JP2007086295A - Developer restricting blade, method of manufacturing same, and developing device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a developer restricting blade capable of preventing image defects due to a turnup and flaw of the blade even in an initial state wherein a developer carrier is not coated with toner, and also preventing image defects such as fogging and a development stripe due to a decrease in electrostatic charging of toner during long-period use. <P>SOLUTION: In the developer restricting blade which has a blade member and a support member pasted together, and is used to restrict the amount of a developer carried on the surface of a developer carrier for carrying the developer on the surface by abutting on the developer carrier, at least a surface layer (abutting surface) of the blade member which comes into contact with the developer carrier has a 0.3 to 1.2 coefficient of static friction and particulates are distributed in an exposed state. <P>COPYRIGHT: (C)2007,JPO&INPIT

Description

  The present invention relates to a developer regulating blade for regulating the amount of developer used for developing and visualizing an electrostatic latent image formed on an image carrier, a method for manufacturing the same, and a developing device equipped with the same. About.

  In an electrophotographic apparatus using an electrophotographic system for image formation, such as a copying machine, a facsimile machine, and a printer, a fine powder is used to visualize (develop) an electrostatic latent image formed on an image carrier (photosensitive drum, etc.). A developer made of colored resin (hereinafter also referred to as toner) is used. In supplying the developer to the surface of the image carrier, the toner stored in the developer container is usually carried on the surface of the developer carrier, and the carried developer is placed on the electrostatic latent image on the image carrier. A method of supplying and attaching is used. The amount of developer carried on the surface of the developer carrying body is adjusted by a blade or the like that is in contact with the developer carrying body.

  FIG. 2 shows a schematic configuration of the developing device portion of the electrophotographic apparatus.

  The toner 16 stored in the developer container 12 is pressed against a developer carrier (also referred to as a developing sleeve or a developing roller) 13 by an elastic roller (toner supply roller) 15 that rotates in the c direction. Thereafter, the developer carrier 13 is rotated in the direction b to be conveyed to the image carrier (electrophotographic photosensitive member) 11 rotating in the direction a, where the electrostatic latent image formed on the image carrier 11 is conveyed. The image is transferred onto the image, and the electrostatic latent image is used as a toner visible image. Note that the blade member 17 of the developer regulating blade 14 is in contact with the developer carrier 13 on the developer carrier 13, and the amount of toner carried on the developer carrier 13 is regulated, so that the thickness is uniform. At the same time as the toner thin film is formed, a predetermined triboelectric charge is imparted to the toner.

  The developer regulating blade is generally formed from a rubber plate, a metallic thin plate, a resin plate, or a laminate of members selected from these. As an example, there is a developer regulating blade constituted by a blade member pressed against a developer carrier and a support member that supports the blade member at a predetermined position. The pressure contact surface of the blade member to the developer carrying member has a function of controlling the frictional charge of the toner and is also called a charge control surface. The surface layer of the charge control surface is sometimes called a charge control layer.

  As the blade member used for the negative toner, for example, a plate material such as urethane rubber, urethane resin, polyamide elastomer or the like is used. Further, as the developer regulating blade used for the positive toner, a metal thin plate laminated with a charge imparting layer such as silicone rubber whose charge is controlled is used.

  As for the non-magnetic toner used for color image formation, since the toner itself does not have magnetism, a high triboelectric charge must be given to the toner to coat the developer carrier. Therefore, the charge control layer is formed of urethane rubber, polyamide resin, polyamide elastomer, silicone rubber, silicone resin, or the like, and is in contact with the developer carrying member to regulate the triboelectric charge amount and regulate the toner carrying amount. Yes.

  In particular, at the present time when high image quality and full color are being developed in image formation using an electrophotographic process, the toner layer on the developer carrying member is further thinned due to the particle size of the toner becoming finer, etc. In addition to high image quality and full color, high-speed image processing and high durability of the apparatus are essential. As a result, in order to achieve the function of the developer regulating blade, it is indispensable to press the developer carrier with a relatively strong pressure. When a conventional developer regulating blade is used in the initial state where no toner is carried on the developer carrying member, the developer regulating blade is turned on with the developer carrying member simultaneously with turning of the blade member or driving of the developer carrying member. A banding phenomenon such as vibbling or bouncing occurs at the contact portion of the toner, and stable toner uptake (carrying) is not achieved. Or, since the charge control surface is damaged by such a phenomenon, image defects such as image unevenness, ghost, and development streak are likely to occur in the initial operation.

  In addition, today, where energy and resource savings are sought, in developing processes using toner that can be fixed at low temperatures for low power consumption, when using for a long period of time, the developer carrier and the developer are regulated with a strong pressure. Since the pressure contact between the blades is repeated, the toner is remarkably deteriorated, a stable charge imparting property cannot be realized, and image defects such as fogging and development streaks may occur.

  In order to prevent such initial turning and banding of the blade member and to suppress image defects such as image unevenness and ghosting, lubricate the blade surface of the developer regulating blade in advance before assembling each part as a process cartridge. A method of applying an agent particle dispersion has been introduced (for example, Patent Document 1). However, when a lubricant particle dispersion is used, these image defects can be solved, but since a volatile solvent is used, the environmental load is large, and solution management for eliminating the dispersion of lubricant particles is difficult.

  A method of directly applying lubricant particles to a developing sleeve without using a solvent is known (for example, Patent Document 2). In this method, since a volatile solvent is not used, the environmental load is small and initial image defects are eliminated. However, since it is necessary to apply lubricant particles during the process of assembling the process cartridge, there is a risk that production tact will be reduced (productivity will be lowered) and cost will be increased.

  On the other hand, a developer having a sponge-like supply member impregnated with fluorine-modified silicone oil as a lubricant in order to suppress the toner from adhering to the surface of the blade member and sticking, and to obtain a good image formation A regulating blade has been introduced (for example, Patent Document 3). However, in such a method for suppressing toner sticking using oil oozing out, not a small amount of oil adheres to the toner, and the oil is removed at the stage of developing the electrostatic latent image on the image carrier. The oil may secondarily transfer and adhere from the adhered toner to the image carrier or other parts, which may cause a harmful effect on the image.

That is, in the developer regulating blade, in the initial state in which the toner is not carried on the developer carrying member, image defects due to the turning of the blade and the occurrence of scratches are suppressed, and the charge imparting property to the toner is lowered during long-term use. Therefore, it is desired to suppress image defects such as fogging and development streaks.
Japanese Patent Publication No. 07-086722 JP 2002-229333 A JP 2001-242701 A

  Accordingly, an object of the present invention is to prevent image defects associated with blade turning and scratches in an initial state where toner is not carried on the developer carrying member, and to impart charge to the toner during long-term use. It is an object of the present invention to provide a developer regulating blade capable of suppressing the occurrence of image defects such as fogging and development streaks due to a decrease, a manufacturing method thereof, and a developing device including the same.

  The present invention is as described, and this solves the above problem.

(1) The blade member has a shape attached to the support member, and controls the amount of developer (toner) carried on the surface of the developer carrying member by contacting the developer carrying member. The developer regulating blade has a static friction coefficient of 0.3 to 1.2 on the contact surface of the blade member with the developer carrying member, and is distributed with fine particles exposed on the contact surface. A developer regulating blade characterized by.

(2) The developer regulating blade according to (1), wherein the fine particles exposed on the contact surface of the blade member with the developer carrying member are made of a resin having a chargeability opposite to that of the toner.

(3) The above-mentioned (1) or (2), wherein the surface occupancy ratio of the fine particle blade member at the contact surface with the developer carrier is 30 to 60% with respect to the projected area of the toner. Developer regulating blade.

(4) The developer regulating blade according to any one of (1) to (3), wherein the blade member is made of a thermoplastic elastomer.

(5) A method for producing a developer regulating blade according to any one of (1) to (4), wherein first, fine particles are coated on a surface transfer sheet, and then the fine particle is coated on the coated surface for the blade member. A blade member sheet is formed by forming a raw material film, a support member sheet is bonded to the exposed surface of the blade member sheet, and the obtained surface transfer sheet, the blade member sheet and the laminated sheet of the support member sheet are cut out, and then the surface A method for producing a developer regulating blade, comprising peeling off a transfer sheet.

(6) A method for producing a developer regulating blade according to any one of (1) to (4), wherein first, fine particles are applied onto a surface transfer sheet, and then the fine particles are applied onto the application surface of the fine particles. The raw material is formed into a blade member sheet, and after the surface transfer sheet and the blade member sheet are cut out into the blade member shape, the support member is bonded to the exposed surface of the blade member sheet, and then the surface transfer sheet is attached. A method for producing a developer regulating blade, characterized by peeling.

(7) The developing device, wherein the developer regulating blade is the developer regulating blade according to any one of (1) to (4).

  In the developer regulating blade of the present invention, the contact surface (charge control surface) with the developer carrying member has a static friction coefficient of 0.3 to 1.2, and the fine particles are adhered to the contact surface. Therefore, in the initial state where the toner is not carried on the developer carrying member, the blade is not turned over or the charge control surface is hardly damaged, and the deterioration of the charge imparting property to the toner is suppressed even during long-term use. Therefore, when this developer regulating blade is incorporated in a developing device of an electrophotographic apparatus, it is possible to provide a good image free from image unevenness, fogging and development streaks.

  Hereinafter, the present invention will be described in detail.

  FIG. 1 is an enlarged cross-sectional view of a portion of the developer regulating blade of the present invention that abuts against a developer carrier.

  The developer regulating blade 22 of the present invention comprises a blade member 20 and a support member 21, and the surface of the blade member 20 that contacts the developer carrying member has a coefficient of static friction of 0.3 to 1.2. The fine particles 32 dispersed in the blade member 20 are exposed and distributed.

  In the present invention, the static friction coefficient is measured by a static friction coefficient measuring device “Haydon Tribogear Type 10” (trade name) manufactured by Shinto Kagaku Co., Ltd. The static friction coefficient measuring machine used here is a friction coefficient measuring machine widely used in each field, and a metal ball indenter or the like is generally used as a contact jig for measurement. Usually, a weight is put on the load of the measurement indenter, and measurement can be performed at a desired load and a test speed. In particular, when evaluating the turning of the blade member, the scratch on the charge control surface, and the banding phenomenon that occur when the developer carrier is driven in the initial state where the developer carrier of the present invention is not coated with toner. It is useful to measure the coefficient of static friction measured in (1). Further, it is more useful to evaluate in a state similar to the developing process, and a roller type measuring element obtained by processing a developer carrier to a specific size is used as a measuring indenter so that the process speed and the contact pressure can be approximated. It is also possible to use an object and make an evaluation by contacting the blade member surface with the same load so as to approximate the actual contact pressure. In the present invention, since it is possible to estimate even when a metal ball indenter is used, the static friction coefficient is measured by a contact surface between a stainless steel ball indenter whose surface is mirror-finished and the blade member surface. The thing was adopted.

  3 and 4 are schematic views showing a state where the developer regulating blade of the present invention is in contact with the developer carrying member. 3 shows that the blade member 20 and the support member 21 are integrated on the entire surface, and FIG. 4 shows that the blade member 20 comes into contact with the developer carrier 24 to uniformly charge the toner and uniformly. A size provided on the support member 21 in a size necessary to be carried on the developer carrier 24 is shown.

  In these drawings, the developer regulating blade 22 integrated with the blade member 20 and the support member 21 is fixed to the developer container 23 at a portion up to the fixing point 25 at the mounting portion of the developer regulating blade 22 of the developer container 23. ing. A pressure contact 26 on the free end side of the developer regulating blade 22 is pressed against the developer carrier 24 and exerts a pressure contact force F. The developer regulating blade 22 can be fixed to the developer container 23 by a known method such as adhesion or screwing.

  The blade member 20 is not particularly limited, and is made of a thermoplastic elastomer selected depending on mechanical characteristics and charging characteristics of toner used. The blade member 20 is laminated on the support member 21 via a reaction curable adhesive, and at least a developer is supported. The fine particles 32 are distributed in an exposed state on the surface (contact surface) that contacts the body.

  In the present invention, it is essential that the blade member 20 has a coefficient of static friction of 0.3 to 1.2 at least on the surface layer of the pressure contact 26 to the developer carrier 24. The coefficient of static friction can be controlled by the surface layer and the fine particles 32 exposed on the surface layer.

  The fine particles used here are preferably lubricant particles because they are generally used as a toner carrier and used to improve slipperiness. In addition, when fine particles having a charging performance opposite to that of the toner are used, it is also a material that imparts good charge to the toner. In order to develop the charge imparting property, it is preferably distributed in an exposed state at least on the surface layer of the blade member in contact with the developer carrying member.

  The fine particles used in the present invention are not particularly limited. For negative toners, fine particles such as nylon, melamine resin, and PMMA resin are preferable. For positive toners, fluorine resin, silicone resin, and the like are used. Fine particles are preferred.

  The particle size of the fine particles is not particularly limited, but may depend on the particle size of the toner, the surface roughness of the developer carrier, etc., but the surface of the blade member that contacts the developer carrier is exposed to the fine particles. It is preferable that the average particle size is 1 μm or less because it is preferable to be smooth even in a distributed state. When the average particle size of the fine particles is larger than 1 μm, when the fine particles themselves form a secondary or tertiary aggregate when the fine particles are exposed on the surface of the blade member, the size of the toner is about the same. The surface may be unevenly adhered to the developer carrying member, which may cause problems on the image. In addition, fine particles having the same size as the average particle diameter of the toner fall off from the surface layer of the blade member during use, resulting in rough blade member surfaces, promoting toner adhesion, and image defects such as development streaks. Sometimes.

  The fine particles distributed on the surface layer of the blade member are not limited to a single layer, and a layer having a certain thickness may be formed, so that the static friction coefficient is in the range of 0.3 to 1.2. It is preferable to form a layer. When this static friction coefficient is less than 0.3, it is necessary to form an excessive fine particle layer in order to realize such a low static friction coefficient. In that case, the initial slipperiness is good, and it is possible to effectively suppress the turning of the blade in the state where the toner is not carried (at the time of initial operation) and the occurrence of scratches on the charge control surface. In spite of the selection of the blade member suitable for the above, the excessively existing fine particles promote the deterioration of the toner and the accumulation of the external additive during the long-term use, and the development streaks are likely to occur. On the other hand, when the coefficient of static friction exceeds 1.2, the blade member is turned over, the charge control surface is scratched, and the banding phenomenon occurs extremely in the initial stage when the toner is not sufficiently carried. Image detriment occurs.

  Further, when the ratio of the fine particles exposed to the surface of the blade member and occupying the surface (surface occupancy ratio) is evaluated to be in the range of 30 to 60% of the toner projected area. This is because, when a toner having an average particle diameter of about 5 μm is used, fine particles exposed on the surface of the blade member having an average particle diameter of 1 μm are used. There will be 15 pieces. With such a fine particle surface occupancy rate, the abutting portion between the blade member and the developer carrying member reliably comes into contact with the carried toner, and the slipping property and the triboelectric charging are good. When the area occupation ratio is less than 30%, even if there are fine particles, the effect as a lubricant cannot be expected, and image defects such as initial image unevenness and streaks are likely to occur. In addition, when the surface occupation ratio exceeds 60%, fine particles are abundant, so the effect as a lubricant is high, but even a blade member selected according to the development process such as surface hardness, In this case, toner fusion occurs on the surface of the blade member, and excessive fine particles exist on the surface of the blade member, which causes excessive charging and causes toner charge-up, resulting in fogging. It becomes easy to do.

  From the above viewpoints, a material is selected as the blade member that has good mechanical characteristics, charging characteristics of the toner used, and good adhesion to the fine particles. Therefore, as a material for forming the blade member, for negative toners, polyester resins, polyester elastomers, polyurethane resins, polyurethane elastomers, polyamide resins, polyamide elastomers, etc. having the opposite charging ability are also used. For positive toners, silicone elastomers with adjusted charging ability are suitable. A blade member can be formed using at least one of these.

  Since the developer regulating blade of the present invention requires that fine particles be distributed on the contact surface with the developer carrying member, a developer regulating blade comprising a blade member and a supporting member is produced as a manufacturing method thereof. Then, the fine particles are adhered to the portion corresponding to the contact surface of the developer carrier, or the fine particles are supplied to the contact surface after incorporating the developer regulating blade to which the fine particles are not adhered, and the fine particles are applied to the contact surface. Although these may be distributed, these methods only have fine particles on the surface and are effective in preventing the blade from turning over only at the beginning of new use. May become frustrating.

  Therefore, the developer regulating blade of the present invention first applies fine particles onto the surface transfer sheet, forms a blade member material on the coated surface, and forms a blade member sheet. A support member sheet is bonded to the exposed surface of the blade member sheet and cut out from the obtained surface transfer sheet, a laminated sheet of the blade member sheet and the support member sheet, or (B) a surface transfer sheet and blade member in a blade member shape The sheet is cut out, a support member is bonded to the exposed surface of the cut blade member sheet, and then the surface transfer sheet is peeled off from the developer regulating blade with the surface transfer sheet. According to (A), the developer regulating blade shown in FIG. 3 can be produced, and according to (B), the developer regulating blade shown in FIG. 4 can be produced.

  FIG. 5 schematically shows an example in which the fine particle layer and the blade member sheet are formed on the surface transfer sheet.

  In order to coat the fine particles 32 on the surface transfer sheet 64, the lubricant particles 32 are charged while rubbing an elastic roller 66 such as a sponge on the surface transfer sheet 64, so that the fine particles 32 are formed on the surface transfer sheet 64. It is fixed electrostatically. The fine particles 32 excessively fed in the molding direction are made to have a desired coat layer thickness by the fine particle layer thickness regulating blade 67 formed of an elastic body. The blade member resin 65 melted and discharged from the die 61 is sandwiched between two opposing rollers 62 and 63 on the surface transfer sheet 64 on which the lubricant particle 32 layer is formed, thereby forming a blade member sheet.

  A support member sheet coated with a reactive curable adhesive in advance is bonded to the exposed surface of the blade member sheet with the surface transfer sheet thus manufactured, and the surface transfer sheet, the blade member sheet, and the support member sheet Is cut into a predetermined shape, and the surface transfer sheet is peeled off to form a developer regulating blade.

  Alternatively, a blade member sheet with a surface transfer sheet is cut into a blade member shape in advance, and then integrated with a support member coated with an adhesive, and the surface transfer sheet is peeled off to form a developer regulating blade. can do.

  The developer regulating blade shown in the present invention can be manufactured without being limited to this, and a manufacturing method that can achieve the object shown in the present invention can be adopted.

  In order to realize a sufficient function as a blade, the thickness of the blade member is preferably 1 μm or more, more preferably 10 μm or more, and may be 50 μm or more, or may be 100 μm or more. On the other hand, in order to achieve more appropriate contact, uniformly charge the developer particles, and suppress wear, the thickness is preferably 300 μm or less, more preferably 100 μm or less, and sometimes 50 μm or less.

  The support member of the developer regulating blade is preferably one having rigidity and springiness effective for bringing the blade member into contact with the developer carrier, for example, a metal such as stainless steel, phosphor bronze, iron, nickel, or fiber reinforced. A sheet-like material such as resin is suitable.

  The thickness of the support member depends on the material in order to achieve the function as a blade, but is preferably 50 μm or more, more preferably 80 μm or more, still more preferably 90 μm or more, most preferably 100 μm or more, while 150 μm or less. Is preferred.

  Further, the thickness of the developer regulating blade (the total thickness of the portion including the laminated structure of the blade member and the support member) is the sum of the thickness of the blade member and the thickness of the support member, and is particularly 51 to 450 μm, for example. preferable.

  When the developer regulating blade of the present invention is used, even when the developer carrying member is not coated with toner, the blade is prevented from turning over and scratches on the charge control surface are suppressed, and the toner is charged during long-term use. The deterioration of the imparting property is also suppressed, there is no image defect such as unevenness and development streak, and a good image can be formed in both initial and long-term use.

  Next, FIG. 2 shows an example of a developing device using the developer regulating blade 22 having the configuration shown in FIG.

  A developer container 12 containing a one-component developer 16 is provided with a developer carrier (developing sleeve) 13 disposed opposite to an electrophotographic photosensitive member 11 of an image carrier that rotates in the direction of arrow a in the figure. A developer is supplied to the electrostatic latent image on the photoconductor 11 so as to be visualized as a toner visible image.

  The developer carrier 13 has a substantially right half circumferential surface that protrudes into the developer container 12 as viewed in the figure, and a substantially left half circumferential surface is exposed to the outside of the developer container 12 so as to face the electrophotographic photosensitive member 11. , Are rotatably arranged. A minute gap is provided between the developer carrier 13 and the electrophotographic photoreceptor 11. The developer carrier 13 is rotationally driven in the direction of the arrow b with respect to the rotational direction a of the electrophotographic photosensitive member 11. In the developer container 12, a developer regulating blade 14 of the present invention is provided above the developer carrier (developing sleeve) 13, and the developing is performed at a position upstream of the blade member 17 in the rotation direction of the developing sleeve 13. An agent supply roller 15 is provided. The developer regulating blade 14 is provided so as to be inclined downward toward the upstream side in the rotational direction of the developing sleeve 13, and the blade member 17 is in contact with the upper outer peripheral surface of the developing sleeve 13 facing the rotational direction. The developer supply roller 15 is in contact with a portion of the developing sleeve 13 opposite to the electrophotographic photoreceptor 11 and is rotatably supported.

  The developer supply roller 15 rotates in the direction of the arrow c, and the toner 16 on the developer supply roller 15 is rubbed against the development sleeve 13 at a portion (nip portion) in contact with the development sleeve 13. Stick on top. Thereafter, as the developing sleeve 13 rotates, the toner 16 adhering to the developing sleeve 13 enters between them at the contact portion between the developer regulating blade 14 and the developing sleeve 13, and develops when passing therethrough. It is further rubbed by both the surface of the sleeve 13 and the blade member 17 and sufficiently charged by friction.

  The charged toner 16 passes through the contact portion between the blade member 17 and the developing sleeve 13 to form a thin layer on the developing sleeve 13, and opens a minute gap to the developing portion facing the electrophotographic photosensitive member 11. Be transported. Then, for example, an alternating voltage in which alternating current is superimposed on direct current is applied as a developing bias between the developing sleeve 13 and the electrophotographic photosensitive member 11 in the developing unit, whereby the toner 16 on the developing sleeve 13 is transferred to the electrophotographic photosensitive member 11. The toner image is transferred corresponding to the electrostatic latent image, and is attached to the electrostatic latent image and developed to be visualized as a toner image.

  The toner 16 remaining on the developing sleeve 13 without being consumed in the development in the developing unit returns to the developer container 12 from the lower portion of the developing sleeve 13 as the developing sleeve 13 rotates. The returned toner 16 is peeled off from the developing sleeve 13 by the developer supply roller 15 at the contact portion with the developing sleeve 13. At the same time, new toner 16 is supplied onto the developing sleeve 13 by the rotation of the elastic roller 15, and the new toner 16 is conveyed again to the contact portion between the developing sleeve 13 and the blade member 17.

  On the other hand, most of the removed toner 16 is conveyed and mixed into the toner 16 in the developer container 12 as the developer supply roller 15 rotates, and the charged charge of the removed toner 16 is dispersed. The

  FIG. 6 shows an example of an electrophotographic apparatus suitable for employing the developing device of the present invention.

  Reference numeral 51 denotes an electrophotographic photosensitive member as an image carrier, which is a drum type electrophotographic photosensitive member having a conductive support such as aluminum and a photosensitive layer formed on the outer peripheral surface thereof as basic constituent layers. It is rotationally driven at a predetermined peripheral speed in the clockwise direction on the drawing around the support shaft. The charging member 52 is a corona discharger that is in contact with the photosensitive member 51 and performs primary charging processing on the surface of the photosensitive member so as to have a predetermined polarity and potential. This may be a charging roller.

  The surface of the electrophotographic photosensitive member 51 that has been uniformly charged by the charging member 52 is then exposed to target image information (laser beam scanning exposure, slit exposure of a document image, etc.) by the exposure means L, so An electrostatic latent image 53 corresponding to target image information is formed on the surface. The latent image is then sequentially visualized as a toner visible image by the developing device 54.

  Then, the toner image is transferred from the sheet feeding means (not shown) by the transfer means 55 in synchronization with the rotation of the electrophotographic photoreceptor 51 and transferred between the electrophotographic photoreceptor 51 and the transfer means 55 at an appropriate timing. Are sequentially transferred onto the surface of the transfer material P conveyed to the surface. The transfer means 55 in this example is a corona discharger, and the toner image on the surface of the photoconductor 51 is transferred to the surface side of the transfer material P by charging the reverse polarity of the toner from the back of the transfer material P. The transfer unit may be a charging roller. In addition, in a color LBP that outputs a color image using four color toners, the toner is temporarily transferred to an intermediate transfer member such as a roller or a belt in order to develop and visualize the four color images, respectively. The image is transferred to the surface side of the transfer material P. The transfer material P that has received the transfer of the toner image is separated from the surface of the photoreceptor 51, sent to the heat fixing roller pair 58, subjected to image fixing, and output as an image formed product.

  Thereafter, the surface of the electrophotographic photosensitive member 51 after the image transfer is cleaned by the cleaning unit 56 after removal of adhering contaminants such as transfer residual toner, and if necessary, the residual charge and the electrostatic residual image are removed by the charge eliminating unit 57. It is repeatedly used for image formation.

  It should be noted that a plurality of elements of the electrophotographic apparatus such as an electrophotographic photosensitive member, a charging member, a developing device, and a cleaning unit can be integrally incorporated as a process cartridge. By doing so, the process cartridge can be attached to and detached from the apparatus main body. For example, the electrophotographic photosensitive member and the developing device and, if necessary, a charging member, a cleaning unit, and the like are integrally incorporated in the process cartridge, and can be detachably configured using a guide unit such as a rail of the apparatus main body.

  Examples of the electrophotographic apparatus that can use the developing device of the present invention include a copying machine, a laser beam printer, an LED printer, or an electrophotographic application apparatus such as an electrophotographic plate making system.

  The present invention will be further described below with reference to examples and comparative examples. Unless otherwise specified, “parts” and “%” represent “parts by mass” and “mass%”, respectively, and reagents and the like used were commercially available high-purity products.

Example 1
A surface transfer sheet in which polyamide elastomer (manufactured by Daicel Degussa, trade name: Daiamide E40S1) is melted at 250 ° C. as a raw material of the blade member, and melamine resin particles (average particle diameter of 0.5 μm) are preliminarily applied as a lubricant. (PET produced by extrusion molding having a thickness of 0.1 mm and a surface roughness Rzjis of 0.3 μm) is extruded so that the thickness after solidification is 0.10 mm. A 2 mm two-layer sheet was prepared by a roll coater method. The obtained two-layer sheet was bonded to phosphor bronze having a thickness of 0.12 mm having spring elasticity as a supporting member, and cut into a shape having a length of 200 m in the longitudinal direction and a width of 22 mm. Next, the sheet for surface transfer was peeled off from the blade of the laminated sheet to obtain a developer regulating blade.

  Next, the static friction coefficient of the charge control surface of the molded developer regulating blade, the thickness of the blade member, and the surface occupation ratio of the fine particles were measured as follows. As a result, the coefficient of static friction was 0.293, the thickness was 2 μm, and the surface occupation ratio was 57%.

[Static friction coefficient measurement]
It measured with the static-friction-coefficient measuring machine based on JISK7125 (Shinto Kagaku Co., Ltd. make, brand name: Haydon tribogear Type 10).

[Layer thickness measurement]
The molded developer regulating blade was cut, the cross section was mirror-polished, and observed with SEM (trade name: S-4300, manufactured by Hitachi, Ltd.), and the thickness was measured.

[Area occupancy measurement]
The surface of the blade member was observed with an SEM (trade name: S-4300, manufactured by Hitachi, Ltd.), the number of exposed melamine resin particles and the diameter were measured, and the exposed area per unit area was calculated.

  The developer regulating blade obtained above is incorporated as a developer regulating blade for a process cartridge of a laser beam printer (manufactured by Canon Inc., product name: Lasershot). Immediately after startup, whether or not scratches are generated on the charge control surface, Check for the occurrence of vertical streaks in the solid black and halftone image output images (initial evaluation), and output solid black and halftone images every 1000 times during continuous 30,000 image formation (endurance) The presence or absence of vertical stripes on the image was examined, and the presence or absence of toner fusion to the charge control surface was examined every 10,000 times (durability evaluation). And it determined by the following evaluation criteria, respectively, and also comprehensively evaluated from these results. Further, the charge amount of the developing sleeve-shaped toner after durability evaluation was measured.

[Initial evaluation]
First, after outputting one solid white mode in a low-temperature and low-humidity environment of 12 ° C. and 10 RH%, the contact surface (charge control surface) of the blade member with the developer carrying member was observed to confirm the presence or absence of scratches. Thereafter, the process cartridge was returned, one solid black image and one halftone image were output, and it was confirmed whether vertical streaks due to scratches on the charge control surface were generated, and the following criteria were used.
A: There is no scratch on the charge control surface, and there are no vertical stripes in both solid black and halftone images.
○: Slight scratches were observed on the charge control surface, but there were no vertical stripes in the solid black and halftone images.
Δ: Scratches are observed on the charge control surface, and vertical stripes can be confirmed in the solid black image, but not in the halftone image.
X: Scratches are observed on the charge control surface, and vertical stripes are confirmed in the solid black and halftone images.

[Durability evaluation]
Image formation was performed a total of 30,000 times in a low temperature and low humidity environment of 12 ° C. and 10 RH%. On the way, solid black and halftone images are output every 1,000 times, the presence or absence of vertical streaks on the image is checked, and whether or not there is a toner fusion on the charge control surface every 10,000 times Were examined and judged according to the following criteria.
A: There are no vertical stripes in the image and there is no fused toner.
○: There are no vertical stripes in the image, and there is a slight amount of fused toner that cannot be confirmed in the image.
Δ: A vertical stripe cannot be confirmed in a halftone image, and a vertical stripe can be confirmed in a solid black image.
X: Vertical streaks can be confirmed in the image for both solid black and halftone, and there are many toner fusion products.

[Toner charge on developer carrier]
After the durability evaluation, the toner carried on the developer carrying member was collected by suction using a metal cylindrical tube and a cylindrical filter, and the amount of charge stored in the condenser and the collected toner mass were measured through the metal cylindrical tube. . From these values, the charge amount per unit mass (μC / g) was calculated.

[Comprehensive evaluation]
Considering the results of the initial evaluation and durability evaluation, the determination was made according to the following criteria.
A: Initial determination of endurance is “A”, “A”, “A”, “A” or “A”, “A”.
○: Initial and endurance judgment is “◯”, “◯”, “◎”, “△”, or “△”, “◎”.
Δ: Initial and durability determination is “Δ”, “Δ”, “O”, “Δ”, or “Δ”, “O”.
X: At least one of the initial and endurance judgments is “x”.

(Examples 2 to 4)
A blade member sheet with a surface transfer sheet was prepared in the same manner as in Example 1 except that the sandwiching pressure of the opposing rollers was adjusted, and a developer regulating blade was prepared in the same manner as in Example 1 below. These developer regulating blades were evaluated in the same manner as in Example 1, and the results are shown in Table 1.

(Comparative Example 1)
As in Example 1, except that polyurethane elastomer (manufactured by DCI Bayer Polymer Co., Ltd., trade name: Pandex T-2190) was used as a raw material for the blade member, and the film was formed without coating with melamine resin particles. A developer regulating blade was prepared. The obtained developer regulating blade was evaluated in the same manner as in Example 1, and the results are shown in Table 1.

(Comparative Example 2)
A blade member sheet with a surface transfer sheet was prepared in the same manner as in Example 1 except that the pressure of the lubricant layer thickness regulating blade was reduced and the melamine resin particle layer was adjusted to be thickly coated. A developer regulating blade was produced in the same manner as in Example 1. The obtained developer regulating blade was evaluated in the same manner as in Example 1, and the results are shown in Table 1.

  From the results of Table 1, as in Comparative Examples 1 and 2, when the static friction coefficient of the surface of the blade member contacting the developer holding body is larger than 1.2, the developer carrying body in the initial state where the toner is not coated It can be seen that a flaw on the charge control surface of the blade member that occurs during driving of the blade member occurs, and vertical stripes due to the flaw occur. Further, in durability evaluation, it is understood that toner fusion occurs due to a decrease in charge amount, and vertical stripes due to this cause begin to occur. If it is less than 0.3, the initial evaluation is good, but the melamine resin particles are excessively present on the surface layer of the charge control surface, so that the flexibility inherent in the blade member is lost and the surface layer is extremely high. It can be seen that in the latter half of the endurance, toner fusion occurs frequently and development streaks are remarkable. On the other hand, as in Examples 1 to 4, in the blade member in which the melamine resin particles are distributed on the surface layer of the charge control surface and the static friction coefficient is in the range of 0.3 to 1.2, the toner Even if the developer carrying member is driven without any scratches, scratches are not generated, there is no problem with the initial image, and in the durability evaluation, there is no toner fusion, and vertical stripes may be generated on the image. And good results are obtained.

FIG. 4 is an enlarged cross-sectional view of a developer regulating blade. It is a schematic diagram for demonstrating an example of a developing device. FIG. 6 is a schematic diagram illustrating a contact state of a developer regulating blade with an electrophotographic photosensitive member. FIG. 6 is a schematic diagram illustrating a contact state of a developer regulating blade with an electrophotographic photosensitive member. It is a figure for demonstrating the manufacturing method of the developer control blade of this invention. It is a schematic diagram for demonstrating an electrophotographic apparatus.

Explanation of symbols

11 Electrophotographic photoreceptor (image carrier)
12 Developer container 13 Developer carrier (developing sleeve, developing roller)
14 Developer regulating blade 15 Elastic roller (toner supply roller, developer supply roller)
16 Developer (toner)
DESCRIPTION OF SYMBOLS 17 Blade member 20 Blade member 21 Support member 22 Developer control blade 23 Developer container 24 Developer carrier 25 Fixed point 26 Pressure contact 32 Fine particle 51 Photoconductor 52 Charging member 53 Electrostatic latent image 54 Developing device 55 Transfer means 56 Cleaning Means 57 Static elimination means 58 Fixing roller 61 Die 62 Roller 63 Roller 64 Sheet for surface transfer 65 Blade member resin 66 Elastic roller 67 Fine particle layer thickness regulating blade

Claims (7)

  A developer regulation for regulating the amount of developer (toner) carried on the surface of the developer carrying member by contacting the developer carrying member with a blade member attached to the support member The blade is characterized in that the static friction coefficient of the contact surface of the blade member with the developer carrying member is 0.3 to 1.2 and the fine particles are distributed on the contact surface. Developer regulating blade.   2. The developer regulating blade according to claim 1, wherein the fine particles exposed on the contact surface of the blade member with the developer carrying member are made of a resin having chargeability opposite to that of the toner.   3. The developer regulation according to claim 1, wherein a surface occupancy ratio of the fine particle blade member at a contact surface with the developer carrying member is 30 to 60% with respect to a projected area of the toner. blade.   The developer regulating blade according to claim 1, wherein the blade member is made of a thermoplastic elastomer.   5. The method for producing a developer regulating blade according to claim 1, wherein first, fine particles are applied on a surface transfer sheet, and then a blade member raw material is formed on the fine particle application surface. Then, a blade member sheet is formed, a support member sheet is bonded to the exposed surface of the blade member sheet, and the obtained surface transfer sheet, the blade member sheet and the laminated sheet of the support member sheet are cut out, and then the surface transfer sheet is formed. A method for producing a developer regulating blade, characterized by peeling.   5. The method for producing a developer regulating blade according to claim 1, wherein first, fine particles are applied on a surface transfer sheet, and then a blade member raw material is formed on the fine particle application surface. Forming a blade member sheet, cutting out the surface transfer sheet and the blade member sheet into a blade member shape, bonding the support member to the exposed surface of the blade member sheet, and then peeling the surface transfer sheet A method for producing a developer regulating blade.   A developing device, wherein the developer regulating blade is the developer regulating blade according to claim 1.

Images