Cleaning blade, image forming apparatus, process cartridge

Abstract

To provide a cleaning blade that prevents wear of an elastic body blade due to contact with a member to be cleaned, prevents passing of residual material and fastening of the residual material to the member to be cleaned, and can be used for a long period.SOLUTION: A cleaning blade 62 has a strip-shaped elastic body blade 622 and a support member 621 that supports the elastic body blade 622, and brings a leading end ridge part of the elastic body blade 622 into contact with a moving member to be cleaned to remove a residual material from a surface of the member to be cleaned. In the cleaning blade, at least a surface layer part including the leading end ridge part of the elastic body blade 622 is formed of rubber having a hysteresis loss rate of 15% or less.SELECTED DRAWING: Figure 2A

Description

[Technical Field]

[0001] The present invention relates to a cleaning blade, an image forming apparatus, and a process cartridge. [Background technology]

[0002] In conventional electrophotographic image forming apparatuses, residual toner adhering to the surface of an image carrier (hereinafter sometimes referred to as a "cleaned member") after a toner image is transferred to a recording medium or an intermediate transfer member in an image forming process is removed by a cleaning device. A cleaning blade is used as the cleaning device because of its simple configuration and excellent cleaning performance. A cleaning blade typically comprises an elastic member made of polyurethane rubber or the like and a support member. The base end of the elastic member is supported by a support member, and the contact portion (tip ridge portion) of the elastic member is pressed against the surface of the image carrier, trapping and scraping off the toner remaining on the image carrier surface. Furthermore, in recent years, electrophotographic image forming apparatuses have been required to be energy-efficient, and low-melting-point toners are increasingly being used.

[0003] However, as shown in FIG. 1A, with a conventional polyurethane rubber cleaning blade 62, the friction between the image carrier 123 and the cleaning blade 62 increases, pulling the cleaning blade 62 in the direction of movement of the image carrier 123 and causing the contact portion (tip ridge portion) 62c of the cleaning blade 62 to curl up. Furthermore, if cleaning is continued with the contact portion 62c of the cleaning blade 62 curled up, local wear X occurs at a location several micrometers away from the contact portion 62c on the tip surface 62a of the cleaning blade 62, as shown in FIG. 1B. Further cleaning in this state increases the local wear X, eventually causing the contact portion 62c to break off, as shown in FIG. 1C. This loss of the contact portion 62c further increases the friction, resulting in poor cleaning performance. In particular, there is a problem of external additives adhering to the image carrier.

[0004] Patent Document 1 discloses a cleaning blade for an electrophotographic device that has an elastic rubber member and a support member, with the aim of providing a cleaning blade that can properly clean small particle size polymerized toner even under low temperature and low humidity conditions, wherein the elastic rubber member has a multi-layer structure of two or more layers that has an edge layer and a layer other than the edge layer, and is made of a material that satisfies the characteristics of a hysteresis loss (B / A) of deflection and bending load of B / A<0.5 in a three-point bending test with the edge layer on top. Furthermore, Patent Document 2 discloses a cleaning blade in which the 100% modulus of the surface layer of the elastic blade is set within a specific range. Summary of the Invention [Problem to be solved by the invention]

[0005] The technique disclosed in Patent Document 1 is not sufficient to prevent damage caused by repeated small deformations of the elastic blade, and there is a problem in that the elastic blade wears out early and its function deteriorates. Even in the technology disclosed in Patent Document 2, there is room for improvement in terms of suppressing wear of the elastic blade and cleaning performance for the member to be cleaned. Therefore, an object of the present invention is to provide a cleaning blade that suppresses wear of the elastic blade due to contact with the member being cleaned, suppresses the passage of residue and the adhesion of residue to the member being cleaned, and enables long-term use. [Means for solving the problem]

[0006] The cleaning blade of the present invention, which solves the above problems, has the following configuration. A cleaning blade having a rectangular elastic blade and a support member for supporting the elastic blade, the cleaning blade removing residue from a surface of a moving member to be cleaned by bringing the leading edge portion of the elastic blade into contact with the moving member, A cleaning blade characterized in that at least a surface layer portion of the elastic blade, including the tip ridge line portion, is made of rubber having a hysteresis loss rate of 15% or less. [Effects of the Invention]

[0007] According to the present invention, a cleaning blade is provided that can be used for a long period of time by suppressing premature wear of the elastic blade due to contact with the member being cleaned, and by suppressing the passage of residue and the adhesion of residue to the member being cleaned. [Brief explanation of the drawings]

[0008] [Figure 1A] FIG. 1A is a schematic diagram illustrating a conventional cleaning blade. [Figure 1B] FIG. 1B is a schematic diagram illustrating a conventional cleaning blade. [Figure 1C] FIG. 1C is a schematic diagram illustrating a conventional cleaning blade. [Figure 2A] FIG. 2A is a schematic diagram illustrating an example of a cleaning blade according to an embodiment of the present invention. [Figure 2B] FIG. 2B is a schematic diagram illustrating an example of a cleaning blade according to an embodiment of the present invention. [Figure 3] FIG. 3 is a schematic diagram illustrating a state in which the edge portion of the elastic blade is brought into contact with the member to be cleaned. [Figure 4] FIG. 4 is a schematic diagram showing an example of the configuration of an image forming apparatus according to an embodiment of the present invention. [Figure 5] FIG. 5 is a diagram showing the schematic configuration of one of the four image forming units in the image forming apparatus. [Figure 6] FIG. 6 is a diagram for explaining the average circularity of the toner. [Figure 7] FIG. 7 is a conceptual diagram for explaining the hysteresis loss rate. DETAILED DESCRIPTION OF THE INVENTION

[0009] As a result of extensive research, the inventors have found that if a conventional cleaning blade using a material with a large hysteresis loss rate at the tip ridgeline is continued to be used in a deformed state as shown in FIG. 1A, wear will progress early at a location slightly away from the edge 62c as shown in FIG. 1B, significantly reducing the cleaning function and causing residues such as toner to slip through and toner and external additives to adhere to the member being cleaned. In the present invention, the above-mentioned problems can be solved by using a material having a hysteresis loss rate of 15% or less for the tip ridge line portion.Embodiments of the present invention will be described in further detail below.

[0010] <Parts to be cleaned> The material, shape, structure, size, etc. of the member to be cleaned are not particularly limited and can be appropriately selected depending on the purpose. Examples of the shape of the member to be cleaned include a drum shape, a belt shape, a flat plate shape, and a sheet shape. The size of the member to be cleaned is not particularly limited and can be appropriately selected depending on the purpose, but a size that is generally used is preferred. The material of the member to be cleaned is not particularly limited and can be appropriately selected depending on the purpose, and examples thereof include metal, plastic, and ceramic. The member to be cleaned is not particularly limited and can be appropriately selected depending on the purpose. When the cleaning blade is applied to an image forming apparatus, the member to be cleaned may be an image carrier.

[0011] <Residue> The residue is not particularly limited as long as it is attached to the surface of the member to be cleaned and is a target for removal by the cleaning blade, and can be appropriately selected depending on the purpose. Examples of the residue include toner, lubricant, inorganic fine particles, organic fine particles, dirt, dust, and mixtures thereof. The following description will be given taking as an example a case where an image carrier such as a photoreceptor is used as the member to be cleaned and the residue is toner, but the present invention is not limited to the following example.

[0012] 2 and 2B are schematic diagrams illustrating an example of the cleaning blade of the present invention. 2A, cleaning blade 62 is composed of a flat support member 621 made of a rigid material such as metal or hard plastic, and a strip-shaped elastic blade 622. Elastic blade 622 is fixed to one end of support member 621 with an adhesive or the like, and the other end of support member 621 is cantilevered on the case of the cleaning device. FIG. 3 is a schematic diagram for explaining a state in which the edge portion of the elastic blade 622 is brought into contact with a member to be cleaned (for example, a photosensitive member). As shown in FIG. 3, the rectangular elastic blade 622 has a tip ridge portion on one side, which is the free end facing the photosensitive element 3, and this tip ridge portion comes into contact with the surface of the photosensitive element 3 as it moves along the surface, thereby performing cleaning to remove powder from the surface of the photosensitive element 3.

[0013] As shown in FIG. 2A, the elastic blade 622 may be composed of a single layer, or as shown in FIG. 2B, the elastic blade 622 may be a laminate having a laminated structure consisting of a base layer 6222 and a surface layer 6221 including a tip ridge portion. There are no particular limitations on the shape, material, size, structure, etc. of the base layer 6222, and these can be selected appropriately depending on the purpose. There are no particular limitations on the size of the elastic blade 622, and these can be selected appropriately depending on the size of the member to be cleaned. The material of the elastic blade 622 is not particularly limited and can be selected appropriately depending on the purpose, but polyurethane rubber, polyurethane elastomer, etc. are suitable because they tend to provide high elasticity.

[0014] A suitable method for manufacturing the elastic blade 622 is as follows. First, a polyurethane prepolymer is prepared using a polyol compound and a polyisocyanate compound. Next, a curing agent and, if necessary, a curing catalyst are added to the polyurethane prepolymer and stirred, and then the mixture is poured into a centrifugal molding machine, heated, crosslinked, and molded into a cylindrical shape. This is then demolded, and a portion is cut into a sheet, stretched on a smooth surface, left at room temperature, and allowed to mature, after which it is cut into strips of the specified dimensions.

[0015] The polyol compound is not particularly limited and can be appropriately selected depending on the purpose. Examples thereof include high-molecular-weight polyols and low-molecular-weight polyols. Examples of the high molecular weight polyol include polyester polyols, which are condensates of alkylene glycols and aliphatic dibasic acids; polyester polyols such as polyester polyols of alkylene glycols and adipic acid, such as ethylene adipate ester polyol, butylene adipate ester polyol, hexylene adipate ester polyol, ethylene propylene adipate ester polyol, ethylene butylene adipate ester polyol, and ethylene neopentylene adipate ester polyol; polycaprolactone polyols such as polycaprolactone ester polyol obtained by ring-opening polymerization of caprolactone; and polyether polyols such as poly(oxytetramethylene) glycol and poly(oxypropylene) glycol. These may be used alone or in combination of two or more. Examples of the low-molecular-weight polyols include dihydric alcohols such as 1,4-butanediol, ethylene glycol, neopentyl glycol, hydroquinone-bis(2-hydroxyethyl)ether, 3,3'-dichloro-4,4'-diaminodiphenylmethane, and 4,4'-diaminodiphenylmethane; and trihydric or higher polyhydric alcohols such as 1,1,1-trimethylolpropane, glycerin, 1,2,6-hexanetriol, 1,2,4-butanetriol, trimethylolethane, 1,1,1-tris(hydroxyethoxymethyl)propane, diglycerin, and pentaerythritol. These may be used alone or in combination of two or more.

[0016] The polyisocyanate compound is not particularly limited and can be appropriately selected depending on the purpose, and examples thereof include methylene diphenyl diisocyanate (MDI), tolylene diisocyanate (TDI), xylylene diisocyanate (XDI), naphthylene 1,5-diisocyanate (NDI), tetramethyl xylene diisocyanate (TMXDI), isophorone diisocyanate (IPDI), hydrogenated xylylene diisocyanate (H6XDI), dicyclohexylmethane diisocyanate (H12MDI), hexamethylene diisocyanate (HDI), dimer acid diisocyanate (DDI), norbornene diisocyanate (NBDI), trimethylhexamethylene diisocyanate (TMDI), etc. These may be used alone or in combination of two or more.

[0017] The curing catalyst is not particularly limited and can be appropriately selected depending on the purpose. Examples of the curing catalyst include secondary amines such as 2-methylimidazole and salts thereof; tertiary amines such as 1,2-dimethylimidazole, triethylenediamine, and diazabicycloundecene and salts thereof; organic acid salts of alkali metals such as potassium acetate and potassium octylate; and organic metal salts such as dibutyltin dilaurate, bismuth carboxylate, and zirconium complexes. The content of the curing catalyst is not particularly limited and can be appropriately selected depending on the purpose, but is preferably 0.01% by mass or more and 0.5% by mass or less, and more preferably 0.05% by mass or more and 0.3% by mass or less.

[0018] The elastic blade 622 can have a single layer or a laminated structure of two or more layers. Although many of the materials of the present invention with a hysteresis loss rate of 15% or less have low hardness, a laminated structure with a base layer made of high-hardness rubber and a surface layer made of a material with a hysteresis loss rate of 15% or less is preferable in that it prevents the tip ridge from curling up more than necessary and achieves both wear resistance and followability. The surface layer including the tip ridge line preferably has a JIS-A hardness of 50° to 65°, and the base layer preferably has a JIS-A hardness of 68° to 85°. The base layer more preferably has a JIS-A hardness of 70° to 80°. If the angle is less than 68°, it is difficult to obtain blade linear pressure, which may result in poor cleaning. Conversely, if the angle is greater than 85°, the base layer is more susceptible to plastic deformation, which may reduce blade linear pressure over the long term and result in poor cleaning. The JIS-A hardness is measured in accordance with JIS K6253, and can be measured, for example, using a micro rubber hardness meter MD-1 manufactured by Kobunshi Keiki Co., Ltd.

[0019] Furthermore, if the hysteresis loss rate of the surface layer is greater than 15%, fatigue wear is likely to progress as the tip ridgeline is repeatedly deformed during use, and premature wear is likely to cause a decrease in cleaning function. The hysteresis loss rate is measured in accordance with JIS K6400-2, and can be measured using, for example, a texture analyzer EZtest manufactured by Shimadzu Corporation. Specifically, a single-layer rubber sample is first processed into a dumbbell shape based on JIS K6251. This is attached to a texture analyzer and stretched to 100% (load) at a tensile speed specified in JIS K6251, for example, a speed of 500 mm / min for a No. 1 dumbbell, and then returned to 0% elongation at the same speed (unload). When the integrated load stress value at this time is W1 and the integrated unload stress value is W2, the hysteresis loss rate is calculated using the following formula. Hysteresis loss rate: (W1-W2) / W1 [%]

[0020] Furthermore, if the tan δ peak temperature of the surface layer is higher than 2° C., the hardness and hysteresis loss rate increase in low-temperature environments, which makes it more susceptible to early wear in winter environments and reduces the cleaning function. The tan δ peak temperature can be measured using a strip-shaped sample with an SII NanoTechnology Inc. DMS6100 or similar under conditions such as tensile mode, a frequency of 10 Hz, and a heating rate of 2°C / min.

[0021] Furthermore, the MSE (micro slurry-jet erosion) wear of the surface layer is an effective indicator of the rate of abrasive wear caused by small amounts of material passing through even when the cleaning blade is maintaining its cleaning function properly.It is known that when the MSE wear is greater than 15 μm, the wear progresses rapidly at a certain point. The MSE wear amount can be measured using an MSE testing device manufactured by Palmeso Co., Ltd., by projecting 100g of a slurry liquid made by dispersing 1μm particle diameter alumina particles in water at a mass concentration of 3% onto the smooth part of the cleaning blade rubber at a speed of 100m / sec and a projection amount of 2g / min, and then measuring the wear depth with a laser microscope (such as the LEXT OLS4100 manufactured by Olympus Corporation).

[0022] The Martens hardness of the surface layer is 0.45N / mm 2If the force is less than 0.75N / mm, the tip edge will be pulled in too much, reducing the cleaning function. 2 If it is larger, the hysteresis loss rate will generally be greater than 15%, which is unsuitable. Martens hardness can be measured using a Fisher Instruments HM-2000 ultra-microhardness tester under conditions such as pressing a Vickers indenter into the sample surface with a force of 9.8 mN for 30 seconds, holding it there for 5 seconds, and then removing it with a force of 9.8 mN for 30 seconds.

[0023] The average thickness of the elastic blade 622 is not particularly limited and can be appropriately selected depending on the purpose, but is preferably 1.0 mm or more and 3.0 mm or less.

[0024] <Supporting member> The shape, size, material, etc. of the support member 621 are not particularly limited and can be appropriately selected depending on the purpose. Examples of the shape of the support member 621 include a flat plate, a strip, and a sheet. The size of the support member 621 is not particularly limited and can be appropriately selected depending on the size of the member to be cleaned. Examples of materials for the support member 621 include metal, plastic, ceramic, etc. Among these, a metal plate is preferable from the viewpoint of strength, and a steel plate such as stainless steel, an aluminum plate, or a phosphor bronze plate is particularly preferable.

[0025] The cleaning blade of the present invention can suppress curling of the contact portion of the leading edge line that contacts the surface of the member to be cleaned, reduces wear and chipping of the contact portion of the leading edge line during use, and can maintain good cleaning performance for a long period of time, so it can be used in a wide variety of fields, but is particularly suitable for use in the image forming apparatus, image forming method, and process cartridge described below.

[0026] (Image forming apparatus and image forming method) The image forming apparatus of the present invention comprises at least an image carrier, a charging means, an exposure means, a developing means, a transfer means, a fixing means, and a cleaning means, and may further comprise other means appropriately selected as necessary. The charging means and the exposure means may be collectively referred to as an electrostatic latent image forming means. The image forming method carried out by the image forming apparatus of the present invention includes at least a charging step, an exposing step, a developing step, a transferring step, a fixing step, and a cleaning step, and may further include other steps appropriately selected as necessary. The charging step and the exposing step may be collectively referred to as an electrostatic latent image forming step. The charging step can be performed by the charging means, the exposure step can be performed by the exposure means, the developing step can be performed by the developing means, the transferring step can be performed by the transferring means, the fixing step can be performed by the fixing means, the cleaning step can be performed by the cleaning means, and the other steps can be performed by the other means. The image carrier (hereinafter sometimes referred to as "electrophotographic photoreceptor" or "photoreceptor") is not particularly limited in terms of material, shape, structure, size, etc., and can be appropriately selected from known ones. Examples of the shape of the image carrier include a drum shape and a belt shape. Examples of the material of the image carrier include inorganic photoreceptors such as amorphous silicon and selenium, and organic photoreceptors (OPC) such as polysilane and phthalopolymethine.

[0027] <Charging Process and Charging Means> The charging step is a step of charging the surface of the image bearing member, and is carried out by a charging unit. The charging can be carried out, for example, by applying a voltage to the surface of the image bearing member using the charging means. The charging means is not particularly limited and can be appropriately selected depending on the purpose. Examples thereof include a known contact charger equipped with a conductive or semiconductive roller, brush, film, rubber blade, etc., and a non-contact charger utilizing corona discharge such as a corotron or scorotron. The shape of the charging means may be any shape, such as a roller, a magnetic brush, or a fur brush, and can be selected according to the specifications and shape of the electrophotographic image forming apparatus. When a magnetic brush is used, the magnetic brush uses various ferrite particles, such as Zn-Cu ferrite, as the charging means, and is composed of a non-magnetic conductive sleeve for supporting the particles and a magnet roll enclosed within the sleeve. When a fur brush is used, the fur brush is made of fur that has been treated with conductivity using carbon, copper sulfide, metal, or metal oxide, and is wound or attached to a metal or other conductive core to form a charger. The charger is not limited to the contact type charger described above, but there is an advantage in that an image forming apparatus in which ozone generated from the charger is reduced can be obtained. It is preferable that the charger is disposed in contact with or out of contact with the image bearing member, and charges the surface of the image bearing member by applying DC and AC voltages in a superimposed manner. It is also preferable that the charger is a charging roller disposed close to the image carrier without contacting it with a gap tape, and that the surface of the image carrier is charged by applying DC and AC voltages superimposed on the charging roller.

[0028] <Exposure process and exposure means> The exposure step is a step of exposing the charged surface of the image bearing member to light, and is carried out by the exposure unit. The exposure can be carried out, for example, by exposing the surface of the image bearing member imagewise using the exposure unit. The optical systems used in the exposure are broadly divided into analog optical systems and digital optical systems. The analog optical systems project an original directly onto an image carrier, while the digital optical systems receive image information as an electrical signal, convert it into an optical signal, and expose an electrophotographic photosensitive member to form an image. The exposing means is not particularly limited as long as it can expose the surface of the image carrier charged by the charging means in the form of an image to be formed, and can be appropriately selected depending on the purpose. Examples of the exposing means include various exposure devices such as a copying optical system, a rod lens array system, a laser optical system, a liquid crystal shutter optical system, and an LED optical system. In the present invention, a backlight system may be employed in which image exposure is performed from the back side of the image carrier.

[0029] <Developing step and developing means> The developing step is a step of developing the electrostatic latent image with the toner to form a visible image. The visible image can be formed, for example, by developing the electrostatic latent image with the toner, and can be formed by the developing unit. The developing means is not particularly limited as long as it can develop using the toner, and can be appropriately selected from known developing means. For example, a suitable developing means is one that has at least a developing unit that stores the toner and can apply the toner to the electrostatic latent image in a contact or non-contact manner. The developing device may be a dry developing device or a wet developing device, and may be a monochromatic developing device or a multicolor developing device. Suitable examples of the developing device include a device having an agitator that frictionally agitates the toner to charge it, and a rotatable magnetic roller. In the developing unit, for example, the toner and, if necessary, a carrier are mixed and stirred, and the toner becomes charged by friction during this process and is held in a standing state on the surface of a rotating magnet roller, forming a magnetic brush. Because the magnet roller is located near the image carrier, a portion of the toner constituting the magnetic brush formed on the surface of the magnet roller moves to the surface of the image carrier by electrical attraction. As a result, the electrostatic latent image is developed with the toner, and a visible toner image is formed on the surface of the image carrier. The toner contained in the developing device may be a developer containing the toner, and the developer may be a one-component developer or a two-component developer.

[0030] -toner- The toner contains toner base particles and an external additive, and may further contain other components as required. The toner may be either a monochrome toner or a color toner. The toner base particles contain at least a binder resin and a colorant, and may contain other components such as a release agent and a charge control agent, if necessary.

[0031] ---Binder resin--- The binder resin is not particularly limited and can be appropriately selected depending on the purpose. Examples of the binder resin include homopolymers of styrene or substituted styrene such as polystyrene resin and polyvinyl toluene resin, styrene-p-chlorostyrene copolymer, styrene-propylene copolymer, styrene-vinyl toluene copolymer, styrene-methyl acrylate copolymer, styrene-ethyl acrylate copolymer, styrene-butyl acrylate copolymer, styrene-methyl methacrylate copolymer, styrene-ethyl methacrylate copolymer, styrene-butyl methacrylate copolymer, styrene-α-chloromethyl methacrylate copolymer, styrene-acrylonitrile copolymer, Examples of suitable resins include styrene-vinyl methyl ether copolymers, styrene-vinyl methyl ketone copolymers, styrene-butadiene copolymers, styrene-isoprene copolymers, styrene-maleic acid copolymers, styrene-maleic acid ester copolymers, polymethyl methacrylate, polybutyl methacrylate, polyvinyl chloride resins, polyvinyl acetate resins, polyethylene resins, polypropylene resins, polyester resins, polyurethane resins, epoxy resins, polyvinyl butyral resins, polyacrylic acid resins, rosin, modified rosin, terpene resins, phenolic resins, aliphatic hydrocarbons, aromatic petroleum resins, chlorinated paraffin, and paraffin wax. These may be used alone or in combination of two or more. Among these, polyester resins are particularly preferred because they can reduce the melt viscosity while ensuring the storage stability of the toner, compared to styrene-based resins and acrylic-based resins. The polyester resin can be obtained, for example, by a polycondensation reaction between an alcohol component and a carboxylic acid component. The alcohol component is not particularly limited and can be appropriately selected depending on the purpose. Examples thereof include diols such as polyethylene glycol, diethylene glycol, triethylene glycol, 1,2-propylene glycol, 1,3-propylene glycol, 1,4-propylene glycol, neopentyl glycol, and 1,4-butenediol; etherified bisphenols such as 1,4-bis(hydroxymethyl)cyclohexane, bisphenol A, hydrogenated bisphenol A, polyoxyethylenated bisphenol A, and polyoxypropylenated bisphenol A; and mixtures thereof having 3 to 2 carbon atoms. Examples include dihydric alcohol units substituted with two saturated or unsaturated hydrocarbon groups; other dihydric alcohol units; and trihydric or higher polyhydric alcohol monomers such as sorbitol, 1,2,3,6-hexanetetrol, 1,4-sorbitan, pentaerythritol, dipentaerythritol, tripentaerythritol, sucrose, 1,2,4-butanetriol, 1,2,5-pentanetriol, glycerol, 2-methylpropanetriol, 2-methyl-1,2,4-butanetriol, trimethylolethane, trimethylolpropane, and 1,3,5-trihydroxymethylbenzene. The carboxylic acid component is not particularly limited and can be appropriately selected depending on the purpose. Examples thereof include monocarboxylic acids such as palmitic acid, stearic acid, and oleic acid; maleic acid, fumaric acid, mesaconic acid, citraconic acid, terephthalic acid, cyclohexanedicarboxylic acid, succinic acid, adipic acid, sebacic acid, and malonic acid; divalent organic acid monomers obtained by substituting these with saturated or unsaturated hydrocarbon groups having 3 to 22 carbon atoms; anhydrides and lower alkyl esters of these acids; and carboxylic acids derived from linoleic acid. Dimer acids include 1,2,4-benzenetricarboxylic acid, 1,2,5-benzenetricarboxylic acid, 2,5,7-naphthalenetricarboxylic acid, 1,2,4-naphthalenetricarboxylic acid, 1,2,4-butanetricarboxylic acid, 1,2,5-hexanetricarboxylic acid, 3,3-dicarboxymethylbutanoic acid, tetracarboxymethylmethane, 1,2,7,8-octanetetracarboxylic acid, Embol trimer acid, and trivalent or higher polyvalent carboxylic acid monomers such as anhydrides of these acids.

[0032] ---Colorant--- The colorant is not particularly limited and can be appropriately selected from known dyes and pigments depending on the purpose. Examples of the colorant include carbon black, nigrosine dye, iron black, naphthol yellow S, Hansa yellow (10G, 5G, G), cadmium yellow, yellow iron oxide, yellow ochre, yellow lead, titanium yellow, polyazo yellow, oil yellow, Hansa yellow (GR, A, RN, R), pigment yellow L, benzidine yellow (G, GR), permanent yellow (NCG), Balkan fast yellow (5G, R), tartrazine lake, quinoline yellow lake, anthrazan yellow BGL, and isoindolinone yellow. , red iron oxide, red lead, vermilion lead, cadmium red, cadmium mercury red, antimony vermilion, permanent red 4R, para red, faise red, parachlor orthonitroaniline red, Lithol Fast Scarlet G, Brilliant Fast Scarlet, Brilliant Kanmin BS, permanent red (F2R, F4R, FRL, FRLL, F4RH), Fast Scarlet VD, Belkan Fast Rubin B, Brilliant Scarlet G, Lithol Rubin GX, permanent red F5R, Brilliant Carmine 6B, Pigment Scarlet 3B, Bordeaux 5B, Toluidine Maroon, Permanent Bordeaux F2K, Helio Bordeaux BL, Bordeaux 10B, Bon Maroon Light, Bon Maroon Medium, Eosin Lake, Rhodamine Lake B, Rhodamine Lake Y, Alizarin Lake, Thioindigo Red B, Thioindigo Maroon, Oil Red, Quinacridone Red, Pyrazolone Red, Polyazo Red, Chrome Vermilion, Benzidine Orange, Perinone Orange, Oil Orange, Cobalt Blue, Cerulean Blue Lu, Alkaline Blue Lake, Peacock Blue Lake, Victoria Blue Lake, Metal-free Phthalocyanine Blue, Phthalocyanine Blue, Fast Sky Blue, Indanthrene Blue (RS, BC), Indigo, Ultramarine Blue, Prussian Blue, Anthraquinone Blue, Fast Violet B, Methyl Violet Lake, Cobalt Purple, Manganese Purple, Dioxane Violet, Anthraquinone Violet, Chrome Green, Zinc Green, Chromium Oxide, Pyridian, Emerald Green, Pigment Green B, Naphthol Green B,Examples of suitable pigments include green gold, acid green lake, malachite green lake, phthalocyanine green, anthraquinone green, titanium oxide, zinc oxide, and lithopone. These pigments may be used alone or in combination. The content of the colorant in the toner is not particularly limited and can be appropriately selected depending on the purpose, but is preferably 1% by mass to 15% by mass, more preferably 3% by mass to 10% by mass. The colorant may be used as a masterbatch in which it is combined with a resin. The resin is not particularly limited and can be appropriately selected from known resins depending on the purpose, and examples thereof include polymers of styrene or its substitution products, styrene copolymers, polymethyl methacrylate resins, polybutyl methacrylate resins, polyvinyl chloride resins, polyvinyl acetate resins, polyethylene resins, polypropylene resins, polyester resins, epoxy resins, epoxy polyol resins, polyurethane resins, polyamide resins, polyvinyl butyral resins, polyacrylic acid resins, rosin, modified rosin, terpene resins, aliphatic hydrocarbon resins, alicyclic hydrocarbon resins, aromatic petroleum resins, chlorinated paraffin, paraffin, etc. These may be used alone or in combination of two or more.

[0033] ---Release agent--- The release agent is not particularly limited and can be appropriately selected depending on the purpose. Examples of the release agent include waxes. Examples of the waxes include carbonyl group-containing waxes, polyolefin waxes, and long-chain hydrocarbons. These may be used alone or in combination of two or more. Among these, carbonyl group-containing waxes are preferred. Examples of the carbonyl group-containing waxes include polyalkanoic acid esters, polyalkanol esters, polyalkanoic acid amides, polyalkylamides, and dialkyl ketones. Examples of the polyalkanoic acid esters include carnauba wax, montan wax, trimethylolpropane tribehenate, pentaerythritol tetrabehenate, pentaerythritol diacetate dibehenate, glycerin tribehenate, and 1,18-octadecanediol distearate. Examples of the polyalkanol esters include tristearyl trimellitate and distearyl maleate. Examples of the polyalkanoic acid amides include dibehenylamide. Examples of the polyalkylamides include tristearyl trimellitate amide. Examples of the dialkyl ketones include distearyl ketone. Among these carbonyl group-containing waxes, polyalkanoic acid esters are particularly preferred. Examples of the polyolefin wax include polyethylene wax and polypropylene wax. Examples of the long-chain hydrocarbons include paraffin wax and sazol wax. The content of the release agent in the toner is not particularly limited and can be appropriately selected depending on the purpose, but is preferably 5% by mass or more and 15% by mass or less.

[0034] ---Charge control agent--- The charge control agent is not particularly limited and can be appropriately selected depending on the purpose. Examples thereof include nigrosine dyes, triphenylmethane dyes, chromium-containing metal complex dyes, molybdate chelate pigments, rhodamine dyes, alkoxyamines, quaternary ammonium salts (including fluorine-modified quaternary ammonium salts), alkylamides, phosphorus simple substance or compounds, tungsten simple substance or compounds, fluorine-based activators, metal salicylate, and metal salts of salicylic acid derivatives. The content of the charge control agent is not particularly limited and can be selected appropriately depending on the purpose, but is preferably 0.1 parts by mass or more and 10 parts by mass or less, and more preferably 0.2 parts by mass or more and 5 parts by mass or less, relative to 100 parts by mass of the toner.

[0035] --External additives-- The external additive is not particularly limited as long as it contains at least silica particles, and can be appropriately selected depending on the purpose. It may also contain, for example, inorganic particles such as silica, titanium oxide, alumina, silicon carbide, silicon nitride, boron nitride, etc.; or resin particles such as polymethyl methacrylate particles and polystyrene particles having an average particle size of 0.05 μm to 1 μm obtained by soap-free emulsion polymerization. These may be used alone or in combination of two or more. Among these, silica whose surface has been hydrophobized is particularly preferred. An example of the silica is silicone-treated silica, which is silica whose surface has been treated with silicone oil (hydrophobization treatment). The surface treatment method is not particularly limited and can be appropriately selected depending on the purpose. Examples of the silicone oil include dimethyl silicone oil, methyl hydrogen silicone oil, and methyl phenyl silicone oil. The silicone-treated silica may be a commercially available product, such as RY200, R2T200S, NY50, or RY50 (all manufactured by Nippon Aerosil Co., Ltd.).

[0036] --Other ingredients-- The other components in the toner are not particularly limited and can be appropriately selected depending on the purpose, and examples thereof include a flowability improver, a cleaning property improver, a magnetic material, and a metal soap. The flow improver is a surface treatment agent that increases hydrophobicity and can prevent deterioration of flow characteristics and charging characteristics even under high humidity conditions. Examples of the flow improver include silane coupling agents, silylating agents, silane coupling agents having a fluorinated alkyl group, organic titanate coupling agents, aluminum coupling agents, silicone oils, and modified silicone oils. The cleaning property improver is added to the toner to remove toner remaining on the image carrier or intermediate transfer body after transfer, and examples thereof include fatty acid metal salts such as zinc stearate, calcium stearate, and stearic acid; polymer fine particles produced by soap-free emulsion polymerization such as polymethyl methacrylate fine particles and polystyrene fine particles; etc. The polymer fine particles preferably have a relatively narrow particle size distribution, and are preferably those with a volume average particle size of 0.01 μm or more and 1 μm or less. The magnetic material is not particularly limited and can be appropriately selected depending on the purpose, and examples thereof include iron powder, magnetite, ferrite, etc. Among these, white materials are preferred in terms of color tone.

[0037] --Toner manufacturing method-- The method for producing the toner is not particularly limited, and can be appropriately selected from conventionally known methods for producing toner depending on the purpose. Examples thereof include a kneading and pulverization method, a polymerization method, a dissolution suspension method, and a spray granulation method. Among these, polymerization methods such as suspension polymerization, emulsion polymerization, and dispersion polymerization are preferred, as they facilitate highly circular and small particle size production in order to improve image quality.

[0038] ---Kneading and pulverization method--- The kneading and pulverization method is a method for producing base particles of the toner by, for example, melting and kneading toner materials containing at least a binder resin and a colorant, and pulverizing and classifying the resulting kneaded product. In the melt-kneading, the toner materials are mixed, and the mixture is placed in a melt-kneader and melt-kneaded. Examples of the melt-kneader that can be used include a single- or twin-screw continuous kneader and a batch kneader using a roll mill. Suitable examples include a KTK twin-screw extruder manufactured by Kobe Steel, Ltd., a TEM extruder manufactured by Toshiba Machine Co., Ltd., a twin-screw extruder manufactured by KCK Engineering Co., Ltd., a PCM twin-screw extruder manufactured by Ikegai Corporation, and a co-kneader manufactured by Buss AG. The melt-kneading is preferably carried out under appropriate conditions that do not cause scission of the molecular chains of the binder resin. Specifically, the melt-kneading temperature is determined with reference to the softening point of the binder resin. If the temperature is higher than the softening point, severe scission may occur, and if the temperature is lower than the softening point, dispersion may not proceed. In the pulverization, the kneaded product obtained by the melt-kneading is pulverized. In this pulverization, it is preferable to first coarsely pulverize the kneaded product and then finely pulverize it. In this case, a method of pulverizing by colliding particles with an impingement plate in a jet stream, pulverizing by colliding particles with each other in a jet stream, or pulverizing in a narrow gap between a mechanically rotating rotor and stator is preferably used. The classification is performed by classifying the pulverized product obtained by the pulverization to adjust the particles to a predetermined particle size. The classification can be performed by removing fine particles using, for example, a cyclone, a decanter, a centrifugal separator, or the like. After the pulverization and classification are completed, the pulverized material is classified in an air current by centrifugal force or the like, thereby producing toner base particles of a predetermined particle size. Next, the external additive is added to the toner base particles. The toner base particles and the external additive are mixed and stirred using a mixer, whereby the external additive is crushed and coated onto the surface of the toner base particles. At this time, it is important from the viewpoint of durability that the external additive, such as silica particles, be uniformly and firmly attached to the toner base particles.

[0039] ---Polymerization method--- In the toner production method using the polymerization method, for example, toner materials including at least a modified polyester resin capable of being bonded with urea or urethane and a colorant are dissolved or dispersed in an organic solvent, and the solution or dispersion is then dispersed in an aqueous medium, subjected to a polyaddition reaction, and the solvent of the dispersion is removed and washed to obtain a toner.

[0040] Examples of the modified polyester resin capable of forming a urea or urethane bond include polyester prepolymers having an isocyanate group, which are obtained by reacting a carboxyl group or a hydroxyl group at the end of a polyester with a polyisocyanate compound (PIC). The modified polyester resins obtained by crosslinking and / or elongating the molecular chains through the reaction of this polyester prepolymer with amines or the like can improve hot offset properties while maintaining low-temperature fixability.

[0041] Examples of the polyisocyanate compound (PIC) include aliphatic polyisocyanates (e.g., tetramethylene diisocyanate, hexamethylene diisocyanate, 2,6-diisocyanatomethyl caproate, etc.); alicyclic polyisocyanates (e.g., isophorone diisocyanate, cyclohexylmethane diisocyanate, etc.); aromatic diisocyanates (e.g., tolylene diisocyanate, diphenylmethane diisocyanate, etc.); araliphatic diisocyanates (e.g., α,α,α',α'-tetramethylxylylene diisocyanate, etc.); isocyanates; and compounds obtained by blocking the polyisocyanates with phenol derivatives, oximes, caprolactam, etc. These compounds may be used alone or in combination of two or more. The ratio of the polyvalent isocyanate compound (PIC) is not particularly limited and can be appropriately selected depending on the purpose. However, the equivalent ratio [NCO] / [OH] of the isocyanate group [NCO] to the hydroxyl group [OH] of the polyester having a hydroxyl group is preferably 5 / 1 to 1 / 1, more preferably 4 / 1 to 1.2 / 1, and even more preferably 2.5 / 1 to 1.5 / 1. The number of isocyanate groups contained per molecule in the polyester prepolymer (A) having the isocyanate group is not particularly limited and can be appropriately selected depending on the purpose, but is preferably 1 or more, more preferably 1.5 to 3 on average, and even more preferably 1.8 to 2.5 on average.

[0042] Examples of the amines (B) to be reacted with the polyester prepolymer include divalent amine compounds (B1), trivalent or higher polyvalent amine compounds (B2), amino alcohols (B3), amino mercaptans (B4), amino acids (B5), and compounds (B6) in which the amino group of B1 to B5 has been blocked. Examples of the divalent amine compound (B1) include aromatic diamines (e.g., phenylenediamine, diethyltoluenediamine, 4,4'-diaminodiphenylmethane, etc.); alicyclic diamines (e.g., 4,4'-diamino-3,3'-dimethyldicyclohexylmethane, diaminecyclohexane, isophoronediamine, etc.); and aliphatic diamines (e.g., ethylenediamine, tetramethylenediamine, hexamethylenediamine, etc.). Examples of the trivalent or higher polyvalent amine compound (B2) include diethylenetriamine and triethylenetetramine. Examples of the amino alcohol (B3) include ethanolamine and hydroxyethylaniline. Examples of the amino mercaptan (B4) include aminoethyl mercaptan and aminopropyl mercaptan. Examples of the amino acid (B5) include aminopropionic acid and aminocaproic acid. Examples of compounds (B6) obtained by blocking the amino group of B1 to B5 include ketimine compounds obtained from the amines of B1 to B5 and ketones (e.g., acetone, methyl ethyl ketone, methyl isobutyl ketone, etc.), oxazolidine compounds, etc. Among these amines (B), B1 and a mixture of B1 and a small amount of B2 are particularly preferred. The ratio of the amines (B) is not particularly limited and can be appropriately selected depending on the purpose. However, the equivalent ratio [NCO] / [NHx] of the isocyanate groups [NCO] in the polyester prepolymer (A) having isocyanate groups to the amino groups [NHx] in the amines (B) is preferably 1 / 2 to 2 / 1, more preferably 1.5 / 1 to 1 / 1.5, and even more preferably 1.2 / 1 to 1 / 1.2.

[0043] According to the above-described method for producing toner by polymerization, it is possible to produce small-particle, spherical toner at low cost with little environmental impact. The dispersing machine for the dispersion is not particularly limited and can be appropriately selected depending on the purpose. Examples thereof include a low-speed shear dispersing machine, a high-speed shear dispersing machine, a friction dispersing machine, a high-pressure jet dispersing machine, and an ultrasonic dispersing machine. Among these, a high-speed shear type disperser is preferred in that it can control the particle size of the dispersion (oil droplets) to 2 μm or more and 20 μm or less. When the high-speed shear disperser is used, conditions such as the rotation speed, dispersing time, and dispersing temperature can be appropriately selected depending on the purpose. The rotation speed is not particularly limited and can be appropriately selected depending on the purpose, but is preferably 1,000 rpm or more and 30,000 rpm or less, and more preferably 5,000 rpm or more and 20,000 rpm or less. The dispersion time is not particularly limited and can be appropriately selected depending on the purpose, but in the case of a batch method, it is preferably 0.1 minutes or more and 5 minutes or less. The dispersion temperature is not particularly limited and can be appropriately selected depending on the purpose, but is preferably from 0° C. to 150° C. under pressure, and more preferably from 40° C. to 98° C. Generally, the higher the dispersion temperature, the easier the dispersion.

[0044] The amount of the aqueous medium used when dispersing the toner materials in the aqueous medium is not particularly limited and can be appropriately selected depending on the purpose. However, the amount is preferably 50 parts by mass or more and 2,000 parts by mass or less, and more preferably 100 parts by mass or more and 1,000 parts by mass or less, relative to 100 parts by mass of the toner materials.

[0045] The method for removing the organic solvent from the dispersion is not particularly limited and can be appropriately selected depending on the purpose. Examples include a method in which the temperature of the entire reaction system is gradually increased to evaporate the organic solvent in the oil droplets, and a method in which the dispersion is sprayed into a dry atmosphere to remove the organic solvent in the oil droplets. When the organic solvent is removed, toner base particles are formed. The toner base particles can be washed, dried, and further classified. The classification can be performed by removing fine particles in a liquid using a cyclone, decanter, centrifugal separation, or the like, or the classification operation can be performed after drying.

[0046] The obtained toner base particles may be mixed with the external additives, and if necessary, particles of the charge control agent, etc. At this time, by applying a mechanical impact force, it is possible to prevent the particles of the external additives, etc. from being detached from the surface of the toner base particles. The method for applying the mechanical impact force is not particularly limited and can be appropriately selected depending on the purpose. Examples include a method for applying an impact force to the mixture using blades rotating at high speed, and a method for introducing the mixture into a high-speed airflow and accelerating it to cause particles to collide with each other or with an appropriate collision plate. The apparatus used in the above method is not particularly limited and can be appropriately selected depending on the purpose. Examples include an Ang Mill (manufactured by Hosokawa Micron Corporation), an apparatus obtained by modifying an I-type Mill (manufactured by Nippon Pneumatic Co., Ltd.) to reduce the grinding air pressure, a Hybridization System (manufactured by Nara Machinery Works, Ltd.), a Cryptron System (manufactured by Kawasaki Heavy Industries, Ltd.), and an automatic mortar.

[0047] The average circularity of the toner is not particularly limited and can be appropriately selected depending on the purpose, but is preferably 0.97 or more, more preferably 0.97 to 0.98. If the average circularity is less than 0.97, satisfactory transferability and high-quality images without dust may not be obtained. The average circularity of the toner can be measured using, for example, a flow particle image analyzer FPIA-1000 manufactured by Sysmex Corporation. The volume average particle size of the toner is not particularly limited and can be appropriately selected depending on the purpose, but is preferably 5.5 μm or less. The ratio (Dv / Dn) of the volume average particle diameter (Dv) to the number average particle diameter (Dn) is not particularly limited and can be appropriately selected depending on the purpose, but is preferably 1.00 or more and 1.40 or less. The closer the ratio (Dv / Dn) is to 1.00, the sharper the particle size distribution. A toner with such a small particle diameter and narrow particle size distribution has a uniform charge distribution of the toner, making it possible to obtain high-quality images with little background fogging, and also enabling a high transfer rate in an electrostatic transfer system. The volume average particle size and particle size distribution of the toner can be measured, for example, by a Coulter Counter method using a Coulter Counter TA-II, a Coulter Multisizer II (both manufactured by Coulter, Inc.), or the like.

[0048] The toner can be mixed with a magnetic carrier to be used as a two-component developer. In this case, the mass ratio of the carrier to the toner in the two-component developer is not particularly limited and can be appropriately selected depending on the purpose, but it is preferably 1 part by mass or more and 10 parts by mass or less of the toner per 100 parts by mass of the carrier. Examples of the magnetic carrier include iron powder, ferrite powder, magnetite powder, and magnetic resin carriers having a particle size of about 20 μm or more and 200 μm or less.

[0049] The coating resin is not particularly limited and can be appropriately selected depending on the purpose. Examples thereof include urea-formaldehyde resin, melamine resin, benzoguanamine resin, urea resin, polyamide resin, epoxy resin, polyvinyl and polyvinylidene resin, acrylic resin, polymethyl methacrylate resin, polyacrylonitrile resin, polyvinyl acetate resin, polyvinyl alcohol resin, polyvinyl butyral resin, polystyrene resin, styrene-acrylic copolymer resin, halogenated olefin resin such as polyvinyl chloride; polyester resin such as polyethylene terephthalate resin, polybutylene terephthalate resin; polycarbonate resin, polyethylene resin, polyvinyl fluoride resin, polyvinylidene fluoride resin, polytrifluoroethylene resin, polyhexafluoropropylene resin, copolymer of vinylidene fluoride and an acrylic monomer, copolymer of vinylidene fluoride and vinyl fluoride, fluoro terpolymer such as terpolymer of tetrafluoroethylene, vinylidene fluoride and a non-fluorinated monomer, and silicone resin. Furthermore, if necessary, the coating resin may contain conductive powder, etc. Examples of the conductive powder include metal powder, carbon black, titanium oxide, tin oxide, and zinc oxide. These conductive powders preferably have an average particle size of 1 μm or less. If the average particle size exceeds 1 μm, it may become difficult to control the electrical resistance. The toner can also be used as a one-component magnetic toner that does not use a carrier, or as a non-magnetic toner.

[0050] <Transfer process and transfer means> The transfer step is a step of transferring the visible image onto a recording medium. A preferred embodiment is one in which an intermediate transfer body is used, the visible image is primarily transferred onto the intermediate transfer body, and then the visible image is secondarily transferred onto the recording medium. A more preferred embodiment is one in which two or more colors, preferably full-color toner, are used as the toner, and the transfer step includes a primary transfer step in which the visible image is transferred onto the intermediate transfer body to form a composite transfer image, and a secondary transfer step in which the composite transfer image is transferred onto a recording medium.

[0051] The transfer can be performed, for example, by charging the image carrier using a transfer unit, and can be performed by the transfer unit. The transfer unit preferably has a primary transfer unit that transfers the visible image onto an intermediate transfer body to form a composite transfer image, and a secondary transfer unit that transfers the composite transfer image onto a recording medium.

[0052] The intermediate transfer member is not particularly limited and can be appropriately selected from known transfer members depending on the purpose, and examples thereof include a transfer belt. The transfer means (the primary transfer means, the secondary transfer means) preferably has at least a transfer device that peels and charges the visible image formed on the image carrier onto the recording medium. The number of transfer devices may be one or more. Examples of the transfer device include a corona transfer device that uses corona discharge, a transfer belt, a transfer roller, a pressure transfer roller, and an adhesive transfer device. The recording medium is typically plain paper, but is not particularly limited as long as it can be used to transfer the unfixed image after development, and can be selected appropriately depending on the purpose. PET base for overhead projectors can also be used.

[0053] <Fixing process and fixing means> The fixing step is a step of fixing the toner image transferred to the recording medium, and can be performed using a fixing device. When two or more colors of toner are used, each color of toner may be fixed as it is transferred to the recording medium, or all colors of toner may be transferred to the recording medium and fixed in a stacked state. The fixing device is not particularly limited, and a thermal fixing method using a known heating and pressurizing device can be used. Examples of the heating and pressurizing device include a combination of a heating roller and a pressure roller, or a combination of a heating roller, a pressure roller, and an endless belt. The heating temperature is not particularly limited and can be selected appropriately depending on the purpose, but is preferably 80°C or higher and 200°C or lower. If necessary, a known optical fixing device, for example, may be used together with the fixing device.

[0054] <Cleaning Process and Cleaning Means> The cleaning step is a step of removing the toner remaining on the image bearing member, and can be suitably carried out by a cleaning means. The cleaning blade of the present invention is used as the cleaning means. The elastic member of the cleaning blade preferably contacts the surface of the image carrier with a pressing force of 10 N / m or more and 100 N / m or less. If the pressing force is less than 10 N / m, poor cleaning is likely to occur due to toner passing through the contact area where the elastic member of the cleaning blade contacts the image carrier surface. If the pressing force exceeds 100 N / m, the cleaning blade may curl up due to increased friction at the contact area. The pressing force is preferably 10 N / m or more and 50 N / m or less. The pressing force can be measured, for example, using a measuring device incorporating a small compression load cell manufactured by Kyowa Electronics Co., Ltd.

[0055] The angle θ formed by the tangent line at the point where the elastic member of the cleaning blade abuts the surface of the image carrier and the end face of the cleaning blade is not particularly limited and can be appropriately selected depending on the purpose, but is preferably 65° or more and 85° or less. If the angle θ is less than 65°, the cleaning blade may curl up, and if it exceeds 85°, poor cleaning may occur.

[0056] <Other steps and other means> Examples of the other means include a static elimination means, a recycling means, and a control means. Examples of the other steps include a static elimination step, a recycling step, and a control step.

[0057] -Static removal process and static removal means- The charge removal step is a step of removing electricity by applying a charge removal bias to the image bearing member, and can be suitably performed by a charge removal unit. The charge eliminating means is not particularly limited as long as it can apply a charge eliminating bias to the image bearing member, and can be appropriately selected from known charge eliminating devices, and a suitable example is a charge eliminating lamp.

[0058] -Recycling process and means- The recycling step is a step of recycling the toner removed in the cleaning step to the developing means, and can be suitably carried out by a recycling means. The recycling means is not particularly limited, and examples thereof include known transport means.

[0059] -Control process and control means- The control step is a step of controlling each of the steps, and can be suitably carried out by a control means. The control means is not particularly limited as long as it can control the movement of each of the means, and can be appropriately selected depending on the purpose. Examples of the control means include devices such as a sequencer and a computer.

[0060] An example of the image forming apparatus of the present invention will now be described with reference to the drawings. 4 is a schematic diagram showing an example of an image forming apparatus 500 of the present invention. The image forming apparatus 500 is equipped with four imaging units 1Y, 1C, 1M, and 1K for yellow, magenta, cyan, and black (hereinafter sometimes referred to as Y, C, M, and K). These units use different colors of Y, C, M, and K toner as image forming substances to form images, but are otherwise configured similarly. A transfer unit 60 equipped with an intermediate transfer belt 14 as an intermediate transfer body is disposed above the four image forming units 1. The toner images of each color formed on the surfaces of the photosensitive members 3Y, 3C, 3M, and 3K equipped in the image forming units 1Y, 1C, 1M, and 1K, which will be described in detail later, are transferred onto the surface of the intermediate transfer belt 14 in an overlapping manner. An optical writing unit 40 is disposed below the four imaging units 1. The optical writing unit 40, which serves as a latent image forming means, emits laser light L based on image information and irradiates the photoconductors 3Y, 3C, 3M, and 3K of the imaging units 1Y, 1C, 1M, and 1K with the laser light L. This forms electrostatic latent images for Y, C, M, and K on the photoconductors 3Y, 3C, 3M, and 3K. The optical writing unit 40 polarizes the laser light L emitted from a light source using a polygon mirror 41, which is driven to rotate by a motor, and irradiates the laser light L onto the photoconductors 3Y, 3C, 3M, and 3K via multiple optical lenses and mirrors. Instead of the above configuration, an LED array for optical scanning can also be used.

[0061] Below the optical writing unit 40, a first paper feed cassette 151 and a second paper feed cassette 152 are arranged so as to be stacked vertically. Each of these paper feed cassettes contains a stack of recording media P, and a first paper feed roller 151a and a second paper feed roller 152a abut against the topmost recording medium P. When the first paper feed roller 151a is driven to rotate counterclockwise in FIG. 4 by a drive unit, the topmost recording medium P in the first paper feed cassette 151 is ejected toward a paper feed path 153, which is arranged to extend vertically on the right side of the cassette in FIG. 4. When the second paper feed roller 152a is driven to rotate counterclockwise in FIG. 4 by a drive unit, the topmost recording medium P in the second paper feed cassette 152 is ejected toward the paper feed path 153. A plurality of conveying roller pairs 154 are arranged in the paper feed path 153. The recording medium P sent into the paper feed path 153 is sandwiched between the rollers of these conveying roller pairs 154 and conveyed within the paper feed path 153 from the bottom to the top in FIG.

[0062] A pair of registration rollers 55 is disposed at the downstream end in the conveying direction of the paper feed path 153. The pair of registration rollers 55 temporarily stops the rotation of both rollers as soon as they sandwich the recording medium P fed from the pair of conveying rollers 154 between their rollers. Then, they send the recording medium P toward the secondary transfer nip, which will be described later, at an appropriate timing.

[0063] FIG. 5 is a diagram showing the schematic configuration of one of the four image forming units 1. As shown in FIG. 5, the imaging unit 1 includes a drum-shaped photosensitive member 3 as an image carrier. Although the photosensitive member 3 is shown as being drum-shaped, it may also be sheet-shaped or endless belt-shaped. Around the photoreceptor 3, there are arranged a charging roller 4, a developing device 5, a primary transfer roller 7, a cleaning device 6, a lubricant applicator 10, a static elimination lamp, and the like. The charging roller 4 is a charging member provided in the charging device as a charging means, and the developing device 5 is a developing means that converts the 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 the primary transfer device as a primary transfer means that transfers the toner image on the surface of the photoreceptor 3 to the intermediate transfer belt 14. The cleaning device 6 is a cleaning means that cleans toner remaining on the photoreceptor 3 after the toner image is transferred to the intermediate transfer belt 14. The lubricant applicator 10 is a lubricant applicator that applies lubricant to the surface of the photoreceptor 3 after cleaning by the cleaning device 6. The static elimination lamp is a static elimination means that eliminates the surface potential of the photoreceptor 3 after cleaning.

[0064] The charging roller 4 is disposed at a predetermined distance from the photoreceptor 3 without contacting it, and charges the photoreceptor 3 to a predetermined polarity and a predetermined potential. The surface of the photoreceptor 3, which has been uniformly charged by the charging roller 4, is irradiated with laser light L from an optical writing unit 40, which is a latent image forming means, based on image information, and an electrostatic latent image is formed.

[0065] The developing device 5 has a developing roller 51 as a developer carrier. A developing bias is applied to this developing roller 51 from a power source. A supply screw 52 and an agitating screw 53 are provided inside the casing of the developing device 5, which agitate the developer contained in the casing while transporting it in opposite directions. A doctor 54 is also provided to regulate the developer carried on the developing roller 51. The toner in the developer agitated and transported by the twin screws, the supply screw 52 and the agitating screw 53, is charged to a predetermined polarity. The developer is then pumped up onto the surface of the developing roller 51, where it 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.

[0066] The cleaning device 6 has a fur brush 101, a cleaning blade 62, etc. The cleaning blade 62 abuts against the photosensitive member 3 in a counter direction to the direction in which the surface of the photosensitive member 3 moves.

[0067] Lubricant applicator 10 includes solid lubricant 103, lubricant pressure spring 103a, etc., and uses fur brush 101 as an applicator brush that applies solid lubricant 103 to photoreceptor 3. Solid lubricant 103 is held by bracket 103b and is pressed toward fur brush 101 by lubricant pressure spring 103a. Solid lubricant 103 is scraped off by fur brush 101, which rotates in the same direction as photoreceptor 3, and lubricant is applied to photoreceptor 3. By applying lubricant to the photoreceptor, the coefficient of friction of the surface of photoreceptor 3 is maintained at 0.2 or less when no image is being formed.

[0068] The charging device is a non-contact close-contact type in which the charging roller 4 is placed close to the photosensitive member 3, but known configurations such as a corotron, scorotron, or solid-state charger can be used as the charging device. Of these charging methods, the contact charging method or the non-contact close-contact type is particularly desirable, as it has advantages such as high charging efficiency, little ozone generation, and the ability to miniaturize the device. The light source for the laser light L of the optical writing unit 40 and the light source for the de-electrification lamp can be any light-emitting material such as a fluorescent lamp, a tungsten lamp, a halogen lamp, a mercury lamp, a sodium lamp, a light-emitting diode (LED), a semiconductor laser (LD), or an electroluminescent (EL). In order to irradiate only light in a desired wavelength range, various 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. Of these light sources, light emitting diodes and semiconductor lasers are preferably used because they have high irradiation energy and emit light with a long wavelength of 600 nm or more and 800 nm or less.

[0069] The transfer unit 60 shown in FIG. 4 includes the intermediate transfer belt 14, a belt cleaning unit 162, a first bracket 63, a second bracket 64, and the like. It also includes four primary transfer rollers 7Y, 7C, 7M, and 7K, a secondary transfer backup roller 66, a drive roller 67, an auxiliary roller 68, and a tension roller 69. The intermediate transfer belt 14 is stretched across these eight rollers and endlessly moves counterclockwise in FIG. 4 by the rotation of the drive roller 67. The four primary transfer rollers 7Y, 7C, 7M, and 7K sandwich the endlessly moving intermediate transfer belt 14 between themselves and the photoreceptors 3Y, 3C, 3M, and 3K, forming primary transfer nips. A transfer bias of the opposite polarity (e.g., positive) to that of the toner is applied to the back surface (inner peripheral surface of the loop) of the intermediate transfer belt 14. As the intermediate transfer belt 14 moves endlessly, it passes through the primary transfer nips for Y, C, M, and K in sequence, and the Y, C, M, and K toner images on the photoreceptors 3Y, 3C, 3M, and 3K are primarily transferred and superimposed onto the front surface of the intermediate transfer belt 14. As a result, a four-color superimposed toner image (hereinafter sometimes referred to as a four-color toner image) is formed on the intermediate transfer belt 14.

[0070] The secondary transfer backup roller 66 sandwiches the intermediate transfer belt 14 between itself and a secondary transfer roller 70 disposed outside the loop of the intermediate transfer belt 14, forming a secondary transfer nip. The registration roller pair 55 described above sends the recording medium P sandwiched between them toward the secondary transfer nip at a timing that synchronizes it with the four-color toner image on the intermediate transfer belt 14. The four-color toner image on the intermediate transfer belt 14 is collectively secondarily transferred to the recording medium P in the secondary transfer nip due to the influence of the secondary transfer electric field formed between the secondary transfer roller 70, to which a secondary transfer bias is applied, and the secondary transfer backup roller 66, and the nip pressure. This, combined with the white color of the recording medium P, forms a full-color toner image.

[0071] After passing through the secondary transfer nip, residual toner that has not been transferred to the recording medium P adheres to the intermediate transfer belt 14. This is cleaned by the belt cleaning unit 162. The belt cleaning unit 162 abuts against the front surface of the intermediate transfer belt 14, thereby scraping off and removing the residual toner on the intermediate transfer belt 14.

[0072] The first bracket 63 of the transfer unit 60 swings at a predetermined rotation angle around the rotation axis of the auxiliary roller 68 as the solenoid is turned on and off. When forming a monochrome image, the image forming apparatus 500 slightly rotates the first bracket 63 counterclockwise in FIG. 4 by driving the solenoid. This rotation causes the primary transfer rollers 7Y, 7C, and 7M for Y, C, and M to revolve counterclockwise in FIG. 4 around the rotation axis of the auxiliary roller 68, thereby separating the intermediate transfer belt 14 from the photoconductors 3Y, 3C, and 3M for Y, C, and M. Then, of the four imaging units 1Y, 1C, 1M, and 1K, only the imaging unit 1K for K is driven to form a monochrome image. This prevents wear on the components of the imaging unit 1 due to unnecessary driving of the imaging units 1 for Y, C, and M during monochrome image formation.

[0073] A fixing unit 80 is disposed above the secondary transfer nip in FIG. 4. This fixing unit 80 includes a pressure / heat roller 81 containing a heat source such as a halogen lamp, and a fixing belt unit 82. The fixing belt unit 82 includes a fixing member, a heating roller 83 containing a heat source such as a halogen lamp, a tension roller 85, a drive roller 86, a temperature sensor, and the like. The endless fixing belt 84 is stretched by the heating roller 83, the tension roller 85, and the drive roller 86 and moves counterclockwise in FIG. 5. During this endless movement, the fixing belt 84 is heated from the back side by the heating roller 83. The pressure / heat roller 81, which is driven to rotate clockwise in FIG. 4, contacts the front side of the heated fixing belt 84 at the location where it is wrapped around the heating roller 83. This forms a fixing nip where the pressure / heat roller 81 and the fixing belt 84 come into contact.

[0074] 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 therebetween, and detects the surface temperature of the fixing belt 84 immediately before it enters the fixing nip. The detection result is sent to a fixing power supply circuit. Based on the detection result from the temperature sensor, the fixing power supply circuit controls the on / off of power supply to the heat source contained in the heating roller 83 and the heat source contained in the pressure heating roller 81.

[0075] After passing through the secondary transfer nip, the recording medium P 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 bottom to the top in FIG. 4 while being sandwiched in the fixing nip inside the fixing unit 80, the recording medium P is heated and pressed by the fixing belt 84, whereby the full-color toner image is fixed onto the recording medium P.

[0076] The recording medium P that has been subjected to the fixing process in this way is discharged outside the apparatus after passing between the rollers of the discharge roller pair 87. A stack section 88 is formed on the top surface of the housing of the image forming apparatus 500 main body, and the recording medium P that has been discharged outside the apparatus by the discharge roller pair 87 is stacked in this stack section 88 in order.

[0077] Four toner cartridges 100Y, 100C, 100M, and 100K containing Y, C, M, and K toners are disposed above the transfer unit 60. The Y, C, M, and K toners in the toner cartridges 100Y, 100C, 100M, and 100K are supplied as needed to the developing devices 5Y, 5C, 5M, and 5K of the imaging units 1Y, 1C, 1M, and 1K. These toner cartridges 100Y, 100C, 100M, and 100K are detachable from the image forming apparatus main body independently of the imaging units 1Y, 1C, 1M, and 1K.

[0078] Next, the image forming operation in the image forming apparatus 500 will be described. First, when a print execution signal is received from an operation unit or the like, a predetermined voltage or current is applied sequentially and at a predetermined timing to the charging roller 4 and the developing roller 51. Similarly, a predetermined voltage or current is applied sequentially and at a predetermined timing to the optical writing unit 40 and the light source such as the static elimination lamp. In synchronization with this, the photoconductor 3 is rotated in the direction of the arrow in FIG. 5 by a photoconductor drive motor serving as a drive means. 4, the surface of the photoreceptor 3 is first uniformly charged to a predetermined potential by the charging roller 4. Then, laser light L corresponding to image information is irradiated onto the photoreceptor 3 from the optical writing unit 40, and the portion of the surface of the photoreceptor 3 irradiated with the laser light L is neutralized, forming an electrostatic latent image. The surface of the photoconductor 3 on which the electrostatic latent image is formed is rubbed by a magnetic brush of developer formed on the developing roller 51 at the portion facing the developing device 5. At this time, the negatively charged toner on the developing roller 51 moves toward the electrostatic latent image by a predetermined developing bias applied to the developing roller 51, and is turned into a toner image (developed). A similar image forming process is performed in each imaging unit 1, and toner images of each color are formed on the surfaces of the photoconductors 3Y, 3C, 3M, and 3K of the imaging units 1Y, 1C, 1M, and 1K. In this way, in the image forming apparatus 500, the electrostatic latent image formed on the photosensitive member 3 is reverse-developed with negatively charged toner by the developing device 5. In this embodiment, an example using an N / P (negative / positive: toner adheres to areas with low potential) non-contact charging roller method has been described, but the present invention is not limited to this.

[0079] The toner images of each color formed on the surface of each photoreceptor 3Y, 3C, 3M, and 3K are sequentially transferred (primary transfer) so as to be superimposed 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 transferred onto a recording medium P, which is fed from a first paper feed cassette 151 or a second paper feed cassette 152, passes between the rollers of a pair of registration rollers 55, and is fed to the secondary transfer nip. At this time, the recording medium P stops temporarily while sandwiched between the pair of registration rollers 55, and is then fed to the secondary transfer nip in synchronization with the leading edge of the image on the intermediate transfer belt 14. The recording medium P with the transferred toner image is separated from the intermediate transfer belt 14 and transported to a fixing unit 80. Then, as the recording medium P with the transferred toner image passes through the fixing unit 80, the toner image is fixed onto the recording medium P by the action of heat and pressure, and the recording medium P with the fixed toner image is ejected to the outside of the image forming apparatus 500 and stacked in a stacking unit 88.

[0080] On the other hand, the surface of the intermediate transfer belt 14 from which the toner image has been transferred onto the recording medium P at the secondary transfer nip is cleaned by a belt cleaning unit 162 to remove any residual toner remaining on the surface. In addition, the surface of the photosensitive member 3, from which the toner images of each color have been transferred to the intermediate transfer belt 14 at the primary transfer nip, has residual toner removed by a cleaning device 6, and is then coated with lubricant by a lubricant application device 10, after which it is de-electrified by a de-electrification lamp.

[0081] As shown in FIG. 5, the imaging unit 1 of the image forming apparatus 500 includes a photosensitive member 3 and process means such as a charging roller 4, a developing device 5, a cleaning device 6, and a lubricant applicator 10 housed in a frame 2. The imaging unit 1 is detachable as a process cartridge from the main body of the image forming apparatus 500. In the image forming apparatus 500, the photosensitive member 3 and process means are replaced as a process cartridge, but the imaging unit 1 may be configured so that each of the photosensitive member 3, charging roller 4, developing device 5, cleaning device 6, and lubricant applicator 10 can be replaced as a unit. The lubricant applicator need not be used. From the viewpoint of improving image quality, it is preferable to use polymerized toner produced by suspension polymerization, emulsion polymerization, or dispersion polymerization, which can easily achieve high circularity and small particle size, as the toner used in the image forming apparatus 500. Among these, it is preferable to use polymerized toner having a volume average particle size of 5.5 μm or less from the viewpoint of forming high-resolution images.

[0082] (Process cartridge) The process cartridge of the present invention comprises at least an image carrier and cleaning means for removing toner remaining on the image carrier, and may further comprise other means as required. The cleaning blade of the present invention is used as the cleaning means. The process cartridge is a device (component) that incorporates an image carrier and the cleaning blade of the present invention, and also includes at least one of a charging means, an exposure means, a developing means, a transfer means, a cleaning means, and a discharging means, and is detachably attached to an image forming apparatus. [Example]

[0083] Hereinafter, the present invention will be further described with reference to Examples and Comparative Examples, but the present invention is not limited to the following examples. Note that "parts" means parts by mass unless otherwise specified.

[0084] <Hysteresis loss rate> The hysteresis loss rate of the surface layer including the tip ridge line portion was measured from the integrated value of the stress at that time by cutting out the sample into a dumbbell No. 7 shape using a texture analyzer manufactured by Shimadzu Corporation in accordance with JIS K6400-2, stretching it 100% at a tensile speed of 200 mm / min, and relaxing it to 0% at the same speed.

[0085] <JIS-A hardness of the elastic member> The JIS-A hardness of the surface layer and the base layer was measured using a micro rubber hardness meter MD-! manufactured by Polymer Instruments Co., Ltd. in accordance with JIS K6253.

[0086] <tanδ peak temperature> The tanδ peak temperature of the surface layer was measured using DMS6100 manufactured by SII NanoTechnology Inc. in accordance with JIS K6394, using a strip-shaped sample, in a tensile mode, at a frequency of 10 Hz, and at a heating rate of 2°C / min.

[0087] <MSE wear amount> The MSE wear amount of the surface layer was measured using an MSE wear device manufactured by Palmesso Co., Ltd. A slurry liquid in which alumina particles having a particle size of 1 μm were dispersed in water at a weight concentration of 3% was projected onto the smooth portion of the rubber for a cleaning blade at a speed of 100 m / sec and a projection amount of 2 g / min at 100 g, and the wear depth was measured with a laser microscope (LEXT OLS4100 manufactured by Olympus Corporation).

[0088] <Martens hardness> The Martens hardness was measured using an ultra-micro hardness meter HM-2000 manufactured by Fischer Instruments so that a Vickers indenter hit a position 20 μm away from the tip ridge line portion of the surface layer, pushing it in with a force of 8 mN for 30 seconds, holding it for 5 seconds, and pulling it out with a force of 9.8 mN for 30 seconds.

[0089] <Average circularity of toner> The average circularity of the toner particles was measured using a flow particle image analyzer (FPIA-2000, manufactured by Sysmex Corporation). Specifically, 0.1 mL to 0.5 mL of a surfactant (alkylbenzene sulfonate) was added as a dispersant to 100 mL to 150 mL of water, from which impurities and solids had been removed, and approximately 0.1 g to 0.5 g of the measurement sample (toner) was then added. The toner suspension was then dispersed in an ultrasonic disperser for 1 to 3 minutes to adjust the dispersion concentration to 3,000 particles / μL to 10,000 particles / μL. This dispersion was then placed in the analyzer and the toner shape and distribution were measured. Based on the measurement results, the perimeter of the actual toner particle projected shape shown in Figure 6(A) was defined as C1, its projected area as S, and the perimeter of a perfect circle shown in Figure 6(B) with the same projected area as S was defined as C2. The average of these values, C2 / C1, was calculated and used as the average circularity.

[0090] <Volume average particle size of toner> The volume average particle size of the toner was determined using the Coulter Counter method. Specifically, the number distribution and volume distribution data of the toner measured using a Coulter Multisizer 2e (manufactured by Beckman Coulter, Inc.) were sent to a personal computer via an interface (manufactured by Nikkaki Bios Co., Ltd.) and analyzed. More specifically, a 1% by mass NaCl aqueous solution using primary sodium chloride was prepared as the electrolyte. 0.1 mL to 5 mL of a surfactant (alkylbenzene sulfonate) was added as a dispersant to 100 mL to 150 mL of this electrolyte solution. 2 mg to 20 mg of the toner sample was then added and dispersed for 1 to 3 minutes using an ultrasonic disperser. Then, 100 mL to 200 mL of the electrolyte solution was placed in a separate beaker, and the dispersed solution was added to the beaker to achieve a predetermined concentration, and the solution was then subjected to the Coulter Multisizer 2e. The aperture used is 100 μm, and the particle diameters of 50,000 toner particles are measured. Thirteen channels were used, with diameters ranging from 2.00 μm to less than 2.52 μm; from 2.52 μm to less than 3.17 μm; from 3.17 μm to less than 4.00 μm; from 4.00 μm to less than 5.04 μm; from 5.04 μm to less than 6.35 μm; from 6.35 μm to less than 8.00 μm; from 8.00 μm to less than 10.08 μm; from 10.08 μm to less than 12.70 μm; from 12.70 μm to less than 16.00 μm; from 16.00 μm to less than 20.20 μm; from 20.20 μm to less than 25.40 μm; from 25.40 μm to less than 32.00 μm; and from 32.00 μm to less than 40.30 μm, and the target was toner particles with a particle size of 2.00 μm to 32.0 μm. The volume average particle size was then calculated based on the formula "volume average particle size = ΣXfV / ΣfV", where "X" is the representative diameter in each channel, "V" is the equivalent volume at the representative diameter in each channel, and "f" is the number of particles in each channel.

[0091] Example 1 <Toner manufacturing example> Toner base particles with an average circularity of 0.98 and a volume average particle size of 4.9 μm were prepared by polymerization. 100 parts by mass of the obtained toner base particles were mixed with 1.5 parts by mass of small-sized silica fine particles (H2000 manufactured by Clariant K.K.), 0.5 parts by mass of small-sized titanium oxide fine particles (MT-150AI manufactured by Teika Corporation), and large-sized silica fine particles (UFP-30H manufactured by Denki Kagaku Kogyo Kabushiki Kaisha) using a Henschel mixer to prepare a toner.

[0092] <Cleaning blade manufacturing example> A urethane rubber (manufactured by Nitta Chemical Industrial Products Co., Ltd.) was prepared by centrifugal molding, with a surface layer of polyester-based urethane rubber adjusted to a hardness of 61° and a base layer of polyester-based urethane rubber adjusted to a hardness of 74° laminated in that order. This was then cut to the specified dimensions and assembled with a support member to prepare a cleaning blade. The surface layer was 0.5 mm thick, and the base layer was 1.5 mm thick. Rubber with the desired hysteresis loss rate was obtained by adjusting the formulation, such as the amount of isocyanate added, the type and compounding ratio of crosslinking agent, so as to simultaneously satisfy the hardness and tan δ peak temperature shown in the table.

[0093] <Cleaning blade evaluation> Next, the cleaning blade 1 thus prepared was attached to a color multifunction printer (RICOH IM C6000) with a predetermined tip penetration (linear pressure: 20 N / m) and attachment angle (approximately 79°). The toner was loaded into the color multifunction printer (RICOH IM C6000), and a chart (A4 size, landscape) with a vertical band and an image area ratio of 0.5% was printed 3 times per job, for a total of 100,000 sheets, under an environment of 23°C and 55% RH. After that, the cleaning ability, the wear depth of the leading edge ridge, the local wear of the leading edge ridge, and the MSE wear depth of the surface layer were evaluated as follows.

[0094] <Cleaning ability> After outputting the 100,000 sheets, 20 sheets of evaluation images (A4 size landscape) with a vertical band pattern 43 mm wide (in the paper running direction) and three charts were output, and the output images were visually observed and the cleaning ability was evaluated according to the following criteria: Abnormal images refer to images that appear as streaks or bands in the printed image, or images with white spots. [Evaluation criteria] ◎: No abnormal images ○: Slight abnormalities are observed, but there is no problem with the quality ×: Abnormal images present

[0095] <Wear depth of tip ridge, localized wear of tip ridge, MSE wear depth of surface layer> The shape of the edge of the cleaning blade was measured using a laser microscope (Olympus LEXT OLS4100). Local wear (chips, etc.) on the edge was also confirmed.

[0096] (Examples 2 to 15, Comparative Examples 1 to 7) The same as in Example 1, except that a cleaning blade made of a single layer of urethane rubber (manufactured by Nitta Chemical Industrial Products Co., Ltd.) or a laminated urethane rubber combination of a surface layer and a base layer with different formulations (both manufactured by Nitta Chemical Industrial Products Co., Ltd.) was used. The characteristic values ​​and evaluation results of each cleaning blade are shown in Tables 1-1 to 1-3 below.

[0097] The compounds indicated by the abbreviations in the table are as follows: MDI: 4,4'-diphenylmethane diisocyanate TDI: 2,4-tolylene diisocyanate

[0098] [Table 1-1]

[0099] [Table 1-2]

[0100] [Table 1-3]

[0101] The results in Table 1 show that the cleaning blades of the examples have a hysteresis loss rate of 15% or less in the surface layer including the tip ridge, and therefore have superior cleaning performance and wear resistance compared to the comparative examples which do not meet this requirement. These results suggest that the cleaning blade of the present invention is prevented from turning over when it comes into contact with the photosensitive member, from passing through powder particles, and from adhering to the photosensitive member, and can be used for a long period of time.

[0102] The present invention relates to the cleaning blade of (1) below, but also includes the following (2) to (8) as embodiments. (1) A cleaning blade having a rectangular elastic blade and a support member for supporting the elastic blade, the blade abutting the leading edge of the elastic blade against a moving member to be cleaned to remove residue from the surface of the member, A cleaning blade characterized in that at least a surface layer portion of the elastic blade, including the tip ridge line portion, is made of rubber having a hysteresis loss rate of 15% or less. (2) The cleaning blade according to (1) above, wherein the surface layer portion including the edge portion that comes into contact with the member to be cleaned is made of rubber having a tan δ peak temperature of 2° C. or less. (3) The cleaning blade according to (1) or (2) above, wherein the surface layer portion including the edge portion that comes into contact with the member to be cleaned is made of rubber having an MSE abrasion amount of 15 μm or less. (4) A cleaning blade according to any one of (1) to (3) above, characterized in that the surface portion including the tip ridge portion that contacts the member to be cleaned is made of rubber having a JIS-A hardness of 50° or more and 65° or less. (5) The cleaning blade according to any one of (1) to (4) above, wherein the cleaning blade is a laminate made of a plurality of rubber layers having different JIS-A hardnesses. (6) The surface layer portion including the tip ridge portion that contacts the cleaning member has a Martens hardness of 0.45 N / mm 2 More than 0.75N / mm 2 The cleaning blade according to any one of (1) to (5) above, which is made of the following rubber: (7) An image forming apparatus having an image carrier, a charging means for charging the surface of the image carrier, an exposure means for exposing the charged image carrier to light to form an electrostatic latent image, a developing means for developing the electrostatic latent image with toner to form a visible image, a transfer means for transferring the visible image to a recording medium, a fixing means for fixing the transferred image on the recording medium, and a cleaning means for removing toner remaining on the image carrier, An image forming apparatus, wherein the cleaning means is the cleaning blade described in any one of (1) to (6) above. (8) A process cartridge having at least an image carrier and a cleaning means for removing toner remaining on the image carrier, characterized in that the cleaning means is a cleaning blade described in any one of (1) to (6) above. [Explanation of symbols]

[0103] 1, 1Y, 1C, 1M, 1K Imaging unit 2 frame 3,3Y,3C,3M,3K photoreceptor 4 Charging roller 5,5Y,5C,5M,5K developing device 6 Cleaning Device 7,7Y,7C,7M,7K Primary transfer roller 10 Lubricant application device 14 Intermediate transfer belt 40 Optical writing unit 41 Polygon Mirror 51 Developing roller 52 Supply screw 53 Mixing screw 54 Doctor 55 Registration roller pair 60 Transcription Unit 62 Cleaning blade 62a Tip surface 62b Cleaning blade surface 62c Tip ridge 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 Fuser unit 81 Pressure and heating roller 82 Fusing belt unit 83 Pressure roller 84 Fixing belt 85 Tension roller 86 Drive roller 87 Paper ejection roller pair 88 Stack Section 100Y, 100C, 100M, 100K toner cartridges 101 Fur Brush 103 Solid Lubricants 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 device 621 Support member 622 Elastic blade (single layer) 6221 Surface layer (lamination) including tip ridge 6222 Base layer (laminate) L laser light P Recording medium X Wear [Prior art documents] [Patent documents]

[0104] [Patent Document 1] Japanese Patent Application Laid-Open No. 2008-268649 [Patent Document 2] Japanese Patent Application Laid-Open No. 2014-85595

Claims

1. A cleaning blade having a rectangular elastic blade and a support member for supporting the elastic blade, the cleaning blade removing residue from a surface of a moving member to be cleaned by bringing a ridge portion of the elastic blade into contact with the moving member, At least a surface layer portion of the elastic blade, including the tip ridge line portion, is made of rubber having a hysteresis loss rate of 15% or less, A cleaning blade characterized in that a surface layer portion including the edge portion that comes into contact with the member to be cleaned is made of rubber having a tan δ peak temperature of 2°C or less.

2. A cleaning blade having a rectangular elastic blade and a support member for supporting said elastic blade, said cleaning blade removing residue from the surface of a moving member to be cleaned by bringing a tip edge of said elastic blade into contact with said member, At least a surface layer portion of the elastic blade, including the tip ridge line portion, is made of rubber having a hysteresis loss rate of 15% or less, a surface layer portion including the edge portion that contacts the cleaning member, the surface layer portion being made of rubber with an MSE abrasion amount of 15 μm or less;

3. A cleaning blade having a rectangular elastic blade and a support member for supporting said elastic blade, said cleaning blade removing residue from the surface of a moving object to be cleaned by bringing a tip edge of said elastic blade into contact with said object, At least a surface layer portion of the elastic blade, including the tip ridge line portion, is made of rubber having a hysteresis loss rate of 15% or less, A cleaning blade characterized in that a surface layer portion including the edge portion that comes into contact with the member to be cleaned is made of rubber having a JIS-A hardness of 50° or more and 65° or less.

4. 4. The cleaning blade according to claim 1, wherein the cleaning blade is a laminate made up of a plurality of rubber layers having different JIS-A hardnesses.

5. A cleaning blade having a rectangular elastic blade and a support member for supporting said elastic blade, said cleaning blade removing residue from the surface of a moving member to be cleaned by bringing a tip edge of said elastic blade into contact with said member, At least a surface layer portion of the elastic blade, including the tip ridge line portion, is made of rubber having a hysteresis loss rate of 15% or less, The surface layer portion including the tip ridge line portion that comes into contact with the cleaning member has a Martens hardness of 0.45 N / mm ２ 0.75N / mm or more ２ A cleaning blade characterized by being made of the following rubber:

6. An image forming apparatus comprising: an image carrier; a charging unit for charging the surface of the image carrier; an exposure unit for exposing the charged image carrier to light to form an electrostatic latent image; a developing unit for developing the electrostatic latent image with toner to form a visible image; a transfer unit for transferring the visible image to a recording medium; a fixing unit for fixing the transferred image on the recording medium; and a cleaning unit for removing toner remaining on the image carrier, 6. An image forming apparatus, wherein the cleaning means is the cleaning blade according to claim 1.

7. 6. A process cartridge comprising at least an image carrier and a cleaning means for removing toner remaining on the image carrier, wherein the cleaning means is a cleaning blade according to claim 1.

Images