JP4250447B2 - Developer carrying member and developing device using the same - Google Patents

Description

【０１１６】
【表２】

【０１１７】
【表３】

【０１１８】
【表４】

【０１１９】
【表５】

【０１２０】
【表６】

【０１２１】
【発明の効果】
本発明によれば、粒径の小さいトナーや高転写性を有するトナーを用いた場合に現れる、トナーのチャージアップ現象及びブロッチを防止し、異なる環境下においても長期に渡って、トナーに適正な帯電量を与えることのできる現像剤担持体、及びそれを用いた現像装置を提供することができる。
【０１２２】
また本発明によれば、異なる環境下においても長期間に渡って、画像濃度低下、及びカブリの如き問題点が発生せず、高品位の画像を安定的に得ることができ、また低温定着性を有するトナーを用いた場合に現れる、現像剤担持体表面へのトナーによるスリーブ汚染及びスリーブ融着を生じず、スジ・ムラ等の不良画像を発生しない現像剤担持体、及びそれを用いた現像装置を提供することができる。
【０１２３】
また本発明によれば、異なる環境下においても長期間に渡って、現像剤担持体表面の表面粗さの変化を小さくすることにより、現像剤担持体上のトナーコート量を一定量に制御することのできる現像剤担持体、及びそれを用いた現像装置を提供することができる。
【図面の簡単な説明】
【図１】本発明の効果を示す模式図である。
【図２】本発明の効果を示す模式図である。
【図３】本発明に用いられる現像装置の模式図である。
【図４】本発明に用いられる現像装置の模式図である。
【図５】本発明に用いられる現像装置の模式図である。
【符号の説明】
３０１ 感光ドラム（潜像担持体）
３０４ 現像剤
３０６ 金属円筒管
３０７ 樹脂被覆層
３０８ 現像スリーブ（現像剤担持体）[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a developer carrier used for developing and developing a latent image formed on a latent image carrier, such as electrophotography, electrostatic recording method, magnetic recording method, and the like. The developing device.
[0002]
[Prior art]
Conventionally, a number of methods are known as electrophotographic methods. Generally, a photoconductive substance is used to form an electric latent image on a latent image carrier (photosensitive drum) by various means, and then The latent image is developed with a developer (toner) to be visualized, and the toner image is transferred to a transfer material such as paper as necessary, and then the toner image is fixed on the transfer material by heat and pressure. To obtain a copy.
[0003]
Development methods in electrophotography are mainly divided into a one-component development method and a two-component development method. In recent years, since it is necessary to reduce the size of a copying apparatus for the purpose of reducing the weight and size of an electrophotographic apparatus, a developing apparatus using a one-component developing system is often used.
[0004]
The one-component development method does not require carrier particles such as glass beads or iron powder unlike the two-component development method, and therefore the development device itself can be reduced in size and weight. Furthermore, since the two-component development method needs to keep the toner concentration in the developer constant, an apparatus that detects the toner concentration and replenishes the necessary amount of toner is required. Therefore, the developing device is also large and heavy here. In the one-component development system, such an apparatus is not necessary, so it is preferable because it can be made small and light.
[0005]
As a developing device using the one-component developing method, a latent image is formed on the surface of a photosensitive drum as a latent image carrier, and the friction between the developer carrier (developing sleeve) and toner and / or the toner on the developing sleeve. A development region in which a positive or negative charge is applied to the toner by friction with the developer layer thickness regulating member for regulating the coating amount, the toner is thinly applied on the developing sleeve, and the photosensitive drum and the developing sleeve face each other. In the development area, toner is developed by flying and adhering to the latent image on the surface of the photosensitive drum to develop the latent image as a toner image.
[0006]
However, when such a one-component development method is used, it is difficult to adjust the toner charge, and various efforts have been made with toner. However, problems related to non-uniformity of toner charge and durability of charge are completely It has not been solved.
[0007]
In particular, while the developing sleeve is repeatedly rotated, the charge amount of the toner coated on the developing sleeve becomes too high due to contact with the developing sleeve, and the toner is attracted by the reflection force on the developing sleeve surface and developed. A so-called charge-up phenomenon that becomes stationary on the surface of the sleeve and does not move from the developing sleeve to the latent image on the photosensitive drum is likely to occur particularly under low humidity. When such a charge-up phenomenon occurs, the toner in the upper layer is difficult to be charged, and the development amount of the toner is reduced, which causes problems such as thin line images and thin image density of solid images. In addition, the toner that is not properly charged due to charge-up becomes poorly regulated and flows out onto the sleeve, causing a so-called blotch phenomenon that becomes spotted and uneven on the wave. Furthermore, since the toner layer formation state of the image portion (toner consumption portion) and the non-image portion is changed and the charging state is different, for example, the position where the solid image having a high image density is once developed is next to the developing sleeve. When the halftone image is developed when the developing position is reached during rotation, a so-called sleeve ghost phenomenon is likely to occur, in which a solid image appears on the image.
[0008]
Recently, in order to digitize the electrophotographic apparatus and further improve the image quality, the toner is reduced in particle size and particle size. For example, in order to improve resolution and character sharpness and faithfully reproduce a latent image, it is common to use toner having a weight average particle diameter of about 5 to 10 μm. Further, from the viewpoint of ecology and for the purpose of further reducing the weight and size of the apparatus, the toner transfer efficiency is improved in order to reduce waste toner. For example, a transfer efficiency improver having an average particle size of 0.1 to 3 μm and a BET specific surface area of 50 to 300 m²/ G of hydrophobic silica fine powder reduces the volume resistance of the toner, improves the transfer efficiency by forming a thin film layer of the transfer efficiency improver on the photosensitive drum, and further reduces the toner itself. A method of improving the transfer efficiency by performing a spheroidizing process by a mechanical impact force is known. Also, the toner fixing temperature tends to be lowered for the purpose of shortening the first copy time and saving power. Under such circumstances, toner in particular under low temperature and low humidity is more likely to adhere electrostatically onto the developing sleeve due to an increase in the amount of charge per unit mass, and toner under high temperature and high humidity is physically exposed from the outside. As a result of using a material that is easy to fluidize and fluidize, it is easy to change the quality, and the toner is easily contaminated with the sleeve and fused with the sleeve.
[0009]
As a method for solving such a phenomenon, in Patent Documents 1 and 2, etc., development in which a coating layer in which a conductive lubricant such as a solid lubricant and carbon is dispersed in a resin is provided on a metal substrate. A method of using a sleeve for a developing device has been proposed. By using this method, it is recognized that the above phenomenon is greatly reduced. However, in this method, when the above powder is added in a large amount, it is good for charge-up and sleeve ghost, but the coating layer is easily scraped, and when the durability is advanced, the surface roughness is low. When the amount of addition is small, the effect of the conductive fine powder such as solid lubricant and carbon is thin and insufficient for charge-up and sleeve ghost. The problem remains.
[0010]
Patent Document 3 proposes a developing sleeve in which a conductive coating layer in which a solid lubricant and conductive fine powder such as carbon and spherical particles are dispersed in a resin is provided on a metal substrate. In this developing sleeve, the wear resistance of the coating layer is improved, the shape of the surface of the coating layer is made uniform, and the change in surface roughness is small. Becomes uniform, and the image quality such as stripes and unevenness such as sleeve ghost, image density, solid image, and the like is further stabilized. However, this developing sleeve is not completely wear-resistant, and in the further long-term durability, the coating layer is worn, and in this case, charging of the toner becomes unstable and causes image defects. In addition, when using the low-temperature fixable toner as described above, the reduction in the surface roughness of the coating layer due to the wear of the coating layer may cause sleeve contamination and sleeve fusion, which may also cause image deterioration. easy.
[0011]
In Patent Document 4, the spherical particles dispersed in the conductive coating layer are conductive spherical particles, and the wear resistance of the coating layer is further improved, thereby further stabilizing the shape of the coating layer surface. In addition, there has been proposed a developing sleeve having a surface layer that can further improve toner charging and suppress sleeve contamination and sleeve fusing by the toner even when the coating layer is somewhat worn. However, in the durability over a longer period, there is a possibility that the change in the surface roughness of the coating layer between the initial durability period and the late durability period will increase due to the difference between the wear amount of the coating layer and the wear amount of the conductive spherical particles. There is a possibility that the toner coat amount in the initial durability period and the late durability period will change, causing image deterioration. Further, when using a small particle size toner having high transferability as described above, the influence of the change in the surface roughness of the coating layer on the toner coating amount is more prominent, and this is also likely to cause image deterioration. .
[0012]
In Patent Documents 5 to 7, a developing sleeve having a surface layer that can further improve toner charging while maintaining the wear resistance of the coating layer by containing a plurality of types of particles in the resin coating layer. Has been proposed. However, in durability over a longer period of time, there may be a large change in the surface roughness of the coating layer between the initial durability stage and the late durability stage due to the difference between the abrasion amount of the coating layer and the abrasion amount of the plural kinds of particles. The toner coat amount in the initial durability period and the late durability period changes, which may cause image deterioration. The same applies to the developing sleeve having a resin coating layer containing at least spherical particles and fibrous particles, which is proposed in Patent Document 8, and the surface roughness of the coating layer is changed even in durability over a longer period. There is a demand for a developing sleeve having a surface layer that has a smaller surface area and a smaller effect on the toner coat amount.
[0013]
[Patent Document 1]
Japanese Patent Laid-Open No. 02-105181
[Patent Document 2]
Japanese Unexamined Patent Publication No. 03-036570
[Patent Document 3]
Japanese Patent Laid-Open No. 03-200986
[Patent Document 4]
Japanese Patent Laid-Open No. 08-240981
[Patent Document 5]
Japanese Patent No. 3131431
[Patent Document 6]
Patent 3182051
[Patent Document 7]
Japanese Patent No. 3182205
[Patent Document 8]
Japanese Patent Laid-Open No. 10-186839
[0014]
[Problems to be solved by the invention]
The object of the present invention is to prevent the toner charge-up phenomenon and blotch that appear when a toner having a small particle diameter or a toner having high transferability is used, and is suitable for the toner for a long time even in different environments. It is an object of the present invention to provide a developer carrying member capable of giving a charge amount and a developing device using the same.
[0015]
It is another object of the present invention to provide a high-quality image stably without causing problems such as a decrease in image density and fog over a long period of time even in different environments, and a low-temperature fixability. Developer carrier that does not cause sleeve contamination and sleeve fusion due to toner on the surface of the developer carrier, and does not generate defective images such as stripes and unevenness, and development using the same Is to provide a device.
[0016]
Another object of the present invention is to control the amount of toner coat on the developer carrier to a constant amount by reducing the change in surface roughness of the surface of the developer carrier over a long period of time even in different environments. It is an object of the present invention to provide a developer carrying member that can be used, and a developing device using the same.
[0017]
[Means for Solving the Problems]
The above object is achieved by the present invention described below.
[0018]
  That is, the present invention provides a developer carrier having a resin coating layer on a cylindrical or columnar substrate surface.
  The resin coating layer is a binder resinWith phenolic resin,The resinCoating layerofFor forming irregularities on the surfaceParticles, the layer thickness is 4 μm or more and 15 μm or less, and
  The particles are
  (1) Spherical carbon particles having a number average particle diameter Dm of 3.0 μm or more and 19.9 μm or less having a hardness greater than the hardness of the resin layer that is the matrix portion of the resin coating layer;
  (2) It consists of spherical particles made of carbon black-dispersed PMMA resin having a number average particle diameter Dn of 3.2 μm or more and 19.6 μm or less and having a hardness smaller than the hardness of the resin layer that is the matrix portion of the resin coating layer. ,and,
  Dm / Dn is 0.9 to 1.0The present invention relates to a developer carrying member.
[0027]
Furthermore, the present invention relates to a developer container, a developer carrier for carrying and transporting the developer contained in the developer container, and a developer carrier disposed close to or in pressure contact with the developer carrier. Developer layer thickness regulating member for forming a thin layer of developer on the bodyWhenAnd the developer is opposed to the latent image carrier by the developer carrier.Transport to development areaAnd a developing device that develops the latent image formed on the latent image carrier with a developer to make a visible image,
  The developer carrier has at least a substrate and a resin coating layer, and
The resin coating layer contains at least a binder resin, a solid lubricant, and spherical particles for forming irregularities on the surface of two or more types of coating layers having different hardnesses. The present invention relates to a developing device characterized in that the hardness is larger than the hardness of a resin layer as a matrix portion, and the hardness of at least one kind of spherical particles of the spherical particles is smaller than the hardness of a resin layer as a matrix portion.
[0028]
DETAILED DESCRIPTION OF THE INVENTION
Next, the developing sleeve used in the present invention and the developing device using the developing sleeve will be described in more detail.
[0029]
First, the material structure of the resin coating layer formed on the surface of the developing sleeve of the present invention will be described in detail.
[0030]
As the binder resin used in the resin coating layer of the present invention, generally known resins can be used. For example, phenol resin, epoxy resin, polyamide resin, polyester resin, polycarbonate resin, polyolefin resin, silicone resin, fluorine resin, styrene resin, vinyl resin, cellulose resin, melamine resin, Examples include urea resins, polyurethane resins, polyimide resins, and acrylic resins. Considering the mechanical strength, a heat or photo-curing resin is more preferable, but a thermoplastic resin can also be applied as long as it has sufficient mechanical strength.
[0031]
In the present invention, the resin coating layer formed on the surface of the developing sleeve by the above-described forming material is used to fix the toner to the surface of the developing sleeve by charge-up or from the surface of the developing sleeve to the toner caused by the charge-up of the toner. In order to prevent charging failure, it is desirable to be conductive. The volume resistance value of the coating layer is preferably 10^FourΩ · cm or less, more preferably 10^ThreeΩ · cm or less. The volume resistance value of the coating layer on the surface of the developing sleeve is 10^FourIf it exceeds Ω · cm, poor charging of the toner is likely to occur, and as a result, blotches (spot images and wave pattern images) are likely to occur.
[0032]
In the present invention, in order to adjust the resistance value of the resin coating layer to the above value, the following conductive fine powder may be contained in the coating layer. Examples of the conductive fine powder used at this time include fine powder of metal powder such as aluminum, copper, nickel, silver, antimony oxide, indium oxide, tin oxide, titanium oxide, zinc oxide, molybdenum oxide, titanium. Examples thereof include metal oxides such as potassium acid, various carbon fibers, furnace black, lamp black, thermal black, acetylene black, and carbon black such as channel black, carbon such as graphite, and metal fibers. Among these, carbon black, especially conductive amorphous carbon, is particularly excellent in electrical conductivity, and can be filled to a certain degree of conductivity by simply filling the polymer material with conductivity and controlling the amount added. Can be preferably used. Dispersion stability when used as a paint can also be good. Moreover, in this invention, when using these electroconductive fine powder, it is preferable to make the addition amount into the range of 1-100 mass parts with respect to 100 mass parts of binder resin. If it is less than 1 part by mass, it is usually difficult to lower the resistance value of the coating layer to a desired level, and there is a high possibility that toner adheres to the binder resin used for the developing sleeve coating layer. When the amount exceeds 100 parts by mass, the strength (wearability) of the coating layer may be lowered particularly when a fine powder having a particle size on the order of submicron is used.
[0033]
Next, generally known solid lubricants can be used as the solid lubricant used in the resin coating layer of the present invention. Examples include graphite, molybdenum disulfide, boron nitride, mica, graphite fluoride, silver-selenium niobium, calcium chloride-graphite, talc, zinc stearate, and other fatty acid metal salts. Since it is not impaired, it is preferably used. Moreover, it is preferable that the addition amount of these solid lubricants which can be used by this invention shall be the range of 1-100 mass parts with respect to 100 mass parts of binder resin. When the amount is less than 1 part by mass, the effect of improving the adhesion of the developer to the surface of the binder resin of the coating layer is small. When the amount exceeds 100 parts by mass, particularly when a material containing a large amount of fine powder having a particle size of submicron order is used. Further, the strength (wearability) of the coating layer can be reduced. These solid lubricants preferably have a number average particle diameter of preferably about 0.2 to 20 μm, more preferably 1 to 15 μm. When the number average particle size of the solid lubricant is less than 0.2 μm, it is difficult to obtain sufficient lubricity, and when the number average particle size exceeds 20 μm, the influence on the shape of the resin coating layer surface is not preferable. Is not preferable in terms of uniform charging of the toner and the strength of the coating layer.
[0034]
Next, spherical particles for forming irregularities on the surface of the coating layer used in the resin coating layer of the present invention (hereinafter referred to as irregularity-forming particles) will be described.
[0035]
Examples of such irregularities-forming particles include, for example, vinyl polymers and copolymers such as polymethyl methacrylate, polyethyl acrylate, polybutadiene, polyethylene, polypropylene, and polystyrene, benzoguanamine resins, phenol resins, polyamides, fluorine resins, and silicones. Resin particles such as resin, epoxy resin, polyester resin, oxide particles such as alumina, zinc oxide, silicone, titanium oxide, tin oxide, carbon particles, conductive particles such as resin particles subjected to conductive treatment, etc. It is also possible to use an organic compound such as a charge control agent in the form of particles. In this case, it also serves to impart triboelectric charge to the toner.
[0036]
Among these irregularity-forming particles, as the resin particles, for example, spherical resin particles by suspension polymerization method, dispersion polymerization method or the like are preferably used. Here, the spherical shape refers to particles having a major axis / minor axis ratio of about 1.0 to 1.5, preferably particles having a major axis / minor axis ratio of 1.0 to 1.2, more preferably It is preferable to use spherical particles. Spherical resin particles can obtain a suitable surface roughness with a smaller addition amount, and a uniform surface shape can be easily obtained. Examples of such spherical resin particles include acrylic resin particles such as polyacrylate and polymethacrylate, polyamide resin particles such as nylon, polyolefin resin particles such as polyethylene and polypropylene, silicone resin particles, phenolic resin particles, Examples include polyurethane resin particles, styrene resin particles, and benzoguanamine particles. The resin particles obtained by the pulverization method may be used after thermally or physically spheroidizing. In addition, when the irregularity-forming particles are spherical in this way, the contact area with the developer layer thickness regulating member to be pressed is reduced, thereby reducing the increase in sleeve rotation torque due to frictional force and toner adhesion. This is more preferable.
[0037]
The surface of such spherical resin particles may be used with inorganic fine powder attached thereto or fixed thereto. As inorganic fine powder, SiO₂, SrTiO_Three, CeO₂, CrO, Al₂O_Three, ZnO, MgO, TiO₂Oxides such as Si_ThreeN_FourNitrides such as SiC, carbides such as SiC, CaSO_Four, BaSO_Four, CaCO_ThreeAnd sulfates and carbonates.
[0038]
Further, the inorganic fine powder may be used after being treated with a coupling agent. In particular, it can be preferably used for the purpose of improving the adhesion to the binder resin or for imparting hydrophobicity to the particles. Examples of such a coupling agent include a silane coupling agent, a titanium coupling agent, and a zircoaluminate coupling agent. More specifically, for example, as a silane coupling agent, hexamethyldisilazane, trimethylsilane, trimethylchlorosilane, trimethylethoxysilane, dimethyldichlorosilane, methyltrichlorosilane, allyldimethylchlorosilane, allylphenyldichlorosilane, Benzyldimethylchlorosilane, bromomethyldimethylchlorosilane, α-chloroethyltrichlorosilane, β-chloroethyltrichlorosilane, chloromethyldimethylchlorosilane, triorganosilylmercaptan, trimethylsilylmercaptan, triorganosilylacrylate, vinyldimethylacetoxysilane, dimethyl Diethoxysilane, dimethyldimethoxysilane, diphenyldiethoxysilane, hexamethyldisiloxane, 1,3-divinyltet Lamethyldisiloxane, 1,3-diphenyltetramethyldisiloxane, and dimethylpolysiloxane containing 2 to 12 siloxane units per molecule and containing hydroxyl groups bonded to one silicon atom at each terminal unit Examples thereof include siloxane. By treating the surface of the spherical resin particles with inorganic fine powder in this way, dispersibility in the paint, uniformity of the coating surface, stain resistance of the coating layer surface, charge imparting property to the toner, coating layer It is possible to improve the wear resistance and the like.
[0039]
Moreover, in order to further improve the stain resistance and wear resistance of the coating layer surface, it is more preferable to impart conductivity to the unevenness forming particles. Examples of the conductive spherical particles include conductive oxide-treated spherical particles such as tin oxide, niobium oxide, manganese oxide, lead oxide, and other metal oxides, and pigments such as barium sulfate. A conductive material coated or a conductive material doped with a metal having a different oxidation number in an insulating metal oxide such as zinc oxide, copper oxide, iridium oxide, etc. There is a conductive spherical particle described in JP-A-8-240981 proposed.
[0040]
The volume resistance of such conductive spherical particles is 10⁶Ω · cm or less, more preferably 10^-3-10⁶The particles are preferably Ω · cm. Volume resistance is 10⁶If it exceeds Ω · cm, it becomes easy to cause toner contamination and fusion with spherical particles exposed on the surface of the coating layer due to abrasion as well as to make quick and uniform charging difficult. That is, by imparting conductivity to the particles, it is difficult to accumulate charges on the surface of the particles due to the conductivity, and it is possible to reduce toner adhesion and improve the chargeability of the toner.
[0041]
Further, the true density of the added irregularity forming particles is 3 g / cm.^ThreeThe following are preferred. True density is 3g / cm^ThreeIf it exceeds 1, the true density difference from the binder resin becomes large, so that the dispersed state of the particles during the production of the paint tends to be non-uniform, and therefore the dispersed state of the unevenness forming particles in the coating layer also becomes non-uniform. Therefore, it becomes difficult to impart uniform roughness to the surface of the coating layer, uniform charging to the toner and insufficient strength of the coating layer, and further, the stain resistance and abrasion resistance which are advantages of these particles are not obtained. There is a possibility that it can not be demonstrated.
[0042]
As described above, examples of the irregularity-forming particles satisfying the above conditions include spherical carbon particles, spherical resin particles surface-treated with a conductive substance, and spherical resin particles in which conductive fine particles are dispersed.
[0043]
In addition, the particle diameter of such irregularity-forming particles is preferably 1.0 μm to 30 μm, more preferably 3.0 μm to 20 μm in terms of number average particle diameter. If the surface roughness is less than 1.0 μm, uniform surface unevenness is difficult, and if the surface roughness is to be increased, the amount added becomes excessive, the resin coating layer becomes brittle, and the wear resistance is extremely lowered. On the other hand, when the particle diameter exceeds 30 μm, the particles protrude too much from the surface of the coating layer, so that the thickness of the toner coat layer becomes too large and the charge of the toner tends to decrease or become non-uniform. There is a risk of leaking points.
[0044]
Furthermore, the resin coating layer of the present invention may contain a charge control agent if necessary. As the charge control agent, those similar to those used for toner particle formation described later can be used.
[0045]
Next, the relationship between the hardness of the unevenness-forming particles used in the resin coating layer of the present invention, the hardness of the resin layer that is the matrix portion, and the relationship between the particle sizes of the multiple types of unevenness-forming particles will be described in detail.
[0046]
In the present invention, the hardness of at least one of the two or more types of unevenness-forming particles having different hardness used for the resin coating layer is larger than the hardness of the resin layer that is the matrix portion, and among the unevenness-forming particles. The hardness of at least one kind of particles is set smaller than the hardness of the resin layer that is the matrix portion. Here, the matrix portion means a portion where the unevenness forming particles are not present on the surface of the coating layer, or a coating layer containing no unevenness forming particles. If only the irregularity-forming particles with a hardness greater than that of the matrix part are used, the wear resistance of the coating layer surface will be improved, but the coating will occur in the later stage of durability due to the difference between the abrasion amount of the irregularity-forming particles and the matrix part. Since the unevenness forming particles protrude from the layer surface and the amount of the unevenness forming particles per unit area increases, the surface roughness of the coating layer tends to increase. As a result, the amount of toner coat in the latter half of the endurance increases, and under low humidity, it may cause image deterioration such as character scattering and fogging. Moreover, if only the irregularity-forming particles having a hardness smaller than that of the matrix portion are used, the shape of the surface of the coating layer at the initial stage of durability becomes uniform, but as the durability progresses, selective wear occurs from the irregularity-forming particles on the surface of the coating layer. Therefore, the surface roughness of the coating layer tends to be small. As a result, the amount of toner coat in the end of durability is reduced, especially under high temperature and high humidity, image deterioration such as image density reduction and solid image streaks / unevenness, and when low temperature fixing toner is used, the toner is contaminated with the sleeve. Or sleeve fusion. 1 and 2 are schematic diagrams showing changes in surface roughness and toner coating amount due to durability.
[0047]
In addition, regarding the relationship between the number average particle diameters of two or more types of unevenness forming particles having different hardnesses used for the resin coating layer, the particle diameter of the largest hardness particle is Dm, and the particle diameter of the smallest hardness particle is Dn. It is preferable that 0.5 ≦ Dm / Dn ≦ 1.5. When the Dm / Dn ratio exceeds 1.5, as described above, the surface roughness of the coating layer tends to increase due to an increase in the abundance of the irregularity-forming particles per unit area at the end of durability. This increases the amount of toner coat in the latter half of the endurance, and also causes image deterioration such as character scattering and fogging under low humidity. Even when the Dm / Dn ratio is smaller than 0.5, as described above, the surface roughness of the coating layer tends to be small because wear occurs selectively from the unevenness forming particles on the surface of the coating layer. It becomes stronger and the toner coat amount in the latter half of the endurance decreases, and image density reduction under high temperature and high humidity, and solid image streaks and unevenness are likely to be noticeable.
[0048]
However, the present inventors have used the surface of the coating layer in the initial durability stage and the late durability stage in combination with the irregularity-forming particles having a hardness that is larger or smaller than the hardness of the matrix portion and the particle size difference satisfying the above relationship. It has been found that the change in roughness can be reduced and the toner coat amount can be controlled to be constant in the early and late durability stages.
[0049]
The hardness in the present invention is an indentation hardness value HUT [68] measured with a diamond indenter having a triangular pyramid with a surface angle of 68 degrees with respect to the axis by an Akashi micro hardness meter MZT-4. It is represented by the following formula (1).
Indentation hardness value HUT [68] = K × F / (h2)²        (1)
[However, K: Coefficient F: Test load h2: Maximum indentation depth of indenter]
[0050]
The hardness value is preferably used because it can be measured with a load smaller than other hardnesses and the like, and a material having elasticity and plasticity can obtain hardness including elastic deformation and plastic deformation.
[0051]
In addition, the sample prepared for measurement uses a sample in which a resin coating layer is formed on the surface of the substrate. However, since the measurement accuracy is improved when the coating layer surface is smooth, a smoothing process such as a polishing process is performed. It is more preferable to measure after applying. In the present invention, the surface of the coating layer was subjected to a polishing process using a # 2000 polishing tape, and the surface roughness Ra after the polishing process was set to be 0.2 or less. The main measurement conditions are as follows.
[0052]
TEST MODE A
Test load F1: 5.00 gf
Reference load F0: 0.50 gf
Pushing speed V: 1.00 μm / sec
Holding time T2: 5 sec
Unloading time T3: 5 sec
[0053]
The test load and the maximum indentation depth of the indenter are preferably in a range that is not affected by the surface roughness of the coating layer surface and is not affected by the base substrate. In the present invention, the maximum indentation of the test load indenter is The measurement was performed by applying a test load so that the depth was about 1 to 2 μm. In addition, the measurement environment was 23 ° C. and 50%, and the number of measurements was 10 times for both the unevenness forming particles and the matrix portion, and the comparison was made from the average value.
[0054]
The surface roughness of the coating layer on the surface of the developing sleeve preferably used in the present invention is generally 0.3 to 3.5 μm in arithmetic average roughness Ra based on JIS B0601. It is preferable to be in the range. However, the preferred surface roughness varies depending on the developing method. For example, in a developing apparatus using a magnetic toner as shown in FIG. 3 and having a magnetic blade disposed with a gap between the developing sleeve as a developer layer thickness regulating member, Ra is 0.3 to 1.5 μm. It is preferable that it exists in a grade. If it is smaller than 0.3 μm, the toner coat amount is insufficient, and the image density is thin due to the insufficient toner coat amount, and the toner charge-up phenomenon or blotch occurs. On the other hand, if it is larger than 1.5 μm, the toner coating amount is excessive, so that the frictional charging becomes non-uniform, and it is easy to cause scattering of characters, fogging, and low image density due to insufficient toner charging. For example, in the case of a developing device in which an elastic member is used in pressure contact with a developing sleeve as shown in FIG. 4, it is preferable that Ra is about 0.8 to 3.5 μm. When the thickness is smaller than 0.8 μm, the toner coat amount is insufficient, and the image density is thin due to the insufficient toner coat amount, and the toner charge-up phenomenon or blotch occurs. Furthermore, toner fusion to the developing sleeve is likely to occur. On the other hand, if it is larger than 3.5 μm, the toner coating amount is excessive, so that the frictional charging becomes non-uniform, and it is easy to cause scattering of characters and fogging, and image density thinning due to insufficient toner charging. Further, in the two-component developing apparatus as shown in FIG. 5, the conveying force varies greatly depending on the magnetic force such as carrier particle and magnet arrangement, the carrier particle size, the developing sleeve-regulating member gap, and the like. Therefore, depending on the occasion, the surface roughness is set to an arbitrary value within the above range, but usually a Ra of about 1.0 to 2.5 μm is preferably used.
[0055]
The surface roughness in the present invention is measured using a surface roughness meter SE-3500 manufactured by Kosaka Laboratory, and the measurement conditions are a cutoff of 0.8 mm, a measurement distance of 8.0 mm, and a feed rate of 0.1 mm / sec. The average of 12 measured values was taken.
[0056]
As a method for obtaining the resin coating layer of the present invention, for example, each component can be dispersed and mixed in a solvent to form a paint, which is then applied to a substrate described later. For dispersion mixing of each component, a known dispersion apparatus using beads such as a sand mill, a paint shaker, a dyno mill, a pearl mill or the like can be suitably used. Moreover, as a coating method, well-known methods, such as a dipping method, a spray method, and a roll coat method, are applicable.
[0057]
In addition, the layer thickness of the resin coating layer having the above-described configuration is preferably 25 μm or less, more preferably 20 μm or less, and further preferably 4 to 20 μm in order to obtain a uniform layer thickness. The thickness is not limited.
[0058]
In the present invention, for example, a metal, an alloy thereof, or a compound thereof is preferably used as the base of the developing sleeve having the resin coating layer formed with the above-described configuration. In particular, stainless steel, aluminum, or an alloy thereof is cylindrical. What was shape | molded in the shape is used suitably. Among them, aluminum is excellent in workability. For example, in the case of a cylindrical substrate, it is particularly preferable because mechanical accuracy such as axial runout and circumferential roundness is improved. The surface of these substrates may be further processed to have a predetermined surface roughness by blasting, filing, cutting, or the like, or may be processed by electrolytic / electroless plating or the like.
[0059]
Further, in the present invention, the base of the developing sleeve having the resin coating layer formed as described above may have an elastic layer on the outer peripheral surface of a core metal such as stainless steel. As the elastic layer formed on the outer peripheral surface of the cored bar, generally, a molded material of silicone rubber, urethane rubber or the like is preferably used, and further contains a conductive agent for adjusting electric resistance. Is particularly preferred. These elastic layers preferably have a predetermined hardness and surface roughness in order to improve the adhesion of the resin coating layer to be a surface layer, or have an intermediate layer on the elastic layer surface. Also good. Further, the surface of the core metal-like substrate may be treated to a predetermined surface roughness by blasting, filing, cutting, or the like, or may be treated by electrolytic / electroless plating or the like.
[0060]
Next, a developing device using a developing sleeve having a resin coating layer formed as described above will be described in detail.
[0061]
As a developing device, for example, a developing device as shown in FIGS. 3 and 4 is known. In FIG. 3, a latent image carrier that carries a latent image formed by a known process, for example, a photosensitive drum 301 is rotated in the direction of arrow A. A developing sleeve 308 as a developer carrying member carries a developer 304 as a one-component magnetic toner contained in a developer container 303 and rotates in the direction of arrow B, whereby the developing sleeve 308 and the photosensitive drum 301 are rotated. The developer 304 is transported to the development area D facing each other. As shown in FIG. 3, the developing sleeve 308 has a resin coating layer 307 formed on a metal cylindrical tube 306 as a substrate, and the developer 304 is magnetically applied on the developing sleeve 308 in the developing sleeve 308. A magnet roller 305 is disposed and fixed to be attracted and held. The developing sleeve 308 and the magnet roller 305 are in a non-contact state.
[0062]
Further, in the developer container 303, by rotating in the direction of arrow C, stirring blades 309 and 310 for stirring the developer 304, a screw 311 for supplying the developer 304 into the developer container 303, and in the developer container 303 A stirring wall 312 for adjusting the amount of the developer is provided.
[0063]
The developer 304 obtains a triboelectric charge that can develop the latent image on the photosensitive drum 301 by friction between the magnetic toners and the resin coating layer 307 on the developing sleeve 308. In the example of FIG. 3, in order to regulate the layer thickness of the developer 304 conveyed to the development area D, a magnetic regulation blade 302 made of a ferromagnetic metal as a developer layer thickness regulation member is provided from the surface of the development sleeve 308. The developing sleeve 308 is suspended from the developer container 303 so as to face the developing sleeve 308 with a gap width of about 50 to 500 μm, and the magnetic lines of force from the N pole of the magnet roller 305 are concentrated on the magnetic regulation blade 302. A thin layer of developer 304 is formed thereon. In the present invention, a nonmagnetic blade and an elastic blade as shown in FIG. 4 can be used instead of the magnetic regulating blade.
[0064]
The thickness of the thin layer of the developer 304 formed on the developing sleeve 308 in this way is preferably thinner than the minimum gap between the developing sleeve 308 and the photosensitive drum 301 in the developing region D.
[0065]
The developing sleeve of the present invention is particularly effective when incorporated in a developing device that develops a latent image with a thin layer of developer as described above, that is, a non-contact developing device. The developer carrier of the present invention can also be applied to a developing device in which the thickness of the agent layer is equal to or greater than the minimum gap between the developing sleeve 308 and the photosensitive drum 301, that is, a contact type developing device.
[0066]
In order to avoid complicated explanation, the following explanation will be made by taking the non-contact developing device as described above as an example.
[0067]
A developing bias voltage is applied to the developing sleeve 308 by a developing bias power source 313 as a biasing means in order to cause the one-component developer 304 having magnetic toner carried on the developing sleeve 308 to fly. When a DC voltage is used as the developing bias voltage, a voltage having a value between the potential of the image portion of the latent image (the region visualized by the developer 304 attached) and the potential of the background portion is developed. Application to the sleeve 308 is preferred.
[0068]
In order to increase the density of the developed image or improve the gradation, an alternating bias voltage may be applied to the developing sleeve 308 to form an oscillating electric field whose direction is alternately reversed in the developing region D. In this case, it is preferable to apply to the developing sleeve 308 an alternating bias voltage in which a DC voltage component having an intermediate value between the potential of the developed image portion and the potential of the background portion is superimposed. In the case of so-called regular development in which toner is attached to a high potential portion of a latent image having a high potential portion and a low potential portion to form a visible image, a toner charged to a polarity opposite to that of the latent image is used. In the case of so-called reversal development in which toner is attached to a low potential portion of a latent image having a high potential portion and a low potential portion for visualization, a toner charged with the same polarity as the polarity of the latent image is used. High potential and low potential are expressed in absolute values. In any of these cases, the developer 304 is charged by at least friction with the developing sleeve 308.
[0069]
FIG. 3 is merely an example of the developing device of the present invention, and it goes without saying that there are various forms in the shape of the developer container 303, the presence or absence of the stirring blades 309 and 310, and the arrangement of the magnetic poles. Of course, these apparatuses can also be used for development using a two-component developer containing toner and carrier.
[0070]
Next, a description will be given of a two-component developing device in which the developing sleeve of the present invention is incorporated. FIG. 5 shows a schematic diagram of a developing apparatus suitable for using a two-component developer. In FIG. 5, a developing chamber 564 of a developing container 553 is provided with a non-magnetic developing sleeve 559 as a developing sleeve opposite to the latent image carrier 551 rotated in the direction of arrow E. A resin coating layer 558 is provided on the surface of the cylindrical nonmagnetic metal 557. A magnetic roller 556 as a magnetic field generating means is fixedly installed in the developing sleeve 559 and forms a developing roller 560. The magnetic roller 556 is magnetized in a five-pole configuration of S1 to S3, N1, and N2. In the developing chamber 564, a two-component developer in which toner and a magnetic carrier are mixed is accommodated. When the developer is fed into the stirring chamber 565 of the developing container 553 through the opening of the partition 554 that is open at the upper end of the developing chamber 564, the toner supplied from the toner chamber 555 into the stirring chamber 565 is the toner feed regulating member 563. And mixed by the first developer stirring / conveying means 562 in the stirring chamber 565. The developer stirred in the stirring chamber 565 is returned to the developing chamber 564 through another opening (not shown) of the partition wall 554, where it is stirred and transported by the second developer stirring and transporting means 561 in the developing chamber 565. Then, it is conveyed to the developing sleeve 559. The developer supplied to the developing sleeve 559 is magnetically constrained by the magnetic force of the magnet roller 556, and is carried on the developing sleeve 559, and a developer layer thickness regulating member 552 provided below the developing sleeve 559. As the developing sleeve 559 rotates in the direction of arrow F while being formed in a thin layer on the developing sleeve 559 due to the regulation in, the toner is conveyed to the developing portion G facing the latent image holding member 551, where the latent image is transferred. The latent image on the carrier 551 is developed. The remaining developer that has not been consumed for development is collected in the developing container 564 by the rotation of the developing sleeve 559. In the developing container 5644, the remaining developer remaining magnetically restrained on the developing sleeve 559 is peeled off by a repulsive magnetic field between S2 and S3 of the same polarity. A scattering preventing member 566 is fixed and installed above the developing sleeve to prevent toner scattering. FIG. 5 is a schematic example to the last, and it goes without saying that there are various forms in the shape of the container, the presence or absence of the stirring member, the arrangement of the magnetic poles, the rotation direction, and the like.
[0071]
Next, the toner used in the developing device of the present invention will be described. The toner is a fine powder in which a resin, a release agent, a charge control agent, a colorant, and the like are mainly melt-kneaded, solidified, pulverized, and then classified to obtain a uniform particle size distribution. As the binder resin used for the toner, generally known resins can be used.
[0072]
For example, styrene such as styrene, α-methylstyrene, p-chlorostyrene, and homopolymers of substituted styrene; styrene-propylene copolymer, styrene-vinyltoluene copolymer, styrene-ethyl acrylate copolymer, styrene -Butyl acrylate copolymer, styrene-octyl acrylate copolymer, styrene-dimethylaminoethyl copolymer, styrene-methyl methacrylate copolymer, styrene-ethyl methacrylate copolymer, styrene-butyl methacrylate copolymer Polymer, styrene-dimethylaminoethyl methacrylate copolymer, styrene-vinyl methyl ether copolymer, styrene-vinyl methyl ketone copolymer, styrene-butadiene copolymer, styrene-isoprene copolymer, styrene-maleic acid Copolymer, styrene-maleic acid Styrenic copolymers such as ter copolymers; polymethyl methacrylate, polybutyl methacrylate, polyvinyl acetate, polyethylene, polypropylene polyvinyl butyral, polyacrylic acid resin, rosin, modified rosin, terpene resin, phenol resin, aliphatic or fat Cyclic hydrocarbon resins, aromatic petroleum resins, paraffin wax, carnauba wax and the like can be used alone or in combination.
[0073]
The toner may contain a pigment. For example, carbon black, nigrosine dye, lamp black, Sudan Black SM, First Yellow G, Benzidine Yellow, Pigment Yellow, India First Orange, Irgadin Red, Paranitroaniline Red, Toluidine Red, Carmine FB, Permanent Bordeaux FRR, Pigment Orange R, Risor Red 2G, Lake Red C, Rhodamine FB, Rhodamine B Lake, Methyl Bio Red B Lake, Phthalocyanine Blue, Pigment Blue, Brilliant Green B, Phthalocyanine Green, Oil Yellow GG, Pomelo First Yellow CGG, Kaya Set Y963, Kaya Set YG, Pomelo First Orange RR, Oil Scarlet, Orazole Bra Down B, pomelo First Scarlet CG, Oil Pink OP, etc. can be applied.
[0074]
In order to use the toner as a magnetic toner, magnetic powder may be contained in the toner. As such magnetic powder, a substance that is magnetized in a magnetic field is used, and there are powders of ferromagnetic metals such as iron, cobalt, and nickel, and alloys and compounds such as magnetite, hematite, and ferrite. The content of the magnetic powder is preferably 15 to 70% by mass with respect to the toner mass.
[0075]
Waxes can be incorporated into the toner for the purpose of improving releasability during fixing and improving fixing properties. Examples of such waxes include paraffin wax and derivatives thereof, microcrystalline wax and derivatives thereof, Fischer Tropus wax and derivatives thereof, polyolefin wax and derivatives thereof, carnauba wax and derivatives thereof, and the derivatives include oxides, Includes block copolymers with vinyl monomers and graft modified products. In addition, alcohols, fatty acids, acid amides, esters, ketones, hydrogenated castor oil and derivatives thereof, plant waxes, animal waxes, mineral waxes, petrolactams, and the like can also be used.
[0076]
Further, if necessary, the toner may contain a charge control agent. Charge control agents include negative charge control agents and positive charge control agents. For example, there are the following substances that control the toner to be negatively charged. For example, organometallic complexes and chelate compounds are effective, and there are monoazo metal complexes, acetylacetone metal complexes, aromatic hydroxycarboxylic acids, and aromatic dicarboxylic acid metal complexes. Other examples include aromatic hydroxycarboxylic acids, aromatic mono- and polycarboxylic acids and metal salts thereof, anhydrides, esters, and phenol derivatives such as bisphenol. Examples of substances for positively charging the toner include the following. Modified products with nigrosine and fatty acid metal salts, etc., quaternary ammonium salts such as tributylbenzylammonium-1-hydroxy-4-naphthosulfonate, tetrabutylammonium tetrafluoroborate, and oniums such as phosphonium salts which are analogs thereof Salts and lake lake pigments (including phosphotungstic acid, phosphomolybdic acid, phosphotungsten molybdic acid, tannic acid, lauric acid, gallic acid, ferricyanide, ferrocyanide) and higher fatty acid metal salts Diorganotin oxides such as dibutyltin oxide, dioctyltin oxide and dicyclohexyltin oxide; diorganotin borates such as dibutyltin borate, dioctyltin borate and dicyclohexyltin borate; guani Emissions compounds, imidazole compounds.
[0077]
The toner is used by externally adding a powder such as an inorganic fine powder as necessary for the purpose of improving fluidity. Examples of such fine powder include silica fine powder, metal oxides such as alumina, titania, germanium oxide and zirconium oxide; carbides such as silicon carbide and titanium carbide; and inorganic fine powders such as nitrides such as silicon nitride and germanium nitride. The body is used. These fine powders can be used after being organically treated with an organosilicon compound, a titanium coupling agent or the like. Examples of organosilicon compounds include hexamethyldisilazane, trimethylsilane, trimethylchlorosilane, trimethylethoxysilane, dimethyldichlorosilane, methyltrichlorosilane, allyldimethylchlorosilane, allylphenyldichlorosilane, benzyldimethylchlorosilane, bromomethyl. Dimethylchlorosilane, α-chloroethyltrichlorosilane, β-chloroethyltrichlorosilane, chloromethyldimethylchlorosilane, triorganosilylmercaptan, trimethylsilylmercaptan, triorganosilylacrylate, vinyldimethylacetoxysilane, dimethylethoxysilane, dimethyldimethoxysilane, Diphenyldiethoxysilane, hexamethyldisiloxane, 1,3-divinyltetramethyldisiloxane, Examples include 1,3-diphenyltetramethyldisiloxane, and dimethylpolysiloxane having 2 to 12 siloxane units per molecule, each containing a hydroxyl group bonded to one Si at a terminal unit. Moreover, you may use what processed the untreated fine powder with the nitrogen-containing silane coupling agent. In particular, a positive toner is preferable. Examples of such treating agents include aminopropyltrimethoxysilane, aminopropyltriethoxysilane, dimethylaminopropyltrimethoxysilane, diethylaminopropyltrimethoxysilane, dipropylaminopropyltrimethoxysilane, dibutylaminopropyltrimethoxysilane, Monobutylaminopropyltrimethoxysilane, dioctylaminopropyltrimethoxysilane, dibutylaminopropyldimethoxysilane, dibutylaminopropylmonomethoxysilane, dimethylaminophenyltrimethoxysilane, trimethoxysilyl-γ-propylphenylamine, trimethoxysilyl-γ -Propylbenzylamine, trimethoxysilyl-γ-propylpiperidine, trimethoxysilyl-γ-propylmorpholine, tri Tokishishiriru -γ- propyl imidazole, and the like.
[0078]
Examples of the method for treating the inorganic fine powder with the silane coupling agent include 1) a spray method, 2) an organic solvent method, and 3) an aqueous solution method. In general, the treatment by a spray method is a method in which a pigment is stirred and an aqueous solution or solvent solution of a coupling agent is sprayed thereto, and then water or solvent is removed and dried at about 120 to 130 ° C. In addition, the treatment by the organic solvent method is to dissolve a coupling agent in an organic solvent (alcohol, benzene, halogenated hydrocarbon, etc.) containing a hydrolysis catalyst together with a small amount of water, and soak the pigment in this. Solid-liquid separation is performed by filtration or pressing and dried at about 120 to 130 ° C. In the aqueous solution method, a coupling agent of about 0.5% is hydrolyzed in water or water-solvent at a constant pH, and after pigment is immersed therein, solid-liquid separation is similarly performed and dried. .
[0079]
It is also possible to use fine powder treated with silicone oil as another organic treatment. As a preferable silicone oil, the viscosity at 25 ° C. is about 0.5 to 10,000 mm.²/ S, preferably 1-1000 mm²For example, methyl hydrogen silicone oil, dimethyl silicone oil, phenyl methyl silicone oil, chlorophenyl methyl silicone oil, alkyl modified silicone oil, fatty acid modified silicone oil, polyoxyalkylene modified silicone oil, fluorine modified silicone Examples include oil. Moreover, you may use the silicone oil which has a nitrogen atom in a side chain. In particular, a positive toner is preferable. The treatment with silicone oil can be performed, for example, as follows. If necessary, the pigment is vigorously disturbed while being heated, and the silicone oil or solution thereof is sprayed or vaporized and sprayed, or the pigment is made into a slurry and the silicone oil or its solution is stirred. It can be easily treated by dropping the solution. These silicone oils are used singly or as a mixture of two or more or in combination or multiple treatments. Moreover, you may use together with the process by a silane coupling agent. Such a toner is preferably used after being subjected to a spheroidizing treatment and a surface smoothing treatment by various methods. As such a method, an apparatus having a stirring blade or a blade, and a liner or a casing, for example, smoothes the surface by a mechanical force when passing the toner through a minute gap between the blade and the liner. Or a method of spheroidizing the toner, a method of suspending the toner in warm water to spheroidize, a method of exposing the toner to a hot air stream and spheroidizing. In addition, as a method for directly producing a spherical toner, there is a method in which a mixture containing a monomer as a toner binder resin as a main component is suspended in water and polymerized to form a toner. As a general method, a polymerizable monomer, a colorant, a polymerization initiator, and, if necessary, a crosslinking agent, a charge control agent, a release agent, and other additives are uniformly dissolved or dispersed in a single amount. After making the body composition, the monomer composition is dispersed in an appropriate particle size using a suitable stirrer in a continuous layer containing a dispersion stabilizer, for example, an aqueous phase, and a polymerization reaction is further performed. This is a method for obtaining a developer having a desired particle size.
[0080]
The toner can be mixed with a carrier and used as a two-component developer.
[0081]
Carrier materials include, for example, magnetic metals such as iron, nickel, cobalt, alloys thereof, alloys containing rare earths, hematite, magnetite, manganese-zinc ferrite, nickel-zinc ferrite, manganese-magnesium Soft ferrites such as ferrite and lithium ferrite, iron-based oxides such as copper-zinc ferrite, and mixtures thereof, as well as ceramic particles such as glass and silicon carbide, resin powder, and resin powder containing magnetic materials Usually, it is used as a granular material having an average particle size of about 20 to 300 μm.
[0082]
Such a carrier may use the above-mentioned granular materials directly as carrier particles, but in order to adjust the triboelectric charge of the toner or prevent toner spent on the carrier, silicone resin, fluororesin, The surface of the particles can be appropriately coated with a coating agent such as an acrylic resin or a phenol resin, and used.
[0083]
Hereinafter, methods for measuring other physical properties related to the present invention will be described.
[0084]
[Measuring method]
(1) Volume resistance measurement of unevenness forming particles (spherical particles)
The granular sample was put into an aluminum ring of 40 mmφ and pressure-formed at 2500 N, and the volume resistance value was measured with a resistivity meter Loresta AP or Hiresta IP (both manufactured by Mitsubishi Yuka) using a 4-terminal probe. The measurement environment was 20 to 25 ° C. and 50 to 60% RH.
[0085]
(2) Measurement of true density of irregularities forming particles (spherical particles)
The true density of the spherical particles used in the present invention was measured using a dry density meter Accupic 1330 (manufactured by Shimadzu Corporation).
[0086]
(3) Particle size measurement of irregularity-forming particles (spherical particles)
Measurement was performed using a Coulter LS230 particle size distribution meter (manufactured by Coulter, Inc.) of a laser diffraction type particle size distribution meter, and the number average particle size calculated from the number distribution was obtained.
[0087]
(4) Ratio of major axis / minor axis of irregularity-forming particles (spherical particles)
Images were taken at about 6000 times using an electron microscope, and the major axis and minor axis of the particles were measured on the photograph. This was measured for 100 samples, and the average value was defined as the major axis / minor axis ratio.
[0088]
(5) Measurement of toner particle size
Measurement was made using a Coulter counter Multisizer II (manufactured by Coulter), and the mass-based weight average diameter calculated from the volume distribution was determined.
[0089]
(6) Measurement of volume resistance of resin coating layer
A resin coating layer is formed on a PET sheet having a thickness of 100 μm at a thickness of 7 to 20 μm, and a volume resistance value is measured with a resistivity meter Loresta AP or Hiresta IP (both manufactured by Mitsubishi Yuka) using a 4-terminal probe. did. The measurement environment was 20 to 25 ° C. and 50 to 60% RH.
[0090]
【Example】
Hereinafter, the present invention will be described in more detail with specific examples.
[0091]
<Irregularity forming particle production example 1>
Concavity and convexity formation particles used for the resin coating layer formed on the surface of the developing sleeve were prepared. As the irregularity forming particles, a coal-based bulk mesophase pitch powder having a number average particle size of 3.0 μm or less using a raikai machine (automatic mortar, manufactured by Ishikawa Factory) on 100 parts by mass of a spherical phenol resin having a number average particle size of 7.5 μm. 14 parts by mass were uniformly coated, thermally stabilized in an oxidizing atmosphere, and then fired at 2,000 ° C. to produce conductive spherical carbon particles obtained by graphitization. The spherical carbon particles have a number average particle size of 7.2 μm and a true density of 1.51 g / cm.^ThreeVolume resistance 7.5 × 10^-2Ω · cm, the major axis / minor axis ratio was 1.15, and the indentation hardness value was larger than the hardness value of the matrix portion of the coating layer. The spherical carbon particles were designated as unevenness forming particles a.
[0092]
<Unevenness-forming particle production examples 2 to 4>
In the irregularity-forming particle production example 1, spherical carbon particles are produced in the same manner as the irregularity-forming particle production example 1 except that spherical phenol resins having a number average particle size of 5.0 μm, 10 μm, and 20 μm are used. By adding, the number average particle diameters were 3.0 μm, 12.8 μm and 19.9 μm, respectively. Table 1 shows the physical properties of the obtained spherical carbon particles. These spherical carbon particles were designated as unevenness forming particles b to d.
[0093]
<Concavity and convexity formation particle production example 5>
Concavity and convexity formation particles used for the resin coating layer formed on the surface of the developing sleeve were prepared. As unevenness forming particles, 100 parts by mass of PMMA resin and 25 parts by mass of carbon black are melt-mixed, kneaded, pulverized, and classified to obtain carbon black-dispersed PMMA resin particles having a number average particle size of 7.0 μm. Spherical carbon black-dispersed PMMA resin particles were produced by performing spheronization using a hybridizer (manufactured by Nara Machinery). The spherical carbon black-dispersed PMMA resin particles have a number average particle diameter of 6.9 μm and a true density of 1.23 g / cm.^ThreeVolume resistance 1.7 × 10¹Ω · cm, the major axis / minor axis ratio was 1.16, and the indentation hardness value was smaller than the hardness value of the matrix portion of the coating layer. The spherical carbon black-dispersed PMMA resin particles were used as the unevenness forming particles e.
[0094]
<Unevenness-forming particle production examples 6 to 8>
In the same manner as in the irregularity-forming particle production example 5, carbon black-dispersed PMMA resin particles having number average particle diameters of 5.0 μm, 10 μm, and 20 μm were prepared, and further a classification step was performed, so Spherical carbon black-dispersed PMMA resin particles having 12.7 μm and 19.6 μm were obtained. Table 1 shows the physical properties of the obtained spherical carbon black-dispersed PMMA resin particles. These spherical carbon black-dispersed PMMA resin particles were used as irregularity-forming particles f to h, respectively.
[0095]
<Development sleeve production example 1>
A paint for applying a resin coating layer on the surface of the developing sleeve was prepared.
・ Phenolic resin intermediate (solid content 50%): 200 parts by mass
Unevenness-forming particles a: 50 parts by mass
・ Unevenness-forming particles e: 10 parts by mass
・ Isopropanol: 240 parts by mass
The material was dispersed using a sand mill. Unevenness-forming particles a and e were added to a methanol solution of a phenol resin intermediate, glass beads were used as media, and sand mill dispersion was advanced to obtain a paint having a solid content of 32%. This paint is sprayed to form a resin coating layer of about 15 μm on the surface of an aluminum cylindrical substrate having an outer diameter of 20 mmφ, which is dried and cured at 150 ° C. for 30 minutes with a hot air dryer, and then a magnet roller and flange To provide a developing sleeve A. Table 2 shows the structure and physical properties of the obtained resin coating layer.
[0096]
<Development sleeve production example 2>
A paint for applying a resin coating layer on the surface of the developing sleeve was prepared.
・ Phenolic resin intermediate (solid content 50%): 200 parts by mass
-Crystalline graphite fine powder: 40 parts by mass
・ Unevenness-forming particles a: 10 parts by mass
・ Unevenness-forming particles e: 10 parts by mass
・ Isopropanol: 240 parts by mass
The material was dispersed using a sand mill. Add crystalline graphite fine powder to a part of methanol solution of phenol resin intermediate, disperse by sand mill using glass beads as media, further add irregularities forming particles a and e, proceed with sand mill dispersion, solid content of 32% Paint was used. This paint is sprayed to form a resin coating layer of about 15 μm on the surface of an aluminum cylindrical substrate having an outer diameter of 20 mmφ. To be a developing sleeve B. Table 2 shows the structure and physical properties of the obtained resin coating layer.
[0097]
<Development sleeve production examples 3 to 9>
Developing sleeves C to I were prepared in the same manner as in developing sleeve manufacturing example 2, except that the paint was prepared with the material configuration and mixing ratio shown in Table 2. Table 2 shows the structure and physical properties of the obtained resin coating layer.
[0098]
<Development sleeve production examples 10-13>
Developing sleeves J to M were prepared in the same manner as in the developing sleeve manufacturing example 1, except that the coating material was prepared with the material configuration and mixing ratio shown in Table 2. Table 2 shows the structure and physical properties of the obtained resin coating layer.
[0099]
<Development sleeve production example 14>
The same as the development sleeve production example 1 except that a paint was prepared with the material composition and mixing ratio shown in Table 2 and a resin coating layer of about 15 μm was formed on the surface of an aluminum cylindrical substrate having an outer diameter of 32.5 mmφ. Thus, a developing sleeve N was produced. Table 2 shows the structure and physical properties of the obtained resin coating layer.
[0100]
<Development sleeve production example 15>
The same as the development sleeve production example 2 except that a paint was prepared with the material composition and mixing ratio shown in Table 2 and a resin coating layer of about 15 μm was formed on the surface of an aluminum cylindrical substrate having an outer diameter of 32.5 mmφ. Thus, a developing sleeve O was produced. Table 2 shows the structure and physical properties of the obtained resin coating layer.
[0101]
<Development Sleeve Production Examples 16-22>
Developing sleeves P to V were produced in the same manner as in the developing sleeve production example 15 except that a paint was produced with the material configuration and mixing ratio shown in Table 2. Table 2 shows the structure and physical properties of the obtained resin coating layer.
[0102]
<Development sleeve production examples 23 to 26>
Developing sleeves W to Z were prepared in the same manner as in developing sleeve manufacturing example 14 except that the coating material was prepared with the material configuration and mixing ratio shown in Table 2. Table 2 shows the structure and physical properties of the obtained resin coating layer.
[0103]
<Toner Production Example 1>
Next, a magnetic negative toner as a one-component developer was prepared.
・ Styrene-acrylic resin: 100 parts by mass
・ Magnetite: 90 parts by mass
・ Negative charge control agent (chromic complex of salicylic acid): 2 parts by mass
・ Hydrocarbon wax: 3 parts by mass
The above materials were mixed with a Henschel mixer, and melt kneaded and dispersed with a biaxial extruder. After cooling the kneaded product, it is finely pulverized by a pulverizer using a jet stream, and further classified using an air stream classifier. The number ratio of particles having a weight average particle diameter of 7.5 μm and 4 μm or less is 12.0. %, A classified product having a distribution in which the mass ratio of particles of 10.1 μm or more is 5.0% was obtained. Next, hydrophobic colloidal silica was externally added and mixed with 100 parts by mass of the classified product using a 1.0 part by mass Henschel mixer to obtain a magnetic toner α as a one-component developer.
[0104]
<Toner Production Example 2>
Next, a magnetic positive toner as a one-component developer was prepared.
・ Styrene-acrylic resin: 100 parts by mass
・ Magnetite: 90 parts by mass
-Positive charge control agent (triphenylmethane compound): 2 parts by mass
・ Hydrocarbon wax: 3 parts by mass
The above materials were mixed with a Henschel mixer, and melt kneaded and dispersed with a biaxial extruder. After cooling the kneaded product, it is finely pulverized by a pulverizer using a jet stream, and further classified using an air stream classifier. The number ratio of particles having a weight average particle diameter of 7.3 μm and 4 μm or less is 15.6. %, A classified product having a distribution in which the mass ratio of particles of 10.1 μm or more is 3.2% was obtained. Next, hydrophobic colloidal silica was externally added and mixed with 100 parts by mass of the classified product using a 1.0 part by mass Henschel mixer to obtain a magnetic toner β as a one-component developer.
[0105]
<Example 1>
Next, using the developing sleeve A and the toner α, it was incorporated into a developing device as shown in FIG. The image was evaluated by applying a predetermined developing bias using a modified machine of Canon photocopier GP405. Image drawing is performed at 23 ° C. and 60% RH normal temperature and humidity (N / N), 23 ° C. and 5% RH normal temperature and low humidity (N / L), and 30 ° C. and 80% RH high temperature and high humidity (H / H). H) Up to 250,000 sheets in the environment. The evaluation results by the following evaluation methods are shown in Table 3.
[0106]
[Evaluation methods]
(1) Amount of toner on sleeve (M / S)
The toner carried on the developing sleeve is sucked and collected by a metal cylindrical tube and a cylindrical filter. From the collected toner mass M and the area S where the toner is sucked, the toner mass M / S (mg per unit area) / Cm²) And calculated as the toner transport amount (M / S).
[0107]
(2) Image density
The density of the solid black image was measured with a reflection densitometer RD918 (manufactured by Macbeth), and the average value of five points was taken as the image density.
[0108]
(3) Fog and inverted fog
The reflectance of the solid white image is measured, the reflectance of the unused transfer paper is measured, and (the worst value of the reflectance of the solid white image−the highest value of the reflectance of the unused transfer paper) is defined as the fog density. . The reflectance was measured with TC-6DS (manufactured by Tokyo Denshoku). However, when the measured value is judged visually, 1.5 or less is a level that can hardly be visually confirmed, about 2.0 to 3.0 is a level that can be confirmed by looking closely, and if it exceeds 4.0, fogging appears at a glance. It is a level that can be confirmed.
[0109]
(4) Character scattering
Using a character chart with an image ratio of about 6.0%, the characters on the obtained image were magnified about 100 times with an optical microscope, the degree of scattering was observed, and the evaluation results were indicated by indices of A to E ranks.
[0110]
(5) Solid image streaks / unevenness
A solid black image and a halftone (HT) image were developed, and streaks and unevenness were visually observed in each image, and the evaluation results were indicated by indices of A to E ranks.
[0111]
(6) Sleeve contamination and fusion with toner (contamination and anti-fusing)
After evaluating the image under each environment, the developing sleeve was removed, and the surface of the sleeve was observed with a field emission type-scanning microscope (FE-SEM), and the evaluation results were indicated by indices of A to E ranks.
[0112]
  <Example 25, Reference Examples 1 and 2, Examples 8 and 9Comparative Examples 1 to 4>
  Image development was evaluated in the same manner as in Example 1 except that the developing sleeves B to M were used instead of the developing sleeve A used in Example 1. The evaluation results are shown in Tables 3-4.
[0113]
<Example 10>
Next, using the developing sleeve N and the toner β, the developing sleeve N and the toner β were incorporated into a developing apparatus as shown in FIG. The image was evaluated by applying a predetermined developing bias using a modified machine of Canon copier GP605. Image drawing is performed at 23 ° C. and 60% RH normal temperature and humidity (N / N), 23 ° C. and 5% RH normal temperature and low humidity (N / L), and 30 ° C. and 80% RH high temperature and high humidity (H / H). H) Up to 500,000 sheets under the environment. The evaluation method was the same as in Example 1, and the obtained evaluation results are shown in Table 5.
[0114]
  <Example 11-14, Reference Examples 3 and 4, Examples 17 and 18Comparative Examples 5-8>
  Images were evaluated in the same manner as in Example 10 except that developing sleeves O to Z were used instead of the developing sleeve N used in Example 10. The evaluation results are shown in Tables 5-6.
[0115]
[Table 1]

[0116]
[Table 2]

[0117]
[Table 3]

[0118]
[Table 4]

[0119]
[Table 5]

[0120]
[Table 6]

[0121]
【The invention's effect】
According to the present invention, the toner charge-up phenomenon and blotch that appear when a toner having a small particle diameter or a toner having high transferability is used, and suitable for the toner for a long time even in different environments. It is possible to provide a developer carrying member capable of giving a charge amount and a developing device using the same.
[0122]
In addition, according to the present invention, problems such as image density reduction and fogging do not occur over a long period of time even in different environments, and high-quality images can be stably obtained, and low-temperature fixability can be obtained. Developer carrier that does not cause sleeve contamination and sleeve fusion due to toner on the surface of the developer carrier, and does not generate defective images such as stripes and unevenness, and development using the same An apparatus can be provided.
[0123]
Further, according to the present invention, the amount of toner coat on the developer carrier is controlled to a constant amount by reducing the change in the surface roughness of the developer carrier over a long period of time even in different environments. It is possible to provide a developer carrier that can be used, and a developing device using the same.
[Brief description of the drawings]
FIG. 1 is a schematic diagram showing the effect of the present invention.
FIG. 2 is a schematic diagram showing the effect of the present invention.
FIG. 3 is a schematic diagram of a developing device used in the present invention.
FIG. 4 is a schematic diagram of a developing device used in the present invention.
FIG. 5 is a schematic diagram of a developing device used in the present invention.
[Explanation of symbols]
301 Photosensitive drum (latent image carrier)
304 Developer
306 Metal cylindrical tube
307 Resin coating layer
308 Development sleeve (developer carrier)

Claims (3)

In a developer carrier having a resin coating layer on a cylindrical or columnar substrate surface,
The resin coating layer includes a phenol resin that is a binder resin and particles for forming irregularities on the surface of the resin coating layer , the layer thickness is 4 μm or more and 15 μm or less, and
The particles are
(1) Spherical carbon particles having a number average particle diameter Dm of 3.0 μm or more and 19.9 μm or less having a hardness greater than the hardness of the resin layer that is the matrix portion of the resin coating layer;
(2) It consists of spherical particles made of carbon black-dispersed PMMA resin having a number average particle diameter Dn of 3.2 μm or more and 19.6 μm or less and having a hardness smaller than the hardness of the resin layer that is the matrix portion of the resin coating layer. ,and,
Developer carrying member Dm / Dn is characterized 0.9-1.0 der Rukoto. The developer carrier according to claim 1, wherein the particles (1) and the particles (2) are spherical with a ratio of major axis / minor axis of 1.0 to 1.5 . A developer container, a developer carrier for carrying and transporting the developer contained in the developer container, and a developer on the developer carrier disposed near or in pressure contact with the developer carrier A developer layer thickness regulating member for forming a thin layer of the developer, and the developer carrying member conveys the developer to a developing region facing the latent image carrier, and is formed on the latent image carrier. In the developing device that develops the latent image with a developer to visualize it,
The developing device according to claim 1, wherein the developer carrying member is the developer carrying member according to claim 1 .

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