JP2018072806A - Cleaning blade, process cartridge and image formation apparatus - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a cleaning blade which can suppress the occurrence of abnormal sound due to curling, abnormal abrasion and the like of a tip ridge part, and maintain the excellent cleaning performance over a long period.SOLUTION: A cleaning blade includes an elastic member which is brought into contact with the surface of a cleaning object member and removes the deposit adhering to the surface of the cleaning object member. The elastic member includes: a base material; and a surface layer formed of a cured substance of a curable composition. The surface layer is formed on at least a portion of the base material lower surface containing a contact part when the surface of the base material facing the downstream side in the travel direction of the cleaning object member with respect to the contact part contacting the cleaning object member is defined as the base material lower surface. The average film thickness of the surface layer in the contact part is equal to or greater than 10 μm and equal to or less than 100 μm.SELECTED DRAWING: Figure 1

Description

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

  Conventionally, in an electrophotographic image forming apparatus, an image carrier (hereinafter, also referred to as “photosensitive member”, “electrophotographic photosensitive member”, or “electrostatic latent image carrier”) as a member to be cleaned, It is known that deposits such as unnecessary transfer residual toner attached to the surface after transferring the toner image to the transfer paper or intermediate transfer member are removed by a cleaning means.

  As the cleaning member of the cleaning means, one that uses a strip-shaped cleaning blade is well known because it can generally be simplified in configuration and has excellent cleaning performance. This is because the base end of the cleaning blade is supported by a support member, the contact portion (tip ridge line portion) is pressed against the peripheral surface of the image carrier, and the toner remaining on the image carrier is dammed and scraped off and removed. .

  In addition, in order to meet the recent demand for higher image quality, an image forming apparatus using a near-spherical toner having a small particle diameter formed by a polymerization method or the like (hereinafter sometimes referred to as “polymerized toner”) is known. ing. The polymerized toner has characteristics such as higher transfer efficiency than conventional pulverized toner, and can meet the demand. However, it is difficult to remove the polymerized toner sufficiently from the surface of the image carrier using a cleaning blade, and there is a problem that cleaning failure occurs. This is because the polymerized toner having a small particle diameter and excellent sphericity passes through a slight gap formed between the cleaning blade and the image carrier.

  In order to suppress the slip-through, it is necessary to increase the cleaning pressure by increasing the contact pressure between the image carrier and the cleaning blade. However, if the contact pressure is increased, turning will occur as shown in FIG. 14A. Moreover, when it uses in the state turned over, local abrasion will arise as shown to FIG. 14B, and a front-end | tip ridgeline part will be missing as shown in FIG. 14C finally.

In order to solve such a problem, for example, Patent Document 1 proposes that a contact layer of an elastic member made of polyurethane elastomer is provided with a surface layer made of a resin having a film hardness of pencil hardness B to 6H. ing.
Patent Document 2 discloses a cleaning blade in which an ultraviolet curable composition containing silicone is impregnated into a rubber elastic member to swell, and then the ultraviolet curable composition is cured by ultraviolet irradiation treatment. Proposed.
Further, Patent Document 3 discloses that a portion including a contact portion of an elastic member is impregnated with at least one selected from an isocyanate compound, a fluorine compound, and a silicone compound, and an elastic member is provided on the surface of the elastic member including the contact portion. A cleaning blade having a harder surface layer has been proposed.
Patent Document 4 proposes a cleaning blade having a surface layer containing lubricating particles and a binder resin.
Further, in Patent Document 5, in an image forming apparatus including a cleaning unit having a cleaning blade, the cleaning blade covers a strip-shaped elastic blade and a tip ridge line portion of the elastic blade, and the elastic blade And a surface layer having a friction coefficient of 0.1 to 0.6.

  The present invention has been made in view of the above background, and provides a cleaning blade capable of suppressing the generation of abnormal noise due to turning of the tip ridge line portion, abnormal wear, etc., and maintaining good cleaning properties over a long period of time. With the goal.

  In order to solve the above-described problems, a cleaning blade of the present invention includes an elastic member that abuts on the surface of a member to be cleaned and removes adhering matter adhering to the surface of the member to be cleaned. And a surface layer made of a cured product of the curable composition, and the surface layer is formed of a base material facing a downstream side in the traveling direction of the member to be cleaned with respect to a contact portion that contacts the member to be cleaned. When the surface is the lower surface of the substrate, it is formed on at least a part of the lower surface of the substrate including the contact portion, and the average film thickness of the surface layer in the contact portion is 10 μm or more and 100 μm or less. Features.

  ADVANTAGE OF THE INVENTION According to this invention, the generation | occurrence | production of the noise by turning over a front-end | tip ridgeline part, abnormal wear, etc. can be suppressed, and the cleaning blade which can maintain favorable cleaning property over a long term can be provided.

FIG. 3 is an enlarged cross-sectional view showing an example of a state where an example of a cleaning blade according to the present invention is in contact with the surface of an image carrier. It is a perspective view which shows an example of the cleaning blade which concerns on this invention. It is a figure explaining an example of the manufacturing method of the cleaning blade which concerns on this invention (the 1). It is a figure explaining an example of the manufacturing method of the cleaning blade which concerns on this invention (the 2). It is a figure explaining the other example of the manufacturing method of the cleaning blade which concerns on this invention (the 1). It is a figure explaining the other example of the manufacturing method of the cleaning blade which concerns on this invention (the 2). It is explanatory drawing of an elastic work rate. 1 is a schematic configuration diagram illustrating an example of an image forming apparatus according to the present invention. 1 is a schematic configuration diagram illustrating an example of an image forming unit included in an image forming apparatus according to the present invention. FIG. 6 is an explanatory diagram for explaining a method for measuring the circularity of toner (part 1); FIG. 6 is an explanatory diagram for explaining a method for measuring the circularity of toner (part 2); It is the schematic for demonstrating the method to measure the Martens hardness of the base material in the front end surface of a braid | blade (the 1). It is the schematic for demonstrating the method to measure the Martens hardness of the base material in the front end surface of a braid | blade (the 2). It is the schematic for demonstrating the method to measure the Martens hardness of the base material in the front end surface of a braid | blade (the 3). It is the schematic for demonstrating the method to measure the Martens hardness of the base material in the front end surface of a braid | blade (the 4). It is a figure for demonstrating an example of the measuring method of the average film thickness of a surface layer. It is a figure for demonstrating an example of the observation method in the measurement of a curvature radius. It is a figure for demonstrating an example of the result obtained in the measurement of a curvature radius. It is a figure for demonstrating an example of the measurement location of the wear width of an elastic member. It is the schematic for demonstrating the preparation method of the cleaning blade which used the curable composition film for the surface layer (the 1). It is the schematic for demonstrating the preparation methods of the cleaning blade which used the curable composition film for the surface layer (the 2). It is the schematic for demonstrating the preparation methods of the cleaning blade which used the curable composition film for the surface layer (the 3). It is a figure which shows the state where the front-end ridgeline part of the conventional cleaning blade was curled. It is a figure explaining the local abrasion of the front end surface of a cleaning blade. It is a figure which shows the state which the front-end ridgeline part of the cleaning blade missing.

  Hereinafter, a cleaning blade, a process cartridge, and an image forming apparatus according to the present invention will be described with reference to the drawings. The present invention is not limited to the embodiments described below, and other embodiments, additions, modifications, deletions, and the like can be changed within a range that can be conceived by those skilled in the art, and any aspect is possible. As long as the functions and effects of the present invention are exhibited, the scope of the present invention is included.

(Cleaning blade)
Conventionally, when a polymerized toner having a small particle diameter and excellent sphericity is used, there is a problem that a slight gap formed between the cleaning blade and the image carrier is generated. In order to suppress the slip-through, it is necessary to increase the contact pressure between the image carrier and the cleaning blade to enhance the cleaning ability. However, when the contact pressure of the cleaning blade is increased, as shown in FIG. 14A, the frictional force between the image carrier 123 and the cleaning blade 62 increases, and the cleaning blade 62 is pulled in the moving direction of the image carrier 123. The leading edge portion 62c of the cleaning blade 62 is turned up. When the turned cleaning blade 62 is restored to its original state against the turn, abnormal noise may occur.

  Furthermore, if the cleaning is continued with the leading edge portion 62c of the cleaning blade 62 turned up, as shown in FIG. 14B, the cleaning blade 62 is locally removed at a location several μm away from the leading edge portion 62c of the leading edge portion 62c of the blade. Wear will occur. In this state, if the cleaning is further continued, this local wear increases. Eventually, as shown in FIG. 14C, the tip edge line portion 62c is lost. If the leading edge portion 62c is missing in this way, there is a problem that the toner cannot be cleaned normally and a cleaning failure occurs. 14A to 14C, 62b is the lower surface of the cleaning blade.

  On the other hand, the cleaning blade of the present invention includes an elastic member that abuts on the surface of the member to be cleaned and removes adhering matter attached to the surface of the member to be cleaned. A surface layer made of a cured product of the composition, and the surface layer has a surface of the base material facing the downstream side in the advancing direction of the member to be cleaned with respect to the contact portion that contacts the member to be cleaned. When the lower surface is formed, it is formed on at least a part of the lower surface of the base material including the contact portion, and the average film thickness of the surface layer in the contact portion is 10 μm or more and 100 μm or less.

  An embodiment of a cleaning blade according to the present invention will be described with reference to FIGS. FIG. 1 is an explanatory view showing a state in which the cleaning blade 62 is in contact with the surface of the photosensitive member 3, and FIG. 2 is a perspective view of the cleaning blade 62. In the cleaning blade 62 in these drawings, a support member 621, an elastic member 624, a base material 622, and a surface layer 623 are illustrated, and the base material 622 of the present embodiment has a strip shape. In addition, a blade tip surface 62a, a blade lower surface 62b, and a tip ridge line portion 62c (also referred to as a contact portion or an edge portion) are illustrated.

In the present invention, the surface in the longitudinal direction of the base material that constitutes the elastic member, the surface facing the downstream side in the traveling direction (rotation direction in this embodiment) of the member to be cleaned is called the lower surface of the base material, and the tip of the base material The tip surface facing the upstream side in the rotational direction of the member to be cleaned including the ridge line portion is referred to as the tip surface of the substrate.
Further, the surface of the elastic member in the longitudinal direction that faces the downstream side in the rotational direction of the member to be cleaned is called a blade lower surface, and the tip of the tip that faces the upstream side in the rotational direction of the member to be cleaned including the tip ridge line portion of the elastic member. The surface is called the blade tip surface.
In FIG. 1, the surface facing the downstream side B of the member to be cleaned is the blade lower surface 62b, and the front surface facing the upstream side A of the member to be cleaned is the blade front surface 62a.
Moreover, the contact part which contact | abuts the surface of the member to be cleaned of an elastic member contains the front-end | tip ridgeline part of an elastic member. In addition, when the tip edge line portion is turned up or when the linear pressure is high, a part of the blade tip surface can also be a contact portion.

  In the present invention, when the average film thickness of the contact portion of the surface layer of the cleaning blade is 10 μm or more and 100 μm or less, the tip ridge line portion can be prevented from turning and excessive stick slip can be suppressed. Furthermore, even when worn due to long-term use, it is possible to prevent the base material of the elastic member from being exposed due to the thick surface layer, to suppress an increase in torque and squeal, and to maintain these functions. As a result, it is possible to maintain both good curling reduction and blade wear resistance, and good cleaning properties over a long period of time. In addition, since it is possible to prevent the base material of the elastic member from coming into contact with the image carrier, it is possible to suppress an increase in torque and an increase in load applied to the rotation of the image carrier. can do. The cleaning blade of the present invention is not limited to the tandem method.

  When the average film thickness of the contact portion of the surface layer exceeds 100 μm, it becomes difficult to maintain the flexibility of the elastic member of the base material, and the ability to follow vibrations caused by the shaft wobbling of the image carrier and minute undulations on the surface of the image carrier. It becomes difficult to cope with the problem and cleaning failure is likely to occur. On the other hand, when the thickness is less than 10 μm, abnormal noise due to abnormal wear or the like is generated.

  A more preferable range of the average film thickness of the surface layer of the contact portion is 12 μm or more and 65 μm or less. By making it 12 μm or more and 65 μm or less, the initial contact portion is less likely to be turned over, and even if the wear progresses, the wear can be stopped in the surface layer, and the exposure of the base material of the elastic member can be suppressed. Even during long-term use, turning and squealing and poor cleaning are less likely to occur.

Here, the average film thickness of the surface layer of the contact portion can be obtained from an arithmetic average value obtained by measuring 10 arbitrary positions of the surface layer in the contact portion.
The method for measuring the thickness of the surface layer of the abutting portion is not particularly limited and can be appropriately selected according to the purpose. For example, the cut surface including the surface layer of the abutting portion is measured using a microscope. The method etc. are mentioned.
Specifically, for example, the thickness of the surface layer at a position of 5 μm from the tip portion (contact side) of the contact portion is measured. In addition, the measurement is usually performed at positions excluding 2 cm at both ends in the longitudinal direction (direction of the contact side).

<Manufacturing method of cleaning blade>
Previously, it was difficult to place a thick film on the contact part with the previous blades produced by spraying or dip coating. Even if there was a 10 μm film near the contact part, the contact part was less than 1 to 3 μm. . In addition, in such a method of attaching a film, the contact portion is rounded, and the edge accuracy is deteriorated. For this reason, there is a possibility that the cleaning property is deteriorated.

In addition, in a conventional technique, for example, Japanese Patent No. 5515865, a manufacturing method is proposed in which a blade having an impregnation and a surface layer is cut after impregnation and cut after an impregnation process in which a coating film is formed. In this case, since the coating film is applied later, the film thickness of the edge portion becomes thin, and the torque may increase over time. Moreover, in patent document 4, the edge is cut | disconnected after film | membrane formation about the braid | blade of a lubricant particle dispersion | distribution coating film. However, since the lubricant particles are dispersed, the surface roughness is large, and even if the edge is cut after the film is formed, the edge accuracy is deteriorated, and the cleaning property may be deteriorated.
In the specific example disclosed in Patent Document 5, since the surface layer is formed by general spray coating, a film thickness of 10 μm or more (for example, implementation) at a position away from the tip (position separated by 50 μm). Even if the layer thickness in Example 1 is 20 μm), it is thin in the vicinity of the tip, and as a result, it does not exceed 10 μm. As a result, the film of the edge portion may be worn over time, and the base rubber may be exposed to cause a problem such as a torque increase.

  On the other hand, the cleaning blade 62 of the present embodiment applies a curable composition that forms the surface layer 623 to a base material 622 made of, for example, urethane rubber, and then cures the resin by ultraviolet irradiation or heating. Yes. Thereafter, the contact portion is cut into a blade shape.

  The surface layer 623 is formed by coating the tip ridge line portion 62c of the cleaning blade 62 by spray coating, dip coating, screen printing, or the like using a curable composition.

  The surface layer on the lower surface of the blade can be formed by bar coating, spray coating, dip coating, brush coating, screen printing, or the like. The film thickness of the surface layer depends on conditions such as the solid content concentration of the coating liquid, coating conditions (bar coating: gap, spray coating: discharge amount / distance / moving speed, dip coating: lifting speed, etc.) It is possible to control by changing appropriately.

  Moreover, the surface layer which consists of hardened | cured material of a curable composition can also be formed by affixing the film of a curable composition on a base material. For example, a film of a curable composition for forming the surface layer 623 is bonded to a base material 622 made of urethane rubber by heat welding, and then processed into a blade shape by cutting the contact portion.

  A part of the manufacturing method of the cleaning blade of this embodiment is shown in FIGS. 3A, 3B, 3C, and 3D. 3A, 3B, 3C, and 3D are views when the elastic member of the cleaning blade is viewed from the side.

  FIG. 3A shows a state in which the curable composition is applied and cured on the base material 622. The tip surface of the base material 622 is cut as shown by the broken line portion, and the elastic member 624 shown in FIG. 3B is shown. Is made. Although the part to cut | disconnect can be changed suitably, for example, the place 1 mm from a front-end | tip is cut | disconnected.

Further, other examples are shown in FIGS. 3C and 3D. FIG. 3C shows a state in which the curable composition is applied to the base material 622 and cured as in FIG. 3A. Here, the front end surface of the base material 622 is not cut as shown in FIG. 3A, but is cut near the center of the base material 622. As a result, the elastic member 524 shown in FIG. 3D is obtained. In this case, two cleaning blades can be produced simultaneously.
In addition to the above, a method of curing a curable composition using a mold to form a right-angle contact portion may be used.

The method of cutting the base material 622 and the surface layer 623 can be changed as appropriate, and for example, a vertical slicer or the like can be used.
The cutting direction can be changed as appropriate, but it is preferable to cut from the surface layer 623 side to the base material 622 side. In this case, the edge accuracy can be improved.

  In this embodiment, after forming a thick film on the lower surface of the blade, the edge is cut to make it possible to achieve both the thick film at the contact portion and the edge accuracy. In addition, a flexible film is preferable for forming a thick film, and it is preferable that curing shrinkage hardly occurs, and an epoxy resin is preferable. Further, it is possible to increase the film thickness by using an acrylic resin having flexibility and using a photobleaching initiator as an initiator.

  In order to form a thick film on the lower surface of the blade using a film, a film made of a polyethylene skeleton material is preferable. Examples of the polyethylene skeleton resin include low density polyethylene, high density polyethylene, and ultra high molecular weight polyethylene. High density polyethylene and ultra high molecular weight polyethylene are more preferable from the viewpoint of wear resistance and low friction.

<To be cleaned>
The member to be cleaned is not particularly limited with respect to its material, shape, structure, size, etc., and can be appropriately selected according to the purpose. Examples of the shape of the member to be cleaned include a drum shape, a belt shape, a flat plate shape, and a sheet shape. There is no restriction | limiting in particular as a magnitude | size of the said member to be cleaned, Although it can select suitably according to the objective, The magnitude | size normally used is preferable.

There is no restriction | limiting in particular as a material of the said to-be-cleaned member, According to the objective, it can select suitably, For example, a metal, a plastic, a ceramic, etc. are mentioned.
The member to be cleaned is not particularly limited and may be appropriately selected according to the purpose. When the cleaning blade is applied to an image forming apparatus, for example, an image carrier may be used.

<Adherent>
The adhering matter is not particularly limited as long as it adheres to the surface of the member to be cleaned and is a removal target of the cleaning blade, and can be appropriately selected according to the purpose. For example, toner, lubricant , Inorganic fine particles, organic fine particles, dust, dust or a mixture thereof. Among these, a toner is preferable, and a low-temperature fixable toner having a glass transition temperature of 50 ° C. or lower is particularly preferable.

<Supporting member>
The cleaning blade of the present embodiment preferably includes a support member and a flat plate-like elastic member having one end connected to the support member and the other end having a free end having a predetermined length. The cleaning blade is disposed such that a contact portion including a tip ridge line portion, which is one end on the free end side of the elastic member, contacts the surface of the member to be cleaned along the longitudinal direction.

  If it is a member which supports the said elastic member as the said supporting member, there will be no restriction | limiting in particular about the shape, a magnitude | size, a material, etc., According to the objective, it can select suitably. Examples of the shape of the support member include a flat plate shape, a strip shape, and a sheet shape. There is no restriction | limiting in particular as a magnitude | size of the said supporting member, According to the magnitude | size of the said member to be cleaned, it can select suitably.

  Examples of the material of the support member include metals, plastics, and ceramics. Among these, a metal plate is preferable from the viewpoint of strength, and a steel plate such as stainless steel, an aluminum plate, and a phosphor bronze plate are particularly preferable.

<Elastic member>
The elastic member includes at least a base material and a surface layer, and further includes other portions as necessary.

<< Base material >>
The base material of the elastic member is not particularly limited with respect to its shape, material, size, structure, etc., and can be appropriately selected according to the purpose.
Examples of the shape include a flat plate shape, a strip shape, and a sheet shape.
There is no restriction | limiting in particular as a magnitude | size, According to the magnitude | size of the said to-be-cleaned member, it can select suitably.
The material for the substrate is not particularly limited and may be appropriately selected depending on the intended purpose. However, polyurethane rubber, polyurethane elastomer, and the like are preferable from the viewpoint that high elasticity is easily obtained.
The shape of the substrate is, for example, a shape composed of a pair of plate surfaces opposed in the thickness direction of the substrate and two pairs of end surfaces orthogonal to the plate surface and opposed in the in-plane direction of the plate surface. Is mentioned.

There is no restriction | limiting in particular as a structure of the said base material, According to the objective, it can select suitably, For example, the single layer structure which consists of one type of material, the two-layer structure which integrally molded two types of different materials, number A multilayer structure in which different types of materials are integrally formed is exemplified.
When manufacturing the base material in which two or more layers are laminated, delamination does not occur by continuously injecting raw materials having different mixing ratios into the centrifugal mold before each layer is completely cured. It is possible to form integrally.

  The material for the base material is not particularly limited and may be appropriately selected depending on the intended purpose. However, urethane rubber is preferable because high elasticity is easily obtained.

  There is no restriction | limiting in particular as a manufacturing method of the base material of an elastic member, According to the objective, it can select suitably. For example, a polyurethane prepolymer is prepared using a polyol compound and a polyisocyanate compound, a curing agent and, if necessary, a curing catalyst are added to the polyurethane prepolymer, crosslinked in a predetermined mold, and placed in a furnace. Then, after the cross-linked product is molded into a sheet by centrifugal molding, the product is allowed to stand at room temperature and aged and cut into a flat plate with a predetermined size.

There is no restriction | limiting in particular as said polyol compound, According to the objective, it can select suitably, For example, high molecular weight polyol, low molecular weight polyol, etc. are mentioned.
Examples of the high molecular weight polyol include a polyester polyol which is a condensate of an alkylene glycol and an aliphatic dibasic acid; ethylene adipate ester polyol, butylene adipate ester polyol, hexylene adipate ester polyol, ethylene propylene adipate ester polyol, ethylene butylene Polyester polyols such as polyester polyols of alkylene glycol and adipic acid such as adipate ester polyol and ethylene neopentylene adipate ester polyol; polycaprolactone polyols such as polycaprolactone ester polyol obtained by ring-opening polymerization of caprolactone; Polyethers such as oxytetramethylene) glycol and poly (oxypropylene) glycol Polyol, and the like. These may be used individually by 1 type and may use 2 or more types together.

  Examples of the low molecular weight polyol include 1,4-butanediol, ethylene glycol, neopentyl glycol, hydroquinone-bis (2-hydroxyethyl) ether, 3,3′-dichloro-4,4′-diaminodiphenyllmethane. Dihydric alcohols such as 4,4′-diaminodiphenylmethane; 1,1,1-trimethylolpropane, glycerin, 1,2,6-hexanetriol, 1,2,4-butanetriol, trimethylolethane, 1, Examples thereof include trivalent or higher polyhydric alcohols such as 1,1-tris (hydroxyethoxymethyl) propane, diglycerin and pentaerythritol. These may be used individually by 1 type and may use 2 or more types together.

  There is no restriction | limiting in particular as said polyisocyanate compound, According to the objective, it can select suitably, For example, a methylene diphenyl diisocyanate (MDI), tolylene diisocyanate (TDI), xylylene diisocyanate (XDI), naphthylene 1,5 -Diisocyanate (NDI), tetramethylxylene diisocyanate (TMXDI), isophorone diisocyanate (IPDI), hydrogenated xylylene diisocyanate (H6XDI), dicyclohexylmethane diisocyanate (H12MDI), hexamethylene diisocyanate (HDI), dimer acid diisocyanate (DDI), Examples include norbornene diisocyanate (NBDI) and trimethylhexamethylene diisocyanate (TMDI). These may be used individually by 1 type and may use 2 or more types together.

  The curing catalyst is not particularly limited and may be appropriately selected depending on the intended purpose. Examples thereof include 2-methylimidazole and 1,2-dimethylimidazole.

  The content of the curing catalyst is not particularly limited and may be appropriately selected depending on the intended purpose, but is preferably 0.01% by mass or more and 0.5% by mass or less, and 0.05% by mass or more and 0.3% by mass. % Or less is more preferable.

The JIS-A hardness of the substrate is not particularly limited and may be appropriately selected depending on the intended purpose, but is preferably 60 degrees or more, and more preferably 65 degrees or more and 80 degrees or less. When the JIS-A hardness is 60 degrees or more, the blade linear pressure is easily obtained, and the area of the contact portion with the image carrier is difficult to increase, so that it is difficult for cleaning failure to occur.
Here, the JIS-A hardness of the substrate can be measured using, for example, a micro rubber hardness meter MD-1 manufactured by Kobunshi Keiki Co., Ltd.

  There is no restriction | limiting in particular in the impact resilience rate based on the JISK6255 specification of the said base material, According to the objective, it can select suitably. Here, the rebound resilience coefficient of the substrate is, for example, No. manufactured by Toyo Seiki Seisakusho at 23 ° C. in accordance with JIS K6255 standard. It can be measured using a 221 resilience tester.

  There is no restriction | limiting in particular in the Martens hardness of the said base material, According to the objective, it can select suitably.

Martens hardness of the substrate is preferably from 2.0 N / mm ² or more, 2.0 N / mm ² or more 5.0 N / mm ² or less being more preferred. By setting the Martens hardness of the base material to 2.0 N / mm ² or more, it is possible to suppress cracking of the surface layer of 10 μm or more, and it is difficult for defective cleaning even to be used for a long time.

The method for measuring the Martens hardness (HM) is as follows.
For the measurement, for example, a micro hardness tester HM-2000 manufactured by Fischer Instruments is used.
The Vickers indenter is pushed into the front end surface of the substrate with a force of 1.0 mN for 10 seconds, held for 5 seconds, and extracted with a force of 1.0 mN for 10 seconds.

The measurement location is a position of 100 μm from the tip ridge line portion of the tip surface of the base material (blade).
As a measuring method, the tip of the blade is cut at about 2 mm, fixed to a slide glass or the like with an adhesive or double-sided tape so that the tip surface faces upward, and the position of 100 μm from the tip ridge line portion of the tip surface is measured. .

You may measure the Martens hardness of a base material in the state where a surface layer exists in the lower surface of a blade.
When there is a surface layer on the blade tip surface, measurement can be performed by exposing the tip surface of the substrate by cutting the tip surface with a razor or the like.

  There is no restriction | limiting in particular in the average thickness of the said base material, Although it can select suitably according to the objective, 1.0 mm or more and 3.0 mm or less are preferable.

<Surface layer>
In the cleaning blade of this embodiment, the tip ridge line portion 62c that comes into contact with the image carrier is formed of a curable composition (not a mixed layer with an elastic member). The surface layer only needs to be formed on the contact portion and the lower surface of the blade, and the surface layer may also be formed on the tip surface. Moreover, the curable composition may be contained inside the elastic member. In addition, as a material of a surface layer, although an epoxy resin is preferable, it demonstrates with the following curable composition.

  The surface layer is preferably a region of 1 mm or more and 7 mm or less from the tip ridge line portion. By setting the thickness to 7 mm or less, the flexibility of the elastic member becomes good and the followability to the photoreceptor is improved, which is preferable in terms of cleaning characteristics.

There is no restriction | limiting in particular as martens hardness of a surface layer, Although it can select suitably according to the objective, It is more preferable that the martens hardness of a surface layer is harder than the Martens hardness of a base material. Its Martens hardness of the surface layer in is preferably 3N / mm ² or more 30 N / mm ² or less.
By making the surface layer a member having a higher hardness than the base material of the elastic member, the surface layer is rigid and thus hardly deformed, and the turning of the tip ridge line portion of the cleaning blade can be suppressed.

  In this embodiment, in order to control the average film thickness of the surface layer of the contact portion of the cleaning blade, each condition was studied earnestly. As a result, the surface layer formation method at the contact portion, the flexibility of the material and the curing shrinkage, and the UV curable resin, by changing the initiator, contact the surface layer thickness of the contact portion. It became possible to control the edge accuracy of the part. The edge accuracy of the cleaning blade is preferably 3.5 μm or less in terms of the radius of curvature of the contact portion.

  A method for forming a surface layer made of a cured product of the curable composition on the contact portion of the elastic member is not particularly limited and may be appropriately selected depending on the purpose. Examples include a method of spraying a curable composition to form a surface layer and curing, and a method of adhering a film made of a cured product of the curable composition to a substrate.

  The method for curing the curable composition of the surface layer formed on the contact portion of the cleaning blade is not particularly limited and may be appropriately selected depending on the intended purpose. For example, irradiation with ultraviolet rays, heating, etc. Processing.

  There is no restriction | limiting in particular as an apparatus which irradiates the said ultraviolet-ray, Although it can select suitably according to the objective, For example, the ultraviolet light source is provided in the inside of an apparatus, and to-be-hardened material is conveyed by conveyance means, such as a conveyor. An apparatus that irradiates ultraviolet rays while enumerating them.

  The ultraviolet light source is not particularly limited as long as it corresponds to the polymerization initiator, and can be appropriately selected according to the purpose. Examples thereof include a lamp and an ultraviolet light emitting semiconductor element.

  Examples of the lamp include metal halide lamps, xenon lamps, carbon arc lamps, chemical lamps, low-pressure mercury lamps, and high-pressure mercury lamps, and commercially available products can be used. Examples of the commercially available products include H valve, D valve, and V valve manufactured by Heraeus.

Examples of the ultraviolet light emitting semiconductor element include an ultraviolet light emitting diode and an ultraviolet light emitting semiconductor laser.
There is no restriction | limiting in particular as long as it corresponds to the polymerization initiator contained in the said curable composition as a kind of the said ultraviolet ray, According to the objective, it can select suitably. For example, ultraviolet rays having a wavelength of 200 nm or more and 400 nm or less, deep ultraviolet rays, g-line, h-line, i-line, KrF excimer laser beam, ArF excimer laser beam, electron beam, X-ray, molecular beam or ion beam can be used.

The ultraviolet irradiation condition is not particularly limited and may be appropriately selected depending on the intended purpose. However, the integrated light amount is preferably 500 mJ / cm ² or more. In order to suppress a decrease in the curing rate due to oxygen inhibition, irradiation in an inert gas (Ar, N ₂ , CO _2, etc.) atmosphere is more preferable.

  The elastic power of the modified cleaning blade is preferably 60% or more and 90% or less. The elastic power is a characteristic value obtained as follows from the accumulated stress at the time of measuring Martens hardness. The Martens hardness is measured using a microhardness meter while performing an operation of pushing the Vickers indenter with a constant force, for example, pressing it for 30 seconds, holding it for 5 seconds, and pulling it for 30 seconds with a constant force.

Here, the integrated stress when pushing the Vickers indenter _{W plast,} when the cumulated stress of the load Jonitera and _{W elast,} the elastic work _rate, defined by the equation _{W elast / W plast × 100 [} %] It is a characteristic value (see FIG. 4). The higher the elastic power, the smaller the plastic deformation, that is, the higher the rubber property. If the elastic power is too low, it is in a state closer to glass than rubber, and the movement of the abutting portion is suppressed too much, and conversely, wear resistance is deteriorated. Usually, the (meth) acrylic resin has a relatively high elastic power in the range of the Martens hardness, and a rubbery state is obtained. However, depending on the structure of the (meth) acrylic resin, the elastic power may be too high, and the posture as a cleaning blade may not be maintained appropriately.

<Curable composition>
The curable composition is a material that forms a cured product (solid polymer) by polymerizing and curing a monomer or oligomer by receiving energy such as light or heat. The energy source varies depending on the type of initiator or stimulus (electron beam) that generates an active species (radical, ion, acid, base, etc.) that initiates polymerization. For example, an ultraviolet curable composition, a thermosetting composition, an electron beam Examples include cured compositions.

  In the ultraviolet curable composition and the electron beam curable composition, a photopolymerization initiator is used, and by irradiating ultraviolet rays or an electron beam, a curing reaction classified into any of radical polymerization, cationic polymerization, and anionic polymerization occurs, A cured product is produced by a polymerization reaction such as vinyl polymerization, vinyl copolymerization, ring-opening polymerization, or addition polymerization.

  The thermosetting composition uses a thermal polymerization initiator to start a curing reaction when heated, and generates a cured product by a polymerization reaction such as isocyanate, radical polymerization, epoxy ring-opening polymerization, or melamine condensation.

  There is no restriction | limiting in particular as said hardened | cured material produced | generated by such reaction, According to the objective, it can select suitably, For example, the hardened | cured material of an acrylic resin, a phenol resin, a urethane resin, an epoxy resin, a silicone resin, amino Examples thereof include a cured product of a resin or a resin having a polyethylene skeleton. A cured product of an epoxy resin is preferable from the viewpoint of less curing shrinkage, and a cured product of a resin having a polyethylene skeleton is preferable from the viewpoint of high durability.

  There is no restriction | limiting in particular as said epoxy resin, Although it can select suitably according to the objective, A glycidyl ether type epoxy resin is preferable. It is more preferable that an epoxy resin having a bisphenol A type skeleton is included, and it can be used in combination with bisphenol F type, brominated bisphenol A type, hydrogenated bisphenol A type, novolak type, biphenyl type, or the like. .

  When a material containing the bisphenol type epoxy resin is used, there is little curing shrinkage, so that a thick surface layer can be easily produced and a desired film thickness can be obtained. Further, when the material containing the bisphenol type epoxy resin is used, the surface layer 623 becomes hard, and the tip edge line portion 62c of the cleaning blade 62 is not turned over, and the tip surface wear as shown in FIG. Can retain sex.

  Moreover, there is no restriction | limiting in particular as a (meth) acrylate compound in the said acrylic resin, Although it can select suitably according to the objective, The (meth) acrylate compound which has a pentaerythritol structure in a molecule | numerator is preferable.

  The (meth) acrylate compound having a pentaerythritol structure in the molecule preferably has a functional group equivalent molecular weight of 110 or less and a number of functional groups of 3 to 6, for example, pentaerythritol tetra (meth) acrylate, pentaerythritol tris. (Meth) acrylate, pentaerythritol tetra (meth) acrylate, pentaerythritol ethoxytetra (meth) acrylate, dipentaerythritol hexa (meth) acrylate, and the like. Among these, pentaerythritol triacrylate, pentaerythritol tetraacrylate, and dipentaerythritol hexaacrylate are preferable.

  When a material having a functional group equivalent molecular weight of 110 or less or a material having a pentaerythritol / triacrylate skeleton is used, the surface layer 623 becomes hard, and the tip edge portion 62c of the cleaning blade 62 is turned up, and the tip surface as shown in FIG. Abrasion does not occur and long-term cleaning properties can be maintained.

  The content of the (meth) acrylate compound having a pentaerythritol structure in the molecule is not particularly limited and may be appropriately selected according to the purpose. However, the solid content is 20% with respect to the curable composition. The mass% is preferably 90% by mass or less and more preferably 50% by mass or more and 80% by mass or less.

In addition to the (meth) acrylate compound having a pentaerythritol structure in the molecule, the curable composition includes a (meth) acrylate compound having a molecular weight of 100 to 1,500, a fluorine-based (meth) acrylate compound, an intramolecular (Meth) acrylate compounds having an alicyclic structure may be contained.
The other (meth) acrylate compound having a molecular weight of 100 or more and 1,500 or less, the fluorine-based (meth) acrylate compound, and the (meth) acrylate compound having an alicyclic structure in the molecule may be appropriately selected. it can.

As the fluorine-based (meth) acrylate compound, those having a perfluoropolyether skeleton are preferable, those having a perfluoropolyether skeleton and having two or more functional groups are more preferable.
There is no restriction | limiting in particular as said fluorine-type (meth) acrylate compound, According to the objective, it can select suitably. For example, 2,2,2-trifluoroethyl acrylate, 2,2,2-trifluoroethyl methacrylate, 2,2,3,3-tetrafluoropropyl acrylate, 2,2,3,3-tetrafluoropropyl methacrylate, 2,2,3,3,4,4,4-heptafluorobutyl acrylate, 2,2,3,3,4,4,4-heptafluorobutyl methacrylate, 2,2,3,4,4,4- Hexafluorobutyl acrylate, 2,2,3,4,4,4-hexafluorobutyl methacrylate, 1,1,1,3,3,3-hexafluoroisopropyl acrylate, 1,1,1,3,3,3 -Hexafluoroisopropyl methacrylate, 1H, 1H, 5H-octafluoropentyl acrylate, 1H, 1H, 5H-octafluorope Til methacrylate, 2,2,3,3,3-pentafluoropropyl acrylate, 2,2,3,3,3-pentafluoropropyl methacrylate, 2,2,3,3,4,4,5,5,5 6,6,7,7-dodecafluoroheptyl acrylate, 3,3,4,4,5,5,6,6,7,7,8,8,8-tridecafluorooctyl acrylate, 3,3,4 , 4,5,5,6,6,7,7,8,8,8-tridecafluorooctyl methacrylate, 2-[(1 ', 1', 1'-trifluoro-2 '-(trifluoromethyl ) -2′-hydroxy) propyl] -3-norbornyl methacrylate, 1,1,1-trifluoro-2- (trifluoromethyl) -2-hydroxy-4-methyl-5-pentyl methacrylate, 3, 3, 4, 4, 5, 5, 6, 6,7,7,8,8,9,9,10,10,10-heptadecafluorodecyl acrylate, 3,3,4,4,5,5,6,6,7,7,8,8, 9,9,10,10,10-heptadecafluorodecyl methacrylate, 3,3,4,4,5,5,6,6,7,7,8,8,9,9,10,10,11, 11, 12, 12, 12-Henicosafluorododecyl acrylate, 3,3,4,4,5,5,6,6,7,7,8,8,9,9,10,10,11,11, 12,12,12-Henicosafluorododecyl methacrylate, 3,3,4,4,5,5,6,6,7,7,8,8,9,9,10,10,11,12,12, 12-Henicosa-11- (trifluoromethyl) dodecyl methacrylate, and the like. These may be used individually by 1 type and may use 2 or more types together.

  As the fluorine-based (meth) acrylate compound, a commercially available product can be used. Examples of the commercially available product include OPTOOL DAC-HP (manufactured by Daikin Industries), MegaFace RS-75 (manufactured by DIC), Viscoat V-3F (Osaka Organic Chemical Industry Co., Ltd.)

  There is no restriction | limiting in particular in content in the said curable composition of the said fluorine-type (meth) acrylate compound, Although it can select suitably according to the objective, 0.1 mass% or more and 50 mass% or less are solid content. Is preferred.

  The other components in the curable composition can be appropriately selected depending on the purpose, and examples thereof include a polymerization initiator, a polymerization inhibitor, and a diluent, but preferably do not contain resin particles or inorganic particles. .

  The polymerization initiator is not particularly limited as long as it initiates polymerization by light or heat, and can be appropriately selected according to the purpose. The photopolymerization initiator is preferably a photoradical polymerization initiator that generates an active species such as a radical or a cation by light energy to initiate polymerization, a photocationic polymerization initiator, or the like, and more preferably a photoradical polymerization initiator. .

  Examples of the radical photopolymerization initiator include aromatic ketones, acylphosphine oxide compounds, aromatic onium salt compounds, organic peroxides, thio compounds (thioxanthone compounds, thiophenyl group-containing compounds, etc.), hexaarylbiimidazoles, and the like. Examples thereof include compounds, ketoxime ester compounds, borate compounds, azinium compounds, metallocene compounds, active ester compounds, compounds having a carbon halogen bond, and alkylamine compounds.

  The radical photopolymerization initiator is not particularly limited and may be appropriately selected depending on the intended purpose. For example, acetophenone, acetophenone benzyl ketal, 1-hydroxycyclohexyl phenyl ketone, 2,2-dimethoxy-2-phenylacetophenone , Xanthone, fluorenone, benzaldehyde, fluorene, anthraquinone, triphenylamine, carbazole, 3-methylacetophenone, 4-chlorobenzophenone, 4,4'-dimethoxybenzophenone, 4,4'-diaminobenzophenone, Michler's ketone, benzoin propyl ether , Benzoin ethyl ether, benzyldimethyl ketal, 1- (4-isopropylphenyl) -2-hydroxy-2-methylpropan-1-one, 2-hydroxy-2-methyl- -Phenylpropan-1-one, thioxanthone, diethylthioxanthone, 2-isopropylthioxanthone, 2-chlorothioxanthone, 2-methyl-1- [4- (methylthio) phenyl] -2-morpholino-propan-1-one, bis ( 2,4,6-trimethylbenzoyl) -phenylphosphine oxide, 2,4,6-trimethylbenzoyl-diphenyl-phosphine oxide, 2,4-diethylthioxanthone, bis- (2,6-dimethoxybenzoyl) -2, 4,4-trimethylpentylphosphine oxide, and the like. These may be used individually by 1 type and may use 2 or more types together.

  Commercially available products can be used as the photoradical polymerization initiator. Examples of the commercially available products include Irgacure 651, Irgacure 184, DAROCUR 1173, Irgacure 2959, Irgacure 127, Irgacure 907, Irgacure 369, Irgacure 379, and DAROCUR. TPO, IRGACURE 819, IRGACURE 784, IRGACURE OXE 01, IRGACURE OXE 02, IRGACURE 754 (above, manufactured by BASF Japan); Speedcure TPO (manufactured by Lambson); KAYACURE DETX-S; LR8883, LR8970 (above, manufactured by BASF); Ubekrill P36 (manufactured by UCB), and the like. These may be used individually by 1 type and may use 2 or more types together.

The content of the polymerization initiator is not particularly limited and may be appropriately selected depending on the intended purpose, but is preferably 1% by mass or more and 20% by mass or less with respect to the curable composition.
When forming a thick film as in the present invention, a photopolymerization initiator having a photobleaching effect with good internal curability is preferred as a photopolymerization initiator, and combined with a photopolymerization initiator with good surface curability. More preferably it is used. The amount of the photopolymerization initiator is more preferably 1% by mass or more and 10% by mass or less with respect to the curable composition.

  There is no restriction | limiting in particular as said polymerization inhibitor, According to the objective, it can select suitably. For example, p-methoxyphenol, cresol, t-butylcatechol, di-t-butylparacresol, hydroquinone monomethyl ether, α-naphthol, 3,5-di-t-butyl-4-hydroxytoluene, 2,2′- Phenol compounds such as methylene bis (4-methyl-6-tert-butylphenol), 2,2′-methylene bis (4-ethyl-6-butylphenol), 4,4′-thiobis (3-methyl-6-tert-butylphenol) P-benzoquinone, anthraquinone, naphthoquinone, phenanthraquinone, p-xyloquinone, p-toluquinone, 2,6-dichloroquinone, 2,5-diphenyl-p-benzoquinone, 2,5-diacetoxy-p-benzoquinone, 2 , 5-Dicaproxy-p-benzoquinone, 2,5-diacyloxy-p- Quinone compounds such as nzoquinone, hydroquinone, 2,5-di-butylhydroquinone, mono-t-butylhydroquinone, monomethylhydroquinone, 2,5-di-t-amylhydroquinone; phenyl-β-naphthylamine, p-benzylaminophenol, Amine compounds such as di-β-naphthylparaphenylenediamine, dibenzylhydroxylamine, phenylhydroxylamine, and diethylhydroxylamine; nitro compounds such as dinitrobenzene, trinitrotoluene, and picric acid; oxime compounds such as quinonedioxime and cyclohexanone oxime; And sulfur compounds such as phenothiazine. These may be used individually by 1 type and may use 2 or more types together.

  There is no restriction | limiting in particular as said diluent, According to the objective, it can select suitably. For example, hydrocarbon solvents such as toluene and xylene; ester solvents such as ethyl acetate, n-butyl acetate, methyl cellosolve acetate, propylene glycol monomethyl ether acetate; methyl ethyl ketone, methyl isobutyl ketone, diisobutyl ketone, cyclohexanone, cyclopentanone, etc. Ketone solvents; ether solvents such as ethylene glycol monomethyl ether, ethylene glycol monoethyl ether and propylene glycol monomethyl ether; alcohol solvents such as ethanol, propanol, 1-butanol, isopropyl alcohol and isobutyl alcohol. These may be used individually by 1 type and may use 2 or more types together.

  The polyethylene skeleton resin is generally a polyethylene which is a crystalline resin obtained by polymerizing ethylene, and is classified according to synthesis conditions such as density, molecular weight, pressure and catalyst. In addition, characteristics and the like vary depending on density, molecular weight, molecular weight distribution, and molecular structure (straight chain, branched, etc.).

  There is no restriction | limiting in particular as resin of the said polyethylene frame | skeleton, Although it can select suitably according to the objective, From a viewpoint of durability or a low friction coefficient, a high density polyethylene and ultra high molecular weight polyethylene are more preferable.

  The cleaning blade 62 according to the present embodiment can prevent the tip ridge line portion 62c coming into contact with the surface of the member to be cleaned, which is an elastic member, has little wear on the tip ridge line portion 62c of the elastic member during use, and has good cleaning properties. It can be maintained for a long time. For this reason, it can be widely used in various fields, but it is particularly preferably used for a process cartridge and an image forming apparatus described below.

(Process cartridge, image forming apparatus and image forming method)
The process cartridge of the present invention includes at least an image carrier and a cleaning unit that removes toner remaining on the image carrier, and the cleaning unit includes the cleaning blade of the present invention. A mechanism for applying a lubricant to the surface of the latent image carrier may be provided as a cleaning auxiliary means.

  The image forming apparatus of the present invention includes an image carrier, a charging unit that charges the surface of the image carrier, an exposure unit that exposes the charged image carrier to form an electrostatic latent image, and the electrostatic Developing means for developing a latent image with toner to form a visible image; transfer means for transferring the visible image to a recording medium; and fixing means for fixing the transferred image transferred to the recording medium; Cleaning means for removing toner remaining on the image carrier, and the cleaning means has the cleaning blade of the present invention. The image carrier may be provided with a mechanism for applying a lubricant as a cleaning auxiliary means.

  The image forming method of the present invention uses a charging step for charging the surface of an image carrier, an exposure step for exposing the charged image carrier to form an electrostatic latent image, and the electrostatic latent image using toner. A developing process for forming a visible image by developing, a transferring process for transferring the visible image to a recording medium, a fixing process for fixing the transferred image transferred to the recording medium, and on the image carrier A cleaning process for removing residual toner, and the cleaning process is performed using the cleaning blade of the present invention.

  Hereinafter, as an image forming apparatus to which the present invention is applied, an embodiment (hereinafter referred to as an embodiment) of an electrophotographic printer (hereinafter simply referred to as a printer 500) will be described. First, a basic configuration of the printer 500 according to the present embodiment will be described.

  FIG. 5 is a schematic configuration diagram illustrating the printer 500. The printer 500 includes four image forming units 1Y, C, M, and K for yellow, magenta, cyan, and black (hereinafter referred to as Y, C, M, and K). These use Y, C, M, and K toners of different colors as image forming substances for forming an image, but the other configurations are the same.

  Above the four image forming units 1Y, 1C, 1M, and 1K, a transfer unit 60 including an intermediate transfer belt 14 as an intermediate transfer member is disposed. The toner images of the respective colors formed on the surfaces of the photoreceptors 3Y, 3C, 3M, and 3K included in the image forming units 1Y, 1C, 1M, and 1K, which will be described in detail later, are superimposed on the surface of the intermediate transfer belt. It is a configuration to be transferred.

  An optical writing unit 40 is disposed below the four image forming units 1Y, 1C, 1M, and 1K. The optical writing unit 40 serving as a latent image forming unit irradiates the photoconductors 3Y, 3C, 3M, and 3K of the image forming units 1Y, 1C, 1M, and 1K with the laser light L emitted based on the image information. Thereby, electrostatic latent images for Y, C, M, and K are formed on the photoreceptors 3Y, 3C, 3M, and 3K. The optical writing unit 40 deflects the laser light L emitted from the light source by the polygon mirror 41 that is rotationally driven by a motor, and passes through the photosensitive members 3Y, 3C, 3M, and 3K via a plurality of optical lenses and mirrors. Is irradiated. Instead of such a configuration, one that performs optical scanning with an LED array may be employed.

  Below the optical writing unit 40, a first paper feed cassette 151 and a second paper feed cassette 152 are arranged to overlap in the vertical direction. In each of these paper feed cassettes, a plurality of transfer papers P as recording media are accommodated in a stack of paper sheets. The uppermost transfer paper P includes a first paper feed roller 151a, The second paper feed rollers 152a are in contact with each other. When the first paper feed roller 151a is driven to rotate counterclockwise in the figure by the driving means, the uppermost transfer paper P in the first paper feed cassette 151 extends vertically on the right side of the cassette in the figure. The paper is discharged toward the paper feed path 153 arranged to exist. Further, when the second paper feeding roller 152 a is driven to rotate counterclockwise in FIG. 5 by the driving means, the uppermost transfer paper P in the second paper feeding cassette 152 is discharged toward the paper feeding path 153. Is done.

  A plurality of conveying roller pairs 154 are arranged in the paper feed path 153. The transfer paper P fed into the paper feed path 153 is conveyed from the lower side to the upper side in FIG. 5 while being sandwiched between the rollers of the conveyance roller pair 154.

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

FIG. 6 is a configuration diagram showing a schematic configuration of one of the four image forming units 1.
As shown in FIG. 6, the image forming unit 1 includes a drum-shaped photoconductor 3 as an image carrier. The photosensitive member 3 has a drum shape, but may be a sheet shape or an endless belt shape.
Around the photoreceptor 3, a charging roller 4, a developing device 5, a primary transfer roller 7, a cleaning device 6, a lubricant application device 10, a static elimination lamp, and the like are disposed. The charging roller 4 is a charging member provided in a charging device as a charging unit, and the developing device 5 is a developing unit that converts a latent image formed on the surface of the photoreceptor 3 into a toner image. The primary transfer roller 7 is a primary transfer member provided in a primary transfer device as a primary transfer unit that transfers a toner image on the surface of the photoreceptor 3 to the intermediate transfer belt 14. The cleaning device 6 is a cleaning unit that cleans the toner remaining on the photoreceptor 3 after the toner image is transferred to the intermediate transfer belt 14. The lubricant application device 10 is a lubricant application unit that applies a lubricant onto the surface of the photoreceptor 3 after the cleaning device 6 performs cleaning. The neutralization lamp is a neutralization unit that neutralizes the surface potential of the photoreceptor 3 after cleaning. In FIG. 6, reference numeral 8 represents a cleaning roller.

  The charging roller 4 is arranged in a non-contact manner with a predetermined distance from the photoconductor 3, and charges the photoconductor 3 to a predetermined polarity and a predetermined potential. The surface of the photoreceptor 3 uniformly charged by the charging roller 4 is irradiated with laser light L from an optical writing unit 40 serving as a latent image forming unit based on image information, thereby forming an electrostatic latent image.

  The developing device 5 has a developing roller 51 as a developer carrier. A developing bias is applied to the developing roller 51 from a power source. In the casing of the developing device 5, a supply screw 52 and a stirring screw 53 are provided for stirring the developer contained in the casing while conveying the developer in opposite directions. A doctor 54 for regulating the developer carried on the developing roller 51 is also provided. The toner in the developer stirred and conveyed by the two screws of the supply screw 52 and the stirring screw 53 is charged to a predetermined polarity. The developer is pumped up on the surface of the developing roller 51, and the developer pumped up is regulated by the doctor 54, and the toner adheres to the latent image on the photoconductor 3 in the development area facing the photoconductor 3. .

  The cleaning device 6 includes a fur brush 101, a cleaning blade 62, and the like. The cleaning blade 62 is in contact with the photoconductor 3 in the counter direction with respect to the surface movement direction of the photoconductor 3. The cleaning blade 62 is the cleaning blade of the present invention. The lubricant application device 10 includes a solid lubricant 103, a lubricant pressure spring 103 a, and the like, and uses a fur brush 101 as an application brush for applying the solid lubricant 103 onto the photoreceptor 3. The solid lubricant 103 is held by the bracket 103b and is pressed toward the fur brush 101 by a lubricant pressurizing spring 103a. Then, the solid lubricant 103 is scraped by the fur brush 101 that rotates in the rotational direction with respect to the rotation direction of the photoconductor 3, and the lubricant is applied onto the photoconductor 3. It is preferable that the coefficient of friction of the surface of the photoconductor 3 is maintained at 0.2 or less during non-image formation by applying a lubricant to the photoconductor.

  The charging device according to the present embodiment is a non-contact proximity arrangement system in which the charging roller 4 is brought close to the photosensitive member 3, and examples of the charging device include corotron, scorotron, and solid state charger (solid state charger). A known configuration can be used. Among these charging methods, the contact charging method or the non-contact proximity arrangement method is more desirable, and has advantages such as high charging efficiency, a small amount of ozone generation, and miniaturization of the apparatus.

The light source of the laser light L of the optical writing unit 40 and the light source such as a static elimination lamp include a fluorescent lamp, a tungsten lamp, a halogen lamp, a mercury lamp, a sodium lamp, a light emitting diode (LED), a semiconductor laser (LD), and an electroluminescence (EL). ) And other luminescent materials can be used.
In addition, various types of filters 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 can be used to irradiate only light in a desired wavelength range.
Among these light sources, light emitting diodes and semiconductor lasers are used favorably because they have high irradiation energy and long wavelength light of 600 to 800 nm.

  In addition to the intermediate transfer belt 14, the transfer unit 60 serving as transfer means includes a belt cleaning unit 162, a first bracket 63, a second bracket 64, and the like. Further, four primary transfer rollers 7Y, 7C, 7M, and 7K, a secondary transfer backup roller 66, a driving roller 67, an auxiliary roller 68, a tension roller 69, and the like are also provided. The intermediate transfer belt 14 is endlessly moved in the counterclockwise direction in the drawing by the rotational driving of the driving roller 67 while being stretched around these eight roller members. The four primary transfer rollers 7Y, 7C, 7M, and 7K sandwich the intermediate transfer belt 14 that is moved endlessly in this manner between the photoreceptors 3Y, 3C, 3M, and 3K to form primary transfer nips. . Then, a transfer bias having a polarity opposite to that of the toner (for example, plus) is applied to the back surface (loop inner peripheral surface) of the intermediate transfer belt 14. The intermediate transfer belt 14 sequentially passes through the primary transfer nips for Y, C, M, and K along with the endless movement thereof, and on the front surface thereof, the intermediate transfer belt 14 is on the photoreceptors 3Y, 3C, 3M, and 3K. Y, C, M, and K toner images are superimposed and primarily transferred. As a result, a four-color superimposed toner image (hereinafter referred to as a four-color toner image) is formed on the intermediate transfer belt 14.

  The secondary transfer backup roller 66 sandwiches the intermediate transfer belt 14 with the secondary transfer roller 70 disposed outside the loop of the intermediate transfer belt 14 to form a secondary transfer nip. The registration roller pair 55 described above feeds the transfer paper P sandwiched between the rollers toward the secondary transfer nip at a timing at which the transfer paper P can be synchronized with the four-color toner image on the intermediate transfer belt 14. The four-color toner image on the intermediate transfer belt 14 is affected by the secondary transfer electric field formed between the secondary transfer roller 70 to which the secondary transfer bias is applied and the secondary transfer backup roller 66, and the influence of the nip pressure. The secondary transfer is performed on the transfer paper P in the secondary transfer nip. Then, combined with the white color of the transfer paper P, a full color toner image is obtained.

  Transfer residual toner that has not been transferred to the transfer paper P adheres to the intermediate transfer belt 14 after passing through the secondary transfer nip. This is cleaned by the belt cleaning unit 162. The belt cleaning unit 162 has a belt cleaning blade 162a in contact with the front surface of the intermediate transfer belt 14, thereby scraping off and removing the transfer residual toner on the intermediate transfer belt 14.

  The first bracket 63 of the transfer unit 60 swings at a predetermined rotation angle about the rotation axis of the auxiliary roller 68 as the solenoid is turned on / off. When forming a monochrome image, the printer 500 rotates the first bracket 63 a little counterclockwise in the drawing by driving the solenoid described above. By this rotation, the primary transfer rollers 7Y, 7C, and 7M for Y, C, and M are revolved counterclockwise in the drawing around the rotation axis of the auxiliary roller 68, so that the intermediate transfer belt 14 is rotated in the Y, C, and Y directions. It is separated from the photoconductors 3Y, 3C, 3M for M. Of the four image forming units 1Y, 1C, 1M, and 1K, only the K image forming unit 1K is driven to form a monochrome image. Accordingly, it is possible to avoid wear of each member constituting the image forming unit due to wasteful driving of the Y, C, and M image forming units during monochrome image formation.

  A fixing unit 80 is disposed above the secondary transfer nip in the drawing. The fixing unit 80 includes a pressure heating roller 81 that contains a heat source such as a halogen lamp, and a fixing belt unit 82. The fixing belt unit 82 includes a fixing belt 84 as a fixing member, a heating roller 83 containing a heat source such as a halogen lamp, a tension roller 85, a driving roller 86, a temperature sensor, and the like. Then, the endless fixing belt 84 is endlessly moved in the counterclockwise direction in the drawing while being stretched by the heating roller 83, the tension roller 85, and the driving roller 86. In the process of endless movement, the fixing belt 84 is heated from the back side by the heating roller 83. A pressure heating roller 81 that is driven to rotate in the clockwise direction in the drawing is in contact with the surface of the fixing belt 84 that is heated in this manner, around the heating roller 83. Thus, a fixing nip where the pressure heating roller 81 and the fixing belt 84 abut is formed.

  A temperature sensor is disposed outside the loop of the fixing belt 84 so as to face the front surface of the fixing belt 84 with a predetermined gap, and the surface temperature of the fixing belt 84 immediately before entering the fixing nip. Is detected. This detection result is sent to the fixing power supply circuit. The fixing power supply circuit performs on / off control of power supply to the heat generation source included in the heating roller 83 and the heat generation source included in the pressure heating roller 81 based on the detection result of the temperature sensor.

  The transfer paper P that has passed through the secondary transfer nip described above is separated from the intermediate transfer belt 14 and then sent into the fixing unit 80. Then, in the process of being conveyed from the lower side to the upper side in the figure while being sandwiched between the fixing nips in the fixing unit 80, the full-color toner image is fixed on the transfer paper P by being heated and pressed by the fixing belt 84. The

  The transfer paper P subjected to the fixing process in this manner is discharged between the discharge roller pair 87 and then discharged outside the apparatus. A stack unit 88 is formed on the upper surface of the housing of the printer 500 main body, and the transfer paper P discharged to the outside by the discharge roller pair 87 is sequentially stacked on the stack unit 88.

  Above the transfer unit 60, four toner cartridges 100Y, 100C, 100M, and 100K that store Y, C, M, and K toners are disposed. The Y, C, M, and K toners in the toner cartridges 100Y, 100C, 100M, and 100K are appropriately supplied to the developing devices of the image forming units 1Y, 1C, 1M, and 1K. These toner cartridges 100Y, 100C, 100M, and 100K are detachable from the printer main body independently of the image forming units 1Y, 1C, 1M, and 1K.

Next, an image forming operation in the printer 500 will be described.
When a print execution signal is received from the operation unit or the like, a predetermined voltage or current is sequentially applied to the charging roller 4 and the developing roller 51 at a predetermined timing. Similarly, a predetermined voltage or current is sequentially applied to the optical writing unit 40 and a light source such as a static elimination lamp at a predetermined timing. In synchronism with this, the photosensitive member 3 is rotationally driven in the direction of the arrow in the figure by a photosensitive member driving motor as driving means.

  When the photoconductor 3 rotates in the direction of the arrow in the figure, the surface of the photoconductor 3 is first uniformly charged to a predetermined potential by the charging roller 4. Then, the laser beam L corresponding to the image information is irradiated onto the photoconductor 3 from the optical writing unit 40, and the portion irradiated with the laser light L on the surface of the photoconductor 3 is neutralized to form an electrostatic latent image. .

  The surface of the photoreceptor 3 on which the electrostatic latent image is formed is rubbed by a developer magnetic brush formed on the developing roller 51 at a portion facing the developing device 5. At this time, the negatively charged toner on the developing roller 51 is moved to the electrostatic latent image side by a predetermined developing bias applied to the developing roller 51 to be converted into a toner image (development). In each image forming unit 1, the same image forming process is executed, and a toner image of each color is formed on the surface of each photoconductor 3Y, 3C, 3M, 3K of each image forming unit 1Y, 1C, 1M, 1K. .

  As described above, in the printer 500, the electrostatic latent image formed on the photoconductor 3 is reversely developed by the developing device 5 with the negatively charged toner. In this embodiment, an example using a non-contact charging roller system of N / P (negative positive: toner adheres to a place where the potential is low) has been described, but the present invention is not limited to this.

  The toner images of the respective colors formed on the surfaces of the photoreceptors 3Y, 3C, 3M, and 3K are sequentially primary-transferred so as to overlap on the surface of the intermediate transfer belt 14. As a result, a four-color toner image is formed on the intermediate transfer belt 14.

  The four-color toner image formed on the intermediate transfer belt 14 is fed from the first paper feed cassette 151 or the second paper feed cassette 152, passed between the rollers of the registration roller pair 55, and fed to the secondary transfer nip. The transfer paper P is transferred. At this time, the transfer paper P is temporarily stopped while being sandwiched between the registration roller pair 55, and is supplied to the secondary transfer nip in synchronization with the leading edge of the image on the intermediate transfer belt 14. The transfer paper P onto which the toner image has been transferred is separated from the intermediate transfer belt 14 and conveyed to the fixing unit 80. Then, the transfer paper P on which the toner image is transferred passes through the fixing unit 80, whereby the toner image is fixed on the transfer paper P by the action of heat and pressure, and the transfer paper P on which the toner image is fixed is the printer. 500 is discharged outside the apparatus and stacked on the stack unit 88.

On the other hand, the transfer residual toner on the surface of the intermediate transfer belt 14 that has transferred the toner image onto the transfer paper P at the secondary transfer nip is removed by the belt cleaning unit 162.
Further, the surface of the photoreceptor 3 on which the toner images of the respective colors are transferred to the intermediate transfer belt 14 at the primary transfer nip, the residual toner after the transfer is removed by the cleaning device 6, and the lubricant is applied by the lubricant applying device 10. Thereafter, the charge is removed by a charge removal lamp.

  As shown in FIG. 6, the image forming unit 1 of the printer 500 includes a photoconductor 3 and a charging roller 4, a developing device 5, a cleaning device 6, a lubricant application device 10, and the like as process means. . The image forming unit 1 can be integrally attached to and detached from the main body of the printer 500 as a process cartridge. In the printer 500, the image forming unit 1 integrally replaces the photosensitive member 3 as a process cartridge and the process means, but the photosensitive member 3, the charging roller 4, the developing device 5, the cleaning device 6, the lubrication device. The composition may be replaced with a new one in the unit such as the agent coating apparatus 10.

Next, toner suitable for the printer 500 to which the present invention is applied will be described.
As the toner used in the printer 500, it is preferable to use a polymerized toner produced by a suspension polymerization method, an emulsion polymerization method, or a dispersion polymerization method, which can easily increase the circularity and reduce the particle size, in order to improve the image quality. In particular, it is preferable to use a polymerized toner having a circularity of 0.97 or more and a volume average particle size of 5.5 μm or less. By using a material having an average circularity of 0.97 or more and a volume average particle size of 5.5 μm or less, a higher resolution image can be formed.

  The “circularity” here is an average circularity measured by a flow type particle image analyzer FPIA-2000 (manufactured by Toa Medical Electronics Co., Ltd.). Specifically, 0.1 to 0.5 ml of a surfactant, preferably an alkylbenzene sulfonate, is added as a dispersant to 100 to 150 ml of water from which impure solids have been removed in advance. Further, a measurement sample (toner About 0.1 to 0.5 g. Thereafter, the suspension in which the toner is dispersed is subjected to a dispersion treatment with an ultrasonic disperser for about 1 to 3 minutes so that the concentration of the dispersion becomes 3000 to 1 [10,000 / μl]. To measure the shape and distribution of the toner. Based on the measurement result, the outer peripheral length of the actual toner projection shape shown in FIG. 7A is C1, the projection area (particle projection area) is S, and the perfect circle shown in FIG. C2 / C1 was calculated when the outer peripheral length (peripheral length) of C2 was C2, and the average value was defined as the circularity.

The volume average particle diameter can be determined by a Coulter counter method. Specifically, the toner number distribution and volume distribution data measured by the Coulter Multisizer 2e type (manufactured by Coulter) are sent to a personal computer via an interface (manufactured by Nikkaki Co., Ltd.) for analysis.
A specific example of the analysis method will be described. A 1% NaCl aqueous solution using first grade sodium chloride is prepared as an electrolyte. Then, 0.1 to 5 ml of a surfactant, preferably an alkylbenzene sulfonate, is added as a dispersant to 100 to 150 ml of the electrolytic aqueous solution. Further, 2 to 20 mg of toner as a test sample is added thereto, and the dispersion treatment is performed for about 1 to 3 minutes with an ultrasonic disperser.
Then, 100 to 200 ml of the electrolytic aqueous solution is put in another beaker, and the solution after the dispersion treatment is added therein to a predetermined concentration and applied to the Coulter Multisizer 2e type.
The aperture is 100 μm, and the particle size of 50,000 toner particles is measured.
As channels, 2.00 to less than 2.52 μm; 2.52 to less than 3.17 μm; 3.17 to less than 4.00 μm; 4.00 to less than 5.04 μm; 5.04 to less than 6.35 μm; 6 Less than 35 to 8.00 μm; less than 8.00 to less than 10.08 μm; less than 10.08 to less than 12.70 μm; less than 12.70 to less than 16.00 μm; less than 16.00 to less than 20.20 μm; Intended for toner particles having a particle size of 2.00 μm or more and 32.0 μm or less using 13 channels of less than 40 μm; 25.40 to less than 32.00 μm; 32.00 to less than 40.30 μm.

  Then, the volume average particle diameter is calculated based on the relational expression “volume average particle diameter = ΣXfV / ΣfV”. However, “X” is the representative diameter in each channel, “V” is the equivalent volume in the representative diameter of each channel, and “f” is the number of particles in each channel.

  In such a polymerized toner, even if an attempt is made to remove the pulverized toner with the cleaning blade 62 in the same manner as when the conventional pulverized toner is removed from the surface of the photoreceptor 3, the polymerized toner cannot be sufficiently removed from the surface of the photoreceptor 3. A cleaning failure occurs. Further, low-temperature fixing toner using a crystalline resin in recent years is greatly deformed when passing through the blade, and is fixed to the edge of the blade or fused to the surface of the photoreceptor. Therefore, when the contact pressure of the cleaning blade 62 to the photosensitive member 3 is increased to improve the cleaning performance, there is a problem that the cleaning blade 62 wears out early.

In addition, the frictional force between the cleaning blade 62 and the photosensitive member 3 is increased, and the leading edge portion of the cleaning blade 62 in contact with the photosensitive member 3 is pulled in the moving direction of the photosensitive member 3 so that the leading edge portion is turned. End up. When the tip ridge line portion of the cleaning blade 62 is turned, various problems such as abnormal noise, vibration, and lack of the tip ridge line portion occur.
The cleaning blade of the present invention does not cause poor cleaning even with the above-described polymerized toner, and does not cause abnormal noise, vibration, or lack of a tip ridge line portion.

  Examples of the present invention will be described below, but the present invention is not limited to these examples.

  The examples and comparative examples shown below are evaluated by changing the base material of the elastic member, the surface layer forming material (curable composition), the surface layer thickness of the contact portion, and the surface layer forming region, respectively. It is what went.

  As the base material of the elastic member, six urethane rubbers (base materials 1 to 6) having JIS-A hardness, 23 ° C. rebound resilience, and Martens hardness (HM) shown in Table 1 were prepared. The measuring method is shown below.

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

<Rebound resilience of substrate>
The rebound resilience of the base material of the elastic member is 23 ° C., No. manufactured by Toyo Seiki Seisakusho. The measurement was performed according to JIS K6255 using a 221 regilynester. The sample used was a stack of 2 mm thick sheets so that the thickness was 4 mm or more.

<Martens hardness of substrate>
On the blade tip surface of the base material of the elastic member, the Martens hardness (HM) of the base material is a microhardness meter HM-2000 manufactured by Fischer Instruments, and the Vickers indenter is pushed in with a force of 1.0 mN for 10 seconds. The measurement was carried out by holding for 5 seconds and withdrawing for 10 seconds with a force of 1.0 mN.

As shown in FIG. 8A, the blade tip surface is measured by cutting the blade tip to a depth of about 2 mm and a width of 100 mm, and fixing it to the slide glass or the like with an adhesive or double-sided tape so that the tip surface faces upward. And the position of 100 micrometers was measured from the front-end ridgeline part of the front end surface.
Details of the measurement position M are shown in FIGS. 8B, 8C, and 8D. 8B and 8C show the measurement position M when the substrate has no surface layer, and FIG. 8D shows the measurement position M with the surface layer on the substrate.

<Example of surface layer formation>
(Preparation example)
-Preparation of curable composition-
From the composition shown in Table 2 below, curable compositions 1 to 9 were prepared by a conventional method. The curable compositions 1-2 are thermosetting compositions, and the curable compositions 3-9 are ultraviolet curable compositions.

  In Table 2, MTHPA represents 3-methyl-4-cyclohexene-1,2-dicarboxylic anhydride, and BDMA represents N, N-dimethylbenzylamine.

  The details of the curable materials used in the curable compositions 1 to 9 are shown in Tables 3 and 4 below.

-Cured film of curable composition-
The cured film of the curable composition shown in Table 5 below was used.

<Example of toner preparation>
A toner prepared by the following polymerization method (Japanese Patent Application Laid-Open No. 2014-92633) was used.

The physical properties of the produced toner are as follows.
Toner base particles: average circularity 0.98, volume average particle size 4.9 μm
External additive: 1.5 parts by mass of small particle size silica (manufactured by Clariant, H2000)
: 0.5 parts by mass of small particle size titanium oxide (manufactured by Teica, MT-150AI)
: Large particle size silica 1.0 part by mass (manufactured by Denki Kagaku Kogyo, UFP-30H)
-Glass transition temperature of toner: 50 ° C

Example 1
<Preparation of cleaning blade 1>
Masking is performed on the lower surface of the substrate 1 leaving a width of 4 mm from the front end surface of the strip-shaped substrate 1 having a thickness of 1.8 mm, and the surface layer having an average film thickness of 25 μm is formed on the lower surface of the substrate 1. Coated to form.
Specifically, the entire lower surface of the substrate 1 was applied by spray coating at a spray gun moving speed of 6 mm / s from the tip surface of the substrate. Thereafter, the masking was removed, and after heating for 3 hours in a constant temperature bath at 110 ° C., the coating was cured by heating for 2 hours in a constant temperature bath at 165 ° C.
Next, it cut | disconnected in 1 mm from the front end surface, and formed the contact part.

  Next, each elastic member having a surface layer formed on the contact portion was fixed to a sheet metal holder (supporting member) with an adhesive so that it could be mounted on a color composite machine (image MPC4500, manufactured by Ricoh). As described above, the cleaning blade 1 having the surface layer formed on the contact portion was produced.

  Various characteristics of the produced elastic member and cleaning blade were measured as follows. The results are shown in Table 6.

<Average thickness of surface layer>
FIG. 9 is a cross-sectional view showing a location where the thickness of the contact portion of the cleaning blade in the embodiment is measured.
As shown in FIG. 9, the elastic member was cut in a plane orthogonal to the longitudinal direction, and this cross-section was faced up, and observed with a digital microscope VHX-2000 (manufactured by Keyence Corporation). The measurement location is a position 5 μm away from the blade contact portion (tip ridge line portion) of the cross section.
As a method of cutting the elastic member into a ring, the elastic member was cut with a razor perpendicular to the longitudinal direction of the elastic member so that the thickness of the elastic member in the longitudinal direction was 3 mm. At that time, if a vertical slicer is used, the cross section can be cut more neatly. The position in the longitudinal direction where the elastic member was cut into a ring was the position excluding the 2 cm portions at both ends.

<Curvature radius of contact part>
As shown in FIG. 10, the radius of curvature of the cleaning blade contact portion (tip edge line portion) in the example was observed with a laser microscope VK-9510 (manufactured by Keyence Corporation). did. FIG. 11 shows an example of measurement. The example shown in FIG. 11 is an example in which the radius of curvature is 2.5 μm, and is obtained using a formula of curvature radius = edge width / √2. In addition, the measurement location was made into the position except the part of 2 cm of both ends.

<Martens hardness of cleaning blade>
On the lower surface of the cleaning blade in the example, the Martens hardness (HM) of the cleaning blade was determined by pushing a Vickers indenter with a force of 1.0 mN for 10 seconds using a micro hardness tester HM-2000 manufactured by Fischer Instruments, for 5 seconds. The sample was held for 10 seconds with a force of 1.0 mN and measured. The measurement position was set to a position 20 μm from the tip ridge line portion, and the measurement was performed such that the Vickers indenter was in contact with the surface layer. In addition, the measurement location was made into the position except the part of 2 cm of both ends.

<Assembly of image forming apparatus>
The produced cleaning blade 1 was attached to a color multifunction machine (image MPC4500, manufactured by Ricoh) (the printer unit has the same configuration as the image forming apparatus 500 shown in FIG. 5), and the image forming apparatus of Example 1 was assembled.
The cleaning blade was attached to the image forming apparatus so that the linear pressure was 20 g / cm and the cleaning angle was 79 °. Further, the apparatus is provided with a lubricant application device on the surface of the photosensitive member, and the coefficient of static friction on the surface of the photosensitive member is maintained at 0.2 or less during non-image formation by applying the lubricant. The method for measuring the coefficient of static friction on the surface of the photoreceptor is the Euler belt method, which is described in paragraph No. 0046 of JP-A-9-166919, for example.

<Image forming conditions>
Using the image forming apparatus, a laboratory environment: 65% RH at 21 ° C., a sheet passing condition: an image area ratio 5%, 3 prints / job, output 50,000 sheets (A4 size landscape), and Thus, various properties were evaluated after passing 50,000 sheets. The results are shown in Table 7.

<Cleanability>
As an evaluation image, a vertical band pattern (with respect to the paper traveling direction) 43 mm width, 3 charts, 20 A4 size sides, output 20 images, visually observe the obtained image, depending on the presence or absence of image abnormality due to poor cleaning, The cleaning property was evaluated. In the following, “◎”, “◯”, and “△” are acceptable, and “×” is unacceptable.

[Evaluation criteria]
A: Toner that has passed through due to poor cleaning cannot be visually confirmed on the photosensitive member even on the printing paper, and even when the photosensitive member is observed with a microscope in the longitudinal direction, no streaky toner slip can be confirmed.
○: Toner that has passed through due to poor cleaning cannot be visually confirmed on the printing paper or the photoreceptor.
Δ: Toner that has passed through due to poor cleaning does not exist on the printing paper, but can be visually confirmed on the photoreceptor.
X: Toner that has passed through due to poor cleaning can be visually confirmed on both the printing paper and the photoreceptor.

<Noise>
As an evaluation of abnormal noise, the presence or absence of abnormal noise was confirmed by human ears at the time of image output for cleaning evaluation, and the following determination was made. At this time, even if there is a difference in sound such as high frequency and low frequency, the presence or absence of occurrence as an abnormal sound was evaluated without distinction as long as it was a sound coming from the blade.

[Evaluation criteria]
○: No abnormal noise occurs ×: An abnormal noise occurs

<Abrasion amount of contact part>
After the output of 50,000 sheets, the amount of wear at the contact portion of the elastic member, as shown in FIG. 12, the wear width as viewed from the front end surface side of the elastic member, is measured with a laser microscope VK-9510 (Keyence). ). The amount of wear of the contact portion of the elastic member is measured when the surface layer is formed, and when the surface layer is not formed, the amount of wear of the base material is measured.

(Comparative Example 1)
The substrate 1 was used as the cleaning blade 27.

(Examples 2, 9, 13, 15, 19, 20 and Comparative Example 2)
-Production of cleaning blades 2, 9, 13, 15, 19, 20, and 28-
In the cleaning blade 1 of Example 1, Example 1 except that the substrate, the curable composition (surface layer forming cured material), the surface layer forming region, and the surface layer thickness shown in Table 6 below were changed. In the same manner as described above, cleaning blades 2, 9, 13, 15, 19, 20, and 28 of Examples 2, 9, 13, 15, 19, 20, and Comparative Example 2 were produced.

(Examples 3, 10, and 14)
-Production of cleaning blades 3, 10, 14-
In the cleaning blade 1 of Example 1, coating was performed while changing the base material, the curable composition (surface layer forming curable material), the surface layer forming region, and the surface layer thickness shown in Table 6 below. The curing conditions differed from those in Example 1, and after preliminary drying for 3 minutes in a constant temperature bath at 80 ° C., curing was carried out by heating for 60 minutes in a constant temperature bath at 80 ° C.
Next, it cut | disconnected in 1 mm from the front end surface, and formed the contact part.

(Examples 4-8, 11, 12, 16-18 and Comparative Examples 3, 5)
-Production of cleaning blades 4-8, 11, 12, 16-18 and 29, 31-
In the cleaning blade 1 of Example 1, coating was performed while changing the base material, the curable composition (surface layer forming curable material), the surface layer forming region, and the surface layer thickness shown in Table 6 below. The curing conditions were different from those in Example 1, and ultraviolet exposure was performed using a high-pressure mercury lamp so that the UV irradiation integrated amount was 6000 mJ / cm ² . At this time, ultraviolet exposure (irradiation atmosphere) was performed in a nitrogen atmosphere. At this time, while the high-pressure mercury lamp is on the upper side, the tip ridge line portion of the blade is set upward to irradiate the ultraviolet ray so that the ultraviolet ray is efficiently irradiated to the tip ridge line portion.
Next, it cut | disconnected in 1 mm from the front end surface, and formed the contact part.

<Measurement method of UV light intensity>
An ultraviolet integrated light quantity at a wavelength of 254 nm was measured using an ultraviolet integrated light quantity meter UIT-250 (manufactured by USHIO INC.). At this time, the measurement was carried out so that the sensor part of the integrating photometer was the same as the height of the ridge line part of the tip of the cleaning blade.

(Comparative Example 4)
-Production of cleaning blade 30-
An area of 3 mm from the front end surface of the strip-shaped substrate 2 having a thickness of 1.8 mm is immersed in the curable composition 3, and the coating is performed by pulling up so that a surface layer having an average thickness of the contact portion of 1 μm is formed. It was. Thereafter, UV exposure was performed using a high-pressure mercury lamp so that the UV irradiation integrated amount was 6000 mJ / cm ² . At this time, ultraviolet exposure (irradiation atmosphere) was performed in a nitrogen atmosphere. At this time, while the high-pressure mercury lamp is on the upper side, the tip ridge line portion of the blade is set upward to irradiate the ultraviolet ray so that the ultraviolet ray is efficiently irradiated to the tip ridge line portion.

(Examples 21 to 26 and Comparative Example 6)
-Production of cleaning blades 21-26 and 32-
After providing a surface layer using a cured film of a curable composition shown in Tables 5 and 6 on a part of the surface of the sheet on a 23 mm × 326 mm flat substrate having a thickness of 1.8 mm, The center was cut so that the size was halved to produce a 11.5 mm × 326 mm strip-shaped sheet.
A manufacturing procedure will be described with reference to FIGS. 13A to 13C.
First, a 23 mm × 326 mm flat substrate 622 having a thickness of 1.8 mm is prepared (FIG. 13A).
Subsequently, a surface layer 623 that is a cured product film of the curable composition is thermally welded to the center of the base material 622 (FIG. 13B).
Subsequently, the center is cut so that the size is halved to obtain a strip-shaped sheet of 11.5 mm × 326 mm (FIG. 13C).
The edge portion of the surface layer after cutting corresponds to the tip ridge line portion of the cleaning blade. The width of the surface layer is determined by the width of the film to be thermally welded.

(Comparative Example 7)
-Production of cleaning blade 33-
Masking is performed on the lower surface of the base material 3 while leaving a width of 5 mm from the front end surface of the strip-shaped base material 3 having a thickness of 1.8 mm, and the curable composition 5 is formed on the lower surface of the base material 3 at a position of 50 μm from the front end surface. The coating was performed so that a surface layer having a thickness of 20 μm was formed.
Specifically, the entire lower surface of the substrate 3 was applied by spray coating at a spray gun moving speed of 6 mm / s from the tip surface of the substrate. Thereafter, the masking was removed, and UV exposure was performed using a high-pressure mercury lamp so that the cumulative amount of UV irradiation was 6000 mJ / cm ² . At this time, ultraviolet exposure (irradiation atmosphere) was performed in a nitrogen atmosphere. At this time, while the high-pressure mercury lamp is on the upper side, the tip ridge line portion of the blade is set upward to irradiate the ultraviolet ray so that the ultraviolet ray is efficiently irradiated to the tip ridge line portion.
Thus, the cleaning blade 33 was obtained.
In addition, the cutting | disconnection in 1 mm from a front end surface like Example 1 was not performed.

  Each of the produced cleaning blades 2 to 33 is attached to a color multifunction machine (image MP C4500, manufactured by Ricoh) in the same manner as the cleaning blade 1 of Example 1, and the image forming apparatuses of Examples 2 to 26 and Comparative Examples 1 to 7 are used. Assembled. Further, in the same manner as in Example 1, the cleaning property, abnormal noise, and wear width were evaluated, and the results are shown in Table 7.

  In the cleaning blades of Examples 1 to 26, since the average film thickness of the surface layer of the contact portion is 10 μm or more and 100 μm or less, the movement of the contact portion of the elastic member is suppressed, and the base rubber is not worn even when worn. Since it was not exposed, it was found that good cleaning properties and abnormal noise can be suppressed even during long-term use. Also, no color misregistration occurred in the tandem image forming apparatus.

On the other hand, in Comparative Example 1, since the surface layer was not formed in the contact portion, the movement of the contact portion of the elastic member could not be suppressed, and the wear-out occurred, resulting in poor cleaning and abnormal noise. .
Moreover, in Comparative Examples 2-7, since the average film thickness of the surface layer of the contact portion was not 10 μm or more and 100 μm or less, poor cleaning and abnormal noise occurred with use over time. In Comparative Example 2, since the average film thickness of the surface layer was too thick, the followability of the elastic member to the photosensitive member was hindered, resulting in poor cleaning. In Comparative Examples 3 and 4, the elastic member of the base material was exposed because the wear width became larger than the average film thickness of the surface layer after long-term use.
In Comparative Example 5, the average film thickness of the surface layer was large, and the film was cracked with use over time, resulting in poor cleaning.
In Comparative Example 4 and Comparative Example 7, the average film thickness at a position 5 μm away from the blade contact portion (tip ridge line portion) is 0.3 μm and 4 μm, respectively. The average film thickness at a position 50 μm away from the part) was 1 μm and 20 μm, respectively.

<Additional evaluation>
For the cleaning blades 13 to 20 of Examples 13 to 20, an additional 30,000 sheets were passed under the same conditions after the evaluation in Table 7, and an evaluation after a total of 80,000 sheets was also performed. The results are shown in Table 8.

In Examples 13 to 20, since the Martens hardness of the base material was 2.0 N / mm ² or more, there was little deformation of the tip of the base material, and the surface layer did not crack even after long-term use of the tip. I was able to maintain sex.

<1> An elastic member that contacts the surface of the member to be cleaned and removes deposits attached to the surface of the member to be cleaned;
The elastic member has a base material and a surface layer made of a cured product of a curable composition,
The base material includes the contact portion when the surface of the base material facing the downstream side in the advancing direction of the member to be cleaned is a lower surface of the base material than the contact portion in contact with the member to be cleaned. Formed on at least a part of the lower surface,
The cleaning blade is characterized in that an average film thickness of the surface layer in the contact portion is 10 μm or more and 100 μm or less.
<2> The cleaning blade according to <1>, wherein the cured product of the curable composition is a cured product of an epoxy resin or a cured product of a resin having a polyethylene skeleton.
<3> The cleaning blade according to <1> or <2>, wherein a radius of curvature of the surface layer in the contact portion is 3.5 μm or less.
<4> The surface layer formed on the lower surface of the base material is formed in an area of 1 mm or more and 7 mm or less from the contact portion, according to any one of <1> to <3>, It is a cleaning blade.
<5> The cleaning blade according to any one of <1> to <4>, wherein a Martens hardness measured by a microhardness meter on a tip surface of the substrate is 2.0 N / mm ² or more. It is.
<6> Martens hardness of the surface layer was measured by a micro hardness meter, the cleaning blade according to any one of the <1> to <5>, wherein the at 3N / mm ² or more 30 N / mm ² or less It is.
<7> A process cartridge having at least an image carrier and cleaning means for removing toner remaining on the image carrier,
A process cartridge in which the cleaning means has the cleaning blade according to any one of <1> to <6>.
<8> An image carrier, a charging unit for charging the surface of the image carrier, an exposure unit for exposing the charged image carrier to form an electrostatic latent image, and the electrostatic latent image with toner. A developing means for forming a visible image by developing the image; a transferring means for transferring the visible image to a recording medium; a fixing means for fixing the transferred image transferred to the recording medium; An image forming apparatus having a cleaning means for removing toner remaining on
An image forming apparatus, wherein the cleaning unit includes the cleaning blade according to any one of <1> to <6>.

DESCRIPTION OF SYMBOLS 1 Image forming unit 2 Frame 3 Photoreceptor 4 Charging roller 5 Developing device 6 Cleaning device 7 Primary transfer roller 10 Lubricant coating device 14 Intermediate transfer belt 40 Optical writing unit 41 Polygon mirror 51 Developing roller 52 Supply screw 53 Stirring screw 54 Doctor 55 Registration roller pair 60 Transfer unit 62 Cleaning blade 62a Blade tip surface 62b Blade lower surface 62c Tip edge line portion 621 Support member 622 Base material 623 Surface layer 624 Elastic member 63 First bracket 64 Second bracket 66 Secondary transfer backup roller 67 Drive Roller 68 Auxiliary roller 69 Tension roller 70 Secondary transfer roller 80 Fixing unit 81 Pressure heating roller 82 Fixing belt unit 84 Fixing belt 83 Heating roller 85 Tension roller 86 Drive roller 87 Discharge roller pair 88 Stack unit 100 Toner cartridge 101 Fur brush 103 Solid lubricant 103a Lubricant pressure spring 103b Bracket 123 Image carrier 151 First paper feed cassette 151a First paper feed roller 152 Second paper feed cassette 152a Second paper feed roller 153 Paper feed path 154 Conveying roller pair 162 Belt cleaning unit 162a Belt cleaning blade 500 Image forming apparatus (printer)

Japanese Patent No. 3602898 JP 2004-233818 A Japanese Patent No. 5532378 Japanese Patent No. 2968243 JP 2009-300751 A

Claims (8)

An elastic member that contacts the surface of the member to be cleaned and removes deposits attached to the surface of the member to be cleaned;
The elastic member has a base material and a surface layer made of a cured product of a curable composition,
The base material includes the contact portion when the surface of the base material facing the downstream side in the advancing direction of the member to be cleaned is a lower surface of the base material than the contact portion in contact with the member to be cleaned. Formed on at least a part of the lower surface,
The cleaning blade, wherein an average film thickness of the surface layer in the contact portion is 10 μm or more and 100 μm or less.   The cleaning blade according to claim 1, wherein the cured product of the curable composition is one of a cured product of an epoxy resin and a cured product of a resin having a polyethylene skeleton.   The cleaning blade according to claim 1, wherein a radius of curvature of the surface layer at the contact portion is 3.5 μm or less.   The cleaning blade according to any one of claims 1 to 3, wherein the surface layer formed on the lower surface of the base material is formed in an area of 1 mm or more and 7 mm or less from the contact portion. The cleaning blade according to any one of claims 1 to 4, wherein the Martens hardness measured by a microhardness meter on the tip surface of the substrate is 2.0 N / mm ² or more. The cleaning blade according to any one of claims 1 to 5 Martens hardness measured the surface layer in the micro hardness tester, characterized in that it is 3N / mm ² or more 30 N / mm ² or less. A process cartridge having at least an image carrier and cleaning means for removing toner remaining on the image carrier;
A process cartridge comprising the cleaning blade according to any one of claims 1 to 6. An image carrier, a charging unit for charging the surface of the image carrier, an exposure unit for exposing the charged image carrier to form an electrostatic latent image, and developing the electrostatic latent image using toner Developing means for forming a visible image, transfer means for transferring the visible image to a recording medium, fixing means for fixing the transferred image transferred to the recording medium, and remaining on the image carrier. An image forming apparatus having cleaning means for removing toner,
An image forming apparatus, wherein the cleaning unit includes the cleaning blade according to claim 1.