JP2001343790A - Carrier for electrophotography, two-component type developer and image-forming device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide the carrier for electrophotography of two-component type developer, with which the electrification properties of toner is stabilized, without being influenced by the environment and satisfactory image quality is obtained over a long period, even if it is used in an image-forming device on which an atmospheric heater is mounted. SOLUTION: In an electrophotographic device, an electrostatic charge image is formed on an electrostatic charge image carrier, by electrifying the electrostatic charge image carrier with an electrifying means and exposing the electrified electrostatic charge image carrier, a toner image is formed on the electrostatic charge image carrier, by developing the electrostatic charge image with a developing means having the two-component type developer. The toner image on the electrostatic charge image carrier is transferred to a transfer material via, or not via an intermediate transfer body, and the toner image on the transfer material is fixed with a heating and pressuring fixing means. For the carrier used in this electrophotographic device, having the atmospheric heater capable of controlling heating of the inside of the device, the moisture absorption quantity TL (mass %), after the carrier is left in 23 deg.C and 5% RH environment and the surface area Sm (cm2/g) of the carrier, satisfy the relation 1.1×10-4<=TL/Sm.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an electrophotographic carrier, a two-component developer having the electrophotographic carrier and a toner, and an image forming apparatus therefor.
More specifically, in the present invention, the electrostatic image carrier is charged by charging means, the charged electrostatic image carrier is exposed to form an electrostatic image on the electrostatic image carrier, and the electrostatic image is recharged. A toner image is formed on an electrostatic image carrier by developing with a developing unit having a component-based developer, and the toner image on the electrostatic image carrier is transferred via an intermediate transfer member or without a transfer material. A two-component developer for developing an electrostatic charge image by an electrophotographic apparatus having an atmosphere heater capable of heating and controlling the inside of the apparatus by transferring the toner image onto the transfer material and fixing the toner image on the transfer material by heating and pressing fixing means. The present invention relates to an electrophotographic carrier to be configured together with a toner, a two-component developer having the electrophotographic carrier and a toner, and an image forming apparatus therefor.

[0002]

2. Description of the Related Art As an electrophotographic method, US Pat.
Various methods are described in JP-B-97,691, JP-B-42-23910 and JP-B-43-24748. In these methods, an electrostatic image is formed by irradiating a photoconductive layer with a light image corresponding to an original, and then toner is adhered on the electrostatic image to develop the electrostatic image, and if necessary, After transferring the toner image onto a transfer material such as paper, the toner image is fixed by heat, pressure, heat and pressure or solvent vapor to obtain a copy or print.

In recent years, with the development of computers and multimedia, there is a demand for means for outputting higher definition full color images in a wide range of fields from offices to homes. Heavy users demand high durability without deterioration in image quality even when copying or printing a large number of sheets, and in small offices and homes, obtain high-quality images, reduce the size of the device from the viewpoint of space saving and energy saving, and reduce waste toner. There is a demand for the reuse or waste tonerlessness (cleanerlessness), and various studies have been made from each viewpoint in order to achieve these objects.

In the electrophotographic method, the step of developing an electrostatic image is to form an image of the charged toner particles on the electrostatic image by utilizing the electrostatic interaction of the electrostatic image.
Among the developers for developing electrostatic images using toner, a one-component developer using a magnetic toner in which a magnetic material is dispersed in a resin, and a non-magnetic toner or a magnetic toner mixed with a magnetic carrier There is a two-component developer, and in a full-color image forming apparatus such as a full-color copying machine or a full-color printer that requires high image quality, a two-component developer in which a non-magnetic toner and a magnetic carrier are mixed is preferably used. ing.

As a magnetic carrier used for a two-component developer, an iron powder carrier, a ferrite carrier, or a magnetic material-dispersed resin carrier in which magnetic fine particles are dispersed in a binder resin are known. In an iron powder carrier, since the volume resistance value of the carrier is low, the charge of the electrostatic charge image leaks through the carrier and disturbs the electrostatic charge image, which may cause an image defect.

Even when a ferrite carrier having a relatively high volume resistance value is used, in particular, in a developing method in which an alternating electric field is applied, charge leakage of an electrostatic charge image through the carrier may not be prevented in some cases. Since these have a large saturation magnetization, the magnetic brush becomes rigid,
In some cases, the magnetic brush may be applied to the toner image.

In order to solve such a problem, there has been proposed a magnetic substance-dispersed resin carrier in which magnetic fine particles are dispersed in a binder resin (hereinafter, referred to as a “dispersed carrier”). Dispersion type carriers are better than ferrite carriers.
The magnetic brush of the carrier does not become rigid because of relatively high volume resistance, small saturation magnetization, and small true specific gravity.
A good toner image without texture can be formed.

Further, in the conventional two-component type developer, a part of the toner particles is deposited on the surface of the carrier particles by mechanical collision such as collision between particles and collision between particles and a developing machine, or heat generated by these. There is a property of so-called "spent formation" in which a film is physically attached to form a film. In such a situation, a film of the components of the toner is gradually accumulated on the surface of the carrier particles, and the frictional charge between the carrier particles and the toner particles is replaced with the frictional charge between the toners, so that the entire developer is charged. The triboelectric charging characteristics are deteriorated, and a large amount of toner adheres to the background portion of the copy image, that is, a so-called “fog” phenomenon occurs, and the copy quality is reduced. Further, when the formation of a film by the toner component on the carrier surface becomes remarkable, the entire developer must be replaced, which leads to an increase in cost.

On the other hand, the dispersion type carrier described above has a small saturation magnetization and a small true specific gravity, which is advantageous for such spent. Further, a small true specific gravity can make the developing device light. It also has the advantage.

In particular, the dispersion type carrier produced by the polymerization method is excellent in fluidity because the particles have little shape distortion and it is relatively easy to form a spherical shape with high particle strength. Since the particle size can be controlled in a wide range, it is expected to be applied to high-speed copying machines and high-speed laser beam printers.

However, the dispersion type carrier has a problem that the magnetic substance may be missing from the carrier particles and the durability should be further improved.

Further, in a toner used for a two-component developer, it is preferable to add inorganic fine particles to the surface of the toner particles for the purpose of improving charging characteristics, fluidity and transferability. When the dispersion type carrier is used in combination with the toner to which the fine particles are externally added, the projections of the unevenness present on the particle surface of the dispersion type carrier scrape the inorganic fine particles existing on the surface of the toner particles into the concave portions. In some cases, a phenomenon called so-called “adhesion of an external additive” may occur, in which the inorganic fine particles adhere. As a result, the charge-imparting ability of the toner to be imparted to the toner is reduced, and the charging characteristics, fluidity, and transferability of the toner itself are impaired, thereby causing image defects.

In order to solve these problems, a method of coating the surface of the dispersion type carrier with a resin can be preferably used. Further, since the charging characteristics of the toner can be easily controlled by the charging characteristics of the resin to be coated, a desired charge can be imparted to the toner by selecting the resin to be coated.

On the other hand, the dispersion type carrier produced by the polymerization method tends to have a higher water adsorption amount than the ferrite carrier due to the fact that the surface has more fine irregularities and more pores inside. In particular, in the case of a polymerizable carrier obtained by polymerizing in an aqueous medium, the monomer to be polymerized has a high water affinity and comes into contact with water during the production process. The amount of water adsorbed tends to be higher than the dispersion type carrier manufactured by the method or the dispersion type carrier polymerized in a hydrophobic solvent,
Particularly, under high temperature and high humidity, fog and toner scattering may be caused due to an extremely low charge.

In order to solve such a problem, Japanese Patent Application Laid-Open No. 09-127736 discloses a method of controlling the amount of water adsorbed under high temperature and high humidity, so that the gradation is improved particularly under high temperature and high humidity, and the image density is improved. It has been proposed to obtain an image with high image quality.

However, as described above, this problem has not been solved in a resin-coated dispersion type carrier which is effective for spent resistance and impact resistance and is also advantageous for toner spent. .

On the other hand, it has been considered to control the temperature and humidity inside the apparatus for the purpose of controlling the amount of moisture adsorbed by the carrier. However, the dispersion type carrier tends to have a higher resistance than the ferrite carrier. When the surface is covered with a resin, the resistance is further increased. When an image is formed under low temperature and low humidity using such a carrier having a small water content, an image with an effective edge can be obtained. A problem such as extremely thinning may occur. Further, the carrier may accumulate an excessive amount of charge, and the charge amount of the toner to be originally provided may become non-uniform. Such a problem may require measures such as suppression of static electricity accumulation during carrier production, and may leave a problem for stable production.

Further, if the inside of the apparatus is heated for the purpose of suppressing the adsorption of moisture to the carrier, thermal damage to the toner is easily caused, and the toner tends to be spent. In recent years, even for full-color toners, toners that do not require oil application to the fixing roller have been demanded.
When a low softening point substance is added to the toner to improve the fixing offset, the above phenomenon becomes more remarkable.

[0019]

As described above, in consideration of the above-mentioned required characteristics of the carrier, the conventional carrier still has a problem to be improved, and further improvement is desired. In particular, in a dispersion type carrier in which magnetic particles are dispersed in a binder resin, an improved carrier which does not cause image deterioration even at low temperature and low humidity has been desired.

An object of the present invention is to propose a dispersion type carrier rear which solves the above problems, a two-component developer having the dispersion type carrier and toner, and an image forming apparatus therefor.

An object of the present invention is to propose a dispersion type carrier having excellent durability, and a two-component developer having the dispersion type carrier and a toner.

An object of the present invention is to propose a dispersion type carrier having excellent environmental characteristics, and a two-component developer having the dispersion type carrier and a toner.

An object of the present invention is to propose a dispersion type carrier having excellent charge-imparting property to a toner, and a two-component developer having the dispersion type carrier and a toner.

An object of the present invention is to provide a dispersion type carrier effective for preventing carrier adhesion on a photoreceptor, a two-component developer having the dispersion type carrier and a toner, and a use of the two-component developer. To provide an image forming apparatus.

[0025]

The above objects can be achieved by the following constitutions of the present invention.

According to a first aspect of the present invention, an electrostatic image carrier is charged by a charging means, and the charged electrostatic image carrier is exposed to form an electrostatic image on the electrostatic image carrier. A toner image is formed on an electrostatic image carrier by developing with a developing means having a two-component developer, and the toner image on the electrostatic image carrier is transferred via an intermediate transfer member or without an intermediate transfer member. The carrier used in an electrophotographic apparatus having an atmosphere heater capable of heating and controlling the inside of the apparatus is transferred to a material, and the toner image on the transfer material is fixed by a heating and pressing fixing unit.
The water adsorption amount TL (mass%) after being left in an environment of 23 ° C. and 5% RH and the surface area Sm (cm ² / g) of the carrier are as follows:
The present invention relates to an electrophotographic carrier, which satisfies the following relationship: 1.1 × 10 ⁻⁴ ≦ TL / Sm.

According to a second aspect of the present invention, an electrostatic image carrier is charged by a charging means, and the charged electrostatic image carrier is exposed to form an electrostatic image on the electrostatic image carrier. A toner image is formed on an electrostatic image carrier by developing with a developing means having a two-component developer, and the toner image on the electrostatic image carrier is transferred via an intermediate transfer member or without an intermediate transfer member. The two-component developer used in an electrophotographic apparatus having an atmosphere heater capable of heating and controlling the inside of the apparatus, wherein the two-component developer is transferred to a material and the toner image on the transfer material is fixed by a heating and pressing fixing means. A two-component developer having an electrophotographic carrier containing specific water and a toner, wherein the toner has an average circularity of 0.960 or more.

According to a third aspect of the present invention, an electrostatic image carrier is charged by charging means, the charged electrostatic image carrier is exposed to form an electrostatic image on the electrostatic image carrier, and the electrostatic image is formed. A toner image is formed on an electrostatic image carrier by developing with a developing means having a two-component developer, and the toner image on the electrostatic image carrier is transferred via an intermediate transfer member or without an intermediate transfer member. An electrophotographic apparatus having an atmosphere heater capable of heating and controlling the inside of the apparatus, which transfers the toner image on the transfer material and fixes the toner image on the transfer material by heating and pressing fixing means, wherein the specific moisture described above is contained. The present invention relates to an image forming apparatus using a two-component developer comprising an electrophotographic carrier and a toner having the above-mentioned specific average circularity.

[0029]

BEST MODE FOR CARRYING OUT THE INVENTION As a result of intensive studies by the present inventors,
Developing means for charging the electrostatic image carrier by charging means, exposing the charged electrostatic image carrier to form an electrostatic image on the electrostatic image carrier, and developing the electrostatic image on a two-component developer To form a toner image on the electrostatic image carrier, and transfer the toner image on the electrostatic image carrier to the transfer material with or without the intermediate transfer member, and An electrophotographic apparatus having an atmosphere heater capable of heating and controlling the inside of the apparatus for fixing a toner image by a heating and pressing fixing unit has a carrier core in which metal compound particles are dispersed in a binder resin. In the dispersion type carrier having the carrier core surface coated with resin, the carrier 2
The water adsorption amount TL (mass%) after standing in a 3 ° C., 5% RH environment preferably satisfies 1.1 × 10 ⁻⁴ ≦ TL / Sm, and preferably 3% of the carrier.
The relationship between the water adsorption TH (mass%) after being left in a 0 ° C. and 80% RH environment and the surface area Sm (cm ² / g) of the carrier is as follows: 6.0 × 10 ⁻⁴ ≦ TH / Sm TL ≦ TH The carrier preferably satisfies the following relationship: 6.0 × 10 ⁻⁴ ≦ TH / Sm ≦ 1.5 × 10 ⁻³ 1.1 × 10 ⁻⁴ ≦ TL / Sm ≦ 5 It has been found that satisfying 0.5 × 10 ^-4 can provide good image quality over a long period of time.

The details will be described below.

When the TL / Sm, which is the amount of water adsorbed per unit surface area of the carrier after being left in an environment of 23 ° C. and 5% RH, is less than 1.1 × 10 ⁻⁴ , the excess is particularly high in a low humidity environment. This causes a charge-up phenomenon that causes the toner to be charged, resulting in a decrease in image density. In an extreme case, the charge accumulated in the carrier hardly leaks and is supplied to the developing device. In some cases, the charged toner is not properly charged, causing an image defect called charge-up fog. Further, the toner may be charged with a substance such as the inner wall of the developing device, and the charge amount of the toner which should be originally provided may be non-uniform.
In addition, image defects such as edge enhancement and electrostatic adhesion of external additives are likely to occur.

More preferably, TL / Sm is 5.5 × 1
If it is less than 0 ^-4 and more than that, it is considered that most of the water is retained inside rather than the surface of the carrier. As a result, the strength of the carrier itself is weak, and it is likely that a stable image cannot be obtained for a long period of time.

Further, when TH / Sm is less than 6.0 × 10 ⁻⁴ , particularly in a high temperature environment, heat generation due to mechanical impact in the developing device cannot be suppressed, and toner spent tends to occur. More preferably, TL ≦ TH and T
When the H / Sm is 1.5 × 10 ⁻³ or less, if the H / Sm is more than 1.5 × 10 ⁻³ , the toner may not be properly charged due to an excessive amount of adsorbed water, and as a result, an image such as fog and scattering may occur. In addition to the occurrence of defects, the developing bias leaks through moisture, disturbing the electrostatic latent image drawn on the photosensitive drum, and may cause image defects.

As a method for adjusting the water content of the carrier, the following methods (A) to (C) can be mentioned. (A) For example, a method in which hydrophilic and hydrophobic organic functional groups are contained in an appropriate amount on the carrier surface. (B) For example, a method in which an organic / inorganic fine particle layer having high hydrophilicity and hydrophobicity is adhered to a carrier surface in an appropriate amount. (C) For example, when forming a coating layer of a resin accompanied by a curing reaction such as a silicone resin on the surface of a carrier core material, (i) flowing humidified nitrogen, and (ii) degassing under reduced pressure. Or (iii) a polar solvent such as alcohol, or a mixture of the polar solvent and water added thereto, which is preliminarily adapted to the carrier core, thereby controlling the water content of the carrier core material immediately before coating, and thereby reacting the coating material. A method of controlling the speed and controlling the functional groups on the carrier surface.

In the present invention, at 30 ° C. and 80 ° C.
% RH after leaving in a 5% RH environment, and the amount of water adsorption TH (mass%) after leaving in a% RH environment.
The measurement of L (% by mass) was performed by the following measurement method.

<Measurement Method of Water Adsorption Amount T> The water content was measured by Karl Fischer coulometric titration of a carrier left in each environment for 24 hours or more. The measuring equipment is AQ-, an automatic heating vaporized moisture measuring system manufactured by Hiranuma Sangyo Co., Ltd.
6, SE-24 was used.

First, a carrier obtained by washing a toner and a fresh carrier before mixing or a toner in an initial developer not subjected to an image-drawing test with water to which a surfactant such as contaminone is added. And 24
After vacuum drying for at least h, completely remove water.

Thereafter, the carrier from which water has been removed is replaced with 30
The sample was left in an environment of 80 ° C. and 80% RH or 23 ° C. and 5% RH, and 0.8 g of a completely conditioned sample was precisely weighed in a glass 20 cc sample tube, and a lid coated with fluorine grease was applied. do. At this time, in order to correct the amount of moisture contained in the air, when the above-mentioned lid is put on, one empty sample tube covered with the same type of packing is prepared at the same time. These were titrated, and the measured value of the sample tube containing the sample in the obtained measured value was subtracted from the measured value of the empty sample tube.
Shows the water content of the sample. The value obtained by dividing the water content of the sample by the weighed value of the sample and multiplying by 100 is the water content of the sample. Titration conditions are as follows: heating temperature = 120 ° C., carrier gas (nitrogen gas) flow rate = 0.2 L / min, Blow gas flow rate = 0.3 L / min, INTERVAL = 30 seconds. At the time of titration, Hydranal Aqualite AG manufactured by Riedel de Heen (Germany) was used as a generated liquid, and Hydranal Aqualite CG manufactured by Riedel de Heen (Germany) was used as a counter electrode.

In the present invention, the surface area Sm of the carrier
(Cm ² / g) and 50% particle size were measured by the following measurement methods.

<Measurement Method of Carrier Surface Area Sm> The measurement of the carrier surface area Sm by spherical approximation is performed by a dry disperser (Rodos <RO) manufactured by SYNPATEC.
The measurement was performed at a feed air pressure of 3 bar and a suction pressure of 0.1 bar using a laser diffraction particle size distribution analyzer (HEROS <HELOS>) equipped with DOS>). The 50% particle size and the particle size distribution based on the volume of the carrier particles were also measured by this apparatus.

The carrier has a 50% particle size (D) on a volume basis, preferably 15 to 60 μm, more preferably 25 to 50 μm. Further careers
The content of particles having a particle size of 2/3 or less (2D / 3 ≧) of the 50% particle size is preferably 5% by volume or less, more preferably 0.1 to 5% by volume or less.

When the 50% particle size of the carrier is less than 15 μm, it may not be possible to sufficiently prevent the carrier from adhering to the non-image area due to particles on the fine particle side of the particle size distribution of the carrier. When the 50% particle size of the carrier is larger than 60 μm, the density of the magnetic brush tends to be impaired, which may cause image unevenness.

The particle size distribution of the carrier of the present invention is 50
When the content of particles having a particle size of not more than 2/3 of the% particle size exceeds 5% by volume, there is a tendency that carrier adhesion due to fine powder of the carrier occurs.

In the present invention, the volume resistivity of the carrier is preferably from 1 × 10 ⁸ to 1 × 10 ¹⁶ Ω · cm, more preferably from 1 × 10 ⁹ to 1 × 10 ¹⁵ Ω · c.
m is good.

The volume resistivity of the carrier is 1 × 10 ⁸ Ω · c
If it is less than m, the carrier tends to adhere to the surface of the photoreceptor, causing damage to the photoreceptor or causing image defects due to being directly transferred onto paper. Further, the developing bias may leak through the carrier and disturb the electrostatic latent image drawn on the photosensitive drum.

The volume resistivity of the carrier is 1 × 10 ¹⁶ Ω · c
If m exceeds m, a sharp edge-enhanced image is likely to be formed, and furthermore, the charge on the carrier surface is hard to leak, so that the image density can be reduced due to the charge-up phenomenon and the charge can be applied to newly replenished toner. In some cases, fogging and scattering may occur due to disappearance. Furthermore, it becomes charged with substances such as the inner wall of the developing device,
In some cases, the charge amount of the toner, which should be given, becomes non-uniform. In addition, such as electrostatic adhesion of external additives
Easy to cause image defects.

The measurement of the volume resistance value of the carrier was carried out using an insulation resistance measuring device for powder manufactured by Vacuum Riko Co., Ltd.
The measurement conditions were as follows: a carrier left for 24 hours or more under the conditions of 23 ° C. and 60% was placed in a measurement cell having a diameter of 20 mm (0.283 cm ² ), and was sandwiched between load electrodes of 120 g / cm ² .
The thickness was 2 mm and the applied voltage was measured at 500 V.

The magnetic properties of the carrier are 1000 / 4π
(KA / m) is preferably 20 to 10
0 (Am ² / kg), more preferably 30 to 65 (Am ² / kg)
/ Kg).

The carrier has a magnetization intensity of 100 (Am ² /
(kg), the density of the magnetic brush formed on the developing sleeve at the developing electrode decreases, the spike length increases, and the rigidity increases, although it depends on the carrier particle size. Sweep unevenness is likely to occur, and particularly, the durability of the developer is likely to deteriorate due to copying or printing a large number of sheets.

The carrier has a magnetization intensity of 20 (Am ² / k
If the value is less than g), the magnetic force of the carrier is reduced even if the carrier fine powder is removed, the carrier is likely to adhere, and the toner transportability is likely to be reduced.

The measurement of the magnetic characteristics of the carrier was performed by using an oscillating magnetic field type automatic magnetic characteristics recording apparatus BHV-3 manufactured by Riken Denshi KK
5 was performed. As the measurement conditions, an external magnetic field of 1000 / 4π (kA / m) was created for the magnetic characteristics of the carrier powder, and the magnetization intensity at that time was determined. The carrier is packed in a cylindrical plastic container so that the carrier particles are tightly packed so that the carrier particles do not move, the magnetization moment is measured in this state, and the actual mass when the sample is placed is measured. And the intensity of magnetization (Am ² / kg).

In the present invention, examples of the metal compound particles used for the carrier core include magnetite or ferrite having magnetism represented by the following formula (1) or (2).

MO.Fe ₂ O ₃ ... (1) M.Fe ₂ O ₄ ... (2) (In the formula, M represents a trivalent, divalent or monovalent metal ion.)

As M, Mg, Al, Si, Ca, S
c, Ti, V, Cr, Mn, Fe, Co, Ni, Cu,
Zn, Sr, Y, Zr, Nb, Mo, Cd, Sn, B
a, Pb, and Li, which can be used alone or in combination.

Specific examples of the compound of the metal compound particles having magnetism include magnetite, Zn--Fe
Ferrite, Mn-Zn-Fe ferrite, Ni-
Zn-Fe ferrite, Mn-Mg-Fe ferrite, Ca-Mn-Fe ferrite, Ca-Mg-Fe
Ferrite, Li-Fe ferrite and Cu-Zn
And iron-based oxides such as Fe-based ferrite.

Further, in the present invention, as the metal compound particles used for the carrier core, a mixture of the above magnetic metal compound and the following nonmagnetic metal compound may be used.

As the non-magnetic metal compound, for example, A
l ₂ O ₃ , SiO ₂ , CaO, TiO ₂ , V ₂ O ₅ , CrO,
MnO ₂ , α-Fe ₂ O ₃ , CoO, NiO, CuO, Z
nO, SrO, include Y ₂ O ₃ and ZrO _2. In this case, one kind of metal compound can be used, but it is particularly preferable to use a mixture of at least two or more kinds of metal compounds. In this case, it is more preferable to use particles having similar specific gravities and shapes in order to increase the adhesion to the binder resin and the strength of the carrier core particles.

Specific examples of the combination include magnetite and hematite, magnetite and γ-Fe
₂ O ₃ , magnetite and SiO ₂ , magnetite and Al ₂ O
_3, magnetite and TiO _2, magnetite and Ca-Mn
-Fe-based ferrite, magnetite and Ca-MgFe-based ferrite can be preferably used. Among them, a combination of magnetite and hematite can be particularly preferably used.

When the above-described magnetic metal compound is used alone or in combination with a non-magnetic metal compound, the number average particle diameter of the magnetic metal compound is determined by the number average particle diameter of the carrier core. It is preferably 0.02 to 2 μm, and more preferably 0.05 to 1 μm.

When the number average particle diameter of the metal compound exhibiting magnetism is less than 0.02 μm, it becomes difficult to obtain preferable magnetic properties. The number average particle size of the magnetic metal compound is 2
When it exceeds μm, it is difficult to obtain a carrier having a preferable range of particle size having high strength due to non-uniform granulation.

When a mixture of a magnetic metal compound and a nonmagnetic compound is used, the number average particle size of the nonmagnetic metal compound is preferably 0.05 to 5 μm, more preferably 0.1 to 3 μm. Good to be. In this case, the number average particle diameter (average particle diameter ra) of the metal compound having magnetism,
The particle size ratio (rb / ra) to the number average particle size (average particle size rb) of the nonmagnetic metal compound is preferably 1.0 to 5.0.
0, more preferably 1.2 to 5.0.

The number average particle diameter of the non-magnetic metal compound is 0.1.
When the thickness is less than 05 μm, favorable resistance cannot be obtained, and the carrier tends to adhere. When the number average particle diameter of the nonmagnetic metal compound exceeds 5 μm, it is difficult to obtain a carrier having a preferable particle diameter due to uneven granulation.

Further, when rb / ra is less than 1.0, ferromagnetic metal compound particles having low specific resistance tend to emerge on the surface, it is difficult to increase the specific resistance of the carrier core, and the effect of preventing carrier adhesion is obtained. It is difficult to obtain. When rb / ra exceeds 5, the strength of the carrier tends to decrease, and the carrier is likely to be destroyed.

The number average particle diameter of the metal oxide was measured by a transmission electron microscope H-800 manufactured by Hitachi, Ltd.
Using a photographic image magnified 00 to 20000 times, 300 or more particles having a particle size of 0.01 μm or more were randomly extracted, and an image processing analysis device Luzex3 manufactured by Nireco Co., Ltd. was used.
Was measured as the metal oxide particle size with the Feret diameter in the horizontal direction, and averaged to calculate the number average particle size.

The volume resistivity of the metal compound dispersed in the binder resin is preferably such that the volume resistivity of the metal compound particles having magnetism is in the range of 1 × 10 ³ Ω · cm or more. When a mixture of a metal compound and a non-magnetic compound is used, the volume resistivity of the magnetic metal compound particles is preferably in a range of 1 × 10 ³ Ω · cm or more,
The other non-magnetic metal compound particles preferably have a higher volume resistivity than the magnetic metal compound particles, and preferably have a volume resistivity of 1 × 10 ⁸ Ω for the non-magnetic metal compound used in the present invention. Cm or more, more preferably 1 × 10 ¹⁰ Ω · cm or more.

If the volume resistivity of the magnetic metal compound particles is less than 1 × 10 ³ Ω · cm, it is difficult to obtain a desired high volume resistivity even if the content is reduced, resulting in charge injection.
It is easy to cause deterioration of image quality and carrier adhesion. When a mixture of a magnetic metal compound and a nonmagnetic compound is used, the volume resistivity of the nonmagnetic metal compound is 1 × 1.
If it is less than 0 ⁸ Ω · cm, the volume resistance of the magnetic carrier core will be low, and it will be difficult to obtain the effects of the present invention.

In the present invention, the method of measuring the volume resistance of the magnetic metal compound and the non-magnetic metal compound is performed according to the method of measuring the volume resistance of the carrier particles.

In the carrier core of the present invention, the content of the metal compound is preferably 80 to the carrier core.
The content is preferably up to 99% by mass.

When the content of the metal compound is less than 80% by mass, the chargeability tends to be unstable, and the carrier is charged particularly in a low-temperature and low-humidity environment, and the residual charge tends to remain. And an external additive easily adhere to the surface of the carrier particles, and a proper specific gravity cannot be obtained. If the content of the metal compound exceeds 99% by weight, the strength of the carrier is reduced, and problems such as cracking of the carrier due to durability are likely to occur.

In a preferred embodiment of the present invention, in the carrier core containing a mixture of a magnetic metal compound and a non-magnetic compound, the content of the magnetic metal compound in the entire metal compound is preferably set. The content is preferably 50 to 95% by mass, more preferably 60 to 95% by mass.

When the content of the metal compound having magnetism in the whole metal compound is less than 50% by mass, the resistance of the core is improved, but the magnetic force as a carrier is reduced and the adhesion of the carrier is reduced. May be invited. If the content of the magnetic metal compound in the whole metal compound exceeds 95% by mass, depending on the specific resistance of the magnetic metal compound, it may not be possible to achieve a more desirable high core resistance.

The binder resin of the carrier core particles used in the present invention is a thermosetting resin, and a part or all of the binder resin is 3%.
It is preferable that the resin is a cross-linked resin. Thereby, the dispersed metal compound particles can be firmly bound, so that the strength of the carrier core can be increased, and the detachment of the metal compound hardly occurs even in a large number of copies,
Furthermore, the coating resin can be coated better,
As a result, it becomes easy to control the amount of adsorbed water within the range of the present invention.

The method for obtaining the magnetic material-dispersed carrier core is not particularly limited to the method described below, but in the present invention, a solution in which the monomer and the solvent are uniformly dispersed or dissolved is used. From the inside, the production method of the polymerization method of generating particles by polymerizing the monomer, particularly, by subjecting the metal oxide dispersed in the carrier core particles to lipophilic treatment, a sharp particle size distribution, fine powder A method for obtaining a small magnetic substance dispersed resin carrier core is as follows.
It is preferably used.

In the present invention, in the case of a carrier used in combination with a small particle size toner having a weight average particle size of 1 to 10 μm to achieve high image quality, the carrier particle size is also reduced according to the particle size of the toner. It is preferable to reduce the particle size, and the above-described production method is particularly preferable because even if the carrier particle size is reduced, a carrier having a small amount of fine powder can be produced regardless of the average particle size.

As the monomer used for the binder resin of the carrier core particles, a radical polymerizable monomer can be used. For example, styrene; o-methylstyrene,
Styrene derivatives such as m-methylstyrene, p-methoxystyrene, p-ethylstyrene, p-tert-butylstyrene; acrylic acid, methyl acrylate, ethyl acrylate, n-butyl acrylate, n-propyl acrylate, acrylic Isobutyl acid, octyl acrylate,
Dodecyl acrylate, 2-ethylhexyl acrylate,
Stearyl acrylate, 2-chloroethyl acrylate,
Acrylates such as phenyl acrylate; methacrylic acid, methyl methacrylate, ethyl methacrylate, n-propyl methacrylate, n-butyl methacrylate, isobutyl methacrylate, n-octyl methacrylate, dodecyl methacrylate, 2-methacrylic acid Ethylhexyl, stearyl methacrylate, phenyl methacrylate,
Methacrylic esters such as dimethylaminomethyl methacrylate, diethylaminoethyl methacrylate, and benzyl methacrylate; 2-hydroxyethyl acrylate, 2-hydroxyethyl methacrylate; acrylonitrile, methacrylonitrile, acrylamide; methyl vinyl ether, ethyl vinyl ether, propyl vinyl ether, vinyl ethers such as 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 and p-methoxyphenyl vinyl ether; butadiene And diene compounds such as

These monomers can be used alone or as a mixture, and a suitable polymer composition that can obtain preferable characteristics can be selected.

As described above, the binder resin of the carrier core particles is preferably three-dimensionally cross-linked. However, as a cross-linking agent for three-dimensionally cross-linking the binder resin,
It is preferable to use a crosslinking agent having two or more polymerizable double bonds per molecule. Examples of such a crosslinking agent include aromatic divinyl compounds such as divinylbenzene and divinylnaphthalene; ethylene glycol diacrylate, ethylene glycol dimethacrylate, triethylene glycol dimethacrylate, tetraethylene glycol dimethacrylate, and 1,3-butylene glycol. Dimethacrylate, trimethylolpropane triacrylate, trimethylolpropane trimethacrylate, 1,4-butanediol diacrylate, neopentyl glycol diacrylate, 1,6-hexanediol diacrylate, pentaerythritol triacrylate, pentaerythritol tetraacrylate, penta Erythritol dimethacrylate, pentaerythritol tetramethacrylate, glycerol Alkoxy dimethacrylate, N, N-divinyl aniline, divinyl ether, and a divinyl sulfide and divinyl sulfone. These may be used by mixing two or more kinds as appropriate. The cross-linking agent can be previously mixed with the polymerizable mixture, or can be added as needed during the polymerization.

Other monomers for the binder resin of the carrier core particles include bisphenols and epichlorohydrin as starting materials for the epoxy resin; phenols and aldehydes of the phenolic resin; ureas and aldehydes of the urea resin; melamine and aldehydes. No.

The most preferred binder resin is a phenolic resin. The starting materials are phenol, m
-Phenol compounds such as cresol, 3,5-xylenol, p-alkylphenol, resorcil, p-tert-butylphenol, and aldehyde compounds such as formalin, paraformaldehyde and furfural. Particularly, a combination of phenol and formalin is preferred.

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 resol resins can be used. Specific examples include amines such as aqueous ammonia, hexamethylenetetramine, diethyltriamine and polyethyleneimine.

In the present invention, the metal compound contained in the carrier core is subjected to lipophilic treatment to sharpen the particle size distribution of the magnetic carrier particles and prevent the metal compound particles from being detached from the carrier. Preferred above.
In the case of forming carrier core particles in which a lipophilic metal compound is dispersed, particles insoluble in a solution are generated at the same time as the polymerization reaction proceeds from a liquid in which a monomer and a solvent are uniformly dispersed or dissolved. At that time, it is considered that the metal oxide has an effect of uniformly and densely taking in the inside of the particles and an effect of preventing aggregation of the particles and sharpening the particle size distribution. Furthermore, when a metal compound subjected to lipophilic treatment is used, there is no need to use a suspension stabilizer such as calcium fluoride, and the suspension stabilizer remains on the carrier surface, thereby impairing the chargeability. It is possible to prevent the nonuniformity of the coating resin and the inhibition of the reaction when coating with a reactive resin such as a silicone resin. Also,
The elimination of the suspension stabilizer on the surface and the associated adverse effects facilitates controlling the amount of adsorbed water within the scope of the present invention.

In the lipophilic treatment, an organic compound having one or more functional groups selected from an epoxy group, an amino group and a mercapto group, or a lipophilic treatment agent which is a mixture thereof is used. Is preferred. In particular, an epoxy group is preferably used in order to easily achieve the range of the amount of adsorbed water of the present invention and to obtain a carrier having a stable charging ability.

The magnetic metal oxide particles are preferably treated with 0.1 to 10 parts by weight, more preferably 0.2 to 6 parts by weight, of the lipophilizing agent per 100 parts by weight of the magnetic metal oxide particles. It is preferable to increase the lipophilicity and hydrophobicity of the magnetic metal oxide particles.

Examples of the lipophilic treating agent having an epoxy group include γ-glycidoxypropylmethyldiethoxysilane, γ-glycidoxypropyltrimethoxysilane, β
-(3,4-epoxycyclohexyl) trimethoxysilane, epichlorohydrin, glycidol and styrene-glycidyl (meth) acrylate copolymer. Examples of the lipophilic treatment agent having an amino group include γ
-Aminopropyltrimethoxysilane, γ-aminopropylmethoxydiethoxysilane, γ-aminopropyltriethoxysilane, N-β (aminoethyl) -γ-aminopropyltrimethoxysilane, N-β (aminoethyl) -γ- Aminopropylmethyldimethoxysilane, N
-Phenyl-γ-aminopropyltrimethoxysilane,
Ethylenediamine, ethylenetriamine, styrene-
A dimethylaminoethyl (meth) acrylate copolymer and isopropyl tri (N-aminoethyl) titanate are used.

As the lipophilic treatment agent having a mercapto group, for example, mercaptoethanol, mercaptopropionic acid and γ-mercaptopropyltrimethoxysilane are used.

The resin for coating the surface of the carrier core is not particularly limited. Specifically, for example, polystyrene, acrylic resin such as styrene-acrylic copolymer, vinyl chloride, vinyl acetate, polyvinylidene fluoride resin, fluorocarbon resin, perfluorocarbon resin, solvent-soluble perfluorocarbon resin, polyvinyl alcohol, polyvinyl acetal, Polyvinyl pyrrolidone, petroleum resin, cellulose, cellulose derivative, novolak resin, low molecular weight polyethylene, saturated alkyl polyester resin, aromatic polyester resin, polyamide resin, polyacetal resin, polycarbonate resin, polyether sulfone resin, polysulfone resin, polyphenylene sulfide resin, poly Ether ketone resin, phenol resin, modified phenol resin, maleic resin, alkyd resin, epoxy resin, acrylic resin, anhydrous male Unsaturated polyester obtained by polycondensation of emissions and terephthalic acid and polyhydric alcohol, urea resins, melamine resins,
Urea-melamine resin, xylene resin, toluene resin, guanamine resin, melamine-guanamine resin, acetoguanamine resin, gliptal resin, furan resin, silicone resin, polyimide resin, polyamideimide resin, polyetherimide resin and polyurethane resin. it can.

Among them, silicone resins are preferably used from the viewpoint of adhesion to the core and prevention of spent. The silicone resin can be used alone, but is preferably used in combination with a coupling agent in order to increase the strength of the coating layer and control the charging to a preferable level. Further, the above-mentioned coupling agent is preferably used as a so-called primer agent, a part of which is treated on the carrier core surface before coating the resin, and the subsequent coating layer has a covalent bond. , Can be formed with higher adhesion.

As the coupling agent, aminosilane is preferably used. As a result, a positively chargeable amino group can be introduced into the carrier surface, and the toner can be favorably imparted with negative charge characteristics. Furthermore, the presence of the amino group activates both the lipophilic treatment agent preferably treated with the metal compound and the silicone resin, so that the adhesion between the silicone resin and the carrier core is further enhanced, and at the same time, the curing of the resin is performed. , A stronger coating layer can be formed.

During the coating treatment of the coating layer, the coating is preferably performed under a reduced pressure at a temperature of 30 ° C. to 80 ° C.

Although the reason is not clear, it is expected to be described in the following (1) to (3). (1) The water content of the carrier core is used to activate the resin, and the water content of the entire carrier can be appropriately controlled. (2) An appropriate reaction proceeds in the coating step, and the coating material is uniformly and smoothly coated on the carrier core surface. (3) In the baking step, low-temperature treatment at a temperature of at least 160 ° C. or less can be performed, and excessive crosslinking of the resin can be prevented, and the durability of the coating layer can be increased.

In the final step, 23 ° C., 60% R
It is preferable to perform a humidity control step by leaving the apparatus in a normal environment such as H for at least 24 hours or more. As a result, it is possible to quickly control the moisture that has disappeared by applying heat during the process to the configuration of the present invention. In addition, the so-called “self-charging of carrier”, which reduces the performance of applying toner to the toner due to the carrier itself retaining charge due to contact between carriers or contact with the walls of the device during the process, is reduced. This makes it possible to give a stable charge to the toner.

The toner for forming the two-component developer in combination with the above-mentioned carrier contains at least a binder resin for a toner and a colorant, and has a weight average particle diameter of 3 to 10 μm, preferably 3 to 10 μm. ８8 μm,
Especially effective. When the weight average particle size of the toner is less than 3 μm, problems such as charge-up are likely to occur particularly in a low-humidity environment, and the effect of using the carrier of the present invention is not sufficiently obtained. Also has low handling properties as a powder. If the weight average particle diameter of the toner exceeds 10 μm, problems such as scattering and fogging are likely to occur particularly under high temperature and high humidity, and the effect of using the carrier of the present invention cannot be sufficiently obtained. Further, since one toner particle becomes large, it is difficult to obtain a high-resolution and dense image. Further, when electrostatic transfer is performed, toner scattering is likely to occur.

The measurement of the average particle size and the particle size distribution of the toner is as follows.
It went as follows.

0.1 to 5 ml of a surfactant (alkylbenzene sulfonate) is added to 100 to 150 ml of the electrolyte solution.
And 2 to 20 mg of a measurement sample is added thereto. The electrolytic solution in which the sample is suspended is subjected to dispersion treatment for 1 to 3 minutes using an ultrasonic disperser, and the volume is measured using a Coulter Counter Multisizer (manufactured by Coulter) using an aperture appropriately adjusted to a toner size such as 17 μm or 100 μm. And a particle size distribution of 0.3 to 40 μm is measured. The number average particle diameter and the weight average particle diameter measured under these conditions are obtained by computer processing, and the cumulative ratio of the number average particle diameter smaller than 1/2 times the diameter cumulative distribution is calculated from the number-based particle diameter distribution,
A cumulative value equal to or smaller than the 1/2 diameter cumulative distribution is obtained. Similarly, a cumulative ratio equal to or larger than the double diameter cumulative distribution of the weight average particle diameter is calculated from the volume-based particle size distribution, and a cumulative value equal to or larger than the double diameter cumulative distribution is obtained.

The toner to be combined with the carrier of the present invention is particularly effective when at least a polyester resin is contained as a binder resin of the toner.
That is, the polyester resin is excellent in fixing property and color mixing property, and is particularly preferably used as a binder resin for a color toner. I was However, when used in combination with the carrier of the present invention, it is possible to suppress excessive charging of the toner and obtain excellent developability.

Other binder resins for the toner include polystyrene; high molecular compounds obtained from styrene derivatives such as poly-p-chlorostyrene and polyvinyltoluene;
Styrene-p-chlorostyrene copolymer, styrene-vinyltoluene copolymer, styrene-vinylnaphthalene copolymer, styrene-acrylate copolymer, styrene-methacrylate copolymer, styrene-α-
Styrene copolymers such as methyl chloromethacrylate copolymer, styrene-acrylonitrile copolymer, styrene-vinyl methyl ketone copolymer, styrene-butadiene copolymer, styrene-isoprene copolymer, styrene-acrylonitrile-indene copolymer Polymer; polyvinyl chloride, phenolic resin, modified phenolic resin, maleic resin, acrylic resin, methacrylic resin, polyvinyl acetate,
Silicone resin; Polyester resin having a monomer selected from aliphatic polyhydric alcohol, aliphatic dicarboxylic acid, aromatic dicarboxylic acid, aromatic dialcohols and diphenols as a structural unit; polyurethane resin, polyamide resin, polyvinyl Butyral, terpene resin, cumarone indene resin, petroleum resin.

Further, the toner has an average circularity of 0.960.
This is one feature.

In a toner having an average circularity of less than 0.960, the change in the fluidity of the developer is likely to be large,
In a long-term durability test, the charge amount easily changes. A toner having an average circularity within the above range has a high transfer efficiency on paper and a small amount of toner placed on the photoreceptor,
Since the same density as that of the conventional toner can be obtained, it is advantageous in terms of cost. In addition, since the toner easily rolls on the carrier and the packing density of the developer tends to be high, there are many chances of contact with the carrier, and it is easy to always maintain stable charge.

The average circularity in the present invention is used as an index for quantitatively expressing the shape of a particle. In the present invention, a flow-type particle image analyzer “FPIA-1000” manufactured by Toa Medical Electronics Co., Ltd. is used. The circularity (ai) of the measured particles is determined by the following equation (3), and the sum of the circularities of all the particles measured as shown by the following equation (4) is calculated as the total number of particles (m ) Is divided by the average circularity (a
m).

[0100]

## EQU00001 ## Circularity (ai) = L0 / L Equation (3) (where L0 represents the circumference of a circle having the same projection area as the toner particle image, and L represents the circumference of the projection image of the toner particle). Shown.)

[0101]

(Equation 2)

The measuring apparatus used in the present invention, “F
After calculating the circularity of each particle, the PIA-1000 calculates the average circularity, divides the circularity from 0.40 to 1.00 into 61 classes by the obtained circularity, and calculates the division points. The calculation method of calculating the average circularity using the center value and frequency of is used. However, the error between each value of the average circularity calculated by this calculation method and each value of the average circularity calculated by the above-described calculation formula directly using the circularity of each particle is extremely small, and is substantially small. Is negligible, and in the present invention, for the reason of handling data such as shortening of calculation time and simplification of calculation operation expression, the above-described calculation expression using the circularity of each particle directly is used. Such a calculation method partially modified using the concept may be used. The measurement procedure is as follows.

A dispersion was prepared by dispersing about 5 mg of magnetic toner in 10 ml of water in which about 0.1 mg of a surfactant was dissolved, and the dispersion was irradiated with ultrasonic waves (20 kHz, 50 W) for 5 minutes. With the liquid concentration being 5,000 to 20,000 / μl, measurement is carried out by the above-mentioned apparatus, and the average circularity and mode circularity of a group of particles having a circle equivalent diameter of 3 μm or more are determined.

The average circularity in the present invention is an index of the degree of unevenness of the magnetic toner. The average circularity is 1.000 when the magnetic toner has a perfect spherical shape. It will be a small value.

As the binder resin used in the toner, the following binder resins can be used.

For example, homopolymers of styrene and its substituted substances such as polystyrene, poly-p-chlorostyrene and polyvinyl toluene; styrene-p-chlorostyrene copolymer, styrene-vinyltoluene copolymer, styrene-
Vinyl naphthalene copolymer, styrene-acrylic ester copolymer, styrene-methacrylic ester copolymer, styrene-α-chloromethyl methacrylate copolymer, styrene-acrylonitrile copolymer, styrene-
Styrene such as vinyl methyl ether copolymer, styrene-vinyl ethyl ether copolymer, styrene-vinyl methyl ketone copolymer, styrene-butadiene copolymer, styrene-isoprene copolymer, styrene-acrylonitrile-indene copolymer -Based copolymer; polyvinyl chloride; phenolic resin; natural modified phenolic resin; natural resin modified maleic resin; acrylic resin; methacrylic resin; polyvinyl acetate; silicone resin; polyester resin; polyurethane; polyamide resin; furan resin; A xylene resin; a polyvinyl butyral; a terpene resin; a cumarone indene resin; Preferred binder resins include styrene copolymers and polyester resins. Further, a crosslinked styrene resin is also a preferable binder resin.

A styrene monomer and a styrene comonomer are used as the polymerizable monomer of the styrene copolymer.
For example, acrylic acid, methyl acrylate, ethyl acrylate, butyl acrylate, dodecyl acrylate, octyl acrylate, 2-ethylhexyl acrylate, phenyl acrylate, methacrylic acid, methyl methacrylate,
Ethyl methacrylate, butyl methacrylate, octyl methacrylate, acrylonitrile, methacrylonitrile,
Monocarboxylic acid having a double bond such as acrylamide or a substitute thereof; for example, dicarboxylic acid having a double bond such as maleic acid, butyl maleate, methyl maleate, and dimethyl maleate; Vinyl chloride, vinyl acetate, vinyl esters such as vinyl benzoate, for example, ethylene, propylene,
Vinyl monomers such as ethylene olefins such as butylene; vinyl ketones such as vinyl methyl ketone and vinyl hexyl ketone; vinyl ethers such as vinyl methyl ether, vinyl ethyl ether and vinyl isobutyl ether; Used alone or in combination.

In the present invention, the TH of the binder resin of the toner is
The number average molecular weight of the F-soluble component is preferably 3,000 to 1,000,000 (more preferably, 6,000 to 200,000).

In the present invention, the THF-soluble component of the toner is prepared as follows.

Using a Soxhlet extractor for the toner in advance,
Extraction is performed with a toluene solvent for 20 hours, and the obtained extract is distilled off with a rotary evaporator to remove toluene, and then dissolved in tetrahydrofuran (THF). A sample obtained by filtering the THF-soluble matter thus obtained through a solvent-resistant membrane filter having a pore diameter of 0.3 μm,
Waters 150C was used, and the column configuration was Showa Denko A-801, 802, 803, 804, 805, 8
06,807, and the number average molecular weight of the THF soluble component can be determined by measuring the molecular weight distribution using a standard polystyrene resin calibration curve.

The styrene-based polymer or styrene-based copolymer may be cross-linked, or may be a mixed resin of a cross-linked resin and a non-cross-linked resin.

As the crosslinking agent for the binder resin, a compound having mainly two or more polymerizable double bonds may be used. For example, aromatic divinyl compounds such as divinylbenzene and divinylnaphthalene; ethylene glycol diacrylate, ethylene glycol dimethacrylate,
Carboxylic acid esters having two double bonds such as 1,3-butanediol dimethacrylate; divinyl compounds such as divinylaniline, divinylether, divinylsulfide and divinylsulfone; and compounds having three or more vinyl groups. Can be These are used alone or as a mixture.

The amount of the crosslinking agent to be added may be as follows.
0.001 to 10 parts by mass relative to 00 parts by mass is preferred.

Further, the toner may contain a charge control agent.

The following substances control the toner to be negatively charged. For example, an organic metal compound and a chelate compound are effective, and further a monoazo metal compound, an acetylacetone metal compound, an aromatic hydroxycarboxylic acid,
Aromatic dicarboxylic acid-based metal compounds are preferably used. Further, aromatic hydroxycarboxylic acids, aromatic mono- and polycarboxylic acids and their metal salts, their anhydrides, their esters, their phenol derivatives such as bisphenol; urea derivatives; metal-containing salicylic acid-based compounds; Metal naphthoic acid compound; Boron compound; Quaternary ammonium salt; Calixarene; Silicon compound; Styrene-acrylic acid copolymer; Styrene-methacrylic acid copolymer; Styrene-acryl-sulfonic acid copolymer; Compounds.

The following substances control the toner to be positively charged.

Modified products such as nigrosine and fatty acid metal salts, guanidine compounds, imidazole compounds, quaternary ammonium salts such as tributylbenzylammonium-1-hydroxy-4-naphthosulfonate, tetrabutylammonium tetrafluoroborate, and the like; Onium salts such as phosphonium salts, which are analogs, and their lake pigments, triphenylmethane dyes and these lake pigments (phosphor tungstic acid,
Phosphomolybdic acid, phosphotungsten molybdic acid, tannic acid, lauric acid, gallic acid, ferricyanide,
Ferrocyanide), metal salts of higher fatty acids; diorganotin oxides such as dibutyltin oxide, dioctyltin oxide and dicyclohexyltin oxide; diorganotin borates such as dibutyltin borate, dioctyltin borate and dicyclohexyltin borate; Or two or more types can be used in combination. Of these, charge control agents such as nigrosine and quaternary ammonium salts are particularly preferably used.

These charge control agents are used in an amount of 0.01 to 20 parts by mass, preferably 0.1 to 10 parts by mass, more preferably 0.2 to 4 parts by mass based on 100 parts by mass of the resin component of the toner. Is good.

As the colorant of the toner used in the present invention, carbon black, a magnetic material, and those prepared in black using the following yellow / magenta / cyan colorants as black colorants are used.

Examples of the yellow colorant include condensed azo compounds, isoindolinone compounds, anthraquinone compounds,
A compound represented by an azo metal complex, a methine compound, or an allylamide compound is used. Specifically, C.I. I. Pigment Yellow 12, 13, 14, 15, 17, 6
2, 74, 83, 93, 94, 95, 109, 110,
111, 128, 129, 147, 168 or 180 are preferably used. Further, C.I. I. Dyes such as Solvent Yellow 93 and 162 may be used in combination.

Examples of the magenta coloring agent include condensed azo compounds, diketopyrrolopyrrole compounds, anthraquinones, quinacridone compounds, basic dye lake compounds, naphthol compounds, benzimidazolone compounds, thioindigo compounds, and perylene compounds. Specifically, C.I.
I. Pigment Red 2, 3, 5, 6, 7, 23, 4
8: 2, 48: 3, 48: 4, 57: 1, 81: 1, 1
44, 146, 166, 169, 177, 184, 18
5, 202, 206, 220, 221 or 254 are preferably used.

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

These colorants can be used alone or as a mixture and in the form of a solid solution. The coloring agent of the present invention,
It is selected from the viewpoint of hue angle, saturation, lightness, weather resistance, OHP transparency, and dispersibility in toner. The amount of the colorant added is
It is used by adding 1 to 20 parts by mass to 100 parts by mass of the resin.

The toner particles contain 1 to 40 solid waxes.
It is suitable that the content is contained by mass%, preferably 2 to 30 mass%. If the amount of the wax is less than 1% by mass, the effect of suppressing the offset is small. If the amount of the wax exceeds 40% by mass, the toner is unevenly distributed on the toner surface, and the sleeve is easily contaminated. And the change in image density tends to be large.

Preferred waxes have a weight average molecular weight (Mw) / number average molecular weight (Mn) of 1.45 or less and a solubility parameter of 8.4 in a molecular weight distribution measured by gel permeation chromatography (GPC). By using a wax of from 10.5 to 10.5, the toner is excellent in fluidity, a uniform fixed image without uneven gloss can be obtained, and further, contamination of the heating member of the fixing device and deterioration of storage stability are hardly caused, and the fixing property is improved. Excellent light transmittance of the fixed image, and when creating a full-color OHP with excellent transparency by melting the toner, a part or all of the wax moderately coats the heating member, without offsetting the toner, In addition to being able to produce full-color OHP and exhibiting good low-temperature fixability, it is also possible to achieve a longer life of the press-contact member. .

The wax contained in the toner used in the present invention has a weight average molecular weight (Mw) / number average molecular weight (Mn) of 1.45 or less, and preferably 1.45 or less, in the molecular weight distribution by GPC using a double column. A value of 30 or less is more preferable in terms of uniformity of the fixed image, good transferability of the toner, and prevention of contamination of the contact charging unit for charging by contacting the photoconductor.

When the value of Mw / Mn of the wax exceeds 1.45, the fluidity of the toner decreases, and
Gloss unevenness of the fixed image is apt to occur, and further, the transferability of the toner is deteriorated and the contact charging means is likely to be contaminated.

In the present invention, the molecular weight distribution of the wax is
It is measured under the following conditions by GPC using a double column.

(GPC Measurement Conditions) Apparatus: GPC-150C (manufactured by Waters) Column: GMH-HT 30 cm double (manufactured by Tosoh Corporation) Temperature: 135 ° C. Solvent: o-dichlorobenzene (addition of 0.1% ionol) Flow rate: 1 0.0 ml / min sample: 0.4 ml of a 0.15% concentration sample was injected. The measurement was carried out under the above conditions, and the molecular weight of the sample was calculated using a molecular weight calibration curve prepared from a monodisperse polyurethane standard sample. Further, the weight-average molecular weight and the number-average molecular weight are calculated by converting into a polyethylene using a conversion formula derived from the Mark-Houwink viscosity formula.

The melting point of the wax used in the present invention is 4
It is preferably from 0 to 150 ° C, particularly preferably from 50 to 120 ° C. If the melting point of the wax is lower than 40 ° C., the blocking resistance of the toner is weakened, the sleeve is easily contaminated when copying a large number of sheets, and when the image forming speed is changed, the coating of the developer becomes non-uniform and the image density becomes low. Unevenness is likely to occur. If the melting point of the wax exceeds 150 ° C,
Excessive energy is required for uniform mixing with the binder resin in the toner production method by the pulverization method, and in the production method of the toner by the polymerization method, the viscosity of the device is increased by increasing the viscosity in order to homogenize the binder resin. It is not preferable because it is difficult to contain a large amount of the compound because the amount of the compound to be converted or compatible is limited.

The melting point of the wax was determined according to ASTM D3418.
It is the temperature of the main peak value (main peak) value in the endothermic curve measured according to −8.

The measurement according to ASTM D3418-8 is performed by using, for example, DSC-7 manufactured by Perkin Elmer. The temperature correction of the device detection unit uses the melting point of indium zinc, and the correction of the calorific value uses the heat of fusion of indium. An aluminum pan was used as a sample, and an empty pan was set as a control.
The measurement is performed in the range of 00 ° C.

In the present invention, the melt viscosity of the wax used at 100 ° C. is preferably from 1 to 50 mPa · s, more preferably from 3 to 30 mPa · s.

When the melt viscosity of the wax is lower than 1 mPa · s, when the toner is developed using a magnetic carrier, the toner is liable to be damaged due to a shear force between the toner and the magnetic carrier. This tends to occur, and it tends to be difficult to always coat a stable amount of the developer at various image forming speeds. When the melt viscosity of the wax exceeds 50 mPa · s, when producing the toner using the polymerization method, the viscosity of the dispersoid is too high, and it is easy to obtain a toner having a fine particle diameter having a uniform particle diameter. And the toner tends to have a wide particle size distribution.

The measurement of the melt viscosity of the wax was performed by using HAAKE.
Cone-plate type rotor (PK
-1).

The wax used in the present invention is:
The molecular weight distribution measured by GPC has two or more peaks or one or more peaks and one or more shoulders, and in the molecular weight distribution, weight average molecular weight (Mw)
Is 200 to 2000, and the number average molecular weight (Mn) is 150 to
Preferably it is 2000. The above molecular weight distribution is
It has been found that any of a single wax or a plurality of waxes may be used, and as a result, crystallinity can be inhibited and transparency can be further improved. The method of blending two or more waxes is not particularly limited,
For example, a media type disperser (ball mill, sand mill, attritor,
It is also possible to perform melt blending using an apex mill, a coball mill, or a handy mill, or to dissolve a wax to be blended in a polymerizable monomer and blend with a media type dispersing machine. At this time, a pigment, a charge control agent, and a polymerization initiator may be used as additives.

The weight average molecular weight (Mw) of the wax is 20.
0-2000, number average molecular weight (Mn) 150-200
It is preferred that More preferably, Mw is 200-
1500, more preferably 300 to 1000, Mn is 200 to 1500, more preferably 250 to 1000.
Good to be. Mw of wax is less than 200 or M
If n is less than 150, the blocking resistance of the toner may decrease. When the Mw of the wax is more than 2,000 or the Mn is more than 2,000, the crystallinity of the wax itself may be exhibited, and the transparency may be reduced.

Examples of the wax that can be used in the present invention include paraffin wax, polyolefin wax, modified products thereof (eg, oxides and grafted products), higher fatty acids, metal salts thereof, amide waxes, and the like. And ester waxes.

Among them, higher quality full color OH
Ester wax is particularly preferred in that a P image can be obtained.

As a method for producing the ester wax preferably used in the present invention, for example, a synthesis method by an oxidation reaction, a synthesis from a carboxylic acid or a derivative thereof, and an ester group introduction reaction represented by a Michael addition reaction are used.

A particularly preferable method for producing the wax used in the present invention is a method utilizing a dehydration condensation reaction of a carboxylic acid compound and an alcohol compound represented by the following formula (5), from the viewpoint of variety of raw materials and ease of reaction. Or the following formula (6)
The reaction from a halogen compound and an alcohol compound represented by the formula (1) is particularly preferred.

[0142]

Embedded image [Wherein, R ₁ and R ₂ represent an organic group such as an alkyl group, an alkenyl group, an aralkyl group and an aromatic group, and n represents an integer of 1 to 4. The organic group has 1 to 50 carbon atoms, preferably 2 to 2 carbon atoms.
The number is preferably 45, more preferably 4 to 30, and further preferably linear. ]

In order to transfer the above-mentioned ester equilibrium reaction to the production system, the reaction is carried out using a large excess of alcohol or in a Dean-Stark water separator in an aromatic organic solvent capable of azeotropic distillation with water. . A method of synthesizing a polyester by adding a base as an acceptor of an acid by-produced in an aromatic organic solvent using an acid halide compound can also be used.

Next, a method for producing the toner used in the present invention will be described. The toner used in the present invention can be manufactured using a pulverized toner manufacturing method and a polymerized toner manufacturing method.

A method for producing a polymerized toner is described in JP-B-56-13.
No. 945, etc., a method of atomizing a molten mixture into air using a disk or other fluid nozzle to obtain a spherical toner, Japanese Patent Publication No. 36-10231, Japanese Patent Application Laid-Open No. 59-53
No. 856, JP-A-59-61842, a method of directly producing a toner using a suspension polymerization method, an aqueous organic solvent which is soluble in a monomer and insoluble in a polymer obtained. An emulsion polymerization method typified by a dispersion polymerization method in which a toner is directly produced using a water-soluble polar polymerization initiator or a soap-free polymerization method in which a toner is produced by directly polymerizing in the presence of a water-soluble polar polymerization initiator, or a method in which primary polar emulsion polymerization particles are prepared in advance. It is possible to produce a toner using a hetero-aggregation method in which polar particles having opposite charges are added and associated.

Among these, polymerized toner particles obtained by a method of directly polymerizing a monomer composition containing at least a polymerizable monomer, a colorant and a wax to form toner particles are preferred.

In the dispersion polymerization method, the obtained toner has an extremely sharp particle size distribution, but the production equipment is limited in view of the narrow selection of materials to be used and the use of organic solvents from the viewpoint of waste solvent treatment and solvent flammability. However, it is complicated and easily complicated. Therefore, a method of directly polymerizing a monomer composition containing at least a polymerizable monomer, a colorant and a wax in an aqueous medium to form toner particles is more preferable. However, the emulsion polymerization method represented by soap-free polymerization is effective because the particle size distribution of the toner is relatively uniform, but when the used emulsifier and the terminal of the initiator are present on the surface of the toner particles, the environmental characteristics are likely to deteriorate.

Accordingly, in the present invention, a suspension polymerization method under normal pressure or under pressure, which can easily obtain a fine particle toner having a sharp particle size distribution, is particularly preferable. A so-called seed polymerization method in which a monomer is further adsorbed onto the polymer particles once obtained and then polymerized using a polymerization initiator can also be suitably used in the present invention.

A preferred embodiment of the toner used in the present invention is a method in which a wax is encapsulated in an outer resin layer by a tomographic plane measurement method of a toner using a transmission electron microscope (TEM). From the viewpoint of fixability, it is necessary to incorporate a large amount of wax into the toner, and it is preferable to include the wax in the outer shell resin layer from the viewpoints of storage stability and fluidity of the toner. When the toner is not encapsulated, the wax cannot be dispersed uniformly, and as a result, the particle size distribution is widened, and the toner is easily fused to the mounting.

As a specific method of encapsulating the wax, the polarity of the material in the aqueous medium is set smaller than that of the main monomer in the wax, and a small amount of a resin or monomer having a large polarity is added. By doing so, a toner having a so-called core-shell structure in which wax is coated with an outer shell resin can be obtained. Toner particle size distribution control and particle size control
Methods and mechanical device conditions such as changing the type and amount of the hardly water-soluble inorganic salt or dispersant that acts as a protective colloid, such as stirring conditions such as the peripheral speed of the rotor, the number of passes, and the shape of the stirring blade, the shape of the container, or the aqueous solution The toner of the present invention can be obtained by controlling the solid concentration in the toner.

In the present invention, a specific method for measuring the tomographic plane of the toner is as follows: after sufficiently dispersing the toner in an epoxy resin which is curable at room temperature, and then dispersing the toner in an atmosphere at a temperature of 40 ° C.
The cured product obtained by curing for days, ruthenium tetroxide,
After dyeing with osmium tetroxide, if necessary, a flaky sample is cut out using a microtome provided with diamond teeth, and the tomographic morphology of the toner is measured using a transmission electron microscope (TEM). In the present invention, it is preferable to use a ruthenium tetroxide dyeing method in order to give a contrast between materials by utilizing a slight difference in crystallinity between the wax used and the resin constituting the outer shell.

In the case where a direct polymerization method is used in the method for producing a toner of the present invention, a toner can be specifically produced by the following production method. A wax, a colorant, a charge control agent, a polymerization initiator, and other additives are added to the monomer, and a monomer composition uniformly dissolved or dispersed by a homogenizer, an ultrasonic disperser, or the like is used as a dispersion stabilizer. The resulting aqueous phase is dispersed with a conventional stirrer or a stirrer such as a homomixer or a homogenizer.
Preferably, the stirring speed and time are adjusted so that the droplets of the monomer composition have the desired size of the toner particles, and the granulation is performed. Thereafter, by the action of the dispersion stabilizer, the stirring may be performed to such an extent that the particle state is maintained and the precipitation of the particles is prevented. The polymerization temperature is 40 ° C. or higher, generally 50 to 90 ° C.
The polymerization is carried out at a temperature set to. In addition, the temperature may be raised in the latter half of the polymerization reaction, and further in the latter half of the reaction or after the end of the reaction to remove unreacted polymerizable monomers and by-products that cause odor at the time of fixing the toner. Part of the aqueous medium may be distilled off. After completion of the reaction, the generated toner particles are collected by washing and filtration, and dried. In the suspension polymerization method, it is generally preferable to use 300 to 3000 parts by mass of water as a dispersion medium with respect to 100 parts by mass of the monomer composition.

The polymerizable monomer for directly obtaining a toner by a polymerization method includes styrene-based monomers such as styrene, o (m-, p-)-methylstyrene and m (p-)-ethylstyrene. Methyl (meth) acrylate, ethyl (meth) acrylate, propyl (meth) acrylate, butyl (meth) acrylate, octyl (meth) acrylate, dodecyl (meth) acrylate, stearyl (meth) acrylate, (Meth) acrylate monomers such as behenyl (meth) acrylate, 2-ethylhexyl (meth) acrylate, dimethylaminoethyl (meth) acrylate, and diethylaminoethyl (meth) acrylate; butadiene, isoprene, and cyclohexene And diene monomers such as (meth) acrylonitrile and acrylamide.

Examples of the polar resin used in the polymerization method of the toner include a polymer of a nitrogen-containing monomer such as dimethylaminoethyl methacrylate and diethylaminoethyl methacrylate, or a styrene-unsaturated carboxylic acid ester. Copolymers of the following; nitrile monomers such as acrylonitrile; halogen-containing monomers such as vinyl chloride; unsaturated carboxylic acids such as acrylic acid and methacrylic acid; unsaturated dibasic acids; unsaturated dibasic acid anhydrides A polymer of a nitro-based monomer or a copolymer of the same with a styrene-based monomer; a polyester; an epoxy resin. More preferred are a copolymer of styrene and (meth) acrylic acid, a copolymer of maleic acid, a saturated polyester resin, and an epoxy resin.

Examples of the polymerization initiator include, for example, 2,2′-
Azobis- (2,4-dimethylvaleronitrile), 2,
2′-azobisisobutyronitrile, 1,1′-azobis (cyclohexane-1-carbonitrile), 2,2 ′
Azo or diazo polymerization initiators such as azobis-4-methoxy-2,4-dimethylvaleronitrile and azobisisobutyronitrile; benzoyl peroxide, methyl ethyl ketone peroxide, diisopropyl peroxycarbonate, cumene hydroperoxide, t-butylhydro Peroxide, di-t-butyl peroxide, dixyl peroxide, 2,4-dichlorobenzoyl peroxide, lauroyl peroxide, 2,2-bis (4,4-t-butylperoxycyclohexyl) propane, tris- (t-butylperoxy) A peroxide initiator such as triazine; a polymer initiator having a peroxide in a side chain; a persulfate such as potassium persulfate and ammonium persulfate; and hydrogen peroxide are used. These can be used alone or in combination of two or more.

The amount of the polymerization initiator to be added is preferably 0.5 to 20 parts by mass based on 100 parts by mass of the polymerizable monomer.

In order to control the molecular weight, a known crosslinking agent or chain transfer agent may be added. The preferable addition amount is 0.001 to 100 parts by mass of the polymerizable monomer.
１５15 parts by mass.

A dispersion medium used for producing a polymerized toner by a polymerization method using emulsion polymerization, dispersion polymerization, suspension polymerization, seed polymerization, or hetero-aggregation method can be prepared by stabilizing an appropriate inorganic or organic compound. It is preferred to use agents. Examples of the inorganic compound stabilizer include, for example, tricalcium phosphate, magnesium phosphate, aluminum phosphate, zinc phosphate, calcium carbonate, magnesium carbonate,
Examples include calcium hydroxide, magnesium hydroxide, aluminum hydroxide, calcium metasilicate, calcium sulfate, barium sulfate, bentonite, silica, and alumina. Examples of organic compound stabilizers include polyvinyl alcohol, gelatin, methylcellulose, methylhydroxypropylcellulose, ethylcellulose, sodium salts of carboxymethylcellulose, polyacrylic acid and salts thereof, starch, polyacrylamide, polyethylene oxide, and poly (hydroxystearic acid). -G-methyl methacrylate-eu-methacrylic acid) copolymer and a nonionic or ionic surfactant.

When the emulsion polymerization method and the hetero-aggregation method are used, an anionic surfactant, a cationic surfactant,
Zwitterionic surfactants and nonionic surfactants are used. It is preferable to use 0.2 to 30 parts by mass of these stabilizers with respect to 100 parts by mass of the polymerizable monomer.

When an inorganic compound is used among these stabilizers, a commercially available one may be used as it is, but in order to obtain fine particles, the inorganic compound may be formed in a dispersion medium.

For finely dispersing these stabilizers, a surfactant may be used in an amount of 0.001 to 0.1 part by mass per 100 parts by mass of the polymerizable monomer. This surfactant is for promoting the stabilizing action of the dispersion stabilizer. Specific examples thereof include sodium dodecylbenzene sulfate, sodium tetradecyl sulfate, sodium pentadecyl sulfate, sodium octyl sulfate, sodium oleate, sodium laurate, potassium stearate, calcium oleate, and the like.

As the colorant used in the polymerization method toner in the present invention, it is necessary to pay attention to the polymerization inhibitory property and the water phase transfer property of the colorant. It is better to perform a hydrophobic treatment without any. In particular, many dyes and carbon blacks have polymerization inhibitory properties, so care must be taken when using them.
As a preferable method for surface-treating the dye system, a method in which a polymerizable monomer is previously polymerized in the presence of these dyes is mentioned, and the obtained colored polymer is added to the monomer system. The carbon black may be treated with a substance that reacts with the surface functional groups of the carbon black, such as polyorganosiloxane, in addition to the same treatment as the above dye.

The melting point of the wax used in the present invention is preferably from 40 to 150 ° C., more preferably from 50 to 120 ° C., as described above. It is higher than the glass transition temperature, and the temperature difference is preferably 100 ° C. or less, more preferably 75 ° C. or less, and further preferably 50 ° C. or less.

When this temperature difference exceeds 100 ° C.,
There is a tendency that the low-temperature fixability decreases. Further, if this temperature difference is too close, the temperature range in which the storage stability of the toner can be compatible with the high-temperature offset resistance becomes narrow,
Preferably, it is 2 ° C. or higher. From this, the glass transition temperature of the binder resin is preferably 40 to 90 ° C,
More preferably, it is good to be 50-85 degreeC.

When the glass transition temperature of the binder resin is lower than 40 ° C., the storage stability of the toner is lowered, the fluidity is deteriorated, and a good image tends not to be obtained. When the glass transition temperature of the binder resin exceeds 90 ° C., the low-temperature fixability is inferior and the transparency of full-color transparency is deteriorated. In particular, the halftone portion tends to be dull and a projection image without saturation is likely to be obtained.

The glass transition temperature (Tg) of the binder resin is A
The measurement is performed according to STM D3418-8. For example, this is performed using Perkin Elmer DSC-7. The temperature correction of the device detector uses the melting points of indium and zinc,
For the correction of the amount of heat, the heat of fusion of indium is used. For the sample, an aluminum pan was used, and an empty pan was set as a control, and the temperature was 20 to 200 ° C. at a heating rate of 10 ° C./min.
Measure within the range. Next, an external additive externally added to the toner particles will be described.

The toner used in the present invention contains fine particles of inorganic fine particles such as silica, alumina and titanium oxide; and fine powders of organic fine particles such as polytetrafluoroethylene, polyvinylidene fluoride, polymethyl methacrylate, polystyrene and silicone. It is preferable that it is done. By externally adding the above-described fine powder to the toner particles, the fine powder exists between the toner and the carrier or between the toner particles, so that the fluidity of the developer is improved and the life of the developer is also improved. I do. The average particle diameter of the fine powder described above is preferably 0.2 μm or less. When the number average particle diameter exceeds 0.2 μm, the effect of improving the fluidity is reduced, and the image quality may be deteriorated due to a defect at the time of development or transfer. The measurement of the number average particle size of these fine powders will be described later.

The surface area of these fine powders is BET
Specific surface area by nitrogen adsorption 30 m ² / g or more by law, is excellent particularly in the range of 5~400m ² / g. The addition amount of the fine powder is preferably 0.1 to 20 parts by mass with respect to 100 parts by mass of the toner particles.

In the negatively chargeable toner which is particularly preferably used in the present invention, it is preferable to use at least one kind of silica which has been subjected to a hydrophobic treatment from the viewpoint of chargeability. That is, since silica or titanium oxide has a higher negative charging property than a fluidizing agent such as alumina, the adhesion to the toner particles is high, and the amount of free external additives is reduced. Therefore, there is a tendency that filming on the electrostatic latent image carrier and that the external additive partially released is transferred to the carrier. Even in such a case, the polymerization carrier of the present invention can suppress the adhesion of the fluidizing agent because the surface irregularities and the like are uniform.

The inorganic fine particles are preferably subjected to a hydrophobic treatment in order to maintain the chargeability under high humidity. An example of the hydrophobic treatment is shown below.

One of the hydrophobizing agents is a silane coupling agent. The amount of the silane coupling agent is 1 to 40 parts by mass, preferably 2 to 35 parts by mass, per 100 parts by mass of the inorganic fine particles. good. When the amount is 1 to 40 parts by mass, the moisture resistance is improved and an aggregate is hardly generated.

Examples of the silane coupling agent used in the present invention include those represented by the following general formula (7).

[0173]

RmSiYn Formula (7) wherein R represents an alkoxy group or a chlorine atom, and m represents 1
Y represents a hydrocarbon group (for example, an alkyl group, a vinyl group, a glycidoxy group, and a methacryl group), and n is an integer of 3-1. ]

Specifically, for example, dimethyldichlorosilane, trimethylchlorosilane, allyldimethylchlorosilane, hexamethyldisilazane, allylphenyldichlorosilane, benzyldimethylchlorosilane, vinyltriethoxysilane, γ-methacryloxypropyltrisilane Examples thereof include methoxysilane, vinyltriacetoxysilane, divinylchlorosilane, and dimethylvinylchlorosilane.

The inorganic fine particles are treated with a silane coupling agent by a dry treatment in which a vaporized silane coupling agent is reacted with a cloud of inorganic fine particles by stirring.
Alternatively, the treatment can be performed by a generally known method such as a wet method in which inorganic fine particles are dispersed in a solvent and a silane coupling agent is dropped. The above-mentioned hydrophobizing treatment can be appropriately used in combination.

As another hydrophobizing agent, silicone oil can be mentioned. Generally, the one represented by the following formula (8) is preferable.

[0177]

Embedded image [In the formula, R ₁ ′ to R ₁₀ ′ may be the same or different and may be hydrogen, hydroxyl, alkyl, halogen, phenyl, substituted phenyl, fatty acid, polyoxyalkylene or perfluoro. It shows an alkyl group, and m and n show an integer. ]

Preferred silicone oils include 25
5-2000mm viscosity at ° C ^Two/ S is preferred
It is used well. Silicone with too low molecular weight and low viscosity
Oil may generate volatiles due to heat treatment
Unfavorable, on the other hand, high viscosity silica with too high molecular weight
Oil makes it difficult to perform surface treatment operations. silicone
Oils include methyl silicone oil and dimethyl silicone oil.
Corn oil, phenylmethyl silicone oil,
Rolphenyl methyl silicone oil, alkyl-modified silicone
Silicone oil, fatty acid modified silicone oil, polio
Xyalkyl-modified silicone oils are preferred.

As the above-mentioned silicone oil, it is preferable to use a negatively chargeable silicone oil having the same polarity as the toner particles in order to enhance the chargeability of the toner.

As a method of treating the inorganic fine particles with silicone oil, a known technique is used. For example, inorganic fine particles and silicone oil may be directly mixed using a mixer such as a Henschel mixer, or a method of spraying silicone oil onto the inorganic fine particles may be used. Alternatively, it may be prepared by dissolving or dispersing a silicone oil in an appropriate solvent, mixing the resulting solution with inorganic fine particles, and then removing the solvent.

The silicone oil is used in an amount of 1.5 to 60 parts by mass, preferably 3.5 to 40 parts by mass, based on 100 parts by mass of the inorganic fine particles to be treated. 1.5-60
By mass, the surface treatment with silicone oil can be performed uniformly, and filming and hollowing out can be suitably prevented,
Prevents a decrease in toner chargeability due to moisture absorption under high humidity,
It is possible to prevent a decrease in image density in durability.

The additive for imparting various toner properties preferably has an average particle size of 0.005 to 0.2 μm from the viewpoint of durability when added to the toner or when added to the toner. The average particle size of the additive means the number average particle size of the toner particles obtained by observing the surface of the toner particles with an electron microscope. As the additives for imparting these properties, for example, the following are used.

In addition to the above-mentioned inorganic fine particles and organic fine particles, other fluidity-imparting agents include, for example, carbon black and carbon fluoride. Each of these is preferably subjected to a hydrophobic treatment.

Examples of the abrasive include metal oxides such as strontium titanate, cerium oxide, aluminum oxide, magnesium oxide and chromium oxide; nitrides such as silicon nitride; carbides such as silicon carbide; and calcium sulfate and sulfuric acid. Metal salts such as barium and calcium carbonate are mentioned.

Examples of the lubricant include fluororesin powders such as vinylidene fluoride and polytetrafluoroethylene; and fatty acid metal salts such as zinc stearate and calcium stearate.

Examples of the charge control particles or the conductivity imparting particles include metal oxides such as tin oxide, titanium oxide, zinc oxide, silicon oxide and aluminum oxide; and carbon black.

These additives are preferably used in an amount of 0.1 to 10 parts by mass, more preferably 0.1 to 5 parts by mass, based on 100 parts by mass of the toner particles. These additives may be used alone or in combination.

The developer used in the present invention is used as a two-component developer by mixing the above-described magnetic carrier and toner.

When a two-component developer is prepared by mixing a toner and a magnetic carrier, the mixing ratio is 2 to 15% by mass, preferably 4 to 13% by mass, as the toner concentration in the developer.
Good results are obtained when the amount is set to be% by mass. Toner density is 2
If the amount is less than 1% by mass, the image density tends to be low.
If the content is more than 5% by mass, fogging and scattering in the machine are liable to occur, and the useful life of the developer is liable to decrease.

The ratio (A / B) between the weight average particle size (A) of the toner and the 50% particle size (B) of the magnetic carrier is from 0.1 to 0.1%.
It is preferably 0.3. If the ratio is less than 0.1, it becomes difficult to appropriately charge the toner, and fog or toner scattering in a high humidity environment is likely to occur. On the other hand, if it exceeds 0.3, the charge amount of the toner particularly under low humidity becomes too high, which tends to cause a decrease in image density and fog.

A specific example of the measurement of the average particle size and the particle size distribution of the toner will be described below.

0.1 to 5 ml of a surfactant (alkylbenzene sulfonate) is added to 100 to 150 ml of the electrolyte solution.
Attach and add 2 to 20 mg of the measurement sample to this. The electrolytic solution in which the sample was suspended was subjected to dispersion treatment with an ultrasonic disperser for 1 to 3 minutes, and the above-mentioned Coulter counter multisizer was used to adjust the volume to 17 to 100 μm using an aperture appropriately adjusted to the toner size. .3-40μ
The particle size distribution of m shall be measured. The number average particle diameter and weight average particle diameter measured under these conditions were determined by computer processing.

Hereinafter, a method of measuring the triboelectric charge amount of the toner will be described.

The toner and the carrier are mixed so as to have an appropriate mixing amount (toner: 2 to 15% by mass), and mixed with a turbula mixer for 120 seconds. This mixed powder (developer)
Is placed in a metal container equipped with a 635-mesh conductive screen at the bottom and suctioned by a suction machine, and the amount of triboelectric charging is determined from the difference in mass before and after suction and the potential accumulated in a condenser connected to the container. At this time, the suction pressure was 250 mm
Hg. With this method, the frictional charge amount of the toner is calculated using the following equation.

[0195]

(Equation 3) (Where W1 is the mass of the mixed powder before suction, W2 is the mass of the mixed powder after suction, C is the capacity of the condenser, and V is the potential accumulated in the condenser.)

Next, the image forming apparatus of the present invention will be described.

As a developing method using the magnetic carrier of the present invention, for example, development can be carried out using a developing means as shown in FIG. Specifically, an AC voltage is applied to the developer carrying member, and an alternating electric field is formed in the developing region, and the developing is performed while the magnetic brush is in contact with the electrophotographic photosensitive member, for example, the photosensitive drum 1. Is preferred. The distance between the developer carrier (developing sleeve) 11 and the photosensitive drum 1 (S−
(D distance) is preferably 100 to 1000 μm in terms of preventing carrier adhesion and improving dot reproducibility. If it is smaller than 100 μm, the supply of the developer tends to be insufficient and the image density is lowered. If it is larger than 1000 μm, the lines of magnetic force from the magnetic pole S ₁ are widened and the density of the magnetic brush is reduced, resulting in poor dot reproducibility or magnetic coating. The force for restraining the carrier is weakened, and carrier adhesion is likely to occur.

The voltage between the peaks of the alternating electric field is 300 to 30.
00V is preferable, the frequency is 500 to 10000 Hz,
Preferably, it is 1000-7000 Hz, and each can be appropriately selected and used depending on the process. In this case, the waveform of the AC bias for forming the alternating electric field may be a triangular wave, a rectangular wave, a sine wave, or a waveform having a changed duty ratio. In order to cope with a change in the speed of forming a toner image, it is preferable to apply a developing bias voltage having a discontinuous AC bias voltage (intermittent alternating superimposed voltage) to the developer carrying member to perform development. . If the applied voltage is lower than 300 V, it may be difficult to obtain a sufficient image density, and it may not be possible to satisfactorily collect fog toner in the non-image area. If the voltage exceeds 5000 V, the latent image may be disturbed via the magnetic brush, which may cause deterioration in image quality.

By using a two-component developer having a well-charged toner, the fog removal voltage (Vback) can be reduced.
And the primary charge of the photoconductor can be reduced, so that the life of the photoconductor can be extended. Vbac
k is preferably 200 V or less, more preferably 150 V or less, depending on the developing system. As the contrast potential, 100 to 400 V is preferably used so that a sufficient image density can be obtained.

If the frequency is lower than 500 Hz, the toner in contact with the electrostatic latent image carrier is returned to the developing sleeve, but sufficient vibration is not applied and fog is liable to occur, although this is related to the process speed. Become. 10,000Hz
When the value exceeds, the toner cannot follow the electric field, and the image quality is likely to be deteriorated.

What is important in the developing method of the present invention is that the photosensitive drum 1 of the magnetic brush on the developing sleeve 11 is used for developing sufficient image density, excellent dot reproducibility, and performing development without adhering magnetic carriers. Is preferably 3 to 8 mm. If the developing contact portion is smaller than 3 mm, it is difficult to sufficiently satisfy a sufficient image density and dot reproducibility. If the developing contact portion is wider than 8 mm, packing of a developer occurs, which stops the operation of the machine, or causes a magnetic carrier. It becomes difficult to sufficiently suppress the adhesion.
As a method of adjusting the developing contact portion, the distance between the regulating blade 15 and the developing sleeve 11 is adjusted, or the developing sleeve 1 is adjusted.
There is a method of appropriately adjusting the contact width by adjusting the distance between the photosensitive drum 1 and the photosensitive drum 1 (distance between SD).

In the image forming apparatus of the present invention, the charging means, the electrostatic latent image forming means, the developing means and the transfer means are arranged in this order along the moving direction of the photosensitive member surface. Between the charging unit and the electrostatic latent image forming unit, and between the electrostatic latent image forming unit and the developing unit, an independent cleaning blade for collecting and storing the transfer residual toner remaining on the photoreceptor. Cleaning means such as the above, but also does not have the above-mentioned cleaning means, and also serves as cleaning for collecting toner remaining on the image carrier after the developing means transfers the toner image onto the transfer material. The present invention is effective in an image forming apparatus.

That is, in the present invention, since the apparatus has an atmosphere heater capable of controlling the temperature inside the apparatus, not only the charging of the toner is stabilized, but also the surface of the photoreceptor, the intermediate transfer member or the transfer It has been found that the resistance value of the belt is also stabilized, the transferability of the toner is improved without being affected by the test environment, and the transfer residual toner is significantly reduced or almost completely eliminated.

In the case of the reversal development, this simultaneous development cleaning method includes an electric field for recovering the toner from the dark portion potential of the photosensitive member by the developing bias to the developer carrying member, and a toner from the developer carrying member to the bright portion potential of the photosensitive member. This is done by the action of the applied electric field.

A DC or AC bias may be applied not only during development but also before and after development to control the potential so that the residual toner on the photoreceptor can be recovered. At this time, the DC bias is located between the light portion potential and the dark portion potential.

In the case of the above-mentioned contact developing method, in the simultaneous cleaning method of development, an electric field acting between the photoreceptor and the developer carrier facing the surface of the photoreceptor via the developer causes the residual toner to be transferred to be removed. Since cleaning is also performed, the surface of the developer carrier or the vicinity of the surface has a potential,
It is necessary to have an electric field in a narrow gap between the surface of the photoconductor and the surface of the developer carrier.

[0207] The volume resistivity of the outermost surface layer of the photoreceptor of the image forming apparatus of the present invention is preferably from 10 ⁷ ~10 ^{1 4} Ωcm, more preferably, 10 ⁸ to 10 ¹³ [Omega] cm
It is.

The outermost layer of the photoreceptor has a volume resistivity of 10 ⁷ Ω.
If it is lower than 10 cm, the latent image may be disturbed especially under high humidity even if an atmosphere heater is used, so-called image deletion may occur. If it is higher than 10 ¹⁴ Ωcm, it is difficult to uniformly charge the photoconductor. It is not preferable because fog or the like may occur.

The structure of the photoreceptor may be the same as that of the photoreceptor usually used in an image forming apparatus. , A charge transport layer and a charge injection layer.

The conductive layer, the undercoat layer, the charge generation layer, and the charge transport layer may be those usually used for a photoreceptor.

For example, when a charge injection layer is used as the outermost surface layer of the photoreceptor, an acrylic resin, a phenol resin, or the like is used as the binder resin. Ultrafine particles such as SnO ₂ or resin particles such as polytetrafluoroethylene may be appropriately dispersed.

The measurement of the volume resistance of the surface layer of the photoreceptor is as follows.

The volume resistivity of the surface layer of the photoreceptor in the present invention is the same as that of the surface layer (thickness: 3 μm) on a polyethylene terephthalate (PET) film having gold deposited on the surface.
m) is prepared, and is measured by applying a voltage of 100 V in an environment of a temperature of 23 ° C. and a relative humidity of 65% using a volume resistance measuring device (4140B pAMATER manufactured by Hewlett Packer).

As the heating element that can be used in the atmosphere heater of the present invention, any of a planar heating element and a rod-shaped heating element can be used, but a planar heating element is more preferable in order to efficiently control the temperature inside the apparatus. The sheet heating element has a heating pattern (not shown) printed thereon. When a voltage is applied to the heating pattern, the sheet heating element generates heat according to the heating pattern of the sheet heating element. In this embodiment, 1
It is driven at 0 V and the time until it reaches 50 ° C. is 10 seconds, and the on / off control is performed in conjunction with the temperature and humidity sensor in the machine. This sheet heating element has an adhesive sheet on the back side of the heat generating pattern, and is generated by attaching the adhesive portion to the lower surface of the paper feed cassette or installing the sheet inside the intermediate transfer belt or the paper transfer belt. Heat can be efficiently transmitted to the image forming site.

The operation of the heating element is preferably performed during a pause. After the start of image formation, the temperature in the image forming apparatus rises due to the driving of the fixing means and the like and does not absorb moisture. Is not necessary.

According to the image forming method of the present invention, three or more developing devices for magenta, cyan and yellow are used for outputting a full-color image in which halftone is particularly important. Using the development method,
In particular, by combining with a developing system that forms a digital latent image, it is possible to develop the dot latent image faithfully without being affected by the magnetic brush and disturbing the latent image. Also in the transfer step, a high transfer rate can be achieved by using a fine-particle-cut toner having a sharp particle size distribution, so that high image quality can be achieved in both the halftone portion and the solid portion.

Further, by using the two-component developer of the present invention together with the initial improvement of image quality, the share of the developer in the developing device is small, and the image quality of the present invention is not reduced even when copying a large number of sheets. The effect of can be fully exhibited.

In order to obtain a tighter image, it is preferable to have developing devices for magenta, cyan, yellow, and black, and to exhibit a tighter image by performing black development last. Can be.

The image forming method of the present invention will be further described with reference to the drawings.

In FIG. 1, the magnetic particles 2 are applied to the surface of the transfer sleeve 22 by the magnetic force of the magnet roller 21.
A charging magnetic brush 3 is formed, and the magnetic brush is brought into contact with the surface of an electrophotographic photosensitive member (hereinafter referred to as “photosensitive member”) 1 to charge the photosensitive member 1. A charging bias is applied to the transport sleeve 22 by a bias applying unit (not shown). By irradiating the charged photoconductor 1 with a laser beam 24 by an exposure device (not shown),
Form a digital electrostatic latent image. The electrostatic latent image formed on the photoreceptor 1 is covered by a toner 19a in a developer 19 carried on a developing sleeve 11 which includes a magnet roller 12 and is applied with a developing bias by a bias applying device (not shown). Developed.

The developing device 4 is provided with a developer chamber R by a partition wall 17.
_1, is divided into the stirring chamber R _2, respectively developer conveying screw 13, 14 is installed. Above the stirring chamber R _2, a toner storage chamber R ₃ containing a replenishing toner 18 is installed, the toner supply opening 20 is provided in a lower portion of the storage chamber R _3.

The developer transport screw 13 rotates to transport the developer in the developer chamber R1 in _one direction along the longitudinal direction of the developing sleeve 11 while stirring. The partition 17 is provided with openings (not shown) on the near side and the back side in the drawing, and the developer conveyed to _one of the developer chambers R1 by the screw 13 passes through the opening of the partition 17 on one side. The developer is sent to the stirring chamber R ₂ and transferred to the developer transport screw 14. In the direction of rotation the screw 13 opposite the screw 14, the developer in the stirring chamber R _2, the developer chamber R ₁
Stirring the toner supplied from the passed developer and toner storage chamber R ₃ from, with mixing, the screw 13 and conveyed in the stirring chamber R ₂ in the opposite direction, through the other opening of the partition wall 17 sent into the developer chamber R _1.

To develop the electrostatic latent image formed on the photoreceptor ₁ , the developer 19 in the developer chamber R1 is pumped up by the magnetic force of the magnet roller 12, and is carried on the surface of the developing sleeve 11. . The developer carried on the developing sleeve 11 is conveyed to the regulating blade 15 with the rotation of the developing sleeve 11, where it is regulated to a thin developer layer having an appropriate thickness. To the development area opposed to it. A magnetic pole (development pole) N ₁ is located at a position corresponding to the development area of the magnet roller 12, and the development pole N ₁ forms a development magnetic field in the development area, and the developer magnetically rises due to the development magnetic field. Thus, a magnetic brush of the developer is generated in the developing area. And the magnetic brush is the photoconductor 1
The toner adhering to the magnetic brush and the toner adhering to the surface of the developing sleeve 11 are transferred to and adhered to the area of the electrostatic latent image on the photoreceptor 1 by the reversal developing method. The electrostatic latent image is developed to form a toner image.

The developer that has passed through the developing area is returned into the developing device 4 as the developing sleeve 11 rotates, and the magnetic pole S
Due to the repelling magnetic field between S ₁ and S ₂ , it is peeled off from the developing sleeve 11 and falls into the developer chamber R ₁ and the stirring chamber R ₂ to be collected.

By the above development, the developer 1 in the developing device 4
T / C ratio of 9 (toner and mixing ratio of the carrier, i.e., toner concentration in the developer) When decreases is, the agitation chamber R in an amount that was seen from the toner storage chamber R ₃ to the amount consumed toner 18 in the developing ₂ and the T / C of the developer 19 is maintained at a predetermined amount. To detect the T / C ratio of the developer 19 in the container 4,
A toner concentration detection sensor that measures a change in the magnetic permeability of the developer using the inductance of the coil is used. The toner concentration detection sensor has a coil (not shown) therein.

The regulating blade 15 disposed below the developing sleeve 11 and regulating the layer thickness of the developer 19 on the developing sleeve 11 is a non-magnetic blade 15 made of a non-magnetic material such as aluminum or SUS316. The distance between the end and the surface of the developing sleeve 11 is 150 to 800 μm.
m, preferably from 250 to 700 μm. If the distance is less than 150 μm, the magnetic carrier is aggregated and clogged during this period, which tends to cause unevenness in the developer layer. In addition, it is difficult to apply the developer necessary for good development, and the density is low. An image is easily formed. This distance is preferably 150 μm or more in order to prevent non-uniform application (so-called blade jam) due to unnecessary particles mixed in the developer. If it is larger than 800 μm, the developing sleeve 1
As the amount of the developer applied on the photosensitive member 1 increases, it is difficult to regulate a predetermined thickness of the developer layer, the adhesion of the magnetic carrier particles to the photoreceptor 1 increases, and the circulation of the developer and the development regulation by the regulating blade 15 are restricted. As a result, toner tribo is reduced and fogging is likely to occur.

Even when the developing sleeve 11 is driven to rotate in the direction of the arrow, the magnetic carrier particle layer is separated from the sleeve surface by the balance between the restraining force based on magnetic force and gravity and the conveying force in the moving direction of the developing sleeve 11. Movement slows down. It falls under the influence of gravity.

Therefore, by appropriately selecting the arrangement positions of the electrodes N and N and the fluidity and magnetic properties of the magnetic carrier particles, the closer the magnetic carrier particle layer is to the sleeve, the more the magnetic pole N ₁ becomes.
To form a moving layer. Due to the movement of the magnetic carrier particles, the developer is conveyed to the developing area with the rotation of the developing sleeve 11 and is used for development.

The developed toner image is transferred onto a conveyed transfer material (recording material) 25 by bias applying means 26.
The toner image transferred by the transfer blade 27, which is a transfer unit to which a transfer bias is applied, and transferred onto the transfer material is fixed to the transfer material by a fixing device (not shown). In the transfer step, the transfer residual toner remaining on the photoreceptor 1 without being transferred to the transfer material is charged in the charging step.
The charge is adjusted and collected during development.

FIG. 3 is a schematic diagram in which the image forming method of the present invention is applied to a full-color image forming apparatus. Also, the full-color image forming apparatus shown in FIG. 3 does not have an independent cleaning unit for collecting and storing the transfer residual toner remaining on the photoconductor, and after the developing unit transfers the toner image onto the transfer material. In this method, a simultaneous development and cleaning method for recovering the toner remaining on the image carrier is performed.

The main body of the full-color image forming apparatus includes a first image forming unit Pa, a second image forming unit Pb,
An image forming unit Pc and a fourth image forming unit Pd are provided side by side, and images of different colors are formed on a transfer material through a process of forming, developing, and transferring a latent image.

The structure of each image forming unit provided in the image forming apparatus will be described by taking the first image forming unit Pa as an example.

The first image forming unit Pa includes a photosensitive member 61a having a diameter of 30 mm as an electrostatic latent image carrier.
The photoreceptor 61a is rotated in the direction of arrow a. The primary charging device 62a as a charging means includes a charging magnetic brush formed on the surface of a sleeve having a diameter of 16 mm.
It is arranged so as to contact the surface of a. Laser light 6
7a is irradiated by an exposure device (not shown) in order to form an electrostatic latent image on the photoconductor 61a whose surface is uniformly charged by the primary charger 62a. Photoconductor 61a
A developing device 63a as a developing unit for developing the electrostatic latent image carried thereon to form a color toner image includes:
Holds color toner. The transfer blade 64a as a transfer unit transfers the color toner image formed on the surface of the photoconductor 61a to the surface of a transfer material (recording material) conveyed by a belt-shaped transfer material carrier 68. The transfer blade 64a can apply a transfer bias by contacting the back surface of the transfer material carrier 68.

The first image forming unit Pa uniformly and primary charges the photosensitive member 61a by the primary charger 62a, and forms an electrostatic latent image on the photosensitive member by the exposure device 67a.
The developing device 63a develops the electrostatic latent image using a color toner, and the developed toner image is transferred to a belt-like shape which carries and conveys a transfer material at a first transfer portion (a contact position between the photoconductor and the transfer material). Transfer blade 64 abutting on the back side of transfer material carrier 68
The transfer is performed on the surface of the transfer material by applying a transfer bias from a.

When the toner is consumed by the development and the T / C ratio decreases, the decrease is detected by a toner density detection sensor 85 for measuring a change in the magnetic permeability of the developer using the inductance of the coil, and the toner is consumed. The toner is replenished from the replenishment toner container 65a according to the amount of toner. The toner density detection sensor 85 has a coil (not shown) therein.

The present image forming apparatus has the same configuration as the first image forming unit Pa, and has a second image forming unit Pb, a third image forming unit Pc, and a second image forming unit Pc having different colors of the color toner held in the developing device. Four image forming units of the fourth image forming unit Pd are provided side by side. For example, yellow toner is used for the first image forming unit Pa, magenta toner is used for the second image forming unit Pb, cyan toner is used for the third image forming unit Pc, and black toner is used for the fourth image forming unit Pd. The transfer of each color toner onto the transfer material is sequentially performed in the transfer section of each image forming unit. In this step, while the registration is being performed, each color toner is superimposed on the same transfer material by one transfer of the transfer material, and when the transfer is completed, the transfer material is separated from the transfer material carrier 68 by the separation charger 69. The fixing device 70 by a conveying means such as a conveying belt.
And a final full-color image is obtained by a single fixing.

The fixing device 70 has a pair of a fixing roller 71 having a diameter of 40 mm and a pressure roller 72 having a diameter of 30 mm.
The fixing roller 71 has heating means 75 and 76 inside.

The unfixed color toner image transferred onto the transfer material passes through the pressure contact portion between the fixing roller 71 and the pressure roller 72 of the fixing device 70, and is applied to the transfer material by the action of heat and pressure. Is established.

In FIG. 3, the transfer material carrier 68 is an endless belt-like member, which is moved in the direction of arrow e by a driving roller 80. In addition, a transfer belt cleaning device 79, a belt driven roller 81, and a belt static eliminator 82 are provided. A pair of registration rollers 83 are for transporting the transfer material in the transfer material holder to the transfer material carrier 68. .

As the transfer means, instead of the transfer blade abutting on the back side of the transfer material support, a contact capable of directly applying a transfer bias by abutting on the back side of the transfer material support such as a roller-shaped transfer roller. It is possible to use transfer means.

Further, in place of the contact transfer means, a non-contact type in which a transfer bias is applied from a corona charger arranged in a non-contact manner on the back side of a generally used transfer material carrier to perform transfer. May be used.

However, it is more preferable to use the contact transfer means in that the amount of ozone generated when the transfer bias is applied can be controlled.

[0243]

EXAMPLES Hereinafter, the present invention will be described specifically with reference to Examples, but the present invention is not limited thereto.

<1> Production of Toner: <Production of Toner 1>
450 parts by mass of an aqueous solution of 1M-Na ₃ PO ₄ was added,
TK homomixer (manufactured by Tokushu Kika Kogyo)
And stirred at 13000 rpm. To this 1.
68 parts by mass of 0M-CaCl ₂ aqueous solution was gradually added to obtain a pH 6.2 aqueous medium containing a calcium phosphate compound.

On the other hand, 166 parts by mass of styrene 34 parts by mass of n-butyl acrylate 10 parts by mass of copper phthalocyanine pigment 1.5 parts by mass of metal compound di-t-butylsalicylate 1.5 parts by mass of saturated polyester 10 parts by mass (acid value 9 mg KOH / g, peak molecular weight 8600) Monoester wax 20 parts by mass (Mw: 500, Mn: 400, Mw / Mn: 1.25) The above material was heated to 60 ° C., and a TK homomixer (manufactured by Tokushu Kika Kogyo Co., Ltd.) ), And was uniformly dissolved and dispersed at 12000 rpm. 10 g of a polymerization initiator 2,2′-azobis (2,4-dimethylvaleronitrile) was dissolved therein,
A polymerizable monomer composition was prepared.

The polymerizable monomer composition was charged into the aqueous medium, and the mixture was stirred at 11,000 rpm for 6 minutes at 60 ° C. in a N ₂ atmosphere using a Clare mixer (manufactured by M Technique Co., Ltd.). The composition was granulated. Thereafter, the temperature was raised to 80 ° C. while stirring the aqueous medium with a paddle stirring blade, and p
The polymerization reaction was performed for 5 hours while maintaining H at 6.2.

After the completion of the polymerization reaction, the mixture was cooled, hydrochloric acid was added to adjust the pH to 2 to dissolve the calcium phosphate compound, and then filtered, washed with water, dried and classified to obtain polymer particles (toner particles).

The following two external additives were externally added to 100 parts by mass of the obtained polymer particles (toner particles).
Remove coarse particles with a sieve of 00 mesh (53 μm mesh)
A negatively charged cyan toner 1 was obtained. The weight average particle size of the cyan toner 1 is 7.6 μm, and the average circularity is 0.977.
And 8.5% by number of toner particles of 2 μm or less.

The first external additive (hydrophobic silica fine powder 0.1.
7 parts by mass) 100 parts by mass of silica fine powder were subjected to hydrophobic treatment with 10 parts by mass of hexamethyldisilazane in the gas phase, and had a BET specific surface area of 40 m ² / g and a number average particle size of 30 nm. is there.

Second external additive (hydrophobic titanium oxide fine powder: 0.5 parts by mass) Hydrophobized with 10 parts by mass of n-hexaltrimethoxysilane in an aqueous medium with respect to 100 parts by mass of titanium oxide fine powder. Treated, with a BET specific surface area of 100
m ² / g, and the number average particle size is 35 nm.

<Production of Toner 2> 100 parts by mass of polyester resin composed of terephthalic acid / fumaric acid / trimellitic anhydride / bisphenol A derivative 100 parts by mass of copper phthalocyanine pigment 5 parts by mass aluminum compound of di-t-butylsalicylic acid 2 Parts by mass The above materials are sufficiently premixed with a Henschel mixer, melt-kneaded with a twin-screw extruder, cooled, roughly crushed to about 1-2 mm using a hammer mill, and then finely crushed by an air jet method. And pulverized. Further, the obtained finely pulverized product was classified to have a weight average particle size of 6.8 μm.
m was obtained as negative triboelectrically-chargeable cyan toner particles.

Negatively charged cyan toner 2 was prepared by externally adding two types of external additives to the obtained cyan toner particles in the same manner as in the production of cyan toner 1. The cyan toner 2 had a weight average particle diameter of 6.8 μm, an average circularity of 0.948, and 28.2% by number of toner particles having a particle size of 2 μm or less.

<Production of Toner 3> As an external additive, 0.0
Cyan Toner 3 was prepared in the same manner as in the preparation of Toner 1, except that 1.0% of 2 μm styrene / methyl methacrylate copolymer resin particles were used. Cyan toner 3
Has a weight average particle size of 7.6 μm, an average circularity of 0.977,
8.2% by number of toner particles of 2 μm or less.

<Production of Toner 4> Magenta polymer particles (toner particles) were obtained in the same manner as in the production of toner 1, except that 12 parts by mass of a quinacridone pigment was used instead of the copper phthalocyanine pigment. To the obtained polymer particles, two kinds of external additives were externally added in the same manner as in the production of the toner 1 to prepare a magenta toner 4 having a negative charge. The magenta toner 4 has a weight average particle size of 7.3 μm and an average circularity of 0.974, 2 μm
The following toner particles accounted for 8.2% by number.

<Production of Toner 5> In place of the copper phthalocyanine pigment, C.I. I. Pigment Yellow 180 and 6 parts by weight of Solvent Yellow 93 were used in the same manner as in the production of Toner 1 to obtain polymerized yellow particles (toner particles). An external additive was externally added to the obtained polymer particles in the same manner as in the production of Toner 1, to prepare a negatively-chargeable yellow toner 5. The yellow toner 5 had a weight average particle diameter of 7.4 μm and an average circularity of 0.971, and 10.5% by number of toner particles of 2 μm or less.

<Production of Toner 6> Black polymer particles (toner particles) were obtained in the same manner as in the production of toner 1, except that 12 parts by mass of carbon black was used instead of the copper phthalocyanine pigment. An external additive was externally added to the obtained polymer particles in the same manner as in the production of the toner 1 to prepare a negatively chargeable black toner 6. The black toner had a weight average particle diameter of 7.8 μm, an average circularity of 0.978, and 7.4% by number of toner particles of 2 μm or less.

<2> Production of Magnetic Carrier: <Production of Magnetic Carrier 1> 50 parts by mass of phenol (hydroxybenzene) 80 parts by mass of 37% by mass aqueous solution of formalin 50 parts by mass of water Surface with silane coupling agent 280 parts by mass of treated magnetite fine particles (50% particle size 0.22 μm, volume resistance value 3 × 10 ⁵ Ωcm) ・ 120 parts by mass of α-Fe ₂ O ₃ fine particles surface-treated with a silane coupling agent (50% (Particle size: 0.38 μm, volume resistivity: 6 × 10 ⁹ Ωcm) ・ 25 parts by mass of aqueous ammonia 15 parts by mass Put the above materials in a four-necked flask, and stir and mix.
The temperature was raised to 85 ° C. in 0 minutes, and reacted and cured for 120 minutes. After cooling to 30 ° C. and addition of 500 parts by weight of water, the supernatant was removed, and the precipitate was washed with water and air-dried. Then, this is subjected to reduced pressure (665 Pa = 5 mmHg) 1
After drying at 60 to 180 ° C. for 24 hours, a magnetic carrier core (A) using a phenol resin as a binder resin was obtained.

The surface of the obtained magnetic carrier core (A) was coated with a 5% by mass methanol solution of γ-aminopropyltrimethoxysilane represented by the following general formula (9).

[0259]

Embedded image

The surface of the magnetic carrier core (A) has a thickness of 0.2
Mass% γ-aminopropyltrimethoxysilane. During the application, the methanol was volatilized during the application while continuously applying a shear stress to the magnetic carrier core (A). On the surface of the magnetic carrier core (A)

[0261]

Embedded image Was confirmed to be present.

While stirring the magnetic carrier core (A) treated with the silane coupling agent in the above-mentioned processing machine at 70 ° C., the silicone resin SR2410 (manufactured by Toray Dow Corning Co., Ltd.) was converted to a silicone resin solid content of 20%. After diluting with toluene, the mixture was added under reduced pressure to give 0.1.
A resin coating of 5% by mass was performed.

Thereafter, the toluene was volatilized while being stirred in an atmosphere of nitrogen gas for 2 hours, and then heat-treated at 140 ° C. for 2 hours in an atmosphere of nitrogen gas to dissolve the coagulation. The above coarse particles were removed to obtain a magnetic carrier 1.

The resulting magnetic carrier 1 has a TH / Sm of 9.1 × 10 ⁻⁴ and a TL / Sm of 2.5 × 10 ⁻⁴ ,
The 50% particle size is 36 μm, and the volume resistance value is 9 × 10 ¹³ Ωc
m, the saturation magnetization at 79.6 KA / m is 41 Am ² /
kg, the residual magnetization was 5.3 Am ² / kg, the true specific gravity was 3.71, and the bulk density was 1.87 g / cm ³ .

<Production of Magnetic Carrier 2> Magnetic Carrier 1
In the production of B, instead of the magnetic carrier core (A), B
TH / Sm was 1.1 × 10 ⁻⁴ , and TL was the same except that a ferrite core having an i-Ni—Zn—Fe composition was used.
/ Sm is 8.3 × 10 ^-5 , 50% particle size 37 μm,
Volume resistivity 8 × 10 ^{1 1} Ωcm, the saturation magnetization 66Am ² / k
g, a magnetic carrier 2 having a residual magnetization of 2.5 Am ² / kg and a true specific gravity of 3.71.

<Production of Magnetic Carrier 3> Magnetic Carrier 1
In the same manner, TH / Sm was 1.7 × 10 ⁻⁴ , TL / Sm was 5.8 × 10 ⁻⁵ , the 50% particle size was 37 μm, and the volume resistivity was the same as above except that the silicone resin was not coated. 7 × 10 ^{1 1} Ωcm, the saturation magnetization 66Am ² / kg, residual magnetization 2.5Am ² / kg, to obtain a magnetic carrier 2 of the true specific gravity of 3.71.

<Production of Magnetic Carrier 4> Magnetic Carrier 1
In the production of the above, 400% by mass of magnetite fine particles having a 50% particle size of 0.22 μm were used, and TH / Sm was 1.5 × 10 ⁻⁴ , except that hematite was not used.
The TL / Sm is 5.4 × 10 ^-4 and the 50% particle size is 33 μm.
m, volume resistivity 9 × 10 ⁹ Ωcm, saturation magnetization 45 Am ² /
kg, a magnetic carrier 4 having a residual magnetization of 3.8 Am ² / kg and a true specific gravity of 3.64.

<Manufacture of Magnetic Carrier 5> Magnetic Carrier 1
In the production of, a thermoplastic styrene resin was used as the binder resin, and 0.02 μm styrene / methyl methacrylate copolymer resin particles were dry-coated with a hybridizer (manufactured by Nara Machinery Co., Ltd.). TH / S
m is 6.1 × 10 ⁻⁴ , TL / Sm is 1.1 × 10 ⁻⁴ , 50% particle size is 38 μm, and volume resistivity is 1.8 × 10 ¹¹ Ω.
cm, saturation magnetization 37 Am ² / kg, residual magnetization 2.4 Am ²
/ Kg, and a magnetic carrier 5 having a true specific gravity of 3.65 was obtained.

<Production of Magnetic Carrier 6> Magnetic Carrier 1
TH / Sm was 8.9 × 1 except that zinc oxide fine particles (2.3 × 10 ¹ Ωcm) having a 50% particle size of 0.75 μm were used instead of hematite.
0 ^-4 , TL / Sm is 2.3 × 10 ^-4 , 50% particle size 37 μm, volume resistivity 7 × 10 ⁹ Ωcm, saturation magnetization 37
Am ² / kg, residual magnetization 2.8Am ² / kg, a true specific gravity of 3.
54 magnetic carriers 6 were obtained.

<3> Production of Photoreceptor: <Production of Photoreceptor 1> The photoreceptor is a photoreceptor using an organic photoconductive substance for negative charging, and five functional layers are formed on a φ30 mm aluminum cylinder. Provided.

The first layer is a conductive particle-dispersed resin layer having a thickness of about 20 μm, which is provided to smooth defects of the aluminum cylinder and to prevent the occurrence of blemishes due to the reflection of laser exposure. It is.

The second layer is a positive charge injection preventing layer (undercoat layer), which serves to prevent the positive charge injected from the aluminum substrate from canceling the negative charge charged on the surface of the photoreceptor. This is a medium resistance layer having a thickness of about 1 μm, the resistance of which is adjusted to about 10 ⁶ Ω · cm by 66-610-12-nylon and methoxymethylated nylon.

The third layer is a charge generation layer, and is a layer having a thickness of about 0.3 μm in which a disazo pigment is dispersed in a resin, and generates a positive and negative charge pair by receiving laser exposure.

The fourth layer is a charge transport layer, in which hydrazone is dispersed in a polycarbonate resin, and is a P-type semiconductor. Therefore, the negative charges charged on the photoreceptor surface cannot move through this layer, and only the positive charges generated in the charge generation layer can be transported to the photoreceptor surface.

[0275] The fifth layer is a charge injection layer, a particle size of about to SnO ₂ ultrafine particles in a photocurable acrylic resin, to increase further the charging member and the contact time of the photosensitive member, performing uniform charging It is obtained by dispersing 0.25 μm ethylene tetrafluoride resin particles. Specifically, oxygen-deficient SnO ₂ particles having a reduced particle size of about 0.03 μm and 12
0% by mass, 20% by mass of ethylene tetrafluoride resin particles, and 1.0% by mass of a dispersant.

As a result, the volume resistivity of the surface layer of the photoreceptor 1 was reduced to 8 × 10 ¹¹ Ωcm, compared with 5 × 10 ¹⁵ Ωcm for the charge transport layer alone.

<4> Production of Magnetic Particles Used for Charging Member: <Production of Magnetic Particle a> 10 parts by mass of MgO and 1 part of MnO
0 parts by mass and 80 parts by mass of Fe ₂ O ₃ are each atomized, water is added and mixed, granulated, fired at 1300 ° C., the particle size is adjusted, and a ferrite core material having an average particle size of 22 μm (Saturation magnetization 63 Am ² / kg).

To this ferrite core material, 10 parts by mass of isopropoxytriisostearoyl titanate was added
What was mixed with 9 parts by mass / 1 part by mass of water was subjected to a surface treatment so as to be 0.1 part by mass, and the 50% particle size was 25.5 μm.
m and magnetic particles a having a volume resistance value of 7 × 10 ⁷ Ωcm were obtained.

Example 1 A two-component cyan developer 1 was obtained by mixing the magnetic carrier 1 (92 parts by mass) obtained above and cyan toner 1 (8 parts by mass) with a V-type mixer.

Next, the developing device of a commercially available copying machine GP55 (manufactured by Canon) was modified as shown in FIG. Specifically, as a developing sleeve, a SUS sleeve having a diameter of 16 mm was subjected to sandblasting to change the surface shape to a surface roughness Rz.
= 12.1 μm was used. The atmosphere heater is installed at the position of the paper feed cassette,
Controlled at ° C.

A magnetic brush a shown in FIG. 1 was used as the charging member, and magnetic particles a were used. The magnetic particles were rotated at 100% in the opposite direction to the contact portion of the photoreceptor, and a DC / AC electric field (- 700 V, 1.5 kHz / 1.2 kVpp) is superimposed and applied to charge the photoconductor 1. Further, the cleaning unit is removed, the developing contrast is set to 250 V, and the reversal contrast with fog is set to −150 V. A developing bias having a discontinuous AC voltage shown in FIG. Both the heating roller and the pressure roller have a surface layer of 1.2 μm with PFA (ethylene tetrafluoride-perfluoroalkyl vinyl ether copolymer).
The roller was changed to a m-coated roller, and the configuration was modified to eliminate the oil application mechanism.

Using an original document having an image area of 25%, 23 ° C./60% (hereinafter also referred to as “N / N”), 23 ° C./5% (hereinafter also referred to as “N / L”), In each environment of 32.5 ° C./90% (hereinafter also referred to as “H / H”), a paper passing test was performed at an image forming speed of 120 mm / sec using CLC80g paper (manufactured by Canon Sales Co., Ltd.). Evaluation was made based on the following evaluation method.

The results are shown in Table 1. As can be seen from Table 1, good results were obtained.

(1) Image Density Image density was measured using a Macbeth densitometer RD918 type (Macbeth) equipped with an SPI filter.
the Densitometer RD918manu
facted by Mcbeth Co. ) Was used to measure the average relative density of five points at the four corners and the center of the image formed on plain paper at the original image density of 1.5.

(2) Halftone Reproducibility Using the original image density of 0.3, the relative density was measured in the same manner as in (1). ◎: 0.3 to 0.4 ○: 0.25 to less than 0.3 △: 0.20 to less than 0.25 ×: less than 0.2

(3) Fog The average reflectance Dr (%) of plain paper before image formation was measured using a reflectometer (“REFLECTOME” manufactured by Tokyo Denshoku Co., Ltd.).
TER MODEL TC-6DS "). On the other hand, a solid white image was formed on plain paper, and the reflectance Ds (%) of the solid white image was measured. Fog (%)
Is calculated from the following equation.

Fog (%) = Dr (%)-Ds (%) ：: less than 0.4% ０．４: 0.4 to less than 0.8% Δ: 0.8 to less than 1.2% x: 1. 2% or more

(4) Solid Uniformity Using the original image density of 1.5, the relative density at five points was measured in the same manner as in (1), and the maximum density difference was measured. ◎: 0.0 to less than 0.05 O: 0.05 to less than 0.15 Δ: 0.15 to less than 0.25 ×: 0.25 or more

Comparative Example 1 The procedure of Example 1 was repeated, except that the magnetic carrier 2 was used.
As shown in the figure, the image density is reduced under the paper passing condition of N / L,
Since fog control also worsened, the evaluation was canceled only after some evaluations. This is presumed to be because the charge leakage function of the carrier itself was reduced due to the small amount of water in the carrier, and the charge uniformity of the toner was impaired.

Example 2 The procedure of Example 1 was repeated, except that the magnetic carrier 3 was used.
As shown in the figure, good results were obtained although the level of fog suppression was slightly reduced under the paper passing conditions under H / H. this is,
It is presumed that because the water content of the carrier was large, the charge-imparting ability of the carrier was reduced even when the atmosphere temperature in the apparatus was controlled. For reference, when the atmosphere heater was removed, fog was observed from the beginning under H / H. This is because the charge-imparting ability of the carrier is further reduced, the charge uniformity of the toner is impaired, and as a result, the transferability is deteriorated, and when applied to a cleaner-less system, it cannot be collected in the development area and fog occurs. It is presumed to have been done.

Example 3 The procedure of Example 2 was repeated, except that the magnetic carrier 4 was used.
As shown in Fig. 7, under the H / H paper passing condition, not only the level of fog suppression was slightly lowered but also the halftone reproducibility and the solid uniformity were lowered, but good results were obtained. This is because the carrier has a large amount of water, so even if the ambient temperature in the machine is controlled, not only the charge-imparting ability of the carrier is reduced, but also the saturation magnetization of the carrier is high, and the regulating power on the toner is strong. It is presumed that the deterioration of the external additive was accelerated.

Example 4 The procedure of Example 2 was repeated except that the magnetic carrier 5 was used.
As shown in Fig. 5, not only the level of fog suppression was slightly lowered but also the halftone reproducibility and solid uniformity were lowered, but good results were obtained. This is due to the fact that the binder resin is a thermoplastic styrene-based resin and has poor solvent resistance, so the dry coating was performed, so the uniformity of the coating resin was reduced and the toner spent resistance was reduced. It is presumed.

Example 5 The procedure of Example 2 was repeated, except that the magnetic carrier 6 was used.
As shown in the figure, not only the level of fog suppression slightly decreased, but also the level of halftone reproducibility decreased,
Good results were obtained. This is presumably because the non-magnetic particles were low-resistance zinc oxide, so that the carrier resistance was reduced, the latent image was disturbed in the development area, and image unevenness was likely to occur.

Example 6 The procedure of Example 1 was repeated, except that cyan toner 2 was used instead of cyan toner 1. As a result, the fog suppression level was reduced as shown in Table 1. was gotten. this is,
It is presumed that because the toner shape became almost non-spherical, when applied to a cleanerless system, the amount of transfer residual toner increased, and the transfer residual toner in the development area could not be completely collected.

Example 7 The same procedures as in Example 1 were carried out except that cyan toner 3 was used.
As shown in the figure, not only the level of fog suppression slightly decreased, but also the level of halftone reproducibility decreased,
Good results were obtained. This is presumed to be due to the fact that, due to the resin particles, the external additive, the mixing property with the carrier was reduced, the charging was likely to be uneven, and the image was likely to be uneven.

Example 8 Using an image forming apparatus shown in FIG. 3 in which a CLC1000 (manufactured by Canon) was modified using yellow toner 5, magenta toner 4, cyan toner 1, and black toner 6, an atmosphere heater was used. When a full-color image was formed under the transfer belt, good results were obtained as in Example 1.

[0297]

[Table 1]

[0298]

According to the present invention, the amount of water absorbed per unit area of the coated carrier is controlled within a specific range, so that the coated carrier is affected by the environment even when used in an image forming apparatus equipped with an atmosphere heater. Thus, the chargeability of the toner is stabilized, and good image quality can be obtained for a long period of time.

[Brief description of the drawings]

FIG. 1 is a diagram showing an embodiment of an image forming apparatus according to the present invention.

FIG. 2 shows a bias having a discontinuous alternating electric field of a developing bias used in the image forming apparatus used in the first embodiment.

FIG. 3 is a diagram showing one embodiment of the full-color image forming apparatus of the present invention.

FIG. 4 is a diagram illustrating an apparatus for measuring the volume resistance of a magnetic carrier according to the present invention.

[Explanation of symbols]

 REFERENCE SIGNS LIST 1 photosensitive drum 4 developing device 11 developing sleeve 12 magnet roller 13, 14 developer transport screw 15 regulating blade 17 partition 18 supply toner 19 developer 19 a toner 19 b magnetic carrier 20 toner supply port 25 transfer material Pa, Pb, Pc, Pd Image forming unit 61a Photosensitive drum 62a Primary charger 63a Developing device 64a Transfer blade 65a Replenishing toner container 68 Transfer material carrier 70 Fixing device 71 Fixing roller 72 Pressure rollers 75, 76 Heating means 80 Drive roller 85 Toner density detection sensor 121 , 122 electrodes 127 sample E cell

──────────────────────────────────────────────────続 き Continued on the front page (51) Int.Cl. ⁷ Identification symbol FI Theme coat ゛ (Reference) G03G 21/20 G03G 21/00 534 (72) Inventor Yuji Mitsuki 3-30-2 Shimomaruko, Ota-ku, Tokyo Within Canon Inc. (72) Inventor Ryoichi Fujita 3-30-2 Shimomaruko, Ota-ku, Tokyo Canon Inc. (72) Inventor Naotaka 3-30-2 Shimomaruko, Ota-ku, Tokyo Canon Inc. (72) Inventor Kenichi Nakayama 3-30-2 Shimomaruko, Ota-ku, Tokyo F-term (reference) in Canon Inc. 2H005 AA08 AA15 BA03 BA11 CA15 CB03 CB07 CB13 EA07 EA10 2H027 JA12 JB19

Claims (27)

[Claims] 1. An electrostatic image carrier is charged by a charging means, the charged electrostatic image carrier is exposed to form an electrostatic image on the electrostatic image carrier, and the electrostatic image is developed by two-component development. A toner image is formed on an electrostatic image carrier by developing with a developing means having an agent, and the toner image on the electrostatic image carrier is transferred to a transfer material with or without an intermediate transfer member. A carrier used in an electrophotographic apparatus having an atmosphere heater capable of heating and controlling the inside of the apparatus for fixing a toner image on a transfer material by a heat and pressure fixing unit is 23 ° C., 5 ° C.
% RH (mass%) after leaving in a% RH environment and the surface area Sm (cm ² / g) of the carrier satisfy the following relationship: 1.1 × 10 ⁻⁴ ≦ TL / Sm Characteristic carrier for electrophotography. 2. The carrier has a water adsorption TH (mass%) after being left in an environment of 30 ° C. and 80% RH, and a water adsorption amount TL (mass) of the carrier after being left in an environment of 23 ° C. and 5% RH. %) And the surface area Sm (cm ² / g) of the carrier are:
2. The electrophotographic carrier according to claim 1, wherein the following relationship is satisfied: 6.0 × 10 ⁻⁴ ≦ TH / Sm TL ≦ TH 3. The carrier has the following relationship: 6.0 × 10 ⁻⁴ ≦ TH / Sm ≦ 1.5 × 10 ⁻³ 1.1 × 10 ⁻⁴ ≦ TL / Sm ≦ 5.5 × 10 ⁻⁴ The electrophotographic carrier according to claim 1, wherein the carrier is satisfied. 4. The electrophotographic device according to claim 1, wherein the carrier core is a magnetic material-dispersed resin carrier in which metal compound particles are dispersed in a binder resin. Career. 5. The carrier core contains at least two or more kinds of metal compound particles, the ratio of the metal compound to the binder resin is 80 to 99% by mass, and one of the metal compound particles is strong. A magnetic material, and the other is nonmagnetic metal compound particles having higher resistance than the ferromagnetic material, wherein the ratio of the ferromagnetic material to the total amount of the metal compound particles is 50 to 95% by mass. The electrophotographic carrier according to any one of claims 1 to 4, wherein: 6. The carrier core according to claim 1, wherein the carrier core contains magnetite as the ferromagnetic material, and contains hematite as at least one of the high-resistance metal compounds. Electrophotographic carrier. 7. The electrophotographic carrier according to claim 1, wherein the binder resin is a phenol resin. 8. The electrophotographic carrier according to claim 1, wherein said carrier core is produced by a polymerization method. 9. An electrostatic image carrier is charged by charging means, the charged electrostatic image carrier is exposed to form an electrostatic image on the electrostatic image carrier, and the electrostatic image is developed by a two-component system. A toner image is formed on an electrostatic image carrier by developing with a developing means having an agent, and the toner image on the electrostatic image carrier is transferred to a transfer material with or without an intermediate transfer member. A two-component developer used in an electrophotographic apparatus having an atmosphere heater capable of heating and controlling the inside of the apparatus, wherein the two-component developer is used for fixing a toner image on a transfer material by a heat-pressure fixing unit. It has a carrier and a toner, and the carrier has a water adsorption amount TL (mass%) after being left in an environment of 23 ° C. and 5% RH, and a surface area Sm (cm) of the carrier.
² / g) satisfy the following relationship: 1.1 × 10 ⁻⁴ ≦ TL / Sm, and the toner has an average circularity of 0.960 or more. 10. The amount of water adsorbed TH (mass%) after the carrier is left in an environment of 30 ° C. and 80% RH, and the amount of water adsorbed TL (mass%) of the carrier after being left in an environment of 23 ° C. and 5% RH. %) And the surface area Sm (cm ² / g) of the carrier satisfy the following relationship: 6.0 × 10 ⁻⁴ ≤ TH / Sm TL ≤ TH. Component developer. 11. The carrier has the following relationship: 6.0 × 10 ⁻⁴ ≦ TH / Sm ≦ 1.5 × 10 ⁻³ 1.1 × 10 ⁻⁴ ≦ TL / Sm ≦ 5.5 × 10 ⁻⁴ The two-component developer according to claim 9, wherein the developer is satisfied. 12. The two-component system according to claim 9, wherein the carrier core is a magnetic material-dispersed resin carrier in which metal compound particles are dispersed in a binder resin. Developer. 13. The carrier core contains at least two or more kinds of metal compound particles, wherein the ratio of the metal compound to the binder resin is 80 to 99% by mass, and one of the metal compound particles is strong. A magnetic material, and the other is nonmagnetic metal compound particles having higher resistance than the ferromagnetic material, wherein the ratio of the ferromagnetic material to the total amount of the metal compound particles is 50 to 95% by mass. The two-component developer according to any one of claims 9 to 12, wherein 14. The carrier core according to claim 9, wherein the carrier core contains magnetite as the ferromagnetic material and hematite as at least one of the high-resistance metal compounds. Two-component developer. 15. The two-component developer according to claim 9, wherein said binder resin is a phenol resin. 16. The two-component developer according to claim 9, wherein said carrier core is produced by a polymerization method. 17. The two-component developer according to claim 9, wherein at least silica fine particles and / or titanium oxide fine particles are externally added to said toner. 18. An electrostatic image carrier is charged by charging means, the charged electrostatic image carrier is exposed to form an electrostatic image on the electrostatic image carrier, and the electrostatic image is developed by a two-component system. A toner image is formed on an electrostatic image carrier by developing with a developing means having an agent, and the toner image on the electrostatic image carrier is transferred to a transfer material with or without an intermediate transfer member. An electrophotographic apparatus having an atmosphere heater capable of heating and controlling the inside of the apparatus, wherein the two-component developer has a carrier and a toner. , The carrier is 23 ° C., 5% R
The water adsorption amount TL (mass%) after being left in the H environment and the surface area Sm (cm ² / g) of the carrier satisfy the following relationship: 1.1 × 10 ⁻⁴ ≦ TL / Sm, An image forming apparatus having an average circularity of 0.960 or more. 19. The water adsorption amount TH (mass%) of the carrier after being left in an environment of 30 ° C. and 80% RH, and the water adsorption amount TL (mass) of the carrier after being left in an environment of 23 ° C. and 5% RH. %) And the surface area Sm (cm ² / g) of the carrier satisfy the following relationship: 6.0 × 10 ⁻⁴ ≦ TH / Sm TL ≦ TH Forming equipment. 20. The carrier has the following relationship: 6.0 × 10 ⁻⁴ ≦ TH / Sm ≦ 1.5 × 10 ⁻³ 1.1 × 10 ⁻⁴ ≦ TL / Sm ≦ 5.5 × 10 ⁻⁴ The image forming apparatus according to claim 18, wherein the image forming apparatus satisfies the condition. 21. The image forming apparatus according to claim 18, wherein the carrier core is a magnetic material-dispersed resin carrier in which metal compound particles are dispersed in a binder resin. . 22. The carrier core contains at least two or more kinds of metal compound particles, wherein the ratio of the metal compound to the binder resin is 80 to 99% by mass, and one of the metal compound particles is strong. A magnetic material, and the other is nonmagnetic metal compound particles having higher resistance than the ferromagnetic material, wherein the ratio of the ferromagnetic material to the total amount of the metal compound particles is 50 to 95% by mass. The image forming apparatus according to any one of claims 18 to 21. 23. The carrier core according to claim 18, wherein the carrier core contains magnetite as the ferromagnetic material, and contains hematite as at least one of the high-resistance metal compounds. Image forming device. 24. The image forming apparatus according to claim 18, wherein said binder resin is a phenol resin. 25. The image forming apparatus according to claim 18, wherein said carrier core is manufactured by a polymerization method. 26. An image forming apparatus according to claim 18, wherein at least silica fine particles and / or titanium oxide fine particles are externally added to said toner. 27. The image forming apparatus according to claim 18, wherein the image forming apparatus does not have a mechanism for collecting and storing the residual toner after transfer between the transfer position and the charging position of the electrostatic image carrier. An image forming apparatus according to any one of the above.