JP5660302B2 - Image forming apparatus - Google Patents

Description

  The present invention relates to an image forming apparatus and a process cartridge using a highly durable cleaning blade, and a method for manufacturing the image forming apparatus.

  In an image forming apparatus using an electrophotographic process, an image is formed by performing a charging process, an exposure process, a development process, and a transfer process on a photoreceptor. The discharge product generated in the charging process and remaining on the surface of the photoreceptor and the residual toner or toner component remaining on the surface of the photoreceptor after the transfer process are removed through a cleaning process.

  From the viewpoint of improving the reliability of image forming equipment, the photoconductor is made of an inorganic material such as amorphous silicon, or has a surface layer in which an acrylate material or inorganic fine particles are dispersed on the surface of the organic photoconductor Photoconductors have come to be used. Since these photoconductors have excellent wear resistance against the cleaning blade, they can achieve a much longer life than before, greatly reducing the number of maintenance, reducing the number of photoconductor replacements, and cost. It was also very favorable environmentally.

  However, even if the life of the photosensitive member can be extended, the number of maintenance operations cannot be reduced unless the life of the cleaning blade can be extended. In recent electrophotographic apparatuses, so-called process cartridges in which a photosensitive member and a member such as a cleaning blade are integrated are increasingly used to facilitate maintenance. For this reason, the life of the cleaning blade becomes rate-limiting even though the photoconductor is sufficiently usable, and the process cartridge has to be replaced.

  The cleaning blade is generally a strip-shaped elastic body such as polyurethane rubber, and supports the base end of the cleaning blade with a support member and presses the tip ridge line portion against the peripheral surface of the photoconductor, Residual toner is damped and scraped off.

  In order to meet the demand for higher image quality in recent years, an image forming apparatus using a toner having a small particle diameter and a nearly spherical shape (hereinafter referred to as a polymerization toner) formed by a polymerization method or the like is known. This polymerized toner has characteristics such as higher transfer efficiency than conventional pulverized toner, and can meet the above requirements. However, it is difficult to remove the polymerized toner sufficiently from the surface of the photoreceptor using a cleaning blade, and there is a problem that cleaning failure occurs. This is because the polymerized toner having a small particle diameter and excellent sphericity passes through a slight gap formed between the cleaning blade and the photosensitive member.

  In order to suppress such slip-through, it is necessary to increase the contact pressure between the photosensitive member and the cleaning blade to enhance the cleaning ability. However, when the contact pressure of the cleaning blade is increased, the frictional force between the photosensitive member 23 and the cleaning blade 262 increases as shown in FIG. 8A, and the cleaning blade 262 is pulled in the moving direction of the photosensitive member 23. The leading edge portion 262c of the cleaning blade 262 is turned up. When the cleaning is continued with the leading edge portion 262c of the cleaning blade 262 turned up, as shown in FIG. 8B, a position several μm away from the leading edge portion 262c of the leading edge surface 262b of the cleaning blade 262. This causes local wear. If the cleaning is further continued in such a state, the local wear becomes large, and finally the leading edge portion 262c is lost as shown in FIG. 8C. If the tip ridge line portion 262c is missing, the toner cannot be properly cleaned, resulting in poor cleaning and the life of the cleaning blade.

  In order to increase the service life of a cleaning blade, for example, Patent Document 1 (Japanese Patent Laid-Open No. 2005-107376) discloses a cleaning blade in which 0.1 mm of isocyanate is laminated on a contact portion of a blade material made of polyurethane elastomer with a photoreceptor. Is disclosed. However, this cleaning blade uses inorganic fine particles in the surface layer, which has excellent performance for a photoreceptor with a smooth surface, such as amorphous silicon, but has improved cleaning properties or abrasion resistance of the photoreceptor. In a photoconductor having a roughened surface such as an organic photoconductor, the tip in contact with the photoconductor is lost early and often causes poor cleaning.

  Japanese Patent Application Laid-Open No. 2000-66555 discloses an image forming apparatus in which the frictional force between the photosensitive member and the cleaning blade is reduced by providing a low abrasion treatment layer on the cleaning blade. . This cleaning blade has a very excellent cleaning property in the initial stage when image formation is not so much performed. However, when image formation is repeated, the low-wear processing material on the outermost surface of the low-wear processing layer falls off, the frictional force between the photosensitive member and the cleaning blade increases, and the cleaning blade is partially chipped. Woke up and had poor cleaning.

Patent Document 3 (Japanese Patent No. 3602898) discloses a cleaning blade in which at least a contact portion of a cleaning blade made of a polyurethane elastomer is impregnated with an acrylic urethane monomer and cured by irradiation with UV light. This cleaning blade has no problem in cleaning performance at the initial stage of image formation, but when the image formation is repeated, the tip in contact with the photosensitive member is chipped and often causes poor cleaning.
Since the hardness of the acrylic urethane monomer of Patent Document 3 cannot be measured in a state of being impregnated in a polyurethane elastomer, the film obtained by applying the acrylic urethane monomer on a glass plate and irradiating it with UV light and curing it has sufficient hardness. The hardness of urethane elastomer impregnated with acrylic urethane monomer and irradiated with UV light is much smaller than expected, almost the same as the hardness of untreated urethane elastomer There was no change or it was softening.

  The present inventors have investigated in detail the reason why the performance of the cleaning blade of Patent Document 3 is poor, and as a result, most of the acrylic urethane monomers that have penetrated into the urethane elastomer are not polymerized or become oligomers with a low molecular weight. Found that not.

  Polymerization of acrylic urethane monomer is polymerized by the polymerization initiator added to acrylic urethane monomer generating radicals by absorbing UV light and chain-breaking double bonds of acrylic urethane monomer. . The lifetime of radicals is usually as short as several tens of nanoseconds, and many radicals are deactivated by oxygen or the like, but if a sufficient amount of UV light is irradiated and monomers are present around the generated radicals, Polymerization proceeds smoothly. However, in the case of acrylic urethane monomer that has penetrated into the cleaning blade, UV light enters through the urethane elastomer, so the amount of radicals generated is very small and the concentration of acrylic urethane monomer itself is small, so most acrylic urethane monomers It was found that the monomer could not be polymerized and the region where the monomer could be polymerized was at most only a few μm. Unreacted acrylic urethane monomers and oligomers in the urethane elastomer weaken the strength of the urethane elastomer, so that it was found that when the cleaning blade was slightly worn out, the cleaning blade was chipped, resulting in poor cleaning.

  An image forming apparatus and a process cartridge capable of forming a high-quality image over a long period of time by using a cleaning blade that solves conventional problems and has both high durability and excellent cleaning properties, and It is an object of the present invention to provide a method for manufacturing the image forming apparatus.

In order to solve the above problems, an image forming apparatus and a process cartridge according to the present invention specifically have technical features described in (1) to (5) below.

(1): a photosensitive member, a charging unit that charges the surface of the photosensitive member, an exposure unit that forms an electrostatic latent image on the charged surface of the photosensitive member, and the electrostatic latent image is converted into a toner image. An image forming apparatus comprising: a developing unit; a transferring unit that transfers a developed toner image to a transfer body; and a cleaning unit that cleans a toner image remaining after transfer with a cleaning blade, wherein the cleaning blade is an elastic body a blade having a surface layer formed by laminating on the surface of the elastic body blade, the, and, acrylate polymers have been impregnated from the surface of the cleaning blade to a depth of less than 100μm or 5 [mu] m, the surface layer An image forming apparatus comprising the acrylate polymer and having a thickness of 0.1 to 3 μm .

With the configuration described in (1) above, since the acrylate polymer is impregnated to a depth of 5 μm to 100 μm, the durability of the cleaning blade is greatly improved, and image formation that enables high-quality image formation over a long period of time An apparatus can be provided. In addition, with the configuration described in (1) above, the hardness of the contact surface and the cut surface of the cleaning blade is moderately increased, and the wear resistance is improved, so that the durability is greatly improved and the image quality is improved over a long period of time. An image forming apparatus capable of forming an image can be provided.

(2): A contact surface that is a surface that contacts the photoreceptor of the cleaning blade and a cut surface that is a cross section perpendicular to the longitudinal direction of the cleaning blade are impregnated from the surface with an acrylate polymer, A cleaning blade not coated with acrylate and a value A / B calculated from a peak area value A of 1700 cm ^{−1 and} a peak area value B of 1597 cm ⁻¹ obtained by microscopic IR by the transmission method of the section of the cleaning blade the distance between the value A0 / B0 calculated from the peak area value B0 of the peak area value A0 and 1597cm ^-1 of 1700 cm ^-1, the ratio of becomes 1.1, the distance from the abutment face surface distance X The distance from the surface of the cut surface is a distance Y, and the ratio of the value X / Y calculated from the distance X and the distance Y is 0.1 to 10. The image forming apparatus as described in (1) above.

  With the configuration described in (2) above, the impregnation depth of the acrylate polymer on the contact surface and the cut surface of the cleaning blade can be accurately grasped, and the ratio of the impregnation depth between the contact surface and the cut surface is adjusted appropriately. Thus, an image forming apparatus capable of forming a high-quality image over a long period can be provided.

(3) : An image forming apparatus manufacturing method for manufacturing an image forming apparatus provided with a cleaning blade as described in (1) or (2) above, wherein the cleaning blade is an elastic body [step (I)]. After the blade is impregnated with a polymerizable acrylate monomer, [Step (II)] is a method for producing an image forming apparatus, wherein the polymerizable acrylate monomer is polymerized by irradiation with energy rays.

With the configuration described in (3) above, a method for manufacturing an image forming apparatus capable of forming a high-quality image over a long period of time by using a highly durable blade capable of performing polymerization of an acrylate polymer in a short time is provided. can do.

(4) : The method (II) is a method for manufacturing an image forming apparatus according to (3) , wherein the energy ray is irradiated in an environment having an oxygen concentration of 2% or less.

With the configuration described in (4) above, the acrylate inside the cleaning blade can be completely polymerized, so the durability of the cleaning blade is greatly improved, and an image forming apparatus capable of forming a high-quality image over a long period of time The manufacturing method of can be provided.

(5) : A process cartridge used in the image forming apparatus described in (1) or (2) above.

With the configuration described in (5) above, it is possible to provide a process cartridge for an image forming apparatus capable of forming a high-quality image over a long period of time.

  According to the present invention, an image forming apparatus and a process cartridge capable of forming a high-quality image over a long period of time by using a cleaning blade having both high durability and excellent cleaning properties, and a method for manufacturing the image forming apparatus Can be provided.

2 is a schematic perspective view showing a configuration of a cleaning blade 62 in an embodiment of an image forming apparatus according to the present invention. FIG. FIG. 2 is an enlarged cross-sectional view of the cleaning blade 62 in FIG. 1. It is the figure which is measuring the peak area value A from IR spectrum. It is the figure which is measuring the peak area value B from IR spectrum. 1 is a schematic configuration diagram illustrating a main part of a printer in an embodiment of an image forming apparatus according to the present invention. (A) It is explanatory drawing which shows the outer periphery length C1 of the actual toner projection shape, and its projection area S. FIG. (B) It is explanatory drawing which shows the outer periphery length C2 of the perfect circle of the same area as the projection area S. FIG. It is explanatory drawing which looked at the cleaning blade for demonstrating a wear width and a wear form from the lower surface side. It is explanatory drawing which shows the structure of the conventional cleaning blade.

  The image forming apparatus according to the present invention includes a photosensitive member, a charging unit that charges the surface of the photosensitive member, an exposure unit that forms an electrostatic latent image on the charged surface of the photosensitive member, and the electrostatic latent image. A developing means for forming a toner image, a transfer means for transferring the developed toner image to a transfer body, and a cleaning means for cleaning a residual toner image with a cleaning blade, wherein the cleaning blade is an acrylate polymer. Is impregnated to a depth of 5 μm or more and 100 μm or less from the surface of the cleaning blade.

The image forming apparatus according to the present invention has a surface (hereinafter referred to as a contact surface) that contacts the photosensitive member of the cleaning blade and a cross section (hereinafter referred to as a cut surface) perpendicular to the longitudinal direction of the cleaning blade member. The acrylate polymer is impregnated from the surface, and is calculated from the peak area value A of 1700 cm ^{−1 and} the peak area value B of 1597 cm ⁻¹ obtained by the microscopic IR method (transmission method) of the section of the cleaning blade. Where the ratio of the value A / B to the value A0 / B0 calculated from the peak area value A0 at 1700 cm ^{−1 and} the peak area value B0 at 1597 cm ⁻¹ of the cleaning blade not coated with acrylate is 1.1 1700 cm obtained by the distance X from the surface of the contact surface and the microscopic IR (transmission method) of the section of the cleaning blade ^-1 peak area value A, the peak area of 1597cm value A / B is calculated from the peak area value B ^-1, the peak area value of 1700 cm ^-1 of the cleaning blade is not coated with the acrylate A0,1597cm ^-1 The ratio with the value X / Y calculated from the distance Y from the surface of the cut surface where the ratio with the value A0 / B0 calculated from the value B0 is 1.1 is 0.1-10. It is characterized by that.

  The present inventors have found that the impregnation depth can be controlled to 5 μm to 100 μm by accurately grasping the impregnation depth of the acrylate of the cleaning blade by using a microscopic IR method (transmission method). At the same time, it has been found that the ratio between the contact surface and the cut surface of the cleaning blade can be adjusted appropriately.

If the polymerization of acrylic urethane monomer is inhibited by oxygen, the amount of UV light is low in an environment with a low oxygen concentration, and the polymerization of acrylate is smooth even in a situation where the concentration of acrylate monomer is low. I thought that it would progress, and repeated diligent studies. As a result, it was found that in an environment having a low oxygen concentration, particularly an oxygen concentration of 2% or less, the cleaning blade can be impregnated with an acrylate monomer and polymerized.
And it discovered that the cleaning blade produced in this way had very excellent durability and cleaning property, and reached the present invention.

Next, the image forming apparatus according to the present invention will be described in more detail.
Although the embodiments described below are preferred embodiments of the present invention, various technically preferable limitations are attached thereto, but the scope of the present invention is intended to limit the present invention in the following description. Unless otherwise described, the present invention is not limited to these embodiments.

<Cleaning blade>
FIG. 1 is a perspective view of the cleaning blade 62, and FIG. 2 is an enlarged cross-sectional view of the cleaning blade 62.
The cleaning blade 62 includes a strip-shaped holder 621 made of a rigid material such as metal or hard plastic, and a strip-shaped elastic blade 622. The elastic blade 622 is fixed to one end of the holder 621 with an adhesive or the like, and the other end of the holder 621 is cantilevered by the case of the cleaning device 6.

[Elastic blade]
An elastic blade (hereinafter also referred to as a cleaning blade base) 622 used as a base of a cleaning blade used in the image forming apparatus of the present invention can be manufactured by a conventionally known composition and method.
The elastic blade 622 preferably has a high rebound resilience so that it can follow the eccentricity of the photosensitive member 3 and minute waviness on the surface of the photosensitive member. Urethane rubber (polyurethane elastomer) which is a rubber containing a urethane group Etc. are suitable. The elastic blade 622 preferably has a surface layer 623 described later on its surface.

  For polyurethane elastomers, polyethylene adipate ester or polycaprolactone ester is usually used as the polyol component, and a prepolymer is prepared using 4,4′-diphenylmethane diisocyanate as the polyisocyanate component, and a curing agent and an optional catalyst are added thereto. In addition, it is manufactured by crosslinking in a predetermined mold, post-crosslinking in a furnace, and then aging at room temperature.

  As the high molecular weight polyol, for example, a polyester polyol which is a condensate of an alkylene glycol and an aliphatic dibasic acid, for example, ethylene adipate ester polyol, butylene adipate ester polyol, hexylene adipate ester polyol, ethylene propylene adipate ester polyol, ethylene Polyester polyols such as butylene adipate ester polyol, polyester glycols of alkylene glycol and adipic acid such as ethylene neopentylene adipate ester polyol, polycaprolactone polyols such as polycaprolactone ester polyol obtained by ring-opening polymerization of caprolactone, Poly (oxy (tetramethylene) glycol, poly (oxypropylene) glycol, etc. Ether-based polyols, or the like is used.

  Other low molecular weight polyols include, for example, 1,4-butanediol, ethylene glycol, neopentyl glycol, hydroquinone-bis (2-hydroxyethyl) ether, 3,3′-dichloro-4,4′-diaminodiphenyl. Dihydric alcohols such as methane, 4,4'-diaminodiphenylmethane, 1,1,1-trimethylolpropane, glycerin, 1,2,6-hexanetriol, 1,2,4-butanetriol, trimethylol Mention may be made of trihydric and higher polyhydric alcohols such as ethane, 1,1,1-tris (hydroxyethoxymethyl) propane, diglycerin, pentaerythritol.

  Specific examples of the curing catalyst include 2-methylimidazole and 1,2-dimethylimidazole, and 1,2-dimethylimidazole is particularly preferably used. Such a catalyst is usually used in an amount of 0.01 to 0.5 parts by weight, preferably 0.05 to 0.3 parts by weight, based on 100 parts by weight of the main agent.

  The acrylate polymer is impregnated to a depth of 5 μm to 100 μm, preferably 8 μm to 80 μm, more preferably 10 μm to 60 μm from the contact surface and cut surface of the cleaning blade.

If the depth of the acrylate polymer impregnating the contact surface and cut surface of the cleaning blade is less than 5 μm, the hardness of the contact surface and the cut surface surface and the vicinity cannot be increased appropriately, preventing blade turning. Inability to do so, rather than a cleaning blade not impregnated with an acrylate polymer, the durability and cleaning properties are deteriorated. In addition, since it is difficult to make the depth impregnated with the acrylate polymer uniform over the entire length of the cleaning blade, the mechanical characteristics of the cleaning blade vary, and the cleaning blade starts from a location with weak mechanical characteristics. Will be easily lost.
In the case where an acrylate polymer is laminated on the contact surface and cut surface of the cleaning blade base (elastic blade) (a surface layer containing an acrylate polymer is laminated), the depth of impregnation of the acrylate polymer If the thickness is smaller than 5 μm, the acrylate polymer film laminated on the surface is liable to be cracked or peeled off, and the durability of the cleaning blade becomes very short.

  If the depth of the acrylate polymer impregnated on the contact surface and the cut surface of the cleaning blade is greater than 100 μm, the flexibility of the entire cleaning blade is reduced, so that the cleaning performance is deteriorated and the cleaning blade is chipped. It becomes easy.

  When laminating an acrylate polymer on the contact surface and cut surface of the cleaning blade base (elastic blade) (lamination of a surface layer containing an acrylate polymer), spraying, dipping, etc. The surface layer is laminated on the contact surface and the cut surface of the cleaning blade base by impregnating by the method and then irradiating energy rays such as UV light and electron beam, and the acrylate polymer in the cleaning blade base. Can be impregnated.

  The oxygen concentration in the vicinity of the cleaning blade when irradiating energy rays is 2% or less, preferably 1% or less. When the oxygen concentration in the vicinity of the cleaning blade is higher than 2%, the acrylate monomer inside the cleaning blade becomes unreacted or only oligomers, so that the strength of the cleaning blade inside is reduced and the cleaning blade is likely to be chipped. It is not preferable.

  Since the acrylate monomer and, if necessary, the solvent that lowers the viscosity of the acrylate monomer usually contain dissolved oxygen, it can be dissolved by bubbling an inert gas such as helium, argon, or nitrogen, or by degassing under reduced pressure. Is preferably removed.

[Surface layer]
The material of the surface layer 623 is preferably a resin, and examples of the resin include acrylic resins, lactone-modified acrylic urethanes, acrylic silicones, thermoplastic urethanes, phenol resins, and the like. More than seeds can be used. Although not limited to this, it is preferable that the same material as the acrylate polymer impregnated in the cleaning blade is used for improving the adhesion of the surface layer and improving the durability of the cleaning blade.

  The layer thickness of the contact surface of the surface layer 623 is preferably 0.1 to 3 [μm]. When the layer thickness is smaller than 0.1 μm, the cleaning blade is easily turned over as in the case where the surface layer is not provided. Further, when the surface layer is the same as the acrylate polymer impregnated in the cleaning blade, it is difficult to make the thickness thinner than 0.1 [μm]. If it is larger than 3 [μm], the rigidity becomes strong, the chipping of the cleaning blade tends to occur, and the wear resistance deteriorates.

<Microscopic IR method (transmission method)>
Next, the microscopic IR method (transmission method) used in the present invention will be described.
The microscopic IR method (transmission method) of the cleaning blade of the present invention measures a section of the cleaning blade. The section of the cleaning blade is prepared by a cryomicrotome, and the section is placed on a silicon wafer for measurement.

[Section preparation]
The cryomicrotome apparatus used in the present invention is EM FCS (manufactured by Leica). The sample is cooled to −100 ° C. with liquid nitrogen and cut. The cutting direction of the cryomicrotome is performed in a direction perpendicular to the contact surface and the cut surface. The part to be cut is a distance of 5 to 10 mm along the contact surface and the cut surface from the contact tip. If it is the said location, the section preparation by a cryomicrotome can be performed stably. The thickness of the section is preferably 300 to 500 nm. If it is 300 nm or less, the sensitivity of the measurement data is lowered because it is too thin, the accurate impregnation depth cannot be measured, and the section may be cut off in the middle. If it is 500 nm or more, it is too thick to transmit light and the measurement data cannot be obtained well, and the section is easily rounded and difficult to collect.

[Peak area value measurement]
A section produced by the cryomicrotome is placed on a silicon wafer and measured by microscopic IR (transmission method). The IR apparatus main body used in the present invention is FT / IR-6100, and the infrared microscope is IRT-5000 (manufactured by JASCO Corporation). The aperture size is 2 × 20 μm square in the vertical direction of the contact surface × the contact surface direction, and is continuously measured by shifting by 2 μm vertically from the contact surface and cut surface surface side of the slice on the silicon wafer. The distance from the contact surface and the cut surface at each measurement point was the surface side end of the measurement region applied to the section.
FIGS. 3 and 4 show an enlarged view of the vicinity of 1700 cm ^{−1 of} the spectrum obtained by the measurement method. The peak area value A of 1700 cm ⁻¹ used in the present invention is the area of the shoulder portion on the low wavelength side of the peak whose peak top is 1733 cm ⁻¹ . FIG. 3 shows how the area value A is measured. The area surrounded by three straight lines corresponds to the area value A. The peak area B of 1579cm ^-1, a peak top is the area of the peak of 1579cm ^-1. FIG. 4 shows a state where the area value B is measured. The area surrounded by three straight lines corresponds to the area value B. Table 1 below shows the integration ranges of the wave number and area of the background start point and end point when obtaining A and B.
The calculation method of A0 and B0 is the same as described above, and can be obtained by measuring a section of the cleaning blade not coated with the acrylate polymer by microscopic IR (transmission method).
If the above method is used, the same result can be obtained by the microscopic ATR method.

[Ratio of A / B to A0 / B0]
A / B and A0 / B0 are calculated from A, B, A0, and B0, and a ratio of A / B to A0 / B0 is obtained. The ratio approaches 1 as the impregnation concentration of the acrylate polymer in the cleaning blade decreases. In the present invention, the portion where the ratio reaches 1.1 is determined as the impregnation depth of the acrylate polymer, and is used for controlling the impregnation depth. If the ratio is 1.1 or more, it can be determined that impregnation of the acrylate polymer is reliable, and the impregnation depth can be determined accurately by reading the portion that has reached 1.1.

<Image forming apparatus>
Next, an electrophotographic printer (hereinafter simply referred to as a printer) which is an embodiment of an image forming apparatus according to the present invention will be described.
FIG. 5 is a schematic configuration diagram illustrating a main part of the printer according to the present embodiment. The printer performs single-color copying, and forms a monochrome image based on image data read by an image reading unit (not shown).

  As shown in FIG. 5, the printer includes a drum-shaped photoconductor 3 as an image carrier. The photosensitive member 3 has a drum shape, but may be a sheet shape or an endless belt shape.

  Around the photosensitive member 3, a charging device 4 as a charging unit, a developing device 5 as a developing unit that converts a latent image into a toner image, and a transfer unit that transfers a toner image onto a transfer sheet (transfer body) as a recording medium. A transfer device 7, a cleaning device 6 as a cleaning unit for cleaning toner remaining on the photoconductor 3 after transfer, a lubricant application device 10 as a lubricant application unit for applying a lubricant on the photoconductor 3, and the photoconductor 3. A static elimination lamp (not shown) or the like for static elimination is arranged.

  The charging device 4 is arranged in a non-contact manner with a predetermined distance from the photoconductor 3, and charges the photoconductor 3 to a predetermined polarity and a predetermined potential. The photosensitive member 3 uniformly charged by the charging device 4 is irradiated with light L based on image data from an exposure device which is a latent image forming unit (not shown) to form an electrostatic latent image.

  The developing device 5 has a developing roller 51 as a developer carrier. A developing bias is applied to the developing roller 51 from a power source (not shown). In the casing of the developing device 5, a supply screw 52 and a stirring screw 53 are provided for stirring the developer contained in the casing while conveying the developer in opposite directions. A doctor 54 for regulating the developer carried on the developing roller 51 is also provided. The toner in the developer stirred and conveyed by the two screws of the supply screw 52 and the stirring screw 53 is charged to a predetermined polarity. The developer is pumped up by the developing roller 51, and the pumped-up developer is regulated by the doctor 54, and the toner adheres to the latent image on the photoconductor 3 in the development area facing the photoconductor 3.

  Although the cleaning device 6 includes the cleaning blade 62, the cleaning device 6 may further include a fur brush. The cleaning blade 62 is in contact with the photoconductor 3 in the counter direction with respect to the surface movement direction of the photoconductor 3. The details of the cleaning blade 62 are as described above.

  The lubricant application device 10 includes a solid lubricant 103, a lubricant pressure spring (not shown), a fur brush 101, and the like, and uses the fur brush 101 as an application brush for applying the solid lubricant 103 onto the photoconductor 3. Yes. The solid lubricant 103 is held by a bracket (not shown) and is pressed toward the fur brush 101 by a lubricant pressurizing spring (not shown). Then, the solid lubricant 103 is scraped by the fur brush 101 that rotates in the rotational direction with respect to the rotation direction of the photoconductor 3, and the lubricant is applied onto the photoconductor 3. By applying the lubricant to the photoconductor, the coefficient of friction of the photoconductor surface is maintained at 0.2 or less during non-image formation.

For the charging device 4, known means such as a corotron, a scorotron, and a solid state charger (solid state charger) are used.
Among these charging methods, the contact charging method or the non-contact proximity arrangement method is more desirable, and has advantages such as high charging efficiency, a small amount of ozone generation, and miniaturization of the apparatus. In the case of the contact charging method or the non-contact proximity arrangement method, it is preferable to provide a cleaning mechanism 8 for the charging device 4 because toner or the like moves from the photoreceptor 3 to the charging device 4 and is contaminated.

In addition, light sources such as fluorescent lamps, tungsten lamps, halogen lamps, mercury lamps, sodium lamps, light emitting diodes (LEDs), semiconductor lasers (LDs), and electroluminescences (ELs) are used as light sources such as exposure apparatuses and static elimination lamps (not shown). General can be used.
In addition, various types of filters such as a sharp cut filter, a band pass filter, a near infrared cut filter, a dichroic filter, an interference filter, and a color temperature conversion filter can be used to irradiate only light in a desired wavelength range.
Among these light sources, a light emitting diode and a semiconductor laser have high irradiation energy and have a long wavelength light of 600 to 800 [nm], so that they are used favorably.

Next, an image forming operation in the printer will be described.
When a print execution signal is received from an operation unit (not shown) or the like, a predetermined voltage or current is sequentially applied to the charging device 4 and the developing roller 51 at predetermined timings. Similarly, a predetermined voltage or current is sequentially applied to the exposure apparatus and the charge removal lamp at predetermined timing. In synchronization with this, the photosensitive member 3 is rotationally driven in a clockwise direction by a photosensitive member driving motor (not shown) as a driving unit.

  When the photoconductor 3 rotates in the clockwise direction, the surface of the photoconductor is first charged to a predetermined potential by the charging device 4. Then, light L corresponding to the image signal is irradiated onto the photoconductor 3 from an exposure device (not shown), and the portion of the photoconductor 3 irradiated with the light L is neutralized to form an electrostatic latent image.

  The photosensitive member 3 on which the electrostatic latent image is formed is rubbed against the surface of the photosensitive member 3 with a magnetic brush of developer formed on the developing roller 51 at a portion facing the developing device 5. At this time, the negatively charged toner on the developing roller 51 is moved to the electrostatic latent image side by a predetermined developing bias applied to the developing roller 51 to be converted into a toner image (development). Thus, in the present embodiment, the electrostatic latent image formed on the photoreceptor 3 is reversely developed by the developing device 5 with the negatively charged toner. In this embodiment, an example using a non-contact charging roller system of N / P (negative positive: toner adheres to a place where the potential is low) has been described, but the present invention is not limited to this.

  The toner image formed on the photoconductor 3 is supplied to a transfer area formed between the photoconductor 3 and the transfer device 7 from a paper supply unit (not shown) through a facing portion between the upper registration roller and the lower registration roller. It is transferred to the transfer paper to be paper. At this time, the transfer paper is supplied onto the transfer belt 14 in synchronism with the leading edge of the image at the facing portion between the upper registration roller and the lower registration roller. In addition, a predetermined transfer bias is applied during transfer onto the transfer paper. The transfer paper onto which the toner image has been transferred is separated from the photoreceptor 3 and conveyed to a fixing device (not shown) as a fixing unit. By passing through the fixing device, the toner image is fixed on the transfer paper by the action of heat and pressure, and the transfer paper is discharged out of the apparatus.

  On the other hand, after the transfer, the surface of the photoreceptor 3 is removed by the cleaning device 6 to remove the residual toner. After the lubricant is applied by the lubricant application device 10, the surface of the photoreceptor 3 is discharged by the charge removal lamp.

The example described above is an embodiment that employs a system in which a toner image is directly transferred from the photoreceptor 3 to a transfer sheet as a transfer body, but the present invention is not limited to this. That is, a so-called intermediate transfer method may be employed in which the toner image is primarily transferred from the photoreceptor 3 to an intermediate transfer belt as an intermediate transfer member, and the toner image on the intermediate transfer belt is secondarily transferred to transfer paper. .
In addition, a color image forming apparatus employing a well-known and commonly used color image forming system that has a plurality of developing devices 5 corresponding to the respective colors and forms a color image may be used.

  Further, in this printer, the photosensitive member 3, the charging device 4, the developing device 5, the cleaning device 6, the lubricant applying device 10 and the like as process means are housed in the frame 2, and the process cartridge 1 is provided from the main body of the apparatus. It is detachable integrally. In this embodiment, the photosensitive member 3 as the process cartridge 1 and the process means are integrally replaced. However, the photosensitive member 3, the charging device 4, the developing device 5, the cleaning device 6, and the lubricant are used. The structure which replaces | exchanges for a new thing in units like the coating device 10 may be sufficient.

〔toner〕
Next, a toner suitable for the printer will be described.
As the toner used in the printer, it is preferable to use a polymerized toner produced by a suspension polymerization method, an emulsion polymerization method, or a dispersion polymerization method, which can easily increase the circularity and reduce the particle size in order to improve the image quality. In particular, it is preferable to use a polymerized toner having a circularity of 0.97 or more and a volume average particle size of 5.5 [μm] or less. By using a material having an average circularity of 0.97 or more and a volume average particle size of 5.5 [μm], a higher resolution image can be formed.

  The “circularity” here is an average circularity measured by a flow type particle image analyzer FPIA-2000 (trade name, manufactured by Toa Medical Electronics Co., Ltd.). Specifically, in 100 to 150 [ml] of water from which impure solids have been removed in advance in a container, 0.1 to 0.5 [ml] of a surfactant, preferably alkylbenzene sulfonate, is added as a dispersant, Further, about 0.1 to 0.5 [g] of a measurement sample (toner) is added. Thereafter, the suspension in which the toner is dispersed is subjected to a dispersion treatment with an ultrasonic disperser for about 1 to 3 minutes so that the concentration of the dispersion becomes 3000 to 1 [10,000 / μl]. To measure the shape and distribution of the toner. Based on the measurement result, the outer peripheral length of the actual toner projection shape shown in FIG. 6A is C1, and the projection area is S. The outer circumference of the perfect circle shown in FIG. C2 / C1 was determined when the length was C2, and the average value was defined as the circularity.

  The volume average particle diameter can be determined by a Coulter counter method. Specifically, the toner number distribution and volume distribution data measured by the Coulter Multisizer 2e type (manufactured by Coulter) are sent to a personal computer via an interface (manufactured by Nikkaki Co., Ltd.) for analysis. More specifically, a 1% NaCl aqueous solution using first grade sodium chloride is prepared as an electrolytic solution. Then, 0.1 to 5 [ml] of a surfactant, preferably alkylbenzene sulfonate, is added as a dispersant to 100 to 150 [ml] of the electrolytic aqueous solution. Further, 2 to 20 [mg] of toner as a test sample is added thereto, and the dispersion treatment is performed for about 1 to 3 minutes using an ultrasonic disperser. Then, 100 to 200 [ml] of the electrolytic aqueous solution is put into another beaker, and the solution after the dispersion treatment is added to the beaker so as to have a predetermined concentration, and then applied to the Coulter Multisizer 2e type. The aperture is 100 [μm], and the particle size of 50,000 toner particles is measured. As a channel, it is less than 2.00-2.52 [micrometer]; 2.52-less than 3.17 [micrometer]; 3.17-less than 4.00 [micrometer]; 4.00-5.04 [micrometer] Less than 5.04 to 6.35 [μm]; 6.35 to less than 8.00 [μm]; 8.00 to less than 10.08 [μm]; 10.08 to less than 12.70 [μm]; 12.70 to less than 16.00 [μm]; 16.00 to less than 20.20 [μm]; 20.20 to less than 25.40 [μm]; 25.40 to less than 32.00 [μm]; Using 13 channels of 00 to less than 40.30 [μm], toner particles with a particle size of 2.00 [μm] or more and 32.0 [μm] or less are targeted. Then, the volume average particle diameter is calculated based on the relational expression “volume average particle diameter = ΣXfV / ΣfV”. However, X is the representative diameter in each channel, V is the equivalent volume in the representative diameter of each channel, and f is the number of particles in each channel.

  The durability test was performed by changing the material, the layer thickness, and the impregnation treatment of the surface layer 623.

[Matrix elastic blade]
As the elastic blade 622, a polyurethane cleaning blade used in Ricoh's imagio Neo C4500 was used.

[Surface layer]
[Example 1]
In Example 1, a surface layer was formed at the contact tip by spray coating.
PC-308WIDE made by Olympus is used as the spray device, and the spray gun is moved at a speed of 7 [mm / s] at a pressure of 0.5 [MPa] from a distance of 40 [mm] from the contact tip. The coating amount was adjusted so as to obtain a predetermined layer thickness. Thereafter, after standing for 5 minutes, vacuum drying was performed at 30 ° C. for 10 minutes, and then ultraviolet (UV) irradiation (1000 mJ / cm ² ) was performed to form a surface layer and polymerize the impregnated polymerizable acrylate monomer.
The chemicals used for the spray coating solution were all freezing vacuum degassed and oxygen removed. Spray coating and drying were performed in an environment with an oxygen concentration of 100 ppm or less in a glass container.

(Acrylate material 1)
Nippon Kayaku KAYARAD DPCA-120: 20 parts Ciba Chemical I-184: 1 part 2-butanol: 79 parts

(Acrylate material 2)
Nippon Kayaku KAYARAD TMPTA: 20 parts Ciba Chemical I-184: 1 part 2-butanol: 79 parts

(Acrylate material 3)
Nippon Kayaku KAYARAD R-526: 20 parts Ciba Chemical I-184: 1 part 2-butanol: 79 parts

  For each of Examples 1 to 10 and Comparative Examples 1 to 4 shown below, two cleaning blades prepared under the same conditions were prepared, and a section with a thickness of 400 nm was prepared with a cryomicrotome at the center in the longitudinal direction, The slices were placed on a silicon wafer, and the film thicknesses of the contact surface layer and the cut surface layer were measured with an optical microscope and SEM. Further, measurement was performed by microscopic IR (transmission method) from a position of 5 mm along the contact surface from the end of the cleaning blade toward the inside, and the depth of impregnation of the acrylate polymer on the contact surface was measured. Similarly, from the edge of the cleaning blade along the contact surface and the cut surface, the measurement is performed by micro IR (transmission method) from the location of 5 mm inward, and the depth of impregnation of the acrylate polymer on the cut surface is determined. It was measured. The acrylate polymer impregnation depths X and Y were evaluated when the ratio of A / B to A0 / B0 reached 1.1.

Acrylate polymer 1 (polymerized from acrylate material 1)
Contact surface layer thickness: 0.9μm
Cut surface layer thickness: 0.8μm
X: 6 μm
Y: 8 μm

[Example 2]
Acrylate polymer 2 (polymerized from acrylate material 2)
Contact surface layer thickness: 0.5 μm
Cut surface layer thickness: 0.6 μm
X: 8 μm
Y: 13 μm

[Example 3]
Acrylate polymer 3 (polymerized from acrylate material 3)
Contact surface layer thickness: 0.5 μm
Cut surface layer thickness: 0.4 μm
X: 10 μm
Y: 17 μm

[Example 4]
In Example 1, the acrylate material 1 is impregnated in the contact surface of the elastic blade and the tip of the cut surface in a state where the inside of the glass container containing the elastic blade is decompressed to 10 mmHg and the interior of the container is decompressed. The acrylate material 1 was poured into the container and kept in that state for 30 seconds. After the inside of the container is under normal pressure and the acrylate material 1 on the surface of the elastic blade is wiped off with a micro wipe, drying and UV irradiation are performed in the same manner as in Example 1 to form a surface layer and polymerize the impregnated polymerizable acrylate monomer. I let you.

Contact surface layer thickness: 0.1 μm
Cut surface layer thickness: 0.1 μm
X: 20 μm
Y: 31 μm

[Example 5]
In Example 4, after the acrylate material 1 was poured into the container, it was dried and UV-irradiated to form a surface layer and impregnated polymerizable acrylate in the same manner as in Example 4 except that the state was maintained for 2 minutes. The monomer was polymerized.

Contact surface layer thickness: 0.1 μm
Cut surface layer thickness: 0.1 μm
X: 90 μm
Y: 98 μm

[Example 6]
In Example 3, a cleaning blade was produced in the same manner as in Example 3 except that the UV irradiation was performed in an environment where the oxygen concentration was 1.8%.

Contact surface layer thickness: 0.5 μm
Cut surface layer thickness: 0.6 μm
X: 8 μm
Y: 12 μm

[Example 7]
A cleaning blade was produced in the same manner as in Example 4 except that the cleaning blade produced in Example 1 was impregnated only in the contact surface in Example 4 and the holding time was 1 min.

Contact surface layer thickness: 1.1 μm
Cut surface layer thickness: 0.8μm
X: 65 μm
Y: 8 μm

[Example 8]
The cleaning blade manufactured in Example 2 was cleaned in the same manner as in Example 4 except that the impregnation place was only the cut surface in Example 4, the acrylate material 2 was used, and the holding time was 1 min. Was made.

Contact surface layer thickness: 0.5 μm
Cut surface layer thickness: 0.9μm
X: 8 μm
Y: 74 μm

[Example 9]
In Example 7, a cleaning blade was produced in the same manner as in Example 7 except that the holding time was 2 min.

Contact surface layer thickness: 1.2 μm
Cut surface layer thickness: 0.8μm
X: 90 μm
Y: 8 μm

[Example 10]
In Example 8, a cleaning blade was produced in the same manner as in Example 8 except that the holding time was 2 min.

Contact surface layer thickness: 0.5 μm
Cut surface layer thickness: 1.1 μm
X: 8 μm
Y: 99 μm

[Comparative Example 1]
The untreated product of the base elastic blade was directly used as a cleaning blade.

[Comparative Example 2]
In Example 3, a cleaning blade was produced in the same manner as in Example 1 except that 2-butanol of the acrylate material 1 was changed from 79 parts to 150 parts.

Contact surface layer thickness: 0.1 μm
Cut surface layer thickness: 0.1 μm
X: 4 μm
Y: 4 μm

[Comparative Example 3]
In Example 4, instead of the acrylate material 1, the acrylate material 3 was used, and after the acrylate material 3 was poured into the container, the state was maintained for 20 minutes, followed by drying and UV irradiation in the same manner as in Example 4. The polymerizable acrylate monomer impregnated while forming the surface layer was polymerized.

Contact surface layer thickness: 0.1 μm
Cut surface layer thickness: 0.1 μm
X: 150 μm
Y: 175 μm

[Comparative Example 4]
In Example 3, 79 parts to 100 parts of 2-butanol of the acrylate material 3 was sprayed, dried, and UV-irradiated all in the air to form a surface layer and polymerize the impregnated polymerizable acrylate monomer. A cleaning blade was produced in the same manner as in Example 3 except that.

Contact surface layer thickness: 0.3 μm
Cut surface layer thickness: 0.4 μm
X: 2 μm
Y: 2 μm

Next, the configuration of the image forming apparatus for which the verification experiment was performed will be described.
The above-described cleaning blade was attached to a color composite machine imagio Neo C4500 manufactured by Ricoh, and image forming apparatuses of Examples 1 to 10 and Comparative Examples 1 to 4 were produced. As the toner, a toner prepared by a polymerization method was used. The physical properties of the toner are as follows.

Toner base: circularity 0.98, average particle size 4.9 [μm]
External additive: 1.5 parts of small particle size silica (Clariant H2000)
0.5 parts small particle size titanium oxide (Taika MT-150AI)
1.0 parts of large particle size silica (UFP-30H manufactured by Denki Kagaku Kogyo)

  The verification experiment was performed in a laboratory environment: 21 [° C.] · 65 [% RH], paper feeding condition: image area ratio 5% chart with 3 prints / job at 50,000 sheets (A4 landscape). And the following items were evaluated.

[Evaluation item]
Occurrence of cleaning failure: Presence / absence (visual observation: evaluated in order of good, ●, ◎, ○, △, ×, XX, and ●, ◎ and ○ were accepted)
Evaluation image: Vertical belt pattern (with respect to the paper traveling direction) 43 [mm] width, 3 chart output 20 sheets (A4 landscape)
Cleaning blade edge wear width and wear form: As shown in FIG. 7, the wear width and wear form seen from the lower surface of the cleaning blade

  The result of the verification experiment of the cleaning blade of Examples 1 to 10 and Comparative Examples 1 to 4 is shown below. In addition, the layer thickness of the surface layer was measured with a cross section of an elastic blade separately coated in the same manner using a Keyence microscope VHX-100. The sample was a cross-section cut using a trimming razor for SEM sample preparation manufactured by Nisshin EM.

The above Table 1 summarizes the results of verification experiments of Examples 1 to 10 and Comparative Examples 1 to 4.
In all of Examples 1 to 10, good cleaning properties could be maintained over time. Moreover, although the abrasion form also had the non-processed comparative example 1 burred, Examples 1-10 did not burrow and had a beautiful wear from the edge. Among them, Example 1 to Example 8 were found to have a smaller wear width than Example 9 to Example 10 and were better. On the other hand, in Comparative Examples 2 to 3, chipping occurred similarly to the untreated product, and the wear width was at the same level as the untreated product. Further, in Comparative Example 4, many chips were generated, and the cleaning property was greatly deteriorated.

DESCRIPTION OF SYMBOLS 1 Process cartridge 2 Frame 3 Photoconductor 4 Charging device 5 Developing device 6 Cleaning device 7 Transfer device 10 Lubricant coating device 14 Transfer belt 51 Developing roller 52 Supply screw 53 Stirring screw 54 Doctor 62 Cleaning blade 62a Tip surface 62b Blade lower surface 62c Tip edge portion 101 Fur brush 103 Solid lubricant 262 Cleaning blade 262a Tip surface 262b Blade lower surface 262c Tip edge portion 621 Holder 622 Elastic blade 623 Surface layer

JP-A-2005-107376 JP 2000-66555 A Japanese Patent No. 3602898

Claims (5)

A photoreceptor,
Charging means for charging the surface of the photoreceptor;
Exposure means for forming an electrostatic latent image on the surface of the charged photoreceptor;
Developing means for converting the electrostatic latent image into a toner image;
Transfer means for transferring the developed toner image to a transfer member;
Cleaning means for cleaning a toner image remaining after transfer with a cleaning blade, and an image forming apparatus comprising:
The cleaning blade has an elastic blade and a surface layer laminated on the surface of the elastic blade, and the acrylate polymer is impregnated to a depth of 5 μm to 100 μm from the surface of the cleaning blade. Tei Te,
The image forming apparatus , wherein the surface layer contains the acrylate polymer and has a thickness of 0.1 to 3 μm . The contact surface that is a surface that contacts the photoconductor of the cleaning blade and the cut surface that is a cross section perpendicular to the longitudinal direction of the cleaning blade are impregnated from the surface with an acrylate polymer,
A cleaning blade not coated with acrylate and a value A / B calculated from a peak area value A of 1700 cm ^{−1 and} a peak area value B of 1597 cm ⁻¹ obtained by microscopic IR by the transmission method of the section of the cleaning blade the distance between the value A0 / B0 calculated from the peak area value B0 of the peak area value A0 and 1597cm ^-1 of 1700 cm ^-1, the ratio of becomes 1.1, the distance from the abutment face surface distance X The distance from the cut surface is a distance Y, and the ratio of the value X / Y calculated from the distance X and the distance Y is 0.1 to 10. Image forming apparatus. A method of manufacturing an image forming apparatus according to claim 1 or 2 , wherein the image forming apparatus includes a cleaning blade.
The cleaning blade is
[Step (I)] After impregnating the elastic blade with the polymerizable acrylate monomer,
[Step (II)] A method for producing an image forming apparatus, comprising producing a polymerized acrylate monomer by irradiating energy rays. The method of manufacturing an image forming apparatus according to claim 3 , wherein the step (II) irradiates energy rays in an environment having an oxygen concentration of 2% or less. A process cartridge used in the image forming apparatus according to claim 1 .