JP2004258053A - Toner and process cartridge - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide toner that prevents inversion fogging and prevents image void, in a process cartridge of a contact one-component developing system using a developer carrier and a latent image carrier. <P>SOLUTION: A drum unit includes a latent image carrier 1, a charged member 2, and a cleaning member 5. A toner unit includes toner t, a developing container 20 storing the toner, a toner conveying means 14, a toner carrier 11 being in contact with the latent image carrier, a toner regulating member 13, and a toner supply roller 12. The drum unit and the toner unit are integrated. The diameter of the latent image carrier and the diameter of the toner carrier are determined and a ratio of the revolving speed of the toner supply roller and the revolving speed of the toner conveying member are determined. A relationship between an amount of coating of toner on the toner carrier, Amg/cm<SP>2</SP>, and a rate at which toner is filled in the toner storage container, Bg/cm<SP>3</SP>, satisfies the condition expressed by 0.9B≤A≤3B. The toner comprises a binding resin, a coloring agent, and wax. The absolute value of triboelectricity is 40mC/kg or more, and the temperature gradient of the contact angle of the toner is 1.03 to 1.3. <P>COPYRIGHT: (C)2004,JPO&NCIPI

Description

【０１２０】
【表２】

【０１２１】
【発明の効果】
以上説明したように、本発明によって、小径の現像剤担持体と小径の潜像担持体を用いた接触一成分現像方式を採用したプロセスカートリッジにおいて、昇温により悪化する反転カブリを防ぎ、昇温によるトナーの流動性悪化が引き起こす画像白抜けを改善するトナーおよびプロセスカートリッジを得ることができた。
【図面の簡単な説明】
【図１】本発明のプロセスカートリッジの概略図である。
【図２】本発明のプロセスカートリッジが適用できるプリンターの概略図である。
【図３】本発明におけるトリボの測定装置の概略図である。
【符号の説明】
１ 潜像担持体
２ 帯電ローラー
４ 転写ローラー
５ クリーニング部材
７ 定着装置
１１ トナー担持体
１２ トナー供給ローラー
１３ 規制部材
２０ 現像装置（現像容器）
ｔ トナー
Ｐ 転写材[0001]
TECHNICAL FIELD OF THE INVENTION
The present invention relates to a toner used in a recording method using an electrophotographic method, an electrostatic recording method, and the like, and a process cartridge. More specifically, the present invention relates to a toner and a process cartridge used in a copying machine, a printer, a facsimile, which form a toner image on a latent electrostatic image carrier in advance and then transfer the image onto a transfer material to form an image.
[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. Particularly, in a printer or a facsimile, since a copying apparatus needs to be small, a process cartridge in which a toner unit centering on a developing device and a drum unit centering on a photoconductor are often used is often used.
[0003]
As a developing method used for a process cartridge, a one-component developing method is often used. In the one-component developing method, a charge is applied to the toner particles by friction between the toner regulating member and the toner particles and friction between the toner carrier and the toner particles. This is a method in which the electrostatic latent image on the latent image carrier is conveyed to a development area opposed thereto, and is developed into a toner image.
[0004]
Unlike the two-component development method, the one-component development method does not require carrier particles such as glass beads, iron powder, and ferrite, so that the development 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 required amount of toner is required, which results in 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.
[0005]
In general, in a non-magnetic one-component developing method, toner is supplied onto a toner carrier by an elastic roller in contact with the toner carrier, and then the toner is thinly applied onto the toner carrier by a toner regulating member, and simultaneously the toner is regulated. Charge is applied to the toner particles by friction with the member and friction with the toner carrier.
[0006]
However, it has been found that in such a developing system, the temperature around these members and the developing device rises due to frictional heat between the toner carrier and the toner supply roller and the toner regulating member that is in contact with the toner carrier.
[0007]
Further, while reducing the diameter of the developer carrying member makes it more advantageous to reduce the size of the developing device, it is necessary to rotate the developer carrying member at a high speed in order to obtain the same number of prints per unit time. Will be more severe.
[0008]
Further, in the contact developing method in which the latent image carrier and the developer carrier are brought into contact, heat is generated due to the friction between the latent image carrier and the developer carrier, and severe.
[0009]
On the other hand, also around the latent image carrier, the friction due to the contact of the charging member and the cleaning member becomes more severe in a small-diameter drum (latent image carrier) for downsizing the drum unit, and heat generation becomes a problem.
[0010]
Further, in the process cartridge, since the toner unit and the drum unit are integrated, the heat generated from each unit is more likely to stay for the above-described reason, compared to the case where the toner unit and the drum unit are formed of separate cartridges, It has been found that the temperature rise is worse.
[0011]
Due to this heat generation, the temperature of the developing area becomes high, causing a problem that the polarity of the charge is opposite to that of the desired charge, that is, a reversal toner is generated and fogging occurs. Further, it has been confirmed that since the toner contained in the container is exposed to a high temperature for a long period of time, problems such as deterioration of the fluidity of the toner, deterioration of the toner transportability, and occurrence of white spots on the image occur.
[0012]
Until now, for example, Patent Document 1 and the like have proposed a process cartridge, but none of them has described the problem caused by heat generation as described above.
[0013]
[Patent Document 1]
JP 2001-117470 A
[0014]
[Problems to be solved by the invention]
SUMMARY OF THE INVENTION An object of the present invention is to provide a process cartridge adopting a contact one-component developing system using a small-diameter developer carrier and a small-diameter latent image carrier to prevent reversal fog, which is deteriorated by temperature rise, and to prevent toner flow by temperature rise. An object of the present invention is to provide a toner and a process cartridge that improve image white spots caused by deterioration in image quality.
[0015]
[Means for Solving the Problems]
The above object is achieved by the present invention described below. That is, the present invention provides a drum unit including at least a latent image carrier; a charging member that contacts and charges the latent image carrier; a cleaning member that removes and collects transfer residual toner on the latent image carrier; At least a toner; a developing container for containing the toner; a toner conveying means which rotates about a fixed shaft in the developing container to stir and convey the toner; a toner carrier in contact with the latent image carrier; A toner unit consisting of a toner regulating member in contact with the carrier via toner; a toner supply roller for supplying toner to the toner carrier; and a latent image carrier having a diameter of 33 mm or less. The diameter of the toner carrier is 20 mm or less, and the ratio of the number of rotations of the toner conveying member to the number of rotations of the toner supply roller is 0.1 or more and 0.5 or less. Bar coating amount Amg / cm ² And the toner filling rate Bg / cm in the toner container. ³ Is a toner used in a process cartridge satisfying the relationship of 0.9B ≦ A ≦ 3B, comprising at least a binder resin, a colorant, and a wax, having an absolute value of tribo of 40 mC / kg or more, and a contact angle of toner. This is achieved by a toner characterized in that the temperature gradient is 1.03 or more and 1.3 or less.
[0016]
Further, the above object is achieved by the present invention described below. That is, in a process cartridge detachably mounted to the image forming apparatus main body, at least a latent image carrier; a charging member that contacts and charges the latent image carrier; and a transfer residual toner on the latent image carrier. A drum unit comprising: a cleaning member for removing and collecting; and at least toner; a developing container for containing the toner; a toner conveying means for rotating around a fixed shaft in the developing container to stir and convey the toner; A process cartridge in which a toner unit comprising: a toner carrier in contact with the carrier; a toner regulating member in contact with the toner carrier via toner; a toner supply roller for supplying toner to the toner carrier; And
The latent image carrier has a diameter of 33 mm or less, the toner carrier has a diameter of 20 mm or less, and the ratio of the number of revolutions of the toner conveying means to the number of revolutions of the toner supply roller is 0.1 or more and 0.5 or less. Toner coating amount on carrier Amg / cm ² And the toner filling rate Bg / cm in the developing container. ³ Is 0.9B ≦ A ≦ 3B,
The toner comprises at least a binder resin, a colorant, and a wax, and has an absolute value of tribo of 40 mC / kg or more and a temperature gradient of a contact angle of 1.03 to 1.3. This is achieved by a process cartridge.
[0017]
BEST MODE FOR CARRYING OUT THE INVENTION
As a result of the inventor's intensive studies, at least the latent image carrier; a charging member that contacts and charges the latent image carrier; a cleaning member that removes and collects transfer residual toner on the latent image carrier; And a toner container for containing the toner; a toner conveying means which rotates about a fixed shaft in the developing container to agitate and convey the toner; and a toner in contact with the latent image carrier A toner regulating member contacting the toner carrier via the toner; a toner supply roller for supplying toner to the toner carrier; 33 mm or less, the diameter of the toner carrier is 20 mm or less, and the ratio of the number of rotations of the toner conveying means to the number of rotations of the toner supply roller is 0.1 or more and 0.5 or less. Toner coat amount Amg / cm on the lifting body ² And the toner filling rate Bg / cm in the toner container. ³ A process cartridge satisfying the relationship of 0.9B ≦ A ≦ 3B is made of at least a binder resin, a colorant, and a wax, has an absolute value of tribo of 40 mC / kg or more, and has a temperature gradient of a contact angle of toner of 1.03. It has been found that by using a toner characterized by the above 1.3 or less, it is possible to prevent reversal fog, which is deteriorated by a rise in temperature, and to improve image white spots caused by deterioration in fluidity of the toner due to a rise in temperature.
[0018]
The details will be described below.
[0019]
In the process cartridge used in the present invention, the diameter of the latent image carrier is preferably 33 mm or less, and the diameter of the toner carrier is preferably 20 mm or less in order to reduce the size of the process cartridge.
[0020]
However, as described above, reducing the diameter of the latent image carrier and the toner carrier has a problem of heat generation in the cartridge, particularly in a process cartridge in which the toner unit and the drum unit are integrated, and this causes the development area to become high temperature and A problem arises in that a reversal toner having a polarity opposite to that of the toner is generated and fogging occurs.
[0021]
As a result of extensive studies by the present inventors, as a cause of the fogging, the toner is exposed to a high temperature, so that the wax added to the toner as an anti-offset agent oozes out on the toner surface and inhibits the chargeability of the toner. It has been found that the temperature gradient of the contact angle of the toner is 1.03 or more and 1.3 or less, and more preferably 1.05 or more and 1.25 or less.
[0022]
Here, the “temperature gradient of the contact angle” is a value (θ2 / θ1) of the contact angle θ1 of the toner at 23 ° C. and the contact angle θ2 of the toner left at 100 ° C. for 2 minutes.
[0023]
When the temperature gradient of the contact angle exceeds 1.3, the toner surface changes greatly due to the exudation of the wax when exposed to a high temperature, and this is not preferable because inverted toner is generated. If the temperature gradient of the contact angle is less than 1.03, the effect of preventing offset at the time of fixing cannot be obtained, which is not preferable.
[0024]
The method for measuring the contact angle is as follows. Toner is 3g toner at 250kN / cm by tableting machine ² To obtain a sample having a diameter of 38 mm. At the time of molding, NP-Transparency TYPE-D was sandwiched between the molding machine and the toner. The sample was left at 23 ° C. and 100 ° C. for 2 minutes, then returned to room temperature, and the contact angle with water was measured with a roll material contact angle meter CA-X roll type (manufactured by Kyowa Interface Chemical Co., Ltd.). The measurement was performed 20 times per sample, and the average value of 18 measured values excluding the maximum value and the minimum value was obtained.
[0025]
In order to make the temperature gradient of the contact angle of the toner 1.03 or more and 1.3 or less, it is preferable that the wax content in the toner be 1% by mass or more and 10% by mass or less.
[0026]
Further, in the present invention, the absolute value of the toner tribo is preferably 40 mC / kg or more, more preferably 45 mC / kg or more and 65 mC / kg or less. If the absolute value of tribo is less than 40 mC / kg, it is not preferable because reversal toner is easily generated.
[0027]
The method of measuring the tribo is as follows. Under the environment of 23 ° C. and a relative humidity of 60%, using a DSP 138 (manufactured by Dowa Iron Powder Co., Ltd.) as a carrier, a mixture obtained by adding 0.5 g of toner to 9.5 g of carrier is placed in a polyethylene bottle having a capacity of 50 to 100 ml 50 times. Shake by hand. Next, 1.0 to 1.2 g of the mixture is placed in a metal measuring container 22 having a 500-mesh screen 23 at the bottom shown in FIG. At this time, the mass of the entire measurement container 22 is weighed and is defined as W1 g. Next, in a suction machine (at least a portion in contact with the measurement container 22 is at least an insulator), the air is suctioned from the suction port 27 and the air volume control valve 26 is adjusted to adjust the pressure of the vacuum gauge 25 to 250 mmAq. In this state, suction is performed for one minute to remove toner by suction. The potential of the electrometer 29 at this time is set to V (volt). Here, 28 is a capacitor whose capacity is C (μF). Further, the mass of the entire measuring machine after suction is weighed and is referred to as W2 (g). The triboelectric charge amount (μC / g; mC / kg) of the toner is calculated as in the following equation.
Triboelectric charge (μC / g) = CV / (W1-W2)
[0028]
As described above, reducing the diameter of the latent image carrier and the toner carrier has a problem of heat generation in the cartridge, particularly in a process cartridge in which a toner unit and a drum unit are integrated. Of the toner, causing a problem in the transportability of the toner in the cartridge.
[0029]
On the other hand, as a result of the study by the present inventor, the ratio of the number of rotations of the toner conveying means to the number of rotations of the toner supply roller was set to 0.1 or more and 0.5 or less, and the toner coat amount Amg / cm ² And the toner filling rate Bg / cm in the toner container. ³ Was found to be improved by setting the relationship of 0.9B ≦ A ≦ 3B.
[0030]
The details of this reason are unknown, but the present inventors speculate as follows from several studies. It has been observed that the deterioration in the fluidity of the toner, which causes image white spots, occurs because the toner external additive is buried in the toner surface. However, even when the toner was left in a temperature rising state occurring in the process cartridge, a state in which the external additive of the toner was buried in the surface was not observed. On the other hand, when the toner was left in a heated state in a state of being packed by tapping, the tendency of the external additive to be buried in the toner surface was confirmed. Further, when the temperature was raised while the toner was always in a flowing state, the external additive did not bury in the toner surface up to a higher temperature. From these results, the ratio of the number of rotations of the toner conveying means to the number of rotations of the toner supply roller was set to 0.1 or more and 0.5 or less, and the toner coat amount Amg / cm ² And the toner filling rate Bg / cm in the toner container. ³ Is assumed to be 0.9B ≦ A ≦ 3B so that the toner inside the process cartridge is always kept in a fluid state to prevent packing of the toner.
[0031]
When the ratio of the number of rotations of the toner conveying unit to the number of rotations of the toner supply roller is less than 0.1, the amount of toner conveyed to the toner supply roller is insufficient, and image whiteout occurs. On the other hand, if it exceeds 0.5, the toner is excessively conveyed and becomes in a packing state, so that the toner causes blocking in a cartridge where the temperature rises sharply.
[0032]
Amount of toner coat on toner carrier Amg / cm ² The amount of toner actually developed depends on the image ratio of the pattern to be printed, but the toner that did not contribute to development is peeled off from the toner carrier by the toner supply roller and returned to the toner container. The amount of toner coated on the toner carrier is determined by the set toner coating amount A, regardless of the image ratio.
[0033]
Toner filling rate Bg / cm ³ Indicates the ratio of the amount of the charged toner to the volume of the area where the toner can exist in the developing device. This value is considered to be an amount correlated with the degree of freedom of the movement of the toner in the developing device.
[0034]
By setting the relationship between A and B so that 0.9B ≦ A ≦ 3B in the initial state of the process cartridge, even if the toner is consumed by continuing printing thereafter, the toner in the process cartridge is consumed. It is possible to keep the toner in a fluid state at all times, thereby preventing toner from staying near the toner carrier. In the case of 0.9B> A, the toner supply becomes excessive, which is not preferable. Also, in the case of A> 3B, if a pattern having a high image ratio is continuously printed, the toner supply becomes insufficient and an image white spot occurs.
[0035]
In the present invention, in order to stabilize the amount of toner coating on the toner carrier, it is preferable that the ratio of the diameter of the toner supply roller to the diameter of the toner carrier be 0.7 or more and 1.3 or less. It is preferable to add 0.3% by mass or more and 2.5% by mass or less of inorganic fine powder subjected to hydrophobic treatment.
[0036]
Further, in the present invention, in order to suppress the temperature rise inside the cartridge and stabilize the toner coating amount on the toner carrier, the toner supply roller rotates in the opposite direction at a portion in contact with the toner carrier, and The ratio of the number of rotations of the toner supply roller to the number of rotations is preferably 0.6 or more and 1.2 or less, and the contact pressure of the toner regulating member with respect to the toner carrier is 15 g / cm or more and 50 g / cm or less. Is preferred.
[0037]
The method for producing the toner of the present invention is not particularly limited. First, the method for producing the toner of the present invention in the suspension polymerization method will be described.
[0038]
First, a monomer system in which a wax, a polar resin, a colorant, a charge control agent, a polymerization initiator, and other additives are added to a polymerizable monomer, and the mixture is uniformly dissolved or dispersed with a homogenizer, an ultrasonic disperser, or the like. Is dispersed in an aqueous phase containing a dispersion stabilizer using a conventional stirrer, homogenizer, homomixer or the like. At this time, the granulation is preferably performed by adjusting the stirring speed and time so that the monomer droplets have a desired size of the developer particles. Thereafter, stirring may be performed to such an extent that the particle state is maintained and the sedimentation of the particles is prevented by the action of the dispersion stabilizer. The polymerization temperature is preferably set to 40 ° C. or higher, generally 50 ° C. to 90 ° C. In addition, the temperature may be raised in the latter half of the polymerization reaction, and further, at the end of the reaction or at the end of the reaction, in order to remove unreacted polymerizable monomers, by-products, etc. which cause odor at the time of fixing the developer. Part of the aqueous medium may be distilled off. After completion of the reaction, the generated developer particles are collected by washing, filtration, and dried. In the suspension polymerization method, it is usually preferable to use 300 parts by mass to 3000 parts by mass of water as a dispersion medium with respect to 100 parts by mass of the monomer system.
[0039]
Particle size distribution control and particle size control of the toner are performed by adjusting the pH of the system during granulation, by changing the type and amount of the hardly water-soluble inorganic salt or dispersant that acts as a protective colloid, and by mechanical device conditions. For example, this can be achieved by controlling the stirring conditions such as the peripheral speed of the rotor, the number of passes, the shape of the stirring blades, and the shape of the container or the solid concentration in the aqueous solution.
[0040]
Examples of the polymerizable monomer used in the present invention include styrene monomers such as styrene, o- (m-, p-) methylstyrene, and m- (p-) ethylenestyrene; methyl (meth) acrylate; Propyl (meth) acrylate, butyl (meth) acrylate, octyl (meth) acrylate, dodecyl (meth) acrylate, stearyl (meth) acrylate, behenyl (meth) acrylate, 2-ethylhexyl (meth) acrylate (Meth) acrylate monomers such as dimethylaminoethyl (meth) acrylate and diethylaminoethyl (meth) acrylate; monomers such as butadiene, isoprene, cyclohexane, (meth) acrylonitrile, and acrylamide It is preferably used.
[0041]
As the polar resin added at the time of polymerization, a styrene (meth) acrylic acid copolymer, a maleic acid copolymer, a polyester resin, and an epoxy resin are preferably used.
[0042]
As the wax used in the present invention, paraffin wax, polyolefin wax, Fischer-Tropsch wax, amide wax, higher fatty acid, ester wax and derivatives thereof, or graft / block compounds thereof are preferably used.
[0043]
As the charge control agent used in the present invention, a known charge control agent can be used, but a charge control agent having no polymerization inhibitory property and having no solubilized substance in an aqueous system is particularly preferable. As specific compounds, salicylic acid, naphthoic acid, dicarboxylic acids, metal compounds of their derivatives, polymer compounds having sulfonic acid in the side chain, boron compounds, urea compounds, silicon compounds, calixarene, etc. are used as negative compounds. As the positive type, a quaternary ammonium salt, a high molecular compound having the quaternary ammonium salt in a side chain, a guanidine compound, an imidazole compound and the like are preferably used. The charge control agent is preferably used in an amount of 0.2 to 10 parts by mass based on 100 parts by mass of the polymerizable monomer.
[0044]
Examples of the polymerization initiator used in the present invention include 2,2′-azobis- (2,4-dimethylvaleronitrile), 2,2′-azobisisobutylnitrile, and 1,1′-azobis (cyclohexane-1). -Carbonitrile), azo-based polymerization initiators such as 2,2'-azobis-4-methoxy-2,4-dimethylvaleronitrile and azobisisobutylnitrile, benzoyl peroxide, methyl ethyl ketone peroxide, diisopropyl peroxycarbonate, cumene hydroxy peroxide, A peroxide-based polymerization initiator such as 2,4-dichlorobenzoyl peroxide and lauroyl peroxide is used.
[0045]
The amount of the polymerization initiator to be added varies depending on the desired degree of polymerization, but is generally used in an amount of 0.5% by mass to 20% by mass based on the monomer. The type of the polymerization initiator varies slightly depending on the polymerization method, but may be used alone or in combination with reference to the 10-hour half-life temperature.
[0046]
Examples of the dispersant used when utilizing suspension polymerization include, for example, inorganic oxides such as tricalcium phosphate, magnesium phosphate, aluminum phosphate, zinc phosphate, calcium carbonate, magnesium carbonate, calcium hydroxide, and hydroxide. Examples include magnesium, aluminum hydroxide, calcium metasilicate, calcium sulfate, barium sulfate, bentonite, silica, alumina, a magnetic substance, and ferrite. As the organic compound, for example, polyvinyl alcohol, gelatin, methylcellulose, methylhydroxypropylcellulose, ethylcellulose, sodium salt of carboxymethylcellulose, starch and the like are used by being dispersed in an aqueous phase.
[0047]
It is preferable to use 0.2 to 2.0 parts by mass of these dispersants based on 100 parts by mass of the polymerizable monomer.
[0048]
As these dispersants, commercially available ones may be used as they are, or they may be obtained by generating the inorganic compound under high-speed stirring in a dispersion medium in order to obtain fine and uniform dispersed particles. . For example, in the case of calcium phosphate, a dispersant suitable for suspension polymerization can be obtained by mixing an aqueous solution of sodium phosphate and an aqueous solution of calcium chloride under high-speed stirring.
[0049]
In order to make these dispersants fine, 0.001 to 0.1 parts by mass of a surfactant may be used in combination. Specifically, commercially available nonionic, anionic and cationic surfactants can be used, for example, sodium dodecyl sulfate, sodium tetradecyl sulfate, sodium pentadecyl sulfate, sodium octyl sulfate, sodium oleate, sodium laurate, potassium stearate, Calcium oleate and the like are preferably used.
[0050]
Next, a method for producing a toner in the pulverization method will be described.
[0051]
Examples of the binder resin used in the pulverization method toner of the present invention include polystyrene, poly-α-methylstyrene, styrene-propylene copolymer, styrene-butadiene copolymer, styrene-vinyl chloride copolymer, and styrene-vinyl acetate. A copolymer, a styrene-acrylate copolymer, a styrene-methacrylate acrylic copolymer, a vinyl chloride resin, a polyester resin, an epoxy resin, a phenol resin, a polyurethane resin and the like can be used alone or in combination. -Acrylic, styrene-methacrylic copolymer resins and polyester resins are preferred.
[0052]
When the pulverized toner of the present invention is controlled to have a positive charge property, it may be modified with a fatty acid metal salt or the like; and may be modified with tributylbenzidylammonium-1-hydroxy-4-naphthosulfonate, tetrabutylammonium tetrafluoroborate or the like. Onium salts such as quaternary ammonium salts and phosphonium salts which are analogs thereof; amine and polyamine compounds; metal salts of higher fatty acids; metal complexes of acetylacetone; diorganotin oxides such as dibutyltin oxide, dioctyltin oxide and dicyclohexyltin oxide Adding diorganotin borate such as dibutyl tin borate, dioctyl tin borate, dicyclohexyl tin borate and the like; In the case of controlling to be negatively charged, an organic metal complex and a chelate compound are effective, and a monoazo metal complex, an acetylacetone metal complex, an aromatic hydroxycarboxylic acid, or an aromatic dicarboxylic acid-based metal complex can be used. The amount used is 0.1 to 15 parts by mass, preferably 0.1 to 10 parts by mass, based on 100 parts by mass of the binder resin.
[0053]
A wax is added to the pulverized toner of the present invention to prevent fixing offset. For example, aliphatic hydrocarbon waxes such as low molecular weight polyethylene, low molecular weight polypropylene, paraffin wax and Fischer-Tropsch wax or oxides thereof; waxes mainly containing aliphatic esters such as carnauba wax and montanic acid ester wax; Part or all of which are deoxidized are exemplified. In addition, saturated linear fatty acids such as palmitic acid, stearic acid, and montanic acid; unsaturated fatty acids such as brassic acid, eleostearic acid, and vinaric acid; stearyl alcohol, aralkyl alcohol, behenyl alcohol, carnaubyl alcohol, and seryl alcohol And polyhydric alcohols such as sorbitol; fatty acid amides such as linoleic acid amide; saturated fatty acid bisamides such as methylenebisstearic acid amide; unsaturated fatty acid amides such as ethylenebisoleic acid amide Aromatic bisamides such as N, N'-distearyl isophthalic acid amide; fatty acid metal salts such as zinc stearate; waxes obtained by grafting an aliphatic hydrocarbon wax with a vinyl monomer such as styrene; Be A partially esterified product of a fatty acid such as henic acid monoglyceride and a polyhydric alcohol; a methyl esterified product having a hydroxyl group obtained by hydrogenation of a vegetable oil or the like can also be used.
[0054]
Next, the binder resin, wax, charge control agent, colorant, etc. are sufficiently mixed by a mixer such as a Henschel mixer or a ball mill, and then melt-kneaded using a heat kneader such as a heating roll, a kneader, or an extruder. Then, a charge control agent and a colorant are dispersed or dissolved in the resin in which the resins are mutually compatible. After cooling and solidifying, the resultant is mechanically pulverized to a desired particle size, and further classified to sharpen the particle size distribution. Alternatively, after cooling and solidifying, the finely pulverized product obtained by colliding with a target under a jet stream is sphericalized by heat or mechanical impact.
[0055]
The toner of the present invention produced as described above can be used by externally adding an inorganic fine powder such as silica, alumina and titania. The inorganic fine powder has a specific surface area (BET) of 20 m. ² / G ~ 400m ² / G. Further, a surface-treated product of the inorganic fine powder may be used by external addition. Examples of the surface treatment agent include a silane coupling agent, a silylating agent, a titanium coupling agent, a silicone oil, and the like.Preferably, a silane coupling agent, a silylating agent, and a silicone oil are used. You may use together.
[0056]
Further, in the present invention, the following inorganic powder can be added in order to improve developability and durability. Metal oxides such as magnesium, zinc, aluminum, cerium, cobalt, iron, zirconium, chromium, manganese, strontium, tin, antimony; composite metal oxides such as calcium titanate, magnesium titanate, strontium titanate; barium sulfate; Metal salts such as calcium carbonate, magnesium carbonate and aluminum carbonate; clay minerals such as kaolin; phosphate compounds such as apatite; silicon compounds such as silica, silicon carbide and silicon nitride; and carbon powders such as carbon black and graphite.
[0057]
For the same purpose, the following organic particles or composite particles can be added. Resin particles such as polyamide resin particles, silicone resin particles, silicone rubber particles, urethane particles, melamine-formaldehyde particles, acrylic particles; rubber, wax, fatty acid compounds, resins and the like, and metals, metal oxides, salts, carbon black, etc. Composite particles composed of inorganic particles; Fluororesins such as polyfluoroethylene and polyvinylidene fluoride; Fluorine compounds such as carbon fluoride; Fatty acid metal salts such as zinc stearate; Fatty acid derivatives such as fatty acids and fatty acid esters; Molybdenum sulfide , Amino acids and amino acid derivatives.
[0058]
Next, the process cartridge of the present invention will be described.
[0059]
FIG. 1 is an example of a developing device applied to the present invention. In FIG. 1, a developing device 20 is located opposite to a latent image carrier 1 at a developing container 10 containing a non-magnetic toner t as a one-component developer and at an opening extending in a longitudinal direction in the developing container. And an electrostatic latent image on the latent image carrier 1 is developed and visualized.
[0060]
As the toner carrier 11, for example, an elastic roller having a surface layer coated on a base layer of an elastic layer can be used.
[0061]
A metal plate such as SUS, a rubber material such as urethane or silicon, or a metal thin plate of SUS or phosphor bronze having spring elasticity is used as a base at a position above the toner carrier 11, and a contact surface with the toner carrier 11 is provided. A regulating member 13 made of, for example, a rubber material adhered to the toner carrier 11 is provided so that the vicinity of the free end is in contact with the outer peripheral surface of the toner carrier 11 by surface contact. The tip side is a so-called counter direction located on the upstream side in the rotation direction of the toner carrier 11 with respect to the contact portion.
[0062]
The toner supply roller 12 is in contact with the contact portion of the toner regulating member 13 with the surface of the toner carrier 11 on the upstream side in the rotation direction of the toner carrier 11 and is rotatably supported. As this structure, a foamed skeleton sponge structure or a fur brush structure in which fibers such as rayon and nylon are planted on a cored bar are suitable for supplying the toner 10 to the toner carrier 11 and removing undeveloped toner. Is preferred.
[0063]
An effective contact width of the toner supply roller with respect to the toner carrier 11 is 1 to 8 mm, and it is preferable that the toner supply roller has a relative speed at the contact portion thereof.
[0064]
The toner conveying member 14 is a rotatable crown member or a rotatable crown member having a tongue member attached thereto so as to be rotatable about a fixed shaft.
[0065]
The thin toner layer formed on the toner carrier 11 is uniformly conveyed to a developing unit which is a portion facing the latent image carrier 1. In this developing section, the toner layer formed on the toner carrier 11 in a thin layer forms an electrostatic charge on the latent image carrier 1 by a DC bias applied between the toner carrier 11 and the latent image carrier 1. The latent image is developed as a toner image.
[0066]
【Example】
Hereinafter, the present invention will be described in more detail with reference to Examples and Comparative Examples. Note that “parts” means parts by mass.
[0067]
<Production Example 1>
400 g of styrene and 100 g of butyl methacrylate as monomers of the vinyl resin were heated to 80 ° C. to sufficiently dissolve 40 g of ester wax (melting point: 75 ° C.). To this, 18 g of dicumyl peroxide was added as a polymerization initiator, and the mixture was placed in a dropping funnel.
[0068]
195 g of polyoxypolyethylene (2,2) -2,2-bis (4-hydroxyphenyl) propane, 60 g of isophthalic acid, 19 g of 1,2,5-benzenetricarboxylic acid as a monomer of the polyester resin, and dibutyl as a catalyst 0.5 g of tin oxide was placed in a 5-liter glass four-necked flask, fitted with a thermometer, a stainless steel stirring rod, a falling condenser, and a nitrogen inlet tube, and heated at 140 ° C. in a mantle heater under a nitrogen stream. The mixture was added dropwise from the above-mentioned dropping funnel over 5 hours while stirring at the temperature described above. The mixture was aged while being kept at 140 ° C., heated, and reacted at 225 ° C. to obtain Binder 1.
[0069]
・ Binder 1 100 parts
・ 8 parts of carbon black
・ 2 parts of salicylic acid metal compound
The above were mixed using a Henschel mixer, melt-kneaded with a twin-screw extruder, coarsely ground with a hammer mill, finely ground with a jet mill, and classified to obtain colored particles.
[0070]
Further, a mixture of 0.5 part of a sulfonic acid group-containing resin (manufactured by Fujikura Kasei Co., Ltd., FCA-1001) with 100 parts of the above colored particles was mixed with a hybridizer type 1 (manufactured by Nara Machinery Co., Ltd.) at 2500 rpm, 3 rpm. Minutes. Silica hydrophobized with hexamethyldisilazane (BET = 180 m ² / G) was externally added with 1.5 parts of Henschel mixer FM10B to obtain toner A.
[0071]
<Production Example 2>
・ Binder 1 100 parts
・ 90 parts of magnetite
・ 2 parts of salicylic acid metal compound
The above were mixed using a Henschel mixer, melt-kneaded with a twin-screw extruder, coarsely pulverized with a hammer mill, finely pulverized using Kryptron (manufactured by Kawasaki Heavy Industries) as a pulverizer, and then classified. Thus, colored particles were obtained.
[0072]
Further, a mixture of 0.5 part of a sulfonic acid group-containing resin (manufactured by Fujikura Kasei Co., Ltd., FCA-1001) with 100 parts of the above colored particles was mixed with a hybridizer type 1 (manufactured by Nara Machinery Co., Ltd.) at 2500 rpm, 3 rpm. Minutes. To 100 parts of the colored particles, 1.5 parts of the silica used in Production Example 1 was externally added with a Henschel mixer FM10B to obtain a toner B.
[0073]
<Production Example 3>
Toner C was obtained in the same manner as in Production Example 2, except that 4 parts of a styrene acrylic resin (Tg = 70 ° C.) was added instead of the sulfonic acid group-containing resin.
[0074]
<Production Example 4>
Toner D was obtained in the same manner as in Production Example 1, except that 4 parts of a styrene acrylic resin (Tg = 55 ° C.) was added instead of the sulfonic acid group-containing resin.
[0075]
<Production Example 5>
Toner E was obtained in the same manner as in Production Example 2 except that the amount of the sulfonic acid group-containing resin was changed to 0.2 part.
[0076]
<Production Example 6>
Toner F was obtained in the same manner as in Production Example 1, except that the amount of the sulfonic acid group-containing resin was changed to 1.1 parts.
[0077]
<Production Example 7>
Toner G was obtained in the same manner as in Production Example 1, except that the addition amount of the ester wax was changed to 7 g.
[0078]
<Production Example 8>
A toner G was obtained in the same manner as in Production Example 1, except that the amount of the ester wax was changed to 110 g.
[0079]
<Production Example 9>
Toner H was obtained in the same manner as in Production Example 1, except that the amount of the hydrophobicized silica was changed to 0.2 part.
[0080]
<Production Example 10>
Toner I was obtained in the same manner as in Production Example 1, except that the addition amount of the hydrophobized silica was changed to 2.7 parts.
[0081]
<Production Example 11>
In a two-liter four-necked flask equipped with a high-speed stirrer CLEARMIX (manufactured by M Technique Co., Ltd.), 630 parts of ion-exchanged water and 0.1 mol / liter of Na were added. ₃ PO ₄ 485 parts of an aqueous solution was added, the rotation speed of Clearmix was adjusted to 14000 rpm, and the mixture was heated to 63 ° C. Here, 1.0 mol / liter of CaCl ₂ An aqueous solution (65 parts) was gradually added, and 10% hydrochloric acid was further added dropwise to add a minute water-insoluble dispersant Ca. ₃ (PO ₄ ) ₂ Was prepared at pH = 5.8.
[0082]
On the other hand, the dispersoid system
・ Styrene monomer 120 parts
・ Butyl acrylate monomer 80 parts
・ 15 parts of carbon black
・ 1.6 parts of salicylic acid metal compound
Was dispersed using an attritor for 15 hours, the following components were added to the above mixture, and the mixture was further dispersed for 5 hours to prepare a dispersoid system.
[0083]
16 parts of saturated polyester (acid value: 9.8 mg KOH / g, peak molecular weight: 15000)
・ 20 parts of ester wax
Next, after adding 5 parts of a polymerization initiator 2,2'-azobis (2,4-dimethylvaleronitrile) to the above-mentioned dispersoid system, it was charged into the above-mentioned dispersion medium, and then under a nitrogen atmosphere at an internal temperature of 58 ° C, Granulated at 17000 rpm for 15 minutes. Thereafter, the stirrer was replaced with a propeller stirrer, and polymerization was carried out for 5 hours while maintaining the temperature at 58 ° C. while stirring at 50 rpm. After the polymerization was completed, the slurry was cooled and dilute hydrochloric acid was added to remove the dispersant. Further, it was washed with water, dried and classified to obtain colored particles.
[0084]
To 100 parts of the coloring particles, 1.2 parts of the hydrophobizing treatment used in Production Example 1 was externally added using a Henschel mixer FM10B to obtain a toner J.
[0085]
<Comparative Production Example 1>
Binder 2 was obtained in the same manner as in Binder 1 of Production Example 1, except that the amount of the ester wax was changed to 4 g.
[0086]
・ Binder 2 100 parts
・ 8 parts of carbon black
・ 2 parts of salicylic acid metal compound
The above were mixed using a Henschel mixer, melt-kneaded with a twin-screw extruder, coarsely ground with a hammer mill, finely ground with a jet mill, and classified to obtain colored particles.
[0087]
Further, 6 parts of a polyester resin (Tg = 70 ° C.) was mixed with 100 parts of the coloring particles, and the mixture was treated at 2500 rpm for 8 minutes using a hybridizer type 1 (manufactured by Nara Machinery Co., Ltd.). To 100 parts of the colored particles, 1.5 parts of the silica used in Production Example 1 was externally added with a Henschel mixer FM10B to obtain a toner K.
[0088]
<Comparative Production Example 2>
Binder 3 was obtained in the same manner as in Binder 1 of Production Example 1, except that the amount of the ester wax added was changed to 150 g.
[0089]
・ Binder 3 100 parts
・ 8 parts of carbon black
・ 2 parts of salicylic acid metal compound
The above were mixed using a Henschel mixer, melt-kneaded with a twin-screw extruder, coarsely ground with a hammer mill, finely ground with a jet mill, and classified to obtain colored particles.
[0090]
To 100 parts of the colored particles, 1.5 parts of silica hydrophobized with hexamethyldisilazane was externally added using a Henschel mixer FM10B to obtain a toner L.
[0091]
<Comparative Production Example 3>
・ Binder 1 100 parts
・ 90 parts of magnetite
・ 2 parts of salicylic acid metal compound
The above were mixed using a Henschel mixer, melt-kneaded with a twin-screw extruder, coarsely ground with a hammer mill, finely ground with a jet mill, and classified to obtain colored particles.
[0092]
Titanium oxide (BET = 100 m) hydrophobized with isobutyltrimethoxysilane was applied to 100 parts of the colored particles. ² / G) 1.3 parts was externally added using a Henschel mixer FM10B to obtain a toner M.
[0093]
<Example 1>
The toner A of Production Example 1 was filled in a process cartridge described below and evaluated.
[0094]
In FIG. 1, a developing device 20 is located at an opening extending in a longitudinal direction in a developing container 10 containing a non-magnetic toner t as a one-component developer and is in contact with the latent image carrier 1. A toner carrier 11 is provided opposite to the toner carrier 11 so that the electrostatic latent image on the latent image carrier 1 is developed and visualized.
[0095]
As the latent image carrier, an organic photoreceptor having a diameter of 30 mm was used.
[0096]
The toner carrier 11 is an elastic roller having a diameter of 16 mm in which a base layer of NBR is coated with ether urethane on the surface.
[0097]
Above the toner carrier 11, a regulating member 13 composed of a phosphor bronze metal thin plate as a base and having a polyamide elastomer adhered to the contact surface side of the toner carrier 11 is provided near the free end side tip. The toner carrier 11 is provided so as to come into contact with the outer peripheral surface of the toner carrier 11 by surface contact. The contact direction of the toner carrier 11 is a so-called counter whose tip end is located upstream of the toner carrier 11 in the rotation direction of the toner carrier 11. Direction. The contact pressure of the toner regulating member 13 with respect to the toner carrier 11 is 25 g / cm (the measurement of the linear pressure is such that three thin metal plates having a known friction coefficient are inserted into the contact portion, and one sheet at the center is fixed with a spring. Converted from the extracted value.)
[0098]
The toner supply roller 12 is in contact with the contact portion of the toner regulating member 13 with the surface of the toner carrier 11 on the upstream side in the rotation direction of the toner carrier 11 and is rotatably supported. The toner supply roller 12 is an elastic roller having a diameter of 12 mm in which a polyurethane foam is provided on a cored bar, and rotates in a counter direction at a contact portion with the toner carrier 11. At this time, the ratio of the number of rotations of the toner supply roller to the number of rotations of the toner carrier was set to 0.8.
[0099]
The toner conveying member 14 is obtained by attaching a tongue-shaped member to a crank-shaped rod so as to be rotatable about a fixed shaft.
The rotation speed of the toner conveying member 14 was adjusted so that the ratio to the rotation speed of the toner supply roller 12 was 0.3.
[0100]
FIG. 2 is a schematic configuration diagram showing an electrophotographic laser beam printer used for evaluation.
[0101]
The above-described process cartridge can be mounted on the printer, and a transfer roller 4, an exposure device 6, and a fixing device 7 are further provided.
[0102]
The charging roller 2 uniformly charges the photosensitive drum 1 to a predetermined polarity and potential by a charging bias applied from a charging bias power supply (not shown).
[0103]
The transfer roller 4 as a transfer unit contacts the surface of the photosensitive drum 1 with a predetermined pressing force to form a transfer nip, and transfers the transfer nip to the latent image carrier 1 by a transfer bias applied from a transfer bias power supply (not shown). The toner image on the surface of the latent image carrier 1 is transferred to the transfer material P at the transfer nip between the rollers 4.
[0104]
The cleaning blade 5 removes the transfer residual toner remaining on the surface of the latent image carrier 1 after the transfer.
[0105]
The exposure device 6 includes a laser driver (not shown), a laser diode, a polygon mirror, and the like. Laser light modulated according to a time-series electric digital image signal of image information input to the laser driver is transmitted from the laser diode. The laser beam is scanned by a polygon mirror that is output and rotates at a high speed, and the surface of the latent image carrier 1 is subjected to image exposure L via a reflection mirror (not shown) to form an electrostatic latent image corresponding to image information. I do.
[0106]
The fixing device 7 includes a rotatable fixing roller 7a and a pressure roller 7b. The surface of the transfer material P is pinched and conveyed by a fixing nip between the fixing roller 7a and the pressure roller 7b. Is heated and pressed to thermally fix the toner image.
[0107]
In this printer, the process speed is 100 mm / s, the peripheral speed of the latent image carrier 1 is 100 mm / s, and the toner carrier 11 is rotated at a peripheral speed of 160 mm / s.
[0108]
In this developing unit, the toner layer formed thin on the toner carrier 11 is charged with a latent image by a DC voltage: Vdc = −270 V bias applied between the toner carrier 11 and the latent image carrier 1. The electrostatic latent image on the body 1 is developed as a toner image.
[0109]
The above process cartridge was filled with the toner A, and a continuous printing test of 2,000 sheets was performed at a printing ratio of 2%. The test was performed in an environment of 30 ° C./50% RH. On the 2,000th sheet, one solid white pattern and ten solid black patterns were continuously printed as samples.
[0110]
<Examples 2 to 11>
Using the process cartridge and the printer used in Example 1, toners B to J shown in Production Examples 2 to 11 were evaluated in the same manner as in Example 1.
[0111]
<Examples 12 to 17>
The process cartridge used in Example 1 was evaluated in the same manner as in Example 1 except that various settings were set to the values shown in Table 1.
[0112]
<Comparative Example 1>
The toner K shown in Comparative Production Example 1 was evaluated in the same manner as in Example 1 using the process cartridge and the printer used in Example 1.
[0113]
<Comparative Example 2>
The toner L shown in Comparative Production Example 2 was evaluated in the same manner as in Example 1 using the process cartridge and the printer used in Example 1.
[0114]
<Comparative Example 3>
The toner M shown in Comparative Production Example 3 was evaluated in the same manner as in Example 1 using the process cartridge and the printer used in Example 1.
[0115]
<Comparative Examples 4 to 7>
The process cartridge used in Example 1 was evaluated in the same manner as in Example 1 except that various settings were set to the values shown in Table 1.
[0116]
[Evaluation method]
(1) Image blank
The density of 40 points in the sample of the tenth solid black pattern is measured. The average value of each of the 5 points of high density and the 5 points of low density was determined, and ranked according to the difference. The density was measured with a reflection densitometer RD918 (manufactured by Macbeth).
A: Difference in density is less than 0.1
B: Density difference is 0.1 or more and less than 0.2
C: density difference is 0.2 or more and less than 0.3
D: The density difference is 0.3 or more
[0117]
(2) Fog
The reflectances of the solid white pattern sample and the unused paper were each measured using TC-6DS (manufactured by Tokyo Denshoku Co., Ltd.) (three-point average), and the difference was determined. The ranking of the evaluation was performed as follows.
A: less than 2.0%
B: 2.0% or more and less than 4.0%
C: 4.0% or more and less than 6.0%
D: 6.0% or more
[0118]
Table 1 shows the evaluation conditions, and Table 2 shows the evaluation results.
[0119]
[Table 1]

[0120]
[Table 2]

[0121]
【The invention's effect】
As described above, according to the present invention, in a process cartridge adopting a contact one-component developing method using a small-diameter developer carrier and a small-diameter latent image carrier, reversal fog, which is deteriorated by an increase in temperature, is prevented. Toner and a process cartridge capable of improving image white spots caused by deterioration of toner fluidity due to the toner.
[Brief description of the drawings]
FIG. 1 is a schematic view of a process cartridge of the present invention.
FIG. 2 is a schematic view of a printer to which the process cartridge of the present invention can be applied.
FIG. 3 is a schematic diagram of an apparatus for measuring a tribo in the present invention.
[Explanation of symbols]
1 Latent image carrier
2 Charging roller
4 Transfer roller
5 Cleaning materials
7 Fixing device
11 Toner carrier
12 Toner supply roller
13 Regulation members
20 Developing device (developing container)
t toner
P transfer material

Claims (13)

A drum unit including at least a latent image carrier; a charging member that contacts and charges the latent image carrier; a cleaning member that removes and collects transfer residual toner on the latent image carrier; A toner carrier that rotates about a fixed shaft in the developer container to stir and transport the toner; a toner carrier in contact with the latent image carrier; And a toner supply roller for supplying toner to the toner carrier, the toner regulating member being in contact with the toner unit, and the latent image carrier has a diameter of 33 mm or less, and the toner carrier has a diameter of 33 mm or less. 20 mm or less, the ratio of the number of rotations of the toner conveying member to the number of rotations of the toner supply roller is 0.1 or more and 0.5 or less, and the toner coat amount Amg / relationship m ² and the toner filling rate Bg / cm ³ in said toner container is a toner used in a process cartridge that satisfies 0.9B ≦ A ≦ 3B,
The toner comprises at least a binder resin, a colorant, and a wax, has an absolute value of tribo of 40 mC / kg or more, and has a temperature gradient of a contact angle of the toner of 1.03 or more and 1.3 or less. toner. 2. The toner according to claim 1, wherein the wax content of the toner is 1% by mass or more and 10% by mass or less. 3. The toner according to claim 1, wherein the temperature gradient of the contact angle of the toner is 1.05 or more and 1.25 or less. 4. The toner according to claim 1, wherein the toner contains 0.3% to 2.5% by mass of a hydrophobically treated external additive. The toner according to any one of claims 1 to 4, wherein an absolute value of a tribo of the toner is 45 mC / kg or more and 65 mC / kg or less. In a process cartridge detachably mounted to the image forming apparatus main body, at least a latent image carrier; a charging member that contacts and charges the latent image carrier; and removes and collects transfer residual toner on the latent image carrier. A drum unit comprising: a cleaning member; a toner container; a developing container for containing the toner; a toner conveying means for rotating around a fixed shaft in the developing container to agitate and convey the toner; A toner cartridge comprising: a toner carrier in contact with the toner carrier; a toner regulating member in contact with the toner carrier via toner; and a toner supply roller for supplying toner to the toner carrier. ,
The diameter of the latent image carrier is 33 mm or less, the diameter of the toner carrier is 20 mm or less, and the ratio of the number of rotations of the toner conveying member to the number of rotations of the toner supply roller is 0.1 or more and 0.5 or less; The relationship between the toner coating amount Amg / cm ² on the carrier and the toner filling rate Bg / cm ^{3 in} the developing container is 0.9B ≦ A ≦ 3B,
The toner comprises at least a binder resin, a colorant, and a wax, and has an absolute value of tribo of 40 mC / kg or more and a temperature gradient of a contact angle of 1.03 to 1.3. Process cartridge. 7. The process cartridge according to claim 6, wherein the wax content of the toner is 1% by mass or more and 10% by mass or less. 8. The process cartridge according to claim 6, wherein the temperature gradient of the contact angle of the toner is 1.05 or more and 1.25 or less. The process cartridge according to any one of claims 6 to 8, wherein the toner contains 0.3% to 2.5% by mass of a hydrophobically treated external additive. 10. The process cartridge according to claim 6, wherein an absolute value of a tribo of the toner is 45 mC / kg or more and 65 mC / kg or less. The process cartridge according to any one of claims 6 to 10, wherein a ratio of a diameter of the toner supply roller to a diameter of the toner carrier is 0.7 or more and 1.3 or less. The toner supply roller rotates in a reverse direction at a portion in contact with the toner carrier, and a ratio of the number of revolutions of the toner supply roller to the number of revolutions of the toner carrier is 0.6 or more and 1.2 or less. The process cartridge according to claim 6, wherein: 13. The process cartridge according to claim 6, wherein a contact pressure of the toner regulating member with respect to the toner carrier is 15 g / cm or more and 50 g / cm or less.

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