JP2916833B2 - Magnetic material-dispersed carrier, two-component developer for electrostatic image development, and method for producing magnetic material-dispersed carrier - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a magnetic material-dispersed carrier and a method for producing the same. The present invention also relates to a two-component developer for developing an electrostatic image having a toner and a carrier.

[0002]

2. Description of the Related Art Generally, in an electrostatic recording apparatus using electrophotography, selenium, OPC (organic photoconductor), α-S
Using a photoconductive material such as i as a photoreceptor, the photoreceptor is uniformly charged by various means, and then illuminated with a light image on the photoreceptor surface to form an electric latent image corresponding to the light image. In general, a method is used in which a latent image is formed on the surface of a photoreceptor, toner is adhered to the latent image using a magnetic brush developing method or the like, and the latent image is developed.

In this developing method, a toner for visualizing the latent image and carrier particles having a magnetic material called a carrier are used, and the carrier is charged with an appropriate amount of positive or negative electric charge by triboelectric charging. Is imparted to the toner, and the toner is carried on the surface by the electrostatic attraction of the triboelectric charging.

[0004] The developer having the toner and the carrier is
A developing layer containing a magnet is coated to a predetermined layer thickness by a developer layer thickness regulating member, and is conveyed to a developing area formed between the photoreceptor and the developing sleeve by using a magnetic force. You.

A predetermined developing bias voltage is applied between the photosensitive member and the developing sleeve, and the toner is developed on the photosensitive member in the developing area.

In general, carriers constituting such a two-component developer are roughly classified into conductive carriers and insulating carriers. There are various characteristics required for these carriers, but particularly important characteristics include appropriate chargeability, pressure resistance to an applied electric field, impact resistance, abrasion resistance, spent resistance, developability, and productivity. Can be

On the other hand, when the true specific gravity increases, the load on the developer increases when the developer is formed to a predetermined layer thickness on the sleeve by the developer layer thickness regulating member. (A) Toner filming (b) Carrier destruction (c) Deterioration of toner is likely to occur, and as a result, deterioration of the developer and accompanying image quality deterioration of the developed image are likely to occur. Further, when the particle size of the carrier increases, the load on the developer increases, so that the above (a) to (c) easily occur, and as a result, the developer tends to deteriorate. It is also well known that, if the carrier particle size is large, (d) the fine line reproducibility of the developed image is poor, that is, the developability is poor.

Accordingly, in a carrier in which the above (a) to (c) are likely to occur, it is necessary to periodically exchange the developer, and it is uneconomical, so that the load on the developer is reduced. Alternatively, it is necessary to prevent the above (a) to (c) and extend the life of the developer by improving the impact resistance and spent resistance of the carrier.

It is necessary to deal with the problem of the developing property (d) by reducing the particle size of the carrier.

To solve the above problems (a) to (d), a carrier having a small particle size in which magnetic particles are dispersed in a binder resin, for example, by a pulverization method disclosed in Japanese Patent Application Laid-Open No. 54-66134. It is also possible to cope with this problem by using a magnetic material-dispersed small particle size carrier. It is also possible to cope with this problem by using a magnetic material-dispersed small particle size carrier by a polymerization method disclosed in JP-A-61-9659.

However, if the magnetic substance-dispersed small particle size carrier does not contain a large amount of magnetic substance in the carrier particles, the magnetic properties of the carrier are not sufficient, and the carrier adheres to the photoreceptor during development. Will occur,
Alternatively, there is a problem that the transportability of the developer on the developing sleeve is not sufficient.

Therefore, in the above-mentioned magnetic substance-dispersed small particle size carrier, it is important to contain a large amount of a magnetic substance. At that time, however, the amount of the magnetic substance increases with respect to the binder resin. When the developer has a predetermined layer thickness on the sleeve by the developer layer thickness regulating member, the impact resistance is weakened, and the magnetic substance is easily missing from the carrier. As a result, the deterioration of the developer is reduced. In this case, it is difficult to prolong the life of the developer, so that it cannot be drastic.

In addition, when a large amount of a magnetic substance is contained in the above-mentioned magnetic substance-dispersed small particle size carrier, the resistance of the carrier decreases due to an increase in the amount of the magnetic substance having a low resistance. There is also a drawback that image defects due to leakage of a bias voltage applied sometimes easily occur.

On the other hand, it is possible to cope with the technique of coating the carrier with a resin, which is disclosed in Japanese Patent Application Laid-Open No. 58-21750. According to the carrier coated with the above resin, spent resistance, impact resistance, and pressure resistance against applied voltage can be improved.
In addition, since the charging characteristics of the toner can be controlled by the charging characteristics of the resin to be coated, a desired charge can be imparted to the toner by selecting the resin to be coated.

The charge amount of a developer using such a carrier coated with an insulating resin is generally low temperature, low humidity,
It tends to change with changes in environmental conditions such as high temperature and high humidity. As a result, for example, under a low temperature and a low humidity, a charge-up causes a decrease in image density and the like, and under a high temperature and a high humidity, a problem such as fogging and scattering due to a tribo reduction occurs.

Further, depending on the coating resin, even if the resistance of the carrier coated with the resin is considered to be an appropriate resistance in measurement, image defects due to leakage of the developing bias voltage are likely to occur. However, there is a problem that the control is difficult when considering the characteristics.

[0017] Therefore, there is a need for a carrier coated with an insulating resin which is further improved.

Various attempts have been made with respect to a carrier not coated with an insulating resin.
Japanese Patent No. 229256 proposes a carrier having a water-soluble quaternary ammonium salt adhered to the surface of ferrite particles. However, when a water-soluble quaternary ammonium salt is used, the quaternary ammonium salt on the surface of the ferrite particles is eluted or desorbed due to long-term storage under high temperature and high humidity or durability, and untreated ferrite particles are removed. The drawback was that it gradually approached the nature. Furthermore, since it is not coated with a resin, the quaternary ammonium salt on the surface of the ferrite particles is easily desorbed even in a normal environment of normal temperature and normal humidity as well as high temperature and high humidity. In comparison with the above, there is a problem that the film is weak against so-called toner spent, that is, a film is formed by toner on the carrier surface, and the life of the developer is short. Furthermore, if not covered with an insulating resin to some extent, even if it is iron oxide powder or ferrite particles, a developing system in which a bias voltage is applied does not cause current leakage or carrier adhesion to the photoconductor. Appropriate. As described above, no method has been found at present that covers the durability, toner spent resistance, and the like of the carrier over coating with an insulating resin.

On the other hand, as the magnetic fine particles to be dispersed in the core material, hard ferrite can be used as disclosed in JP-A-59-501840.

However, in consideration of the above-mentioned required characteristics of the carrier, the conventionally used carrier still has a problem to be improved, and a carrier with further improvement is expected.

In a magnetic material-dispersed carrier in which magnetic particles are dispersed in a binder resin and the surface of which is covered with a resin, (1) Spent resistance (2) Impact resistance (prevention of carrier destruction) ( 3) Prevention of toner deterioration (4) Developability (5) Prevention of carrier adhesion on photoreceptor (6) Control of carrier resistance (7) Stabilization of toner chargeability (longer life in chargeability) (8) ) Stabilization of toner chargeability against environmental fluctuations (9) It is desired to further improve the density of the magnetic brush for obtaining high-definition images.

In particular, in recent years, the toner particle size has tended to be reduced from the standpoint of high image quality. Therefore, the change in the amount of charge of the toner due to changes in the temperature and humidity of the environment tends to be even greater, and the There is a problem that it is more difficult to achieve both the prevention of toner scattering and fogging due to a decrease in the amount of charge in a humid environment and the prevention of low image density by charge-up in a low humid environment.

[0023]

SUMMARY OF THE INVENTION The main object of the present invention is to:
This solves the problem of the magnetic material-dispersed carrier whose surface is coated with a resin as described above. As a result, it is not necessary to replenish the carrier at the time of running, and at the time of running, when the toner fluctuates when the humidity fluctuates. An object of the present invention is to provide a magnetic material-dispersed carrier excellent in developability and developer life by stabilizing chargeability.

More specifically, in a magnetic material-dispersed carrier in which the surface of a core material containing magnetic particles and a binder resin as described above is coated with a resin, the carrier has an impact resistance, a resistance value, and a charge application to toner. An object of the present invention is to provide a magnetic material-dispersed carrier having improved stability by the characteristics of a resin to be coated and excellent in developability and developer life.

It is a further object of the present invention to provide a magnetic material-dispersed carrier having an appropriate resistance and having little current leakage or adhesion of the carrier onto a photosensitive member even when a bias voltage is applied. Things.

Another object of the present invention is to provide a magnetic material-dispersed carrier capable of reducing the share of toner, suppressing toner deterioration, and stably providing high image quality for a long period of time.

Another object of the present invention is to provide a method for producing a magnetic material-dispersed carrier which can solve the above-mentioned problems.

Another object of the present invention is to provide a composition having a weight average particle size of 10 μm.
An object of the present invention is to provide a two-component developer for developing an electrostatic image with small environmental fluctuation even when a toner having a small particle diameter of m or less is used.

Another object of the present invention is to provide a two-component developer for electrostatic image development capable of obtaining a high-definition image with a large density of "spikes" of a magnetic brush per unit area on a sleeve. It is.

[0030]

The present invention has a core material in which magnetic fine particles are dispersed in a binder resin,
In the magnetic material-dispersed carrier in which the surface of the core material is coated with a resin coating layer, the magnetic fine particles include strontium ferrite, barium ferrite, or lead ferrite, and the ferrite is in a periodic table IA, IIA, III.
A, IVA, VA, VIA, IB, IIB, IVB, V
B, VIB, VIIB, VIII may be included, the content of other elements is less than 1 wt%,
The coercive force of the carrier is 300 Gauss or more under a magnetic field of 10 K Oersted, and the resin coating layer is made of an insulating resin material and the following formula.

[0031]

Embedded image (Wherein R ₁ , R ₂ , R ₃ and R ₄ represent an alkyl group, an aryl group or an aralkyl group and may be the same or different from each other, and A represents an organic anion or a polyacid ion). And a quaternary ammonium salt.

According to the present invention, there is provided a two-component developer for developing an electrostatic image, comprising the above-mentioned magnetic substance-dispersed carrier and toner.

Further, according to the present invention, a carrier coating solution containing a resin material is applied to a core material obtained by dispersing magnetic fine particles in a binder resin, and dried to coat the surface of the core material with a resin coating layer. In the method for producing a magnetic material-dispersed carrier, the magnetic fine particles may be strontium ferrite,
Barium ferrite or lead ferrite, wherein the ferrite is selected from the periodic tables IA, IIA, IIIA, IV
A, VA, VIA, IB, IIB, IVB, VB, VI
B, VIIB, and VIII may be included, the content of other elements is less than 1 wt%, and the coercive force of the carrier is 300 under a magnetic field of 10 K Oersted.
Gauss or more, wherein the carrier coating solution contains an insulating resin material, a solvent for dispersing or dissolving the insulating resin material, and a quaternary ammonium salt represented by the above formula. This is a method for producing a magnetic material-dispersed carrier.

Hereinafter, the present invention will be described in detail. The carrier of the present invention improves various disadvantages of the conventional resin-coated magnetic material dispersed carrier, and has an impact resistance, an electric resistance value, a long-term stable charge application to the toner, and a charge to the toner independent of environmental fluctuations. It is excellent in application stability, and thereby, the carrier of the present invention is extremely excellent in developability, developer life, and can obtain a high-definition image, although details are unknown, but for the following reasons Believe in things.

When the surface of the carrier of the present invention was observed with a scanning electron microscope, it was observed that the carrier core material was uniformly coated with the coating resin. Therefore, it is considered that the uniform coating property improves the impact resistance, the resistance value, and the stability of applying a charge to the toner of the magnetic material-dispersed carrier used in the present invention.

That is, when the carrier surface is divided into minute portions, and when the coating is uniform,
It is considered that the impact resistance, the resistance value, and the charge imparting property to the toner show the same characteristics in any part.

Further, although the mechanism by which the quaternary ammonium salt used in the present invention improves the environmental dependency of the resin coating layer coated on the surface of the carrier core material is not clear, the insulating coating resin can be used under low humidity. It is speculated that the phenomenon of charge-up may be prevented by the quaternary ammonium salt of the present invention acting as a leak site.

On the other hand, by mixing the quaternary ammonium salt with a resin material and coating the carrier core material, the resin has good adhesiveness to the carrier core material and good abrasion resistance, which are characteristics of the resin. The life of the carrier is greatly extended,
In addition, it is considered that the quaternary ammonium salt of the present invention is exposed on the carrier surface, thereby suppressing a change in resistance due to an environmental change.

The quaternary ammonium salt used in the present invention may be contained in the toner as a positive charge control agent for the toner. The effect of the present invention is as follows. Cannot be expressed.

Further, the present inventors use a specific magnetic material for the magnetic fine particles constituting the carrier core material, so that the carrier has a specific resistance value, magnetic characteristics, and the like. It is presumed that high-definition images can be obtained as a result of preventing leakage and carrier adhesion and forming a dense magnetic brush with developer.

The quaternary ammonium salt used in the present invention is shown.

<General formula>

[0043]

Embedded image In A, specific examples of A include an organic sulfate ion, an organic sulfonate ion, an organic phosphate ion, a polyacid ion,
Carboxylate ions. Preferably it is an organic anion, more preferably an aromatic anion. The reason is that the use of a quaternary ammonium salt that is hardly soluble or insoluble in water is a major feature of the present invention. By using A as the above-mentioned anion, a quaternary ammonium salt that is hardly soluble in water is obtained. The property that elution or desorption does not occur under moisture is obtained. Further, in the present invention, the quaternary ammonium salt is used by mixing with an insulating resin material. However, it is preferable that the quaternary ammonium salt is hardly soluble in water from the viewpoint of improving compatibility with the resin and uniformly mixing the resin. It is.

In the present invention, a method of preparing a carrier coating solution by dispersing a quaternary ammonium salt as undissolved particles in a solution in which a resin material is dissolved or dispersed, and a method of preparing a quaternary ammonium salt in advance There are two methods of preparing a carrier coating solution by mixing a salt dissolved in a solvent with a solution in which a resin material is dissolved or dispersed.

In the latter method, it is necessary to select a solvent that sufficiently dissolves the quaternary ammonium salt and is compatible with the solvent in which the resin is dissolved. Specifically, the quaternary ammonium salt used in the present invention is 1 g / 100 g.
(Solvent) It is necessary to use a solvent exhibiting the above solubility.
Strong polar ketones, amines,
Alcohols can be mentioned, and generally, alcohols can be preferably used. However, the choice is not solely determined by the solubility of the quaternary ammonium salt in the solvent, but it is necessary to take into account the compatibility of the resin with the solvent.

As described above, it is important that the quaternary ammonium salt used in the present invention is insoluble or hardly soluble in water.
When the solubility in water is defined by the weight (g) dissolved in g, the quaternary ammonium salt used in the present invention is 1.0%.
g / 100 g (H ₂ O, 20 ° C.), preferably 0.1 g.
It is less than 3 g / 100 g (H ₂ O, 20 ° C.).

The method for measuring the solubility in water according to the present invention is described below.

In a conical flask equipped with a stopper, 100 g of distilled water and 2.00 g of a quaternary ammonium salt to be dissolved were added.
After sealing and shaking in a shaking water bath at a temperature of 20 ± 0.5 ° C. at a shaking frequency of 60 times / min for 8 hours, the mixture is filtered using a filter medium such as filter paper to measure xg of insoluble matter. I do.
The solubility (amount) of the quaternary ammonium salt dissolved in 100 g of distilled water is represented by 2.00-x (g / 100 g H ₂ O).

Next, when the above-mentioned quaternary ammonium salt is dissolved in a solvent to prepare a carrier coating solution, a method for measuring the solubility of the quaternary ammonium salt in a solvent is as follows. The method was adopted.

100 g of an optional solvent in a conical flask with a stopper
And 50.0 g of a quaternary ammonium salt to be dissolved are added, sealed, and shaken in a shaking water bath at a temperature of 20 ± 0.5 ° C. at a shaking frequency of 60 times / min for 8 hours. The mixture is filtered using a filter medium as described above, and the insoluble content xg is measured. The solubility (amount) of the quaternary ammonium salt dissolved in 100 g of the solvent is represented by 50.0-x (g / 100 g solvent).

The solubility of the quaternary ammonium salt used in the present invention in any solvent is 1.0 g / 100 g.
(Solvent) or more, preferably 5.0 g / 100 g (solvent)
It is better to be above.

R of the quaternary ammonium salt used in the present invention
₁ , R ₂ , R ₃ and R ₄ are preferably compounds having 1 to 20 carbon atoms, more preferably compounds having 1 to 18 carbon atoms.

The quaternary ammonium salts which can be used in the present invention are roughly classified into two groups, wherein R ₄ in the general formula is an alkyl group type or an aryl group or aralkyl group type.
Divided into streets.

Examples of quaternary ammonium salts wherein R ₄ is an alkyl group are shown below.

[0055]

Embedded image

[0056]

Embedded image

[0057]

Embedded image

[0058]

Embedded image Examples of quaternary ammonium salts in which R ₄ is an aryl group or an aralkyl group are shown below.

[0059]

Embedded image

[0060]

Embedded image

[0061]

Embedded image

[0062]

Embedded image

[0063]

Embedded image

[0064]

Embedded image

[0065]

Embedded image

[0066]

Embedded image The quaternary ammonium salt in the present invention contains a lake compound as shown in <Example 4> and <Example 10>. This laked product is obtained by treating a usual quaternary ammonium salt with a general laker. Lakers can include heteropolyacids and polyacids such as phosphotungsten and molybdenum.

The amount of the quaternary ammonium salt of the present invention added to the core material-coated resin material is 0.5 wt% to 30 watts.
t%, preferably in the range of 1.0 wt% to 20 wt%. If the addition is less than 0.5 wt%, the effect of stabilizing the charge and the resistance to environmental fluctuations, which are the characteristics of the present invention, is not remarkable.
The coating on the carrier core material is not uniform.

Examples of the resin material to be coated include insulating resins used alone for general carrier coating or mixtures thereof.

The resin material to be coated is preferably a vinyl resin. For example, styrene, o
-Methylstyrene, m-methylstyrene, p-methylstyrene, p-phenylstyrene, p-ethylstyrene,
2,4-dimethylstyrene, pn-butylstyrene,
p-tert-butylstyrene, pn-hexylstyrene, pn-octylstyrene, pn-nonylstyrene, pn-decylstyrene, pn-dodecylstyrene, p-methoxystyrene, p-chloro styrene,
3,4-dichlorostyrene, m-nitrostyrene, o-
Styrene derivatives such as nitrostyrene and p-nitrostyrene, and ethylene and unsaturated monoolefins such as ethylene, propylene, butylene and isobutylene; unsaturated diolefins such as butadiene and isoprene; vinyl chloride, vinylidene chloride and vinyl bromide , Vinyl halides such as vinyl fluoride; vinyl esters such as vinyl acetate, vinyl propionate, and vinyl benzoate; methacrylic acid and methyl methacrylate, ethyl methacrylate, propyl methacrylate, n-butyl methacrylate;
Isobutyl methacrylate, n-octyl methacrylate,
Α-methylene aliphatic monocarboxylic esters such as dodecyl methacrylate, 2-ethylhexyl methacrylate, stearyl methacrylate, phenyl methacrylate;
Acrylic acid and methyl acrylate, ethyl acrylate, n-butyl acrylate, isobutyl acrylate, propyl acrylate, n-octyl acrylate, dodecyl acrylate, 2-ethylhexyl acrylate, stearyl acrylate, 2-chloroethyl acrylate Acrylates such as phenyl acrylate; maleic acid;
Maleic acid half ester; vinyl ethers such as vinyl methyl ether, vinyl ethyl ether and vinyl isobutyl ether; vinyl ketones such as vinyl methyl ketone, vinyl hexyl ketone and methyl isopropenyl ketone; N-vinyl pyrrole, N-vinyl carbazole, N- N-vinyl compounds such as vinyl indole and N-vinyl pyrrolidone; vinyl naphthalenes; acrylic acid or methacrylic acid derivatives such as acrylonitrile, methacrylonitrile, and acrylamide; Things are used.

Acrylic copolymer resins such as styrene-methacrylate copolymers and styrene-acrylate copolymers are suitable because of their excellent durability and long service life.

In particular, it is effective to copolymerize an acrylic resin containing a hydroxyl group from the viewpoint of adhesion to the carrier core material and the action of exposing the quaternary ammonium salt of the present invention to the carrier surface.

Examples of the acrylic resin monomer containing a hydroxyl group include 2-hydroxyethyl acrylate, 2-hydroxypropyl acrylate, hydroxybutyl acrylate, 2-hydroxy-3-phenyloxypropyl acrylate, and methacrylic acid 2 -Hydroxyethyl, 2-hydroxypropyl methacrylate, hydroxybutyl methacrylate, 2-hydroxy-3 methacrylate
-Phenyloxypropyl. These monomers have a copolymer hydroxyl number of 1 to 100 (KOH
(mg / g).

The binder resin used for the core material in the structure of the carrier of the present invention includes all resins obtained by polymerizing a vinyl monomer. Specifically, those already mentioned as the coating resin for the core material can be used.

In addition to resins obtained by polymerization from vinyl monomers, non-vinyl condensation resins such as polyester resins, epoxy resins, phenol resins, urea resins, polyurethane resins, polyimide resins, cellulose resins, polyether resins and the like, And a mixture of the above-mentioned vinyl resin.

The magnetic material used for the magnetic fine particles constituting the carrier core material in the present invention must contain at least one of Sr ferrite, Ba ferrite, and Pb ferrite. Rate tables IA, IIA, IIIA, IVA, VA, VIA,
IB, IIB, IVB, VB, VIB, VIIB, VI
Although a group II element may be included, other elements are preferably 1 wt% or less.

As described above, this is important for controlling the resistance of the core material to an optimum value, and for increasing the density of the "spikes" of the magnetic brush on the sleeve and preventing the carrier from adhering. . For the same reason, the carrier of the present invention has a coercive force of 300 K at a magnetic field of 10 K Oersted.
Gauss or more, preferably 500 Gauss or more.

The magnetic force at a magnetic field of 1 k Oe is preferably 5 emu / g to 59 emu / g, more preferably 10 emu / g to 19 emu / g. The magnetic characteristics of the carrier described below are values measured by VSM manufactured by Toei Kogyo.

The magnetic fine particles preferably have a primary average particle diameter of 2.0 μm or less. When it is larger than 2.0 μm, the surface of the core material is not dense, and uniform coating cannot be performed. Furthermore, the specific resistance of the magnetic fine particles according to the present invention must be 10 ⁷ Ω · cm or more, and the content with respect to the total amount of the carrier must be 30% by weight or more, preferably 50% by weight or more. If it is less than 30% by weight, desired magnetic properties cannot be obtained.

The carrier of the present invention has an average particle size of 10 to 60.
It can be preferably used in the range of μm. If it is smaller than 10 μm, carrier adhesion to the photoreceptor is likely to occur, and
If it exceeds 60 μm, the share of the developer in the developing device will be large, causing the deterioration of the developer, especially the peeling of the external additive of the toner particles and the change in shape, and the deterioration of the image. Furthermore, when the particle size is large, the specific surface area is small, so that the amount of toner that can be retained when constituting the developer is small, and an image lacking in definition is obtained. Incidentally, the average particle diameter of the carrier of the present invention is obtained by randomly extracting 500 or more carrier particles by an optical microscope or a scanning electron microscope, and determining the average value of the maximum chord length in the horizontal direction of the extracted carrier particles. It was measured as an average particle size.

The true specific gravity of the carrier of the present invention is 1.5
A range of -5.0 is preferred. More preferably 1.5 to
4.5. If the true specific gravity exceeds 5.0, it is not preferable from the viewpoint of deterioration of the developer due to a large share of the developer in the developing device. If the true specific gravity is less than 1.5, it is practically impossible to obtain desired magnetic characteristics. The true specific gravity of the carrier in the present invention was measured by a true denser (manufactured by Seishin Enterprise).

The specific resistance of the carrier of the present invention is 10 ⁸ to 10
A range of ¹³ Ω · cm is appropriate. If it is less than 10 ⁸ Ω · cm, current leaks from the sleeve to the surface of the photoreceptor in the developing area in a developing method in which a bias voltage is applied, and a good image cannot be obtained. On the other hand, if it exceeds 10 ¹³ Ω · cm, a charge-up phenomenon is caused under conditions such as low humidity, which causes image deterioration such as density loss, transfer failure and fog. The specific resistance of the carrier of the present invention was measured using the cell shown in FIG. That is, the cell A was filled with a carrier, the electrodes 1 and 2 were arranged so as to be in contact with the filled carrier, a voltage was applied between the electrodes, and the current flowing at that time was measured to determine the specific resistance. The measurement condition is that the contact area S of the filled carrier with the cell is about 2.3 cm.
^{2. The} thickness d is about 1 mm, the load on the upper electrode is 275 g, and the applied voltage is 100 V. Here, since the carrier is a powder, the specific resistance may change depending on the filling rate, and thus care must be taken.

In the present invention, the sphericity of the carrier (long axis /
The short axis is desirably 2 or less. When the sphericity of the carrier in the present invention exceeds 2, the effect of reducing the share of the developer and the effect of improving the fluidity of the developer tend to decrease. Accordingly, the sphericity is desirably 2 or less in order to prevent the deterioration of the developer which can be achieved by the carrier in the present invention and the effect of improving the developing characteristics.

Means for achieving the above-mentioned sphericity of 2 or less in the carrier of the present invention include a method of heating the core material and thermally melting the surface to form a sphere, or a method of mechanically forming a sphere. Alternatively, the method of producing the core material is as follows: magnetic particles, a polymerization initiator, a suspension stabilizer, and the like are added to a monomer solution of a binder resin used in the core material, and then dispersed and granulated and polymerized. If the usual suspension polymerization method for obtaining the material is used, the sphericity of the carrier can be achieved 2 or less without performing the treatment on the core material.

Next, a method of manufacturing a carrier according to the present invention will be described.

The method of manufacturing a carrier according to the present invention comprises two steps of preparing a core material and applying a resin coating.

First, as a method for producing a core material, the binder resin and the magnetic fine particles are mixed at a desired ratio, and an appropriate melt-mixing device such as a three-roll or extruder is used. Kneading at a temperature, cooling, and then pulverizing and classifying, or by dissolving the binder resin in a soluble solvent, mixing the magnetic fine particles into a slurry, and manufacturing using a spray drier. Granules, a method of drying, or adding magnetic fine particles, a polymerization initiator, a suspension stabilizer, etc. to a monomer solution of a binder resin for a core material,
There is a suspension polymerization method of granulating and polymerizing after dispersing. In particular, according to the polymerization method, it is easy to control the sphericity to 2 or less, so that it is a more preferable method for producing a core material for obtaining the effects of the present invention.

In the present invention, as a method of coating the surface of the carrier core material with a resin coating layer, the above resin material is dissolved or suspended in an organic solvent such as toluene, xylene and tetrahydrofuran. A quaternary ammonium salt is added at a predetermined ratio, mixed well with a mixer to prepare a carrier coating solution according to the present invention, and applied to a carrier core material by a general coating apparatus such as a spray method or a fluidized bed method. However, considering that the core material is made of a resin, a treatment method in which the coating resin is quickly coated so that the core materials do not adhere to each other is desirable, and a selection and treatment of a solvent that dissolves the coating resin is desirable. It is preferable to use a treatment method in which the conditions such as temperature and time are sufficiently controlled, and the coating and drying are simultaneously advanced in such a manner that the core material always flows. It is. Note that the resin coating amount varies depending on the true specific gravity of the core material, and the optimum value needs to satisfy the following relational expression.

1 / 2X ≦ resin coating amount ≦ 50 / X (% by weight) (X: true specific gravity of core material) More preferably, 1 / X ≦ resin coating amount ≦ 25 / X (% by weight).

If the resin coating amount is less than 1/2 ×% by weight, it is difficult to coat the surface of the core material uniformly, and even if it can be coated, it cannot be said that the carrier has sufficient strength.
On the other hand, when the content exceeds 50 / X% by weight, it becomes difficult to coat uniformly. Further, uncoated resin is generated by being liberated alone and adheres to the photoreceptor, which may cause image deterioration.

The method of dispersing the quaternary ammonium salt in the carrier coating solution according to the present invention includes a method of dispersing the quaternary ammonium salt in the carrier coating solution as undissolved particles and a method of dispersing the quaternary ammonium salt in the carrier coating solution. It can be carried out by dissolving in advance in an arbitrarily selected solvent, mixing with a carrier coating solution, further mixing well with a mixer, dissolving the other solution and dispersing the quaternary ammonium salt.

The former method has the advantage that any of the quaternary ammonium salts of the present invention can be used and the range of choice is wide.

On the other hand, the latter method is limited to those in which the quaternary ammonium salt can be dissolved in a solvent, and thus has a narrow range of choices, but has the following advantages.

By dissolving the quaternary ammonium salt, not only a better effect can be obtained with a smaller amount than in the former method in which the quaternary ammonium salt is simply dispersed as undissolved particles, Since it is considered that the particles are microscopically dispersed in the resin molecular chain and exist in a uniform state, the triboelectric charging ability with the toner is improved at the same contact opportunity as compared with the case where the toner is simply dispersed. Therefore, it is possible to hasten the rise of the toner charge.

The two-component developer for developing an electrostatic image of the present invention comprises 10 to 1000 parts by weight, preferably 30 to 50 parts by weight of the above-mentioned magnetic material-dispersed carrier with respect to 10 parts by weight of the toner.
0 parts by weight are preferably mixed and used.

The toner according to the present invention has a weight average particle diameter of 1 to 20 μm, preferably 4 to 13 μm, and more preferably 4 to 10 μm.

Further, in terms of resolution and toner consumption, the toner according to the present invention has a toner particle size distribution
It is preferably within the following range.

That is, toner particles having a particle size of 5 μm or less are 17 to 60% by number of all particles, and 8 to 12.7 μm
Is preferably 1 to 30% by number of the total number of particles, and particles having a particle size of 16 μm or more are preferably less than 2.0% by volume of the total number of particles.

The preferred structure of the toner according to the present invention will be described in more detail.

As described above, the toner particles having a particle size of 5 μm or less preferably account for 17 to 60% by number of the total number of particles, preferably 25 to 50% by number, and more preferably 30% by number.
~ 50% by number is good. If the toner particles having a particle diameter of 5 μm or less are less than 17% by number, the amount of toner particles effective for high image quality is small. In particular, as the toner is used by continuing copy or printout, the effective toner particle component is reduced. As a result, the balance of the particle size distribution of the toner deteriorates, and the image quality gradually decreases. If it exceeds 60% by number, the toner particles tend to aggregate with each other,
Since the toner mass becomes larger than the original particle size, the image quality becomes rough, the resolution is reduced, the difference in density between the edge portion and the inside of the latent image is increased, and the image tends to be slightly hollow.

The toner particles having a particle size in the range of 8 to 12.7 μm are, as described above, 1 to 30% by number, preferably 1 to 23%
It is preferably a number%, more preferably 8 to 20 number%. If it is more than 23% by number, especially 30% by number
When the ratio exceeds, the image quality is deteriorated, and unnecessary development (that is, excessive toner application) occurs, which causes an increase in toner consumption. On the other hand, if it is less than 1% by number, it becomes difficult to obtain a high image density. N / V between the number% (N%) and the volume% (V%) of the toner particle group having a particle size of 5 μm or less.
= −0.04N + k, where 4.5 ≦ k ≦ 6.
Indicates a positive number in the range of 5. Preferably, 4.5 ≦ k ≦ 6.
0, more preferably 4.5 ≦ k ≦ 5.5. As indicated above, 17 ≦ N ≦ 60, preferably 25 ≦ N ≦
50, more preferably 30 ≦ N ≦ 50.

When k <4.5, the number of toner particles having a particle diameter smaller than 5.0 μm is small, and the image density, resolution and sharpness are inferior. The appropriate presence of fine toner particles, which was conventionally considered unnecessary, contributes to the closest packing of the toner in the development and contributes to forming a uniform image without roughness. In particular, by uniformly filling the fine lines and the outline of the image, the sharpness is further enhanced visually. If k <4.5, these characteristics are inferior due to the lack of the particle size distribution component.

From another viewpoint, in order to satisfy the condition of k <4.5 in production, it is necessary to cut a large amount of fine powder by means such as classification, which is disadvantageous in terms of yield and toner cost. It will be. If k> 6.5, the image density tends to decrease as copying is continued due to the presence of unnecessarily fine powder. Such a phenomenon is caused by excessive fine-powder non-magnetic toner particles having an unnecessary charge being charged and adhered to the developing sleeve or / and the carrier, causing normal non-magnetic toner to be carried on the developing sleeve or the carrier and charged. It is thought to be caused by inhibiting the application.

As described above, the amount of toner particles having a particle size of 16 μm or more is preferably less than 2.0% by volume, more preferably 1.0% by volume or less, and further preferably 0.5% by volume or less. It is. When the content is more than 2.0% by volume, not only does it hinder the reproduction of fine lines, but also, in the transfer, 16 μm is applied to the thin layer surface of the toner particles developed on the photoreceptor.
m or more of the coarse toner particles protrude,
The delicate state of contact between the photoreceptor and the transfer paper via the toner layer is made irregular, causing fluctuations in the transfer conditions and causing poor transfer images.

The weight average particle size and the particle size distribution of the toner can be measured by various methods. In the present invention, the measurement was performed using a Coulter counter.

As a measuring device, Coulter Counter T
An interface (manufactured by Nikkaki) that outputs the number distribution and volume distribution using A-II type (manufactured by Coulter) and CX
-1 Connect a personal computer (Canon),
As the electrolytic solution, a 1% NaCl aqueous solution is prepared using primary sodium chloride. The measuring method is 100 to 100
To 150 ml, 0.1 to 5 ml of a surfactant, preferably an alkylbenzene sulfonate, is added as a dispersant, and 2 to 20 mg of a measurement sample is further added. The electrolytic solution in which the sample was suspended was subjected to a dispersion treatment for about 1 to 3 minutes using an ultrasonic disperser, and the particle size distribution of particles of 2 to 40 μm based on the number was measured using the Coulter Counter TAII, using an aperture of 100 μm. Was measured, and then a value according to the present invention was determined.

As the binder resin used in the toner according to the present invention, the following binder resin for toner can be used when a heating / pressing roller fixing device having a device for applying oil is used.

For example, homopolymers of styrene such as polystyrene, poly-p-chlorostyrene and polyvinyltoluene and their substituted products; styrene-p-chlorostyrene copolymer, styrene-vinyltoluene copolymer, styrene-
Vinyl naphthalene copolymer, styrene-acrylic ester copolymer, styrene-methacrylic ester copolymer, styrene-α-chloromethyl methacrylate copolymer, styrene-acrylonitrile copolymer, styrene-
Styrene such as vinyl methyl ether copolymer, styrene-vinyl ethyl ether copolymer, styrene-vinyl methyl ketone copolymer, styrene-butadiene copolymer, styrene-isoprene copolymer, styrene-acrylonitrile-indene copolymer Copolymers: polyvinyl chloride, phenolic resin, natural modified phenolic resin, natural resin modified maleic acid resin, acrylic resin, methacrylic resin, polyvinyl acetate, silicone resin, polyester resin, polyurethane, polyamide resin, furan resin, epoxy resin , Xylene resin, polyvinyl butyral, terpene resin, cumarone indene resin, and petroleum resin.

In the heat and pressure roller fixing method in which almost no oil is applied, the offset phenomenon in which a part of the toner image on the toner image support member is transferred to the roller and the adhesion of the toner to the toner image support member are important. It is a problem.
These problems must be taken into account at the same time because toners that fix with less heat energy tend to block or cake during storage or in a developer. Therefore, in the present invention, when using the heating / pressing roller fixing method in which almost no oil is applied, the selection of the binder resin is more important. Preferred binder resins include crosslinked styrenic copolymers and crosslinked polyesters.

Examples of the comonomer for the styrene monomer of the styrene copolymer include acrylic acid, methyl acrylate, ethyl acrylate, butyl acrylate, and the like.
Double bonds such as dodecyl acrylate, octyl acrylate, 2-ethylhexyl acrylate, phenyl acrylate, methacrylic acid, methyl methacrylate, ethyl methacrylate, butyl methacrylate, octyl methacrylate, acrylonitrile, methacrylonitrile, acrylamide Or a substituted product thereof; for example, a dicarboxylic acid having a double bond such as maleic acid, butyl maleate, methyl maleate, or dimethyl maleate and a substituted product thereof; for example, vinyl chloride, vinyl acetate, vinyl benzoate Vinyl esters such as ethylene, propylene and butylene; vinyl ketones such as vinyl methyl ketone and vinyl hexyl ketone; vinyl methyl ether and vinyl ethyl ether Ether, such as vinyl ethers vinyl isobutyl ether; such vinyl monomers are used alone or two or more.

As the cross-linking agent, compounds having two or more polymerizable double bonds are mainly used, for example, aromatic divinyl compounds such as divinylbenzene and divinylnaphthalene; for example, ethylene glycol diacrylate, ethylene glycol diacrylate Methacrylate, 1,3
A double bond such as butanediol dimethacrylate
Carboxylic acid esters having one or more divinylaniline, divinyl ether, divinyl sulfide, divinyl sulfone divinyl compound; and compounds having three or more vinyl groups are used alone or as a mixture. The crosslinking agent is 0.01 to 10% by weight based on the binder resin.
It is preferable to use the binder resin (preferably 0.05 to 5% by weight) at the time of synthesizing the binder resin from the viewpoint of offset resistance and fixability.

When the pressure fixing method is used, a binder resin for a pressure fixing toner can be used. For example, polyethylene, polypropylene, polymethylene, polyurethane elastomer, ethylene-ethyl acrylate copolymer,
There are ethylene-vinyl acetate copolymer, ionomer resin, styrene-butadiene copolymer, styrene-isoprene copolymer, linear saturated polyester, and paraffin.

The toner according to the present invention has charge controllability in the toner particles (internal addition) or mixed with the toner particles (external addition).
It is preferable to use them. The charge control agent makes it possible to control the optimal charge amount according to the development system. In particular, in the present invention, it is possible to further stabilize the balance between the particle size distribution and the charge, and by using the charge control agent It is possible to further clarify the function separation and the complementarity for higher image quality for each particle size range described above. As the positive charge control agent, a modified product of nigrosine and a fatty acid metal salt; tributylbenzylammonium-1-hydroxy-4-naphthosulfonate,
Quaternary ammonium salts such as tetrabutylammonium tetrafluoroborate; dibutyltin oxide; diorganotin oxides such as dioctyltin oxide and dicyclohexyltin oxide; dibutyltin borate, dioctyltin borate, and dicyclohexyltin borate alone or in combination of two or more be able to. Of these, charge control agents such as nigrosine and quaternary ammonium salts are particularly preferably used.

General formula

[0114]

Embedded image Or a copolymer with a polymerizable monomer such as styrene, acrylate or methacrylate as described above can be used as the positive charge control agent. In this case, these charge control agents also act as (all or part of) the binder resin.

As the negative charge controlling agent which can be used in the present invention, for example, organometallic complexes and chelate compounds are effective. Examples thereof are aluminum acetylacetonate, iron (II) acetylacetonate, 3,5- Di-t
There is chromium tert-butylsalicylate. Particularly preferred are acetylacetone metal complexes (including monoalkyl-substituted and dialkyl-substituted products), salicylic acid-based metal complexes (including monoalkyl-substituted and dialkyl-substituted products) and salts, particularly salicylic acid-based metal complexes or salicylic acid-based metal salts. Is preferred.

The above-mentioned charge control agent (having no action as a binder resin) is preferably used in the form of fine particles. In this case, the number average particle size of the charge control agent is
Specifically, it is preferably 4 μm or less (more preferably 3 μm or less).

At the time of internal addition to the toner, such a charge control agent is preferably used in an amount of 0.1 to 20 parts by weight (more preferably 0.2 to 10 parts by weight) based on 100 parts by weight of the binder resin.

It is preferable to add fine silica powder to the toner according to the present invention. When the toner and the silica fine powder are combined, abrasion is remarkably reduced because the silica fine powder is interposed between the toner particles and the surface of the carrier or the sleeve. As a result, the life of the toner and the carrier and / or the sleeve can be prolonged, and a stable chargeability can be maintained. Thus, a two-component developer having more excellent toner and carrier can be used for a long time. It is possible.

In particular, in the case of a toner having a weight average particle diameter of 10 μm or less, the specific surface area is larger than that of a toner having a weight average particle diameter of more than 10 μm, and the toner particles are brought into contact with the carrier due to triboelectric charging. In this case, the number of times of contact between the toner particle surface and the carrier is increased as compared with a toner having a volume average particle diameter of more than 10 μm, so that abrasion of the toner particles and contamination of the carrier are more likely to occur. By adding the powder, a good two-component developer can be obtained.

As the silica fine powder, both silica fine powder produced by a dry method and a wet method can be used, but from the viewpoint of filming resistance and durability, it is preferable to use a silica fine powder obtained by a dry method.

The dry method referred to here is, for example, a method for producing silica fine powder produced by vapor phase oxidation of a silicon halide.

On the other hand, as a method for producing the silica fine powder used in the present invention by a wet method, various conventionally known methods can be applied.

The silica fine powder used herein may include anhydrous silicon dioxide (colloidal silica); and silicates such as aluminum silicate, sodium silicate, potassium silicate, magnesium silicate and zinc silicate.

Among the above-mentioned silica fine powders, those having a specific surface area of 30 m ² / g or more (particularly 50 to 400 m ² / g) by nitrogen adsorption measured by the BET method give good results. It is preferable to use 0.01 to 8 parts by weight, preferably 0.1 to 5 parts by weight of silica fine powder with respect to 100 parts by weight of the toner.

When the toner according to the present invention is used as a positively chargeable toner, the silica fine powder added for preventing the toner from being worn and preventing the carrier and the sleeve surface from being stained is more negatively charged than negatively charged. It is preferable to use positively-chargeable silica fine powder without impairing the charging stability, and when using as negatively-chargeable toner, it is preferable to use negatively-chargeable silica fine powder for the same reason.

Since the silica fine powder is generally negatively charged, a method for obtaining a positively charged silica fine powder is to use the above-mentioned untreated silica fine powder and at least one nitrogen atom in the side chain. There is a method of treating with a silicon oil having an organo group, a method of treating with a nitrogen-containing silane coupling agent, or a method of treating with both.

In the present invention, the positively-charged silica refers to a silica having a positive tribocharge with respect to the iron powder carrier when measured by a blow-off method.

As the silicon oil having a nitrogen atom in the side chain used for treating the silica fine powder, a silicon oil having at least a partial structure represented by the following formula can be used.

[0129]

Embedded image (Wherein, R ₁ represents hydrogen, an alkyl group, an aryl group or an alkoxy group, R ₂ represents an alkylene group or a phenylene group, R ₃ and R ₄ represents hydrogen, an alkyl group or an aryl group,, R ₅ Represents a nitrogen-containing heterocyclic ring.) In the above formula, the alkyl group, the aryl group, the alkylene group, and the phenylene group may have an organo group having a nitrogen atom, as long as the chargeability is not impaired. It may have a halogen substituent. The silicone oil is used in an amount of 1 to 50% by weight, preferably 5 to 30% by weight, based on the silica fine powder.

The nitrogen-containing silane coupling agent used in the present invention generally has a structure represented by the following formula.

Rm-Si-Yn (R represents an alkoxy group or halogen, Y represents an amino group or an organo group having at least one nitrogen atom, m and n are integers of 1 to 3, and m + n =
4. Examples of the organo group having at least one nitrogen atom include an amino group having an organic group as a substituent, a nitrogen-containing heterocyclic group, or a group having a nitrogen-containing heterocyclic group. As the nitrogen-containing heterocyclic group, there is an unsaturated heterocyclic group or a saturated heterocyclic group, and known ones can be applied. Examples of the unsaturated heterocyclic group include the following.

[0132]

Embedded image

Examples of the saturated heterocyclic group include the following.

[0134]

Embedded image

The heterocyclic group used in the present invention is preferably a 5- or 6-membered ring in consideration of stability.

Examples of such treating agents include aminopropyltrimethoxysilane, aminopropyltriethoxysilane, dimethylaminopropyltrimethoxysilane,
Diethylaminopropyltrimethoxysilane, dipropylaminopropyltrimethoxysilane, dibutylaminopropyltrimethoxysilane, monobutylaminopropyltrimethoxysilane, dioctylaminopropyltrimethoxysilane, dibutylaminopropyltrimethoxysilane, dibutylaminopropyltrimethoxysilane,
There are dibutylaminopropylmonomethoxysilane, dimethylaminophenyltriethoxysilane, trimethoxysilyl-γ-propylphenylamine, and trimethoxysilyl-γ-propylbenzylamine. Further, as the nitrogen-containing heterocycle, those having the above-mentioned structures can be used. Examples of such compounds include methoxysilyl-γ-propylpiperidine, trimethoxysilyl-γ-propylmorpholine, and trimethoxysilyl-γ-propylimidazole. There is. The silane coupling agent is used in an amount of 1 to 50% by weight, preferably 5 to 30% by weight, based on the silica fine powder.

The amount of the treated positive or negative silica fine powder is 0.01 to 100 parts by weight of the toner.
The effect is exhibited when the amount is from 8 to 8 parts by weight, and particularly preferably, the amount is from 0.
When added in an amount of 1 to 5 parts by weight, it exhibits positive or negative chargeability having excellent stability. In a preferred embodiment, the addition form is preferably such that 0.1 to 3 parts by weight of the treated silica fine powder is attached to the surface of the toner particles with respect to 100 parts by weight of the toner. The untreated fine silica powder described above can be used in the same application amount.

The silica fine powder used in the present invention may be treated with a silane coupling agent or a treating agent such as an organosilicon compound for the purpose of imparting hydrophobicity, if necessary. It is treated with a treating agent.
Examples of such a treating agent include hexamethyldisilazane, trimethylsilane, trimethylchlorosilane, trimethylethoxysilane, dimethyldichlorosilane, methyltrichlorosilane, allyldimethylchlorosilane,
Allylphenyldichlorosilane, benzyldimethylchlorosilane, bromomethyldimethylchlorosilane, α-chloroethyltrichlorosilane, β-chloroethyltrichlorosilane, chloromethyldimethylchlorosilane, triorganosilylmercaptan, trimethylsilylmercaptan, triorganosilyl acrylate, Vinyldimethylacetoxysilane, dimethylethoxysilane, dimethyldimethoxysilane, diphenyldiethoxysilane,
Hexamethyldisiloxane, 1,3-divinyltetramethyldisiloxane, 1,3-diphenyltetramethyldisiloxane, and 2 to 12 siloxane units per molecule, one for each terminal unit There is a dimethylpolysiloxane containing a hydroxyl group bonded to Si. These are used alone or in a mixture of two or more. The treatment agent is 1 to 1 based on the silica fine powder.
It is preferred to use 40% by weight.

Instead of silica fine powder, BET specific surface area 5
Fine titanium oxide powder (TiO ₂ ) of 0 to 400 m ² / g may be used. Further, a mixed powder of silica fine powder and titanium oxide fine powder may be used.

It is also possible to add a fine powder of a fluorine-containing polymer (for example, a fine powder of polytetrafluoroethylene, polyvinylidene fluoride or a tetrafluoroethylene-vinylidene fluoride copolymer) to the toner according to the present invention. It is. In particular, polyvinylidene fluoride fine powder is preferred in terms of fluidity and abrasiveness. The amount added to the toner is 0.01 to 2.0 wt%, particularly 0.02%.
To 1.5 wt% (more preferably, 0.02 to 1.0 wt%).
wt%) is preferred.

As the coloring agent, conventionally known dyes and / or pigments can be used. For example, carbon black, phthalocyanine blue, peacock blue,
Permanent red, lake red, rhodamine lake, Hansa yellow, permanent yellow, benzidine yellow and the like can be used. The content is 0.1 to 20 parts by weight, preferably 0.5 to 20 parts by weight, based on 100 parts by weight of the binder resin.
It is preferably at most 2 parts by weight, more preferably from 0.5 to 9 parts by weight.
Good by weight.

The toner according to the present invention contains low-molecular-weight polyethylene, low-molecular-weight polypropylene, microcrystalline wax,
It is also a preferred embodiment of the present invention to add a waxy substance such as carnauba wax, sasol wax and paraffin wax in an amount of 0.5 to 5% by weight.

The toner according to the present invention may further contain other additives as necessary.

To prepare the toner according to the present invention, a vinyl-based or non-vinyl-based thermoplastic resin, if necessary, a pigment or dye as a colorant, a charge control agent, and other additives are mixed with a mixer such as a ball mill. After thoroughly mixing, using a hot kneader such as a heating roll, kneader, or extruder, disperse or disperse the pigment or dye in the resin mixed with each other by melting, kneading, and kneading, and cooling. After singulation, toner particles can be obtained by crushing and strict classification. The toner particles can be used as a toner as it is, but if necessary, an external additive such as silica fine powder is added to the obtained toner particles, and the toner particles and the external additive are added using a mixer such as a Henschel mixer. By mixing the above, a toner can be obtained.

The method of measuring the triboelectric charge amount of the toner with respect to the carrier in the present invention will be described in detail with reference to FIG.

FIG. 2 is an explanatory diagram of a triboelectric charge amount measuring device. A magnetic brush (toner and toner) on a developer carrier whose frictional charge is to be measured is measured in a metal measuring container 22 having a conductive screen 21 of 400 mesh (which can be appropriately changed to a size that does not allow the passage of carrier particles) at the bottom. The mixture (carrier mixture of the present invention) is put into the metal lid 23. At this time, the weight of the entire measurement container 22 is weighed and set as W ₁ (g). Next, in the suction device 24 (at least the portion in contact with the measurement container 22 is at least an insulator), suction is performed from the suction port 25 and the air volume control valve 26 is adjusted to adjust the pressure of the vacuum gauge 27 to 70 mmHg. In this state, suction is sufficiently performed (about 1 minute) to remove the toner by suction. At this time, the potential of the electrometer 28 is set to V (volt). Reference numeral 29 denotes a capacitor having a capacity of C (μ
F). Further, the weight of the whole measurement container after suction is weighed to be W ₂ (g). The triboelectric charge amount Q (μC / g) is calculated as in the following equation.

Q (μC / g) = C × V / (W ₁ −W ₂ ) Here, the measurement condition is that the temperature / humidity is 23 ° C./65% RH.

[0148]

DESCRIPTION OF THE PREFERRED EMBODIMENTS The present invention will be described below with reference to embodiments and drawings. This does not limit the invention in any way. still,
All percentages and parts in the following formulations are% by weight and parts by weight.

Example 1 Styrene 12.0% 2-ethylhexyl acrylate 3.0% Sr-ferrite particles (mol% Fe ₂ O ₃ : SrO = 85: 15) 85.7% The above materials were placed in a container. The mixture was heated to a temperature of 70 ° C. and dissolved to obtain a monomer mixture. While maintaining the temperature at 70 ° C., the initiator azobisisonitrile was added and dissolved to prepare a monomer composition. This was put into a 2 liter flask containing 1.2 liter of a 1% PVA aqueous solution and stirred at 70 ° C. with a homogenizer at 4500 rpm for 10 minutes to granulate the composition. Then, while stirring with a paddle stirrer, 70 ° C, 1
Polymerization was performed for 0 hours. After the completion of the polymerization reaction, the reaction product was cooled, and the obtained magnetic material-dispersed styrene acrylic slurry was washed and filtered. This was dried to obtain magnetic material-dispersed resin particles.

The following resin coating layer was coated on the surface of the obtained magnetic substance dispersed resin particles.

Styrene-2-hydroxyethyl methacrylate-methyl methacrylate copolymer (monomer composition weight ratio = 40: 10: 50, hydroxyl value (KOH mg / g) = 30) 20% of the above styrene copolymer To 100 parts of a mixed solution of acetone and methyl ethyl ketone (mixing weight ratio = 1: 1), 1 part of the quaternary ammonium salt shown in <Example 8> as particles is added as it is, and the mixture is stirred by a stirrer until it is sufficiently mixed. To prepare a carrier coating solution.

Next, this carrier coating solution was applied to the magnetic material-dispersed resin particles by a coating machine (Spira Coater, manufactured by Okada Seiko Co., Ltd.). The obtained magnetic substance-dispersed resin carrier after application was dried at a temperature of 90 ° C. for 1 hour to remove the solvent, thereby obtaining a resin-coated magnetic substance-dispersed resin carrier in which the surfaces of the magnetic substance-dispersed fine particles were covered with a resin coating layer. Observation with an electron microscope confirmed that the core material was uniformly coated with the resin.

Table 1 summarizes the physical properties of the obtained carriers.

On the other hand, a polyester resin obtained by condensing 100 parts of propoxylated bisphenol and fumaric acid 5 parts of a phthalocyanine pigment 5 parts of a chromium complex of di-tert-butylsalicylic acid 4 parts The mixture was melt-kneaded three times with a three-roll mill, cooled, and coarsely ground to a particle size of about 1 to 2 mm using a hammer mill.
Next, it was pulverized by a pulverizer using an air jet method. Further, the obtained finely pulverized product is classified to obtain a negatively chargeable cyan powder (toner) having a weight average diameter of 8.2 μm.
I got

100 parts of the above cyan toner and 0.5 parts of silica fine powder hydrophobized with hexamethyldisilazane were mixed with a Henschel mixer to prepare a cyan toner having silica fine powder on the surface of toner particles.

A temperature / humidity ratio of L / L (temperature 15 ° C./humidity 10% RH), N / N
N (temperature 23 ° C./humidity 60% RH), H / H (temperature 30
(C ° / 90% RH) for 4 days, mixed at a toner concentration of 5%, and measured the charge amount by the method of FIG. From the above results, it can be seen that, as shown in Table 4, the change in the charge amount with respect to the environmental change is small.

Next, the carrier and the cyan toner were mixed at a toner concentration of 5% in an N / N environment to prepare a developer, and a full-color leather copying machine CLC-500 (Canon Inc.) having a development contrast fixed at 350 V was used. Using a remodeling machine in which the blade of the developing device was made non-magnetic or the like, a copy durability test of 10,000 sheets was conducted under the above various environments. The above results show that, as shown in Table 4, the durability is excellent and the change with respect to environmental fluctuation is small. In addition, no carrier was adhered to the photoreceptor, and the developer spikes were dense, and higher image quality was achieved as compared with the conventional art.

Next, the above-mentioned cyan toner and carrier were mixed in a temperature / humidity environment of N / N (23 ° C./60% RH) so as to have a toner concentration of 5% to obtain a developer. 100 g of the obtained developer was put in a 250 cc plastic bottle, and shaken with a Turbula mixer for 1 hour. Thereafter, the developer was taken out, and the developer was observed with an electron microscope. As a result,
As shown in Table 3, no detachment of the magnetic substance from the carrier, no peeling of the coating agent, and no filming by the toner were observed. Also, no detachment or burial of the external additive of the toner was observed.

A developer was obtained by mixing the cyan toner and the above-mentioned resin carrier in a temperature / humidity environment of L / L (15 ° C./10% RH) so that the toner concentration was 5%. Under the same environment, the full color laser copier CLC-
It was placed in a modified developing device for 500, and idling was performed for 30 minutes by driving an external motor (peripheral speed: 300 rpm). Thereafter, using a CLC-500 remodeling machine, a developing contrast of 3
An image was displayed at 50 V. As a result, the density of the solid image was sufficient, and the reproducibility of the halftone portion was also good.

Comparative Example 1 The magnetic material-dispersed resin particles used in Example 1 were used as carriers without being coated with a resin.

Table 1 shows the physical properties of this carrier. Also,
This carrier was subjected to the same test as in Example 1.

As a result of the shaking test, desorption of the magnetic substance from the carrier was observed by observation with an electron microscope.

Comparative Example 2 The coating resin used in Example 1 was coated in the same manner as in Example 1 except that 45 μm reduced iron particles were used instead of the magnetic material-dispersed resin particles used in Example 1.
Table 1 shows the physical properties of the obtained carrier. The same measurement or test as in Example 1 was performed using this carrier.

As a result of the shaking test, the carrier did not change from that before shaking, but a slight burial of the external additive on the toner surface was observed. Further, the ears of the developer were coarse, and as a result of an image display test, a slight roughness was observed particularly in a halftone portion.
As a result of the durability test of 10,000 sheets, line images were disturbed.

Comparative Example 3 Styrene 12.0% 2-ethylhexyl acrylate 3.0% Cu-Zn ferrite particles 85.0% (mol% Fe ₂ O ₃ : CuO: ZnO = 60: 17: 23) The above material was granulated in the same manner as in Example 1 to obtain magnetic material-dispersed resin particles. The surface of the obtained particles was coated with the same resin coating layer as in Example 1. According to observation with an electron microscope,
It was confirmed that the core material was uniformly coated with the resin.

Further, the same cyan toner as in Example 1 and the above-mentioned carrier were mixed in the same manner as in Example 1, and a test was conducted. Roughness was seen in the image coarsely.
Further, carrier adhesion to the photoreceptor was observed.

(Comparative Example 4) Styrene-methacrylic acid 2-
Hydroxyethyl-methyl methacrylate copolymer (monomer composition weight ratio = 40: 10: 50, hydroxyl value (KOHmg / g) = 30) 20% acetone and methyl ethyl ketone (mixing weight ratio = 1) of the above styrene copolymer Using 100 parts of the mixed solution of 1), the same carrier core material as in Example 1 was applied in the same manner as in Example 1 to obtain a carrier in which the surface of the carrier core material was covered with a resin coating layer. Table 1 shows the physical properties of this carrier. A test similar to that of Example 1 was performed using this carrier. As can be seen from the results in Table 4, in the carrier in which the resin coating layer containing no quaternary ammonium salt according to the present invention was coated on the carrier core material, it was found that the charge amount greatly changed due to environmental changes.

Example 2 Using the same formulation as in Example 1, the mixture was heated to a temperature of 70 ° C. in a container and dissolved to obtain a monomer mixture. While maintaining the temperature at 70 ° C., the initiator azobisisonitrile was added and dissolved to prepare a monomer composition. This was put into a 2 liter flask containing 1.2 liter of a 1% PVA aqueous solution, and stirred at 70 ° C. with a homogenizer at 2400 rpm for 10 minutes to granulate the composition.
Thereafter, polymerization was performed at 70 ° C. for 10 hours while stirring with a paddle stirrer. After completion of the polymerization reaction, the reaction product is cooled,
Wash the obtained magnetic material dispersed styrene acrylic slurry,
Filtered. This was dried to obtain magnetic material-dispersed resin particles.
The particle diameter of the obtained magnetic substance dispersed resin particles was 74 μm. The surface of the magnetic material-dispersed resin particles was coated in the same manner as in Example 1 to obtain a carrier. Table 1 shows the physical properties of the obtained carrier. A test similar to that of Example 1 was performed using this carrier.

As a result of an image display test after idling under low humidity, a slight roughness was observed particularly in the halftone portion, but this did not cause any practical problem.

(Example 3) Styrene-2-ethylhexyl acrylate 23% -butyl acrylate copolymer (monomer composition ratio = 80: 10: 1)
0) Sr-ferrite (mol% Fe ₂ O _3: SrO =
85:15) 77% The above materials were sufficiently premixed with a Henschel mixer, melt-kneaded at least twice with a three-roll mill, cooled, and coarsely ground to a particle size of about 2 mm using a hammer mill. Next, it was pulverized to a particle size of about 53 μm by a pulverizer using an air jet method. Further, the obtained finely pulverized product was put into a Mechanomill MM-10 (manufactured by Okada Seiko Co., Ltd.) and mechanically sphericalized. The spheroidized finely pulverized particles were further classified to obtain magnetic substance-dispersed resin particles. The particle size of the obtained magnetic material-dispersed resin particles was 51 μm.

A coating layer was provided on the surface of the obtained magnetic material-dispersed resin particles in the same manner as in Example 1 to obtain a resin-coated carrier.

Table 1 shows the physical properties of this carrier. Also,
This carrier was subjected to the same test as in Example 1.

As a result, as in Example 1, there was little change in the amount of charge when the environment fluctuated, there was no carrier adhesion, and the results were good in the shaking test and the image output test.

(Example 4) Polyester resin Ba-ferrite (mol% Fe ₂ O ₃ : BaO = 85) obtained by condensing 23% (50/40/10) of ethoxylated bisphenol-fumaric acid-trimellitic acid : 15) 77% Spherical magnetic resin-dispersed resin particles were obtained in the same manner as in Example 3 except that the above material was used. The particle size of the particles was 52 μm.

A coating resin was applied to the obtained magnetic material-dispersed resin fine particles as follows.

To 100 parts of a 10% solution of a styrene-methyl methacrylate-2-ethylhexyl copolymer (monomer composition weight ratio = 55: 25: 20) in 100 parts, was added <Example 1
0.8% of the quaternary ammonium salt shown in
0 parts were added and stirred with a stirrer until the mixture was sufficiently mixed to prepare a carrier coating solution.

The carrier coating solution was applied to the magnetic material-dispersed resin fine particles by an applicator (a Spira coater manufactured by Okada Seiko Co., Ltd.). The carrier after application is obtained at 60 ° C.
Heating was performed for 3 hours to obtain a carrier in which the surface of the carrier core material was coated with a coating resin.

Table 1 shows the physical properties of the obtained carrier. When a test similar to that of the first embodiment was performed,
Similar good results were obtained.

(Example 5) Magnetic material-dispersed resin particles were produced in the same manner as in Example 4 except that the amount of Ba-ferrite was changed to 40% (the remainder was a polyester resin). This was coated in the same manner as in Example 4 using the coating resin used in Example 4 to obtain a magnetic material-dispersed resin carrier. Table 1 shows the physical properties of this carrier. The carrier was tested in the same manner as in Example 1.
The results of the shaking test were as good as in Example 4. However, carrier adhesion to the photosensitive drum was slightly observed, and the density of the solid image was lower than that of Example 4 in an image output test under low humidity. Although it was slightly lower than that, it was not a problem in practical use.

(Example 6) Phenol 5.5% Formaldehyde 2.5% (Formaldehyde about 37%, methanol about 10%, water is the rest) Sr-ferrite (mol% Fe ₂ O ₃ : SrO = 85: 15) 92.0% Using ammonia as a basic catalyst and calcium fluoride as a polymerization stabilizer, the above materials were gradually heated to a temperature of 80 ° C while stirring in an aqueous phase, and polymerization was performed for 2 hours. . The particle diameter of the obtained magnetic substance dispersed resin particles was 43 μm. The coating resin used in Example 1 was added to the resin particles by 1
The coating was carried out in the same manner as in Example 1 by using the carrier coating solution in which the quaternary ammonium salt shown in <Example 8> was attached as particles to the methyl ethyl ketone solution in which 0 wt% was dissolved in the same manner as in Example 1. Table 1 shows the physical properties of the obtained resin-coated carrier. In addition, a test similar to that of Example 1 was performed using this carrier, and good results similar to those of Example 1 were obtained.

(Example 7) As the carrier core material, the same material as in Example 6 was used. Moreover, coating was performed in the same manner as in Example 6 using the following coating resin.

Further, as a toner, styrene-2-ethylhexyl acrylate-100 parts dimethylaminoethyl methacrylate copolymer (monomer composition weight ratio = 80/15/5) copper phthalocyanine 4 parts low molecular weight polypropylene 5 parts Weight average diameter 12.2μ as in Example 1.
m blue particles were obtained. To 100 parts of the particles, 0.8 part of positively chargeable colloidal silica treated with an amino-modified silicone oil was mixed with a Henschel mixer to obtain a positively chargeable cyan toner.

The charge amount of the toner under various environments was measured in the same manner as in Example 1 except that the toner concentration was changed to 8% using the toner and the carrier. The above results are shown in Table 4.
As can be seen from FIG.

Next, the toner and the carrier are mixed under N / N so that the toner concentration becomes 8% to prepare a developer.
A copy durability test was conducted under various environments using a modified machine in which the blade of a Canon NP-4835 developing machine was made non-magnetic, etc. under various environments. A good image having a stable image density was obtained irrespective of environmental fluctuations.

Next, the toner and the carrier were subjected to a toner concentration of 5% in an environment where the temperature / humidity was N / N (23 ° C./60% RH).
% To obtain a developer. The obtained developer 10
0 g was placed in a 250 cc plastic bottle, and shaken with a turbula mixer for 1 hour. Then remove the developer,
The developer was observed with an electron microscope. As a result, no detachment of the magnetic substance from the carrier, no peeling of the coating agent, and no filming with the toner were observed. Also, no detachment or burial of the external additive of the toner was observed.

Next, the toner and the carrier were subjected to a temperature / humidity L / L (15 ° C./10% RH) environment at a toner concentration of 8%.
% To obtain a developer. This was put in a color developing device of a modified copy machine NP-4835 made by Canon under the same environment, and idle rotation was performed for 30 minutes by driving an external motor.
Thereafter, an image was displayed using a modified NP-4835 machine. As a result, the density of the solid image was sufficient, and the reproducibility of the halftone portion and the sharpness of the line image were also good.

Comparative Example 5 A quaternary ammonium salt represented by the following formula was dissolved in distilled water to prepare a 0.5% adjusted solution. The same carrier core particles as in Example 1 having an average particle diameter of 44 μm were immersed in this adjusted liquid, stirred for 20 minutes, filtered, and then dried at 105 ° C. for 2 hours to obtain a carrier. The same evaluation as in Example 1 was performed using the obtained carrier and the same toner as in Example 1. Table 4 shows the results.
As shown in Fig. 7, although the amount of charge was not largely different in each environment, the difference in image density due to environmental fluctuation became larger in the copy durability test. After the shaking test using a turbula mixer, the carrier surface was observed with an electron microscope, and toner filming was observed. (R represents a C ₁₂ ~ ₁₈ alkyl group.) (Example 8) Styrene - and phenyl acrylate copolymer (monomer composition weight ratio = 50/50) 20% methyl ethyl ketone solution 100 parts of the above styrene copolymer 1.0% ethanol solution of quaternary ammonium salt in which the quaternary ammonium salt shown in <Example 8> was dissolved (solubility: 1.0 g / 100 g (ethanol) or more)
20 parts were stirred by a stirrer until they were sufficiently mixed to prepare a carrier coating solution.

This carrier coating solution was applied to the same core material as used in Example 6 in the same manner as in Example 6 using a coating machine (Spira Coater, manufactured by Okada Seiko Co., Ltd.). The obtained carrier after application was dried at 60 ° C. for 3 hours to remove the solvent to obtain a carrier in which the surface of the carrier core material was coated with a coating resin.

Using the carrier described above, a test similar to that of Example 1 was performed.

L / L (15 ° C./10%), N / N (23
C / 60%) and H / H (30 ° C./90%) in an image output durability test, the initial reflection image density was H / H: 1.53, N / N: 1.50. , L / L: 1.
48 / H, 1.52 N
/ N: 1.49, L / L: 1.49, and a good image with little influence from environmental fluctuation was obtained.

Further, a polybin shaking test was performed using a Turbula mixer in the same manner as in Example 1. Table 3 shows the results.

Further, during a series of image output tests, the amount of carrier adhered to the photosensitive drum or paper was extremely small, and the depth of the developer was dense, so that an image of higher quality was obtained as compared with the related art.

(Comparative Example 6) Styrene-2-ethylhexyl methacrylate-butyl methacrylate copolymer (monomer composition weight ratio = 50: 10: 40) Nigrosine dye was added to 100 parts of a 20% methyl ethyl ketone solution of the styrene copolymer. N-0 dissolved N-07
7 was stirred with a stirrer until 20 parts of a 1.0% acetone solution was sufficiently mixed to prepare a carrier coating solution.

This carrier coating solution was applied to a core material similar to that used in Example 7 in the same manner as in Example 7 using a coating machine (Spira Coater, manufactured by Okada Seiko Co., Ltd.). The obtained carrier after application was dried at 60 ° C. for 3 hours to remove the solvent to obtain a carrier in which the surface of the carrier core material was coated with a coating resin.

The same measurement or test as in Example 1 was performed using this carrier. As shown in Table 4, the environmental stability of charging was improved by adding Nigrosine N-07 as a charge control agent. You can see that it is not. Further, when image durability was performed, the reflection image density was initially H / H: 1.04, N / N: 1.25, L
/ L: 1.43, and H / H:
0.73, N / N: 0.95, L / L: 1.14, which indicates that the reflection image density is significantly lower than in the initial stage. Further, black fog is recognized in the image after the durability, and nigrosine N-07 is detached from the carrier surface.
It was found that it was developed or scattered to cause image quality deterioration. In addition, a polybin shaking test was performed using a turbula mixer in the same manner as in Example 1. Table 3 shows the results.

[0196]

[Table 1]

[0197]

[Table 2]

[0198]

[Table 3]

[0199]

[Table 4]

Example 9 Polyester resin obtained by condensing 100 parts of propoxylated bisphenol and fumaric acid 5 parts of phthalocyanine pigment 5 parts of chromium complex of di-tert-butylsalicylic acid 4 parts Pre-mixed, melt-kneaded at least twice with a three-roll mill, cooled, coarsely pulverized with a cutter mill, and finely pulverized with a fine pulverizer using a jet stream, and the obtained finely pulverized powder is obtained. The powder was classified by a fixed-wall air classifier to produce a classified powder. In addition, the obtained classified powder is multi-divided using the Coanda effect (Nippon Mining Co., Ltd. elbow jet classifier)
Then, the ultrafine powder and the coarse powder were strictly classified and removed at the same time to obtain a cyan powder (toner) having a weight average particle size of 6.6 μm.
Table 5 shows the particle size distribution of this toner.

100 parts of the above cyan toner and 0.5 parts of silica fine powder hydrophobized with hexamethyldisilazane were mixed by a Henschel mixer to prepare a cyan toner having silica fine powder on the surface of toner particles.

A test was conducted in the same manner as in Example 1 except that the cyan toner obtained as described above was used instead of the toner used in Example 1, and the same results as in Example 1 were obtained. Example 1 is in terms of resolution and toner consumption.
Even better.

[0203]

[Table 5]

[0204]

The magnetic material-dispersed carrier of the present invention contains the above specific quaternary ammonium salt on the surface of a carrier core material in which magnetic fine particles having specific magnetic characteristics are contained in a binder resin. Since the resin coating layer is formed, the following effects are obtained. (1) The carrier "ears" on the sleeve are made dense, and a high-definition image can be obtained. (2) A change in the amount of charge due to environmental fluctuation is extremely small, and a stable image density can be obtained. (3) The effect of (2) is not impaired by the durability. (4) Carrier deterioration such as toner spent due to durability is small. (5) Deterioration of the developer due to durability, in particular, deterioration of the toner (exfoliation and burial of the external additive on the toner surface) is small, and high image quality is stably obtained.

The two-component developer for developing an electrostatic image of the present invention has the following effects since it contains the carrier having the above-mentioned structure as a carrier. (1) The density of "spikes" of the magnetic brush per unit area on the sleeve is large, and a high-definition image can be obtained. (2) An image having a stable image density with very little change in the charge amount due to environmental fluctuations can be obtained. (3) The effect of (2) is not impaired by the durability. (4) Since there is little carrier deterioration such as toner spent due to durability, a good image can be formed over a long period of time.

In the method for producing a carrier for electrophotography according to the present invention, a carrier coating solution containing the above specific quaternary ammonium salt is applied to a carrier core material to form a resin coating layer on the surface of the carrier core material. Therefore, it is possible to obtain an electrophotographic carrier in which the quaternary ammonium salt is uniformly dispersed in the resin coating layer.

[Brief description of the drawings]

FIG. 1 is a schematic diagram schematically showing an electric resistance measuring device.

FIG. 2 is a schematic view schematically showing an apparatus for measuring the triboelectric charge of the toner of the two-component developer of the present invention.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Main electrode 2 Upper electrode 3 Insulator 4 Ammeter 5 Voltmeter 6 Constant voltage device 7 Carrier 8 Guide ring 21 Conductive screen 22 Measuring container 23 Lid 24 Suction machine 25 Suction port 26 Air flow control valve 27 Vacuum gauge 28 Electrometer 29 condenser

Continuation of the front page (56) References JP-A-63-50866 (JP, A) JP-A-62-229256 (JP, A) JP-A-61-120164 (JP, A) JP-A-59-216155 (JP, A) , A) (58) Field surveyed (Int. Cl. ⁶ , DB name) G03G 9/107 G03G 9/113

Claims (20)

(57) [Claims] 1. A method in which magnetic fine particles are dispersed in a binder resin.
Having a core material, and covering the surface of the core material with a resin coating layer.
Wherein the magnetic fine particles are strontium ferrite, burr
Ferrite or lead ferrite.
Sites are listed in the periodic rate tables IA, IIA, IIIA, IVA, V
A, VIA, IB, IIB, IVB, VB, VIB, V
IIB, VIII, and other elements.
Element content is 1wt%  TheCareerHas a coercive force of 10K Oersted
And more than 300 Gauss,  The resin coating layer is composed of an insulating resin material and the following formula:(Where R₁, R_Two, R_ThreeAnd R_FourIs an alkyl or aryl group
Or an aralkyl group, which are the same or different
A may represent an organic anion or a polyacid ion.
You. A quaternary ammonium salt represented by
A magnetic material-dispersed carrier characterized by the following: 2. The magnetic material-dispersed carrier according to claim 1, wherein the true specific gravity of the carrier is 1.5 to 5.0. 3. The magnetic material-dispersed carrier according to claim 1, wherein the carrier has a particle size of 10 μm to 60 μm. 4. A carrier having a specific resistance of 10 ⁸ Ω · cm to 1
4. The magnetic material-dispersed carrier according to claim 1, wherein the carrier is 0 ¹³ Ω · cm. 5. The magnetic material-dispersed carrier according to claim 1, wherein the core material in which the magnetic fine particles are dispersed in the binder resin is produced by a polymerization method. 6. The magnetic material-dispersed carrier according to claim 1, wherein the quaternary ammonium salt is a lake. 7. The magnetic material-dispersed carrier according to claim 1, wherein R ₄ represents an aryl group or an aralkyl group. 8. R ₁ , R ₂ and R _{3 each} represent an alkyl group or an aryl group, and R ₄ has the following formula: 7. The magnetic material-dispersed carrier according to claim 1, wherein the carrier is an aryl group or an aralkyl group represented by (n is 0, 1, 2, or 3). 9. The method according to claim 1, wherein R ₄ represents an alkyl group.
A magnetic material-dispersed carrier as described in the above. 10. The magnetic material-dispersed carrier according to claim ₁ , wherein R ₁ , R ₂ , R ₃ and R ₄ represent an alkyl group. 11. The magnetic material-dispersed carrier according to claim 1, wherein the resin coating layer contains an acrylic resin. 12. The quaternary ammonium formed by dissolving an insulating resin material and the quaternary ammonium salt in a solvent having a solubility in the quaternary ammonium salt of 1.0 g / 100 g (solvent) or more. The magnetic substance-dispersed carrier according to claim 1, wherein the carrier is formed from a carrier coating solution containing a dissolution solution. 13. R _1, R ₂ and R ₃ is an alkyl group or an aryl group indicates, A is a magnetic material-dispersed carrier according to claim 12, wherein an organic anion. 14. A method of dispersing magnetic fine particles in a binder resin.
And a carrier whose surface is covered with a resin coating layer
Two-component developer for developing electrostatic images with toner
The magnetic fine particles may include strontium ferrite, burr
Ferrite or lead ferrite.
The sites are the periodic tables IA, IIA, IIIA, IVA, V
A, VIA, IB, IIB, IVB, VB, VIB, V
IIB, VIII, and other elements.
Element content is 1wt%  TheCareerHas a coercive force of 10K Oersted
And more than 300 Gauss,  The resin coating layer comprises an insulating resin material and the following formula:(Where R₁, R_Two, R_ThreeAnd R_FourIs an alkyl or aryl group
Or an aralkyl group, which are the same or different
A may represent an organic anion or a polyacid ion.
You. A quaternary ammonium salt represented by
A two-component developer for developing electrostatic images. 15. The two-component developer according to claim 14, wherein the quaternary ammonium salt is a lake. 16. The two-component developer according to claim 14, wherein R ₁ , R ₂ , R ₃ and R ₄ represent an alkyl group. 17. A carrier coating solution containing a resin material.
Is a core material obtained by dispersing magnetic fine particles in a binder resin.
And dry it and coat the surface of the core material with a resin coating layer
In the method for producing a magnetic material-dispersed carrier, the magnetic fine particles may include strontium ferrite, burr
Ferrite or lead ferrite.
The sites are the periodic tables IA, IIA, IIIA, IVA, V
A, VIA, IB, IIB, IVB, VB, VIB, V
IIB, VIII, and other elements.
Element content is 1wt%  TheCareerHas a coercive force of 10K Oersted
And more than 300 Gauss,  The carrier coating solution comprises an insulating resin material and the insulating resin material.
A solvent for dispersing or dissolving the fat material, and the following formula:(Where R₁, R_Two, R_ThreeAnd R_FourIs an alkyl or aryl group
Or an aralkyl group, which are the same or different
A may represent an organic anion or a polyacid ion.
You. A quaternary ammonium salt represented by
A method for producing a magnetic material-dispersed carrier. 18. The carrier coating solution according to claim 17, wherein the quaternary ammonium salt is in the form of particles in which the insulating resin material is not dissolved or dispersed in a solution in which the insulating resin material is dispersed or dissolved. A method for producing a magnetic material dispersed type carrier. 19. The carrier coating solution, wherein the quaternary ammonium salt is dissolved in a solvent having a solubility in the quaternary ammonium salt of 1.0 g / 100 g (solvent) or more. 18. The method according to claim 17, wherein the insulating resin material is mixed or dispersed in a solution in which the insulating resin material is dispersed or dissolved. 20. R _1, R ₂ and R ₃ indicates an alkyl group or an aryl group, A is the method of manufacturing a magnetic material-dispersed carrier according to claim 19, wherein an organic anion.