JP2004126005A - Nonmagnetic one-component developer, developing unit, process cartridge, and image forming method - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a developer for full colors in which filming, fogging by toner deterioration, longitudinal streaks by fusion of the toner to a layer thickness regulating member, cleaning defect and rough feel are reduced, while transferability is maintained at a high level. <P>SOLUTION: The developer is used for a developing device having: an electrostatic latent image carrier which carries an electrostatic latent image; a developer carrier which is used for the developing device to develop the electrostatic latent image by migrating the developer to the electrostatic latent image deposited on the electrostatic latent image carrier and carries the developer on its surface and comes in direct or indirect contact with the surface of the electrostatic latent image carrier at least during development; and the layer thickness regulating member which regulates the layer thickness of the developer layer on the developer carrier by coming into direct or indirect contact with the developer carrier. The volume average grain size of the developer is 4 to 10 μm, the shape coefficient SF-1 is 115 to 140, the average circularity is 0.950 to 0.990 and the BET specific surface area is 2.0 to 7.0 m<SP>2</SP>/g. <P>COPYRIGHT: (C)2004,JPO

Description

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【表２】

【０２５６】
【表３】

【０２５７】
【発明の効果】
本発明はトナーのＳＦ−１、円形度、ＢＥＴ比表面積を前記範囲に規定することにより、懸濁重合法による真球状トナーや粉砕法によるトナーでは困難であったクリーニング性と転写性を両立させながら、更に帯電性を安定させることが可能となった。このことにより転写性やクリーニング性に厳しい、中間転写体を持ち、ドラムが１つのカラーマシンにおいても今まで以上に好適に用いることが可能となった。また、本構成の現像ユニットやプロセスカートリッジにおいてブレード粗さや現像ローラー粗さを調整することにより、通常ならトナー劣化によるカブリやブレード融着による縦スジが発生する領域でも本発明のトナーは問題無く使用することができ、帯電性付与や画質向上を容易にした。更に現像ローラーの硬度を規定することにより上記最適条件のバランスを崩さず、長期に維持するのに非常に有効である。また、これらの構成はトナーの円形度や分子量、外添剤量を調整することにより、より効果的に機能させることが可能となった。更に、マシン本体側のブレードバイアスを調整することにより、通常使用されることの無い過酷な条件においても問題無く使用することが可能となった。
【図面の簡単な説明】
【図１】本発明の画像形成装置に係るシーケンスを示す図である。
【図２】本発明の画像形成装置の一例を示す図である。
【図３】本発明の画像形成装置の他の例を示す図である。
【図４】本発明の画像形成装置に係るシーケンスを示す図である。
【図５】現像カートリッジの構成図である。
【図６】本発明の画像形成装置の他の例を示す図である。
【符号の説明】
１　感光ドラム（像担持体）
２　帯電ローラ
３　露光器
４　現像器（現像手段）
５　転写ローラ
６　クリーニング手段
７　定着器
８，８ａ，８ｂ，８ｃ，８ｄ　現像ローラ（現像剤担持体）
９，９ａ，９ｂ，９ｃ，９ｄ　現像ブレード（現像剤規制部材）
１０　現像バイアス電源（電圧印加手段）
１１　ブレードバイアス電源（電圧印加手段）
１２，１２ａ，１２ｂ，１２ｃ，１２ｄ　供給ローラ
１３，１３ａ，１３ｂ，１３ｃ，１３ｄ　撹拌部材
１４　制御回路（制御手段）
１５　モータ
１６　中間転写体クリーニング装置
１７　転写ローラ
１８　転写ベルト
１９　現像バイアス電源（電圧印加手段）
２０　ブレードバイアス電源（電圧印加手段）
２１　制御部（制御手段）
２２　現像器
２２ａ，２２ｂ，２２ｃ，２２ｄ　現像カートリッジ（現像手段）
２２ｘ　ロータリ
２３　モータ
２４　中間転写体
Ｐ　転写紙[0001]
TECHNICAL FIELD OF THE INVENTION
The present invention relates to a toner, a developing unit, a process cartridge, and an image forming method used in a recording method using an electrophotographic method, an electrostatic recording method, or the like. More specifically, a toner, a developing unit, and a process cartridge used in an image forming apparatus such as a copying machine, a printer, and a facsimile, which form a developer image on an electrostatic latent image carrier in advance and then transfer the image onto a transfer material to form an image. And an image forming method.
[0002]
[Prior art]
In recent years, devices using electrophotography have been applied to devices such as printers and fax machines in addition to conventional copying machines. In particular, in the case of printers and fax machines, in order to reduce the size of the copying machine and to facilitate maintenance, the development unit, mainly the development unit, and the drum unit, mainly the electrostatic latent image carrier (hereinafter also referred to as "drum"), The use of a process cartridge in which two units are formed and a process cartridge in which the two units are integrated has been increasingly used.
[0003]
As a developing system used for these developing units and process cartridges, there are many one-component developing systems that are advantageous for miniaturization. The one-component developing method uses a one-component developer (hereinafter, also referred to as “toner”), friction between a layer thickness regulating member (hereinafter, also referred to as “blade”) and toner particles, and a developer carrier (hereinafter, “developing roller”). ), The toner particles are charged by friction of the toner particles, and at the same time, the toner is thinly applied on the developing roller, and the toner is conveyed to a developing area where the developing roller and the drum are opposed to each other, and the electrostatic latent image on the drum is formed. It is developed and visualized as a toner image.
[0004]
Unlike the two-component developing method, which requires carrier particles such as glass beads, iron powder, and ferrite, the one-component developing method does not require carrier particles, so that the developing device itself can be reduced in size and weight. Further, in the two-component developing method, since it is necessary to keep the toner concentration in the developer constant, a device for detecting the toner concentration and replenishing a necessary amount of toner is required, which causes an increase in the size and weight of the developing device. . Also in this regard, the one-component developing method is advantageous in reducing the size and weight. Further, in full-color printing, it is difficult to use a magnetic powder as a color developer, and thus a non-magnetic toner has been used as a developer.
[0005]
In recent years, a contact developing method of directly or indirectly bringing a drum and a developing roller into contact with each other and developing the toner by contacting the drum with a toner has been used in order to achieve high image quality and full color.
[0006]
However, if the development is performed by directly or indirectly contacting the drum and the developing roller, toner and external additives are rubbed against the drum during development, so that a rain-like image due to fusion to the drum (hereinafter referred to as “filing”). (Called “ming”). Further, since the toner is rubbed between the drum and the developing roller, white background stain (hereinafter, referred to as “fog”) and roughness in the latter half of durability due to toner deterioration are liable to occur. Further, the deterioration of the toner promotes the fusion of the toner to the blade in contact with the developing roller, and may cause vertical stripes on the image. In order to eliminate such image defects, there has been a method in which toner particles are formed into a sphere to improve transferability while suppressing toner deterioration in a durability test (for example, see Patent Document 1). However, since the toner is spherical, the transferability is improved, but the cleaning performance is deteriorated, and streaks are likely to occur in the image as defective cleaning.
[0007]
To improve this, the degree of circularity of the toner is reduced (for example, see Patent Document 2), or an external additive for improving the cleaning property is added (for example, see Patent Document 3), so that the cleaning property and the transfer are improved. However, if the circularity is reduced, the transferability is deteriorated, and the addition of external additives requires the addition of a member such as fusion to the surface of the electrostatic latent image carrier or fusion to the layer thickness regulating member. It is liable to cause contamination, and it has been difficult to achieve both cleaning property and transfer property without adverse effects.
[0008]
[Patent Document 1]
JP 2001-13732 A (page 11)
[Patent Document 2]
JP-A-9-160283 (page 2)
[Patent Document 3]
JP 2000-35692 A (page 13)
[0009]
[Problems to be solved by the invention]
The present invention relates to an electrostatic latent image carrier that carries an electrostatic latent image, and a developing device that develops the electrostatic latent image by transferring a developer to the electrostatic latent image carried by the electrostatic latent image carrier Used at least during development, a developer carrier that carries the developer on the surface and directly or indirectly contacts the electrostatic latent image carrier surface, and directly or indirectly contacts the developer carrier. In a developing device having a layer thickness regulating member for regulating the layer thickness of the developer layer on the developer carrying member, filming, fogging due to toner deterioration, and An object of the present invention is to provide a toner, a developing unit, a process cartridge, and an image forming method in which vertical streaks due to fusion, defective cleaning, and roughness are improved.
[0010]
[Means for Solving the Problems]
The above object is achieved by the present invention described below.
[0011]
That is, the present invention provides an electrostatic latent image carrier for carrying an electrostatic latent image, and a developing method for developing the electrostatic latent image by transferring a developer to the electrostatic latent image carried on the electrostatic latent image carrier. A developer carrying member which is used in an apparatus and at least at the time of development, carries the developer on the surface and comes into direct or indirect contact with the surface of the electrostatic latent image carrier, and comes into direct or indirect contact with the developer carrying member A developer used in a developing apparatus having a layer thickness regulating member that regulates the layer thickness of the developer layer on the developer carrier, and
The developer has a volume average particle size of 4 to 10 μm, a shape factor SF-1 of 115 to 140, an average circularity of 0.950 to 0.990, and a BET specific surface area of 2.0 to 7.0 m.²/ G, a non-magnetic one-component developer for color, a process cartridge, and an image forming method.
[0012]
BEST MODE FOR CARRYING OUT THE INVENTION
As a result of intensive studies by the present inventors, an electrostatic latent image carrier that carries an electrostatic latent image, and a developer transferred to the electrostatic latent image carried by the electrostatic latent image carrier, Used in a developing device that develops a latent image, a developer carrier that carries the developer on the surface at least at the time of development and directly or indirectly contacts the electrostatic latent image carrier surface, A layer thickness regulating member for regulating the layer thickness of the developer layer on the developer carrier by direct or indirect contact, wherein the developer has a volume average particle diameter of 4 to 10 μm and a shape factor SF -1 is 115 to 140, the average circularity is 0.950 to 0.990, and the BET specific surface area is 2.0 to 7.0 m.²/ G, non-magnetic one-component full-color toner, a process cartridge, and an image forming method, while maintaining a high level of transferability, fusing to a blade or blade, filming, poor cleaning, etc. It has been found that roughening and vertical streaks and toner leakage under more severe conditions can be improved.
[0013]
The details will be described below.
[0014]
An image forming apparatus used in the present invention includes an electrostatic latent image carrier that carries an electrostatic latent image, and a developer that transfers the developer to the electrostatic latent image that is carried on the electrostatic latent image carrier. Used in a developing device that develops an image, at least at the time of development, a developer carrier that carries the developer on the surface and directly or indirectly contacts the electrostatic latent image carrier surface; Or a layer thickness regulating member for regulating the layer thickness of the developer layer on the developer carrying member by indirect contact. The image forming apparatus used in the present invention is not particularly limited as long as it satisfies the requirements described above, and can take various forms. Examples of such an image forming apparatus include various image forming apparatuses such as a copying machine, a printer, and a facsimile.
[0015]
Further, the image forming apparatus used in the present invention can include various components such as means and members in addition to the electrostatic latent image carrier and a developing device described later. For example, the image forming apparatus used in the present invention can be suitably used in a cleanerless system, but can also have a cleaning member provided in contact with the drum to remove transfer residual toner on the drum. It is. According to such a configuration, the surface of the electrostatic latent image carrier can be cleaned before one image forming process is completed and before the next image forming process is started. This is preferable for preventing image defects accompanying the above.
[0016]
As such a cleaning member, a known cleaning member such as an elastic blade of rubber or the like, a rotatable roll-shaped brush member, or a roll member having a surface formed by an elastic layer is used. The cleaning member is generally provided at an opening of the waste toner container that opens toward the drum. The removed transfer residual toner is stored in a waste toner container.
[0017]
The image forming apparatus used in the present invention preferably has a charging member provided in contact with the drum and charging the drum. According to such a configuration, it is possible to prevent the generation of ozone when the drum is charged by the discharge, and it is possible to charge the drum at a lower voltage. It is preferable from the viewpoint of prevention.
[0018]
As such a charging member, for example, a charging roller having a core metal and a conductive elastic layer formed on the core metal peripheral surface, a conductive sleeve, and a magnetic force generated on the conductive sleeve peripheral surface A known contact charging member such as a magnetic brush charging member having magnetic force generating means such as a magnet roll and conductive magnetic particles carried on a conductive sleeve is used.
[0019]
Further, in the present invention, a process cartridge in which the electrostatic latent image carrier, the developing device, the above-described charging member and the cleaning member, and the like are integrated and detachably mounted to the image forming apparatus main body is also preferably used. Can be In the process cartridge, known means is adopted as a means for integrally forming the electrostatic latent image carrier and the like and a means for detachably mounting the same on the main body.
[0020]
The developing device used in the present invention can be used in various forms as long as it satisfies the above requirements. Even in a developing device integrated into a main body of a copying machine, a printer, a facsimile, etc., a drum, a cleaner, and a developing roller Even if the developing device satisfies the above requirements, such as a developing device in which a developing unit and a drum unit in which a developing roller and a toner storing container are integrated are separated, a process cartridge in which a toner storing container is integrated, Although any of them can be used, a process cartridge in which a drum, a cleaner, a developing roller, and a toner storage container are integrated from the viewpoint of ease of maintenance is preferable, and a developing unit and a drum unit in which the developing roller and toner storage container are integrated are more preferable. Is a separate developing device, and is more economically preferable.
[0021]
As the developer carrier used in the present invention, an appropriate form may be used according to the type of the developer to be used.For example, the surface of a metal roller may be coated with a polymer elastic material, A developing roller formed by integrally molding a polymer elastic body with a cored bar is preferable.
[0022]
As the polymer elastic body in the developing roller, various polymer compositions having elasticity are used. For example, EPDM (ethylene-propylene-diene terpolymer), urethane, silicone rubber, nitrile butadiene rubber, chloroprene rubber A resin selected from styrene-butadiene rubber, butadiene rubber, and the like, and conductive fine particles such as carbon and titanium oxide dispersed and mixed as an electric resistance adjusting material in the resin, and an ionic conductive material in the resin described above, for example. An electric resistance adjusting resin using an inorganic ionic conductive material such as sodium perchlorate, calcium perchlorate, and sodium chloride is used.
[0023]
As the developing roller, a roller having an Asker C hardness of 30 ° or more and less than 90 ° according to JIS-K6301 Asker C scale hardness meter is preferable. When Asker C hardness is less than 30 °, it is preferable for drum scraping and toner deterioration, but there is a possibility that tribo application to toner due to environmental temperature becomes unstable and fog is easily generated. Further, when Asker C hardness is 90 ° or more, there is a possibility that toner deterioration is deteriorated. Further, the angle is more preferably 30 ° to 60 °. These have a ten-point average roughness Rz of 5 to 15 μm (more preferably 5 to 10 μm) and an arithmetic average roughness Ra of 0.5 to 1.5 μm (more preferably 0.7 to 1.3 μm). It works more effectively, and by combining this combination with the toner of the present invention, the deterioration of the toner is suppressed, and the generation of vertical stripes and fog due to blade fusion is suppressed while maintaining good transferability and cleaning properties for a long period of time. It is effective to do. The Asker C hardness of the developing roller can be adjusted by, for example, the thickness of the elastic polymer.
[0024]
The developing device used in the present invention includes, at least at the time of development, a developer carrier that carries a developer on the surface and directly or indirectly contacts the surface of the electrostatic latent image carrier, and a developer carrier directly or indirectly on the developer carrier. And a layer thickness regulating member that regulates the layer thickness of the developer layer on the developer carrier in contact with the developer carrier. The form of the layer thickness regulating member is not particularly limited, either, but is provided in direct or indirect contact with the developing roller and regulates toner carried on the developing roller to control the amount of toner coating on the developing roller. It is preferable that the blade is a blade. Such a configuration is preferable in controlling the amount of toner coating on the developing roller. As such a blade, a known blade such as a flexible plate member or a metal plate such as SUS or phosphor bronze is used.
[0025]
As the layer thickness regulating member, the ten-point average roughness Rz of the nip portion in direct or indirect contact with the developer carrier is preferably in the range of 0.1 to 5.0 μm. When Rz is less than 0.1 μm, there is a possibility that the charge may not be sufficiently applied during the regulation of the toner layer thickness, or the toner may leak from the nip portion. On the other hand, if Rz is larger than 5.0 μm, the toner easily fuses to the blade when regulating the toner layer thickness, and may appear as vertical stripes on the image. More preferably, it is 0.1 to 2.0 μm.
[0026]
In the present invention, the roughness control of the layer thickness regulating member is effective not only for maintaining the good chargeability of the toner of the present invention for a long period of time, but also exerts a remarkable effect on preventing the occurrence of vertical stripes in the toner of the present invention. This was clarified in this study.
[0027]
In the present invention, at the time of image formation, the developer carrier and the blade are set to substantially the same potential, and the developing is performed at least in part during non-image formation during which the developer carrier is rotating and image formation is not performed. It is also possible to control the bias so that the blade has a larger potential difference on the same polarity side as the charged polarity of the developer compared to the developer carrier, so that the occurrence of vertical streaks due to the fusion of the blade can be reduced. It is much better than using. Although the reason for this is not clear, the constitution of the present invention is not likely to cause deterioration of the toner, and the effect of the external additive imparting fluidity and chargeability to the toner is maintained even after the durability test. It is considered that the blade fusion prevention measure such as this configuration works more effectively than the conventional toner.
[0028]
For the drum used in the present invention, it is preferable to use an organic photoreceptor from the viewpoint of high image quality such as filming and drum scraping and safety. Se-based photoreceptors have problems in heat resistance, abrasion resistance, mechanical strength, stability over time, and toxicity, and require careful handling of disposal as well as usage. Amorphous silicon photoreceptors have recently attracted attention, but in addition to low productivity, high cost, low surface resistance and easy filming under high humidity, this configuration is difficult to use. It is.
[0029]
Various resins such as polycarbonate resin, polystyrene resin, polyarylate resin, polyphenylene ether acrylic resin, phenol resin, alkyd resin, diaryl phthalate resin, epoxy resin, vinyl chloride resin, methacrylate resin, polyamide resin, Polyphenylene oxide resin, polysulfone resin and the like can be used, but as a main component of the binder resin used for the drum surface layer, a polycarbonate resin or a polyarylate resin is more preferable. One possible reason for this is that polycarbonate resin or polyarylate resin is structurally higher in mechanical strength than a general resin used for the surface layer of another electrophotographic photosensitive member. In addition, the affinity for the toner and the discharge product is suppressed to a low level, which is effective for preventing fusion.
[0030]
The development of the electrostatic latent image in the present invention is performed by a contact developing method in which the electrostatic latent image carrier and the developer carrier are directly or indirectly contacted. This is because when the electrostatic latent image carrier and the developer carrier are not in contact with each other during development, the lines of electric force concentrate on the edge portion of the electrostatic latent image on the electrostatic latent image carrier. This is because the toner is unevenly developed at the edge portion of the image, and it is difficult to form an image of a desired image quality. Incidentally, "indirect contact" in the present invention refers to a state in which the electrostatic latent image carrier and the developer carrier are in contact with each other via a toner at a nip formed opposite to each other.
[0031]
In the development of the electrostatic latent image in the present invention, the electrostatic latent image carrier and the developer carrier may be in direct or indirect contact with each other during development, and the electrostatic latent image carrier and the developer carrier may be in contact with each other. May be installed at a predetermined position that directly or indirectly contacts, or the electrostatic latent image carrier and the developer carrier relatively move during development to directly or indirectly contact each other. It may be arranged at a position. In the present invention, the steps other than the developing step are not particularly limited, and each step in a known image forming method is employed.
[0032]
Since the toner of the present invention has both transferability and cleaning properties, it is particularly suitably used in an image forming apparatus using an apparatus using an intermediate transfer member. As the intermediate transfer member, a drum-shaped one or a belt-shaped one is suitably used.
[0033]
Various materials are used for the intermediate transfer belt. In the case of a so-called plastic belt, although the length of the belt is small due to durability, stress cracking is liable to occur due to the durability, and it is difficult to extend the life. In the case of a rubber belt, although stress cracking due to durability is small, elongation occurs due to durability, and image displacement easily occurs. As a countermeasure, a highly durable belt can be obtained by inserting a highly durable core material into the rubber belt.
[0034]
Materials that can be used as the intermediate transfer belt include polycarbonate (PC), nylon (PA), polyester (PET), polyethylene naphthalate (PEN), polysulfone (PSU), polyethersulfone (PEI), and polyether. Imide (PEI), polyether nitrile (PEN), polyether ether ketone (PEEK), thermoplastic polyimide (TPI), thermosetting polyimide (PI), PES alloy, polyvinylidene fluoride (PVdF), ethylene tetrafluoroethylene There are polymers (ETFE), etc., and the elastomer type is a polyolefin-based thermoplastic elastomer, polyester-based thermoplastic elastomer, polyurethane-based thermoplastic elastomer, polyurethane-based thermosetting elastomer, polystyrene-based thermoplastic. Elastomers, polyamide thermoplastic elastomers, fluorine-based thermoplastic elastomer, polybutadiene thermoplastic elastomer, polyethylene-based thermoplastic elastomers, ethylene-vinyl acetate type thermoplastic elastomers, polyvinyl chloride type thermoplastic elastomers, and the like.
[0035]
When the intermediate transfer member is in the form of a drum, the intermediate transfer member comprises a rigid conductive support and an elastic layer covering the surface.
[0036]
As the conductive support, a metal such as aluminum, iron, copper, and stainless steel, an alloy, and a conductive resin in which carbon, metal particles, and the like are dispersed, or the like can be used. And those in which the inside of the cylinder is reinforced.
[0037]
The elastic layer is not particularly limited, but includes styrene-butadiene rubber, high styrene rubber, butadiene rubber, isoprene rubber, ethylene-propylene copolymer, nitrile butadiene rubber (NBR), chloroprene rubber, butyl rubber, and silicone rubber. Elastomer rubbers such as fluorine rubber, nitrile rubber, urethane rubber, acrylic rubber, epichlorohydrin rubber and norbornene rubber are preferably used. Resins such as polyolefin resins, silicone resins, fluorine resins, polycarbonates, and copolymers and mixtures thereof may be used.
[0038]
Further, a surface layer in which lubricating powder having high lubricity and water repellency is dispersed in an arbitrary binder may be provided on the surface of the elastic body.
[0039]
The lubricant is not particularly limited, but various kinds of fluororubber, fluoroelastomer, carbon fluoride and polytetrafluoroethylene (PTFE), polyvinylidene fluoride (PVDF), ethylene-tetrafluoroethylene copolymer in which fluorine is bonded to graphite or graphite (ETFE) and fluorine compounds such as tetrafluoroethylene-perfluoroalkylvinylether copolymer (PFA), silicone compounds such as silicone resin particles, silicone rubber and silicone elastomer, polyethylene (PE), polypropylene (PP), polystyrene ( PS), an acrylic resin, a polyamide resin, a phenol resin, an epoxy resin and the like are preferably used.
[0040]
Further, a conductive agent may be added to the binder of the surface layer as needed to control the resistance. Examples of the conductive agent include various conductive inorganic fine particles and carbon black, an ionic conductive agent, a conductive resin, and a conductive particle-dispersed resin.
[0041]
Next, a method for producing a toner will be described.
[0042]
The method for producing the toner base of the present invention includes a mixing step using a mixer such as a Henschel mixer, a ball mill, and a V-type mixer, and a kneading step using a hot kneader such as a hot roll kneader or an extruder. There is a method in which the kneaded material is cooled and solidified and then subjected to a pulverizing step using a pulverizer such as a jet mill and a pulverized material classifying step.
[0043]
As another method, there is a method in which a component containing a monomer, a colorant, and the like is manufactured through a step of granulating and polymerizing the component. The toner of the present invention may be manufactured through a step of granulating / polymerizing a component containing at least a monomer and a colorant as a manufacturing process.
[0044]
However, the toner of the non-magnetic one-component developer of the present invention can be used even if it is a so-called pulverized toner or a spherical toner obtained by suspension polymerization. It is most preferable to add a pH adjuster, a flocculant, a stabilizer, or the like to the aqueous dispersion containing the fine particles of the molding agent, to aggregate a large number of the fine particles, and to heat-bond the aggregated particles.
[0045]
In this toner manufacturing method, in the aggregating step, resin particles, colorant particles, release agent fine particles, and the like that are uniformly dispersed in the mixed liquid are aggregated to form aggregated particles. In the heat fusing step, the resin in the agglomerated particles is melted and fused to form toner particles.
[0046]
Hereinafter, the method for producing the toner of the present invention will be described in detail.
[0047]
The resin particle dispersion is obtained by dispersing at least resin particles in a dispersant. Examples of the resin include a thermoplastic binder resin. Specific examples thereof include homopolymers or copolymers of styrenes such as styrene, parachlorostyrene, and α-methylstyrene (styrene-based resins); Methyl acrylate, ethyl acrylate, n-propyl acrylate, n-butyl acrylate, lauryl acrylate, 2-ethylhexyl acrylate, methyl methacrylate, ethyl methacrylate, n-propyl methacrylate, lauryl methacrylate, methacrylic acid 2 -Homopolymers or copolymers of esters having a vinyl group such as ethylhexyl (vinyl resin); Homopolymers or copolymers of vinyl nitriles such as acrylonitrile and methacrylonitrile (vinyl resin); vinyl methyl Vinyl ethers such as ether and vinyl isobutyl ether alone Homopolymer or copolymer of vinyl ketones such as vinyl methyl ketone, vinyl ethyl ketone and vinyl isopropenyl ketone (vinyl resin); ethylene, propylene, butadiene, isoprene, etc. Homopolymers or copolymers of olefins (olefin resins); non-vinyl condensation resins such as epoxy resins, polyester resins, polyurethane resins, polyamide resins, cellulose resins, polyether resins, and non-vinyl condensation resins thereof And a vinyl-based monomer. These resins may be used alone or in combination of two or more.
[0048]
Among these resins, vinyl resins are particularly preferable. A vinyl resin is advantageous in that a resin particle dispersion can be easily prepared by emulsion polymerization or seed polymerization using an ionic surfactant or the like. Examples of the vinyl monomer include acrylic acid, methacrylic acid, maleic acid, cinnamic acid, fumaric acid, vinyl sulfonic acid, ethylene imine, vinyl pyridine, vinyl polymer acid such as vinyl amine and vinyl polymer base. Examples of the starting material include monomers. In the present invention, the resin particles preferably contain the vinyl-based monomer as a monomer component, and a styrene-acryl resin having a small change in the charge amount of the toner in an environment of high temperature and high humidity or low temperature and low humidity is preferable. In the present invention, among these vinyl monomers, vinyl polymer acids are more preferable in terms of easiness of a reaction for forming a vinyl resin, and specific examples thereof include acrylic acid, methacrylic acid, maleic acid, and cinnamic acid. Dissociable vinyl monomers having a carboxyl group as a dissociating group, such as acid and fumaric acid, are particularly preferred in terms of controlling the degree of polymerization and the glass transition point. Further, at this time, a chain transfer agent, a cross-linking agent, and the like can be used in combination to adjust the molecular weight.
[0049]
For example, the chain transfer agent is not particularly limited, and examples thereof include mercaptans such as octyl mercaptan, dodecyl mercaptan, tert-dodecyl mercaptan, halogen compounds such as carbon tetrabromide, and disulfides.
[0050]
Further, as the crosslinking agent, those having two or more unsaturated bonds such as divinylbenzene, divinylnaphthalene, divinyl ether, diethylene glycol methacrylate, ethylene glycol dimethacrylate, polyethylene glycol dimethacrylate, and diallyl phthalate can be used. Particularly, divinylbenzene is preferably used.
[0051]
In the present invention, the radical polymerization initiator can be appropriately used as long as it is water-soluble. For example, persulfates (potassium persulfate, ammonium persulfate, etc.), azo compounds [4,4'-azobis-4-cyanovaleric acid and its salts, 2,2'-azobis (2-amidinopropane) salts, etc.], persulfates Examples include peroxide compounds such as hydrogen oxide and benzoyl peroxide.
[0052]
Further, the radical polymerization initiator can be used as a redox initiator in combination with a reducing agent, if necessary. By using the redox initiator, the polymerization activity can be increased, the polymerization temperature can be reduced, and the polymerization time can be further reduced.
[0053]
As the polymerization temperature, any temperature may be selected as long as it is equal to or higher than the minimum radical generation temperature of the polymerization initiator. For example, a temperature in the range of 50 ° C to 80 ° C is used. It is also possible to polymerize at room temperature or a temperature close thereto by using a polymerization initiator started at room temperature, for example, a combination of hydrogen peroxide and a reducing agent (such as ascorbic acid).
[0054]
Surfactants that can be used in the polymerization include sulfonates (sodium dodecylbenzenesulfonate, sodium arylalkyl polyethersulfonate, 3,3-disulfonediphenylurea-4,4-diazo-bis-amino-8-). Sodium naphthol-6-sulfonate, ortho-carboxybenzene-azo-dimethylaniline, sodium 2,2,5,5-tetramethyl-triphenylmethane-4,4-diazo-bis-β-naphthol-6-sulfonate ), Sulfates (sodium dodecyl sulfate, sodium tetradecyl sulfate, sodium pentadecyl sulfate, sodium octyl sulfate, etc.), fatty acid salts (sodium oleate, sodium laurate, sodium caprate, sodium caprylate, sodium caproate) , Potassium stearate, calcium oleate), and the like.
[0055]
The average particle size of the resin particles is usually 1 μm or less, preferably 0.01 to 1 μm. When the average particle size exceeds 1 μm, the particle size distribution of the finally obtained toner is widened, or free particles are generated, which tends to cause deterioration in performance and reliability. On the other hand, when the average particle size is within the above range, the above-described disadvantages are eliminated, the uneven distribution between toners is reduced, the dispersion in the toner is improved, and the dispersion in performance and reliability is reduced.
[0056]
The colorant particle dispersion is obtained by dispersing at least colorant particles in a dispersant. Examples of the coloring agent include a phthalocyanine pigment, a monoazo pigment, a bisazo pigment, a magnetic powder, and a quinacridone pigment. Specific examples of these include, for example, carbon black, chrome yellow, Hansa yellow, benzidine yellow, selenium yellow, quinoline yellow, permanent orange GTR, pyrazolone orange, vulcan orange, watch young red, permanent red, brillantamine 3B, and brillantamine. 6B, Dupont Oil Red, Pyrazolone Red, Risor Red, Rhodamine B Lake, Lake Red C, Rose Bengal, Aniline Blue, Ultramarine Blue, Calco Oil Blue, Methylene Blue Chloride, Phthalocyanine Blue, Phthalocyanine Green, Malachite Green Oxalate Various pigments: acridine, xanthene, azo, benzoquinone, azine, anthraquinone, dioxane Various dyes such as gin, thiazine, azomethine, indico, thioindico, phthalocyanine, aniline black, polymethine, triphenylmethane, diphenylmethane, thiazine, thiazole, and xanthene dyes; . These colorants may be used alone or in combination of two or more.
[0057]
The average particle size of the colorant particles is preferably 0.5 μm or less, more preferably 0.2 μm or less. When the average particle size exceeds 0.5 μm, irregular reflection of visible light cannot be prevented, and when coarse particles are present, coloring power, color reproducibility, and OHP permeability are adversely affected, and aggregated particles described below are used. In the forming step, the resin particles and the colorant particles do not aggregate, or even if aggregated, they may be detached at the time of fusion, which is not preferable because the quality of the obtained toner may be deteriorated. On the other hand, when the average particle size is within the above range, there is no disadvantage, the uneven distribution between toners is reduced, the dispersion in the toner is improved, and the dispersion in performance and reliability is reduced. .
[0058]
The release agent particle dispersion is obtained by dispersing at least release agent particles in a dispersant.
[0059]
As the release agent, those having a melting point of 150 ° C. or less, preferably 40 ° C. to 130 ° C., and particularly preferably 40 ° C. to 110 ° C. are used. For example, low molecular weight polyolefins such as polyethylene; silicones having a melting point (softening point) upon heating; fatty acid amides such as oleamide, erucamide, ricinoleamide, and stearamide; ester waxes such as stearyl stearate Vegetable waxes such as carnauba wax, rice wax, candelilla wax, wood wax and jojoba oil; animal waxes such as beeswax; montan wax, ozokerite, ceresin, paraffin wax, microcrystalline wax, Fischer-Tropsch wax, esters Mineral and petroleum waxes such as wax; and particles of modified products thereof.
[0060]
The average particle diameter of the release agent particles is preferably 2.0 μm or less, more preferably 1.0 μm or less. When the average particle size exceeds 2.0 μm, the wax content tends to be varied between the toners, which adversely affects the long-term stability of the image. On the other hand, when the average particle size is within the above range, uneven distribution among toners is reduced, dispersion in the toner is improved, and variations in performance and reliability are reduced. The combination of the colorant particles, the resin particles, and the release agent particles is not particularly limited, and can be appropriately selected depending on the purpose.
[0061]
In addition to the resin particle dispersion, the colorant particle dispersion, and the release agent dispersion, a particle dispersion obtained by dispersing appropriately selected particles in a dispersant may be further mixed.
[0062]
The particles contained in the particle dispersion are not particularly limited and may be appropriately selected depending on the purpose. Examples thereof include internal additive particles, charge control agent particles, inorganic particles, and abrasive particles. In the present invention, these particles may be dispersed in the resin particle dispersion or the colorant particle dispersion.
[0063]
Examples of the charge control agent particles include particles of a quaternary ammonium salt compound, a nigrosine compound, and a compound of a complex of aluminum, iron, chromium, zinc, zirconium, and the like. In addition, as the charge control agent particles in the present invention, a material that is hardly dissolved in water is preferable from the viewpoint of controlling the ionic strength that affects the stability at the time of aggregation and fusion and recycling wastewater.
[0064]
The average particle size of each of the above-mentioned particles is usually 1 μm or less, preferably 0.01 to 1 μm. When the average particle size exceeds 1 μm, the particle size distribution of the finally obtained toner is widened, or free particles are generated, which tends to cause deterioration in performance and reliability. On the other hand, when the average particle size is within the above range, the above-described disadvantages are eliminated, the uneven distribution between toners is reduced, the dispersion in the toner is improved, and the dispersion in performance and reliability is reduced.
[0065]
Examples of the dispersant included in the resin particle dispersion, the colorant particle dispersion, the release agent dispersion, the particle dispersion, and the like include, for example, an aqueous medium containing a polar surfactant. Examples of the aqueous medium include water such as distilled water and ion-exchanged water, and alcohols. These may be used alone or in combination of two or more. The content of the polar surfactant in the polar dispersant cannot be specified unconditionally, and can be appropriately selected depending on the purpose.
[0066]
Examples of the polar surfactant include anionic surfactants such as sulfate ester type, sulfonate type, phosphate ester type and soap type; and cationic surfactants such as amine salt type and quaternary ammonium salt type. Is mentioned. Specific examples of the anionic surfactant include sodium dodecylbenzenesulfonate, sodium dodecylsulfate, sodium alkylnaphthalenesulfonate, sodium dialkylsulfosuccinate, and the like. Specific examples of the cationic surfactant include alkylbenzene dimethyl ammonium chloride, alkyl trimethyl ammonium chloride, distearyl ammonium chloride and the like. These may be used alone or in combination of two or more.
[0067]
In the present invention, these polar surfactants and non-polar surfactants can be used in combination. Examples of the non-polar surfactant include polyethylene glycol-based, alkylphenol ethylene oxide adduct-based, and polyhydric alcohol-based nonionic surfactants.
[0068]
The content of the resin particles in the resin particle dispersion is usually 5 to 60% by mass, preferably 10 to 40% by mass. The content of the resin particles in the aggregated particle dispersion when the aggregated particles are formed may be 50% by mass or less, and is preferably about 2 to 40% by mass.
[0069]
The content of the colorant particles and the like is about 1 to 10% by mass, preferably about 2 to 6% by mass in the aggregated particle dispersion when the aggregated particles are formed.
[0070]
The content of the release agent particles and the like is about 0.5 to 20% by mass, preferably about 1 to 10% by mass in the aggregated particle dispersion when the aggregated particles are formed. When the content is more than 5% by mass, the particle size distribution may be widened and the characteristics may be deteriorated. In this case, for example, when resin particles are generated, the above problem can be solved by performing seed polymerization on the release agent.
[0071]
The content of each particle such as the additive particles is about 0.01 to 5% by mass and about 0.5 to 2% by mass in the aggregated particle dispersion when the aggregated particles are formed. preferable. If the content is outside the above range, the effect of dispersing the release agent particles or the like may not be sufficient, or the particle size distribution may be widened and the characteristics may be deteriorated.
[0072]
Further, in order to control the chargeability of the obtained toner, the charge control particles and the resin particles may be added after the aggregated particles are formed.
[0073]
The resin particle dispersion is prepared, for example, as follows. That is, the resin in the resin particles is a homopolymer or copolymer (vinyl resin) of a vinyl monomer such as the ester having a vinyl group, the vinyl nitrile, the vinyl ether, or the vinyl ketone. In some cases, the vinyl monomer is subjected to emulsion polymerization or seed polymerization in an ionic surfactant to form a homopolymer or copolymer (vinyl resin) of the vinyl monomer. A dispersion is prepared by dispersing the particles in an ionic surfactant. When the resin in the resin particles is a resin other than the homopolymer or copolymer of the vinyl monomer, if the resin is soluble in an oily solvent having a relatively low solubility in water. The resin is dissolved in the oily solvent, and the solution is dispersed in water with an ionic surfactant or a polymer electrolyte using a disperser such as a homogenizer, and then heated or reduced in pressure to remove the oily solvent. By evaporating, a dispersion liquid in which resin particles made of a resin other than the vinyl resin are dispersed in the ionic surfactant is prepared.
[0074]
The means for dispersion is not particularly limited, and examples thereof include a dispersion device known per se such as a rotary shearing homogenizer, a ball mill having a medium, a sand mill, and a dyno mill.
[0075]
The colorant particle dispersion, the release agent dispersion, the particle dispersion, and the like are prepared, for example, by adding particles such as the colorant particles to a dispersant and dispersing using a dispersing means. Is done.
[0076]
(Aggregation step)
The formation of aggregated particles is to form aggregated particles in the liquid mixture to prepare an aggregated particle dispersion. The agglomerated particles can be formed in the mixture by, for example, adding and mixing a pH adjuster, an aggregating agent, and a stabilizer into the mixture and appropriately adding temperature, mechanical power, and the like.
[0077]
Examples of the pH adjuster include alkalis such as ammonia and sodium hydroxide, and acids such as nitric acid and citric acid. Examples of the coagulant include monovalent metal salts such as sodium and potassium; divalent metal salts such as calcium and magnesium; trivalent metal salts such as iron and aluminum; and alcohols such as methanol, ethanol and propanol. Can be
[0078]
Examples of the stabilizer mainly include the polar surfactant itself or an aqueous medium containing the same. For example, when the polar surfactant contained in the aqueous dispersion is anionic, cationic stabilizers can be selected.
[0079]
The addition and mixing of the coagulant and the like are preferably performed at a temperature equal to or lower than the glass transition point of the resin contained in the mixed solution. When the mixing is performed under this temperature condition, the aggregation proceeds in a stable state. The mixing can be performed using, for example, a known mixing device, homogenizer, mixer, or the like.
[0080]
The average particle size of the aggregated particles formed here is not particularly limited, but is usually controlled to be approximately the same as the average particle size of the toner to be obtained. The control can be easily performed, for example, by appropriately setting and changing the temperature and the stirring and mixing conditions. Through the above aggregated particle forming step, aggregated particles having an average particle diameter substantially the same as the average particle diameter of the toner are formed, and an aggregated particle dispersion obtained by dispersing the aggregated particles is prepared.
[0081]
(Heat fusion process)
The heat fusing step is a step of fusing the aggregated particles by heating. Before the fusion step, the pH adjuster, the polar surfactant, the non-polar surfactant, and the like can be appropriately added to prevent fusion between toner particles.
[0082]
The heating temperature may be from the glass transition temperature of the resin contained in the aggregated particles to the decomposition temperature of the resin. Therefore, the heating temperature is different depending on the type of resin of the resin particles and the resin fine particles, and cannot be specified unconditionally, but generally, the glass of the resin contained in the aggregated particles or the adhered particles. The transition point temperature is １４０140 ° C. In addition, the heating can be performed using a heating device / apparatus known per se.
[0083]
As the time for the fusion, a short time is sufficient if the heating temperature is high, and a long time is necessary if the heating temperature is low. That is, the fusion time depends on the heating temperature and cannot be specified unconditionally, but is generally 30 minutes to 10 hours.
[0084]
In the present invention, the toner obtained after the completion of the fusing step can be washed, dried, and the like under appropriate conditions. In addition, to the surface of the obtained toner, inorganic particles such as silica, alumina, titania, and calcium carbonate, and resin particles such as a vinyl resin, a polyester resin, and a silicone resin are added by applying a shearing force in a dry state. May be. These inorganic particles and resin particles function as external additives such as a flow aid and a cleaning aid.
[0085]
<Non-magnetic one-component developer>
The volume average particle diameter of the toner is preferably 4 to 10 μm, more preferably 5 to 8 μm. If the average particle size is less than 4 μm, the chargeability tends to be insufficient, and the developability may decrease. If the average particle size exceeds 10 μm, the image resolution may decrease.
[0086]
The molecular weight of the toner of the present invention is preferably 40,000 to 120,000 in terms of weight average molecular weight. If the weight-average molecular weight is less than 40,000, there is a possibility that the toner may aggregate during storage to cause toner leakage or roughening, or may be fused to a blade to easily cause vertical stripes. If the weight average molecular weight is larger than 120,000, the fixability may be poor, and if the toner is an agglutination method, the toner may be finely powdered in a developing machine, which may cause fogging or poor cleaning.
[0087]
Therefore, in order to more effectively achieve transferability and cleaning property, which are the most important characteristics of the toner of the present invention, it is desirable to set the molecular weight within the above range, whereby the roughness of the blade and the roughness of the developing roller can be improved. The effect of adjusting the hardness can be maximized.
[0088]
As the external additive used in the present invention, known inorganic fine powder or resin particles are used. However, silica, alumina, titania or a composite oxide thereof is preferably used in order to improve charge stability, developability, fluidity, and storage stability. It is preferable to be selected from inorganic fine powders. Further, silica is more preferable. For example, as the silica, both a so-called dry method produced by a vapor phase oxidation of a silicon halide or an alkoxide or a so-called fumed silica, and a so-called wet silica produced from an alkoxide, water glass or the like are used. Although possible, there are few silanol groups on the surface and inside the silica fine powder, and Na₂O, SO₃ ^2-Dry silica with less production residue such as is preferred. In the case of fumed silica, it is also possible to obtain a composite fine powder of silica and another metal oxide by using another metal halide such as aluminum chloride and titanium chloride together with a silicon halide in the manufacturing process. Is also included.
[0089]
The amount of silica used as an external additive in the present invention is preferably from 2 to 8 parts by mass based on the total mass ratio of the toner.
[0090]
If the amount of silica is less than 2 parts by mass, the fluidity of the toner may be poor or the chargeability may be poor, and fog, roughness, and vertical stripes may be deteriorated. Conversely, if the amount is more than 8 parts by mass, the fluidity is too high, causing toner leakage, causing filming on the drum, and deteriorating the fixing property.
[0091]
The amount of the silica in the present invention is an optimum amount for uniformly covering the toner particles of the present invention having irregularities in an optimum range, whereby the fluidity and chargeability of the toner of the present invention are effectively maintained for a long period of time. You. In addition, the adjustment of the roughness of the blade, the roughness and the hardness of the developing roller works very effectively, and a stable high-quality image can be maintained for a long period of time.
[0092]
The external additive used in the present invention may be, if necessary, a silicone varnish, various modified silicone varnishes, silicone oil, various modified silicone oils, a silane coupling agent, a functional group for the purpose of hydrophobicity, charge control, and the like. It is possible and preferable to use a silane coupling agent, a treating agent such as an organosilicon compound, an organotitanium compound, or a combination of various treating agents.
[0093]
For example, silane coupling agents include, for example, typically dimethyldichlorosilane, trimethylchlorosilane, allyldimethylchlorosilane, hexamethyldisilazane, allylphenyldichlorosilane, benzyldimethylchlorosilane, vinyltriethoxysilane, γ -Methacryloxypropyltrimethoxysilane, vinyltriacetoxysilane, divinylchlorosilane, dimethylvinylchlorosilane and the like. The above-mentioned silane coupling agent treatment of the inorganic fine powder is performed by a dry treatment in which a vaporized silane coupling agent is reacted with a cloud of inorganic fine powder by stirring or the like, or a silane cup in which the inorganic fine powder is dispersed in a solvent. The treatment can be performed by a generally known apparatus such as a wet method in which a ring agent is dropped.
[0094]
It is particularly preferred that the external additive used in the present invention is further treated with at least silicone oil.
[0095]
The average particle diameter of the silicone oil-treated external additive is preferably 0.1 μm or less, more preferably 0.002 to 0.05 μm. The oil treatment amount of the silicone oil-treated inorganic fine powder is preferably from 1 to 30% by mass, particularly preferably from 1 to 20% by mass, based on the treated external additive. Furthermore, the oil viscosity of the silicone oil is preferably 1 to 10000 mm²/ S, 50 to 1000 mm²/ S is more preferable.
[0096]
Examples of the silicone oil used in the present invention include dimethyl silicone oil, alkyl-modified silicone oil, α-methylstyrene-modified silicone oil, chlorophenyl silicone oil, and fluorine-modified silicone oil. A known technique is used for the apparatus of the silicone oil treatment.For example, the silica fine powder and the silicone oil may be directly mixed using a mixer such as a Henschel mixer or a device for spraying the silicone oil on the base silica. good. Alternatively, it may be prepared by dissolving or dispersing a silicone oil in an appropriate solvent, mixing with a base silica fine powder, and removing the solvent.
[0097]
In the one-component developer of the present invention, other additives such as a lubricant powder such as a polyfluoroethylene powder, a zinc stearate powder, and a polyvinylidene fluoride powder; Abrasives such as silicon carbide powder and strontium titanate powder; fluidity-imparting agents such as titanium oxide powder and aluminum oxide powder; anti-caking agents or conductive agents such as carbon black powder, zinc oxide powder and tin oxide powder A small amount of an imparting agent or organic and inorganic fine particles of opposite polarity can be used as a developing property improver.
[0098]
As the external addition method, a conventionally known method such as a Henschel mixer can be used.
[0099]
In the present invention, the circularity is measured in a circle equivalent diameter-circularity scattergram based on the number of toners measured by a flow-type particle image measuring device, and in the present invention, “FPIA-1000” (Toa) The measurement was performed using a medical electronics company, and calculated using the following equation.
Circularity = Circumference length with the same projected area as the particle image / Perimeter of the particle projection image
[0100]
Here, the “particle projection area” is the area of the binarized toner particle image.
[0101]
As a specific measuring method, 10 ml of ion-exchanged water from which impurity solids and the like have been removed in advance in a container is prepared, and a surfactant, preferably an alkylbenzene sulfonate, is added as a dispersing agent thereto, and then further measured. Add 0.02 g of sample and disperse uniformly. As a means for dispersing, using a UH-50 type ultrasonic disperser (manufactured by SMT Corporation) with a titanium alloy chip of 5Φ attached as a vibrator, performing a dispersion treatment for 5 minutes, I do. At this time, the dispersion is appropriately cooled so that the temperature of the dispersion does not exceed 40 ° C.
[0102]
The shape of the toner is measured using the above-mentioned flow type particle image measuring apparatus, and the concentration of the dispersion liquid is readjusted so that the concentration of the toner particles at the time of measurement becomes 3000 to 10,000 particles / μl. measure. After the measurement, the average circularity of the toner is obtained using this data.
[0103]
This value indicates how close the toner is to a sphere. A value of 1.000 is a true sphere, and a value smaller than that indicates that the toner gradually becomes indefinite.
[0104]
The average circularity of the toner of the present invention is preferably from 0.950 to 0.990, more preferably from 0.955 to 0.980.
[0105]
Next, the shape factor SF-1 of the toner in the present invention will be described. SF-1 means that 100 toner images are sampled at random using Hitachi FE-SEM (S-800), and the image information is introduced into an image analyzer (Luzex3) manufactured by Nireco via an interface and analyzed. And the value obtained by the following equation is defined.
SF-1 = ｛(MXLNG)²/ AREA ×× (π / 4) × 100
(MXLNG: absolute maximum length, AREA: toner projection area)
[0106]
The shape factor SF-1 of the toner indicates a degree of sphericity, and a value smaller than 115 indicates that the toner is gradually spherical, and 100 is a true sphere. If it is larger than 140, the shape gradually changes from a spherical shape to an irregular shape.
[0107]
The toner of the present invention is a spherical toner having moderate unevenness, and this shape has both transferability and cleaning properties.
[0108]
As a general toner physical property with respect to this SF-1 value, a spherical toner having an SF-1 value close to 100 has good transferability but poor cleaning performance, and an irregular shape having an SF-1 value exceeding 140. Some toners have good cleaning properties but poor transfer properties. However, the biggest feature of the toner of the present invention is that the above is not merely adjusted to an intermediate value, but a value that is measured as a substantially spherical shape in the circularity and has an appropriate unevenness in SF-1 value. By configuring the shape to be measured as described above, it is possible to make the transfer property more compatible with the spherical toner and the cleaning property more compatible with the irregular toner.
[0109]
Further, the toner of the present invention makes it possible to maintain stable chargeability for a long period of time by defining the following BET specific surface area in an optimum range.
[0110]
The measurement of the BET specific surface area is performed by using a known device such as a degassing device VacuPrep 061 (manufactured by Micromesotics) and a BET measuring device Gemini 2375 (manufactured by Micromesotics). The BET specific surface area in the present invention is the value of the multipoint BET specific surface area. Specifically, the following procedure is performed.
[0111]
After measuring the mass of the empty sample cell, the measurement sample is filled so as to be between 0.1 and 5.0 g. Further, the sample cell filled with the sample is set in the degassing device, and degassing is performed at room temperature for 3 hours. After the degassing, the mass of the entire sample cell is measured, and the accurate mass of the sample is calculated from the difference from the empty sample cell. Next, an empty sample cell is set in the balance port and the analysis port of the BET measuring device. A Dewar bottle containing liquid nitrogen is set at a predetermined position, and P0 is measured by a saturated vapor pressure (P0) measurement command. After the P0 measurement is completed, the degas-prepared sample cell is set in the analysis port, the sample mass and P0 are input, and the measurement is started by the BET measurement command. Thereafter, the BET specific surface area is automatically calculated.
[0112]
The optimum BET specific surface area value (BET value) of the toner of the present invention is 2.0 to 7.0 m.²/ G. BET value is 2.0m²If the value is smaller than / g, the chargeability is inferior and fog is worsened, and the transferability may be inferior. In addition, 7.0m²If it is larger than / g, the resistance due to friction increases, and fogging may be deteriorated in filming on a drum or in a durability test. Further, the toner may be deteriorated under the influence of severe storage.
[0113]
The average particle diameter of the toner can be determined by using, for example, a Coulter Counter TA-II or a Coulter Multisizer (manufactured by Coulter) and an interface (manufactured by Nikkaki) for outputting the number distribution and volume distribution and a PC9801 personal computer (manufactured by NEC). It can be measured with a connected measuring device. In this measurement, an electrolytic solution is used. For this electrolytic solution, for example, a 1% aqueous NaCl solution prepared using primary sodium chloride or ISOTONR-II (manufactured by Coulter Scientific Japan) can be used.
[0114]
As a measuring method, 0.1 to 5 ml of a surfactant (preferably an alkylbenzene sulfonate) is added as a dispersant to 100 to 150 ml of the aqueous electrolytic solution, and 2 to 20 mg of a measurement sample is further added. The electrolyte in which the sample was suspended was subjected to a dispersion treatment for about 1 to 3 minutes using an ultrasonic disperser, and the volume and number of toner particles of 2 μm or more were measured using the Coulter Counter TA-II using an aperture of 100 μm. To calculate a volume distribution and a number distribution. Then, the volume average particle diameter determined from the volume distribution and the number average particle diameter determined from the number distribution according to the present invention are determined.
[0115]
The surface roughness measuring device in this embodiment uses a contact detection unit PU-DJ2S for a surf coder SE3300 manufactured by Kosaka Laboratory Co., Ltd. based on JIS B0601, and the measuring conditions are a measuring length of 2.5 mm and a vertical direction. The magnification was 2000 times, the horizontal magnification was 100 times, the cutoff was 0.8 mm, and the phase compensation was R + W type. The arithmetic average roughness Ra and the ten-point average roughness Rz were measured.
[0116]
Next, an example of the image forming apparatus of the present invention will be described with reference to FIGS.
[0117]
First, the image forming apparatus of the present embodiment will be described with reference to FIG. The image forming apparatus according to the present embodiment is a reversal developing system in which toner is adhered to an exposed portion of an image carrier to visualize the image, and a developer carrier carrying negatively charged toner is brought into contact with the image carrier to perform development. Is a one-component image forming apparatus.
[0118]
In FIG. 2, reference numeral 1 denotes a photosensitive drum as an image carrier, which is rotatable in an arrow x direction. The surface of the photosensitive drum 1 is uniformly charged to a negative polarity by a charging roller 2 as a primary charger. Then, as the photosensitive drum 1 rotates, the uniformly charged surface is exposed by the exposure device 3. As the charges in the exposed portion disappear, an electrostatic latent image is formed on the photosensitive drum 1.
[0119]
Reference numeral 4 denotes a developing unit, which is a developing unit that transfers toner as a developer to a portion to be exposed of the electrostatic latent image to visualize the electrostatic latent image. The toner used is a non-magnetic one-component toner. Further, the present embodiment is a so-called reversal developing system for transferring toner to a portion to be exposed.
[0120]
The toner transferred onto the photosensitive drum 1 is transferred to the transfer paper P by a transfer roller 5 as a transfer charger. The toner remaining on the photosensitive drum 1 without being transferred is removed from the photosensitive drum 1 by the cleaning unit 6.
[0121]
The toner on the transfer paper P is heat-melted by the fixing device 7 and fixed on the transfer paper P to form a permanent image.
[0122]
The developing device 4 includes a developing roller 8 as a developer carrier, a supply roller 12 for supplying toner to the developing roller 8, a developing blade 9 as a developer regulating member, and a stirring member 13 for transporting the toner to the supply roller 12 side. .
[0123]
The developing roller 8 is rotatable in the direction of arrow y by a motor 15 as a driving device. Since the developing roller 8 is a so-called contact development in which development is performed by contacting the surface of the photosensitive drum 1, the developing roller 8 desirably has elasticity such as rubber. A voltage of about −400 V is supplied to the developing roller 8 from a developing bias power supply 10. The toner on the developing roller 8 is transferred to the exposed portion on the photosensitive drum 1 due to the potential difference between the exposed portion on the photosensitive drum 1 and the potential supplied from the developing bias power supply 10.
[0124]
The developing blade 9 is made of a thin metal plate, and is brought into contact with the developing roller 8 by utilizing the elasticity of the thin plate. As the material of the metal thin plate, stainless steel, phosphor bronze, or the like can be used. In the present embodiment, a phosphor bronze thin plate having a thickness of 0.1 mm is used. The toner is frictionally charged by the rubbing between the developing blade 9 and the developing roller 8 to be charged, and the layer thickness is regulated at the same time. A predetermined voltage is supplied to the developing blade 9 from a blade bias power supply 11.
[0125]
Reference numeral 14 denotes a control device (control means). The control device 14 controls the rotation of the developing roller 8 and controls the voltage values of the developing bias power supply 10 and the blade bias power supply 11 as voltage applying means.
[0126]
FIG. 1 is a diagram showing a sequence according to the present embodiment. FIG. 1 shows a case where two sheets are continuously printed.
[0127]
In FIG. 1, the graph of the rotation of the photosensitive drum and the graph of the rotation of the developing roller respectively indicate that the photosensitive drum 1 or the developing roller 8 is driven to rotate when it is convex upward.
[0128]
In this embodiment, since the photosensitive drum 1 and the developing roller 8 are always in contact with each other, the rotation of the photosensitive drum 1 and the rotation of the developing roller 8 are performed in synchronization. However, in the case of so-called non-contact development where the photosensitive drum and the developing roller are always separated, or in the case where a mechanism capable of separating the photosensitive drum 1 and the developing roller 8 is provided, the rotation of the photosensitive drum 1 and the developing roller 8 is It is done asynchronously.
[0129]
In FIG. 1, when a print output is requested from a personal computer (not shown) or the like, the rotation of the photosensitive drum 1 and the developing roller 8 causes the same potential of about -400 V from the developing bias power supply 10 and the blade bias power supply 11. Each is applied. At the beginning of the rotation of the developing roller 8 and the like, it is a preparatory rotation time before an image is still drawn, that is, at the time of non-image formation.
[0130]
The time of image formation refers to the time of each process for forming a toner image on a portion of the transfer paper P excluding a blank area. In addition, non-image formation refers to when the developing roller is rotating except during image formation. For example, the rotation before preparation, the rotation after preparation, or the so-called “sheet interval” between prints corresponds to the time of non-image formation.
[0131]
After the pre-preparation rotation is started and a voltage of about -400 V is applied from the developing bias power supply 10 and the blade bias power supply 11, a voltage of about -600 V is applied to the blade bias power supply 11 for a moment. The time during which -600 V is applied was set to 150 msec in this embodiment.
[0132]
At the time of non-image formation which does not affect the image on the transfer paper P, -600 V is applied to the developing blade 9 and -400 V is applied to the developing roller 8. That is, a potential difference that can be transferred from the developing blade side to the developing roller side is supplied to the negatively charged particles (toner and external additive). Therefore, the negative external additive adhering to the developing blade 9 immediately after the start of the rotation of the developing roller is transferred to the developing roller 8 side.
[0133]
After a momentary application of -600 V to the developing blade 9 and -400 V to the developing roller 8, the voltages of the developing bias power supply 10 and the blade bias power supply 11 become almost the same potential, -400 V, which is the first image forming area. Image formation is performed (at the time of image formation).
[0134]
During the image formation, the developing roller 8 and the developing blade 9 have substantially the same potential, and the rotation of the developing roller 8 causes the charge of the toner layer to move the negative polarity from the contact portion of the developing blade 9 to the fixed end. External additives transfer. However, the reversal toner and the positive external additive do not adhere to the developing blade 9.
[0135]
When the image formation for the first sheet is completed, a so-called “paper interval” is formed between the image formation and the next image formation. During this sheet interval, a voltage of -600 V is applied to the developing blade 9 for 150 msec as in the pre-preparation rotation. Due to the bias applied to the developing blade 9, the negative external additive adhered from the contact portion of the developing blade 9 to the fixed end side during the first image formation is transferred to the developing roller 8 side. Since this is performed while the developing roller 8 is rotating, the negative external additive does not return to the developing blade 9 side again.
[0136]
Then, the second image formation is performed in the same manner as the first image formation. At the time of image formation, the negative external additive adheres and accumulates from the contact portion of the developing blade 9 to the free end tip as described above.
[0137]
The image formation for the second sheet is completed, and rotation starts after preparation for the next print.
[0138]
At this time, a voltage of -600 V is applied to the developing blade 9 for 150 msec in the same manner as the pre-preparation rotation and the sheet interval. Due to the bias applied to the developing blade 9, the negative external additive adhered from the contact portion of the developing blade 9 to the fixed end side during the first image formation is transferred to the developing roller 8 side. Since this is performed while the developing roller 8 is rotating, the negative external additive does not return to the developing blade 9 side again.
[0139]
Then, after the preparation, the rotation operation ends, and the rotation of the developing roller 8 and the photosensitive drum 1 stops.
[0140]
In this way, the negative external additive adhered from the contact portion of the developing blade 9 at the time of image formation to the fixed end side is applied to the developing roller 8 with a momentary potential difference between the developing blade 9 and the developing roller 8 during non-image formation. By returning, the developing blade 9 can be refreshed. As a result, since the negative external additive attached to the fixed end side from the developing blade contact portion is not deposited, it is possible to prevent the toner from being fused to the developing blade 9.
[0141]
The timing when an electric potential difference is generated between the developing blade 9 and the developing roller 8 at the time of non-image formation is that the toner carrying amount regulated on the developing roller 8 when the electric potential difference is applied from the same electric potential. Is changed, and a density step occurs on the image.
[0142]
Further, it is not necessary to perform the time for making a momentary potential difference between the developing blade 9 and the developing roller 8 every time. For example, it is possible to perform the time during pre-preparation rotation before image formation or only during the post-preparation rotation.
[0143]
In the present embodiment, the time for making the potential difference between the developing blade 9 and the developing roller 8 for a moment is 150 msec, but this is not a limitation. However, it takes about 5 msec or more to refresh the developing blade 9. Although there is no upper limit on the application time, an increase in the application time leads to a decrease in the printing speed. Therefore, an upper limit of about several seconds is sufficient.
[0144]
Further, in the present embodiment, the potential difference is only once for 150 msec. However, for example, a plurality of potential differences can be generated during the pre-preparation rotation.
[0145]
Next, an example of the image forming apparatus of the present invention will be further described with reference to FIGS. The same parts as those of the above-described image forming apparatus are denoted by the same reference numerals, and description thereof is omitted.
[0146]
FIG. 3 is a schematic diagram of the image forming apparatus according to the present embodiment. This image forming apparatus is a color image forming apparatus, and generally includes a photosensitive drum 1 serving as an image carrier, a charging roller 2 serving as a charging unit, an exposure unit 3 for giving image information, and an electrostatic latent image on the photosensitive drum 1. The image forming apparatus includes a developing device 22 for visualizing an image and an intermediate transfer member 24.
[0147]
The developing device 22 includes a rotary 22x as a rotating support, a yellow developing cartridge 22a, a magenta developing cartridge 22b, a cyan developing cartridge 22c, and a black developing cartridge 22d.
[0148]
In this embodiment, the image forming apparatus is an electrophotographic color printer, and is separated into four colors of yellow Y, magenta M, cyan C, and black Bk based on image data from a personal computer or a workstation (not shown). Then, toner images of each color are sequentially formed based on the decomposed image data, and the toner images are superimposed on the intermediate transfer body 24 and collectively transferred to a transfer material (recording medium) such as paper to obtain a full-color image. The image forming apparatus of the present embodiment is a so-called rotary type color printer that employs a developing device configured by mounting a plurality of developing units, that is, developing cartridges 22a, 22b, 22c, and 22d, in a rotary 22x. You.
[0149]
In FIG. 3, the image forming apparatus includes a photoconductive organic photosensitive drum 1 as an image carrier. When the image forming operation starts, the photosensitive drum 1 is driven to rotate in the direction of arrow q. The surface of the photosensitive drum 1 is uniformly charged to a predetermined dark area potential by applying a bias to a core of the charging roller 2 as a contact charging unit. Next, according to the first color yellow (Y) image data, scanning exposure is performed by a laser beam whose ON / OFF control is performed by the exposure device 3, and a first electrostatic latent image is formed as a light portion potential. Is done.
[0150]
The electrostatic latent image thus formed is developed and visualized by a developing unit (developing cartridge) mounted in the rotary 22x of the developing unit 22. The rotary 22x includes a first developing cartridge 22a containing yellow (Y) toner as the first color toner, a second developing cartridge 22b containing magenta (M) toner as the second color toner, and a second developing cartridge 22b. A configuration in which a third developing cartridge 22c containing cyan (C) toner as the third color toner and a fourth developing cartridge 22d containing black (Bk) toner as the fourth color toner are mounted and integrated. When the image of each color is formed, the photosensitive drum is rotated to the position facing the photosensitive drum (in the direction of arrow r).
[0151]
The developing cartridge (22a, 22b, 22c or 22d) located at the developing position facing the photosensitive drum 1 has a developing roller as a developer carrying member having a toner regulated to a predetermined layer thickness. The developing is performed by applying a predetermined bias to the core metal of the developing roller. Each of the Y, M, C, and Bk developing cartridges 22a, 22b, 22c, and 22d is individually replaceable as a single cartridge (developing cartridge) depending on the degree of wear.
[0152]
First, the first electrostatic latent image is developed and visualized by the first developing cartridge 22a containing Y toner as the first color toner. The developing method can be used irrespective of contact / non-contact. In the present embodiment, a contact developing method using a non-magnetic one-component toner that combines image exposure and reversal development is used.
[0153]
The visualized toner image of the first color is provided on a cylinder at a first transfer portion, which is a nip portion between the intermediate transfer member 24 as a second image carrier, and a surface layer having releasability from the conductive elastic layer. The electrostatic transfer (primary transfer) is performed on the surface of the intermediate transfer body 24 formed from the above.
[0154]
The intermediate transfer body 24 has a circumferential length longer than the maximum length of the transfer material that can be passed, and is pressed against the photosensitive drum 1 with a predetermined pressing force while maintaining a substantially constant speed with the circumferential speed of the photosensitive drum 1. The photosensitive drum 1 is rotationally driven at a peripheral speed in a direction opposite to the rotational direction of the photosensitive drum 1 (the direction of arrow s in FIG. 3) (at the contact portion, the surface of the photosensitive drum 1 and the surface of the intermediate transfer body 24 move in the same direction).
[0155]
The toner image formed on the surface of the photosensitive drum 1 as described above is applied to the cylinder portion of the intermediate transfer body 24 by applying a voltage (primary transfer bias) having a polarity opposite to the charge polarity of the toner. Then, electrostatic transfer (primary transfer) is performed on the surface of the intermediate transfer body 24.
[0156]
The toner remaining on the surface of the photosensitive drum 1 after the primary transfer is removed by the cleaning unit 6 to prepare for the next latent image formation.
[0157]
Subsequently, the same process is repeated, and each time, the toner image of the second color developed with the M toner, the toner image of the third color developed with the C toner, and the toner image of the fourth color developed with the Bk toner are sequentially formed. A color toner image is formed by being transferred and laminated on the surface of the intermediate transfer member 24.
[0158]
Thereafter, the transfer belt 18 that has been separated from the surface of the intermediate transfer member 24 is pressed against the surface of the intermediate transfer member 24 with a predetermined pressing force and is driven to rotate. The transfer belt 18 includes a transfer roller 17. By applying a voltage (secondary transfer bias) having a polarity opposite to the charging polarity of the toner to the transfer roller 17, the intermediate transfer member 24 is applied to the surface of the transfer paper P conveyed at a predetermined timing. The color toner images stacked on the surface are collectively transferred (secondary transfer), and the transfer paper P is conveyed to the fixing device 7. The transfer paper P is discharged out of the apparatus after the toner image is fixed as a permanent image by the fixing device 7, and a desired color print image is obtained.
[0159]
The toner remaining on the surface of the intermediate transfer body 24 after the completion of the secondary transfer is removed by the intermediate transfer body cleaning device 16 which comes into contact with the surface of the intermediate transfer body 24 at a predetermined timing.
[0160]
FIG. 5 is a configuration diagram showing developing cartridges 22a, 22b, 22c, and 22d respectively containing Y, M, C, and Bk toners, which are the developing units of the present embodiment. 3 is detachable by opening and closing a developing cartridge replacement cover (not shown) with respect to the rotary type color printer as the image forming apparatus shown in FIG. It can be taken out in the upper arrow D direction.
[0161]
In the rotary type color printer shown in FIG. 3, it is necessary to attach and detach the developing cartridge at the take-out position, and replace the yellow, magenta, and black developing cartridges 22a, 22b, and 22d other than the cyan developing cartridge 22c in the drawing. In this case, it is necessary to rotate the rotary 22x to rotate the cartridge to be removed to the mounting / removing position (the position 22c in the drawing).
[0162]
Hereinafter, the case of the Y toner developing cartridge 22a will be described for simplicity, but the same applies to the other color developing cartridges 22b, 22c, and 22d.
[0163]
The developing cartridge 22a of the present embodiment shown in FIG. 5 is a reversal developing unit that contains a non-magnetic one-component Y toner as a developer.
[0164]
The developing cartridge 22a is a developing roller 8a that performs development by contacting the photosensitive drum 1 while being rotated in the direction of arrow e in the figure, and a toner supply unit that supplies toner to the developing roller 8a by rotating in the direction of f in the figure. , A developing blade 9a as a developer regulating member for regulating the amount of toner applied and the amount of charge on the developing roller 8a, a stirring member 13a for supplying and agitating the toner to the supply roller 12a, and the like.
[0165]
In FIG. 4, when a print output is requested from a personal computer (not shown) or the like, the photosensitive drum 1 rotates and the rotary 22x revolves so as to bring the first color developing cartridge 22a to a position facing the photosensitive drum 1. To start.
[0166]
When the first color (yellow) developing cartridge 22a comes to a position facing the photosensitive drum 1, the developing roller 8a starts pre-preparation rotation. At the same time, a voltage is supplied from a developing bias power supply 19 and a blade bias power supply 20 as voltage applying means under the control of a control unit (control means) 21. At this time, a voltage of about −400 V is applied to the developing roller 8 a from the developing bias power supply 19, and a sawtooth voltage having a peak at −600 V is applied to the developing blade 9 a from the blade bias power supply 20. Two sawtooth-wave voltages applied from the blade bias power supply 20 are applied, and the cycle is applied for 100 msec per wave.
[0167]
During non-image formation, which is a time that does not affect the image on the transfer paper P, a sawtooth voltage having a peak of −600 V is applied to the developing blade 9 a and a −400 V voltage is applied to the developing roller 8 a. That is, a potential difference that can be transferred from the developing blade 9a side to the developing roller 8a side is supplied to the negatively charged particles (toner and external additive). Therefore, the negative external additive adhering to the developing blade 9a immediately after the rotation of the developing roller 8a is transferred to the developing roller 8a side.
[0168]
After a momentary application of -600 V (sawtooth) to the developing blade 9a and -400 V to the developing roller 8a, the voltages of the developing bias power supply 19 and the blade bias power supply 20 become substantially the same potential, -400 V, and the first color Image formation is performed on the image formation area (at the time of image formation).
[0169]
At the time of image formation, the developing roller 8a and the developing blade 9a have substantially the same potential, so that the rotation of the developing roller 8a causes the charge of the toner layer to move the negative polarity from the contact portion of the developing blade 9a to the fixed end. Of the external additive is transferred. However, the reversal toner and the positive external additive do not adhere to the developing blade 9a.
[0170]
When the image formation of the first color is completed, the developing cartridge 22a is rotated after preparation, and at this time, one sawtooth voltage having a peak of -600 V is applied from the blade bias power supply 20. By this operation, the negative external additive attached to the developing blade 9a of the yellow developing cartridge 22a is transferred to the developing roller 8a side during image formation, and the developing blade 9a can be refreshed.
[0171]
The rotation of the developing roller 8a is turned off, and the rotary 22x revolves between formation of the next color (magenta) image. During the revolution of the rotary 22x, the voltage supply from the developing bias power supply 19 and the blade bias power supply 20 is turned off.
[0172]
The revolution of the rotary 22x is completed, and the developing cartridge 22b of the second color (magenta) stops at the position facing the photosensitive drum 1.
[0173]
Then, similarly to the first color (yellow), the developing roller 8b starts rotating before preparation. At the same time, voltages are supplied from the developing bias power supply 19 and the blade bias power supply 20. At this time, a voltage of about −400 V is applied from the developing bias power supply 19, and a sawtooth voltage having a peak of −600 V is applied from the blade bias power supply 20. Two sawtooth-shaped voltages applied from the blade bias power supply 20 are applied, and the cycle is applied for 100 msec per wave. Then, the second color image formation is performed in the same manner as the first color image formation. At the time of image formation, as described above, the negative external additive adheres and accumulates from the contact portion of the developing blade 9b to the free end tip. The above operation is performed up to the fourth color.
[0174]
In this way, by transferring the negative external additive adhered on the developing blade during the previous image formation to the developing roller side during the pre-preparation rotation of each color, the accumulation of the external additive on the developing blade is prevented, and stable. Image forming apparatus can be provided.
[0175]
When the image formation for the fourth color is completed, the rotation starts after the preparation for the fourth color, and a single sawtooth voltage having a peak of -600 V is applied from the blade bias power supply 20 as described above. Thereafter, the rotation of the developing roller 8d is turned off, and the rotary 22x revolves. Before the revolution of the rotary 22x, the voltage supply from the developing bias power supply 19 and the blade bias power supply 20 is turned off.
[0176]
When the image formation is completed and the revolution of the rotary 22x is completed, the intermediate transfer body 24 and the photosensitive drum 1 and the like are rotated after the main body for the next printing, and the photosensitive drum 1 stops when the post-body rotation is completed.
[0177]
Next, as a further example of a full-color image forming apparatus having an intermediate transfer member applied to the image forming apparatus of the present invention, a color image forming apparatus (copier or laser beam printer) using an electrophotographic process is shown in FIG. Shown in
[0178]
The image forming apparatus shown in FIG. 6 includes an organic photoreceptor (hereinafter, referred to as a “photoreceptor”) 51, which is a rotating drum-type electrostatic latent image carrier that is used repeatedly, and a photosensitive member 51 that is disposed in contact with the photoreceptor 51. A primary charger 52 for uniformly charging the body 51; a developing means 54 having four developing devices; an intermediate transfer belt 55 on which the toner image on the photoconductor 51 is transferred; A primary transfer roller 56 for transferring the toner image on the photoreceptor 51 onto the transfer member 55; a secondary transfer roller 57 for transferring the toner image on the intermediate transfer belt 55 to the transfer material P by applying a voltage; A fixing device 65 for fixing the applied toner image by applying heat and pressure, a cleaning device 63 having a cleaning member for removing transfer residual toner remaining on the photoreceptor 51 after transfer, and an intermediate transfer after transfer Cleaning charging member 59 for removing transfer residual toner remaining on the belt 55, and a paper feed roller 61 for transporting the transfer material P to a secondary transfer nip formed by the intermediate transfer belt 55 and the secondary transfer roller 57. And a transfer material guide 60.
[0179]
The photoconductor 51 is driven to rotate at a predetermined peripheral speed (process speed) in a direction indicated by an arrow in the drawing. The primary charger 52 is a rotatable roller having elasticity and conductivity, and is connected to a power supply 82. The developing means 54 is a rotatable roller having four developing devices of a yellow developing device 41, a magenta developing device 42, a cyan developing device 43, and a black developing device 44. Each of the developing devices 41 to 44 has the same configuration as the above-described developing device, and has a developing roller provided outside the developing unit. The developing means 54 is rotatably provided so as to rotate at the time of development and to transport and support any of the developing devices 41 to 44 to a position where the photoconductor 1 and the developing roller are in direct or indirect contact with each other. Have been.
[0180]
The intermediate transfer belt 55 is an endless belt that is rotatably supported by a rotationally driven pulley 58 and a driven pulley 62, and is driven to rotate clockwise with respect to the paper surface at the same peripheral speed as the photosensitive member 51 in the drawing. The primary transfer roller 56 is a conductive rotatable roller, and is connected to a power supply 80. The secondary transfer roller 57 is supported in parallel with the pulley 58, and is provided on the lower surface of the intermediate transfer belt 55 so as to be separated therefrom. Further, the secondary transfer roller 57 is connected to a power supply 81. The fixing device 65 is a heat and pressure fixing device having a heating roller and a pressure roller similarly to the fixing device described above. The cleaning charging member 59 is a rotatable roller composed of, for example, a metal core and a conductive elastic layer formed on a peripheral surface thereof, and is connected to a power supply 83.
[0181]
The photoconductor 51 is uniformly charged to a predetermined polarity and potential by the primary charger 52 during the rotation process. The power supply 82 of the primary charger applies, for example, an alternating current to a direct current, but may apply only a direct current. Next, exposure means (not shown) (a color separation / imaging exposure optical system for a color original image, a scanning exposure system using a laser scanner for outputting a laser beam modulated according to a time-series electric digital pixel signal of image information, etc.) , An electrostatic latent image corresponding to a first color component image (for example, a yellow component image) of a target color image is formed.
[0182]
Next, the electrostatic latent image is developed by the first developing device (yellow color developing device 41) with the yellow toner Y as the first color. At this time, the developing means 54 conveys and supports only the yellow developing device 41 to the developing position facing the photoconductor 51, and the other second to fourth developing devices (the magenta developing device 42 and the cyan developing device 42). The developing device 43 and the black developing device 44) are transported and supported to positions away from the developing position.
[0183]
The first color yellow toner image formed and carried on the photoconductor 51 is applied to the intermediate transfer belt 5 from the primary transfer roller 6 at a nip portion between the photoconductor 51 and the intermediate transfer belt 55. Are primarily transferred to the outer peripheral surface of the intermediate transfer belt 5 sequentially. After the transfer of the first color yellow toner image onto the intermediate transfer belt 55, the surface of the photoconductor 51 is cleaned by the cleaning device 63.
[0184]
Hereinafter, similarly, the magenta toner image of the second color, the cyan toner image of the third color, and the black toner image of the fourth color are sequentially superimposed on the intermediate transfer belt 55 and transferred, and the composite color corresponding to the target color image is transferred. A toner image is formed. A primary transfer bias for sequentially superimposing transfer of the first to fourth color toner images from the photoconductor 51 to the intermediate transfer belt 55 is applied from a bias power supply 80 with a polarity (+) opposite to that of the toner. The applied voltage is, for example, in the range of +100 V to 2 kV.
[0185]
In the primary transfer process of the toner images of the first to third colors from the photoreceptor 51 to the intermediate transfer belt 55, the secondary transfer roller 57 can be separated from the intermediate transfer belt 55.
[0186]
The composite color toner image transferred onto the intermediate transfer belt 55 is transferred onto the transfer material P. For transfer from the intermediate transfer belt 55 to the transfer material P, the secondary transfer roller 57 contacts the intermediate transfer belt 55, while the intermediate transfer belt 55 and the secondary transfer roller The transfer material P is fed to the contact nip with the transfer 57 at a predetermined timing, and a secondary transfer bias is applied to the secondary transfer roller 57 from the power supply 81. With this secondary transfer bias, the composite color toner image is secondarily transferred from the intermediate transfer belt 55 to the transfer material P. The transfer material P to which the toner image has been transferred is introduced into the fixing device 65 and is heated and fixed.
[0187]
After the image transfer to the transfer material P is completed, a cleaning charging member 59 that is freely detachable is brought into contact with the intermediate transfer belt 55, and a bias having a polarity opposite to that of the photoconductor 51 is applied to the transfer material P. The transfer residual toner remaining on the intermediate transfer belt 55 without being transferred to the P is given a charge having a polarity opposite to that of the primary transfer. Note that the bias power supply 83 applies an alternating current to a direct current. The transfer residual toner charged to a polarity opposite to that of the primary transfer is electrostatically transferred to the photoconductor 51 in a nip portion with the photoconductor 51 and in the vicinity thereof, and the intermediate transfer belt 55 is cleaned. Since this step can be performed simultaneously with the primary transfer, a decrease in throughput does not occur.
[0188]
【Example】
Hereinafter, the present invention will be described specifically with reference to Examples and Comparative Examples. In addition, "part" in the following examples and the like is "part by mass".
[0189]
-Preparation of resin particle dispersion 1-
・ Styrene 71 parts by mass
・ N-butyl acrylate 29 parts by mass
・ Acrylic acid 3 parts by mass
・ Divinylbenzene 0.5 parts by mass
・ Dodecanethiol 2 parts by mass
・ Carbon tetrabromide 1 part by mass
1.5 parts by mass of a non-ionic surfactant (Nonipol 400, manufactured by Sanyo Chemical Co., Ltd.) and an anionic surfactant (Neogen SC, manufactured by Dai-ichi Kogyo Seiyaku Co., Ltd.) Ion exchange in which 3.5 parts by mass was dissolved in 140 parts by mass of ion-exchanged water, dispersed in a flask, emulsified, and slowly mixed with 10 parts by mass of ammonium persulfate for 10 minutes. After adding 10 parts by mass of water and purging with nitrogen, the content in the flask was heated in an oil bath until the temperature reached 70 ° C. while stirring, and the emulsion polymerization was continued for 5 hours. Thus, a resin particle dispersion 1 in which resin particles having an average particle size of 0.08 μm were dispersed was prepared.
[0190]
-Preparation of resin particle dispersion liquid 2-
・ Styrene 75 parts by mass
・ N-butyl acrylate 25 parts by mass
・ Acrylic acid 2 parts by mass
1.5 parts by mass of a non-ionic surfactant (Nonipol 400, manufactured by Sanyo Chemical Co., Ltd.) and an anionic surfactant (Neogen SC, manufactured by Dai-ichi Kogyo Seiyaku Co., Ltd.) 2.) An ion exchange solution in which 2.2 parts by mass was dissolved in 120 parts by mass of ion-exchanged water was dispersed and emulsified in a flask, and 1.0 part by mass of ammonium persulfate was dissolved therein while slowly mixing for 10 minutes. After adding 10 parts by mass of water and purging with nitrogen, the content in the flask was heated in an oil bath until the temperature of the flask reached 70 ° C. while stirring, and the emulsion polymerization was continued for 5 hours. A resin particle dispersion liquid 2 was prepared by dispersing resin particles having a size of .29 μm.
[0191]
-Preparation of resin particle dispersion 3-
・ Styrene 70 parts by mass
・ Methyl methacrylate 5 parts by mass
・ N-butyl acrylate 25 parts by mass
・ Acrylic acid 2 parts by mass
1.5 parts by mass of a non-ionic surfactant (Nonipol 400, manufactured by Sanyo Chemical Co., Ltd.) and an anionic surfactant (Neogen SC, manufactured by Dai-ichi Kogyo Seiyaku Co., Ltd.) 1.) 1.5 parts by mass of a solution obtained by dissolving 1.5 parts by mass in 120 parts by mass of ion-exchanged water are dispersed in a flask, emulsified, and slowly mixed for 10 minutes while 1.0 part by mass of ammonium persulfate is dissolved therein. After adding 10 parts by mass of water and purging with nitrogen, the content in the flask was heated in an oil bath until the temperature of the flask reached 70 ° C. while stirring, and the emulsion polymerization was continued for 5 hours. A resin particle dispersion 3 was prepared by dispersing resin particles having a diameter of 0.52 μm.
[0192]
--- Preparation of resin particle dispersion 4--
・ Styrene 76 parts by mass
・ N-butyl acrylate 24 parts by mass
・ Acrylic acid 2 parts by mass
・ Dodecyl mercaptan 1.5 parts by mass
1.5 parts by mass of a non-ionic surfactant (Nonipol 400, manufactured by Sanyo Chemical Co., Ltd.) and an anionic surfactant (Neogen SC, manufactured by Dai-ichi Kogyo Seiyaku Co., Ltd.) 1.) 1.0 part by mass of a solution of 1.0 part by mass in 100 parts by mass of ion-exchanged water was dispersed in a flask, emulsified, and slowly mixed for 10 minutes while 1.0 part by mass of ammonium persulfate was dissolved therein. After adding 10 parts by mass of water and purging with nitrogen, the content in the flask was heated in an oil bath until the temperature of the flask reached 70 ° C. while stirring, and the emulsion polymerization was continued for 5 hours. A resin particle dispersion liquid 4 was prepared by dispersing resin particles of 0.86 μm.
[0193]
--- Preparation of resin particle dispersion 5--
・ Styrene 73 parts by mass
・ N-butyl acrylate 25 parts by mass
・ Divinylbenzene 2 parts by mass
・ Acrylic acid 2 parts by mass
1.5 parts by mass of a non-ionic surfactant (Nonipol 400, manufactured by Sanyo Chemical Co., Ltd.) and an anionic surfactant (Neogen SC, manufactured by Dai-ichi Kogyo Seiyaku Co., Ltd.) In a flask prepared by dissolving 2.2 parts by mass of ion-exchanged water in 120 parts by mass of ion-exchanged water, dispersing in a flask, emulsifying, and slowly mixing for 10 minutes while dissolving 0.7 parts by mass of ammonium persulfate therein. After adding 10 parts by mass of water and purging with nitrogen, the content in the flask was heated in an oil bath until the temperature of the flask reached 70 ° C. while stirring, and the emulsion polymerization was continued for 5 hours. A resin particle dispersion liquid 5 was prepared by dispersing resin particles having a diameter of 0.31 μm.
[0194]
-Preparation of resin particle dispersion 6-
・ Styrene 80 mass parts
・ N-butyl acrylate 20 parts by mass
・ Acrylic acid 3 parts by mass
1.5 parts by mass of a non-ionic surfactant (Nonipol 400, manufactured by Sanyo Chemical Co., Ltd.) and an anionic surfactant (Neogen SC, manufactured by Dai-ichi Kogyo Seiyaku Co., Ltd.) In a flask prepared by dissolving 2.2 parts by mass of 120 parts by mass of ion-exchanged water in a flask, emulsifying, and slowly mixing for 10 minutes, 1.7 parts by mass of ammonium persulfate was dissolved therein. After adding 10 parts by mass of water and purging with nitrogen, the content in the flask was heated in an oil bath until the temperature of the flask reached 70 ° C. while stirring, and the emulsion polymerization was continued for 5 hours. A resin particle dispersion 6 was prepared by dispersing resin particles having a particle size of 0.28 μm.
[0195]
--- Preparation of release agent particle dispersion--
・ Ester wax (melting point 65 ° C) ℃ 50 parts by mass
・ Anionic surfactant 5 parts by mass
(Daiichi Kogyo Seiyaku Co., Ltd .: Neogen SC)
・ Ion exchange water: 200 parts by mass
The above was heated to 95 ° C., dispersed using a homogenizer (Ultra Turrax T50, manufactured by IKA), and then dispersed using a pressure discharge homogenizer to disperse a release agent having an average particle diameter of 0.5 μm. A release agent particle dispersion liquid was prepared.
[0196]
--- Preparation of Colorant Particle Dispersion 1--
・ C. I. Pigment Red 122 20 parts by mass
・ Anionic surfactant 2 parts by mass
(Daiichi Kogyo Seiyaku Co., Ltd .: Neogen SC)
・ Ion-exchanged water: 78 parts by mass
The above components were mixed and dispersed using a sand grinder mill. When the particle size distribution in the colorant particle dispersion 1 was measured using a particle size measuring device (LA-700, manufactured by Horiba, Ltd.), the average particle size of the colorant particles contained was 0.2 μm and 1 μm. Was not observed.
[0197]
--- Preparation of Colorant Particle Dispersion 2--
C. I. Pigment Red 122 is C.I. I. Pigment Blue 15: 3, except that Colorant Particle Dispersion 2 was prepared in the same manner as Colorant Particle Dispersion 1.
[0198]
--- Preparation of colorant particle dispersion 3--
C. I. Pigment Red 122 is C.I. I. Pigment Yellow 17 was prepared in the same manner as Colorant Particle Dispersion 1, except that Pigment Yellow 17 was used.
[0199]
--- Preparation of colorant particle dispersion 4--
C. I. Colorant particle dispersion 4 was prepared in the same manner as colorant particle dispersion 1, except that Pigment Red 122 was changed to carbon black.
[0200]
--- Preparation of charge control particle dispersion--
.A metal compound of di-alkyl-salicylic acid 20 parts by mass
(Charge control agent, Bontron E-84, manufactured by Orient Chemical Industries)
・ Anionic surfactant 2 parts by mass
(Daiichi Kogyo Seiyaku Co., Ltd .: Neogen SC)
・ Ion-exchanged water: 78 parts by mass
The above components were mixed and dispersed using a sand grinder mill. When the particle size distribution of the charge control particle dispersion 1 was measured using a particle size measuring device (LA-700, manufactured by Horiba, Ltd.), the average particle size of the charge control particles contained was 0.2 μm and 1 μm. Was not observed.
[0201]
(Toner Production Example 1)
<Mixed liquid preparation>
・ Resin particle dispersion 2 360 parts by mass
・ Colorant dispersion 1 40 parts by mass
・ Release agent dispersion 70 parts by mass
The above was charged into a 1-liter separable flask equipped with a stirrer, a cooling pipe, and a thermometer and stirred. This mixture was adjusted to pH = 5.2 using 1N-potassium hydroxide.
[0202]
<Aggregated particle formation>
To this mixture, 150 parts by mass of a 10% aqueous sodium chloride solution was dropped as a coagulant, and the mixture was heated to 57 ° C. while stirring the inside of the flask in a heating oil bath. At this temperature, 3 parts by mass of the resin particle dispersion 2 and 10 parts by mass of the charge control agent particle dispersion were added. After maintaining at 50 ° C. for 2 hours, observation with an optical microscope confirmed that aggregated particles having an average particle size of about 6.2 μm were formed.
[0203]
<Fusing process>
Thereafter, 3 parts by mass of an anionic surfactant (manufactured by Daiichi Kogyo Seiyaku Co., Ltd .: Neogen SC) was added thereto, and the stainless steel flask was sealed. Heat and hold for 4 hours. After cooling, the reaction product is filtered, washed sufficiently with ion-exchanged water, dried in a fluidized bed at 45 ° C., and dispersed in a gas phase at 200 to 300 ° C. by a spray drier to adjust the shape. Thus, a magenta toner base 1 was obtained. The value of the BET specific surface area is 50 (m²/ G) of 1.2 parts by mass of a hydrophobic silica having a BET specific surface area of 200 (m²/ G) of hydrophobic silica was externally added to the toner 1 using a Henschel mixer FM10B. Table 1 shows the physical properties of Toner 1.
[0204]
(Toner Production Example 2)
A toner 2 was obtained in the same manner except that the resin particle dispersion 2 at the time of preparing the mixed solution of the toner production example 1 was changed to the resin particle dispersion 3. Table 1 shows the physical properties.
[0205]
(Toner Production Example 3)
A toner 3 was obtained in the same manner except that the resin particle dispersion 2 at the time of preparing the mixed solution of the toner production example 1 was changed to the resin particle dispersion 4.
[0206]
(Toner Production Example 4)
Toner 4 was prepared in the same manner except that the resin particle dispersion 2 at the time of preparing the mixture of the toner production example 1 was changed to the resin particle dispersion 3, and the resin particle dispersion 2 at the time of forming the aggregated particles was changed to the resin particle dispersion 3. Obtained.
[0207]
(Toner Production Example 5)
Toner 5 was obtained in the same manner as in Toner Production Example 1, except that the resin particle dispersion 2 at the time of forming the aggregated particles was changed to the resin particle dispersion 1.
[0208]
(Toner Production Example 6)
A toner 6 was obtained in the same manner except that the resin particle dispersion 2 used in preparing the mixed liquid in Toner Production Example 1 was changed to the resin particle dispersion 5. Table 1 shows the physical properties.
[0209]
(Toner Production Example 7)
A toner 7 was obtained in the same manner except that the resin particle dispersion liquid 2 in preparing the mixed liquid of the toner production example 1 was changed to the resin particle dispersion liquid 6. Table 1 shows the physical properties.
[0210]
(Toner Production Example 8)
Toner 8 was obtained in the same manner except that the hydrophobic silica of Toner Production Example 1 was changed to 4.4 parts by mass of hydrophobic silica (8.8 parts by mass in total).
[0211]
(Toner Production Example 9)
Toner 9 was obtained in the same manner as in toner production example 1, except that the hydrophobic silica was changed to 0.7 parts by mass of hydrophobic silica (total of 1.4 parts by mass).
[0212]
(Toner Production Example 10)
Toner 10 was obtained in the same manner as in Toner Production Example 1, except that 70 parts by mass was used instead of 150 parts by mass of the 10% aqueous sodium chloride solution at the time of forming the aggregated particles. Table 1 shows the physical properties.
[0213]
(Toner Production Example 11)
Toner 11 was obtained in the same manner as in Toner Production Example 2, except that 150 parts by mass of the 10% aqueous sodium chloride solution at the time of forming the aggregated particles was changed to 200 parts by mass. Table 1 shows the physical properties.
[0214]
(Toner Production Example 12)
Toner 12 was prepared in the same manner except that the resin particle dispersion 2 at the time of preparing the mixture of the toner production example 1 was changed to the resin particle dispersion 4, and the resin particle dispersion 2 at the time of forming the aggregated particles was changed to the resin particle dispersion 1. Obtained.
[0215]
(Toner Production Example 13)
Toner 13 was prepared in the same manner except that the resin particle dispersion 2 at the time of preparing the mixture of the toner production example 1 was changed to the resin particle dispersion 1, and the resin particle dispersion 2 at the time of forming the aggregated particles was changed to the resin particle dispersion 1. Obtained.
[0216]
(Toner Production Example 14)
The toner 14 was prepared in the same manner except that the resin particle dispersion 2 at the time of preparing the mixture of the toner production example 1 was changed to the resin particle dispersion 4, and the resin particle dispersion 2 at the time of forming the aggregated particles was changed to the resin particle dispersion 4. Obtained.
[0219]
(Toner Production Example 15)
All of the hydrophobic silicas of toner production example 1 had a BET specific surface area of 50 (m²/ G) of hydrophobic silica (total 2.4 parts by mass), to obtain toner 15.
[0218]
(Toner Production Example 16)
The hydrophobic silica of Toner Production Example 1 had a BET specific surface area of 200 (m²/ G) of hydrophobic silica (2.4 parts by mass in total) to obtain toner 16.
[0219]
For each evaluation item, regarding filming, images after continuous printing of 1000 sheets were evaluated, and 100 cm²If the number of crests per filming is less than 0.5, it is ranked as A, from 0.5 to less than 1.5, B, from 1.5 to less than 3, C and from 3 to D. . Regarding fog, images after continuous printing of 10,000 sheets were evaluated. If fog was less than 1%, A was evaluated. If fog was less than 3%, B was evaluated. Ranked. Incidentally, the value of fog was measured by measuring the reflected light on a solid white image with a reflectometer (manufactured by Tokyo Denshoku Co., Ltd.) and evaluating the difference from the blank. With regard to roughness, four-stage ABCD visual judgment was made based on whether two colors of a solid image were overlaid and the background color was visible. A was a case where no roughness was visible, B was a case where a slight roughness was seen but the background color was not visible, C was a case where the background was slightly visible, and D was a case where the background color was completely visible. Regarding the vertical streaks derived from the blade fusion, if the vertical streaks are less than one per 10 cm width, A, if it is one or more and less than three, B, if it is three or more and five or less, C, five or more If any, it was D. Concerning the cleaning performance, a solid image of yellow was formed on the next image obtained by superimposing the solid image in two colors (magenta when yellow was evaluated), and the number of vertical stripes was one per 10 cm width. If it is less than A, it is B if it is 1 or more and less than 3, C if it is 3 or more and 5 or less, and D if it is 5 or more. The transferability was measured by using a tape to collect the transfer residual toner on the drum immediately after the solid image was transferred from the drum, and measuring the reflected light of the tape with a reflectometer (manufactured by Tokyo Denshoku Co., Ltd.). %, A was ranked from 1% to less than 3%, B was ranked from 3% to less than 5%, and D was ranked from 5% to 5%.
[0220]
<Example 1>
Using the printer shown in FIG. 6, 150 g of the toner 1 was filled in the cartridge shown in FIG. 5, and a test of continuous printing of 10,000 sheets at a printing ratio of 2% was performed. At that time, the yellow toner used was the toner 1 in which the colorant particle dispersion 1 was replaced by the colorant particle dispersion 3, the cyan toner was replaced by the colorant particle dispersion 2, and the black toner was the colorant particle dispersion. 4 was prepared in the same manner as magenta toner 1, and evaluated at the same time. Hereinafter, four colors were similarly prepared for toner 2 and thereafter, and the simultaneous evaluation was performed. In each test, a solid black pattern, a solid white pattern, a two-color solid image superimposed pattern, and a halftone image were printed as a sample on the initial and 1000th and 10,000th sheets, and the image and transfer residue on the drum at that time were printed. The toner was also confirmed.
[0221]
Regarding severe streaking and severe leakage, a blade bias was applied using the printer shown in FIG. 3, 150 g of toner was filled in the process cartridge shown in FIG. 5, and this cartridge was placed in a 50 ° C. gear oven. After storage for 20 days, a test of 2,000 continuous prints was performed under an environment of 20 ° C. and 40% at a print ratio of 2%. In the evaluation, a solid black pattern, a solid white pattern, and a halftone image were printed as samples on the initial and 2000th sheets, and the image at that time and the toner leakage amount (for four colors) after printing 2000 sheets were also confirmed. Severe streaks are evaluated in the same manner as vertical streaks. Regarding the amount of severe leakage, A for 50 mg or less in all four colors, B for 50 to 200 mg or less, C for 200 to 500 mg or less, 500 mg or less When there was much, it was evaluated as D.
[0222]
Table 2 shows the configuration at that time, and Table 3 shows the results.
[0223]
<Example 2>
Evaluation was performed in the same manner as in Example 1 except that the toner was changed to 2. Table 2 shows the configuration, and Table 3 shows the results.
[0224]
<Example 3>
Evaluation was performed in the same manner as in Example 1 except that the toner was changed to 3. Table 2 shows the configuration, and Table 3 shows the results.
[0225]
<Example 4>
Evaluation was performed in the same manner as in Example 1 except that the toner was changed to 4. Table 2 shows the configuration, and Table 3 shows the results.
[0226]
<Example 5>
Evaluation was performed in the same manner as in Example 1 except that the toner was changed to 5. Table 2 shows the configuration, and Table 3 shows the results.
[0227]
<Example 6>
Evaluation was performed in the same manner as in Example 1 except that the toner was changed to 6. Table 2 shows the configuration, and Table 3 shows the results.
[0228]
<Example 7>
Evaluation was performed in the same manner as in Example 1 except that the toner was set to 7. Table 2 shows the configuration, and Table 3 shows the results.
[0229]
<Example 8>
Evaluation was performed in the same manner as in Example 1 except that the toner was changed to 8. Table 2 shows the configuration, and Table 3 shows the results.
[0230]
<Example 9>
Evaluation was performed in the same manner as in Example 1 except that the toner was changed to 9. Table 2 shows the configuration, and Table 3 shows the results.
[0231]
<Example 10>
Evaluation was performed in the same manner as in Example 1 except that the blade had an Rz of 2.7 (μm). Table 2 shows the configuration, and Table 3 shows the results.
[0232]
<Example 11>
Evaluation was performed in the same manner as in Example 1 except that the blade had an Rz of 5.5 (μm). Table 2 shows the configuration, and Table 3 shows the results.
[0233]
<Example 12>
Evaluation was performed in the same manner as in Example 1 except that the Asker C hardness of the developing roller was 70 °. Table 2 shows the configuration, and Table 3 shows the results.
[0234]
<Example 13>
Evaluation was performed in the same manner as in Example 1 except that the developing roller had an Rz of 12 (μm). Table 2 shows the configuration, and Table 3 shows the results.
[0235]
<Example 14>
The evaluation was performed in the same manner as in Example 1 except that the arithmetic average roughness Ra of the developing roller was 1.5 (μm). Table 2 shows the configuration, and Table 3 shows the results.
[0236]
<Example 15>
Evaluation was performed in the same manner as in Example 1 except that the Asker C hardness of the developing roller was 95 °. Table 2 shows the configuration, and Table 3 shows the results.
[0237]
<Example 16>
The evaluation was performed in the same manner as in Example 1 except that the Asker C hardness of the developing roller was 25 °. Table 2 shows the configuration, and Table 3 shows the results.
[0238]
<Example 17>
Evaluation was performed in the same manner as in Example 1 except that the developing roller had an Rz of 4 (μm). Table 2 shows the configuration, and Table 3 shows the results.
[0239]
<Example 18>
The evaluation was performed in the same manner as in Example 1 except that the developing roller had an Rz of 17 (μm). Table 2 shows the configuration, and Table 3 shows the results.
[0240]
<Example 19>
Evaluation was performed in the same manner as in Example 1 except that the arithmetic average roughness Ra of the developing roller was 0.4 (μm). Table 2 shows the configuration, and Table 3 shows the results.
[0241]
<Example 20>
The evaluation was performed in the same manner as in Example 1 except that the arithmetic average roughness Ra of the developing roller was 1.8 (μm). Table 2 shows the configuration, and Table 3 shows the results.
[0242]
<Comparative Example 1>
Evaluation was performed in the same manner as in Example 1 except that the toner 1 was changed to the toner 10. Table 2 shows the configuration, and Table 3 shows the results.
[0243]
<Comparative Example 2>
Evaluation was performed in the same manner as in Example 1 except that the toner 1 was changed to the toner 11. Table 2 shows the configuration, and Table 3 shows the results.
[0244]
<Comparative Example 3>
Evaluation was performed in the same manner as in Example 1 except that the toner 1 was changed to the toner 12. Table 2 shows the configuration, and Table 3 shows the results.
[0245]
<Comparative Example 4>
Evaluation was performed in the same manner as in Example 1 except that the toner 1 was changed to the toner 13. Table 2 shows the configuration, and Table 3 shows the results.
[0246]
<Comparative Example 5>
Evaluation was performed in the same manner as in Example 1 except that the toner 1 was changed to the toner 14. Table 2 shows the configuration, and Table 3 shows the results.
[0247]
<Comparative Example 6>
Evaluation was performed in the same manner as in Example 1 except that the toner 1 was changed to the toner 15. Table 2 shows the configuration, and Table 3 shows the results.
[0248]
<Comparative Example 7>
Evaluation was performed in the same manner as in Example 1 except that toner 16 was used instead of toner 1. Table 2 shows the configuration, and Table 3 shows the results.
[0249]
<Comparative Example 8>
Evaluation was performed in the same manner as in Example 1 except that toner 1 was used as toner 8 and ten-point average roughness Rz of the blade was set to 5.8 (μm). Table 2 shows the configuration, and Table 3 shows the results.
[0250]
<Comparative Example 9>
Evaluation was performed in the same manner as in Example 1 except that toner 1 was used as toner 8 and the Asker C hardness of the developing roller was 96 °. Table 2 shows the configuration, and Table 3 shows the results.
[0251]
<Comparative Example 10>
The evaluation was performed in the same manner as in Example 1 except that the toner 1 was used as the toner 8 and the ten-point average roughness Rz of the developing roller was 18 (μm). Table 2 shows the configuration, and Table 3 shows the results.
[0252]
<Comparative Example 11>
Evaluation was made in the same manner as in Example 1 except that toner 1 was used as toner 8 and arithmetic mean roughness Ra of the developing roller was 1.7 (μm). Table 2 shows the configuration, and Table 3 shows the results.
[0253]
<Comparative Example 12>
The toner 1 was used as the toner 8, the ten-point average roughness Rz of the blade was 5.7 (μm), the Asker C hardness of the developing roller was 97 °, the Rz of the developing roller was 17 (μm), and the arithmetic average roughness of the developing roller. Evaluation was performed in the same manner as in Example 1 except that Ra was 1.8 (μm). Table 2 shows the configuration, and Table 3 shows the results.
[0254]
[Table 1]

[0255]
[Table 2]

[0256]
[Table 3]

[0257]
【The invention's effect】
According to the present invention, by defining the SF-1, the circularity, and the BET specific surface area of the toner within the above ranges, it is possible to achieve both the cleaning property and the transfer property, which are difficult with the spherical toner by the suspension polymerization method or the toner by the pulverization method. However, the charging property can be further stabilized. This makes it possible to use the intermediate transfer member which is strict in transferability and cleaning performance and more suitably in a color machine with a single drum. Also, by adjusting the roughness of the blade and the roughness of the developing roller in the developing unit and the process cartridge of this configuration, the toner of the present invention can be used without problem even in an area where fogging due to toner deterioration and vertical streaks due to blade fusion normally occur. To facilitate the charging and the improvement of image quality. Further, by regulating the hardness of the developing roller, it is very effective to maintain the above-mentioned optimum conditions in balance and maintain it for a long period of time. Further, these configurations can be made to function more effectively by adjusting the circularity, molecular weight, and external additive amount of the toner. Further, by adjusting the blade bias on the machine body side, it has become possible to use the device under severe conditions that are not normally used without any problem.
[Brief description of the drawings]
FIG. 1 is a diagram illustrating a sequence according to an image forming apparatus of the present invention.
FIG. 2 is a diagram illustrating an example of the image forming apparatus of the present invention.
FIG. 3 is a diagram illustrating another example of the image forming apparatus of the present invention.
FIG. 4 is a diagram showing a sequence according to the image forming apparatus of the present invention.
FIG. 5 is a configuration diagram of a developing cartridge.
FIG. 6 is a diagram illustrating another example of the image forming apparatus of the present invention.
[Explanation of symbols]
1 Photosensitive drum (image carrier)
2 charging roller
3 Exposure device
4 Developer (developing means)
5 transfer roller
6 Cleaning means
7 Fixing unit
8, 8a, 8b, 8c, 8d developing roller (developer carrier)
9, 9a, 9b, 9c, 9d Developing blade (developer regulating member)
10 ° developing bias power supply (voltage applying means)
11 blade bias power supply (voltage applying means)
12, 12a, 12b, 12c, 12d supply roller
13, 13a, 13b, 13c, 13d Stirring member
14 control circuit (control means)
15 motor
16 intermediate transfer body cleaning device
17 transfer roller
18 transfer belt
19 ° developing bias power supply (voltage applying means)
20 ° blade bias power supply (voltage applying means)
21 Control unit (control means)
22 developer
22a, 22b, 22c, 22d Developing cartridge (developing means)
22x @ rotary
23 motor
24 intermediate transfer member
P transfer paper

Claims (35)

An electrostatic latent image carrier that carries an electrostatic latent image, and a developing device that develops an electrostatic latent image by transferring a developer to the electrostatic latent image carried by the electrostatic latent image carrier; At least during development, a developer carrier that carries the developer on the surface and directly or indirectly contacts the surface of the electrostatic latent image carrier, and a developer carrier that directly or indirectly contacts the developer carrier. A developer used in a developing device having a layer thickness regulating member that regulates the layer thickness of the developer layer on the body,
The developer has a volume average particle size of 4 to 10 μm, a shape factor SF-1 of 115 to 140, an average circularity of 0.950 to 0.990, and a BET specific surface area of 2.0 to 7.0 m ² /. g, a non-magnetic one-component developer for color. 2. The non-magnetic one-component developer according to claim 1, wherein the ten-point average roughness Rz of the layer thickness regulating member is 0.1 to 5.0 [mu] m. The developer carrier has a Asker C hardness of 30 ° to 90 °, a ten-point average roughness Rz of 5 to 15 μm, and an arithmetic average roughness Ra of 0.5 to 1.5 μm. The non-magnetic one-component developer according to claim 1. The developer carrier has a Asker C hardness of 30 ° to 60 °, a ten-point average roughness Rz of 5 to 10 μm, and an arithmetic average roughness Ra of 0.7 to 1.3 μm. The non-magnetic one-component developer according to claim 1, wherein The non-magnetic one-component developer according to any one of claims 1 to 4, wherein the developer has an average circularity of 0.955 to 0.980. 6. The image forming apparatus according to claim 1, wherein the image forming apparatus is a full-color compatible apparatus having an intermediate transfer member, and the number of the electrostatic latent image carrier is one per apparatus. Non-magnetic one-component developer. 7. The non-magnetic one-component developer according to claim 1, wherein the weight average molecular weight Mw of the developer is from 40,000 to 120,000. The non-magnetic one-component developer according to any one of claims 1 to 7, wherein the amount of silica in the external additive used in the developer is 2 to 8 parts by mass in total toner mass ratio. At the time of image formation, the developer carrying member and the developer regulating member are set at substantially the same potential, and the developing is carried out at least in part during non-image forming while the developer carrying member is rotating and no image is formed. 9. The method according to claim 1, wherein the bias is controlled so that the developer regulating member generates a larger potential difference on the same side as the charged polarity of the developer as compared with the developer carrier. Non-magnetic one-component developer. An electrostatic latent image carrier that carries an electrostatic latent image, and a developing device that develops an electrostatic latent image by transferring a developer to the electrostatic latent image carried by the electrostatic latent image carrier; At least during development, a developer carrier that carries the developer on the surface and directly or indirectly contacts the surface of the electrostatic latent image carrier, and a developer carrier that directly or indirectly contacts the developer carrier. A process cartridge having a layer thickness regulating member for regulating the layer thickness of the developer layer on the body,
The developer has a volume average particle size of 4 to 10 μm, a shape factor SF-1 of 115 to 140, an average circularity of 0.950 to 0.990, and a BET specific surface area of 2.0 to 7.0 m ² /. a non-magnetic one-component developer for a color g. The process cartridge according to claim 10, wherein the ten-point average roughness Rz of the layer thickness regulating member is 0.1 to 5.0 μm. The developer carrier has a Asker C hardness of 30 ° to 90 °, a ten-point average roughness Rz of 5 to 15 μm, and an arithmetic average roughness Ra of 0.5 to 1.5 μm. The process cartridge according to claim 10, wherein: The developer carrier has a Asker C hardness of 30 ° to 60 °, a ten-point average roughness Rz of 5 to 10 μm, and an arithmetic average roughness Ra of 0.7 to 1.3 μm. The process cartridge according to claim 10, wherein 14. The process cartridge according to claim 10, wherein the developer has an average circularity of 0.955 to 0.980. 15. The process cartridge according to claim 10, wherein the developer has a weight average molecular weight Mw of 40,000 to 120,000. 16. The process cartridge according to claim 10, wherein the amount of silica in the external additive used in the developer is 2 to 8 parts by mass in total toner mass ratio. At the time of image formation, the developer carrying member and the developer regulating member are set at substantially the same potential, and the developing is carried out at least in part during non-image forming while the developer carrying member is rotating and no image is formed. 17. The method according to claim 10, wherein the bias is controlled such that the developer regulating member generates a larger potential difference on the same side as the charged polarity of the developer as compared with the developer carrier. Process cartridge. In a developing unit using a developing device having a developer carrier and a layer thickness regulating member that directly or indirectly contacts the developer carrier and regulates the layer thickness of the developer layer on the developer carrier, The developer has a volume average particle diameter of 4 to 10 μm, a shape factor SF-1 of 115 to 140, an average circularity of 0.950 to 0.990, and a BET specific surface area of 2.0 to 7.0 m ² / g. A non-magnetic one-component developer for color is used. 19. The developing unit according to claim 18, wherein the ten-point average roughness Rz of the layer thickness regulating member is 0.1 to 5.0 [mu] m. The developer carrier has a Asker C hardness of 30 ° to 90 °, a ten-point average roughness Rz of 5 to 15 μm, and an arithmetic average roughness Ra of 0.5 to 1.5 μm. 20. The developing unit according to claim 18, wherein The developer carrier has a Asker C hardness of 30 ° to 60 °, a ten-point average roughness Rz of 5 to 10 μm, and an arithmetic average roughness Ra of 0.7 to 1.3 μm. The developing unit according to claim 18, wherein: 22. The developing unit according to claim 18, wherein the average circularity of the developer is 0.955 to 0.980. 23. The image forming apparatus according to claim 18, wherein the image forming apparatus is a full-color compatible apparatus having an intermediate transfer body, and the number of the electrostatic latent image carrier is one per apparatus. Development unit. 24. The developing unit according to claim 18, wherein the developer has a weight average molecular weight Mw of 40,000 to 120,000. The developing unit according to any one of claims 18 to 24, wherein the amount of silica in the external additive used in the developer is 2 to 8 parts by mass in total toner mass ratio. At the time of image formation, the developer carrying member and the developer regulating member are set at substantially the same potential, and the developing is carried out at least in part during non-image forming while the developer carrying member is rotating and no image is formed. 26. The method according to claim 18, wherein the bias is controlled so that the developer regulating member generates a larger potential difference on the same side as the charged polarity of the developer as compared with the developer carrier. Development unit. An electrostatic latent image carrier that carries an electrostatic latent image, and a developing device that develops an electrostatic latent image by transferring a developer to the electrostatic latent image carried by the electrostatic latent image carrier; At least during development, a developer carrier that carries the developer on the surface and directly or indirectly contacts the surface of the electrostatic latent image carrier, and a developer carrier that directly or indirectly contacts the developer carrier. In an image forming method using a developing device having a layer thickness regulating member that regulates the layer thickness of the developer layer on the body,
The developer has a volume average particle size of 4 to 10 μm, a shape factor SF-1 of 115 to 140, an average circularity of 0.950 to 0.990, and a BET specific surface area of 2.0 to 7.0 m ² /. An image forming method, wherein a non-magnetic one-component developer for color, which is g, is used. 28. The image forming method according to claim 27, wherein the ten-point average roughness Rz of the layer thickness regulating member is 0.1 to 5.0 [mu] m. 28. The developer carrier having a Asker C hardness of 30 to 90 degrees, a ten-point average roughness Rz of 5 to 15 [mu] m, and Ra = 0.5 to 1.5 [mu] m. Or the image forming method according to 28. The developer carrier has a Asker C hardness of 30 ° to 60 °, a ten-point average roughness Rz of 5 to 10 μm, and an arithmetic average roughness Ra of 0.7 to 1.3 μm. 30. The image forming method according to claim 27 or 29. 31. The image forming method according to claim 27, wherein the average circularity of the developer is 0.955 to 0.980. 32. The image forming apparatus according to claim 27, wherein the image forming apparatus is a full-color compatible apparatus having an intermediate transfer body, and the number of the electrostatic latent image carrier is one per apparatus. Image forming method. 33. The image forming method according to claim 27, wherein the developer has a weight average molecular weight Mw of 40000 to 120,000. The image forming method according to any one of claims 27 to 33, wherein the amount of silica in the external additive used in the developer is 2 to 8 parts by mass in total toner mass ratio. At the time of image formation, the developer carrying member and the developer regulating member are set at substantially the same potential, and the developing is carried out at least in part during non-image forming while the developer carrying member is rotating and no image is formed. 35. The method according to claim 27, wherein the bias is controlled so that the developer regulating member generates a larger potential difference on the same polarity side as the charged polarity of the developer as compared with the developer carrier. Image forming method.

Images