JP2017009959A - Development apparatus and image forming method - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a development apparatus capable of accurately detecting an amount of a toner remaining in a development apparatus.SOLUTION: There is a development apparatus having a toner storage section storing a toner carrier which has a region formed of a nonmagnetic conductive resin member existing on the bottom surface of the toner storage section, uses the toner carrier as a first electrode and the region as a second electrode, and detects an amount of a toner in the toner storage section based on electrostatic capacity between the first electrode and the second electrode, where the toner is a toner having toner particles containing a binder resin and a magnetic body, (i) saturation magnetization in a magnetic field of the toner of 796 kA/m is 15.0 Am/kg or more and 35.0 Am/kg or less, and (ii) a dielectric constant at 40°C and 100 kHz of the toner is 25.0 pF/m or more and 60.0 pF/m or less.SELECTED DRAWING: Figure 1

Description

  The present invention relates to a developing device and an image forming method used in a recording method using an electrophotographic method, an electrostatic recording method, and an electrostatic printing method.

  In an image forming apparatus using an electrophotographic image forming process, a process cartridge system is adopted in which a photosensitive member and process means acting on the photosensitive member are integrally formed into a cartridge and the cartridge can be attached to and detached from the image forming apparatus main body. ing.

  According to this process cartridge system, the maintenance of the apparatus can be performed by the user himself / herself without depending on the service person, so that the operability can be remarkably improved. For this reason, this process cartridge system is widely used in image forming apparatuses.

  Further, in the process cartridge type image forming apparatus, since the user himself replaces the process cartridge as described above, a toner remaining amount detecting means for notifying the user when the toner is consumed is provided. Many. As one method of this toner remaining amount detecting means, there is a method of detecting a toner amount by detecting a change in electrostatic capacitance between a plurality of electrodes arranged in a process cartridge.

  As a configuration of these electrodes, an electrode plate detection type in which an electrode plate is arranged at a predetermined interval from the toner carrier and the electrostatic capacitance between the toner carrier and the toner carrier is detected (for example, patent document). 1). In general, SUS304 or SUS316 is used for the electrode plates used in these inventions.

  However, when these SUS electrodes are used, the magnetic toner adheres to the electrodes when the magnetic toner is used. This is because SUS304 or SUS316 austenitic steel is magnetized by being subjected to stress or heat such as cutting or cutting, thereby causing martensitic transformation and precipitation of a ferrite layer.

  As a result, the magnetic toner adheres to the magnetized electrode, and the accuracy of detecting the remaining amount of toner decreases.

  In order to detect the remaining amount of toner with high accuracy, improvements from toner have also been made. For example, Patent Document 2 proposes using toner from which easily adhering components have been removed to increase the remaining toner detection accuracy. It is described that this system can accurately determine the remaining amount of toner even in an environment where the fluidity of the toner is lowered, such as a high temperature and high humidity environment.

  However, the above proposal is an evaluation based on continuous output, and is not an evaluation that takes into account a situation where the fluidity of the toner is more likely to change, such as an intermittent evaluation or a situation where the environment changes. Further, there is no description regarding the electrical characteristics and magnetic characteristics of the toner, and there is still room for improvement.

  In this way, there is still room for studying the remaining amount detection with high accuracy.

JP 2007-264612 A JP 2002-323791 A

  An object of the present invention is to accurately detect the amount of toner remaining in the developing device regardless of the environment and the printing state, and to notify the user of the remaining amount of toner and the remaining printable number of sheets sequentially. Therefore, it is possible to provide a developing device and an image forming method having a toner remaining amount detecting unit useful for the user.

The present invention is a developing device including a toner carrier, and a toner container that contains toner and has a toner stirring member that supplies the toner to the toner carrier.
There is a region formed of a nonmagnetic conductive resin member on the bottom surface of the toner container,
Using the toner carrier as a first electrode and the region as a second electrode, detection of the amount of toner in the toner container based on the capacitance between the first electrode and the second electrode Is done,
The toner is a toner having toner particles containing a binder resin and a magnetic material,
(I) the saturation magnetization of the toner at a magnetic field of 796 kA / m is 15.0 Am ² / kg or more and 35.0 Am ² / kg or less;
(Ii) The developing device is characterized in that the toner has a dielectric constant of 25.0 pF / m to 60.0 pF / m at 40 ° C. and 100 kHz.

The present invention also relates to an image forming method for developing an electrostatic latent image formed on an electrostatic latent image carrier with toner carried on the toner carrier, and detecting the amount of toner in the toner container. Because
A toner carrier and a toner agitating member that contains the toner and supplies the toner to the toner carrier are provided inside, and an area formed of a nonmagnetic conductive resin member exists on the bottom surface of the toner carrier. A developing device having a toner container
Rotating the toner stirring member about a direction parallel to the longitudinal direction of the toner carrier as a rotation axis;
When the developing device is installed in the printer body, a line parallel to the printer installation surface passing through the rotation center axis of the toner stirring member is arranged so as to pass below the lower end of the toner carrier,
The toner is supplied to the toner carrier from below the toner carrier, and development is performed with the toner carried on the toner carrier,
The amount of toner in the toner container is detected by using the toner carrier as the first electrode and the region as the second electrode, and detecting the capacitance between the first electrode and the second electrode. Based on
The toner is a toner having toner particles containing a binder resin and a magnetic material,
(I) the saturation magnetization of the toner at a magnetic field of 796 kA / m is 15.0 Am ² / kg or more and 35.0 Am ² / kg or less;
(Ii) The present invention relates to an image forming method using a toner having a dielectric constant of 25.0 pF / m or more and 60.0 pF / m or less at 40 ° C. and 100 kHz.

  As described above, according to the present invention, it is possible to accurately detect the amount of toner remaining in the developing device regardless of the environment and the printing state.

1 is a schematic configuration diagram of an image forming apparatus having a developing device according to an embodiment of the present invention. 1 is a schematic cross-sectional view of a developing device according to an embodiment of the present invention. FIG. 3 is a schematic cross-sectional view of a toner remaining amount detecting unit according to an embodiment of the present invention. It is a field diagram in which a conductive resin member is formed. It is explanatory drawing explaining an example of the conductive resin sheet which concerns on this invention. FIG. 6 is a relationship diagram between a remaining toner amount and electrostatic capacity according to an embodiment of the present invention. FIG. 6 is an example of a relationship diagram between a remaining toner amount and electrostatic capacity in an example according to the present invention and a comparative example. FIG. 6 is a diagram illustrating a state of toner in a toner container. It is explanatory drawing of the measuring method of resistance.

  As a result of intensive studies on the toner remaining amount detecting means and the toner used therefor, the present inventors have used a specific configuration and member as an electrode, and further controlled the magnetic characteristics and electrical characteristics of the toner, so that the environment The present inventors have found that the remaining amount of toner can be detected accurately regardless of the printing state.

  A developing device and an image forming apparatus according to the present invention will be described below with reference to the drawings. However, the dimensions, materials, shapes, and relative arrangements of the components described are to be changed as appropriate according to the configuration of the apparatus to which the invention is applied and various conditions, and the scope of the invention is limited to the following. Not intended to do.

<Description of Image Forming Apparatus and Image Forming Process>
FIG. 1 shows a schematic configuration of an electrophotographic laser beam printer as an example of the image forming apparatus of the present invention.

  An image forming apparatus (printer) 12 using the electrophotographic technology of the present case includes a photoreceptor 1 which is an electrostatic latent image carrier. Around the photoconductor 1, in order along the rotation direction of the photoconductor 1, a charging roller 2 as a charging unit, an exposure device 6 as an exposure unit, a developing device 3 as a developing unit, a transfer roller 4 as a transfer unit, A cleaning device 5 having a cleaning blade 5a as a cleaning means is disposed. A fixing device 7 is disposed downstream of the transfer nip N formed between the photosensitive member 1 and the transfer roller 4 in the transfer material conveyance direction.

<Detailed Description of Image Forming Apparatus>
In this embodiment, the photosensitive member 1 has an OPC photosensitive layer on an aluminum drum base, and has a predetermined circumference by a driving unit (not shown) provided on the image forming apparatus main body (printer main body) side. It is rotationally driven in the direction of the arrow (clockwise) at high speed.

  A charging roller 2 as a charging unit uniformly charges the photosensitive member 1 to a predetermined polarity and potential by a charging bias applied from a charging bias power source (not shown). As the charging bias, an AC voltage Vpp at which the charging roller 2 is sufficiently discharged and a DC voltage Vdc corresponding to the photosensitive member dark portion potential Vd are superimposed and applied. For the AC AC component of the charging bias, constant current control is performed such that a constant current always flows between the photoconductor 1 and the charging roller 2.

  The exposure apparatus 6 uses a laser output unit to output laser light (exposure beam L) obtained by modulating image information input from a personal computer (not shown) or the like according to a time-series electrical digital image signal by a video controller (not shown). (Not shown). The exposure beam L scans and exposes the surface of the charged photoreceptor 1 to form an electrostatic latent image corresponding to image information.

  The developing device 3, the voltage applying unit 15, and the toner remaining amount detecting unit 17 (not shown) will be described in detail later.

  A transfer roller 4 serving as a transfer unit contacts the surface of the photoreceptor 1 with a predetermined pressing force to form a transfer nip portion N, and a transfer bias is applied from a transfer bias power source (not shown). With this transfer bias, the toner image on the surface of the photoconductor 1 is transferred to a transfer material P such as paper at the transfer nip N between the photoconductor 1 and the transfer roller 4.

  The fixing device 7 includes a heating roller and a pressure roller provided with a halogen heater (not shown) inside. While the transfer material P is nipped and conveyed at the fixing nip between the fixing roller and the pressure roller, the toner image transferred onto the surface of the transfer material P is heated, melted and pressed to be thermally fixed to obtain a permanent image. The permanent image on the transfer material P that has been fixed is discharged out of the image forming apparatus 12.

  A cleaning blade 5a as a cleaning unit cleans toner remaining without being transferred onto the photoreceptor 1, and the photosensitive drum 1 is again used for image formation.

  The photosensitive member 1, the charging roller 2, the developing device 3, and the cleaning blade 5a are integrated as a unit, and form a detachable process cartridge in the image forming apparatus main body.

<Details of developing device>
Details of the developing device 3 will be described with reference to FIG. The developing device 3 includes a developing container 3a as a toner storage unit, toner T, a toner agitating member 10 for agitating the toner T, a toner carrier 8 and a magnet roller 8a as a developer carrier, and a toner T on the toner carrier 8. The developing blade 11 that regulates the layer thickness and frictionally charges, the seal member 3 b that seals the toner T, and the antenna member 14 that detects the remaining amount of toner.

  The stirring member 10 includes a support rod and a stirring sheet. Both ends of the support rod are supported by the developing container 3a and rotate clockwise in the drawing. As the stirring sheet, a PPS sheet having a thickness of 100 μm was used, and one end in the short direction was pressure-bonded to the support rod.

  The toner carrier 8 is a non-magnetic aluminum sleeve surface coated with a medium resistance resin layer. The arrangement is opposite the surface of the photoreceptor 1, and both ends of the sleeve are rotatably supported by the opening of the developing device 3. The sleeve is connected to voltage application means 15 disposed in the image forming apparatus main body, and applies a bias at a predetermined timing during printing.

  A magnet roller 8a, which is a magnetic field generating means, is in the toner carrier 8, and a plurality of magnetic poles N and S are alternately formed. In addition, the magnetic poles are always kept in the same direction because they are always held at a fixed position without rotating.

  The magnetic force of these magnetic poles is preferably 50 mT or more and 120 mT or less from the viewpoint of improving the toner transportability and improving the remaining toner accuracy described below.

  The developing blade 11 has a urethane rubber blade bonded and fixed to a support sheet metal. The support sheet metal is fixed to the developing container 3a so as to come into contact with the toner carrier 8 with an appropriate contact pressure in order to appropriately regulate the layer thickness of the toner T and to perform frictional charging.

  The seal member 3b is adhered in the developing container 3a so that the toner T does not leak from the region in the drawing in order to prevent toner leakage during transportation. The antenna member 14 will be described in detail later.

  With the above configuration, after the seal member 3 b is removed, the toner T is sent to the vicinity of the toner carrier 8 by the stirring member 10. The toner T in the vicinity of the toner carrier 8 is supplied to the surface of the toner carrier 8 by the magnetic field of the magnet roller 8a. Thereafter, the toner T on the surface of the toner carrier 8 is optimized by the developing blade 11 and is charged by friction charging. The charged toner T visualizes the electrostatic latent image on the photoreceptor 1 as a toner image in the developing region 31.

  FIG. 2A and FIG. 2B show two developing devices in which the positional relationship between the stirring member 10 and the toner carrier 8 is different. FIG. 2 (b) shows that the agitating member 10 rotates with the direction parallel to the longitudinal direction of the toner carrier as the rotation axis, and the printer is installed through the rotation center axis of the agitating member 10 when the developing device is installed in the printer body. FIG. 3 is a schematic diagram of a developing device in which a line parallel to the surface passes below a lower end of a toner carrier and supplies toner to the toner carrier from below the toner carrier. Compared with the developing device (FIG. 2 (a)) that supplies toner to the toner carrier due to its own weight, the developing device having such a structure causes the toner to circulate in the toner container and to make the toner layer more uniform. Therefore, it is a preferable form from the viewpoint of improving the accuracy of detecting the remaining amount of toner.

<Detailed Explanation of Toner Remaining Detection Unit>
Next, with reference to FIG. 3, the toner remaining amount detecting means, which is a feature of the present invention, will be described.

  In the present invention, the toner remaining amount detecting means 17 includes a voltage applying means 15 for applying a bias to the electrodes, a toner carrier 8 as an electrode, an antenna member 14 as an opposite electrode, and a toner remaining amount detecting device 18. Become. The toner carrier 8 is as described above.

  The antenna member 14 is a nonmagnetic conductive resin member in which conductivity is ensured by dispersing carbon in polystyrene resin (hereinafter referred to as PS resin). Thus, by using the non-magnetic conductive resin member as the antenna member, the remaining amount detection accuracy of the toner can be improved without magnetizing the electrode.

  Further, the conductive resin member is preferably a flexible conductive resin sheet. The conductive resin sheet having flexibility is installed along the lower surface of the toner container. As a result, the conductive resin sheet can contact toner more densely with the toner accumulated by gravity as a surface instead of a point, and the remaining amount of toner can be measured more accurately. It is not necessary to use PS resin or carbon as long as it is non-magnetic and conductive.

  The conductive resin member was bonded and fixed with a double-sided tape near the toner carrier 8 on the bottom surface of the inner wall of the developing container 3a. The fixing method may be any method that can be fixed to the frame as an electrode, such as insert molding, coating, and two-color molding. The conductive resin member is disposed so as to be in contact with a contact (not shown) disposed in front of the bottom surface of the conductor developing container 3a, and is grounded via a toner remaining amount detecting device 18 disposed in the image forming apparatus. It is connected to the.

  In the above configuration, by applying a bias to the toner carrier 8 by the voltage application means 15, the electrostatic capacity between the toner carrier 8 and the antenna member 14 can be detected by the toner remaining amount detection device 18. At this time, since the dielectric constant of the toner is larger than the dielectric constant of air, the detected capacitance increases as the amount of toner existing between the electrodes increases. In the configuration of the present embodiment, sequential remaining amount detection for sequentially detecting capacitance during printing is performed.

<About antenna members>
The antenna member 14 is arranged so that a nonmagnetic or diamagnetic conductive resin member is opposed to the vertically lower side of the toner carrier so that the toner, which is a magnetic material, does not adhere. Specifically, the bottom surface of the inner wall of the developer container 3a was adhered and fixed to the vicinity of the toner carrier 8 with a double-sided tape.

  The antenna member 14 is preferably arranged in the vicinity of the toner carrier 8 in the short direction. This is because the toner that is regulated and dropped by the developing blade 11 is accurately detected as the remaining toner.

  In this embodiment, the conductive resin sheet is provided so that a part of the conductive resin sheet overlaps with a part of the toner carrier in the direction of gravity so that the electrostatic capacity can be detected more appropriately (see FIG. 3). Region A).

  When the antenna member 14 is in the vicinity of the lower portion of the toner carrier 8 and the toner is likely to be deposited on the electrode surface by gravity, the conductive resin sheet containing resin adheres to the magnetic toner with magnetic force. Therefore, the remaining amount of toner can be measured accurately.

  Also in this embodiment, a conductive resin sheet is provided below the toner carrier in the direction of gravity.

  Further, as shown in FIG. 4, the region 14 formed of the nonmagnetic conductive resin member on the bottom surface of the toner storage portion is 50 with respect to the longitudinal direction of the toner carrier 8 when the developing device is viewed from above. In view of improving the remaining toner detection accuracy, it is preferable that the amount is 40% or more in the direction orthogonal to the longitudinal direction of the toner carrier 8. In particular, it is effective in an environment where the toner has good fluidity such as a low temperature and low humidity environment.

Further, the resistance of the conductive resin member measured by the method described later is 1.0 × 10 ³ Ω or more and 1.0 × 10 ⁵ Ω or less to the antenna member of magnetic toner in a low temperature and low humidity environment. It is preferable for controlling the adhesion of the resin.

  FIG. 5 shows a cross-sectional view of the conductive resin member. Here, a configuration in which a carbon material is dispersed in a resin, a configuration in which another resin layer is sandwiched between resin layers in which the carbon material is dispersed, and a configuration in which a carbon material is applied to the surface of the resin layer on the toner carrier side will be described.

  FIG. 5A shows a conductive resin sheet having a three-layer structure in which a resin layer of PS resin 14d is sandwiched between conductive layers 14c (20 μm to 40 μm) in which carbon black is mixed with PS resin and dispersed.

  In this case, the conductive layer becomes the electrode portion, and the entire conductive resin sheet becomes the electrode. In the electrical connection with the outside, when the conductive resin sheet is cut, the conductive layers on both sides are deformed and connected. It is conceivable to connect an external electrical contact to that part.

  Further, it is also possible to use a conductive resin sheet having a single layer structure (single layer structure) in which carbon black 14e is mixed with EVA resin 14d as shown in FIG. 5B. In this case, the whole becomes an electrode part.

  Furthermore, a conductive resin sheet having a two-layer structure in which carbon black 14e is printed on PS resin 14d as shown in FIG. 5C can also be used.

  In this embodiment, a flexible single-layer conductive resin sheet in which carbon black is dispersed in the EVA substrate shown in FIG. 5B is used.

<Toner remaining amount calculation method>
Next, a method for calculating the remaining amount of toner will be described with reference to FIG.

  FIG. 6 is a relationship diagram between the remaining amount of toner and the capacitance according to the present invention. The vertical axis represents the electrostatic capacity detected by the toner remaining amount detecting means 17, and the horizontal axis represents the toner remaining amount. In the configuration of this embodiment, the capacitance does not change from the initial time (when the toner is fully loaded) to 20% (dotted line A). This is because a sufficient amount of toner remains, and the amount of toner between the toner carrier 8 and the antenna member 14 does not change. When the remaining amount of toner is 20% or later, the electrostatic capacity decreases linearly as the remaining amount of toner decreases. This indicates that the amount of toner between the toner carrier 8 and the antenna member 14 changes according to the remaining amount of toner.

Here, when new, the difference between the electrostatic capacity C _{0 when} no toner is present between the toner carrier 8 and the antenna member 14 and the electrostatic capacity when the toner remaining amount is in the range of Full to 20% is ΔE ₀ . did. Further, when the average value of the electrostatic capacity during printing of one image is output as the electrostatic capacity C, the toner is placed between the electrostatic capacity during image printing and the toner carrier 8 and the antenna member 14. The difference from the electrostatic capacity C ₀ in the absence of this was taken as ΔE. Therefore, the current remaining toner amount is calculated by the following equation (1).
Current remaining toner amount = 20% × ΔE / ΔE ₀ Formula (1)

  The detection result is transmitted to the user by being displayed on a display unit (not shown) in the image forming apparatus or a monitor (not shown) of a personal computer.

  FIG. 7A shows the relationship between the remaining amount of toner actually measured after endurance and the output electrostatic capacity in the configuration of this embodiment. FIG. 7B shows the relationship between the remaining amount of toner actually measured and measured in Comparative Example 1 and the output capacitance. The horizontal axis is the remaining amount of toner actually remaining in the developer container 3a, and the vertical axis is the capacitance.

  In FIG. 7A, which is the configuration of the present embodiment, there is no change in capacitance when the remaining amount of toner is between 100% and 20%. In the area where the remaining amount of toner is 20% or less, the electrostatic capacity decreases linearly as the remaining amount of toner decreases. Here, white spots occurred on the image at the timing of (1) in FIG. At this time, no toner adhered to the antenna member 14. Therefore, even if the developing device is shaken at the timing (1), the white spots were not recovered.

  On the other hand, as shown in FIG. 7B, in Comparative Example 1, as in the configuration of the present embodiment, there is no change in the electrostatic capacity when the remaining amount of toner is between 100% and 20%. In the area where the remaining amount of toner is 20% or less, the electrostatic capacity decreases linearly as the remaining amount of toner decreases. However, a blank image occurred at a timing when the remaining amount of toner is larger than that in the configuration of the present embodiment ((2) in FIG. 7B). When the antenna member 14 was confirmed at this time, the toner adhered to the antenna member 14. Even if the same amount of toner remains between the electrodes, the toner adhering to the antenna member 14 cannot be developed. Therefore, white spots have occurred at timing (2) when the detected toner amount is large.

  The toner is attached to the antenna member 14 because the antenna member 14 is magnetized. Further, when the toner adhering to the antenna member 14 was sucked and the remaining amount of toner was measured again, the detected remaining amount of toner (3) was obtained as in Example 1. The image at that time was a blank image as in the timing (2). As described above, in the first comparative example, the generation timing of the whiteout image differs depending on the amount of toner attached to the antenna member 14. Further, the amount of toner attached to the antenna member 14 varies from one developing device to another. Therefore, the remaining toner detection accuracy is lowered.

  As described above, in the configuration of this example, since the toner does not adhere to the antenna member 14 at the timing (1), it is shown that the toner between the electrodes can be used with good reproduction. That is, a decrease in the remaining toner detection accuracy due to the toner adhering to the antenna member 14 can be suppressed, and the remaining toner detection accuracy is improved.

  Next, in order to detect the remaining amount of toner more precisely, toner design is also important.

  In the toner remaining amount detecting means of the present invention, a conductive resin member is present as a part of the bottom surface of the toner containing portion as an electrode. Therefore, the presence of the toner layer in a uniform state with no voids on this surface is important in improving the accuracy of toner remaining amount detection.

  In the toner container, the toner may cause electrostatic aggregation or magnetic aggregation due to the magnetic force of the stirring member or the toner carrier.

  If the agglomerated toner is present in the toner layer, it may be impossible to accurately detect the remaining amount.

As a result of intensive studies, the present inventors have found that (i) the saturation magnetization of the toner at a magnetic field of 796 kA / m is 15.0 Am ² / kg or more and 35.0 Am ² / kg or less, and (ii) the toner is 40 ° C. The dielectric constant at 100 kHz was found to be 25.0 pF / m or more and 60.0 pF / m or less.

  When the remaining amount of toner decreases, a large amount of residual toner remains around the toner carrier. As a result, unlike the case where the toner is present behind the toner container, the toner is more easily affected by the magnetic force of the toner carrier, and the magnetic aggregation is likely to occur (the state as shown in FIG. 8A). ).

Therefore, it is necessary to consider the magnetic factor of the toner. Therefore, the saturation magnetization of the toner in a magnetic field of 796 kA / m is 15.0 Am ² / kg or more and 35.0 Am ² / kg or less, preferably 20.0 Am ² / kg or more and 33.0 Am ² / kg or less. It is preferable for suppressing magnetic aggregation. When the saturation magnetization of the toner is larger than 35.0 Am ² / kg, a minute toner aggregate due to magnetic aggregation is likely to occur, and the remaining amount detection accuracy of the toner is lowered. On the other hand, if it is smaller than 15.0 Am ² / kg, the toner carrier cannot carry the toner, and a part of the toner is scattered, so that image defects such as scattering are likely to occur.

  The toner of the present invention is characterized in that the dielectric constant at 40 ° C. and 100 kHz is 25.0 pF / m or more and 60.0 pF / m or less, preferably 28.0 pF / m or more and 50.0 pF / m or less. .

  The dielectric constant is one standard indicating the ease of electric polarization when an electric field is applied, and the larger the value, the easier the polarization.

  As described above, the toner remaining amount is detected by applying the AC voltage component of the developing bias to the toner carrier 8 by the voltage application unit 15 and looking at the capacitance between the toner carrier 8 and the antenna member 14. ing. For this reason, the toner existing between the toner carrier 8 and the antenna member 14 is affected by the developing bias and is easily polarized.

  When the dielectric constant is smaller than 25.0 pF / m, it indicates that the polarization ability of the toner is small. As a result, unevenness in polarization ability may occur and electrostatic aggregation may occur. On the other hand, when it is larger than 60.0 pF / m, the toner surface has a large polarization, tends to be excessively charged, increases the adhesion to the toner container wall surface, and the remaining toner detection accuracy decreases (as shown in FIG. 8B). State). This is likely to occur in situations where the operating environment changes significantly, such as when moving from a low temperature and low humidity ring to a high temperature and high humidity environment and performing continuous printing.

  As described above, by using a specific configuration and member as an electrode and further precisely controlling the magnetic characteristics and electrical characteristics of the toner, it is possible to accurately detect the remaining amount of toner regardless of the environment or printing state. Can do.

The specific gravity of the toner of the present invention is 1.35 g / cm ³ or more and 1.75 g / cm ³ or less, preferably 1.40 g / cm ³ or more and 1.70 g / cm ³ or less.

  In the toner remaining amount detecting means of the present invention, a conductive resin member is present as a part of the bottom surface of the toner containing portion as an electrode. Therefore, the toner needs to be uniformly present on the surface. Therefore, it is preferable to control the specific gravity of the toner so that the conductive resin member can be uniformly contacted, and the accuracy of the remaining amount is improved particularly in a high temperature and high humidity environment where the fluidity is deteriorated.

  Also, the design of the magnetic material is important from the viewpoint of controlling the saturation magnetization of the toner and the specific gravity of the toner.

  Examples of the magnetic material used in the toner of the present invention include iron oxides such as magnetite, maghemite, and ferrite, and iron oxides containing other metal oxides: metals such as Fe, Co, and Ni, or these metals and Al. , Co, Cu, Pb, Mg, Ni, Sn, Zn, Sb, Be, Bi, Cd, alloys with metals such as Ca, Mn, Se, Ti, W, V; and magnetic materials such as mixtures thereof Can be used.

Specifically, iron trioxide (Fe ₃ O ₄ ), iron sesquioxide (γ-Fe ₂ O ₃ ), iron oxide zinc (ZnFe ₂ O ₄ ), iron oxide magnesium (MgFe ₂ O ₄ ), iron powder (Fe), cobalt powder (Co), nickel powder (Ni) and the like. In the present invention, at least magnetic iron is contained as a magnetic material, and one or more of the above magnetic materials can be arbitrarily selected and used as necessary.

In the present invention, it is preferable to control the magnetic properties and the addition amount of the magnetic material so that the saturation magnetization amount in a magnetic field of 796 kA / m after toner formation is 15.0 Am ² / kg or more and 35.0 Am ² / kg or less.

The magnetic characteristics of these magnetic materials when 796 kA / m is applied are such that the coercive force is 1.5 kA / m or more and 12.0 kA / m or less, and the saturation magnetization is 50.0 Am ² / kg or more and 200.0 Am ² / kg or less (preferably Is preferably 50.0 Am ² / kg or more and 100.0 Am ² / kg or less) and a remanent magnetization of 2.0 Am ² / kg or more and 20.0 Am ² / kg or less.

  The amount of the magnetic substance contained in the toner of the present invention is preferably 30 parts by mass or more and 90 parts by mass or less, and 40 parts by mass with respect to 100 parts by mass of the binder resin, in order to control the saturation magnetization and specific gravity of the toner. More preferably, it is more than 70 parts by weight.

  Further, from the viewpoint of dispersibility of the magnetic substance in the toner, the average particle diameter of the magnetic substance is preferably 0.08 μm or more and 0.3 μm or less.

  In the present invention, it is preferable that a different metal such as silicon, alumina, zinc, titanium or the like is contained inside and / or on the surface of the magnetic body. This is because the magnetic cohesiveness can be lowered, and the dispersibility of the magnetic substance in the toner can be improved.

  Moreover, it is preferable that the magnetic body of the present invention reduces the magnetic cohesive force by applying mechanical shear in the slurry state after the synthesis of the magnetic body. By performing such a process, the fine dispersibility at the time of toner production is drastically improved.

  Furthermore, in order to control the saturation magnetization of the toner at a magnetic field of 796 kA / m, a desired shape such as octahedron, hexahedron, or sphere can be selected as the shape of the magnetic material.

  The binder resin used for the toner base particles of the present invention will be described below.

  In order to control the dielectric constant of the toner of the present invention, a binder resin can be appropriately selected. Examples of the binder resin include polyester resins, vinyl resins, epoxy resins, and polyurethane resins.

  The alcohol component and acid component that can be used when synthesizing the polyester resin component are as follows.

  The following are mentioned as an alcohol component. Ethylene glycol, propylene glycol, 1,3-butanediol, 1,4-butanediol, 2,3-butanediol, diethylene glycol, triethylene glycol, 1,5-pentanediol, 1,6-hexanediol, neopentyl glycol , 2-ethyl-1,3-hexanediol, bisphenol A hydride, and aromatic diol include bisphenol represented by the following formula (1) and derivatives thereof, and diols represented by the following formula (2). It is done.

（式中、Ｒはエチレン又はプロピレン基であり、ｘ、ｙはそれぞれ１以上の整数であり、かつ、ｘ＋ｙの平均値は２〜１０である。）

(In the formula, R is an ethylene or propylene group, x and y are each an integer of 1 or more, and the average value of x + y is 2 to 10.)

  Examples of the acid component include the following. Benzene dicarboxylic acids such as phthalic acid, terephthalic acid, isophthalic acid, and phthalic anhydride, or anhydrides thereof; alkyl dicarboxylic acids such as succinic acid, adipic acid, sebacic acid, azelaic acid, or anhydrides thereof; Succinic acid or anhydride thereof substituted with the following alkyl or alkenyl groups; unsaturated dicarboxylic acids such as fumaric acid, maleic acid, citraconic acid, itaconic acid or anhydrides thereof. Examples of the trihydric or higher polyhydric alcohol component include sorbitol, 1,2,3,6-hexanetetrol, 1,4-sorbitan, pentaerythritol, dipentaerythritol, tripentaerythritol, 1,2,4-butanetriol. 1,2,5-pentanetriol, glycerol, 2-methylpropanetriol, 2-methyl-1,2,4-butanetriol, trimethylolethane, trimethylolpropane, 1,3,5-trihydroxybenzene It is done.

  Trivalent or higher polyvalent carboxylic acid components include trimellitic acid, pyromellitic acid, 1,2,4-benzenetricarboxylic acid, 1,2,5-benzenetricarboxylic acid, 2,5,7-naphthalenetricarboxylic acid, 1,2,4-naphthalenetricarboxylic acid, 1,2,4-butanetricarboxylic acid, 1,2,5-hexanetricarboxylic acid, 1,3-dicarboxyl-2-methyl-2-methylenecarboxypropane, tetra (methylene Carboxyl) methane, 1,2,7,8-octanetetracarboxylic acid, empor trimer acid, and anhydrides thereof.

  The polyester resin is usually obtained by commonly known condensation polymerization.

  On the other hand, examples of the vinyl monomer for producing the vinyl resin or the vinyl polymer unit include the following.

  Styrene; o-methylstyrene, m-methylstyrene, p-methylstyrene, p-methoxystyrene, p-phenylstyrene, p-chlorostyrene, 3,4-dichlorostyrene, p-ethylstyrene, 2,4-dimethyl Styrene, pn-butyl styrene, p-tert-butyl styrene, pn-hexyl styrene, pn-octyl styrene, pn-nonyl styrene, pn-decyl styrene, pn-dodecyl styrene Styrene and its derivatives such as: styrene unsaturated monoolefins such as ethylene, propylene, butylene and isobutylene; unsaturated polyenes such as butadiene and isoprene; halogenated such as vinyl chloride, vinylidene chloride, vinyl bromide and vinyl fluoride Vinyls: Vinyl acetate, vinyl propionate, vinyl benzoate Vinyl esters such as: methyl methacrylate, ethyl methacrylate, propyl methacrylate, n-butyl methacrylate, isobutyl methacrylate, n-octyl methacrylate, dodecyl methacrylate, 2-ethylhexyl methacrylate, stearyl methacrylate, methacrylic acid Α-methylene aliphatic monocarboxylic acid esters such as phenyl, dimethylaminoethyl methacrylate, diethylaminoethyl methacrylate; methyl acrylate, ethyl acrylate, n-butyl acrylate, isobutyl acrylate, propyl acrylate, n-acrylate Acrylic esters such as octyl, dodecyl acrylate, 2-ethylhexyl acrylate, stearyl acrylate, 2-chloroethyl acrylate, phenyl acrylate; vinyl methyl ether Vinyl ethers such as vinyl ethyl ether and vinyl isobutyl ether; vinyl ketones such as vinyl methyl ketone, vinyl hexyl ketone and methyl isopropenyl ketone; N-vinyl pyrrole, N-vinyl carbazole, N-vinyl indole, N-vinyl pyrrolidone N-vinyl compounds such as these; vinyl naphthalenes; acrylic acid or methacrylic acid derivatives such as acrylonitrile, methacrylonitrile and acrylamide.

  Furthermore, the following are mentioned. Unsaturated dibasic acids such as maleic acid, citraconic acid, itaconic acid, alkenyl succinic acid, fumaric acid, mesaconic acid; unsaturated such as maleic acid anhydride, citraconic acid anhydride, itaconic acid anhydride, alkenyl succinic acid anhydride Dibasic acid anhydride: maleic acid methyl half ester, maleic acid ethyl half ester, maleic acid butyl half ester, citraconic acid methyl half ester, citraconic acid ethyl half ester, citraconic acid butyl half ester, itaconic acid methyl half ester, alkenyl succinic acid Half-esters of unsaturated dibasic acids such as acid methyl half ester, fumaric acid methyl half ester and mesaconic acid methyl half ester; Unsaturated dibasic acid esters such as dimethylmaleic acid and dimethylfumaric acid; Acrylic acid, Methacrylic acid Α, β-unsaturated acids such as crotonic acid and cinnamic acid; α, β-unsaturated acid anhydrides such as crotonic acid anhydride and cinnamic anhydride, and anhydrides of the α, β-unsaturated acid and lower fatty acids A monomer having a carboxyl group such as alkenylmalonic acid, alkenylglutaric acid, alkenyladipic acid, acid anhydrides and monoesters thereof.

  Further, acrylic acid or methacrylic acid esters such as 2-hydroxyethyl acrylate, 2-hydroxyethyl methacrylate, 2-hydroxypropyl methacrylate; 4- (1-hydroxy-1-methylbutyl) styrene, 4- (1-hydroxy-1 -Methylhexyl) Monomers having a hydroxy group such as styrene.

  In the toner of the present invention, the vinyl resin or the vinyl polymer unit may have a crosslinked structure crosslinked with a crosslinking agent having two or more vinyl groups. The following are mentioned as a crosslinking agent used in this case. Aromatic divinyl compounds (divinylbenzene, divinylnaphthalene); diacrylate compounds linked by alkyl chains (ethylene glycol diacrylate, 1,3-butylene glycol diacrylate, 1,4-butanediol diacrylate, 1,5- Pentanediol acrylate, 1,6-hexanediol diacrylate, neopentylglycol diacrylate, and acrylates of the above compounds replaced with methacrylate); diacrylate compounds linked by an alkyl chain containing an ether bond (for example, , Diethylene glycol diacrylate, triethylene glycol diacrylate, tetraethylene glycol diacrylate, polyethylene glycol # 400 diacrylate, polyethylene glycol # 600 , Dipropylene glycol diacrylate, and acrylates of the above compounds replaced with methacrylate); diacrylate compounds entrapped with chains containing aromatic groups and ether bonds [polyoxyethylene (2) -2 , 2-bis (4hydroxyphenyl) propane diacrylate, polyoxyethylene (4) -2,2-bis (4hydroxyphenyl) propane diacrylate, and acrylates of the above compounds replaced with methacrylate]; polyester type Diacrylate compounds (“MANDA” manufactured by Nippon Kayaku Co., Ltd.).

  The following are mentioned as a polyfunctional crosslinking agent. Pentaerythritol triacrylate, trimethylol ethane triacrylate, trimethylol propane triacrylate, tetramethylol methane tetraacrylate, oligoester acrylate, and acrylates of the above compounds replaced with methacrylate; triallyl cyanurate, triallyl trimellitate .

  These crosslinking agents can be used in an amount of 0.01 to 10.00 parts by mass, and more preferably 0.03 to 5.00 parts by mass with respect to 100 parts by mass of other monomer components.

  Among these cross-linking agents, those which are preferably used for the resin component from the viewpoint of low-temperature fixability and offset resistance, are bonded with aromatic divinyl compounds (particularly divinylbenzene), chains containing aromatic groups and ether bonds. Diacrylate compounds are mentioned.

  The following are mentioned as a polymerization initiator used for superposition | polymerization of the said vinyl-type resin or a vinyl-type polymer unit. 2,2′-azobisisobutyronitrile, 2,2′-azobis (4-methoxy-2,4-dimethylvaleronitrile), 2,2′-azobis (2,4-dimethylvaleronitrile), 2, 2'-azobis (2-methylbutyronitrile), dimethyl-2,2'-azobisisobutyrate, 1,1'-azobis (1-cyclohexanecarbonitrile), 2- (carbamoylazo) -isobutyronitrile 2,2′-azobis (2,4,4-trimethylpentane), 2-phenylazo-2,4-dimethyl-4-methoxyvaleronitrile, 2,2-azobis (2-methylpropane), methyl ethyl ketone peroxide, Ketone peroxides such as acetylacetone peroxide, cyclohexanone peroxide, 2,2-bis (tert-butyl) Peroxy) butane, tert-butyl hydroperoxide, cumene hydroperoxide, 1,1,3,3-tetramethylbutyl hydroperoxide, di-tert-butyl peroxide, tert-butylcumyl peroxide, dicumyl peroxide , Α, α'-bis (tert-butylperoxyisopropyl) benzene, isobutyl peroxide, octanoyl peroxide, decanoyl peroxide, lauroyl peroxide, 3,5,5-trimethylhexanoyl peroxide, benzoyl peroxide M-trioyl peroxide, di-isopropyl peroxydicarbonate, di-2-ethylhexyl peroxydicarbonate, di-n-propyl peroxydicarbonate, di-2-e Xylethylperoxycarbonate, dimethoxyisopropylperoxydicarbonate, di (3-methyl-3-methoxybutyl) peroxycarbonate, acetylcyclohexylsulfonyl peroxide, tert-butylperoxyacetate, tert-butylperoxyisobutyrate, tert-butyl peroxyneodecanoate, tert-butyl peroxy 2-ethylhexanoate, tert-butyl peroxylaurate, tert-butyl peroxybenzoate, tert-butyl peroxyisopropyl carbonate, di-tert- Butyl peroxyisophthalate, tert-butyl peroxyallyl carbonate, tert-amyl peroxy 2-ethylhexanoate, di-tert-butyl perper Carboxymethyl hexahydro terephthalate, di -tert- butyl peroxy azelate.

  The binder resin of the present invention may be a hybrid resin in which a polyester resin and a vinyl resin are partially reacted.

  When the binder resin of the present invention is a hybrid resin, it is preferable that the vinyl resin and / or the polyester resin component contain a monomer component capable of reacting with both resin components. Examples of monomers that can react with the vinyl resin among the monomers constituting the polyester resin component include unsaturated dicarboxylic acids such as fumaric acid, maleic acid, citraconic acid, and itaconic acid, or anhydrides thereof. Among the monomers constituting the vinyl resin component, those capable of reacting with the polyester resin component include those having a carboxyl group or a hydroxy group, and acrylic acid or methacrylic acid esters.

  As a method for obtaining a reaction product of a vinyl resin and a polyester resin, a polymer containing a monomer component capable of reacting with each of the vinyl resin and the polyester resin listed above is present. A method obtained by polymerizing a resin is preferred.

  The glass transition temperature (Tg) of the resin used as the binder resin is preferably 50 ° C. or higher and 75 ° C. or lower from the viewpoint of toner durability and fixability. From the same viewpoint, the softening point is 80 ° C. or higher. It is preferable that it is 150 degrees C or less.

  One type of resin may be used as the binder resin, but a plurality of types may be used in combination. From the viewpoint of achieving both low-temperature fixability and durability, a plurality of types of resins having different Tg and softening points may be used in combination. Are preferably used.

  The toner of the present invention preferably contains a release agent. The release agent is not limited as long as it can improve the releasability at the time of fixing. For example, aliphatic hydrocarbon waxes such as polyolefin copolymer, polyolefin wax, microcrystalline wax, paraffin wax, and Fischer-Tropsch wax. Is mentioned.

  Further, these mold release agents include those obtained by sharpening the molecular weight distribution using a press perspiration method, a solvent method, a recrystallization method, a vacuum distillation method, a supercritical gas extraction method or a melt liquid crystal deposition method.

  Specific examples of the release agent include the following.

  Biscol (registered trademark) 330-P, 550-P, 660-P, TS-200 (Sanyo Chemical Industries), High Wax 400P, 200P, 100P, 410P, 420P, 320P, 220P, 210P, 110P (Mitsui Chemicals) ), Sazole H1, H2, C80, C105, C77 (Schumann Sazol), HNP-1, HNP-3, HNP-9, HNP-10, HNP-11, HNP-12 (Nippon Seiki Co., Ltd.), Unilin (registered trademark) 350, 425, 550, 700, Unicid (registered trademark), Unicid (registered trademark) 350, 425, 550, 700 (Toyo Adre Co., Ltd.), wood wax, beeswax, rice wax, candelilla wax Carnauba wax (available from Celerica NODA).

  The timing of adding the release agent may be added at the time of melt-kneading during toner production or may be at the time of production of the binder resin, and is appropriately selected from existing methods. These release agents may be used alone or in combination.

  The release agent is preferably added in an amount of 0.5 to 20.0 parts by mass with respect to 100.0 parts by mass of the total amount of the binder resin.

  The melting point peak temperature of the release agent is preferably 60 ° C. or higher and 180 ° C. or lower, and more preferably 70 ° C. or higher and 110 ° C. or lower, from the viewpoint of toner durability and low-temperature fixability.

  The toner of the present invention may contain a crystalline polyester resin as a binder resin.

  If necessary, conventionally known pigments and dyes may be used in combination for adjusting the color of the toner.

  The toner of the present invention preferably contains a charge control agent from the viewpoint of further improving the charging stability.

  As the charge control agent, an organometallic complex or a chelate compound in which the acid group or hydroxyl group present at the terminal of the binder resin used in the present invention and the central metal are likely to interact is preferable. For example, monoazo metal complexes; acetylacetone metal complexes; aromatic hydroxycarboxylic acid or aromatic dicarboxylic acid metal complexes or metal salts are preferably used.

  As specific examples, Spiro Black TRH, T-77, T-95 (Hodogaya Chemical Co., Ltd.), BONTRON (registered trademark) S-34, S-44, S-54, E-84, E -88, E-89 (Orient Chemical Co., Ltd.).

  One kind of charge control agent may be used, or two or more kinds may be used in combination.

  Further, the toner of the present invention preferably has toner particles containing a binder resin and a magnetic substance, at least silica fine powder, and external additive A.

  As the silica fine powder, treated silica fine particles obtained by hydrophobizing silica fine particles produced by vapor phase oxidation of a silicon halogen compound are preferably used. The treated silica fine particles preferably have a degree of hydrophobicity of 30 or more and 98 or less titrated by a methanol titration test.

  Examples of the method for hydrophobizing silica fine particles include a method of chemically treating with an organosilicon compound that reacts or physically adsorbs with silica fine particles. A preferred method is a method of treating silica fine particles produced by vapor phase oxidation of a silicon halogen compound with an organosilicon compound. Examples of organosilicon compounds include the following. Hexamethyldisilazane, trimethylsilane, trimethylchlorosilane, trimethylethoxysilane, dimethyldichlorosilane, methyltrichlorosilane, allyldimethylchlorosilane, allylphenyldichlorosilane, benzyldimethylchlorosilane, bromomethyldimethylchlorosilane, α- Chlorethyltrichlorosilane, β-chloroethyltrichlorosilane, chloromethyldimethylchlorosilane, triorganosilyl mercaptan, trimethylsilyl mercaptan, triorganosilyl acrylate, vinyldimethylacetoxysilane, dimethylethoxysilane, dimethyldimethoxysilane, diphenyldiethoxysilane, 1 -Hexamethyldisiloxane, 1,3-divinyltetramethyldisiloxane, 1,3-diphenyltetramethyl Ludisiloxane and dimethylpolysiloxane containing 2 to 12 siloxane units per molecule and containing hydroxyl groups bonded to Si in each of the terminal units. These are used alone or in a mixture of two or more.

The silica fine particles may be treated with silicone oil, or may be treated with a combination of silicone oil and the organosilicon compound. As the silicone oil, those having a viscosity at 25 ° C. of 30 mm ² / s or more and 1000 mm ² / s or less are preferable. Examples thereof include dimethyl silicone oil, methylphenyl silicone oil, α-methylstyrene modified silicone oil, chlorophenyl silicone oil, and fluorine modified silicone oil.

  Examples of the method for hydrophobizing silica fine particles with silicone oil include the following methods. A method in which silica fine particles treated with a silane coupling agent and silicone oil are directly mixed using a mixer such as a Henschel mixer; a method in which silicone oil is sprayed onto silica fine particles as a base. Alternatively, after dissolving or dispersing silicone oil in an appropriate solvent, silica fine particles are added and mixed to remove the solvent. The silicone oil-treated silica is more preferably obtained by heating the silica in an inert gas at a temperature of 200 ° C. or higher (more preferably 250 ° C. or higher) to stabilize the surface coating after the silicone oil treatment.

  The silica fine powder is preferably used in an amount of 0.1 parts by mass or more and 8.0 parts by mass or less, more preferably 0.1 parts by mass or more and 4.0 parts by mass or less with respect to 100.0 parts by mass of the toner particles.

  The number average particle diameter (DB) of the silica fine powder is preferably 5 nm or more and 50 nm or less.

  In addition to the silica fine powder, an external additive A larger than the number average particle diameter (DB) of the silica fine powder is preferably contained.

  The external additive A is inorganic fine particles such as silica, alumina and titanium oxide, organic fine particles such as resin fine particles, and organic-inorganic composite fine particles having a number average particle diameter (DA) of 70 nm to 300 nm. The number average particle diameter (DA) may be measured with the external additive A alone, or the external additive A adhering to the toner may be measured from the toner observation.

  For example, any silica produced by using a conventionally known technique such as a gas phase decomposition method, a combustion method, or a deflagration method can be used, but an alkoxysilane is hydrolyzed with a catalyst in an organic solvent in which water exists. Silica particles produced by a known sol-gel method in which the solvent is removed from the silica sol suspension obtained by the condensation reaction and dried to form particles can also be used. Further, the organic / inorganic composite fine particles can be produced according to the description in the examples of WO 2013/063291.

  The organic-inorganic composite fine particles have a plurality of convex portions derived from the inorganic fine particles on the surface thereof. By adopting a structure having convex portions on the surface of the fine particles, it is easy to obtain an anchoring effect on the surface of the toner particles, it is possible to suppress detachment of the external additive from the toner particles, and desired fluidity can be obtained through durability. . As a result, the accuracy of toner remaining amount detection is improved in the second half of the endurance.

  The material used for the organic-inorganic composite fine particles is not particularly limited, but it is preferable to use at least one inorganic oxide particle selected from the group consisting of silica, titanium oxide, and alumina as the inorganic fine particles for the vinyl resin particles. It is more preferable to use

  It is known that toner undergoes so-called toner deterioration in which an external additive is embedded in toner particles due to toner agitation in the developing device. This situation is likely to occur in the second half of the endurance when the toner amount is low. When toner deterioration occurs, the adhesion between the toner particles increases, and the toners tend to aggregate and become aggregated particle lumps. As a result, the toner remaining amount detection accuracy tends to decrease. However, the inclusion of the external additive A having such a specific particle diameter suppresses the occurrence of toner deterioration and improves the remaining toner detection accuracy. In particular, when continuous printing is performed in a high-temperature and high-humidity environment where toner deterioration is likely to occur, the effect is likely to appear significantly.

Further, the volume resistivity of the external additive A is preferably 1.0 × 10 ¹⁰ Ω · cm or more and 1.0 × 10 ¹⁵ Ω · cm or less in order to increase the accuracy of toner remaining amount detection.

  If necessary, other external additives may be added to the toner. For example, charging aids, conductivity imparting agents, anti-caking agents, release agents at the time of heat roller fixing, lubricants, resin fine particles and inorganic fine powders that function as abrasives. Examples of the lubricant include polyfluoroethylene fine particles, zinc stearate fine particles, and polyvinylidene fluoride fine particles. Of these, polyvinylidene fluoride fine particles are preferred. Examples of the abrasive include cerium oxide fine particles, silicon carbide fine particles, and strontium titanate fine particles.

  The method for producing the toner particles of the present invention is not particularly limited, and the kneaded product obtained by melt-kneading the resin component and, if necessary, toner constituent materials such as a colorant, a release agent, and a charge control agent after uniform mixing. After cooling, pulverization and classification, and a so-called pulverization method can be used in which the fluidity modifier and the like are sufficiently mixed using a mixer such as a Henschel mixer to obtain the toner of the present invention.

  As another method, toner particles can be produced by a so-called polymerization method such as an emulsion polymerization method or a suspension polymerization method.

  The following method can be used as a method for producing toner particles obtained through at least the melt-kneading step and the pulverizing step. The resin component and, if necessary, the wax, colorant, charge control agent, and other additives are sufficiently mixed by a mixer such as a Henschel mixer or a ball mill. The mixture is melt kneaded using a thermal kneader such as a twin-screw kneading extruder, a heating roll, a kneader, or an extruder. At that time, wax, magnetic iron oxide particles, and a metal-containing compound may be added. The melt-kneaded product is cooled and solidified, and then pulverized and classified to obtain toner particles. Further, if necessary, the toner particles and the external additive can be mixed with a mixer such as a Henschel mixer to obtain a toner. In the present invention, the external addition step may be multistage external addition.

  The following are mentioned as a mixer. Mitsui Henschel Mixer (Mitsui Miike Chemical Co., Ltd.); Super Mixer (Kawata); Ribocorn (Okawara Seisakusho); Nauta Mixer, Turbulizer, Cyclomix (Hosokawa Micron); Spiral Pin Mixer (Pacific Ocean) Kiko Co., Ltd.); Redige mixer (manufactured by Matsubo). Examples of the kneader include the following. KRC Kneader (manufactured by Kurimoto Iron Works); Bus Co Kneader (manufactured by Buss); TEM type extruder (manufactured by Toshiba Machine); TEX twin-screw kneader (manufactured by Nippon Steel Works); Steel mill); three roll mill, mixing roll mill, kneader (manufactured by Inoue Seisakusho); kneedex (manufactured by Mitsui Mining); MS-type pressure kneader, nider ruder (manufactured by Moriyama Seisakusho); Banbury mixer (Kobe Steel) (Made by the company). Examples of the pulverizer include the following. Counter jet mill, micron jet, inomizer (manufactured by Hosokawa Micron); IDS type mill, PJM jet crusher (manufactured by Nippon Pneumatic Industrial Co., Ltd.); cross jet mill (manufactured by Kurimoto Iron Works Co., Ltd.); SK; jet mill (manufactured by Seishin Enterprise Co., Ltd.); kryptron (manufactured by Kawasaki Heavy Industries, Ltd.); turbo mill (manufactured by Turbo Industry Co., Ltd.); super rotor (manufactured by Nisshin Engineering Co., Ltd.).

  Examples of the classifier include the following. Classifier, Micron Classifier, Spedic Classifier (manufactured by Seishin Enterprise); Turbo Classifier (manufactured by Nissin Engineering); Micron Separator, Turboplex (ATP), TSP Separator (manufactured by Hosokawa Micron); Elbow Jet (Japan) Iron Mining Co., Ltd.), Dispersion Separator (manufactured by Nippon Pneumatic Industrial Co., Ltd.); YM Microcut (manufactured by Yaskawa Shoji Co., Ltd.).

  Examples of the sieving apparatus used for sieving coarse particles include the following. Ultrasonic (manufactured by Sakae Sangyo Co., Ltd.); Resonator Sheave, Gyroshifter (Tokuju Kosakusha Co., Ltd.); Vibrasonic System (manufactured by Dalton Co.); Soniclean (manufactured by Shinto Kogyo Co., Ltd.); Micro shifter (manufactured by Hadano Sangyo Co., Ltd.); circular vibrating sieve.

  Next, it describes regarding the measuring method of each physical property which concerns on this invention.

<Measurement of dielectric constant of toner>
1 g of the toner is weighed and molded into a disk-shaped measurement sample having a diameter of 25 mm and a thickness of 1 mm or less (preferably 0.5 to 0.9 mm) over a period of 2 minutes under a load of 19600 kPa (200 kg / cm ² ). This measurement sample is mounted on ARES (manufactured by Rheometric Scientific F.E.) equipped with a dielectric constant measuring jig (electrode) having a diameter of 25 mm, and the temperature is fixed at 40 ° C. to 1.47 N (150 g). ), The dielectric constant of the inorganic fine powder at a frequency of 100 kHz was determined.

<Magnetic properties of toner and magnetic material>
The magnetic properties of magnetic iron oxide can be measured using a vibrating sample magnetometer VSM-3S-15 (manufactured by Toei Kogyo Co., Ltd.) with an external magnetic field of 796 kA / m (10 kOe).

<Method for measuring number average particle diameter of external additive A>
The number average particle diameter of the external additive A is measured using a scanning electron microscope “S-4800” (trade name; manufactured by Hitachi, Ltd.). By observing the toner to which the external additive A is externally added, the major axis of 100 primary particles of the external additive A is randomly measured in the field of view enlarged up to 200,000 times, and the number average particle diameter (D1) Ask for. The observation magnification is appropriately adjusted according to the size of the external additive A.

<Method for measuring volume resistivity of external additive A>
As a device, a Keithley Instruments 6517 type electrometer / high resistance system is used. An electrode having a diameter of 25 mm is connected to 6517, and a load of 1.0 to 2.0 N (102 to 204 g) is applied with 0.1 to 0.5 g of external additive A separated from the toner between the electrodes. Measure the distance between the electrodes.

In 6517, the resistance value when a voltage of 1,000 V is applied to the sample for 1 minute is measured, and the volume resistivity is calculated using the following equation.
Volume resistivity (Ω · cm) = R ÷ L
R: Resistance value (Ω)
L: Distance between electrodes (cm)

<Method for Measuring Softening Point Tm of Binder Resin and Toner>
The softening point is measured as follows. The softening point is measured by using a constant load extrusion type capillary rheometer “Flow Characteristic Evaluation Device Flow Tester CFT-500D” (manufactured by Shimadzu Corporation) according to the manual attached to the device. In this device, while applying a constant load from the top of the measurement sample with the piston, the measurement sample filled in the cylinder is heated and melted, and the melted measurement sample is pushed out from the die at the bottom of the cylinder, and the piston drop amount at this time A flow curve showing the relationship between temperature and temperature can be obtained.

  In the present invention, the “melting temperature in the 1/2 method” described in the manual attached to the “flow characteristic evaluation apparatus Flow Tester CFT-500D” is the softening point. The melting temperature in the 1/2 method is calculated as follows. First, ½ of the difference between the piston lowering amount Smax at the time when the outflow ends and the piston lowering amount Smin at the time when the outflow starts is obtained (this is X. X = (Smax−Smin) / 2). And the temperature of the flow curve when the amount of piston descent in the flow curve is the sum of X and Smin is the melting temperature Tm in the 1/2 method.

  As a measurement sample, about 1.0 g of a sample is compression-molded at about 10 MPa using a tablet molding compressor (for example, NT-100H, manufactured by NPA System) in an environment of 25 ° C. for about 60 seconds. A cylindrical shape having a diameter of about 8 mm is used.

The measurement conditions of CFT-500D are as follows.
Test mode: Temperature rising start temperature: 50 ° C
Achieving temperature: 200 ° C
Measurement interval: 1.0 ° C
Temperature increase rate: 4.0 ° C./min
Piston cross-sectional area: 1.000 cm ²
Test load (piston load): 10.0 kgf (0.9807 MPa)
Preheating time: 300 seconds Die hole diameter: 1.0 mm
Die length: 1.0mm

<Method for Measuring Glass Transition Temperature (Tg) of Binder Resin and Toner and Melting Point of Release Agent>
The glass transition temperature (Tg) and the melting point of the release agent are measured at room temperature and normal humidity according to ASTM D3418-82 using a differential scanning calorimeter (DSC) and MDSC-2920 (manufactured by TA Instruments). To do.

  As a measurement sample, a binder resin or a product obtained by accurately weighing about 3 mg of toner is used. This is put in an aluminum pan and an empty aluminum pan is used as a reference. The measurement temperature range is 30 ° C. or more and 200 ° C. or less, once the temperature is increased from 30 ° C. to 200 ° C. at a temperature increase rate of 10 ° C./min, then the temperature is decreased from 200 ° C. to 30 ° C. at a temperature decrease rate of 10 ° C./min. The temperature is raised to 200 ° C. at a temperature rising rate of 10 ° C./min. In the DSC curve obtained in the second temperature raising process, the intersection point between the baseline intermediate line before and after the specific heat change and the differential heat curve is defined as the glass transition temperature Tg of the resin. The maximum endothermic peak temperature of the DSC curve obtained in the second temperature raising process is defined as the melting point.

<Particle size of magnetic material>
Using a transmission electron microscope (TEM) H-7500 (manufactured by Hitachi, Ltd.) or a scanning electron microscope (SEM) S-4800 (manufactured by Hitachi, Ltd.), magnetic iron oxide was photographed at a magnification of 20,000 to 100,000. The sample can be observed at an arbitrary magnification as a baking magnification of 1 to 5 times. For the particle size, 100 particles of 0.03 μm or more are selected at random, the maximum length (μm) of each particle is measured, and the average is taken as the number average particle size.

<Method for Measuring Weight Average Particle Size (D4) of Toner Particles>
The weight average particle diameter (D4) of the toner is calculated as follows. As a measuring device, a precise particle size distribution measuring device “Coulter Counter Multisizer 3” (registered trademark, manufactured by Beckman Coulter, Inc.) using a pore electrical resistance method equipped with a 100 μm aperture tube is used. For setting the measurement conditions and analyzing the measurement data, the attached dedicated software “Beckman Coulter Multisizer 3 Version 3.51” (manufactured by Beckman Coulter, Inc.) is used. Note that the measurement is performed with 25,000 effective measurement channels.

  As the electrolytic aqueous solution used for the measurement, special grade sodium chloride is dissolved in ion-exchanged water so as to have a concentration of about 1% by mass, for example, “ISOTON II” (manufactured by Beckman Coulter, Inc.) can be used.

  Prior to measurement and analysis, the dedicated software was set as follows.

  On the “Change Standard Measurement Method (SOM)” screen of the dedicated software, set the total count in the control mode to 50,000 particles, set the number of measurements once, and set the Kd value to “standard particles 10.0 μm” (Beckman Coulter Set the value obtained using By pressing the “Threshold / Noise Level Measurement Button”, the threshold and noise level are automatically set. In addition, the current is set to 1600 μA, the gain is set to 2, the electrolyte is set to ISOTON II, and the “aperture tube flush after measurement” is checked.

  In the “Pulse to particle size conversion setting” screen of the dedicated software, the bin interval is set to logarithmic particle size, the particle size bin is set to 256 particle size bin, and the particle size range is set to 2 μm to 60 μm.

The specific measurement method is as follows.
(1) About 200 ml of the electrolytic aqueous solution is put in a glass 250 ml round bottom beaker exclusively for Multisizer 3, set on a sample stand, and the stirrer rod is stirred counterclockwise at 24 rotations / second. Then, the dirt and bubbles in the aperture tube are removed by the “aperture flush” function of the dedicated software.
(2) About 30 ml of the electrolytic aqueous solution is put into a glass 100 ml flat bottom beaker. As a dispersant, “Contaminone N” (trade name; 10% by weight aqueous solution of a neutral detergent for cleaning a precision measuring instrument having a pH of 7 comprising a nonionic surfactant, an anionic surfactant and an organic builder, Wako Pure Chemical Industries, Ltd. About 0.3 ml of a diluted solution obtained by diluting about 3 times by mass with ion exchange water is added.
(3) Two oscillators with an oscillation frequency of 50 kHz are incorporated with the phase shifted by 180 degrees, and an ultrasonic disperser “Ultrasonic Dissipation System Tetora150” (trade name; manufactured by Nikka Ki Bios) with an electrical output of 120 W is prepared. To do. About 3.3 l of ion-exchanged water is placed in the water tank of the ultrasonic disperser, and about 2 ml of Contaminone N is added to the water tank.
(4) The beaker of (2) is set in the beaker fixing hole of the ultrasonic disperser, and the ultrasonic disperser is operated. And the height position of a beaker is adjusted so that the resonance state of the liquid level of the electrolyte solution in a beaker may become the maximum.
(5) In a state where the electrolytic aqueous solution in the beaker of (4) is irradiated with ultrasonic waves, about 10 mg of toner is added to the electrolytic aqueous solution little by little and dispersed. Then, the ultrasonic dispersion process is continued for another 60 seconds. In the ultrasonic dispersion, the temperature of the water tank is appropriately adjusted so as to be 10 ° C. or higher and 40 ° C. or lower.
(6) To the round bottom beaker of (1) installed in the sample stand, the electrolyte solution of (5) in which the toner is dispersed is dropped using a pipette, and the measurement concentration is adjusted to about 5%. . The measurement is performed until the number of measured particles reaches 50,000.
(7) The measurement data is analyzed with the dedicated software attached to the apparatus, and the weight average particle diameter (D4) is calculated. The “average diameter” on the “analysis / volume statistics (arithmetic average)” screen when the graph / volume% is set by the dedicated software is the weight average particle diameter (D4).

<Method for measuring resistance of conductive resin member>
A method for measuring the resistance of the conductive resin member in this embodiment will be described.
.

  As shown in FIG. 9, the contact point (point A) at the corresponding position in the conductive resin member surface on the side in contact with the toner at the position for electrical connection, and the surface in contact with the toner on the conductive resin member The point (point B) that is the farthest among the contacts on the toner carrier 8 side is defined as the measurement point (1). Conductive grease is applied to the measurement point (1) in a circle with a diameter of 5 mm, and resistance measurement is performed between the measurement point (1) and the contact point using Fluke 87V manufactured by Fluke.

  Hereinafter, the present invention will be specifically described with reference to examples.

  This embodiment was evaluated according to the above description of the image forming apparatus and image forming process, and the detailed description of the image forming apparatus. As an applied bias, a short waveform having an AC voltage Vpp of 1400 V, a DC voltage of Vdc of −400 V, and a frequency of 2500 Hz was applied.

  Further, in this embodiment, the exposure beam L is adjusted so that the bright portion potential Vl on the photosensitive drum becomes −130V.

<Antenna member 1>
The conductive resin sheet as the antenna member 1 was obtained by dispersing 35% by mass of carbon black in EVA. The resistance measured by the method described above was 1.0 × 10 ⁴ Ω.

  Further, the total thickness t of the conductive resin sheet is 0.1 mm, the long width is 210 mm, and the short width is 35 mm. From the short end far from the toner carrier at the front end in FIG. The conductive resin sheet is extended to the outside of the developer container 3a in order to conduct to the contact point. From there, it is connected to ground via a contact (not shown) of the main body and a toner remaining amount detecting device 18 arranged in the above-mentioned image forming apparatus.

  Here, as a method for fixing the conductive resin sheet, any method can be used as long as it can be fixed to the frame as an electrode, such as insert molding, coating, and two-color molding. Here, for example, when insert molding is performed, the position accuracy of the arrangement of the conductive resin sheet is compatible or adhered and fixed to the inner wall of the developing container 3a with higher accuracy than the fixing method using the double-sided tape described in the present embodiment. be able to. As a result, the distance accuracy with the toner carrier, which is an electrode, is improved, leading to improved residual detection accuracy. Details are listed in Table 1.

<Antenna members 2 to 5>
It was produced in the same manner as the antenna member 1 except that the carbon amount and dispersion were adjusted and the resistance of the conductive resin sheet was adjusted so as to be as shown in Table 1 below. Details are listed in Table 1.

<Antenna member 6>
As the antenna member 6, SUS304 which was rolled to a thickness of 500 μm and cut into a strip shape of 216 mm in the longitudinal direction and 15 mm in the lateral direction was used. Although SUS304 is non-magnetic, application of stress causes the austenite layer to undergo martensitic transformation and become magnetized. The antenna member 6 for the comparative example is also stressed and magnetized by rolling and cutting. Details are listed in Table 1.

<Example of production of binder resin 1>
-Bisfer A ethylene oxide adduct (2.0 mol addition) 40.0 mol part-Bisfer A propylene oxide adduct (2.3 mol addition) 60.0 mol part-Terephthalic acid 60.0 mol part-Trimellitic anhydride 20. 0 mol part / acrylic acid 10.0 mol part 70 parts by mass of the above polyester monomer mixture was charged into a four-necked flask and equipped with a decompression device, a water separation device, a nitrogen gas introduction device, a temperature measurement device, and a stirring device, under a nitrogen atmosphere. And stir at 160 ° C. A mixture of 30 parts by mass of a vinyl polymerization monomer (styrene: 90.0 mol parts, butyl acrylate: 10.0 mol parts) constituting the vinyl polymer portion and 2.0 mol parts of benzoyl peroxide as a polymerization initiator. It dropped over 4 hours from the dropping funnel. Then, after reacting at 160 ° C. for 5 hours, the temperature was raised to 230 ° C., 0.05% by mass of tetraisobutyl titanate was added, and the reaction time was adjusted so as to obtain a desired viscosity. The obtained resin 1 had a softening point of 110 ° C. and Tg of 58 ° C.

<Manufacture of binder resin 2>
・ Terephthalic acid 46.0 mol
・ Trimellitic anhydride 1.0 mol
Ethoxylated bisphenol A (2.2 mol adduct): 2.0 mol
Propoxylated bisphenol A (2.2 mol adduct): 51.0 mol
The polyester monomer is charged into a 5 liter autoclave together with an esterification catalyst (dibutyltin oxide). A reflux condenser, a water separator, an N ₂ gas introduction pipe, a thermometer and a stirring device were attached thereto, and a polycondensation reaction was performed at 230 ° C. while introducing N ₂ gas into the autoclave. At that time, the polymerization time was adjusted so that the obtained polyester resin had a desired softening point. The obtained resin 2 had a softening point of 105 ° C. and Tg of 60 ° C.

<Manufacture of binder resin 3>
・ Terephthalic acid 42.0mol
・ Trimellitic anhydride 5.0 mol
Ethoxylated bisphenol A (2.2 mol adduct): 5.0 mol
Propoxylated bisphenol A (2.2 mol adduct): 48.0 mol
The polyester monomer is charged into a 5 liter autoclave together with an esterification catalyst (dibutyltin oxide). A reflux condenser, a water separator, an N ₂ gas introduction pipe, a thermometer and a stirring device were attached thereto, and a polycondensation reaction was performed at 230 ° C. while introducing N ₂ gas into the autoclave. At that time, the polymerization time was adjusted so that the obtained polyester resin had a desired softening point. The obtained resin 3 had a softening point of 120 ° C. and Tg of 58 ° C.

<Manufacture of binder resin 4>
Terephthalic acid 50.0mol
Ethylene glycol 30.0 mol
Neopentyl glycol 20.0 mol
The polyester monomer is charged into a 5 liter autoclave together with an esterification catalyst (dibutyltin oxide). A reflux condenser, a water separator, an N ₂ gas introduction pipe, a thermometer and a stirring device were attached thereto, and a polycondensation reaction was performed at 230 ° C. while introducing N ₂ gas into the autoclave. At that time, the polymerization time was adjusted so that the obtained polyester resin had a desired softening point. The obtained resin 4 had a softening point of 110 ° C. and a Tg of 58 ° C.

<Manufacture of binder resin 5>
Styrene 71 parts by mass Acrylic acid-n-butyl 24 parts by mass Monobutyl maleate 5 parts by mass Divinylbenzene 0.005 parts by mass 2,2-bis (4,4-di-tert-butylperoxycyclohexyl) propane (half-life 10 (Time, temperature; 92 ° C.) 0.1 part by mass Into a four-necked flask, 300 parts by mass of xylene is charged, and the inside of the container is sufficiently replaced with nitrogen while stirring, and then heated to 160 ° C. and refluxed. Under this reflux, the above mixed solution was added dropwise over 4 hours and then held for 2 hours to complete the polymerization, whereby Resin 5 was obtained. The obtained resin 5 had a softening point of 110 ° C. and Tg of 60 ° C.

<Manufacture of magnetic body 1>
Using ferrous sulfate, 50 liters of an aqueous iron sulfate solution containing 2.0 mol / liter of Fe (2+) was prepared. Moreover, 10 liters of sodium silicate aqueous solution containing 0.23 mol / liter of Si (4+) was prepared using sodium silicate, and this was added to the iron sulfate aqueous solution. Subsequently, 42 liters of 5.0 mol / liter NaOH aqueous solution was stirred and mixed with the mixed aqueous solution to obtain a ferrous hydroxide slurry. This ferrous hydroxide slurry was adjusted to a pH of 12.0 and a temperature of 90 ° C., and 30 liter / min of air was blown in, and an oxidation reaction was performed until 50% of the ferrous hydroxide became magnetic iron oxide particles. Next, 20 l / min of air was blown until 75% of the magnetic iron oxide particles were produced, and then 10 l / min of air was blown until 90% of the magnetic iron oxide particles were produced. Further, when the ratio of the magnetic iron oxide particles exceeded 90%, air was blown in at 5 liters / min to complete the oxidation reaction, thereby obtaining a slurry containing octahedral core particles.

94 ml of an aqueous solution of sodium silicate (containing 13.4% by mass of Si) and 288 ml of an aqueous aluminum sulfate solution (containing 4.2% by mass of Al) were simultaneously added to the slurry containing the core particles. Thereafter, the temperature of the slurry was adjusted to 80 ° C., the pH was adjusted to 5 or more and 9 or less with dilute sulfuric acid, and a coating layer containing silicon and aluminum was formed on the surface of the core particles. The obtained magnetic body was filtered by a conventional method, dried and pulverized to obtain a magnetic body 1. Magnetic substance 1 having a number-average particle size of 0.12nm, Hc = 11.5kA / m, was ^{σs = 85.0Am 2 /kg,σr=14.0Am 2 / kg} .

<Manufacture of magnetic body 2>
A magnetic body 2 was prepared in the same manner as the magnetic body 1 except that a spherical magnetic body was prepared by changing the pH and temperature. Magnetic 2 having a number-average particle size of 0.12nm, Hc = 6.4kA / m, was ^{σs = 75.0Am 2 /kg,σr=6.1Am 2 / kg} .

<Manufacture of magnetic body 3>
In a ferrous sulfate aqueous solution, 1.00 equivalent or more and 1.10 equivalent or less of caustic soda solution with respect to iron element, and SiO ₂ in an amount of 0.50% by mass in terms of silicon element with respect to iron element are mixed. An aqueous solution containing ferrous hydroxide was prepared. The pH of the aqueous solution was 8.0, and an oxidation reaction was performed at 85 ° C. while blowing air to prepare a slurry liquid having seed crystals.

Subsequently, the ferrous sulfate aqueous solution was added to this slurry liquid so that it might become 0.90 equivalent or more and 1.20 equivalent or less with respect to the original alkali amount (sodium component of caustic soda). Thereafter, the slurry liquid was maintained at pH 7.6, and an oxidation reaction was promoted while blowing air to obtain a slurry liquid containing magnetic iron oxide. After filtration and washing, the water-containing slurry was once taken out. At this time, a small amount of water-containing sample was collected and the water content was measured. Next, this water-containing sample was put into another aqueous medium without being dried, stirred and redispersed with a pin mill while circulating the slurry, and the pH of the redispersed liquid was adjusted to 4.8. Then, 1.6 parts by mass of n-hexyltrimethoxysilane coupling agent with respect to 100 parts by mass of the magnetic material (the amount of the magnetic material was calculated as a value obtained by subtracting the water content from the water-containing sample) was added while stirring. Decomposition was performed. Thereafter, the mixture was sufficiently stirred, and the dispersion was subjected to surface treatment at a pH of 8.6. The produced hydrophobic magnetic material is filtered with a filter press, washed with a large amount of water, dried at 100 ° C. for 15 minutes, and then at 90 ° C. for 30 minutes. 0.24 μm magnetic body 3 was obtained. The number average particle diameter 0.12nm of the magnetic 3, Hc = 7.2kA / m, was ^{σs = 78.0Am 2 /kg,σr=8.1Am 2 / kg} .

<Toner Production Example 1>
-Resin 1 100.0 parts by mass-Magnetic substance 1 60.0 parts by mass-Fischer-Tropsch wax (DSC peak temperature: 105 ° C) 2.0 parts by mass-Charge control agent (T-77: manufactured by Hodogaya Chemical Co., Ltd.) 0 parts by mass The above materials were mixed with a Mitsui Henschel mixer (FM-75 type, manufactured by Mitsui Miike Chemical Co., Ltd.), and then rotated at a twin-screw kneader (Ikegai Iron Works Co., Ltd. PCM-30 type)). The mixture was kneaded under the conditions of 3.3 s ⁻¹ and a kneading temperature of 130 ° C. The obtained kneaded material was cooled and coarsely pulverized to 1 mm or less with a hammer mill to obtain a coarsely pulverized material. The obtained coarsely pulverized product was finely pulverized with a mechanical pulverizer (T-250 manufactured by Turbo Kogyo Co., Ltd.). Further, the finely pulverized powder thus obtained was classified using a multi-division classifier utilizing the Coanda effect to obtain negative triboelectrically chargeable toner particles having a weight average particle diameter of 7.0 μm.

  To 100.0 parts by mass of the obtained toner particles, 0.8 parts by mass of hydrophobic silica fine particles having a primary average particle diameter of 16 nm and surface-treated with 20.0% by mass of hexamethyldisilazane, and external additive A- Toner 1 was obtained by adding 1.0 part by mass of 1 and mixing with a Mitsui Henschel mixer (FM-75 model, manufactured by Mitsui Miike Chemical Co., Ltd.).

  Various physical properties of the toner 1 are as described in Table 3.

<Toner Production Example 2>
After adding 450 parts by mass of 0.1M Na ₃ PO ₄ aqueous solution to 720 parts by mass of ion-exchanged water and heating to 60 ° C., 67.7 parts by mass of 1.0 M CaCl ₂ aqueous solution was added to stabilize the dispersion. An aqueous medium containing the agent was obtained.
Styrene 78.0 parts by mass n-butyl acrylate 22.0 parts by mass Divinylbenzene 0.6 parts by mass Magnetic material 3 85.0 parts by mass Polyester resin 3.0 parts by mass Charge control agent Bontron E-88 (Orient Chemical Co., Ltd.) 2.0 parts by mass The above formulation was uniformly dispersed and mixed using a disper blade to obtain a composition. This composition was heated to 60 ° C., and 15.0 parts by mass of ester wax (behenyl behenate) was added and mixed therein. After dissolution, 7.0 parts by mass of dilauroyl peroxide was dissolved as a polymerization initiator, A polymerizable monomer composition was obtained.

Said aqueous medium a polymerizable monomer composition was charged in, 60 ° C., T. under N ₂ atmosphere K. The mixture was stirred at 12000 rpm for 10 minutes with a homomixer (manufactured by Tokushu Kika Kogyo Co., Ltd.) and granulated. Thereafter, the mixture was reacted at 74 ° C. for 6 hours while stirring with a paddle stirring blade. After completion of the reaction, the suspension was cooled, washed with hydrochloric acid, filtered and dried to obtain negative triboelectrically charged toner particles having a weight average particle diameter of 7.0 μm.

  To 100.0 parts by mass of the obtained magnetic toner particles, 0.8 parts by mass of hydrophobic silica fine particles having a primary average particle size of 16 nm and surface-treated with 20.0% by mass of hexamethyldisilazane and external additive A shown in Table 2 -1 was added in an amount of 1.0 part by mass, and mixed with a Mitsui Henschel mixer (manufactured by Mitsui Miike Chemical Co., Ltd., FM-75 type) to obtain toner 2.

  Various properties of the toner 2 are as described in Table 3.

<Toner Production Examples 3 to 20>
The toner was prepared in the same manner as the magnetic toner 1 except that the toner formulation was changed as shown in Table 3. Table 3 shows the physical properties of Toners 3 to 20.

[Example 1]
A commercially available laser printer (Laser Jet P4515n, manufactured by hp) was used for unfixed image output in the examples.

  The evaluation machine was modified so that each of the developing devices shown in FIGS. 2 (a) and 2 (b) could enter. Further, the evaluation machine was modified and used so that the applied bias and the like were in the above-described conditions. The developing device C-1 in the embodiment shows the type shown in FIG. 2B, and the developing device C-2 shows the type shown in FIG.

<Toner remaining detection accuracy (environmental evaluation)>
Using normal plain paper for copying machines (75 g / m ² ), low-temperature and low-humidity environment evaluation (15 ° C., 5% RH) and high-temperature and high-humidity environment (30 ° C., 85% RH) The images were output in an intermittent mode in which two images were output every 10 seconds. Then, the remaining amount of toner at the time when the remaining amount of toner was detected was actually measured and compared with the value of the output signal from the remaining amount detection device to obtain the remaining amount detection error.
Remaining amount detection error (%) = {| (actually remaining amount) − (remaining amount detected value) | / (actually remaining amount)} × 100
A: The remaining amount detection error is less than 2.0% B: The remaining amount detection error is not less than 2.0% and less than 3.0% C: The remaining amount detection error is not less than 3.0% and less than 5.0% D: the remaining amount detection error is 5.0% or more and less than 7.0% E: the remaining amount detection error is 7.0% or more and less than 10.0% F: the remaining amount detection error is 10.0 % Or more

<Toner remaining amount detection accuracy (environmental fluctuation evaluation)>
Continuous printing is performed on ordinary copying machine plain paper (75 g / m ² ) in a low-temperature, low-humidity environment (15 ° C, 5% RH). , 85% RH), the remaining amount of toner at the time when the remaining amount of toner is 5% is actually measured, and compared with the value of the output signal from the remaining amount detection device, the remaining amount detection error is obtained.
Remaining amount detection error (%) = {| (actually remaining amount) − (remaining amount detected value) | / (actually remaining amount)} × 100
A: The remaining amount detection error is less than 2.0% B: The remaining amount detection error is not less than 2.0% and less than 3.0% C: The remaining amount detection error is not less than 3.0% and less than 5.0% D: The remaining amount detection error is 5.0% or more.

<Spattering evaluation>
In a low-temperature and low-humidity environment (temperature 15 ° C, humidity 10%), continuous printout is performed in a low-temperature and low-humidity environment (15 ° C, 5% RH). A document on which a total of 25 prints, 5 in width and 5 in width, were output. The images were adjusted so that the left and right margins were 80 mm and the top and bottom margins were 10 mm.

The generated scattering level was evaluated by observing a total of 25 letters of “A” of 8 points. The criteria for determining scattering are shown below. The evaluation results are shown in Table 4.
A: When observed with a magnifier with a magnification of 25, the total number of scattering around the image is 5 or less.
B: When observed with a magnifying glass having a magnification of 25, the total number of scattering around the image is 6 or more and 10 or less.
C: When observed with a magnifying glass having a magnification of 25, the total number of scattering around the image is 11 or more and 15 or less.
D: When observed with a magnifying glass having a magnification of 25 times, the total number of scattering around the image is 16 or more, and there are one or more occurrences of scattering even visually.

[Examples 2 to 17]
Evaluation was performed in the same manner as in Example 1 except that the magnetic toner and the developing device were changed as shown in Table 4-1. The evaluation results are shown in Table 4-1.

[Comparative Examples 1 to 6]
Evaluation was performed in the same manner as in Example 1 except that the magnetic toner and the developing device were changed as shown in Table 4-2. The evaluation results are shown in Table 4-2.

  DESCRIPTION OF SYMBOLS 1 Electrophotographic photosensitive member (image carrier), 2 charging roller (charging means), 3 developing device (developing means), 3a developing container (toner storage part), 4 transfer device (transfer means), 5 cleaning device, 5a cleaning Blade, 6 exposure device, 7 fixing device, 8 developing sleeve (toner carrier), 8a magnet roller, 9 cartridge side memory, 10 toner stirring member, 11 developing blade, 12 image forming device, 13 process cartridge, 14 antenna member ( Conductive resin sheet), 15 voltage applying means, 17 toner remaining amount detecting means, 18 toner remaining amount detecting device, 31 developing area, N transfer nip, T toner, P transfer material

Claims (7)

A developing device having a toner carrier and a toner containing part that contains toner and has a toner stirring member for supplying the toner to the toner carrier,
There is a region formed of a nonmagnetic conductive resin member on the bottom surface of the toner container,
Using the toner carrier as a first electrode and the region as a second electrode, detection of the amount of toner in the toner container based on the capacitance between the first electrode and the second electrode Is done,
The toner is a toner having toner particles containing a binder resin and a magnetic material,
(I) the saturation magnetization of the toner at a magnetic field of 796 kA / m is 15.0 Am ² / kg or more and 35.0 Am ² / kg or less;
(Ii) A developing device in which the toner has a dielectric constant at 40 ° C. and 100 kHz of 25.0 pF / m or more and 60.0 pF / m or less.   The developing device according to claim 1, wherein the conductive resin member is a flexible conductive resin sheet. The developing device according to claim 1, wherein a resistance of the conductive resin member is 1.0 × 10 ³ Ω or more and 1.0 × 10 ⁵ Ω or less. The toner stirring member rotates about a direction parallel to the longitudinal direction of the toner carrier as a rotation axis,
When the developing device is installed in the printer body, a line parallel to the printer installation surface passing through the rotation center axis of the toner stirring member is arranged so as to pass below the lower end of the toner carrier,
The developing device according to claim 1, wherein the developing device is a member that supplies toner to the toner carrier from below the toner carrier.   A region formed of the non-magnetic conductive resin member on the bottom surface of the toner container located below the rotation axis of the toner stirring member is related to the longitudinal direction of the toner carrier when the developing device is viewed from above. 5. The developing device according to claim 1, wherein the developing device is 50% or more and 40% or more in a direction orthogonal to a longitudinal direction of the toner carrier. The toner is a toner having a binder resin, a toner particle containing a magnetic material, at least silica fine powder, and an external additive A,
The number average particle diameter (DA) of the external additive A is 70 nm or more and 300 nm or less, and DA is larger than the number average particle diameter (DB) of the silica fine powder. The developing device according to one item. An image forming method in which an electrostatic latent image formed on an electrostatic latent image carrier is developed with toner carried on the toner carrier, and the amount of toner in the toner container is detected.
A toner carrier and a toner agitating member that contains the toner and supplies the toner to the toner carrier are provided inside, and an area formed of a nonmagnetic conductive resin member exists on the bottom surface of the toner carrier. A developing device having a toner container
Rotating the toner stirring member about a direction parallel to the longitudinal direction of the toner carrier as a rotation axis;
When the developing device is installed in the printer body, a line parallel to the printer installation surface passing through the rotation center axis of the toner stirring member is arranged so as to pass below the lower end of the toner carrier,
The toner is supplied to the toner carrier from below the toner carrier, and development is performed with the toner carried on the toner carrier,
The amount of toner in the toner container is detected by using the toner carrier as the first electrode and the region as the second electrode, and detecting the capacitance between the first electrode and the second electrode. Based on
The toner is a toner having toner particles containing a binder resin and a magnetic material,
(I) the saturation magnetization of the toner at a magnetic field of 796 kA / m is 15.0 Am ² / kg or more and 35.0 Am ² / kg or less;
(Ii) An image forming method comprising using a toner having a dielectric constant of 25.0 pF / m to 60.0 pF / m at 40 ° C. and 100 kHz.

Images