JP2006184875A - Cleaning device, and image forming method and image forming apparatus using same - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a cleaning device capable of maintaining or improving good cleaning property over a prolonged period of time, and an image forming apparatus using the same. <P>SOLUTION: In the cleaning device having a cleaning blade for removing residual toner on an image carrier, the toner has a volume average particle diameter of ≤6.0 μm and a circularity of ≥0.95, the cleaning blade has a free length L of 7-12 mm and a thickness t of 1-3 mm, the ratio between the free length L of the cleaning blade and the diameter D of the image carrier is 1/5≤L/D≤1/2, the cleaning blade also has a hardness of 70-80° and a modulus of impact resilience of 20-45%, the angle between a tangential direction of a point of contact of the image carrier with the cleaning blade and a cut surface of the cleaning blade is 70-80°, and additive particles having a particle diameter of ≤100 nm in an additive in the toner slip through the cleaning blade in an amount of 4.0×10<SP>3</SP>to 4.0×10<SP>5</SP>/mm<SP>2</SP>by number. <P>COPYRIGHT: (C)2006,JPO&NCIPI

Description

  The present invention relates to a cleaning device having a cleaning blade that is pressed against the surface of an image carrier to form a contact portion and removes toner remaining on the surface of the image carrier, an image forming method using the same, and an image forming device It is about.

2. Description of the Related Art Conventionally, in an electrophotographic image forming apparatus such as a copying machine, a printer, or a fax machine, an electrostatic latent image is formed on an image carrier, and the electrostatic latent image is visualized as a toner image. After transfer to the transfer material, toner or paper dust that did not contribute to the transfer remains on the surface of the image carrier. It is comprised so that it may prepare for an image formation process. As the cleaning device, a device composed of a blade member or other cleaning member that is pressed against the surface of the image carrier is used.
A typical one of these is a blade cleaning method using a blade formed of a polyurethane (specifically, an organic compound having at least a urethane bond) material. This blade cleaning system is a system in which the edge of the blade member is pressed against the surface of the image carrier to forcibly remove the toner remaining on the surface of the image carrier. This method is widely adopted because it has a simple structure and a high cleaning effect.

  There are two methods for arranging the blades of the cleaning device on the photoconductor: the counter method and the trailing method. Counter systems that can remove toner more efficiently and improve its cleaning properties have become mainstream.

  On the other hand, in recent years, there has been a demand for a toner having a small particle size in order to improve image quality. As a production method for reducing the toner particle size, a polymerization method is effective from the viewpoint of production cost, not a conventional pulverization method. The small particle size toner produced by the polymerization method has a shape close to a sphere and a sharp particle size distribution, so that a good image with excellent fine line reproducibility and digital image dot reproducibility can be obtained. have. Furthermore, since the shape is spherical, unlike the toner obtained by the pulverization method, the contact area with the image carrier is reduced and the releasability from the image carrier is improved, so that the amount of residual toner can be reduced. Has characteristics.

  However, when polymerized toner with a small particle size is used, it is difficult to clean because the shape is close to a true sphere and the particle size is smaller than that of a toner produced by a conventional pulverization method. It has the disadvantage that cleaning failure occurs. In particular, when the blade edge is worn or chipped due to repeated use, cleaning failure is likely to occur. In addition, due to the use, the photoreceptor is worn and fine irregularities are formed, and cleaning defects are likely to occur even when the surface roughness increases.

  The performance for removing the transfer residual toner on the surface of the image carrier depends on the contact pressure of the cleaning blade against the image carrier. In order to clean a polymerized toner having a small particle diameter and a spherical shape as compared with a toner produced by a conventional pulverization method, the contact pressure must be increased. However, in the counter system, if the contact pressure is increased too much, the cleaning blade is turned up due to the frictional force with the image carrier, and cleaning failure occurs. Further, increasing the contact pressure not only promotes wear of the image carrier due to friction but also promotes wear of the cleaning blade itself.

  Various methods have been proposed to solve these problems. As an example, in JP-A-2000-122347 (Patent Document 1), a predetermined amount of an additive having a specific shape and particle size is contained in the developer, so that the additive accumulates at the edge of the cleaning blade, In order to improve the cleaning performance with respect to the transfer residual toner, an image forming apparatus capable of suppressing the occurrence of image defects due to poor cleaning even when spherical toner is used is disclosed.

  Japanese Patent Application Laid-Open No. 2001-142371 (Patent Document 2) discloses that the edge of the portion of the cleaning blade that comes into contact with the image carrier is roughened in advance, so that the external additive in the toner is selectively removed from the cleaning blade and By slipping from the surface of the image carrier and maintaining good cleaning performance without shaving unevenness and poor cleaning over a long period of time, it is good even when using a toner having an external additive and an image carrier having a large dynamic hardness. An electrophotographic apparatus capable of stably forming an image is disclosed.

  Japanese Patent Application Laid-Open No. 2003-307985 (Patent Document 3) discloses that a cleaning aid that is externally added and mixed in spherical toner is intentionally retained upstream of the contact portion of the cleaning blade. Disclosed is a cleaning device that can remove substantially spherical toner, which is difficult to clean without increasing contact pressure, from the image carrier, and can maintain good cleaning performance over a long period of time without shortening the life of the image carrier. Yes.

  However, in Patent Document 1, the volume average particle size of the additive is 1 to 8 μm, which is the same size as the toner, and the additive does not stay at the edge of the cleaning blade but slips between the image carrier and the cleaning blade. In such a case, the toner is also removed from the starting point, resulting in poor image quality due to poor cleaning. Furthermore, there are no provisions regarding the physical properties of the cleaning blade itself and the contact conditions of the cleaning blade, and this effect cannot be obtained depending on the physical properties of the blade or the contact conditions.

  In the technique described in Patent Document 2, the cleaning blade is maintained at a long period of time by selectively passing through the external additive in the toner by intentionally roughening the edge of the cleaning blade. It is not practical to manufacture a cleaning blade that has been roughened intentionally because it leads to increased costs, and when it is actually mounted, the roughened edge protrusions wear or become chipped. Toner slips through and causes poor cleaning.

  Further, in the device described in Patent Document 3, the cleaning aid stays for a certain width on the upstream side of the contact portion to prevent the toner from slipping between the image carrier and the cleaning blade, and the transfer residual toner from the image carrier. However, if there are no particles between the image carrier and the cleaning blade, the frictional force between the two will increase, the blade will be caught and the contact state will change, and the cleaning performance will be reduced. End up. Furthermore, blade wear and chipping are promoted, and the cleaning performance cannot be maintained over a long period of time. Furthermore, the blade is turned over. As described above, conventionally, strong pressure contact with the image carrier has been required for good cleaning with the cleaning blade, but strong pressure contact causes more severe wear, turning, deformation, chipping, etc. of the cleaning blade. Therefore, it is generally difficult to achieve both good cleaning by the cleaning blade and ensuring the durability of the cleaning blade, even if other conditions are adjusted appropriately. Although this tendency was remarkable when using, it was found that a certain amount of slipping of the cleaning aid was necessary to solve this problem.

JP 2000-122347 A JP 2001-142371 A JP 2003-307985 A

Accordingly, the present invention has been made to solve the above-mentioned problems of the prior art, and the object of the present invention is to first form an abutting portion by being pressed against the surface of the image carrier to form an image carrier. In the cleaning blade for removing the toner remaining on the surface of the body, even when polymerized toner that is a small particle size and spherical toner is used, the margin of cleaning ability is increased, and the abrasion resistance and chipping resistance of the cleaning blade are increased. It is an object of the present invention to provide a cleaning device that is excellent in performance and can maintain and improve good cleaning properties over a long period of time, and an image forming method and an image forming device using the same.
It is another object of the present invention to provide a cleaning device that can obtain a stable cleaning property even in a low temperature environment in which a cleaning failure is likely to occur, an image forming method using the same, and an image forming device.
Furthermore, to provide an image forming method and an image forming apparatus capable of obtaining an image having high resolution and sharpness of characters and good transferability without halftone unevenness by using a polymerization toner which is a small particle size / spherical toner. is there.
Furthermore, even when polymerized toner, which is a small particle size / spherical toner, is used, cleaning is performed with a contact pressure equivalent to that of toner manufactured by a conventional pulverization method without increasing the contact pressure of the cleaning blade. By establishing the above, an object of the present invention is to provide an image forming apparatus capable of reducing the torque for driving the image carrier and reducing the durability and power consumption of the image forming apparatus.

That is, the said subject is solved by (1)-(7) of this invention.
(1) “In a cleaning device having a cleaning blade that is pressed against the surface of the image carrier to form a contact portion and removes toner remaining on the surface of the image carrier, the volume average particle size of the toner is 6. 0 μm or less, circularity is 0.95 or more, the cleaning blade is made of a polyurethane rubber plate, the free length L of the cleaning blade is between 7 mm ≦ L ≦ 12 mm, and the thickness t is between 1 mm ≦ t ≦ 3 mm The ratio of the free length L of the cleaning blade to the diameter D of the image bearing member is between 1/5 ≦ L / D ≦ 1/2, the hardness of the leaning blade is 70 to 80 °, and the repulsion at 25 ° C. The elastic modulus is 20 to 45%, the cleaning blade is brought into contact with the image carrier in a counter manner, and the tangential direction of the contact point between the image carrier and the cleaning blade The angle formed by the cutting surface of the blade is set to be 70 to 80 °, and an additive is externally mixed in the toner. Among the additives, an additive having a particle size of 100 nm or less is included. An amount of slipping between the cleaning blade and the image carrier is 4.0 × 10 ³ to 4.0 × 10 ⁵ pieces / mm ² ”;
(2) “The cleaning device according to (1) above, wherein a 300% modulus of the cleaning blade is 300 kg / cm ² or more”;
(3) “The cleaning device according to the item (1) or (2), wherein the tear strength of the cleaning blade is 50 kg / cm or more”;
(4) “The cleaning device according to any one of (1) to (3) above, wherein a tan δ (10 Hz) peak temperature of the cleaning blade is set to 5 ° C. or lower”;
(5) Any of the above items (1) to (4), wherein the contact pressure between the image carrier and the cleaning blade is set to 0.2 to 0.5 N / cm The cleaning device according to claim 1;
(6) “An image carrier that carries a latent image on its surface, a developing unit that develops the latent image into a toner image, a transfer unit that transfers the toner image to a transfer member, and the items (1) to (1). An image forming apparatus having at least the cleaning device according to any one of (5) ”;
(7) “Using the image forming apparatus described in (6) above, a latent image is formed and supported on the surface of the image carrier, the latent image is developed into a toner image, and the toner image is transferred. An image forming method characterized by removing toner remaining on the surface of an image bearing member while being transferred to a body ”.

  As will be apparent from the following detailed and specific description, according to the present invention, in the cleaning blade for removing toner remaining on the surface of the image carrier by forming a contact portion by being pressed against the surface of the image carrier. Even when polymerized toner, which is a small particle size and spherical toner, is used, the margin of cleaning ability can be increased, and it has excellent wear resistance and chipping resistance, and maintains and improves good cleaning performance over a long period of time. The cleaning device having a cleaning blade capable of performing the above, an image forming method using the same, and an image forming apparatus can be provided.

  In addition, it is possible to provide a cleaning device that can obtain a stable cleaning property even in a low temperature environment in which cleaning failure is likely to occur, an image forming method using the same, and an image forming device.

Furthermore, it is possible to provide an image forming method and an image forming apparatus capable of obtaining an image having high resolution and sharpness of characters, good transferability and no halftone unevenness by using a polymerization toner which is a small particle size / spherical toner. The extremely excellent effect of being able to be produced is exhibited.
Furthermore, even when polymerized toner, which is a small particle size / spherical toner, is used, cleaning is performed with a contact pressure equivalent to that of toner manufactured by a conventional pulverization method without increasing the contact pressure of the cleaning blade. By realizing the above, it is possible to reduce the torque for driving the image carrier, and it is possible to provide an image forming apparatus capable of reducing the durability and power consumption of the image forming apparatus. The

  Hereinafter, the present invention will be specifically described with reference to the drawings. FIG. 1 is a sectional view of an example of a cleaning device according to the present invention as seen from the side. In the figure, (1) shows the image carrier, (2) shows the cleaning blade, (3) shows the blade holder, and (D) shows the diameter of the image carrier. (Θ) is an abutment angle, and is composed of an extension line (Y) of the cut surface of the cleaning blade and a tangent line (X) at the contact point between the image carrier and the cleaning blade. FIG. 2 is an example of a cross-sectional view of an example of a cleaning blade according to the present invention as viewed from the side. In the figure, (t) indicates the thickness of the blade, and (L) indicates the free length.

  In order to solve the above-mentioned problems of the prior art, in the present invention, the toner has a volume average particle diameter of 6.0 μm or less and a circularity of 0.95 or more, and the cleaning blade is urethane rubber. It consists of a plate, the free length L is 7 mm ≦ L ≦ 12 mm, the thickness t is 1 mm ≦ t ≦ 3 mm, and the ratio of the free length L to the diameter D of the image carrier is 1/5 ≦ L / D ≦ 1/2 Is set to

The ratio of the free length L to the diameter D of the image carrier is more preferably 1/4 ≦ L / D ≦ 1/3. If the ratio of the free length L to the diameter D of the image carrier is less than 1/5, toner slips out easily, and if it is greater than 1/2, blade turning tends to occur.
The hardness of the cleaning blade at the surface temperature of the image carrier is 70 to 80 °, the rebound resilience is 20 to 45% at 25 ° C., the tangential direction of the contact point between the image carrier and the cleaning blade, and the cut surface of the cleaning blade Is set to 70 to 80 °.

  In the present invention, the hardness of the cleaning blade is defined by a JIS K6253 hardness test. The hardness is 70 to 80 °, more preferably 72 to 76 °, as the surface temperature of the image carrier. If the hardness is less than 70 °, it is soft and easily worn. Therefore, as will be apparent from examples shown later, even if other conditions are within the scope of the present invention, toner slip easily occurs and the hardness exceeds 80 °. Therefore, abrasion is promoted on the photosensitive member side, fogging is likely to occur, and chipping is likely to occur on the blade side, and the cleaning property of the small particle size toner cannot be ensured.

The average particle diameter of the additive passing through between the image carrier and the cleaning blade is preferably 100 nm or less, more preferably 10 to 60 nm. Additives with an average particle size of more than 100 nm exhibit a dam effect by staying at the blade edge when other conditions are within the scope of the present invention, as will be apparent from examples shown later. Can keep.
The amount of the additive that passes between the image carrier and the cleaning blade is determined by detaching the surface of the image carrier after passing through the blade and observing with an S-4200 FE-SEM manufactured by Hitachi, Ltd. The number of additives corresponding to an area of 600 μm × 400 μm is counted and used as a slip-through amount. The amount by which the additive having an average particle size of 100 nm or less in the toner slips between the image carrier and the cleaning blade is 4.0 × 10 ³ to 4.0 × 10 ⁵ pieces / mm ² , more preferably 2.0 × 10. ^It is good that it is 4-2.0 * 10 < ⁵ > piece / mm < ² >. When the amount of slipping through the additive is less than 4.0 × 10 ³ pieces / mm ² , the frictional force between the image carrier and the cleaning blade cannot be reduced, and the contact state changes due to the entrainment of the blade edge and the cleaning performance is improved. Not only will this decrease, but also wear and chipping will be promoted, and good cleaning properties cannot be maintained over a long period of time. On the other hand, generally used additives themselves have very high hardness. Therefore, if the amount of slipping between the image carrier and the cleaning blade is more than 2.0 × 10 ⁵ pieces / mm ² , the image carrier or the cleaning agent is used. The blade is damaged, and the life of the image carrier and the cleaning blade is remarkably reduced.

The 300% modulus of the cleaning blade is specified by the JIS K6251 tensile test. The 300% modulus should be 300 kg / cm ² or more. When the 300% modulus is less than 300 kg / cm ² , the blade edge is deformed and stress concentration occurs, and it is easy to tear off. Therefore, it is weak against abrasion and chipping, and toner slips easily.

The tan δ (10 Hz) peak temperature of the cleaning blade is preferably set to 5 ° C. or lower, more preferably 0 ° C. or lower. When the peak temperature of tan δ is higher than 5 ° C., it is used near or below the glass transition point in a low temperature environment, and the blade itself does not exhibit rubber properties, so that the cleaning property is lowered and the blade chatter easily occurs. The tan δ (10 Hz) peak temperature of the cleaning blade in the present invention was measured according to the dynamic property test method of JIS K6394 vulcanized rubber and thermoplastic rubber. A rheometer (ARES manufactured by Rheometrics) was used as a measuring instrument.
The tear strength of the cleaning blade is defined by the JIS K6252 tear test. The tear test is preferably 50 kg / cm or more. When the tear strength is less than 50 kg / cm, chipping of the blade edge is likely to occur, and the durability of the blade is deteriorated. When the tear strength is 50 kg / cm or more, chipping of the blade can be prevented even under high temperature and high humidity.

In order to keep the amount of additive slipping between the cleaning blade and the image carrier in the range of 4.0 × 10 ³ to 4.0 × 10 ⁵ pieces / mm ² , the material and thickness of the cleaning blade Depending on the free length and the material of the image carrier, the contact pressure between the image carrier and the cleaning blade is 0.2 to 0.5 N / cm, more preferably 0.25 to 0.4 N / cm. It is good. If the contact pressure is less than 0.2 N / cm, the pressure contact with the image carrier by the cleaning blade is weak even if other conditions are within the scope of the present invention, as will be apparent from examples shown later. When the contact pressure is greater than 0.5 N / cm, a large torque is required to rotate the image bearing member, and blade noise is likely to occur. The blade is bent, and the image carrier is brought into a so-called belly contact state, and defective cleaning occurs.

In addition, by using a small particle diameter toner having a volume average particle diameter of 6.0 μm or less, the particle diameter distribution of the toner becomes sharp and it becomes easy to be uniformly charged, so that the electrostatic adhesion with the image carrier is uniform. Therefore, an image with high resolution and high character sharpness can be obtained.
Furthermore, when the circularity of the toner is 0.95 or more, in addition to the above, it is possible to obtain an image with good transferability and no halftone unevenness.
The volume average particle size of the toner of the present invention is measured with a particle size measuring device (“Multisizer III”, manufactured by Beckman Coulter, Inc.) with an aperture diameter of 100 μm and analyzed with analysis software (Beckman Coulter Multisizer 3 Version 3.51). Went. Specifically, 0.5 ml of 10 wt% surfactant (alkylbenzene sulfonate Neogen SC-A; Daiichi Kogyo Seiyaku) was added to a glass 100 ml beaker, 0.5 g of each toner was added, and the mixture was stirred with a micropartel. Subsequently, 80 ml of ion-exchanged water was added. The obtained dispersion was subjected to a dispersion treatment for 10 minutes with an ultrasonic disperser (W-113MK-II, manufactured by Honda Electronics Co., Ltd.). The dispersion was measured using the Multisizer III and Isoton III (manufactured by Beckman Coulter) as the measurement solution. In the measurement, the toner sample dispersion was dropped so that the concentration indicated by the apparatus was 8 ± 2%. In this measurement method, it is important that the concentration is 8 ± 2% from the viewpoint of the reproducibility of the particle size. Within this concentration range, no error occurs in the particle size.
The average circularity of the toner of the present invention is measured using a flow type particle image analyzer (“FPIA-2100”; manufactured by Sysmex Corporation) for measurement of ultrafine toner, and analysis software (FPIA-2100 Data Processing Program for FPIA). Analysis was performed using version 00-10). Specifically, 0.1 to 0.5 ml of 10 wt% surfactant (alkylbenzene sulfonate Neogen SC-A; Daiichi Kogyo Seiyaku) is added to a glass 100 ml beaker, and each toner 0.1 to 0 is added. 0.5 g was added and stirred with a microspatel, and then 80 ml of ion-exchanged water was added. The obtained dispersion was subjected to a dispersion treatment for 3 minutes with an ultrasonic disperser (manufactured by Honda Electronics Co., Ltd.). The shape and distribution of the toner were measured using the FPIA-2100 until the density of the dispersion was 5000 to 15000 / μl. In this measurement method, it is important that the concentration of the dispersion liquid is 5000 to 15000 / μl from the viewpoint of measurement reproducibility of the average circularity. In order to obtain the dispersion concentration, it is necessary to change the conditions of the dispersion, that is, the amount of surfactant to be added and the amount of toner. The amount of the surfactant varies depending on the hydrophobicity of the toner as in the measurement of the toner particle diameter described above. If it is added in a large amount, noise due to bubbles is generated, and if it is too small, the toner cannot be sufficiently wetted. It will be enough. Further, the toner addition amount differs from the particle size, and it is necessary to decrease the small particle size and increase the large particle size. When the toner particle size is 3 to 7 μm, the toner amount is 0.1 to 0. By adding 0.5 g, the dispersion concentration can be adjusted to 5000 to 15000 / μl.

  The blade used in the present invention is preferably formed of a polyurethane (specifically, an organic compound having at least a urethane bond) material. As is well known, polyurethane is obtained by a reaction between an isocyanate compound and a polyol compound. In the present invention, known raw materials can be used.

  Specific examples of the isocyanate compound to be used are tolylene diisocyanate, 4,4-diphenylmethane diisocyanate, 1,5-naphthalene diisocyanate, triphenylmethane triisocyanate, tolidine diisocyanate, xylene diisocyanate, hexamethylene diisocyanate, dicyclohexylmethane diisocyanate, Examples include isophorone diisocyanate.

  Examples of the polyol compound include polyether polyols, polyester polyols, acrylic polyols, epoxy polyols, and the like. For example, as raw material monomers constituting the acrylic polyols, methyl acrylate, ethyl acrylate, isopropyl acrylate, acrylic acid n -Butyl, 2-ethylhexyl acrylate, ethyl methacrylate, isopropyl methacrylate, n-butyl methacrylate, isobutyl methacrylate, n-hexyl methacrylate, lauryl methacrylate, acrylic acid, methacrylic acid, maleic acid, itaconic acid, methacrylic acid 2-hydroxyethyl acid, hydroxypropyl methacrylate, 2-hydroxyethyl acrylate, hydroxypropyl acrylate, acrylamide, N-methylolacrylamide, Acetone acrylamide, glycidyl methacrylate, styrene, vinyl toluene, vinyl acetate, acrylonitrile.

  The small particle / spherical toner is preferably a toner obtained by polymerizing a polymerizable monomer in an aqueous medium, and more preferably a toner obtained by associating resin particles in an aqueous medium. The production method is suspension polymerization or adding an emulsion of necessary additives, and emulsion polymerization of monomers in the liquid (in an aqueous medium) to prepare fine polymer particles (resin particles). Thereafter, the resin particles can be produced by a method in which an organic solvent and a flocculant are added to associate the resin particles.

Details of the small particle size / spherical toner and developer used in the present invention are as follows.
As resins, polystyrene resin, epoxy resin, polyester resin, polyamide resin, styrene acrylic resin, styrene methacrylate resin, polyurethane resin, vinyl resin, polyolefin resin, styrene butadiene resin, phenol resin, polyethylene resin, silicon resin, butyral resin, terpene There are resins, polyol resins and the like.

  Examples of vinyl resins include styrene such as polystyrene, poly-p-chlorostyrene, and polyvinyltoluene, and homopolymers thereof: styrene-p-chlorostyrene copolymer, styrene-propylene copolymer, styrene-vinyltoluene copolymer. Polymer, styrene-vinyl naphthalene copolymer, styrene-methyl acrylate copolymer, styrene-ethyl acrylate copolymer, styrene-butyl acrylate copolymer, styrene-octyl acrylate copolymer, styrene-methacrylic copolymer Acid methyl copolymer, styrene-ethyl methacrylate copolymer, styrene-butyl methacrylate copolymer, styrene-α-chloromethyl methacrylate copolymer, styrene-acrylonitrile copolymer, styrene-vinyl methyl ether copolymer Coalescence, styrene-vinyl ethyl acetate Copolymer, styrene-vinyl methyl ketone copolymer, styrene-butadiene copolymer, styrene-isoprene copolymer, styrene-acrylonitrile-indene copolymer, styrene-maleic acid copolymer, styrene-maleic acid ester Styrene copolymers such as copolymers: polymethyl methacrylate, polybutyl methacrylate, polyvinyl chloride, polyvinyl acetate and the like.

  The polyester resin is composed of a dihydric alcohol as shown in the following group A and a dibasic acid salt as shown in the group B, and further a trihydric or higher alcohol as shown in the group C or Carboxylic acid may be added as a third component.

  Group A: ethylene glycol, triethylene glycol, 1,2-propylene glycol, 1,3-propylene glycol, 1,4 butanediol, neopentyl glycol, 1,4 butenediol, 1,4-bis (hydroxymethyl) cyclohexane Bisphenol A, hydrogenated bisphenol A, polyoxyethylenated bisphenol A, polyoxypropylene (2,2) -2,2′-bis (4-hydroxyphenyl) propane, polyoxypropylene (3,3) -2, 2-bis (4-hydroxyphenyl) propane, polyoxyethylene (2,0) -2,2-bis (4-hydroxyphenyl) propane, polyoxypropylene (2,0) -2,2′-bis (4 -Hydroxyphenyl) propane and the like.

Group B: maleic acid, fumaric acid, mesaconic acid, citraconic acid, itaconic acid, glutaconic acid, phthalic acid, isophthalic acid, terephthalic acid, cyclohexanedicarboxylic acid, succinic acid, adipic acid, sebacic acid, malonic acid, linolenic acid, or These acid anhydrides or esters of lower alcohols.
Group C: Trivalent or higher alcohols such as glycerin, trimethylolpropane and pentaerythritol, and trivalent or higher carboxylic acids such as trimellitic acid and pyromellitic acid.

  As the polyol resin, an alkylene oxide adduct of an epoxy resin and a dihydric phenol, or a compound having one active hydrogen in the molecule that reacts with the glycidyl ether and the epoxy group, and an active hydrogen that reacts with the epoxy resin in the molecule. There are those obtained by reacting two or more compounds.

The following are used as the pigment used in the present invention.
Examples of black pigments include azine dyes such as carbon black, oil furnace black, channel black, lamp black, acetylene black, and aniline black, metal salt azo dyes, metal oxides, and composite metal oxides.

  Examples of yellow pigments include cadmium yellow, mineral fast yellow, nickel titanium yellow, navel yellow, naphthol yellow S, hansa yellow G, hansa yellow 10G, benzidine yellow GR, quinoline yellow lake, permanent yellow NCG, and tartrazine lake. .

  Examples of the orange pigment include molybdenum orange, permanent orange GTR, pyrazolone orange, Vulcan orange, indanthrene brilliant orange RK, benzidine orange G, and indanthrene brilliant orange GK.

Examples of red pigments include Bengala, Cadmium Red, Permanent Red 4R, Resol Red, Pyrazolone Red, Watching Red Calcium Salt, Lake Red D, Brilliant Carmine 6B, Eosin Lake, Rhodamine Lake B, Alizarin Lake, Brilliant Carmine 3B.

  Examples of purple pigments include fast violet B and methyl violet lake.

  Examples of blue pigments include cobalt blue, alkali blue, Victoria blue lake, phthalocyanine blue, metal-free phthalocyanine blue, phthalocyanine blue partially chlorinated, fast sky blue, and indanthrene blue BC.

Examples of green pigments include chrome green, chromium oxide, pigment green B, and malachite green lake.
These can use 1 type (s) or 2 or more types.

  Especially for color toners, uniform dispersion of good pigments is essential. Instead of putting pigments directly into a large amount of resin, a master batch in which pigments are once dispersed at a high concentration is prepared and diluted. The method of throwing in is used.

  A charge control agent is blended (internally added) inside the toner particles. However, it may be used by mixing (external addition) with toner particles. The charge control agent enables optimal charge amount control according to the development system. In particular, in the present invention, the balance between the particle size distribution and the charge amount can be further stabilized.

  For controlling the toner to be positively charged, nigrosine and quaternary ammonium salts, triphenylmethane dyes, imidazole metal complexes and salts can be used alone or in combination of two or more. Further, salicylic acid metal complexes, salts, organic boron salts, calixarene compounds, and the like are used for controlling the toner to be negatively charged.

  A release agent can be internally added to prevent offset during fixing. Release agents include natural waxes such as candelilla wax, carnauba wax, rice wax, montan wax and derivatives thereof, paraffin wax and derivatives thereof, polyolefin wax and derivatives thereof, sazol wax, low molecular weight polyethylene, and low molecular weight polypropylene. And alkyl phosphate esters. The melting point of these release agents is preferably 65 to 90 ° C. When the temperature is lower than this range, blocking during storage of the toner is likely to occur, and when the temperature is higher than this range, an offset is likely to occur in a region where the fixing roller temperature is low.

  An additive may be added for the purpose of improving the dispersibility of a release agent or the like. Additives include styrene acrylic resin, polyethylene resin, polystyrene resin, epoxy resin, polyester resin, polyamide resin, styrene methacrylate resin, polyurethane resin, vinyl resin, polyolefin resin, styrene butadiene resin, phenol resin, butyral resin, terpene resin, There are polyol resins and the like, and two or more of these resins may be mixed.

  Examples of the method for producing the toner according to the present invention include a pulverization method and a polymerization method (suspension polymerization, emulsion polymerization dispersion polymerization, emulsion aggregation, emulsion association, etc.), but are not limited to these production methods.

  The toner of the present invention may be modified by embedding child particles on the surface of the base particles. Fine irregularities can be formed on the toner surface by mixing organic resin particles, inorganic fine particles or the like that are 1/10 or less of the base particles, and fixing them to the base surface by heat treatment or the like.

  In the toner, one or more inorganic and organic fine particles may be mixed and used as an external additive. The fluidity and charging characteristics of the toner can be adjusted.

As the inorganic fine particles, general hydrophobized inorganic particles can be used in combination, but the average particle size of the hydrophobized primary particles is 1 to 100 nm, more preferably 10 to 60 nm. desirable. Moreover, it is preferable that the specific surface area by BET method is 20-500 m < ² > / g.

  Any of them can be used as long as the conditions are satisfied. For example, silica fine particles, hydrophobic silica, fatty acid metal salts (such as zinc stearate and aluminum stearate), metal oxides (such as titania, alumina, tin oxide, and antimony oxide), fluoropolymers, and the like may be contained.

  Particularly suitable additives include hydrophobized silica, titania, titanium oxide, and alumina fine particles. As silica fine particles, there are HDK H 2000, HDK H 2000/4, HDK H 2050EP, HVK21, HDK H 1303 (Clariant Japan) and R972, R974, RX200, RY200, R202, R805, R812 (Nippon Aerosil). . Further, as titania fine particles, P-25 (Nippon Aerosil), STT-30, STT-65C-S (above Titanium Industry), TAF-140 (Fuji Titanium Industry), MT-150W, MT-500B, MT-600B MT-150A (taker above). In particular, as hydrophobized titanium oxide fine particles, T-805 (Nippon Aerosil), STT-30A, STT-65S-S (above Titanium Industry), TAF-500T, TAF-1500T (above Fuji Titanium Industry), MT -100S, MT-100T (above Taka), IT-S (Ishihara Sangyo), etc.

  The organic fine particles used in the present invention may be thermoplastic resins or thermosetting resins. For example, vinyl resin, polyurethane resin, epoxy resin, polyester resin, polyamide resin, polyimide resin, silicon resin, phenol resin, melamine Resins, urea resins, aniline resins, ionomer resins, polycarbonate resins, and the like. As the organic fine particles, two or more of the above resins may be used in combination. Of these, vinyl resins, polyurethane resins, epoxy resins, polyester resins, and combinations thereof are preferred because an aqueous dispersion of fine spherical resin particles is easily obtained.

The vinyl resin is a polymer obtained by homopolymerization or copolymerization of a vinyl monomer, such as a styrene- (meth) acrylate resin, a styrene-butadiene copolymer, a (meth) acrylic acid-acrylate polymer, Examples include styrene-acrylonitrile copolymers, styrene-maleic anhydride copolymers, styrene- (meth) acrylic acid copolymers, and the like.
These are merely examples, and the small particle size / spherical toner may of course be manufactured by a method other than the above manufacturing method.

FIG. 3 is a schematic view showing an example of the image forming apparatus of the present invention, and FIG. 4 is a schematic view illustrating an example of a process cartridge that can be mounted on the image forming apparatus of the present invention.
In the image forming apparatus of FIG. 3, (101) is a photosensitive drum which is a latent image carrier, (102) is a developing device disposed on the side of the photosensitive drum (101), (103) is a developing housing, (104) is a developing sleeve as a developer carrier, (105a, 105b) is a developer accommodating portion, and (106) is a first doctor blade as a developer regulating member. A developing housing (103) having an opening on the photosensitive drum (101) side and a toner hopper (108) as a toner containing portion for containing the toner (107) are provided therein, and are adjacent to the toner hopper (108). A developer accommodating portion (105a) for accommodating a developer composed of toner (107) and a carrier as magnetic particles is provided near the photosensitive drum (101). The latent image carrier (101), the charger (136) for uniformly charging the surface of the latent image carrier (101), and the developing means (102) are attached to and detached from the image forming apparatus main body. It is configured as an integral structure.

  Inside the toner hopper (108), a toner agitator (111) is disposed as toner supply means that is rotated by a drive means (not shown). The toner agitator (111) rotates in the direction of the arrow so that the toner (107) in the toner hopper (108) is sent to the toner supply port (110) while stirring. A developing sleeve is disposed in a space between the photosensitive drum (101) and the toner hopper (108). The developing sleeve (104) that is rotationally driven in the direction of the arrow in the figure by a driving means (not shown) has a magnet (104a) as a magnetic field generating means disposed in the position relative to the developing device (102). Have.

  A first doctor blade (106) is integrally attached to a side of the developer accommodating portion (105a) opposite to the side attached to the developing housing (103). The first doctor blade (106) is disposed in a state where a certain gap is maintained between its tip and the outer peripheral surface of the developing sleeve (104). A second doctor blade (112) is disposed in a portion of the developer container (105a) located in the vicinity of the toner supply port (110).

  With the above configuration, the toner (107) sent out from the toner hopper (108) by the toner agitator (111) passes through the toner supply port (110) and is carried on the developing sleeve (104). To the developer container (105a). The developer in the developer container (105a) is carried on the developing sleeve (104) and conveyed to a position facing the outer peripheral surface of the photosensitive drum (101), and only the toner (117) is transferred to the photosensitive drum. By electrostatically coupling with the electrostatic latent image formed on (101), a toner image is formed on the photosensitive drum (101).

  The developer traveling around the developing sleeve (104) is braked by the developer staying inside when passing through the developer accommodating portion (105a), so that the conveyance speed is lowered. The developer layer thickness of the developing sleeve (104) near the second doctor blade (112) increases. As the toner concentration increases, the frictional force between the developers decreases and the conveyance speed decreases, so that the layer thickness further increases and the second developer regulating member (112) prevents the progress. . When this state is reached, the opening (114) is blocked by the staying developer (113) that has been prevented from advancing, so that the toner intake is stopped. Conversely, when the toner concentration decreases, the frictional force between the developers increases, and the staying developer (113) is taken into the developer accommodating portion (105a). The toner comes in contact with the toner. The toner density of the developer can be automatically controlled by the above action.

  Around the drum-shaped photoconductor (101) as an image carrier, in addition to the developing device, a charging unit (136), a cleaning blade (135), a waste toner storage case (131), a waste toner (132), and a cleaning unit A waste toner collecting roller (133) for sending the waste toner cleaned in step (1) to the waste toner storage case (131), and a drum case (134) for holding the photosensitive member, the charging means, and the cleaning means are provided. The drum case and the developing device are integrated to constitute an image forming apparatus. The cleaning blade (135) according to the present invention is installed so as to protrude from the blade support member (135a) by a predetermined amount, and in order to clean the surface of the image carrier, the cleaning blade (135) is in a counter direction toward the surface of the image carrier. The drum case (134) is fixed with screws (135b).

  An image carrier (photoconductor) is driven to rotate at a predetermined peripheral speed. In the rotation process, the photosensitive member is uniformly charged with a positive or negative predetermined potential on its peripheral surface by the charging unit, and then receives image exposure light from an image exposing unit such as slit exposure or laser beam scanning exposure. An electrostatic latent image is sequentially formed on the peripheral surface of the body, and the formed electrostatic latent image is then developed with toner by a developing unit, and the developed toner image is transferred between the photosensitive member and the transfer unit from the paper feeding unit. Then, the image is sequentially transferred to the transfer material fed in synchronization with the rotation of the photosensitive member by the transfer means. The transfer material that has received the image transfer is separated from the surface of the photosensitive member, introduced into the image fixing means, and fixed on the image, and printed out as a copy (copy). The surface of the photoreceptor after the image transfer is cleaned by removing the transfer residual toner by the cleaning means, and after being further neutralized, it is repeatedly used for image formation.

The process cartridge of the present invention uses the toner of the present invention, has a photosensitive member and a cleaning unit, and may integrally support at least one unit selected from a charging unit and a developing unit. The process cartridge is detachable from the main body. FIG. 4 shows a schematic configuration of an example of the process cartridge of the present invention.
In the figure, the entire process cartridge has a photosensitive member, a charging unit, a developing unit, and a cleaning unit using the cleaning blade of the present invention. In the image forming apparatus having the process cartridge of the present invention, the photosensitive member is rotationally driven at a predetermined peripheral speed. In the rotation process, the photosensitive member is uniformly charged with a positive or negative predetermined potential on its peripheral surface by the charging unit, and then receives image exposure light from an image exposing unit such as slit exposure or laser beam scanning exposure. An electrostatic latent image is sequentially formed on the peripheral surface of the body, and the formed electrostatic latent image is then developed with toner by a developing unit, and the developed toner image is transferred between the photosensitive member and the transfer unit from the paper feeding unit. Then, the image is sequentially transferred to the transfer material fed in synchronization with the rotation of the photosensitive member by the transfer means. The transfer material that has received the image transfer is separated from the surface of the photosensitive member, introduced into the image fixing means, and fixed, and printed out as a copy (copy). The surface of the photoreceptor after the image transfer is cleaned by removing the transfer residual toner by the cleaning blade of the present invention as a cleaning means, and after being further neutralized, it is repeatedly used for image formation.

  Hereinafter, the present invention will be described in more detail with reference to Examples and Comparative Examples. In addition, this invention is not limited to the Example and comparative example which are illustrated here.

<Evaluation blade>
A urethane rubber cleaning blade with different physical properties was prototyped and evaluated.
Table 1 shows the physical properties of the blade.

<Evaluation toner>
Polymerized toners having different volume average particle diameter and circularity were made and evaluated. Details of the toner are as follows. That is, a toner material liquid in which at least a polyester prepolymer having a functional group containing a nitrogen atom, polyester, a colorant, and a release agent is dispersed in an organic solvent is obtained by crosslinking and / or elongation reaction in an aqueous medium. It is what was done. The base toner includes 1.5% by weight of hydrophobized silica fine particles having a primary particle size of 12 nm, 0.5% by weight of hydrophobized titanium oxide fine particles having a primary particle size of 15 nm, and a large particle size silica having a primary particle size of 120 nm. 1.0% by weight of each was added and used.
Table 2 shows the physical properties of the polymerized toner.

<Contact condition>
The evaluation was performed by changing the angle θ formed between the tangential direction of the contact point of the image carrier and the evaluation blade and the cut surface of the evaluation blade and the contact pressure.
Table 3 shows the contact conditions of the evaluation blade.

<Evaluation method>
Evaluation was performed by a combination of the evaluation blade, the evaluation toner, and the contact condition. The evaluation toner and the evaluation blade were evaluated by replacing the standard blade and toner of a Ricoh color laser printer (IPSiO Color 8000; OPC photoreceptor mounted). The contact conditions were set using an improved IPSiO Color 8000 cleaning device.
Evaluation is initial cleaning performance with IPSiO Color 8000, cleaning performance in low-temperature and low-humidity environment (10 ° C / 15% RH), cleaning performance after running 80,000 sheets, blade edge wear / chip condition, image quality (Resolving power, sharpness difference, halftone reproducibility) were ranked in 5 stages. Further, the rank of the photoreceptor driving torque compared with the conventional pulverized toner (IPSiO Color 8000 condition) was evaluated in five stages. The higher the rank, the better. Further, the surface of the image carrier after passing the cleaning blade after running 80,000 sheets was peeled off, and the amount of slipping through the additive having an average particle diameter of 100 nm or less corresponding to an area of 600 μm × 400 μm was examined. The results are shown in Table 4.

It is a figure which shows the structural example of the cleaning blade contact state in this invention. It is a figure which shows the structural example of the cleaning blade in this invention. 1 is a diagram illustrating an example of an image forming apparatus of the present invention. FIG. 3 is a diagram illustrating an example of a process cartridge that can be attached to and detached from the image forming apparatus of the present invention.

Explanation of symbols

1 and 2
1 Image carrier 2 Cleaning blade 3 Blade holder θ Contact angle t Blade thickness L Blade free length

FIG.
DESCRIPTION OF SYMBOLS 101 Photosensitive drum 102 Developing apparatus 103 Developing housing 104 Developer carrying body 104a Magnet 105a, 105b Developer accommodating part 106 Developer regulating member 107 Toner 108 Toner hopper 110 Toner supply port 111 Toner agitator 112 Second doctor blade 113 Retained developer 114 Opening 117 Toner 131 Waste toner storage case 132 Waste toner 133 Waste toner collection roller 134 Drum case 135 Cleaning blade 135a Blade support member 135b Screw 136 Charging means

Claims (7)

In a cleaning device having a cleaning blade that is pressed against the surface of an image carrier to form a contact portion and removes toner remaining on the surface of the image carrier, the volume average particle diameter of the toner is 6.0 μm or less and a circular shape The cleaning blade is made of a polyurethane rubber plate, the free length L of the cleaning blade is 7 mm ≦ L ≦ 12 mm, and the thickness t is 1 mm ≦ t ≦ 3 mm. The ratio of the free length L to the diameter D of the image carrier is 1/5 ≦ L / D ≦ 1/2, the hardness of the leaning blade is 70 to 80 °, and the rebound resilience at 25 ° C. is 20 45%, the cleaning blade is brought into contact with the image carrier in a counter manner, the tangential direction of the contact between the image carrier and the cleaning blade, and the cleaning blade The angle formed with the cut surface of the roller is set to be 70 to 80 °, an additive is externally mixed in the toner, and among the additives, an additive having a particle size of 100 nm or less is included. A cleaning device, wherein an amount of slipping between the cleaning blade and the image carrier is 4.0 × 10 ³ to 4.0 × 10 ⁵ pieces / mm ² . The cleaning apparatus according to claim 1, wherein a 300% modulus of the cleaning blade is 300 kg / cm ² or more.   The cleaning device according to claim 1, wherein the cleaning blade has a tear strength of 50 kg / cm or more.   4. The cleaning device according to claim 1, wherein a tan δ (10 Hz) peak temperature of the cleaning blade is set to 5 ° C. or less. 5.   The cleaning apparatus according to claim 1, wherein a contact pressure between the image carrier and the cleaning blade is set to 0.2 to 0.5 N / cm.   The cleaning unit according to claim 1, an image carrier that carries a latent image on a surface, a developing unit that develops the latent image into a toner image, a transfer unit that transfers the toner image to a transfer member, and the cleaning unit. An image forming apparatus. A latent image is formed and supported on the surface of the image carrier using the image forming apparatus according to claim 6, the latent image is developed into a toner image, the toner image is transferred to a transfer body, and An image forming method comprising removing toner remaining on a surface of a carrier.

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