JP7452215B2 - Cleaning blade, process cartridge, and image forming device - Google Patents

Description

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

Conventionally, in electrophotographic image forming apparatuses, residual toner adhering to the surface of an image bearing member (sometimes referred to as a member to be cleaned) after a toner image is transferred to a recording medium or an intermediate transfer member during the image forming process is removed. , removed by cleaning means.

As the cleaning means, a cleaning blade is used because it has a simple structure and has excellent cleaning performance. The cleaning blade is usually composed of an elastic member made of polyurethane rubber or the like and a support member. and supporting a proximal end of the elastic member with a support member, pressing a contact portion (tip ridgeline portion) of the elastic member against the surface of the image carrier to dam up toner remaining on the surface of the image carrier; It is scraped off and removed.

In the cleaning means using the cleaning blade, since the cleaning blade and the image carrier are in contact with each other, friction occurs between the cleaning blade and the image carrier, and the force necessary to rotate the image carrier is generated. A problem may occur in which the torque increases and the image carrier stops. Furthermore, due to the sliding friction between the cleaning blade and the image carrier, the abutment part may wear out, the abutment part may turn over, and toner may slip through the turned-up part, resulting in a problem of poor cleaning. be.

For this purpose, it is possible to apply a lubricant to the abutting part of the cleaning blade (see, for example, Patent Documents 1 and 2), or to modify the abutting part of the cleaning blade with a curable composition or the like (for example, see Patent Documents 1 and 2). (See References 3 and 4) have been proposed.
Further, when assembling the image forming apparatus and replacing the cleaning blade, a step of applying toner or a metal soap such as zinc stearate to the contact portion of the cleaning blade, which is called touch-up, is performed. , it may also prevent problems such as those mentioned above.

SUMMARY OF THE INVENTION An object of the present invention is to provide a cleaning blade that can suppress an increase in torque and provide good cleaning performance even immediately after the start of use.

The cleaning blade of the present invention as a means for solving the above problems includes:
A cleaning blade having an elastic member that comes into contact with a surface of a member to be cleaned and removes residue on the surface of the member to be cleaned,
The elastic member has a coating layer containing fine particles and a binder resin,
The coating layer is formed on at least a portion of the contact portion including the contact side where the elastic member and the member to be cleaned contact, including the contact side;
The coating layer has a surface roughness (Ra) of 0.08 μm to 0.5 μm.

According to the present invention, it is possible to provide a cleaning blade that can suppress an increase in torque and provide good cleaning performance even immediately after the start of use.

FIG. 1 is a schematic cross-sectional view of an example showing a state in which a cleaning blade is in contact with the surface of an image carrier. FIG. 2 is a perspective view showing an example of the cleaning blade of the present invention. FIG. 3 is a schematic cross-sectional view showing an example of the image forming apparatus of the present invention. FIG. 4 is a schematic cross-sectional view showing an example of an image forming unit in the image forming apparatus shown in FIG. FIG. 5 is a schematic diagram showing a method of forming a coating layer performed in an example.

(cleaning blade)
The cleaning blade of the present invention is a cleaning blade having an elastic member that comes into contact with the surface of a member to be cleaned and removes residue attached to the member to be cleaned.
The elastic member has a coating layer containing fine particles and a binder resin, and further has other members as necessary.

Usually, the cleaning blade (hereinafter also referred to as the "blade") and the image carrier (hereinafter also referred to as the "photoreceptor") are increased in sliding properties to prevent the blade from turning over, or the photoreceptor is removed by increasing the torque. In order to reduce the torque so that the blade does not stop, a process (commonly known as touch-up) is performed in which toner or metal soap such as zinc stearate is applied to the tip of the blade when assembling the unit or replacing the blade. As the image forming apparatus operates, toner gradually accumulates between the blade and the photoconductor, and when this state is reached, the behavior of the blade becomes stable, so the metal soap (touch-up agent) must function until this state is reached. Bye.

However, conventional touch-ups are often performed manually, and the amount of touch-up agent applied may vary depending on the person performing the work. Further, the conventional touch-up agent has a problem in that it comes off from the cleaning blade before the behavior of the cleaning blade becomes stable.
Due to these causes, cleaning failure due to curling of the cleaning blade and increase in torque of the image carrier may occur before the behavior of the cleaning blade becomes stable.

Furthermore, there is a trade-off relationship between preventing an increase in torque and improving cleaning performance. In order to prevent the torque from increasing, if the contact portion of the cleaning blade is made smooth, particles such as toner may slip through the cleaning blade, resulting in poor cleaning performance. On the contrary, if the contact portion of the cleaning blade is made uneven in order to improve cleaning performance, the torque increases. For this reason, it has been difficult to improve cleaning performance while preventing an increase in torque.

As one method for preventing an increase in torque and improving cleaning performance, a method has been proposed in which particles (fine particles) are placed on the contact portion of the cleaning blade.
Japanese Patent No. 2853598 discloses a cleaning method in which PMMA (polymethyl methacrylic acid) particles are dispersed in a fluorinated solvent and dropped onto the tip of the blade to improve the sliding properties between the cleaning blade and the photoreceptor. Blade is listed.
However, if particles dispersed in a solvent are simply applied, the adhesion of the fine particles to the cleaning blade is weak, so that they tend to separate from the cleaning blade. Therefore, the problem that the cleaning blade sometimes turns over and the torque of the image carrier increases before the behavior of the cleaning blade becomes stable remains unsolved.

Therefore, the present inventors investigated a method for preventing the particles from detaching from the cleaning blade. As a result, we found that it is possible to prevent particle detachment by dispersing particles in a mixture of solvent and binder resin and applying the dispersion to the cleaning blade, instead of dispersing particles only in a solvent. I found it. Furthermore, the inventors have discovered that by setting the surface roughness Ra of the part to which the particles are applied to 0.08 to 0.5 μm, it is possible to prevent the cleaning blade from turning over and from increasing the torque of the image carrier, leading to the completion of the present invention. .

<Elastic member>
The elastic member has a coating layer, and further has other members as necessary.

The shape, material, size, structure, etc. of the elastic member are not particularly limited, and can be appropriately selected depending on the purpose. Examples of the shape of the elastic member include a flat plate, a strip, a sheet, and the like. The size of the elastic member is not particularly limited and can be appropriately selected depending on the size of the member to be cleaned.
The material of the elastic member is not particularly limited and can be appropriately selected depending on the purpose, but polyurethane rubber, polyurethane elastomer, etc. are preferable because they tend to have high elasticity.

The elastic member is not particularly limited and can be appropriately selected depending on the purpose. For example, a polyurethane prepolymer is prepared using a polyol compound and a polyisocyanate compound, and a curing agent and a curing agent are added to the polyurethane prepolymer. Add a curing catalyst if necessary, crosslink in a specified mold, post-crosslink in a furnace, form into a sheet by centrifugal molding, leave at room temperature, mature, and form into specified dimensions. , manufactured by cutting into flat plates.

The polyol compound is not particularly limited and can be appropriately selected depending on the purpose, and examples thereof include high molecular weight polyols, low molecular weight polyols, and the like.
Examples of the high molecular weight polyols include polyester polyols that are condensates of alkylene glycol and aliphatic dibasic acids; ethylene adipate ester polyols, butylene adipate ester polyols, hexylene adipate ester polyols, ethylene propylene adipate ester polyols, and ethylene butylene. Polyester polyols such as polyester polyols of alkylene glycol and adipic acid such as adipate ester polyols and ethylene neopentylene adipate ester polyols; polycaprolactone polyols such as polycaprolactone ester polyols obtained by ring-opening polymerization of caprolactone; Examples include polyether polyols such as oxytetramethylene) glycol and poly(oxypropylene) glycol. These may be used alone or in combination of two or more.

Examples of the low molecular weight polyol include 1,4-butanediol, ethylene glycol, neopentyl glycol, hydroquinone-bis(2-hydroxyethyl)ether, and 3,3'-dichloro-4,4'-diaminodiphenylmethane. , 4,4'-diaminodiphenylmethane and other dihydric alcohols; 1,1,1-trimethylolpropane, glycerin, 1,2,6-hexanetriol, 1,2,4-butanetriol, trimethylolethane, Examples include trihydric or higher polyhydric alcohols such as 1,1,1-tris(hydroxyethoxymethyl)propane, diglycerin, and pentaerythritol. These may be used alone or in combination of two or more.

The polyisocyanate compound is not particularly limited and can be appropriately selected depending on the purpose, for example, methylene diphenyl diisocyanate (MDI), tolylene diisocyanate (TDI), xylylene diisocyanate (XDI), naphthylene 1,5 -diisocyanate (NDI), tetramethylxylylene diisocyanate (TMXDI), isophorone diisocyanate (IPDI), hydrogenated xylylene diisocyanate (H6XDI), dicyclohexylmethane diisocyanate (H12MDI), hexamethylene diisocyanate (HDI), dimer acid diisocyanate (DDI), Examples include norbornene diisocyanate (NBDI), trimethylhexamethylene diisocyanate (TMDI), and the like. These may be used alone or in combination of two or more.

The curing catalyst is not particularly limited and can be appropriately selected depending on the purpose, and examples thereof include 2-methylimidazole, 1,2-dimethylimidazole, and the like.
The content of the curing catalyst is not particularly limited and can be appropriately selected depending on the purpose, but is preferably 0.01% by mass to 0.5% by mass, and 0.05% by mass to 0.3% by mass. is more preferable.

The JIS-A hardness of the elastic member is not particularly limited and can be appropriately selected depending on the purpose, but is more preferably from 65 degrees to 83 degrees. When the JIS-A hardness is within a preferable range, the following problems can be prevented.
- It is difficult to obtain linear blade pressure, and the area of contact with the image carrier tends to expand, resulting in poor cleaning.
・The problem is that it becomes too hard and tends to chip.
The elastic member is not particularly limited and can be selected as appropriate depending on the purpose, but it is recommended to use a laminate that is integrally molded with two or more types of rubber with different JIS-A hardnesses to improve wear resistance and conformability. This is preferable because it allows both gender and gender to be compatible.
Here, the JIS-A hardness of the elastic member can be measured using, for example, Micro Rubber Hardness Meter MD-1 manufactured by Kobunshi Keiki Co., Ltd.

The rebound modulus of the elastic member according to the JIS K6255 standard is not particularly limited and can be appropriately selected depending on the purpose, but is preferably 36% to 73% at 23°C, and 52% to 73%. More preferred. When the repulsion elasticity coefficient is within a preferable range, the following problems can be prevented.
- A problem in which the entire elastic member loses its flexibility and cannot follow the vibrations and roughness of the image carrier, resulting in poor cleaning.
- A problem where the repulsion becomes too strong, causing blade squeal.
Here, the impact resilience coefficient of the elastic member is, for example, based on the JIS K6255 standard and measured at 23°C as No. 1 manufactured by Toyo Seiki Seisakusho Co., Ltd. It can be measured using a 221 resilience tester.

The average thickness of the elastic member is not particularly limited and can be appropriately selected depending on the purpose, but is preferably 1.0 mm to 3.0 mm.

<<Coating layer>>
The coating layer (surface coating layer) is formed on at least a portion of the contact portion including the contact side where the elastic member and the member to be cleaned, which will be described later, contact.
The covering layer is preferably formed on the entire contact side, and may be formed on the entire elastic member.
The coating layer contains fine particles and a binder resin, and further contains other components as necessary.

-Fine particles-
The fine particles are not particularly limited and can be appropriately selected depending on the purpose, and include, for example, fine particles of inorganic compounds, fine resin particles, and the like.
Examples of the inorganic compound fine particles include silica, alumina, and zirconia.
Examples of the resin fine particles include fluororesins, acrylic resins, styrene resins, and vinyl diameter resins.
These may be used alone or in combination of two or more. Among these, fluororesins are preferred.

Examples of the fluororesin (fluororesin fine particles, fluororesin micropowder) include polytetrafluoroethylene (PTFE), fluorinated ethylene-propylene copolymer (FEP), and perfluoroalkoxy polymer (PFA). , chlorotrifluoroethylene copolymer (CTFE), tetrafluoroethylene-chlorotrifluoroethylene copolymer (TFE/CTFE), ethylene-chlorotrifluoroethylene copolymer (ECTFE), polychlorotrifluoroethylene (PCTFE) Examples include.
Among these, PTFE is preferred as it has the best properties among resin materials. Such micropowder of fluororesin such as PTFE is obtained by emulsion polymerization method.

Polytetrafluoroethylene (PTFE) may be appropriately synthesized or a commercially available product. Examples of the commercially available products include Dyneon TF Micro Powder TF-9201Z, Dyneon TF Micro Powder TF-9207Z (all manufactured by 3M), Nano FLON119N, FLUORO E (all manufactured by Shamrock), and TLP10F-1 (all manufactured by Mitsui). - DuPont Fluorochemical Co.), KTL-500F (manufactured by Kitamura Co., Ltd.), and Algoflon L203F (manufactured by SOLVAY).

The shape of the fine particles is not particularly limited and can be appropriately selected depending on the purpose, but is preferably spherical.
The volume average particle diameter of the fine particles is not particularly limited and can be selected as appropriate depending on the purpose, but the volume-based average particle diameter measured by laser diffraction/scattering method, dynamic light scattering method, image imaging method, etc. (50% volume diameter, median diameter) is preferably 1 μm or less, more preferably 0.5 μm or less, and even more preferably 0.3 μm or less.
When the volume average particle diameter is 1 μm or less, it is possible to prevent problems such as easy sedimentation in a solvent and difficulty in stable dispersion. Moreover, if it is 0.5 μm or less, it can be more stably dispersed in the non-aqueous solvent described below.
The volume average particle diameter of the fine particles is preferably 0.1 μm or more.
The volume average particle diameter of the fine particles can be measured, for example, by collecting the fine particles from a cleaning blade and measuring them by a laser diffraction/scattering method using a Microtrack (manufactured by Nikkiso Co., Ltd.), or by using a scanning electron microscope ( Examples include a method of directly observing and measuring the particles on the cleaning blade using an SEM (SEM).
Note that the volume average particle diameter of the fine particles is almost the same between the fine particles added to the coating layer when manufacturing the cleaning blade and the fine particles present in the coating layer.

-Binder resin-
The binder resin is not particularly limited as long as it can uniformly and stably disperse the above-mentioned fine particles, and can be selected as appropriate depending on the purpose, but includes vinyl butyral, vinyl acetate, and vinyl alcohol as constituent units. Terpolymers (terpolymers) are preferred.
The terpolymer is made by reacting polyvinyl alcohol (PVA) with butyraldehyde (BA), and has a structure having a butyral group, an acetyl group, and a hydroxyl group. By changing the ratio of vinyl butyral, vinyl acetate, and vinyl alcohol in the terpolymer, it is possible to control the solubility in the non-aqueous solvent described below.

The terpolymer may be synthesized as appropriate, or a commercially available product may be used. As the commercially available products, S-LEC B series, K (KS) series, SV series, manufactured by Sekisui Chemical Co., Ltd., Movitar series, manufactured by Kuraray Co., Ltd., etc. can be used.
Specifically, Eslec BM-1 (hydroxyl group amount: 34 mol%, butyralization degree 65 ± 3 mol%, average molecular weight: 40,000), Eslec BH-3 (hydroxyl group amount: 34 mol%, butyralization degree 65 ± 3 mol%, Average molecular weight: 110,000), BH-6 (hydroxyl group amount: 30 mol%, degree of butyralization 69 ± 3 mol%, average molecular weight: 92,000), BX-1 (hydroxyl group amount: 33 ± 3 mol%, acetalization degree of 66 mol%, average molecular weight: 100,000), BX-5 (amount of hydroxyl groups: 33±3 mol%, degree of acetalization 66 mol%, average molecular weight: 130,000), BM-2 (amount of hydroxyl groups: 31 mol%, butyralization degree of butyralization 68±3 mol%, average molecular weight: 52,000), BM-5 (hydroxyl group amount: 34 mol%, butyralization degree 65±3 mol%, average molecular weight: 53,000), BL-1 (hydroxyl group amount: : 36 mol%, degree of butyralization 63 ± 3 mol%, average molecular weight: 19,000), BL-1H (hydroxyl group amount: 30 mol%, degree of butyralization 69 ± 3 mol%, average molecular weight: 20,000), BL- 2 (amount of hydroxyl groups: 36 mol%, degree of butyralization 63 ± 3 mol%, average molecular weight: 2.7), BL-2H (amount of hydroxyl groups: 29 mol%, degree of butyralization 70 ± 3 mol%, average molecular weight: 28,000 ), the same BL-10 (hydroxyl group amount: 28 mol%, butyralization degree 71 ± 3 mol%, average molecular weight: 15,000), the same KS-10 (hydroxyl group amount: 25 mol%, acetalization degree 65 ± 3 mol%, average Molecular weight: 17,000) (manufactured by Sekisui Chemical Co., Ltd.), Mobital B145 (hydroxyl group amount: 21 to 26.5 mol%, degree of acetalization: 67.5 to 75.2 mol%), Mobital B16H (hydroxyl group amount: : 26.2 to 30.2 mol%, degree of acetalization 66.9 to 73.1 mol%, average molecular weight: 10,000 to 20,000) (manufactured by Kuraray Co., Ltd.). These may be used alone or in combination of two or more.

The content of the binder resin is preferably 0.1% to 15% by mass, more preferably 0.1% to 10% by mass, and even more preferably 0.1% to 5% by mass, based on the fine particles. Preferably, 0.1% to 3% by weight is particularly preferred.
When the content of the binder resin is 0.1% by mass or more, it is possible to prevent problems such as poor dispersion stability and easy settling of fine particles, and when it is 15% by mass or less, problems such as increased viscosity can be prevented. It can be prevented.

-Other ingredients-
The other components are not particularly limited and can be appropriately selected depending on the purpose, and include, for example, non-aqueous solvents (non-aqueous solvents).
Examples of the non-aqueous solvent include γ-butyrolactone, acetone, methyl ethyl ketone, hexane, heptane, octane, 2-heptanone, cycloheptanone, cyclohexanone, cyclohexane, methylcyclohexane, ethylcyclohexane, methyl-n-pentylketone, and methylisobutyl. Ketone, methyl isopentyl ketone, ethylene glycol, diethylene glycol, propylene glycol, dipropylene glycol, ethylene glycol monoacetate, ethylene glycol monomethyl ether acetate, ethylene glycol monoethyl ether acetate, diethylene glycol monoacetate, diethylene glycol diethyl ether, propylene glycol monoacetate, Dipropylene glycol monoacetate, propylene glycol diacetate, propylene glycol monomethyl ether, propylene glycol monomethyl ether acetate, propylene glycol monoethyl ether acetate, cyclohexyl acetate, ethyl 3-ethoxypropionate, dioxane, methyl lactate, ethyl lactate, methyl acetate, Ethyl acetate, butyl acetate, methyl pyruvate, ethyl pyruvate, methyl methoxypropionate, ethyl ethoxypropionate, anisole, ethylbenzyl ether, cresyl methyl ether, diphenyl ether, dibenzyl ether, phenethol, butylphenyl ether, benzene, ethylbenzene , diethylbenzene, pentylbenzene, isopropylbenzene, toluene, xylene, cymene, mesitylene, methanol, ethanol, isopropanol, butanol, methyl monoglycidyl ether, ethyl monoglycidyl ether, butyl monoglycidyl ether, phenyl monoglycidyl ether, methyl diglycidyl ether, Ethyl diglycidyl ether, butyl diglycidyl ether, phenyl diglycidyl ether, methylphenol monoglycidyl ether, ethylphenol monoglycidyl ether, butylphenol monoglycidyl ether, mineral spirit, 2-hydroxyethyl acrylate, tetrahydrofurfuryl acrylate, 4-vinylpyridine , N-methyl-2-pyrrolidone, 2-ethylhexyl acrylate, 2-hydroxyethyl methacrylate, hydroxypropyl methacrylate, glycidyl methacrylate, neopentyl glycol diacrylate, hexanediol diacrylate, trimethylolpropane triacrylate, methacrylate, methyl methacrylate, styrene , perfluorocarbon, hydrofluoroether, hydrochlorofluorocarbon, hydrofluorocarbon, perfluoropolyether, N,N-dimethylformamide, N,N-dimethylacetamide, dioxolane, and various silicone oils. These may be used alone or in combination of two or more.

The method for producing the coating layer is not particularly limited and can be selected depending on the purpose. For example, a non-aqueous solvent and a binder resin are mixed, and the resulting mixture (binder resin dispersion) is mixed with fine particles. is added, mixed, and applied to the elastic member.
In the present invention, it is desirable that the average particle diameter of the fine particles in the binder resin dispersion as determined by dynamic light scattering method (average particle diameter as determined by cumulant method analysis of scattering intensity distribution) is 1 μm or less.
Even when fine particles with a volume average particle size of 1 μm or less are used, the particles usually aggregate to become secondary particles with a particle size of 1 μm or more.
By dispersing these fine particles to a particle size of 1 μm or less, a stable dispersion can be obtained even when the binder resin dispersion has a low viscosity and is stored for a long period of time. Examples of the dispersion method include methods using a dispersion machine such as an ultrasonic dispersion machine, a three-roll mill, a ball mill, a bead mill, and a jet mill.
Note that the volume average particle diameter of the fine particles in the binder resin dispersion is preferably 1 μm or less, more preferably 0.5 μm or less, and even more preferably 0.3 μm or less, from the standpoint of obtaining a uniform dispersion.

The surface roughness (Ra) of the coating layer is 0.08 μm to 0.5 μm, preferably 0.15 μm to 0.25 μm. If the surface roughness is less than 0.08 μm, the cleaning performance may deteriorate, and if it exceeds 0.5 μm, torque may increase.
The surface roughness can be controlled by the amount of the fine particles.

The surface roughness (Ra) can be measured and calculated using the roughness measurement mode of a laser microscope (LEXT OLS4500, manufactured by Olympus Corporation) according to the following conditions.
-Measurement condition-
Measurement points: 5 arbitrary points in the longitudinal direction at 20 μm from the tip of the bottom surface of the cleaning blade Magnification: 50x Measurement distance: 2 mm in the longitudinal direction at each point
Calculation method: Adopt the average value of Ra obtained at each location

The method for forming the coating layer is not particularly limited and can be appropriately selected depending on the purpose. For example, a method of dipping an elastic member in a dispersion of a binder resin and fine particles may be mentioned. In addition to dipping, coating methods such as spray coating and dispenser may also be used.

<Parts to be cleaned>
The material, shape, structure, size, etc. of the member to be cleaned are not particularly limited and can be appropriately selected depending on the purpose. Examples of the shape of the member to be cleaned include a drum shape, a belt shape, a flat plate shape, and a sheet shape. The size of the member to be cleaned is not particularly limited and can be appropriately selected depending on the purpose, but it is preferably a size that is normally used.

The material of the member to be cleaned is not particularly limited and can be appropriately selected depending on the purpose, and examples include metal, plastic, and ceramic.
The member to be cleaned is not particularly limited and can be appropriately selected depending on the purpose, and when the cleaning blade is applied to an image forming apparatus, examples thereof include an image carrier.

<Residue>
The residue is not particularly limited as long as it adheres to the surface of the member to be cleaned and is to be removed by the cleaning blade, and can be selected as appropriate depending on the purpose. For example, toner, lubricant, etc. , inorganic fine particles, organic fine particles, dirt, dust, or a mixture thereof.

<Other parts>
The other members are not particularly limited and can be appropriately selected depending on the purpose, and include, for example, a support member.
The shape, size, material, etc. of the support member are not particularly limited and can be appropriately selected depending on the purpose. Examples of the shape of the support member include a flat plate, a strip, and a sheet. The size of the support member is not particularly limited and can be appropriately selected depending on the size of the member to be cleaned.
Examples of the material of the support member include metal, plastic, and ceramic. Among these, metal plates are preferred from the viewpoint of strength, and steel plates such as stainless steel, aluminum plates, and phosphor bronze plates are particularly preferred.

Here, an example of the cleaning blade in the present invention will be described with reference to the drawings.
In addition, in each drawing, the same components are given the same reference numerals, and duplicate explanations may be omitted. Further, the number, position, shape, etc. of the following constituent members are not limited to this embodiment, and can be set to a preferable number, position, shape, etc. for implementing the present invention.

FIG. 1 is a schematic cross-sectional view showing a state in which a cleaning blade of the present invention is in contact with the surface of an image carrier.
As shown in FIG. 1, the cleaning blade 62 includes a flat support member 621 made of a rigid material such as metal or hard plastic, and a flat elastic member 622. The elastic member 622 is fixed to one end of the support member 621 with an adhesive or the like, and the other end of the support member 621 is cantilevered to the case of the cleaning device.

2 is a perspective view and an enlarged view of the vicinity of the contact portion of the cleaning blade shown in FIG. 1. FIG.
As shown in FIG. 2, the cleaning blade 62 includes a support member 621 and a flat elastic member 622, which is connected at one end to the support member 621 and has a free end of a predetermined length at the other end. A contact portion 62c, which is one end on the free end side of 622, is arranged so as to contact the surface of the image carrier along the longitudinal direction.
The elastic member 622 has a coating layer 62d on at least a portion including the contact side of the contact portion 62c.

(Image forming apparatus and image forming method)
The image forming apparatus of the present invention includes at least an image bearing member, a charging means, an exposure means, a developing means, a transfer means, a fixing means, and a cleaning means, and further includes appropriately selected others as necessary. have the means of Note that the charging means and the exposure means may be collectively referred to as an electrostatic latent image forming means.

The image forming method used in the present invention includes at least a charging step, an exposure step, a developing step, a transfer step, a fixing step, and a cleaning step, and further includes other steps appropriately selected as necessary. . Note that the charging process and the exposure process may be collectively referred to as an electrostatic latent image forming process.

The image forming method used in the present invention can be suitably carried out by the image forming apparatus of the present invention, the charging step can be performed by the charging means, and the exposing step can be performed by the exposing means. The developing step can be performed by the developing means, the transferring step can be performed by the transferring means, the fixing step can be performed by the fixing means, and the cleaning step can be performed by the cleaning means. The other steps can be performed by the other means.

<Image carrier>
The image carrier (hereinafter sometimes referred to as "electrophotographic photoreceptor" or "photoreceptor") is not particularly limited in its material, shape, structure, size, etc., and may be appropriately selected from known ones. can do. Examples of the shape of the image carrier include a drum shape and a belt shape. Examples of the material of the image carrier include inorganic photoreceptors such as amorphous silicon and selenium, and organic photoreceptors (OPC) such as polysilane and phthalopolymethine.

<Charging process and charging means>
The charging step is a step of charging the surface of the image carrier, and is performed by the charging means.
The charging means is not particularly limited as long as it can charge the surface of the image carrier, and can be appropriately selected depending on the purpose. For example, a conductive or semiconductive roller, Examples include contact chargers that are known per se and are equipped with brushes, films, rubber blades, etc., and non-contact chargers that utilize corona discharge such as corotrons and scorotrons.
The charging means may take any form, such as a roller, a magnetic brush, or a fur brush, and can be selected according to the specifications and form of the electrophotographic image forming apparatus. When using a magnetic brush, the magnetic brush uses various ferrite particles such as Zn-Cu ferrite as a charging means, and is composed of a non-magnetic conductive sleeve for supporting this, and a magnet roll included in this. . Or, when using a brush, for example, the fur brush is made of fur that has been conductively treated with carbon, copper sulfide, metal, or metal oxide, and is wound around a metal or other conductively treated core; It can be used as a charger by pasting it on.
Although the charger is not limited to the contact type charger as described above, there is an advantage that an image forming apparatus in which ozone generated from the charger is reduced can be obtained.
It is preferable that the charger is disposed in contact with or in a non-contact state with the image carrier, and charges the surface of the image carrier by applying DC and AC voltages in a superimposed manner.
In addition, the charger is a charging roller that has a gap tape and is placed close to the image carrier in a non-contact manner, and the surface of the image carrier is charged by applying DC and AC voltages to the charging roller in a superimposed manner. preferable.

<Exposure process and exposure means>
The exposure step is a step of exposing the charged surface of the image carrier, and is performed by the exposure means. The exposure can be performed, for example, by imagewise exposing the surface of the image carrier using the exposure means.
Optical systems used in the exposure are broadly classified into analog optical systems and digital optical systems. The analog optical system is an optical system that directly projects an original onto the surface of the image carrier using an optical system, and the digital optical system is an optical system that receives image information as an electrical signal and converts the electrical signal into an optical signal. This is an optical system that exposes an image carrier to light to form an image.
The exposure means is not particularly limited as long as it can expose the charged image carrier to form an electrostatic latent image, and can be appropriately selected depending on the purpose, such as a copying optical system, Examples include various exposure devices such as a rod lens array system, a laser optical system, a liquid crystal shutter optical system, and an LED optical system.
In the present invention, a back-light method may be adopted in which imagewise exposure is performed from the back side of the image carrier.

<Developing process and developing means>
The developing step is a step of developing the electrostatic latent image into the toner image, and is performed by the developing means.
The developing means is not particularly limited as long as it can develop the electrostatic latent image into a toner image, and can be appropriately selected depending on the purpose. Preferred examples include those having at least a developing device capable of applying the toner in a contact or non-contact manner.
The developing device may be of a dry type developing type or a wet type developing type, and may also be a single color developing device or a multicolor developing device. Preferred examples include those comprising a container and a rotatable magnetic roller.
In the developing device, for example, the toner and carrier are mixed and stirred as necessary, and the toner is charged by friction at that time and is held in a spiked state on the surface of the rotating magnet roller, and is magnetically A brush is formed. Since the magnet roller is disposed near the image carrier, a portion of the toner constituting the magnetic brush formed on the surface of the magnet roller is electrically attracted to the electrostatic latent image. The image carrier is moved to the surface of the image carrier by force. As a result, the electrostatic latent image is developed with the toner, and the toner image is formed on the surface of the image carrier.
The toner contained in the developing device may be a developer containing the toner, and the developer may be a one-component developer or a two-component developer.
Note that the toner can also be used as a one-component magnetic toner that does not use a carrier, or a non-magnetic toner.

<Transfer process and transfer means>
The transfer step is a step of transferring the toner image onto a recording medium, and is performed by the transfer means.
The transfer process includes, for example, a primary transfer process in which an intermediate transfer body is used to transfer the toner image onto the surface of the intermediate transfer body to form a composite transfer image, and a primary transfer process in which the composite transfer image is transferred to a recording medium. An embodiment including a secondary transfer step is preferable.
The transfer means is not particularly limited as long as it can transfer the toner image to the recording medium, and can be appropriately selected depending on the purpose, and the toner image is transferred to the surface of the intermediate transfer body to form a composite transfer image. A preferred embodiment includes a primary transfer means for transferring the composite transfer image to a recording medium, and a secondary transfer means for transferring the composite transfer image to a recording medium.
It is preferable that the primary transfer means and the secondary transfer means include at least a transfer device for peeling and charging the toner image formed on the surface of the image carrier onto a recording medium.
The transfer device is not particularly limited and can be appropriately selected depending on the purpose, and includes, for example, a corona transfer device using corona discharge, a transfer belt, a transfer roller, a pressure transfer roller, an adhesive transfer device, and the like. The number of the transfer devices may be one, or two or more.

The recording medium is not particularly limited as long as it can transfer the unfixed toner image after development, and can be appropriately selected depending on the purpose, and is typically plain paper. However, for example, a PET base for OHP can also be used.

<Fixing process and fixing means>
The fixing step is a step of fixing the toner image transferred to the recording medium, and is performed by the fixing means. Note that when using two or more color toners, the toners of each color may be fixed each time they are transferred to the recording medium, or the toners of all colors may be transferred to the recording medium and fixed in a layered state. Good too.
The fixing means is not particularly limited as long as it can fix the toner image transferred to the recording medium, and can be appropriately selected depending on the purpose. can be adopted.
Examples of the heating and pressing means include a combination of a heating roller and a pressure roller, a combination of a heating roller, a pressure roller, and an endless belt, and the like. The heating temperature is not particularly limited and can be appropriately selected depending on the purpose, but is preferably 80°C to 200°C. Note that, if necessary, for example, a known optical fixing device may be used in conjunction with the fixing means.

<Cleaning process and cleaning means>
The cleaning step is a step of removing the toner remaining on the surface of the image carrier, and is performed by the cleaning means.
As the cleaning means, one in which the cleaning blade of the present invention is fixed to a support member is used.

The linear pressure applied by the elastic member to the surface of the image carrier is not particularly limited and can be appropriately selected depending on the purpose, but is preferably 10 N/m or more and 100 N/m or less, and 10 N/m or more. More preferably, it is 50 N/m or less. When the linear pressure is 10 N/m or more and 100 N/m or less, cleaning defects such as the toner slipping between the contact portion and the member to be cleaned are less likely to occur, and the curling of the elastic body is suppressed. It can be made easier.
Note that the linear pressure can be measured using, for example, a measuring device incorporating a compact compression type load cell manufactured by Kyowa Dengyo Co., Ltd.

There is no particular restriction on the angle formed by the tangent to the member to be cleaned and the tip surface of the free end of the elastic member at the position where the contact portion of the elastic member contacts (hereinafter referred to as "cleaning angle"); Although it can be selected as appropriate depending on the purpose, it is preferably 65° or more and 85° or less.
When the cleaning angle is 65° or more and 85° or less, it becomes easier to suppress the occurrence of curling of the elastic member, and it becomes easier to reduce the occurrence of cleaning defects.

<Other processes and other means>
Examples of the other processes include a static elimination process, a recycling process, and a control process.
Examples of the other means include static elimination means, recycling means, and control means.

-Static elimination process and static elimination means-
The static elimination process is a process of applying a static elimination bias voltage to the image carrier to eliminate static electricity, and is performed by the static elimination means.
The static eliminating means is not particularly limited as long as it can apply a static eliminating bias voltage to the image carrier, and can be appropriately selected depending on the purpose, such as a static eliminating lamp.

-Recycling process and recycling means-
The recycling step is a step in which the toner removed in the cleaning step is recycled by the developing means, and is performed by the recycling means.
The recycling means is not particularly limited and can be appropriately selected depending on the purpose, and includes known conveyance means.

-Control process and control means-
The control step is a step of controlling each of the steps, and is performed by a control means.
The control means is not particularly limited as long as it can control the movement of each of the means, and can be appropriately selected depending on the purpose, and examples thereof include equipment such as a sequencer and a computer.

Here, an example of the image forming apparatus of the present invention will be described with reference to the drawings.
FIG. 3 is a schematic configuration diagram showing an example of an image forming apparatus 500 of the present invention. This image forming apparatus 500 includes four image forming units 1Y, 1C, 1M, and 1K for yellow, magenta, cyan, and black (hereinafter sometimes referred to as Y, C, M, and K). . These use Y, C, M, and K toners of different colors as image forming materials for forming images, but otherwise have the same configuration.

A transfer unit 60 including an intermediate transfer belt 14 as an intermediate transfer body is arranged above the four image forming units 1. The toner images of each color formed on the surfaces of the photoreceptors 3Y, 3C, 3M, and 3K provided in the image forming units 1Y, 1C, 1M, and 1K, which will be described in detail later, are superimposed on the surface of the intermediate transfer belt 14. This is the configuration to be transferred.
Further, an optical writing unit 40 is arranged below the four image forming units 1. The optical writing unit 40, which is a latent image forming means, irradiates the photoreceptors 3Y, 3C, 3M, and 3K of the image forming units 1Y, 1C, 1M, and 1K with laser light L emitted based on image information. As a result, electrostatic latent images for Y, C, M, and K are formed on the photoreceptors 3Y, 3C, 3M, and 3K. Note that the optical writing unit 40 polarizes the laser beam L emitted from the light source by a polygon mirror 41 that is rotationally driven by a motor, and polarizes the laser beam L to the photoreceptors 3Y, 3C, 3M, and 3K via a plurality of optical lenses and mirrors. It irradiates the area. Instead of the configuration described above, it is also possible to adopt one that performs optical scanning using an LED array.

Below the optical writing unit 40, a first paper feed cassette 151 and a second paper feed cassette 152 are arranged so as to overlap in the vertical direction. Each of these paper feed cassettes accommodates a plurality of recording media P in the form of a stack of sheets, and the topmost recording medium P has a first paper feed roller 151a, a second paper feed The rollers 152a are in contact with each other. When the first paper feed roller 151a is rotated counterclockwise in FIG. 3 by a driving means (not shown), the topmost recording medium P in the first paper feed cassette 151 is moved vertically on the right side of the cassette in FIG. The paper is discharged toward a paper feed path 153 that is arranged so as to extend from one side to the other. Further, when the second paper feed roller 152a is rotated counterclockwise in FIG. be done.

A plurality of transport roller pairs 154 are arranged within the paper feed path 153 . The recording medium P fed into the paper feed path 153 is conveyed from the bottom to the top in FIG.

A registration roller pair 55 is disposed at the downstream end of the paper feed path 153 in the conveyance direction. The registration roller pair 55 temporarily stops the rotation of both rollers as soon as the recording medium P sent from the transport roller pair 154 is sandwiched between the rollers. Then, the recording medium P is sent out toward a secondary transfer nip, which will be described later, at an appropriate timing.

FIG. 4 is a schematic diagram showing the configuration of one of the four image forming units 1.
As shown in FIG. 4, the image forming unit 1 includes a drum-shaped photoreceptor 3 as an image carrier. Although the photoreceptor 3 is shown to have a drum-like shape, it may also have a sheet-like shape or an endless belt-like shape.
Around the photoreceptor 3, a charging roller 4, a developing device 5, a primary transfer roller 7, a cleaning device 6, a lubricant coating device 10, a static elimination lamp (not shown), and the like are arranged. The charging roller 4 is a charging member included in a charging device as a charging means, and the developing device 5 is a developing device that converts a latent image formed on the surface of the photoreceptor 3 into a toner image. The primary transfer roller 7 is a primary transfer member included in a primary transfer device as a primary transfer means that transfers the toner image on the surface of the photoreceptor 3 to the intermediate transfer belt 14 . The cleaning device 6 is a cleaning unit that cleans toner remaining on the photoreceptor 3 after the toner image is transferred to the intermediate transfer belt 14. The lubricant applicator 10 is a lubricant applicator that applies lubricant onto the surface of the photoreceptor 3 after cleaning by the cleaning device 6 . A static elimination lamp (not shown) is a static elimination means that eliminates the surface potential of the photoreceptor 3 after cleaning.

The charging roller 4 is disposed at a predetermined distance from the photoreceptor 3 in a non-contact manner, and charges the photoreceptor 3 to a predetermined polarity and a predetermined potential. The surface of the photoreceptor 3, which has been uniformly charged by the charging roller 4, is irradiated with laser light L based on image information from an optical writing unit 40, which is a latent image forming means, to form an electrostatic latent image.
The developing device 5 includes a developing roller 51 as a developer carrier. A developing bias is applied to the developing roller 51 from a power source (not shown). A supply screw 52 and an agitation screw 53 are provided in the casing of the developing device 5 to agitate the developer contained in the casing while conveying it in opposite directions. Further, a doctor 54 for regulating the developer carried on the developing roller 51 is also provided. The toner in the developer stirred and conveyed by the two screws, the supply screw 52 and the stirring screw 53, is charged to a predetermined polarity. Then, the developer is pumped onto the surface of the developing roller 51, the pumped developer is regulated by the doctor 54, and the toner adheres to the latent image on the photoreceptor 3 in the development area facing the photoreceptor 3. .

The cleaning device 6 includes a fur brush 101, a cleaning blade 62, and the like. The cleaning blade 62 is in contact with the photoconductor 3 in a counter direction with respect to the surface movement direction of the photoconductor 3. Note that the details of the cleaning blade 62 are as described above.
The lubricant applicator 10 includes a solid lubricant 103, a lubricant pressure spring 103a, and the like, and uses a fur brush 101 as an applicator brush for applying the solid lubricant 103 onto the photoreceptor 3. The solid lubricant 103 is held by the bracket 103b, and is pressurized toward the fur brush 101 by a lubricant pressure spring 103a. Then, the solid lubricant 103 is scraped off by the fur brush 101 that rotates in a rotational direction with respect to the rotational direction of the photoreceptor 3, and the lubricant is applied onto the photoreceptor 3. By applying a lubricant to the photoreceptor, the coefficient of friction on the surface of the photoreceptor 3 is maintained at 0.2 or less during non-image formation.

The charging device is a non-contact close arrangement method in which the charging roller 4 is placed close to the photoreceptor 3. As the charging device, there are known charging devices such as a corotron, a scorotron, and a solid state charger. configuration can be used. Among these charging methods, the contact charging method or the non-contact close arrangement method is particularly preferable, and has advantages such as high charging efficiency, low amount of ozone generation, and miniaturization of the device.

Light sources such as the laser beam L of the optical writing unit 40 and the static elimination lamp include fluorescent lamps, tungsten lamps, halogen lamps, mercury lamps, sodium lamps, light emitting diodes (LEDs), semiconductor lasers (LDs), and electroluminescence (EL) lamps. ) can be used.
In addition, various filters such as a sharp cut filter, band pass filter, near infrared cut filter, dichroic filter, interference filter, color temperature conversion filter, etc. can also be used in order to irradiate only light in a desired wavelength range.
Among these light sources, light emitting diodes and semiconductor lasers have high irradiation energy and have long wavelength light of 600 nm or more and 800 nm or less, and are therefore favorably used.

The transfer unit 60 as a transfer means shown in FIG. 3 includes, in addition to the intermediate transfer belt 14, a belt cleaning unit 162, a first bracket 63, a second bracket 64, and the like. It also includes four primary transfer rollers 7Y, 7C, 7M, and 7K, a secondary transfer backup roller 66, a drive roller 67, an auxiliary roller 68, a tension roller 69, and the like. The intermediate transfer belt 14 is endlessly moved counterclockwise in FIG. 3 by the rotation of the drive roller 67 while being stretched around these eight roller members. The four primary transfer rollers 7Y, 7C, 7M, and 7K sandwich the intermediate transfer belt 14, which is thus endlessly moved, between the photoreceptors 3Y, 3C, 3M, and 3K to form primary transfer nips, respectively. . Then, a transfer bias having a polarity opposite to that of the toner (for example, positive) is applied to the back surface (loop inner peripheral surface) of the intermediate transfer belt 14. As the intermediate transfer belt 14 moves endlessly, it sequentially passes through the primary transfer nips for Y, C, M, and K. Y, C, M, and K toner images are superimposed and primarily transferred. As a result, a four-color superimposed toner image (hereinafter sometimes referred to as a four-color toner image) is formed on the intermediate transfer belt 14.

The secondary transfer backup roller 66 sandwiches the intermediate transfer belt 14 with a secondary transfer roller 70 disposed outside the loop of the intermediate transfer belt 14 to form a secondary transfer nip. The registration roller pair 55 described above feeds the recording medium P sandwiched between the rollers toward the secondary transfer nip at a timing that can be synchronized with the four-color toner image on the intermediate transfer belt 14. The four-color toner image on the intermediate transfer belt 14 is formed due to the effects of the secondary transfer electric field formed between the secondary transfer roller 70 to which the secondary transfer bias is applied and the secondary transfer backup roller 66, and the nip pressure. , are collectively secondary-transferred onto the recording medium P within the secondary-transfer nip. Combined with the white color of the recording medium P, this results in a full-color toner image.

Transfer residual toner that was not transferred to the recording medium P adheres to the intermediate transfer belt 14 after passing through the secondary transfer nip. This is cleaned by belt cleaning unit 162. Note that the belt cleaning unit 162 has a belt cleaning blade 162a in contact with the front surface of the intermediate transfer belt 14, and thereby scrapes and removes transfer residual toner on the intermediate transfer belt 14.

The first bracket 63 of the transfer unit 60 is configured to swing at a predetermined rotation angle about the rotation axis of the auxiliary roller 68 as a solenoid (not shown) is turned on and off. When forming a monochrome image, the image forming apparatus 500 rotates the first bracket 63 slightly counterclockwise in FIG. 3 by driving the solenoid described above. This rotation causes the primary transfer rollers 7Y, 7C, and 7M for Y, C, and M to revolve counterclockwise in FIG. , M photoreceptors 3Y, 3C, and 3M. Of the four image forming units 1Y, 1C, 1M, and 1K, only the K image forming unit 1K is driven to form a monochrome image. This makes it possible to avoid wear and tear on the members constituting the image forming unit 1 due to unnecessary driving of the Y, C, and M image forming units 1 during monochrome image formation.

A fixing unit 80 is disposed above the secondary transfer nip in FIG. The fixing unit 80 includes a pressure heating roller 81 containing a heat source such as a halogen lamp, and a fixing belt unit 82. The fixing belt unit 82 includes a fixing belt 84 as a fixing member, a heating roller 83 containing a heat source such as a halogen lamp, a tension roller 85, a drive roller 86, a temperature sensor (not shown), and the like. Then, the endless fixing belt 84 is moved endlessly in the counterclockwise direction in FIG. 3 while being stretched by the heating roller 83, the tension roller 85, and the driving roller 86. During this endless movement process, the fixing belt 84 is heated from the back side by the heating roller 83. A pressure heating roller 81, which is driven to rotate clockwise in FIG. 3, is in contact with the front side of the fixing belt 84, which is heated in this manner, at a portion where it is wound around the heating roller 83. As a result, a fixing nip is formed in which the pressure heating roller 81 and the fixing belt 84 come into contact with each other.

A temperature sensor (not shown) is disposed outside the loop of the fixing belt 84 so as to face the front surface of the fixing belt 84 with a predetermined gap therebetween. Detects surface temperature. This detection result is sent to a fixing power supply circuit (not shown). The fixing power supply circuit controls on/off the supply of power to the heat generation source included in the heating roller 83 and the heat generation source included in the pressure and heating roller 81 based on the detection result by the temperature sensor.

The recording medium P that has passed through the above-described secondary transfer nip is separated from the intermediate transfer belt 14 and then sent into the fixing unit 80 . The full-color toner image is fixed onto the recording medium P by being heated and pressed by the fixing belt 84 while being conveyed from the bottom to the top in FIG. be done.

The recording medium P that has been subjected to the fixing process in this manner passes between the rollers of the paper ejection roller pair 87 and is then ejected out of the image forming apparatus. A stacking section 88 is formed on the upper surface of the casing of the main body of the image forming apparatus 500, and the recording media P discharged from the image forming apparatus by the paper discharging roller pair 87 are sequentially stacked in this stacking section 88.

Four toner cartridges 100Y, 100C, 100M, and 100K containing Y, C, M, and K toners are arranged above the transfer unit 60. The Y, C, M, and K toners in the toner cartridges 100Y, 100C, 100M, and 100K are appropriately supplied to the developing devices 5Y, 5C, 5M, and 5K of the image forming units 1Y, 1C, 1M, and 1K. These toner cartridges 100Y, 100C, 100M, and 100K can be attached to and detached from the main body of the image forming apparatus independently of the image forming units 1Y, 1C, 1M, and 1K.

Next, an image forming operation in image forming apparatus 500 will be described.
First, when a print execution signal is received from an operation unit (not shown), a predetermined voltage or current is sequentially applied to the charging roller 4 and the developing roller 51 at a predetermined timing. Similarly, predetermined voltages or currents are sequentially applied to the light sources such as the optical writing unit 40 and the static elimination lamp at predetermined timings. Further, in synchronization with this, the photoreceptor 3 is rotationally driven in the direction of the arrow in FIG. 3 by a photoreceptor drive motor (not shown) serving as a driving means.

When the photoreceptor 3 rotates in the direction of the arrow in FIG. 3, the surface of the photoreceptor 3 is first uniformly charged to a predetermined potential by the charging roller 4. Then, a laser beam L corresponding to the image information is irradiated from the optical writing unit 40 onto the photoconductor 3, and the portion of the surface of the photoconductor 3 that is irradiated with the laser beam L is charged and an electrostatic latent image is formed. .
The surface of the photoreceptor 3 on which the electrostatic latent image is formed is rubbed by a magnetic brush of developer formed on a developing roller 51 at a portion facing the developing device 5 . At this time, the negatively charged toner on the developing roller 51 is moved toward the electrostatic latent image side by a predetermined developing bias applied to the developing roller 51, and is formed into a toner image (developed). In each image forming unit 1, a similar image forming process is executed, and toner images of each color are formed on the surfaces of each photoreceptor 3Y, 3C, 3M, and 3K of each image forming unit 1Y, 1C, 1M, and 1K. .
In this manner, in the image forming apparatus 500, the electrostatic latent image formed on the photoreceptor 3 is reversely developed by the developing device 5 using negatively charged toner. In the present embodiment, an example using an N/P (negative/positive: toner adheres to areas with low potential) non-contact charging roller system has been described, but the present invention is not limited to this.

The toner images of each color formed on the surface of each photoreceptor 3Y, 3C, 3M, and 3K are sequentially primarily transferred onto the surface of the intermediate transfer belt 14 so as to overlap. As a result, a four-color toner image is formed on the intermediate transfer belt 14.
The four-color toner image formed on the intermediate transfer belt 14 is fed from the first paper cassette 151 or the second paper cassette 152, passes between a pair of registration rollers 55, and is fed to the secondary transfer nip. The image is transferred onto a recording medium P. At this time, the recording medium P is temporarily stopped while being sandwiched between the pair of registration rollers 55, and is supplied to the secondary transfer nip in synchronization with the leading edge of the image on the intermediate transfer belt 14. The recording medium P onto which the toner image has been transferred is separated from the intermediate transfer belt 14 and conveyed to the fixing unit 80. When the recording medium P to which the toner image has been transferred passes through the fixing unit 80, the toner image is fixed onto the recording medium P by the action of heat and pressure. It is discharged to the outside of the forming apparatus 500 and stacked in the stack section 88 .

On the other hand, the belt cleaning unit 162 removes the transfer residual toner from the surface of the intermediate transfer belt 14 on which the toner image has been transferred to the recording medium P in the secondary transfer nip.
Further, the cleaning device 6 removes residual toner after the transfer from the surface of the photoconductor 3 on which the toner images of each color have been transferred to the intermediate transfer belt 14 in the primary transfer nip, and the lubricant is applied by the lubricant applicator 10. Afterwards, the static electricity is removed using a static electricity removal lamp.

As shown in FIG. 4, the image forming unit 1 of the image forming apparatus 500 includes a photoreceptor 3 and processing means such as a charging roller 4, a developing device 5, a cleaning device 6, a lubricant applying device 10, etc. housed in a frame 2. It is being The image forming unit 1 is integrally removable from the main body of the image forming apparatus 500 as a process cartridge. In the image forming apparatus 500, the image forming unit 1 replaces the photoreceptor 3 as a process cartridge and the process means integrally. , the lubricant applicator 10 may be replaced with a new unit.

(process cartridge)
The process cartridge of the present invention includes at least an image carrier and a cleaning means for removing toner remaining on the image carrier, and further includes other means as necessary.
As the cleaning means, the cleaning blade of the present invention is used.
The process cartridge incorporates an image carrier and the cleaning blade of the present invention, and also includes at least one of charging means, exposure means, developing means, transfer means, cleaning means, and static elimination means, This is a device (component) that can be attached to and detached from an image forming apparatus.

Examples of the present invention will be described below, but the present invention is not limited to these Examples in any way. However, "parts" means "parts by mass" unless otherwise specified.

(Example 1)
<Elastic member>
The elastic member used was a polyurethane elastomer sheet produced by centrifugal molding and having the following average thickness (film thickness), JIS-A hardness, 23° C. rebound modulus, and Martens hardness (HM).
Average thickness: 1.8mm
JIS-A hardness: 70°
23℃ rebound modulus: 50%
Martens hardness (HM): 1.0N/mm ²

<Measurement of JIS-A hardness>
The JIS-A hardness of the elastic member was measured at 23° C. using a micro rubber hardness meter (MD-1, manufactured by Kobunshi Keiki Co., Ltd.) according to JIS K6253.

<Measurement of rebound modulus of elastic member>
The rebound modulus of the elastic member was measured at 23° C. using a resilience tester (No. 221, manufactured by Toyo Seiki Seisakusho Co., Ltd.) according to JIS K6255. The sample used was a stack of sheets with a thickness of 2 mm so that the thickness was 4 mm or more.

<Measurement of Martens hardness>
The Martens hardness (HM) of the elastic member is determined based on ISO14577 by using a nanoindenter (ENT-3100, manufactured by Elionix), pressing a Berkovich indenter under a load of 1,000 μN for 10 seconds, holding it for 5 seconds, and then applying the same load. The measurement was performed by removing the sample at high speed for 10 seconds.
The measurement location was 20 μm from the ridgeline of the tip of the bladed sheet after molding.

<Processing into cleaning blade>
The obtained polyurethane elastomer sheet is subjected to post-curing to complete the curing reaction in the urethane sheet and eliminate unreacted substances in the urethane sheet, and curing to stabilize the physical properties, and then adhered to a holder and cleaned. Processed into a blade.

<Preparation of coating layer>
39 parts of polytetrafluoroethylene (PTFE) micropowder (TF9201Z, manufactured by 3M, volume average particle diameter 200 nm) as fine particles and butyral (PVB) resin (S-LEC BL-10, Sekisui Chemical Co., Ltd.) as a binder resin. A fine particle dispersion was prepared by using a hydroxyl group (28 mol %, butyralization degree 71 ± 3 mol %, average molecular weight 15,000) made by the company Co., Ltd., and 60 parts of isopropyl alcohol as a non-aqueous solvent.
In this preparation, after the binder resin was sufficiently dissolved in isopropyl alcohol, fine particles were added thereto, and the mixture was further stirred and mixed to obtain a fine particle dispersion.
The cleaning blade was immersed in the fine particle dispersion to a depth of 2 mm from the blade tip surface, and pulled up at a pulling speed of 1 mm/s to the blade tip portion (including the contact side) necessary for the cleaning function. In order to collect the PTFE particles, the cleaning blade of Example 1 was prepared by tilting it at about 45 degrees as shown in FIG. 5 and drying it at room temperature for 30 minutes.

(Examples 2 to 5, Comparative Examples 1 to 4)
Cleaning blades of Examples 2 to 5 and Comparative Examples 1 to 4 were produced in the same manner as in Example 1 except that the conditions listed in Table 1 were changed.
Note that Comparative Example 1 is a cleaning blade made of only an elastic member without a coating layer.
Further, Comparative Example 4 is a cleaning blade having a coating layer that does not contain fine particles (a coating layer containing only a binder resin).

(Example 6)
95 parts of polymethyl methacrylic acid (PMMA) water dispersion (MX100W, manufactured by Nippon Shokubai Co., Ltd., volume average particle diameter 150 nm) as fine particles and polyvinyl butyral (PVB) resin (S-LEC KW-M, Sekisui) as a binder resin. (manufactured by Kagaku Kogyo Co., Ltd., degree of acetalization: 24±3 mol%) to prepare a fine particle dispersion.
The cleaning blade was immersed in the fine particle dispersion to a depth of 2 mm from the blade tip surface, and pulled up at a pulling speed of 1 mm/s to the blade tip portion (including the contact side) necessary for the cleaning function. In order to collect the PMMA particles, the cleaning blade of Example 6 was prepared by tilting it at about 45° as shown in FIG. 5 and drying it at 100° C. for 30 minutes.

(Example 7)
A cleaning blade in Example 7 was produced in the same manner as in Example 3, except that the binder resin in Example 3 was replaced with polyvinyl alcohol (VC-13, manufactured by Japan Vinyl Acetate Popal Co., Ltd.).

<Measurement of surface roughness Ra>
The surface roughness of the obtained cleaning blade was measured using the roughness measurement mode of a laser microscope (LEXT OLS4500, manufactured by Olympus Corporation) under the following conditions.
Measurement points: 5 arbitrary points in the longitudinal direction at 20 μm from the tip of the bottom surface of the cleaning blade Magnification: 50x Measurement distance: 2 mm in the longitudinal direction at each point
Calculation method: Adopt the average value of Ra obtained at each location

<Assembling the image forming device>
The prepared cleaning blade was attached to a process cartridge of a color multifunction device (imagio MP C4500, manufactured by Ricoh Co., Ltd.) (the printer section has a configuration similar to the image forming apparatus 500 shown in FIG. 4), and an image forming apparatus was assembled.
The cleaning blade was attached to the image forming apparatus so that the linear pressure was 20 g/cm and the cleaning angle was 79°.

<Torque evaluation>
The images were output using the above-mentioned image device under the following conditions. During output, the driving torque of the photoreceptor was measured. After outputting, the tip of the cleaning blade was observed with a laser microscope (LEXT OLS4500, manufactured by Olympus Corporation), and the torque was evaluated based on the following evaluation criteria. The evaluation results are listed in Table 2. Note that "initial" in the evaluation criteria refers to the 1st to 500th sheets.
Environment: 23℃/45%RH
Paper passing conditions: Blank chart Number of output sheets: 5,000 sheets (A4 size landscape)
-Evaluation criteria-
◎: The rate of change in torque increase was within 50% of the initial value, and the photoreceptor did not stop due to the increase in driving torque. Furthermore, even after printing, when the blade was observed, there were no signs of curling.
○: The rate of change in torque increase is within 50% of the initial value, and the photoreceptor does not stop due to the increase in driving torque. However, when observing the blade after printing, there were traces of curling, but the level was not enough to cause the toner to come off, so there was no problem in actual use.
×: The photoreceptor stopped due to an increase in torque, and when the blade was observed after printing, there were traces of curling to the extent that the toner came off, which is a problem in practical use.

<Cleanability evaluation>
Output was performed using the above image forming apparatus under the following conditions. Thereafter, the edge portion of the cleaning blade and the surface of the photoreceptor were observed using the laser microscope described above, and evaluated based on the following evaluation criteria. The evaluation results are listed in Table 2.
Environment: 27℃/80%RH
Paper feeding conditions: 3 prints/job of 5% image area ratio Number of output sheets: 50,000 sheets (A4 size landscape)
-Evaluation criteria-
◎: Due to poor cleaning, the toner that has slipped through cannot be visually confirmed on the printing paper or on the photoreceptor, and even when observing the photoreceptor in the longitudinal direction with a microscope, it is not possible to see any streaks of toner slipping through. ○: Due to poor cleaning The toner that has slipped through cannot be visually confirmed on the printing paper or the photoconductor. ×: The toner that has slipped through due to poor cleaning can be visually confirmed on the printing paper or the photoconductor.

It was found that the lower the surface roughness Ra, the lower the torque, but it is necessary to increase the surface roughness in order to improve the cleaning performance, and there is a trade-off relationship between the torque and the cleaning performance.
The reason why the torque evaluation and cleaning performance evaluation results of Comparative Example 1 are both "x" is because the torque is high due to the lack of a coating layer, and because the high torque causes the blade to easily roll up, the toner may come off. This is due to the fact that Comparative Example 2 had a high surface roughness Ra, so the torque evaluation result was x, and Comparative Example 3 had a too low surface roughness Ra, so the cleaning performance evaluation result was x.

Examples of aspects of the present invention are as follows.
<1> A cleaning blade having an elastic member that comes into contact with the surface of a member to be cleaned and removes residue on the surface of the member to be cleaned,
The elastic member has a coating layer containing fine particles and a binder resin,
The coating layer is formed on at least a portion of the contact portion including the contact side where the elastic member and the member to be cleaned contact, including the contact side;
The cleaning blade is characterized in that the coating layer has a surface roughness (Ra) of 0.08 μm to 0.5 μm.
<2> The cleaning blade according to <1>, wherein the fine particles have a spherical shape.
<3> The cleaning blade according to any one of <1> to <2>, wherein the fine particles have a volume average particle size of 1 μm or less.
<4> The cleaning blade according to any one of <1> to <3>, wherein the surface roughness (Ra) is 0.15 μm to 0.25 μm.
<5> The cleaning blade according to any one of <1> to <4>, wherein the fine particles contain polytetrafluoroethylene.
<6> The cleaning blade according to any one of <1> to <5>, wherein the binder resin is a terpolymer containing vinyl butyral, vinyl acetate, and vinyl alcohol as constituent units.
<7> An image bearing member, a charging means for charging the surface of the image bearing member, an exposure means for exposing the charged surface of the image bearing member to form an electrostatic latent image, and an electrostatic latent image to be exposed to toner. At least one of a developing means for developing an image and a transfer means for transferring the toner image onto a recording medium comes into contact with the surface of the image carrier to remove residues on the surface of the image carrier. cleaning means;
The process cartridge is characterized in that the cleaning means includes the cleaning blade according to any one of <1> to <6>.
<8> An image bearing member, a charging means for charging the surface of the image bearing member, an exposing means for exposing the charged image bearing member to light to form an electrostatic latent image, and an electrostatic latent image is exposed to toner. a developing device for developing an image; a transfer device for transferring the toner image onto a recording medium; a fixing device for fixing the toner image transferred to the recording medium; a cleaning means for removing residue on the surface of the image carrier;
The image forming apparatus is characterized in that the cleaning means includes the cleaning blade according to any one of <1> to <6>.

According to the cleaning blade described in any one of <1> to <6> above, the process cartridge described in <7> above, and the image forming apparatus described in <8> above, various conventional problems are solved and the present invention is achieved. The purpose of the invention can be achieved.

3 Image carrier 14 Intermediate transfer belt 60 Transfer unit 62 Cleaning blade 62a Blade tip surface 62b Blade lower surface 62c Contact portion 62d Covering layer 80 Fixing unit 500 Printer 621 Support member 622 Elastic member

Japanese Patent Application Publication No. 8-220962 Japanese Patent Application Publication No. 2000-147972 Japanese Patent Application Publication No. 6-348193 JP 2017-16083 Publication

Claims (8)

A cleaning blade having an elastic member that comes into contact with a surface of a member to be cleaned and removes residue on the surface of the member to be cleaned,
The elastic member has a coating layer containing fine particles and a binder resin, and the content of the binder resin is 0.1% by mass to 15% by mass with respect to the fine particles ,
The coating layer is formed on at least a portion of the contact portion including the contact side where the elastic member and the member to be cleaned contact, including the contact side;
A cleaning blade characterized in that the coating layer has a surface roughness (Ra) of 0.08 μm to 0.5 μm. The cleaning blade according to claim 1, wherein the fine particles have a spherical shape. The cleaning blade according to claim 1, wherein the fine particles have a volume average particle size of 1 μm or less. The cleaning blade according to claim 1, wherein the surface roughness (Ra) is 0.15 μm to 0.25 μm. The cleaning blade according to any one of claims 1 to 4, wherein the fine particles contain polytetrafluoroethylene. The cleaning blade according to any one of claims 1 to 5, wherein the binder resin is a terpolymer containing vinyl butyral, vinyl acetate, and vinyl alcohol as constituent units. an image carrier, a charging means for charging the surface of the image carrier, an exposure means for exposing the charged surface of the image carrier to form an electrostatic latent image, and developing the electrostatic latent image into a toner image. at least one of a developing means for transferring the toner image to a recording medium, and a cleaning means for removing residue on the surface of the image carrier by coming into contact with the surface of the image carrier. , has
A process cartridge, wherein the cleaning means includes a cleaning blade according to any one of claims 1 to 6. an image carrier, a charging means for charging the surface of the image carrier, an exposure means for exposing the charged image carrier to light to form an electrostatic latent image, and developing the electrostatic latent image into a toner image. a developing means for transferring the toner image to a recording medium; a fixing means for fixing the toner image transferred to the recording medium; cleaning means for removing residue on the surface of the
An image forming apparatus characterized in that the cleaning means includes a cleaning blade according to any one of claims 1 to 6.