JPH1090954A - Electrophotographic carrier, method for producing the same, and developer using the carrier - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a carrier excellent in environmental stability, capable of instantly adding a charging ability to a toner, having a good start-up characteristic and a good durability, and a method thereof. A manufacturing method is provided. SOLUTION: A carrier core material has a coating resin layer made of a silicone resin or a modified silicone resin containing a silane coupling agent having a quaternary ammonium salt structure, and the quaternary ammonium salt in the coating resin is provided. The content of the silane coupling agent having a structure is 6 to 25% by weight.
A resin-coated carrier for electrophotographic development, characterized in that:

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a resin-coated carrier for an electrophotographic developer used in an electrophotographic process such as a copying machine and an electrostatic recording system, a method for producing the same, and a developer using the carrier.

[0002]

2. Description of the Related Art A two-component developer used for electrophotography is composed of a toner and a carrier. The carrier is mixed and stirred with the toner in a developing box to give a desired charge to the toner and to take on the charge. Is a carrier material that carries the toner to the electrostatic latent image on the photoconductor and forms a toner image.

[0003] The carrier remains on the magnet roll,
The toner is returned to the developing box again, mixed and stirred again with new toner, and used repeatedly. Therefore, the carrier is required to be able to continuously obtain desired charging characteristics in all environments during use.

However, the conventional developer has two problems due to collision between carriers due to agitation or friction between the developing box and the carrier. That is, the toner is fused to the surface of the carrier and spent is caused. On the other hand, the carrier resistance changes due to peeling and falling off of the resin coating layer on the carrier surface, which causes a problem of image deterioration (insufficient image density, poor fog on the image, etc.) after printing, compared with the image at the initial stage. is there. Further, there is a problem that not only deterioration of the developer (carrier) due to agitation, but also a change in the environment at the time of printing durability causes a decrease in the charge amount at high temperature and high humidity, causing toner scattering and image fogging failure. At low temperature and low humidity,
Conversely, the amount of charge increases, causing a problem of insufficient image density, and the life of the developer eventually becomes short at present. In particular, since a full-color carrier has a larger solid portion than a printing portion as compared with a conventional copying machine printer or the like, a large amount of toner is transferred to a photoreceptor, and the durability of the carrier is further required.

[0005] In order to stabilize the charge due to the above-mentioned spent and environmental change during printing, various methods of coating with various resins have been proposed, but no satisfactory method has yet been obtained. In other words, carriers coated with silicone-based resins and fluorine-based resins have low critical surface tension, are less likely to cause spent to fuse toner to the carrier surface, and have a long life as a developer. In addition, since the chargeability of the carrier is weak, toner scatters a lot, causing contamination inside the apparatus and, at the very least, image defects, and the overall life is short in the overall evaluation. In addition, resin is used to prevent deterioration of an image (insufficient image density, poor image fog, etc.) due to separation of the coating resin layer on the carrier surface due to collision between carriers due to agitation or friction between the developing box and the carrier, etc. It has been proposed to use a silane coupling agent in order to improve the adhesion of the coating layer (JP-A-60-1).
No. 9156). However, in this technique, although the adhesion of the coating layer is improved, there is a problem that toner scattering and fogging on an image occur due to variation in the amount of charge under various environments.

On the other hand, in order to improve the adhesion between the carrier core agent and the silicone resin, a carrier in which a coating layer made of a silicone resin is provided on the surface of the carrier core agent treated with a silane coupling agent (Japanese Patent Application Laid-Open No. 62-121463). No.),
And a chargeable fine powder and a silane coupling agent contained in the silicon resin for coating the carrier core material, wherein the concentration of the silane coupling agent has a concentration gradient with respect to the thickness direction of the silicon resin coating layer. Latent image carrier
04189).

However, these compounds have no or little component of the effective silane coupling agent having a polar group on the outermost surface of the carrier, or cause a component-containing variation due to a change in layer thickness after lapse of time. On the other hand,
There is not enough charging ability, the charging ability changes over time,
Toner scattering occurs during printing, and satisfactory toner cannot be obtained.In recent years, in order to improve the charging characteristics of a resin-coated carrier obtained by coating a carrier core material with a resin, an intermediate material is added to the carrier core material in advance. It has been proposed to provide a resin layer containing an aminosilane coupling agent as a layer and provide an outermost resin coating via this intermediate layer (JP-A-5-72815, JP-A-5-134467). However, although the durability of these resin-coated carriers is improved to some extent by exhibiting the properties unique to the silane coupling agent, the effectiveness of the amino group as a charge control site is limited and this amino group is The improvement of the charging characteristics was still insufficient, for example, the charging characteristics were changed because the layer was not disposed on the outermost surface of the carrier and the thickness of the outermost layer decreased with the lapse of time.

In these carriers, since the respective constituent components in the carrier resin layer are not uniform, the silicone resin-coated carrier undergoes a temporal change during standing, and the curing of the outermost layer and the intermediate layer in the resin layer is shifted. , A large difference occurs in the charging characteristics from the initial toner at the time of manufacture, or in the case of adding a conductive material,
When the charge amount decreases at high humidity and the resin layer peels or falls off during printing, the resistance of the carrier changes greatly and the final evaluation does not indicate durability.

On the other hand, in a resin-coated carrier using the above-mentioned conventional aminosilane coupling agent, the aminosilane coupling agent is contained in an amount of 3% by weight based on the coating resin.
In most cases, the content is less than or equal to or less than 5% by weight in the resin as described in JP-A-61-140951. JP-A-7-10
Japanese Patent No. 4522 discloses a resin-coated carrier having a coating layer made of a resin containing an aminosilane coupling agent or a modified silicone resin on a carrier core material. In this aminosilane coupling agent, a resin containing an amino group nitrogen is contained. Although the ratio is high, the secondary or tertiary amino groups contained in the main chain hardly contribute to the improvement of the charging characteristics. Conversely, at high humidity, the charging characteristics fluctuate, and due to the high content of amino groups, There are drawbacks such as difficulty in obtaining sufficient adhesive strength.

In recent years, there has been an increasing demand for uniform reproduction of images having many solid portions such as barcodes and images such as graphic designs, in place of slips having a large number of printing portions such as printers. There are more solid portions, and the amount of toner consumption and replenishment increases significantly. In the electrophotographic development process, it is desired that the toner constantly maintain desired charging characteristics in all environmental conditions. However, under recent high toner consumption and replenishment development conditions, what is satisfactory at present is: Not obtained.

Therefore, in the conventional carrier and developer, spent is prevented, and the improvement of the adhesion of the carrier coating layer is improved. By using an aminosilane coupling agent, the ability to impart a slight charge to the toner is improved. However, none of the toners has a good start-up charging characteristic particularly under high temperature and high humidity conditions. The ability to charge to a small particle size toner concentration for high resolution used in printers and full-color machines with many solid parts in recent years is not sufficient, and the charge amount gradually increases with the replenished toner during printing. At present, it is not possible to increase the durability, and ultimately sufficient durability has not been obtained.

[0012]

SUMMARY OF THE INVENTION Accordingly, an object of the present invention is to solve the above-mentioned problems in the prior art, to provide excellent environmental stability, and to instantly supply toner newly replenished by repeated copying. It is an object of the present invention to provide a carrier having good rising characteristics and good durability capable of adding a charging ability and to provide a method for producing the carrier, and to improve the performance of an electrophotographic developer. Another object of the present invention is to provide a carrier suitable for improving the durability of a full-color developer that frequently consumes a large amount of toner and often comes into contact with a high-density toner, and a method for producing the same. An object of the present invention is to reduce the copying cost per sheet by extending the life of the developer. It is still another object of the present invention to provide a carrier having a uniform coating layer, and to provide a developer having a long storage life without aging in quality as a developer.

[0013]

Means for Solving the Problems The inventors of the present invention have conducted intensive studies on the above-mentioned problems, and as a result, they have been coated with a silicone resin or a modified silicone resin containing a silane coupling agent having a quaternary ammonium salt structure. In the resin-coated carrier, we found that there was a relationship between the content of the silane coupling agent in the coating resin and the charging ability of the toner, especially at high temperature and high humidity. It has been found that, depending on the configuration of the silane coupling agent and the baking conditions of the coating layer, a resin coating carrier having good charge rising characteristics and a durable property can be obtained in various environments, and furthermore, particularly, the number of times of contact with the toner is large The present invention was found to be effective in combination with the surface properties and particle size of the carrier core material for full-color machines. This has led to the formation.

That is, according to the present invention, the carrier core material has a coating resin layer made of a silicone resin or a modified silicone resin containing a silane coupling agent having an ammonium salt structure. Wherein the content of the silane coupling agent is from 6 to 25% by weight.

Hereinafter, the present invention will be described in detail. The resin-coated carrier of the present invention has, on a carrier core material, a coating resin layer made of a silicone-based resin or a modified silicone-based resin containing a silane coupling agent having an ammonium salt structure. The content of the silane coupling agent in the coating resin is 6 to 25% by weight, preferably 1 to 25% by weight.
2 to 22% by weight. Also, particularly preferably 14 to 1
8% by weight. The content ratio of the silane coupling agent is 6
If the content is less than 10% by weight, the content of the quaternary ammonium salt is too small, and the toner cannot be sufficiently charged under high humidity.
On the other hand, if it exceeds 25% by weight, the absolute value of the charge amount will increase under low humidity, and the image density will decrease. Further, if the silane coupling agent is contained more than necessary in the coating resin, delamination is caused, and durability cannot be obtained.

The silane coupling agent used in the present invention has the following formula.

[0017]

Embedded image (However, R ₁ is an alkyl group having 1 to 25 carbon atoms, R ₂ ,
R ₃ , R ₅ and R ₆ are an alkyl group having 1 to 2 carbon atoms, R ₄ is an alkylene group having 1 to ₄ carbon atoms, n = 2 or 3, and X ⁻ is a halogen ion. As for R _{4, an} aliphatic alkylene group is more suitable than a phenylene group for use in combination with a silicone resin because of its structure. It is necessary that at least n = 2,
Most preferably, n = 3. This is because it reacts with the base resin in the silicone resin or the modified silicone resin, and the silane coupling agent adheres firmly.

The silicone resin may be any straight silicone resin having an organosiloxane bond, and commercially available products are KR-271 and K-271 manufactured by Shin-Etsu Chemical Co., Ltd.
R-255, Toray Dow Corning Silicone S
R-2410, SR-2406, SR-2411, phenylmethyl silicone resin (Dow Corning Toray)
Silicone SH804) Toshiba Silicone TSR
-127B, TSR-144 and the like. If necessary, a catalyst or the like may be added to these silicone resins. As the modified silicone resin, alkyd resin,
Polyester resin, epoxy resin, polyurethane resin,
Modified silicone resin such as acrylic resin can be used,
As commercially available products, KR-206 (modified with alkyd resin), KR-9706 (modified with acrylic resin) manufactured by Shin-Etsu Chemical Co., Ltd.,
ES-1001N (modified with epoxy resin) and SR-2101 (modified with alkyd resin) manufactured by Dow Corning Toray Silicone Co., Ltd. Further, a phenylmethyl-based silicone is preferable, and such a silicone is excellent in terms of film strength and reactivity with a silane coupling agent.

As the core material in the resin-coated carrier of the present invention, conventionally known materials can be used. For example,
Examples include ferromagnetic metals such as iron and cobalt, magnetite, hematite ferrite, and the like. Preferably, it is better to use ferrite or iron whose surface is easy to control,
Particularly, ferrite is preferable. As for the surface property of the carrier core material in the present invention, the surface property index is preferably in the range of 1.0 to 2.1, and particularly preferably 1.5 to 2.0. When the surface property index is less than 1.0, the surface property becomes too smooth, and sintering of the particles of the carrier core material occurs, so that a uniform shape cannot be maintained and a uniform resin coating is difficult. In addition, the carriers are granulated with excess resin, and good coating cannot be performed. On the other hand, when the surface property index exceeds 2.1, the surface property is not smooth, the resin layer penetrates into the carrier core material, and it is difficult to uniformly coat the surface. Even if the coating amount is increased, the thickness of the resin coating layer varies due to the unevenness of the outermost surface of the core material, and the effective function of the silane coupling agent cannot be obtained, and good durability cannot be obtained.

The surface property index referred to here means the BET method (Bru method).
It is expressed as a value obtained by dividing the specific surface area by the nauer Emmett Teller method) by the specific surface area by the air permeation method, and serves as a scale for evaluating carrier surface properties. The specific surface area by the BET method is N ₂
By replacing the gas, it is possible to measure not only the unevenness of the surface area of the carrier core material but also the pores inside the carrier core material that are continuous from the surface. It is a good measurement method for calculating quantities. The specific surface area by the air permeation method is a method of measuring the specific surface area from the time required for air to pass through the carrier filled in the cell, and the value is relatively limited to the surface portion of the carrier core material. This is a measurement method suitable for measuring the area.

Accordingly, the surface property index can be represented by calculating the value of each specific surface area obtained by these two measurements by the following equation. Surface index = specific surface area by the BET method (cm ² / g) /
Specific surface area by air permeation method (cm ² / g) For example, for measurement of specific surface area by BET method, an apparatus similar to or similar to Flow Soap II2300 manufactured by Shimadzu Corporation can be used. For the measurement of the specific surface area by the air permeation method, an apparatus similar to or similar to SS-200 manufactured by Shimadzu Corporation can be used.

The particle size of the carrier core material in the present invention is preferably 20 to 100 μm, particularly 30 to 65 μm.
m is preferred. If the average particle size is less than 20 μm, the number of fine particles in the distribution of carrier particles increases, the magnetization per particle decreases, and carrier scattering occurs. On the other hand, when the average particle size of the carrier exceeds 100 μm, the specific surface area decreases and toner is scattered. Further, in a full color having many solid portions, reproduction of the solid portion is particularly poor, which is not preferable. The solvent used for forming the coating resin layer in the present invention is, for example, toluene, xylene, methyl ethyl ketone, methyl isobutyl ketone, and cellsol butyl acetate.

The amount of the resin coated in the resin-coated carrier is 0.1 to 5.0% by weight based on the total amount of the resin-coated carrier.
And preferably in the range of 0.15 to 2.0% by weight. When the coating amount of the resin is less than 0.1% by weight, the range of the surface property index (1.0%) of the carrier core material used in the present invention is used.
In 2.1 to 2.1), a uniform coating cannot be formed on the carrier surface. When the content exceeds 5.0% by weight, the coating layer becomes too thick, and the carrier particles are granulated. It tends not to be obtained. The method of forming the coating resin layer on the carrier core material is to dissolve the silicone resin or the modified silicone resin containing the silane coupling agent described above in a solvent, and then dipping the carrier core material and spraying. After uniformly applying the same resin solution by brush coating or the like, the solvent is removed by drying, and then baking is performed.

The baking apparatus may be either an external heating system or an internal heating system, for example, a fixed or fluidized electric furnace, a rotary electric furnace, a burner furnace, or a microwave baking. The baking temperature is preferably from 180 to 300 ° C.
20-280 ° C is optimal. If the baking temperature is lower than 180 ° C., the silicone resin containing the silane coupling agent or the modified silicone resin is not sufficiently cured, and the coating resin layer which does not fall off with the carrier core material is tough. I can't get it. Further, the reaction between the silane coupling agent and the silicone base range does not proceed sufficiently. On the other hand, if the temperature exceeds 300 ° C., a part of the silicone resin and a part of the silane coupling agent may be decomposed, so that the surface layer of the resin may be roughened and a uniform coating layer may not be obtained. Further, it is preferable to perform the preliminary firing at a relatively low temperature before performing the above-described printing. By performing the preliminary firing, the solvent used when forming the coating resin layer can be removed cleanly, so that the carrier particles do not granulate even if heated at a high temperature in the subsequent main firing. .

[0025]

Hereinafter, the present invention will be described in detail with reference to examples. The present invention is not limited to these examples. Example 1 Using ferrite particles (trade name: F-2035, manufactured by Powder Tech), an average particle size of 65 μm, and a surface property index of 1.3.
(BET method specific surface area: 267 cm ² / g, air permeation method specific surface area: 205 cm ² / g), a silicone core resin (trade name: SR-2411, solid content: 20)
Octadecyldimethyl [3- (methyldimethoxysilyl) propyl] ammonium chloride in an amount of 8% by weight to the solid content of Dow Corning Toray Silicone Co., Ltd.)
% By weight, dissolved in a toluene solvent, and coated with 0.7% by weight on a carrier core material using a fluidized bed.
Further, baking is performed at 200 ° C. for 2 hours (temporary firing is performed at 100 ° C.
/ 1 hour) to obtain a carrier coated with the resin. As the toner used for evaluation of this carrier,
Various types of magenta, cyan, yellow and black toners of Ricoh color PPC toner type F commercially available from Ricoh Co., Ltd. were used. Using this carrier and the toner of each color shown above, each color was adjusted to a developer having a toner concentration of 8.0% by weight, and the printing durability evaluation (10) was performed using a color copying machine PRETER650 (manufactured by Ricoh Company, Ltd.). (2,000 sheets). Table 2 shows the image evaluation at that time. Table 2
In the above, the results were represented by five ranks of ◎ to ×, and the image evaluation was ranked. Δ or more is a practical level. The specific evaluation method is as follows.

Image Evaluation of Carrier Image Density (ID) Copies were made under appropriate exposure conditions. D. Was evaluated.
The image density of the solid portion was measured with a Macbeth densitometer and ranked. ：: Uniform density non-uniformity, original density very well reproduced. ：: Original density is reproduced without density unevenness. Δ: Image density is good. (Practically feasible level) ▲: Density unevenness or edge effect, non-uniform image, image density lower than document density. X: The image density is low as a whole, and is significantly lower than the document density.

Fog on the image The fog on the image was evaluated by using a colorimetric colorimeter Z-300 manufactured by Nippon Denshoku Industries Co., Ltd. to evaluate toner fog on a white background image. It is, of course, possible to use an equivalent device. ◎: less than 0.5% ：: 0.5 to less than 1.0% Δ: 1.0 to less than 1.5% ：: 1.5 to less than 2.5% ×: 2.5% or more

Carrier Adhesion Carrier adhesion on the image, ie, the level of vitiligo, was evaluated and ranked. ◎: Not present in 10 A3 sheets ：: 1 to 5 out of 10 A3 sheets △: Over 5 out of 10 A3 sheets, within 3 out of 3 A3 sheets: Out of 3 A3 sheets More than 5 and up to 10 ×: more than 10 out of 3 A3 paper

Toner Scattering Undesirable toner scattering such as the degree of toner scattering, which becomes a stain on the copy paper, and the charging charger stain, were evaluated and ranked.

Environmental Variation of Charging The amount of charge (Q _LL ) after storing the developer in an environment of 10 ° C. and 15% for 24 hours and the amount (Q _MW ) of the developer after storing for 24 hours in a 30 ° C. and 85% environment And the difference ΔQ (ΔQ = Q _LL −Q
_MW (μc / g)) was determined and ranked to evaluate the environmental change of charging. ◎: ΔQ = less than 3 μc ○: ΔQ = more than 3 μc, less than 5 μc Δ: ΔQ = more than 5 μc, less than 7 μc ▲: ΔQ = more than 7 μc, less than 12 μc ×: ΔQ = more than 12 μc. The measurement of the charge amount is performed by E-SPART A manufactured by Hosokawa Micron Co., Ltd.
Determined using NALYZER. Of course, an equivalent device can be used.

Rise of Charging The developer supplied with the new toner is stirred and mixed in a developing machine, and the charging application speed for the supplied toner is obtained from the fluctuation value of the charging amount during the stirring time, and ranked. The rising properties were evaluated. ：: Very good level in the evaluation of charge rising property. ：: No problem in the charging rise evaluation. Δ: Practically usable level in charging rise property evaluation. ：: There is a problem in the charging rise evaluation, and the level cannot be used. ×: There is a problem and the level cannot be used practically.

Example 2 Using ferrite particles (trade name: F-400, manufactured by Powder Tech), an average particle diameter of 26 μm and a surface property index of 2.1.
(BET method specific surface area: 1217 cm ² / g, air permeation method specific surface area: 580 cm ² / g)
Silicone resin (trade name: SR-2411, solid content 2)
0% by weight, octadecyldimethyl [3- (methyldimethoxysilyl) propyl] ammonium chloride was mixed with 25% by weight of the solid content of Dow Corning Toray Silicone Co., Ltd.), and the carrier was obtained in the same manner as in Example 1. 2.1% by weight coating on the core material,
Baking was performed at 0 ° C. for 3 hours (temporary baking was performed at 140 ° C./1.5 hours) to obtain a carrier coated with the above resin. Using this carrier and each toner used in Example 1, each color was prepared as a developer having a toner concentration of 8.0% by weight.
Printing durability was evaluated using ETER650 (manufactured by Ricoh Co., Ltd.). Table 2 shows the image evaluation at that time.

Example 3 Using ferrite particles (trade name: F-300, manufactured by Powder Tech), an average particle diameter of 44 μm and a surface property index of 1.7.
(BET method specific surface area: 546 cm ² / g, air permeation method specific surface area: 322 cm ² / g), a silicone resin (trade name: SR-2411, solid content: 20)
16% by weight of octadecyldimethyl [3- (triethoxysilyl) propyl] ammonium chloride based on the solid content of Dow Corning Silicone Toray Silicone Co., Ltd.), and the carrier core was prepared in the same manner as in Example 1. The material was coated at 0.9% by weight, and baked at 250 ° C. for 3 hours (calcination was performed at 125 ° C./1.5 hours).
A carrier coated with the above resin was obtained. Using this carrier and each of the toners used in Example 1, each color was prepared as a developer having a toner concentration of 8.0% by weight.
Printing durability was evaluated using R650 (manufactured by Ricoh Co., Ltd.). Table 2 shows the image evaluation at that time.

Example 4 Using ferrite particles (trade name: F-350, manufactured by Powder Tech), an average particle size of 38 μm, and a surface property index of 1.9.
(BET method specific surface area: 705 cm ² / g, air permeation method specific surface area: 371 cm ² / g), a silicone resin (trade name: SR-2411, solid content: 20)
20% by weight of octadecyldimethyl [3- (triethoxysilyl) propyl] ammonium chloride was mixed with the solid content of Dow Corning Silicone Toray Co., Ltd.) in the same manner as in Example 1. The material was coated at 1.5% by weight and baked at 280 ° C. for 3 hours (temporary firing was 140 ° C./1.5 hours).
A carrier coated with the above resin was obtained. Using this carrier and each of the toners used in Example 1, each color was prepared as a developer having a toner concentration of 8.0% by weight.
Printing durability was evaluated using R650 (manufactured by Ricoh Co., Ltd.). Table 2 shows the image evaluation at that time.

Example 5 Using ferrite particles (trade name: F-2535, manufactured by Powder Tech), an average particle size of 60 μm and a surface property index of 1.5 were used.
(BET method specific surface area: 347 cm ² / g, air permeation method specific surface area: 231 cm ² / g), a silicone resin (trade name: SR-2411, solid content: 20)
12% by weight of octadecyldimethyl [3- (triethoxysilyl) propyl] ammonium chloride was mixed with the solid content of Dow Corning Silicone Toray Co., Ltd.) in the same manner as in Example 1. The material was coated at 0.8% by weight and baked at 240 ° C. for 3 hours (temporary firing was 120 ° C./1.5 hours).
A carrier coated with the above resin was obtained. Using this carrier and each of the toners used in Example 1, each color was prepared as a developer having a toner concentration of 8.0% by weight.
Printing durability was evaluated using R650 (manufactured by Ricoh Co., Ltd.). Table 2 shows the image evaluation at that time.

Example 6 Using ferrite particles (trade name: F-3040, manufactured by Powder Tech), an average particle size of 47 μm, and a surface property index of 1.8.
(BET method specific surface area: 557 cm ² / g, air permeation method specific surface area: 310 cm ² / g), a silicone resin (trade name: SR-2411, solid content: 20)
6% by weight of octadecyldimethyl [3- (triethoxysilyl) propyl] ammonium chloride was mixed with the solid content of Dow Corning Silicone Toray Co., Ltd.), and the carrier core was prepared in the same manner as in Example 1. 0.3 wt% coating on the material
Baking was performed for a period of time (temporary baking was 110 ° C./1 hour) to obtain a carrier coated with the resin. Using this carrier and each toner used in Example 1, each color was prepared as a developer having a toner concentration of 8.0% by weight.
Using 50 (manufactured by Ricoh Co., Ltd.), printing durability was evaluated.
Table 2 shows the image evaluation at that time.

Example 7 Using ferrite particles (trade name: F-3035, manufactured by Powder Tech), an average particle diameter of 54 μm, and a surface property index of 1.8.
(BET method specific surface area: 484 cm ² / g, air permeation method specific surface area: 270 cm ² / g) Modified silicone resin (trade name: KR-9706, solid content 50% by weight, Shin-Etsu Chemical Co., Ltd.) Octadecyldimethyl [3- (trimethoxysilyl) propyl]
6% by weight of ammonium chloride was mixed, and in the same manner as in Example 1, 0.4% by weight was coated on the carrier core material and baked at 220 ° C. for 3 hours (calcination at 110 ° C./1. 5 hours), a carrier coated with the resin was obtained. Using this carrier and the toners used in Example 1, the toner concentration of each color was 8.0% by weight.
And the printing durability was evaluated using PRETER650 (manufactured by Ricoh Co., Ltd.). Table 2 shows the image evaluation at that time.

Example 8 Using ferrite particles (trade name: F-1530, manufactured by Powder Tech), an average particle size of 85 μm, and a surface property index of 1.1.
(BET method specific surface area: 188 cm ² / g, air permeation method specific surface area: 170 cm ² / g), modified silicone resin (trade name: KR-9706, solid content 50% by weight, Shin-Etsu Chemical Co., Ltd.) Octadecyldimethyl [3- (trimethoxysilyl) propyl]
6% by weight of ammonium chloride was mixed, and in the same manner as in Example 1, 0.4% by weight was coated on the carrier core material and baked at 220 ° C. for 3 hours (calcination at 110 ° C./1. 5 hours), a carrier coated with the resin was obtained. Using this carrier and the toners used in Example 1, the toner density of each color was 6.0% by weight.
And the printing durability was evaluated using PRETER650 (manufactured by Ricoh Co., Ltd.). Table 2 shows the image evaluation at that time.

Example 9 Using ferrite particles (trade name: F-400, manufactured by Powder Tech), an average particle diameter of 30 μm, and a surface property index of 3.5
(BET specific surface area: 2076 cm ² / g, air permeation specific surface area: 592 cm ² / g)
25% by weight of octadecyldimethyl [3- (methyldimethoxysilyl) propyl] ammonium chloride was mixed with the solid content of the modified silicone resin (trade name: KR-9706, solid content 50% by weight, manufactured by Shin-Etsu Chemical Co., Ltd.), In the same manner as in Example 1, the carrier core material was coated at 2.1% by weight, and baked at 280 ° C. for 3 hours (temporary calcination was 140 ° C./1.5 hours), and coated with the above resin. Got a career. This carrier and each toner used in Example 1 were used, and the toner density of each color was 8.
0% by weight of a developer,
(Ricoh Co., Ltd.) was used to evaluate printing durability. Table 2 shows the image evaluation at that time.

Example 10 The carrier core material used in Example 8 was phenylmethyl silicone resin (trade name: SH804, nonvolatile content 60
%, Solid content of Dow Corning Toray Silicone Co., Ltd.) and 6% by weight of octadecyldimethyl [3- (trimethoxysilyl) propyl] ammonium chloride were mixed, and the carrier core material was obtained in the same manner as in Example 1. Against
It was coated at 0.4% by weight and baked at 220 ° C. for 3 hours (temporary calcination was 110 ° C./1.5 hours) to obtain a carrier coated with the above resin. Using this carrier and the toners used in Example 1, each color was prepared as a developer having a toner concentration of 6.0% by weight.
Using 50 (manufactured by Ricoh Co., Ltd.), printing durability was evaluated.
Table 2 shows the image evaluation at that time. Example 1 above
Table 1 shows the summary of Nos. To 10.

Comparative Example 1 Using the carrier core material used in Example 1, the solid content of a silicone resin (trade name: SR-2411, solid content 20% by weight, manufactured by Dow Corning Toray Silicone Co., Ltd.) was determined. Octadecyldimethyl [3- (methyldimethoxysilyl) propyl] ammonium chloride was mixed at 3% by weight, coated and baked in the same manner as in Example 1 with the same amount of resin to obtain a carrier. This carrier was prepared as a developer in the same manner as in Example 1, and the printing durability was evaluated using the same machine. Table 2 shows the image evaluation at that time.

Comparative Example 2 Using the carrier core material used in Example 1, based on the solid content of a silicone resin (trade name: SR-2411, solid content 20% by weight, manufactured by Dow Corning Toray Silicone Co., Ltd.) Octadecyldimethyl [3- (methyldimethoxysilyl) propyl] ammonium chloride at 30% by weight
The mixture was mixed, coated and baked in the same manner as in Example 1 with the same amount of resin to obtain a carrier. This career,
A developer was prepared in the same manner as in Example 1, and the printing durability was evaluated using the same machine. Table 2 shows the image evaluation at that time.
Shown in

Comparative Example 3 Using the carrier core material used in Example 7, N-β- (aminoethyl) -γ-aminopropylmethyldimethoxysilane was added to the same resin as used in Example 7 at the same ratio. The mixture was mixed, coated and baked in the same manner as in Example 7 with the same amount of resin to obtain a carrier. This career,
A developer was prepared in the same manner as in Example 7, and the printing durability was evaluated using the same machine. Table 2 shows the image evaluation at that time.
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Comparative Example 4 Example 7 was repeated except that the carrier core material used in Example 7 was not used and octadecyldimethyl [3- (trimethoxysilyl) propyl] ammonium chloride was not used.
Coating and baking were carried out in the same manner and with the same amount of resin to obtain a carrier. This carrier was prepared as a developer in the same manner as in Example 7, and the printing durability was evaluated using the same machine. Table 2 shows the image evaluation at that time.

Comparative Example 5 Using ferrite particles (trade name: F-8020, manufactured by Powder Tech), an average particle diameter of 150 μm, and a surface property index of 1.
3 (BET specific surface area: 146 cm ² / g, air permeation specific surface area: 113 cm ² / g)
Silicone resin (trade name: SR-2411, solid content 2)
0% by weight, octadecyldimethyl [3- (methyldimethoxysilyl) propyl] ammonium chloride was mixed with 30% by weight based on the solid content of Dow Corning Silicone Toray Co., Ltd., and the carrier was obtained in the same manner as in Example 1. 0.3% by weight coating on core material
Baking was performed at 0 ° C. for 2 hours (temporary baking was performed at 100 ° C./1 hour) to obtain a carrier coated with the above resin. Using this carrier and the toners used in Example 1, each color was prepared as a developer having a toner concentration of 5.0% by weight.
Printing durability was evaluated using ETER650 (manufactured by Ricoh Co., Ltd.). Table 2 shows the image evaluation at that time.

Comparative Example 6 Using ferrite particles (trade name: F-2035, manufactured by Powder Tech), an average particle size of 65 μm, and a surface property index of 5.5.
(BET specific surface area: 1750 cm ² / g, air permeation specific surface area: 318 cm ² / g)
Silicone resin (trade name: SR-2411, solid content 2)
0% by weight, octadecyldimethyl [3- (methyldimethoxysilyl) propyl] ammonium chloride was mixed with 30% by weight based on the solid content of Dow Corning Silicone Toray Co., Ltd., and the carrier was obtained in the same manner as in Example 1. 0.3% by weight coating on core material
Baking was performed at 0 ° C. for 2 hours (temporary baking was performed at 100 ° C./1 hour) to obtain a carrier coated with the above resin. Using this carrier and each toner used in Example 1, each color was prepared as a developer having a toner concentration of 8.0% by weight.
Printing durability was evaluated using ETER650 (manufactured by Ricoh Co., Ltd.). Table 2 shows the image evaluation at that time.

Comparative Example 7 Using ferrite particles (trade name: F-500, manufactured by Powder Tech), an average particle diameter of 17 μm, and a surface property index of 5.5.
(BET method specific surface area: 4854 cm ² / g, air permeation method specific surface area: 883 cm ² / g)
Silicone resin (trade name: SR-2411, solid content 2)
0% by weight and 3% by weight of octadecyldimethyl [3- (methyldimethoxysilyl) propyl] ammonium chloride with respect to the solid content of Dow Corning Silicone Toray Co., Ltd.), and the carrier was obtained in the same manner as in Example 1. 5.0% by weight coating on the core material,
Baking was performed at 2 ° C. for 2 hours (temporary baking was performed at 90 ° C. for 1 hour) to obtain a carrier coated with the above resin. Using this carrier and the toners used in Example 1, each color was prepared into a developer having a toner concentration of 9.0% by weight.
650 (manufactured by Ricoh Co., Ltd.) was used to evaluate the printing durability. Table 2 shows the image evaluation at that time.

Comparative Example 8 Using the carrier core material used in Example 1, a silicone resin (trade name: SR-2411, solid content 20% by weight, manufactured by Dow Corning Toray Silicone Co., Ltd.) was dissolved in a toluene solvent. , Using a fluidized bed with respect to the carrier core material.
7% by weight coating. At that time, octadecyldimethyl [3- (methyldimethoxysilyl) propyl] ammonium chloride is gradually added to the silicone resin liquid so that the concentration of octadecyldimethyl [3- (methyldimethoxysilyl) propyl] ammonium chloride gradually decreases. The silicone resin was coated so that the concentration of the silane coupling agent had a concentration gradient. Octadecyldimethyl [3- (methyldimethoxysilyl) propyl] ammonium chloride was added in a total amount of 8% by weight to the silicone resin. Further, baking was performed at 200 ° C. for 2 hours (temporary baking was performed at 100 ° C. for 1 hour) to obtain a carrier coated with the above resin. This carrier was prepared as a developer in the same manner as in Example 1, and the printing durability was evaluated using the same machine. Table 2 shows the image evaluation at that time. Table 1 summarizes the above Comparative Examples 1 to 8.

Overall Evaluation Each image evaluation in the printing durability test was comprehensively evaluated and ranked. ◎: Very good level in each image evaluation ：: Level without any problem in each image evaluation レ ベ ル: Practically usable level in each image evaluation ：: There is a problematic item in each image evaluation, Unusable level x: Level that has problems in most evaluations and cannot be used practically

[0050]

[Table 1-1]

[0051]

[Table 1-2]

[0052]

[Table 2]

[0053]

As described above in detail and specifically,
The carrier having a uniform coating layer of the present invention and the developer using the carrier are a coating resin comprising a silicone-based function or a modified silicone resin in which a carrier core material contains a silane coupling agent having a quaternary ammonium salt structure. By having a layer and a specific ratio of a silane coupling agent having a quaternary ammonium salt structure in the coating resin, the toner has excellent environmental stability and stands up characteristics with respect to a toner supplied by repeated copying. It is possible to obtain a developer containing a carrier and a toner having good durability, and it is possible to obtain a carrier having the above-mentioned characteristics by the production method of the present invention.

Claims (6)

[Claims] 1. A carrier core material comprising a coating resin layer made of a silicone-based resin or a modified silicone-based resin containing a silane coupling agent having a quaternary ammonium salt structure, and a silane coupling in the coating resin. A resin-coated carrier for electrophotographic development, wherein the content of the agent is 6 to 25% by weight. 2. The resin-coated carrier for electrophotographic development according to claim 1, wherein the silane coupling agent is represented by the following structural formula. Embedded image (However, R ₁ is an alkyl group having 1 to 25 carbon atoms, R ₂ ,
R ₃ , R ₅ and R ₆ are an alkyl group having 1 to 2 carbon atoms, R ₄ is an alkylene group having 1 to ₄ carbon atoms, n = 2 or 3, and X ⁻ is a halogen ion. ) 3. The carrier core material has a surface property index of 1.0.
~ 2.1 and the average particle size is 20 ~ 100
3. The resin-coated carrier for electrophotographic development according to claim 1, wherein the thickness is μm. 4. The resin-coated carrier for electrophotographic development according to claim 1, wherein the silicone resin is a phenylmethyl silicone resin. 5. A silane coupling agent is contained in a silicone resin or a modified silicone resin in a total amount of 6 to 25% by weight, and this is dissolved in a solvent to form a resin solution. A method for producing a resin-coated carrier for electrophotographic development, comprising: uniformly coating a core material to form a coating resin layer, heating the coating resin layer at 180 ° C. or lower, and then baking the coating resin layer at 180 to 300 ° C. Method. 6. An electrophotographic developer comprising the carrier according to claim 1 and a non-magnetic toner.