JPH0643686A - Electrostatic charge image developing method - Google Patents

Abstract

PURPOSE:To develop an electrostatic charge image with the durability of the pressure control body of a pressure-type developer, durability of the developer and cleanability improved by using a developer using a specified composite fine particle instead of the high-hardness inorg. fine particle. CONSTITUTION:A pressure control body 30 is opposed to a magnet body 21 and pressed by a developing sleeve 22, and the supply of a developer carried by the sleeve 20 to the developing region 40 is controlled. Sideway movement of the control body 30 is restricted by a holder 66 fixed to a housing 60, and the body is pressed on the sleeve 22 with a specified pressure. In this developing device, a developer obtained by adding the composite fine particle formed by fixing inorg. particles of 5-100nm size to the surface of an org. fine particle of 0.1-5mum size to the developer is used. Since the composite org. fine particle is easy to visco-elastically deform, the control body 30 is not damaged by the deformation buffer when there is the composite org. fine particle between the surface of the sleeve 22 and the control body 30.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an electrostatic image developer used in electrophotography, electrostatic recording and electrostatic printing.

[0002]

2. Description of the Related Art The development of an electrostatic image has been mostly shifted to dry development for convenience of handling, but as a dry developer, a one-component system containing a magnetic toner capable of forming a visible image and having a magnetic force transporting property. There is a developer and a two-component developer containing a colored toner that forms a visible image and a magnetic carrier that holds and conveys the toner and that contributes to triboelectric charging with the toner.

Such a developer is required to have many functional characteristics in terms of developability and fixability. For example, electrostatic, thermal or strength physical properties, chemical properties, flowability, and blocking of toner are required. The powder characteristics related to the particle size distribution, etc. are problematic, and accordingly, various additives for the shape and material of the toner particles, the forming method, and characteristic complementation are blended and used.

Further, in order to guarantee stability by repetition, the cleaning property must be good without the change of the constituent particles in the developer and the contamination of the photoreceptor and the like.

On the other hand, in electrophotography and the like, as a condition for forming a good image without unevenness, it is required that a thin developer layer having a uniform thickness can be stably supplied to the developing area.

Conventionally, there has been proposed a technique of using a developer amount regulator having various structures such as an elastic blade, an elastic roller, and a rotating roller as a developer amount regulating means.

In these conventional techniques, when the rotation speed of the developer transport body, the pressing position and the pressing force of the developer amount controlling body, etc. are changed, the change is easily affected, and the thin layer has a uniform thickness. It is still difficult to stably supply such a developer layer to the developing area.

Under these circumstances, a developer carrying body having a fixed magnet body inside thereof and having rigidity outside thereof and carrying a developer to a developing area, and the developing device at a position facing the magnet body are provided. The surface of the developer carrier is pressed to regulate the amount of the developer carried on the surface of the developer carrier to the developing area,
The pressing contact portion with the developer transport body has rigidity and magnetism,
A pressing type developing device provided with a rod-shaped developer amount pressing regulator having a contact pressing portion with a radius of curvature of 0.5 to 15 mm has been proposed (Japanese Patent Laid-Open No. 2-50184).

According to the above-mentioned pressing type developing device, it is possible to stably supply a thin developer layer having a uniform thickness to the developing region under an environment of normal temperature and normal humidity. When images were continuously formed in an environment of high temperature and high humidity of 33 ° C. and a relative humidity of 80%, there was a problem that white streaks or uneven density occurred in the obtained image.

That is, in the above-mentioned pressing method, when the developer passes between the developer amount pressing restricting body and the developer transporting body, the developer is rubbed against the pressing portion of the pressing restricting body so that the friction heat is generated. However, when images are continuously formed in an environment of high temperature and high humidity, the frictional heat is remarkably accumulated and the temperature of the pressing portion of the pressure regulating body gradually rises. . However, when this temperature exceeds the softening point of the binder resin of the toner constituting the developer, the toner is fused to the pressing portion of the pressure regulating body when the developer is rubbed by the pressing portion of the pressure regulating body, Due to the fused toner, unevenness occurs in the developer layer supplied to the developing area,
White streaks or uneven density occur in the resulting image.

In addition, it is known that inorganic fine particles having a polishing effect on the photoconductor are added to the developer in order to improve cleaning (Japanese Patent Laid-Open No. 60-136752). Since the inorganic fine particles are required to have a polishing effect, an inorganic material having a high hardness is used. However, in this case, when used in the above method, the pressure regulating body is scratched by being rubbed by these inorganic fine particles, which hinders the transportability of the developer and causes defects such as white streaks on the image again. Cause

As described above, it is necessary to combine a developer composition suitable for a developing method including a pressing method or a step in which a behavior similar to that of the pressing method is inherent.

[0013]

SUMMARY OF THE INVENTION It is an object of the present invention to provide an electrostatic charge image developing method having good durability, developer durability and cleanability of a pressing type developer amount pressing regulator based on the above circumstances. .

[0014]

The object of the present invention is a developing method in which a developer containing colored particles formed of at least a resin and a colorant and a carrier is conveyed to a developing area by controlling a developer layer by a pressing method. And 0.1 to 5 more in the developer.
It is achieved by an electrostatic charge image developing method characterized by using a developer obtained by adding and mixing composite fine particles formed by fixing inorganic fine particles of 5 to 100 nm on the surface of organic fine particles of μm.

In the present invention, not only the inorganic fine particles having high hardness but also the composite fine particles in which the inorganic fine particles are adhered to the surface of the organic fine particles are used, so that the cleaning property of the toner on the photosensitive member is maintained and the pressure regulating member is maintained. It became possible to reduce the abrasion effect.

That is, in the case of the composite fine particles in which the inorganic fine particles are adhered to the surface of the organic fine particles, the surface of the composite fine particles is coated with a material having a high hardness, so that the polishing effect on the photosensitive member is exhibited similarly to the inorganic fine particles. However, since the base particles of the composite fine particles are composed of organic fine particles, viscoelastic deformation is more likely to occur than the inorganic fine particles themselves. Therefore, the composite organic fine particles were present between the sleeve surface and the pressure regulator. In this case, no damage is caused by the deformation cushioning.

The above composite fine particles have an average particle diameter of 0.1 to 5
It is formed by fixing inorganic fine particles of 5 to 100 nm on the surface of organic fine particles of μm.

The average particle size of the organic fine particles constituting the composite fine particles is 0.1 to 5.0 μm, and particularly preferably 0.2 to 5.0 μm, from the viewpoints of improvement of cleaning property and stability of triboelectric charging property. The average particle size of the organic fine particles is the laser diffraction type particle size distribution measuring device "HELOS" equipped with a wet dispersion machine.
The average particle diameter on a volume basis measured by (manufactured by SYMPATEC).

The inorganic fine particles used in the present invention are particles having a primary particle diameter of 5 to 100 nm. The primary particle diameter of the inorganic fine particles is the number-based average particle diameter observed by a scanning electron microscope and measured by image analysis.

Examples of the material forming the inorganic fine particles include silicon oxide, titanium oxide, aluminum oxide, zinc oxide, zirconium oxide, cerium oxide, tungsten oxide, antimony oxide, copper oxide, tellurium oxide, manganese oxide, barium titanate, and titanium. Examples include strontium oxide, magnesium titanate, silicon nitride and carbon nitride.

Particularly suitable as these inorganic fine particles are titanium oxide, alumina oxide and zirconium oxide.
The reason for this is that these materials have a small surface area and little water adsorption.

The inorganic fine particles constituting the composite fine particles are subjected to a hydrophobic treatment, and it is particularly preferable that the degree of hydrophobicity is 30 or more. The hydrophobicity is measured by the methanol wettability method.

As the hydrophobic treatment agent for the inorganic fine particles, a titanium coupling agent, a silane coupling agent, a long-chain carboxylic acid and its metal salt, a surfactant and the like are used.

The composite fine particles are formed by adhering hydrophobically treated inorganic fine particles on the surface of organic fine particles. Here, “fixed” means that the inorganic fine particles are not simply attached to the resin particles by an electrostatic force, but the length of the portion of the inorganic fine particles embedded in the resin particles is 5 to 95%. Such a state can be confirmed by observing the surface of the composite fine particles with a transmission electron microscope or an ordinary electron microscope.

When fixing the inorganic particles to the surface of the resin particles, it is preferable to first make the organic particles spherical and then fix the inorganic particles to the surface of the organic particles. This is because when the organic fine particles are spherical, the inorganic fine particles are fixed uniformly and the release of the inorganic fine particles is effectively prevented.

As means for making the organic fine particles spherical,
A method in which resin particles are once melted by heat and then spray-granulated, a method in which hot-melted resin particles are jetted into water to form spheres, and a spherical resin particle is prepared by suspension polymerization method or emulsion polymerization method. Examples thereof include a method of synthesizing.

Means for fixing the inorganic fine particles to the surface of the organic fine particles include a method of mixing the organic fine particles and the inorganic fine particles and then applying heat, a so-called mechanochemical method of mechanically fixing the inorganic fine particles to the surface of the organic fine particles. The method is used.

Specifically, organic fine particles and inorganic fine particles are mixed and stirred and mixed by a Henschel mixer, a V-type mixer, a turbula mixer, etc., the inorganic fine particles are adhered to the surface of the organic fine particles by electrostatic force, and then the surface is Introduce organic fine particles with inorganic fine particles attached to a heat treatment device such as a nilo atomizer or a spray dryer, and apply heat to soften the surface of the organic fine particles to fix the inorganic fine particles to the surface, or electrostatic force on the surface of the organic fine particles. After adhering the inorganic fine particles to the surface of the organic fine particles by using a device such as an Ong mill, a free mill, a hybridizer or the like, which is modified from the impact type crusher and can give mechanical energy. The method of making it etc. are used.

When the composite fine particles are obtained, the amount of the inorganic fine particles to be mixed with the organic fine particles may be an amount that can uniformly cover the surface of the organic fine particles. Specifically, depending on the specific gravity of the inorganic fine particles, for organic fine particles,
Usually, the inorganic fine particles are used in a proportion of 5 to 100 wt%, preferably 5 to 80 wt%. If the proportion of the inorganic fine particles is too small, the cleaning property tends to deteriorate, and conversely, if the proportion of the inorganic fine particles is too large, the inorganic fine particles are likely to be released.

When the composite fine particles are added to the developer and used, the amount added is controlled depending on the surface area of the colored particles, but generally the present invention is applied to the colored particles having a volume average particle diameter of 11 μm. 0.01 ~ 5.0wt%, preferably 0.1
It is recommended to use ~ 2.0wt%. If the addition amount is too small, cleaning failure occurs (toner adheres to the photoconductor and black spots appear as an image). On the other hand, when the amount is too large, the development is adversely affected and, for example, the density is lowered. When the average particle size of the colored particles is different, it is advisable to add them in a ratio of the surface area based on the surface area of the particles of 11 μm described above. Specifically, for a toner of 5.5 μm, this addition amount is required to be 4 times. That is, it is advisable to add it as the square of the ratio of the average particle diameter.

The organic fine particles constituting the composite fine particles are preferably resin particles made of an acrylic polymer, a styrene polymer, a styrene-acrylic polymer or the like.

The acrylic polymer constituting the organic fine particles is a homopolymer or a copolymer obtained by polymerizing a monomer selected from acrylic acid or acrylic acid ester, methacrylic acid or methacrylic acid ester. Acrylic monomers used to obtain such acrylic copolymers include acrylic acid, methyl acrylate, ethyl acrylate, n-butyl acrylate, isobutyl acrylate, propyl acrylate, n-acrylate.
Actyl, dodecyl acrylate, lauryl acrylate,
2-ethylhexyl acrylate, stearyl acrylate,
2-Chloroethyl acrylate, Phenyl acrylate, α-
Propyl chloroacrylate, n-butyl methacrylate, isobutyl methacrylate, n-octyl methacrylate, dodecyl methacrylate, lauryl methacrylate, 2-ethylhexyl methacrylate, stearyl methacrylate, phenyl methacrylate, dimethylaminoethyl methacrylate,
Diethylaminoethyl methacrylate and the like can be mentioned.

An acrylic polymer can be obtained from one or more of the above acrylic monomers, but in the present invention, one or more other monomers are copolymerized with other monomers, if necessary. It may be In this case, it is preferable to use the acrylic monomer in a proportion of 50% by weight or more in the monomer composition.

Examples of the styrene-based monomer used to obtain the styrene-based polymer that constitutes the organic fine particles include styrene, o-methylstyrene, m-methylstyrene, p-methylstyrene, α-methylstyrene, p- Ethylstyrene, 2,4
-Dimethylstyrene, pn-butylstyrene, p-tert-butylstyrene, pn-hexylstyrene, pn-octylsulstyrene, pn-nonylstyrene, pn-decylstyrene,
Examples thereof include pn-dodecylstyrene, p-methoxystyrene, p-phenylstyrene, p-chlorostyrene, and 3,4-dichlorostyrene.

A styrenic polymer is obtained from one or more of the above-mentioned styrenic monomers, but in the present invention, one or more other monomers are copolymerized, if necessary. It may be one. In this case, it is preferable to use the styrene-based monomer in the monomer composition in a proportion of 50% by weight or more.

The styrene-acrylic copolymer constituting the organic fine particles can be obtained by using one or more of the above acrylic monomers and one or more of the above styrene monomers. If necessary, one or more other monomers may be copolymerized. In that case, it is preferable that the total amount of the acrylic monomer and the styrene monomer in the monomer composition is 50% by weight or more.

Examples of the other monomer include acrylic acid or methacrylic acid derivatives such as acrylonitrile, methacrylonitrile and acrylamide, vinyl esters such as vinyl acetate, vinyl butyrate and vinyl benzoate, vinyl methyl ether, vinyl ethyl ether. And vinyl ethers, vinyl methyl ketones, butadiene, isoprene, and other dienes, maleic acid, fumaric acid, and other unsaturated carbodienoic acids, and the like.

The colored particles constituting the developer of the present invention are colored particles containing at least a resin and a colorant. The average particle size of the colored particles is usually in the range of 1 to 30 μm.

As the resin constituting the colored particles, polyester resin, styrene resin, acrylic resin, styrene-acrylic copolymer resin, epoxy resin and the like are used.

For the colored particles used in the present invention, all the colorants used in ordinary toners can be used. Specifically, carbon black, magnetite, nigrosine dye, aniline dye, ferrite and the like can be used. The addition amount of the colorant is controlled as necessary, but generally 0.1 to 10 wt% is added. When used as a magnetic toner, it is preferable to add 20 to 70 wt% of magnetic powder in order to retain the toner on the magnetic brush.

It is also possible to add and use a fluidity improver such as hydrophobic silica or a cleaning aid such as fatty acid metal salt. When addition and mixing are performed, it is preferable that the particles are present in a free state rather than being fixed to the colored particles. In addition, when mixing is performed, a turbula mixer,
It is preferable to mix using a Henschel mixer or the like.

The colored particles contain a binder resin, a colorant, and other additives such as a charge control agent and a release agent, which are optionally used, and the average particle size thereof is usually 1 to 30 μm
Is the range.

The charging polarity of the colored particles themselves is determined by the developing method. The chargeability of the colored particles can be controlled by the type and amount of the charge control agent, the combination with the resin and the like.
Examples of the charge control agent include salicylic acid derivatives and metal-containing complexes.

Examples of the releasing agent include low molecular weight polyolefin and the like.

In the present invention, when a two-component developer is prepared, a carrier is further used in addition to the colored particles and the composite organic fine particles.

The carrier is not particularly limited, but an uncoated carrier made of magnetic particles, a resin-coated carrier obtained by coating the surface of the magnetic particles with a resin, and magnetic particles dispersedly contained in a binder resin. The magnetic substance-dispersed carrier and the like can be used.

The magnetic particles constituting the carrier include
A substance that is strongly magnetized in that direction by a magnetic field, such as iron,
Ferrite, magnetite, iron, nickel, cobalt and other metals or alloys exhibiting ferromagnetism, compounds containing these elements, alloys containing no ferromagnetic elements but exhibiting ferromagnetism by appropriate heat treatment, For example, particles made of an alloy of a type called a Heusler alloy such as manganese-copper-aluminum or manganese-copper-tin or chromium dioxide can be used.

As the coating resin for the resin-coated carrier or the binder resin for the magnetic substance-dispersed carrier, for example, a styrene-acrylic copolymer, a silicone compound, a fluorine resin or the like can be preferably used.

The average particle size of the carrier is preferably 20 to 200 μm, particularly preferably 40 to 150 μm. When the average particle size is too small, the carrier adheres to the electrostatic latent image to form a fixed image, so-called carrier adhesion phenomenon occurs, and as a result, the image may become unclear, while when the average particle size is too large, the image Flow may occur.

In the pressing method in the developing method of the present invention, the radius of curvature of the pressing regulator is preferably 0.5 to 15 mm.

When the radius is small, there is a problem that the transportability is not stable, and further there is a problem in the manufacturing stability. On the other hand, when the radius is large, the stress on the developer layer becomes large and the durability of the developer is lowered. The preferred range is
It is 1.0 to 10 mm.

The pressing force of the pressing regulator is 1 to 15 gf / mm.
Is preferred.

When the pressing force is small, the regulation force is insufficient and the conveyance becomes unstable. On the other hand, when the pressing force is large, the stress on the developer increases, so that the durability of the developer decreases. The preferred range is 3 to 10 gf / mm.

According to the pressing method under the above conditions, even if the rotation speed of the developer transporting member, the pressing position by the developer amount regulating member, the pressing force and the like change under the environment of normal temperature and normal humidity, this change It is possible to stably supply a thin developer layer having a uniform thickness to the developing area without being affected. Then, for example, even in an environment of high temperature and high humidity of 33 ° C. and 80% relative humidity, toner fusion to the developer amount regulating member is effectively prevented, and a thin developer layer having a uniform thickness is formed. It can be stably supplied to the developing area.

The thin developer layer means a developer layer of 100 to 500 μm in the developing area.

Therefore, good development without unevenness can be achieved in both environments of normal temperature and normal humidity and high temperature and high humidity, and an image without white streaks and uneven density can be stably formed.

FIG. 1 shows a structural example of a developing device applied to the present invention. In FIG. 1, 20 is a developer transport body, 30
Is a developer amount pressing regulator.

The magnet body 21 constituting the developer transport body 20 is fixed inside the developer transport body 20, and N poles and S poles are alternately arranged on the outer periphery thereof.

The developing sleeve 22 constituting the surface of the developer carrier 20 is made of rigid non-magnetic stainless steel and is rotated in the direction of the arrow.

The pressure regulating body 30 has a cylindrical rod shape with a radius of curvature of 3 mm in cross section and is made of magnetic stainless steel (SUS416) which is a material having rigidity and polarity.

The pressing restricting body 30 is arranged in a state of being pressed by the developing sleeve 22 at a position facing the magnet body 21, and the developing area of the developer carried on the developing sleeve 22.
It regulates the amount supplied to 40.

The pressure regulating body 30 is grinded to a surface roughness of 0.5 S and is not provided with a surface coating. In addition, you may provide a surface coating as needed.

The pressing regulator 30 is restrained from lateral movement by a holder 66 attached to the housing 50.
Moreover, it is pressed against the developing sleeve 22 with a pressing force of 1 to 15 gf / mm.

In FIG. 1, 10 is an image forming body, 61 is a first stirring member, 62 is a second stirring member, 63 is a supply roller, 64 is a scraper, and 65 is a stirring partition plate.

In this developing device, the toner in the container rotates the first stirring member 61 rotating in the arrow direction and the second stirring member 62 rotating so as to overlap each other in the opposite direction.
After being sufficiently agitated and mixed with the carrier by means of, the toner is conveyed to the surface of the developing sleeve 22 by the supply roller 63. That is, the first stirring member 61 and the second stirring member 62 are screw-shaped members having a left-handed helix angle that rotate in mutually opposite arrow directions, and are pushed backward by the thrust of the second stirring member 62. The conveyed toner and carrier successively pass over the agitating partition plate 65 whose upper edge is slanted toward the back side of the drawing, move to the first agitating member 61 side, and are conveyed to the front side of the drawing by its thrust, and in the meantime. Friction charging is performed by the stirring and mixing action of the toner and the carrier. Then, the developer is deposited in layers on the peripheral surface of the developing sleeve 22 by the supply roller 63 rotating in the arrow direction.

The developer adhered on the developing sleeve 22 is
A thin layer is formed when passing between the pressure regulation body (30).

The gap between the developing sleeve surface and the photoreceptor surface is
It may be larger or smaller than the layer thickness of the developer layer. Further, the developing bias may be only the DC component, but the AC bias may be applied simultaneously.

[0068]

EXAMPLES Hereinafter, more specific examples will be described, but the present invention is not limited to these examples.

The surface-treated inorganic fine particles, colored particles, and composite fine particles were prepared as the developers of this example and the comparative example as follows, and a two-component developer was prepared, and the performance was evaluated.

A. Example of colored particle preparation Polyester resin 100 parts Low molecular weight polypropylene 4 parts Carbon black 10 parts Metal-containing complex dye 1 part The above are mixed in a Henschel mixer, melt-kneaded and pulverized.
Classified, the volume average particle size by coulter counter is 11μ
m colored particles were obtained.

B. Preparation example of composite fine particles Preparation example 1 of composite fine particles
40 g of hydrophobic titanium oxide whose surface having a primary particle diameter of 15 nm was treated with aluminum stearate was added to g and mixed with a turbula mixer. Then, using a hybridizer (manufactured by Nara Machinery Co., Ltd.) with a modified crusher, a peripheral speed of 100 m / se
The composite fine particles in which titanium oxide was adhered to the surface of the organic fine particles were prepared by treating under the condition of c for 3 minutes. This is referred to as "composite fine particle 1".

Preparation Example 2 of Composite Fine Particles In Preparation Example 1 of composite fine particles, organic fine particles having an average particle diameter of 2.0 μm were used in place of the organic fine particles having an average particle diameter of 1.0 μm, and the surface was surfaced with trimethoxyoctylsilane. Composite fine particles were obtained in the same manner except that 30 parts of the treated hydrophobic titanium oxide was used. This is referred to as "composite fine particle 2".

Composite Fine Particle Preparation Example 3 Composite fine particles were obtained in the same manner as in the composite fine particle preparation 1 except that aluminum stearate was used for the surface having a primary particle diameter of 20 nm instead of the hydrophobic titanium oxide. This is referred to as "composite fine particle 3".

C. Preparation Example of Developer 0.4 wt% of hydrophobic silica (R-972: manufactured by Nippon Aerosil Co., Ltd.) was added to the above-mentioned colored particles, and composite fine particles were further added to obtain a toner. In addition, these toners and the average particle size
A carrier coated with a styrene-methylmethacrylate copolymer (composition ratio: styrene: methylmethacrylate = 60: 40) in a thickness of 1.0 μm on the surface of 40 μm ferrite particles was mixed to adjust the toner amount to 7 wt%. To obtain a developer.

The developers shown in Table 1 below were prepared according to the type and addition amount of the composite fine particles. For comparison with the present invention, a developer containing strontium titanate having an average particle diameter of 1.0 μm instead of the composite particles and a developer containing no composite particles were prepared.

[0076]

[Table 1]

As an evaluation, a copying machine DC-8028 manufactured by Konica
Was modified to use a laminated organic photoconductor, and evaluation was performed using a developing device as shown in FIG.

The developing conditions and apparatus conditions are shown below.

[0079] Development conditions: the photosensitive member surface potential = -550 V DC bias = -250 V AC bias = V _PP: -50~-450V frequency = 1.8kHz Dsd = 300μm (gap of the developer layer and the photosensitive member) pressure = 10 gf / Mm Pressing regulator = Magnetic stainless steel (SUS416), Radius = 3 mm The evaluation conditions are 20,000 sheets of printing under low temperature and low humidity (10 ° C / 20% RH) environment, and whether there is an image defect and pressing regulation. The presence or absence of body damage was evaluated. The results are also shown in Table 1.

[0080]

According to the constitution of the present invention, no image defect is caused in repeated use, and no damage is caused on the pressure regulating body.

[Brief description of drawings]

FIG. 1 is a cross-sectional view of an example of a developing device that can be used for implementing the present invention.

[Explanation of symbols]

 10 Image Forming Body 20 Developer Conveying Body 21 Magnet Body 22 Developing Sleeve 30 Developer Amount Pressing Limiting Body 40 Developing Area 50 Housing 61 First Agitating Member 62 Second Agitating Member 63 Supply Roller 64 Scraper 65 Agitating Partition Plate 66 Holder

 ─────────────────────────────────────────────────── ─── Continuation of the front page (72) Inventor Watako Ohira Konica Co., Ltd. 2970 Ishikawacho, Hachioji City, Tokyo

Claims (1)

[Claims] 1. A developing method in which a developer containing colored particles formed of at least a resin and a colorant and a carrier is conveyed to a developing area by controlling a developer layer by a pressing method to convey the developer. A method of developing an electrostatic charge image, further comprising using a developer obtained by adding and mixing composite fine particles formed by fixing inorganic fine particles of 5 to 100 nm on the surface of organic fine particles of 0.1 to 5 μm.