JP2009150985A - Toner, developing method, and image forming method - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a toner satisfying requirements for a high-speed process, high image qualities, high durability, low environmental load, response to various media and high environmental stability. <P>SOLUTION: In a developing device with a developer carrier carrying and conveying a developer for developing an electrostatic latent image on an image carrier, and a toner to be used for the device, the developing device includes a developer supplying/removing means for supplying and removing a developer to and from the developer carrier, and the developer supplying/removing means includes a conductive material and a high resistance material layered on the surface of the conductive material and having a volume resistivity of not less than 10<SP>9</SP>Ωcm. In the toner, the relationship between a volume resistance value A and a volume resistance value B satisfies an expression: 10<SP>-3</SP>≤A/B≤10<SP>4</SP>, and the toner has an aggregation degree C of from 20 to 90 (%) under conditions of application of an oscillated electric field and normal temperature and normal pressure. <P>COPYRIGHT: (C)2009,JPO&INPIT

Description

  The present invention relates to a toner for use in an image forming apparatus such as an electrophotographic system or an electrostatic recording system, such as an electrophotographic system or an electrostatic recording system, in which a developer is attached to a latent image formed on an image carrier and visualized. And an image forming method.

  Recent copiers and printers are becoming increasingly demanding in terms of miniaturization, weight reduction and high reliability, and demands on performance have become severe.

  A conventional developing device has a developer supply member that supplies a developer to a developer carrier that conveys the developer in order to visualize an electrostatic latent image formed on the image carrier. There is.

  Further, after the electrostatic latent image is visualized, the developer remains on the developer carrying member as a history, but the conventional developing device has a developer removing member for removing the residual developer. There is something that is.

  When the developer supplying member or the developer removing member is in contact with the developer carrying member, if the image forming operation is repeated many times, the deterioration of the developer proceeds and an image defect occurs.

  Therefore, according to another prior art, in order to reduce the load on the developer, the developer supply member and the developer removal member are arranged in non-contact with the developer carrier (see, for example, Patent Document 1). ).

  FIG. 6 shows an example of a conventional developing device having such a configuration. FIG. 6 shows a cross section of a drum-shaped electrophotographic photosensitive member (hereinafter referred to as “photosensitive drum”) 110 as an image carrier and a developing device 111.

  In this example, the developing device 111 is provided with a developing roller 113 as a developer carrying member that conveys the magnetic one-component toner 112 in order to visualize the electrostatic latent image on the photosensitive drum 110. In order to remove residual toner that has not contributed to visualization on the developing roller 113, a rotating electrode 114 is disposed in a non-contact manner, and an AC voltage on which a DC voltage is superimposed is applied to the electrode 114. A scraping member 115 is in contact with the electrode 114 in order to remove the toner 112 on the surface of the electrode 114.

  Further, a supply member 116 for supplying the toner 112 to the developing roller 113 is disposed in the vicinity of the developing roller 113, and the toner is produced by the effect of the stirring of the supply member 116 and the magnetic force of the magnetic rubber layer 113 </ b> A constituting the developing roller 113. 112 is supplied.

  In order to achieve such a demand, many proposals for improving the developing device have been made.

  Also, toners for image forming methods have been proposed in which toner properties are defined from the viewpoint of toner flying properties and image formation is performed by applying a bias between a latent image carrier and a developer carrier (for example, Patent Documents 2 to 2). 5). However, there is room for improvement with respect to further higher image quality and developer deterioration, and further improvement is required under more severe environmental conditions.

  As described above, there is no developing device and toner that can solve various problems as a whole.

JP 63-106768 A JP-A-6-222605 JP-A-6-222607 JP-A-6-222608 JP-A-6-222611

  In view of the above circumstances, an object of the present invention is to provide a toner and an image forming method that satisfy high speed, high image quality, high durability, and high environmental stability.

  The above object is achieved by the present invention described below.

That is, a toner used in a developing device having a developer carrier that carries and transports a developer to develop an electrostatic latent image on the image carrier,
The developing device includes a developer supply / removal unit that supplies and removes the developer to and from the developer carrier.
The developer supply / removal means includes a conductive material and a high resistance material having a volume resistance of 10 ⁹ Ωcm or more laminated on the surface of the conductive material.
The developer supply / removal means is disposed in non-contact with the developer carrier,
At the developer supply / removal position facing the developer carrier, the developer conveyance direction on the developer carrier and the developer conveyance direction on the developer supply / removal means are opposite directions,
An oscillating electric field is formed between the developer supplying / removing means and the developer carrying member,
The developer is a one-component developer composed of toner or a two-component developer composed of toner and carrier,
The relationship between the volume resistance value A of the toner and the volume resistance value B of the high resistance material is 10 ⁻³ ≦ A / B ≦ 10 ^4.
The toner is characterized in that the toner has an aggregation degree C of 20 to 90 (%) under application of an oscillating electric field and normal temperature and pressure.

According to the present invention,
(1) Since the developer on the developer carrying member can be removed and supplied by one developer supply / removal member, the development device can be downsized and the load on the developer can be reduced.
(2) Stable supply of developer and removal of developer are good.
(3) A developer excellent in suppressing toner deterioration and excellent in suppressing member contamination can be obtained.
(4) A developer having excellent development stability can be obtained.

The present invention relates to a toner used in a developing device having a developer carrier for carrying and transporting a developer for developing an electrostatic latent image on the image carrier,
The developing device includes a developer supply / removal unit that supplies and removes the developer to and from the developer carrier.
The developer supply / removal means includes a conductive material and a high resistance material having a volume resistance of 10 ⁹ Ωcm or more laminated on the surface of the conductive material.
The developer supply / removal means is disposed in non-contact with the developer carrier,
At the developer supply / removal position facing the developer carrier, the developer conveyance direction on the developer carrier and the developer conveyance direction on the developer supply / removal means are opposite directions,
An oscillating electric field is formed between the developer supplying / removing means and the developer carrying member,
The developer is a one-component developer composed of toner or a two-component developer composed of toner and carrier,
The relationship between the volume resistance value A of the toner and the volume resistance value B of the high resistance material is 10 ⁻³ ≦ A / B ≦ 10 ^4.
The toner is characterized in that the aggregation degree C is 20 to 90 (%) under application of an oscillating electric field and normal temperature and pressure.

  In the present invention, with respect to the developing device to be used, by satisfying the above items, stable developability can be maintained even in various situations from a low temperature and low humidity environment to a high temperature and high humidity environment. Good results are obtained in the removal of the agent.

  In the present invention, with respect to the toner used, the development stability and transferability are good even in various situations from a low temperature and low humidity environment to a high temperature and high humidity environment by satisfying the above items. In particular, good results can be obtained in a low-temperature and low-humidity environment, particularly in an extremely low-humidity environment where the toner charge amount is high and it is difficult to stably supply the developer and remove the developer.

  Hereinafter, the present invention will be described in detail.

In the present invention, first, the developing device includes a developer supplying / removing unit that supplies and removes the developer to and from the developer carrying member. The developer supplying / removing unit includes a conductive material and a surface of the conductive material. And a high resistance material having a volume resistance of 10 ⁹ Ωcm or more laminated on the developer, and the developer supply / removal means needs to be disposed in a non-contact manner with respect to the developer carrier. .

  When toner is used in a developing device, the design of the removal and supply of toner from the developer carrier is important.

  In order to remove and supply the nonmagnetic toner from the developer carrying member in a non-contact manner, an electrical action is required. However, when the developing carrier and the conductive developer supplying / removing means are operated in a non-contact manner, a leak (current flow) occurs between the developing carrier and the conductive developer supplying / removing means. .

Therefore, in the present invention, an electric field leakage is provided by providing a developer supplying / removing means having a conductive material and a high resistance material having a volume resistance of 10 ⁹ Ωcm or more laminated on the surface of the conductive material. It is possible to apply a high-voltage electric field without causing the supply and the supply removal efficiency is improved.

When the volume resistance value laminated on the surface of the conductive material is less than 10 ⁹ Ωcm, leakage occurs when a high-voltage electric field is applied, and coating defects are likely to occur.

In the present invention, the relationship between the volume resistance value A of the toner and the volume resistance value B of the high resistance material is then 10 ⁻³ ≦ A / B ≦ 10 ^4.
It is necessary to be.

  Although the detailed reason is unknown, it is considered that a high voltage electric field is uniformly applied by controlling the relationship between the volume resistance value A of the toner and the volume resistance value B of the high resistance material, so that the toner coat property is good.

When the relationship between the volume resistance value A of the toner and the volume resistance value B of the high resistance material (A / B) is less than 10 ⁻³ , the responsiveness to the electric field of the toner is good, but the conductivity of the toner itself increases. Leakage is likely to occur. If the relationship (A / B) between the volume resistance value A of the toner and the volume resistance value B of the high resistance material exceeds 10 ⁴ , the responsiveness to the electric field of the toner will be low and the toner coat properties will not be satisfactory.

  In the present invention, the toner cohesion degree C (hereinafter referred to as an oscillating electric field application coagulation degree C) measured under application of an oscillating electric field and normal temperature and normal pressure of the toner needs to be 20 to 90 (%).

  By controlling the oscillating electric field applied aggregation degree C to 20 to 90 (%), even when a high voltage electric field is applied, the response is good and image nonuniformity due to charge-up does not occur.

  When the oscillating electric field application aggregation degree C is less than 20 (%), the responsiveness is poor even when a high voltage electric field is applied, and a ghost is likely to occur. When the oscillating electric field applied aggregation degree C exceeds 90 (%), when a high voltage electric field is applied, toner aggregates are generated and coating defects are likely to occur.

  Here, the cohesion degree (vibration electric field application cohesion degree) method when the oscillating electric field of the present invention is applied is shown below.

<Measuring method of applied electric field coagulation degree>
The degree of aggregation of the toner in the present invention was measured as follows.

  As a measuring apparatus, a powder tester (manufactured by Hosokawa Micron Co., Ltd.) having a digital vibrometer (manufactured by DEGITAL VIBLATIONMETER MODEL 1332 SHOWA SOKKI CORPORATION) was used.

  As a measuring method, 635 mesh, 390 mesh, and 200 mesh sieves were placed on a vibrating table in the order of opening, that is, the 200 mesh sieve was placed on top so that the metal surface was in contact.

  Further, an AC / DC composite wave having the following conditions was applied to the uppermost mesh, and the lowermost mesh was dropped to ground via a capacitor.

  As the high voltage application device, an amplifier (MODEL615-3 manufactured by TREK) was used.

<Applied voltage conditions>
DC voltage: 1.0 kV
Waveform: Rectangular wave (ratio 50:50)
Vibration (alternating current) voltage: -1.0 kV to +1.0 kV

  1 g of accurately weighed sample was added to the set 200 mesh sieve, the displacement value of the digital vibrometer was adjusted to 0.60 mm (peak-to-peak), and vibration was applied for 60 seconds. Thereafter, the mass of the sample remaining on each sieve was measured to obtain the degree of aggregation based on the following formula.

The measurement samples at that time were each previously left for 24 hours in an environment of 23 ° C. and 60% RH, and the measurement was performed in an environment of 23 ° C. and 60% RH.
Aggregation degree (%) = (residual sample mass on 200 mesh sieve / 5 g) × 100 + (390 mesh)
Residual sample weight on a sieve sieve / 5g) × 60 + (635 mesh sieve
Remaining sample mass / 5g) × 20

<Toner and external additive volume resistance measurement method>
The volume resistance value of the toner was measured by the following method.

That is, the measurement was performed in a state where a cylinder having a lower electrode with a diameter of 5 mm was tapped with 0.3 to 1.0 g of a conductive material, an upper electrode with a diameter of 15 mm was placed, and a load of 350 g was applied. At this time, after measuring the thickness of the sample, the applied voltage was swept from 0V to 100V. The electric field was calculated from the measured resistance value, sample thickness, and applied voltage, and the volume resistance value at 1 × 10 ⁴ V / cm was determined.

  An apparatus used for measuring the volume resistance value is shown in FIG.

  In FIG. 8, 11 indicates a lower electrode, 12 indicates an upper electrode, 14 indicates an ammeter, 15 indicates a constant voltage device, 17 indicates a measurement sample, 18 indicates a guide ring, and d indicates a measurement. The thickness of a sample is shown, A shows a volume resistance measuring cell.

  The sample was filled in the cell A, electrodes 11 and 12 were arranged so as to be in contact with the filled sample 17, a voltage was applied between the electrodes, and the current flowing at that time was measured by an ammeter 14. The measurement conditions were 23 ° C., 65% environment, and sample thickness of 0.5 to 1.0 mm.

  Furthermore, in the present invention, it is preferable to satisfy the following conditions because the effects described above are increased.

The relationship between the volume resistance value A of the toner and the volume resistance value B of the high resistance material is 10 ⁻² ≦ A / B ≦ 10 ³ , and the aggregation degree of the toner is 30 to 30 as measured under application of an oscillating electric field and normal temperature and pressure. It is preferable that it is 80 (%).

When the BET specific surface area of the toner is D (m ² / g) and the weight average diameter of the toner is E (μm), the value of B is 3.0 to 9.0, and the relational expression D / E is 0. .20 to 0.60 is preferable.

  The value of D / E is a measure of the surface area of the particles, and it is considered that the larger the value, the easier it is to charge an applied electric field to the toner surface layer. High image quality can be achieved by controlling this value.

  When the value of D / E is less than 0.20, the responsiveness of the toner to the electric field is lowered, and the toner coat property is not satisfactory. When the value of D / E exceeds 0.60, the toner has good responsiveness to the electric field, but the conductivity of the toner itself increases, and leakage tends to occur.

<Toner BET specific surface area measurement method>
The BET specific surface area of the toner is measured as follows.

  The BET specific surface area is obtained by a BET multipoint method using, for example, a fully automatic gas adsorption amount measuring apparatus (Autosoap 1) manufactured by Yuasa Ionics Co., Ltd., using nitrogen as the adsorption gas. As a sample pretreatment, deaeration is performed at 50 ° C. for 10 hours.

<Method for measuring weight average particle diameter of toner>
For measurement of the weight average particle diameter of the toner, a Coulter Counter TAII type or Coulter Multilyzer (manufactured by Coulter Inc.) was used. As the electrolytic solution, 1% NaCl aqueous solution was prepared using first grade sodium chloride.

  In 100 to 150 ml of this electrolytic aqueous solution, 0.1 to 5 ml of a surfactant, preferably alkylbenzene sulfonate, is added as a dispersant, and 2 to 20 mg of a measurement sample is further added. The electrolytic solution in which the sample is turbid is subjected to a dispersion treatment with an ultrasonic disperser for about 1 to 3 minutes, and the volume and number of toners having a size of 2 μm or more are measured with the measuring device using a 100 μm aperture, The number distribution was calculated, and the weight-based weight average particle diameter D4 was determined from the volume distribution.

When the quietness density F (g / cm ³ ) and the tap density of the toner are G (g / cm ³ ), the degree of compression [(G−F) / G] × 100 is preferably 10 to 60.

  The compressibility value is a measure of the ease of compaction of the powder, and it is considered that the larger the value, the easier it is to charge the toner surface layer with the applied electric field. High image quality can be achieved by controlling this value.

  When [(G−F) / G] × 100 is less than 10, the responsiveness of the toner to the electric field is lowered, and the toner coat property is not satisfactory. When the value of [(G−F) / G] × 100 exceeds 60, the toner has good responsiveness to the electric field, but the conductivity of the toner itself increases, and leakage tends to occur.

  The quietness density, tap density, and degree of compression are measured by the following method using a powder tester (manufactured by Hosokawa Micron).

The quietness density (g / cm ³ ) of the toner is uniformly 30% from above through a sieve having an opening of 608 μm (24 mesh) into a cylindrical container having a diameter of 5.03 cm, a height of 5.03 cm, and a volume of 100 cm ^3. It is measured by sieving for 2 seconds and grinding off the toner on the upper surface of the cylindrical container.

The toner tap density (g / cm ³ ) was determined by measuring the quietness density of the toner, putting a cylindrical cap on the cylindrical container, adding powder to the upper edge, and tapping with a tap height of 1.8 cm. Do it once. After completion, the measurement is performed by removing the cap and grinding the powder on the upper surface of the container.

The degree of compression is calculated by the following formula.
Compressibility = [(G−F) / G] × 100
(Where F is the quietness density of the toner and G is the tap density of the toner.)

  The average circularity measured by the flow type particle image measuring device of the toner is preferably 0.960 to 0.995.

  Here, the flow type particle image measuring apparatus is an apparatus that statistically performs image analysis of particle imaging, and the average circularity is calculated by the arithmetic average of the circularity obtained by the following equation using the apparatus.

  In the above equation, the perimeter of the particle projection image is the length of the contour line obtained by connecting the edge points of the binarized particle image, and the perimeter of the equivalent circle is the binarized particle This is the length of the outer circumference of a circle having the same area as the image. The equivalent circle diameter is the diameter of a circle having the same area as the area of the measured two-dimensional image of the particles.

  FPIA-2100 (manufactured by Sysmex Corporation) is used as a flow type particle image measuring apparatus. As a measuring method, 0.02 g of a measurement sample is added to 10 ml (20 ° C.) of a solution prepared by adding 0.1 to 0.5% by mass of a surfactant (preferably Wako Pure Chemicals Contaminone) to ion-exchanged water. To prepare a sample dispersion. As a means for dispersion, an ultrasonic disperser UM-50 manufactured by SMT Co., Ltd. (vibrator is a titanium alloy chip of 5φ) is used, and the dispersion time is set to 5 minutes. Cooled to. In the measurement, the range of 0.60 to 400 μm is divided into 226 channels, and in the actual measurement, particles are measured in a range where the equivalent circle diameter is 0.60 μm or more and less than 159.21 μm.

  When the average circularity is 0.960 to 0.995, since the toner shape is almost spherical, the remaining amount of toner on the developing carrier is small, and a good result is obtained with a small load during collection.

  When the average circularity is less than 0.960, a large amount of toner remains, and fusion due to contamination of the developing carrier tends to occur.

In the present invention, the toner is preferably a toner that satisfies the following relational expressions (1) and (2).
0 ≦ Et100 (mJ) ≦ 500 (1)
1.00 ≦ Et10 / Et100 ≦ 1.60 (2)
[However, Et100 (mJ) entered the toner powder layer in the container while rotating the propeller blade counterclockwise at 100 mm / sec, and started measurement at a position 100 mm from the bottom of the toner powder layer. Represents the total Et of the rotational torque and the vertical load obtained when approaching 10 mm from the bottom surface. Et10 (mJ) is the sum of the rotational torque and the vertical load when rotated at 10 mm / sec. It represents Et. ]

  As a result of intensive studies, the present inventors have found that the relational expressions (1) and (2) have a high correlation with the stress applied to the toner in the developing device, and thus have a high correlation with the durability of the developer. I found out. Here, the stress applied to the toner is immediately before the toner is supplied from the developer supply / removal means to the developer carrier, and immediately before the nip portion between the developer carrier to which the toner is applied and the developing blade. It means the stress that the toner receives. In other words, between the developer supply / removal means and the developer carrier, the toner can easily accumulate due to the peripheral speed difference caused by the rotation of the two members, and the toner coating amount between the developer carrier and the development blade. It is considered that stress is applied to the toner by applying force due to the rotation of the developer supply / removal means and the developer carrier. The measured values Et100 (mJ) and Et10 (mJ) in the relational expressions (1) and (2) are obtained by measuring the energy applied when the propeller blade enters the toner powder layer. Believe that the toner powder layer corresponds to the toner reservoir, and the propeller blade corresponds to the rotation of the developer supply / removal means and the developer carrier.

  In the present invention, Et100 (mJ) is controlled to 500 or less to reduce the stress applied to the toner in the developing device, and in the case of high-speed long-term durable printing, member contamination and external additives due to the seepage of wax It has been found that toner deterioration such as embedding of toner and crushing of toner particles is suppressed, and a stable image can be obtained. In particular, in the case of a non-magnetic one-component developer, immediately before the toner is supplied from the developer supply / removal means to the developer carrier, and at the nip portion between the developer carrier to which the toner is applied and the developing blade. Immediately before the toner coat amount is regulated, the toner can easily collect, and the toner is easily stressed. In particular, in the latter half of the endurance, the deteriorated toner accumulates, causing problems such as fogging and development streaks. It was easy. Therefore, it is very important to control Et100 (mJ) to 500 or less, and from the same viewpoint, Et100 (mJ) is preferably controlled to 470 or less. More preferably, it is 450 or less.

  Furthermore, Et100 (mJ) is more preferably controlled to 150 or more. As a result, it is possible to apply an appropriate stress to the toner, to charge the toner quickly, uniformly and sharply, and to prevent fogging and scattering due to poor charging.

  Et10 / Et100 is required to be 1.00 or more and 1.60 or less, and more preferably 1.20 or more and 1.60 or less. Et10 / Et100 monitors the dependency of the rotational speed on the stress applied to the toner. When this is applied to the situation in the developing device, when image is printed using gloss paper preferably used for obtaining a photographic image, or when a transparent sheet (OHT) is used, The case where the process speed drops to 1/2 speed or 1/3 speed, which is a means preferably used to achieve higher image quality, is considered to be applicable.

  By suppressing Et10 / Et100 to 1.60 or less, it is possible to reduce the stress applied to the toner even in a situation where the speed is varied, and to achieve a long life.

  On the other hand, by controlling Et10 / Et100 to 1.20 or more, even when the speed is variable, it is possible to apply an appropriate stress to the toner and to charge the toner quickly, uniformly and sharply. It has the effect of preventing fogging and scattering due to defects.

Examples of methods for controlling these Et100 and Et10 / Et100 values include the following methods (A) to (D). These methods may be performed independently, but may be achieved by combining a plurality.
(A) For example, a method of controlling toner particle size distribution by classification or the like, and suppressing the toner packing by causing appropriate fine powder and coarse powder to exist.
(B) For example, a method of increasing the average circularity of the toner and reducing the contact area between the toner particles.
(C) For example, a method in which an appropriate amount of an organic / inorganic fine particle layer treated with a treatment agent having low surface energy and high hydrophobicity is adhered to the toner surface.
(D) For example, by dispersing toner particles in an aqueous medium and flowing steam or the like, the entire system is heated to 100 ° C., thereby eliminating minute irregularities on the toner surface, thereby reducing the surface energy of the toner. Method.

<Measuring method of Et100 (mJ) and Et10 (mJ)>
Et100 (mJ) and Et10 (mJ) in the present invention are measured by using a powder fluidity analyzer, powder rheometer FT-4 (manufactured by Freeman Technology) (hereinafter sometimes abbreviated as FT-4). To do.

  Specifically, the measurement is performed by the following operation. In all operations, as shown in FIG. 1, the propeller blade is a 48 mm diameter blade dedicated to FT-4 measurement (the rotation axis exists in the normal direction at the center of the blade plate of 48 mm × 10 mm). The outermost edges (24 mm from the rotating shaft) are smoothly twisted counterclockwise such that the portion 12 mm from the rotating shaft is 35 ° and the material is made of SUS, model number: C210. May be abbreviated as blade).

  23 for a cylindrical split container (model number: C203, 82 mm in height from the bottom of the container to the split part. The material is glass. Hereinafter, it may be abbreviated as a container). A toner powder layer is formed by adding 100 g of toner left in a 60 ° C., 60% environment for 3 days or more.

(1) Conditioning operation (a) The rotation speed of the blade in the clockwise direction with respect to the powder layer surface (the direction in which the powder layer is loosened by the rotation of the blade) is the peripheral speed 60 at the outermost edge of the blade. (Mm / sec), the speed at which the angle between the trajectory drawn by the outermost edge of the moving blade and the surface of the powder layer is 5 (deg) (the angle formed by the vertical approach speed to the powder layer) In this case, the toner particles are allowed to enter from the surface of the powder layer to a position 10 mm from the bottom surface of the toner powder layer. After that, in the clockwise rotation direction with respect to the powder layer surface, the blade rotation speed is 60 (mm / sec), and the vertical entry speed into the powder layer is 2 (deg). Then, an operation of entering the position 1 mm from the bottom surface of the toner powder layer is performed. Thereafter, in the clockwise rotation direction with respect to the powder layer surface, the rotation speed of the blade is 60 (mm / sec), the extraction speed from the powder layer is 5 ° (deg), and the toner powder It is moved from the bottom of the body layer to a position of 100 mm and extracted. When the extraction is completed, the toner attached to the blade is wiped off by rotating the blade alternately in small clockwise and counterclockwise directions.

  (B) By performing the series of operations (1) to (a) five times, the air entrained in the toner powder layer is removed, and a stable toner powder layer is formed.

(2) Split operation A toner powder layer having the same volume is formed by scraping the toner powder layer at the split portion of the above-described cell dedicated to FT-4 measurement and removing the toner on the powder layer.

(3) Measurement operation (i) Measurement of Et100 (a) A conditioning operation similar to (1) to (a) above is performed once. Next, the rotational speed of the blade is 100 (mm / sec) in the counterclockwise direction (the direction in which the powder layer is pushed by the rotation of the blade), and the direction perpendicular to the powder layer is The approach speed is made to approach 10 mm from the bottom surface of the toner powder layer at an angle of 5 (deg). After that, in the clockwise rotation direction with respect to the powder layer surface, the blade rotation speed is 60 (mm / sec), and the vertical entry speed into the powder layer is 2 (deg). Then, an operation of entering the position 1 mm from the bottom of the powder layer is performed. After that, in the clockwise rotation direction with respect to the powder layer surface, the blade rotation speed is 60 (mm / sec), and the vertical extraction speed from the powder layer is 5 (deg). Extract from the bottom of the powder layer to a position of 100 mm. When the extraction is completed, the toner attached to the blade is wiped off by rotating the blade alternately in small clockwise and counterclockwise directions.

  (B) The above-described series of operations is repeated seven times, and at the seventh time, the rotation speed of the blade is 100 (mm / sec), the measurement starts from a position 100 mm from the bottom surface of the toner powder layer, and a position 10 mm from the bottom surface. Let Et100 be the total Et of the rotational torque and the vertical load that is obtained when it is made to enter.

(Ii) Measurement of Et10 (a) Using the toner powder layer for which the measurement of Et100 has been completed, the above operations (3)-(i)-(a) are performed once.

  (B) Next, in the series of operations in (3)-(i)-(a), the blade was moved into the toner powder layer at a rotational speed of 100 (mm / sec). / Sec) for measurement.

  (C) Subsequently, the measurement was performed by sequentially reducing the rotational speed to 40 (mm / sec) and 10 (mm / sec) in the same manner as in (3)-(ii)-(b), and the rotational speed was 10 (mm / sec). sec), the measurement Et is started from the position of 100 mm from the bottom surface of the toner powder layer, and the total Et of the rotational torque and the vertical load obtained when the toner powder is moved to the position of 10 mm from the bottom surface is defined as Et10.

  The method for producing the toner of the present invention is a method in which a toner is directly produced using a suspension polymerization method; toner particles are produced by direct polymerization in the presence of a water-soluble polymerization initiator that is soluble in a monomer. Examples thereof include production of toner particles by an emulsion polymerization method typified by a soap-free polymerization method. In addition, production of an interfacial polymerization method such as a microcapsule production method, an in situ polymerization method, a coacervation method, and the like can also be mentioned. Furthermore, an interfacial association method for aggregating at least one kind of fine particles to obtain a desired toner may be used. Alternatively, a method in which the toner obtained by the pulverization method is spheroidized by a mechanical impact force can be used.

  Among these, a suspension polymerization method that can easily obtain toner particles having a small particle diameter is particularly preferable. When suspension polymerization is used as a method for producing toner particles, the toner particles can be produced directly by the following production method.

  Adds a colorant, polymerization initiator, cross-linking agent, and other additives to the monomer, and contains a dispersion stabilizer that is uniformly dissolved or dispersed by a homogenizer, ultrasonic disperser, etc. Disperse in an aqueous medium with a normal stirrer, homomixer or homogenizer. Preferably, granulation is performed by adjusting the stirring speed and time so that the droplets of the monomer composition have a desired toner particle size. Thereafter, stirring may be carried out to such an extent that the particle state is maintained and the sedimentation of the particles is prevented by the action of the dispersion stabilizer. The polymerization is carried out at a polymerization temperature of 40 ° C. or higher, usually 50 to 80 ° C. (preferably 55 to 70 ° C.). The temperature may be raised in the latter half of the polymerization reaction, and the pH may be changed as necessary. In the present invention, in order to remove unreacted polymerizable monomers and by-products that cause odor during toner fixing, the aqueous medium is partially distilled off in the latter half of the reaction or after the completion of the reaction. May be. After completion of the reaction, the produced toner particles are collected by washing and filtration and dried.

  The following describes the material of the polymerization toner.

  As the polymerizable monomer used when the toner of the present invention is produced by the polymerization method, a vinyl polymerizable monomer capable of radical polymerization is used. As the vinyl polymerizable monomer, a monofunctional polymerizable monomer is mainly used. Monofunctional polymerizable monomers include styrene; α-methylstyrene, β-methylstyrene, o-methylstyrene, m-methylstyrene, p-methylstyrene, 2,4-dimethylstyrene, pn-butyl. Styrene, p-tert-butyl styrene, pn-hexyl styrene, pn-octyl styrene, pn-nonyl styrene, pn-decyl styrene, pn-dodecyl styrene, p-methoxy styrene, p -Styrene derivatives such as phenylstyrene; methyl acrylate, ethyl acrylate, n-propyl acrylate, iso-propyl acrylate, n-butyl acrylate, iso-butyl acrylate, tert-butyl acrylate, n-amyl acrylate, n-hexyl acrylate, 2 -Ethylhexyl acrylate acrylic polymerizable monomers such as n-octyl acrylate, n-nonyl acrylate, cyclohexyl acrylate, benzyl acrylate, dimethyl phosphate ethyl acrylate, diethyl phosphate ethyl acrylate, dibutyl phosphate ethyl acrylate, 2-benzoyloxyethyl acrylate; Methyl methacrylate, ethyl methacrylate, n-propyl methacrylate, iso-propyl methacrylate, n-butyl methacrylate, iso-butyl methacrylate, tert-butyl methacrylate, n-amyl methacrylate, n-hexyl methacrylate, 2-ethylhexyl methacrylate, n-octyl methacrylate , N-nonyl methacrylate, diethyl phosphate ethyl methacrylate Methacrylic polymerizable monomers such as dibutyl phosphate ethyl methacrylate; methylene aliphatic monocarboxylic acid esters; vinyl esters such as vinyl acetate, vinyl propionate, vinyl butyrate, vinyl benzoate, vinyl formate; vinyl methyl ether Vinyl ether such as vinyl ethyl ether and vinyl isobutyl ether; vinyl ketone such as vinyl methyl ketone, vinyl hexyl ketone and vinyl isopropyl ketone.

  In the present invention, the above monofunctional polymerizable monomers are used alone or in combination of two or more.

  In the present invention, a water-soluble initiator may be used in combination as an aid to the reaction. Examples include ammonium persulfate, potassium persulfate, 2,2′-azobis (N, N′-dimethyleneisobutyroamidine) hydrochloride, 2,2′-azobis (2-aminodinopropane) hydrochloride, azobis (isobutyl) Amidine) hydrochloride, sodium 2,2′-azobisisobutyronitrile sulfonate, ferrous sulfate or hydrogen peroxide.

  In order to control the degree of polymerization of the polymerizable monomer, a chain transfer agent, a polymerization inhibitor or the like can be further added and used.

  Dispersion stabilizers include tricalcium phosphate, magnesium phosphate, aluminum phosphate, zinc phosphate, calcium carbonate, magnesium carbonate, calcium hydroxide, magnesium hydroxide, aluminum hydroxide, calcium metasilicate, calcium sulfate, and barium sulfate. , Bentonite, silica, alumina, hydroxyapatite and the like. Usually, it is preferable to use 300 to 3000 parts by weight of water as a dispersion medium with respect to 100 parts by weight of the monomer composition.

  As the organic compound, for example, polyvinyl alcohol, gelatin, methylcellulose, methylhydroxypropylcellulose, ethylcellulose, sodium salt of carboxymethylcellulose, starch and the like are used. These dispersants are preferably used in an amount of 0.2 to 2.0 parts by mass with respect to 100 parts by mass of the polymerizable monomer.

  Other dispersion stabilizers preferably used include sparingly water-soluble metal salts of sulfuric acid, carbonic acid, phosphoric acid, pyrophosphoric acid, and polyphosphoric acid. These are acid alkali metal salts and metal halide salts under high-speed stirring in a dispersion medium. It is preferable to prepare by this reaction.

  In order to make these dispersants fine, 0.001 to 0.1% by mass of a surfactant may be used in combination. Specifically, commercially available nonionic, anionic and cationic surfactants can be used. For example, sodium dodecyl sulfate, sodium tetradecyl sulfate, sodium pentadecyl sulfate, sodium octyl sulfate, sodium oleate, sodium laurate, potassium stearate, calcium oleate and the like are preferably used.

  In the present invention, when a condensation compound is used, for example, polyester, polycarbonate, phenol resin, epoxy resin, polyamide, cellulose and the like can be mentioned. More preferably, polyester is desired due to the variety of materials.

  Examples of the wax used in the present invention include paramethylene wax, polyolefin wax, microcrystalline wax, polymethylene wax such as Fischer Tropish wax, amide wax, ketone wax, higher fatty acid, long chain alcohol, ester wax, and graft compounds thereof. And derivatives such as block compounds.

  Examples of the wax preferably used include linear alkyl alcohols having 15 to 100 carbon atoms, linear fatty acids, linear acid amides, linear esters, and montan derivatives. Those from which impurities such as liquid fatty acids have been previously removed from these waxes are also preferred.

  Further, the wax preferably used is a low molecular weight alkylene polymer obtained by polymerizing alkylene with radical polymerization under high pressure or Ziegler catalyst or other catalyst under low pressure; alkylene obtained by thermally decomposing high molecular weight alkylene polymer Polymer: A low molecular weight alkylene polymer produced as a by-product in the polymerization of alkylene, separated and purified; a hydrocarbon polymer distillation residue obtained from a synthesis gas consisting of carbon monoxide and hydrogen by the age method, or a distillation residue And polymethylene wax obtained by extracting and fractionating specific components from a synthetic hydrocarbon obtained by hydrogenation. These waxes may contain an antioxidant.

  The content in the toner is preferably 6 to 15% by mass of wax.

  The colorant used in the present invention is carbon black or a known yellow / magenta / cyan colorant as shown below.

  As the yellow colorant, compounds typified by condensed azo compounds, isoindolinone compounds, anthraquinone compounds, azo metal complexes, methine compounds, and allylamide compounds are used. Specifically, C.I. I. CI Pigment Yellow 12, 13, 14, 15, 17, 62, 74, 83, 93, 94, 95, 109, 110, 111, 128, 129, 147, 151, 154, 155, 168, 180, etc. are preferably used. It is done.

  As the magenta colorant, condensed azo compounds, diketopyrrolopyrrole compounds, anthraquinones, quinacridone compounds, basic dye lake compounds, naphthol compounds, benzimidazolone compounds, thioindigo compounds, and perylene compounds are used. Specifically, C.I. I. Pigment Red 2, 3, 5, 6, 7, 23, 48; 2, 48; 3, 48; 4, 57; 1, 81; 1, 122, 146, 166, 150, 169, 177, 184, 185, 202, 206, 220, 221, 254 are particularly preferred.

  As the cyan colorant used in the present invention, copper phthalocyanine compounds and derivatives thereof, anthraquinone compounds, basic dye lake compounds, and the like can be used. Specifically, C.I. I. Pigment Blue 1, 7, 15, 15: 1, 15: 2, 15: 3, 15: 4, 60, 62, 66 and the like are particularly preferably used.

  These colorants can be used alone or in combination and further in the form of a solid solution. The colorant of the present invention is selected from the viewpoints of hue angle, saturation, brightness, weather resistance, OHP transparency, and dispersibility in the toner. The colorant is added in an amount of 1 to 20 parts by mass with respect to 100 parts by mass of the resin.

  As the toner additive that can be used in the present invention, oil-treated inorganic fine particles such as silica and titania are preferably used. In addition to oxides such as zirconium oxide and magnesium oxide, silicon carbide, silicon nitride, boron nitride, aluminum nitride, magnesium carbonate, organosilicon compounds, and the like can be used in combination.

In the present invention, it is preferable to use at least one external additive having a volume resistivity H of 10 ⁴ ≦ H ≦ 10 ¹² (Ωcm) in the toner.

Silica is preferable in that the coalescence of the primary particles can be controlled arbitrarily to some extent depending on the starting material or the oxidation conditions such as temperature. For example, the silica can be either a so-called dry method produced by vapor phase oxidation of silicon halide or alkoxide, or a so-called wet silica produced from alkoxide, water glass, etc. However, dry silica is preferable because it has few silanol groups on the surface and inside of the silica fine powder and few production residues such as Na ₂ O and SO ₃ ²⁻ . In dry silica, it is also possible to obtain composite fine powders of silica and other metal oxides by using other metal halogen compounds such as aluminum chloride and titanium chloride together with silicon halogen compounds in the production process. Is also included.

  Furthermore, the silica is preferably hydrophobized in order to reduce the dependency of the toner charge amount on the environment, such as temperature and humidity, and to prevent excessive release from the toner surface. Examples of the hydrophobizing agent include coupling agents such as a silane coupling agent, a titanium coupling agent, and an aluminum coupling agent. In particular, the silane coupling agent reacts with residual groups on the inorganic oxide fine particles or adsorbed water to achieve a uniform treatment, which is preferable in terms of stabilizing charging of the toner and imparting fluidity.

The silane coupling agent has the following general formula Rm SiYn
R: an alkoxy group m: an integer of 1 to 3, Y: an alkyl group, a vinyl group, a glycidoxy group, a hydrocarbon group including a methacryl group n: an integer of 1 to 3, for example, vinyltrimethoxysilane, vinyl Triethoxysilane, γ-methacryloxypropyltrimethoxysilane, vinyltriacetoxysilane, methyltrimethoxysilane, methyltriethoxysilane, isobutyltrimethoxysilane, dimethyldimethoxysilane, dimethyldiethoxysilane, trimethylmethoxysilane, hydroxypropyltrimethoxy Examples include silane, phenyltrimethoxysilane, n-hexadecyltrimethoxysilane, and n-octadecyltrimethoxysilane.

More preferably, C _a H _{2a + 1} —Si (OC _b H _{2b + 1} ) ₃
(A = 4 to 12, b = 1 to 3)
It is. Here, when a in the general formula is smaller than 4, the treatment becomes easy, but the hydrophobicity cannot be sufficiently achieved. On the other hand, if a is greater than 12, the hydrophobicity is sufficient, but the coalescence between the particles increases, and the fluidity imparting ability decreases.

  When b is larger than 3, the reactivity is lowered and the hydrophobicity is not sufficiently performed. Therefore, a in the above general formula is 4 to 12, preferably 4 to 8, and b is 1 to 3, preferably 1 to 2.

  With respect to the oil treatment of silica, untreated silica may be directly treated with oil, but it is more preferable from the viewpoint of charging stability that the hydrophobized silica is further treated with oil. As the oil, dimethylpolysiloxane, methylhydrogenpolysiloxane, paraffin, mineral oil and the like can be used, and among them, dimethylpolysiloxane excellent in environmental stability is preferable. The appropriate amount of oil used for the treatment is 2 to 40 parts by mass with respect to 100 parts by mass of the silica fine particle matrix.

  In the toner of the present invention, other additives such as a lubricant powder such as polyethylene fluoride powder, zinc stearate powder and polyvinylidene fluoride powder; An abrasive such as strontium titanate powder, an anti-caking agent such as aluminum oxide powder, or a conductivity imparting agent such as carbon black powder, zinc oxide powder or tin oxide powder, and organic and inorganic fine particles of reverse polarity. A small amount can be used as a developability improver.

  Hereinafter, a developing device, a process cartridge, and an image forming apparatus according to the present invention will be described in more detail with reference to the drawings. However, the dimensions, materials, shapes, and relative arrangements of the components described in this embodiment should be appropriately changed according to the configuration of the apparatus to which the invention is applied and various conditions. It is not intended to limit the scope to the following embodiments.

Example 1
FIG. 2 is a schematic sectional view of an image forming apparatus to which the developing device according to the present invention is applied, and FIG. 3 is a schematic sectional view of the developing device.

  First, an image forming operation by the image forming apparatus of this embodiment will be described.

  In this embodiment, the image forming apparatus 20 includes a drum-shaped electrophotographic photosensitive member as an image carrier, that is, a photosensitive drum 21, and the photosensitive drum 21 is rotatably supported in an arrow A direction. Around the photosensitive drum 21, a charging device 22, an exposure device 23, and a developing device 24 are arranged.

  First, the photosensitive drum 21 is uniformly charged by the charging device 22, and then exposed in the present embodiment by the laser light 23 </ b> L from the laser optical device that is the exposure device 23, and an electrostatic latent image is formed on the surface thereof. It is formed.

  The electrostatic latent image is developed by a developing device 24 arranged to face the photosensitive drum 21 and visualized as a toner image. In this embodiment, the developing device 24 is detachable from the image forming apparatus main body 20A as a cartridge.

  The visualized toner image on the photosensitive drum 21 is transferred to a transfer material 26 as a recording medium by a transfer roller 25 as a transfer device.

  The untransferred toner remaining on the photosensitive drum 21 without being transferred is scraped off by a cleaning blade 27 a that is a cleaning member provided in the cleaning device 27 and stored in a waste toner container 28. The cleaned photosensitive drum 21 repeats the above operation to form an image.

  On the other hand, the transfer material 26 onto which the toner image has been transferred is permanently fixed by a fixing device 29 and then discharged outside the apparatus.

  Next, the developing device 24 will be further described with reference to FIG.

  In this embodiment, the developing device 24 includes a developing container 31 that stores a negatively charged nonmagnetic one-component toner 32 as a developer. The developing device 24 is located at an opening extending in the longitudinal direction in the developing container 31, and includes a developing roller 33 as a developer carrying member disposed to face the photosensitive drum 21. Develop and visualize the image. In this embodiment, the developing roller 33 has an elastic layer 33B formed on a core metal 33A. The detailed configuration of the developing roller 33 will be described later.

  The photosensitive drum 21 is a rigid body having an aluminum cylinder as a base and a photosensitive layer having a predetermined thickness coated around it. At the time of image formation, the charging device 22 uniformly charges the charging potential Vd = −500V, and the portion exposed by the laser beam 23L according to the image signal becomes Vl = −100V. A DC voltage Vdc = −300 V is applied as a developing bias from the power supply 40 to the core 33A of the developing roller 33 with respect to the Vl portion, and is reversely developed with negatively charged toner.

  The developing roller 33 having elasticity is provided horizontally at the opening, with the substantially right half circumference shown in FIG. 3 protruding into the developing container 31 and the left substantially half circumferential surface exposed from the developing container 31. The surface exposed from the developing container 31 faces the photosensitive drum 21 located on the left side of the developing device 24 so as to be pressed and brought into contact with the photosensitive drum 21 by a predetermined amount. In the present embodiment, the developing roller 33 enters and contacts the photosensitive drum 21 by 50 μm.

  The developing roller 33 is rotationally driven in the direction of arrow B in FIG. The surface has moderate irregularities in order to improve the establishment of rubbing with the toner 32 and to carry the toner 32 well.

In this embodiment, the developing roller 33 has a two-layer structure in which urethane rubber is used as a base layer as the elastic layer 33B and acrylic / urethane rubber is coated on the surface. The surface roughness Ra was 0.6 to 1.3 μm, and the resistance was 10 ^{4 to} 10 ⁷ Ω.

  Here, a method for measuring resistance will be described.

  The developing roller 33 is brought into contact with an aluminum sleeve having the same diameter as that of the photosensitive drum 21 with a contact load of 500 gf. The aluminum sleeve is further rotated at a peripheral speed equal to that of the photosensitive drum 21.

  In this embodiment, the photosensitive drum 21 rotates at a peripheral speed of 90 mm / sec and has a diameter of 30 mm, and the developing roller 33 rotates at a peripheral speed of 120 mm / sec faster than that of the photosensitive drum 21 and has a diameter of 20 mm.

  Next, a DC voltage of −300 V that is equal to the developing bias in this embodiment is applied to the developing roller 33. At that time, a resistance of 10 kΩ is provided on the ground side, and the current is calculated by measuring the voltage at both ends thereof, thereby calculating the resistance of the developing roller 33.

  In this embodiment, the developing device 24 is positioned above the developing roller 33, and a developing blade 35 as a developer regulating member having elasticity is disposed. The developing blade 35 is supported by a support metal plate 38, and the abutting direction is a counter direction in which the tip on the free end side with respect to the abutting portion is positioned upstream in the rotation direction of the developing roller 33. .

  As a method of supporting the developing blade 35 on the support metal plate 38, any method such as fastening with a screw or welding or welding can be employed. Further, the developing blade 35 and the support metal plate 38 are at the same potential as the developing roller 33, and therefore, the same voltage as the developing bias is applied when developing the electrostatic latent image on the photosensitive drum 31. .

  The material of the developing blade 35 is SUS, but it may be a metal such as phosphor bronze, a rubber material such as silicon or urethane, or a resin such as PET as long as it has elasticity. In addition, the bias applied to the developing blade 35 may not be the same potential as the developing bias, and a suitable bias may be selected for regulating the toner 32.

  A high resistance material coated electrode roller 34 as a means for supplying / removing the developer to / from the developing roller 33 is disposed on the developing roller 33 diagonally to the right in FIG. The configuration of the high resistance material coated electrode roller 34 will be described later.

  The electrode high resistance material coated electrode roller 34 is arranged in non-contact with the developing roller 33, and the position (region) where the electrode high resistance material coated electrode roller 34 and the developing roller 33 are arranged to face each other is described later. A developer supply / removal position (region) TS to be formed is formed. The size of the minimum gap S between the developing roller 33 and the high resistance material coated electrode roller 34 in the developer supply / removal region TS is applied between the developing roller 33 and the high resistance material coated electrode roller 34 as described later. Although it is determined by the maximum electric field strength formed by the required voltage, it can be usually 10 to 400 μm, and in this embodiment, it is 150 μm.

  More specifically, the high resistance material coated electrode roller 34 is rotatably supported and is driven to rotate in the same direction (C direction) as the developing roller 33. That is, at the developer supply / removal position TS, the rotation direction (toner conveyance direction) of the development roller 34 is opposite to the rotation direction (toner conveyance direction) of the high resistance material coating electrode roller 34. In this example, the high resistance material coated electrode roller 34 was driven to rotate in the rotational direction C at a peripheral speed of 80 mm / sec.

  In the present embodiment, a bias in which a sine wave AC voltage 4 kVpp and a frequency of 400 Hz are superimposed on a +2.0 kV DC voltage is applied to the high resistance material coated electrode roller 34 from the power source 39 of the image forming apparatus. As a result, an oscillating electric field is formed between the developing roller 33 and the high resistance material coated electrode roller 34 in the developer supply / removal region TS.

  The high resistance material coated electrode roller 34 is configured by laminating a high resistance material 34B on the surface of the conductive material 34A. In this embodiment, the high-resistance material-coated electrode roller 34 is obtained by laminating a 100 μm-thick polycarbonate resin 34B on the surface of a SUS cored bar 34A having a diameter of 11.5 mm.

  The arrangement and configuration of the high-resistance material-coated electrode roller 34 and the basis for determining the applied voltage will be described later.

  In the developing device 24 configured as described above, during the developing operation, as shown in FIG. 3, the toner 32 in the developing container 31 has a high resistance when the high resistance material coated electrode roller 34 rotates in the direction of arrow C. It is carried by the material coating electrode roller 34 and is carried to the vicinity of the developing roller 33, that is, to the developer supply / removal region TS.

  The toner 32 carried on the high resistance material coated electrode roller 34 is applied from the power source 39 at the position of the gap S between the developing roller 33 and the high resistance material coated electrode roller 34, that is, in the developer supply / removal region TS. Is conveyed (supplied) to the developing roller 33 by the oscillating electric field generated by the alternating voltage. At that time, the toner 32 is frictionally charged by the developing roller 33 and adheres to the developing roller 33.

  Thereafter, the toner 32 is sent under pressure contact with the developing blade 35 as the developing roller rotates in the direction of arrow B, and receives a proper tribo (friction charge amount) and forms a thin layer on the developing roller 33. .

  The toner layer formed as a thin layer on the developing roller 33 is uniformly conveyed to the developing unit TD which is a portion facing the photosensitive drum 21. In this developing unit TD, the toner layer formed on the developing roller 33 as a thin layer is transferred from the electrostatic latent image on the photosensitive drum 21 by a developing bias applied by the power source 40 between the developing roller 33 and the photosensitive drum 21. And developed as a toner image.

  Undeveloped toner that has not been consumed in the developing unit TD is transferred and collected from the lower part of the developing roller 33 into the developing container 31 together with the rotation B of the developing roller 33.

  The collected undeveloped toner on the developing roller 33 is a high-resistance material-coated electrode roller in the developer supply / removal region TS in which the high-resistance material-coated electrode roller 34 and the developing roller 33 are arranged to face each other with a gap S therebetween. The toner is removed from the surface of the developing roller 33 by an AC voltage (a voltage that vibrates on the positive side from the developing bias of −300 V) applied to the developing bias on the side opposite to the polarity of the toner 32.

  Most of the toner removed from the surface of the developing roller 33 is conveyed along with the rotation of the high-resistance material-coated electrode roller 34 and is supplied again to the developing roller 33 to repeat the above-described operation.

  The reason why the image is improved by generating an oscillating electric field between the insulating coat electrode roller 34 and the developing roller 33 was found in the following experiment.

  The vicinity of the toner supply unit was visualized by forming the end in the longitudinal direction of the developing device 24 with a transparent acrylic plate.

  As a result, by generating the oscillating electric field, as shown in FIG. 4, the toner 32A conveyed by the insulating coat electrode roller 34 moves in the developer supply / removal area TS, that is, the toner supply. A movement E in which the toner 32 </ b> A is carried by the developing roller 33 due to the electric field generated in the portion F was observed. This is considered that the toner 32A temporarily retained in the toner supply unit F is triboelectrically charged with the developing roller 33 and is carried on the developing roller 33 by a mirror image force.

  In this embodiment, the core metal of the high-resistance material-coated electrode roller 34 is made of SUS. However, a resin or rubber in which a conductive agent is dispersed may be used. As long as it functions. The high resistance coating material only needs to have pressure resistance against a desired maximum electric field. As a material, a polycarbonate resin is used in this embodiment, but other resins such as polyester, polyethylene, polyimide, urethane, and phenol may be used, or a resin having high pressure resistance such as a fluororesin, or silicon rubber, etc. Or a high resistance inorganic compound such as alumite.

  In this embodiment, the roller-shaped insulating coat electrode roller 34 is used as the developer supply / removal means 34. However, the surface of the conductive endless belt may be coated with a high resistance material. The maximum electric field in the vicinity of the supply position may be in the relationship described in this embodiment.

  In the present embodiment, the case where the present invention is applied to a cartridge including a developing device that can be attached to and detached from the image forming apparatus main body 20A has been described. However, it is fixed in the image forming apparatus main body and replenishes only toner. Further, the developing device 24, the photosensitive drum 21, the cleaning device 27, and the charging device 22 are integrally formed in FIG. 1 so as to be detachable from the image forming apparatus main body 20A. You may apply to a process cartridge.

As described above, according to the present embodiment, the electrode roller coated with the high resistance material is disposed with a gap in the vicinity of the developing roller, the high resistance material coated electrode roller and the developing roller are rotated in the same direction, and the high resistance material coated electrode By forming an oscillating electric field between the roller and the developing roller, and in particular, applying an AC voltage to the high-resistance material-coated electrode roller, the maximum electric field between the high-resistance material-coated electrode roller core and the developing roller Is set to 8.0 × 10 ⁶ V / m or more, the toner can be supplied to and removed from the developing roller, whether it is magnetic or non-magnetic, with one part of the insulating coat electrode roller, and the developing device can be downsized. In addition, a reduction in rotational driving torque and a low load on the toner can be obtained.

(Example of non-magnetic one-component full-color image forming apparatus)
FIG. 7 is a schematic configuration diagram of an example of an image forming apparatus according to the present invention. The image forming apparatus of this example is a tandem type electrophotographic color (multicolor image) printer of a tandem type in which a plurality of image bearing members (latent image carriers) as photosensitive drums are arranged one above the other. Even when the developing device described above is inserted into a non-magnetic one-component full-color image forming apparatus, a high-quality image can be obtained without any problem.

  PY, PM, PC, and PBk are first to fourth image forming units (image forming units) for forming toner images of yellow (Y), magenta (M), cyan (C), and black (Bk), respectively. Unit), which are arranged in the image forming apparatus main body in parallel from the bottom to the top.

  These first to fourth image forming units PY, PM, PC, and PBk have the same configuration and electrophotographic image forming function except that the colors of the toner images to be formed are different as described above. Yes. That is, each of the first to fourth image forming units includes a drum-type electrophotographic photosensitive member (photosensitive drum) 1 as a first image carrier, a charging roller 2 as a primary charging unit, and a laser as an exposure unit. The irradiation device 3 includes a toner developing device 4 as a developing unit, a primary transfer roller 5 as a primary transfer unit, a blade cleaning device 6 as a cleaning unit, and the like. The developers accommodated in the toner developing devices 4 of the first to fourth image forming units are yellow toner, cyan toner, magenta toner, and black toner, respectively. Each color toner will be described later.

  The image forming apparatus according to the present exemplary embodiment includes four processes of the photosensitive drum 1, the charging roller 2, the developing device 4, and the blade cleaning device 6 in each of the first to fourth image forming units PY, PM, PC, and PBk. The apparatus is a process unit (process cartridge) that is detachable and replaceable with respect to the main body of the image forming apparatus.

  Reference numeral 30 denotes an endless belt-shaped intermediate transfer belt as a second image carrier, and the photosensitive drum 1 side (printer front side) of the first to fourth image forming portions PY, PM, PC, and PBk described above. In FIG. 3, the four image forming units are arranged in the vertical direction by being suspended between a plurality of support rollers (not shown). In each of the first to fourth image forming units, the primary transfer roller 5 is pressed against the photosensitive drum 1 via the intermediate transfer belt 30. A contact portion between each photosensitive drum 1 and the intermediate transfer belt 30 is a primary transfer portion.

  In each of the first to fourth image forming units PY, PM, PC, and PBk, each photosensitive drum 1 that is driven to rotate forward is charged by a charging roller 2 to which a charging bias is applied from a power circuit (not shown) during the rotation process. Primary charging processing is uniformly performed to a predetermined polarity and potential, and the charging processing surface is subjected to each of the image patterns of yellow, magenta, cyan, and black, which are color separation component images of full-color images, by the LED array device 3. The optical image exposures LY, LM, LC, and LBk are performed, and an electrostatic latent image of image information is formed on each photosensitive drum 1. Each of the electrostatic latent images is developed as a toner image by the developing device 4 so that each of the first to fourth image forming portions PY, PM, PC, and PBk has an electrophotographic process on the surface of each photosensitive drum 1. As a result, yellow, magenta, cyan, and black color toner images, which are color separation component images of the full-color image, are formed at a predetermined sequence control timing.

  Then, in each of the first to fourth image forming units PY, PM, PC, and PBk, the yellow, magenta, cyan, and black color toner images formed on the surface of each photosensitive drum 1 are the positive images of the respective photosensitive drums 1. The first to fourth image forming units PY, PM, PC, and PBk with respect to the surface of the intermediate transfer belt 30 that is driven to rotate at the same speed as the photosensitive drum 1 in the clockwise direction of the forward arrow in the rotation direction. In the primary transfer portion, the images are sequentially superimposed and transferred to the primary transfer roller by a primary transfer bias applied from a power supply circuit (not shown). As a result, an unfixed full-color toner image (mirror image) is synthesized and formed on the surface of the intermediate transfer belt 30 that is rotationally driven.

  In each of the first to fourth image forming units PY, PM, PC, and PBk, the transfer residual toner remaining on each photosensitive drum 1 after the primary transfer of the toner image to the intermediate transfer belt 30 is the first to fourth images. Returned to the formation part PY / PM / PC / PBk and stored.

  32 is a secondary transfer roller, and 32a is a counter roller. The counter roller 32a is disposed inside the intermediate transfer belt at the lower end side of the intermediate transfer belt 30, and the secondary transfer roller 32 sandwiches the intermediate transfer belt 30 between the counter roller 32a and the intermediate transfer belt 30. Is disposed in contact with the outer surface. A contact portion between the secondary transfer roller 32 and the intermediate transfer belt 30 is a secondary transfer portion.

  Reference numeral 40 denotes a paper feed cassette disposed in the lower part of the main body of the image forming apparatus, in which a transfer material P as a final recording medium is stacked and accommodated. The CPU 80 drives the conveying means (pickup roller) 31 at a predetermined sequence control timing to separate and feed one transfer material P in the paper feed cassette 40, and feeds it to the secondary transfer section at a predetermined timing. . The unfixed full-color toner image synthesized and formed on the intermediate transfer belt 30 is transferred onto the surface of the transfer material P by a secondary transfer bias applied from a power supply circuit (not shown) to the secondary transfer roller 32 in the secondary transfer portion. It will be batch-transcribed.

  The transfer material P that has passed through the secondary transfer portion is separated from the surface of the intermediate transfer belt 30 and sent to the fixing device 7 by the transport belt 35.

  The transfer residual toner remaining on the intermediate transfer belt 30 is positively charged by a bias applied from a power supply circuit (not shown) from the charging brush 33, is reversely transferred from the intermediate transfer belt to the photosensitive drum, and is applied to the photosensitive drum. It is cleaned by the contacted blade.

  The unfixed full-color toner image on the transfer material P sent to the fixing device 7 is melted and fixed to the transfer material P by applying heat and pressure by the fixing device 7, passes through the sheet path 41, and the upper surface of the image forming apparatus main body. The sheet is discharged as a color image formed product onto a paper discharge tray 36 disposed in the above.

  EXAMPLES Hereinafter, the present invention will be specifically described by way of examples, but this does not limit the present invention in any way.

<Synthesis of binder resin>
<Synthesis example of polar resin (1)>
The following raw materials are put into a four-neck flask equipped with a thermometer, a stirrer, a reflux condenser and a nitrogen gas introduction tube, and a catalyst amount of 0.5% by mass with respect to 100 parts by mass of the following raw materials. The titanium oxalate compound was added, and nitrogen gas was passed through a four-necked flask and gradually heated while stirring. The mixture was reacted at 150 ° C. for 10 hours. The reaction was promoted. As a result, a precursor polyester resin (1) (acid value 5 mgKOH / g) having a weight average molecular weight Mw of 11000 was obtained.

-Diol component represented by the general formula (1) 55 mol%

（式中、Ｒはエチレン又はプロピレン基を表し、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乃至１０である。本実施例ではｘ＋ｙの平均値は３である。）
・イソフタル酸 ２０ｍｏｌ％
・テレフタル酸 ２５ｍｏｌ％

(In the formula, R represents 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. In this embodiment, the average value of x + y is 3. )
・ Isophthalic acid 20mol%
・ Terephthalic acid 25mol%

  Thereafter, 100 parts by mass of the precursor polyester resin (1) was placed in a four-necked flask and heated to a temperature of 150 ° C., 0.5 parts by mass of trimellitic anhydride was added, and the polymer of the precursor polyester resin (1) was gradually heated. A polar resin (1) having a terminal modified with trimellitic acid was prepared.

<Example of toner production>
(Black toner production example 1)
3 parts by mass of tricalcium phosphate is added to 900 parts by mass of ion-exchanged water heated to 65 ° C., and stirred at 10,000 rpm using a TK homomixer (made by Tokushu Kika Kogyo Co., Ltd.) to obtain an aqueous medium. It was.

on the other hand,
Styrene 80 parts by mass n-butyl acrylate 20 parts by mass polar resin (1) 3 parts by mass polar resin (2) 2 parts by mass (polycondensate of propylene oxide modified bisphenol A and terephthalic acid,
Tg = 55 ° C., Mn = 2500, Mw / Mn = 1.9)
Carbon black (carbon black Nipex 30 pH: 9.0) 10 parts by mass charge control agent 1: aromatic oxycarboxylic acid Zn compound (Bontron E-84: manufactured by Orient Chemical Co., Ltd.) 4 parts by mass charge control agent 2: methylcalixarene 1 Part by mass The above formulation was uniformly dispersed and mixed using an attritor (Mitsui Miike Chemical Co., Ltd.). This monomer composition is heated to 65 ° C.
Paraffin wax (1) 10 parts by mass (DSC endothermic peak: 69 ° C., Mw: 700, Mn: 500)
Was mixed and dissolved, and 5 parts by mass of a polymerization initiator (t-butylperoxypivalate) was dissolved in this.

The polymerizable monomer system was put into the aqueous medium, and the mixture was granulated by stirring at 10,000 rpm for 7 minutes with a TK homomixer in an N ₂ atmosphere at 70 ° C. Thereafter, the mixture was reacted at 70 ° C. for 4 hours while stirring with a paddle stirring blade. Finally, the liquid temperature was raised to 85 ° C. and stirring was continued for 3 hours.

  Hydrochloric acid was added to the suspension cooled to room temperature (25 ° C.) to dissolve the calcium phosphate salt, followed by filtration and washing with water to obtain wet colored particles.

  Next, the particles were dried at 40 ° C. for 12 hours to obtain black colored particles (1) having a weight average particle diameter of 5.8 μm.

  Thereafter, 0.5 parts by mass of a titania fine powder having a primary particle diameter of 50 nm subjected to a hydrophobization treatment and silica having a primary particle diameter of 20 nm which has also been subjected to a hydrophobization process to 100 parts by mass of black particles (1) 1.5 parts by mass of fine powder was added and uniformly diffused using a Henschel mixer manufactured by Mitsui Mining Co., Ltd. to obtain a black toner (1). The physical properties are shown in Table 1.

(Black toner production example 2)
<< Preparation of Resin Particle Dispersion 1 >>
-90 parts by weight of styrene-20 parts by weight of n-butyl acrylate-3 parts by weight of acrylic acid-6 parts by weight of dodecanethiol-1 part by weight of carbon tetrabromide These are mixed and dissolved in a nonionic surfactant (SANYO Kasei Co., Ltd .: Nonipol 400) 1.5 parts by mass and anionic surfactant (Daiichi Kogyo Seiyaku Co., Ltd .: Neogen SC) 2.5 parts by mass dissolved in ion-exchanged water 140 parts by mass Disperse in the flask, emulsify, and slowly mix for 10 minutes. Then, 10 parts by mass of ion-exchanged water in which 1 part by mass of ammonium persulfate is dissolved is added, and after nitrogen replacement, the inside of the flask is stirred. The contents were heated in an oil bath until the content reached 70 ° C., and emulsion polymerization was continued for 5 hours. Thus, a resin particle dispersion 1 was prepared by dispersing resin particles having an average particle size of 0.17 μm, a glass transition point of 57 ° C., and a weight average molecular weight (Mw) of 11,000.

<< Preparation of resin particle dispersion 2 >>
-Styrene 75 parts by mass-n-Butyl acrylate 25 parts by mass-Acrylic acid 2 parts by mass Mixing and dissolving 1.5 parts by mass of a nonionic surfactant (Sanyo Kasei Co., Ltd .: Nonipol 400) And an anionic surfactant (Daiichi Kogyo Seiyaku Co., Ltd .: Neogen SC) 3 parts by mass dissolved in 140 parts by mass of ion-exchanged water, dispersed in a flask, emulsified, and slowly mixed for 10 minutes. Then, 10 parts by mass of ion-exchanged water in which 0.8 part by mass of ammonium persulfate was dissolved was added thereto, and after nitrogen substitution, the contents in the flask were heated with an oil bath until the temperature reached 70 ° C. while stirring. A resin obtained by dispersing emulsion particles having an average particle size of 0.1 μm, a glass transition point of 61 ° C., and a weight average molecular weight (Mw) of 550,000 as it is for 5 hours. To prepare a child dispersion 2.

<< Preparation of release agent particle dispersion >>
-Ester wax (melting point 65 ° C) 50 parts by mass-Anionic surfactant 5 parts by mass (Daiichi Kogyo Seiyaku Co., Ltd .: Neogen SC)
・ Ion-exchanged water 200 parts by mass The above was heated to 95 ° C. and dispersed using a homogenizer (manufactured by IKA: Ultra Turrax T50), and then dispersed with a pressure discharge homogenizer, and the average particle size was 0.5 μm. A release agent particle dispersion was prepared by dispersing the release agent.

<< Preparation of Colorant Particle Dispersion 1 >>
Carbon black 20 parts by mass Anionic surfactant 2 parts by mass (Daiichi Kogyo Seiyaku Co., Ltd .: Neogen SC)
-Ion exchange water 78 mass parts The above was mixed and it disperse | distributed using the sand grinder mill. When the particle size distribution in the colorant particle dispersion 1 was measured using a particle size measuring device (LA-700, manufactured by Horiba, Ltd.), the average particle size of the contained colorant particles was 0.2 μm and 1 μm. No coarse particles exceeding were observed.

<Preparation of charge control particle dispersion>
20 parts by mass of a metal compound of di-alkyl-salicylic acid (charge control agent, Bontron E-88, manufactured by Orient Chemical Industries)
・ Anionic surfactant 2 parts by mass (Daiichi Kogyo Seiyaku Co., Ltd .: Neogen SC)
-Ion exchange water 78 mass parts The above was mixed and it disperse | distributed using the sand grinder mill. When the particle size distribution in this charge control particle dispersion was measured using a particle size measuring device (LA-700, manufactured by Horiba, Ltd.), the average particle size of the charge control particles contained was 0.2 μm, and 1 μm No larger coarse particles were observed.

<Preparation of liquid mixture>
-Resin particle dispersion 1 250 parts by mass-Resin particle dispersion 2 110 parts by mass-Colorant particle dispersion 1 50 parts by mass-Release agent particle dispersion 70 parts by mass It put in the 1 liter separable flask with which it equipped, and stirred. The mixture was adjusted to pH = 5.2 using 1N potassium hydroxide.

<Agglomerated particle formation>
As a flocculant, 150 parts by mass of a 10% sodium chloride aqueous solution was dropped into this mixed solution, and the mixture was heated to 57 ° C. while stirring the inside of the flask in a heating oil bath. At this temperature, 3 parts by mass of the resin particle dispersion 2 and 10 parts by mass of the charge control agent particle dispersion were added. After maintaining at 50 ° C. for 1 hour, it was confirmed by observation with an optical microscope that aggregated particles (A) having an average particle diameter of about 4.9 μm were formed.

<Fusion process>
Then, after adding 3 parts of an anionic surfactant (Daiichi Kogyo Seiyaku Co., Ltd .: Neogen SC) here, the stainless steel flask was sealed and heated to 105 ° C. while stirring with a magnetic seal. And held for 3 hours. Then, after cooling, the reaction product was filtered, thoroughly washed with ion exchange water, and then dried to obtain toner particles (2).

  Thereafter, 0.5 parts by mass of a titania fine powder having a primary particle diameter of 50 nm subjected to a hydrophobization treatment and silica having a primary particle diameter of 20 nm which has also been subjected to a hydrophobization process with respect to 100 parts by mass of the black particles (2). 1.5 parts by mass of fine powder was added and uniformly dispersed using a Henschel mixer manufactured by Mitsui Mining Co., Ltd. to obtain a black toner (2). Table 1 shows the physical properties of the black toner (2).

(Black toner production example 3)
Instead of the black toner production example 1, neither the charge control agent 1 nor 2 is added, and the titania fine powder having a primary particle diameter of 50 nm subjected to the hydrophobization treatment is changed from 0.5 parts by mass to 3.0 parts by mass. The black toner (3) was prepared in the same manner as in the black toner production example 1 except that the silica fine powder having a primary particle diameter of 15 nm subjected to the hydrophobic treatment was changed from 1.5 parts by weight to 0.1 parts by weight. Got.

(Black toner production example 4)
In place of Black toner production example 1, the amount of charge control agent 1 added is changed from 4 parts by weight to 10 parts by weight, and no titania fine powder having a primary particle diameter of 50 nm subjected to hydrophobic treatment is added. A black toner (4) was obtained in the same manner as in the black toner production example 1 except that the silica fine powder having a primary particle size of 15 nm subjected to the hydrophobic treatment was changed from 1.5 parts by mass to 3.0 parts by mass. .

(Black toner production example 5)
In place of Black Toner Production Example 1, the amount of charge control agent 1 added was changed from 4 parts by weight to 10 parts by weight, carbon black was not added, and the dye was changed to a black dye. The titania fine powder with a secondary particle size of 50 nm was changed from 0.5 parts by mass to 0.3 parts by mass, and the silica fine powder with a primary particle size of 15 nm subjected to the hydrophobization treatment was changed from 1.5 parts by mass to 2.0 parts by mass. A black toner (5) was obtained in the same manner as in the black toner production example 1 except that the amount of the toner was changed to a part.

(Black toner production example 6)
Instead of the black toner production example 1, the amount of carbon black added is changed from 10 parts by mass to 20 parts by mass, and the titania fine powder having a primary particle diameter of 50 nm subjected to the hydrophobizing process and the hydrophobizing process are performed. A black toner (6) was obtained in the same manner as in the black toner production example 1 except that the amount of silica fine powder having a primary particle size of 15 nm was adjusted.

(Black toner production examples 7 to 10)
Instead of the black toner production example 1, the amount of tricalcium phosphate added and the rotation number of the TK homomixer were changed to change the toner weight average particle diameter, and the same as in the black toner production example 1. Black toners (7) and (10) were obtained.

(Black toner production example 11)
Instead of the black toner production example 1, the charge control agents 1 and 2 are not added, and the hydrophobic titania fine powder having a primary particle diameter of 50 nm is changed from 0.2 parts by mass to 2.0 parts by mass. Black toner (11) in the same manner as in black toner production example 1 except that the silica fine powder having a primary particle size of 15 nm subjected to the hydrophobic treatment was changed from 1.5 parts by weight to 0.2 parts by weight. Got.

(Black toner production example 12)
Instead of Black Toner Production Example 1, the amount of charge control agent 1 added was changed from 4 parts by mass to 8 parts by mass, and 0.5 mass of titania fine powder having a primary particle diameter of 50 nm subjected to hydrophobization treatment. Black toner production example 1 except that the silica fine powder having a primary particle size of 15 nm subjected to hydrophobic treatment was changed from 1.5 parts by weight to 2.5 parts by weight. Similarly, black toner (12) was obtained.

(Black toner production examples 13 to 14)
Black toners (13) and (14) were obtained in the same manner as in the black toner production example 1, except that the addition amounts of titania fine powder and silica fine powder were changed instead of the black toner production example 1.

(Black toner production example 15)
-Polar resin (1) 100 parts by mass-Paraffin wax (1) 10 parts by mass (DSC endothermic peak: 69 ° C, Mw: 700, Mn: 500)
Charge control agent: Aromatic oxycarboxylic acid Zn compound (Bontron E-84: manufactured by Orient Chemical Co., Ltd.) 4 parts by massPigment: Black pigment 10 parts by mass (carbon black Nipex 30 pH: 9.0)
The above materials were kneaded and pulverized to obtain pulverized particles (1). Thereafter, 100 parts by mass of the pulverized particles (1) whose particle size distribution was adjusted were subjected to the same treatment as in (Black Toner Production Example 1) to obtain Black Toner (15).

(Black toner production example 16)
The pulverized particles (1) obtained by pulverization in Toner Production Example 15 are subjected to surface treatment by changing the number of rotations and time in a machine with a rotor rotating, and then the particle size distribution is adjusted to obtain black particles (16). Got. Thereafter, the same treatment as in (Black Toner Production Example 1) was performed on 100 parts by mass of the black particles (16) to obtain a black toner (16).

(Black toner production examples 17 to 19)
Instead of the black toner production example 1, it was the same as the black toner production example 1 except that the addition amounts of the titania fine powder and the silica fine powder were changed and the processing time and the number of revolutions were changed in the Henschel mixer. Thus, black toners (17) to (19) were obtained.

(Black toner production examples 20 to 21)
Black toners (20) to (21) were prepared in the same manner as in black toner production example 1 except that the external additive (b) was changed to the external additive having the physical properties shown in Table 1 instead of the black toner production example 1. Got.

(Toner Production Examples 22 to 24)
C. replaces the pigment with carbon black. I. A magenta toner (1) was obtained in the same manner as in Toner Production Example 1 except that 5 parts by mass of Pigment Red 122 was used. In addition, C.I. I. A cyan toner (1) was obtained in the same manner as in Toner Production Example 1 except that 5 parts by mass of Pigment Blue 15: 3 was used. Furthermore, C.I. I. A yellow toner 1 was obtained in the same manner as in Toner Production Example 1 except that 5 parts by mass of Pigment Yellow 93 was used.

<Example 1>
(Image evaluation)
Using the obtained toner 1, image evaluation was performed according to the following method.

  As the image forming apparatus, a modified machine in which the process speed of a commercially available CLJ-1500 (manufactured by HP) CLJ-1500 (manufactured by HP) was changed to 100 mm / second was used.

  Similarly, the cartridge used for CLJ-1500 was changed to the configuration shown in FIG.

As a transfer material, LETTER size XEROX 4024 paper (manufactured by XEROX, 75 g / m ² ) was used.

  As an evaluation of the present invention, a storage mode of 0 ° C./5%/14 days is provided as a pre-processing before image evaluation, and then an image with a print ratio of 1% in a low temperature and low humidity environment (15 ° C./10%) is obtained. In the single color mode, 5000 sheets were printed in the following continuous printing method.

  The image forming speed was set to the speed in the plain paper mode.

  Image evaluation was performed based on the following evaluation criteria using the 100th and 5000th images.

  Each evaluation result is shown in Table 2.

<Examples 2 to 21>
The obtained toners 2 and 5 to 21 were used, and the image evaluation was performed by changing as shown in Table 2 instead of Example 1. The results are shown in Table 3.

<Example 22>
The obtained black toner 1, yellow toner 1, magenta toner 1 and cyan toner 1 were used for image evaluation according to the following method.

  As the image forming apparatus, a commercially available laser printer HP CLJ-3700 (manufactured by HP) with a modified machine in which the process speed was changed to 100 mm / second was used.

Similarly, the cartridge used for CLJ-3700 was changed to the configuration shown in FIG.
Each color was ranked A in all evaluation items.

<Comparative Examples 1 and 2>
The obtained toners 3 to 4 were used, and the image evaluation was performed by changing as shown in Table 4 instead of Example 1. The results are shown in Table 5.

<Comparative Examples 3 to 4>
Using the obtained toners 5 to 6, the coated electrode roller having a resistance changed by carbon or resin as shown in Table 4 instead of Example 1 was used for image evaluation. The results are shown in Table 5.

<Comparative Examples 5 to 7>
The obtained toner 16 was used, and the image evaluation was performed by changing to the electrode roller not coated as shown in Table 4 instead of Example 1. The results are shown in Table 5.

  Furthermore, an experiment was also conducted on the rotation direction of the high-resistance material-coated electrode roller 34.

  In Comparative Example 6, the applied voltage configuration is the same as that in Example 1, and the rotation of the high-resistance material-coated electrode roller 34 is stopped. As a result, there is no toner conveyance D by the high-resistance material coated electrode roller 34 at the toner supply position F in FIG. 4, and the followability of solid black is poor.

  In Comparative Example 7, the applied voltage configuration is the same as that of Example 1, and the rotation of the high-resistance material-coated electrode roller 34 is set in the direction H opposite to that of the developing roller 33 as shown in FIG. As a result, as shown in FIG. 5, the toner supply I is first performed with respect to the rotation of the developing roller, and then the toner removal J is performed downstream of the toner supply position by the vibration voltage on the side opposite to the toner with respect to the developing bias. Therefore, the followability of solid black is bad.

  From the above, the rotation direction of the high resistance material coated electrode roller 34 is the same direction as the developing roller 33, that is, in the developer supply / removal region TS where the high resistance material coated electrode roller 34 and the developing roller 33 face each other. It has been found that the direction opposite to the developing roller 33 is optimal.

<Comparative Example 8>
Using the obtained toner 16, image evaluation was performed without applying an AC voltage to the high-resistance material-coated electrode roller as shown in Table 4 instead of Example 1. The results are shown in Table 5.

[Developability evaluation method]
(Image density change)
The image density is measured with a Macbeth densitometer or a color reflection densitometer (for example, Colorreflection densityometer X-RITE 404 Amanufactured by X-Rite Co.).
Evaluation is based on the difference between the initial density and the density after 10,000-sheet durability.
A: 10% or less B: Over 10% and 20% or less C: Over 20% and 30% or less D: Over 30%

(Charge amount change)
The change in the charge amount was evaluated based on the following evaluation criteria for the amount of change in the charge amount value after the end of durability of the developer in the developer container and after the passage of 5000 sheets.
A: Change amount is 10% or less.
B: Change amount exceeds 10% and is 15% or less.
C: The amount of change exceeds 15% and is 20% or less.
D: The amount of change exceeds 20%.

(Measurement of fogging)
The fog was measured using a REFECTOMETER MODEL TC-6DS (manufactured by Tokyo Denshoku Co., Ltd.) and calculated according to the following formula. A lower fog value is better.
Fog (reflectance;%) = (reflectance of standard paper;%) − (reflectance of white solid portion of sample;%)
A: 1.5% or less B: More than 1.5% and less than 2.0% C: More than 2.0% and less than 2.5% D: More than 2.5%

(Solid uniformity)
The obtained solid image on the transfer paper was evaluated as A, B, C, and D with a density difference of 5 points.
A: 0.1% or less B: Over 0.1% and 0.2% or less C: Over 0.2% and 0.3% or less D: Over 0.3%

(ghost)
The ghost was observed on a halftone image after a solid patch of 3 cm square, the density of the ghost portion and other portions was measured, and the difference was evaluated based on the following evaluation criteria.
A: The density difference is 5% or less.
B: The density difference exceeds 5% and is 15% or less.
C: Concentration difference exceeds 15% and is 25% or less.
D: The density difference exceeds 25%.

(leak)
Leakage was evaluated based on the following evaluation criteria by printing 100 half-tone images on the entire surface, observing the images.
A: It does not occur at all.
B: One linear leak mark is generated.
C: 5 or less linear leak marks are generated.
D: A linear leak mark occurs over 5 sheets.

It is explanatory drawing of the propeller type | mold blade of a powder fluidity | liquidity analyzer. 1 is a schematic configuration diagram illustrating an embodiment of an image forming apparatus according to the present invention. 1 is a schematic configuration diagram illustrating an embodiment of a developing device according to the present invention. It is a figure explaining the motion of the developer in the developing device according to the present invention. It is a figure explaining a motion of the developer in the developing device in an experimental example. It is a figure explaining a prior art example. It is a schematic block diagram explaining the other Example of the image forming apparatus which concerns on this invention. It is explanatory drawing of the toner volume resistance value measuring apparatus in this invention.

Explanation of symbols

DESCRIPTION OF SYMBOLS 20 Image forming apparatus 20A Image forming apparatus main body 21 Photosensitive drum (image carrier)
DESCRIPTION OF SYMBOLS 22 Charging device 23 Exposure device 24 Developing device 25 Transfer roller 27 Cleaning device 29 Fixing device 31 Developing container 32 Toner 33 Developing roller (developer carrier)
34 High resistance material coated electrode roller (Developer supply / removal means)
35 Developing Blade 39 Power Supply 40 Developing Bias Power Supply 50 Developing Device 51 Developing Container 52 Developing Sleeve 53 Elastic Blade 55 Power Supply 60 Developing Bias Power Supply

Claims (13)

A toner used in a developing method for developing an electrostatic latent image on an image carrier by a developing device having a developer carrier that carries and conveys the developer,
The developing device includes a developer supply / removal unit that supplies and removes the developer to and from the developer carrier.
The developer supply / removal means includes a conductive material and a high resistance material having a volume resistance of 10 ⁹ Ωcm or more laminated on the surface of the conductive material.
The developer supply / removal means is disposed in non-contact with the developer carrier,
At the developer supply / removal position facing the developer carrier, the developer conveyance direction on the developer carrier and the developer conveyance direction on the developer supply / removal means are opposite directions,
An oscillating electric field is formed between the developer supplying / removing means and the developer carrying member,
The developer is a one-component developer composed of toner or a two-component developer composed of toner and carrier,
The relationship between the volume resistance value A of the toner and the volume resistance value B of the high resistance material is 10 ⁻³ ≦ A / B ≦ 10 ^4.
The toner has a cohesion degree C of 20 to 90 (%) under application of an oscillating electric field and normal temperature and pressure. The relationship between the volume resistance value A of the toner and the volume resistance value B of the high resistance material is 10 ⁻² ≦ A / B ≦ 10 ³
2. The toner according to claim 1, wherein the toner has a degree of aggregation of the toner of 30 to 80 (%) measured under application of an oscillating electric field and normal temperature and pressure. When the BET specific surface area of the toner is D (m ² / g) and the weight average particle diameter (D4) of the toner is E (μm), the value of E is 3.0 to 9.0. The toner according to claim 1, wherein / E is 0.20 to 0.60. When the toner has a quiet density F (g / cm ³ ) and a tap density G (g / cm ³ ), the degree of compression represented by [(G−F) / G] × 100 is 10 to 60. The toner according to claim 1, wherein the toner is a toner. 5. The toner according to claim 1, wherein the toner contains at least one external additive having a volume resistance value H of 10 ⁴ ≦ H ≦ 10 ¹² (Ωcm).   6. The toner according to claim 1, wherein an average circularity measured by the flow type particle image measuring device of the toner is 0.960 to 0.995. The toner according to claim 1, wherein the toner satisfies the following relational expressions (1) and (2).
0 ≦ Et100 (mJ) ≦ 500 (1)
1.00 ≦ Et10 / Et100 ≦ 1.60 (2)
[However, Et100 (mJ) is allowed to vertically enter the toner powder layer in the container while rotating the peripheral speed of the outermost edge of the propeller blade at 100 mm / sec, and 100 mm from the bottom surface of the powder layer. This represents the sum of the rotational torque and the vertical load obtained when starting measurement from the position and entering the position 10 mm from the bottom, and Et10 (mJ) represents the rotational torque when rotated at 10 mm / sec. Represents the total vertical load. ]   The toner according to claim 1, wherein the developer comprises only a one-component toner.   The toner according to claim 1, wherein the toner is a nonmagnetic toner.   The toner according to claim 1, wherein the toner is a developing device that applies a DC voltage to the developer carrying member and applies an AC voltage to the developer supply / removal unit. The developing device is characterized in that a maximum electric field generated between the conductive material of the developer supplying / removing means and the developer carrying member is 8.0 × 10 ⁶ V / m or more. The toner according to claim 1. A developing method for developing an electrostatic latent image on an image carrier by a developing device having a developer carrier that carries and conveys the developer,
The developing device includes a developer supply / removal unit that supplies and removes the developer to and from the developer carrier.
The developer supply / removal means includes a conductive material and a high resistance material having a volume resistance of 10 ⁹ Ωcm or more laminated on the surface of the conductive material.
The developer supply / removal means is disposed in non-contact with the developer carrier,
At the developer supply / removal position facing the developer carrier, the developer conveyance direction on the developer carrier and the developer conveyance direction on the developer supply / removal means are opposite directions,
An oscillating electric field is formed between the developer supplying / removing means and the developer carrying member,
The developer is a one-component developer composed of toner or a two-component developer composed of toner and carrier,
The relationship between the volume resistance value A of the toner and the volume resistance value B of the high resistance material is 10 ⁻³ ≦ A / B ≦ 10 ^4.
And the toner has a cohesion degree C of 20 to 90 (%) under application of an oscillating electric field and normal temperature and pressure. A step of developing the electrostatic latent image on the image carrier by a developing device having a developer carrier that carries and conveys the developer, and then a transfer step of transferring to the transfer material with or without the intermediate transfer member An image forming method comprising:
The developing device includes a developer supply / removal unit that supplies and removes the developer to and from the developer carrier.
The developer supply / removal means includes a conductive material and a high resistance material having a volume resistance of 10 ⁹ Ωcm or more laminated on the surface of the conductive material.
The developer supply / removal means is disposed in non-contact with the developer carrier,
At the developer supply / removal position facing the developer carrier, the developer conveyance direction on the developer carrier and the developer conveyance direction on the developer supply / removal means are opposite directions,
An oscillating electric field is formed between the developer supplying / removing means and the developer carrying member,
The developer is a one-component developer composed of toner or a two-component developer composed of toner and carrier,
The relationship between the volume resistance value A of the toner and the volume resistance value B of the high resistance material is 10 ⁻³ ≦ A / B ≦ 10 ^4.
An image forming method, wherein the toner has an aggregation degree C of 20 to 90 (%) under application of an oscillating electric field and normal temperature and pressure.

Images