JP2008033282A - Conductive blade member and manufacturing method thereof - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a conductive blade member having an electric resistance which is a stable middle resistance and is hardly uneven, over the whole blade, and to provide a manufacturing method of the conductive blade member. <P>SOLUTION: The blade member comprises: a blade main body made of a conductive rubber member made by mixing a rubber base material with carbon black and crosslinking the mixture; and a resin layer disposed on one surface side in the thickness direction of the blade main body, wherein the blade main body and the resin layer are integrally molded by centrifugal molding, the resin layer has a true density smaller than that of the rubber base material and comprises a resin whose fusing point is a molding temperature of the centrifugal molding or less. <P>COPYRIGHT: (C)2008,JPO&INPIT

Description

  The present invention relates to a conductive blade member and a method for manufacturing the same, and more particularly, to a toner image carrier on which a toner image is formed in an electrophotographic method and thereafter the toner image is transferred to a transfer material. The present invention relates to a conductive blade member suitable for use as a cleaning blade member for removing toner, a printing squeegee, a charging blade member, a transfer blade member, a developing blade member, and the like, and a method for manufacturing the conductive blade member.

The conductive blade member having rubber elasticity and controlled conductivity is important in the electrophotographic process, but the molecules constituting the rubber itself have a resistivity (10 ⁵ to 10 ⁸ Ωcm) required by the process. ) As a specific resistance value is rare, and only a limited number such as epichlorohydrin has been put into practical use. In many cases, conductive fine particles such as carbon black are added to chemically stable substrates such as silicone rubber, EPDM, and polyurethane to maintain the required elastic modulus, mechanical strength, and temperature and humidity characteristics. After imparting properties, a coating layer for adjusting resistance is formed. This is because the resistance of the conductive blade member composed of only a single layer is likely to vary due to a slight difference in the blending amount of carbon black.

  However, the blade member consisting of a conductive layer added with carbon black and a coating layer has a problem that it is easy to peel off due to weak adhesion between the blade body and the coating layer, and the surface is coated after forming the blade. There was a problem that it took.

  On the other hand, since the blade member is in contact with the photoconductor for a long period of time, it is required to have good wear resistance and a low coefficient of friction. In recent years, further, as the unit has a longer life, the photoconductor has become highly durable, and accordingly, the blade is also required to have high durability. In order to make a highly durable blade, it is necessary to increase the hardness of the blade. However, if the hardness of a single-layer blade is increased, the contact pressure on the photosensitive member becomes too high and the film on the surface of the photosensitive member will not peel off. There is a problem that it occurs or the blades become loose. Therefore, a cleaning blade having a plurality of structures has been proposed (see, for example, Patent Document 1).

  Although this cleaning blade uses a plurality of types of materials, the layer on the cleaning edge side in contact with the member to be cleaned, and other layers showed excellent characteristics by supplementing the respective characteristics, Since the plurality of layers are sequentially formed by centrifugal molding, there is a problem that labor and cost are required.

  In the case of centrifugal molding, there is a problem that it is difficult to control the thickness and it is difficult to form a thin layer of 500 μm or less. If the cleaning edge layer in contact with the member to be cleaned becomes too thick, the characteristics of the other layers cannot be fully exhibited.

JP 2004-184462 A

  SUMMARY OF THE INVENTION In view of such circumstances, the present invention provides a highly durable conductive blade member having a stable middle resistance throughout the blade and having a small variation in electrical resistance, and a method for manufacturing the same. And

  A first aspect of the present invention that solves the above-described problems is a blade body made of a conductive rubber member obtained by crosslinking a carbon base material with carbon black and provided on one surface side in the thickness direction of the blade body. The blade body and the resin layer are integrally formed by centrifugal molding, and the resin layer has a true density lower than that of the rubber base material and has a melting point of the centrifugal layer. The conductive blade member is made of a resin having a molding temperature equal to or lower than the molding temperature.

According to a second aspect of the present invention, in the conductive blade member according to the first aspect, the electrical resistance value from the surface on the blade body side to the surface on the resin layer side of the conductive blade member is 1.0 × 10 ^5. -1.0 * 10 < ⁸ > (ohm) It exists in the electroconductive blade member characterized by the above-mentioned.

  According to a third aspect of the present invention, in the conductive blade member according to the first or second aspect, the rubber base material is made of cast urethane rubber or cast silicone rubber. is there.

  According to a fourth aspect of the present invention, in the conductive blade member according to any one of the first to third aspects, the thickness of the resin layer is 25% or less with respect to the total thickness. There is a conductive blade member.

  According to a fifth aspect of the present invention, in the conductive blade member according to any one of the first to fourth aspects, the resin layer has a thickness of 500 μm or less.

  A sixth aspect of the present invention is the conductive blade member according to the fifth aspect, wherein the resin layer has a thickness of 100 μm or less.

  According to a seventh aspect of the present invention, in the conductive blade member according to any one of the first to sixth aspects, the resin is blended to be 30 parts by weight or less with respect to 100 parts by weight of the rubber base material. The conductive blade member is characterized in that it is molded.

  According to an eighth aspect of the present invention, a rubber base, carbon black, and a resin having a lower true density than that of the rubber base are molded from a mixed state by a centrifugal molding machine, and the molding is higher than the melting point of the resin. A conductive blade member having a blade body made of a conductive rubber member and a resin layer on one side in the thickness direction of the blade body is obtained by molding at a temperature. In the manufacturing method.

According to a ninth aspect of the present invention, in the method for manufacturing a conductive blade member according to the eighth aspect, the electrical resistance value from the surface on the blade body side to the surface on the resin layer side of the conductive blade member is 1.0. A conductive blade member manufacturing method is characterized by obtaining a conductive blade member having a size of × 10 ^{5 to} 1.0 × 10 ⁸ Ω.

  According to a tenth aspect of the present invention, in the method for producing a conductive blade member according to the eighth or ninth aspect, the resin is in a powder form or a pellet form. is there.

  An eleventh aspect of the present invention is the method for producing a conductive blade member according to any one of the eighth to tenth aspects, wherein the rubber base material is made of cast urethane rubber or cast silicone rubber. There is a method for manufacturing a conductive blade member.

  According to a twelfth aspect of the present invention, in the method for manufacturing a conductive blade member according to any one of the eighth to eleventh aspects, the thickness of the resin layer is 25% or less with respect to the total thickness. It is in the manufacturing method of the electroconductive blade member characterized by forming in.

  A thirteenth aspect of the present invention is characterized in that, in the method for producing a conductive blade member according to any one of the eighth to twelfth aspects, the resin layer is molded so that the thickness of the resin layer is 500 μm or less. It exists in the manufacturing method of an electroconductive blade member.

  According to a fourteenth aspect of the present invention, there is provided the conductive blade member manufacturing method according to the thirteenth aspect, wherein the resin layer is molded so that the thickness of the resin layer is 100 μm or less. In the manufacturing method.

  According to a fifteenth aspect of the present invention, in the method for producing a conductive blade member according to any one of the eighth to fourteenth aspects, the resin is 30 parts by weight or less with respect to 100 parts by weight of the rubber base material. Thus, there is a method for producing a conductive blade member characterized by blending and molding.

  The conductive blade member of the present invention is obtained by integrally forming a blade body made of a conductive rubber member in which carbon black is blended with a rubber base material and a resin layer by centrifugal molding. And the resin layer have high adhesion. This conductive blade member has a medium resistance as a whole by thinly providing a resin layer with a high electrical resistance value on one side in the thickness direction of the blade body in which carbon black is sufficiently blended to reduce the electrical resistance value. It can be. In addition, since a thin resin layer having a uniform thickness is provided on the surface of the blade body, it becomes a highly durable conductive blade member having a stable medium resistance and a small variation in electric resistance over the entire blade. .

  The method for producing a conductive blade member according to the present invention includes a rubber base material, carbon black, and a resin having a lower true density than the rubber base material, which are separated from the melting point of the resin while being centrifuged from a mixed state by a centrifugal molding machine. By molding at a high molding temperature, a conductive blade member having a blade body and a resin layer on one side in the thickness direction of the blade body is obtained. Unlike the centrifugal molding method in which is introduced, the conductive blade member can be easily molded at low cost. Because this manufacturing method is easy to control the wall thickness, a thin resin layer with a high electrical resistance value is provided on one side in the thickness direction of the blade body, which is sufficiently blended with carbon black to reduce the electrical resistance. Therefore, a medium-resistance conductive blade member can be manufactured. Further, since a thin resin layer having a uniform thickness can be provided on the surface, it is possible to manufacture a highly durable conductive blade member having a stable medium resistance and a small variation in electrical resistance over the entire blade. it can.

  The conductive blade member of the present invention includes a blade main body made of a conductive rubber base material obtained by crosslinking carbon black into a rubber base material, and a resin layer provided on one side in the thickness direction of the blade main body. The blade body and the resin layer are integrally formed by centrifugal molding. Here, “the blade body and the resin layer are integrally formed by centrifugal molding” means that the blade body raw material (rubber substrate) and the resin layer raw material (resin) are separated while being centrifuged. Is different from the one in which the blade main body and the resin layer are sequentially formed to form two layers.

  The conductive blade member of the present invention is composed of two layers of a blade body and a resin layer made of a conductive rubber member obtained by blending carbon black into a rubber base material and crosslinking, so that carbon black is sufficiently blended in the blade body. can do. In other words, the conductive blade member of the present invention has a thin resin layer on one side of the blade body, so that it can be electrically connected with a dispersion state of carbon black and a slight difference in addition amount as in a conventional conductive blade member. There is no problem that the resistance value is likely to fluctuate significantly, and a larger amount of carbon black can be blended in the blade body than in the prior art. Since a high-resistance but thin resin layer is provided on one side of the blade body, which is sufficiently mixed with carbon black and has a low resistance, a conductive blade member with a medium resistance that is stable throughout.

  In addition, since the conductive blade member of the present invention is formed by centrifugal molding, the surface layer (resin layer) is a thin layer having a high degree of flatness and a uniform thickness, and the electric resistance value of the entire blade is low. The conductive blade member has medium resistance with reduced variations.

  Since this conductive blade member is made of a resin whose resin layer has a true density lower than that of the rubber base and whose melting point is equal to or lower than the molding temperature of centrifugal molding, the blade body and the resin layer are integrally molded by centrifugal molding. can do. That is, since the melting point of the resin is equal to or lower than the molding temperature of centrifugal molding, the resin can be melted by being heated to the molding temperature during centrifugal molding, and the resin and the rubber base material have different true densities. Therefore, since the rubber base material and the resin can be separated by centrifugation, the rubber base material, the carbon black, and the resin are simultaneously introduced into the centrifugal molding machine, and the thickness of the blade body is reduced. A resin layer can be formed on the direction side. The true density here is not the bulk density in the apparent volume of particles with large irregularities, but the density in the volume when all the gaps are eliminated.

  As described above, the conductive blade member of the present invention is different from the conventional conductive blade member coated on the surface of the blade body, because the blade body and the resin layer are integrally formed by centrifugal molding, Is a conductive blade member that is high and difficult to peel off. Moreover, it can be easily molded at low cost.

  The method for producing a conductive blade member according to the present invention includes a rubber base material, carbon black, and a resin having a lower true density than the rubber base material, which are separated from the melting point of the resin while being centrifuged from a mixed state by a centrifugal molding machine. By molding at a high molding temperature, a conductive blade member having a blade body and a resin layer on one surface side in the thickness direction of the blade body is obtained. According to this manufacturing method, it is possible to easily and integrally form a conductive blade member composed of two layers of a blade body composed of a conductive rubber member and a resin layer. Further, since a thin surface layer (resin layer) can be formed, a highly durable and medium resistance conductive blade member can be manufactured. That is, the method for producing a conductive blade member of the present invention can provide a thin high-resistance resin layer on one side of the blade body, which has become low resistance by sufficiently blending carbon black. The overall resistance can be medium. The resin constituting the resin layer has a relatively high hardness compared to the conductive rubber member constituting the blade body, but the manufacturing method of the present invention can provide a thin resin layer, so the hardness of the entire blade It is possible to obtain a highly durable conductive blade member without significantly increasing the height.

  In addition, since a thin resin layer having a uniform thickness can be provided on the surface, it is possible to manufacture a conductive blade member having an electric resistance value that is stable and has a small variation across the entire blade. . Furthermore, since there is no need to perform centrifugal molding a plurality of times, the above-described conductive blade member can be manufactured at low cost.

  The conductive blade member of the present invention becomes a highly durable conductive blade member by appropriately selecting a resin to be a resin layer according to the application. By forming a high-hardness resin layer on one surface side in the thickness direction of the blade body, for example, when contacting the photoreceptor, the resin layer is a surface layer that contacts the photoreceptor, etc. A conductive blade member having a low coefficient of friction can be obtained without significantly increasing the contact pressure.

  The conductive blade body according to the present invention is made of a conductive rubber member obtained by blending carbon black into a rubber base material and crosslinking it. Carbon black used as a conductive agent for the conductive blade member has electrical conductivity and is insoluble in a polymer base material such as a rubber member, and is relatively inexpensive and easily takes a three-dimensional structure. In addition, the conductivity is not easily affected by temperature and humidity. The type of carbon black is not particularly limited, and examples thereof include ketjen black (manufactured by Lion Corporation) and talker black # 5500 (manufactured by Tokai Carbon Corporation).

  In addition to carbon black, an ionic conductive agent can also be used as a conductive agent. The ion conductive agent is not particularly limited, and examples thereof include lithium perchlorate. In addition to the ionic conductive agent, a carbon black dispersant may be used. Examples of the carbon dispersant include Disparon DA-703-50 (trade name: manufactured by Enomoto Kasei Co., Ltd.). Each of the ionic conductive agent and the carbon black dispersant may be used alone or in combination.

The conductive blade member of the present invention can contain a large amount of carbon black in the blade body. For this reason, the blade body can have low resistance (volume resistivity of 1.0 × 10 ⁴ Ωcm or less) and no variation. The blending amount of carbon black may be appropriately adjusted so that the blade body has a desired electric resistance value, and is not particularly limited.

The carbon black blended in the rubber base material has a true density as small as 1.70 to 2.10 g / cm ³ and a particle size as small as about 10 nm to 500 nm. For this reason, carbon black is dispersed in the rubber base material without being centrifuged like a resin having a large particle diameter in centrifugal molding.

  The compounding amount of carbon black is preferably 0.4 to 5.0 parts by weight with respect to 100 parts by weight of the rubber base material. Carbon rubber can be blended in a large amount in the rubber base material compared to conventional ones. However, if the amount of carbon black is too large, the viscosity of the conductive rubber base material mixed with the rubber base material and carbon black will increase. It is not preferable because the conductive rubber base material and the resin are difficult to centrifuge.

  The blade body according to the present invention is composed of a conductive rubber member in which carbon black is mixed with a rubber base material and crosslinked. Examples of the rubber base material include thermosetting rubber materials, and cast polyurethane rubber or cast silicone rubber is preferable.

  The casting type liquid polyurethane is a mixture of a high molecular weight polyol, an isocyanate compound, a chain extender, a crosslinking agent and the like.

  Examples of the polyol include polyester polyol, polycarbonate polyol, and polyether polyol.

  On the other hand, as isocyanate compounds, 4,4′-diphenylmethane diisocyanate (MDI), 2,6-toluene diisocyanate (TDI), 1,5-naphthalene diisocyanate (NDI), 3,3-dimethyldiphenyl-4-diisocyanate (TODI) ) And paraphenylene diisocyanate (PPDI). Furthermore, examples of the chain extender include dihydric alcohols such as butanediol and ethylene glycol, or aromatic diamines. Moreover, as a crosslinking agent, polyhydric alcohols, such as a trimethylol propane and glycerol, can be mentioned, for example.

  The resin layer according to the present invention is made of a resin having a true density lower than that of the rubber substrate and a melting point equal to or lower than the molding temperature of centrifugal molding. In addition, resin here refers to a thermoplastic resin from the characteristic, and contains a thermoplastic elastomer. A resin having a true density smaller than that of the rubber base is used because the carbon black compounded in the rubber base is liable to settle in the radial direction inside the centrifugal molding machine, that is, on the mold surface side by centrifugation. This is for separation on the mold surface side. Also, a resin having a melting point equal to or lower than the centrifugal molding temperature is used because the resin is melted and separated by being heated to the molding temperature during centrifugal molding, and the resin layer is formed on one side of the blade body in the thickness direction. This is because can be formed.

  The conductive rubber base material is preheated and put into a centrifugal molding machine, and the melting point of the resin is preferably higher than the preheating temperature. This is because if the melting point of the resin is lower than the preheating temperature, the resin melts during centrifugation, making it difficult to separate the conductive rubber substrate and the resin.

  Here, the preheating temperature is, for example, 70 to 100 ° C., and the molding temperature for centrifugal molding is, for example, about 180 to 200 ° C. For this reason, although it changes with preheating temperature and the shaping | molding temperature of centrifugal molding, it is preferable that melting | fusing point of resin is 80-190 degreeC, More preferably, it is 110-160 degreeC.

  As the resin to be the resin layer, it is preferable to use a powder or pellet. This is because it is relatively easy to separate from the conductive rubber base material during centrifugal molding. The resin is preferably centrifuged and then melted by heating to form a resin layer, but may be heated so that the resin melts during the centrifugation. Even in this case, the molten resin is centrifuged. In addition, as for powder-form or pellet-form resin, a particle size is 1.0-5000 micrometers, for example, Preferably it is 3-500 micrometers. By being in this range, the rubber base material and the resin are easily centrifuged, and the conductive blade member provided with the resin layer on the one surface side in the thickness direction of the blade body can be easily formed. If the resin particle size is too small, it becomes difficult to centrifuge the conductive rubber base material and the resin when forming the conductive blade member by centrifugal molding. If the resin particle size is too large, a thin resin layer This is not preferable because it becomes difficult to mold the material.

  If it is difficult to separate the conductive rubber base material and resin mixed with the rubber base material and carbon black, it is necessary to mix the rubber base material and carbon black so that the curing reaction rate of the conductive rubber base material is slow. You may make it select the material of a rubber base material so that a ratio, molding conditions, etc. may be selected or the viscosity of a conductive rubber base material may fall.

  At this time, it is preferable to use a conductive rubber base material and a resin having relatively low compatibility. Since the conductive rubber base material and the resin have different true densities, they are separated by centrifugation. However, if the conductive rubber base material and the resin are highly compatible, the conductive rubber is particularly affected when the resin melts during the separation. This is because the base material and the resin are compatible and may not be centrifuged. However, the conductive rubber base material and the resin must have a certain degree of compatibility. Specifically, it is preferable that the blade body and the resin layer are compatible so that an integral conductive blade member can be formed. If the compatibility between the conductive rubber substrate and the resin is too low, the resin layer of the molded conductive blade member will be easily peeled off.

  Moreover, it is preferable that surface micro hardness Hs of the resin layer measured with a micro hardness meter is 70-95 degrees. This is because by using a resin layer having a relatively high hardness, a highly durable blade member having a low friction coefficient and excellent wear resistance can be obtained. Since the blade member according to the present invention has a high-hardness resin layer on one side in the thickness direction, ether-based polyurethane having low wear resistance but excellent temperature dependency can also be used as a rubber base material. In this way, by providing a resin layer with high hardness and excellent wear resistance on one side of the blade body in the thickness direction, the blade body has excellent wear resistance even when a rubber base with low wear resistance is used. A blade member. At this time, the micro hardness Hs of the blade body is preferably 60 to 80 °. By making the resin layer in contact with the toner adhering body high in hardness and making the belt main body low in hardness compared to the resin layer, it becomes a conductive blade member having high durability and excellent wear resistance and sag resistance. Because.

  The resin of the resin layer according to the present invention may be appropriately selected according to the true density of the rubber base material as long as the above-described conditions are satisfied.

  When the conductive blade member is centrifugally molded using a rubber base material, carbon black, and a resin having a true density smaller than that of the rubber base material, a resin layer is formed on the inner side of the blade body made of the conductive rubber member in the centrifugal mold. Is formed. This is because the resin having a lower true density than the rubber base material is separated inward in the radial direction of the rubber base material by centrifugal force.

When the rubber base material is polyurethane, the true density of the polyurethane is about 1.0 to 1.3 g / cm ³ , so it varies depending on the type of polyurethane, but the true density is lower than the rubber base material and the melting point is Examples of resins having a molding temperature lower than that of centrifugal molding and high hardness include olefin resins such as polypropylene and polyethylene, polyamide resins having a melting point of 200 ° C. or less such as nylon 11 and nylon 12, olefin elastomers (TPO), and styrene resins. An elastomer (TPS) can be mentioned.

When the rubber base material is silicone rubber, the true density of the silicone rubber is about 0.95 to 0.98 g / cm ³ , so the true density is smaller than this, the melting point is below the molding temperature of centrifugal molding, and Examples of the high-hardness resin include olefin resins such as polypropylene and polyethylene, olefin elastomer (TPO), and styrene elastomer (TPS).

Examples of the olefin elastomer (TPO) include Zelas # 7023 (manufactured by Mitsubishi Chemical Corporation) and Zelas # MC601 (manufactured by Mitsubishi Chemical Corporation). Examples of the styrene elastomer (TPS) include Hibler 5127. (Manufactured by Kuraray Plastics), Hibler 5125 (manufactured by Kuraray Plastics) and the like. The above-described resin has a high resistance (volume resistivity 1.0 × 10 ⁹ Ωcm or more). By providing a thin resin layer with a high resistance (volume resistivity 1.0 × 10 ⁹ Ωcm or more) on the surface of the blade body having a low resistance (volume resistivity 1.0 × 10 ⁴ Ωcm or less), the blade member has a medium resistance. can do.

On the other hand, the thickness of the resin layer is preferably 25% or less with respect to the thickness of the entire conductive blade member. Moreover, it is preferable that the thickness of a resin layer is 500 micrometers or less, More preferably, it is 100 micrometers or less. By setting the thickness of the resin layer within this range, a highly durable conductive blade member capable of sufficiently exhibiting the characteristics of the blade body can be obtained. If the thickness of the resin layer is greater than 500 μm, the blade body cannot fully exhibit its characteristics such as loss of flexibility, the overall hardness of the conductive blade member may increase, or the conductive blade This is not preferable because the member may have a high resistance (1.0 × 10 ⁹ Ω or more).

  The blending amount of the resin is not particularly limited, but it is preferably blended and molded so as to be 30 parts by weight or less with respect to 100 parts by weight of the rubber base material. By blending the resin layer so as to be in this range, a highly durable blade member that can sufficiently exhibit the characteristics of the blade body can be obtained.

As described above, the blade member of the present invention has a high resistance (volume resistivity of 1) on a blade body which has a low resistance (volume resistivity: 1.0 × 10 ⁴ Ωcm or less) by incorporating a relatively large amount of carbon black. 0.0 × 10 ⁹ Ωcm or more), the electrical resistance value from the surface of the conductive blade member on the blade body side to the surface on the resin layer side is 1.0 × 10 ^{5 to} 1.0 ×. 10 ⁸ Ω is preferable.

  The conductive blade member of the present invention has a high degree of flatness by being molded by a centrifugal molding method. That is, since the surface layer (resin layer) is a uniform layer having a high degree of flatness, it becomes a conductive blade member in which variation in electric resistance value is suppressed with a medium resistance over the entire blade.

  Here, the manufacturing method of the electroconductive blade member of this invention is demonstrated in detail. First, a rubber base material, carbon black, and a resin are mixed and preheated. Then, a mixture of the rubber base material, carbon black, and resin is put into a centrifugal molding machine, and is molded by centrifugation while rotating the drum at a predetermined rotational speed.

  The rubber base material, carbon black, and resin that are put into the centrifugal molding machine are carbon black and a rubber base material with a high true density that is due to centrifugal force due to rotation. Separate inward. At this time, carbon black is dispersed in the rubber base material put into the centrifugal molding machine and reacts at the molding temperature of centrifugal molding, and the resin is separated from the rubber base material and carbon black and melted at the molding temperature of centrifugal molding. A melt film having a uniform thickness is formed.

  When the rubber base material containing carbon black is cured and the resin is melted, the rotation of the drum is stopped, and demolding and cooling are performed.

  When the melted coating of the demolded resin becomes a hard coating by cooling, cut one end into a sheet, and after aging as necessary, the longitudinal direction of the conductive blade member is along the circumferential direction By cutting, the blade body and the resin layer are uniform in thickness, and these two layers are integrally formed to obtain a conductive blade member.

  As described above, the manufacturing method of the conductive blade member of the present invention is the same as that described above, in which the blade body material (conductive rubber substrate) and the resin layer material (resin) are simultaneously charged by centrifugal molding. The layers can be formed integrally. Thus, the method for producing a conductive blade member of the present invention can easily form a conductive blade member with high adhesion at low cost.

  Moreover, the manufacturing method of the electroconductive blade member of this invention can control wall thickness easily by controlling the quantity of the raw material thrown into a drum. Specifically, for example, by controlling the amount of resin, the thickness of the resin layer can be 500 μm or less, and further 100 μm or less. Since the thickness of the resin layer can be reduced in this way, a high resistance resin layer (surface layer) is provided on one surface side in the thickness direction of the low resistance blade body to provide a medium resistance blade member. Can do. In addition, by setting the thickness of the resin layer within this range, the characteristics of the belt body (characteristics of the conductive rubber base material) can be sufficiently exhibited. That is, according to the manufacturing method of the present invention, a highly durable conductive blade member can be molded while maintaining the characteristics of the conductive rubber member.

  In the method for producing a conductive blade member of the present invention, it is preferable to mold the resin layer so that the thickness of the resin layer is 25% or less. This is because if the resin layer is thicker than this, the conductive blade member may have a high resistance, and the characteristics of the blade body cannot be sufficiently exhibited.

  As described above, the method for producing a conductive blade member of the present invention can provide a thin resin layer having a uniform thickness on the surface, so that a stable medium resistance and a small variation in electric resistance can be obtained over the entire blade. A conductive blade member having the same can be manufactured.

  Hereinafter, although an example of embodiment of the electroconductive blade member of this invention is shown in FIG. 1, this invention is not limited to this.

  A cleaning blade 10 shown in FIG. 1 is used, for example, in a cleaning unit that removes toner on a toner adhering member, and a conductive blade member 12 is fixed to a support plate 11 as shown in the figure. Here, the conductive blade member 12 includes a blade body 12A made of a conductive rubber base material and a resin layer 12B. The cleaning blade 10 is a portion where the resin layer 12B contacts the toner adhering body.

  As described above, the conductive blade member of the present invention is suitable for use as an electrophotographic photosensitive member, a transfer drum and transfer belt used in a transfer process, or a cleaning blade member used for charging / discharging / cleaning an intermediate conveyance belt. However, the present invention is not limited to this, and is suitable for use in, for example, a developing blade, a charging blade, a transfer blade, a toner regulating blade, etc. for use in a developing process for charge flattening, charge removal and charging. . The conductive blade member of the present invention can be smoothed, neutralized, and charged by contacting a charged body such as a photoconductor to smooth the charge on the charged body.

  Hereinafter, although the electroconductive blade member of this invention is demonstrated based on an Example, this invention is not limited to this.

(Example 1)
100 parts by weight of a caprolactone-based polyol having a molecular weight of 2000, 46 parts by weight of 4,4′-diphenylmethane diisocyanate (MDI), 1.4 parts by weight of carbon black, and 1,4-butanediol / trimethylolpropane mixed liquid (70 / 30) was blended in an amount of 11.2 parts by weight to obtain a raw material for the blade body.

The resin layer raw material was 5.1 parts by weight of polyethylene (PE) powder having a particle size of 3 to 12 μm and a true density of 0.92 g / cm ³ .

  These blade body materials and resin layer materials are preheated, put into a rotating drum of a 300 mm diameter centrifugal molding machine, centrifuged (at 150 ° C., rotated at 1400 rpm (about 350 G)), and removed from the cylinder The sheet was cooled and cut to obtain a sheet having a total blade thickness of 2.0 mm and a resin layer thickness of 70 μm. This was aged and then cut into test pieces.

(Example 2)
A test piece was obtained in the same manner as in Example 1 except that 22 parts by weight was used instead of 5.1 parts by weight of polyethylene (PE) powder and the thickness of the resin layer was 250 μm.

(Comparative Example 1)
A test piece was obtained in the same manner as in Example 1 except that the resin layer was not formed.

(Comparative Example 2)
A urethane sheet (1) having a thickness of 1200 μm was formed in the same manner as in Example 1 using the raw material of the blade body of Example 1 without using the raw material of the resin layer. Subsequently, a urethane sheet (2) having a thickness of 800 μm is provided on the surface of the urethane sheet (1) using the same raw material as that of the blade main body of Example 1 except that carbon black is not used, and consists of two layers. A test piece of Comparative Example 2 was obtained.

(Comparative Example 3)
A urethane sheet (3) having a thickness of 1500 μm was formed in the same manner as in Example 1 by using the raw material of the blade body of Example 1 without using the raw material of the resin layer. Subsequently, an attempt was made to provide a urethane sheet (4) having a thickness of 500 μm on the surface of the urethane sheet (3) using the same raw material as that of the blade body of Example 1 except that carbon black was not used. The test piece having a uniform thickness could not be produced without flowing over the entire surface of the urethane sheet (3).

(Test Example 1)
The electrical resistance value was measured about the test piece of each Example and each comparative example. In addition, the test piece was pinched | interposed using two electrode members, and the electrical resistance value of the test piece was measured at three places by ULTRA HIGH REISTANCE METER R8340A (made by Advantest Corporation). The results are shown in Table 1 below.

The electrical resistance value of the test piece of Example 1 is 3.6 × 10 ^{6 to} 1.1 × 10 ⁷ Ω, and the electrical resistance value of the test piece of Example 2 is 2.3 × 10 ^{7 to} 7.6 × 10 ^7. Ω and medium resistance. Further, the variation in electric resistance value was small and stable.

On the other hand, the electrical resistance value of the test piece of Comparative Example 1 was stable with little variation, but the electrical resistance value was a low resistance of 6.2 × 10 ^{3 to} 1.7 × 10 ⁴ Ω.

The electrical resistance value of the test piece of Comparative Example 2 in which the two layers were formed in sequence was as high as 8.7 × 10 ^{8 to} 3.5 × 10 ⁹ Ω because the surface layer was thick.

  From this, it was found that the conductive blade member of the present invention is a stable conductive blade member having a medium resistance and a small variation in electric resistance.

It is a figure which shows an example of embodiment of the electroconductive blade member of this invention.

Explanation of symbols

DESCRIPTION OF SYMBOLS 10 Cleaning blade 11 Support plate 12 Conductive blade member

Claims (15)

A blade main body made of a conductive rubber member obtained by crosslinking carbon black into a rubber base material and a resin layer provided on one surface side in the thickness direction of the blade main body, the blade main body and the resin And the resin layer is made of a resin having a true density smaller than that of the rubber base material and a melting point equal to or lower than the molding temperature of the centrifugal molding. Conductive blade member. 2. The conductive blade member according to claim 1, wherein an electrical resistance value from a surface on the blade body side to a surface on the resin layer side of the conductive blade member is 1.0 × 10 ^{5 to} 1.0 × 10 ⁸ Ω. A conductive blade member. 3. The conductive blade member according to claim 1, wherein the rubber base material is made of cast urethane rubber or cast silicone rubber. 4. 4. The conductive blade member according to claim 1, wherein a thickness of the resin layer is 25% or less with respect to a total thickness. 5. The conductive blade member according to claim 1, wherein the resin layer has a thickness of 500 μm or less. The conductive blade member according to claim 5, wherein the resin layer has a thickness of 100 μm or less. The conductive blade member according to any one of claims 1 to 6, wherein the resin is blended and molded so that the resin is 30 parts by weight or less with respect to 100 parts by weight of the rubber base material. A conductive blade member. By molding a rubber base material, carbon black, and a resin having a lower true density than the rubber base material from a mixed state using a centrifugal molding machine at a molding temperature higher than the melting point of the resin, A method for producing a conductive blade member, comprising: obtaining a conductive blade member having a blade body made of a rubber member and a resin layer on one side in the thickness direction of the blade body. 9. The method for manufacturing a conductive blade member according to claim 8, wherein an electrical resistance value from the surface of the conductive blade member on the blade body side to the surface on the resin layer side is 1.0 × 10 ^{5 to} 1.0 × 10 ^8. A method for producing a conductive blade member, comprising obtaining a conductive blade member that is Ω. The method for manufacturing a conductive blade member according to claim 8 or 9, wherein the resin is in a powder form or a pellet form. The method for manufacturing a conductive blade member according to any one of claims 8 to 10, wherein the rubber substrate is made of cast urethane rubber or cast silicone rubber. The method for producing a conductive blade member according to any one of claims 8 to 11, wherein the resin layer is molded so that the thickness of the resin layer is 25% or less with respect to the total thickness. A method for manufacturing a blade member. The method for producing a conductive blade member according to any one of claims 8 to 12, wherein the resin layer is molded so that the thickness of the resin layer is 500 µm or less. The method for manufacturing a conductive blade member according to claim 13, wherein the resin layer is molded so that the thickness of the resin layer is 100 μm or less. In the manufacturing method of the electroconductive blade member in any one of Claims 8-14, it mix | blends and shape | molds so that the said resin may be 30 weight part or less with respect to 100 weight part of said rubber base materials. A method for producing a conductive blade member.

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