JPH11258857A - Carrier for developing electrostatic charge image, its production, electrostatic charge image developer, image forming method and apparatus for producing silicon resin coated carrier - Google Patents

Abstract

PROBLEM TO BE SOLVED: To obtain a fog-free carrier by spray-coating a layer of magnetic material particles in horizontal revolving motion with a coating fluid from the rear for the progress direction of the revolution to form silicone resin coatings on the surfaces of the magnetic material particles and drying the coating fluid. SOLUTION: Magnetic material particles are put in a cylindrical apparatus, a plate-shaped rotator 33 is rotated at a high speed and a heated air flow is introduced into the apparatus from the gap between the inner wall of the apparatus and the rotating body 33. A layer of the magnetic material particles revolving in a rope form near the peripheral edge of the rotator 33 is sprayed with a coating fluid by means of sprays 34 from the rear for the progress direction of the revolution to form silicone resin coatings on the surfaces of the particles. The coating fluid on the particles is then dried with a dried air flow(AF) and optionally further heat-treated. The surfaces of the magnetic substance particles are thus uniformly coated with coatings of a silicone resin compsn.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for producing a silicone-based resin-coated carrier by spraying a coating solution obtained by dissolving a silicone-based resin composition in a solvent into a magnetic particle layer horizontally rotating in a rope shape. The present invention relates to a method, an electrostatic image developing carrier obtained by the manufacturing method, a developer using the electrostatic image developing carrier, an image forming method, and an apparatus for manufacturing a silicone resin-coated carrier.

[0002]

2. Description of the Related Art Conventionally, as a developer used in electrophotography and the like, a one-component developer composed of only a toner and a two-component developer composed of a carrier and a toner are known. Of these, the two-component developer has a more stable charging property and does not require the inclusion of magnetic particles in the toner, so that the saturation of the toner image is high and it is suitable for a color image. Accordingly, two-component developers are more commonly used today.

Among them, a two-component developer using a carrier in which the surface of magnetic particles is coated with a resin (hereinafter, also referred to as a coating carrier) is particularly preferably used because of its excellent durability and triboelectric charging properties. Have been.

However, when a phenomenon in which a part of the toner constituents adheres and fuses to the carrier surface (hereinafter, also referred to as a toner spent phenomenon) occurs, the ability of the carrier to impart triboelectricity to the toner is reduced, and the background fog, The toner scatters in the machine.

In addition, the magnetic particles themselves are exposed on the carrier surface due to wear of the coating resin layer due to repeated use or peeling of the coating resin layer. , Fog of the ground and scattering of the toner in the machine.

Particularly, in continuous copying, since a large shearing force is applied to the toner and the carrier, the coating resin is easily worn and peeled off, and the toner spent phenomenon is accelerated. That is, it is the durability of the carrier itself that determines the durability of the two-component developer.

[0007] In recent years, silicone resins have been proposed as coating resins for achieving high durability of the carrier itself.

[0008] This is because the silicone resin has a three-dimensional cross-linked structure, so that the abrasion resistance can be greatly improved. Further, since the silicone resin itself is a low surface energy material, the toner spent phenomenon is reduced. Is less likely to occur, thereby achieving high durability.

As a method for producing a silicone resin-coated carrier, conventionally, (1) a coating solution prepared by dissolving a coating resin in a solvent is spray-coated on the surface of magnetic particles using a fluidized bed, Subsequently, a method of obtaining a coating carrier by drying [fluid type (also referred to as fluidized bed type) spray coating method], (2) immersing magnetic particles in a coating solution prepared by dissolving a coating resin in a solvent, A method of coating and then drying to obtain a coating carrier [immersion coating method], (3) A coating solution prepared by dissolving a coating resin in a solvent is applied to the surface of the magnetic particles, and then baked. A method of sintering to obtain a coating carrier [sintering type coating method] is known.

However, in the techniques (1), (2) and (3), a coating solution prepared by dissolving a coating resin in a solvent is used to coat the surface of the magnetic particles with a resin coating layer. This is a so-called wet coating method for forming, so that there is an essential problem that granulation is apt to occur during the coating treatment and the yield is low.

A step of pulverizing the granulated material for the purpose of improving the yield can be added, but the exposing of the magnetic material surface of the granulated material due to the pulverization, the peeling of the resin coating layer, the magnetic particle Since there was a problem that the carrier itself was cracked and the triboelectricity of the carrier was deteriorated, no combination of a wet coating method and a crushing method capable of obtaining a carrier having a good coating layer has been found. This is the actual situation.

Further, when a silicone resin-coated carrier is used for a two-component developer, there is an essential problem that a phenomenon that a charge amount gradually increases by repeated use, that is, a so-called charge-up phenomenon occurs. doing.

In particular, during continuous copying, a large shear force is applied to the toner and the carrier, so that the charge-up phenomenon becomes remarkable.

Therefore, Japanese Patent Application Laid-Open No. 64-91144 discloses that
A method of stabilizing the charge amount by applying mechanical stirring in advance until the charge amount of the toner and the carrier becomes 1.2 to 2.5 times has been proposed.

However, in this method, a mechanical impact force is continuously applied until the charge amount is stabilized, so that an excessive impact force is applied and the silicone-coated resin of the carrier is damaged. When this carrier is used, there is a problem that the amount of charge of the developer decreases when copying is repeated, and the occurrence of background fog and toner scattering increase. That is, there is a problem that the durability of the developer is reduced.

[0016]

As a result of repeated studies by the present inventors, when a carrier coated with a silicone resin is manufactured by applying a conventional wet coating method,
In the conventional wet coating method, as the particle diameter of the magnetic particles becomes smaller, the chance that the magnetic particles contact each other on the surface through the coating magnetic layer increases, and the frictional force between the magnetic particles decreases. As a result, it becomes difficult to disintegrate the magnetic particles from each other, and as a result, it is difficult to achieve an efficient coating treatment with a very low yield. It turned out that there is still room for improvement.

The present invention has been made in view of the circumstances described above, and it is an object of the present invention to provide a method for exposing the surface of magnetic particles, remarkably uneven resin coating film thickness, and peeling of a resin coating layer. It has a good silicone-based resin coating layer with no defects in the coating film, and further suppresses the charge-up phenomenon in which the charge amount gradually increases due to repeated use, and a stable charge amount can be obtained from the beginning of copying. As a result, a carrier in which a high-quality image with high density and no fog can be obtained for a long period of time, a method of manufacturing the carrier, an apparatus of manufacturing the carrier,
An object of the present invention is to provide a developer and an image forming method.

[0018]

The above object of the present invention is achieved by the following constitution.

(1) In a carrier in which a silicone resin is coated on the surface of magnetic particles, the carrier coated with the silicone resin is coated with a coating solution prepared by dissolving a silicone resin composition in a solvent. Spray-coating is applied from the back to the direction of the rotatable rotation of the magnetic particles in the magnetic particle layer which is horizontally rotating in a rope shape, after forming a silicone resin film on the magnetic material surface. A carrier for developing an electrostatic charge image, which is obtained by a method for producing a carrier for developing an electrostatic charge image, which is dried, and optionally heat-treated to obtain a carrier coated with a silicone resin.

(2) A method for producing a silicone resin-coated carrier in which a coating solution prepared by dissolving a silicone resin composition in a solvent is coated on the surfaces of magnetic particles.
A coating solution prepared by dissolving a silicone resin composition in a solvent is sprayed from the back into the magnetic particle layer that is horizontally rotating in a rope shape with respect to the direction of the rope rotation of the magnetic particles. A method for producing a carrier for developing an electrostatic image, comprising applying a silicone-based resin film on the surface of a magnetic material, followed by drying and, if necessary, heat treatment to obtain a silicone-based resin film carrier.

(3) Coating solution prepared by dissolving a silicone resin composition in a solvent in an electrostatic image developer comprising a toner and a carrier containing at least a binder resin and a colorant. Was spray-coated from the back with respect to the traveling direction of the rope-like rotation of the magnetic particles in a magnetic particle layer horizontally rotating in a rope-like manner, thereby forming a silicone-based resin film on the surface of the magnetic substance. Thereafter, drying and, if necessary, heat treatment are performed to obtain a silicone-based resin film carrier. The electrostatic image developer is a silicone-based resin film carrier obtained by a method for producing a carrier for electrostatic image development.

(4) An electrostatic image developer consisting of a toner and a carrier containing at least a binder resin and a colorant is applied to a developer layer having a thickness of 20 to 500 by a developer regulating member.
μm, and the carrier is prepared by dissolving a silicone-based resin composition in a solvent. Spray-coating is applied to the moving magnetic material particle layer from the rear in the direction of the rope-like rotation of the magnetic material particles to form a silicone-based resin film on the magnetic material surface, followed by drying and drying as necessary. An image forming method, wherein the carrier is a silicone-based resin-coated carrier obtained by a method for producing a carrier for developing an electrostatic image, wherein the carrier is subjected to a heat treatment.

(5) A magnetic particle layer is formed by a dish-shaped rotator rotating horizontally and at a high speed and a gap air flow supplied from the outside of the dish-shaped rotator, and the magnetic particle layer is horizontally rotated in a rope shape. A mechanism for dissolving the silicone-based resin composition in a solvent from the back in the direction of the progress of the rope-like horizontal rotation of the magnetic particles in the magnetic particle layer horizontally rotating in the rope-like shape. An apparatus for producing a carrier coated with a silicone resin, comprising: a mechanism for spraying a coating liquid; and a mechanism for forming a silicone resin coating on the surface of magnetic particles, followed by drying and heat treatment as necessary.

That is, the inventors of the present invention apply the magnetic particles by spraying a coating solution obtained by dissolving a silicone resin composition in a solvent into a magnetic particle layer horizontally rotating in a rope shape. As a result, the present inventors have found that a carrier having a good silicone-based resin coating layer can be obtained, thereby completing the present invention.

Hereinafter, the present invention will be described in detail.

The carrier of the present invention is a resin-coated carrier in which the surface of magnetic particles is coated with a silicone resin. Examples of the magnetic particles used in the present invention include iron powder, magnetite, various ferrites, and composite magnetic particles (a so-called resin dispersion type) composed of a resin and a magnetic material obtained by a melt kneading method, a melt spraying method, a polymerization method, or the like. Carrier having the same configuration as the carrier).

Preferred are magnetite, various ferrites, and composite magnetic particles.

As ferrite, copper, zinc, nickel,
Ferrite containing a heavy metal such as manganese and light metal ferrite containing an alkali metal and / or an alkaline earth metal are preferred, and light metal ferrite containing an alkali metal and / or an alkaline earth metal is particularly preferred.

The composition of the magnetic material contains an alkali metal such as Li and Na and / or an alkaline earth metal such as Mg, Ca, Sr and Ba, and has the following composition.

(M ₂ O) _x (Fe ₂ O ₃ ) _{1 -x} or (M
O) _x (Fe ₂ O ₃ ) _{1 -x} Further, M ₂ O and / or Fe ₂ O ₃ may be partially substituted with an alkaline earth metal oxide. M is an alkali metal such as Li and Na described above and / or M
The alkaline earth metals of g, Ca, Sr, and Ba are shown. Further, x is 30 mol% or less, preferably 18 mol%.
1% or less, and preferably 1 to 10 mol% of the alkaline earth metal and / or alkali metal oxide to be further substituted. More preferably, it is 3 to 15 mol%.

The reason why the light metal ferrite or magnetite is preferable is not limited to the problem of environmental pollution of waste, which has become severe in recent years. This is because, in addition to these, the carrier itself can be reduced in weight, and there is an advantage that stress on the toner can be reduced.

The average particle diameter of the magnetic particles is 50 μm.
Below, and preferably 8 to 45 μm. 15 to 35
μm is preferred. The saturation magnetization is preferably 20 to 80 emu / g.

The silicone resin coated on the surface of the magnetic particles of the present invention may be any conventionally known silicone resin, and may be an organosiloxane represented by the following general formula (1). Straight silicone and alkyd, polyester, consisting only of bonds
A silicone resin modified with epoxy, urethane, or the like may be used.

[0034]

Embedded image General formula (1)

(Wherein R ¹ and R ⁴ are each a hydrogen atom,
An alkyl group having 1 to 4 carbon atoms or a phenyl group, R ² and R ³ are a hydrogen atom, an alkoxy group having 1 to 4 carbon atoms, a phenyl group, a phenoxy group, an alkenyl group having 2 to 4 carbon atoms,
An alkenyloxy group having 2 to 4 carbon atoms, a hydroxy group, a carboxyl group, an ethylene oxide group, a glycidyl group or

[0036]

Embedded image

(R ⁵ is a hydroxy group, a carboxyl group,
An alkyl group having 1 to 4 carbon atoms, an alkoxy group having 1 to 4 carbon atoms, an alkenyl group having 2 to 4 carbon atoms, an alkenyloxy group having 2 to 4 carbon atoms, a phenyl group or a phenoxy group), R ⁵
And R ⁴ are the same. k, l, m, n, p, and q represent an integer of 1 or more. ).

Each of these substituents is unsubstituted,
For example, it may have a substituent such as an amino group, a hydroxy group, a carboxyl group, a mercapto group, an alkyl group, a phenyl group, an ethylene oxide group, a glycidyl group, and a halogen atom.

The silicone resin coating the magnetic particles of the present invention is a condensation reaction type silicone resin which cures by a heat dehydration condensation reaction, a room temperature moisture curing reaction, etc., and is represented by the following general formula (2) or (3). It has been cured by the reaction shown by.

[0040]

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In the formula, R ₁ and R ₂ each represent a substituent such as an alkyl group, and OX represents an alkoxy group, a ketoxy group, an acetoxy group, an aminoxy group or the like. Among them, those in which the substituent is a methyl group have a dense coating layer and can be a carrier having good durability.

Commercially available straight silicone resins include KR271, KR255 and KR1 manufactured by Shin-Etsu Chemical Co., Ltd.
52, Dow Corning Toray Silicone SR2
411 and SR2405. In addition, commercially available modified silicone resins include KR206 manufactured by Shin-Etsu Chemical Co., Ltd.
(Alkyd modification), KR5208 (acrylic modification),
ES1001N (epoxy-modified), KR305 (urethane-modified), S by Dow Corning Toray Silicone
R2115 (epoxy modification), SR2110 (alkyd modification) and the like.

The silicone resin composition is coated on the surface of the magnetic particles by spray coating as a coating solution prepared by dissolving in a solvent.

Solvents for dissolving the silicone resin composition include toluene, xylene, benzene, MEK, MIB
K and the like.

The resin solid content of the commercially available silicone resin is generally adjusted to 30 to 50%. In the present invention, a coating liquid is prepared by diluting with a solvent described above to a resin solid content concentration suitable for spray coating. The resin solids concentration of the coating solution varies depending on the type of the resin, the magnetic particles and the surface condition, but is preferably 4 to 20% by weight. If the resin solids concentration exceeds 20% by weight, the formation of granules becomes remarkable, and the yield and the film forming properties of the obtained carrier are poor. On the other hand, if the content is less than 4% by weight, there is a problem that the coating takes a long time and productivity is poor.

The silicone resin forms a three-dimensional network structure by condensation reaction (hereinafter referred to as “curing”), and an organic metal salt or an amine is added as a catalyst for accelerating the curing.
As the organic metal salt, an organic tin compound, an organic aluminum compound, an organic zinc compound, an organic titanium compound or the like is used. Particularly, a compound represented by the following structure is preferably used.

[0047]

Embedded image

The coating solution of the present invention comprises a silicone resin composition,
A diluting solvent, a curing catalyst, a silane coupling agent, and the like, if necessary, are homogenized by stirring and mixing using a homogenizer or the like.

The silicon-based resin coating layer of the present invention can contain a silane coupling agent for improving the film forming property and stabilizing the charging property.

As the silane coupling agent contained in the coating layer, a compound represented by the following general formula (4) is effective.

YRSix ₃ General formula (4) In the formula, X is a hydrolyzable group bonded to a silicon atom, such as a chloro group, an alkoxy group, an acetoxy group, an alkylamino group or a propenoxy group, and Y is an organic matrix. R is a C1-20 alkyl or alkylene group such as a vinyl group, a methacryl group, an epoxy group, a glycidoxy group, an amino group, and a mercapto group.

Among these silane coupling agents, an aminosilane coupling agent having an amino group in Y is preferable for obtaining a developer having a negative charge property, and an epoxy silane coupling agent having an amino group for Y is preferable for obtaining a developer having a positive charge property. Epoxysilane coupling agents having groups are preferred. Specific examples of the silane coupling agent include the following.

[0053]

Embedded image

[0054]

Embedded image

[0055]

Embedded image

In order to coat the surface of the magnetic particles of the present invention with a silicon resin, a magnetic particle layer is formed by a dish-shaped rotator rotating horizontally and at high speed and a gap air flow supplied from the outside of the dish-shaped rotator. And a mechanism for horizontally rotating the layer magnetic material layer in a rope shape, in the magnetic particle layer moving horizontally in the rope shape with respect to the traveling direction of the rope-like horizontal rotation of the magnetic material particle layer. And a mechanism for spraying a coating solution prepared by dissolving the silicone-based resin composition in a solvent from the rear, and forming a silicone-based resin coating on the surfaces of the magnetic particles, followed by drying and heat treatment as necessary. An apparatus for producing a silicone-based resin-coated carrier having a mechanism is used.
As such a device, for example, an apparatus as shown in FIG. 4 is used.

FIG. 4 is a schematic sectional view showing an example of an apparatus for producing a silicone resin-coated carrier according to the present invention.

In this figure, a silicone-based resin-coated carrier manufacturing apparatus 31 is roughly divided into a cylindrical outer cylinder 32 having a predetermined diameter, and the outer cylinder 32 rotatably disposed inside the outer cylinder 32. A rotating body 33 having a diameter slightly smaller than the inner diameter of the rotating body 32, a spray 34 disposed on the rotating body 33 and spraying a coating liquid, and a lower part of the rotating body 33 of the outer cylinder 32. Supply air to the dish-shaped rotating body 3
An air supply device 35 for generating a gap air flow from a gap between the outer cylinder 3 and the outer cylinder 32, and a heater 36 for heating the supply air supplied from below the dish-shaped rotating body 33 are provided.

The outer cylinder 32 is made of a material such as iron, synthetic resin, or the like, and is formed of a cylindrical small-diameter portion 32a having a predetermined diameter and a large-diameter portion 32b having a diameter larger than the diameter. I have. Further, the outer cylinder 32 is arranged such that the small diameter portion 32a is on the lower side and the large diameter portion 32b is on the upper side.
A lower portion of the small diameter portion 32a of the outer cylinder 32 is communicated with an air supply device 35 via an air supply system duct 37, and air supply air (Ar) is supplied from the air supply device 35 below the small diameter portion 32a. Side. This air supply duct 3
A heating heater 36 is provided in the middle of 7 so that the supply air (Ar) from the supply device 35 can be heated. The upper portion of the large-diameter portion 32b of the outer cylinder 32 is communicated with an exhaust system through an exhaust duct 38 so that the inside of the outer cylinder 32 can be exhausted.

A disk-shaped rotating body 33 having a disk shape is horizontally arranged on the small diameter portion 32a of the outer cylinder 32. The diameter of the dish-shaped rotator 33 is slightly smaller than the inner diameter of the small-diameter portion 32a, and a predetermined gap is provided between the inner diameter of the small-diameter portion 32a of the outer cylinder 32 and the outer periphery of the dish-shaped rotator 33. Is formed. Since the gap is formed, when the supply air (Ar) is supplied from the air supply device 35, a gap air flow is formed from the outside of the dish-shaped rotating body 33.

This dish-shaped rotating body 33 has a rotating shaft 40 provided at the center of a disk shape. The rotating shaft 40 is rotatably fixed to a fixed piece 42 via a thrust bearing 41 near the dish-shaped rotating body 33. In addition, the rotating shaft 40 has a thrust bearing 43 on the lower side in the figure.
And is rotatably fixed to the fixing piece 44 via. The fixing pieces 42 and 44 are fixed to the inner wall of the small diameter portion 32a of the outer cylinder 32, respectively. A pulley 45 is fixed to the end of the rotating shaft 40. An electric motor 46 is provided outside the outer cylinder 32. A pulley 47 is fixed to a rotating shaft of the electric motor 46.
The V-belt 4 is located between the pulley 47 and the pulley 45.
8 have been bridged. The rotating force of the electric motor 46 causes the dish-shaped rotating body 33 to rotate at a high speed via the pulley 47, the V-belt 48, and the pulley 45. The dish-shaped rotating body 33 has the following structure. That is, the conical body 50 is fixed on the center axis on the upper side in the figure of the dish-shaped rotator 33 with its bottom portion facing the rotator. The outer periphery of the dish-shaped rotating body 33 is slightly curved toward the upper side in the vertical direction. Reference numeral 49 denotes an inlet for magnetic particles.

As the heater 36 for heating the air supply, an electric heater, a steam heater or the like may be used, or a heater using waste heat using an air heat exchanger or the like may be used. .

In this embodiment, the dish-like rotating body 3
Although the electric motor 46 was used as a drive source for rotating the motor 3, the present invention is not limited to this, and a hydraulic motor, an air motor,
An internal combustion turbine, a steam turbine, an internal combustion engine, or any other prime mover that can supply torque may be used.

Further, in order to rotate the dish-shaped rotator 33, the rotating force from the electric motor 46 is transmitted to the rotating shaft 40 of the dish-shaped rotator 33 via a pulley 47, a V-belt 48 and a pulley 45. However, the present invention is not limited to this, and it is also possible to use another driving force transmission method or directly rotate the dish-shaped rotating body 33 by the motor.

The operation of the apparatus 1 for manufacturing a carrier coated with a silicone resin having such a structure will be described based on FIG. 4 with reference to FIGS. FIG. 5 is an explanatory diagram showing only a half from the center axis to explain the operation of the apparatus. FIG. 6 is a diagram for explaining the state of movement of the magnetic particle layer on the dish-shaped rotating body 33.

The magnetic particles were charged into the apparatus, the dish-shaped rotator 33 was rotated at a high speed, and further heated from the gap formed between the inner wall of the cylindrical apparatus and the outer peripheral edge of the dish-shaped rotator 33. An air flow is introduced into the apparatus, and the coating liquid is applied to the magnetic particle layer rotating in the form of a rope near the outer peripheral edge of the dish-shaped rotator 33 from the side of the apparatus using the nozzle 34 in the form of a rope-like rotation of the magnetic substance particles. The coating liquid is sprayed from the rear with respect to the direction of travel to form a silicone resin film on the surface of the magnetic particles.

First, the power supply of the air supply device 35 is turned on to supply air to the air supply system duct 37. Next, the power supply of the heater 36 is turned on to heat the air supply passing through the air supply system duct 37, and the heated air supply is supplied to the inside of the outer cylinder 32. Next, the magnetic particles are supplied from the inlet 49 into the dish-like rotating body 3 in the apparatus.
Put on 3.

Further, the power of the electric motor 46 is turned on to rotate the electric motor 46. Then, the electric motor 46
Rotates the dish-shaped rotator 33 at high speed via the pulley 47, the V-belt 48, and the pulley 45.

When the inside of the outer cylinder 32 is sufficiently warmed, the spray liquid is used to dissolve the silicone-based resin composition in a solvent, and the coating liquid prepared is dispensed in the form of a rope. Spray from the rear in the direction of rotation.

In the state where the apparatus has entered the steady operation, the magnetic particles are removed by the centrifugal force of the horizontal high-speed rotation of the dish-shaped rotator 33 as shown in FIG. A magnetic particle layer 30 in which a large number of magnetic particles are locally concentrated on the inner wall side of 32a is formed. Further, when the magnetic particle layer 30 goes near the inner wall of the small-diameter portion 32 a of the outer cylinder 32, the dish-shaped rotator 33 and the small-diameter portion 32
A is blown upward as indicated by an arrow X by spraying a gap air flow (AF) that has passed through a gap formed with the inner wall of the disk-shaped rotating body 3 as indicated by an arrow X in FIG.
3 is moved to the center side.

Since the dish-shaped rotator 33 is rotating at high speed horizontally in the direction K in the drawing, the magnetic particle layer 30
6 makes a horizontal rotational movement on the dish-shaped rotator 33 while rotating in a rope-like shape, as shown by a symbol Y in FIG.

That is, the magnetic particle layer 30 is composed of the dish-shaped rotator 33 that rotates horizontally and at high speed in the direction K in FIG.
Due to the gap air flow (AF) supplied from the outside of No. 3, horizontal rotational movement is performed in a rope shape as shown by an arrow Y in FIG. 6.

As described above, the silicone resin composition is applied to the magnetic particle layer 30 horizontally rotating in the form of a rope as shown by the arrow Y in FIG. A coating solution prepared by dissolving in a solvent is sprayed. As a result, the surface of the particles constituting the magnetic particle layer 30 is uniformly coated with the sprayed coating liquid to a uniform thickness. Further, the coating liquid applied to each particle of the magnetic material particle layer 30 is dried by a dry air flow (AF), and further subjected to a heat treatment if necessary.

The high-speed air flow (A
F) is converted at a low speed in the large diameter portion 32b of the outer cylinder 32, so that the magnetic particles that have flown out of the magnetic particle layer 30 by the air flow (AF) are again rotated by their own weight in a plate-like shape. You will return to body 33.

By such an operation, the magnetic particle layer 30
The coating of the silicone resin composition is uniformly coated on the surface of each magnetic fine particle constituting the above.

The peripheral speed of the dish-shaped rotating body varies depending on the particle size and bulk density of the magnetic particles, the properties of the coating solution, the amount of air supplied, and the like, but is preferably about 3 m / s to 15 m / s, and particularly preferably 4 m / s. s to 12 m / s is preferred. When the peripheral speed is less than 3 m / s, the magnetic particle layer cannot be rotated horizontally in a mesh pattern, and there is a problem that granules are easily generated. The obtained resin-coated carrier has a sufficient charge-up phenomenon. Can not be suppressed. Further, in the range exceeding 15 m / s, there is a problem that the coating layer peels off due to collision of magnetic particles and mutual friction.

The gap formed between the inner diameter of the small diameter portion 32a of the outer cylinder 32 and the outer periphery of the dish-shaped rotator 33 is
The rotation speed, the amount of the magnetic particles, the diameter of the magnetic particles, the specific gravity, the amount of gap air to be supplied, and the like vary depending on the number of rotations, but it is preferably about 2 mm to 10 mm, and if it exceeds 10 mm, the magnetic particles are suspended. The magnetic particle layer cannot be horizontally rotated in a rope shape by a dish-shaped rotator, and there is a problem that granules are easily generated. The obtained resin-coated carrier cannot sufficiently suppress the charge-up phenomenon. On the other hand, if the thickness is less than 2 mm, an air layer cannot be formed in the gap between the outer periphery of the apparatus and the magnetic particle layer, and the magnetic particle layer cannot be horizontally rotated in a rope shape by the dish-shaped rotator.

The coating liquid comprising the silicone resin composition of the present invention is applied from the injection nozzle 34 attached to the side wall of the coating apparatus to the magnetic particle layer from the back in the traveling direction of horizontal rotation in the form of a rope. It is what is injected.
It is preferable that the injection nozzle 34 is, for example, a two-fluid nozzle composed of a double tube, and injects a coating liquid of the silicon-based resin composition from the inner nozzle and heat air from the outer tube. Such a nozzle 34 is attached to one or more locations on the inner wall of the apparatus.

The injection angle of the injection nozzle 34 is preferably about 45 ± 20 °, more preferably 45 ± 15 °, in the direction of rotation in relation to the straight line connecting the spray and the center of the dish-shaped rotator.

The speed at which the coating liquid is sprayed from the spray nozzle 34 differs depending on the coating liquid supply speed, the coating liquid air supply amount, and the liquid cross-sectional area and the air cross-sectional area of the two-fluid nozzle.
A value obtained by dividing the application air supply amount by the air cross-sectional area of the two-fluid nozzle, which is approximately 300 m / s to 500 m / s,
If it exceeds 500 m / s, the resin coating layer is undesirably peeled off. On the other hand, if it is less than 300 m / s, there is a problem that the granulated material increases because the effect of crushing the granulated material cannot be obtained in the air flow.

The drying time of the resin-coated carrier in the drying step is suitably from 15 minutes to 1 hour.

The optional heat treatment is performed in the range of 150 ° C. to 250 ° C., and the heat treatment time is about 1 hour to 5 hours. This heat treatment is performed to stabilize or accelerate the curing reaction, and is not always necessary when the curing reaction has sufficiently proceeded.

The layer thickness of the coating resin is 0.01 to 2.
0 μm is preferable, and particularly preferably 0.01 to 1.0 μm. When the layer thickness is larger than 2.0 μm, the image density is low,
Good images cannot be obtained. When the layer thickness is less than 0.01 μm, electric charges are injected from the developing sleeve, and carrier adhesion easily occurs on the surface of the photoconductor. For the measurement of the layer thickness of the coating resin, the carrier particles were broken, the fracture surface was observed with a scanning microscope, and several places were randomly extracted, and the average value was defined as the layer thickness.

The amount of the coating resin is 0.01 to the magnetic particles.
To 15% by weight, particularly 0.05 to 1% by weight.
It is preferably 0 wt%. Resin amount is 0.01wt
%, A uniform coating layer cannot be formed on the carrier surface, and if it exceeds 15 wt%, the coating layer becomes too thick, and the carrier particles are granulated, resulting in non-uniform carrier particles having poor fluidity. Tends to be obtained. Carriers outside these preferred ranges do not provide sufficient chargeability and charge rise characteristics.

The volume average particle diameter of the toner used together with the carrier is usually about 4 to 15 μm,
Is particularly desirable in terms of obtaining high image quality. As additives other than the colorant and the release agent, for example, a charge control agent, a cleaning property improving agent, a fluidity improving agent, and the like can be used.

The mixing ratio with the carrier is preferably such that the toner concentration is 1 to 15% by weight.

For measuring the volume average particle size of the toner, a Coulter counter is usually used. As the Coulter counter, for example, Coulter TA-11 (manufactured by Coulter Inc.) is used. The measurement was performed using a toner with an electrolytic solution ISOTONE-
11 (manufactured by Nikkaki Co., Ltd.), dispersed, and performed with the above-mentioned Coulter Counter. Measure 2 to increase accuracy
It is good to do it three times.

The binder resin constituting the toner is not particularly limited, and resins conventionally used for this type of application can be used. Specifically, for example, a styrene resin, a styrene-acrylic resin, a styrene-butadiene resin, an ester resin, and an epoxy resin can be used. Among them, an ester-based resin and a styrene-acrylic-based resin can be preferably used as those having a stable triboelectric charging property. These resins are used alone or as a mixture of two or more.

The coloring agent is not particularly limited, and many dyes and pigments such as carbon black, phthalocyanine blue, Pigment Green B and Solvent Red 49 conventionally used for this kind of application can be used. For example, as a black toner, carbon black, a nigrosine dye, or the like is used, and as a pigment required for yellow, magenta, and cyan toners, C.I. I. Pigment Blue 15/3, C.I. I. Pigment Blue 15, C.I. I. Pigment Blue 15/6, C.I. I. Pigment Blue 6
8, C.I. I. Pigment Red 48-3, C.I. I. Pigment Red 122, C.I. I. Pigment Red 21
2, C.I. I. Pigment Red 57-1, C.I. I. Pigment Yellow 17, C.I. I. Pigment Yellow 8
1, C.I. I. Pigment Yellow 154 and the like can be suitably used.

As the release agent, for example, low molecular weight polyolefin, aliphatic ester and aliphatic ester wax, carnauba wax and the like can be used. As the charge control agent, for example, a nigrosine dye, a metal complex dye, or the like can be used.

The method for producing the toner includes a binder resin, a colorant,
The release agent is mixed with a Henschel mixer, etc., and kneaded while dispersing the colorant and the release agent into a predetermined dispersion diameter under various conditions, and thereafter, through the respective steps of pulverization and classification, and further, in some cases, cleaning. A fluidity improver, a fluidity improver and the like can be externally added and mixed.

As another toner manufacturing method, a polymerization method can be applied.

Specific examples of the polymerization method include a suspension polymerization method, an emulsion polymerization / granulation method, and a similar method thereof. The starting material is a polymerizable monomer, and the pulverizing / classifying process can be eliminated or simplified.

The melt-kneading and pulverizing method has an essential problem that the cost of the pulverizing / classifying process increases as the particle size of the toner decreases, so that the production cost increases dramatically. On the other hand, in the polymerization method, the toner particle size hardly correlates with the manufacturing cost. Therefore, the polymerization method is a toner manufacturing method suitable for reducing the toner particle size and sharpening the particle size distribution with higher precision of an image. .

As an example of the suspension polymerization method, a colorant and other additives are dispersed in a monomer (dispersion step), a monomer droplet is formed by primary stirring in an aqueous phase, and a monomer droplet is formed by secondary stirring. Droplets are polymerized to obtain a toner (polymerization step).

The shape is a true sphere and a sphere. Further, the particle size and the particle size distribution depend on the concentration of the suspension stabilizer and the dispersant, the stirring speed of primary and secondary stirring, time, and temperature.

As one example of the emulsion polymerization method, monomers are polymerized in an aqueous solvent to obtain primary particles having a submicron diameter (polymerization step). Next, a coloring agent and other additives are added and adsorbed on the surface of the primary particles and then associated to form secondary particles of several μm (dispersion / association step). Further, the secondary particles are agglomerated in a dispersion medium (granulation step), heated to a temperature equal to or higher than the glass transition temperature of the polymer, and the interface between the secondary particles is fused to form toner particles (ripening step).

Further, the monomer is polymerized in the presence of a colorant and other additives to obtain colorant-containing primary particles having a submicron diameter (polymerization step), and the primary particles are associated in the presence of an aggregating agent ( It is also possible to heat the polymer to a temperature equal to or higher than the glass transition temperature of the polymer and fuse the interface between the primary particles to form toner particles (aging process).

In the emulsion polymerization / association method, the shape of the toner can be controlled in a wide range from spherical to irregular.

The toner obtained by the polymerization method is dried after washing, and if necessary, a cleaning improver, a fluidity improver and the like can be externally added and mixed.

As the cleaning property improver externally added to the toner, for example, aliphatic metal salts such as zinc stearate and lithium stearate, and polymer fine particles such as a fluorine-based polymer and a styrene-acrylic polymer may be used. it can. As the fluidity improver, for example, inorganic fine particles are used, such as silica, alumina, titanium oxide, titanate, zinc oxide, silicon carbide, silicon nitride, chromium oxide, zirconium oxide, magnesium oxide, barium carbonate, barium sulfate, and the like. Inorganic oxide fine particles are preferably used. These inorganic oxide fine particles are preferably subjected to a hydrophobic treatment with a silane coupling agent or the like.

The developing method according to the present invention is preferably a so-called non-contact developing method in which a gap is provided between the developer layer on the developing sleeve and the latent image forming member during development. in this case,
The layer thickness of the developer layer on the developing sleeve is generally thinner than that of the contact developing method, and is suitably 20 to 500 μm.

Thin-layer non-contact development system In the thin-layer non-contact development system, a developer layer having a thickness of preferably 20 to 500 μm is formed on the surface of a developer carrier in a development area. Particularly preferably, a developer layer of 50 to 300 μm is formed.
In order to form the thin layer, there are a magnetic blade using a magnetic force, a method of pressing a developer layer regulating rod against the surface of a developer carrying member, and the like. Further, there is a method in which a urethane blade, a phosphor bronze plate or the like is brought into contact with the surface of the developer carrier to regulate the developer layer.

As the developer carrying member, a developing device having a magnet built in the carrying member is used, and as the material constituting the developer carrying member surface, aluminum or aluminum or stainless steel whose surface is oxidized is used. Can be

The pressing force of the pressing regulating member is 1 to 15 g.
f / mm is preferred. When the pressing force is small, the conveyance becomes unstable due to insufficient regulating force. On the other hand, when the pressing force is large, the stress on the developer increases, and the durability of the developer decreases. The preferred range is 3 to 1.
0 gf / mm.

The gap between the developer carrier and the surface of the photoreceptor needs to be larger than the developer layer.
It is preferable that the width is 0 μm or more. In particular, a preferable range in which the gap is wider than that of the developer layer is 15 to 200 μm. Further, it is preferable to apply an AC bias as an alternating electric field in addition to a DC component as a developing bias. The alternating electric field is 1000 to 3000 Hz, and the voltage is 500 to 200 in absolute value from peak to peak (Vp-p).
0V is a suitable range.

The size of the developer carrier is 10 mm in diameter.
Those having a size of ４０40 mm are preferred. When the diameter is small, the mixing of the developer is insufficient, and it is difficult to secure sufficient mixing to perform charging to the toner, and when the diameter is too large, the centrifugal force on the developer becomes large, A problem of toner scattering occurs.

Next, the image forming method of the present invention will be described. Hereinafter, an example of the non-contact developing method will be described with reference to FIG.

FIG. 1 is a schematic view of a non-contact developing type developing section which can be suitably used in the image forming method of the present invention, wherein 1 is a photosensitive member, 2 is a developer carrier, and 3 is a toner of the present invention. Contained two-component developer, 4 is a developer layer regulating member, 5 is a development area, 6 is a developer layer, and 7 is a power supply for forming an alternating electric field.

The two-component developer containing the toner of the present invention is carried by a magnetic force on a developer carrier 2 having a magnet 2B therein, and is conveyed to the development area 5 by movement of the development sleeve 2A. At the time of this conveyance, the developer layer 6 is regulated by the developer layer regulating member 4 to a layer having a thickness so as not to come into contact with the photoconductor 1 in the developing region 5.

The minimum gap (Dsd) of the developing area 5 is determined by the thickness (preferably 20 to 5) of the developer layer 6 conveyed to the area.
00 μm), for example, about 100 to 1000 μm. The power source 7 for forming the alternating electric field is preferably an alternating current having a frequency of 1 to 10 kHz and a voltage of 1 to 3 kVp-p. The power supply 7 may have a configuration in which direct current is added in series to alternating current as necessary. 300 when applying DC voltage
~ 800V is preferred.

When the toner of the present invention is applied to a color image forming system, a system in which a single color image is formed on a photosensitive member and sequentially transferred to an image support (this is referred to as a sequential transfer system and is shown in FIG. 2). Alternatively, a method in which a single-color image is developed a plurality of times on a photoreceptor to form a color image and then collectively transferred to an image support (this is referred to as a collective transfer method and is shown in FIG. 3).
And the like.

The image forming method in FIGS. 2 and 3 will be described in detail below.

As the developer carrier used in the present invention, as shown in FIGS. 1 to 3, a developing device having a magnet 2B built in the carrier is used, and a sleeve forming the surface of the developer carrier is used. As 2A, aluminum or aluminum or stainless steel whose surface is oxidized is used.

An example of the sequential transfer method shown in FIG. 2 will be described below.

Reference numeral 11 denotes a charger serving as a charging electrode, and reference numeral 12 denotes a developing unit including developing units for respectively loading yellow, magenta, cyan, and black toners, which is divided into four units corresponding to four color toners. . The basic configuration of these developing units is the same as the schematic diagram of the developing unit shown in FIG. Reference numeral 14 denotes a photosensitive drum, reference numeral 13 denotes a cleaning unit, reference numeral 15 temporarily holds a single-color toner image formed on the photosensitive drum, further holds the next single-color toner image thereon, and finally holds a desired single-color toner image. Transfer drum for forming a multicolor image, 1
Reference numeral 6 denotes a transfer unit for transferring a transfer material onto which a toner image on a transfer drum is transferred. Reference numeral 17 denotes an attraction electrode provided inside the transfer drum 15 for performing corona discharge from the inside to electrostatically attract the transfer material to the drum; Reference numeral 18 denotes a transfer electrode for sequentially transferring the toner image formed on the photosensitive drum 14 to the transfer drum, 19 denotes a peel electrode for peeling off the transfer material electrostatically attracted onto the transfer drum 15, and 20 denotes after the transfer material is peeled. And a removal electrode for removing charges remaining on the transfer drum.

A charge is uniformly formed on the photosensitive drum 14 by the charging electrode 11, and thereafter, imagewise exposure (not shown) is performed to form an electrostatic latent image. This electrostatic latent image is developed by a developing device that holds one color toner (for example, black toner) of the developing unit 12, and a one color toner image is formed on the photosensitive drum 14. On the other hand, the transfer material transported onto the transfer drum 15 by the transport unit 16 is
The toner is electrostatically attracted onto the transfer drum by 7 and conveyed to the transfer unit.

The toner image formed on the photosensitive drum 14 is transferred to the transferred transfer material at the transfer section. The toner remains on the photosensitive drum 14 after the transfer of the transferred image, and the remaining toner is cleaned by the cleaning unit 13 and used for the next process. When forming a multicolor image, a toner image of another color is formed by development according to a similar process,
The image is transferred to the transfer drum 15 one by one. Eventually, a desired toner image is formed on the transfer material adsorbed on the transfer drum 15. The transfer material on which the desired toner image has been formed is peeled off by the peeling electrode 19, and is conveyed to the fixing unit.
A final fixed multicolor toner image is obtained. On the other hand, the charge remaining on the transfer drum 15 is removed by the removing electrode 20 and used for the next process.

Next, the batch transfer method will be described with reference to FIG.

The components of the apparatus are the same as in the example shown in FIG. However, reference numeral 10 denotes a transport unit that transfers the toner image while transporting the transported transfer material. Photoconductor drum 1
An electric charge is uniformly formed on the electrode 4 by a charging electrode, and then an electrostatic latent image is formed by a latent image forming means (not shown).
This electrostatic latent image is developed by a developing device that holds one color toner (for example, black toner) of the developing unit 12, and a one color toner image is formed on the photosensitive drum. In the illustrated example, this toner image is not transferred, and a charge is uniformly formed again by the charging electrode 11 on the photosensitive drum having the toner image as it is, and further, an electrostatic latent image is formed. Then, the toner image is developed by a developing device having a toner of a different color from the above, and a toner image of another color is formed by being superimposed on the previous toner image. During this time the cleaning unit 1
3. The transfer electrode 18 and the transport unit 10 are not operated, and are retracted from the photosensitive drum 14 so as not to disturb the toner image on the photosensitive drum 14.

After the desired image formation is completed and the multicolor toner image is formed, the toner image on the photosensitive drum is transferred to the transfer material conveyed by the conveyance unit 16 while being conveyed by the conveyance unit 10. The toner image is transferred by the electrode 18. The transfer material carrying the transferred toner image is transported to a fixing unit and fixed, and a final multicolor toner image is formed on the transfer material. Since the toner remains on the photosensitive drum 14 after the transfer of the toner image, it is cleaned by the cleaning unit 13 and used for the next process.

The toner image formed on the photoreceptor by the various methods described above is transferred to a transfer material such as paper in a transfer step. The transfer method is not particularly limited, and various methods such as a so-called corona transfer method and a roller transfer method can be adopted.

Example

[Manufacture of carrier 1] Li ₂ O ₃ : Fe ₂ O ₃ = 25 mol
%: 75 mol was pulverized and mixed in a wet ball mill for 5 hours, and then granulated and dried by a spray drier, and the obtained powder was fired at 900 ° C. for 2 hours using an electric furnace. Further, the obtained fired powder was pulverized and mixed again in a wet ball mill for 5 hours in the presence of a dispersant and a binder to prepare a slurry. The slurry obtained by granulating and drying the slurry with a spray dryer was heated to 1200 ° C. using an electric furnace.
It was baked for 3 hours. The obtained fired powder was crushed and classified to obtain a ferrite core 1 having a volume average particle size of 65 μm.

Next, the ferrite core particles 1: 100
Silicone resin 1 having the following structure with respect to parts by weight:
1.5 parts by weight and 10.2 parts by weight of γ-aminopropyltrimethoxysilane with respect to 100 parts by weight of the silicone resin were dissolved in toluene to prepare a coating liquid 1 having a resin solid concentration of 10% by weight.

A mechanism for horizontally rotating a magnetic particle layer in a rope shape by means of a dish-shaped rotator rotating horizontally and a gap air flow supplied from the outside of the dish-shaped rotator. In a body particle layer, a coating apparatus having a mechanism for spraying a coating solution prepared by dissolving a silicone resin composition in a solvent from the rear with respect to the traveling direction of the rope-like rotation of the magnetic particles, the ferrite core The particles 1 are charged, the dish-shaped rotator is rotated at a peripheral speed of 10 m / s, and a gap air flow heated by an electric heater is introduced. Spraying the coating liquid 1 from the rear with respect to the direction of progress of the rope-like rotation of the ferrite core particles in the rope-like rotation of the ferrite core particle layer using a two-fluid nozzle from above, To form a recone resin coating film. At this time, the thermometer inserted into the ferrite core particle layer rotating in the form of a rope from the wall of the device showed 60 to 80 ° C. After the supply of the coating liquid was completed, drying was continued while only the compressed air was blown from the two-fluid nozzle. At this time, the thermometer indicated 80 to 100 ° C. Thereafter, the reading of the thermometer was lowered to 50 ° C. and discharged. Thereafter, a heat treatment was performed at 200 ° C. for 2 hours, followed by crushing and # 150 (opening 105 μm).
The components on the sieve were removed with a stainless sieve of m) to obtain a silicone resin-coated carrier 1 having an average particle diameter of 66 μm.
The component on the sieve was 1 part by weight.

The silicone resin 1 is an aggregate of segments represented by the following general formulas (1) and (2). R in the formula is CH3, and the ratio of segments (1) and (2) is
(1) / (2) = 2/98.

[0127]

Embedded image

[0128]

[Manufacture of the carrier 2] A mechanism for rolling and rotating a magnetic particle layer by a dish-shaped rotator moving horizontally and a flow and a gap air flow supplied from the center and outside of the dish-shaped rotator. A fluid having a mechanism for spraying a coating solution prepared by dissolving a silicone resin composition in a solvent from the rear with respect to the traveling direction of the tumbling flow of the magnetic particles in the flowing magnetic particle layer. Except for using a layer coating apparatus, the average particle diameter was 6
A 7 μm silicone resin-coated carrier 2 was obtained. The on-screen component was 37 parts by weight.

[0129]

[Production of Toner] 100 parts of styrene acrylic resin, 8 parts of carbon black, 3 parts of low molecular weight polypropylene, and 2 parts of a charge control agent (exemplary compound 1) are added, melted and kneaded. 8.5 μm colored particles were obtained. Next, 0.8 wt% of hydrophobic silica was added to the colored particles and mixed with a high-speed stirring device to obtain a toner.

[0130]

Embedded image

[0131]

[Adjustment of Developer] Using the carrier 1 (for the present invention) and the carrier 2 (for comparison) and the above toner, developers 1 and 2 having a toner concentration of 4% by weight were respectively adjusted.

[0132]

[Evaluation of actual photograph] Konica color copier Konic equipped with positively chargeable organic photoreceptor and magnetic permeability type toner density sensor
Using a remodeled machine of a7028, 40,000 copies of actual photography were evaluated (environmental conditions: temperature 25 ° C., humidity 55 RH%).

The operating conditions of the machine are as follows. Photoconductor surface potential = +650 V DC bias = +250 V AC bias = Vp-p: +50 to +450 V Alternating electric field frequency = 2500 Hz Distance between current sleeve and photoconductor = 300 µm Press regulating force = 10 gf / mm Press regulating rod = SUS416 (made of magnetic stainless steel) ) /
3 mm diameter Developer layer thickness = 150 μm Developing sleeve = 20 mm (average charge amount) The toner charge amount at the start and after 50,000 copies were measured.

Evaluation results are shown in Table 1.

[0135]

[Evaluation Items] (1) Variation in copy number of primary adhesion amount The toner developed on a unit area on the photoreceptor was sampled, and the primary adhesion amount (developed toner amount) [mg / cm2] was determined. The primary adhesion amount was measured immediately after the developer adjustment and every 10,000 copies, and the variation (Δ primary adhesion amount) with respect to the copy number was evaluated. ：: Δ primary adhesion amount: less than 0.1 mg / cm 2, Δ: Δ primary adhesion amount: 0.1 mg / cm 2 or more and 0.2 mg / cm 2
Less than cm2, ×: Δ primary adhesion amount = 0.2 mg / cm2 or more (2) Fogging and toner scattering The fogging after 40,000 copies and toner scattering around the developing machine were visually observed. A level having no practical problem was represented by ○, and a level having practical problem was represented by ×.

[0136]

[Table 1]

As is clear from Table 1, in Example 1, there was no change in the primary adhesion amount in the initial stage of actual photographing, the primary adhesion amount was stable up to 40,000 copies, and the image density was stably high. A high-quality image was obtained without occurrence of fogging and toner scattering, and sufficient durability was confirmed. On the other hand, in Comparative Example 1, since the primary adhesion amount was lower than at the beginning of the actual shooting, and sufficient image density could not be obtained at the time of 20,000 copies, the actual shooting was stopped at 20,000 copies.

[0138]

According to the present invention, a carrier having a good silicone-based resin coating layer and a method for producing the same can be provided. Furthermore, the charge-up phenomenon, in which the charge amount gradually increases due to repeated use, is suppressed, and a stable charge amount is obtained from the beginning of copying, and as a result, a high-density, fog-free, high-quality image is obtained over a long period of time. , A carrier manufacturing method, a developer, and an image forming method.

[Brief description of the drawings]

FIG. 1 is a schematic view showing an example of a non-contact developing system.

FIG. 2 is a schematic diagram illustrating an example of a sequential transfer method.

FIG. 3 is a schematic view showing an example of a batch transfer method.

FIG. 4 is a schematic view showing one example of a method for producing a silicone resin-coated carrier according to the present invention.

FIG. 5 is an explanatory diagram showing only a half from a central axis to explain an operation of the apparatus.

FIG. 6 is a view for explaining a motion state of a magnetic particle layer on a dish-shaped rotating body.

[Explanation of symbols]

 REFERENCE SIGNS LIST 1 photoconductor 2 developer carrier 2A developing sleeve 2B magnet 3 two-component developer (containing toner of the present invention) 4 developer layer regulating member 5 developing area 6 developer layer 7 power supply for forming alternating electric field 11 charger REFERENCE SIGNS LIST 12 developing unit 13 cleaning unit 14 photoreceptor drum 15 transfer drum 16 transfer unit 17 suction electrode 18 transfer electrode 19 peeling electrode 20 removing electrode 21 transfer unit 31 silicone resin-coated carrier manufacturing apparatus 32 outer cylinder 33 dish-shaped rotating body 34 spray 35 air supply device 36 heating heater 37 air supply system duct 38 rotating shaft 45 pulley 46 electric motor 47 pulley 48 V belt 49 inlet for magnetic particles

Claims (5)

[Claims] In a carrier comprising a silicone resin coated on the surface of magnetic particles, the carrier coated with the silicone resin is coated with a coating solution prepared by dissolving a silicone resin composition in a solvent. In a magnetic particle layer that is horizontally rotating in a zigzag manner, spray coating is applied from the rear with respect to the traveling direction of the rope-like rotation of the magnetic particles to form a silicone-based resin film on the magnetic material surface, A carrier for developing an electrostatic charge image, obtained by a method for producing a carrier for developing an electrostatic charge image, which is dried and heat-treated as necessary to obtain a carrier coated with a silicone resin. 2. A method for producing a silicone-based resin-coated carrier in which a coating solution prepared by dissolving a silicone-based resin composition in a solvent is coated on the surface of magnetic particles, wherein the silicone-based resin composition is dissolved in a solvent. The coating solution adjusted in the above manner is placed in a magnetic particle layer that is horizontally rotating in a rope shape,
Spray-applying from the back with respect to the direction of the rope-like rotation of the magnetic particles, forming a silicone-based resin film on the surface of the magnetic material, followed by drying and, if necessary, heat treatment, to form a silicone-based resin-coated carrier. A method for producing a carrier for developing an electrostatic image, characterized by comprising the steps of: 3. An electrostatic image developer comprising a toner and a carrier containing at least a binder resin and a colorant, wherein the carrier comprises a coating solution prepared by dissolving a silicone resin composition in a solvent. After spray coating from the back with respect to the traveling direction of the rope-like rotation of the magnetic particles into the magnetic particle layer which is horizontally rotating in the form of a rope, after forming a silicone resin film on the surface of the magnetic substance An electrostatic image developer, which is a carrier coated with a silicone resin obtained by a method for producing a carrier for developing an electrostatic image, which is dried, and optionally subjected to a heat treatment to obtain a carrier having a silicone resin film. 4. An electrostatic image developer comprising a toner and a carrier containing at least a binder resin and a colorant, is thinned to a developer layer thickness of 20 to 500 .mu.m by a developer regulating member. In an image forming method in which an electrostatic charge image on a formed body is developed in a non-contact manner, the carrier is prepared by dissolving a silicone resin composition in a solvent. In the inside, spray coating is applied from the rear with respect to the traveling direction of the rope-like rotation of the magnetic material particles, a silicone resin film is formed on the surface of the magnetic material, and then drying and heat treatment are performed as necessary. An image forming method, wherein the carrier is a silicone resin-coated carrier obtained by a method for producing a carrier for developing an electrostatic image, which obtains a coated carrier. 5. A magnetic particle layer is formed by a dish-shaped rotator that rotates horizontally at high speed and a gap air flow supplied from outside of the dish-shaped rotator, and the magnetic particle layer is horizontally rotated in a rope shape. A mechanism for dissolving a silicone-based resin composition in a solvent from the back in the direction of the rope-like horizontal rotation of the magnetic particle layer in the magnetic particle layer that is horizontally rotating in the rope shape. An apparatus for spraying a coated coating liquid, and a mechanism for forming a silicone-based resin coating on the surface of the magnetic particles, followed by drying and, if necessary, heat-treating the carrier. .