the cleaning power is reduced, and image stains are likely to occur. An elastic body such as urethane rubber is used for the cleaning blade 81, and the hardness measured according to JIS K-6253 is 2
Those in the range of 0 ° to 90 ° are preferred.

If the angle is smaller than 20 °, the blade is too soft and the blade is easily turned. Also, if it is larger than 90 °,
Lack of ability to follow slight irregularities and foreign matter on the photoconductor
Slippage of toner particles is likely to occur. Hardness 60 ° -8
An angle of 0 ° is particularly preferred.

The hardness of the cleaning blade is JIS
It is a value measured by K6301.

The thickness of the cleaning blade 81 is preferably in the range of 1 mm to 3 mm, and
Particularly preferred is a range of m to 2.5 mm. The length of the portion not restricted by the blade holder 83, that is, the free length of the blade is preferably 2 mm to 20 mm, and 3 mm to 1 mm.
Particularly preferred is a range of 5 mm.

For the cleaning blade, a conventionally known elastic material such as polyurethane is used. As the toner used in the toner developing means 4, a toner produced by a conventionally known pulverization method of forming toner particles by pulverization or a granulation polymerization method of forming toner particles by polymerization can be used.

From the viewpoint of high image quality, the average particle size of the deposited particles is 8.5.
μm or less is desirable, and 7.0 μm or less is particularly preferred.

(2) Embodiment 2 of the Invention
(Embodiment of invention described in 27) The image forming apparatus has the above-described configuration shown in FIG.

The main components such as the cleaning roller 82, the bias voltage applied to the photoreceptor 1 by the power supply 84, the removing means exemplified by the scraper 89, the cleaning blade 81, the toner used in the developing means 4, etc. The one described in the first embodiment is used as it is. The following is used as the photoconductor 1.

The contact angle between the outermost layer surface of the photoreceptor used in the present embodiment (hereinafter referred to as the present photoreceptor) and pure water is preferably 90 degrees or more, and the upper limit thereof is 18 degrees.
0 degrees.

By using the photoreceptor having such a highly releasable surface, the abrasion of the cleaning roller is reduced, and a uniform electric field is formed between the photoreceptor and the cleaning roller to perform uniform cleaning. Cleaning defects such as generation of residual toner due to cleaning are prevented. In addition, since the photosensitive member and the cleaning roller move at a stable speed ratio at the contact portion, a cleaning electric field is stably formed, and uniform and good cleaning is performed. Further, the phenomenon that the toner transferred to the cleaning roller is transferred again to the photoreceptor is prevented, and excellent cleaning is performed.

The present photoreceptor, which is an electrophotographic photoreceptor having a highly releasable surface, is achieved by, for example, uniformly dispersing a fluororesin powder in the surface layer. Specific examples of the fluororesin powder include polymers such as tetrafluoroethylene, hexafluoropropylene, trifluoroethylene, chlorotrifluoroethylene, vinylidene fluoride, vinyl fluoride, and perfluoroalkyl vinyl ether, and copolymers thereof. Coalescing is used. The particle size of the fluororesin powder can be used in the range of 0.01 to 5 μm, and the molecular weight can be used in the range of 3000 to 5,000,000.

The fluororesin powder is dispersed as a photosensitive layer composition together with a binder resin. As a dispersion method, a sand mill, a ball mill, a roll mill, a homogenizer, a nanomizer, a paint shaker, an ultrasonic wave, or the like is used. At the time of dispersion, a fluorine-based surfactant, a graft polymer, a coupling agent, or the like may be additionally used.

The content of the fluororesin powder in the outermost surface layer of the photoreceptor is preferably 2 to 70% by mass, more preferably 4 to 55% by mass. If it is less than 2% by mass, the decrease in surface energy is insufficient, and if it exceeds 70% by mass, the film strength of the surface layer is reduced.

As the binder resin for dispersing the fluororesin powder, polyester, polyurethane, polyarylate, polyethylene, polystyrene, polybutadiene,
Examples include polycarbonate, polyamide, polypropylene, polyimide, polyamideimide, polysulfone, polyallyl ether, polyacetal, nylon, phenolic resin, acrylic resin, silicone resin, epoxy resin, urea resin, allyl resin, alkyd resin, butyral resin, and the like. Further, reactive epoxy and (meth) acrylic monomers and oligomers can be used after mixing and curing.

The photosensitive layer of the present photoreceptor has a single layer or a laminated structure. In the case of a stacked structure, a charge generation layer that generates photocarriers and a charge transport layer in which carriers move are stacked. The surface layer may be formed on either the charge generation layer or the charge transport layer.

The single-layer photosensitive layer can have a thickness of 5 to 100 μm, more preferably 10 to 60 μm. The charge generation material and the charge transport material are contained in an amount of 20 to 80% by mass, and more preferably 30 to 70% by mass. In the laminated photoreceptor, the thickness of the charge generation layer is 0.001 to 6 μm, more preferably 0.01 to 2 μm. The amount of the charge generation material is 10 to 100% by mass, and more preferably 40 to 100% by mass. The thickness of the charge transport layer is 5 to 100 μm, and more preferably 10 to 60 μm. The amount of charge transport material is 2
It is 0 to 80% by mass, and more preferably 30 to 70% by mass.

The charge generating materials used in the present embodiment include phthalocyanine pigments, polycyclic quinone pigments, azo pigments, perylene pigments, indigo pigments, quinacridone pigments,
Examples include azurenium salt dyes, squarylium dyes, cyanine dyes, pyrylium dyes, thiopyrylium dyes, xanthene dyes, quinone imine dyes, triphenylmethane dyes, styryl dyes, selenium, selenium-tellurium, amorphous silicon, and cadmium sulfide.

The charge transport material used in the present embodiment includes pyrene compounds, carbazole compounds, hydrazone compounds, N, N-dialkylaniline compounds, diphenylamine compounds, triphenylamine compounds, triphenylmethane compounds, pyrazoline compounds, and styryl compounds. And stilbene compounds.

In the present photoreceptor, a protective layer may be laminated on the photosensitive layer. The thickness of the protective layer can be 0.01 to 20 μm, more preferably 0.1 to 10 μm. The protective layer may contain the above-described charge generation material or charge transport material, a metal and its oxide, nitride, salt, alloy, or a conductive material such as carbon.

As the binder resin used for the protective layer,
Polyester, polyurethane, polyarylate, polyethylene, polystyrene, polybutadiene, polycarbonate, polyamide, polypropylene, polyimide, polyamideimide, polysulfone, polyallyl ether, polyacetal, nylon, phenolic resin, acrylic resin, silicone resin, epoxy resin, urea resin, allyl Resins, alkyd resins, butyral resins, and the like. Further, reactive epoxy and (meth) acrylic monomers and oligomers can be used after mixing and curing.

The conductive support used in the present photoreceptor is
Metals and alloys such as iron, copper, nickel, aluminum, titanium, tin, antimony, indium, lead, zinc, gold, and silver, and oxides, carbons, and conductive resins thereof can be used. The shapes include a cylindrical shape, a belt shape, and a sheet shape. The conductive material may be molded, but may be applied as a paint or may be deposited.

An undercoat layer may be provided between the conductive support and the photosensitive layer. The undercoat layer is mainly made of a binder resin, but may contain the conductive material or the acceptor.
Examples of the binder resin forming the undercoat layer include polyester, polyurethane, polyarylate, polyethylene, polystyrene, polybutadiene, polycarbonate, polyamide, polypropylene, polyimide, polyamideimide, polysulfone, polyallyl ether, polyacetal, nylon, phenolic resin, and acrylic resin. , Silicone resin, epoxy resin, urea resin, allyl resin, alkyd resin, butyral resin and the like.

For the method of manufacturing the present photoreceptor, methods such as vapor deposition and coating are used. For coating, a bar coater, knife coater, roll coater, attritor, spray, dip coating, electrostatic coating, powder coating, or the like is used.

[0170]

EXAMPLES In the examples described in the following [A] and [B], charging, exposure, development, transfer,
An image was formed using an image forming apparatus having elements for performing each of the fixing and cleaning processes.

Incidentally, a negatively charged OPC photoreceptor is used as the photoreceptor, a negative electrostatic latent image is formed on the photoreceptor, and a toner image is formed on the photoreceptor by reversal development using negatively charged toner. did.

The moving speed of the photosensitive member is 370 mm in linear speed.
/ Sec, and a volume average particle size of 6.5 μm as a toner.
Was used.

[A] Example of Embodiment 1 (1) Example A-1 Photoconductor The photoconductor A-1 was manufactured as follows.

<Intermediate layer> Titanium chelate compound (TC-750: manufactured by Matsumoto Pharmaceutical) 30 g Silane coupling agent (KBM-503: manufactured by Shin-Etsu Chemical Co., Ltd.) 17 g 2-propanol 150 ml 0.4 μm, provided on an aluminum drum substrate cut to have a dry film thickness of 0.4 μm.
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 Transport Layer> 200 g of a charge transport substance (4-methoxy-4 ′-(4-methyl-α-phenylstyryl) triphenylamine), 300 g of polycarbonate (TS2050: manufactured by Teijin Chemicals Limited), and 2,000 ml 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.
Was prepared.

(2) Example A-2 The photoreceptor A-2 was prepared as follows.

A present photoconductor A-2 was produced in the same manner as the present photoconductor A-1, except that the aluminum drum substrate of Example A-1 was cut so as to have a surface roughness of 0.3 μm. .

(3) Example A-3 The photoreceptor A-3 was prepared as follows.

A charge transport layer was prepared in the same manner as in the photoreceptor A-1. <Resin Layer> Methyltrimethoxysilane 150 g Phenyltrimethoxysilane 30 g Antioxidant (Exemplified 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 A-3 was formed.

(4) Comparative Example A-1 Comparative photosensitive member A-1 was prepared as follows.

Except for subjecting the aluminum drum substrate used in the production of the present photoreceptor A-1 to mirror finishing,
Comparative Photoconductor A-1 was prepared in the same manner as in Comparative Example 1.

(5) Comparative Example A-2 A comparative photosensitive member A- was prepared in the same manner as the present photosensitive member A-1, except that an aluminum drum base machined so that the surface roughness of the base tube became 2.5 μm was used. 2 was produced. Photoconductor A-1
A-3 and surface roughness Rz of comparative photoconductors A-1 and A-2
With a surface roughness meter (Surfcoder manufactured by Kosaka Laboratory Co., Ltd.)
SE-30H). The measurement value conditions and measurement results are shown below.

Measurement conditions Measurement speed: 0.1 mm / s Measurement distance: 15 mm Stylus: 2 μm Cleaning roller Made of conductive urethane foam, with a surface resistivity of 10 ³ Ω /
□, a cleaning roller composed of an elastic roller having a hardness of 30 °. A roller formed by winding urethane (having a thickness of 25 mm) around a metal shaft having a diameter of 6 mm so as to have a diameter of 16 mm so as to have a contact width of 2 mm with respect to a photosensitive member. I let it.

At the contact portion, the photosensitive member moves in the forward direction at a peripheral speed ratio of 1: 1. Bias voltage 20μA with constant current power supply for cleaning roller
And a positive bias voltage was applied.

Removing Means Two SUS scrapers were brought into contact with the cleaning roller by a counter method.

Cleaning Blade A cleaning blade made of urethane rubber having a thickness of 2.00 mm, a free length of 10 mm, and a hardness of 70 ° was contacted at a contact angle of 15 °.
It was brought into contact with the photoreceptor by a counter method of °. Contact weight is 2
It was 0 g / cm.

Developer A two-component developer composed of a toner and a carrier was used, and the toner was produced by a granulation polymerization method using a volume average particle diameter of 6.
The thing of 5 μm was used.

As a result of conducting an image forming experiment on 200,000 sheets under the above conditions and the following environmental conditions, the following results were obtained.

A. High temperature and high humidity (temperature 3
0 ° C., relative humidity 80%) b. Normal temperature and normal humidity (temperature: 20 ° C., relative humidity: 50%) for 100,000 to 200,000 sheets. In Examples A-1 to A-3, the image formation of 200,000 sheets was performed without causing blade turning up. An image of high quality was obtained.

With respect to Comparative Example A-1, the initial (1
Blade formation occurs in the formation of 10,000 images)
The imaging experiment had to be stopped.

In Comparative Example A-2, a good image was formed in the same manner as in the example up to the formation of 130,000 sheets of images, but after 130,000, cleaning failure due to wear of the cleaning blade occurred. Black or white streaks occurred on the image. This tendency became remarkable as the image forming process progressed, and the image formation was stopped at 150,000 sheets.

[B] Example of Embodiment 2 Photoconductor (1) Example B-1 A photoconductor (hereinafter referred to as the present photoconductor) B-1 according to the present embodiment was manufactured as follows. .

10 parts by mass of conductive titanium oxide (tin oxide coating, average primary particle size 0.4 μm), 10 parts by mass of phenol resin precursor (resole type), 10 parts by mass of methanol,
And 10 parts by mass of butanol after sand mill dispersion,
After dip coating on an aluminum cylinder and curing at 140 ° C., a conductive layer having a volume resistivity of 5 × 10 ⁹ Ωcm and a thickness of 20 μm was provided.

Next, 10 parts by mass of methoxymethylated nylon having the following structural formula (methoxymethylation degree: about 30%)

[0196]

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After mixing and dissolving 150 parts by mass of isopropanol, dip coating was performed on the conductive layer to form an undercoat layer of 1 μm.

Next, 4 parts by mass of TiOPc having strong peaks at 9.5 degrees and 27.1 degrees in the diffraction angle 2θ ± 0.2 degrees in the X-ray diffraction spectrum of CuKα and polyvinyl butyral (trade name: Eslec BM2, Sekisui Chemical 2 parts by mass) and 60 parts by mass of methyl ethyl ketone were dispersed in a sand mill using φ1 mm glass beads for 4 hours to prepare a dispersion for a charge generation layer. This is dip coated, 0.3μ
m of charge generation layers.

Next, triphenylamine 1 having the following structural formula
0 parts by mass,

[0200]

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10 parts by mass of a polycarbonate resin (bisphenol Z, viscosity average molecular weight 20,000), 50 parts by mass of monochlorobenzene, and 15 parts by mass of dichloromethane were mixed by stirring, and then dip-coated on the charge generation layer.
A 0 μm charge transport layer was provided.

Next, an acrylic monomer 3 having the following structural formula
0 parts by mass,

[0203]

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50 parts by mass of ultrafine tin oxide particles having an average particle size of 400 ° C. before dispersion, 20 parts by mass of fine powder of polytetrafluoroethylene resin (average particle size: 0.18 μm), 2-methylthioxanthone 18 as a photopolymerization initiator Parts by mass and 150 parts by mass of ethanol were dispersed in a sand mill for 66 hours.

A film was formed by dip coating the above-prepared solution on the above-mentioned charge transporting layer, and 800 W / cm was applied with a high-pressure mercury lamp.
Light curing was performed for 60 seconds at a light intensity of ² and then 120
C. for 2 hours in hot air to obtain a surface layer. At this time, the thickness of the obtained surface layer was 3 μm.

(2) Examples B-2 and B-3 The photoreceptors B-2 and B-3 were produced as follows.

The same aluminum drum, conductive layer, undercoat layer, charge generation layer and charge transport layer as those of Example B-1 were prepared.

Next, 30 parts by mass of the same acrylic monomer as in Example B-1, 50 parts by mass of ultrafine tin oxide particles,
2 parts by mass of a polytetrafluoroethylene resin fine powder, 18 parts by mass of a photopolymerization initiator, and 150 parts by mass of ethanol were dispersed in a sand mill for 66 hours.

Separately, 30 parts by mass of an acrylic monomer, 50 parts by mass of ultrafine tin oxide particles, 6 parts by mass of polytetrafluoroethylene resin fine powder, 18 parts by mass of a photopolymerization initiator, ethanol 150 parts by mass were dispersed in a sand mill for 66 hours. A film was formed from these prepared solutions on the above-mentioned charge transport layer by a dip coating method, and a surface layer of 3 μm was obtained under the same conditions as in Example B-1.

(3) Comparative Example A comparative photoreceptor was produced as follows.

In the present photoreceptor B-1, a photoreceptor in which no fine powder of polytetrafluoroethylene resin was mixed in the surface layer was used as a comparative photoreceptor.

[Contact Angle] The contact angle of the surface of the photosensitive drum with respect to pure water was compared using a drop-type contact angle meter.
As a result, the contact angle of the photoreceptor of Example B-1 showed a large value of 118 degrees, realizing a low energy surface, while the comparative photoreceptor achieved a small contact angle of 80 degrees and obtained a low energy surface. I couldn't.

Cleaning roller Made of conductive urethane foam and having a surface resistivity of 10 ³ Ω /
□, a cleaning roller composed of an elastic roller having a hardness of 30 °, in which urethane was wound around a 6 mm-diameter metal shaft so as to have a diameter of 16 mm (thickness: 25 mm) and was brought into contact with the photoreceptor so as to have a contact width of 2 mm.

At the contact portion, the photosensitive member moves in the forward direction at a peripheral speed ratio of 1: 1. Bias voltage 20μA with constant current power supply for cleaning roller
And a positive bias voltage was applied.

Removing Means A SUS scraper was brought into contact with the cleaning roller by a counter method.

Cleaning Blade A cleaning blade made of urethane rubber having a thickness of 2.00 mm, a free length of 10 mm, and a hardness of 70 ° was contacted at a contact angle of 15 °.
It was brought into contact with the photoreceptor by a counter method of °. Contact weight is 2
It was 0 g / cm.

Developer A two-component developer consisting of a toner and a carrier is used, and the toner has a volume average particle diameter produced by a granulation polymerization method.
The thing of 5 μm was used.

An image forming experiment was conducted on 200,000 sheets under the above conditions and the following environmental conditions. As a result, the following results were obtained.

A. Normal temperature and normal humidity (temperature 2
0 ° C, 50% relative humidity) b. In 100,000 to 200,000 sheets, low temperature and low humidity (temperature: 10 ° C., relative humidity: 20%) In Examples B1 to B3, no cleaning failure occurred until image formation of 200,000 sheets, and image defects such as black stripes and white stripes It has been confirmed that high-quality images free from defects can be output stably.

In the comparative example, initial (up to 100,000 sheets)
Although good images were obtained up to, cleaning failure occurred due to abrasion of the surface of the cleaning roller in image formation of 130,000 or more sheets, and white streaks and black streaks occurred in the images. This tendency becomes remarkable as the image formation progresses,
At the end of 150,000 sheets, the bias voltage is set to +55 μA.
As a result, the white stripes and the black stripes disappeared, but discharge from the cleaning roller to the photosensitive member occurred, and a good image was not obtained.

[0221]

According to the first, third, fourth or fifth aspect of the present invention,
The blade is prevented from being turned up by the cleaning action of the cleaning roller, and high-performance cleaning means is realized for a long period of time. As a result, it is possible to use the toner having a small particle diameter, and an image forming apparatus capable of forming a high-quality image for a long period of time is realized.

According to the second or seventeenth aspect of the present invention, uniform cleaning performance is obtained irrespective of the level of the potential existing on the photosensitive member, and a high-quality image can be formed.

According to the invention of claim 6 or 21, an image forming apparatus which consumes a small amount of toner, generates no waste toner, and has a low environmental load is realized.

According to the invention of claim 7 or 22, since the cleaning performance of the cleaning roller is maintained satisfactorily for a long period of time, it is possible to form a high-quality image for a long period of time.

According to the invention of claim 8 or 23, the cleaning performance of the cleaning roller is maintained more favorably over a long period of time.

According to the ninth, tenth, or eleventh aspect of the present invention, a long-life photoreceptor is used in which abrasion due to cleaning is small and image forming performance and cleaning performance are maintained high for a long period of time. And an image forming apparatus in which excellent image forming performance is maintained.

According to the twelfth, thirteenth, fourteenth, twenty-fourth, twenty-fourth, and twenty-sixth aspects of the present invention, an image forming apparatus capable of forming a high-quality image with good cleaning and no image contamination can be realized.

According to the fifteenth or twenty-seventh aspect of the present invention, an image forming apparatus having high resolution and capable of forming an image with excellent gradation expression is realized.

According to the invention of claim 16, 18, 19, or 20, cleaning failure due to wear of the cleaning roller, instability of the peripheral speed ratio of the photosensitive member of the cleaning roller at the contact portion, and toner transfer from the cleaning roller to the photosensitive member. Retransfer and the like are prevented, and poor cleaning due to these is prevented. As a result, high image quality is maintained over a long period of time, and it is possible to form a high quality image using a small particle size toner.

[Brief description of the drawings]

FIG. 1 is an enlarged view of a contact portion between a photoconductor and a cleaning roller.

FIG. 2 is a diagram illustrating an image forming apparatus according to an embodiment of the present invention.

FIG. 3 is a diagram illustrating a cleaning unit of the image forming apparatus of FIG. 2;

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Photoconductor 2 Charging means 3 Exposure means 4 Developing means 5 Transfer means 6 Separation means 7 Fixing means 8 Cleaning means 9 Recycling means 81 Cleaning blade 82 Cleaning roller 84 Power supply 89 Scraper

──────────────────────────────────────────────────続 き Continued on the front page (51) Int.Cl. ⁷ Identification symbol FI Theme coat ゛ (Reference) G03G 5/147 G03G 5/147 502 502 9/08 9/08 21/00 312 15/08 507 15/08 507D 507L 21/00 318 326 F-term (reference) 2H005 EA05 2H034 BA01 BC03 BC04 BC05 BC07 BC08 BC09 BF01 BF03 BF05 BF06 BF07 CA01 CB01 2H068 AA09 AA29 AA41 AA59 BB32 BB44 BB49 AD37 FC03 2 AA02 FA07 GA02 GA57 GA58 HA12 HA20 HA41

Claims (27)

[Claims] A photoconductor, a latent image forming unit for forming an electrostatic latent image on the photoconductor, a developing unit for developing the electrostatic latent image on the photoconductor to form a toner image on the photoconductor; An image forming apparatus comprising: a transfer unit that transfers a toner image on the photoconductor to a recording material; and a cleaning unit that cleans the photoconductor after the transfer, wherein the cleaning unit has a conductive or A cleaning roller having a semiconductive elastic body, a cleaning blade disposed downstream of the cleaning roller in the direction of movement of the photoconductor, and a cleaning blade in contact with the surface of the photoconductor. A constant current power supply for applying a bias voltage having a polarity opposite to the charged polarity of the toner to the cleaning roller and removing the toner from the cleaning roller. And the photosensitive member has a removing means for the surface roughness R
z is in the range of 0.1 μm to 2.5 μm. 2. The image forming apparatus according to claim 1, wherein the constant current power supply outputs a constant current of 1 μA to 50 μA. 3. The cleaning roller according to claim 1, wherein the cleaning roller has a resistance of 10 ² Ω /
The image forming apparatus according to claim 1, wherein the image forming apparatus has a surface resistivity of □ to 10 ¹⁰ Ω / □. 4. The image forming apparatus according to claim 1, wherein the cleaning roller is made of an elastic material. 5. The image forming apparatus according to claim 1, wherein the cleaning roller includes a foam material and a resin film covering the foam material. 6. The image forming apparatus according to claim 1, further comprising a recycling unit that supplies the toner collected by the cleaning unit to the developing unit and reuses the toner.
Item 10. The image forming apparatus according to item 1. 7. The image forming apparatus according to claim 1, wherein said removing unit comprises a blade. 8. The image forming apparatus according to claim 1, wherein a plurality of said removing units are provided. 9. The image forming apparatus according to claim 1, wherein the photoconductor has a surface layer containing a siloxane-based resin having a crosslinked structure. 10. The image forming apparatus according to claim 1, wherein the photoconductor has a surface layer containing a siloxane-based resin having a structural unit having charge transporting performance. . 11. A structure in which the photoreceptor has a conductive support, an intermediate layer, a photosensitive layer, and a surface layer containing a siloxane-based resin having a crosslinked structure, and the various layers are laminated in the above order. The image forming apparatus according to claim 1, further comprising: 12. The cleaning blade according to claim 11, wherein
The image forming apparatus according to any one of claims 1 to 11, wherein cleaning is performed by contacting the photoconductor with a counter method with a load of g / cm to 30 g / cm. 13. The cleaning blade according to claim 1, wherein
2. The cleaning device according to claim 1, wherein the cleaning is performed by contacting the photoconductor with a counter method at a contact angle θ of 40 °.
13. The image forming apparatus according to any one of claims 12 to 12. 14. The cleaning blade according to claim 1, wherein
The image forming apparatus according to any one of claims 1 to 13, wherein the image forming apparatus is made of an elastic body having a hardness in a range of 90 to 90 °. 15. The developing means has a volume average particle diameter of 3 μm.
The image forming apparatus according to any one of claims 1 to 14, wherein development is performed using a toner of m to 8.5 m. 16. A photoreceptor, a latent image forming means for forming an electrostatic latent image on the photoreceptor, a developing means for developing the electrostatic latent image on the photoreceptor to form a toner image on the photoreceptor, An image forming apparatus comprising: a transfer unit that transfers a toner image on the photoconductor to a recording material; and a cleaning unit that cleans the photoconductor after the transfer, wherein the cleaning unit has a conductive or A cleaning roller having a semiconductive elastic body, a cleaning blade disposed downstream of the cleaning roller in the direction of movement of the photoconductor, and a cleaning blade in contact with the surface of the photoconductor. A constant-current power supply for applying a bias voltage having a polarity opposite to the polarity of the toner that has contributed to the cleaning roller, and collecting toner from the cleaning roller; And it has a removal means for removing said photosensitive member, an image forming apparatus having a contact angle with pure water and having a surface of more than 90 degrees. 17. The image forming apparatus according to claim 16, wherein the constant current power supply outputs a current of 1 μA to 50 μA. 18. The cleaning roller according to claim 1, wherein the cleaning roller has a resistance of 10 ² Ω.
The image forming apparatus according to claim 16, wherein the image forming apparatus has a surface resistivity of / 10 to 10 ¹⁰ Ω / □. 19. The cleaning device according to claim 16, wherein the cleaning roller is made of an elastic material.
Item 10. The image forming apparatus according to item 1. 20. The image forming apparatus according to claim 16, wherein said cleaning roller comprises a foam material and a resin film covering said foam material. 21. The image forming apparatus according to claim 16, further comprising a recycling unit that supplies the toner collected by the cleaning unit to the developing unit and reuses the toner. 22. An image forming apparatus according to claim 16, wherein said removing means comprises a blade. 23. The image forming apparatus according to claim 16, wherein a plurality of said removing units are provided. 24. The cleaning blade, wherein:
The image forming apparatus according to any one of claims 16 to 23, wherein cleaning is performed by contacting the photoconductor with a counter method with a load of g / cm to 30g / cm. 25. The cleaning blade according to claim 1, wherein
The image forming apparatus according to any one of claims 16 to 24, wherein cleaning is performed by contacting the photosensitive member with a contact angle of 40 °. 26. The cleaning blade according to claim 20, wherein:
The image forming apparatus according to any one of claims 16 to 25, wherein the image forming apparatus is made of an elastic body having a hardness in a range of 90 to 90 degrees. 27. The developing device according to claim 27, wherein the volume average particle diameter is 3 μm.
The image forming apparatus according to any one of claims 16 to 26, wherein development is performed using a toner of m to 8.5 m.