Cleaning blade, method for manufacturing a cleaning blade, and electrophotographic apparatus

Abstract

The present invention provides a cleaning blade, a method for manufacturing a cleaning blade, and an electrophotographic apparatus that can effectively suppress temperature rise caused by frictional heat between the cleaning blade and the object to be cleaned over a long period of time. [Solution] A cleaning blade having a blade-shaped elastic member and a support member, wherein one end of the elastic member contains polyurethane and graphene, the other end of the elastic member is supported by the support member, and the carbon atom ratio in the graphene is 75 atomic percent or more.

Description

Technical Field

[0001] The present disclosure relates to a cleaning blade, a method for manufacturing the cleaning blade, and an electrophotographic apparatus having the cleaning blade.

Background Art

[0002] Generally, in an electrophotographic process, a cycle consisting of steps of charging, exposing, developing, transferring, and cleaning residual toner on a photoreceptor is repeatedly performed. As a method for cleaning the residual toner, a method of bringing an elastic member into contact with the surface of the photoreceptor is common. In particular, since polyurethane has excellent mechanical strength such as wear resistance, a cleaning blade using polyurethane as an elastic member is preferably used. In a cleaning method using such a cleaning blade, in order to sufficiently clean, it is necessary to press the cleaning blade against the photoreceptor with a large pressure. As a result, the frictional resistance increases, the blade portion of the cleaning blade is turned up, abnormal noise due to chattering occurs, and a temperature rise due to frictional heat between the cleaning object and the cleaning blade is likely to occur. In particular, when the temperature rise due to frictional heat is large, problems such as toner melting between the cleaning blade and the photoreceptor and adhering to the surface of the photoreceptor, and a part of the paper powder component melting between the cleaning blade and the transfer member and adhering to the periphery of the blade tip occur, which may cause cleaning failure where a white-out image is output. In order to effectively suppress the temperature rise due to frictional heat, for example, a method of increasing the thermal conductivity of the cleaning blade can be considered. For example, in Patent Document 1, a cleaning blade containing carbon nanotubes having a high thermal conductivity in a portion contacting the member to be cleaned is disclosed.

Prior Art Documents

Patent Documents

[0003]

Patent Document 1

[0004] Our inventors' investigations revealed that when a cleaning blade containing carbon nanotubes in the portion that contacts the material being cleaned is used, it is presumed that the temperature rise caused by frictional heat is effectively suppressed immediately after the start of use, and that the occurrence of overexposed images is less likely to occur. However, it is presumed that when used in an electrophotographic device for a long period of time, the temperature rise suppression effect gradually decreases, and as a result, overexposed images tend to occur. [Means for solving the problem]

[0005] This disclosure provides means to solve the above-mentioned problems. One aspect of this disclosure relates to the provision of a cleaning blade that can suppress the occurrence of whiteout images over a long period of time. Furthermore, this disclosure aims to provide a method for manufacturing the cleaning blade. Furthermore, other aspects of this disclosure are toward providing an electrophotographic apparatus having a cleaning blade relating to this disclosure.

[0006] According to one aspect of the present disclosure, a cleaning blade is provided having a blade-shaped elastic member and a support member, characterized in that one end of the elastic member contains polyurethane and graphene, and the other end of the elastic member is supported by the support member. Furthermore, according to one aspect of this disclosure, a method for manufacturing a cleaning blade relating to this disclosure is provided. Furthermore, according to other aspects of the present disclosure, an electrophotographic apparatus is provided, characterized by having a cleaning blade according to the present disclosure. [Effects of the Invention]

[0007] According to this disclosure, it is possible to provide a cleaning blade, a method for manufacturing a cleaning blade, and an electrophotographic apparatus that can suppress the occurrence of whiteout images and chipping of blade edges over a long period of time. [Brief explanation of the drawing]

[0008] [Figure 1] This is a cross-sectional view showing an example of a blade member composed of a single layer relating to this disclosure. [Figure 2(a)] This is a cross-sectional view showing an example of a blade member composed of two layers according to this disclosure. [Figure 2(b)] This is a cross-sectional view showing an example of a blade member composed of two layers according to this disclosure. [Figure 2(c)] This is a cross-sectional view showing an example of a blade member composed of two layers according to this disclosure. [Figure 2(d)] This is a cross-sectional view showing an example of a blade member composed of two layers according to this disclosure. [Figure 3] This is an explanatory diagram illustrating an example of the schematic configuration of the electrophotographic apparatus related to this disclosure. [Modes for carrying out the invention]

[0009] A cleaning blade according to an embodiment of the present disclosure is a cleaning blade having a blade-shaped elastic member and a support member, characterized in that one end of the elastic member contains polyurethane and graphene, and the other end of the elastic member is supported by the support member. In the present disclosure, graphene means a planar (two-dimensional structure) material mainly in which carbon atoms are bonded in a hexagonal shape, and is different from, for example, a tubular material such as carbon nanotubes.

[0010] The inventors speculate that the cause of the above problem is as follows: When a cleaning blade containing carbon nanotubes is used in an electrophotographic device for a long period of time, it is continuously exposed to the ozone atmosphere generated by the discharge phenomenon in the electrophotographic device. As a result, the carbon nanotubes undergo oxidative degradation due to the ozone, which reduces the thermal conductivity of the carbon nanotubes. This makes it easier for the temperature to rise due to frictional heat between the cleaning blade and the object being cleaned, leading to the occurrence of white areas in the image.

[0011] As a result of diligent research by the inventors, it was found that the graphene according to this disclosure not only exhibits high thermal conductivity, but also undergoes slower oxidative degradation by ozone compared to carbon nanotubes, making it easier to maintain high thermal conductivity over a long period of time. The inventors speculate that the reason for this is that the planar structure formed by sp2 carbon in graphene is energetically more stable than the curved structure formed by sp2 carbon in carbon nanotubes, thus making it less susceptible to oxidative degradation by ozone. Therefore, in this disclosure, it is hypothesized that by using graphene, it is possible to effectively suppress the temperature rise caused by frictional heat between the cleaning blade and the object being cleaned over a long period of time with excellent thermal conductivity, thereby suppressing the occurrence of whiteout images.

[0012] <Cleaning Blade> A cleaning blade according to an embodiment of this disclosure is described in detail below.

[0013] (Cleaning blade configuration) As shown in Figures 1 and 2(a) to 2(d), the cleaning blade of this disclosure is used with an elastic member 12 supported by a rigid plate-shaped support member 11 made of metal or the like. The elastic member 12 may be, for example, an elastic member 12 composed of a single layer as shown in FIG. 1, or an elastic member 12 composed of two layers as shown in FIGS. 2(a) to 2(d). In the case of the configuration shown in FIG. 1, the elastic member 12 contains polyurethane and graphene. In the case of the configuration shown in FIGS. 2(a) to 2(d), at least the surface layers 14A to 14D contain polyurethane and graphene, and together with the polyurethane layer 13, it is the elastic member 12. In the cleaning blade of the present disclosure, the contact portion that contacts the member to be cleaned is the elastic member 12 in the case of the configuration shown in FIG. 1, and the surface layers 14A to 14D in the case of the configuration shown in FIGS. 2(a) to 2(d). In terms of being able to achieve both high-level elastic properties and thermal conductivity properties of the elastic member, an elastic member composed of two layers as shown in FIGS. 2(a) to 2(d) is preferable.

[0014] Hereinafter, the elastic member composed of two layers as shown in FIGS. 2(a) to 2(d) will be described in detail.

[0015] (Constituent materials of the elastic member) - Polyurethane layer - The polyurethane layer contains polyurethane obtained by at least polymerizing a polyol compound and a polyisocyanate compound. The polyurethane may contain, if necessary, polyurethane obtained by polymerizing a resin having a functional group capable of reacting with the isocyanate group of the polyisocyanate compound in addition to the polyol compound.

[0016] The polyol compound is preferably a polyol having a number average molecular weight of 500 or more. Examples of the polyol compound include well-known polyols such as polyester polyol obtained by dehydration condensation of a low molecular weight polyol and a dibasic acid, polycarbonate polyol obtained by reaction of a low molecular weight polyol and an alkyl carbonate, polycaprolactone polyol, and polyether polyol. Commercially available products of polyols include, for example, Placcel 205 and Placcel 24 manufactured by Daicel Corporation. These polyols may be used alone or in combination of two or more.

[0017] Polyols with a number average molecular weight of less than 500 may also be used as materials that function as chain length extenders and crosslinking agents. Examples of low molecular weight polyol compounds include 1,3-propanediol, 1,4-butanediol, 1,5-pentanediol, 1,6-hexanediol, 1,7-heptanediol, 1,8-octanediol, 1,9-nonanediol, 1,10-decanediol, 1,11-undecanediol, 1,12-dodecanediol, 1,13-tridecanediol, 1,14-tetradecanediol, 1,18-octadecanediol, and 1,20-eicosanediol. Among these, 1,4-butanediol is preferably used as the low molecular weight polyol compound. Other examples include diols (bifunctional), triols (trifunctional), or tetraols (tetrafunctional).

[0018] Examples of polyisocyanate compounds include 4,4'-diphenylmethane diisocyanate (MDI), 2,6-toluene diisocyanate (TDI), 1,6-hexane diisocyanate (HDI), 1,5-naphthalene diisocyanate (NDI), and 3,3'-dimethylbiphenyl-4,4'-diisocyanate (TODI). 4,4'-diphenylmethane diisocyanate (MDI), 1,5-naphthalene diisocyanate (NDI), and hexamethylene diisocyanate (HDI) are more preferred. These polyisocyanate compounds may be used individually or in combination of two or more.

[0019] Resins having functional groups that can react with isocyanate groups (hereinafter referred to as "functional group-containing resins") are preferably flexible, and more preferably are aliphatic resins with a linear structure from the viewpoint of flexibility. Specific examples of functional group-containing resins include acrylic resins containing two or more hydroxyl groups, polybutadiene resins containing two or more hydroxyl groups, and epoxy resins containing two or more epoxy groups. Examples of commercially available acrylic resins containing two or more hydroxyl groups include Actflow (grades: UMB-2005B, UMB-2005P, UMB-2005, UME-2005, etc.) manufactured by Soken Chemical Co., Ltd. Examples of commercially available polybutadiene resins containing two or more hydroxyl groups include R-45HT, manufactured by Idemitsu Kosan Co., Ltd. Epoxy resins having two or more epoxy groups are preferably flexible and tough. In terms of molecular structure, such epoxy resins are preferably those having a structure in their main chain that allows for high main chain mobility (flexible skeleton). Examples of flexible skeletons include alkylene skeletons, cycloalkane skeletons, and polyoxyalkylene skeletons, with polyoxyalkylene skeletons being particularly preferred.

[0020] Furthermore, in terms of physical properties, epoxy resins with a lower viscosity relative to their molecular weight are preferred compared to conventional epoxy resins. Specifically, it is desirable that the weight-average molecular weight is within the range of 900 ± 100 and the viscosity at 25°C is within the range of 15000 ± 5000 mPa·s, and more preferably within the range of 15000 ± 3000 mPa·s. Examples of commercially available epoxy resins having these characteristics include DIC's EPLICONEXA-4850-150.

[0021] -Surface layer- The polyurethane used for the surface layer can be the same type of polyurethane used for the polyurethane layer described above. The graphene used for the surface layer can be any known type. In terms of excellent thermal conductivity, graphene with a carbon atom ratio of 75 atomic% or more, and more preferably graphene with a carbon atom ratio of 95 atomic% or more, is preferred. Furthermore, the carbon atom ratio of carbon materials, including graphene, was measured using an X-ray photoelectron spectrometer, the PHI5000 VersaProbe II, manufactured by ULVAC-PHI. Using the measured carbon atom ratio and oxygen atom ratio, the ratio of the measured carbon atom ratio to the sum of the measured carbon atom ratio and oxygen atom ratio was expressed as the carbon atom ratio of the sample in atomic percent. In order to achieve a high level of both elastic properties and thermal conductivity in the elastic member, it is preferable that the graphene in the surface layer be contained in an amount of 5% to 30% by mass relative to the total solid content of the surface layer.

[0022] (Manufacturing of elastic components) -Manufacturing of polyurethane layer- The polyurethane layer can be manufactured using common polyurethane manufacturing methods such as the prepolymer method or the one-shot method. The polyurethane layer can be formed by creating a sheet from a polyurethane layer-forming composition using, for example, centrifugal molding or extrusion molding, and then cutting or otherwise processing it.

[0023] Examples of catalysts used in the production of polyurethane layers include amine compounds such as tertiary amines, quaternary ammonium salts, and organometallic compounds such as organotin compounds. Examples of the above-mentioned tertiary amines include trialkylamines such as triethylamine, tetraalkyldiamines such as N,N,N',N'-tetramethyl-1,3-butanediamine, amino alcohols such as dimethylethanolamine, ethoxylated amines, ethoxylated diamines, esteramines such as bis(diethylethanolamine)adipate, cyclohexylamine derivatives such as triethylenediamine (TEDA) and N,N-dimethylcyclohexylamine, morpholine derivatives such as N-methylmorpholine and N-(2-hydroxypropyl)-dimethylmorpholine, and piperazine derivatives such as N,N'-diethyl-2-methylpiperazine and N,N'-bis-(2-hydroxypropyl)-2-methylpiperazine. Examples of quaternary ammonium salts include 2-hydroxypropyltrimethylammonium octylate, 1,5-diazabicyclo[4.3.0]nonene-5(DBN)octylate, 1,8-diazabicyclo[5.4.0]undecene-7(DBU)octylate, DBU oleate, DBU-p-toluenesulfonate, DBU formate, and 2-hydroxypropyltrimethylammonium formate. Examples of organotin compounds include dialkyltin compounds such as dibutyltin dilaurate and dibutyltin di(2-ethylhexoate), as well as stannous 2-ethylcaproate and stannous oleate.

[0024] Among these catalysts, triethylenediamine (TEDA), a tertiary ammonium salt, is preferred for its hydrolysis resistance, while quaternary ammonium salts are preferred for their processability. Among quaternary ammonium salts, 1,5-diazabicyclo[4.3.0]nonene-5(DBN)·octylate, 1,8-diazabicyclo[5.4.0]undecene-7(DBU)-octylate, and DBU-formate are preferred due to their high reaction activity.

[0025] The catalyst content is preferably in the range of 0.0005% by mass or more and 0.03% by mass or less of the total polyurethane layer constituting the elastic member. These can be used alone or in combination of two or more.

[0026] - Surface layer manufacturing - The surface layer according to this disclosure can be formed by impregnating the surface of a polyurethane layer with a surface layer coating liquid. The surface layer coating liquid may contain polyurethane and graphene, or it may contain an isocyanate compound and graphene. When using a surface layer coating liquid containing an isocyanate compound and graphene, polyurethane can be formed between the polyol on the surface of the polyurethane layer and the isocyanate in the surface layer coating liquid. It is preferable that the surface layer coating liquid contains an isocyanate compound, a polyol compound, and graphene.

[0027] <Electrophotographic device> Next, an electrophotographic apparatus using a cleaning blade according to an embodiment of this disclosure will be described. Figure 3 is an explanatory diagram illustrating an example of a schematic configuration of an electrophotographic apparatus. As shown in Figure 3, the electrophotographic apparatus 100 is a tandem-type intermediate transfer full-color printer in which yellow, magenta, cyan, and black image forming units 109Y, 109M, 109C, and 109Bk are arranged along an intermediate transfer belt (ITB) 101. In image forming unit 109Y, a yellow toner image is formed on the electrophotographic photoreceptor and transferred to the intermediate transfer belt 101. In image forming unit 109M, a magenta toner image is formed using the same procedure as in image forming unit 109Y and transferred over the yellow toner image on the intermediate transfer belt 101. In image forming units 109C and 109Bk, a cyan toner image and a black toner image are formed using the same procedure as in image forming unit 109Y and transferred sequentially over the intermediate transfer belt 101. The four-color toner images supported on the intermediate transfer belt 101 are transported to the secondary transfer section T2 and transferred to the recording material P in one go. The recording material P, onto which the four-color toner images have been transferred, is separated from the intermediate transfer belt 101 by curvature and fed to the fixing device 112. The fixing device 112 heats and pressurizes the recording material P using fixing rollers 112a and pressure rollers 112b to melt the toner and fix the image to the surface. After that, the recording material P is discharged from the machine.

[0028] The image forming units 109Y, 109M, 109C, and 109Bk are substantially identical in configuration, except for the different toner colors used in their respective developing units: yellow, magenta, cyan, and black. Below, the toner image formation process for the black image forming unit 109Bk will be described, and redundant explanations regarding the other image forming units 109Y, 109M, and 109C will be omitted. Also, the symbols Y, M, C, and Bk representing the toner colors yellow, magenta, cyan, and black will be omitted as appropriate. The image forming unit 109Bk has a charging roller 104, an exposure device 105, a developing device 106, a primary transfer roller 107, and a cleaning blade 108 for the electrophotographic photoreceptor arranged around the electrophotographic photoreceptor 103. The electrophotographic photoreceptor 103 has a photosensitive layer with a negative charge polarity formed on the surface of an aluminum tube and is driven in the direction of the arrow by a motor (not shown). The charging roller 104 is subjected to an oscillating voltage, which is a negative polarity DC voltage superimposed with an AC voltage, to negatively charge the surface of the electrophotographic photoreceptor 103. The exposure device 105 scans a laser beam, which is ON-OFF modulated with scan line image data obtained by unfolding a black separated color image, using a rotating mirror to write an electrostatic image of the image onto the surface of the electrophotographic photoreceptor 103. The developing device 106 uses a stirring member to triboelectrically charge a two-component developer containing a non-magnetic toner with negative charge polarity and a magnetic carrier. The developer is transported by a transport member and carried on a developing sleeve. The developer carried on the developing sleeve is then transported to the part facing the electrophotographic photoreceptor 103 after its thickness is restricted by a regulating blade. The developing sleeve is held at a predetermined distance from the electrophotographic photoreceptor 103. By applying an oscillating voltage, which is a negative DC voltage superimposed with an AC voltage, to the developing sleeve, the negatively charged toner is transferred to the exposed area of ​​the electrophotographic photoreceptor 103, which has become relatively positive, and the electrostatic image is reversed and developed.

[0029] In this embodiment, a known toner can be used, which is a binder resin to which a coloring agent, a charge control agent, etc., has been added. Furthermore, a toner with a volume-average particle size of 4 μm to 15 μm can be preferably used. The primary transfer roller 107 forms a primary transfer section T1 between the electrophotographic photoreceptor 103 and the intermediate transfer belt 101. By applying a positive DC voltage to the primary transfer roller 107, the toner image supported on the electrophotographic photoreceptor 103 is primary transferred to the intermediate transfer belt 101. The cleaning blade 108 for the electrophotographic photoreceptor contacts the electrophotographic photoreceptor 103 in the direction opposite to its driving direction to collect any remaining toner transfer from the electrophotographic photoreceptor 103. The cleaning blade 108 for the electrophotographic photoreceptor is composed of a blade-shaped elastic member and a support member. The contact edge of the elastic member of the cleaning blade 108 contacts the electrophotographic photoreceptor 103. The secondary transfer roller 111 contacts the outer surface of the intermediate transfer belt 101 between the image forming unit 109Bk and the cleaning blade 102 for the intermediate transfer body in the toner image transport direction. The secondary transfer roller 111 contacts the intermediate transfer belt 101, whose inner surface is supported by the opposing roller (drive roller) 110, to form the secondary transfer section T2. ​​By applying a positive DC voltage to the secondary transfer roller 111, the full-color toner image carried on the intermediate transfer belt 101 is secondary transferred to the recording material P.

[0030] The cleaning blade 102 for the intermediate transfer body contacts the tension roller 115 in the direction opposite to the drive direction of the intermediate transfer belt 101, and collects the remaining toner on the intermediate transfer belt 101. The cleaning blade 102 for the intermediate transfer body is composed of a blade-shaped elastic member and a support member. The contact edge of the elastic member of the cleaning blade 102 for the intermediate transfer body is in contact with the intermediate transfer body. The heating element 116 is positioned near the contact point between the intermediate transfer belt 101 and the cleaning blade 102 for the intermediate transfer body, and heats the area near the contact point between the intermediate transfer belt 101 and the cleaning blade 102 for the intermediate transfer body. As the heating element 116, contact heating or non-contact heating methods such as ceramic heaters, halogen lamps, and lasers can be used. Furthermore, the position of the heating element 116 is not limited to the configuration shown in Figure 3, as long as it can heat the area near the contact point between the intermediate transfer belt 101 and the cleaning blade 102 for the intermediate transfer body. The intermediate transfer belt 101 is a belt member that is driven to transport in the direction of arrow R, and is tensioned by a drive roller 110, which is a drive member, tension rollers 113 and 114, which are tension members, and a tension roller 115 that applies a predetermined tension to the intermediate transfer belt 101. The drive roller 110 also functions as a secondary transfer roller located in the secondary transfer section T2. ​​However, the number of rollers that tension the intermediate transfer belt 101 is not limited to the configuration shown in Figure 3. [Examples]

[0031] The following describes embodiments of this disclosure, but this disclosure is not limited to these embodiments. In the following description, unless otherwise specified, all "parts" are based on mass.

[0032] <Fabrication of electrophotographic photoreceptors> Zinc oxide: (Average particle size 70 nm, specific surface area value 15 m²) 2 100 parts of (Teika Co., Ltd.) were mixed with 500 parts of tetrahydrofuran by stirring, and 1.3 parts of silane coupling agent (KBM503: Shin-Etsu Chemical Co., Ltd.) were added and stirred for 2 hours. Toluene was then removed by vacuum distillation, and the mixture was baked at 120°C for 3 hours to obtain zinc oxide surface-treated with silane coupling agent. 110 parts of surface-treated zinc oxide were mixed with 500 parts of tetrahydrofuran by stirring, and a solution of 0.6 parts of alizarin dissolved in 50 parts of tetrahydrofuran was added. The mixture was stirred at 50°C for 5 hours. After that, the zinc oxide with alizarin was filtered off by vacuum filtration, and then dried under reduced pressure at 60°C to obtain alizarin-treated zinc oxide. A mixture was obtained by mixing 60 parts of alizarin-containing zinc oxide, 13.5 parts of a hardening agent (blocked isocyanate Sumijule 3175, manufactured by Sumitomo Bayer Urethane Co., Ltd.), 15 parts of butyral resin (Eslec BM-1, manufactured by Sekisui Chemical Co., Ltd.), and 85 parts of methyl ethyl ketone. 38 parts of this mixture were mixed with 25 parts of methyl ethyl ketone, and the mixture was dispersed for 2 hours using a sand mill with 1 mm diameter glass beads to obtain a dispersion. To the obtained dispersion, 0.005 parts of dioctyltin dilaurate and 45 parts of silicone resin particles (Tospar 145, manufactured by Montive Performance Materials Japan LLC) were added to obtain a coating solution for the undercoat. This coating solution was applied to a cylindrical aluminum substrate by immersion coating, and dried and cured at 170°C for 30 minutes to obtain an undercoat with a thickness of 22 μm.

[0033] Next, a coating solution for the charge generation layer was prepared by mixing 1 part of hydroxygallium phthalocyanine, which has strong diffraction peaks at Bragg angles (2θ±0.2°) of 7.5°, 9.9°, 12.5°, 16.3°, 18.6°, 25.1°, and 28.3° in its X-ray diffraction spectrum, with 1 part of polyvinyl butyral (Eslec BM-S, manufactured by Sekisui Chemical Co., Ltd.) and 80 parts of n-butyl acetate. This mixture was then dispersed with glass beads in a paint shaker for 1 hour. The resulting coating solution was then immersed on a conductive support with a base layer and heated and dried at 100°C for 10 minutes to form a charge generation layer with a thickness of 0.15 μm.

[0034] A coating solution for the charge transport layer was prepared by dissolving 15 parts of a compound represented by the following formula (CTM1) and 30 parts of a compound represented by the following formula (CTM2) as charge transport materials, and 25 parts of a polymer compound having repeating units represented by the following formula (PCZ1) (viscosity-average molecular weight: 40,000) and 30 parts of a polymer compound having repeating units represented by the following formula (PCZ2) (pm:pn=0.2:0.8, viscosity-average molecular weight = 55,000) as binder resins in 350 parts of toluene and 150 parts of tetrahydrofuran. The obtained coating solution was applied to the above charge generating layer by immersion coating, and heated at 130°C for 45 minutes to form a charge transport layer with a thickness of 13 μm. An electrophotographic photoreceptor was fabricated through the above process. [ka] [ka] [ka] [ka]

[0035] <Fabrication of the intermediate transfer belt> The intermediate transfer belt was manufactured using the following method. The base layer has a thickness of 60 μm and a volume resistivity ρv = 5 × 10⁻⁶. 9 (Ω cm), surface resistivity ρs=1×10 10 The outer surface of a cylindrical film made of polyimide resin containing an electronically conductive material of (Ω / □) was polished using an abrasive film (KOVAX Rapika WA#800) and a HORIBA IG-320 gloss meter to a score of 60 to obtain the base layer. The coating solution for surface formation is as follows. Dipentaerythritol hexaacrylate 31.0 parts by mass Pentaerythritol triacrylate 4.0 parts by mass Pentaerythritol tetraacrylate 11.0 parts by mass Methyl ethyl ketone 40 parts by mass Antimond-doped tin oxide nanoparticles (N-100P, manufactured by Ishihara Sangyo Co., Ltd.) 7.0 parts by mass Photopolymerization initiator (Omnirad 184 manufactured by IGM resin) 5.0 parts by mass The above composition was mixed and dispersed in a stirring homogenizer, and then dispersed using a dispersion device, Nanomizer (manufactured by Yoshida Machinery Industry Co., Ltd.), to obtain a coating solution for surface layer formation. The above coating solution was applied to a base layer made of polished polyimide resin using a ring coating method, and then placed in a 60°C drying oven for 2 minutes. After that, it was cured with ultraviolet light at 1500 mJ / cm to obtain an intermediate transfer belt with a surface film thickness of 5 μm.

[0036] <Creating a cleaning blade> (Example: Cleaning blade (1)) Polycaprolactone polyol (Daicel Chemical Industries, Ltd., Praxel 205) and polycaprolactone polyol (Daicel Chemical Industries, Ltd., Praxel 240) were used as hard segment materials for the polyol compound. In addition, an acrylic resin containing two or more hydroxyl groups (Sokken Chemical Co., Ltd., Actflow UMB-2005B) was used as a soft segment material, and the hard segment material and the soft segment material were mixed in a ratio of 8:2 (mass ratio). Next, 4,4'-diphenylmethane diisocyanate (Nippon Polyurethane Industries, Ltd., Myrionate MT) was added as an isocyanate compound to 100 parts of this mixture of hard segment material and soft segment material, and the mixture was reacted at 70°C for 3 hours under a nitrogen atmosphere. Subsequently, the above isocyanate compound was further added, and the mixture was reacted at 70°C for 3 hours under a nitrogen atmosphere to obtain a prepolymer. Next, this prepolymer was heated to 100°C and degassed under reduced pressure for 1 hour. Subsequently, a mixture of 1,4-butanediol and trimethylolpropane was added to the prepolymer and mixed for 3 minutes without introducing air bubbles to prepare a polyurethane layer-forming composition. Then, the polyurethane layer-forming composition was poured into a prepared centrifugal molding machine and cured. Next, 85 parts of 4,4'-diphenylmethane diisocyanate (manufactured by Nippon Polyurethane Industries Co., Ltd., Myrionate MT) and 15 parts of graphene (carbon content 95 atomic%) were added, mixed while heated to 45°C, and dispersed for 3 hours using a sand mill with 1 mmφ glass beads to prepare a surface layer coating solution. The polyurethane layer obtained above was immersed in the surface layer coating solution at 80°C for 5 minutes, then removed, aged by heating, and then dried at room temperature to form a surface layer with a thickness of 10 μm, thereby obtaining an elastic member. The elastic member was cut and bonded to a support member to create the Example Cleaning Blade (1), which was used as a cleaning blade for an electrophotographic photoreceptor and a cleaning blade for an intermediate transfer body.

[0037] (Example: Cleaning blade (2)) In the preparation of Example Cleaning Blade (1), Example Cleaning Blade (2) was prepared in the same manner as Example Cleaning Blade (1), except that the surface layer coating solution was prepared by changing 95 parts of 4,4'-diphenylmethane diisocyanate and 5 parts of graphene (carbon content 95 atomic%).

[0038] (Example: Cleaning blade (3)) In the preparation of Example Cleaning Blade (1), Example Cleaning Blade (3) was prepared in the same manner as in Example Cleaning Blade (1), except that the surface layer coating solution was prepared by changing the amount of 4,4'-diphenylmethane diisocyanate to 70 parts and graphene (carbon content 95 atomic%) to 30 parts.

[0039] (Example: Cleaning blade (4)) In the preparation of Example Cleaning Blade (1), Example Cleaning Blade (4) was prepared in the same manner as Example Cleaning Blade (1), except that the thickness of the surface layer was changed to 2 μm.

[0040] (Example: Cleaning blade (5)) In the preparation of Example Cleaning Blade (1), Example Cleaning Blade (5) was prepared in the same manner as Example Cleaning Blade (1), except that the thickness of the surface layer was changed to 50 μm.

[0041] (Example: Cleaning blade (6)) In the preparation of Example Cleaning Blade (1), Example Cleaning Blade (6) was prepared in the same manner as in Example Cleaning Blade (1), except that the surface layer coating solution was prepared by changing the amount of 4,4'-diphenylmethane diisocyanate to 80 parts and graphene (carbon content 75 atomic%) to 20 parts.

[0042] (Example: Cleaning blade (8)) Except for the preparation of the cleaning blade (1) in Example, in Example, 50 parts of 4,4'-diphenylmethane diisocyanate, 35 parts of polycaprolactone polyol, and 15 parts of graphene (carbon content 95 atomic%) were added, mixed while heated to 45°C, and dispersed for 3 hours using a sand mill with 1 mmφ glass beads to prepare the surface layer coating solution, Example cleaning blade (8) was prepared in the same manner as the preparation of Example cleaning blade (1).

[0043] (Comparative example: Cleaning blade (1)) Comparative example cleaning blade (1) was prepared in the same manner as in example cleaning blade (1), except that the surface layer coating solution was prepared without using graphene (carbon content of 95 atoms) in the preparation of example cleaning blade (1).

[0044] (Comparative example: Cleaning blade (2)) Comparative example cleaning blade (2) was prepared in the same manner as in example cleaning blade (1), except that graphene (carbon content 95 atomic%) was replaced with single-walled carbon nanotubes (carbon content 98 atomic%) in the preparation of the surface layer coating solution.

[0045] (Comparative example: Cleaning blade (3)) Comparative example cleaning blade (3) was prepared in the same manner as in example cleaning blade (1), except that the surface layer coating solution was prepared by changing the composition of cleaning blade (1) to 70 parts of 4,4'-diphenylmethane diisocyanate and 30 parts of graphite (carbon content 98 atomic%).

[0046] (Comparative example: Cleaning blade (4)) Comparative example cleaning blade (4) was prepared in the same manner as in example cleaning blade (1), except that the surface layer coating solution was prepared by changing the composition of cleaning blade (1) to 70 parts of 4,4'-diphenylmethane diisocyanate and 30 parts of graphene (carbon atom content 50 atomic%).

[0047] <Evaluation of cleaning blades for electrophotographic photoconductors> The fabricated electrophotographic photoconductor and cleaning blade for the electrophotographic photoconductor were mounted on a Canon iRC5870 printer. Using A4 paper (210 x 297 mm, manufactured by ASKUL Corporation, Multi Paper Super White + Paper), 5,000 and 500,000 images with an image density of 1% were printed under high temperature and high humidity conditions (35°C, 85% RH). Subsequently, one image with 50% full-surface halftone was printed, and the presence or absence of white areas due to toner fusion on the resulting halftone images was evaluated according to the following criteria. In addition, the tip of the edge of the cleaning blade for the electrophotographic photoreceptor was observed with an optical microscope to evaluate the presence or absence of chipping of the blade edge. The results are shown in Table 1.

[0048] Image quality evaluation criteria 5: No white areas were detected. 4: One small white spot on the image (0.5mm in size) 2 Image defects (less than a certain amount of white space) are observed. 3: There are 2-3 minor white areas in the image, but they are within an acceptable range. 2: One unacceptable white defect in the image (size 0.5mm). 2 The above can be observed. 1: Unacceptable levels of whiteout image defects are observed in multiple areas of the image.

[0049] Evaluation criteria for blade edge chipping A: No chipping occurred. B: Minor chipping (less than 15 μm depth) is present but does not affect the image, and is within an acceptable range. C: Image defects (defect depth of 15 μm or more) have occurred.

[0050] [Table 1]

[0051] <Evaluation of the intermediate transfer material cleaning blade> The fabricated intermediate transfer belt and intermediate transfer cleaning blade were mounted on a Canon iRC5870 printer. Using A4 paper (210 x 297 mm, manufactured by ASKUL Corporation, Multi Paper Super White + paper), 5,000 and 500,000 images with an image density of 1% were printed under low temperature and low humidity conditions (12°C, 10% RH). Subsequently, one solid white image was printed from each side, and the presence or absence of vertical streaks caused by toner leakage on the resulting solid white image was evaluated according to the following criteria. In addition, the tip of the edge of the intermediate transfer material cleaning blade was observed with an optical microscope to evaluate the presence or absence of chipping of the blade edge. The results are shown in Table 2.

[0052] Image quality evaluation criteria 5: No vertical streaks were observed in the image. 4: One small white spot on the image (0.5mm in size) 2 Image defects (less than a certain amount of white space) are observed. 3: There are 2-3 minor white areas in the image, but they are within an acceptable range. 2: One unacceptable white defect in the image (size 0.5mm). 2 The above can be observed. 1: Unacceptable levels of whiteout image defects are observed in multiple areas of the image.

[0053] Evaluation criteria for blade edge chipping A: No chipping occurred. B: Minor chipping (less than 15 μm depth) is present but does not affect the image, and is within an acceptable range. C: Image defects (defect depth of 15 μm or more) have occurred.

[0054] [Table 2]

[0055] As described above, the cleaning blade of this disclosure using graphene not only has excellent thermal conductivity, but it is also presumed that the temperature rise due to frictional heat at the blade edge was effectively suppressed even at the early stage of use, after printing 5,000 sheets, and no deterioration in image quality was observed. Even after long-term use of 500,000 sheets, the decrease in thermal conductivity of graphene at the blade edge was small, and high thermal conductivity was maintained, so it is presumed that the temperature rise due to frictional heat at the blade edge was effectively suppressed, and no deterioration in image quality was observed. On the other hand, conventional cleaning blades made of other carbon materials or those that do not contain carbon materials showed insufficient suppression of temperature rise due to frictional heat at the blade edge during long-term use of 500,000 sheets, resulting in a deterioration in image quality.

[0056] This embodiment includes the following configurations and methods. [Configuration 1] A cleaning blade having a blade-shaped elastic member and a support member, wherein one end of the elastic member contains polyurethane and graphene, the other end of the elastic member is supported by the support member, and the carbon atom ratio in the graphene is 75 atomic percent or more. [Configuration 2] The cleaning blade according to configuration 1, wherein the elastic member is an elastic member having a polyurethane layer containing polyurethane and a surface layer containing polyurethane and graphene on the surface of the polyurethane layer. [Configuration 3] The cleaning blade according to configuration 1 or 2, wherein the carbon atom ratio in the graphene is 95 atomic percent or more. [Method 1] A method for manufacturing a cleaning blade as described in Configuration 2, characterized in that the surface layer is obtained by applying a surface layer coating solution containing an isocyanate compound, a polyol compound, and graphene to the surface of a polyurethane layer containing polyurethane. [Structure 4] An electrophotographic apparatus comprising a cleaning blade as described in any one of configurations 1 to 3. [Explanation of symbols]

[0057] 11 Support member 12 Elastic members 13. Polyurethane layer 14A, 14B, 14C, 14D surface layer 100 Electrophotographic apparatus 101 Intermediate Transfer Belt 102 Cleaning blade for intermediate transfer material 103 Electrophotographic photoreceptor 104 Electrostatic Roller 105 Exposure apparatus 106 Developing device 107 Primary Transfer Roller 108 Cleaning blade for electrophotographic photoconductor 109Y, 109M, 109C, 109Bk Image Forming Units 110 Drive Roller 111 Secondary transfer roller 112 Fixing device 113, 114 Tensioning rollers 115 Tension Roller 116 Heating element

Claims

1. A cleaning blade having a blade-shaped elastic member and a support member, wherein one end of the elastic member contains polyurethane and graphene, the other end of the elastic member is supported by the support member, and the carbon atom ratio in the graphene is 75 atomic percent or more.

2. The cleaning blade according to claim 1, wherein the elastic member is an elastic member having a polyurethane layer containing polyurethane and a surface layer containing polyurethane and graphene on the surface of the polyurethane layer.

3. The cleaning blade according to claim 1, wherein the carbon atom ratio in the graphene is 95 atomic percent or more.

4. A method for manufacturing a cleaning blade according to claim 2, characterized in that the surface layer is obtained by applying a surface layer coating solution containing an isocyanate compound, a polyol compound, and graphene to the surface of a polyurethane layer containing polyurethane.

5. An electrophotographic apparatus comprising a cleaning blade according to any one of claims 1 to 3.

Images