JP2003029466A - Manufacturing method of resin-coated carrier for electrophotographic developer - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a method for manufacturing resin-coated carrier constituted so that the resistance of developer may be kept low and fixed even in a small- sized developing device, irregularities in an solid image may be prevented at forming the solid image, also, toner may be thoroughly electrified, and toner- scattering, surface staining, staining like seams may be prevented, and a good image can be obtained, dispensing with the installation of a toner replenishing mechanism and a toner concentration sensor. SOLUTION: As for a method for hardening the resin-coated carrier (material to be dried) in a multistage stationary drying furnace, a drying processing is performed under a condition where the relation of B>=A is satisfied as to the thickness A of each layer of the material to be dried in containers arranged at many stages and a distance B between one and the other containers.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a developer carrier used for electrophotography, electrostatic printing and the like for copying machines, printers, facsimiles and the like, and a method for manufacturing the same.

[0002]

2. Description of the Related Art In a dry two-component developer used in a two-component developing method, fine toner particles are held on a surface of a relatively large carrier particle by an electric force generated by friction between both particles, and electrostatic When approaching the latent image, the attraction force in the latent image direction on the toner particles due to the electric field formed by the electrostatic latent image overcomes the binding force between the toner particles and the carrier particles,
The toner particles are attracted and attracted onto the electrostatic latent image to visualize the electrostatic latent image. Then, the developer is repeatedly used while replenishing the toner consumed by the development. Therefore, in the two-component developing method, it is necessary to keep the mixing ratio of the carrier and toner (toner density) constant in order to obtain a stable image density, and it is necessary to install a toner replenishment mechanism and a toner density sensor for that purpose. However, there is a drawback that the developing device becomes large and its operating mechanism becomes complicated. on the other hand,
Unlike the two-component developing method, the one-component developing method does not use a developer in which carrier particles and toner particles are mixed, but incorporates an electric force generated by friction between the toner and the developing sleeve or a toner containing a magnetic substance and a magnet. The toner is held on the developing sleeve by the magnetic force between the developing sleeves, and when the electrostatic latent image is approached, the electric field formed by the electrostatic latent image attracts toner particles in the direction of the latent image to the toner particles. By overcoming the coupling force between the sleeves, the toner particles are attracted and adhered onto the electrostatic latent image to visualize the electrostatic latent image. As described above, the one-component developing method has an advantage that the developing device can be downsized because it is not necessary to control the toner concentration, but the number of toner particles in the developing region is smaller than that in the two-component developing method, so The amount of toner developed on top was insufficient, making it difficult to support high-speed copying machines.

As a method for improving these drawbacks, Japanese Patent Publication No. 5-67233 proposes a two-component developing method which does not require toner density control. In order to charge the toner by taking the toner into the developer with the layer thickness regulating member and charging the toner, a replenishment mechanism for replenishing the toner and a sensor for detecting the toner concentration are not required. In the case of a high-speed machine in which the linear speed of the developing sleeve is high because the amount of developer cannot be increased as compared with the component developing device, the toner cannot be sufficiently charged and the background stain occurs. Further, in order to impart sufficient charge to the toner, it is necessary to increase the regulation stress in the layer thickness regulating member, so that the toner film is formed on the carrier surface by heat generation due to collision of developer particles. There is a drawback that so-called spent formation occurs, the charging characteristics of the carrier decrease with use time, and toner scattering, background stain, and the like occur. Further, in the developer used in the above-described small-sized developing device, since it is necessary to impart the charge to the replenished toner in a short time, a large amount of the replenished toner is mixed with the developer quickly. Although the fluidity improver was added, when such a developer is repeatedly used, excessive fluidity improver in the toner is fixed on the electrostatic latent image carrier, and a streak-like abnormal image occurs. There was a drawback. Further, when the stirring stress of the developer is increased, there is a problem that a so-called charge-up phenomenon occurs in which the charge amount of the toner becomes larger than necessary in addition to the phenomenon of the spent formation. Further, since the amount of developer is small in these small-sized developing devices, the amount of toner consumed is large when a document having a small amount of toner held by the developer and a large image area is continuously copied, There is a drawback that the image density becomes low because the toner density in the developer changes extremely. Furthermore, in this developing device, the amount of toner taken in is different between a portion where the developer moves actively and a portion where the developer does not move, or a portion where the developer is large and a portion where the developer is small, and the toner concentration becomes partially unstable and the image Density unevenness and fog are likely to occur.

Therefore, there is a technique for solving the density unevenness and fog in the longitudinal direction of the apparatus by disposing two toner supply members in the toner hopper and allowing the developer to pass through the path formed by each toner supply member. JP-A-63-42
No. 82 publication. However, since two toner supply members are used, there is a problem that the developing unit becomes large and the cost increases.
Further, in the developing method using the two-component developing method that does not require the toner concentration control, in order to maintain stable image quality while considering the toner concentration followability and charging stability, the toner concentration in the developer is However, the resistance in the developer in the state where the toner and the carrier are mixed becomes high, and unevenness occurs at the time of a solid image, so that a good image cannot be maintained. In order to improve the above various problems and problems,
It is necessary that the resistance of the developer be used as a carrier to be stably low. Therefore, a resin-coated carrier is used, and the carrier has been dried and sintered in a static drying oven to reduce the resistance. Other methods of drying / sintering the coated resin after carrier coating include rotary drying ovens, batch stirring type, and structures that drop while flowing on a rotating disk, but in all methods the carrier shape is spherical. As a result of smoothing of the surface and the smoothening of the surface state, the inter-carrier resistance becomes high, which is disadvantageous in reducing the carrier resistance. On the other hand, in a stationary single-stage internal air circulation type drying furnace in which the particle shape becomes non-uniform, variations in quality are reduced because of the single stage, but there is a limit to the amount that can be treated at one time as compared with the multi-stage type. Further, if the thickness of the dried product is set to a large value in a single step and the treatment is carried out, unevenness in the drying causes variations in charging characteristics and resistance value, etc., and stable production cannot be achieved. Therefore, a method of using a static multi-stage internal air circulation type drying furnace has been used, but in comparison with the above carrier induction type, variations in charge amount, variations in resistance value, deterioration in fluidity due to uneven drying and sintering, There is a drawback that the bulk density decreases, and it is becoming difficult to deal with it with general processing methods and conditions, and development of a manufacturing method that can maintain stable quality while ensuring productivity has been required. .

[0005]

SUMMARY OF THE INVENTION The present invention has been made in view of the above background. A first object of the present invention is to provide a developer carrier in which the resistance of the developer is low and constant even in a small-sized developing device, and at the time of solid image formation. It is an object of the present invention to provide a method for producing a developer capable of obtaining a good image free from betula. A second object is to provide a method for producing a developer capable of sufficiently imparting a charge to a toner even in a small-sized developing device and obtaining a good image without toner scattering, background stain, and streak-like stain. Is to provide. A third object is to provide a small-sized and inexpensive developer for use in an image forming method / apparatus which does not require a toner replenishing mechanism and a toner concentration sensor.

[0006]

The above object of the present invention can be achieved by the following means. That is, according to the present invention, firstly, in claim 1, in a method of curing carrier particles (material to be dried) coated with a resin in a multi-stage static drying oven, in the storage containers arranged in multi-stages. Provided is a method for producing a resin-coated carrier for an electrophotographic developer, characterized in that the thickness A of the material-to-be-dried layer and a distance B between the other layers have a relationship of B ≧ A. Secondly, in claim 2, in the method for producing a resin-coated carrier for an electrophotographic developer according to claim 1, the A and B have a relationship of A × 2.0 ≧ B ≧ A. A method for producing a resin-coated carrier for an electrophotographic developer is provided. Thirdly, in claim 3, in the method for producing a resin-coated carrier for an electrophotographic developer according to claim 1 or 2, the curing bath atmosphere temperature is from 260 ° C to 350 ° C. A method for producing a resin-coated carrier for an agent is provided. Fourth, in claim 4, any one of claims 1 to 3
In the method for producing a resin-coated carrier for an electrophotographic developer according to the item 1, there is provided a method for producing a resin-coated carrier for an electrophotographic developer, characterized in that the temperature difference in the atmosphere in the curing tank is ± 3 ° C or less.

Fifth, in the fifth aspect of the present invention, in the method for producing a resin-coated carrier for an electrophotographic developer according to any one of the first to fourth aspects, the pressure in the atmosphere of the curing tank is 0 to -500 Pa. A method for producing a resin-coated carrier for an electrophotographic developer is provided. Sixth, in a sixth aspect of the present invention, in the method for producing a resin-coated carrier for an electrophotographic developer according to any one of the first to fifth aspects, a material to be dried is subjected to a cooling process after a curing treatment under a constant control environment. There is provided a method for producing a resin-coated carrier for an electrophotographic developer, which is characterized by cooling with. Seventh, in the seventh aspect, in the method for producing a resin-coated carrier for an electrophotographic developer according to any one of the first to sixth aspects, processing is performed by setting the processing intervals per unit processing amount to the same intervals. A method for producing a resin-coated carrier for an electrophotographic developer is provided. Eighth, in Claim 8, there is provided a resin-coated carrier manufacturing apparatus for electrophotographic developer capable of carrying out the method for manufacturing a resin-coated carrier for electrophotographic developer according to any one of Claims 1 to 7. Provided.

[0008]

BEST MODE FOR CARRYING OUT THE INVENTION The present invention is described in detail below.
The present invention is configured in a multi-stage static drying furnace for treating coated carrier particles, in which a material to be dried is moved on a belt-shaped moving body from an inlet to an outlet and dried. FIG. 1 is a cross-sectional view showing an example of a multi-stage container for containing a material to be dried, and FIG. 2 is a cross-sectional view showing an example of a developing device. The operation of the multi-stage static drying oven will be described with reference to the example of FIG. 3. Drying of the coated carrier 30 in this drying oven is performed after the coated carrier 30 is placed at the inlet (on the right side of FIG. 3) and then at equal intervals. To move in the drying zone on the belt. When the drying is completed, it moves in the same manner in the cooling zone and the drying is completed. A predetermined amount of the coated carrier 30 is housed in each of the containers 40 arranged in a vertical positional relationship. Specifically, the processing is performed as follows. First, the coated carrier 30 to be dried and sintered is spread in multiple stages. At this time, the thickness A of the material to be dried in each stage must be the same. Then placed at the entrance of the drying oven. The movement of each stage container 40 introduced into the drying furnace is carried out by the stage containers set at uniform intervals. It is preferable that each stage is divided into five or more stages.
At this time, the interval B from the thickness A of the material to be dried to the upper and lower stages (see FIG. 1) is one or more intervals B with respect to the thickness A (B
≧ A). Preferably, A × 2.0 ≧ B ≧ A. If the conditions are set to an interval of less than 1, the circulation of hot air is disturbed and uniform heating of the entire layer is not sufficiently performed,
Uniform drying cannot be obtained, and the degree of drying is strong on the surface of the layer, and weak drying occurs in the deep portion, which causes variations in the charge amount and resistance value.

Further, in the drying of the developer carrier of the present invention, a better result can be obtained by setting the atmosphere temperature to 260 to 350 ° C. in order to stabilize the productivity and quality. If the temperature is lower than 260 ° C., the coating resin is not dried, the binder resin is not cured, and the charge amount is increased after being made into a developer, the image quality is deteriorated due to the toner spent, and the drying in a sufficient standing state is hindered. 350 ° C
In the temperature range above 100 ° C, it becomes a peroxide state and the redeposition phenomenon of the oxide of the coating resin occurs, the charge amount rises in the developing machine, the charge control component is decomposed, and the developer life is shortened due to insufficient gasification of the coating film due to gasification of the resin. Decrease and increase in the degree of film curing cause the toner spent to be promoted and the developer carrying member to be abraded. Further, it is necessary to control the temperature variation within the drying furnace to ± 3 ° C., which is the ambient temperature setting temperature. The setting of the internal temperature, in the static drying device which is the drying method of the present invention, it is necessary to accurately control the temperature distribution variation and prevent the above-mentioned problems due to uneven drying or excessive drying. It becomes possible to do. Regarding the replacement of the dry atmosphere, it is effective to replace it appropriately. However, if the replacement amount is large, the quality will be improved due to the local adhesion of the convection oxide in the coating resin gasification atmosphere if there is a problem due to a decrease in the ambient temperature or without replacement. This causes variations and makes it difficult to maintain stable images in the developing machine. Further, it is also useful for avoiding the risk of explosion due to the residue of the organic solvent which may be used during coating.

The progress of the moving body on the belt during the drying operation is also one of the controlling factors. The speed of the moving body on the belt introduced into the furnace naturally goes at a constant interval, but it is also necessary to make the introduction interval and span constant. The material to be dried put in at uneven intervals is
During drying, the temperature is raised to the same temperature as the ambient temperature. The increased material to be dried becomes radiant heat to the material to be dried next introduced together with the heating atmosphere, and causes unevenness in drying from the time of introduction at equal intervals, which causes the above-mentioned quality variation. In addition, sufficient stability conditions are required even in the processing environment after leaving the drying furnace. The object carrier to be dried has the same temperature as the temperature inside the furnace when it goes out of the furnace, and if it is cooled down to room temperature in a general environment and is performed in an environment, the influence of temperature and humidity in that environment is affected. Receive a great deal. This is remarkably observed in the carrier using the static dry sintering method, and the static space reduces the voids between the carriers as much as possible and increases the surface area. When the surface area is increased, water adsorption occurs in a general environment, and the carrier developer charging is greatly affected. In the manufacturing method of the present invention, the environment used for cooling is 25 ° C.
In the following, it is preferable to use, for example, air that has passed through a dehumidifier that can create an environment with a constant water content. Desirably 20
It is even better to use an air conditioner capable of controlling the relative humidity to be 50% or less at a temperature below 50 ° C.

The core particles of the carrier constituting the developer in the present invention may be conventionally known ones, for example, ferromagnetic metals such as iron, cobalt and nickel; alloys and compounds such as magnetite, hematite and ferrite; Examples thereof include a composite of ferromagnetic fine particles and a resin. Examples of the resin forming the coating layer include polyolefin resins such as polyethylene, polypropylene, chlorinated polyethylene, and chlorosulfonated polyethylene; polystyrene,
Polyvinyl and polyvinylidene resins such as acrylic (eg, polymethylmethacrylate), polyacrylonitrile, polyvinyl acetate, polyvinyl alcohol, polyvinyl butyral, polyvinyl chloride, polyvinylcarbazole, polyvinyl ether, polybiliketone; vinyl chloride-vinyl acetate copolymers; organo Silicone resins composed of siloxane bonds or modified products thereof (eg modified products such as alkyd resins, polyester resins, epoxy resins, polyurethanes); polytetrafluoroethylene, polyvinyl fluoride, polyvinylidene fluoride, polychlorotrifluoroethylene, etc. Fluorine resin; polyamide; polyester; polyurethane; polycarbonate; amino resin such as urea-formaldehyde resin; epoxy resin. Among them, silicone resin or a modified product thereof, and fluororesin, particularly silicone resin or a modified product thereof, are preferable from the viewpoint of preventing toner spent. As the silicone resin, any conventionally known silicone resin may be used, and examples thereof include straight silicones consisting only of organosiloxane bonds represented by the following formula and silicone resins modified with alkyd, polyester, epoxy, urethane and the like. To be

[Chemical 1]

In the above formula, R1 is a hydrogen atom or a carbon atom of 1 to 4
An alkyl group or a phenyl group, R2 and R3 are a hydrogen group, an alkoxy group having 1 to 4 carbon atoms, a phenyl group, a phenoxy group, an alkenenyl group having 2 to 4 carbon atoms, and an alkenyloxy group having 2 to 4 carbon atoms. , A hydroxy group, a carboxyl group, an ethylene oxide group, a glycidyl group, or a group represented by the following formula.

[Chemical 2] In the above formula, R4 and R5 are 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, a phenoxy group, k, l , M, n, o, p are integers of 1 or more. Each of the above substituents 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, in addition to an unsubstituted group. .

The carrier used in the present invention may have a conductivity-imparting material dispersed in the coating layer. The dispersed conductive material may be a conventionally known material, for example, iron, gold,
Metals such as copper; iron oxides such as ferrite and magnetite; pigments such as carbon black. Among them, particularly by using a mixture of furnace black and acetylene black which is one of carbon black, it is possible to effectively adjust the conductivity by adding a small amount of conductive fine powder,
Further, it becomes possible to obtain a carrier having excellent abrasion resistance of the coating layer. These conductive fine powders have a particle size of 0.01 to 1
It is preferably about 0 μm, preferably 2 to 30 parts by weight, more preferably 5 to 20 parts by weight, based on 100 parts by weight of the coating resin. Further, a silane coupling agent, a titanium coupling agent or the like may be added to the carrier coating layer for the purpose of improving the adhesiveness with the core particles and the dispersibility of the conductivity-imparting agent. Examples of the silane coupling agent used in the present invention include compounds represented by the following general formula.

## STR00003 ## YRSiX3 wherein X is a hydrolyzable group bonded to a silicon atom and includes a chloro group, an alkoxy group, an acetoxy group, an alkylamino group, a propenoxy group and the like. Y is an organic functional group that reacts with the organic matrix and includes vinyl group, methacryl group, epoxy group, glycidoxy group, amino group, mercapto group and the like. R is an alkyl group having 1 to 20 carbon atoms or an alkylene group. Among these silane coupling agents, an aminosilane coupling agent having an amino group in Y is preferable in order to obtain a developer having a negative charging property, and an epoxy silane coupling agent in Y is preferable in order to obtain a developer having a positive charging property. Epoxy silane coupling agents are preferred. As a method for forming the coating layer, the coating layer forming liquid may be applied to the surface of the carrier core particles by a method such as a spraying method or a dipping method as in the conventional method.
The thickness of the coating layer is preferably 0.1 to 20 μm. These are only one aspect of the present invention, and the technical scope of the present invention is not limited thereby.

[0014]

EXAMPLES Next, the present invention will be described in more detail by way of examples. However, the present invention is not limited to the following examples. In the examples, all parts are parts by weight. Carrier Production Example 1 2 parts by weight of polyvinyl alcohol and 60 parts by weight of water were placed in a ball mill and mixed for 12 hours with respect to 100 parts by weight of magnetite prepared by a wet method to prepare a magnetite slurry. This slurry was spray-granulated with a spray dryer to obtain spherical particles having an average size of 54 μm. The particles were fired in a nitrogen atmosphere at a temperature of 1000 ° C. for 3 hours and then cooled to obtain core particles 1. Next, the following mixture was dispersed with a homomixer for 15 minutes to form a coating layer forming liquid 1
(Dispersion liquid 1) was prepared. Silicone resin solution 100 parts Toluene 80 parts Methyltrimethoxysilane 5 parts Carbon black 10 parts This coating layer forming liquid is coated on the surface of 1500 parts by weight of core particles by a fluidized bed type coating device to give a silicone resin coated carrier A. Obtained. Examples 1 to 6 and Comparative Examples 1 to 5 The silicone resin-coated carrier A obtained as described above was cured under the manufacturing conditions shown in Table 1. The following items were fixed conditions in manufacturing. Coat device: Rolling flow type coating device Static drying oven: Hot air circulating electric drying oven (Fig. 3) Carrier particles: 50-70 μm magnetite carrier Drying treatment amount: 50 Kg / batch Obtained cured carrier A: Toner (20 parts by weight) was added to 100 parts by weight, and mixed with a Turbula mixer to prepare a developer.

Next, the developing device shown in FIG. 2 was incorporated into NX-720 manufactured by Ricoh Co., Ltd., and an image output test was conducted, and the image quality was evaluated by the following evaluation items. The results are shown in Table 1 and Table 2.
Shown in. << Evaluation method for each evaluation item >> (Resistance characteristics, charging characteristics) Charging characteristics are reference values (target values)
On the other hand, according to the degree of deviation, the layers were classified into 5 stages, the object with the smallest deviation was set as (⊚), and the evaluation was classified according to the deviation. (Toner Density Stability) Toner density stability is classified into 5 levels according to the degree of deviation from the reference value (target value),
The item with the smallest deviation was designated as (⊚) and evaluated according to the deviation. (Solid image density unevenness) Describes the width from the minimum density to the maximum density of A3 solid image. (Developer fluidity) Within the range (good) with respect to the reference value (target value), outside the range (faster) ), The slow thing was evaluated as (slow). The overall evaluation is divided into 4 grades including product productivity and quality. Rank 4 is (◎) and Rank 1 is (x)
And

[Table 1]

[Table 2]

[0016]

As described above, according to the method of manufacturing the resin-coated carrier for electrophotographic development of claim 1, the thickness A of the article to be fired (resin-coated carrier) in the multi-stage container is different from that of other layers. Since the interval B has a relationship of B ≧ A, uniform drying of the resin-coated carrier is obtained, and since the resistance is low and there is no variation in the charge amount and the resistance value, the toner is sufficiently charged. That is, a developer capable of obtaining a stable and good image can be manufactured. Further, the obtained developer was used in a small-sized developing device that does not require a toner replenishing mechanism and a toner concentration sensor, and a good image without stickiness could be obtained during solid image formation. According to the method for producing a resin-coated carrier for electrophotographic development of claim 2, the relationship between A and B is A × 2.0 ≧ B ≧ A, that is, the distance B from the other stage is defined by the thickness of the resin-coated carrier layer. Since the width is expanded to within twice the size A, the above-mentioned effect can be further improved. According to the method for producing a resin-coated carrier for electrophotographic development of claim 3, in the curing treatment, since the temperature of the atmosphere in the curing tank is from 260 ° C to 350 ° C, the uncured or peroxide state does not occur and the productivity is improved. Further, it is possible to obtain a better result in terms of quality stabilization. According to the method for producing a resin-coated carrier for electrophotographic development of claim 4, in the curing treatment, since the temperature difference in the atmosphere of the curing tank is ± 3 ° C. or less, uneven drying or excessive drying due to variation in temperature distribution. Is prevented, and the above-mentioned problems can be prevented.

According to the method for producing a resin-coated carrier for electrophotographic development of claim 5, the pressure in the atmosphere of the curing tank is from 0 to −
Since it is 500 Pa, oxide adhesion to the carrier after drying is reduced, and a carrier having a more stable charge amount can be obtained. In addition, since the gas concentration in the drying furnace is kept low, the safety is high. According to the method for producing a resin-coated carrier for electrophotographic development of claim 6, in the curing treatment, the material to be dried is cooled under a constant control environment after the curing treatment, so that the influence of temperature and humidity in a normal environment is exerted. Therefore, it does not suffer from the adverse effect on the charge of the developer due to the moisture adsorption of the carrier. According to the method for producing a resin-coated carrier for electrophotographic development according to claim 7, in the above-mentioned processing, the processing intervals per unit processing amount are set to be the same, and therefore,
It does not cause quality variations due to uneven drying, such as a material to be dried that has been introduced at uneven intervals. According to the apparatus for producing a resin-coated carrier for electrophotographic development of claim 8, since the above-mentioned production method can be carried out, uniform drying of the resin-coated carrier can be obtained, charging of toner is sufficiently performed, and low resistance is obtained. Thus, it is possible to manufacture a resin-coated carrier having no variation in charge amount and resistance value.

[Brief description of drawings]

FIG. 1 is a cross-sectional view showing an example of a multi-stage container for containing a material to be dried.

FIG. 2 is a sectional view showing an example of a developing device.

FIG. 3 is a side view showing an example of a multi-stage static drying oven.

[Explanation of reference numerals] 13 developing device, 15 developer carrier, 16a developer accommodating portion, 17 first doctor blade, 18 toner,
19 toner hopper, 20 toner supply opening, 21
Toner agitator, 22 developer, 23 second doctor blade, 30 container for storing dried material (bat), 4
0 coated carrier, 50 curing bath

Claims (8)

[Claims] 1. A method of curing a resin-coated carrier (material to be dried) in a multistage static drying oven,
A method for producing a resin-coated carrier for an electrophotographic developer, characterized in that a thickness A of a material layer to be dried in a storage container arranged in multiple stages and a distance B between the other stages have a relation of B ≧ A. 2. The method for producing a resin-coated carrier for an electrophotographic developer according to claim 1, wherein A and B are A ×
A method for producing a resin-coated carrier for an electrophotographic developer, which has a relationship of 2.0 ≧ B ≧ A. 3. The method for producing a resin-coated carrier for an electrophotographic developer according to claim 1, wherein the curing atmosphere temperature is 260 ° C. to 350 ° C. Production method. 4. The method for producing a resin-coated carrier for an electrophotographic developer according to claim 1, wherein
A method for producing a resin-coated carrier for an electrophotographic developer, characterized in that a temperature difference in a curing tank atmosphere is ± 3 ° C or less. 5. The method for producing a resin-coated carrier for an electrophotographic developer according to claim 1,
The method for producing a resin-coated carrier for an electrophotographic developer, wherein the pressure in the atmosphere of the curing tank is 0 to -500 Pa. 6. The method for producing a resin-coated carrier for an electrophotographic developer according to claim 1, wherein
A method for producing a resin-coated carrier for an electrophotographic developer, which comprises cooling a material to be dried in a cooling process after a curing treatment under a constant control environment. 7. The method for producing a resin-coated carrier for an electrophotographic developer according to claim 1,
A method for producing a resin-coated carrier for an electrophotographic developer, which is characterized in that the treatment intervals per unit treatment amount are set to be the same. 8. An apparatus for producing a resin-coated carrier for an electrophotographic developer, which can carry out the method for producing a resin-coated carrier for an electrophotographic developer according to claim 1.