JP5708971B2 - Image forming apparatus - Google Patents

Description

  The present invention relates to an image forming apparatus using an electrophotographic method, and more particularly to an image forming apparatus capable of maintaining print image quality over time and reducing fixing of a developing sleeve due to friction between a developer and a developing sleeve.

Conventionally, in an image forming process using an electrophotographic method, an image forming apparatus that develops an electrostatic latent image on an image carrier using a two-component developer has been widely used. In this image forming apparatus, a two-component developer composed of toner and carrier is magnetically attracted to the surface of the developer carrying member to form a magnetic brush, and the toner in the magnetic brush is transferred to a latent image by a developing electric field, thereby forming a latent image. The image is developed.
In general image forming apparatuses as well as image forming apparatuses using a two-component developer, an image is transferred onto transfer paper, the image on the transfer paper is heated and melted, and then the image is fixed by applying pressure to the image. Heat fixing is performed.
This image forming substance is composed of at least a powder such as black called toner.

The power used when the fixing device that performs the heat fixing heats and melts the image occupies most of the power required for the image forming apparatus.
In recent years, low power consumption of an image forming apparatus has been demanded from the viewpoint of energy saving. For this purpose, it is necessary to lower the temperature for melting the image to enable low-temperature fixing.
Further, the market demands that the image quality can be as high as that of offset printing in both electrophotographic systems.

  In view of the above viewpoints, development of toner having a small particle diameter has been actively conducted in recent years. By reducing the particle size of the toner, the amount of heat required for fixing can be reduced as compared with the conventional case, so that low-temperature fixing can be realized. Further, by reducing the particle size, the number of particles per pixel increases and the dot shape becomes uniform, so that the image resolution is increased. This leads to higher image quality.

However, a toner having a small particle diameter generally tends to have a strong adhesive force, and the toner gradually sticks to a developer carrying member (hereinafter referred to as a sleeve) of the developing device, thereby inhibiting development. This is called sleeve fixation. Since the fixing of the sleeve is likely to occur in the non-image portion when the same document is continuously printed, the toner is pressed against the developing sleeve by the electric field that attracts the toner in the non-image portion to the developing sleeve.
It is considered that it proceeds to fusion in the process of being rubbed by the carrier many times on the developing sleeve. As the sleeve fixing progresses, the toner density control is affected, and the image quality deteriorates, for example, the image density becomes thin.

To adjust the toner density, generally, a reference toner pattern is formed on the latent image carrier, the density of the toner pattern is detected by a light-reflective photosensor, and a toner replenishing device is used according to the detection result. A toner density control method for controlling toner supply to the developing device is used.
In this toner density control method, among the output values of the light reflection type photosensor, the output of the light reflection type photosensor with respect to the toner pattern on the latent image carrier is Vsp, and the toner non-adhered portion (background portion) on the image carrier. If the output value of the light-reflective photosensor is Vsg, normally, toner supply control is performed so that Vsp / Vsg becomes constant.

When the toner adhesion amount of the reference toner pattern decreases, Vsp / Vsg increases, and it is determined that the toner concentration of the developer in the developing device is low, and the toner replenishment is performed from the toner replenishing device to the developing device. Is kept constant.
On the contrary, when Vsp / Vsg is low, it is determined that the toner concentration of the developer in the developing device is high, and the toner is not replenished.

If the fixing of the sleeve is proceeding at the position where the reference toner pattern is formed, the effective development voltage becomes higher by the amount of toner fixing than the actual voltage when the toner pattern is formed. Since the adhesion amount of the toner pattern increases, Vsp / Vsg becomes low.
In this state, the toner replenishment amount tends to be smaller than the required amount. When the sleeve is further fixed, this tendency becomes conspicuous, causing a problem in density adjustment and causing problems such as a decrease in density. Further, the phenomenon in which the toner adhesion amount increases due to the fixing of the sleeve is remarkable from the start of image formation until the image is formed for the entire circumference of the sleeve, and there is a phenomenon in which the circumference of the sleeve is darkened from the leading edge of the image.

  As a countermeasure against the sticking of the sleeve, in Japanese Patent Application Laid-Open No. 2002-323797 of Patent Document 1, the developer regulating member is grounded, and an electric field is formed between the developer carrying member and the developer carrying member is weakly adhered. The toner is transferred to the developer regulating member by this electric field to prevent the sleeve from sticking. However, toner with low adhesion can be peeled off, but toner with strong adhesion remains stuck to the sleeve and cannot be completely prevented. In Japanese Patent Application Laid-Open No. 2004-004209 of Patent Document 2, the gap between the latent image carrier and the developer carrier is set to be wide to some extent, and the toner adheres to or is pressed against the surface of the developer carrier by the electric field effect. It has been proposed to prevent this, but this can also weaken the adhesion of the toner to the developer carrying member, but does not completely prevent the toner from sticking.

  These inventions are not completely prevented, and the above-mentioned problem occurs due to the sleeve fixing at the reference toner pattern forming position.

  The present invention relates to an image forming apparatus using an electrophotographic system, and an object thereof is to provide an image forming apparatus capable of maintaining print image quality over time and reducing fixing of a developing sleeve due to friction between a developer and a developing sleeve.

As a result of intensive studies, the present inventors have specifically described the following technical features (1) to (3) as an image forming apparatus according to the present invention in order to solve the above problems. We have found that one is highly preferred.
(1) “A developer container containing a two-component developer containing at least a binder resin, a colorant, a toner containing a wax and a carrier, and a latent image carried by an opening provided in the developer container The developer is disposed on the surface of the latent image carrier, rotates so that the developer in the developer container is supported on the surface, and rotates on the surface of the latent image carrier. A developing device comprising: a developer carrying member that is supplied and developed; and a developer carrying member that imparts a carrying force to the developer along the axial direction of the developer carrying member and stirs the developer; An electrostatic latent image of a reference toner pattern is formed on the latent image carrier, the reference toner pattern is developed by the developer carrier, the reflection density of the reference toner pattern is detected, and the detected output value In an image forming apparatus that performs density adjustment, the toner F -The characteristic spectral peak height W of the wax and the characteristic spectral peak of the binder resin measured by the ATR method (total reflection method) using IR (Fourier transform infrared spectroscopic measurement device) The peak ratio W / R indicated using the height R is 0.050 to 0.100, and the toner has a particle size of 0.6 to 1.0 μm measured by a flow particle image analyzer (FPIA). The ratio of particles having an equivalent circle diameter is 4 to 7% by number, the ratio of particles having an equivalent circle diameter of 0.6 to 2.0 μm is 8 to 12% by number, and the equivalent circle diameter of 0.6 to 3.0 μm. the proportion of particles having is 18 to 22% by number, and the longitudinal direction of the average irregularity interval of said developer carrying member Sm ([mu] m), the arithmetic average roughness Ra ([mu] m) and 10-point average roughness Rz ([mu] m) is An image forming apparatus having the following formula.
20 ≦ Sm ≦ 60 Formula (1)
0.1 ≦ Ra ≦ 0.6 (2)
0 <Rz ≦ 8.0 Equation (3). ";

( 2 ) “The image forming apparatus according to item (1), wherein the image forming apparatus uses a toner obtained by mixing an external additive.”
( 3 ) “The image forming apparatus according to (1) or (2), wherein the image forming apparatus uses a toner mixed with silica or titanium oxide as the external additive”.

  According to the present invention, an image forming apparatus using an electrophotographic system is extremely excellent in that it can provide an image forming apparatus capable of maintaining print image quality over time and reducing fixing of a developing sleeve due to friction between a developer and a developing sleeve. Show the effect.

It is a graph which shows the characteristic IR spectrum of wax. It is a graph which shows the characteristic IR spectrum of the polyester resin which is an amorphous resin. It is a figure which shows the grinding process which is a run-out precision process of the image development sleeve which concerns on embodiment. 1 is a diagram illustrating a main part of an example of an image forming apparatus of the present invention.

As a result of intensive studies by the present inventors, a developer container that contains a two-component developer containing at least a binder resin, a pigment, a wax-containing toner and a carrier, and an opening provided in the developer container The developer is disposed so as to face the latent image carrier, and the developer in the developer container is carried and rotated on the surface, and the surface of the latent image carrier is opposed to the latent image carrier. Development comprising a developer carrying member for supplying toner to a latent image and developing, and a developer carrying member for applying a carrying force to the developer along the axial direction of the developer carrying member and stirring the developer An electrostatic latent image of a reference toner pattern is formed on the latent image carrier, the reference toner pattern is developed by the developer carrier, and the reflection density of the reference toner pattern is detected and detected. The image forming apparatus that adjusts the density according to the output value There are, using the toner of the FT-IR (Fourier transform infrared spectroscopy measurement device) ATR technique was determined by (total reflection method), of the wax characteristic spectral peak height W and the binder resin The peak ratio W / R shown using the peak height R of the characteristic spectrum is 0.050 to 0.100, and the toner was measured with a flow particle image analyzer (FPIA). The proportion of particles having an equivalent circle diameter of 6 to 1.0 μm is 4 to 7 % by number , 0 . The proportion of particles having an equivalent circle diameter of 6 to 2.0 μm is 8 to 12 % by number , 0 . The proportion of particles having a circle-equivalent diameter of 6 to 3.0 μm is 18 to 22 % by number, and the average unevenness interval Sm (μm) in the longitudinal direction of the developer carrier, arithmetic average roughness Ra (μm) An image forming apparatus, wherein the 10-point average roughness Rz (μm) is in the range of the following formula.
20 ≦ Sm ≦ 60 (1)
0.1 <= Ra <= 0.6 ... Formula (2)
0 <Rz ≦ 8.0 (Expression (3))
It has been found that the object of the present invention can be achieved very well.

The present invention is described in further detail below.
That is, as a result of repeated investigations, the present inventors have studied the amount of fine powder of toner, the average interval of irregularities (Sm) in the longitudinal direction of the sleeve, and the arithmetic average roughness ( The relationship between Ra) and 10-point average roughness (Rz) was found to be important. Although the detailed mechanism is not known, the ratio of the number of particles in the particle size distribution of the toner to be used, particularly the equivalent circle diameter of 3 μm or less, is defined, and the sleeve Sm, Ra, and Rz have values satisfying the above formula. Thus, it is considered that the toner can be prevented from being caught in the groove and the sticking of the sleeve can be avoided.
When the Sm, Ra, and Rz are larger than the threshold value, the toner is caught in the groove, and the sleeve is fixed. On the other hand, when the Sm, Ra, and Rz are smaller than the threshold value, there is a problem that the developer is poorly drawn and a sufficient print density cannot be obtained.

[Toner particle size]
As a method for measuring the particle diameter of the toner, a Coulter counter method, a laser beam diffraction method, a light scattering method, an image analysis method, or the like is used. Among these, the image analysis method is suitable for accurately measuring particles of 3 μm or less such as ultrafine powder. Among them, the flow type particle image analyzer (FPIA, manufactured by Sysmex Corporation) is suitable for measuring the equivalent circle diameter (diameter of a circle having the same peripheral length as that of the particles) of one toner particle of 3 μm or less.
In the present invention, the point is that the amount of ultrafine powder is defined by the measured value of the flow type particle image analyzer. As a result, it is possible to provide a toner that can reduce sleeve contamination while using a toner having a small particle diameter.

  In the present invention, the ratio of particles having an equivalent circle diameter of 0.6 to 1.0 μm is 4 to 7% by number or less, and the ratio of particles having an equivalent circle diameter of 0.6 to 2.0 μm is 8 to 12% by number or less. When the ratio of particles having an equivalent circle diameter of 0.6 to 3.0 μm is 18 to 22% by number or less, the problem of sleeve contamination can be overcome. If the ratio of particles having an equivalent-circle diameter of 0.6 to 1.0 μm exceeds the range, not only sleeve contamination but also toner scattering is likely to occur during development, and internal contamination occurs. Further, even in the case of less than the range, the space of the toner layer of the unfixed image becomes large. As a result, there is a problem that the thermal conductivity is deteriorated at the time of fixing and the image quality is inferior.

Ultra fine powder is removed mainly in the classification process. When the container is filled with the toner after sieving after mixing the external additive or when the container is filled with the toner, the ultrafine powder is scattered. As a result, the content of the ultrafine powder is reduced, but it cannot be actively reduced.
The classification is adjusted to a desired particle size distribution by a wind classifier or the like. When a wind classifier is used, it is possible to adjust the cut of ultrafine powder and fine powder by adjusting the air volume when the toner is put into the classifier.

  Next, a toner particle diameter measuring method using FPIA 2100 will be described as an example. Put a spatula cup of toner in a beaker, add 1 ml of surfactant, and apply ultrasonic waves in water for 30 seconds. Further, 60 ml of physiological saline is added and ultrasonic waves are applied in water for 60 seconds. 0.30 μl of the dispersion thus prepared is sucked and measured in the HPF mode in the range of 0.6 to 400 μm with 1-fold dilution. The particle content of 1 μm or less, 2 μm or less, or 3 μm or less is obtained from the obtained data.

[Developer carrier (sleeve)]
The sleeve is manufactured as follows. Referring to FIG. 3, first, aluminum is extruded hot to form a cylindrical shape. As the material of the developing sleeve, brass, stainless steel, conductive resin or the like can be used in addition to aluminum, but aluminum is often used from the viewpoint of cost and accuracy. Next, a groove extending in the axial direction is formed on the outer periphery of the sleeve by cold-drawing cylindrical aluminum from the inner peripheral surface of the die having V-shaped convex portions formed on the inner peripheral surface. Here, the inner diameter of the die may be slightly smaller than the outer diameter of the sleeve, and processing for increasing the deflection accuracy of the sleeve may be performed simultaneously with the processing of the groove. The number of sleeves is about 50 to 100. The groove may be formed at the time of hot extrusion production of aluminum.

  Next, a flange (652a) is press-fitted and fixed to one side of the raw tube. Grinding is performed on the outer periphery of the developing sleeve in such a state. The state is shown in the figure. One holding portion (780) of the grinding device holds the boss portion (651a), and the other holding portion (780) holds the end portion of the sleeve. The boss portion (651a) is supported as a journal portion of the sleeve so that the doctor blade can rotate freely, and is supported by a shaft of a magnet, which is a journal portion of the developing roller. Therefore, by grinding with the boss portion (651a) as a reference, high runout accuracy is maintained even when incorporated in the developing device. Then, the sleeve is rotated by rotating the holding portion (780). Then, the grinding wheel (710a) is slid in the axial direction of the developing sleeve (650), and grinding is performed until the outer peripheral runout of the developing sleeve (650) becomes 20 μm or less. At the same time, the outer periphery of the boss portion (651a) as the sleeve journal portion is also ground with another grindstone (710b) to increase the deflection accuracy of the boss portion (651a) as the sleeve journal portion. Thereby, the gap fluctuation between the doctor blade and the sleeve and the gap fluctuation between the photosensitive member and the sleeve can be suppressed.

  Returning to the toner again, the present invention further uses a toner FT-IR (Fourier Transform Infrared Spectrometer) to measure the characteristic spectrum peak height W of the wax measured by the ATR method (total reflection method). It is also important that the peak ratio W / R expressed using the peak height R of the characteristic spectrum of the binder resin is 0.050 to 0.100. When the peak ratio is 0.050 or less, sleeve fixation does not occur, but offset occurs during fixing. On the other hand, when the peak ratio is 0.100 or more, wax tends to adhere to the sleeve surface, and fine powder toner is easily fixed to the trigger.

The amount of surface wax is determined from the peak intensity ratio obtained from the ATR spectrum by the ATR method (total reflection method) using FT-IR (Fourier transform infrared spectroscopic measurement device). Since the ATR method requires a smooth surface, the toner is pressure-molded to create a smooth surface. At this time, pressure molding was performed by applying 1 t to 0.6 g of toner for 30 sec to obtain a pellet having a diameter of 20 mm. In the present invention, W is a characteristic spectrum of a wax of 2850 cm ⁻¹ (FIG. 1), and R is a peak height of a characteristic spectrum of a binder resin (for example, 829 cm ⁻¹ in the case of a polyester resin, FIG. 2). , W / R can be calculated as the peak intensity ratio. In the present invention, the peak intensity ratio is obtained by converting the spectrum to absorbance and using the peak height.

  In the present invention, any known wax can be used for the toner, and in particular, de-free fatty acid type carnauba wax, montan wax and oxidized rice wax can be used alone or in combination. The carnauba wax is preferably a microcrystalline one, having an acid value of 5 or less and a particle size of 1 μm or less when dispersed in a toner binder. The montan wax generally refers to a montan wax refined from minerals, and like a carnauba wax, it is microcrystalline and preferably has an acid value of 5 to 14. The oxidized rice wax is obtained by air-oxidizing rice bran wax, and the acid value is preferably 10-30. As other mold release agents, any conventionally known mold release agents such as solid silicone varnish, higher fatty acid higher alcohol, montan ester wax, and low molecular weight polypropylene wax can be mixed and used. The amount of these release agents used is 1 to 20 parts by weight, preferably 3 to 10 parts by weight, based on the toner resin component.

  As the external additive, any conventionally known external additive such as silica, titanium oxide, silicon carbide, aluminum oxide, barium titanate or the like can be used alone or in combination. The amount of these external additives used is 0.1 to 5 parts by weight, preferably 0.5 to 2 parts by weight, based on the toner weight.

  In the present invention, silica or titanium oxide is mixed. By using these external additives, the rising of the charge of the toner becomes much better than when it is not mixed, and the fluidity is further improved, leading to an improvement in image quality.

The binder resin used in the present invention is preferably a polyester resin that can achieve low-temperature fixing.
The polyester resin is obtained by condensation polymerization of alcohol and carboxylic acid. Examples of the alcohol used include glycols such as ethylene glycol, diethylene glycol, triethylene glycol and propylene glycol, etherified bisphenols such as 1.4-bis (hydroxymethyl) cyclohexane and bisphenol A, and other divalent alcohols. Mention may be made of monomers and trihydric or higher polyhydric alcohol monomers.

  Examples of carboxylic acids include divalent organic acid monomers such as maleic acid, fumaric acid, phthalic acid, isophthalic acid, terephthalic acid, succinic acid, and malonic acid, 1,2,4-benzenetricarboxylic acid, 1 , 2,5-benzenetricarboxylic acid, 1,2,4-cyclohexanetricarboxylic acid, 1,2,4-naphthalenetricarboxylic acid, 1,2,5-hexanetricarboxylic acid, 1,3-dicarboxyl-2-methylenecarboxy Mention may be made of trivalent or higher polyvalent carboxylic acid monomers such as propane and 1,2,7,8-octanetetracarboxylic acid. Here, the glass transition temperature Tg of the polyester resin is preferably 55 ° C. or higher, more preferably 60 ° C. or higher, from the viewpoint of heat preservation.

In the present invention, as the resin component in the toner, a resin other than the polyester resin can be used in combination as long as the performance of the toner is not impaired. Examples of usable resins in this case include the following, but are not limited thereto. Polystyrene, chloropolystyrene, poly α-methylstyrene, styrene / chlorostyrene copolymer, styrene / propylene copolymer, styrene / butadiene copolymer, styrene / vinyl chloride copolymer, styrene / vinyl acetate copolymer, styrene / Maleic acid copolymer, styrene / acrylic acid ester copolymer (styrene / methyl acrylate copolymer, styrene / ethyl acrylate copolymer, styrene / butyl acrylate copolymer, styrene / octyl acrylate copolymer) Styrene / phenyl acrylate copolymer), styrene / methacrylic acid ester copolymer (styrene / methyl methacrylate copolymer, styrene / ethyl methacrylate copolymer, styrene / butyl methacrylate copolymer, styrene) / Phenyl methacrylate copolymer, etc.) Styrene resins (homopolymers or copolymers containing styrene or styrene-substituted products) such as styrene / α-chloromethyl acrylate copolymer, styrene / acrylonitrile / acrylate ester copolymer, vinyl chloride resin, styrene / Vinyl acetate copolymer, rosin-modified maleic resin, phenol resin, epoxy resin, polyethylene resin, polypropylene resin, ionomer resin, polyurethane resin, silicone resin, ketone resin, ethylene / ethyl acrylate copolymer, xylene resin, polyvinyl butyral resin Petroleum resin, hydrogenated petroleum resin, etc. These resins are not limited to single use but can be used in combination of two or more.
Also, these production methods are not particularly limited, and any of bulk polymerization, solution polymerization, emulsion polymerization, and suspension polymerization can be used.

  Examples of the colorant of the present invention include carbon black, lamp black, iron black, aniline blue, phthalocyanine blue, phthalocyanine green, Hansa Yellow G, rhodamine 6C lake, calco oil blue, chrome yellow, quinacridone, benzidine yellow, rose bengal, Any conventionally known dyes and pigments such as dyes and pigments such as triallylmethane dyes can be used alone or in combination, and can be used as black toners or full color toners. The amount of these colorants to be used is usually 1 to 30% by weight, preferably 3 to 20% by weight, based on the toner resin component.

  In the present invention, a charge control agent may be used as necessary. As the charge control agent, any conventionally known charge control agent such as a nigrosine dye, a metal complex dye, or a quaternary ammonium salt can be used by mixing with a zirconium compound. The amount of these charge control agents used is 0.1 to 10 parts by weight, preferably 1 to 5 parts by weight, based on the toner resin component.

The toner production method includes a pulverization method, a suspension polymerization method, an emulsion polymerization method and the like, and is not particularly limited. Here, the grinding method will be described.
As an apparatus for melt-kneading the toner for producing the pulverized toner, a batch-type two-roll, a Banbury mixer, a continuous twin-screw extruder, a continuous single-screw kneader, or the like is preferably used.
For pulverization, coarse pulverization can be performed using a hammer mill, a rotoplex, or the like, and a fine pulverizer using a jet stream or a mechanical pulverizer can be used. The average particle size is 3 to 15 μm. It is desirable to do so.

  In the external addition of the external additive to the toner base, the toner base and the external additive are mixed and stirred using a mixer, and the external additive is crushed and coated on the toner surface. At this time, it is important in terms of durability that external additives such as inorganic fine particles and resin fine particles are uniformly and firmly attached to the toner base.

[Image forming apparatus]
FIG. 4 is a schematic diagram for explaining an example of an image forming apparatus and an image forming method having the developing device of the present invention, and the following modifications also belong to the category of the present invention.

  In FIG. 4, a charging device (not shown) for charging the drum surface around the photosensitive drum (20), which is an electrostatic latent image carrier, for forming a latent image on a uniformly charged surface. An exposure unit composed of a laser beam (not shown), a developing device (40) for forming a toner image by attaching charged toner to a latent image on the drum surface, and a non-transfer device for transferring the toner image on the formed drum to recording paper. An illustrated transfer device and a cleaning device (not shown) for removing residual toner on the drum are sequentially arranged. In such a configuration, the photoreceptor (20) whose surface is uniformly charged by the charging charger of the charging device forms an electrostatic latent image by the exposure means, and forms a toner image by the developing device (40). . The toner image is transferred from the surface of the photosensitive drum (20) to a recording sheet conveyed from a paper supply tray (not shown) by a transfer device such as a transfer belt. The recording paper that electrostatically adheres to the photosensitive drum during this transfer is separated from the photosensitive drum by the separation claw. The toner image on the unfixed recording paper is fixed on the recording paper by a fixing device (not shown). On the other hand, toner remaining on the photosensitive drum without being transferred is removed and collected by a cleaning device. The residual toner is removed and initialized, and the next image forming process is used.

The configuration of the developing device (40) will be further described. The developing device (40) disposed opposite to the photosensitive drum (20) as a latent image carrier has a developing sleeve (41 as a developer carrier). ), A developer accommodating member (42), a doctor blade (43) as a regulating member, a support case (44), and the like.
To a support case (44) having an opening on the side of the photosensitive drum (20), a toner hopper (45) as a toner storage portion for storing the toner (21) is joined. In the developer accommodating portion (46) that accommodates the developer composed of toner (21) and carrier particles (23) adjacent to the toner hopper (45), the toner particles (21) and carrier particles (23) are agitated. In addition, a developer stirring mechanism (47) is provided for imparting friction / release charges to the toner particles.

Inside the toner hopper (45), a toner agitator (48) and a toner replenishing mechanism (49) are disposed as toner supplying means rotated by a driving means (not shown).
The toner agitator (48) and the toner replenishing mechanism (49) send out the toner (21) in the toner hopper (45) toward the developer container (46) while stirring.
A developing sleeve (41) is disposed in a space between the photosensitive drum (20) and the toner hopper (45). The developing sleeve (41), which is driven to rotate in the direction of the arrow by a driving means (not shown), has a relative position relative to the developing device (40) in order to form a magnetic brush made of carrier particles (23). A magnet (not shown) is provided as magnetic field generating means.
A regulating member (doctor blade) (43) is integrally attached to the side of the developer accommodating member (42) facing the side attached to the support case (44). In this example, the regulating member (doctor blade) (43) is disposed in a state where a certain gap is maintained between the tip thereof and the outer peripheral surface of the developing sleeve (41).

Using such a device without limitation, the image forming method of the present invention is performed as follows.
That is, with the above configuration, the toner (21) sent out from the toner hopper (45) by the toner agitator (48) and the toner replenishing mechanism (49) is transported to the developer accommodating portion (46), where the developer agitation is performed. By stirring by the mechanism (47), a desired friction / peeling charge is imparted, and the carrier particles (23) and the developer are carried on the developing sleeve (41) as a developer, and the outer peripheral surface of the photosensitive drum (20). A toner image is formed on the photosensitive drum (20) by being transported to the opposite position and only the toner (21) is electrostatically coupled with the electrostatic latent image formed on the photosensitive drum (20). Is done. In the process, an electrostatic latent image of a reference toner pattern is formed on the photosensitive drum (20) which is a latent image carrier, and this latent image is developed by a developing sleeve (41) as a developer carrier. The reflection density of the reference toner pattern developed on the photosensitive drum (20) is monitored by an ID sensor (not shown), and the detected output value is a drive control circuit (not shown) for the developing device (40). The density is adjusted by feeding back to the above.

EXAMPLES The present invention will be further described below with reference to examples, but the present invention is not limited thereto.
In the following, “part” means part by mass, and “%” means mass%.

<Production Example of Toner 1>
Polyester resin (A) 45 parts (weight average molecular weight 5,000, Tg 63 ° C., THF insoluble content 0%, softening point 143 ° C.,
・ Molecular weight peak 4,200)
Polyester resin (B) 45 parts (weight average molecular weight 5,800, Tg 62 ° C., chloroform insoluble content 20%, softening point 99 ° C.,
・ Molecular weight peak 3,600)
・ Styrene / acrylic resin 15 parts (weight average molecular weight 26,000, Tg 66 ° C., chloroform insoluble content 4%, softening point 143 ° C., molecular weight peak 4,300)
-Wax 5.2 parts (defree fatty acid type carnauba wax)
・ 10 parts of carbon black (# 44: manufactured by Mitsubishi Chemical Corporation)
-1 part of zirconia compound 1 A mixture of the above composition was sufficiently stirred and mixed in a Henschel mixer, heated and melted at a temperature of 130 to 140 ° C for about 30 minutes with a roll mill, cooled to room temperature, and the resulting kneaded product was jetted. A toner base was obtained by pulverization and classification with a mill and an air classifier. The air pressure of the jet mill was set to 0.65 MPa, and the air volume at the classifier was set to 60 m ³ / h. The toner base thus obtained was mixed by adding 0.5 wt% of hydrophobic silica and 0.5 wt% of titanium oxide to obtain [Toner 1]. The ratio of particles having an equivalent circle diameter of 0.6 to 1.0 μm in the obtained toner is 4%, and the ratio of particles having an equivalent circle diameter of 0.6 to 2.0 μm is 8% by number, 0.6 to The proportion of particles having a circle-equivalent diameter of 3.0 μm was 18% by number, and W / R was 0.100.

[Evaluation]
<Manufacture of carriers>
Silicone resin solution 132.2 parts [solid content 23% by mass (SR2410: manufactured by Toray Dow Corning Silicone)]
・ Aminosilane 0.66 part [100% by mass of solid content (SH6020: manufactured by Toray Dow Corning Silicone)]
31 parts of conductive particles 1 [base: alumina, surface treatment; lower layer = tin dioxide / upper layer = indium oxide containing tin dioxide, particle size: 0.35 μm, particle powder specific resistance: 3.5 Ω · cm]
-300 parts of toluene was dispersed with a homomixer for 10 minutes to obtain a silicone resin coating film forming solution. Volume average particle size: 70 μm calcined ferrite powder is used as the core material, and the temperature inside the coater is 40 ° C. by a Spira coater (Okada Seiko Co., Ltd.) so that the coating film forming solution has a film thickness of 0.15 μm on the surface of the core material. And dried. The obtained carrier was fired in an electric furnace at 300 ° C. for 1 hour.
After cooling, the ferrite powder bulk was pulverized using a sieve having an opening of 125 μm to obtain [Carrier 1].
4% by mass of the toner 1 produced as described above and 96% by mass of the prototype carrier 1 are mixed, and the resulting two-component developer is used to make the image forming apparatus shown in FIG. Printing is performed with MF-200, and evaluation images are printed at 50,000 sheets / day, initial and 100,000 sheets, respectively. As an evaluation condition of the evaluation machine, the linear velocity was set to 450 mm / sec. Sleeves with Sm, Ra and Rz of 20, 0.1 and 1.0 μm were used.
The image evaluation was made by comparing the printed image after printing 100,000 sheets with the first printed image and visually judging using a sample. In the sleeve evaluation, the most severely stained part was measured with a Macbeth densitometer and judged from the density.

<Image evaluation>
○: The image quality is equivalent to the first image ×: Image quality is inferior to the first image <Sleeve Evaluation>
○: Concentration is 1.0 or less ×: Concentration is 1.0 or more The results are shown in Table 1.

  Evaluation was performed in the same manner as in Example 1 except that 4 parts of the wax was used. The results are shown in Table 1.

  Evaluation was performed in the same manner as in Example 1 except that sleeves having Sm, Ra and Rz of 60, 0.6 and 8.0 μm were used. The results are shown in Table 1.

Evaluation was performed in the same manner as in Example 1 except that 5 parts of wax, the air volume in the classifier was 500 m ³ / h, and the sleeves had Sm, Ra and Rz of 60, 0.6 and 8.0 μm, respectively.
The results are shown in Table 1.

Evaluation was performed in the same manner as in Example 1 except that 3.8 parts of wax, air volume in a classifier was 500 m ³ / h, and Sm, Ra and Rz of the sleeve were 60, 0.6 and 8.0 μm, respectively. did. The results are shown in Table 1.

Evaluation was conducted in the same manner as in Example 1 except that 5 parts of the wax and the air volume in the classifier were 500 m ³ / h. The results are shown in Table 1.

[Comparative Example 1]
Evaluation was performed in the same manner as in Example 1 except that 5.4 parts of the wax and the air volume of the classifier were 650 m ³ / h. The results are shown in Table 1.

[Comparative Example 2]
Evaluation was performed in the same manner as in Example 1 except that the amount of the wax was changed to 5.4 parts. The results are shown in Table 1.

[Comparative Example 3]
Evaluation was performed in the same manner as in Example 1 except that the amount of the wax was 3.8 parts. The results are shown in Table 1.

[Comparative Example 4]
Evaluation was conducted in the same manner as in Example 1 except that sleeves having Sm, Ra and Rz of 65, 0.7 and 9.0 μm were used. The results are shown in Table 1.

[Comparative Example 5]
Evaluation was performed in the same manner as in Example 1 except that 4.8 parts of wax, air volume in a classifier was 450 m ³ / h, and sleeves Sm, Ra, and Rz were 60, 0.6, and 8.0 μm, respectively. did. The results are shown in Table 1.

[Comparative Example 6]
Evaluation was performed in the same manner as in Example 1 except that the air volume in the classifier was 500 m ³ / h, and the sleeve Sm, Ra, and Rz were 60, 0.6, and 8.0 μm, respectively. The results are shown in Table 1.

[Comparative Example 7]
3.6 parts of wax, air volume in the classifier 500 meters ³ / h, the same evaluation as in Example 1 except for using those Sm sleeve, Ra and Rz are each 60,0.6 and 8.0μm did. The results are shown in Table 1.

[Comparative Example 8]
Evaluation was performed in the same manner as in Example 1 except that 5.0 parts of the wax, the air volume in the classifier was 500 m ³ / h, and the sleeves had Sm, Ra and Rz of 18, 0.08 and 0.8 μm, respectively. did. The results are shown in Table 1.

20 Electrostatic latent image carrier (photosensitive drum)
DESCRIPTION OF SYMBOLS 21 Toner 23 Carrier particle 40 Developing apparatus 41 Developing sleeve 42 Developer accommodating member 43 Doctor blade as regulating member 44 Support case 45 Toner accommodating portion (toner hopper)
46 Developer storing portion 47 Developer stirring mechanism 48 Toner agitator 49 Toner replenishing mechanism

JP 2002-323797 A JP 2004-004209 A

Claims (3)

A developer container that contains a two-component developer containing at least a binder resin, a colorant, a toner containing wax, and a carrier, and an opening provided in the developer container that faces the latent image carrier. The developer in the developer container is carried on the surface and rotated, and the toner is supplied to the latent image on the surface of the latent image carrier and developed at a position facing the latent image carrier. A developing device comprising: a developer carrying member that performs the above operation; and a developer carrying member that applies a conveying force to the developer along the axial direction of the developer carrying member and stirs the developer. An electrostatic latent image of a reference toner pattern is formed on the body, the reference toner pattern is developed by the developer carrier, the reflection density of the reference toner pattern is detected, and the density adjustment is performed based on the detected output value In an image forming apparatus, the FT-IR of the toner A characteristic spectral peak height W of the wax and a characteristic spectral peak height R of the binder resin measured by the ATR method (total reflection method) using a Fourier transform infrared spectroscopic measurement apparatus). The peak ratio W / R shown by using the above is 0.050 to 0.100, and the toner has an equivalent circle diameter of 0.6 to 1.0 μm measured by a flow type particle image analyzer (FPIA). Of particles having an equivalent circle diameter of 4 to 7% by number, particles having an equivalent circle diameter of 0.6 to 2.0 μm, and 8 to 12% by number of particles having an equivalent circle diameter of 0.6 to 3.0 μm. ratio is 18 to 22% by number, and the longitudinal direction of the average irregularity interval of said developer carrying member Sm ([mu] m), the arithmetic average roughness Ra ([mu] m) and 10-point average roughness Rz ([mu] m) is of the formula An image forming apparatus having a range.
20 ≦ Sm ≦ 60 Formula (1)
0.1 ≦ Ra ≦ 0.6 (2)
0 <Rz ≦ 8.0 Equation (3)

The image forming apparatus according to claim 1 , wherein the image forming apparatus uses a toner obtained by mixing an external additive. 3. The image forming apparatus according to claim 1, wherein the image forming apparatus uses toner mixed with silica or titanium oxide as the external additive.

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