Electrophotographic cleaning blade, process cartridge, and electrophotographic image forming apparatus

Abstract

The present invention relates to an electrophotographic cleaning blade, a process cartridge, and an electrophotographic image forming apparatus. An electrophotographic cleaning blade includes an elastic member and a support member that supports the elastic member, wherein the elastic member is composed of a polyurethane having a urethane group; at least one surface of the elastic member has a cured layer obtained by impregnating the polyurethane with an aromatic isocyanate and curing it; the cured layer has an uretdione group formed by uretdionization of the aromatic isocyanate, and in FT-IR measurement of a surface of the cured layer using diamond as an ATR crystal, a peak intensity ratio value Ia / Ib of a peak intensity Ia of carbonyl stretching vibration (vC=O) originating from the uretdione group to a peak intensity Ib of NH bending vibration (δNH) originating from the urethane group is at least 0.300.

Description

Technical Field

[0001] This disclosure relates to an electrophotographic cleaning blade, a processing box, and an electrophotographic image forming apparatus for use in an electrophotographic image forming apparatus. Background Technology

[0002] In electrophotographic image forming apparatus, a cleaning component is provided to remove residual toner remaining on the surface of the image carrier or intermediate transfer body, such as a photosensitive element, after the toner image has been transferred from the image carrier or intermediate transfer component to the transfer target component. Hereinafter, the image carrier and intermediate transfer component are also referred to as the cleaning component. One type of cleaning component used for cleaning is an electrophotographic cleaning blade.

[0003] Electrophotographic cleaning squeegees are primarily made of polyurethane. However, when using conventional cleaning squeegees made of polyurethane, the high coefficient of friction between the polyurethane and the component being cleaned can cause the squeegee to curl and break.

[0004] In contrast, Japanese Patent Application Publication No. 2007-052062 discloses a surface-hardened scraper in which the surface of the cleaning scraper is impregnated with isocyanate to achieve high hardness and low friction at the contact points with the components being cleaned. This surface-hardened scraper inhibits curling and provides advantageous cleaning performance.

[0005] In recent years, there has been a need to further improve the printing speed and extend the lifespan of electrophotographic image forming equipment. To achieve these improvements, electrophotographic cleaning blades are required that can maintain a high level of cleaning performance over extended periods, even when the components being cleaned are driven at high speeds.

[0006] However, the inventors have recognized that surface-hardened scrapers, such as those described in Japanese Patent Application Publication No. 2007-052062, may experience wear on the contact surface during high-speed operation and long-term use, leading to reduced cleaning performance and contamination of the charging roller as the number of printed pages increases. Summary of the Invention

[0007] Therefore, there is a need for an electrophotographic cleaning blade that consistently exhibits excellent cleaning performance, even in high-speed systems and over extended periods. This disclosure provides an electrophotographic cleaning blade that is wear-resistant even in high-speed systems and during long-term use, and that can exhibit excellent cleaning performance over a long period. This disclosure also provides a processing cartridge and an electrophotographic image forming apparatus having the aforementioned electrophotographic cleaning blade.

[0008] This disclosure relates to an electrophotographic cleaning squeegee, which includes an elastic member and a support member supporting the elastic member, wherein...

[0009] The elastic component is made of polyurethane with urethane groups;

[0010] At least one surface of the elastic member has a cured layer obtained by impregnating polyurethane with an aromatic isocyanate and then curing it.

[0011] The cured layer has ureidone groups formed by the uretization of aromatic isocyanates, and

[0012] In FT-IR measurements on the surface of a cured layer using diamond as an ATR crystal, the peak intensity ratio Ia / Ib of the peak intensity of the carbonyl stretching vibration (νC=O) originating from the diketone group to the peak intensity of the NH bending vibration (δNH) originating from the urethane group is at least 0.300.

[0013] Furthermore, this disclosure relates to a processing box including an electrophotographic cleaning scraper.

[0014] Furthermore, this disclosure relates to an electrophotographic image forming apparatus including an electrophotographic cleaning squeegee.

[0015] The features of this disclosure will become apparent from the following description of the embodiments with reference to the accompanying drawings. The following description of the embodiments is illustrated by way of example. Attached Figure Description

[0016] Figure 1 This is a schematic perspective view of an electrophotographic cleaning squeegee.

[0017] Figure 2 This is a diagram showing the state in which the edge of the cleaning scraper is in contact with the component being cleaned when the treatment box is stationary.

[0018] Figure 3 This is a diagram illustrating a method for observing wear conditions. Detailed Implementation

[0019] In this disclosure, unless otherwise stated, the expression "from XX to YY" or "XX to YY" indicating a numerical range refers to a numerical range that includes both a lower limit and an upper limit. When a numerical range is stated in stages, the upper and lower limits of each numerical range can be arbitrarily combined. Furthermore, in this disclosure, statements such as "selected from at least one of the groups consisting of XX, YY, and ZZ" mean any of XX, YY, ZZ, combinations of XX and YY, combinations of XX and ZZ, combinations of YY and ZZ, or combinations of XX, YY, and ZZ. When XX is a group, multiple members can be selected from XX, and this also applies to YY and ZZ.

[0020] Examples of components to be cleaned that can be applied to an electrophotographic cleaning squeegee (hereinafter also simply referred to as a "cleaning squeegee") according to one aspect of this disclosure include image-bearing components such as photosensitive components and annular belts such as intermediate transfer belts. Below, embodiments of a cleaning squeegee according to one aspect of this disclosure will be described in detail using an image-bearing component as an example of a component to be cleaned; however, this disclosure is not limited thereto. Furthermore, in the following description, components having the same function are given the same reference numerals in the drawings, and their description may be omitted.

[0021] Composition of a cleaning scraper

[0022] A cleaning squeegee includes an elastic member and a support member supporting the elastic member. The cleaning squeegee cleans the surface of a moving component by bringing a portion of the elastic member into contact with the surface of the component being cleaned. The elastic member is made of polyurethane having urethane groups, and at least one surface of the elastic member has a cured layer obtained by impregnation and curing with an aromatic isocyanate. The cured layer has urea diketone groups formed by ureidyl diketylation of the aromatic isocyanate. For example, the elastic member has a cured layer at the contact portion with the component being cleaned. That is, at least a portion of the cured layer is the contact portion with the component being cleaned.

[0023] Figure 1 This is a schematic perspective view of a cleaning scraper 1 according to one aspect of the present disclosure. The cleaning scraper 1 includes an elastic member 2 and a support member 4 supporting the elastic member 2, and has a cured layer 3 at the front end of the elastic member 2.

[0024] Figure 2 The diagram schematically illustrates an example of a cleaning scraper in contact with a component being cleaned according to one aspect of the present disclosure. The elastic member 2 has a main surface 5 facing the component being cleaned 7, and a front end surface 6 forming a front end side edge 5-1 together with the main surface 5. Reference numeral 8 indicates the direction of rotation of the component being cleaned.

[0025] Urea diketone bond

[0026] As a result of extensive research, the inventors have discovered that in a cured layer formed by impregnating polyurethane with isocyanate and then curing, the ureidoylation of isocyanate on the surface of the cured layer enhances abrasion resistance, resulting in excellent cleaning performance over a long period of time. The inventors believe the reason for this is as follows.

[0027] Due to long-term friction between the cleaning scraper and the component being cleaned, the contact area between the scraper and the component wears down. Three-dimensional cross-linked polyurethane has high abrasion resistance and is not easily worn, but in the cured layer formed by impregnation and curing with isocyanate, it is believed that the impregnating material will detach, making the cured layer prone to wear.

[0028] Although the impregnating material is bonded within the polyurethane network, insufficient interaction between the polyurethane backbone and the impregnating material is believed to cause the impregnating material to detach due to long-term friction. Therefore, scrapers obtained by impregnating and curing with isocyanate gradually wear down during long-term use. On the other hand, it is believed that the interaction between the impregnating material and the urethane backbone is enhanced through ureidolated on the surface of the cured layer, making the impregnating material less likely to detach. Therefore, the wear resistance of the cured layer is considered improved, and excellent cleaning performance can be achieved over a long period.

[0029] The cured layer has urea diketone groups generated through the curing of aromatic isocyanates. In FT-IR measurements of the surface of the cured layer using diamond as the ATR crystal, the peak intensity of the carbonyl stretching vibration (νC=O) originating from the urea diketone groups is defined as peak intensity Ia, and the peak intensity of the NH bending vibration (δNH) originating from the urethane groups is defined as peak intensity Ib. It is necessary that the ratio of peak intensity Ia to peak intensity Ib, Ia / Ib, is 0.300 or higher. Ia / Ib is preferably 0.330 or higher.

[0030] The carbonyl stretching vibration (νC=O) derived from the diketone group is shown at 1755 cm⁻¹ -1 Up to 1780cm -1 The peak at 1530 cm⁻¹. The NH bending vibration (δNH) originating from the urethane group shows a peak at 1530 cm⁻¹. -1 Nearby peaks.

[0031] The peak intensity ratio Ia / Ib represents the amount of urea diketone groups relative to urethane groups on the scraper surface. When Ia / Ib is above 0.300, the urea diketone groups are present at a level sufficient to provide abrasion resistance. When a sufficient amount of urea diketone groups is present, the interaction between the impregnating material and the urethane backbone is enhanced, making it difficult for the impregnating material to detach from the urethane backbone, thus improving abrasion resistance. Therefore, the abrasion resistance of the cured layer is improved, and excellent cleaning performance can be achieved over a long period.

[0032] There is no specific upper limit for Ia / Ib. Ia / Ib is, for example, 0.300 to 0.500, preferably 0.330 to 0.500, more preferably 0.330 to 0.400, and even more preferably 0.330 to 0.380.

[0033] Methods for increasing the Ia / Ib ratio on the surface of the impregnated cured layer include impregnation with an isocyanate while impregnating with a catalyst having ureidyldiketation activity, and impregnation with an isocyanate containing ureidyldiketone bonds.

[0034] Constituent materials

[0035] Supporting components

[0036] The cleaning scraper disclosed herein has a support member that supports an elastic member. There are no particular limitations on the material constituting the support member, and examples include: metallic materials, such as steel plates, stainless steel plates, galvanized steel plates, and chromium-free steel plates; and resin materials, such as 6-nylon and 6,6-nylon.

[0037] Furthermore, there are no particular restrictions on the shape and structure of the supporting components. For example, such as Figure 2 As shown, one end of the elastic member 2 of the cleaning scraper is supported by the support member 4.

[0038] elastic member

[0039] The elastic component is made of polyurethane containing urethane groups. The polyurethane is preferably a polyurethane elastomer. The polyurethane constituting the elastic component mainly comprises reaction products of urethane raw materials such as polyols, chain extenders, crosslinking agents, polyisocyanates, catalysts, and other additives.

[0040] The raw materials for polyurethane will be described in detail below.

[0041] Examples of polyols include the following: polyester polyols, such as polyethylene adipate polyol, polybutylene adipate polyol, polyhexyl adipate polyol, (polyethylene / polypropylene) adipate polyol, (polyethylene / polybutene) adipate polyol, and (polyethylene / polypentene) adipate polyol; polycaprolactone-based polyols obtained by ring-opening polymerization of caprolactone; polyether polyols such as polyethylene glycol, polypropylene glycol, and polytetramethylene glycol; and polycarbonate diols. These can be used alone or in combination of two or more.

[0042] Among the aforementioned polyols, polyester polyols using adipate esters are preferred because they produce polyurethanes with excellent mechanical properties. Polyester polyols using butylene adipate are more preferred. For example, commercially available products can be used, such as "Nippolan 3027 (product name, manufactured by Tosoh Corporation)" with a number average molecular weight of 2500 and "Nippolan 4010 (product name, manufactured by Tosoh Corporation)" with a number average molecular weight of 2000.

[0043] As chain extenders, diols and polyols with three or more components that can extend the chains of polyurethane elastomers can be used.

[0044] Examples of diols include ethylene glycol (EG), diethylene glycol (DEG), propylene glycol (PG), dipropylene glycol (DPG), 1,4-butanediol (1,4-BD), 1,6-hexanediol (1,6-HD), 1,4-cyclohexanediol, 1,4-cyclohexanediethanol, xylenediethanol (terephthalic acid diethanol), and triethylene glycol.

[0045] Examples of polyols with three or more nucleotides include trimethylolpropane, glycerol, pentaerythritol, and sorbitol. These can be used alone or in combination of two or more. It is preferred to use these polyols with three or more nucleotides as crosslinking agents. Among the above polyols, trimethylolpropane is more preferred.

[0046] Examples of polyisocyanates include 4,4'-diphenylmethane diisocyanate (4,4'-MDI), polymeric MDI (pMDI), 2,4-toluene diisocyanate (2,4-TDI), 2,6-toluene diisocyanate (2,6-TDI), phenylenediamine diisocyanate (XDI), 1,5-naphthylene diisocyanate (1,5-NDI), terephthalic diisocyanate (PPDI), hexamethylene diisocyanate (HDI), isophorone diisocyanate (IPDI), 4,4'-dicyclohexylmethane diisocyanate (hydrogenated MDI), tetramethylphenylenediamine diisocyanate (TMXDI), and carbodiimide-modified MDI.

[0047] Among the aforementioned polyisocyanates, 4,4'-MDI or polymeric MDI, which exhibit high reactivity and produce good mechanical properties, are preferred. The polyurethane preferably has a structure in which at least one of the groups selected from 4,4'-diphenylmethane diisocyanate and polymeric MDI has been reacted. This structure is, for example, a structure in which at least one of the groups selected from 4,4'-diphenylmethane diisocyanate and polymeric MDI has undergone urethane esterification.

[0048] The urethane raw material may include a prepolymer formed by the reaction of a polyol and a polyisocyanate. The prepolymer is preferably a reaction product of at least one selected from the group consisting of 4,4'-diphenylmethane diisocyanate and polymeric MDI with the aforementioned polyester polyol.

[0049] As catalysts, catalysts commonly used for curing polyurethane elastomers can be used. Examples include tertiary amine catalysts, and specifically, the following can be examples: amino alcohols, such as dimethylethanolamine, N,N,N'-trimethylaminopropylethanolamine, and N,N'-dimethylhexanolamine; trialkylamines, such as triethylamine; tetraalkyldiamines, such as N,N,N',N'-tetramethyl-1,3-butanediamine; triethylenediamine, piperazine compounds, and triazine compounds. Organometallic acid salts, such as potassium acetate and potassium octanoate, can also be used. Furthermore, metal catalysts commonly used for urethane esterification, such as dibutyltin dilaurate, can also be used. These can be used alone or in combination of two or more.

[0050] N,N'-dimethylhexanolamine is preferred as a catalyst. Examples of commercially available products include Kaolizer No. 25 (product name, manufactured by Kao Corporation). An ethylene glycol solution of potassium acetate is also preferred. Examples of commercially available products include POLYCAT 46 (product name, manufactured by Air Products Japan Ltd.).

[0051] For example, polyurethane preferably includes at least one polyol selected from the group consisting of polyester polyols and polyether polyols, a polyol with three or more components, and at least one polyisocyanate selected from the group consisting of 4,4'-MDI and pMDI as constituent components.

[0052] The raw materials constituting the elastic component may optionally include additives such as pigments, plasticizers, waterproofing agents, antioxidants, ultraviolet absorbers, and light stabilizers.

[0053] Curing layer

[0054] At least one surface of the elastic member has a cured layer obtained by impregnating polyurethane with an aromatic isocyanate and curing it, and the cured layer has urea diketone groups formed from the aromatic isocyanate. The urea diketone groups are formed, for example, by the urea diketation of the aromatic isocyanate. The cured layer is formed, for example, on the front end portion of the elastic member 2 including the front end surface 6. The cured layer is obtained by impregnating the elastic member with an aromatic isocyanate and curing it. The urea diketone groups are formed by the curing of the aromatic isocyanate. For example, the cured layer is a layer in which the aromatic isocyanate is impregnated into the polyurethane and urea diketated.

[0055] Furthermore, the cured layer is preferably obtained by impregnating polyurethane with an impregnation agent and then curing it. The impregnation agent contains at least an aromatic isocyanate. In addition to the aromatic isocyanate, a catalyst may be impregnated into the cured layer. These impregnation materials may be diluted with a solvent.

[0056] The impregnation material is described in detail below.

[0057] Examples of aromatic isocyanates include at least one selected from the group consisting of 4,4'-diphenylmethane diisocyanate (4,4'-MDI), polymeric MDI (pMDI), 2,4-toluene diisocyanate (2,4-TDI), 2,6-toluene diisocyanate (2,6-TDI), phenyl dimethylene diisocyanate (XDI), 1,5-naphthylene diisocyanate (1,5-NDI), p-phenylene diisocyanate (PPDI), and carbodiimide-modified MDI.

[0058] From the viewpoint of better wear resistance, aromatic isocyanates preferably include at least one selected from the group consisting of 4,4'-diphenylmethane diisocyanate, polymeric MDI and carbodiimide-modified MDI, and more preferably include polymeric MDI.

[0059] The content of aromatic isocyanate in the impregnation agent is, for example, 10.00% to 90.00% by mass, preferably 15.00% to 70.00% by mass, and more preferably 20.00% to 60.00% by mass.

[0060] The impregnation agent may contain an aromatic isocyanate and a catalyst. Preferably, a catalyst with urea diketation activity is used as the catalyst. That is, the cured layer preferably contains a catalyst with urea diketation activity. Furthermore, it is preferable to form the cured layer by impregnation with an aromatic isocyanate and a catalyst with urea diketation activity, followed by curing.

[0061] Specific examples of catalysts include: antimony pentafluoride, triethylphosphine, dibutylethylphosphine, tri-n-propylphosphine, triisopropylphosphine, tri-n-butylphosphine, triisobutylphosphine, tri-tert-butylphosphine, tripentylphosphine, trioctylphosphine, tribenzylphosphine, benzylmethylphosphine, amino-substituted phosphine, imidazole, guanidine and pyridine, boron trifluoride, 1,2-dimethylimidazole, tris(N,N-dimethylamino)phosphine, tris(N,N-diethylamino)phosphine, and tris(N,N-diethylamino)phosphine. Phosphine, cyclic amidine, 1,8-diazabicyclo[5.4.0]undec-7-ene, phenolic salts of 1,8-diazabicyclo[5.4.0]undec-7-ene, 2-ethylhexanoate of 1,8-diazabicyclo[5.4.0]undec-7-ene, formate of 1,8-diazabicyclo[5.4.0]undec-7-ene, 4-aminopyridine and 4-dialkylaminopyridine, etc.

[0062] The catalyst is preferably at least one selected from the group consisting of phenolic salts of 1,8-diazabicyclo[5,4,0]undec-7-ene and 2-ethylhexanoate of 1,8-diazabicyclo[5,4,0]undec-7-ene.

[0063] The catalyst content in the impregnation agent is, for example, 0.01% to 3.00% by mass, preferably 0.02% to 1.00% by mass, and more preferably 0.02% to 0.50% by mass.

[0064] The impregnation agent may optionally contain a solvent. The solvent may be selected from known solvents that have low solubility in polyurethane, and there are no particular limitations. Examples of solvents include at least one organic solvent selected from the group consisting of 2-butanone, methyl isobutyl ketone, acetone, butyl acetate, ethyl acetate, and xylene.

[0065] The solvent content in the impregnation agent is, for example, 5.00% by mass to 90.00% by mass, preferably 30.00% by mass to 85.00% by mass, and more preferably 40.00% by mass to 80.00% by mass.

[0066] Methods for producing cleaning scrapers

[0067] There are no particular limitations on the method of producing the cleaning scraper according to this disclosure, and a suitable method can be selected from known methods.

[0068] There are no particular limitations on the method for producing elastic components comprising polyurethane elastomers, but it is preferable to include the following steps. The polyurethane elastomer composition, using urethane as a raw material, is preferably manufactured by a prepolymer method using a prepolymer having the most uniform molecular weight distribution possible. Firstly, it is preferable to include a step of reacting a polyol with a polyisocyanate to obtain the prepolymer. The NCO content in the prepolymer is not particularly limited, but is preferably from 3.00% to 15.00% by mass, and more preferably from 6.00% to 10.00% by mass.

[0069] Next, a mixture of crosslinking agent and catalyst, and optionally polyol and chain extender (curing agent), is added to the obtained prepolymer, and the components are mixed to obtain a polyurethane elastomer composition. Preferably, the polyol is added to the curing agent.

[0070] After the support member is placed in a mold for forming the cleaning scraper, a polyurethane elastomer composition is injected into the mold cavity and cured by heat to obtain a cleaning scraper in which the plate-shaped scraper member and the support member are integrated. Known release agents can be applied to the mold.

[0071] Optionally, the polyurethane elastomer sheet can be separately formed from the above-mentioned polyurethane raw material composition, cut into strips to prepare elastic components, and then the adhesive portion of the elastic component can be superimposed on a support component coated with adhesive or bonded to adhesive, and bonded by heating and pressure.

[0072] Next, a cured layer is formed on the polyurethane. Using known methods, the obtained polyurethane-containing cleaning blade is impregnated with an impregnation treatment solution containing an aromatic isocyanate and, if desired, a catalyst and solvent. For example, impregnation can be achieved by immersing the blade in a liquid mixture of isocyanate and catalyst. Alternatively, the blade can be first immersed in the catalyst and then in the isocyanate. Alternatively, the isocyanate and catalyst can be applied using a dispenser device. The isocyanate and catalyst can be diluted with a solvent.

[0073] The concentration of the catalyst relative to the isocyanate is, for example, 0.01% to 3% by mass, preferably 0.05% to 3% by mass, and more preferably 0.1% to 2% by mass. A concentration of 0.01% by mass or more is sufficient to promote diketation.

[0074] Following the above impregnation treatment, the aromatic isocyanate is cured to obtain a cleaning scraper with a cured layer. Heating is preferably performed to cure the aromatic isocyanate. Heating promotes the impregnation of the impregnating material into the polyurethane. It also promotes urea diketation. Preferred curing of the aromatic isocyanate is by heating. The heating temperature is preferably in the range of 60°C to 160°C. The heating time should be sufficient to allow urea diketation to proceed fully, for example, 10 minutes to 300 minutes.

[0075] Processing box and electrophotographic image forming equipment

[0076] A cleaning squeegee can be incorporated into and used in a processing cartridge configured to be detachably mounted on an electrophotographic image forming apparatus. The processing cartridge preferably includes a cleaning squeegee. Specifically, for example, in a processing cartridge comprising an image-bearing member as the object to be cleaned and a cleaning squeegee configured to clean the surface of the image-bearing member, the cleaning squeegee according to this embodiment can be used as a cleaning squeegee. The aforementioned processing cartridge contributes to the stable formation of high-quality electrophotographic images.

[0077] Furthermore, the electrophotographic image forming apparatus preferably includes a cleaning blade. The electrophotographic image forming apparatus includes an image-carrying member, such as a photosensitive element, and a cleaning blade configured to clean the surface of the image-carrying member; preferably, the cleaning blade is the aforementioned cleaning blade. The aforementioned electrophotographic image forming apparatus can stably form high-quality electrophotographic images.

[0078] Example

[0079] The present disclosure is described below with reference to production examples, embodiments, and comparative examples, but the present disclosure is not limited to these embodiments. Unless otherwise stated in the embodiments and comparative examples, reagents or industrial chemicals are used as raw materials.

[0080] In Examples 1 to 11 and Comparative Examples 1 to 5 below, production and evaluation were carried out. Figure 1The one-piece molded cleaning scraper shown is illustrated. The composition of the polyurethane elastomer composition, the physical properties of the obtained elastic component, and the evaluation results of each example and comparative example are shown in Tables 1 and 2.

[0081] Example 1

[0082] Supporting components

[0083] Prepare 1.6mm thick galvanized steel sheets and process them to obtain support members with L-shaped cross-sections, such as... Figure 2 As shown in Figure 4. Furthermore, a one-component urethane-metal adhesive (product name: Chemlok 219, manufactured by Lord Corporation) is applied to the area of ​​the support member that contacts the elastic member.

[0084] Preparation of raw materials for elastic components

[0085] prepolymer

[0086] - Isocyanate, 4,4'-diphenylmethane diisocyanate (Product name: Millionate MT, manufactured by Tosoh Corporation): 327.0g

[0087] - Polyol, butylene adipate polyester polyol with a number average molecular weight of 2500 (product name: Nippolan 3027, manufactured by Tosoh Corporation): 673.0g

[0088] The above materials were reacted at 80°C for 3 hours to obtain a prepolymer with an NCO content of 8.80% by mass.

[0089] curing agent

[0090] - Hexamethylene adipate polyester polyol with a number average molecular weight of 1000 (product name: Nippolan 3027, manufactured by Tosoh Corporation): 168.3g

[0091] 1,4-Butanediol (manufactured by Tokyo Chemical Industry Co., Ltd.): 12.9g

[0092] - Trimethylolpropane (manufactured by Tokyo Chemical Industry Co., Ltd.): 23.8g

[0093] -N,N'-Dimethylhexanolamine (Product name: Kaolizer No. 25, manufactured by Kao Corporation): 0.35g

[0094] - Potassium acetate (product name: POLYCAT 46, manufactured by Evonik Co., Ltd.): 0.08g

[0095] The above materials are mixed to prepare a curing agent.

[0096] Then, polyurethane composition A is obtained by mixing the obtained prepolymer with a curing agent.

[0097] The adhesive application area of ​​the support member is configured to protrude into the mold cavity of the mold for the cleaning scraper. Polyurethane composition A is injected into the mold for the cleaning scraper, cured at 130°C for 5 minutes, and then demolded to obtain an integral molded body of polyurethane and support member.

[0098] The mold used was coated with release agent A before the polyurethane elastomer composition was injected. Release agent A was a mixture of 5.06g of ELEMENT14 PDMS 1000-JC (product name, manufactured by Momentive Performance Materials Inc.), 6.19g of ELEMENT14 PDMS 10K-JC (product name, manufactured by Momentive Performance Materials Inc.), 3.75g of SR1000 (product name, manufactured by Momentive Performance Materials Inc.), and 85g of EXXSOL DSP145 / 160.

[0099] The front end of the polyurethane elastomer of the integrally molded body is appropriately cut to obtain a plate-shaped elastic member having a main surface and a front end edge formed together with the main surface. The angle of the front end edge is 90 degrees, and the distances of the elastic member in the short direction, the thickness direction, and the long direction are 7.5 mm, 1.8 mm, and 240 mm, respectively.

[0100] Formation of the curing layer

[0101] Prepare the materials shown below and mix them in the stated proportions to produce an impregnation treatment agent for forming a cured layer.

[0102] - 4,4'-Diphenylmethane diisocyanate (Product name: Millionate MT, manufactured by Tosoh Corporation): 25.00% by mass

[0103] - 1,8-diazabicyclo[5.4.0]undec-7-enphenol salt (product name: U-CAT SA1, manufactured by SunApro Ltd.): 0.25% by mass

[0104] - 2-Butanone (manufactured by Kishida Chemical Co., Ltd.): 74.75% by mass

[0105] Using an "Aero Jet" applicator (manufactured by Musashi Engineering Co., Ltd.), a total of 45 mg of impregnation treatment agent for forming a cured layer is applied to the cut surface of the scraper at a constant discharge rate while the scraper is moved along its length. The scraper is then placed in an electric furnace at 120°C and heat-treated for 30 minutes. In this manner, a clean scraper with a cured layer is obtained.

[0106] The obtained cleaning scraper was evaluated using the following methods.

[0107] FT-IR analysis of elastic components using the ATR method

[0108] The IR spectrum of the cured layer surface was measured using the ATR method with FT-IR.

[0109] A sample for use is obtained by cutting out the elastic component of the cleaning scraper from the following measurement locations.

[0110] The FT-IR measurement conditions are described below.

[0111] Equipment: FT / IR-4700 (manufactured by JASCO Corporation)

[0112] Measurement mode: ATR method (crystal: diamond)

[0113] Total number of times: 64

[0114] Measurement locations: The length of the front edge of the cleaning scraper is represented by L, and the positions at 1 / 8L, 1 / 2L, and 7 / 8L from one end of the edge are measured.

[0115] From the obtained peak intensities, the peak intensity ratio Ia / Ib of the νC=O peak intensity derived from the diketone group and the δNH peak intensity derived from the carbamate group was calculated. The arithmetic mean of this ratio is shown in Table 1.

[0116] Evaluation of cleaning performance and abrasion resistance

[0117] The motor of the color laser beam printer (product name: HP Color LaserJet Enterprise 5700dn, manufactured by HP Co.) was modified to double the drive speed. A cleaning blade obtained by the above method was incorporated into the cyan cartridge of the printer as a cleaning blade for the photosensitive component, which is the component being cleaned. The toner in the developing unit of the cyan cartridge was completely replaced with toner 1 described below.

[0118] Next, the printer and cartridge were moved to a low-temperature and low-humidity environment (temperature 15°C, relative humidity 10%), and 10,000 images were printed. Additionally, the used developing unit was replaced with a developing unit from a separately prepared cyan cartridge, and another 10,000 images were printed. This process was repeated to obtain a total of 50,000 printed images. After printing 50,000 images, halftone images were output as evaluation images. The presence or absence of image defects (stripes on the image) caused by the cleaning scraper was visually inspected, and an image evaluation was performed.

[0119] A: No image defects occurred.

[0120] B: Image defects have occurred.

[0121] In addition, the cleaning blade was observed after printing 50,000 images, and the amount of wear on the cleaning blade was evaluated using the following methods.

[0122] Methods for evaluating wear

[0123] The following describes a method for evaluating wear.

[0124] Equipment: VK-X100 shape measurement laser microscope

[0125] like Figure 3 As shown, the cleaning scraper was tilted at a 45° angle relative to microscope 9, and a height image of the leading edge was obtained. After evaluating 50,000 images, a height image of the leading edge was obtained in the same manner. The difference in the height of the leading edge before and after image evaluation was defined as the wear amount 11.

[0126] Measurement locations in the length direction: The length of the leading edge of the cleaning scraper is denoted by L, and measurements are taken at positions of 1 / 8L, 1 / 2L, and 7 / 8L from one end of the edge. Table 1 shows the arithmetic mean of the wear amount 11 at these three points.

[0127] Production method of colorant 1

[0128] As an evaluation toner, toner 1 prepared by the following method is used. In the following text, unless otherwise stated, "parts" are based on mass.

[0129] Steps for preparing aqueous medium 1

[0130] A total of 650.0 parts by weight of ion-exchanged water was added to a reaction vessel equipped with a stirrer, thermometer, and reflux condenser, along with 14.0 parts by weight of sodium phosphate (dodecahydrate, manufactured by Rasa Industries, Ltd.). The mixture was maintained at 65°C for 1.0 hour while being purged with nitrogen. While stirring at 15,000 rpm using a TK homogenizer (manufactured by Tokushu Kika Kogyo Co., Ltd.), a calcium chloride aqueous solution prepared by dissolving 9.2 parts by weight of calcium chloride (dihydrate) in 10.0 parts by weight of ion-exchanged water was added in one step to prepare an aqueous medium containing a dispersing stabilizer. Furthermore, 10% by weight of hydrochloric acid was added to the aqueous medium to adjust the pH to 5.0, resulting in aqueous medium 1.

[0131] Steps for preparing polymerizable monomer compositions

[0132] - Styrene: 60.0 parts

[0133] - CI Pigment Blue 15:3: 6.5 parts

[0134] The above materials were fed into a grinding mill (manufactured by Mitsui Miike Chemical Engineering Co., Ltd.) and further dispersed at 220 rpm for 5.0 hours using 1.7 mm diameter zirconia particles to prepare a pigment dispersion. The following materials were added to the pigment dispersion.

[0135] - Styrene: 20.0 parts

[0136] - n-Butyl acrylate: 20.0 parts

[0137] - Crosslinking agent (divinylbenzene): 0.3 parts

[0138] - Saturated polyester resin: 5.0 parts

[0139] (A condensation polymer of propylene oxide-modified bisphenol A (2 molar adduct) and terephthalic acid (molar ratio 10:12), glass transition temperature Tg=68℃, weight-average molecular weight Mw=10000, molecular weight distribution Mw / Mn=5.12)

[0140] - Fehling wax (melting point 78°C): 7.0 parts

[0141] The mixture was kept at 65°C, and the components were uniformly dissolved and dispersed at 500 rpm using a TK homogenizer (manufactured by Tokushu Kika Kogyo Co., Ltd.) to prepare a polymerizable monomer composition.

[0142] Granulation steps

[0143] While maintaining the temperature of aqueous medium 1 at 70°C and the rotation speed of the TK homogenizer at 15,000 rpm, the polymerizable monomer composition was added to aqueous medium 1, along with 10.0 parts of tert-butyl peroxypentanoate as a polymerization initiator. Granulation was then carried out for 10 minutes, while maintaining the same stirring device at 15,000 rpm.

[0144] Polymerization and distillation steps

[0145] After the granulation step, the agitator was replaced with a propeller blade, and polymerization was carried out for 5.0 hours while maintaining the temperature at 70°C with stirring at 150 rpm. The temperature was then raised to 85°C and heated for 2.0 hours to complete the polymerization reaction.

[0146] Subsequently, the reflux condenser of the reaction vessel was replaced with a cooling condenser, the slurry was heated to 100°C, and distilled for 6 hours to remove unreacted polymerizable monomers, thereby obtaining a toner masterbatch dispersion.

[0147] Polymerization of organosilicon compounds

[0148] In a reaction vessel equipped with a stirrer and thermometer, weigh 60.0 parts of ion-exchanged water and adjust the pH to 4.0 using 10% hydrochloric acid by mass. Heat the mixture while stirring until the temperature reaches 40°C.

[0149] Then, 40.0 parts of methyltriethoxysilane as the organosilicon compound were added, and the mixture was stirred for at least 2 hours to carry out hydrolysis. The endpoint of hydrolysis was visually confirmed by the absence of oil-water separation and the formation of a monolayer. The mixture was then cooled to obtain a hydrolyzed solution of the organosilicon compound.

[0150] The temperature of the obtained toner masterbatch dispersion was lowered to 55°C, and then 25.0 parts of hydrolyzed organosilicon compound solution were added to initiate the polymerization of the organosilicon compound. The reaction system was kept in place for 15 minutes, and then the pH was adjusted to 5.5 with a 3.0% by mass sodium bicarbonate aqueous solution. After maintaining the reaction at 55°C with stirring for 60 minutes, the pH was adjusted to 9.5 with a 3.0% by mass sodium bicarbonate aqueous solution, and the reaction system was maintained for another 240 minutes to obtain the toner particle dispersion.

[0151] Washing and drying steps

[0152] After the polymerization step is completed, the toner particle dispersion is cooled, hydrochloric acid is added to the toner particle dispersion to adjust the pH to below 1.5, and the mixture is stirred and allowed to stand for 1 hour. Then, solid-liquid separation is performed using a pressure filter to obtain a toner cake. This is then re-slurryed with deionized water to form a dispersion again, and then solid-liquid separation is performed using the same filter to obtain the toner cake.

[0153] The obtained toner cake was dried and graded in a constant temperature bath at 40°C for 72 hours to obtain toner 1.

[0154] Examples 2 to 8

[0155] Except for changes to the material and amount of the impregnating agent (hereinafter also referred to as "treatment agent") used to form the cured layer as shown in Table 1, the cleaning squeegee was manufactured in the same manner as in Example 1. The obtained cleaning squeegee was evaluated in the same manner as in Example 1. The evaluation results are shown in Table 1.

[0156] In addition to those shown in Example 1, details of the materials used are as follows.

[0157] - Carbodiimide-modified MDI (product name: Millionate MTL, manufactured by Tosoh Corporation)

[0158] - Polymerized MDI (Product name: Millionate MR-200, manufactured by Tosoh Corporation)

[0159] - 1,8-diazabicyclo[5.4.0]undec-7-ene 2-ethylhexanoate (Product name: U-CAT SA102, manufactured by Sun Apro Co., Ltd.)

[0160] - Tributylphosphine (manufactured by Tokyo Chemical Industry Co., Ltd.)

[0161] Example 9

[0162] Polyurethane composition B was prepared by modifying the formulations of the prepolymer and curing agent as follows. Apart from this, a cleaning blade was prepared in the same manner as in Example 1, and the obtained cleaning blade was evaluated in the same manner as in Example 1. The evaluation results are shown in Table 1.

[0163] prepolymer

[0164] - Isocyanate, 4,4'-diphenylmethane diisocyanate (Product name: Millionate MT, manufactured by Tosoh Corporation): 188.3g

[0165] - Isocyanate, polymeric MDI (product name: Millionate MR-200, manufactured by Tosoh Corporation): 210.0g

[0166] - Polyol, butylene adipate polyester polyol with a number average molecular weight of 2500 (product name: Nippolan 3027, manufactured by Tosoh Corporation): 601.7g

[0167] The above materials were reacted at 80°C for 3 hours to obtain a prepolymer with an NCO content of 10.4% by mass.

[0168] curing agent

[0169] - Hexamethylene adipate polyester polyol with a number average molecular weight of 1000 (product name: Nippolan 3027, manufactured by Tosoh Corporation): 328.8g

[0170] - Trimethylolpropane (manufactured by Tokyo Chemical Industry Co., Ltd.): 58.0g

[0171] - N,N'-Dimethylhexanolamine (Product name: Kaolizer No. 25, manufactured by Kao Corporation): 0.53g

[0172] - Potassium acetate (product name: POLYCAT 46, manufactured by Evonik Co., Ltd.): 0.17g

[0173] The above materials are mixed to prepare a curing agent.

[0174] Polyurethane composition B is then obtained by mixing the curing agent with the obtained prepolymer.

[0175] Example 10

[0176] Immerse the cleaning squeegee in the treatment agent shown in Table 1 and leave for 5 minutes to impregnate the squeegee with the treatment agent. Then, immerse the cleaning squeegee in butyl acetate for a few seconds to remove any remaining treatment agent from the surface, and then blow air over it.

[0177] The scraper is then placed in an electric furnace at 120°C and heat-treated for 30 minutes. In this way, a cleaning scraper with a cured layer is obtained.

[0178] The obtained cleaning scrapers were evaluated in the same manner as in Example 1. The evaluation results are shown in Table 1.

[0179] Example 11

[0180] The treatment agent is divided into two parts, A and B, and then coated in two stages. The treatment agent and coating method are described below.

[0181] Treatment Agent A

[0182] - 1,8-diazabicyclo[5.4.0]undec-7-enphenol salt (product name: U-CAT SA1, manufactured by SunApro Co., Ltd.): 1.0% by mass

[0183] - 2-Butanone (manufactured by Kishida Chemical Co., Ltd.): 99.0% by mass

[0184] Treatment agent B

[0185] - Polymerized MDI (Product Name: Millionate MR-200, manufactured by Tosoh Corporation): 25% by mass

[0186] - 2-Butanone (manufactured by Kishida Chemical Co., Ltd.): 75.0% by mass

[0187] Two Aero Jet dispenser application devices (manufactured by Musashi Engineering Co., Ltd.) are used to apply the treatment agents used to form the cured layer onto the cleaning squeegee. Specifically, using the first dispenser, a total of 10 mg of treatment agent A is applied to the squeegee-cutting surface at a constant discharge rate while the squeegee is moved along its length. Then, using the second dispenser, a total of 45 mg of treatment agent B is applied to the squeegee-cutting surface at a constant discharge rate while the squeegee is moved along its length.

[0188] The scraper is then placed in an electric furnace at 120°C and heat-treated for 30 minutes. In this way, a cleaning scraper with a cured layer is obtained.

[0189] In addition, the cleaning squeegee was prepared in the same manner as in Example 1, and the obtained cleaning squeegee was evaluated in the same manner as in Example 1. The evaluation results are shown in Table 1.

[0190] Comparative Examples 1 to 3

[0191] Except for changes in the material and amount of the treatment agent as shown in Table 1, the cleaning squeegee was manufactured in the same manner as in Example 1, and the obtained cleaning squeegee was evaluated in the same manner as in Example 1. The evaluation results are shown in Table 1.

[0192] Compare Examples 4 and 5

[0193] Except for changes in the material and amount of the treatment agent as shown in Table 1, the cleaning squeegee was manufactured in the same manner as in Example 10, and the obtained cleaning squeegee was evaluated in the same manner as in Example 1. The evaluation results are shown in Table 1.

[0194] [Table 1]

[0195]

[0196] The composition of the treatment agent in Example 11 is described in the main text of the specification.

[0197] [Table 2]

[0198]

[0199] According to this disclosure, an electrophotographic cleaning blade can be provided that is wear-resistant even in high-speed systems and during long-term use, and can exhibit excellent cleaning performance over a long period of time. Furthermore, according to this disclosure, a processing cartridge and an electrophotographic image forming apparatus having the aforementioned electrophotographic cleaning blade can be provided.

[0200] Although this disclosure has been described with reference to embodiments, it should be understood that this disclosure is not limited to the disclosed embodiments. The scope of the appended claims shall be given the broadest interpretation to cover all such modifications and equivalent structures and functions.

Claims

1. An electrophotographic cleaning squeegee, comprising an elastic member and a support member supporting the elastic member, wherein... The elastic member is made of polyurethane with urethane groups; At least one surface of the elastic member has a cured layer obtained by impregnating the polyurethane with an aromatic isocyanate and curing it. The cured layer has ureidone groups formed by the ureidodiketation of the aromatic isocyanate, and In FT-IR measurements on the surface of a cured layer using diamond as an ATR crystal, the peak intensity ratio Ia / Ib of the peak intensity of the carbonyl stretching vibration (νC=O) originating from the diketone group to the peak intensity of the NH bending vibration (δNH) originating from the urethane group is at least 0.

300.

2. The electrophotographic cleaning blade according to claim 1, wherein the polyurethane has a structure formed by a reaction of at least one selected from the group consisting of 4,4'-diphenylmethane diisocyanate and polymeric MDI.

3. The electrophotographic cleaning blade according to claim 1 or 2, wherein the aromatic isocyanate is at least one selected from the group consisting of 4,4'-diphenylmethane diisocyanate, polymeric MDI, and carbodiimide-modified MDI.

4. The electrophotographic cleaning blade according to claim 1 or 2, wherein the aromatic isocyanate comprises polymeric MDI.

5. The electrophotographic cleaning blade according to claim 1 or 2, wherein the cured layer comprises a catalyst having diuretic activity.

6. The electrophotographic cleaning blade according to claim 1 or 2, wherein the cured layer is obtained by impregnating the polyurethane with the aromatic isocyanate and a catalyst having diketylation activity and then curing it.

7. The electrophotographic cleaning squeegee according to claim 1 or 2, wherein at least a portion of the cured layer is in contact with the component being cleaned.

8. A processing box comprising an electrophotographic cleaning scraper according to any one of claims 1 to 7.

9. An electrophotographic image forming apparatus comprising an electrophotographic cleaning blade according to any one of claims 1 to 7.

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