JP2008164949A - Full-color image forming method - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a full-color image forming method by which a high-resolution and high-definition image can be obtained. <P>SOLUTION: The full-color image forming method includes development with at least yellow, magenta, cyan and black developers, wherein each of the developers is a two-component developer including a toner and a carrier, the carrier A used in the black developer has an intensity of magnetization per unit volume at 1,000/4π (kA/m), σ<SB>VA</SB>(1,000) being 120×10<SP>-3</SP>≤σ<SB>VA</SB>(1,000)≤163×10<SP>-3</SP>(Am<SP>2</SP>/cm<SP>3</SP>), the carrier B used in at least one developer other than the black developer has an intensity of magnetization per unit volume at 1,000/4π (kA/m), σ<SB>VB</SB>(1,000) being 164×10<SP>-3</SP>≤σ<SB>VB</SB>(1,000)≤220×10<SP>-3</SP>(Am<SP>2</SP>/cm<SP>3</SP>), and the toner used in the black developer includes a carbon black. <P>COPYRIGHT: (C)2008,JPO&INPIT

Description

  The present invention relates to a full-color image forming method used in a recording method such as an electrophotographic method, an electrostatic recording method, or a toner jet method.

  In recent years, equipment using electrophotography has been applied to devices such as fax machines and printers in addition to conventional copying machines. As the base of equipment expands in this way, there is a strong demand for higher speed, longer life, higher stability, and full color.

  Above all, the need for full-color electronic photography is increasing in the number of outputs for maps, design drawings, photographs, etc., excellent in color reproduction, details are not crushed or interrupted, and extremely fine In addition, there is a demand for faithful reproduction.

  The use environment of the machine is spreading in various ways. For example, in an office, there is a case where a color image is put on a text in black letters and printed continuously.

  In the case of full-color images, it is common to use a method (called UCR) that replaces the overlap of yellow, magenta, and cyan with black and reduces the color toner by that amount in order to increase sharpness and consumption. It has become.

  As described above, color developing devices other than black may be operated at an extremely low printing rate, and cyan toner, magenta toner, and yellow toner, which are less consumed than black toner, are consumed in the developing device. However, the toner stays over and is repeatedly agitated, so that the toner is overcharged, resulting in a problem of poor image density due to a decrease in developability and transferability.

  Among full-color image forming apparatuses, a two-component developer is preferably used in the case of a full-color copying machine or a full-color printer that requires high image quality at high speed.

  In such an image forming apparatus using a two-component developer, when printing is performed at high speed and continuously in a low humidity environment with a low printing rate, image density defects are remarkably generated.

  Furthermore, overcharged toner strongly adheres to the carrier particles in the two-component developer, and the newly supplied toner cannot be charged, and fogging or toner scattering may occur. is there.

  It is disclosed that such image defects caused by overcharging can be prevented by containing a charge adjustment resin in black toner and not containing a charge adjustment resin in cyan toner, magenta toner, and yellow toner (Patent Document 1). reference).

  However, the cleaner-less system (see Patent Document 2), which is preferably used for the purpose of achieving downsizing of the developing device and reducing waste by effectively using the transfer residual toner, is a slight cause of image density defects. In many cases, a residual toner or a fog toner caused by a charging failure leads to further image defects. For this reason, there is still room for improvement.

  In addition, in a full-color image forming apparatus having a so-called rotary rotary (refer to Patent Document 3) that is preferably used from the viewpoint that it is inexpensive, small-sized, hardly causes color misregistration, and can achieve high image quality, the revolution of the developing device is revolved. Due to the effects of and the shock caused by the stop, the structure is harsh against scattering. For this reason, like the above-described cleanerless system, there is still room for improvement.

JP 2006-17861 A JP 2002-207354 A JP 2004-280072 A

The present invention is to solve the above-mentioned problems of the prior art.
(1) That is, an object of the present invention is to provide a full color image forming method capable of obtaining a high resolution and high definition image.
(2) Furthermore, an object of the present invention is to provide a full-color image forming method capable of suppressing image defects even when printing is performed at high speed and continuously in a low humidity environment while achieving the object of (1). is there.
(3) Furthermore, an object of the present invention is to provide a full-color image forming method adapted to a cleanerless system while achieving the objects (1) and (2).
(4) Furthermore, an object of the present invention is to provide a full-color image forming method adapted to the rotary development system while achieving the objects (1) and (2).

  As a result of intensive studies, the present inventors have found that the above-described problems can be solved by the following configuration, and have reached the present invention.

That is, the present invention provides a charging step for charging an electrostatic charge image carrier; a latent image forming step for forming an electrostatic charge image on the charged electrostatic charge image carrier; and the electrostatic charge image held on the developer carrier. A full-color image forming method comprising: a development step of developing a developer image using at least four color developers of yellow, magenta, cyan, and black; and a transfer step of transferring the formed toner image onto a transfer material. ,
The developer is a two-component developer having at least a toner and a carrier,
The carrier has a magnetization intensity σ _VA (1000) per unit volume at 1000 / 4π (kA / m) of carrier A used in the black developer of 120 × 10 ⁻³ ≦ σ _VA (1000) ≦ 163. × 10 ^-3 (Am ² / cm ³ )
The magnetization intensity σ _VB (1000) per unit volume at 1000 / 4π (kA / m) of carrier B used for at least one developer other than the black developer is 164 × 10 ⁻³ ≦ σ _VB (1000) ≦ 220 × 10 ⁻³ (Am ² / cm ³ )
And
The present invention relates to a full-color image forming method, wherein the toner used for the black developer contains carbon black.

  The full-color image forming method of the present invention has an effect that a high-definition and high-quality image can be obtained by controlling the amount of magnetization per unit volume of the carrier in the two-component developer within a certain range. In addition, by controlling the magnetic characteristics of carriers other than black within a certain range, the developability of the toner is enhanced, and an image defect can be suppressed even when printing is performed continuously at high speed in a low humidity environment. Furthermore, it is suitable for a cleaner-less system, and has the effect of reducing the size of the developing device and reducing waste by effectively using the transfer residual toner. Furthermore, it is suitable for the rotary development system, and has the effect of reducing the size and cost of the machine.

  Hereinafter, the present invention will be described in detail with reference to embodiments of the present invention.

The full-color image forming method of the present invention comprises a charging step for charging an electrostatic charge image carrier; a latent image formation step for forming an electrostatic charge image on the charged electrostatic charge image carrier; and an electrostatic charge image on a developer carrier. A full-color image having at least a development step of developing with a developer of at least four colors of yellow, magenta, cyan and black held to form a toner image; a transfer step of transferring the formed toner image to a transfer material In the forming method, the developer is a two-component developer having at least a toner and a carrier, and the carrier per unit volume at 1000 / 4π (kA / m) of carrier A used for the black developer. The strength of magnetization σ _VA (1000) is
120 × 10 ⁻³ ≦ σ _VA (1000) ≦ 163 × 10 ⁻³ (Am ² / cm ³ )
The magnetization intensity σ _VB (1000) per unit volume at 1000 / 4π (kA / m) of carrier B used for at least one developer other than the black developer is
164 × 10 ⁻³ ≦ σ _VB (1000) ≦ 220 × 10 ⁻³ (Am ² / cm ³ )
The toner used for the black developer is characterized by containing carbon black.

  In full-color image formation, for example, there are many cases in which a color image is placed at one point on a text of black characters and continuously printed. Also, it is common to use a method (called UCR) in which the overlap of yellow, magenta, and cyan is replaced with black and the color toner is reduced by that amount.

  As a result, the black developing device tends to be operated at a relatively high printing rate, and the black developer tends to have a relatively high toner consumption. From the viewpoint of toner replacement in the developing device, it means that the replacement is quick, and one of the characteristics required for the black developer is that the rising of the charge is quick. At the same time, as typified by character reproducibility, a characteristic of high reproducibility for a line image that is often black is generally required.

  On the other hand, color developing devices other than black tend to be operated at an extremely low printing rate, and at least cyan, magenta, and yellow developers other than black developers tend to consume less toner.

  As a result, the toner stays in the developing unit without being consumed, and only the agitation is repeatedly performed, so that the toner is overcharged, and there is a problem that the image density is deteriorated due to a decrease in developability and a deterioration in transferability. . When the image is printed in a specific environment, such as under low humidity, it may lead to fogging or scattering.

  Therefore, one of the characteristics required for a developer other than black is to suppress overcharging. Further, even if the toner is overcharged, high developability that can develop a necessary amount of toner is required.

In order to satisfy the above required characteristics, the magnetization intensity σ _VA (1000) per unit volume in the carrier A used for the black developer is set to 120 × 10 ⁻³ ≦ σ _VA (1000) ≦ 163 × 10 ⁻³ ( It has been found that by controlling to Am ² / cm ³ ), the rising of the charge is quick and the reproducibility of the line image is enhanced.

  Although the mechanism is not clear, in order to form magnetic spikes on the developer carrier, once the chained carrier has finished developing the toner and returned to the stirring chamber in the developer unit, the chain state is It is presumed that the ease with which the toner is replenished improves the mixability of newly supplied toner and improves the charge rise. Regarding the reproducibility of the line image, it is presumed that the magnetic spikes on the developer carrying member are in a dense state with no magnetic repulsion between the spikes, so that the latent image can be easily reproduced.

When σ _VA (1000) is less than 120 × 10 ⁻³ , carrier particles cannot be held by the developer carrying member, and carrier adhesion to the photoreceptor occurs. When σ _VA (1000) exceeds 163 × 10 ⁻³ , charging rise is deteriorated and the reproducibility of the line image is deteriorated.

  Further, it is premised that the toner used for the black developer contains at least carbon black. In the case where a conductive material such as carbon black is contained, a sufficient charge develops leakage, so that sufficient developability can be maintained.

On the other hand, the magnetization intensity σ _VB (1000) per unit volume at 1000 / 4π (kA / m) of carrier B used for at least one color other than the black developer is 164 × 10 ⁻³ ≦ σ _VB ( 1000) ≦ 220 × 10 ⁻³ (Am ² / cm ³ ) to suppress overcharge, and even when overcharged, high developability that can develop a required amount of toner is obtained. I found it.

  Although the mechanism is not clear, in order to form magnetic spikes on the developer carrying member, once the carrier that has been chained finishes developing the toner and is returned to the stirring chamber in the developing unit, the chain is appropriately chained. It is presumed that the ease of maintaining the state can moderately suppress the mixing of newly supplied toner and suppress overcharge. In addition, the magnetic spikes on the developer carrier have a moderate magnetic repulsion between the spikes, so they are in a sparse state, and it is assumed that high developability can be obtained that can develop even the toner behind the magnetic spikes. is doing. Needless to say, the above-described effects are such that the reproduction of the latent image is not impaired.

When σ _VB (1000) is less than 164 × 10 ⁻³ , the effect of suppression of overcharging and high developability is diminished. When σ _VB (1000) exceeds 220 × 10 ⁻³ , the mixing of newly supplied toner is inhibited and the reproducibility of the latent image is impaired. Further, since the agent compression at the developer regulating portion in the developing device becomes high, the deterioration of the toner is easily promoted and the developer becomes a short-life developer.

  Further, as described above, the use of carrier A as the black developer and carrier B as at least one developer other than black reduces the size of the developing device and reduces waste by effectively utilizing the residual toner. It is particularly effective in cleanerless systems that are preferably used for the purpose.

  In cleanerless systems, a slight amount of residual toner that contributes to poor image density and fogging toner caused by poor charging can trigger the contamination of the charging roller. In some cases, a vicious cycle is repeated in which a negative charge is inhibited and a new fog toner is generated. The vicious circle is not limited to a problem in one developing device. In particular, in a cleanerless system in which the developing device is arranged in tandem, the fog toner transferred to the transfer material is retransferred to another developing device. As a result, other developing devices may be adversely affected. For this reason, it is necessary to strictly control the adverse effects of images due to overcharging as described above, and this configuration can achieve this.

  In addition, as described above, the use of carrier A as a black developer and carrier B as at least one developer other than black is inexpensive and small in size, is less likely to cause color misregistration, and can achieve high image quality. Therefore, it is also effective in a full color image forming apparatus having a so-called rotary rotary (refer to Patent Document 3) that is preferably used.

  The rotary developing system is configured to develop each color toner on one electrostatic charge image carrier while the developing device revolves. Therefore, not only the rotation of the developer carrying member but also the influence of the revolution of the developing device and the shock caused by the stop, the structure is severe against scattering. Further, such a scattering problem is not limited to a problem in one developing device, like the cleanerless system. In the case of a two-component developer, it is necessary to constantly monitor the toner concentration in the developer (hereinafter referred to as T / D ratio) with the main body or a sensor attached to the developing device. From the viewpoint, it is usual to monitor with one sensor attached to the main body. For this reason, if one developing device scatters and contaminates the sensor, another developing device may cause a false detection of the T / D ratio, which may cause another image problem. For this reason, it is necessary to strictly control the adverse effects of images due to overcharging as described above, and this configuration can achieve this.

  Carrier B is effective when used for at least one developer other than black, but it is more effective when used for both magenta and cyan developers. The reason is not clear, but magenta and cyan developers have a large difference between the initial charge amount and the charge amount after overcharging, and the deviation from the development conditions such as the initially set development bias is large. I guess it is because it ends up.

  Carrier B is more preferably used in at least yellow, magenta and cyan developers.

The magnetization intensity per unit volume in carriers A and B, σ _VA (1000), σ _VB (1000) is the amount of magnetization (Am ² / kg) when an external magnetic field of 1000 / 4π (kA / m) is applied. ) Multiplied by the true specific gravity of the carrier.

The magnetic properties of the carrier can be measured using, for example, an oscillating magnetic field type magnetic property automatic recording device BHV-35 manufactured by Riken Denshi Co., Ltd. Measurement conditions when using this apparatus are as follows: an external magnetic field of 1000 / 4π (kA / m) is created, and the cylindrical plastic container is packed so as to be sufficiently dense so that the carrier does not move. In this state, the magnetization moment is measured, the actual weight when the sample is put is measured, and the amount of magnetization (Am ² / kg) is obtained.

  The amount of magnetization of the carrier can be adjusted by a method such as the type and blending amount of the metal compound particles to be used and the combined use with metal oxide particles described later.

  The true specific gravity of the carrier can be measured by, for example, a dry automatic densimeter AccuPick 1330 (manufactured by Shimadzu Corporation).

  The full-color image forming method of the present invention is effective when the process speed is 150 mm / sec or higher and / or the peripheral speed of the developer carrier is 230 mm / sec or higher.

  When the process speed is high, the toner is stirred at a higher speed, so that it is easy to be overcharged and it is easy to cause image defects.Therefore, it is necessary to control the image problems caused by overcharge more strictly. Can be achieved. Even when the process speed is less than 150 mm / sec, as in the case of the rotary development method, the effect can be obtained equally if the peripheral speed of the developer carrier is 230 mm / sec or more.

  The full color image forming method of the present invention develops while supplying at least one color of a black replenishment developer comprising a toner and a carrier, a yellow color replenishment developer, a magenta color replenishment developer, and a cyan color replenishment developer. It is more effective. This is because the maintenance interval of the apparatus can be further expanded by the configuration of the present invention, leading to reduction in running cost.

  Hereinafter, the preferable form of the carrier used for this invention is demonstrated in detail.

  Carriers A and B used in the present invention are magnetic material-dispersed resin carriers having a carrier core in which metal compound particles are dispersed in a binder resin, and the surface of the carrier core being coated with a silicone resin. Is preferred.

  In the case of a carrier core in which metal compound particles are dispersed in a binder resin, the true specific gravity of the carrier particles can be reduced, so that the magnetization intensity per unit volume can be controlled within the scope of the present invention. It becomes easy.

  Carriers A and B used in the present invention preferably have a true specific gravity of 2.0 to 4.5 from the viewpoint of easily controlling the amount of magnetization per unit volume within the scope of the present invention.

  Carriers A and B of the present invention are preferable from the viewpoint of increasing the rise of charge by coating the carrier core with a silicone resin. Further, even during long-term image output, it is possible to prevent so-called toner spent, in which toner adheres firmly to the carrier surface. As a result, it is possible to prevent a decrease in the charge imparting performance of the carrier due to durability, leading to prevention of fogging and toner scattering.

  The viewpoint that the silicone resin that coats the carrier core is used together with a silane coupling agent having a functional group selected from an epoxy group, an amino group, and a mercapto group to obtain an appropriate charge amount and prevent overcharging. To preferred.

  The amount to be treated on the carrier core is preferably 0.5% by mass to 2.0% by mass with respect to the mass of the carrier core as the total amount of the silane coupling agent and the silicone resin.

  In particular, it is preferable that the ratio of Si intensity to Fe intensity as measured by fluorescent X-ray measurement and the Si / Fe value satisfy 0.005 ≦ Si / Fe ≦ 0.035.

  When the Si / Fe ratio of the carrier is less than 0.005, sufficient effects on the charge rising property and durability cannot be obtained. When the Si / Fe ratio exceeds 0.035, there is a case where an image defect due to overcharging is caused.

  From the viewpoint of preventing overcharge, the Si / Fe ratio is preferably different between the carrier A and the carrier B. The carrier A is 0.015 ≦ Si / Fe ≦ 0.035, and the carrier B is 0.005. ≦ Si / Fe ≦ 0.015 is preferable.

  In the present invention, the Si / Fe ratio was measured by the following measuring method.

<Method for measuring Si / Fe ratio>
The carrier and the toner not using Si and Fe components are mixed and shaken at a toner concentration ratio of 8%, packed in a ring with a diameter of 28 mm, and a sample press molding machine (BRE-32: manufactured by MAEKAWA TESTING MACHINE) Then, the Si strength and the Fe strength were measured by fluorescent X-rays (ZSX-100e: manufactured by Rigaku Denki Kogyo Co., Ltd.) by pressing at 20 MPa for 1 min. The measurement conditions are: target: Rh, atmosphere: vacuum, measurement diameter: 20 mm. Regarding Si intensity, tube voltage: 50 kV, tube current: 50 mA, filter: OUT, attenuator: 1/1, slit: Std, spectral crystal: PET, detector: PC, PHA LL-UL: 100-300, peak: 109.04, measurement time: 40 sec. Regarding the Fe intensity, X-ray output: tube voltage: 50 kV, tube current: 50 mA, filter: OUT, attenuator: 1/1, slit: Std, spectral crystal: LiF1, detector: SC, PHA LL-UL: 100-300, peak: 57.5, measurement time: 40 sec. The Si / Fe ratio was determined by dividing the measured strength of Si by the measured strength of Fe.

  Further, it is more preferable that the carrier core is firstly treated with a silane coupling agent and then coated with a silicone resin, and the ratio of silane coupling agent treatment amount: silicone resin coating amount is 1: 1 to It is preferably 1: 3.

  From the viewpoint of preventing overcharge, it is preferable that the carrier A and the carrier B have different amounts of silane coupling agent and silicone resin to be treated on the carrier core. Carrier A preferably has a ratio of silane coupling agent treatment amount: silicone resin coating amount of 1: 1.5 to 1: 3, more preferably 1: 1.5 to 1: 2.5. Carrier B preferably has a ratio of silane coupling agent treatment amount: silicone resin coating amount of 1: 1 to 1: 2, more preferably 1: 1 to 1: 1.5.

  Carriers A and B of the present invention have a volume average particle size of 25 to 60 μm, and more preferably 30 to 50 μm.

  When the volume average particle diameter of the carrier is less than 25 μm, the contact area with the toner becomes wide, and thus overcharging may not be suppressed. Further, in the particle size distribution of the carrier particles, carrier adhesion to the non-image area by particles on the fine particle side may not be prevented satisfactorily. When the volume average particle diameter of the carrier particles exceeds 60 μm, the density of the magnetic brush tends to be impaired, and it may be difficult to faithfully reproduce the latent image.

The carrier A of the present invention has a volume resistivity value (R _A ) of 1.0 × 10 ^{11 to} 1.0 × 10 ¹³ (Ω ···) when an electric field strength of 5.0 × 10 ³ [V / cm] is applied. cm), and the carrier B has a volume resistivity (R _B ) of 5.0 × 10 ^{6 to} 5.0 × 10 ¹⁰ (Ω · ¹⁰ ) when an electric field strength of 5.0 × 10 ³ [V / cm] is applied. cm).

When the volume specific resistance value (R _A ) of the carrier A is less than 1.0 × 10 ¹¹ (Ω · cm), the edge effect is too low, and it may be difficult to obtain a sharp and tight line image. is there.

When the volume specific resistance value (R _A ) of the carrier A exceeds 1.0 × 10 ¹³ (Ω · cm), the charge leakage hardly occurs even in combination with the toner containing carbon black. It may cause electrification.

When the volume resistivity value (R _B ) of the carrier B is less than 5.0 × 10 ⁶ (Ω · cm), the developing bias leaks onto the electrostatic charge image carrier through the carrier and disturbs the latent image. As a result, there may be a case where the image becomes fuzzy or an appropriate image density cannot be obtained.

When the volume specific resistance value (R _B ) of the carrier B exceeds 5.0 × 10 ¹⁰ (Ω · cm), charge leakage hardly occurs and overcharging may occur.

  The volume specific resistance value of the carrier can be adjusted by methods such as the types and addition amounts of metal compound particles and metal oxide particles described later, the amount of binder resin, and the types and addition amounts of the surface coating agent for the carrier core. It is.

The specific resistance of the carrier can be measured using, for example, a powder insulation resistance measuring instrument manufactured by Vacuum Riko Co., Ltd. In the case of using this measuring instrument, 1 g of a carrier left at 23 ° C. and 60% for 24 hours or more is placed in a measuring cell having a diameter of 18 mm, and sandwiched between load electrodes to which a load of 120 g / cm ² is applied, and the thickness is about 1 mm. Measurement is performed by applying a voltage of 100 V to 1000 V in increments of 200 V at a measurement interval of 30 seconds.

  Further, as the particle size distribution of the carriers A and B of the present invention, the content of carrier particles of 20 μm or less by the mesh method is 0.01 to 3% by mass, and the content of 75 μm or more is 0.01 to 3% by mass. It is desirable to be.

  When the content of carrier particles of 20 μm or less is less than 0.01% by mass, the developer is likely to be densely clogged, and the agent is liable to be deteriorated.

If the content of carrier particles of 20 μm or less exceeds 3% by mass, toner overcharging may not be effectively prevented. In addition, there is a case where image defects due to carrier adhesion occur.
Even when the content of carrier particles of 75 μm or more is less than 0.01% by mass, the developer may be easily deteriorated due to the high density of the developer.

  When the amount exceeds 3% by mass, a sufficient surface area for giving an appropriate charge amount to the toner cannot be obtained, and the toner is easily scattered in the apparatus. In addition, the fineness of the magnetic brush is likely to be lost, and it may be difficult to faithfully reproduce the latent image.

Furthermore, the magnetic property σ ₁₀₀₀ at 1000 / 4π of carrier particles of 20 μm or less by the mesh method is preferably 30 to 50 Am ² / kg from the viewpoints of toner charge rising and carrier adhesion.

  The volume average particle size and particle size distribution of the carrier can be adjusted by the production conditions of the carrier particles, classification of the carrier particles by sieving or various classifiers, and mixing of classified products.

  The volume average particle diameter of the carrier of the present invention refers to a volume-based 50% average particle diameter measured by, for example, a laser diffraction particle size distribution meter (manufactured by Horiba, Ltd.).

  Also, for the measurement of the fine powder amount of 20 μm or less and the coarse powder amount of 75 μm or more by the mesh method, a mesh with each mesh is prepared and, for example, an electromagnetic experimental sieve shaker (Fritche Japan Analyset Type 3) is used. Can be measured. As a measurement method when this shaker is used, Timer = 5 min, Amplitude intensity = 2, and 500 g of the sample is used.

  Carrier cores of carriers A and B used in the present invention include, for example, surface-oxidized or unoxidized iron, nickel, copper, zinc, cobalt, manganese, chromium, and rare earth magnetic metals, their magnetic alloys, Magnetic particles selected from the group consisting of these magnetic oxides, and magnetic material-dispersed carriers in which metal compound particles such as magnetic powder are dispersed in a resin.

  As described above, the carrier core used in the present invention is preferably a magnetic material dispersion type carrier in which metal compound particles such as magnetic powder are dispersed in a resin, but a magnetic material dispersion type carrier obtained by a polymerization method, Since the sphericity is high and uniform particles can be easily obtained, the density of the magnetic brush on the developer carrier is easily controlled, and the effects of the present invention are easily manifested in terms of line reproducibility and developability. Therefore, it is preferable.

  The magnetic substance-dispersed resin carrier preferably used in the present invention preferably has a content of metal compound particles in the carrier particles of 80 to 95% by mass.

  When the content of the metal compound particles in the magnetic material-dispersed resin carrier particles is less than 80% by mass, an appropriate specific gravity for obtaining the configuration of the present invention cannot be obtained. Furthermore, although it is related to the magnetic properties of the carrier particles, carrier adhesion to the photoreceptor is likely to occur. On the other hand, if the amount exceeds 95% by mass, the strength of the carrier particles is lowered, and problems such as cracking of the carrier particles due to durability are likely to occur.

The content of the metal compound particles is obtained by the following equation by measuring the mass (W1) of the initial carrier particles and the mass (W2) of the residue remaining after treatment with a strong acid having a pH of 1 or less for 24 hours or more. .
[(W1-W2) / W1] × 100

  The magnetic material-dispersed resin carrier preferably used in the present invention preferably has a weight reduction rate W (%) of 8.0 to 12.0 in a thermal mass measuring device (TGA).

  If it is less than 8.0%, the rise of toner charge may be delayed. If it exceeds 12.0%, the reason is not clear, but the particles with poor dispersibility and low magnetic properties of the metal compound particles increase, which adversely affects toner overcharging and carrier adhesion. There is a case.

  The thermogravimetry can be measured by, for example, a thermogravimetric measuring apparatus TA-TGA2950 (manufactured by TA Instruments Inc.), and after holding the pan containing the sample at 50 ° C. for 1 minute, under an oxygen atmosphere Thus, it can be measured by heating at a heating rate of 50 ° C./min.

  The binder resin of the magnetic material-dispersed resin carrier is preferably a thermosetting resin, and more preferably a resin partially or wholly crosslinked three-dimensionally, such as a thermosetting resin containing a phenol resin. preferable. By using this resin, the dispersed metal compound particles can be firmly bound, so that the strength of the magnetic material dispersed resin carrier can be increased, and the metal compound particles are not easily detached even when a large number of copies are made. Thus, a more stable image without toner scattering in the apparatus can be obtained.

  In addition, the carriers A and B of the present invention are preferably used by treating the surface of the carrier core with a coating resin and / or a coupling agent, but by using a thermosetting resin as a binder resin, adhesion and uniformity can be achieved. And a better coat can be formed.

  As a monomer used for the binder resin of the magnetic substance-dispersed resin carrier, a radical polymerizable monomer polymerizable monomer can be used. For example, styrene; styrene derivatives such as o-methyl styrene, m-methyl styrene, p-methoxy styrene, p-ethyl styrene, p-tertiary butyl styrene; acrylic acid, methyl acrylate, ethyl acrylate, n-butyl acrylate Acrylates such as n-propyl acrylate, isobutyl acrylate, octyl acrylate, dodecyl acrylate, 2-ethylhexyl acrylate, stearyl acrylate, 2-chloroethyl acrylate, phenyl acrylate; methacrylic acid, methyl methacrylate , Ethyl methacrylate, n-propyl methacrylate, n-butyl methacrylate, isobutyl methacrylate, n-octyl methacrylate, dodecyl methacrylate, 2-ethylhexyl methacrylate, stearyl methacrylate, meta Methacrylic acid esters such as phenyl silylate, dimethylaminomethyl methacrylate, diethylaminoethyl methacrylate, benzyl methacrylate; 2-hydroxyethyl acrylate, 2-hydroxyethyl methacrylate; acrylonitrile, methacrylonitrile, acrylamide; methyl vinyl ether, ethyl Vinyl ether, propyl vinyl ether, n-butyl ether, isobutyl ether, β-chloroethyl vinyl ether, phenyl vinyl ether p-methylphenyl ether, p-chlorophenyl ether, p-bromophenyl ether, p-nitrophenyl vinyl ether, p-methoxyphenyl vinyl ether And vinyl ethers; and diene compounds such as butadiene.

  These monomers can be used alone or in combination, and a suitable polymer composition can be selected so that preferable characteristics can be obtained.

  As described above, the binder resin of the magnetic material-dispersed resin carrier is preferably three-dimensionally cross-linked, and a cross-linking agent that forms such a cross-link is preferably used. As the crosslinking agent, it is preferable to use a crosslinking agent having two or more polymerizable double bonds per molecule.

  Cross-linking agents include aromatic divinyl compounds such as divinylbenzene and divinylnaphthalene; ethylene glycol diacrylate, ethylene glycol dimethacrylate, triethylene glycol dimethacrylate, tetraethylene glycol dimethacrylate, 1,3-butylene glycol dimethacrylate, trimethylol Propane triacrylate, trimethylolpropane trimethacrylate, 1,4-butanediol diacrylate, neopentyl glycol diacrylate, 1,6-hexanediol diacrylate, pentaerythritol triacrylate, pentaerythritol tetraacrylate, pentaerythritol dimethacrylate, penta Erythritol tetramethacrylate, glycerol acoxydimethacrylate DOO, N, N-divinyl aniline, divinyl ether, divinyl sulfide, and divinyl sulfone.

  Two or more kinds of these crosslinking agents may be appropriately mixed and used. The cross-linking agent can be mixed in advance with the polymerizable mixture, or can be appropriately added during the polymerization as necessary.

  Other binder resin monomers used in magnetic dispersion resin carriers include bisphenols and epichlorohydrin starting from epoxy resins; phenols and aldehydes starting from phenolic resins; starting materials from urea resins There may be mentioned urea and aldehydes, and melamine and aldehydes which are starting materials for melamine resins.

  The most preferred binder resin is a phenol resin. Examples of the starting material include phenol compounds such as phenol, m-cresol, 3,5-xylenol, p-alkylphenol, resorcil, and p-tert-butylphenol, and aldehyde compounds such as formalin, paraformaldehyde, and furfural. A combination of phenol and formalin is particularly preferable.

  When these phenol resins or melamine resins are used, a basic catalyst can be used as a curing catalyst. As the basic catalyst, various catalysts used in the production of ordinary resole resins can be used. Specific examples include amines such as aqueous ammonia, hexamethylenetetramine, diethyltriamine, and polyethyleneimine.

Examples of the metal compound particles used in the magnetic material-dispersed resin carrier of the present invention include magnetite or ferrite represented by the formula MO · Fe ₂ O ₃ or MFe ₂ O ₄ exhibiting magnetism. In the formula, M represents a trivalent, divalent or monovalent metal ion.

  As M, Mg, Al, Si, Ca, Sc, Ti, V, Cr, Mn, Fe, Co, Ni, Cu, Zn, Sr, Y, Zr, Nb, Mo, Cd, Sn, Ba, Pb, Li etc. are mentioned.

  As the metal compound particles, a compound having a single M or a compound containing a plurality of types of M can be used. Examples of such metal compound particles include magnetite, Zn—Fe ferrite, Mn—Zn—Fe ferrite, Ni—Zn—Fe ferrite, Mn—Mg—Fe ferrite, Ca—Mn—Fe ferrite, Ca Examples thereof include iron-based oxides such as -Mg-Fe-based ferrite, Li-Fe-based ferrite, and Cu-Zn-Fe-based ferrite.

Examples of the metal compound particles include ferromagnetic metal compound particles such as magnetite and ferrite described above, and metal oxide particles that exhibit weaker magnetism than the above (hereinafter also referred to simply as “metal oxide particles”). It is preferable from the viewpoint of maintaining appropriate resistance. About the magnetism of a metal oxide particle, it should just be weaker than the said metal compound particle, and contains nonmagnetism. Examples of such metal oxide particles include Al ₂ O ₃ , SiO ₂ , CaO, TiO ₂ , V ₂ O ₅ , CrO, MnO ₂ , α-Fe ₂ O ₃ , CoO, NiO, CuO, ZnO, and SrO. , Y ₂ O ₃ , ZrO _{2 and the} like.

As described above, in the case of using a mixture of at least two kinds of metal compound particles, it is possible to use metal compound particles having similar specific gravity and shape to improve the adhesion to the binder resin and the strength of the carrier particles. More preferred to increase. As such a combination, for example, a combination of magnetite and hematite, magnetite and γ-Fe ₂ O ₃ , magnetite and SiO ₂ , magnetite and Al ₂ O ₃ , magnetite and TiO ₂ can be preferably used. Among these, a combination of magnetite and hematite can be particularly preferably used.

  When such metal compound particles are used, the number average particle size of the metal compound particles exhibiting ferromagnetism varies depending on the particle size of the carrier particles, but is preferably 0.02 to 2 μm. When two or more kinds of metal compound particles are used, the metal compound particles exhibiting ferromagnetism preferably have a number average particle size of 0.02 to 2 μm, and the metal oxide particles have a number average particle size of 0.05 to 5 μm. Those are preferred.

  In this case, the particle size ratio rb / ra of the number average particle size (average particle size ra) of the metal compound particles exhibiting ferromagnetism and the number average particle size (average particle size rb) of the metal oxide particles exceeds 1.0. It is preferably 5.0 or less, more preferably 1.2 to 4.5. When the ratio is less than 1.0 times, metal compound particles having a low specific resistance and exhibiting ferromagnetism are likely to appear on the surface, and it is difficult to increase the specific resistance of carrier particles and to prevent the effect of preventing leakage of development bias.

  If it exceeds 5 times, the strength of the carrier particles tends to be lowered and the carrier particles are likely to be destroyed, resulting in the scattering of the toner into the machine.

  The number average particle diameter of the metal compound can be measured, for example, with a transmission electron microscope H-800 manufactured by Hitachi, Ltd. When this microscope is used, 300 or more particles having a particle size of 0.01 μm or more are randomly extracted using a photographic image magnified 5000 to 20000 times by the microscope, and image processing analysis made by Nireco Corporation, for example. The number average particle size may be calculated by measuring the diameter of the metal compound particles with the apparatus Luzex 3 as the particle diameter of the metal compound particles and averaging.

The specific resistance of the metal compound particles dispersed in the binder resin is preferably such that the metal compound particles exhibiting ferromagnetism are in the range of 1 × 10 ³ Ω · cm or more, and in particular, two or more kinds of metal compound particles are mixed and used. In this case, the specific resistance of the metal compound particles exhibiting ferromagnetism is preferably in the range of 1 × 10 ³ Ω · cm or more, and the metal oxide particles having higher specific resistance than the metal compound particles exhibiting ferromagnetism are used. It is preferable. The specific resistance of the metal oxide particles used in the present invention is preferably 1 × 10 ⁸ Ω · cm or more, more preferably 1 × 10 ¹⁰ Ω · cm or more.

If the specific resistance of the metal compound particles exhibiting ferromagnetism is less than 1 × 10 ³ Ω · cm, it may be difficult to obtain a desired specific resistance even if the content is reduced, which may lead to charge injection of a developing bias.

When metal oxide particles are used, if the specific resistance of the metal oxide particles is less than 1 × 10 ⁸ Ω · cm, the specific resistance of the magnetic substance dispersed resin carrier is lowered, and similarly, charge injection for developing bias is performed. Invite.

  The specific resistance of the metal compound particles can be adjusted by the type of metal compound particles, the type of metal oxide particles, the type of treatment agent in the lipophilic treatment described later, treatment conditions, and the like.

  The specific resistance of the metal compound is measured by applying a voltage of 100 V, in accordance with the carrier specific resistance measuring means.

  The metal compound particles contained in the magnetic material-dispersed resin carrier of the present invention have been subjected to lipophilic treatment to sharpen the particle size distribution of the magnetic carrier particles and to release the metal compound particles from the carrier particles. It is preferable for preventing separation. In particular, when carrier particles are produced in a polymerization method that is preferably used, particles insolubilized in the solution are generated at the same time as the polymerization reaction proceeds from a liquid in which the monomer and the solvent are uniform. At that time, it is considered that the lipophilic treatment has an effect that the metal oxide is uniformly and densely incorporated inside the particles and an effect of preventing the aggregation of the particles and sharpening the particle size distribution.

  Furthermore, when the metal compound particles subjected to the lipophilic treatment are used, it is not necessary to use a suspension stabilizer such as calcium fluoride. In addition, charging stability inhibition due to the suspension stabilizer remaining on the surface of the carrier particles, coating resin non-uniformity at the time of coating, reaction inhibition when a reactive substance such as a silicone resin and / or a coupling agent is coated. Can be prevented.

  The oleophilic treatment is treated with an oleophilic treatment agent that is an organic compound having one or more functional groups selected from an epoxy group, an amino group, and a mercapto group, or a mixture thereof. preferable. In particular, when carrier particles are produced by a polymerization method that is preferably used, the charge imparting performance is improved by treating with a treatment agent having a group as described above having a balance between lipophilicity and hydrophobicity and hydrophilicity. It is possible to obtain stable and highly durable carrier particles having high particle strength. Among these, an epoxy group is particularly preferably used.

  The metal compound particles are treated with 0.1 to 10 parts by mass (more preferably 0.2 to 6 parts by mass) of a lipophilic treatment agent per 100 parts by mass. It is preferable for enhancing the properties.

  Examples of the lipophilic agent having an amino group include γ-aminopropyltrimethoxysilane, γ-aminopropylmethoxydiethoxysilane, γ-aminopropyltriethoxysilane, and N-β (aminoethyl) -γ-aminopropyl. Trimethoxysilane, N-β (aminoethyl) -γ-aminopropylmethyldimethoxysilane, N-phenyl-γ-aminopropyltrimethoxysilane, ethylenediamine, ethylenetriamine, styrene- (meth) acrylic acid dimethylaminoethyl copolymer And isopropyltri (N-aminoethyl) titanate.

  Examples of the lipophilic agent having a mercapto group include mercaptoethanol, mercaptopropionic acid, and γ-mercaptopropyltrimethoxysilane.

  Examples of the lipophilic agent having an epoxy group include γ-glycidoxypropylmethyldiethoxysilane, γ-glycidoxypropyltrimethoxysilane, β- (3,4-epoxycyclohexyl) trimethoxysilane, epichlorohydrin, Examples thereof include glycidol and styrene- (meth) acrylate glycidyl copolymer.

  A preferred form of the toner used in the present invention will be described in detail.

  The toner used in the present invention is preferably a toner having a weight average particle diameter of 3 to 10 μm.

  In the case of a toner of less than 3 μm, image defects due to overcharging are likely to occur. Furthermore, the fluidity tends to deteriorate, and the reproducibility of the latent image may be inferior. Also, the toner itself has low handling properties as a powder. If it exceeds 10 μm, one toner particle becomes large, so that it is difficult to obtain a denser image with high resolution. In addition, toner scattering during transfer tends to occur.

  The weight average particle diameter of the toner can be determined, for example, as follows.

  1 to 5 ml of a surfactant (for example, alkylbenzene sulfonate) is added to 100 to 150 ml of pure water, and 2 to 20 mg of a measurement sample is added thereto. The electric field liquid in which the sample is suspended is subjected to dispersion treatment with an ultrasonic disperser for 1 to 3 minutes, and the weight average particle diameter is measured using a laser scan particle size distribution analyzer CIS-100 (manufactured by GALAI).

  The color toner according to the present invention preferably contains a release agent, and by containing an appropriate amount of wax as the release agent, the electrostatic charge image carrier or Further, it is possible to prevent toner fusion to a member such as a charging roller.

  Examples of waxes that can be used in the color toner according to the present invention include petroleum waxes such as paraffin wax, microcrystalline wax, petrolactam, and derivatives thereof, montan wax and derivatives thereof, hydrocarbon waxes and derivatives thereof according to the Fischer-Tropsch method, Polyolefin waxes and their derivatives typified by polypropylene and polyethylene, natural waxes and their derivatives such as carnauba wax, candelilla wax, etc. The derivatives include oxides, block copolymers with vinyl monomers, and graft modified products. . Furthermore, fatty acids such as higher aliphatic alcohols, stearic acid, palmitic acid, or compounds thereof, acid amide waxes, ester waxes, ketones, hydrogenated castor oil and derivatives thereof, plant waxes, animal waxes, etc. can also be used. In the present invention, ester waxes represented by the following general formulas (I) to (VI) are preferably used.

（式中、ａ及びｂは０乃至４の整数であり、ａ＋ｂは４である。Ｒ₁及びＲ₂は炭素数が１乃至４０の有機基である。ｍ及びｎは０乃至２５の整数であり、ｍとｎは同時に０になることはない。）

(Wherein, a and b are integers from 0 to 4, and a + b is 4. R ₁ and R ₂ are organic groups having 1 to 40 carbon atoms. M and n are integers from 0 to 25. Yes, m and n are not 0 at the same time.)

（式中、ａ’及びｂ’は０乃至３の整数であり、ａ’＋ｂ’は１乃至３である。Ｒ₁’及びＲ₂’は炭素数が１乃至４０の有機基であり、Ｒ₁’とＲ₂’との炭素数差が３以上である。Ｒ₃は水素原子、炭素数が１以上の有機基である。但し、ａ’＋ｂ’＝２のとき、Ｒ₃のどちらか一方は、炭素数が１以上の有機基である。ｋは１乃至３の整数である。ｍ’及びｎ’は０乃至２５の整数であり、ｍ’とｎ’が同時に０になることはない。）

(Wherein a ′ and b ′ are integers of 0 to 3, a ′ + b ′ is 1 to 3, R ₁ ′ and R ₂ ′ are organic groups having 1 to 40 carbon atoms, R _The difference in carbon number between ₁ ′ and R ₂ ′ is 3 or more, R ₃ is a hydrogen atom or an organic group having 1 or more carbon atoms, provided that either of R ₃ when a ′ + b ′ = 2. One is an organic group having 1 or more carbon atoms, k is an integer of 1 to 3. m ′ and n ′ are integers of 0 to 25, and m ′ and n ′ are simultaneously 0. Absent.)

（式中、Ｒ₄及びＲ₆は炭素数６乃至３２を有する有機基であり、Ｒ₄とＲ₆は同じものであってもなくても良い。Ｒ₅は炭素数１乃至２０を有する有機基を示す。）

(Wherein, R ₄ and R ₆ is an organic group having 6 to 32 carbon atoms, R ₄ and R ₆ may or may not be the same as .R ₅ Organic having 1 to 20 carbon atoms Group.)

（式中、Ｒ₇及びＲ₉は炭素数６乃至３２を有する有機基であり、Ｒ₇とＲ₉は同じものであってもなくても良い。Ｒ₈は以下に示すいずれかである。

(Wherein, R ₇ and R ₉ is an organic group having 6 to 32 carbon atoms, R ₇ and R ₉ it may or may not be the same as .R ₈ is either below.

（式中、ｘは１乃至１０の整数、ｙは１乃至２０の整数を示す。））

(In the formula, x represents an integer of 1 to 10, and y represents an integer of 1 to 20.)

（式中、ｃは０乃至４の整数であり、ｄは１乃至４の整数であり、ｃ＋ｄは４である。Ｒ₁₀は炭素数が１乃至４０の有機基である。ｚ及びｗは０乃至２５の整数であり、ｚとｗが同時に０になることはない。）

(Wherein c is an integer of 0 to 4, d is an integer of 1 to 4, and c + d is 4. R ₁₀ is an organic group having 1 to 40 carbon atoms. Z and w are 0. (It is an integer from 25 to 25, and z and w are not 0 at the same time.)

（式中、Ｒ₁₁及びＲ₁₂は、同一又は異なる炭素数１５乃至４５の炭化水素基を示す。）

(Wherein R ₁₁ and R ₁₂ represent the same or different hydrocarbon groups having 15 to 45 carbon atoms.)

  In the toner relating to the image forming method of the present invention, the content of these wax components is preferably in the range of 0.5 to 25 parts by mass with respect to 100 parts by mass of the binder resin. When the content is less than 0.5 parts by mass, the effect of suppressing toner fusion to a member such as an electrostatic charge image carrier or a charging roller is poor, and when it exceeds 25 parts by mass, the long-term storage stability deteriorates. The dispersibility of other color toner materials is deteriorated, leading to deterioration of toner fluidity and image characteristics.

  As the binder resin when the toner particles according to the present invention are produced by a pulverization method, styrene such as polystyrene and polyvinyltoluene and a homopolymer of a substituted product thereof; styrene-propylene copolymer, styrene-vinyltoluene copolymer Styrene-vinyl naphthalene copolymer, styrene-methyl acrylate copolymer, styrene-ethyl acrylate copolymer, styrene-butyl acrylate copolymer, styrene-octyl acrylate copolymer, styrene-dimethyl acrylate Aminoethyl copolymer, styrene-methyl methacrylate copolymer, styrene-ethyl methacrylate copolymer, styrene-butyl methacrylate copolymer, styrene-dimethylaminoethyl methacrylate copolymer, styrene-vinyl methyl ether copolymer Polymer, styrene-vinylethyl Styrene copolymers such as ether copolymer, styrene-vinyl methyl ketone copolymer, styrene-butadiene copolymer, styrene-isoprene copolymer, styrene-maleic acid copolymer, styrene-maleic acid ester copolymer Polymethyl methacrylate, polybutyl methacrylate, polyvinyl acetate, polyethylene, polypropylene, polyvinyl butyral, silicone resin, polyester resin, polyamide resin, epoxy resin, polyacrylic resin and the like can be used alone or in combination. In particular, a styrene copolymer and a polyester resin are preferable in terms of development characteristics, fixing properties, and the like.

  The toner particles according to the present invention are preferably produced by a polymerization method. In this case, examples of the polymerizable monomer constituting the binder resin component include the following.

  Styrene monomers such as styrene, o-methylstyrene, m-methylstyrene, p-methylstyrene, p-methoxystyrene, p-ethylstyrene; methyl acrylate, ethyl acrylate, n-butyl acrylate, acrylic acid Acrylic esters such as isobutyl, n-propyl acrylate, n-octyl acrylate, dodecyl acrylate, 2-ethylhexyl acrylate, stearyl acrylate, 2-chloroethyl acrylate, and phenyl acrylate; methyl methacrylate, methacrylic acid Ethyl, n-propyl methacrylate, n-butyl methacrylate, isobutyl methacrylate, n-octyl methacrylate, dodecyl methacrylate, 2-ethylhexyl methacrylate, stearyl methacrylate, phenyl methacrylate, dimethyl methacrylate Aminoethyl, methacrylic acid esters such as diethylaminoethyl methacrylate; and other acrylonitrile, methacrylonitrile, and the like monomers acrylamide. These monomers can be used alone or in combination. Among the above-mentioned monomers, styrene or a styrene derivative is preferably used alone or mixed with other monomers from the viewpoint of the development characteristics and durability of the color toner.

  In the present invention, the toner particles preferably contain a polyester resin.

  According to the study by the present inventors, the strength of the toner surface is increased by adding a polyester resin, and when an additive such as an inorganic fine particle is externally added together with the toner particle, the inorganic fine particle on the surface of the toner particle is Due to the long-term durability, the effect of preventing the toner particles from being embedded in the toner particles is increased, and the image density reduction due to the long-term durability can be prevented.

  The polyester resin preferably has a weight average molecular weight (Mw) of 6000 to 100,000. When the Mw is less than 6000, the effect of preventing the external additive from being buried in the toner particles is small, and the effect of preventing the decrease in image density due to durability is not observed. On the other hand, when Mw exceeds 100,000, the dispersion of the condensation resin in the toner particles deteriorates, and the particle size distribution of the finally obtained toner becomes broad.

  In both the polymerization method and the pulverization method, the glass transition temperature (Tg) of the binder resin is preferably 40 to 70 ° C., and more preferably 45 to 65 ° C. These monomers are used alone or generally so that the theoretical glass transition temperature (Tg) described in publication polymer handbook 2nd edition III-p139-192 (manufactured by John Wiley & Sons) is 40 to 70 ° C. It is used by mixing appropriately.

  The toner in the present invention contains a colorant in order to impart coloring power.

  Examples of the organic pigment or dye preferably used in the present invention include the following.

  As the organic pigment or organic dye as the cyan colorant, a copper phthalocyanine compound and a derivative thereof, an anthraquinone compound, a basic dye lake compound, or the like can be used. Specifically, C.I. I. Pigment blue 1, C.I. I. Pigment blue 7, C.I. I. Pigment blue 15, C.I. I. Pigment blue 15: 1, C.I. I. Pigment blue 15: 2, C.I. I. Pigment blue 15: 3, C.I. I. Pigment blue 15: 4, C.I. I. Pigment blue 60, C.I. I. Pigment blue 62, C.I. I. And CI Pigment Blue 66.

  As organic pigments or organic dyes as magenta colorants, condensed azo compounds, diketopyrrolopyrrole compounds, anthraquinones, quinacridone compounds, basic dye lake compounds, naphthol compounds, benzimidazolone compounds, thioindigo compounds, perylene compounds are used. . Specifically, C.I. I. Pigment red 2, C.I. I. Pigment red 3, C.I. I. Pigment red 5, C.I. I. Pigment red 6, C.I. I. Pigment red 7, C.I. I. Pigment violet 19, C.I. I. Pigment red 23, C.I. I. Pigment red 48: 2, C.I. I. Pigment red 48: 3, C.I. I. Pigment red 48: 4, C.I. I. Pigment red 57: 1, C.I. I. Pigment red 81: 1, C.I. I. Pigment red 122, C.I. I. Pigment red 144, C.I. I. Pigment red 146, C.I. I. Pigment red 166, C.I. I. Pigment red 169, C.I. I. Pigment red 177, C.I. I. Pigment red 184, C.I. I. Pigment red 185, C.I. I. Pigment red 202, C.I. I. Pigment red 206, C.I. I. Pigment red 220, C.I. I. Pigment red 221, C.I. I. And CI Pigment Red 254.

  As the organic pigment or organic dye as the yellow colorant, compounds represented by condensed azo compounds, isoindolinone compounds, anthraquinone compounds, azo metal complexes, methine compounds, and allylamide compounds are used. Specifically, C.I. I. Pigment yellow 12, C.I. I. Pigment yellow 13, C.I. I. Pigment yellow 14, C.I. I. Pigment yellow 15, C.I. I. Pigment yellow 17, C.I. I. Pigment yellow 62, C.I. I. Pigment yellow 74, C.I. I. Pigment yellow 83, C.I. I. Pigment yellow 93, C.I. I. Pigment yellow 94, C.I. I. Pigment yellow 95, C.I. I. Pigment yellow 97, C.I. I. Pigment yellow 109, C.I. I. Pigment yellow 110, C.I. I. Pigment yellow 111, C.I. I. Pigment yellow 120, C.I. I. Pigment yellow 127, C.I. I. Pigment yellow 128, C.I. I. Pigment yellow 129, C.I. I. Pigment yellow 147, C.I. I. Pigment yellow 151, C.I. I. Pigment yellow 154, C.I. I. Pigment yellow 168, C.I. I. Pigment yellow 174, C.I. I. Pigment yellow 175, C.I. I. Pigment yellow 176, C.I. I. Pigment yellow 180, C.I. I. Pigment yellow 181, C.I. I. Pigment yellow 191, C.I. I. And CI Pigment Yellow 194.

These colorants can be used alone or mixed and further used in the form of a solid solution.
The colorant used for the toner in the present invention is selected from the viewpoint of hue angle, saturation, brightness, light 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 binder resin.

  The toner according to the present invention may contain a charge control agent in order to stabilize the charge characteristics. As the charge control agent, known ones can be used. Particularly, a charge control agent that has a high charging speed and can stably maintain a constant charge amount is preferable. Further, when a color toner is produced by a polymerization method, a charge control agent having a low polymerization inhibitory property and substantially free from a solubilized product in an aqueous dispersion medium is particularly preferable. Specific compounds include metal compounds of aromatic carboxylic acids such as salicylic acid, alkylsalicylic acid, dialkylsalicylic acid, naphthoic acid and dicarboxylic acid as a negatively chargeable charge control agent, metal salts or metal complexes of azo dyes or azo pigments, Examples thereof include a polymer compound having a sulfonic acid or carboxylic acid group in the side chain, a boron compound, a urea compound, a silicon compound, and calixarene. Examples of the positively chargeable charge control agent include a quaternary ammonium salt, a polymer compound having the quaternary ammonium salt in the side chain, a guanidine compound, a nigrosine compound, and an imidazole compound.

  The charge control agent is preferably used in an amount of 0.5 to 10 parts by mass with respect to 100 parts by mass of the resin. However, in the non-magnetic toner related to the image forming method of the present invention, it is not indispensable to add a charge control agent. By actively utilizing frictional charging with a toner layer thickness regulating member or a developer carrying member, It is not always necessary to include a charge control agent.

  When the toner particles according to the present invention are produced by a polymerization method, the polymerization initiator used in the production of the toner particles is one having a half-life of 0.5 to 30 hours during the polymerization reaction. The toner is preferably used at a ratio of 0.5 to 20 parts by mass with respect to the part by mass, and can give the toner a desired strength and appropriate melting characteristics. As polymerization initiators, 2,2′-azobis- (2,4-dimethylvaleronitrile), 2,2′-azobisisobutyronitrile, 1,1′-azobis (cyclohexane-1-carbonitrile), Azo or diazo polymerization initiators such as 2,2′-azobis-4-methoxy-2,4-dimethylvaleronitrile, azobisisobutyronitrile; benzoyl peroxide, methyl ethyl ketone peroxide, diisopropyl peroxycarbonate, cumene Examples thereof include peroxide polymerization initiators such as hydroperoxide, 2,4-dichlorobenzoyl peroxide, lauroyl peroxide, and t-butylperoxy 2-ethylhexanoate.

  When the color toner particles according to the present invention are produced by a polymerization method, a crosslinking agent may be added, and a preferable addition amount is 0.001 to 15% by mass of the polymerizable monomer composition.

  Here, as the crosslinking agent, compounds having two or more polymerizable double bonds are mainly used. For example, aromatic-divinyl compounds such as divinylbenzene and divinylnaphthalene; for example, ethylene glycol diacrylate, ethylene glycol diacrylate Carboxylic acid ester having two double bonds such as methacrylate, 1,3-butanediol dimethacrylate, etc .; Divinyl compounds such as divinylaniline, divinyl ether, divinyl sulfide, divinyl sulfone, etc .; and having three or more vinyl groups Compound; etc. are used alone or as a mixture.

  When the toner particles according to the present invention are produced by a polymerization method, they are generally necessary as the above-described toner composition, that is, a toner such as a colorant, a release agent, a plasticizer, a charge control agent, and a crosslinking agent in the polymerizable monomer. In a water-based medium containing a dispersion stabilizer, a polymerizable monomer system in which components and other additives are appropriately added and uniformly dissolved or dispersed by a dispersing machine such as a homogenizer, a ball mill, a colloid mill, or an ultrasonic dispersing machine Suspend in At this time, the particle size of the obtained toner particles becomes sharper by using a high-speed disperser such as a high-speed stirrer or an ultrasonic disperser to obtain a desired toner particle size at a stretch. The polymerization initiator may be added at the same time as other additives are added to the polymerizable monomer, or may be mixed immediately before being suspended in the aqueous medium. Also, a polymerization initiator dissolved in a polymerizable monomer or solvent can be added immediately after granulation and before starting the polymerization reaction.

  After granulation, stirring may be performed using a normal stirrer to such an extent that the particle state is maintained and particle floating and sedimentation are prevented.

  When the toner according to the present invention is produced by a polymerization method, known surfactants and organic / inorganic dispersants can be used as dispersion stabilizers. Among them, inorganic dispersants are difficult to produce harmful ultrafine powders, and their steric hindrance. Since the dispersion stability is obtained by the property, the stability is not easily lost even when the reaction temperature is changed, and the toner can be easily used because it is easy to wash and does not adversely affect the toner. Examples of such inorganic dispersants include polyvalent metal phosphates such as calcium phosphate, magnesium phosphate, aluminum phosphate and zinc phosphate; carbonates such as calcium carbonate and magnesium carbonate; calcium metasuccinate, calcium sulfate and barium sulfate. Inorganic salts: Inorganic oxides such as calcium hydroxide, magnesium hydroxide, aluminum hydroxide, silica, bentonite, and alumina can be used.

  These inorganic dispersants are desirably used alone in an amount of 0.2 to 20 parts by mass with respect to 100 parts by mass of the polymerizable monomer. However, although it is difficult to generate ultrafine particles, the toner is atomized. Since it is insufficient, 0.001 to 0.1 parts by mass of a surfactant may be used in combination. Examples of the surfactant include sodium dodecylbenzene sulfate, sodium tetradecyl sulfate, sodium pentadecyl sulfate, sodium octyl sulfate, sodium oleate, sodium laurate, sodium stearate, potassium stearate and the like.

  When these inorganic dispersants are used, they may be used as they are, but in order to obtain finer particles, the inorganic dispersant particles can be generated in an aqueous medium. For example, in the case of calcium phosphate, a sodium phosphate aqueous solution and a calcium chloride aqueous solution can be mixed with high-speed stirring to produce water-insoluble calcium phosphate, which enables more uniform and fine dispersion. At the same time, water-soluble sodium chloride salt is produced as a by-product. However, if water-soluble salt is present in the aqueous medium, dissolution of the polymerizable monomer in water is suppressed, and ultrafine toner is generated by emulsion polymerization. This is more convenient. Since it becomes an obstacle when removing the remaining polymerizable monomer at the end of the polymerization reaction, it is better to replace the aqueous medium or desalinate with an ion exchange resin. The inorganic dispersant can be almost completely removed by dissolving with an acid or alkali after completion of the polymerization.

  In the polymerization step, the polymerization is preferably carried out at a polymerization temperature of 40 ° C. or higher, generally 50 to 90 ° C. In order to consume the remaining polymerizable monomer, it is possible to raise the reaction temperature to 90 to 150 ° C. at the end of the polymerization reaction.

  The polymerized toner particles can be filtered, washed and dried by a known method after the polymerization is completed, and external additives such as inorganic fine particles are mixed and adhered to the surface to obtain a toner. Moreover, it is one of the desirable forms of this invention to put a classification process in a manufacturing process and to cut coarse powder and fine powder.

  When the toner particles according to the present invention are produced by a pulverization method, a known method is used. For example, a binder resin, a release agent, a charge control agent, a colorant and other necessary components for toner particles and other components are used. Additives etc. are thoroughly mixed by a mixer such as a Henschel mixer or ball mill, and then melted and kneaded using a heat kneader such as a heated roll, kneader or extruder to make the resins compatible with each other, cooled, solidified and pulverized. Thereafter, classification and surface treatment as necessary can be performed to obtain toner particles. Either the classification or the surface treatment may be performed first. In the classification step, it is preferable to use a multi-division classifier in terms of production efficiency.

  The pulverization step can be performed by a method using a known pulverizer such as a mechanical impact type or a jet type. In order to obtain a toner having a specific degree of circularity, it is preferable that the toner is further pulverized by heat, or is subjected to an auxiliary mechanical shock treatment. Further, a hot water bath method in which finely pulverized (classified as necessary) toner particles are dispersed in hot water, a method of passing in a hot air stream, or the like may be used.

  As a means for applying a mechanical impact force, for example, a device such as a mechanofusion system manufactured by Hosokawa Micron Co., Ltd. or a hybridization system manufactured by Nara Machinery Co., Ltd., centrifugal force is applied to the inside of the casing by non-magnetic toner particles using blades rotating at high speed. And a method of applying a mechanical impact force to the toner particles by a force such as a pressing force, a compressive force, and a frictional force.

  Furthermore, the toner particles according to the present invention can be used as a method for obtaining spherical toner particles by using a disk or a multi-fluid nozzle described in Japanese Patent Publication No. 56-13945, etc. to atomize the molten mixture into the air, or as a polymerization method. In addition to the turbid polymerization method, a dispersion polymerization method in which toner particles are directly generated using an aqueous organic solvent that is soluble in the monomer and insoluble in the obtained polymer, or directly polymerized in the presence of a water-soluble polar polymerization initiator. The toner particles can also be produced by a method of producing toner particles using an emulsion polymerization method typified by a soap-free polymerization method for producing toner particles.

  In the present invention, the toner contains inorganic fine particles, and the primary average particle diameter of the inorganic fine particles is preferably 4 to 80 nm.

Further, a product having a specific surface area of 10 m ² / g or more by nitrogen adsorption measured by the BET method, particularly a product in the range of 30 to 400 m ² / g is preferable because good results can be obtained.

  In addition, what hydrophobized inorganic fine particles is more preferable in order to speed up the start of charging.

  As the hydrophobic treatment of inorganic fine particles, for example, as a first-stage reaction, a silylation reaction is performed with a silane coupling agent or the like, and a silanol group is eliminated by chemical bonding. A hydrophobic thin film is formed on the surface with silicone oil. The method is applicable.

  Examples of silane coupling agents used for hydrophobizing treatment include hexamethyldisilazane, trimethylsilane, trimethylchlorosilane, trimethylethoxysilane, dimethyldichlorosilane, methyltrichlorosilane, allyldimethylchlorosilane, and allylphenyldichlorosilane. , Benzyldimethylchlorosilane, bromomethyldimethylchlorosilane, α-chloroethyltrichlorosilane, β-chloroethyltrichlorosilane, chloromethyldimethylchlorosilane, triorganosilane mercaptan, trimethylsilyl mercaptan, triorganosilyl acrylate, vinyldimethylacetoxysilane, Dimethylethoxysilane, dimethyldimethoxysilane, diphenyldiethoxysilane, hexamethyldisiloxane, 1,3-divinyl Examples thereof include tetramethyldisiloxane and 1,3-diphenyltetramethyldisiloxane.

Preferred silicone oils are those having a viscosity at 25 ° C. of about 30 to 1,000 mm ² / s (cSt), such as dimethyl silicone oil, methylphenyl silicone oil, α-methylstyrene modified silicone oil, chlorophenyl silicone. Oil, fluorine-modified silicone oil and the like are preferable.

  For example, the silicone oil treatment method may be performed by directly mixing inorganic fine particles treated with a silane coupling agent and silicone oil using a mixer such as a Henschel mixer, or injecting silicone oil onto the base inorganic fine particles. Depending on how you do it. Alternatively, the silicone oil may be dissolved or dispersed in an appropriate solvent, and then mixed with the base inorganic fine particles to remove the solvent.

  As the inorganic fine particles used in the present invention, fine particles such as silica, titanium oxide, alumina, strontium titanate, and magnesium oxide can be preferably used.

  The toner used in the present invention includes, for example, a lubricant powder such as polyethylene fluoride powder, zinc stearate powder and polyvinylidene fluoride powder; or an abrasive such as cerium oxide powder, silicon carbide powder and strontium titanate powder; Development of fine particles with medium to large particle sizes exceeding 30 nm, such as spherical silica particles and spherical resin particles, and other organic particles with opposite polarity, and inorganic particles, such as spherical silica particles and spherical resin particles, for the purpose of improving cleaning properties, etc. A small amount can also be used as a property improver. These additives can also be used after hydrophobizing the surface.

For example, as the silica fine particles, both a so-called dry method produced by vapor phase oxidation of silicon halide or dry silica called fumed silica, and so-called wet silica produced from water glass or the like can be used. However, dry silica is preferred because it has few silanol groups on the surface and inside of the silica fine particles, and few production residues such as Na ₂ O, 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.

  The total amount of inorganic fine particles added is preferably 0.1 to 3.0 parts by mass with respect to 100 parts by mass of toner particles.

  When the addition amount is less than 0.1 parts by mass, the toner is separated from the carrier and developability is deteriorated. In some cases, the fluidity is lowered and the reproducibility of the latent image is poor. If it exceeds 3.0 parts by mass, overcharging may occur. Furthermore, the fixability is also deteriorated.

  The toner used in the present invention preferably contains three or more kinds of inorganic fine particles.

  The same element may be included, or all inorganic fine particles may be composed of different elements. Preferably, when at least two of the three types are made of the same element, the charge distribution can be kept sharper, there is no fogging and scattering, and high image quality can be stably obtained over a long period of time.

  The inorganic fine particles may be added internally or externally to the toner. However, it is preferable that the inorganic fine particles exist in the vicinity of the surface of the toner by external addition. Thus, it is easy to obtain effects such as prevention of toner fusion to such a member, maintenance of high developability and high transferability, toner scattering, and fog reduction.

Among the three types of inorganic fine particles, at least one of them has a relatively small specific surface area by nitrogen adsorption measured by the BET method, that is, the one having a range of 10 to 100 m ² / g is used for high developability. It is preferable for obtaining high transferability and maintaining high image quality due to long-term durability.

In addition, at least one of the three types of inorganic fine particles has a relatively large specific surface area by nitrogen adsorption measured by the BET method, that is, a particle having a range of 100 to 400 m ² / g is used. It is preferable because an effect of reducing fog is easily obtained.
A cleanerless image forming method preferably used in the present invention will be described with reference to the accompanying drawings.

  A developing device 4 in FIG. 1 is a two-component contact developing device (two-component magnetic brush developing device), and holds a developer composed of a carrier and toner on a developing sleeve 41 containing a magnet roller. A developer regulating blade 42 is provided in the developing sleeve 41 with a predetermined gap, and a thin developer layer is formed on the developing sleeve 41 as the developing sleeve 41 rotates. The developing sleeve 41 is arranged so as to have a predetermined gap with the photosensitive drum 1, and at the time of development, the developer thin layer formed on the developing sleeve 41 can be developed while being in contact with the photosensitive drum 1. Is set to In the developing device 4, there are stirring screws 43 and 44 for stirring the developer, which rotate in synchronism with the rotation of the sleeve, stir the supplied toner and carrier, and give a predetermined tribo to the toner. ing. In FIG. 1, 2 is a charging roller which is a charging means, and 3 is exposure light.

  FIG. 2 is a view of the developing device 4 as viewed from above, and shows the circulation state and the longitudinal arrangement of the developer. As the screws 43 and 44 rotate, the developer circulates in the direction of the arrow. A sensor 45 is provided on the upstream side wall surface of the screw 44 of the developing device 4 to detect the change in the magnetic permeability of the developer to detect the toner concentration in the developer. The toner supply is slightly downstream of the sensor 45. An opening is provided. After performing the developing operation, the developer is conveyed to the sensor 45 unit, where the toner concentration is detected, and in order to maintain the toner concentration in the developer constant according to the detection result, a developer supply unit (hereinafter referred to as a developer supplying unit) The toner is supplied from the T-CRG) 5 through the opening 46 of the developing device 4. The replenished toner is conveyed by the screw 44 in the direction of the arrow, mixed with the carrier and given an appropriate tribo and then carried to the vicinity of the sleeve 41, where a thin layer is formed on the developing sleeve 41 and used for development. A toner replenishing screw 51 is provided in the T-CRG 5, and the toner replenishment amount is controlled by the rotation speed (rotation time).

  FIG. 3 is an example of a color laser printer using a developing unit that also serves to collect transfer residual toner. The color laser printer shown in FIG. 3 has a plurality of photosensitive drums 411 that are first electrostatic charge image carriers, and sequentially performs multiple transfer on an intermediate transfer belt 466 that is a second image carrier. A four-drum (tandem) printer that obtains a full-color print image.

  In FIG. 3, an endless intermediate transfer belt 466 is suspended from a driving roller 466a, a tension roller 466b, and a secondary transfer counter roller 466c, and rotates in the direction of the arrow in the drawing.

  Four photosensitive drums 411 are arranged in series corresponding to each color in the moving direction of the intermediate transfer belt 466.

  The photosensitive drum 411 having a yellow developing device is uniformly charged to a predetermined polarity and potential by a primary charging roller 422 in the course of rotation, and then image exposure means (not shown) (color separation / imaging of a color original image). By receiving an image exposure 433 by an exposure optical system, a laser scanning scanning exposure system that outputs a laser beam modulated in response to a time-series electric digital pixel signal of image information, a first color component image (this In this case, an electrostatic latent image corresponding to the yellow component image) is formed. Next, the electrostatic latent image is developed with yellow toner, which is the first color, by a first developing device 444 (yellow developing device).

  The yellow image formed on the electrostatic image carrier 1 enters the primary transfer nip portion with the intermediate transfer belt 466. In the transfer nip portion, a voltage applying member 477 is brought into contact with the back side of the intermediate transfer belt 466. The voltage application member 477 includes primary transfer bias sources 477a to 477d so that a bias can be applied independently at each port. The intermediate transfer belt 466 first transfers yellow at the port of the first color, and then sequentially transfers multiple colors of magenta, cyan, and black at each port from the photosensitive drum 1 corresponding to each color after the above-described steps. The toner remaining on the photosensitive drum 1 is recharged by the primary charging roller 422 and collected by the developing unit. Alternatively, the transfer residual toner passes through the developing unit, is sent to the non-image area of the intermediate transfer belt, and is collected by a cleaner device 499 disposed around the intermediate transfer belt. The four-color full-color image formed on the intermediate transfer belt 466 is then collectively transferred to the transfer material P by the secondary transfer roller 488 and melted and fixed by a fixing device (not shown) to obtain a color print image.

In the present invention, as a preferable process condition when using the charging roller, when the contact pressure of the roller is 5 to 300 N / m and the AC voltage is superimposed on the DC voltage, the AC voltage = 0.5. -5 kVpp, AC frequency = 50 Hz-5 kHz, DC voltage = ± 0.2- ± 1.5 kV, and when DC voltage is used, DC voltage = ± 0.2- ± 5 kV.
The material of the charging roller and charging blade as the contact charging means is preferably conductive rubber, and a release coating may be provided on the surface thereof. As the releasable coating, nylon resin, PVDF (polyvinylidene fluoride), PVDC (polyvinylidene chloride), and the like are applicable. In selecting the material of the transfer belt, in order to improve registration at each color port, a material that expands and contracts is not desirable, and a resin-based or rubber belt with a metal core or a resin + rubber belt is desirable.

  The present invention relates to an image forming method having a rotary rotary preferably used in the present invention, and having a method (auto-refresh method) in which a black developer is developed while replenishing a developer for replenishment consisting of toner and carrier. explain.

  FIG. 4 is a schematic configuration diagram of an example of a full-color image forming apparatus in which the developing device replacement body 13 and the intermediate transfer body 45 having a rotary developing unit for each color of the rotary rotation system are mounted. The surface of the electrostatic latent image carrier 1 is uniformly charged to a negative polarity by the charging device 15. Next, the exposure device 14 performs image exposure corresponding to the first color, for example, a yellow image, and an electrostatic latent image corresponding to the yellow image is formed on the surface of the electrostatic latent image carrier 1.

  The developing device exchanger 13 has a rotationally moving configuration, and a schematic configuration diagram is shown in FIG. Before the leading edge of the electrostatic latent image corresponding to the yellow image reaches the developing position, the yellow developing device faces the electrostatic latent image carrier 1, and then the magnetic brush rubs the electrostatic latent image, A yellow toner image is formed on the electrostatic latent image carrier.

  FIG. 6 is a schematic configuration diagram of the developing devices 2, 3, 4, and 5 in FIG.

  The yellow, magenta, and cyan developing devices 2, 3, and 4 that do not use the auto-refresh developing method do not have 34 to 39 developer recovery function units.

  As shown in FIG. 6, each developing device used for development includes, for example, a developing sleeve 6 as a developer carrying member, a magnet roller 8, a regulating member 7, developer conveying screws 10 and 11, and a scraper (not shown). Etc. are provided.

  With reference to FIG. 4, the flow of transport until the developer in the developing device is developed will be described. The developing sleeve 6 contains a fixed magnet roller 8 and is driven to rotate with a predetermined developing interval between the developing sleeve 6 and the peripheral surface of the electrostatic latent image carrier 1. The developing sleeve 6 and the electrostatic latent image carrier 1 may be in contact with each other. The regulating member 7 has rigidity and magnetism, and is pressed against the developing sleeve 6 with a predetermined load with no developer interposed therebetween, or is disposed with a predetermined interval between the developing sleeve 6 and the developing member 6. And so on. The pair of developer conveying screws 10 and 11 has a screw structure, and conveys and circulates the developer in the opposite directions so that the toner and the carrier are sufficiently stirred and mixed and then sent to the developing sleeve 6 as a developer. It is. The magnet roller 8 is composed of, for example, a magnet having four magnetic poles having the same magnetic force in which N poles and S poles are alternately arranged at equal intervals, a magnet roller having eight poles, or a portion in contact with the scraper. In order to form a repulsive magnetic field and facilitate the peeling of the developer, one pole may be missing to form five poles, and the developer may be included in a fixed state in the developing sleeve 6.

  The pair of developer conveying screws 10 and 11 serve as agitating members that rotate in directions opposite to each other, and are supplied from the supply developer container (FIG. 5: 2a, 3a, 4a, 5a). The replenishment developer to be replenished is conveyed by the thrust of the screw of the agent storage device 9 and is made into a homogeneous two-component developer that is triboelectrically charged by the mixing action of the toner and the carrier. The two-component developer is deposited in layers on the peripheral surface.

  The developer on the surface of the developing sleeve 6 forms a uniform layer by the regulating member 7 provided to face the magnetic pole of the magnet roller 8. The uniformly formed developer layer develops the latent image on the peripheral surface of the electrostatic latent image carrier 1 in the development region, and forms a toner image.

  The toner image is transferred to the intermediate transfer body 45 by the transfer device 40.

  As described above, when the yellow copy cycle is completed, the electrostatic latent image carrier 1 that has finished transferring the yellow toner is then subjected to a pre-cleaning process as necessary, and then neutralized by the static eliminator. The yellow toner remaining on the surface is scraped off by the cleaning device 18.

  Then, the developing device 13 is rotated, and the developing devices 3, 4, and 5 are sequentially switched so as to oppose the electrostatic latent image carrier 1, and magenta, cyan, and black toner images are intermediated in the same copy cycle as described above. It is transferred to the transfer body 45.

  When each of the above copy cycles is executed, the toner image for each color component is transferred to the same position on the intermediate transfer body 45 by the transfer device 40, and the toner for each color component is overlaid. One toner image is formed. On the other hand, the transfer material 12 such as paper or transparent sheet accommodated in the paper feed tray 25 is fed one by one to the registration roller 25 by the feed roller 28, and the transfer material 12 is intermediately synchronized with the intermediate transfer body 45. It is conveyed between the transfer body 45 and the transfer roller 43. After the toner image on the intermediate transfer body 45 is transferred by the transfer roller 43, the transferred transfer material 12 is separated from the intermediate transfer body 45 by the peeling finger 44 and introduced into the fixing device 21 by the transport belt 20. Then, after the toner image is fixed on the transfer material 12, the toner image is discharged to the outside, thereby completing one copy mode.

  In addition, the surface of the intermediate transfer member 45 having the toner image transferred to the transfer material is neutralized by a neutralization device (not shown), and then the surface is cleaned by the cleaning device 23, and the next copy cycle is awaited.

  When the copying operation as described above is repeated, the toner in the developer stored in the developing tank 17 in the developing device of FIG. 6 is gradually consumed, and the ratio of the toner to the carrier, that is, the toner concentration is decreased. To go. This change in toner density is feedback controlled by a toner density sensor (not shown) provided in the developing tank 17 so that the toner density always falls within an appropriate range necessary for development.

  By the above control, the replenishment developer is discharged from the replenishment developer container to the replenishment developer container 9, and then the replenishment developer is supplied from the replenishment port of the replenishment developer container 9 by the propulsive force of the screw. Is supplied to the developing tank 17 in the developing unit.

  Further, in the black developer 5 using the auto-refresh development system, the replenishment developer in which the toner and the carrier of the present invention are mixed is replenished from the replenishment developer container 5a to the replenishment developer container 9. The mouth is opened, and the black developer 5 is supplied.

Next, discharge of excess developer from the black developing device 5 using the rotational movement in the rotationally moving developing device exchanger 13 shown in FIG. 4 will be described with reference to FIG.
In a full-color image forming apparatus including a developing device exchanger 13 having a rotary developing unit adopting a rotational movement method, the developing devices 2, 3, 4, and 5 are rotated and moved inside the developing device exchanger 13 during development. The image is rotated and moved to a position facing the electrostatic latent image carrier 1 to perform development. When not developed, the image is rotated to a position not opposed to the electrostatic latent image carrier 1.

  The developer (deteriorated carrier) that has become excessive at the position where the developing device 5 is opposed to the electrostatic latent image carrier 1 and performing the developing operation is discharged from the developer-side developer provided in the developing device 5. Overflowing from the outlet 34, the intermediate developer collecting unit 37 and the developer collecting auger 36 are moved by the rotating operation, and discharged to a developer collecting container 39 provided on the rotation center shaft of the rotary rotating type developing device.

  Specifically, the developing method according to the present invention applies an AC voltage to the developing sleeve to form an alternating electric field in the developing area and develops the magnetic brush in contact with the electrostatic latent image carrier 1. Is preferably performed. The distance between the developing sleeve 6 and the electrostatic latent image carrier 1 (SD distance) is preferably 100 to 1000 μm in terms of preventing carrier adhesion and improving dot reproducibility. If it is narrower than 100 μm, the supply of developer tends to be insufficient, resulting in low image density. If it exceeds 1000 μm, the lines of magnetic force from the magnetic pole S 1 spread and the density of the magnetic brush decreases, resulting in poor dot reproducibility and restraining the carrier. The force is weakened and carrier adhesion tends to occur.

  The voltage between the peaks of the alternating electric field is preferably 300 to 3000 V, and the frequency is 500 to 10000 Hz, which can be appropriately selected depending on the process. In this case, the waveform of the AC bias for forming the alternating electric field includes a triangular wave, a rectangular wave, a sine wave, or a waveform with a changed duty ratio. In order to cope with the change in the formation speed of the toner image sometimes, it is preferable to perform development by applying a developing bias voltage (intermittent alternating voltage) having a discontinuous AC bias voltage to the developing sleeve. When the applied voltage is lower than 300 V, it is difficult to obtain a sufficient image density, and the fog toner in the non-image portion may not be recovered well. If the voltage exceeds 3000 V, the latent image may be disturbed via the magnetic brush, leading to a reduction in image quality.

  By using a two-component developer having a well-charged toner, the fog removal voltage (Vback) can be lowered, and the primary charge of the electrostatic latent image carrier can be lowered. The life of the image carrier can be extended. Vback is 200 V or less, more preferably 150 V or less, although it depends on the development system. The contrast potential is preferably 100 to 400 V so that a sufficient image density is obtained.

  On the other hand, when the frequency is lower than 500 Hz, although related to the process speed, when the toner in contact with the electrostatic latent image carrier is returned to the developing sleeve, sufficient vibration is not applied and fogging is likely to occur. If it exceeds 10,000 Hz, the toner cannot follow the electric field, and the image quality is likely to deteriorate.

  What is important in the development method in the present invention is that the electrostatic latent image carrier 1 of the magnetic brush on the developing sleeve 6 is used to develop a sufficient image density, excellent dot reproducibility, and without carrier adhesion. The contact width (development contact portion) is preferably 3 to 8 mm. If the developing contact portion is narrower than 3 mm, it is difficult to satisfactorily satisfy a sufficient image density and dot reproducibility, and if it is larger than 8 mm, developer packing may occur and the operation of the machine may be stopped. In addition, it becomes difficult to sufficiently suppress carrier adhesion.

  As a method for adjusting the developing contact portion, the distance between the regulating member 7 and the developing sleeve 6 is adjusted, or the distance between the developing sleeve 6 and the electrostatic latent image carrier 1 (the distance between S and D) is adjusted. There is a method of appropriately adjusting the contact width.

  The configuration of the electrostatic latent image carrier may be the same as that of an electrostatic latent image carrier used in a normal image forming apparatus. For example, a conductive layer and an undercoat are sequentially formed on a conductive substrate such as aluminum or SUS. And a photoconductor having a layer, a charge generation layer, a charge transport layer, and a charge injection layer as required. The conductive layer, undercoat layer, charge generation layer, and charge transport layer may be those used for ordinary photoreceptors. For example, a charge injection layer or a protective layer may be used as the outermost surface layer of the photoreceptor.

  Hereinafter, the effect of the present invention will be specifically described with reference to examples. The present invention is not limited to these examples.

(1) Production of Carrier A (for black developer) (Carrier Production Example 1)
Phenol 7.5 parts by mass formalin solution 11.25 parts by mass (about 40% formaldehyde, about 10% methanol, the rest is water)
Spherical magnetite fine particles (average particle size 0.20 μm, specific resistance 4 × 10 ⁵ Ω · cm)
88.0 parts by mass (lipophilic treatment with 2.0% by mass of γ-glycidoxypropyltrimethoxysilane)
Aqueous ammonia and water as a basic catalyst were placed in this slurry in a flask, heated and held at 85 ° C. over 40 minutes with stirring and mixing, and reacted for 3 hours to produce and cure a phenol resin. After cooling, after adding water, the supernatant liquid is removed, the precipitate is washed with water, dried by heating in a nitrogen stream containing 30% oxygen under normal pressure, and containing magnetite fine particles with a phenol resin as a binder resin. Spherical magnetic carrier core particles were obtained.

  The core surface was treated with 0.5% by mass of γ-aminopropyltrimethoxysilane diluted with a toluene solvent on the obtained carrier core particles. Subsequently, a mixture of 1.0% by mass of straight silicone resin whose substituents are all methyl groups and 0.02% by mass of γ-aminopropyltrimethoxysilane was dissolved in toluene and coated. Further, this magnetic coat carrier is baked at 140 ° C., coarse particles aggregated with a 100 mesh sieve are cut, fine particles and coarse particles are then removed by a multi-division wind classifier, and the particle size distribution is adjusted, and carrier C-1 Got. Table 1 shows the physical properties of the obtained carrier C-1.

(Carrier production example 2)
In Carrier Production Example 1, the carrier core particles are surface treated with 0.3% by mass of γ-aminopropyltrimethoxysilane diluted with a toluene solvent, and then the straight silicone resin 1 in which all substituents are methyl groups. Carrier C-2 was obtained in the same manner as in Carrier Production Example 1 except that a mixture of 0.02% by mass and 0.02% by mass of γ-aminopropyltrimethoxysilane was dissolved in toluene. Table 1 shows the physical properties of the obtained carrier C-2.

(Carrier production example 3)
In Carrier Production Example 1, except that the surface treatment of the carrier core particles was dry-coated with 0.5% by mass of 0.02 μm styrene / methyl methacrylate copolymer resin particles with a hybridizer (manufactured by Nara Machinery Co., Ltd.) Carrier C-3 was obtained in the same manner as Carrier Production Example 1. Table 1 shows the physical properties of the obtained carrier C-3.

(Carrier Production Example 4)
In Carrier Production Example 1, Carrier C-4 was obtained in the same manner as Carrier Production Example 1 except that the amounts of phenol and formalin solution were adjusted so that the magnetite fine particles were 90.0 parts by mass. Table 1 shows the physical properties of the obtained carrier C-4.

(Carrier Production Example 5)
In Carrier Production Example 1, Carrier C-5 was obtained in the same manner as Carrier Production Example 1 except that the amounts of phenol and formalin solution were adjusted so that the magnetite fine particles were 86.0 parts by mass. Table 1 shows the physical properties of the obtained carrier C-5.

(Carrier Production Example 6)
In Carrier Production Example 1, Carrier C-6 was obtained in the same manner as Carrier Production Example 1 except that the amounts of phenol and formalin solution were adjusted so that the magnetite fine particles were 85.5 parts by mass. Table 1 shows the physical properties of the obtained carrier C-6.

(Carrier Production Example 7)
In Carrier Production Example 6, the amount of phenol and formalin solution is adjusted so that the magnetite fine particles are 85.5 parts by mass, and carrier core particles are obtained by heating and drying in a nitrogen stream containing 50% oxygen. Except for this, carrier C-7 was obtained in the same manner as in carrier production example 6. Table 1 shows the physical properties of the obtained carrier C-7.

(Carrier Production Example 8)
In Carrier Production Example 1,
Octahedral magnetite fine particles (average particle size 0.21 μm, specific resistance 3 × 10 ⁵ Ω · cm)
(Lipophilic treatment with 2.0% by mass of γ-glycidoxypropyltrimethoxysilane)
A carrier C-8 was obtained in the same manner as in Carrier Production Example 1 except that Table 1 shows the physical properties of the obtained carrier C-8.

(2) Production of carrier B (for developer excluding black) (carrier production example 9)
Phenol 6.3 parts by mass formalin solution 9.25 parts by mass (formaldehyde about 40%, methanol about 10%, the rest is water)
Spherical magnetite fine particles (average particle size 0.35 μm, specific resistance 5 × 10 ⁵ Ω · cm)
90.0 parts by mass (lipophilic treatment with 1.0% by mass of γ-glycidoxypropyltrimethoxysilane)
Aqueous ammonia and water as a basic catalyst were placed in this slurry in a flask, heated and held at 85 ° C. over 40 minutes with stirring and mixing, and reacted for 3 hours to produce and cure a phenol resin. After cooling, after adding water, the supernatant liquid is removed, the precipitate is washed with water, dried by heating in a nitrogen stream containing 10% oxygen under normal pressure, and containing magnetite fine particles with phenol resin as binder resin Spherical magnetic carrier core particles were obtained.

  The core surface was treated with 0.3% by mass of γ-aminopropyltrimethoxysilane diluted with a toluene solvent on the obtained carrier core particles. Subsequently, a mixture of 0.4% by mass of a straight silicone resin whose substituents are all methyl groups and 0.01% by mass of γ-aminopropyltrimethoxysilane was dissolved in toluene and coated. Furthermore, this magnetic coat carrier was baked at 140 ° C., coarse particles aggregated with a 100 mesh sieve were cut, fine particles and coarse particles were then removed with a multi-division wind classifier to adjust the particle size distribution, and carrier C-9 Got. Table 2 shows the physical properties of the obtained carrier C-9.

(Carrier Production Example 10)
In Carrier Production Example 9, the surface treatment of the carrier core particles was performed with 0.2% by mass of γ-aminopropyltrimethoxysilane diluted with a toluene solvent, and then the straight silicone resin 0 in which all the substituents were methyl groups Carrier C-10 was obtained in the same manner as in Carrier Production Example 1 except that a mixture of .4 mass% and γ-aminopropyltrimethoxysilane 0.01 mass% was dissolved in toluene and treated. Table 2 shows the physical properties of the obtained carrier C-10.

(Carrier Production Example 11)
In Carrier Production Example 9, the surface treatment of the carrier core particles was performed with 0.3% by mass of γ-aminopropyltrimethoxysilane diluted with a toluene solvent, and then the straight silicone resin 0 in which all the substituents were methyl groups. Carrier C-11 was obtained in the same manner as Carrier Production Example 1 except that a mixture of 0.7% by mass and 0.02% by mass of γ-aminopropyltrimethoxysilane was dissolved in toluene. Table 2 shows the physical properties of the obtained carrier C-11.

(Carrier Production Example 12)
In Carrier Production Example 9, except that the surface treatment of the carrier core particles was dry-coated with 0.5% by mass of 0.02 μm styrene / methyl methacrylate copolymer resin particles with a hybridizer (manufactured by Nara Machinery Co., Ltd.) Carrier C-12 was obtained in the same manner as in Carrier Production Example 9. Table 2 shows the physical properties of the obtained carrier C-12.

(Carrier Production Example 13)
In Carrier Production Example 9, Carrier C-13 was obtained in the same manner as Carrier Production Example 9 except that the amounts of phenol and formalin solution were adjusted so that the magnetite fine particles were 91.0 parts by mass. Table 2 shows the physical properties of the obtained carrier C-13.

(Carrier Production Example 14)
In Carrier Production Example 9, Carrier C-14 was obtained in the same manner as Carrier Production Example 9, except that the amounts of phenol and formalin solution were adjusted so that the magnetite fine particles were 89.5 parts by mass. Table 2 shows the physical properties of the obtained carrier C-14.

(Carrier Production Example 15)
In Carrier Production Example 9, Carrier C-15 was obtained in the same manner as Carrier Production Example 9, except that the amounts of phenol and formalin solution were adjusted so that the magnetite fine particles were 91.5 parts by mass. Table 2 shows the physical properties of the obtained carrier C-15.

(Carrier Production Example 16)
In Carrier Production Example 14, Carrier C-16 was obtained in the same manner as Carrier Production Example 14 except that carrier core particles were obtained by heating and drying under a nitrogen stream containing 30% oxygen. Table 2 shows the physical properties of the obtained carrier C-16.

(Carrier Production Example 17)
They were weighed so that the molar ratio was Fe ₂ O ₃ = 40 mol%, CuO = 20 mol%, ZnO = 40 mol%, and mixed using a ball mill. After calcining this at a temperature of 1000 ° C., the bakable product was pulverized by a ball mill. 100 parts by mass of the obtained powder 0.5 parts by mass of poly (sodium methacrylate) and water were placed in a wet ball mill and mixed to obtain a slurry. The obtained slurry was granulated with a spray dryer. This is sintered at a temperature of 1300 ° C., coarse particles are removed with a sieve having an opening of 250 μm, and then classified with an air classifier (Elbow Jet Lab EJ-L3, manufactured by Nippon Steel Mining Co., Ltd.) to adjust the particle size. To obtain carrier core particles. The surface of the obtained carrier core particles was subjected to a surface treatment in the same manner as in Carrier Production Example 9 to obtain Carrier C-17. Table 2 shows the physical properties of the obtained carrier C-17.

(3) Toner production (Toner Production Example 1)
After adding 250 parts by mass of 0.1 M Na ₃ PO ₄ aqueous solution to 405 parts by mass of ion-exchanged water and heating to 60 ° C., 40.0 parts by mass of 1.07 M CaCl ₂ aqueous solution was gradually added to calcium phosphate. An aqueous medium containing salt was obtained.

On the other hand, the following formulation was uniformly dispersed and mixed using an attritor (Mitsui Miike Chemical Co., Ltd.).
Styrene 80 parts by mass n-butyl acrylate 20 parts by mass Divinylbenzene 0.2 parts by mass Polyester resin comprising ethylene oxide, propylene oxide adduct of bisphenol A and terephthalic acid (Mw = 9000, Tg = 72 ° C., acid value = 13)
5.0 parts by mass Negatively chargeable charge control agent (Al compound of ditertiary butylsalicylic acid) 1 part by mass C.I. I Pigment Yellow 17 8.0 parts by mass This monomer composition is heated to 60 ° C., and there is an ester wax mainly composed of behenyl behenate (maximum endothermic peak 72 ° C. during temperature rise measurement in DSC) 12 masses. Then, 3 parts by mass of the polymerization initiator 2,2′-azobis (2,4-dimethylvaleronitrile) [t _1/2 = 140 minutes, at 60 ° C.] was dissolved therein.

The polymerizable monomer system is charged into the aqueous medium, and stirred at 10,000 rpm for 15 minutes using a TK homomixer (Special Machine Industries Co., Ltd.) at 60.5 ° C. and N ₂ atmosphere. Granulated. Thereafter, the mixture was reacted at 60.5 ° C. for 6 hours while stirring with a paddle stirring blade. Thereafter, the liquid temperature was raised to 80 ° C., and stirring was further continued for 4 hours. After completion of the reaction, distillation was further performed at 80 ° C. for 3 hours, and then the suspension was cooled, hydrochloric acid was added to dissolve the calcium phosphate salt, and filtration and washing were performed to obtain wet colored particles.

  Next, the particles were dried at 40 ° C. for 12 hours to obtain colored particles (toner particles).

100 parts by mass of the toner particles, 0.4 parts by mass of hydrophobic silica fine particles treated with hexamethyldisilazane and dimethylsiloxane and having a BET value of 80 m ² / g, and hydrophobic particles having a BET value of 150 m ² / g treated in the same manner. The yellow toner T- was mixed with 0.3 part by mass of silica fine particles and 0.5 part by mass of hydrophobic titania fine particles having a BET value of 180 m ² / g treated in the same manner using a Henschel mixer (Mitsui Miike Chemical Co., Ltd.). 1 was obtained. Table 3 shows the composition of the obtained toner T-1.

(Toner Production Example 2)
In Toner Production Example 1, with respect to 100 parts by mass of toner particles, only 0.7 part by mass of hydrophobic silica fine particles treated with hexamethyldisilazane and dimethylsiloxane and having a BET value of 80 m ² / g were added to a Henschel mixer (Mitsui Miike Chemical Industries). A yellow toner T-2 was obtained in the same manner as in Toner Production Example 1 except that the mixing was carried out using a machine. Table 3 shows the composition of the obtained toner T-2.

(Toner Production Example 3)
Styrene / n-butyl acrylate copolymer (mass ratio 85/15, Mw = 33000)
Polyester resin comprising 80 parts by mass of bisphenol A ethylene oxide, propylene oxide adduct and terephthalic acid (Mw = 9000, Tg = 72 ° C., acid value = 13) 4.5 parts by mass negative charge control agent (ditertiary butylsalicylic acid Al metal compound) 3 parts by mass C.I. I Pigment Yellow 17 Ester wax mainly composed of 8 parts by weight behenyl behenate (maximum endothermic peak at 72 ° C. during temperature rise measurement in DSC) 5 parts by weight The above materials were mixed in a blender and heated to 130 ° C. The kneaded material melted and kneaded with a loader was coarsely pulverized with a hammer mill (manufactured by Hosokawa Micron Corporation), and then finely pulverized with a finely pulverizing machine using an air jet method. The collision plate was adjusted to be 90 degrees with respect to the collision direction. The resulting finely pulverized product was subjected to air classification to obtain toner particles. Thereafter, spheronization treatment was performed using a batch type impact surface treatment apparatus (treatment temperature 40 ° C., rotational treatment blade peripheral speed 75 m / sec, treatment time 2.5 minutes).

100 parts by mass of the toner particles, 0.4 parts by mass of hydrophobic silica fine particles treated with hexamethyldisilazane and dimethylsiloxane and having a BET value of 80 m ² / g, and hydrophobic particles having a BET value of 150 m ² / g treated in the same manner. The yellow toner T- was mixed with 0.3 part by mass of silica fine particles and 0.5 part by mass of hydrophobic titania fine particles having a BET value of 180 m ² / g treated in the same manner using a Henschel mixer (Mitsui Miike Chemical Co., Ltd.). 3 was obtained. Table 3 shows the composition of the obtained toner T-3.

(Toner Production Example 4)
(Preparation of release agent fine particle dispersion)
78.33 parts of demineralized water, 10 parts by mass of an ester compound mainly composed of behenyl behenate (maximum endothermic peak 72 ° C. during temperature rise measurement in DSC) and 1.7 parts of sodium dodecylbenzenesulfonate were mixed to 90 ° C. The mixture was emulsified by high-pressure shearing to obtain a release agent fine particle dispersion.

(Preparation of resin fine particle dispersion)
In a reactor (with a high-shear stirring device, volume 1 liter flask), 150 parts by mass of ion-exchanged water, 1.5 parts by mass of nonionic surfactant (manufactured by Sanyo Chemical Co., Ltd .: Nonipol 400) and anionic surfactant 3.5 parts by mass of an agent (Daiichi Kogyo Seiyaku Co., Ltd .: Neogen SC) was added.

Next, styrene 71 parts by mass nbutyl acrylate 29 parts by mass acrylic acid 3 parts by mass octanethiol 0.35 parts by mass carbon tetrabromide 0.7 parts by mass While adding and slowly mixing, 10 parts by mass of ion-exchanged water having 3.2 parts by mass of ammonium persulfate dissolved therein was added dropwise over 10 minutes. Ten minutes later, the contents were heated in an oil bath while stirring the contents until the contents reached 65 ° C, and after 1 hour, the temperature was further raised to 70 ° C and emulsion polymerization was continued for 4 hours under a nitrogen atmosphere. After a predetermined time, cooling was performed until the temperature reached room temperature at a rate of 2 ° C. per minute. Thus, a resin particle dispersion in which resin particles are dispersed was prepared.

(Preparation of colorant fine particle dispersion)
・ C. I. Pigment Yellow 17 20 parts by mass, anionic surfactant (Daiichi Kogyo Seiyaku Co., Ltd .: Neogen SC) 2 parts by mass, ion-exchanged water 78 parts by mass The above were mixed and dispersed using a sand grinder mill.

(Preparation of charge control fine particle dispersion)
-Negatively chargeable charge control agent (Al compound of ditertiary butylsalicylic acid) 25 parts by mass-Anionic surfactant (Daiichi Kogyo Seiyaku Co., Ltd .: Neogen SC) 2 parts by mass-Ion-exchanged water 78 parts by mass Mix and disperse using a sand grinder mill. When the particle size distribution in this charge control fine particle dispersion was measured using a particle size measurement device (LA-920, 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.

(Manufacture of toner)
-Resin fine particle dispersion 360 parts by mass-Colorant fine particle dispersion 40 parts by mass-Release agent fine particle dispersion 70 parts by mass-Charge control particle dispersion 7 parts by mass-Anionic surfactant (Daiichi Kogyo Seiyaku Co., Ltd.) Manufactured by: Neogen SC) 2 parts by mass A toner was produced by the following procedure using each of the above components. A resin fine particle dispersion and an anionic surfactant were charged into a reactor (a 1 liter flask having a baffle and an anchor blade with a baffle) and mixed uniformly, and then the colorant fine particle dispersion was added and mixed uniformly. While stirring the obtained mixed dispersion, 0.7 part by mass of aluminum sulfate aqueous solution as a solid content was dropped (aggregation step).

  After completion of the dropwise addition, the system was replaced with nitrogen, and the system was maintained at 50 ° C. for 1 hour and further at 55 ° C. for 1 hour.

  After completion of the predetermined time, the charge control fine particle dispersion, the release agent fine particle dispersion, and the aluminum sulfate aqueous solution (0.6 parts by mass as a solid content) are added, and then maintained at 60 ° C. for 1 hour and at 90 ° C. for 1 hour. (Heat fusion process). The reaction at this time was performed in a nitrogen atmosphere.

  After the predetermined time, the particle size was adjusted by classification after filtering, washing, and drying to obtain colored particles (toner particles).

100 parts by mass of the toner particles, 0.4 parts by mass of hydrophobic silica fine particles treated with hexamethyldisilazane and dimethylsiloxane and having a BET value of 80 m ² / g, and hydrophobic particles having a BET value of 150 m ² / g treated in the same manner. The yellow toner T- was mixed with 0.3 part by mass of silica fine particles and 0.5 part by mass of hydrophobic titania fine particles having a BET value of 180 m ² / g treated in the same manner using a Henschel mixer (Mitsui Miike Chemical Co., Ltd.). 4 was obtained. Table 3 shows the composition of the obtained toner T-4.

(Toner Production Example 5)
In Toner Production Example 1, the colorant is C.I. Magenta toner T-5 was obtained in the same manner as in Toner Production Example 1 except that I Pigment Red 122 was changed to 8 parts by mass. Table 3 shows the composition of the obtained toner T-5.

(Toner Production Example 6)
In Toner Production Example 3, 0.6 parts by mass of hydrophobic silica fine particles having a BET value of 80 m ² / g treated with hexamethyldisilazane and dimethylsiloxane, and hydrophobic titania having a BET value of 180 m ² / g treated in the same manner A magenta toner T-6 was obtained in the same manner as in Toner Production Example 3 except that 0.6 part by mass of fine particles was mixed with a Henschel mixer (Mitsui Miike Chemical Co., Ltd.). Table 3 shows the composition of the obtained toner T-6.

(Toner Production Example 7)
In Toner Production Example 3, the colorant is C.I. A magenta toner T-7 was obtained in the same manner as in Toner Production Example 1 except that I Pigment Red 122 was changed to 8 parts by mass. Table 3 shows the composition of the obtained toner T-7.

(Toner Production Example 8)
In Toner Production Example 4, the colorant is C.I. Cyan toner T-8 was obtained in the same manner as in Toner Production Example 4 except that I Pigment Red 122 was changed to 10 parts by mass. Table 3 shows the composition of the obtained toner T-8.

(Toner Production Example 9)
In Toner Production Example 1, the colorant is C.I. A cyan toner T-9 was obtained in the same manner as in Toner Production Example 1 except that I Pigment Blue 15: 3 was changed to 7.5 parts by mass. Table 3 shows the composition of the obtained toner T-9.

(Toner Production Example 10)
In Toner Production Example 9, 0.6 part by mass of hydrophobic silica fine particles having a BET value of 80 m ² / g treated with hexamethyldisilazane and dimethylsiloxane, and hydrophobic titania having a BET value of 180 m ² / g treated in the same manner Magenta toner T-10 was obtained in the same manner as in Toner Production Example 9 except that 0.6 part by mass of fine particles was mixed with a Henschel mixer (Mitsui Miike Chemical Co., Ltd.). Table 3 shows the composition of the obtained toner T-10.

(Toner Production Example 11)
In Toner Production Example 3, the colorant is C.I. A cyan toner T-11 was obtained in the same manner as in Toner Production Example 3 except that I Pigment Blue 15: 3 was changed to 8 parts by mass. Table 3 shows the composition of the obtained toner T-11.

(Toner Production Example 12)
In Toner Production Example 4, the colorant is C.I. A cyan toner T-12 was obtained in the same manner as in Toner Production Example 4 except that I Pigment Blue 15: 3 was changed to 10 parts by mass. Table 3 shows the composition of the obtained toner T-12.

(Toner Production Example 13)
In Toner Production Example 1, black toner T-13 was obtained in the same manner as in Toner Production Example 1 except that carbon black was changed to 8 parts by mass as the colorant. Table 3 shows the composition of the obtained toner T-13.

(Toner Production Example 14)
In Toner Production Example 13, only 0.5 parts by mass of hydrophobic silica fine particles treated with hexamethyldisilazane and dimethylsiloxane and having a BET value of 150 m ² / g are mixed with a Henschel mixer (Mitsui Miike Chemical Co., Ltd.). Except for, a black toner T-14 was obtained in the same manner as in Toner Production Example 13. Table 3 shows the composition of the obtained toner T-14.

(Toner Production Example 15)
In Toner Production Example 3, cyan toner T-15 was obtained in the same manner as in Toner Production Example 3 except that carbon black was changed to 8 parts by mass as the colorant. Table 3 shows the composition of the obtained toner T-15.

(Toner Production Example 16)
In Toner Production Example 4, cyan toner T-16 was obtained in the same manner as in Toner Production Example 4 except that carbon black was changed to 10 parts by mass as the colorant. Table 3 shows the composition of the obtained toner T-16.

(Toner Production Example 17)
In Toner Production Example 13, as a colorant, C.I. I. Pigment Yellow 17 (3 parts by mass), C.I. I. Pigment red 122 in 3 parts by mass, C.I. Black toner T-17 was obtained in the same manner as in Toner Production Example 13 except that I Pigment Blue 15: 3 was changed to 3 parts by mass to obtain 3 color black. Table 3 shows the composition of the obtained toner T-17.

[Example 1]
Carrier C-1 and black toner T-13, carrier C-9 and yellow toner T-1, magenta toner T-5, and cyan toner T-9 are adjusted so that the ratio of the toner to the total mass is 8% by mass. The mixture was uniformly mixed to produce a four-component two-component developer.

  Commercially available iRC5180 (manufactured by Canon Inc., process speed = 227 mm / sec, sleeve peripheral speed = 386 mm / sec) modified so that the resulting four-color two-component developer can output an image of 55 sheets / min. ) And replenishing toner corresponding to each color, using a full-color original document of A4 size in which the image area of black is adjusted to 10% and the image area of yellow, magenta, and cyan is adjusted to 1%. The image output test of 60,000 sheets was performed in a full color mode in a normal temperature and low humidity environment (23 ° C., 4% RH) and a normal temperature and normal humidity environment (23 ° C., 50% RH).

  When the image density, fine line reproducibility, charge rising, fogging, and toner scattering were evaluated based on the following evaluation methods, good results were obtained. The evaluation results are shown in Table 4. In the following evaluation results A to E, A to C were regarded as practical levels.

(Image density)
The image density was measured with a color reflection densitometer (X-RITE 404A manufactured by X-Rite Co.) after printing the solid image. The measurement was performed by measuring and averaging five points at the four corners and the center of the solid image.

(Fine line reproducibility)
After the completion of the image drawing test, the fine line reproducibility was measured by the following method. That is, an image obtained by copying an original document with a thin line accurately having a width of 100 μm under a proper copying condition as a measurement sample, and using a Luzex 450 particle analyzer as a measurement device, an enlarged monitor image is used to display the line width by an indicator. Measure. At this time, since the measurement position of the line width is uneven in the width direction of the fine line image of the toner, the average line width of the unevenness is used as the measurement point. From this, the fine line reproducibility value (%) is calculated by the following equation.

(Line width of copied image obtained from measurement) / (Original line width) × 100
The worst color among the four colors was shown based on the following evaluation criteria.

(Evaluation criteria)
A: Less than 102% B: Less than 102-104% C: Less than 104-106% D: Less than 106-108% E: 108% or more

(Charge rising)
The rising characteristics of charging are shown in% based on the following evaluation criteria in% in the charge amount change width of the 100th developer from the initial stage in the image forming test. The charge amount was measured by using an apparatus as shown in FIG. 7 described below.

About 0.5 g of a sample is put in a metal measuring container 522 equipped with a 635 mesh conductive screen 533 at the bottom, and a metallic lid 544 is placed. Suction is performed for 3 minutes with a suction machine, and the triboelectric charge amount is obtained from the mass difference before and after suction and the potential accumulated in the capacitor connected to the container. The suction pressure is 250 mmHg. The calculation formula for obtaining the triboelectric charge amount Q (μC / g) is calculated using the following formula.
Q (μC / g) = (C × V) / (W1−W2)
(W1 is the mass before suction, W2 is the mass after suction, C is the capacitance of the capacitor, and V is the potential accumulated in the capacitor.)

(Evaluation criteria)
A: Change amount of charge amount is 0 to 10
B: Change amount of charge amount is 11 to 20%
C: Change amount of charge amount is 21 to 30%
D: Change amount of charge amount is 31 to 40%
E: Change amount of charge amount is 41 to 50%

(Cover)
For fogging, after completion of the image output test, the reflection density meter (densitometer TC6MC: Tokyo Denshoku Technical Center) was used to measure the reflection density of the white paper and the non-image area of the printed paper. The difference in the reflection density between the two colors was shown based on the following evaluation criteria, with the reflection density of the blank paper as a reference and the worst level among the four colors.

(Evaluation criteria)
A: Less than 0.6% B: 0.6 to less than 1.6% C: 1.6 to less than 2.6% D: 2.6 to less than 4.1% E: 4.1% or more

(Toner scattering)
For toner scattering, the developing device after the completion of the image output test is taken out and set in an idle rotating machine. A3 paper is placed about 10 cm away from the sleeve circumference of the developing device, and is rotated idly for 5 minutes so that scattered toner adheres to the paper. The toner adhering to the paper was allowed to stand at 70 ° C. for 5 hours to be fixed on the paper, and the reflection density of the scattered toner was measured using a reflection densitometer (densitometer TC6MC: Tokyo Denki Technical Center). Also, the reflection density of the blank paper was measured in advance, and the difference between the reflection densities of the two was evaluated using the reflection density of the blank paper as a reference. The measurement was carried out by measuring five points on the paper at the four corners and the center and taking the average. The evaluation criteria were as follows, and the worst color among the four colors was shown based on the following evaluation criteria.
A: Less than 1.1% B: 1.1 to less than 5.1% C: Less than 5.1 to 10.1% D: Less than 10.1 to 20.1% E: 20.1% or more

[Examples 2 to 10 and Comparative Examples 1 to 3]
Using the developers shown in each example of Table 4, the same examination as in Example 1 was performed for Examples 2 to 10 and Comparative Examples 1 to 3. The evaluation results are shown in Table 4.

Example 11
Commercially available iRC3220 (manufactured by Canon Inc., process speed = 148 mm / sec, sleeve peripheral speed = 250 mm) modified to be able to output an image of 35 sheets / min using the developer shown in Example 9 of Table 4. / Sec), the same examination as in Example 1 was performed except that was used. The evaluation results are shown in Table 4.

Example 12
Commercially available iRC5180 (manufactured by Canon Inc., process speed = 301 mm / sec, sleeve peripheral speed = 511 mm) modified to allow image output of 73 sheets / min using the developer shown in Example 1 of Table 4. / Sec), the same examination as in Example 1 was performed except that was used. The evaluation results are shown in Table 4.

Example 13
A commercially available iRC3170 (manufactured by Canon Inc., process speed = 149 mm / sec, sleeve circumference), which was modified so that an image output of 8 sheets / min in full color mode was made using the same two-color two-component developer as in Example 1. A4 size full color original with 10% black image area and 1% yellow, magenta, and cyan image area while replenishing toner corresponding to each color using speed = 253mm / sec) Using a manuscript, a 60,000-image print test was performed in full color mode in a normal temperature and low humidity environment (23 ° C., 4% RH) and a normal temperature and normal humidity environment (23 ° C., 50% RH). Good results were obtained. Incidentally, black was supplied with a replenishment developer in which carrier C-1 and black toner T-13 were uniformly mixed so that the ratio of the toner to the total mass was 85% by mass.

It is a block diagram of the developing device used for a cleaner-less system. It is the block diagram which looked at the developing device of Drawing 1 from the upper part. It is a block diagram of the image forming apparatus used for a cleaner-less system. 1 is a configuration diagram of an image forming apparatus including a rotary developing type developing device and an intermediate transfer member. It is an enlarged block diagram of the developing device of a rotary developing system. It is sectional drawing of the developing device used for a rotary image development system. FIG. 3 is a configuration diagram of a toner triboelectric charge measuring device.

Claims (13)

A charging step of charging the electrostatic charge image carrier; a latent image forming step of forming an electrostatic charge image on the charged electrostatic charge image carrier; yellow, magenta, cyan held on the developer carrier; In a full-color image forming method comprising: a developing step of developing using at least four colors of black developer to form a toner image; a transferring step of transferring the formed toner image to a transfer material;
The developer is a two-component developer having at least a toner and a carrier,
The carrier has a magnetization intensity σ _VA (1000) per unit volume at 1000 / 4π (kA / m) of carrier A used in the black developer of 120 × 10 ⁻³ ≦ σ _VA (1000) ≦ 163. × 10 ^-3 (Am ² / cm ³ )
The magnetization intensity σ _VB (1000) per unit volume at 1000 / 4π (kA / m) of carrier B used for at least one developer other than the black developer is 164 × 10 ⁻³ ≦ σ _VB (1000) ≦ 220 × 10 ⁻³ (Am ² / cm ³ )
And
A full-color image forming method, wherein the toner used in the black developer contains carbon black.   The full-color image according to claim 1, wherein the carriers A and B are magnetic material-dispersed resin carriers in which a carrier core surface in which metal compound particles are dispersed in a binder resin is coated with a silicone resin. Forming method. When the electric field intensity of the carrier A is 5.0 × 10 ³ [V / cm], the resistance (R _A ) is 1.0 × 10 ¹¹ ≦ (R _A ) ≦ 1.0 × 10 ¹³ (Ω · cm)
And the volume resistivity value (R _B ) when the electric field intensity of the carrier B is 5.0 × 10 ³ [V / cm] is 5.0 × 10 ⁶ ≦ (R _B ) ≦ 5.0 × 10 ¹⁰ ( Ω · cm)
The full-color image forming method according to claim 1, wherein: The carriers A and B have a weight reduction rate W in a thermogravimetric measurement apparatus (TGA).
8.0 ≦ (W) ≦ 12.0 (%)
The full-color image forming method according to claim 1, wherein:   5. The full color image forming method according to claim 1, wherein the carrier B is used for at least magenta and a cyan developer.   6. The full color image forming method according to claim 1, wherein the carrier B is used in at least yellow, magenta and cyan developers.   The full-color image forming method according to claim 1, wherein the process speed is 150 mm / sec or more and / or the peripheral speed of the developer carrying member is 230 mm / sec or more.   The full-color image according to any one of claims 1 to 7, wherein the developer carrying member also serves to collect transfer residual toner, and development devices of at least four colors of yellow, magenta, cyan, and black are arranged in a tandem type. Forming method.   The full-color image forming method according to claim 1, wherein at least yellow, magenta, and cyan developing devices are arranged in a rotatable rotary unit.   10. The development is performed while supplying at least one of a black replenishment developer, a yellow replenishment developer, a magenta replenishment developer, and a cyan replenishment developer composed of a toner and a carrier. A full-color image forming method described in 1.   The full-color image forming method according to any one of claims 1 to 10, wherein the toner includes toner particles containing at least a colorant and inorganic fine particles, and the inorganic fine particles include at least three kinds. .   12. The full-color image forming method according to claim 1, wherein the toner is granulated in an aqueous medium and produced.   The full-color image forming method according to claim 1, wherein the toner is produced by a suspension polymerization method.

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