JP2008155087A - Liquid coating head, liquid applicator, and coating method - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a liquid coating head which is capable of forming a coated material with good dimensional precision and to provide a liquid applicator and a coating method using the same. <P>SOLUTION: The liquid coating head is an annular coating head having an annular slit to discharge liquid over the inner circumference. It is provided with an annular distribution chamber communicating with the annular slit and a supply port to supply the liquid from the outside to the distribution chamber. Further, an annular piston for extruding the liquid supplied into the distribution chamber by pressurization is arranged in front of the distribution chamber. <P>COPYRIGHT: (C)2008,JPO&INPIT

Description

  The present invention relates to a coating head used for forming a coating layer on a peripheral surface of a cylindrical substrate, and a coating method using the same.

  The present invention also relates to a method for producing an elastic roller and a developing roller using the coating method. Furthermore, the present invention relates to a process cartridge and an image forming method using the developing roller.

  The electrophotographic image forming apparatus includes a roller-shaped functional member (hereinafter referred to as “roller member”) having a coating layer containing rubber or resin on the peripheral surface of a cylindrical or columnar base (hereinafter abbreviated as “cylindrical base”). (Omitted) is often used.

In manufacturing such a roller member, a so-called ring coating method has been proposed as a method for uniformly applying a coating material for forming a coating layer on the peripheral surface of a cylindrical substrate (Patent Documents 1 to 3).
JP 2003-190870 A JP 2006-150266 A JP 2005-152830 A

  Along with the further improvement in the quality of electrophotographic images in recent years, higher accuracy has been demanded for elastic rollers and the like used in electrophotographic apparatuses. In order to satisfy the above requirements, it has been recognized that it is necessary to further improve the stability of the amount of paint discharged from the annular slit of the ring coating head.

  Accordingly, an object of the present invention is to provide a liquid coating head capable of forming a coating with good dimensional accuracy, a liquid coating apparatus using the same, and a coating method.

  Another object of the present invention is to provide a method for manufacturing an elastic roller with good runout accuracy.

  Another object of the present invention is to provide a method for producing a developing roller having good runout accuracy and little resistance unevenness in the circumferential direction.

  Another object of the present invention is to provide a process cartridge and an electrophotographic apparatus capable of forming an excellent image.

  The liquid coating head according to the present invention is an annular liquid coating head having an annular slit for discharging liquid over the entire inner circumference, and an annular distribution chamber communicating with the annular slit; A supply port for supplying liquid to the distribution chamber from the outside, and an annular piston for pressurizing the liquid supplied into the distribution chamber and pushing it out from the annular slit is disposed facing the distribution chamber. It is characterized by.

  The liquid coating apparatus according to the present invention includes the above-described liquid coating head, means for supporting a cylindrical substrate coaxially with the liquid coating head, and the cylindrical substrate and the liquid coating head relative to each other. And means for moving.

A coating method according to the present invention is a coating method for coating a peripheral surface of a cylindrical substrate using the above liquid coating apparatus,
(I) supporting the cylindrical substrate coaxially with the liquid coating head;
(Ii) supplying paint to the distribution chamber from the supply port of the liquid coating head, and distributing the paint over the entire circumference of the distribution chamber;
(Iii) applying the coating material in the distribution chamber distributed in the step (ii) to the peripheral surface of the cylindrical substrate by driving the annular piston and discharging it from the annular slit;
(Iv) A step of relatively moving the liquid coating head and the cylindrical substrate.

An elastic roller manufacturing method according to the present invention is an elastic roller manufacturing method using the above-described liquid coating apparatus,
(I) supporting the cylindrical substrate coaxially with the liquid coating head;
(Ii) supplying a paint containing liquid rubber from the supply port of the liquid coating head to the distribution chamber, and distributing the paint over the entire circumference of the distribution chamber;
(Iii) applying the paint in the distribution chamber distributed in the step (ii) to the peripheral surface of the cylindrical substrate by driving an annular piston to discharge the paint from the annular slit;
(Iv) a step of relatively moving the liquid coating head and the cylindrical substrate, and (v) a step of curing the liquid rubber in the coating applied to the peripheral surface of the cylindrical substrate. Features.

  The elastic roller according to the present invention is manufactured by the above-described elastic roller manufacturing method.

  The developing roller according to the present invention is manufactured by using a coating material containing a conductive agent as a coating material among the above-described elastic roller manufacturing methods.

  The process cartridge according to the present invention integrally supports a developer having at least a toner, a developer container containing the developer, and the developing roller, and is detachable from the electrophotographic apparatus main body. It is characterized by.

  An electrophotographic apparatus according to the present invention includes a developer having toner, a developer container containing the developer, the developing roller, an electrophotographic photosensitive member, a charging unit, an exposure unit, and a transfer unit. It is characterized by that.

  According to the present invention, the coating liquid distributed over the entire circumference of the distribution chamber is pressurized by the annular piston and extruded from the annular slit, whereby the coating liquid can be discharged uniformly in the circumferential direction. As a result, a coating layer having a more uniform thickness can be formed on the peripheral surface of the cylindrical substrate. Therefore, the outer diameter accuracy and the deflection accuracy can be further increased, and further, an elastic roller and a developing roller with extremely little resistance unevenness in the circumferential direction can be obtained.

  In addition, it is possible to provide a process cartridge and an image forming apparatus that can supply a high-quality electrophotographic image by using a developing roller that is excellent in outer diameter accuracy and deflection accuracy and has very little resistance unevenness.

  Hereinafter, although the form of this invention is demonstrated, this invention is not limited by this.

・ Description of FIG. 1;
FIG. 1 is a schematic explanatory view of a liquid coating apparatus using a liquid coating head according to the present invention.

  A column 2 is mounted substantially vertically on the gantry 1. A precision ball screw 3 is attached to the top of the gantry 1 and the column 2 in parallel to the vertical direction. Reference numeral 14 denotes a linear guide, two of which are mounted on the column 2 in parallel with the precision ball screw 3. The LM guide 4 connects the linear guide 14 and the precision ball screw 3, and a rotary motion is transmitted from the servo motor 5 through the pulley 6 so that the LM guide 4 can move up and down.

  The column 2 is provided with a coating head 8 for supplying a coating material to the peripheral surface of the cylindrical base 102 and discharging a liquid, for example, an uncured liquid rubber, from an annular slit. Further, an upper bracket 71 and a lower bracket 72 are attached to the LM guide 4. A lower holding shaft 9 that holds and fixes the cylindrical base body 102 is attached to the lower bracket 72. Further, the upper holding shaft 10 is attached to the upper bracket 71, and the upper holding shaft 10 is disposed so as to be concentric with the lower holding shaft 9 to hold the cylindrical base body 102.

  Further, the central axis of the coating head 8 is supported so as to be parallel to the moving direction of the lower holding shaft 9 and the upper holding shaft 10. Further, when the lower holding shaft 9 and the upper holding shaft 10 are moved, the central axis of the annular slit opened inside the coating head 8 and the central axes of the lower holding shaft 9 and the upper holding shaft 10 are concentric. It has been adjusted. With such a configuration, the central axis of the annular slit of the coating head 9 and the central axis of the cylindrical substrate can be aligned with each other. A uniform gap is formed between the inner peripheral surface of the coating head and the peripheral surface of the cylindrical substrate 102.

・ Coating head;
FIG. 2A is a schematic sectional view of the coating head 8 in FIG. 2B and 2C are cross-sectional views taken along lines AA and BB, respectively, of the coating head shown in FIG.

  The coating head 8 includes a hollow cylindrical inner ring (hereinafter referred to as an inner ring) 201 and a hollow cylindrical outer ring (hereinafter referred to as an outer ring) 205 having at least one supply port 11. Hereinafter, the cap ring 202 is held. A ring-shaped piston 208 is disposed between the inner ring and the outer ring. The annular slit 203 opened to the inside is controlled by the inner ring 201 and the cap ring 202.

  The inner ring 201 has a throttle step 207, and an annular liquid distribution chamber 206 is formed between the minimum outer diameter portion of the inner ring 201 and the outer ring 205. Therefore, the annular slit 203 communicates with the annular distribution chamber 206.

  The outer ring 205 has a supply port 11 for supplying paint to the distribution chamber 206.

  Reference numeral 208 denotes a ring-shaped piston that pressurizes the paint supplied into the distribution chamber 206 from the supply port 11 and discharges it from the annular slit 203. The paint distributed over the entire circumference of the distribution chamber 206 by driving the piston 208 is discharged from the annular slit 203 with a uniform pressure.

  When the outer diameter of the inner ring constituting the sliding portion of the piston 208 is d1min and the inner diameter of the outer ring is r2, the value of [r2 / d1min] is in the range of 1.05 to 2.0. In particular, it is preferably in the range of 1.2 to 1.4.

  By setting the value of [r2 / d1min] within the above range, the thickness of the piston 208 can be sufficiently increased. Therefore, the durability when extruding a high-viscosity coating liquid can be made more reliable. Further, since the volume of the sliding portion of the piston 208 is ensured, it is not necessary to lengthen the coating head 8 in the axial direction.

  At this time, the outer diameter d1min of the inner ring is preferably 20.00 mm or more and 95.0 mm or less, and the inner diameter r2 of the outer ring is preferably 21.0 mm or more and 100.0 mm or less. If both d1min and r2 are within the above numerical range, the ring-shaped piston within the coating head 8 can be made thinner and the durability when extruding a highly viscous coating liquid can be maintained. Moreover, it is not necessary to lengthen the coating head 8 in the axial direction.

  In FIG. 2, reference numeral 11 denotes a supply port for the coating liquid to the distribution chamber 206. The supply port 11 is connected to the material supply valve 13 via the coating liquid conveying pipe 12 shown in FIG. The material supply valve 13 shown in FIG. 1 includes a mixing mixer, a material supply pump, a material fixed amount discharge device, a material tank, and the like in front of the material supply valve 13 so that a fixed amount (a constant amount per unit time) can be discharged. The coating solution is weighed from a material tank by a material dispensing device and mixed by a mixing mixer. Thereafter, the coating liquid mixed by the material supply pump is sent from the material supply valve 13 to the supply port 11 via the pipe 12 and supplied to the distribution chamber 206 of the coating head.

  The ring-shaped piston 208 disposed facing the distribution chamber 206 is driven upward in FIG. 2A so that the coating liquid supplied in an annular shape into the distribution chamber 206 is extruded and discharged from the annular slit 203. And applied to the peripheral surface of the shaft core body.

  Here, although the example in which the coating head 8 is composed of a plurality of members is shown, it may be an integral mold, or may be composed of two or five or more members. The inner diameter L of the coating head 8 (the width of FIG. 9 and the annular slit 203 is appropriately selected depending on the film thickness, viscosity, solid content, and coating speed of the coating solution to be applied around the shaft core.

-Application | coating method using the said application | coating head, an elastic roller manufacturing method Next, the method of forming the layer of the uncured material of the cylindrical shape (roll shape) which consists of an application liquid on a shaft core outer peripheral surface is demonstrated. When the coating head 8 is fixed and the shaft core body 102 is moved in the axial direction, the shaft core body 102 is held by the shaft core lower holding shaft 9 and the shaft core upper holding shaft 10 shown in FIG. Next, the shaft core body is moved so that the coating start position of the coating layer on the shaft core body 102 is matched with the annular slit 203 of the coating head 8.

  On the other hand, the coating head 8 places the piston 208 in the most retracted position as shown in FIG. Next, as shown in FIG. 3B, the coating liquid is supplied from the coating liquid supply port 11 to the distribution chamber 206, and the coating liquid is supplied into the distribution chamber 206 in an annular shape. Here, the supply amount of the coating liquid to the distribution chamber 206 may be appropriately set in consideration of the thickness of the coating film formed on the peripheral surface of the shaft core, the length of the shaft core, and the like. At this time, the amount of the coating liquid is not limited to one elastic roller, and a desired number of liquids are weighed in advance and filled in the coating head for continuous coating without filling. You can also

  Next, as shown in FIG. 3C, the piston 208 is driven in the direction of arrow A in FIG. 3C to push the coating liquid in the distribution chamber 206 toward the annular slit 203, and the annular slit 203. Discharge from. At the same time as the coating liquid is discharged, the shaft core body held by the shaft core body holding shaft is moved in the axial direction (particularly in the vertical direction) to form a cylindrical shape (roll) on the outer peripheral surface of the shaft core body Shape) of uncured material is formed.

  According to the above method, since the pressure can be uniformly applied to the coating liquid distributed annularly in the distribution chamber using the ring-shaped piston, the amount of the coating liquid from the annular slit is made more uniform. be able to. For this reason, there is no uneven discharge of the coating liquid in the circumferential direction at the time of discharge, and an elastic roller can be manufactured with high deflection accuracy.

  In addition, when supplying the coating liquid from the supply port 11 to the distribution chamber 206, the influence of the shear history and weld line that may be generated in the coating liquid on the coating film formed on the peripheral surface of the shaft core is greatly suppressed. can do.

  As a result, a coating method and a coating apparatus are provided in which uneven resistance does not occur in the circumferential direction on the coated elastic roller. Here, the coating head 8 is fixed and the shaft core body 102 is moved. On the other hand, the shaft core body 102 is fixed, and the coating head 8 can be moved in the central axis direction of the shaft core body 102. That is, by moving the coating head relative to the shaft core body, a cylindrical (roll-shaped) uncured material layer made of the coating liquid is formed on the outer peripheral surface of the shaft core body. .

  The speed at which the ring-shaped piston 208 is driven may be constant or variable. By varying the driving speed, for example, the layer thickness of the coating liquid can be adjusted in the longitudinal direction of the roller.

  The viscosity of the coating solution is preferably 10 Pa · s or more and 5000 Pa · s or less. The viscosity is a value at a temperature of 25 ° C. By setting the viscosity of the coating liquid within the above range, the coating liquid does not sag in the direction of gravity due to its own weight, and the external dimensions and the accuracy of the shake can be improved. Moreover, since the coating solution viscosity is high at the shear rate in the pipe for supplying the material, it is possible to prevent the apparatus from being subjected to a high load and causing difficulty in stable material supply.

  The coating liquid formed on the outer peripheral surface of the shaft core is cross-linked and cured to form an elastic layer.

  At this time, since the uncured coating liquid having a cylindrical shape (roll shape) has adhesiveness, it is preferable to perform the heat treatment by a non-contact heat treatment method. Examples of the heat treatment method include an infrared heating method, a hot air heating method, and a nichrome heat heating method. In particular, infrared heating is preferred because the apparatus is simple and the layer of the uncured product can be uniformly heat-treated in the axial direction. At this time, heat treatment can be uniformly performed in the circumferential direction by fixing the infrared heating device and rotating the axial core body provided with the cylindrical (roll-shaped) uncured material layer in the circumferential direction. The heat treatment temperature on the surface of the coating solution is preferably 100 ° C. or more and 250 ° C. or less at which the curing reaction starts although it depends on the material used. For example, in the case of performing infrared heating, the distance between the infrared heating device and the uncured coating liquid layer, the output, and the like may be adjusted according to the characteristics of the material (thermal conductivity, specific heat). Moreover, what is necessary is just to adjust the temperature and direction of a hot air when performing hot air heating.

  Here, for the purpose of stabilizing physical properties of the elastic layer after curing, removing reaction residues and unreacted low-molecular components in the elastic layer, etc., secondary curing is performed in which the elastic layer formed by curing is further subjected to heat treatment or the like. It may be done.

・ About development roller;
The elastic roller according to the present invention can be used as a developing roller.

  A schematic diagram of an example is shown in FIG. FIG. 4A shows a cross section parallel to the longitudinal direction of the developing roller, and FIG. 4B shows a cross section perpendicular to the longitudinal direction.

  The shaft core body 102 of the developing roller according to the present invention may be any material as long as it is conductive, and can be appropriately selected from carbon steel, alloy steel, cast iron, and conductive resin. Here, examples of the alloy steel include stainless steel, nickel chromium steel, nickel chromium molybdenum steel, chromium steel, chromium molybdenum steel, nitriding steel to which Al, Cr, Mo and V are added. From the viewpoint of strength, a metal one is preferable. Furthermore, as a countermeasure against rust, the shaft core material can be plated and oxidized. As the type of plating, both electroplating and electroless plating can be used. From the viewpoint of dimensional stability, electroless plating is preferable. Examples of the electroless plating used here include nickel plating, copper plating, gold plating, Kanigen plating, and other various alloy plating. Examples of the nickel plating include Ni-P, Ni-B, Ni-WP, and Ni-P-PTFE composite plating. Each film thickness is preferably 0.05 μm or more, more preferably 0.1 to 30 μm.

  The developing roller is always in pressure contact with the photosensitive member, the developing blade, and the toner. For this reason, in order to reduce the damage given to these members, it is important to obtain a good image by using a material having a low hardness and a small compression set. Further, it is preferable that the surface of the developing roller has wear resistance and high durability. For this reason, the developing roller used in the present invention has an elastic layer 42 around the shaft core body 102.

  At this time, the hardness of the elastic layer 42 is preferably 10 degrees or more and 80 degrees or less in terms of Asker C hardness for the above reason. By setting the hardness of the elastic layer within the above range, the contact portion between the elastic roller and the contact member is unlikely to be deformed due to permanent strain even during a long-term stop. As a result, it is possible to suppress the occurrence of image defects such as density unevenness due to the deformation. In addition, when a high pressure is repeatedly applied to the toner during contact development, an external additive that imparts fluidity to the toner is buried in or separated from the toner, and the toner is fixed to the elastic roller as the remaining amount of toner decreases, so-called The deterioration of the image quality of the output image can be suppressed by filming. The elastic layer 42 need not be a single layer, and may be a multilayer.

  Examples of the material used for forming the elastic layer 42, that is, the constituent material of the coating liquid, include liquid diene rubber (butadiene rubber, isoprene rubber, nitrile rubber, chloroprene rubber, ethylene propylene rubber), liquid silicone rubber, and liquid urethane rubber. These materials can be used alone or in combination. Furthermore, foams of these materials may be used for the elastic layer. In particular, it is important that the elastic layer has a moderately low hardness and sufficient deformation recovery force. Accordingly, it is preferable to use liquid silicone rubber or liquid urethane rubber as the material used for the elastic layer. In particular, it is more preferable to use an addition reaction cross-linkable liquid silicone rubber that has good processability, high stability of dimensional accuracy, and does not generate a reaction by-product during the curing reaction.

  In order to obtain a conductive roller such as a developing roller, a conductive agent can be appropriately added to the liquid rubber to adjust to a desired resistance. A conductive agent having an ion conduction mechanism (ionic conductive agent) and a conductive agent having an electron conduction mechanism (electron conductive agent) can be appropriately selected and used as the conductive agent.

..Ionic conductive agents
Examples of the ionic conductive agent include the following.
_{··· LiCF 3 SO 3, NaClO 4} , LaClO 4, LiAsF 6, LiBF 4, NaSCN, KSCN, periodic table Group 1 metal salts such as NaCl;
... Ammonium salts such as NH ₄ Cl, (NH ₄ ) ₂ SO ₄ , NH ₄ NO ₃ ;
... Salts of Group 2 metals of the periodic table such as Ca (ClO ₄ ) ₂ and Ba (ClO ₄ ) ₂ ;
... A complex of any one of the above salts with a polyhydric alcohol such as 1,4-butanediol, ethylene glycol, polyethylene glycol, propylene glycol, polypropylene glycol, or a derivative thereof;
... A complex of any of the above salts with a monool such as ethylene glycol monomethyl ether, ethylene glycol monoethyl ether, polyethylene glycol monomethyl ether, polyethylene glycol monoethyl ether;
... Cationic surfactants such as quaternary ammonium salts;
... Anionic surfactants such as aliphatic sulfonates, alkyl sulfates, and alkyl phosphates;
... Amphoteric surfactants such as betaine.

..Electronic conductive agents
Moreover, the following are mentioned as an electronic electrically conductive agent.
... Carbon-based materials such as carbon black and graphite;
... Metals or alloys such as aluminum, silver, gold, tin-lead alloys, copper-nickel alloys;
... Metal oxides such as zinc oxide, titanium oxide, aluminum oxide, tin oxide, antimony oxide, indium oxide, silver oxide;
... Substances with various fillers subjected to conductive surface treatment with copper, nickel or silver.

  These ionic conductive agents and electronic conductive agents can be used alone or in admixture of two or more in the form of powder or fiber. Among these, carbon black is preferable from the viewpoint that it is easy to reduce conductivity and is economical.

・ Development roller layer configuration;
In addition, the surface layer 43 may be formed on the outer periphery of the elastic layer 42 in order to improve the wear resistance like the developing roller used in the present invention. Similarly to the elastic layer, the surface layer does not have to be a single layer, and may be a multilayer.

Next, the surface layer 43 will be described. As in the embodiment of the present invention, the surface layer 43 may be formed around the elastic layer 42 to optimize the roller surface. Examples of the material used for the surface layer 43 include the following.
..Epoxy resin; diallyl phthalate resin; polycarbonate resin; fluororesin; polypropylene resin; urea resin; melamine resin; silicon resin; polyester resin; Resin; Silicone resin; Acrylic urethane resin; Water-based resin, etc.

In addition, two or more kinds selected from the above resin group can be used in combination. Among these, it is particularly preferable to use a nitrogen-containing compound (for example, a urethane resin or an acrylic urethane resin) because the toner can be stably charged. The urethane resin used here is obtained from an isocyanate compound and a polyol. The following are mentioned as an isocyanate compound.
..Diphenylmethane-4,4'-diisocyanate; 1,5-naphthalene diisocyanate; 3,3'-dimethylbiphenyl-4,4'-diisocyanate;4,4'-dicyclohexylmethanediisocyanate; p-phenylene diisocyanate; isophorone Diisocyanate; carbodiimide-modified MDI; xylylene diisocyanate; trimethylhexamethylene diisocyanate; tolylene diisocyanate; naphthylene diisocyanate; paraphenylene diisocyanate; hexamethylene diisocyanate;

  In addition, any two selected from the above compound group, or a mixture of two or more thereof can also be used. The mixing ratio may be any ratio.

The following are mentioned as a polyol.
..As divalent polyols (diols), ethylene glycol, diethylene glycol, propylene glycol, dipropylene glycol, 1,4-butanediol, hexanediol, neopentyl glycol, 1,4-cyclohexanediol, 1,4-cyclohexanedi Methanol, xylene glycol, triethylene glycol.
.. 1,1,1-trimethylolpropane, glycerin, pentaerythritol, sorbitol as a trivalent or higher polyol. Furthermore, polyols such as high molecular weight polyethylene glycol, polypropylene glycol, and ethylene oxide-propylene oxide block glycol obtained by adding ethylene oxide and propylene oxide to diol and triol.

  Moreover, these materials can also be mixed and used. The mixing ratio is appropriately determined.

  Further, as a method for applying the surface layer 43, generally known coating methods such as a ring coating method, a dipping method, a roll coating method, and a spray coating method can be used. It is preferable to use the dipping method because the thickness of the surface layer 43 can be easily controlled. In the dipping method, it is preferable to use a material having a viscosity of 5 cps or more and 50 cps or less. By setting the viscosity within the above range, it is possible to prevent the shape from collapsing before the material is cured and stabilized. Further, it is not difficult to form the surface layer 43 uniformly on the surface of the elastic layer 42.

  Furthermore, these surface layers 43 can be used with conductivity imparted. As a method for imparting conductivity, it is possible to use a method similar to the above-described method for making the elastic layer conductive.

  Furthermore, the thickness of the surface layer 43 is preferably 1 μm or more and 500 μm or less, and particularly preferably 1 μm or more and 50 μm or less. By setting the thickness of the surface layer 43 within the above range, deterioration due to wear or the like when an image is repeatedly output can be suppressed. Further, the hardness of the roller surface is increased, and toner deterioration can be promoted and toner fusing can be suppressed.

Application to charging roller The elastic roller according to the present invention can be used as a charging roller in the same manner as the developing roller described above.

-Cartridges, electrophotographic devices;
An example of a process cartridge and an electrophotographic apparatus on which the developing roller according to the present invention is mounted is shown as a schematic diagram in FIG. This will be described below with reference to FIG.

  The image forming apparatus includes four image forming units 508a to 508d that form yellow, cyan, magenta, and black images, respectively, and are provided in tandem.

  Each image forming unit includes a photoreceptor 501, a charging device 502, an exposure device (not shown) that gives a writing beam 503, a developing device 504, a cleaning device 505, and a transfer roller as an image transfer device 506. .

  The photosensitive member 501, the charging device 502, the developing device, and the cleaning device 505 are integrated to form a process cartridge.

  The developing device 504 includes a developing container 510 that contains a one-component developer (one-component toner) 509 and a developing device that is located in an opening extending in the longitudinal direction in the developing container 510 and is opposed to the photoconductor 501. And a roller 40.

  The electrostatic latent image on the photoreceptor 501 is developed and visualized. Further, a toner supply roller 511 is provided. A toner supply roller 511 and a developing blade 512 are also provided. The toner supply roller 511 supplies the one-component toner 509 to the developing roller 40 and scrapes from the developing roller 40 the one-component toner 509 carried on the developing roller 40 without being used for development.

  The developing blade 512 regulates the carrying amount of the one-component toner 509 on the developing roller 40 and applies frictional charging.

  The surface of the photoreceptor 501 is uniformly charged to a predetermined polarity and potential by the charging device 502. The image information is modulated, and the surface layer of the charged photoconductor 501 is irradiated as a beam 503 from the image exposure apparatus to form an electrostatic latent image. Next, one-component toner is supplied from the developing device 504 having the developing roller 40 of the present invention onto the formed electrostatic latent image, and a toner image is formed on the surface of the photoreceptor 501. This toner image is transferred to a transfer material (paper) 507 as a recording material such as paper which is supplied in synchronization with the rotation when the toner image comes to a portion facing the image transfer device 506 as the photosensitive member 501 rotates. Transcribed.

  In the drawing, four image forming units 508 a to 508 d are formed in a series of manner so that predetermined color images are superimposed on one transfer material 507. Therefore, the transfer material 507 is synchronized with the image formation of each image forming unit. That is, the image formability is synchronized with the insertion of the transfer material 507.

  Therefore, the transfer roller 513 for transporting the transfer member 507 is sandwiched between the photosensitive member 501 and the image transfer device 506 so that the driving roller 514, the tension roller 515, and the driven roller 516 of the transfer conveyor belt 513. It is laid around.

  Further, the transfer material 507 is conveyed in a form electrostatically adsorbed to the transfer conveyance belt 513 by the action of the adsorption roller 517. Reference numeral 518 denotes a supply roller for supplying the transfer material 507.

  The transfer material 507 on which the image has been formed is peeled off from the transfer conveyance belt 513 by the action of the peeling device 519 and sent to the fixing device 520, and the toner image is fixed on the transfer material 507, thereby completing the printing. On the other hand, the photosensitive member 501 after the transfer of the toner image to the transfer material 507 is further rotated, the surface of the photosensitive member 501 is cleaned by the cleaning device 505, and is discharged by a discharging device (not shown) if necessary. Thereafter, the photoreceptor 501 is used for the next image formation. In the figure, reference numerals 521 and 522 denote bias power sources for the image transfer device 506 and the suction roller 517, respectively.

  Here, the apparatus for directly transferring the toner image of each color to the tandem type transfer material has been described, but any apparatus that uses the developing roller of the present invention as the developing roller may be used. Specifically, for example, a monochrome single-color image forming apparatus can be mentioned.

  Another example is an image forming layer that temporarily forms a color image by superimposing toner images of respective colors on a transfer roller or a transfer belt, and collectively transfers the image onto a transfer member. Furthermore, an image forming apparatus or the like in which each color developing unit is arranged on a rotor or arranged in parallel with a photosensitive member can be mentioned.

  Further, the image forming apparatus according to the present invention includes not only a process cartridge but also an image forming apparatus in which a photosensitive member, a charging device, and a developing device are directly incorporated.

  Hereinafter, the present invention will be described in more detail with reference to examples. First, various evaluation and measurement methods performed in Examples will be described.

(Image evaluation)
Electrophotographic process cartridge (nominal life: 6000 sheets, A4 size, 5% printing rate, manufactured by hp, trade name: print cartridge black, print cartridge cyan, print cartridge magenta, print cartridge yellow) The roller created in the example was incorporated as a developing roller for each color.

Next, this electrophotographic process cartridge was incorporated into an electrophotographic image forming apparatus (trade name: Color Laserjet 3700, manufactured by hp, print resolution of 600 dpi). Then, using this image forming apparatus, an image (solid image, halftone image) was output, and density unevenness (roller pitch) was evaluated as image evaluation 1. Further, this image forming apparatus was evaluated in the same manner by using a printer with a print resolution modified to 1200 dpi. This is image evaluation 2. Image evaluations 1 and 2 were evaluated as follows.
A: All images are good visually.
B: Density unevenness is slightly confirmed with solid and halftone, but there is no practical problem.
C: Density unevenness is confirmed in all images.

(Runout accuracy measurement)
The deflection accuracy of the elastic roller is measured with a non-contact laser length measuring device (manufactured by Keyence, product name: LS-5000) which is arranged perpendicularly to the rotation axis by rotating the elastic roller around the central axis of the shaft core. The elastic layer thickness was measured and obtained by subtracting the minimum layer thickness from the maximum layer thickness. The elastic layer thickness is a value obtained by subtracting the distance from the reference measured in advance to the core metal outer peripheral surface from the distance from the reference to the elastic roller outer peripheral surface. The shake accuracy is obtained at a pitch of 1 cm in the axial direction of the elastic layer, and the maximum value among the values is defined as the value of the shake accuracy of the elastic roller. Evaluation was performed as follows.
A: Runout accuracy is within 30 μm.
B: Runout accuracy is greater than 30 μm, but no streaks or irregularities are observed on the coated surface.
C: Runout accuracy is greater than 30 μm, and streaks and irregularities are observed on the coated surface.

(Measurement of elastic roller resistance and resistance unevenness)
Details will be described with reference to FIG.

  A load of 500 grams was applied to both ends of the shaft core of the elastic roller 40 and pressed against the metal drum 62 rotating at 24 rpm, and a voltage of 50 V was applied between the shaft of the metal drum 62 and the elastic roller 40.

  Then, the current value is obtained from the voltage value applied to the resistance of 10 kΩ connected in series with the conductive roller, the resistance value of the conductive roller is calculated from the current value, and the maximum value and the minimum value of the conductive roller resistance in one cycle. Is the resistance value of the conductive roller.

Also, the maximum and minimum resistance values in one round of the conductive roller are taken, and the value of 1- (minimum resistance value / maximum resistance value) is defined as the resistance unevenness of the conductive roller.
Evaluation was made according to the following criteria.

A: Resistance unevenness is 0 or more and less than 0.1,
B: Resistance unevenness is 0.1 or more and less than 0.5,
C: Resistance unevenness is 0.5 or more and 0.7 or less.

(Viscosity measurement)
For the viscosity measurement, Rheo Stress 600 (trade name) manufactured by Haake was used.

  About 1 g of an uncured coating solution was sampled and placed on a sample stage, and a cone plate (diameter 35 mm, inclination angle 1 °) was gradually approached to set a measurement gap at a position of about 50 μm from the sample stage.

At that time, the coating solution extruded around was removed so as not to affect the measurement. The temperature of the sample stage was set so that the sample temperature was 25 ° C., and the measurement was started after being left for 10 minutes after setting the sample. The range of the shear rate applied to the sample from 0.1s ^-1 to the start and 10, is changed by 0.2 s ^-1, and viscosity divided by the shear rate ^{1s -1} shear stress of shear rate ^{1s -1} did.

(Example 1)
In producing the elastic roller, the shaft core is nickel-plated on a round rod-shaped iron shaft having an outer diameter of 6 mm, and further a primer DY35-051 (trade name: Toray Dow Corning Co., Ltd.) Manufactured) and baked at 150 ° C. for 30 minutes.

  Add 8 parts by mass of carbon black (MA11, manufactured by Mitsubishi Chemical Corporation) to 100 parts by mass of each of the liquids A and B of addition reaction crosslinkable liquid silicone rubber (manufactured by Toray Dow Corning). Degassed for a minute. Thereafter, liquid A and liquid B blended with carbon black are respectively set in the raw material tanks attached to the coating apparatus, and sent to a static mixer using a pressure pump, and liquids A and B are 1: 1 on a mass basis. The silicone rubber mixed solution was used as a coating solution. The viscosity was 545 Pa · s.

  The shaft core body is clamped by the shaft core body holding shaft shown in the coating apparatus of the form shown in FIG. 3, and the shaft core body holding member is vertically raised from the bottom to the top at a speed of 30 mm / s. Moved. At the same time, the ring-shaped piston of the coating head is raised, and the silicone rubber mixture is discharged at 2.52 ml / sec from the annular slit 203 of the coating head having the configuration shown in FIG. An uncured coating solution was formed in a cylindrical shape (roll shape) on the outer peripheral surface. The inner diameter of the coating head was 12.1 mm, and the width of the annular slit 203 was 1.0 mm.

  Further, the outer diameter (d1min) of the inner ring constituting the sliding portion of the ring-shaped piston in the coating head was 36.0 mm, and the inner diameter (r2) of the outer ring was 43.2 mm. Therefore, r2 / d1min = 1.2.

  Next, infrared heating was applied to the uncured elastic layer. Infrared heating lamp (trade name: manufactured by Hybeck, trade name: HYL25) is set at a heat treatment temperature (surface temperature of the non-heated body. Hereinafter, the heat treatment temperature refers to the surface temperature of the non-heated body). It arrange | positioned so that the distance with the layer surface of might be set to 60 mm. Then, the shaft core provided with the uncured material layer was heated for 4 minutes while rotating in the circumferential direction at 60 rpm to cure the uncured coating solution to obtain an elastic layer.

  Thereafter, secondary curing at a temperature of 200 ° C. for 4 hours in an electric furnace is performed for the purpose of stabilizing physical properties after curing of the silicone rubber elastic layer and removing reaction residues and unreacted low molecular components in the silicone rubber elastic layer. Went.

  In this way, an elastic roller having an elastic layer on the outer periphery of the shaft core was manufactured.

  Table 1 shows the result of the runout accuracy measurement of the roller manufactured here.

Thereafter, a surface layer was provided on the elastic roller. The material formulation of the surface layer is shown.
Polyurethane polyol prepolymer (trade name: Takelac TE5060, manufactured by Mitsui Takeda Chemical Co.): 100 parts by mass;
・ Isocyanate (trade name: Coronate 2521, manufactured by Nippon Polyurethane Co., Ltd.): 77 parts by mass;
Carbon black (trade name: MA100, manufactured by Mitsubishi Chemical Corporation): 24 parts by mass;
・ Methyl ethyl ketone (MEK)
These were dispersed with a horizontal disperser (trade name: NVM-03, manufactured by IMEX) for 1 hour under conditions of a peripheral speed of 7 m / s, a flow rate of 1 cc / min, and a dispersion temperature of 15 ° C.

  After dispersion, MEK was further added so that the solid content was 25% by mass and the film thickness was adjusted to 20 μm.

  Next, the surface layer raw material was immersed in the outer periphery of the elastic roller at a penetration speed of 100 mm / s in a cylinder having a diameter of 32 mm circulated at a liquid flow rate of 250 cc / min and a liquid temperature of 23 ° C., and stopped for 10 seconds.

  Thereafter, the film was pulled up under conditions of an initial speed of 400 mm / s and an final speed of 200 mm / s and naturally dried for 10 minutes. Next, the raw material of the surface layer was cured by heat treatment at a temperature of 140 ° C. for 60 minutes, and an elastic roller provided with the surface layer was obtained. An elastic roller provided with a surface layer was incorporated in an electrophotographic process cartridge as a developing roller. Table 1 shows the result of image output.

(Example 2)
The following were used as A liquid and B liquid of addition reaction crosslinking type liquid silicone rubber.

[Liquid A]
The following silicone base polymer and carbon black were mixed and defoamed with a planetary mixer for 30 minutes to obtain a silicone base material. A solution A was prepared by adding 0.02 part by mass of an isopropyl alcohol solution of chloroplatinic acid (platinum content: 3% by mass) to 100 parts by mass of the base material.
-100 parts by mass of a silicone base polymer (weight average molecular weight Mw = 100000, manufactured by Toray Dow Corning)
-Carbon black (trade name: MA77, manufactured by Mitsubishi Chemical Corporation) 3 parts by mass [Liquid B]
To 100 parts by mass of the silicone base material, 1.5 parts by mass of organohydrogenpolysiloxane (viscosity 10 mPa · s, SiH content 1% by mass, manufactured by Toray Dow Corning Co., Ltd.) was added and mixed. The thing was made into B liquid.

  The viscosity of the liquid mixture of the liquid A and the liquid B was 10 Pa · s. An elastic roller with a surface layer was prepared in the same manner as in Example 1 except that the above mixed solution was used, and various evaluations were performed. The results are shown in Table 1.

(Example 3)
16 parts by mass of carbon black (MA11, manufactured by Mitsubishi Chemical Corporation) was added to 100 parts by mass of each of the liquids A and B of addition reaction crosslinkable liquid silicone rubber (manufactured by Toray Dow Corning Co., Ltd.). . The viscosity of the silicone rubber mixed solution that is the elastic layer forming material was 5000 Pa · s.

  Except for the above, an elastic roller was prepared in the same manner as in Example 1, and various evaluations were performed. The results are shown in Table 1.

Example 4
An elastic roller was prepared and evaluated in the same manner as in Example 1 except that r2 = 72.0 mm and r2 / d1min = 2.0. The results are shown in Table 1.

(Example 5)
An elastic roller was prepared and evaluated in the same manner as in Example 1 except that r2 = 46.8 mm and r2 / d1min = 1.3. The results are shown in Table 1.

(Example 6)
An elastic roller was prepared and evaluated in the same manner as in Example 1 except that r2 = 50.4 mm and r2 / d1min = 1.4. The results are shown in Table 1.

(Example 7)
An elastic roller was obtained in the same manner as in Example 1. After measuring the deflection accuracy of the elastic roller, a surface layer was provided in the same manner as in Example 1. An elastic roller provided with a surface layer was incorporated into an electrophotographic process cartridge as a charging roller, and image evaluation was performed (the developing roller used originally with the electrophotographic process cartridge was used).

(Example 8)
An elastic roller was obtained in the same process as in Example 1, but various evaluations were performed without providing a surface layer. The results are shown in Table 1.

Example 9
An elastic roller was prepared and evaluated in the same manner as in Example 1 except that r2 = 36.7 mm and r2 / d1min = 1.02. The results are shown in Table 1.

(Example 10)
An elastic roller was prepared and evaluated in the same manner as in Example 1 except that r2 = 144.0 mm and r2 / d1min = 4.0. The results are shown in Table 1.
(Comparative Example 1)
In Example 1, an elastic roller was prepared in the same manner as in Example 1 except that the coating head shown in FIG. 7 was used. In addition, the size of the distribution chamber of the coating head and the dimension of the annular slit were the same as those of the coating head according to Example 1.

  Further, only the supply pressure from the material supply pump was used for supplying the coating liquid to the distribution chamber and discharging the coating liquid from the annular slit. 7A is a schematic sectional view when viewed from the front of the coating head, and FIG. 7B is a schematic diagram when viewed from the top.

  The elastic roller according to Comparative Example 1 thus obtained was evaluated in the same manner as in Example 1. The results are shown in Table 1.

(Comparative Example 2)
In Example 1, an elastic roller was prepared in the same manner as in Example 1 except that the coating head shown in FIG. 8 was used. In addition, the size of the distribution chamber of the coating head and the dimension of the annular slit were the same as those of the coating head according to Example 1.

  Further, only the supply pressure from the material supply pump was used for supplying the coating liquid to the distribution chamber and discharging the coating liquid from the annular slit. 8A is a schematic sectional view when viewed from the front of the coating head, and FIG. 8B is a schematic diagram when viewed from the top.

  The elastic roller according to Comparative Example 1 thus obtained was evaluated in the same manner as in Example 1. The results are shown in Table 1.

It is a schematic diagram which shows the example of the coating apparatus which concerns on this invention. (A) It is a schematic diagram which shows the example of the coating head which concerns on this invention. (B) It is sectional drawing in the AA of the coating head shown to Fig.2 (a). (C) It is sectional drawing in the BB line of the coating head shown to Fig.2 (a). It is the figure which showed the specific behavior of the coating head which concerns on this invention. (A) It is a figure which shows the initial state of a coating head. (B) It is a figure which shows a supply process to the coating liquid to a distribution chamber. (C) It is a figure which shows the state which driven the piston. It is sectional drawing which shows the elastic roller which concerns on this invention. (A) It is an axial sectional view of an elastic roller. (B) It is sectional drawing of the direction orthogonal to the axial direction of the elastic roller shown to Fig.4 (a). 1 is a schematic cross-sectional view for explaining an example of an image forming apparatus according to the present invention. Schematic of an apparatus for measuring the resistance of an elastic roller according to the present invention 2 is a schematic view of a coating head used in Comparative Example 1. FIG. (A) It is a cross-sectional schematic when the coating head is seen from the front. (B) It is the schematic when the coating head is seen from the upper surface. 6 is a schematic view of a coating head used in Comparative Example 2. FIG. (A) It is a cross-sectional schematic when the coating head is seen from the front. (B) It is the schematic when the coating head is seen from the upper surface.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Stand 2 Column 3 Ball screw 4 LM guide 5 Servo motor 6 Pulley 71 Upper bracket 72 Lower bracket 8 Coating head 9 Shaft core lower holding shaft 10 Shaft core upper holding shaft 11 Supply port 12 Piping 13 Material supply valve 14 Linear guide DESCRIPTION OF SYMBOLS 101 Elastic layer 102 Shaft core 201 Inner ring 202 Cap ring 203 Annular slit 204 Elastic layer material discharge port 205 Outer ring 206 Liquid distribution chamber 207 Restriction step part 208 Ring-shaped piston 301 Ring-shaped member 40 Elastic roller 42 Elastic layer 43 Surface Layer 62 Metal drum 501 Photoconductor 502 Charging device 503 Image exposure device (writing beam)
504 Development device 505 Cleaning device 506 Image transfer device 507 Transfer material (paper)
508a to d Image forming unit 509 One-component toner 510 Developing container 511 Toner supply roller 512 Developing blade 513 Transfer / conveying belt 514 Driving roller 515 Tension roller 516 Followed roller 517 Adsorption roller 518 Supply roller 519 Separating device 520 Fixing device 521 Image transfer Device bias power supply 522 Suction roller bias power supply

Claims (13)

  An annular liquid coating head having an annular slit for discharging liquid over the entire inner circumference, and an annular distribution chamber communicating with the annular slit, and supplying the liquid from the outside to the distribution chamber And an annular piston for pressurizing the liquid supplied into the distribution chamber and extruding it from the annular slit, and facing the distribution chamber. head.   The coating head includes a hollow cylindrical inner ring and an outer ring, and the inner ring and the outer ring form the annular slit and an annular distribution chamber communicating with the annular slit. The liquid coating head according to claim 1. The liquid coating head according to claim 2, wherein when the outer diameter of the inner ring is d1min and the inner diameter of the outer ring is r2, they satisfy the relationship represented by the following formula (1):
1.05 ≦ r2 / d1min ≦ 2.0 (1) A liquid coating head according to any one of claims 1 to 3,
Means for supporting the cylindrical substrate coaxially with the liquid coating head;
A liquid coating apparatus comprising: means for relatively moving the cylindrical substrate and the liquid coating head. A coating method for coating a peripheral surface of a cylindrical substrate using the liquid coating apparatus according to claim 4,
(I) supporting the cylindrical substrate coaxially with the liquid coating head;
(Ii) supplying paint to the distribution chamber from the supply port of the liquid coating head, and distributing the paint over the entire circumference of the distribution chamber;
(Iii) applying the coating material in the distribution chamber distributed in the step (ii) to the peripheral surface of the cylindrical substrate by driving the annular piston and discharging it from the annular slit;
(Iv) A coating method comprising a step of relatively moving the liquid coating head and the cylindrical substrate.   The coating method according to claim 5, wherein the paint has a viscosity of 10 Pa · s to 5000 Pa · s. An elastic roller manufacturing method using the liquid coating apparatus according to claim 4,
(I) supporting the cylindrical substrate coaxially with the liquid coating head;
(Ii) supplying a paint containing liquid rubber from the supply port of the liquid coating head to the distribution chamber, and distributing the paint over the entire circumference of the distribution chamber;
(Iii) applying the paint in the distribution chamber distributed in the step (ii) to the peripheral surface of the cylindrical substrate by driving an annular piston to discharge the paint from the annular slit;
(Iv) a step of relatively moving the liquid coating head and the cylindrical substrate, and (v) a step of curing the liquid rubber in the coating applied to the peripheral surface of the cylindrical substrate. A method for producing an elastic roller.   The method for producing an elastic roller according to claim 7, wherein the paint contains liquid silicone rubber.   The method for producing an elastic roller according to claim 8, wherein the paint further contains a conductive agent.   An elastic roller manufactured by the method for manufacturing an elastic roller according to claim 7.   A developing roller manufactured by the method for manufacturing an elastic roller according to claim 9.   A developer having at least a toner, a developer container containing the developer, and the developing roller according to claim 11 are integrally supported, and are detachable from the main body of the electrophotographic apparatus. Process cartridge.   A developer having toner, a developer container containing the developer, the developing roller according to claim 11, an electrophotographic photosensitive member, a charging unit, an exposure unit, and a transfer unit are provided. Electrophotographic device.

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