CN116830046A

CN116830046A - Cleaning blade, lubricant leveling blade, process cartridge, and image forming apparatus

Info

Publication number: CN116830046A
Application number: CN202280010716.2A
Authority: CN
Inventors: 大森匡洋; 重里圭一郎; 木村秀树
Original assignee: Ricoh Co Ltd
Current assignee: Ricoh Co Ltd
Priority date: 2021-02-15
Filing date: 2022-01-27
Publication date: 2023-09-29

Abstract

A cleaning blade for cleaning a rotating body is provided. The cleaning blade includes: an edge layer having a tip portion that contacts the rotating body; and a coating layer located at the tip end portion of the edge layer. The coating layer includes a first fluorine-based resin and a second fluorine-based resin that is not compatible with the first fluorine-based resin. The cleaning blade has a diameter of 0.5-3N/mm at a distance of 20 μm from the tip edge line portion of the edge layer ² Is a marshi hardness of (c).

Description

Cleaning blade, lubricant leveling blade, process cartridge, and image forming apparatus

Technical Field

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

Background

In the electrophotographic image forming process, a cleaning device that removes residual toner adhering to the surface of an image carrier is used. As the cleaning device, a cleaning blade composed of an elastic body made of urethane rubber and a supporting body supporting the elastic body is widely used. The lubricant supplying device supplies lubricant to the surface of the image carrier after the cleaning blade cleans the image carrier. As the lubricant supply device, a lubricant leveling blade composed of an elastomer made of urethane rubber and a support body supporting the elastomer is widely used. It is known that a lubricant such as a metal soap is applied to the tip ridge portion of the elastomer of each of the cleaning blade and the lubricant leveling blade.

The cleaning blade and the lubricant leveling blade are required to have lubricity to prevent an increase in torque, which is a force required to rotate the image carrier, and to reduce friction with the image carrier. In addition, the lubricant applied to the cleaning blade and the lubricant leveling blade needs to have adhesion to their substrates to prevent falling off from the substrates.

In order to reduce the frictional force between the cleaning blade and the image carrier, a cleaning blade coated with a lubricant containing a fluorine-based compound, which is vinylidene fluoride, has been proposed (for example, as in patent documents 1 to 5). In order to provide an elastic body of a cleaning blade with appropriate flexibility and hardness and to prevent curling or abrasion wear of a tip ridge portion of the cleaning blade, a cleaning blade having a mahalanobis hardness of 1.0 to 15.0N/mm2 at a position 20 μm from the tip ridge portion of the elastic body has been proposed (for example, refer to patent document 6). In order to improve the slidability of the cleaning blade, a cleaning blade in which PMMA (polymethyl methacrylate) particles are dispersed in a fluorine-based solvent and coated is proposed (for example, patent document 7).

CITATION LIST

Patent literature

[PTL 1]

Japanese unexamined patent application publication No.2000-147972

[PTL 2]

Japanese unexamined patent application publication No.2004-101551

[PTL 3]

Japanese patent No.3278733

[PTL 4]

Japanese unexamined patent application publication No. H10-214009

[PTL 5]

Japanese unexamined patent application publication No. H6-348193

[PTL 6]

Japanese unexamined patent application publication No.2017-16083

[PTL 7]

Japanese patent No.2853598

Disclosure of Invention

Technical problem

An object of the present invention is to provide a cleaning blade capable of reducing an increase in torque even immediately after the start of use of an image forming apparatus, thereby exhibiting excellent cleaning performance.

Solution to the problem

Embodiments of the present invention provide a cleaning blade for cleaning a rotating body. The cleaning blade includes: an edge layer having a tip portion that contacts the rotating body; and a coating layer located at the tip end portion of the edge layer. The coating layer includes a first fluorine-based resin and a second fluorine-based resin that is not compatible with the first fluorine-based resin. The cleaning blade has a diameter of 0.5-3N/mm at a distance of 20 μm from the tip edge line portion of the edge layer ² Is a marshi hardness of (c).

Embodiments of the present invention provide a lubricant smoothing blade for smoothing lubricant applied to a rotating body. The lubricant smoothing blade includes: an edge layer having a tip portion that contacts the rotating body; and a coating layer located at the tip end portion of the edge layer. The coating layer includes a first fluorine-based resin and a second fluorine-based resin that is not compatible with the first fluorine-based resin. The lubricant leveling blade is positioned 20 μm away from the top edge line part of the edge layer The position is 0.5-3N/mm ² Is a marshi hardness of (c).

Embodiments of the present invention provide a process cartridge. The process cartridge includes: an image carrier; at least one of the following devices: a charger for charging a surface of the image carrier; an exposure device for irradiating a charged surface of the image carrier to form an electrostatic latent image; a developing device that develops the electrostatic latent image into a visible image; or a transfer device for transferring the visible image onto a recording medium; and a cleaning device for removing residues on the surface of the image carrier, the cleaning device including the cleaning blade.

An embodiment of the present invention provides an image forming apparatus. The image forming apparatus includes: an image carrier; a charger for charging a surface of the image carrier; an exposure device for irradiating a charged surface of the image carrier to form an electrostatic latent image; a developing device that develops the electrostatic latent image into a visible image; a transfer device for transferring the visible image onto a recording medium; a fixing device for fixing the transferred visible image on the recording medium; and a cleaning device for removing residues on the surface of the image carrier, the cleaning device including the cleaning blade.

Effects of the invention

According to some embodiments of the present invention, there is provided a cleaning blade capable of reducing an increase in torque even immediately after the start of use of an image forming apparatus, thereby exhibiting excellent cleaning performance.

Drawings

The drawings are intended to depict exemplary embodiments of the invention, and should not be interpreted as limiting the scope thereof. The drawings are not to be regarded as being drawn to scale unless specifically indicated otherwise. Moreover, the same or similar reference numerals designate the same or similar parts throughout the several views.

[ FIG. 1]

Fig. 1 is a schematic sectional view illustrating that a cleaning blade is in contact with a surface of a rotating body according to an embodiment of the present invention.

[ FIG. 2]

Fig. 2 is a schematic perspective view of the cleaning blade shown in fig. 1.

[ FIG. 3]

Fig. 3 is a schematic cross-sectional view of another cleaning blade according to an embodiment of the present invention.

[ FIG. 4]

Fig. 4 is a schematic cross-sectional view of a lubricant smoothing blade in accordance with one embodiment of the invention.

[ FIG. 5]

Fig. 5 is a schematic cross-sectional view showing a lubricant leveling blade in contact with a surface of a rotating body according to an embodiment of the present invention.

[ FIG. 6]

Fig. 6 is a view for explaining the angle of the tip ridge portion of the lubricant leveling blade according to the embodiment of the present invention.

[ FIG. 7]

Fig. 7 is a schematic cross-sectional view showing an image forming apparatus according to an embodiment of the present invention.

[ FIG. 8]

Fig. 8 is a schematic cross-sectional view showing an image forming unit in the image forming apparatus shown in fig. 7.

[ FIG. 9]

Fig. 9 is a diagram illustrating a method of forming a coating according to an embodiment of the present invention.

DETAILED DESCRIPTION OF EMBODIMENT (S) OF INVENTION

The words used herein are words of description of specific embodiments only and are not intended to limit the invention. As used herein, the singular forms "a", "an" and "the" are intended to include the plural forms as well, unless the context clearly indicates otherwise.

In describing the embodiments illustrated in the drawings, specific terminology is employed for the sake of clarity. However, the disclosure of this specification is not intended to be limited to the specific terms so selected, and it is to be understood that each specific element includes all technical equivalents that operate in a similar manner, with similar functions, and achieve similar results.

Cleaning blade

This embodimentIs used for cleaning the rotating body. The cleaning blade includes an edge layer and a coating. The edge layer has a tip portion that contacts the rotating body. The coating is located at the top end of the edge layer. The coating includes a first fluorine-based resin (first fluorine-based resin) and a second fluorine-based resin (second fluorine-based resin) that is not compatible with the first fluorine-based resin. The cleaning blade has a thickness of 0.5-3N/mm at a distance of 20 μm from the tip edge portion of the edge layer ² Is a marshi hardness of (c). The cleaning blade may further include other members as needed.

The cleaning blade of this embodiment contacts the surface of the rotating body to remove the residue adhering to the rotating body.

The residue is not particularly limited as long as it adheres to the surface of the rotating body and is removed by the cleaning blade. Examples of such residues include, but are not limited to, toners, lubricants, inorganic particles, organic particles, dust, and mixtures thereof.

The conventional cleaning blade has the following disadvantages: when the cleaning blade is in contact with the rotating body (e.g., an image carrier), the torque, which is a force required to rotate the rotating body, increases due to friction generated between the cleaning blade and the rotating body, and the rotating body thereby stops rotating. In addition, the contact portion of the cleaning blade with the rotating body is worn out due to friction. The cleaning blade is thereby rolled up and allows toner to slip therethrough, resulting in poor cleaning.

In an attempt to improve the slidability of the cleaning blade and prevent the cleaning blade from turning up or increasing torque, a process called "touch-up" is widely used to apply a lubricant such as metallic soap (e.g., zinc stearate) and PMMA (i.e., polymethacrylic acid) particles to the tip portion of the cleaning blade. Generally, with the action of the image forming apparatus, toner gradually accumulates between the cleaning blade and the image carrier and serves as a lubricant. Therefore, the lubricant needs to exhibit lubricity for a short period of time from when the image forming apparatus starts to operate until the behavior of the cleaning blade becomes stable. However, the fine particles contained in the conventional lubricant have weak adhesion to the substrate, and undesirably separate from the cleaning blade before the behavior of the cleaning blade becomes stable.

It is known that "preventing torque increase" and "improving cleanliness" are in a trade-off relationship with each other.

When the contact portion of the cleaning blade with the rotating body is smoothed by applying a lubricant thereto to prevent an increase in torque, toner is allowed to pass through the contact portion, resulting in deterioration of cleaning performance.

When the contact portion of the cleaning blade and the rotating body is uneven to increase friction force in order to improve cleaning performance, torque increases.

It is difficult to improve the cleaning property while preventing an increase in torque.

As a result of diligent studies, the inventors of the present invention found that falling-off of particles can be prevented by coating a dispersion in which the particles are dispersed in a mixture of a solvent and a binder component, instead of a dispersion in which the particles are dispersed only in a solvent, to form a coating layer on a cleaning blade. Further, the present inventors have found that the use of a fluorine-based material having slidability for the particles and the binder component can prevent the cleaning blade from tilting or the torque of the image carrier from increasing.

In addition, the present inventors found that the thickness of the film is 0.5 to 3N/mm at a position 20 μm away from the tip ridge portion of the edge layer ² When the hardness of the shoe is equal to the hardness of the shoe, the sliding effect is exerted without adversely affecting the cleaning effect.

Therefore, the cleaning blade of the present embodiment is used to clean the rotating body. The cleaning blade includes an edge layer and a coating layer. The edge layer has a tip portion that contacts the rotating body. A coating is located at the top end of the border layer. The coating layer includes a first fluorine-based resin and a second fluorine-based resin that is not compatible with the first fluorine-based resin. The cleaning blade has a diameter of 0.5-3N/mm at a distance of 20 μm from the tip edge line portion of the edge layer ² Is a marshi hardness of (c). The cleaning blade can reduce an increase in torque even immediately after the start of use of the image forming apparatus, thereby exhibiting excellent cleaning performance.

Coating layer

The coating layer contains a first fluorine-based resin and a second fluorine-based resin that is not compatible with the first fluorine-based resin, and further contains other components as required.

The coating layer is a layer provided on one end portion of the peripheral side surface of the blade base material described later, which is used as the tip end of the cleaning blade.

The coating layer may be formed on at least a portion of the blade substrate including a contact edge of the cleaning blade in contact with the rotating body. The coating may be formed on the entire contact edge or on the entire face of the blade base. Wherein it is preferred that the coating is formed on the entire contact edge.

In the present invention, the surface area of the blade substrate where no coating is provided may be referred to as a non-coated area.

In the present invention, "insoluble" means a property that a plurality of substances are not completely mixed with each other to form an interface therebetween, and "compatible" means a property that a plurality of substances are completely mixed with each other to not form an interface therebetween.

In the present invention, the "immiscible state" means a state in which an interface exists between the first fluorine-based resin and the second fluorine-based resin, and a part of the interface is compatible.

In a preferred embodiment in the immiscible state, the coating has an islands-in-the-sea structure.

The sea-island structure refers to a structure of a coating layer formed on a cleaning blade, in which a continuous phase of one component is represented by "sea (or" matrix ")", and the other component is represented by "islands (or" domains ") formed in" sea ".

In the present invention, the sea-island structure means a state in which the first fluorine-based resin as a domain is not compatible with the second fluorine-based resin as a matrix and there is no compatible portion.

In the case where the coating layer has such an island structure, the domains are preferably in the form of particles.

Preferably, the coating layer of the cleaning blade has an average film thickness of 2 to 10 μm.

If the average film thickness of the coating layer is 2 μm or more, the sliding effect can be sufficiently exhibited. If the average film thickness of the coating layer is 10 μm or less, the coating layer can be prevented from falling off.

The average film thickness of the coating layer may be an average value of film thicknesses (μm) measured at 3 or more portions of the coating layer.

The measurement position of the film thickness of the coating layer is not particularly limited, and examples thereof include a position 20 μm away from both end portions of the coating layer and a center portion of the coating layer.

The average film thickness of the coating layer can be measured by scraping a part of the coating layer with a doctor blade, a cotton swab, or the like, and measuring the shape with a three-dimensional measuring device such as a contact coarser machine (SURFTEST SJ-500, manufactured by Sanfeng Co., ltd.), a laser microscope (LEXT OLS4100, manufactured by Olympus Co.).

Hereinafter, a cleaning blade according to an embodiment of the present invention will be described with reference to the accompanying drawings. The application of the cleaning blade provided herein is for illustrative purposes only and is not intended to be limiting.

In the drawings, the same components are denoted by the same reference numerals, and overlapping description may be omitted. The number, positions, shapes, etc. of the constituent members are not limited to those in the following embodiments, and may be appropriately set to suit a particular application.

Fig. 1 is a schematic cross-sectional view showing a state in which the cleaning blade of the present embodiment is in contact with the surface of the rotating body. Fig. 2 is a perspective view of the cleaning blade in fig. 1 including an enlarged view of the vicinity of a contact portion thereof. The cleaning blade 62 includes a cleaning blade support member 621 and a cleaning blade base 622. The cleaning blade supporting member 621 is a flat plate made of a rigid material such as metal or hard plastic. The cleaning blade base 622 has one end connected to the cleaning blade supporting member 621 and the other end as a free end having a specific length. The cleaning blade base 622 is fixed to one end of the cleaning blade supporting member 621 with an adhesive or the like. The other end of the cleaning blade supporting member 621 is supported in a cantilever manner by the housing of the cleaning device. The cleaning blade base 622 has a cleaning blade tip surface 62a, a cleaning blade lower surface 62b, a cleaning blade contact portion 62c, and a cleaning blade side surface 62d, the cleaning blade contact portion 62c being one end of the free end side of the cleaning blade base 622. Further, the cleaning blade base 622 has a coating 623 on at least a portion including the contact edge in the cleaning blade contact portion 62 c.

The cleaning blade 62 is disposed such that the cleaning blade contact portion 62c is in contact with the photoconductive body 3 in the longitudinal direction.

Fig. 3 is a sectional view of a cleaning blade according to another embodiment of the present invention. The cleaning blade 62 includes a cleaning blade support member 621 and a cleaning blade base 622. The cleaning blade base 622 includes an edge layer 622a and a base layer 622b each having elasticity, a contact portion 62c, and a coating 623 in at least a portion including a contact edge in the contact portion 62 c. In addition, the cleaning blade tip surface 62a, the cleaning blade lower surface 62b, and the cleaning blade side surface 62d are omitted in the drawing.

First fluorine-based resin

In the present invention, the fluorine-based resin means a resin containing fluorine in a molecule. The fluorine-containing olefin polymer is preferable, and the olefin polymer having a fluorine atom substituted for a hydrogen atom is more preferable.

In a preferred embodiment of the present invention, the first fluorine-based resin forms domains in the sea-island structure of the coating layer.

Preferably, the type and the amount of addition of the first fluorine-based resin are selected so that the first fluorine-based resin can form domains in the second fluorine-based resin.

The shape of the domain is not particularly limited, and may be appropriately selected according to the purpose, and may be regular or irregular. Preferably, the shape of the domain is regular.

In the case where the domain is regular in shape, it is preferably spherical.

When the domain is spherical, it is preferably in the form of particles.

The fluorine-based resin of such a shape prevents damage to the rotating body or the blade base of the cleaning blade when it comes off from the coating layer.

The volume average particle diameter (for example, 50% volume diameter and median diameter) of the first fluororesin is not particularly limited and may be appropriately selected according to the application, but is preferably 0.1 to 1 μm, more preferably 0.5 μm or less, and still more preferably 0.3 μm or less. When the volume average particle diameter is 1 μm or less, the first fluorine-based resin is prevented from precipitating and being unstable dispersed in the solvent. When the volume average particle diameter is 0.5 μm or less, the first fluorine-based resin can be dispersed in the nonaqueous solvent more stably.

The method for measuring the volume average particle diameter (e.g., 50% volume diameter, median diameter) is not particularly limited, and may be appropriately selected to suit a particular application, and may be laser diffraction/scattering, dynamic light scattering, or imaging.

For example, the volume average particle diameter may be measured by collecting particles from a coating layer of a cleaning blade, performing laser diffraction/scattering measurement on the particles using an instrument MICROTRAC (manufactured by Nikkiso corporation), or directly observing and measuring the particles on the cleaning blade using a Scanning Electron Microscope (SEM).

The volume average particle diameter of the particles present in the coating layer is substantially the same as the volume average particle diameter of the particles before being added to the dispersion liquid applied to the cleaning blade.

The proportion of the first fluorine-based resin in the coating layer is not particularly limited, and may be appropriately selected to suit a specific application. In order to obtain the sliding effect, it is preferably 4 to 8% by mass, more preferably 4.5 to 5.5% by mass. When the proportion of the first fluorine-based resin in the coating layer is 8 mass%, the sliding effect achieved by including the first fluorine-based resin is maximized. When the proportion of the first fluorine-based resin in the coating layer is 4 mass% or more, the sliding effect is sufficiently exhibited.

Specific examples of the first fluorine-based resin include, but are not limited to, polytetrafluoroethylene (PTFE), fluorinated ethylene-propylene copolymer (FEP), perfluoroalkoxy Polymer (PFA), chlorotrifluoroethylene Copolymer (CTFE), tetrafluoroethylene-chlorotrifluoroethylene copolymer (TFE/CTFE), ethylene-chlorotrifluoroethylene copolymer (ECTFE), and Polychlorotrifluoroethylene (PCTFE). Among them, polytetrafluoroethylene (PTFE) is preferable in order to further improve the slidability of the cleaning blade.

Polytetrafluoroethylene (PTFE) may be obtained synthetically or from commercial sources.

Specific examples of commercial products of Polytetrafluoroethylene (PTFE) include DYNEON TF ultrafine powder TF-9201Z, DYNEON TF ultrafine powder TF-9207Z (manufactured by 3M corporation), nanoFLON 119N, FLUOROE (manufactured by Shamrock Technologies corporation), TLP10F-1 (manufactured by DuPont-Mitsui Fluorochemicals corporation), KTL-500F (manufactured by Xidocun corporation), ALAFLON L203F (manufactured by Suwei corporation), and the like, but are not limited thereto.

Second fluorine-based resin

In this embodiment, the coating layer further comprises a second fluorous resin to improve adhesion of the first fluorous resin to the cleaning blade substrate and prevent peeling of the coating layer. Therefore, the cleaning blade is prevented from tilting, and the torque is prevented from increasing.

In a preferred embodiment of the present invention, the second fluorine-based resin forms a matrix in the island structure of the coating layer.

Preferably, the type and amount of addition of the second fluorine-based resin are selected so that the second fluorine-based resin can form a matrix of the first fluorine-based resin.

The second fluorine-based resin is not particularly limited and may be appropriately selected to suit a specific application as long as the first fluorine-based resin can be uniformly and stably dispersed. Specific examples thereof include, but are not limited to, vinylidene fluoride (VdF), hexafluoropropylene (HFP), and Tetrafluoroethylene (TFE). Among them, copolymers of these materials are preferable, and terpolymers of VdF-HFP-TFE are more preferable from the viewpoint of improving lubricity and adhesion to a blade base material.

Preferably, the proportion of VdF, HFP and TFE in the VdF-HFP-TFE terpolymer is 30 mol% to 80 mol%, 10 mol% to 35 mol% and 5 mol% to 35 mol%, respectively, to impart softness to the blade and solubility in the solvent.

The second fluorine-based resin may be mixed with a fluorine-based oil.

The fluorine-based oil not only improves the adhesive function but also improves the sliding function.

Specific examples of the fluorine-based oil include, but are not limited to, oils having Tetrafluoroethylene (TFE) oligomer or perfluoroether as a main skeleton.

In the case of a mixture of the second fluorine-based resin and the fluorine-based oil, the content of the second fluorine-based resin in the mixture is preferably 90 to 99 mass%, more preferably 95 to 98 mass%, to prevent the fluorine-based oil from oozing out and contaminating the photoreceptor.

The fluorine-based oil having a perfluoroether as a main skeleton is not particularly limited as long as it has slidability and does not inhibit dispersion of the fluorine-based resin, and may be appropriately selected depending on the application. In view of the kinematic viscosity, an average molecular weight of 2000 to 3500 is preferable.

In the present invention, the first fluorine-based resin and the second fluorine-based resin may be the same material or different materials. When the first fluorine-based resin and the second fluorine-based resin are the same material, the coating layer may be formed by a method in which the first fluorine-based resin and the second fluorine-based resin are in an incompatible state. For example, when the second fluorine-based resin is added to the first fluorine-based resin cured in advance and cured, an interface is formed between the first fluorine-based resin and the second fluorine-based resin, thereby forming a coating layer in which the first fluorine-based resin and the second fluorine-based resin are partially incompatible. The coating may also be formed by adding a hydrophilic substituent to the first fluorine-based resin and a hydrophobic substituent to the second fluorine-based resin.

Other components

The other components are not particularly limited and may be appropriately selected according to the specific application. Specific examples thereof include, but are not limited to, non-fluorine-based resin particles composed of the above-mentioned fluorine-based resin.

The non-fluorine-based resin particles are not particularly limited, and may be appropriately selected to suit a particular application. Specific examples thereof include particles of inorganic compounds, acrylic resins, styrene resins, and vinyl resins.

Specific examples of the inorganic compound particles include, but are not limited to, silica, alumina, and zirconia.

Each of these may be used alone or in combination with others.

The shape of the non-fluorine-based resin particles is not particularly limited and may be appropriately selected depending on the application, but the non-fluorine-based resin particles are preferably spherical. The non-fluorine-based resin particles of such a shape can prevent damage to the rotating body or blade base of the cleaning blade when they come off from the coating layer.

The volume average particle diameter (for example, 50% volume diameter, median diameter) of the non-fluorine-based resin is not particularly limited and may be appropriately selected depending on the application, but is preferably 0.1 to 1. Mu.m, more preferably 0.5 μm or less, and still more preferably 0.3 μm or less. When the volume average particle diameter is 1 μm or less, the non-fluorine-based resin particles are prevented from precipitating and being unstably dispersed in the solution. If the particle size is 0.5 μm or less, the dispersion in a nonaqueous solvent can be made more stable.

For example, the volume average particle diameter may be measured by collecting particles from the coating layer of the cleaning blade, performing laser diffraction/scattering measurement on the particles using an instrument MICROTRAC (manufactured by Nikkiso corporation), or directly observing and measuring the particles of the cleaning blade by using a Scanning Electron Microscope (SEM).

The method for forming the coating layer is not particularly limited, and may be appropriately selected to suit a particular application. For example, the coating layer may be formed by adding the first fluorine-based resin to a mixture of the solvent and the second fluorine-based resin (i.e., the second fluorine-based resin dispersion), mixing them, and applying the resultant particle dispersion onto the blade substrate of the cleaning blade.

The solvent is not particularly limited and may be appropriately selected depending on the application. Examples thereof include fluorine-containing organic solvents.

Specific examples of the fluorine-containing organic solvent include, but are not limited to, hydrofluoroethers (HFEs), perfluorocarbons (PFCs), and Perfluoroethers (PFEs).

Each of these may be used alone or in combination with others.

The average particle diameter of the fine particles in the second fluorine-based resin dispersion (for example, the average particle diameter measured by the cumulative analysis method in the scattering intensity distribution) measured by the dynamic light scattering method is preferably 1 μm or less, more preferably 0.5 μm or less, still more preferably 0.3 μm or less.

Generally, particles having a volume average particle diameter of 1 μm or less are aggregated into secondary particles having a particle diameter of 1 μm or more. Therefore, when the secondary particles formed by aggregation are dispersed in such a manner that they have a particle diameter of 1 μm or less, the second fluorine-based resin dispersion can be kept stable even when stored for a long period of time at a low viscosity.

The dispersion method is not particularly limited and may be appropriately selected according to the application. Specific examples thereof include, but are not limited to, methods using a dispersing machine such as an ultrasonic dispersing machine, a three-roll mill, a ball mill, a bead mill, and a jet mill.

The method for forming the coating layer is not particularly limited, and may be appropriately selected to suit a particular application. Examples include, but are not limited to, an impregnation method that impregnates all or a portion of the blade substrate of the cleaning blade in the particle dispersion. In addition to the dipping method, spraying method coating or dispenser method coating may be used.

Scraper blade base member

In the present invention, the blade base of the cleaning blade may also be simply referred to as "base".

The shape of the blade base may be appropriately selected according to the specific application as long as the blade base has a structure capable of removing residues on the rotating body. Preferably, the contact edge of the contact portion of the squeegee base that contacts the rotation body is linear. The blade base may have, for example, a plate shape.

The structure of the blade base is not particularly limited and may be appropriately selected to suit a particular application. Examples thereof include, but are not limited to, a single-layer structure, a laminated structure, and a laminated structure combining a plurality of members. Among them, a single-layer structure and a laminated structure combining a plurality of members are preferable from the viewpoint of easy processing into a cleaning blade.

In the case where the blade base has a laminated structure, the layer adjoining the rotating body may be referred to as an edge layer, and the layers other than the edge layer may be referred to as a base layer. In the case where the blade base has a single-layer structure, the blade base is constituted only by the edge layer.

In the case of a laminated structure in which a plurality of members are combined, it is preferable that the mahalanobis hardness values of the plurality of members are different from each other.

The material of the blade base is not particularly limited, and may be appropriately selected according to the purpose. In order to prevent abrasion of the blade base and to sufficiently remove the residue from the rotating body, it is preferable that the material has proper elasticity and hardness. The material of the blade base may be, for example, an elastic material.

The elastic material is not particularly limited, and may be appropriately selected to suit a particular application as long as it has high elasticity. Specific examples thereof include, but are not limited to, urethane rubber, silicone rubber, fluororubber, nitrile rubber (NBR), and Ethylene Propylene Diene Monomer (EPDM). Among them, polyurethane rubber is preferable because of its durability and non-staining property.

The size of the blade base is not particularly limited, and may be appropriately selected according to the size of the rotating body.

The Marsh hardness of the urethane rubber in the cleaning blade of the present embodiment is not particularly limited, and may be appropriately selected depending on the application, and is preferably 0.5 to 2N/mm ² . When the mahalanobis hardness of the urethane rubber in the cleaning blade is within the above-described desired range, undesired phenomena such as cleaning failure and chipping can be prevented. Here, when the linear pressure of the blade is difficult to reach a desired level and the area of the contact portion with the image carrier increases, cleaning failure may be caused, and when the blade base is too hard, chipping may be caused.

The method for producing the blade base is not particularly limited, and may be appropriately selected according to the application. For example, the blade base may be manufactured by: preparing a polyurethane prepolymer using a polyol compound and a polyisocyanate compound, adding a curing agent to the polyurethane prepolymer, and optionally a curing catalyst as needed, centrifugally forming the resultant using a mold, standing the resultant at room temperature for curing, and cutting the resultant into a flat plate having a predetermined size.

The polyol compound is not particularly limited and may be appropriately selected according to the application. Examples include, but are not limited to, high molecular weight polyols and low molecular weight polyols.

Specific examples of the high molecular weight polyol include, but are not limited to, polyester polyols as condensates of alkylene glycols and aliphatic dibasic acids; polyester polyols such as alkylene glycols, e.g., ethylene adipate polyol, butene adipate polyol, hexadiene adipate polyol, ethylene propylene adipate polyol, ethylene butene adipate polyol, ethylene neopentyl adipate polyol, and polyester polyol of adipic acid; polycaprolactone-based polyols such as polycaprolactone ester polyols obtained by ring-opening polymerization of caprolactone; polyether polyols such as poly (oxytetramethylene) glycol and poly (oxypropylene) glycol.

Each of these may be used alone or in combination with others.

Specific examples of the low molecular weight polyol include, but are not limited to, diols such as 1, 4-butanediol, ethylene glycol, neopentyl glycol, hydroquinone-bis (2-hydroxyethyl) ether, 3 '-dichloro-4, 4' -diaminodiphenylmethane, and the like; and tri-or higher polyhydric alcohols such as 1, 1-trimethylol propane, glycerin, 1,2, 6-hexanetriol, 1,2, 4-butanetriol, trimethylolethane, 1-tris (hydroxyethoxymethyl) propane, diglycerin, pentaerythritol, and the like.

Each of these may be used alone or in combination with others.

The polyisocyanate compound is not particularly limited and may be appropriately selected depending on the application. Specific examples thereof include, but are not limited to, methylene diphenyl diisocyanate (MDI), toluene Diisocyanate (TDI), xylene Diisocyanate (XDI), 1, 5-Naphthalene Diisocyanate (NDI), tetramethyl xylene diisocyanate (TMXDI), isophorone diisocyanate (IPDI), hydrogenated xylene diisocyanate (H6 XDI), dicyclohexylmethane diisocyanate (H12 MDI), hexamethylene Diisocyanate (HDI), dimer acid diisocyanate (DDI), norbornene diisocyanate (NBDI), and trimethyl hexamethylene diisocyanate (TMDI).

Each of these may be used alone or in combination with others.

The curing agent is not particularly limited and may be appropriately selected depending on the application. Examples include, but are not limited to, amines and alcohols.

Each of these may be used alone or in combination with others.

The curing agent may be used to adjust the hardness of the blade substrate.

The curing catalyst is not particularly limited and may be appropriately selected according to the use. Specific examples thereof include, but are not limited to, 2-methylimidazole and 1, 2-dimethylimidazole.

The proportion of the curing catalyst to the total mass of the prepolymer and the curing agent is not particularly limited, and may be appropriately selected depending on the application, but is preferably 0.01 to 0.5 mass%, more preferably 0.05 to 0.3 mass%.

The rebound resilience of the blade substrate according to Japanese Industrial Standard (JIS) K6255 is not particularly limited, and may be appropriately selected to suit a specific application, but is preferably 10% to 80% at 23 ℃.

When the rebound resilience is within the desired range, undesirable phenomena such as cleaning failure and squeaking of the blade can be prevented. Here, when the entire blade base loses flexibility and becomes unable to follow the runout or roughness of the image carrier, cleaning failure occurs, and when rebound becomes too strong, blade ringing (i.e., abnormal sound) occurs.

The rebound resilience of the blade substrate can be measured at 23℃according to JISK6255 using, for example, a No.221 rebound resilience tester manufactured by Toyo Seiki Seisaku-sho company.

Hardness of Martin

The Marble hardness of the cleaning blade at a position 20 μm away from the tip ridge portion of the edge layer is 0.5-3N/mm ² In this case, the sliding effect can be fully exhibited.

In order to exert an excellent sliding effect, it is preferable that the cleaning blade has a Marsh hardness of 0.5 to 2N/mm at a position 20 μm from the tip edge line portion of the edge layer ² 。

The Marble hardness of the cleaning blade at a position 20 μm from the tip edge line portion of the edge layer was 0.5N/mm ² In the above, the first fluorine-based resin and the second fluorine-based resin can be prevented from adhering insufficiently to the edge layer without achieving the desired degree of sliding effect. The Marsh hardness of the cleaning blade at a position 20 μm from the tip edge line portion of the edge layer was 3N/mm ² In the following cases, the first fluorine-based resin and the second fluorine-based resin can be preventedThe fluorine-based resin excessively adheres to the edge layer to suppress an undesirable phenomenon of cleaning action.

In the present invention, the measurement of the mahalanobis hardness is performed for the cleaning blade which has been processed.

The Hardness of Magnus (HM) was measured by pressing a Berkovich indenter into a sample at a load of 1,000. Mu.N for 10 seconds, holding for 5 seconds, and pulling out at the same loading rate for 10 seconds using a nanoindenter (FNT-3100, manufactured by ELIONIX Co.) according to ISO 14577.

The mahalanobis hardness of the edge layer was measured at a position 20 μm from the top edge line portion of the edge layer.

The mahalanobis hardness of the underlayer may be measured at any position, but for ease of measurement, it is preferable to measure at a position 20 μm from the end of the underlayer.

The Martin hardness is the median of the values measured at the 4-6 positions.

Rotating body

The rotating body is not particularly limited and may be appropriately selected according to the application. Examples include, but are not limited to, image carriers and photoreceptors.

The structure and size of the rotating body are not particularly limited, and may be appropriately selected to suit a particular application.

The material of the rotary body is not particularly limited and may be appropriately selected according to the purpose. Examples include, but are not limited to, metals, plastics, and ceramics.

The shape of the rotating body is not particularly limited and may be appropriately selected according to the application. Examples include, but are not limited to, drum, belt, flat, and sheet.

Other parts

The other components are not particularly limited and may be appropriately selected according to the purpose. Examples include, but are not limited to, a support.

Support body

The shape of the support is not particularly limited and may be appropriately selected to suit a particular application. Examples include, but are not limited to, a plate shape.

The structure of the support is not particularly limited and may be appropriately selected to suit a particular application.

The size of the support is not particularly limited, and may be appropriately selected according to the size of the rotating body.

The material of the support is not particularly limited and may be appropriately selected to suit a particular application. Examples include, but are not limited to, metals, plastics, and ceramics. Among them, from the viewpoint of strength, metals are preferable, and steel (e.g., stainless steel), aluminum, and phosphor bronze are particularly preferable.

Lubricant leveling scraper

The cleaning blade of the present embodiment can be used as a lubricant leveling blade that levels a lubricant applied to the surface of a rotating body after the cleaning blade cleans the rotating body.

The lubricant leveling blade of the present embodiment is used for leveling lubricant applied to a rotating body. The lubricant smoothing blade includes an edge layer and a coating. The edge layer has a distal end portion that contacts the rotating body. The coating is disposed at the top end of the border layer. The coating layer contains a first fluorine-based resin and a second fluorine-based resin that is not compatible with the first fluorine-based resin. The lubricant leveling blade has a thickness of 0.5-3N/mm at a distance of 20 μm from the tip edge line part of the edge layer ² Is a marshi hardness of (c). The lubricant smoothing blade may also include other components as desired.

In the case of using a cleaning blade as a lubricant leveling blade, if it is 0.5 to 3N/mm at a position 20 μm from the tip ridge portion of the edge layer ² The hardness of (c) can exhibit good lubricant application properties.

The lubricant leveling blade of the present embodiment will be described below with reference to the drawings.

Fig. 4 is a schematic cross-sectional view showing a lubricant leveling blade according to the present embodiment. Fig. 5 is a schematic cross-sectional view showing a state in which the lubricant leveling blade of fig. 4 is in contact with the surface of the rotating body. The lubricant flat blade 104 includes a lubricant flat blade support member 1041 and a lubricant flat blade base 1042. The lubricant leveling blade supporting member 1041 is a flat plate made of a rigid material such as metal or hard plastic. The lubricant flat blade base 1042 has one end coupled to the lubricant flat blade supporting member 1041 and the other end as a free end having a specific length. The lubricant flat blade base 1042 is fixed to one end of the lubricant flat blade supporting member 1041 with an adhesive or the like. The other end of the lubricant leveling blade supporting member 1041 is supported in a cantilever manner by the housing of the cleaning device.

The lubricant flat blade base 1042 has a lubricant flat blade tip surface 104a, a lubricant flat blade lower surface 104b, and a lubricant flat blade contact portion 104c, the lubricant flat blade contact portion 104c being one end of the lubricant flat blade base 1042 on the free end side. In addition, at least a portion of the contact edge of the lubricant flat blade substrate 1042 in the portion including the lubricant flat blade contact portion 104c may have the same layer structure as the cleaning blade shown in fig. 3.

Image forming apparatus and image forming method

The image forming apparatus of the present embodiment includes: an image carrier; a charging device that charges a surface of the image carrier; an exposure device that exposes a charged surface of the image carrier to form an electrostatic latent image; a developing device that develops the electrostatic latent image into a visible image; a transfer device that transfers the visible image onto a recording medium; a fixing device that fixes the transferred visible image on the recording medium; and a cleaning device that removes residues (e.g., toner) on the surface of the image carrier. The image forming apparatus may further include a lubricant applying device that applies a lubricant to a surface of the image carrier and other devices as needed.

The charging device and the exposure device may be collectively referred to as an "electrostatic latent image forming device".

The cleaning device and the lubricant applying device include a cleaning blade and a lubricant leveling blade, respectively, according to some embodiments of the present invention.

The image forming method of the present embodiment includes a charging process, an exposing process, a developing process, a transfer process, a fixing process, and a cleaning process, and further includes a lubricant applying process and other processes as necessary. The charging process and the exposure process may be collectively referred to as an "electrostatic latent image forming process".

The image forming method is suitably performed by an image forming apparatus. The charging process may be performed by a charging device. The exposure process may be performed by an exposure apparatus. The developing process may be performed by a developing device. The transfer process may be performed by a transfer device. The fixing process may be performed by a fixing device. The cleaning process may be performed by a cleaning device. The cleaning device includes the cleaning blade of the present embodiment. The lubricant application process can be performed by a lubricant application device provided with the lubricant leveling blade of the present embodiment. Other processes may be performed by other corresponding devices.

Image carrier

The structure and size of the image carrier are not particularly limited, and may be appropriately selected from known structures and sizes.

The shape of the image carrier is not particularly limited and may be appropriately selected to suit a particular application. Examples include, but are not limited to, drums and belts.

The material of the image carrier is not particularly limited and may be appropriately selected to suit a particular application. Examples thereof include, but are not limited to, inorganic photosensitive materials such as amorphous silicon, selenium, and the like, organic photosensitive materials (OPC) such as polysilane, phthalopolymer, and the like.

Charging device and charging process

The charging step is a step of charging the surface of the image carrier, and is performed by a charging device.

The charging device is not particularly limited, and may be appropriately selected to suit a particular application as long as it is capable of charging the surface of the image carrier. Specific examples thereof include, but are not limited to, contact chargers equipped with conductive or semiconductive rollers, brushes, films or rubber blades and non-contact chargers employing corona discharge, such as wire corona and scorotrons.

The shape of the charger is determined according to the specification or configuration of the image forming apparatus, and may be in the form of a roller, a magnetic brush, or a fur brush.

The magnetic brush may be composed of various ferrite particles (e.g., zn-Cu ferrite) used as a charger, a non-magnetic conductive sleeve for supporting the charger, and a magnetic roller contained in the conductive sleeve.

The brush may be made of fur that has been subjected to conductive treatment with carbon, copper sulfide, metal or metal oxide. Such a brush is wound around or attached to a metal or a mandrel that has been subjected to a conductive treatment to form a charger.

The charger is not limited to a contact charger. However, a contact charger is preferred because the amount of by-product ozone is small.

Preferably, the charger is provided in contact with or not in contact with the image carrier, and is capable of charging the surface of the image carrier by applying a direct-current voltage and an alternating-current voltage thereto in superposition.

Preferably, the charger is a charging roller configured to have a gap belt, disposed close to but not in contact with the image carrier, capable of charging the surface of the image carrier by applying a direct-current voltage and an alternating-current voltage superimposed on the surface of the image carrier.

Exposure apparatus and exposure process

The exposure step is a step of irradiating the charged surface of the image carrier with light, and is performed by an exposure apparatus. The exposure process may be performed by irradiating the surface of the image carrier with light containing image information by an exposure device.

The optical system in the exposure apparatus is roughly classified into an analog optical system and a digital optical system.

The analog optical system projects the original document directly onto the surface of the image carrier.

The digital optical system receives image information as an electrical signal, converts the electrical signal into an optical signal, and irradiates the image carrier with the optical signal to form an image.

The exposure apparatus is not particularly limited, and may be appropriately selected to suit a specific application as long as it can irradiate a charged image carrier with light to form an electrostatic latent image. Specific examples thereof include, but are not limited to, various exposer types of exposure optical system type, rod lens array type, laser optical system type, liquid crystal shutter optical system type, light Emitting Diode (LED) optical system type.

The exposure may also be performed by irradiating the back surface of the image carrier with light containing image information.

Developing process and developing device

The developing step is a step of developing the electrostatic latent image into a toner image, and is performed by a developing device.

The developing device is not particularly limited, and may be appropriately selected to suit a particular application as long as it can develop an electrostatic latent image into a toner image. Examples thereof include developing devices that contain toner and are capable of applying toner to an electrostatic latent image in a contact or non-contact manner.

The developing device may be of a dry developing type or a wet developing type. The developing device may be a monochromatic developing device or a multicolor developing device. For example, the developing device may include a stirrer that friction-stir and charge the toner and a rotatable magnetic roller.

In the developing device, the toner particles and the carrier particles are mixed and stirred. The toner particles are charged by friction and held on the surface of the rotating magnetic roller, thereby forming a magnetic brush.

The magnet roller is disposed close to the image carrier such that a portion of toner particles constituting the magnet brush formed on the surface of the magnet roller moves to the surface of the image carrier by the electric attraction force of the electrostatic latent image. As a result, the electrostatic latent image is developed with toner to form a toner image on the surface of the image carrier.

The toner contained in the developing device may be a developer containing toner, and the developer may be a one-component developer or a two-component developer.

The toner may be a magnetic toner or a non-magnetic toner used as a one-component developer without using a carrier.

Transfer process and transfer apparatus

The transfer step is a step of transferring the toner image onto the recording medium, and is performed by a transfer device.

The transfer process preferably includes: a primary transfer step of transferring the toner image onto a surface of an intermediate transfer unit to form a composite transfer image; and a secondary transfer step of transferring the composite transfer image onto a recording medium.

The transfer device is not particularly limited, and may be appropriately selected to suit a particular application as long as it can transfer a toner image onto a recording medium. Preferably, the transfer device includes: a primary transfer device that transfers the toner image onto a surface of an intermediate transfer device to form a composite transfer image; and a secondary transfer device that transfers the composite transfer image onto a recording medium.

The primary transfer device and the secondary transfer device each preferably include a transfer device that peels a toner image formed on an image carrier toward a recording medium by charging.

The transfer device is not particularly limited and may be appropriately selected according to the application. Specific examples thereof include, but are not limited to, a corona transfer device using corona discharge, a transfer belt, a transfer roller, a pressure transfer roller, and an adhesive transfer device. The number of the transferers is at least 1, but may be 2 or more.

The recording medium is not particularly limited, and may be appropriately selected to suit a particular application as long as an unfixed toner image can be transferred thereto. Specific examples include, but are not limited to, plain paper, polyethylene terephthalate (PET) sheet for projector (OHP).

Fixing process and fixing device

The fixing step is a step of fixing the transferred toner image on the recording medium, and is performed by a fixing device. In the case of using toners of two or more colors, the toner of each color may be fixed each time the toner is transferred onto the recording medium, or may be fixed after the toners of all colors are transferred and stacked on the recording medium.

The fixing device is not particularly limited, and may be appropriately selected to suit a particular application as long as it can fix the transferred toner image on the recording medium. The fixing device may employ a heat fixing method using a known heat and pressure assembly.

The heating and pressurizing assembly is not particularly limited and may be appropriately selected to suit a particular application. Specific examples thereof include, but are not limited to, combinations of a heating roller and a pressing roller, and combinations of a heating roller, a pressing roller, and an endless belt.

The heating temperature is not particularly limited, and may be appropriately selected depending on the application, and is preferably 80℃to 200 ℃. The fixing device may be used with the light fixer as needed.

Cleaning process and cleaning device

The cleaning process is a process of removing toner remaining on the surface of the image carrier, and is performed by a cleaning device.

The cleaning device includes a cleaning blade according to one embodiment of the present invention.

The line pressure applied to the image carrier surface by the blade base of the cleaning blade is not particularly limited, and may be appropriately selected to suit a particular application, but is preferably 10 to 100N/m, more preferably 10 to 50N/m. When the line pressure is 10 to 100N/m, poor cleaning in which toner slides between the contact portion and the rotating body is unlikely to occur, preventing curling of the elastic body.

The line pressure may be measured using a measuring device, such as that available from KYOWA ELECTRONIC INSTRUMENTS, which is assembled with a small compression load cell.

The angle ("cleaning angle") formed between the tangent of the image carrier at the position in contact with the contact portion of the blade base of the cleaning blade and the tip surface of the free end of the blade base is not particularly limited, and may be appropriately selected to suit a specific application, but is preferably 65 ° to 85 °.

When the cleaning angle is 65 DEG to 85 DEG, curling of the blade base body can be prevented, and occurrence of cleaning failure can be reduced.

Lubricant applying step and lubricant applying apparatus

The lubricant applying step is a step of applying a lubricant to the surface of the image carrier, and is performed by a lubricant applying device.

The application of the lubricant may be performed by: the lubricant is molded into a solid shape, the solid lubricant is pressed against the fur brush using a pressure spring, the fur brush is rotated to apply the lubricant to the surface of the image carrier, and then the lubricant is uniformly applied using a lubricant leveling blade.

The lubricant applying device is provided with the lubricant leveling blade of the present embodiment.

The line pressure at which the blade substrate of the blade is coated onto the surface of the image carrier by the lubricant leveling is not particularly limited, and may be appropriately selected to suit a specific application, but is preferably 5 to 15N/m, more preferably 5 to 10N/m. When the line pressure is 5 to 15N/m, the performance of applying the lubricant to the image carrier is stabilized, preventing the tip ridge line portion from being pulled in.

Preferably, the tip ridge portion of the lubricant leveling blade has an angle θ of 90 ° to 140 °. When the angle θ of the tip ridge line portion is an obtuse angle within the above range, the lubricant is prevented from being pulled in to smooth the blade tip surface 104a, stabilizing the application of the lubricant. When the angle θ of the tip ridge portion of the lubricant leveling blade is 140 ° or less, the edge effect becomes remarkable, and the lubricant application function is improved.

As shown in fig. 6, the angle θ of the tip ridge portion is an angle of a blade corner portion angle formed by two faces facing the surface of the image carrier on the upstream side and the downstream side in the surface moving direction of the image carrier with the lubricant flattening blade tip ridge portion 104c interposed therebetween.

Other procedures and other devices

Examples of the other steps include a power removal step, a recycling step, and a control step. Other devices may include, for example, a deaerator, a recycler, and a controller.

Power removing procedure and power removing device

The charge removing process is a process of applying a charge removing bias voltage to the image carrier to remove charges, and is performed by a charge remover.

The charge remover is not particularly limited, and may be appropriately selected to suit a specific application as long as it can apply a charge removing bias to the image carrier. Specific examples of static eliminators include, but are not limited to, static eliminating lamps.

Recycle process and recycle device

The recycling process is a process of recycling the toner removed in the cleaning process of the developing device, and is performed by a recycler.

The recycler is not particularly limited and may be appropriately selected to suit the particular application. Specific examples thereof include, but are not limited to, conveyors.

Control process and controller

The control step is a step of controlling each step, and is executed by a controller.

The controller is not particularly limited, and may be appropriately selected to suit a particular application as long as it can control each device. Specific examples thereof include, but are not limited to, sequencers and computers.

Hereinafter, an image forming apparatus of an embodiment of the present invention is described with reference to the drawings. The application of the cleaning blade provided herein is for illustrative purposes only and is not intended to be limiting.

Fig. 7 is a schematic diagram showing an image forming apparatus 500 according to an embodiment of the present invention. The image forming apparatus 500 includes four image forming units 1Y, 1M, 1C, and 1K for forming yellow, magenta, cyan, and black ("Y, M, C and K") images, respectively. The image forming units 1Y, 1M, 1C, and 1K have the same configuration except that toners of different colors (i.e., yellow, magenta, cyan, and black toners) are respectively contained as image forming materials.

Above the four image forming units 1Y, 1C, 1M, and 1K (hereinafter collectively referred to as "image forming unit 1"), a transfer unit 60 is provided. The transfer unit 60 includes an intermediate transfer belt 14 as an intermediate transfer unit. The image forming units 1Y, 1M, 1C, and 1K include respective photoreceptors 3Y, 3M, 3C, and 3K on which toner images having respective colors are to be formed. The toner images are superimposed on each other on the surface of the intermediate transfer belt 14.

An optical writing unit 40 is arranged below the four imaging units 1. The optical writing unit 40 serving as a latent image forming device emits laser light L to the photoreceptors 3Y, 3M, 3C, and 3K in the respective image forming units 1Y, 1M, 1C, and 1K based on image information. Thus, electrostatic latent images of yellow, magenta, cyan, and black images are formed on the respective photoreceptors 3Y, 3M, 3C, and 3K. In the optical writing unit 40, laser light L is emitted from a light source, deflected by a polygon mirror 41 rotationally driven by a motor, and guided to the photoreceptors 3Y, 3M, 3C, and 3K through a plurality of optical lenses and mirrors. Alternatively, the optical writing unit 40 may be replaced with another unit that performs optical scanning with a Light Emitting Diode (LED) array.

Below the optical writing unit 40, the first sheet feeding cassette 151 and the second sheet feeding cassette 152 are arranged to overlap each other in the vertical direction. In each sheet feeding cassette, a plurality of recording media P are stored in a stacked state. The uppermost recording medium P in each sheet feeding cassette is in contact with the first sheet feeding roller 151a or the second sheet feeding roller 152 a. When the first sheet feeding roller 151a is driven by the driver to rotate in the counterclockwise direction in fig. 7, the uppermost recording medium P in the first sheet feeding cassette 151 is fed to the sheet feeding path 153 extending vertically on the right side of the sheet feeding cassette in fig. 7. When the second sheet feeding roller 152a is driven by the driver to rotate in the counterclockwise direction in fig. 7, the uppermost recording medium P in the second sheet feeding cassette 152 is fed to the sheet feeding path 153.

In the sheet supply path 153, a plurality of conveying roller pairs 154 are provided. The recording medium P supplied to the sheet supply path 153 is conveyed upward in fig. 7 in the sheet supply path 153 while being nipped by the rollers of the conveying roller pair 154.

At the downstream end of the sheet feeding path 153 with respect to the conveying direction of the recording medium P, a registration roller pair 55 is provided. The rollers of the registration roller pair 55 nip the recording medium P supplied by the conveying roller pair 154, and immediately thereafter stop rotating. Then, the registration roller pair 55 timely conveys the recording medium P to a secondary transfer nip (to be described later).

Fig. 8 is a schematic diagram showing one of the four imaging units 1.

As shown in fig. 8, each image forming unit 1 includes a drum-shaped photoconductor 3 serving as an image carrier. The photoconductive body 3 is in the shape of a drum, but may be in the shape of a sheet or an endless belt.

Around the photoconductor 3, a charging roller 4, a developing device 5, a cleaning device 6, a primary transfer roller 7, a lubricant applying device 10, and a charge eliminating lamp are provided. The charging roller 4 is a charging member provided to a charging device (charger). The developing device 5 develops the latent image formed on the surface of the photoreceptor 3 into a toner image. After the toner image has been transferred from the photoconductive body 3 onto the intermediate transfer belt 14, the cleaning device 6 removes residual toner particles remaining on the photoconductive body 3. The primary transfer roller 7 is a primary transfer member of a primary transfer device that transfers a toner image from the surface of the photoreceptor 3 onto the intermediate transfer belt 14. The lubricant applying device 10 applies a lubricant to the surface of the photoconductive body 3 which has been cleaned by the cleaning device 6. The static eliminator is a static eliminator for eliminating the surface potential of the photoreceptor 3 that has been cleaned.

The charging roller 4 is disposed at a predetermined distance from the photoconductive body 3 without contacting the photoconductive body 3. The charging roller 4 charges the photoconductive body 3 to a predetermined potential having a predetermined polarity. After the charging roller 4 has uniformly charged the surface of the photoreceptor 3, the optical writing unit 40 emits laser light L to the charged surface of the photoreceptor 3 based on image information to form an electrostatic latent image.

The developing device 5 includes a developing roller 51 serving as a developer carrier. The developing roller 51 is applied with a developing bias from a power supply. In the housing of the developing device 5, a supply screw 52 and a stirring screw 53 for stirring the developer contained in the housing while conveying the developer in mutually opposite directions are provided. Further, a blade 54 for regulating the developer carried on the developing roller 51 is provided in the casing. When the developer is stirred and conveyed by the supply screw 52 and the stirring screw 53, toner particles in the developer are charged to have a predetermined polarity. The developer is then carried on the surface of the developing roller 51, and is regulated by the blade 54. In a development region where the developing roller 51 faces the photoreceptor 3, toner particles in the developer adhere to a latent image formed on the photoreceptor 3.

The cleaning device 6 includes a brush 101 and a cleaning blade 62. The cleaning blade 62 contacts the photoconductive body 3 so as to face the moving direction of the surface of the photoconductive body 3. Details of the cleaning blade 62 are as described above.

The lubricant applying device 10 includes a solid lubricant 103, a lubricant pressurizing spring 103a, and a lubricant leveling blade 104. The fur brush 101 functions as a coating brush for coating the solid lubricant 103 onto the photoconductive body 3. The solid lubricant 103 is held by the bracket 103b, and is pressurized toward the brush 101 side by the lubricant pressurizing spring 103 a. When the fur brush 101 rotates to follow the rotation of the photoconductive body 3, the solid lubricant 103 is scraped off by the fur brush 101, and the scraped lubricant is applied to the photoconductive body 3 by the lubricant leveling blade 104. When the lubricant is applied to the photoconductive body 3, the friction coefficient of the surface of the photoconductive body 3 is kept to 0.2 or less during non-image formation. Details of the lubricant leveling blade are described above.

The charger adopts a noncontact approach arrangement in which the charging roller 4 is disposed close to the photoconductive body 3 without contacting the photoconductive body 3. As the charger, a known charger such as a corotron, a scorotron, a solid state charger, or the like may be used. Among these chargers, a contact charging method and a noncontact proximity configuration method are preferable because they have advantages in terms of high charging efficiency, less ozone generation, and compact size.

Examples of the light source of the light writing unit 40 that emits the laser light L and the light source of the electricity removing lamp include all light emitting substances such as a fluorescent lamp, a tungsten lamp, a halogen lamp, a mercury lamp, a sodium vapor lamp, a Light Emitting Diode (LED), a Laser Diode (LD), and Electroluminescence (EL).

In order to emit only light having a desired wavelength, any type of filter may be used, such as a sharp cut filter, a band pass filter, a near infrared cut filter, a dichroic filter, an interference filter, and a color temperature conversion filter.

Among these light sources, light emitting diodes and semiconductor lasers are preferable because they can emit long wavelength light (600-800 nm) having high energy.

Referring to fig. 7, a transfer unit 60 serving as a transfer device includes a belt cleaning unit 162, a first carriage 63, and a second carriage 64 in addition to the intermediate transfer belt 14. The transfer unit 60 further includes four primary transfer rollers 7Y, 7M, 7C, and 7K, a secondary transfer backup roller 66, a driving roller 67, an auxiliary roller 68, and a tension roller 69. The intermediate transfer belt 14 is tensioned by these eight rollers, and is rotationally driven by a driving roller 67 to move endlessly in the counterclockwise direction in fig. 7. The four primary transfer rollers 7Y, 7M, 7C, and 7K and the corresponding photosensitive bodies 3Y, 3M, 3C, and 3K sandwich the endless moving intermediate transfer belt 14, thereby forming corresponding primary transfer nips therebetween. Then, the back surface of the intermediate transfer belt 14 (i.e., the inner peripheral surface of the ring) is applied with a transfer bias having a polarity opposite to that of the toner (e.g., positive polarity). When the intermediate transfer belt 14 continuously moves while passing through primary transfer nips of yellow, magenta, cyan, and black in order, the toner images of yellow, magenta, cyan, and black formed on the respective photoconductive bodies 3Y, 3M, 3C, and 3K are superimposed on each other on the outer peripheral surface of the intermediate transfer belt 14. Thus, a composite toner image in which toner images of four colors are superimposed on each other 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 provided outside the loop of the intermediate transfer belt 14 to form a secondary transfer nip therebetween. The registration roller pair 55 feeds the recording medium P sandwiched between the rollers to the secondary transfer nip portion at a timing that can be synchronized with the composite toner image on the intermediate transfer belt 14. The composite toner image on the intermediate transfer belt 14 is secondarily transferred onto the recording medium P in the secondary transfer nip by the action of the secondary transfer electric field and the nip pressure. The secondary transfer electric field is formed between the secondary transfer roller 70 to which the secondary transfer bias is applied and the secondary transfer backup roller 66. The resultant toner image is combined with the white color of the recording medium P to form a full-color toner image.

On the intermediate transfer belt 14 that has passed through the secondary transfer nip, residual toner particles that have not been transferred onto the recording medium P remain. These residual toner particles are removed by the belt cleaning unit 162. The belt cleaning unit 162 includes a belt cleaning blade 162a that contacts the outer peripheral surface of the intermediate transfer belt 14. The belt cleaning blade 162a scrapes off the residual toner particles from the intermediate transfer belt 14.

The first carriage 63 of the transfer unit 60 may swing around the rotation axis of the auxiliary roller 68 at a predetermined angle according to the on/off driving operation of the solenoid. When the image forming apparatus 500 is to form a black-and-white image, the first carriage 63 is rotated slightly counterclockwise in fig. 7 by driving the solenoid. This rotation of the first carriage 63 causes the primary transfer rollers 7Y, 7M, and 7C to rotate counterclockwise in fig. 7 about the rotation axis of the auxiliary roller 68 to move the intermediate transfer belt 14 away from the photoconductive bodies 3Y, 3M, and 3C. Therefore, of the four image forming units 1Y, 1M, 1C, and 1K, only the image forming unit 1K for black image starts to operate to form a black-and-white image. Since unnecessary driving of the imaging units 1Y, 1M, and 1C is avoided during formation of the black-and-white image, undesired degradation of the constituent members of the imaging units 1Y, 1M, and 1C can be prevented.

Above the secondary transfer nip in fig. 7, a fixing unit 80 is provided. The fixing unit 80 includes a pressing roller 81 and a fixing belt unit 82. The pressing roller 81 internally contains a heat source such as a halogen lamp. The fixing belt unit 82 includes a fixing belt 84 serving as a fixing member, a heating roller 83 including a heat source (e.g., halogen lamp) therein, a tension roller 85, a driving roller 86, and a temperature sensor. The fixing belt 84 in the form of an endless belt is tensioned by a heating roller 83, a tension roller 85, and a driving roller 86, and is moved endlessly in a counterclockwise direction in fig. 7. The fixing belt 84 is heated from the back surface side thereof by the heating roller 83 while moving in an endless manner. The pressing roller 81 contacts the outer peripheral surface of the fixing belt 84 at a position where the fixing belt 84 is wound around the heating roller 83. The pressing roller 81 is driven to rotate clockwise in fig. 7. Accordingly, the pressing roller 81 and the fixing belt 84 form a fixing nip therebetween.

The temperature sensor is disposed outside the loop of the fixing belt 84, facing the outer peripheral surface of the fixing belt 84, with a predetermined gap formed therebetween. The temperature sensor detects the surface temperature of the fixing belt 84 immediately before the fixing belt 84 enters the fixing nip. The detection result is sent to the fixing power supply circuit. The fixing power supply circuit controls the supply of electric power to the heat sources included in the heating roller 83 and the pressing roller 81 based on the detection result.

Then, the recording medium P having passed through the secondary transfer nip is separated from the intermediate transfer belt 14 and then supplied to the fixing unit 80. The recording medium P is supplied upward in fig. 7 while being sandwiched by fixing nip portions in the fixing unit 80. In this process, the recording medium P is heated and pressed by the fixing belt 84, and the full-color toner image is fixed on the recording medium P.

The recording medium P having the fixed image thereon is discharged to the outside of the image forming apparatus 500 by the discharge roller pair 87. On the top surface of the housing of the image forming apparatus 500, a stack portion 88 is formed. The recording mediums P discharged by the discharge roller pair 87 are sequentially stacked on the stacking portion 88.

Above the transfer unit 60, four toner cartridges 100Y, 100M, 100C, and 100K that respectively contain yellow toner, magenta toner, cyan toner, and black toner are provided. Yellow, magenta, cyan, and black toners contained in the respective toner cartridges 100Y, 100M, 100C, and 100K are supplied to the respective developing devices 5Y, 5M, 5C, and 5K in the respective image forming units 1Y, 1M, 1C, and 1K. The toner cartridges 100Y, 100M, 100C, and 100K are independent of the image forming unit 1Y,

1M, 1C, and 1K, are detachably mounted on the image forming apparatus main body.

Next, an image forming action of the image forming apparatus 500 is described below.

In response to receiving the print execution signal from the operation panel, the charging roller 4 and the developing roller 51 are each applied with a predetermined voltage or current at a predetermined timing. Similarly, the light source and the erasing lamp in the light writing unit 40 are each applied with a predetermined voltage or current at a predetermined timing. The photoreceptor 3 is driven to rotate in the direction indicated by the arrow in fig. 7 by the photoreceptor drive motor in synchronization with the application of the voltage or current.

When the photosensitive body 3 rotates in the direction indicated by the arrow in fig. 7, the surface of the photosensitive body 3 is uniformly charged to a predetermined potential by the charging roller 4. The optical writing unit 40 emits laser light L to the charged surface of the photoreceptor 3 based on image information. The portion of the surface of the photoreceptor 3 irradiated with the laser light L is subjected to charge removal to form an electrostatic latent image.

The surface of the photoreceptor 3 having the electrostatic latent image thereon is rubbed by a magnetic brush formed of the developer on the developing roller 51 at a position where the photoreceptor 3 faces the developing device 5. When a developing bias is applied to the developing roller 51, negatively charged toner particles on the developing roller 51 move onto the electrostatic latent image, forming a toner image. This image forming process is performed in each of the image forming units 1Y, 1M, 1C, and 1K to form yellow, magenta, cyan, and black toner images on the photoreceptors 3Y, 3M, 3C, and 3K, respectively.

Accordingly, in the image forming apparatus 500, the electrostatic latent image formed on the photosensitive body 3 is reversely developed by the negatively charged toner particles by the developing device 5. In the present embodiment, an N/P (i.e., negative/positive) developing system (in which toner particles are attached to a low potential region) and a noncontact charging roller manner are employed, but the developing and charging system is not limited thereto.

The toner images formed on the photoreceptors 3Y, 3M, 3C, and 3K are primary-transferred onto the surface of the intermediate transfer belt 14 in a sequential manner so that they overlap each other on the surface of the intermediate transfer belt 14. Thus, a composite toner image is formed on the intermediate transfer belt 14.

The composite toner image (also referred to as "toner image" for simplicity) formed on the intermediate transfer belt 14 is transferred onto a recording medium P fed from the first sheet feeding cassette 151 or the second sheet feeding cassette 152 to the secondary transfer nip via the registration roller pair 55. The recording medium P is temporarily stopped by being nipped by the registration roller pair 55, and then supplied to the secondary transfer nip portion in synchronization with the leading end of the toner image on the intermediate transfer belt 14. Then, the recording medium P having the transferred toner image is separated from the intermediate transfer belt 14 and supplied to the fixing unit 80. When the recording medium P having the transferred toner image passes through the fixing unit 80, the toner image is fixed on the recording medium P due to heat and pressure. The recording medium P with the fixed toner image is discharged to the outside of the image forming apparatus 500, stacked at the stacking portion 88.

On the other hand, after the toner image has been transferred from the surface of the intermediate transfer belt 14 onto the recording medium P in the secondary transfer nip, the belt cleaning unit 162 removes residual toner particles remaining on the surface of the intermediate transfer belt 14.

Similarly, after the toner image has been transferred from the surface of the photoreceptor 3 onto the intermediate transfer belt 14 in the primary transfer nip, the cleaning device 6 removes residual toner particles remaining on the surface of the photoreceptor 3. The lubricant application device 10 then applies lubricant to the cleaned surface, which is de-energized by the de-energizing lamp.

As shown in fig. 8, each image forming unit 1 of the image forming apparatus 500 has a frame body 2 that accommodates a photosensitive body 3, and a process device including a charging roller 4, a developing device 5, a cleaning device 6, and a lubricant applying device 10. The image forming unit 1 is integrally detachable as a process cartridge from the main body of the image forming apparatus 500. Therefore, in the image forming apparatus 500, by replacing each of the image forming units 1 as a process cartridge, the photoconductive body 3 and the process device can be replaced at the same time. Alternatively, each of the photoconductive body 3, the charging roller 4, the developing device 5, the cleaning device 6, and the lubricant applying device 10 may be replaced independently.

Process cartridge

The process cartridge of the present embodiment includes: an image carrier; at least one of a charger, an exposure device, a developing device, and a transfer device; and a cleaning device that contacts the surface of the image carrier to remove residues on the surface of the image carrier. The process cartridge may further include other devices, such as a lubricant applying device that contacts the surface of the image carrier to apply a lubricant to the surface of the image carrier.

The lubricant application device includes a lubricant leveling blade according to one embodiment of the present invention.

The process cartridge is a device (component) detachably mountable to an image forming apparatus, and includes: an image carrier; at least one of a charger, an exposure device, a developing device, and a transfer device; and a cleaning device, and optionally a lubricant application device.

Examples

Hereinafter, the present invention will be further described by way of examples and comparative examples, but the present invention is not limited to the following examples. In the following description, "parts" means "parts by mass" unless otherwise specified.

Example 1

Preparation of blade base of cleaning blade

Polyurethane elastomer sheets obtained by the treatments of centrifugal molding, curing and post-crosslinking are used for the edge layer and the base layer, respectively. The average thickness and the mahalanobis Hardness (HM) of the edge layer and the base layer are as follows.

Average thickness: 2.0[ mm ]

Mahalanobis Hardness (HM) of the edge layer: 0.5[ N/mm ] ² ]

Mahalanobis Hardness (HM) of the base layer: 2.0[ N/mm ] ² ]

And bonding the edge layer and the substrate layer to each other to prepare the scraper substrate. Bonding the scraper substrate with the metal plate.

Preparation of the coating

Preparation of particle Dispersion A

Into the spiral tube were placed 6 parts of Polytetrafluoroethylene (PTFE) fine powder (TF 9201Z, manufactured by 3M company, having a volume average particle diameter of 200 nm) as a first fluorine-based resin, 2 parts of a VdF-HFP-TFE terpolymer composed of vinylidene fluoride (VdF), hexafluoropropylene (HFP) and Tetrafluoroethylene (TFE) as a second fluorine-based resin, and 92 parts of 1, 2-tetrafluoroethyl 2, 2-trifluoroethyl ether (manufactured by HFE-347,Tokyo Chemical Industry company) as a fluorine-based dispersion medium, and stirred with a stirrer. Thus, a particle dispersion a was prepared.

Preparation of particle Dispersion B

6 parts of Polytetrafluoroethylene (PTFE) fine powder (TF 9201Z, manufactured by 3M company, having a volume average particle diameter of 200 nm) as a first fluorine-based resin, 2 parts of polyvinylidene fluoride (PVdF) as a second fluorine-based resin, and 92 parts of 1, 2-tetrafluoroethyl 2, 2-trifluoroethyl ether (HFE-347,Tokyo Chemical Industry company) as a fluorine-based dispersion medium were placed in a spiral tube, and stirred using a stirrer. Thus, particle dispersion B was prepared.

Preparation of particle Dispersion C

6 parts of Polytetrafluoroethylene (PTFE) fine powder (TF 9201Z, manufactured by 3M company, having a volume average particle diameter of 200 nm) as a first fluorine-based resin, 2 parts of a VdF-HFP copolymer composed of vinylidene fluoride (VdF) and Hexafluoropropylene (HFP) as a second fluorine-based resin, and 92 parts of 1, 2-tetrafluoroethyl 2, 2-trifluoroethyl ether (manufactured by HFE-347,Tokyo Chemical Industry company) as a fluorine-based dispersion medium were placed in a spiral tube, and stirred using a stirrer. Thus, a particle dispersion C was prepared.

Preparation of particle Dispersion D

Into a spiral tube, 95 parts of an aqueous polymethyl methacrylate (PMMA) dispersion (MX 100W, manufactured by Japanese catalyst Co., ltd., having a volume average particle diameter of 150 nm) and 5 parts of a polyvinyl butyral (PVB) resin (S-LEC KW-M, manufactured by SEKISUI CHEMICAL Co., ltd., having an acetalization degree of 24.+ -. 3 mol%) as a second fluorine-based resin were placed, and stirred using a stirrer. Thus, a particle dispersion D was prepared.

Dipping

One end surface of the peripheral side surface of the cleaning blade, which is used as the tip end of the cleaning blade (hereinafter, sometimes referred to as "cleaning blade tip end surface"), was immersed in the particle dispersion a so as to be perpendicular to the horizontal surface, and lifted up at a lifting speed of 1mm/s from the tip end surface of the cleaning blade to a depth of 2 mm. In order to concentrate PTFE particles imparting a cleaning function to the portion including the contact edge of the tip surface of the cleaning blade, the cleaning blade was inclined at about 45℃as shown in FIG. 9, and dried at room temperature (25 ℃) for 30 minutes. Thus, the cleaning blade of example 1 was prepared.

Examples 2 to 9

Cleaning blades of examples 2 to 9 were produced in the same manner as in example 1, except that the mahalanobis hardness of the edge layer, the mahalanobis hardness of the base layer, and the average thickness of the coating layer in the cleaning blade were changed to those shown in tables 1 to 3.

Examples 10 to 12 and comparative examples 1 to 7

Cleaning blades of examples 10 to 12 and comparative examples 1 to 7 were produced in the same manner as in example 1, except that the first fluorine-based resin, the second fluorine-based resin, the dispersion medium, the mahalanobis hardness of the edge layer, the mahalanobis hardness of the base layer, and the average thickness of the coating layer in the cleaning blade were changed to those shown in tables 1 to 3.

In example 10, example 11 and comparative example 2, particle dispersion B, particle dispersion C and particle dispersion D were used, respectively.

The cleaning blade of comparative example 1 includes a blade base body provided with no coating layer.

Assembly of image forming apparatus

The respective cleaning blades obtained in examples 1 to 12 and comparative examples 1 to 7 were mounted on a process cartridge of a color multifunction peripheral (IMAGIO MP C4500, manufactured by Ricoh corporation) whose printing section had the same configuration as that of the image forming apparatus 500 shown in fig. 7 to assemble the image forming apparatus.

The cleaning blade was mounted on the image forming apparatus to be a line pressure of 20g/cm and a cleaning angle of 79 °.

Determination of Martin hardness

The mahalanobis hardness of the edge layer and the mahalanobis hardness of the base layer of each of the cleaning blades obtained in examples 1 to 12 and comparative examples 1 to 7 were measured.

The Hardness of Magnus (HM) can be measured according to ISO 14577 using a nanoindenter (ENT-3100, manufactured by ELIONIX) by pressing a Berkovich indenter into a sample at a load of 1,000 μN for 10 seconds, holding for 5 seconds, and pulling out at the same loading rate for 10 seconds. The results are shown in tables 1 to 3.

The mahalanobis hardness of the edge layer was measured at a position 20 μm away from the edge line portion at the tip of the edge layer. The mahalanobis hardness of the base layer was measured at a position 20 μm from the end of the base layer.

The Martin hardness is the median of the values measured at the 4-6 positions.

Measurement of average thickness of coating

The average thickness of the coating layers of the respective cleaning blades obtained in examples 1 to 12 and comparative examples 1 to 7 was measured. The results are shown in tables 1 to 3.

The average thickness was measured by scraping a part of the coating layer with a doctor blade, a cotton swab, or the like, and measuring the shape using a contact surface roughness meter (SURFTEST SJ-500, manufactured by Sanfeng corporation).

TABLE 1

TABLE 2

TABLE 3 Table 3

Evaluation of Torque increase Rate

With the above-described image forming apparatus, output is performed under the following conditions to measure the rate of change of the increase in the driving torque of the photoconductor. After the output, the tip portion of the cleaning blade was observed with a laser microscope (LEXT OLS 4500, manufactured by olympus corporation), and the torque increase rate was evaluated according to the following criteria. The evaluation results are shown in tables 1 to 3. The "initial value" defined in the evaluation criterion refers to a value obtained in the initial stage of outputting the 1 st to 500 th sheets.

Environment: 23 ℃/45% RH

Output conditions: white paper chart

Number of output sheets: 5000 pieces (A4 size transverse)

Evaluation criterion

A: the rate of change of the torque increase is within 50% of the initial value, and the photoconductor does not stop due to the increase of the driving torque. Even after the output, the tip end portion of the cleaning blade was observed, and no trace of curl was found at all.

B: the rate of change of the torque increase is within 50% of the initial value, and the photoconductor does not stop due to the increase of the driving torque. However, when the tip portion of the cleaning blade after the output is observed, there is a curl mark, but it does not reach the level of toner passing, and therefore there is no problem in practical use.

C: the photoreceptor stops due to the increase in torque. When the tip portion of the cleaning blade after the discharge is observed, there is a curl trace of the toner passing degree, which is problematic in practical use.

Evaluation of image quality (cleaning Performance)

With the above-described image forming apparatus, output is performed under the following conditions. Thereafter, the tip end portion of the cleaning blade and the surface of the photoreceptor were observed with a laser microscope (LEXT OLS 4500, manufactured by olympus corporation), and evaluated according to the following criteria. The evaluation results are shown in tables 1 to 3.

Environment: 27 ℃/80% RH

Output conditions: 3 prints/jobs of chart with image area ratio of 5%

Number of output sheets: 50000 (A4 size transverse)

Evaluation criterion

A: toner particles that were not scraped off due to poor cleaning were not visually confirmed on either the printing sheet or the photoreceptor, and streak-like toner was not confirmed to be scraped off even when the photoreceptor was observed in the longitudinal direction with a microscope.

B: toner particles that were not scraped off due to poor cleaning were not visually confirmed on either the printing sheet or the photoreceptor, but streak-like toner was confirmed not to be scraped off when the photoreceptor was observed in the longitudinal direction with a microscope.

C: toner particles that were not scraped off due to poor cleaning were visually confirmed on the print sheet or the photoreceptor.

Reference example 1

Preparation of lubricant leveling blade

A lubricant leveling blade of reference example 1 was produced in the same manner as in example 1, except that the average thickness was changed to 1.4 mm.

Lubricant leveling blades of reference examples 2 to 10 were prepared in the same manner as in reference example 1, except that the mahalanobis hardness of the edge layer, the mahalanobis hardness of the base layer, and the average thickness of the coating layer in the lubricant leveling blades were changed as shown in tables 4 to 6.

Reference examples 11 and 12 and reference comparative examples 1 to 6

The lubricant leveling blades of reference examples 11 and 12 and reference examples 1 to 6 were prepared in the same manner as in reference example 1, except that the first fluorine-based resin, the second fluorine-based resin, the dispersion medium, the mahalanobis hardness of the edge layer, the mahalanobis hardness of the base layer, and the average thickness of the coating layer in the lubricant leveling blades were changed as shown in tables 4 to 6.

In reference example 11, reference example 12, and reference comparative example 2, particle dispersion B, particle dispersion C, and particle dispersion D were used, respectively.

The lubricant leveling blade of reference example 1 includes a blade base body provided with no coating layer.

Assembly of image forming apparatus

The image forming apparatus was assembled in the same manner as in examples 1 to 12 and comparative examples 1 to 7. The lubricant leveling blades of reference examples 1 to 12 and reference comparative examples 1 to 6 were attached to the image forming apparatus so that the line pressure was 10g/cm and the angle θ of the tip edge line portion was 90 ° to 140 °.

Determination of Martin hardness

The mahalanobis hardness of the edge layers and the mahalanobis hardness of the base layers of the lubricant leveling blades obtained in reference examples 1 to 12 and reference comparative examples 1 to 6 were measured in the same manner as in examples 1 to 12 and comparative examples 1 to 7. The results are shown in tables 4 to 6.

Determination of the average thickness of the coating

The average thickness of the coating layers of the lubricant leveling blades obtained in reference examples 1 to 12 and reference comparative examples 1 to 6 was measured in the same manner as in examples 1 to 12 and comparative examples 1 to 7. The results are shown in tables 4 to 6.

TABLE 4 Table 4

TABLE 5

TABLE 6

Evaluation of image quality (Lubricant coating Property)

The above-described image forming apparatuses provided with the respective lubricant leveling blades obtained in reference examples 1 to 12 and reference comparative examples 1 to 6 were used, and outputted under the following conditions. Thereafter, a halftone image is output, and the degree of unevenness in the photoreceptor longitudinal direction is evaluated. It is known that the more uniform the lubricant applied in the longitudinal direction of the photoreceptor, the less the unevenness on the image.

Environment: 23 ℃/50% RH

Output conditions: continuously outputting a graph (i.e., white paper) having an image area rate of 0%

Number of output sheets: 200000 pieces (A4 size horizontal)

Evaluation criterion

A: the halftone image has little or no non-uniformity.

B: halftone images have non-uniformity in part, and there is no problem in practical use.

C: the entire halftone image has unevenness, and is not suitable for practical use.

Embodiments of the present invention include the following items (1) to (15).

(1)

A cleaning blade for cleaning a rotating body, the cleaning blade comprising:

An edge layer having a tip portion that contacts the rotating body; and

a coating layer located on the top end of the edge layer,

wherein the coating layer comprises a first fluorine-based resin and a second fluorine-based resin which is not compatible with the first fluorine-based resin,

wherein the cleaning blade has a diameter of 0.5 to 3N/mm at a position 20 μm from the tip edge line portion of the edge layer ² Is a marshi hardness of (c).

(2)

The cleaning blade according to the above (1), wherein the cleaning blade has a diameter of 0.5 to 2N/mm at a position 20 μm from the tip ridge portion of the edge layer ² Is a marshi hardness of (c).

(3)

The cleaning blade according to the above (1) or (2), wherein the coating layer has an average thickness of 2.0 to 10.0 μm at a position 20 μm from the tip ridge line portion of the edge layer.

(4)

The cleaning blade according to any one of the above (1) to (3), wherein the first fluorine-based resin contains spherical fine particles which contain polytetrafluoroethylene and have a volume average particle diameter of 1 μm or less.

(5)

The cleaning blade according to any one of the above (1) to (4), wherein the second fluorine-based resin is mixed with a fluorine-based oil.

(6)

The cleaning blade according to the above (5), wherein the fluorine-based oil has an average molecular weight of 2000 to 3500.

(7)

The cleaning blade according to any one of the above (1) to (6), wherein the second fluorine-based resin is a polymer, copolymer, or terpolymer containing one, two, or three kinds selected from vinylidene fluoride, hexafluoropropylene, and tetrafluoroethylene, respectively.

(8)

The cleaning blade according to any one of the above (1) to (7), wherein the base body of the cleaning blade has a single-layer structure of polyurethane rubber or a multi-layer structure of a plurality of polyurethane rubbers having different hardness values.

(9)

The cleaning blade according to any one of the above (1) to (8), wherein the urethane rubber or each of the plurality of urethane rubbers has a Martin hardness of 0.5 to 2N/mm ² 。

(10)

A lubricant smoothing blade for smoothing lubricant applied to a rotating body, the lubricant smoothing blade comprising:

an edge layer having a tip portion that contacts the rotating body; and

a coating layer located on the top end of the edge layer,

wherein the lubricant leveling blade has a thickness of 0.5 to 3N/mm at a position 20 μm from the tip edge line portion of the edge layer ² Is a marshi hardness of (c).

(11)

The lubricant leveling blade according to the above (10), wherein the tip ridge portion has an angle θ of 90 ° to 140 °.

(12)

A process cartridge, comprising:

an image carrier;

at least one of the following components:

a charger for charging a surface of the image carrier;

an exposure device for irradiating a charged surface of the image carrier to form an electrostatic latent image;

a developing device that develops the electrostatic latent image into a visible image; or (b)

A transfer device for transferring the visible image onto a recording medium; and

a cleaning device for removing residues on a surface of the image carrier, the cleaning device comprising the cleaning blade according to any one of claims 1 to 9.

(13)

The process cartridge according to the above (12), further comprising a lubricant applying device that applies a lubricant to the surface of the image carrier, the lubricant applying device comprising the lubricant leveling blade according to the above (10) or (11).

(14)

An image forming apparatus comprising:

an image carrier;

a charger for charging a surface of the image carrier;

A developing device that develops the electrostatic latent image into a visible image;

a transfer device for transferring the visible image onto a recording medium;

a fixing device for fixing the transferred visible image on the recording medium; and

(15)

The image forming apparatus according to the above (14), further comprising a lubricant applying device that applies a lubricant to the surface of the image carrier, the lubricant applying device comprising the lubricant leveling blade according to the above (10) or (11).

The cleaning blade according to the above (1) to (9), the lubricant leveling blade according to the above (10) and (11), the process cartridge according to the above (12) and (13), and the image forming apparatus according to the above (14) and (15) solve various problems existing in the past and achieve the object of the present invention.

The above embodiments are illustrative and not limiting of the invention. Thus, many additional modifications and variations are possible in light of the above teaching. For example, elements and/or features of different illustrative embodiments may be combined with each other and/or substituted for each other within the scope of the invention.

The present patent application is based on and claims priority from japanese patent application nos. 2021-021849 and 2021-107228, filed to the japanese patent office on, respectively, day 15 of 2021, 2 and day 29 of 2021, 6, and the entire disclosures of each of which are incorporated herein by reference.

List of reference numerals

1. Image forming unit

1Y image forming unit (for yellow)

1C image Forming Unit (for cyan)

1M image Forming Unit (for magenta)

1K image Forming Unit (for Black)

10. Lubricant coating device

101. Brush with brush body

103. Solid lubricant

103a Lubricant compression spring

103b bracket

104. Lubricant leveling scraper

104a lubricant levels the blade tip surface

104b lubricant levels the lower surface of the screed

104c lubricant leveling blade contact

1041. Lubricant leveling blade support member

1042. Lubricant leveling scraper substrate

14. Intermediate transfer belt

151. First sheet feeding cassette

152. Second sheet feeding cassette

151a first sheet feeding roller

152a second sheet-feeding roller

153. Sheet feeding path

154. Conveying roller pair

162. Belt cleaning unit

162a belt cleaning blade

2. Frame body

3. Photosensitive body

3Y photoreceptor (for yellow)

3C photoreceptor (for cyan)

3M photoreceptor (for magenta)

3K photoreceptor (for black)

4. Charging roller

40. Optical writing unit

41. Polygon mirror

5. Developing device

51. Developing roller

52. Feed screw

53. Stirring screw

54. Scraper blade

55. Alignment roller pair

6. Cleaning device

60. Transfer unit

62. Cleaning blade (cleaning blade)

62a cleaning blade tip surface

62b cleaning blade lower surface

62c cleaning blade contact portion

62d cleaning blade side surface

621. Cleaning blade supporting member

622. Cleaning blade base

622a edge layer

622b substrate layer

623. Coating layer

63. First bracket

64. Second bracket

66. Secondary transfer printing supporting roller

67. Driving roller

68. Auxiliary roller

69. Tensioning roller

7. Primary transfer roller

7Y primary transfer roller (for yellow)

7C primary transfer roller (for cyan)

7M primary transfer roller (for magenta)

7K primary transfer roller (for black)

70. Secondary transfer roller

80. Fixing unit

81. Pressure roller

82. Fixing belt unit

83. Heating roller

84. Fixing belt

85. Tensioning roller

86. Driving roller

87. Output roller pair

88. Stacking part

100Y toner box (for yellow)

100C toner cartridge (for cyan)

100M toner cartridge (for magenta)

100K toner box (for black)

500. Image forming apparatus with a plurality of image forming units

L laser

P recording medium

Angle of the theta blade corner angle.

Claims

1. A cleaning blade for cleaning a rotating body, the cleaning blade comprising:

an edge layer having a tip portion that contacts the rotating body; and

a coating layer located on the top end of the edge layer,

2. The cleaning blade according to claim 1, wherein the edge layer has a thickness of 0.5 to 2N/mm at a position 20 μm from the tip ridge portion ² Is a marshi hardness of (c).

3. The cleaning blade according to claim 1 or 2, wherein the cleaning blade has an average thickness of 2.0 to 10.0 μm at a position 20 μm from the tip ridge line portion of the edge layer.

4. The cleaning blade according to any one of claims 1 to 3, wherein the first fluorine-based resin contains spherical fine particles which contain polytetrafluoroethylene and have a volume average particle diameter of 1 μm or less.

5. The cleaning blade according to any one of claims 1 to 4, wherein the second fluorine-based resin is mixed with a fluorine-based oil.

6. The cleaning blade according to claim 5, wherein the fluorine-based oil has an average molecular weight of 2000 to 3500.

7. The cleaning blade according to any one of claims 1 to 6, wherein the second fluorine-based resin is a polymer, copolymer, or terpolymer containing one, two, or three kinds respectively selected from vinylidene fluoride, hexafluoropropylene, and tetrafluoroethylene.

8. The cleaning blade according to any one of claims 1 to 7, wherein a base body of the cleaning blade has a single-layer structure of polyurethane rubber or a multi-layer structure of a plurality of polyurethane rubbers having different mahalanobis hardness values.

9. The cleaning blade according to any one of claims 1 to 8, wherein the urethane rubber or each of the plurality of urethane rubbers has a mahalanobis hardness of 0.5 to 2N/mm ² 。

10. A lubricant smoothing blade for smoothing lubricant applied to a rotating body, the lubricant smoothing blade comprising:

an edge layer having a tip portion that contacts the rotating body; and

a coating layer located on the top end of the edge layer,

11. The lubricant smoothing blade of claim 10, wherein the tip ridge portion has an angle θ of 90 ° to 140 °.

12. A process cartridge, comprising:

an image carrier;

at least one of the following components:

a charger for charging a surface of the image carrier;

13. A process cartridge according to claim 12, further comprising a lubricant applying device that applies a lubricant to a surface of said image carrier, the lubricant applying device comprising the lubricant leveling blade according to claim 10 or 11.

14. An image forming apparatus comprising:

An image carrier;

a charger for charging a surface of the image carrier;

a transfer device for transferring the visible image onto a recording medium;

15. The image forming apparatus according to claim 14, further comprising a lubricant applying device that applies a lubricant to a surface of the image carrier, the lubricant applying device including the lubricant leveling blade according to claim 10 or 11.