JP2003122058A - Color replenishing developer, black one-component magnetic developer and color image forming device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a color replenishing developer, a black one-component magnetic developer and a color image forming device capable of obtaining good image quality for a long period by stabilizing the electrification of toner without being influenced by environment. SOLUTION: The color replenishing developer obtained by mixing 2 to 50% mass of color non-magnetic toner to 1% mass of carrier particle and the black one-component magnetic developer having the average circularity of >=0.970 and having B/A (defining the dispersibility of iron particle oxide) of <0.001 and D/C of <=0.02, are used in the color image forming device.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a color color replenishing developer and a black one-component magnetic developing agent for use in recording methods utilizing electrophotography, electrostatic recording, magnetic recording, toner jet recording, and the like. It is related to agents. More specifically, the present invention relates to a copying machine, a printer, a fax machine or the like which uses a black magnetic toner and a color non-magnetic toner in combination and forms a toner image on an image carrier in advance and then transfers the image onto a transfer material to form an image. The present invention relates to a color replenishment developer and a black one-component magnetic developer used.

[0002]

2. Description of the Related Art Conventionally, a number of methods are known as electrophotography, but generally, a photoconductive material is used, and it is fixed on an image carrier (hereinafter referred to as "photoreceptor") by various means. An electrostatic latent image is formed, then the electrostatic latent image is developed with toner to form a visible image, and the toner image is transferred to a transfer material such as paper, if necessary, and then transferred onto the transfer material by heat or pressure. A toner image is fixed on the product to obtain a copy.

As a method of visualizing an electric latent image, a cascade developing method, a magnetic brush developing method, a pressure developing method and the like are known.

In the developing method using the insulating magnetic toner, a considerable amount of a fine powdery magnetic material is mixed and dispersed in the insulating magnetic toner, and a part of the magnetic material is exposed on the surface of the toner particles. Therefore, there is a problem in that the fluidity and triboelectricity of the magnetic toner are affected, and as a result, various characteristics required for the magnetic toner such as developing characteristics and durability of the magnetic toner are varied or deteriorated.

From these points, various proposals have been made in the past regarding the magnetic iron oxide contained in the magnetic toner, but there are still some points to be improved.

On the other hand, for the toner, a binder resin, a magnetic material, etc. are melt-mixed, uniformly dispersed, and then pulverized by a fine pulverizer,
Although a toner having a desired particle size has been manufactured (crushed) by classifying with a classifier, there is a limitation in the selection range of materials for making the toner into a fine particle size. For example, the resin magnetic substance dispersion must be sufficiently brittle and capable of being finely pulverized by an economically usable manufacturing apparatus. From this requirement, in order to make the resin magnetic material dispersion brittle, when the resin magnetic material dispersion is actually finely pulverized at a high speed, particles in a wide particle size range are likely to be formed, and particularly a relatively large proportion of fine particles ( The problem arises that it contains particles that are too crushed. Further, such a highly brittle material is often subjected to further pulverization or pulverization when used as a developing toner in a copying machine or the like.

Further, in the pulverizing method, it is difficult to disperse solid fine particles such as magnetic powder or coloring agent into the resin completely and uniformly. Depending on the degree of dispersion, fog increases and image density decreases. Cause. Furthermore, the grinding method is essentially
Since the magnetic iron oxide particles are exposed on the surface of the toner, problems still remain in the fluidity of the toner and the charging stability in a harsh environment.

In order to overcome the problems of the toner by the crushing method as described above, and further, to satisfy the above-mentioned requirements, a method for producing a toner by a polymerization method has been proposed.

A toner by polymerization (hereinafter referred to as a polymerized toner) can easily be made into fine particles, and since the shape of the obtained toner is spherical, it is excellent in fluidity and can improve image quality. Be advantageous.

However, when the polymerized toner contains a magnetic material, its fluidity and charging characteristics are significantly lowered. This is because the magnetic particles are generally hydrophilic and therefore easily exist on the toner surface. In order to solve this point, the surface of the magnetic material in the polymerized toner is modified (Japanese Patent Laid-Open No. 59-200254 and Japanese Patent Laid-Open No. 59-2002).
56, JP-A-59-200257, JP-A-59-224102, etc.), a method of containing magnetic particles only in a specific portion inside the toner particles (JP-A-7- No. 72654). However, none of them have been satisfactory.

The electrophotographic apparatus is widely used in addition to a conventional so-called copying machine for copying a manuscript, as well as a computer for which demand has grown remarkably in recent years and a printer as an output means of a word processor. Printer device is LE
D and LBP printers have become the mainstream of the market these days, and as the direction of technology, higher resolution, that is, conventional 300,
What was 400 dpi is 600, 800, 1200
It is becoming dpi. Accordingly, the developing system is also required to have higher definition. In addition, the functions of copying machines are also becoming more sophisticated, and as a result, they are moving toward digitalization. In this direction, since the method of forming an electrostatic latent image with a laser is the main method, it is also advancing toward the direction of high resolution, and here again, as with printers, high resolution and high definition development methods are required. ing.

Particularly in recent years, in such printers and copying machines, not only conventional black and white image output, but also color shift of images output in the office has been raised due to diversification and sophistication of information in the OA market. It is emphasized that color image output is added.

In such an environment, conventionally, a plurality of developing devices respectively accommodating developers of different colors are provided, and one or a plurality of recording cycles are performed on a photosensitive drum as an image carrier by using an electrophotographic method. A multicolor image forming apparatus has been proposed in which a toner image of a plurality of colors is formed by a method described above, and the toner images of the plurality of colors are collectively transferred and fixed on a recording material to obtain a desired multicolor image.

In a multicolor image forming apparatus, a non-magnetic color toner is often used in order to reproduce colors vividly in the developing process of color toner other than black toner. These non-magnetic color toners have an electrostatic property which is an important part in electrophotography,
Since it does not have a magnetic component which is excellent in charge imparting, it is often used as a two-component developer by mixing with magnetic powder generally called carrier particles.

At present, in the two-component developing method which is the mainstream for color toners, the toner is consumed by the development and the carrier particles are retained in the developing device without being consumed. Therefore, the toner components are transferred to the surface of the carrier particles. Contamination occurs, or the carrier particles themselves are subjected to stress in the developing device, and the resin coating layer is peeled off, which affects developer characteristics such as charging properties, and the image density fluctuates or fogging occurs.

As a method for solving this problem, for example,
In Japanese Patent Publication No. 21591/1990, carrier particles are added together with toner consumed by development, and carrier particles in the developing device are replaced little by little to suppress changes in charge amount and stabilize image density. There is disclosed a developing device that performs the so-called trickle developing device. However, since the carrier particles used are iron powder carrier particles with a large saturation magnetization, the stress on the carrier particles in the developing device is large, and the carrier easily deteriorates during repeated copying operations, so replenishment is required. If the carrier amount is not increased, image deterioration is likely to occur quickly, which is not a satisfactory method.

On the other hand, in Japanese Patent Laid-Open No. 3-145678, carrier particles having a resistance value higher than that of carrier particles previously stored in a developing device are mixed with toner to maintain chargeability and reduce image quality. It is disclosed to suppress. Further, Japanese Patent Application Laid-Open No. 11-223960 discloses that toner is contained in carrier particles for imparting a higher charge amount to the toner to maintain chargeability and suppress deterioration of image quality. However, in these methods, since the amount of carrier particles to be replaced is different due to the difference in toner consumption, the resistance or charge amount of the developer in the developing device is changed, and the fluctuation of the image density is likely to occur. Was not.

Further, in Japanese Patent Laid-Open No. 8-234550,
A method is disclosed in which a plurality of types of replenishment toner containing carrier particles having different physical properties from the carrier particles previously stored in a developing device are used and each toner is replenished sequentially. However, in reality, it is extremely difficult to replenish the replenishment toner containing a plurality of carrier particles having different physical properties in one toner replenishment container to the developing device in order not to mix the toner particles. It is very difficult to obtain a stable image for a long period of time because the amount of toner is large relative to the amount of carrier particles.

On the other hand, the following concerns are expected in the image forming method using the black magnetic toner and the color non-magnetic toner.

As the electrophotographic process becomes faster, the untransferred transfer residual magnetic toner is pressed against the surface of the photoreceptor,
This is the point that toner fusion is apt to occur, where abrasion or scraped parts due to scraping of the surface of the photoconductor becomes a generation nucleus. In particular, it is immeasurable that the magnetic substance has a great influence on the abrasion of the surface of the susceptor as compared with the non-magnetic color toner.

Problems such as abrasion of the photosensitive member and defective transfer are likely to occur when a developer composed of irregular toner particles is used. It is considered that this is because the transferability of the irregular toner is low and the edge portion of the toner particles easily scratches the surface of the photoconductor. Further, the problem of shaving becomes particularly noticeable when the magnetic toner in which the magnetic substance is exposed on the surface of the toner particles is used as described above. This is easy to understand considering that the exposed magnetic body is directly pressed against the photoconductor.

Further, in recent years, a development / cleaning structure having no cleaning device has been attracting attention from the viewpoints of downsizing of the device and effective utilization of toner from the viewpoint of ecology. Conventionally, when a magnetic toner containing a magnetic material is used in a developing / cleaning structure, the magnetic material is exposed on the toner surface, and therefore, the toner is not transferred between the photoconductor and the toner carrier via the toner during development. Partial conduction occurs and the electrostatic charge image on the photoconductor is disturbed, making it difficult to obtain a high-definition image.
Also, the magnetic toner whose magnetic material is exposed on the toner surface is
Since the transfer residual toner is insufficiently charged, the smooth recovery of the toner on the photoconductor in the developing process is hindered. Furthermore, when the photoconductor is rubbed against the toner and the toner carrier, the photoconductor is greatly worn by the magnetic material exposed on the toner surface, which shortens the life of the photoconductor. As a result, the originally imageless area becomes a so-called ghost image, which is a printed image that is image-wise soiled with toner.

As described above, it is desired that the magnetic material-containing toner used in the developing / cleaning structure does not have the magnetic material exposed on the toner surface.

Further, in the structure having the cleaning device, if the pressing force of the cleaning member is weakened to prolong the life of the photosensitive member, the amount of transfer residual toner that slips through the cleaning member increases accordingly. It can be said that reducing the amount of such slipping toner as much as possible is very important in the system for collecting in the developing process.

When the conventional magnetic toner containing the magnetic substance is used, the above-mentioned problems occur because the magnetic substance is exposed on the surface of the toner in all the conventional magnetic toners. Is the major cause. In the case of a magnetic toner in which the magnetic material is exposed on the toner surface, the resistance of the magnetic material is lower than the resistance of the resin that the toner has, so the charging characteristics under high humidity tend to be poor, and the fog suppression deteriorates. This causes undesirable effects such as deterioration of transferability, generation of ghosts due to deterioration of transfer residual toner collection property, and deterioration of photoreceptor performance due to rubbing against the photoreceptor.

That is, in the actual state, no magnetic toner having good initial characteristics and stability in the developing / cleaning constitution has been found so far.

[0027]

SUMMARY OF THE INVENTION An object of the present invention is to solve the above problems of the prior art.

That is, the object of the present invention is not easily influenced by the environment, has a stable charging performance, has a high image density even after long-term use, suppresses the generation of fog, and is excellent in image reproducibility. Another object is to provide a color image forming apparatus capable of obtaining a stable image throughout the life of the main body, a color color replenishing developer and a black one-component magnetic developer used for the same.

[0029]

Means for Solving the Problems That is, the present invention is as follows. (1) At least a black one-component magnetic developer, a yellow two-component developer, a magenta two-component developer and a cyan two-component developer, and a yellow replenishment developer, a magenta color replenishment developer and a cyan color replenishment. Developer for color color replenishment for use in a color image forming apparatus containing a developer for replenishing the color of the developer and forming a visible image by using the developer An agent,
A non-magnetic toner selected from the group consisting of a yellow non-magnetic toner, a magenta non-magnetic toner and a cyan non-magnetic toner in an amount of 2 to 50 parts by mass with respect to 1 part by mass of carrier particles. Replenishing developer for color. (2) At least a black one-component magnetic developer, a yellow two-component developer, a magenta two-component developer and a cyan two-component developer, and a yellow replenishment developer, a magenta color replenishment developer and a cyan color replenishment. Black developer for use in a color image forming apparatus containing a developer for replenishing the color of the developer and forming a visible image using the developer to develop the image. The black one-component magnetic developer has black magnetic toner particles containing at least a binder resin and iron oxide, and i) is present on the surface of the black magnetic toner particles measured by X-ray photoelectron spectroscopy. The ratio (B / A) of the iron element content (B) to the carbon element content (A) is less than 0.001 and ii) the projected area equivalent diameter of the black one-component magnetic developer is C,
When the minimum value of the distance between the iron oxide and the surface of the black magnetic toner particles in the cross-section observation of the black one-component magnetic developer using a transmission electron microscope (TEM) is D, D / C ≦ 0.02
Is 50% by number or more, and iii) the average circularity of the black one-component magnetic developer is 0.9.
A black one-component magnetic developer having a content of 70 or more. (3) At least a black one-component magnetic developer, a yellow two-component developer, a magenta two-component developer and a cyan two-component developer, and a yellow color replenishment developer, a magenta color replenishment developer and a cyan color replenishment. A color image forming apparatus containing at least a developing device for accommodating a developer for replenishing color of the developer and forming a visible image by using the developer, the black image forming device comprising: The component magnetic developer is the black one-component magnetic developer of the present invention, and the yellow color replenishing developer, the magenta color replenishing developer and the cyan color replenishing developer are the color replenishing developer of the present invention. A color image forming apparatus characterized by being an agent.

[0030]

BEST MODE FOR CARRYING OUT THE INVENTION Hereinafter, the present invention will be described in detail by showing embodiments of the present invention.

The present invention is a developing device for forming and developing a visible image using at least a black one-component magnetic developer, a yellow two-component developer, a magenta two-component developer and a cyan two-component developer. A yellow color replenishing developer, a magenta color replenishing developer and a cyan color replenishing developer, a color color replenishing developer of the developer, and a black one-component magnetic development, which are used in a color image forming apparatus including Regarding agents. <1> Black One-Component Magnetic Developer of the Present Invention The black one-component magnetic developer of the present invention has black magnetic toner particles containing at least a binder resin and iron oxide, and i) by X-ray photoelectron spectroscopy analysis. The ratio (B / A) of the content (B) of the iron element to the content (A) of the carbon element present on the surface of the black magnetic toner particles measured is less than 0.001, and ii) black one-component magnetic development Let C be the projected area equivalent diameter of the agent,
When the minimum value of the distance between the iron oxide and the surface of the black magnetic toner particles in the cross-section observation of the black one-component magnetic developer using a transmission electron microscope (TEM) is D, D / C ≦ 0.02
Is 50% by number or more, and iii) the average circularity of the black one-component magnetic developer is 0.9.
It is characterized by being 70 or more.

When the black one-component magnetic developer of the present invention is produced by a pulverization method, a known method can be used.
As a known method, for example, a thermoplastic resin as a binder resin, a magnetic iron oxide, a release agent, a charge control agent, and in some cases, a component necessary as a toner such as a colorant and other additives and a Henschel mixer are used. After sufficiently premixing in a mixer such as a ball mill, the premixture is melt-kneaded using a heat kneader such as a heating roller, a kneader or an extruder, and the resins and other toner constituent materials are mixed. After dispersion or dissolution, solidification by cooling, pulverization, classification, surface treatment if necessary to obtain toner particles, and fine powder as an external additive or the like is added as necessary to add a developer ( (Also referred to as “toner”) can be obtained. Either the classification or the surface treatment may be performed first. In terms of production efficiency, it is preferable to use a multi-division classifier in the classification step. The crushing process can be performed by using a known crushing device such as a mechanical shock type or a jet type. In order to obtain a developer having a specific circularity according to the present invention, it is preferable to further apply heat to pulverize or to supplementally apply a mechanical impact. Further, a hot water bath method in which finely pulverized toner particles (classified as necessary) are dispersed in hot water, a method of passing through a hot air stream, or the like may be used.

Examples of mechanical impact type pulverizers include mechanical impact type pulverizers such as Kawasaki Heavy Industries, Ltd.'s Kryptron System and Turbo Kogyo's turbo mill. In addition, like the devices such as Hosokawa Micron's Mechano-Fusion System and Nara Machinery's Hybridization System, the blades that rotate at high speed press the toner into the inside of the casing by centrifugal force, compressing force, friction force, etc. Alternatively, a method of applying a mechanical impact force to the toner may be used.

In the case of performing a process of applying a mechanical shock,
From the viewpoint of preventing aggregation and productivity, it is preferable to set the atmospheric temperature during the treatment to a temperature near the glass transition point Tg of the toner (that is, a temperature in the range of the glass transition point Tg of the toner ± 30 ° C.). More preferably, the glass transition point Tg ± 2 of the toner
Performing the treatment at a temperature in the range of 0 ° C. is particularly effective for improving the transfer efficiency.

As the thermoplastic resin as the binder resin when the black one-component magnetic developer of the present invention is produced by the pulverization method as described above, styrene such as polystyrene and polyvinyltoluene, or a homopolymer of a substitution product thereof is used. Styrene-propylene copolymer, styrene-vinyltoluene copolymer, styrene-vinylnaphthalene copolymer, styrene-
Methyl acrylate copolymer, styrene-ethyl acrylate copolymer, styrene-butyl acrylate copolymer, styrene-octyl acrylate copolymer, styrene-dimethylaminoethyl acrylate copolymer, styrene-methacrylic acid Methyl copolymer, styrene-ethyl methacrylate copolymer, styrene-butyl methacrylate copolymer, styrene-dimethylaminoethyl methacrylate copolymer, styrene-vinyl methyl ether copolymer, styrene-vinyl ethyl ether Styrene-based copolymers such as copolymers, styrene-vinyl methyl ketone copolymers, styrene-butadiene copolymers, styrene-isoprene copolymers, styrene-maleic acid copolymers, styrene-maleic acid ester copolymers ; Polymethylmethacrylate, polybutylmeth Relate, polyvinyl acetate, polyethylene, polypropylene, polyvinyl butyral, silicone resins, polyester resins, polyamide resins, epoxy resins, polyacrylic acid resins, rosin, modified rosin,
Tempel resin, phenol resin, aliphatic or alicyclic hydrocarbon resin, aromatic petroleum resin, paraffin wax,
Carnauba wax can be used alone or in combination. In particular, styrene-based copolymers and polyester resins are preferable in terms of development characteristics, fixability and the like.

The black one-component magnetic developer according to the present invention preferably contains a release agent. The intention is that the offset resistance is good, the magnetic iron oxide is well dispersed in the binder resin, and a high-density visible image can be obtained. Further, if the magnetic toner and the non-magnetic toner are present on the same image carrier as in the configuration of the image forming apparatus of the present invention, the fixing properties of both toners are different, and after fixing, the toner is relatively fixed. Compared to non-magnetic toner capable of keeping the layer surface smooth, the magnetic toner layer surface is in a rough state, so when the transfer material such as paper and sheet is peeled from the fixing heating roller, The releasability must be better, and the addition of an auxiliary release agent leads to a further improvement in fixing property.

The release agent has a melting start temperature of 40 ° C. or higher, preferably 50 ° C. or higher, and at least 2 or more in the range of 50 to 250 ° C., preferably 70 to 200 ° C. as measured by DSC. Two or more kinds having melting points or different melting points can be mixed and used.
This is because when the melting start temperature of the release agent is 40 ° C. or lower,
This is because a material having poor blocking resistance and having a plurality of melting points between 50 and 250 ° C. can exert a releasing effect over a wide range from low temperature to high temperature.

Further, as a more preferable method of using the releasing agent, it is desirable to use a combination of two or more releasing agents having different melting points and having no polar group and a releasing agent having a polar group. . This is because most of the non-polar release agents are present in the matrix resin, and conversely most of the release agents having polar groups are present in the domain resin. This is because it also has a releasing effect. Therefore, it can be present in the matrix resin and the domain resin, and is 50 to 2
There is no problem even if only one type of release agent is used, as long as it has a plurality of melting points at 50 ° C.

Examples of the release agent having no polar group used in the black one-component magnetic developer of the present invention include the following. Low molecular weight polyethylene, low molecular weight polypropylene,
Aliphatic hydrocarbon wax such as microcrystalline wax and paraffin wax, oxide of aliphatic hydrocarbon wax such as oxidized polyethylene wax, or block copolymer thereof, carnauba wax, sazol wax, montanic acid ester wax, etc. The waxes containing the fatty acid ester as a main component, and those obtained by partially or entirely deoxidizing the fatty acid ester such as deoxidized carnauba wax.

Examples of the releasing agent having a polar group used in the present invention include the following. Palmitic acid, saturated linear fatty acids such as stearic acid and montanic acid, unsaturated fatty acids such as blancinic acid, eleostearic acid, and vinalinaric acid, stearyl alcohol, aralkyl alcohol, behenyl alcohol, carnaubayl alcohol, ceryl alcohol, Saturated alcohols such as melicyl alcohol,
Polyhydric alcohols such as sorbitol, linoleic acid amides, oleic acid amides, fatty acid amides such as lauric acid amides, methylenebisstearic acid amide, ethylenebiscapric acid amide, ethylenebislauric acid amide,
Saturated fatty acid bisamides such as hexamethylenebisstearic acid amide, ethylene bisoleic acid amide, hexamethylenebisoleic acid amide, N, N'-dioleyl adipamide, N, N'-dioleyl sebacic acid amide Aromatic bisamides such as saturated fatty acid amides, m-xylene bisstearic acid amide, N, N′-distearylisophthalic acid amide, fatty acid metal salts such as calcium stearate, calcium laurate, zinc stearate, magnesium stearate ( (Generally called metal soap), waxes obtained by grafting aliphatic hydrocarbon wax with vinyl monomers such as styrene and acrylic acid, partial ester of fatty acid such as behenic acid monoglyceride and polyhydric alcohol For hydrogenation of compounds and vegetable oils Methyl ester compounds and the like having a hydroxyl group obtained I.

The amount of the release agent used in the black one-component magnetic developer of the present invention is 0.1 to 100 parts by weight of the binder resin.
20 parts by mass, preferably 0.5 to 10 parts by mass is desirable. This is because if the amount of the releasing agent is 20 parts by mass or more, the blocking resistance and the high temperature offset are deteriorated, and if it is less than 0.1 parts by mass, the releasing effect becomes small.

These release agents are usually added to the binder resin by dissolving the binder resin in a solvent, raising the temperature of the binder resin solution, and then adding and mixing with stirring or a method of mixing at the time of kneading. Contained. The black one-component magnetic developer has sufficient charging ability for the black magnetic toner particles themselves, and more uniform charging performance can be obtained by aligning the developer shapes, and the toner from the image carrier to the transfer material such as paper Transfer efficiency is also greatly improved.
In other words, in the output of a black-and-white image mainly of a line image, it can be said that it is one of the important developer performances for achieving high resolution as well as reproducibility of minute dot images.

From the above, in the black one-component magnetic developer of the present invention, higher image quality and higher stability are achieved by increasing the average circularity of the black one-component magnetic developer. it is conceivable that.

Therefore, the present inventors obtain the above performance by setting the average circularity of the black one-component magnetic developer (hereinafter, also referred to as "magnetic toner") to 0.970 or more. I found a thing. The circularity can be produced by the above-mentioned pulverizing method, but in the pulverizing method, it is necessary to perform mechanical, thermal or some special treatment in order to make the average circularity of the magnetic toner 0.970 or more. Therefore,
It is preferably produced by a suspension polymerization method or the like.

The reason for setting the average circularity of the magnetic toner to 0.970 or more is as follows. Considering the reduction in the number of component parts due to the recent miniaturization of output devices and the zero emission that does not generate waste from copiers and printers, magnetic toner adhesion to the non-image area on the image carrier and It is necessary to reduce the transfer residual toner amount. For that purpose, it is necessary that the chargeability of the magnetic toner particles is sufficient and uniform, but further, when a magnetic toner having a fine particle size is used from the viewpoint of high image quality, the adhesive force of the magnetic toner particles is increased. Since the number of magnetic toner particles increases, the shape of the magnetic toner particles also has a great influence on the adhesion of the magnetic toner to the non-image area on the image carrier. From these things, the magnetic toner particles are close to spherical, and the more uniform the shape is, the smaller the area of adhesion of the particles becomes, and the magnetic toner adhesion to the non-image area on the image carrier and the transfer residual toner amount are reduced. This is because it is preferable to improve the average circularity of the magnetic toner based on the idea that high image quality and durability stability are achieved.

When the black one-component magnetic developer used in the present invention is obtained by suspension polymerization or the like, even if a magnetic toner is produced by suspension polymerization using ordinary magnetic iron oxide,
Magnetic iron oxide is poorly dispersible, so that magnetic iron oxide is unevenly distributed on the surface of the magnetic toner, or magnetic iron oxide moves randomly during granulation in an aqueous medium and is dragged by it to distort the particle shape. Therefore, since it is difficult to obtain a magnetic toner having an average circularity of 0.970 or more, it is necessary to use a magnetic iron oxide that is subjected to a high level of uniform hydrophobicity.

The inventors of the present invention have made earnest studies on the homogenization and stabilization of the charging of the magnetic toner, and as a result, the content (A) of the carbon element present on the surface of the magnetic toner particles measured by X-ray photoelectron spectroscopy analysis (A). Elemental iron content (B)
Ratio (B / A) of less than 0.001 and the average circularity of the magnetic toner of 0.970 or more are extremely effective for uniformizing and stabilizing the charging property of the magnetic toner, and It was found that abrasion, charging failure and transfer failure were remarkably suppressed, and that a high-definition image free from fog and other image defects could be stably obtained even after long-term use.

In particular, the magnetic toner having a circularity of 0.970 or more has almost no edge portion on the surface. Therefore, even if the magnetic toner has a process step in which a contact member typified by a charging member and a cleaning member is present, it is exposed to light. Since the surface of the photoconductor is not scratched at the pressure contact portion with the body, abrasion of the photoconductor surface can be suppressed. These effects become more prominent even in an image forming method including a contact transfer step in which voids in the transfer are likely to occur.

In obtaining the black developer according to the present invention by the suspension polymerization method or the like, the average circularity of the magnetic toner is 0.970.
In order to achieve the above, it is difficult to achieve the conventional polymerization method using magnetic iron oxide.

The reason is that the conventional magnetic iron oxide has not been sufficiently and uniformly hydrophobized.

When the magnetic toner is produced by the suspension polymerization method, the dispersibility of the magnetic iron oxide particles in the binder resin can be improved by using the magnetic iron oxide whose surface is hydrophobized. Even when a large amount of magnetic iron oxide is exposed on the surface of the magnetic toner particles, the charging performance of the magnetic toner can be improved under any environment if the surface of the magnetic iron oxide is uniformly hydrophobized. It's hard to lose.

Therefore, various methods for making the surface of magnetic iron oxide hydrophobic have been proposed. However, it is difficult to obtain a sufficiently and uniformly hydrophobized magnetic iron oxide by the conventional methods. In addition, when a large amount of a treating agent is used or a highly viscous treating agent is used, the degree of hydrophobicity is surely increased, but coalescence of magnetic iron oxide particles and the like occur, and the hydrophobicity and dispersibility Compatibility was not always achieved.

In general, since the untreated iron oxide surface has hydrophilicity, it is necessary to hydrophobize the hydrophilic magnetic iron oxide in order to obtain hydrophobic magnetic iron oxide. The surface treatment method does not provide sufficient uniformity of hydrophobicity, and the conventional magnetic toner obtained by the polymerization method using such magnetic iron oxide changes its chargeability depending on humidity etc. It was lacking.

On the other hand, the magnetic iron oxide according to the present invention is
For example, when hydrophobizing, the surface treatment is performed while hydrolyzing the coupling agent while dispersing so that the magnetic iron oxide has a primary particle size in an aqueous medium, resulting in a very high level of hydrophobization uniformity. Is planned. Compared with the treatment in the gas phase, the hydrophobic treatment method in an aqueous medium is less likely to cause coalescence of magnetic iron oxides, and the hydrophobic treatment causes the electrostatic repulsion between the magnetic iron oxide particles to work. Since iron oxide is subjected to surface treatment in the state of almost primary particles, highly uniform hydrophobization is achieved.

The method of treating the surface of iron oxide while hydrolyzing the coupling agent in an aqueous medium does not require the use of a coupling agent such as chlorosilanes and silazanes which generate gas, and further, Up to now, iron oxide particles have easily coalesced with each other in the gas phase, and a highly viscous coupling agent, which has been difficult to treat satisfactorily, can now be used, and the effect of hydrophobization is great.

Examples of the coupling agent usable in the present invention include a silane coupling agent and a titanium coupling agent. A silane coupling agent is more preferably used and is represented by the following general formula (I).

[0057]

R _m SiY _n (I) (In the formula, R represents an alkoxy group, m represents an integer of 1 to 3, and Y represents a hydrocarbon group such as an alkyl group, a vinyl group, a glycidoxy group, or a methacryl group. And n is an integer of 1 to 3, provided that m + n = 4.) Examples of the silane coupling agent represented by the general formula (I) include vinyltrimethoxysilane, vinyltriethoxysilane, γ-methacryloxypropyltrimethoxysilane, vinyltriacetoxysilane, methyltrimethoxysilane, methyltriethoxysilane, isobutyltrimethoxysilane, dimethyldimethoxysilane, dimethyldiethoxysilane, trimethylmethoxysilane,
Examples thereof include hydroxypropyltrimethoxysilane, phenyltrimethoxysilane, n-hexadecyltrimethoxysilane and n-octadecyltrimethoxysilane.

In particular, it is preferable to hydrophobize the magnetic iron oxide in an aqueous medium using an alkyltrialkoxysilane coupling agent represented by the following general formula (II).

[0059]

Embedded image C _p H _{2p + 1} —Si— (OC _q H _{2q + 1} ) ₃ (II) (wherein p represents an integer of 2 to 20 and q represents an integer of 1 to 3) If p in the formula is less than 2, the hydrophobic treatment is easy, but it may be difficult to impart sufficient hydrophobicity. If p is greater than 20, the hydrophobicity is sufficient, but the magnetic property is high. The coalescence of iron oxide particles increases, and it may be difficult to sufficiently disperse the iron oxide particles in the magnetic toner.

When q is larger than 3, the reactivity of the silane coupling agent is lowered and it becomes difficult to sufficiently hydrophobize the silane coupling agent.

In particular, alkyl in which p is an integer of 2 to 20 (more preferably an integer of 3 to 15) and q is an integer of 1 to 3 (more preferably an integer of 1 or 2). It is preferable to use a trialkoxysilane coupling agent.

The treatment amount is 0.05 to 20 parts by mass, preferably 0.1 to 10 parts by mass, based on 100 parts by mass of iron oxide.

In the present invention, the aqueous medium is a medium containing water as a main component. Specifically, water itself as an aqueous medium, water with a small amount of a surfactant added,
Examples include water to which a pH adjuster is added and water to which an organic solvent is added. The surfactant is preferably a nonionic surfactant such as polyvinyl alcohol. The surfactant is preferably added in an amount of 0.1 to 5 mass% with respect to water. Examples of the pH adjuster include inorganic acids such as hydrochloric acid.

Stirring is carried out, for example, with a mixer having stirring blades (specifically, a high shear mixing device such as an attritor or TK homomixer) so that the iron oxide particles become primary particles in an aqueous medium. It is good to do enough.

Since the surface of the iron oxide thus obtained is uniformly subjected to the hydrophobic treatment, when it is used as a toner material, the dispersibility in the toner is very good and there is no exposure from the toner surface.

Therefore, by using such iron oxide, the ratio of the iron element content (B) to the carbon element content (A) present on the surface of the magnetic toner measured by X-ray photoelectron spectroscopy analysis. The magnetic toner of the present invention having a (B / A) of less than 0.001 can be obtained, and the charging uniformity and stabilization of the magnetic toner can be achieved. By using this magnetic toner, high image quality and high durability can be obtained. Stability can be achieved. Furthermore, by setting (B / A) to less than 0.0005, the charging property and stability are further improved.

The magnetic iron oxide used in the magnetic toner of the present invention is produced, for example, by the following method.

An aqueous solution containing ferrous hydroxide is prepared by adding an alkali equivalent to the iron component, such as sodium hydroxide or the like, to the aqueous solution of ferrous sulfate. Air is blown while maintaining the pH of the prepared aqueous solution at pH 7 or higher (preferably pH 8 to 10), and the oxidation reaction of ferrous hydroxide is carried out while heating the aqueous solution to 70 ° C. or higher to obtain the core of magnetic iron oxide particles. First, a seed crystal that becomes

Next, an aqueous solution containing about 1 equivalent of ferrous sulfate is added to the slurry-like liquid containing seed crystals, based on the amount of alkali added previously. While maintaining the pH of the solution at 6 to 10, the reaction of ferrous hydroxide is promoted while air is blown in, and magnetic iron oxide particles are grown around the seed crystal.

The pH of the solution shifts to the acidic side as the oxidation reaction proceeds, but it is preferable that the pH of the solution is not less than 6. The pH of the liquid is adjusted at the end of the oxidation reaction, and the magnetic iron oxide is sufficiently stirred so as to become primary particles, a coupling agent is added and sufficiently mixed and stirred, and after stirring, filtered and dried,
By lightly crushing, hydrophobically treated magnetic iron oxide particles can be obtained. Alternatively, after the oxidation reaction is completed, the iron oxide particles obtained by washing and filtering are redispersed in another aqueous medium without drying, and then the pH of the redispersion liquid is adjusted and sufficiently stirred. A coupling treatment may be performed by adding a silane coupling agent.

In any case, it is important to make the untreated magnetic iron oxide particles produced in the aqueous solution hydrophobic in the state of the water-containing slurry before the drying step. This is because if untreated magnetic iron oxide particles are dried as they are, coalescence due to agglomeration of the particles is unavoidable. This is because the treatment is difficult, and the magnetic toner using such surface-treated magnetic iron oxide has a characteristic of B /
This is because it is difficult to achieve A <0.001.

As ferrous sulfate used in the production of magnetic iron oxide, iron sulfate produced as a by-product in titanium production by the sulfuric acid method and iron sulfate produced as a result of cleaning the surface of a steel sheet can be used. It is also possible to use a ferrous salt such as iron chloride instead of ferrous sulfate. The method for producing magnetic iron oxide by the aqueous solution method generally prevents an increase in viscosity during the reaction, and
An iron concentration of 0.5 to 2 mol / liter is used in consideration of the solubility of iron sulfate. Generally, the thinner the concentration of iron sulfate, the finer the particle size of the product tends to be. In addition, in the reaction, the larger the amount of air and the lower the reaction temperature, the easier the atomization.

By using the hydrophobic magnetic iron oxide thus produced in the magnetic toner produced by the polymerization method, the black one-component magnetic developer of the present invention having excellent image characteristics and stability can be obtained. It will be possible.

Japanese Patent Publication No. 60-3181 also discloses a method for producing a magnetic polymerized toner containing magnetic fine particles whose surface is wet-treated with a silane coupling agent. However, Japanese Examined Patent Publication No. 60-3181 discloses only wet surface treatment of a dry powdery untreated magnetic material with a silane coupling agent. In such untreated dry magnetic particles, coalescence of the particles due to primary aggregation during drying cannot be avoided, so that even if wet surface treatment is performed, it is difficult to make individual magnetic particles uniform and hydrophobic. . Therefore, even if a polymerized toner is produced by using such a surface-treated magnetic material, B / A <which is a characteristic of the magnetic toner according to the present invention.
Achieving 0.001 is difficult.

Also, assuming that the diameter of the projected area of the magnetic toner is C, and the minimum value of the distance between the magnetic iron oxide and the surface of the magnetic toner particles in the cross-sectional observation of the magnetic toner using a transmission electron microscope (TEM). When D is set, the number of magnetic toners satisfying the relationship of D / C ≦ 0.02 is 50% or more, which is also one of the aspects necessary for the magnetic toner of the present invention.

In the present invention, the number of magnetic toners satisfying the relationship of D / C ≦ 0.02 needs to be 50% or more, preferably 65% or more, more preferably 75% or more.

When the number of magnetic toners satisfying the relationship of D / C ≦ 0.02 is less than 50%, magnetic oxidation is at least outside the boundary line of D / C = 0.02 in the majority of magnetic toners. There will be no iron particles at all. If such magnetic toner particles are assumed to be spherical, the space where magnetic iron oxide does not exist is at least 11.5 on the surface of the magnetic toner particles when one magnetic toner particle is the entire space.
% Will exist.

In practice, the magnetic iron oxide is not evenly arranged at the closest position to form the inner wall inside the magnetic toner, so that it is clear that the magnetic iron oxide content is 12% or more. In the magnetic toner composed of such magnetic toner particles, the various problems described above are likely to occur.

In the present invention, specific D by TEM
As a method for measuring / C, a cured product obtained by sufficiently dispersing magnetic toner particles to be observed in an epoxy resin that is curable at room temperature and then curing in an atmosphere of 40 ° C. for 2 days is used, or A method of freezing and observing as a flaky sample by a microtome equipped with diamond teeth is preferable.

The specific method of determining the proportion of the corresponding number of particles is as follows.

For the magnetic toner particles for determining D / C by TEM, the equivalent circle diameter is obtained from the cross-sectional area of the micrograph,
A magnetic toner particle having a value within a range of ± 10% of the number average particle diameter (D1) measured by a Coulter counter, which will be described later, is set as the corresponding magnetic toner particle, and the distance between the corresponding magnetic toner particle and the surface of the magnetic iron oxide particle. Minimum value (D)
Is measured and D / C is calculated.

The micrograph at this time is preferably 10,000 to 20,000 times in magnification in order to perform highly accurate measurement. In the present invention, a transmission electron microscope (H-600 manufactured by Hitachi) is used as an apparatus and observed at an accelerating voltage of 100 kV, and the magnification is 1
Observe and measure using a microscope image of 10,000 times.

B / A <0.001 is satisfied, and D / C ≦
The magnetic toner having the number of magnetic toners satisfying the relation of 0.02 is 50% or more means that the magnetic iron oxide is localized on the surface of the magnetic toner or, conversely, is extremely encapsulated. Rather than being a magnetic toner that is unevenly distributed inside, magnetic iron oxide is dispersed in the magnetic toner substantially uniformly, and exposure of magnetic iron oxide to the surface of the magnetic toner is suppressed. Toner. When the dispersed state of the magnetic iron oxide is non-uniform, it is difficult to satisfy the characteristics B / A <0.001 and D / C ≦ 0.02 of the magnetic toner of the present invention.

Even when an image forming method is used in which the magnetic toner is pressed against the surface of the image bearing member by a charging member, a transfer member or the like, by using the magnetic toner in which the magnetic iron oxide is hardly exposed on the surface of the magnetic toner particles. The surface of the image carrier is scarcely scraped, and it is possible to significantly reduce the scraping of the image carrier and the fusion of the magnetic toner over a long period of time. As described above, the magnetic iron oxide is hardly exposed on the surface of the magnetic toner particles, but in order to create a state in which the magnetic iron oxide is concentrated on the outermost surface layer of the magnetic toner particles, the surface of the magnetic iron oxide is subjected to a hydrophobic treatment. It is considered possible to prepare a magnetic toner satisfying the above relationship of D / C ≦ 0.02. When magnetic toner is produced by a polymerization method using magnetic iron oxide that has not been subjected to a hydrophobic treatment, it is easily exposed on the surface of the magnetic toner particles. While suppressing the exposure of magnetic iron oxide to the surface,
It is possible to concentrate the magnetic iron oxide on the outermost surface layer inside the magnetic toner particles.

The volume average particle diameter of the magnetic toner of the present invention is preferably 2 to 10 μm, more preferably 3.5 to 8 μm. By having a particle size in the above range, it becomes easier to have a more uniform charging characteristic, the charging start-up characteristic is also improved, and it is possible to rapidly charge up to a desired charge amount, whereby the non-image area is formed. The fogging in the image is remarkably improved, and the development efficiency is increased, so that a clearer and higher density image can be obtained. The magnetic iron oxide used in the magnetic toner of the present invention is 1 part with respect to 100 parts by mass of the binder resin.
It is preferable to use 0 to 200 parts by mass, more preferably 20 to 180 parts by mass. Mixing amount of magnetic iron oxide is 1
If it is less than 0 parts by mass, the coloring power of the developer is poor and it is difficult to suppress fog. On the other hand, if it is more than 200 parts by mass, the coercive force due to the magnetic force to the developer carrying member is increased and the developability is lowered. In addition to making it difficult to uniformly disperse the magnetic iron oxide in the magnetic toner particles, the fixing property is deteriorated.

Further, the magnetic iron oxide used in the toner of the present invention may contain elements such as phosphorus, cobalt, nickel, copper, magnesium, manganese, aluminum and silicon, and iron tetraoxide and γ-iron oxide are included. It is a main component, and these are used alone or in combination of two or more. These magnetic iron oxide is preferably a BET specific surface area by nitrogen adsorption method 2~30m ² / g, especially 3~28m ² /
g, and a Mohs hardness of 5 to 7 is preferable.

The shape of magnetic iron oxide includes octahedron, hexahedron, sphere, needle, scale, and the like, but those with less anisotropy such as octahedron, hexahedron, sphere, and amorphous are preferred. It is preferable for increasing the image density. Such a shape is S
It can be confirmed by EM or the like.

The particle size of magnetic iron oxide is 0.03 μm.
In the particle size measurement for particles having the above particle size, the volume average particle size is 0.1 to 0.3 μm, and the number of particles of 0.03 to 0.1 μm is 40% by number or less. Is preferred.

When an image is obtained from a magnetic toner using a magnetic iron oxide having a volume average particle diameter of less than 0.1 μm, the tint of the image shifts to reddish, the blackness of the image becomes insufficient, and a halftone image is obtained. In general, it is not preferable because the tendency to feel reddish color becomes stronger. Further, since the surface area of the magnetic iron oxide is increased, the dispersibility is reduced and the energy required for production is increased, which is not efficient. Further, the effect of the magnetic iron oxide as a coloring agent becomes weak and the density of the image may be insufficient, which is not preferable.

On the other hand, the volume average particle size of magnetic iron oxide is 0.3.
If the particle size exceeds μm, the mass per particle becomes large, so that there is a high possibility that the probability of being exposed on the toner surface will increase due to the difference in specific gravity with the binder resin component during manufacturing, and that the manufacturing equipment will wear out significantly. It is not preferable because it causes lumpiness and lowers the sedimentation stability of the dispersion.

When the number of particles of the magnetic iron oxide having a particle size of 0.1 μm or less exceeds 40% by number in the magnetic toner, the surface area of the magnetic iron oxide increases, the dispersibility decreases, and the particles aggregate in the magnetic toner. It is preferably 40% by number or less because lumps are likely to occur and the charging property of the magnetic toner is impaired, and the coloring power is likely to decrease. Furthermore, 30
If the number is less than or equal to%, the tendency becomes smaller, so
More preferable.

Magnetic iron oxide having a particle size of less than 0.03 μm has a small stress due to its small particle size during the production of the magnetic toner, and therefore has a low probability of appearing on the surface of the magnetic toner particles. Further, even if it is exposed on the surface of the particles, it hardly acts as a leak site, and there is practically no problem. Therefore, in the present invention, attention is paid to particles of 0.03 to 0.1 μm, and the number% thereof is defined.

Further, if the number of particles of 0.3 μm or more in the magnetic iron oxide exceeds 10% by number, the coloring power is lowered and the image density tends to be lowered. Since it is too small, it is stochastically difficult to exist near the surface of the magnetic toner particles and to contain a uniform number in each magnetic toner particle, which is not preferable. More preferably, it is 5% by number or less.

In the present invention, it is preferable to use the magnetic iron oxide production conditions set so as to satisfy the above-mentioned particle size distribution conditions, or those whose particle size distribution has been adjusted in advance such as pulverization and classification. . As the classification method, for example, a method using sedimentation separation such as centrifugation or thickener, or a means such as a wet classification apparatus using a cyclone is suitable.

The volume average particle size and particle size distribution of the magnetic iron oxide used in the black one-component magnetic developer are determined by the following measuring methods.

With the particles sufficiently dispersed, the projected area of each of 100 magnetic iron oxide particles in the visual field was measured by a transmission electron microscope (TEM) with a photograph at a magnification of 30,000. The equivalent diameter of a circle equal to the projected area of each particle thus obtained is determined as each particle diameter. Further, based on the result, the calculation of the volume average particle size, the particle size of 0.03 to 0.1 μm,
The number% of particles of 0.3 μm or larger is calculated. The particle size is measured for particles having a particle size of 0.03 μm or more. It is also possible to measure the particle size with an image analysis device.

The volume average particle size and particle size distribution of the magnetic iron oxide in the magnetic toner particles are determined by the following measuring method.

Magnetic toner particles to be observed were sufficiently dispersed in an epoxy resin and then cured in an atmosphere at a temperature of 40 ° C. for 2 days to obtain a cured product. The projected area of each of 100 magnetic iron oxides in the visual field was measured with a microscope (TEM) at a magnification of 10,000 to 40,000 times, and the equivalent diameter of a circle equal to the measured projected area of each particle was iron oxide. It is calculated as the particle size of. Furthermore, based on the result, 0.03 to 0.1
The number% of particles of μm and particles of 0.3 μm or more is calculated. It is also possible to measure the particle size with an image analysis device.

When the magnetic toner of the present invention is produced by the suspension polymerization method, magnetic iron oxide, a colorant, a releasing agent, a charge control agent, and
Components necessary for the toner such as a cross-linking agent and other additives, for example, an organic solvent, which is added to reduce the viscosity of the polymer produced in the polymerization reaction, a dispersant, etc. are appropriately added, and a homogenizer, ball mill, colloid mill, super The polymerizable monomer system uniformly dissolved or dispersed by a disperser such as a sonic disperser is suspended in an aqueous medium containing a dispersion stabilizer.
At this time, it is preferable to use a high-speed disperser such as a high-speed stirrer or an ultrasonic disperser to make the size of the desired magnetic toner particles at once because the particle size of the obtained magnetic toner particles becomes sharp. Regarding the timing of addition of the polymerization initiator, it may be added at the same time when other additives are added to the polymerizable monomer, or may be mixed immediately before being suspended in the aqueous medium. It is also possible to add a polymerization initiator dissolved in a polymerizable monomer or a solvent immediately after granulation and before starting the polymerization reaction.

After granulation, stirring may be carried out using an ordinary stirrer to such an extent that the particle state is maintained and the particles are prevented from floating and settling.

The following may be mentioned as the polymerizable monomer constituting the polymerizable monomer system used when the magnetic toner of the present invention is produced by the polymerization method.

Styrene-based monomers such as styrene, o-methylstyrene, m-methylstyrene, p-methylstyrene, p-methoxystyrene, p-ethylstyrene; methyl acrylate, ethyl acrylate, n-butyl acrylate. , Isobutyl acrylate, n-propyl acrylate,
Acrylic esters such as n-octyl acrylate, dodecyl acrylate, 2-ethylhexyl acrylate, stearyl acrylate, 2-chloroethyl acrylate, phenyl acrylate; methyl methacrylate, ethyl methacrylate, n-propyl methacrylate, Methacrylic acid n-
Methacrylic esters such as butyl, isobutyl methacrylate, n-octyl methacrylate, dodecyl methacrylate, 2-ethylhexyl methacrylate, stearyl methacrylate, phenyl methacrylate, dimethylaminoethyl methacrylate, diethylaminoethyl methacrylate; acrylonitrile, methacrylic acid. Examples include ronitrile and acrylamide.

These polymerizable monomers may be used alone or in combination. Among the above-mentioned polymerizable monomers, it is preferable to use styrene or a styrene derivative alone or in combination with other polymerizable monomers, from the viewpoint of developing characteristics and durability of the magnetic toner.

As the polymerization initiator used in the present invention, one having a half-life of 0.5 to 30 hours at the time of the polymerization reaction is used at an addition amount of 0.5 to 20% by mass of the polymerizable monomer. By doing so, a polymer having a maximum in the molecular weight of 10,000 to 100,000 can be obtained, and the magnetic toner can be provided with desired strength and appropriate melting characteristics.

As the polymerization initiator, 2,2'-azobis- (2,4-dimethylvaleronitrile), 2,2'-azobisisobutyronitrile and 1,1'-azobis (cyclohexane-1-carbonitrile) are used. Nitrile), 2,2'-azobis-4-methoxy-2,4-dimethylvaleronitrile,
Azo- or diazo-type polymerization initiators such as azobisisobutyronitrile; peroxides such as benzoyl peroxide, methyl ethyl ketone peroxide, diisopropyl peroxycarbonate, cumene hydroperoxide, 2,4-dichlorobenzoyl peroxide, lauroyl peroxide An oxide type polymerization initiator may be used.

In the method for producing the magnetic toner of the present invention by the suspension polymerization method, a crosslinking agent may be added, and the preferable addition amount is 0.001 to 15 mass% of the polymerizable monomer.

Further, in the suspension polymerization method for the magnetic toner of the present invention, a known surfactant such as a dispersion stabilizer or an organic / organic
Inorganic dispersants can be used, among which inorganic dispersants are less likely to produce harmful ultrafine powder, and because of their steric hindrance, dispersion stability is obtained, so stability is unlikely to collapse even when the reaction temperature is changed, and cleaning is easy. Since the magnetic toner is unlikely to be adversely affected, it can be preferably used.

Examples of such inorganic dispersants include polyvalent metal phosphates such as calcium phosphate, magnesium phosphate, aluminum phosphate and zinc phosphate; carbonates such as calcium carbonate and magnesium carbonate; calcium metasilicate, calcium sulfate and sulfuric acid. Inorganic salts such as barium; inorganic oxides such as calcium hydroxide, magnesium hydroxide, aluminum hydroxide, silica, bentonite and alumina. It is preferable to use 0.2 to 20 parts by mass of these inorganic dispersants alone or in combination of two or more with respect to 100 parts by mass of the polymerizable monomer.

For the purpose of producing a finer magnetic toner, 0.001 to 0.1 part by mass of a surfactant may be used in combination. Examples of the surfactant include sodium dodecylbenzene sulfate, sodium tetradecyl sulfate, sodium pentadecyl sulfate, sodium octyl sulfate, sodium oleate, sodium laurate, sodium stearate, potassium stearate and the like.

When these inorganic dispersants are used, they may be used as they are, but in order to obtain finer particles, the inorganic dispersant particles can be generated in an aqueous medium.

For example, in the case of calcium phosphate, a water-insoluble calcium phosphate can be produced by mixing an aqueous solution of sodium phosphate and an aqueous solution of calcium chloride under high-speed stirring, and more uniform and fine dispersion is possible. At this time, a water-soluble sodium chloride salt is by-produced at the same time, but when the water-soluble salt is present in the aqueous medium, the dissolution of the polymerizable monomer in water is suppressed, and the ultrafine toner particles due to emulsion polymerization are generated. It is more convenient because it is less likely to occur. Since it becomes an obstacle when removing the remaining polymerizable monomer at the end of the polymerization reaction, it is better to replace the aqueous medium or desalt with an ion exchange resin.
The inorganic dispersant can be removed almost completely by dissolving with an acid or an alkali after the completion of the polymerization.

In the polymerization step, the polymerization temperature is 40
Polymerization is carried out at a temperature of not less than 0 ° C, generally 50 to 90 ° C. When the polymerization is carried out within this temperature range, the release agent to be sealed inside is deposited by phase separation and the encapsulation becomes more complete. In order to consume the remaining polymerizable monomer, it is possible to raise the reaction temperature to 90 to 150 ° C. at the end of the polymerization reaction.

In the present invention, a resin may be added to the polymerizable monomer system for polymerization. For example, since a polymerizable monomer is water-soluble, it cannot be used because it dissolves in an aqueous suspension and causes emulsion polymerization, and thus cannot be used. For example, an amino group, a carboxylic acid group, a hydroxyl group, a sulfonic acid group, a glycidyl group, or a nitrile group. When it is desired to introduce a hydrophilic functional group-containing monomer component into a magnetic toner, a copolymer such as a random copolymer, a block copolymer, or a graft copolymer of these and a vinyl compound such as styrene or ethylene is used. It can be used in the form of a polycondensate such as polyester or polyamide, or a polyaddition polymer such as polyether or polyimine. When a high molecular polymer containing such a polar functional group is allowed to coexist in a magnetic toner,
It is possible to obtain a magnetic toner having excellent anti-offset property, anti-blocking property, and low-temperature fixability by causing the wax component to be phase-separated and becoming more strongly encapsulated.

The amount of the resin added to the polymerizable monomer system is preferably 1 to 20 parts by mass with respect to 100 parts by mass of the polymerizable monomer. If the amount used is less than 1 part by mass, the effect of addition is small, while if it exceeds 20 parts by mass,
It becomes difficult to design various physical properties of the magnetic toner.
The average molecular weight of the resin containing these polar functional groups is 300.
0 or more is preferably used. When the molecular weight is less than 3,000, especially 2,000 or less, the resin tends to concentrate near the surface, so that the developability, blocking resistance and the like are likely to be adversely affected, which is not preferable. Further, when a resin having a molecular weight different from the molecular weight range of the magnetic toner obtained by polymerizing the monomer is dissolved in the monomer and polymerized, a magnetic toner having a wide molecular weight distribution and high offset resistance can be obtained. Can be done.

In addition to magnetic iron oxide, other coloring agents may be used in combination with the magnetic toner. Examples of the coloring material that can be used in combination include magnetic or non-magnetic inorganic compounds, known dyes and pigments. Specifically, for example, ferromagnetic metal particles such as cobalt and nickel, or chromium, manganese, copper, zinc, aluminum, alloys in which a rare earth element is added to these, hematite, titanium black, nigrosine dye / pigment, carbon black, Examples include phthalocyanine.
These may also be used by treating the surface.

The magnetic toner according to the present invention is preferably mixed with an inorganic fine powder, particularly a hydrophobicized inorganic fine powder, as a fluidity improver. For example, titanium oxide fine powder,
It is preferable to add and use silica fine powder and alumina fine powder, and it is particularly preferable to use silica fine powder.

The inorganic fine powder used for the magnetic toner is B
The specific surface area by nitrogen adsorption measured by ET method is 30 m ² /
A substance having a weight of at least g, particularly a substance having a range of 50 to 400 m ² / g can give good results, and is therefore preferable.

The fine silica powder used in the present invention includes both so-called dry method produced by vapor phase oxidation of a silicon halogen compound or dry silica called fumed silica and so-called wet silica produced from water glass. However, dry silica, which has few silanol groups on the surface and inside and has no production residue, is preferably used.

Further, the fine silica powder used in the present invention is preferably one which has been subjected to a hydrophobic treatment. The hydrophobic treatment is applied by treating with an organic silicon compound or the like that reacts or physically adsorbs with the fine silica powder. As a preferred method, a method of treating dry silica fine powder produced by vapor phase oxidation of a silicon halogen compound with a silane coupling agent, or treating with a silane coupling agent and an organosilicon compound such as silicone oil at the same time Is mentioned.

Examples of the silane coupling agent used for the hydrophobic treatment include hexamethyldisilazane, trimethylsilane, trimethylchlorosilane, trimethylethoxysilane, dimethyldichlorosilane, methyltrichlorosilane, allyldimethylchlorosilane, allylphenyl. Dichlorosilane, benzyldimethylchlorosilane, bromomethyldimethylchlorosilane, α-chloroethyltrichlorosilane, β-chloroethyltrichlorosilane,
Chlormethyldimethylchlorosilane, triorganosilane mercaptan, trimethylsilylmercaptan, triorganosilylacrylate, vinyldimethylacetoxysilane, dimethylethoxysilane, dimethyldimethoxysilane, diphenyldiethoxysilane, hexamethyldisiloxane, 1,3-divinyltetramethyldimethyl Examples include siloxane and 1,3-diphenyltetramethyldisiloxane.

Examples of the organic silicon compound include silicone oil and the like. The preferred silicone oil has a viscosity of about 30 to 1,000 mm at 25 ° C.
² / s (cSt) is used, for example, dimethyl silicone oil, methylphenyl silicone oil, α-
Methylstyrene-modified silicone oil, chlorophenyl silicone oil, fluorine-modified silicone oil and the like are preferable.

As the method for treating the silicone oil, for example, silica fine powder treated with a silane coupling agent and silicone oil may be directly mixed by using a mixer such as a Henschel mixer. The method of injecting oil may also be used. Alternatively, it may be prepared by dissolving or dispersing silicone oil in an appropriate solvent, mixing the base silica fine powder, and removing the solvent.

If necessary, an external additive other than the fluidity improver may be added to the magnetic toner according to the present invention. For example, for the purpose of improving the cleaning property,
The primary particle size exceeds 30 nm (preferably the specific surface area is 5
0m less than ² / g) particles, more preferably a primary particle size of 5
0 nm or more (preferably specific surface area less than 30 m ² / g)
It is also one of the preferable forms to further add inorganic fine particles or organic fine particles having a spherical shape. For example, it is preferable to use spherical silica particles, spherical polymethylsilsesquioxane particles, and spherical resin particles.

Further other additives, for example, lubricant powder such as Teflon (registered trademark) powder, zinc stearate powder, polyvinylidene fluoride powder and the like; or polishing agent such as cerium oxide powder, silicon carbide powder and strontium titanate powder; caking Inhibitors; or conductivity imparting agents such as carbon black powder, zinc oxide powder, tin oxide powder; and organic fine particles and inorganic fine particles having opposite polarities can be added in a small amount as a developing property improver. These additives can also be used by hydrophobizing the surface thereof.

The above-mentioned external additive is preferably used in an amount of 0.1 to 5 parts by mass (preferably 0.1 to 3 parts by mass) per 100 parts by mass of the magnetic toner.

<2> Color Replenishment Developer and Color Two-Component Developer of the Present Invention Yellow color replenishment developer, magenta color replenishment developer and cyan color replenishment developer of the present invention The color replenishing developer is characterized by being contained in a mixing ratio of 2 to 50 parts by mass of the color non-magnetic toner to 1 part by mass of the carrier.

The color two-component developer used in the color image forming apparatus of the present invention is preferably contained in an amount of 11 to 12 parts by mass of carrier with respect to 1 part by mass of color non-magnetic toner. First, the color non-magnetic toner used in the color replenishing developer and the color two-component developer of the present invention will be described below.

The color non-magnetic toner for constituting the color two-component developer contains at least a binder resin for toner and a colorant.

As the colorant for the yellow, cyan, and magenta toners, which are color non-magnetic toners, dye-based colorants and pigment-based colorants may be used alone or in combination with dyes and pigments. . In particular, when a dye-based colorant is used, the color reproducibility of the primary color is dramatically improved, the color reproducibility of the secondary colors represented by red, green, and blue is improved, and the color reproduction range is expanded. Good light transmission is achieved also in the OHP image.

However, when the dye-based coloring agent is used alone, the weather resistance is poor and the color may disappear due to long-term storage. Therefore, when the dye-based coloring agent is used to enhance the color reproducibility, the hiding power is relatively high. It is desirable to use it in combination with a pigment colorant.

The above colorant is appropriately selected from the following group,
These may be used alone or in combination, but are not necessarily limited to these.

As the pigment-based colorant used as the yellow colorant, condensed azo compounds, isoindolinone compounds, anthraquinone compounds, azo metal complexes, methine compounds, compounds represented by allylamide compounds and the like are used. Specifically, C.I. I. Pigment Yellow 1
2, 13, 14, 15, 17, 62, 74, 83, 9
3, 94, 95, 109, 110, 111, 128, 1
29,147,168,180 etc. are used suitably.

Solvent Yellow 9, 17, 24, 31, 35, 58, 93, 10 is used as a dye-based coloring agent.
0, 102, 103, 105, 112, 162, 16
3, Disperse Yellow 3, 42, 64, 82, 16
0, 201 and the like are preferably used.

As the magenta colorant, pigment type colorants such as condensed azo compounds, diketorolopyrrole compounds, anthraquinones, quinacridone compounds, basic dye lake compounds, naphthol compounds, benzimidazole compounds, thioindigo compounds, perylene compounds, etc. Is used. Specifically, C.I. I. Pigment Red 2,
3, 5, 6, 7, 23, 48: 2, 48: 3, 48:
4, 57: 1, 81: 1, 122, 144, 146, 1
66, 169, 177, 184, 185, 202, 20
6, 220, 221, 254, Pigment Violet 19 and the like are particularly preferable.

As the dye-based coloring agent, condensed azo compounds, anthraquinone compounds and the like are used. Specifically, C.I. I. Disperse Violet 26, 31, C.I.
I. Disperse Red 4, 5, 60, 91, C.I. I.
Solvent Red 8, 49, 52, BASF Neo
penMagenta 525, Bayer Macr
OlexRED H and the like are particularly preferable.

As the cyan colorant used in the present invention, copper phthalocyanine compounds and their derivatives, anthraquinone compounds, basic dye lake compounds and the like can be used. Examples of pigment-based colorants include C.I. I. Pigment Blue 1, 7, 15, 15: 1, 15: 2, 15:
3, 15: 4, 60, 62, 66 and the like can be particularly preferably used.

Further, as the dye-based coloring agent, solvent blue 36, 63, 64, 67, 68, 70, 97, BA
NeopenCyan 742 manufactured by SF and Macrolex Blue3R manufactured by Bayer are particularly preferable.

In the case of a color toner, the colorant is selected from the viewpoints of hue angle, saturation, brightness, weather resistance, OHP transparency, and dispersibility in the toner. It is preferable to add 1 to 20 parts by mass to 100 parts by mass of the binder resin before use. When the amount added is less than the lower limit, the transparency is improved, but the coloring power tends to be extremely lowered, and thus it becomes impossible to obtain an image density that maintains a good visible image quality. Further, when the value exceeds the upper limit, the light transmittance tends to be remarkably reduced, so that OH
As a result, the color reproducibility of the projected image due to P is hindered, and fixing peeling occurs.

When the color nonmagnetic toner of the present invention is manufactured by a pulverization method, a known method can be used. As a known method, for example, a binder resin, a colorant, which will be described later,
In some cases, components necessary for color non-magnetic toner such as a release agent and a charge control agent and other additives are thoroughly mixed in a mixer such as a Henschel mixer or a ball mill, and then a heating roller, a kneader or an extruder. Melt kneading using such a heat kneader, cooling and solidifying, pulverizing, classifying, and if necessary surface treatment to obtain toner particles, and adding fine powder as an external additive as necessary. A color non-magnetic toner can be obtained by mixing them.
Either the classification or the surface treatment may be performed first. In terms of production efficiency, it is preferable to use a multi-division classifier in the classification step.

The binder resin used when the color non-magnetic toner of the present invention is manufactured by the pulverization method is a homopolymer of styrene such as polystyrene and polyvinyltoluene or a substitution product thereof; styrene-propylene copolymer, styrene-
Vinyltoluene copolymer, styrene-vinylnaphthalene copolymer, styrene-methyl acrylate copolymer, styrene-ethyl acrylate copolymer, styrene-butyl acrylate copolymer, styrene-octyl acrylate copolymer, Styrene-dimethylaminoethyl acrylate copolymer, styrene-methylmethacrylate copolymer, styrene-ethylmethacrylate copolymer, styrene-butylmethacrylate copolymer, styrene-dimethylaminoethylmethacrylate copolymer Copolymer, styrene-vinyl methyl ether copolymer, styrene-vinyl ethyl ether copolymer, styrene-vinyl methyl ketone copolymer, styrene-butadiene copolymer, styrene-isoprene copolymer, styrene-maleic acid copolymer , Styrene-maleic acid ester Styrene-based copolymers such as coalesce; polymethylmethacrylate, polybutylmethacrylate, polyvinyl acetate, polyethylene, polypropylene, polyvinyl butyral, silicone resin, polyester resin, polyamide resin, epoxy resin, polyacrylic acid resin, rosin, modified rosin, Tempel resin, phenol resin, aliphatic or alicyclic hydrocarbon resin, aromatic petroleum resin, paraffin wax, carnauba wax and the like can be used alone or in combination. In particular, styrene-based copolymers and polyester resins are preferable in terms of development characteristics, fixability and the like.

Like the magnetic toner, the above color non-magnetic toner preferably contains a release agent for the purpose of enhancing anti-offset property. Usually, the toner image is
In the transfer step, the toner image is transferred onto the transfer material, and then the toner image is fixed onto the transfer material by energy such as heat and pressure, so that a semi-permanent image is obtained. As a fixing method at this time, a heat roller type fixing is generally often used, and an extremely high-definition image can be obtained by using a toner having a volume average particle diameter of 10 μm or less. When a transfer material such as paper is used, it enters the gaps between the fibers of the paper, the heat reception from the heat fixing roller becomes insufficient, and low-temperature offset easily occurs. However, in the color non-magnetic toner of the present invention, by containing an appropriate amount of wax as a release agent, it is possible to prevent abrasion of the photoconductor while achieving both high resolution and offset resistance. Become.

The wax as a releasing agent usable in the color non-magnetic toner in the present invention is a petroleum wax such as paraffin wax, microcrystalline wax, petrolactam and its derivatives, montan wax and its derivatives, and carbonization by the Fischer-Tropsch method. Hydrogen wax and its derivatives, polyolefin wax represented by polyethylene and its derivatives, natural wax such as carnauba wax and candelilla wax and its derivatives are included. The derivatives here include oxides, block copolymers with vinyl monomers, and graft modified products. Further, higher aliphatic alcohols, fatty acids such as stearic acid and palmitic acid or compounds thereof, acid amide wax, ester wax, ketone, hydrogenated castor oil and its derivatives, plant wax and animal wax can also be used.

Among these waxes, the DSC curve measured by a differential scanning calorimeter showed 40 to 1 when the temperature was raised.
Those having a maximum endothermic peak in the region of 10 ° C are preferable,
Those having a maximum endothermic peak in the region of 45 to 90 ° C. are more preferable. By having the maximum endothermic peak in the above temperature range, releasability can be effectively exhibited while greatly contributing to low temperature fixing. This maximum endothermic peak is 40 ° C
If it is less than the above range, the self-cohesive force of the wax becomes weak, and as a result, the high temperature offset resistance deteriorates. On the other hand, if the maximum endothermic peak exceeds 110 ° C., the fixing temperature becomes high and low-temperature offset easily occurs, which is not preferable. Further, when granulating / polymerizing in an aqueous medium to directly obtain a toner by a polymerization method, if the maximum endothermic peak temperature is high, problems such as precipitation of a wax component mainly during granulation occur, which is not preferable.

The maximum endothermic peak temperature of wax is measured by
It is carried out according to "ASTM D 3418-8". For the measurement, for example, Perkin Elmer DSC-7 is used.
The melting point of indium and zinc is used to correct the temperature of the device detection unit, and the heat of fusion of indium is used to correct the amount of heat. An aluminum pan is used as a measurement sample, an empty pan is set as a control, and measurement is performed at a temperature rising rate of 10 ° C./min.

In the color non-magnetic toner of the present invention, the content of the wax is preferably in the range of 0.5 to 50 parts by mass with respect to 100 parts by mass of the binder resin.
If the wax content is less than 0.5 parts by mass, the low-temperature offset suppressing effect is poor, and if it exceeds 50 parts by mass, the long-term storability is deteriorated and the dispersibility of other toner materials is deteriorated. Fluidity and image characteristics.

A charge control agent may be added to the color non-magnetic toner in order to stabilize the charging characteristics. At that time, a colorless or pale color charge control agent that does not affect the color tone of the toner is preferable. In order to stabilize the charging characteristics of the negatively chargeable developer according to the present invention, a preferable colorless or light-colored negatively charge control agent is, for example, a metal complex of alkyl-substituted salicylic acid (for example, a chromium complex of di-tert-butylsalicylic acid or Examples thereof include organic metal complexes such as zinc complex). When the negative charge control agent is blended with the toner, it is added in an amount of 0.1 to 10 parts by mass, preferably 0.5 to 8 parts by mass, based on 100 parts by mass of the binder resin. For color non-magnetic toner,
The volume average particle diameter is preferably 3 to 10 μm.

The volume average particle diameter of the color non-magnetic toner is 10
When it is more than μm, the reproducibility of the fine dot image tends to be deteriorated, so that the charging stability of the color nonmagnetic toner under the severe environment obtained by the present invention cannot be sufficiently exhibited. On the other hand, when the volume average particle diameter of the color non-magnetic toner is smaller than 3 μm, the fluidity of the toner becomes extremely low, and problems such as fog and low density due to charging failure are likely to occur.

That is, the color non-magnetic toner of the present invention shows remarkable effects on the image as compared with the conventional example, such as improvement in charging stability and fluidity, when the volume average particle diameter is 2 to 2.
10 μm (more preferably 3 to 10 μm), and 3.5 to 8.0 μ in terms of further higher image quality.
m is preferred.

Like the magnetic toner, the color non-magnetic toner according to the present invention includes the above-mentioned inorganic fine powder or hydrophobized inorganic fine powder as the fluidity improving agent, and if necessary, other than the fluidity improving agent. External additives may be added.

Next, in order to obtain the yellow two-component developer, the magenta two-component developer, the cyan two-component developer and the color replenishing developer of the present invention, the color non-magnetic toner is mixed. The carrier particles used as described above will be described below.

The carrier particles used in the non-magnetic toner of the present invention are preferably magnetic particle-dispersed resin carrier particles containing at least inorganic compound particles and a binder resin.

The particle diameter of the magnetic particle-dispersed resin carrier particles is such that the volume average particle diameter (here, 50% particle diameter (D) based on volume) is preferably 15 to 60 μm, more preferably 25 to 50 μm. good. When the 50% particle diameter of the magnetic particle-dispersed resin carrier particles is less than 15 μm, the fluidity of the carrier particles is lowered, and fine powder is likely to be accumulated, so that uniform carrier particles may not be satisfactorily collected. . When the 50% particle diameter of the magnetic particle-dispersed resin carrier particles is larger than 60 μm, the denseness of the magnetic brush is likely to be impaired in the developing device of the two-component developing system, which may cause image unevenness. is there.

In order to obtain carrier particles having a particle size in a preferred range, the production is carried out by a polymerization method in which particles are produced from a solution in which a monomer and a solvent are uniform, and in the production,
This can be achieved by using, as the inorganic compound particles dispersed in the carrier core particles, those subjected to a lipophilic treatment.

In the present invention, a magnetic particle-dispersed resin cap is used.
The volume resistance value of the rear particles is 1 × 10 ⁸~ 1 x 10¹⁶Ω ・
cm is preferable, and more preferably 1 × 10⁹
~ 1 x 10¹⁵It is good that it is Ω · cm.

When the volume resistance value of the magnetic particle-dispersed resin carrier particles is less than 1 × 10 ⁸ Ω · cm, the carrier particles and the color non-magnetic toner in the replenishing developer are liable to be liberated, and quantitative replenishment is performed. Becomes difficult.

If the volume resistance value of the magnetic particle-dispersed resin carrier particles exceeds 1 × 10 ¹⁶ Ω · cm, a sharp edge-enhanced image is likely to be formed, and furthermore, the charge on the surface of the carrier particles becomes difficult to leak. Image density may be reduced due to the charge-up phenomenon, and fogging and scattering may occur due to non-uniform charging of newly replenished carrier particles and color non-magnetic toner. Further, the inner wall of the replenishing container may be electrically charged, and the color non-magnetic toner to be originally provided may have a non-uniform charge amount. In addition, image defects such as electrostatic attachment of external additives are likely to occur.

The volume resistance value of the magnetic particle-dispersed resin carrier particles is measured using a powder insulation resistance measuring instrument manufactured by Vacuum Riko Co., Ltd. The measurement conditions are as follows: carrier particles that have been left for 24 hours or more at 23 ° C. and 60% diameter 20 mm
(0.283 cm ² ) in a measuring cell, 120 g /
It is sandwiched between load electrodes of cm ^{2 and has} a thickness of 2 mm, and the applied voltage is measured at 500V.

The true specific gravity of the magnetic particle-dispersed resin carrier particles is preferably 2.5 to 4.5, more preferably 2.8 to 4.2. If the true specific gravity exceeds 4.5, the difference in specific gravity from the toner becomes large, it becomes difficult to stably collect the magnetic particle-dispersed resin carrier particles, and the apparatus tends to be complicated. On the other hand, when the true specific gravity is less than 2.5, carrier adhesion is likely to occur although it is related to the magnetic characteristics of the magnetic particle-dispersed resin carrier particles.

The magnetic characteristics of the magnetic particle-dispersed resin carrier particles are that the strength of magnetization at 1000 / 4π (kA / m) is
Preferably 20~65 (Am ² / kg), is it a good low magnetic force such as a more preferably 25~45 (Am ² / kg). When the magnetic particle-dispersed resin carrier particles have a magnetization intensity of more than 65 (Am ² / kg), which is related to the carrier particle size, stress in the developing device increases and carrier deterioration is promoted, which is for replenishment. Unless the amount of carrier particles in the developer is increased, durability deterioration of the developer is liable to occur particularly when copying or printing a large number of sheets.

When the magnetic particle-dispersed resin carrier particles have a magnetization intensity of less than 20 (Am ² / kg), the magnetic force of the carrier particles is lowered even if the carrier fine powder particles are removed, and carrier adhesion is likely to occur. If the amount of carrier in the developer for toner is not increased, the toner transporting property tends to decrease.

The residual magnetization (σr) of the magnetic particle-dispersed resin carrier particles is preferably 0.1 to ²⁰ Am ² / kg. When the residual magnetization exceeds 20 Am ² / kg, the fluidity of the magnetic particle-dispersed resin carrier particles deteriorates and the mixing property with the toner particles deteriorates. If it is less than 0.1 Am ² / kg, on the contrary, the fluidity is too good, and the replenished toner particles may be imperfectly mixed with the magnetic particle-dispersed resin carrier particles.

The magnetic characteristics of the magnetic particle-dispersed resin carrier particles are measured using an oscillating magnetic field type automatic recording apparatus for magnetic characteristics BHV-35 manufactured by Riken Denshi Co., Ltd. As the measurement conditions, the magnetic properties of the carrier powder particles are 1000 / 4π (k
An external magnetic field of (A / m) is generated, and the strength of magnetization at that time is obtained. The carrier particles are packed in a cylindrical plastic container so that the carrier particles are packed sufficiently tightly so that they do not move, and the magnetization moment is measured in this state.
The actual mass when the sample is put in is measured to determine the strength of magnetization (Am ² / kg).

Inorganic compound particles used in the magnetic particle-dispersed resin carrier particles in the present invention include metal compound particles such as magnetite or ferrite having magnetism represented by the following formula (III) or (IV). .

[0164]

Embedded image MO.Fe ₂ O ₃ (III) M.Fe ₂ O ₄ (IV) (In the formula, M represents a trivalent, divalent or monovalent metal ion.) The above formulas (III) and ( M in IV) is Mg, A
l, Si, Ca, Sc, Ti, V, Cr, Mn, Fe,
Co, Ni, Cu, Zn, Sr, Y, Zr, Nb, M
Examples thereof include o, Cd, Sn, Ba, Pb and Li, and these can be used alone or in combination.

Specific examples of the above-mentioned magnetic metal compound particles include magnetite and Zn--Fe.
Series ferrite, Mn-Zn-Fe series ferrite, Ni-
Zn-Fe ferrite, Mn-Mg-Fe system ferrite, Ca-Mn-Fe system ferrite, Ca-Mg-Fe
Series ferrite, Li-Fe series ferrite and Cu-Zn
Examples include iron-based oxides such as —Fe-based ferrite.

Further, as the inorganic compound fine particles used for the magnetic particle-dispersed resin carrier particles in the present invention, the above-mentioned magnetic metal compound particles and the following non-magnetic metal compound particles may be mixed and used.

As the non-magnetic metal compound, for example, Al
₂ O ₃ , SiO ₂ , CaO, TiO ₂ , V ₂ O ₅ , CrO, M
nO ₂ , α-Fe ₂ O ₃ , CoO, NiO, CuO, Zn
O, SrO, Y ₂ O ₃ and ZrO ₂ are mentioned. In this case, one kind of non-magnetic metal compound particles can be used, but it is particularly preferable to use at least two kinds of non-magnetic metal compound particles as a mixture. In that case, it is more preferable to use metal compound particles having a similar specific gravity and shape in order to improve the adhesion to the binder resin and the strength of the magnetic particle-dispersed resin carrier particles.

Specific examples of the combination include, for example, magnetite and hematite, magnetite and γ-Fe.
₂ O ₃ , magnetite and SiO ₂ , magnetite and Al ₂ O
₃ , magnetite and TiO ₂ , magnetite and Ca-Mn
-Fe ferrite, magnetite and Ca-Mg-Fe
A system ferrite can be preferably used. Among them, a combination of magnetite and hematite can be used particularly preferably. When the metal compound particles having magnetism described above are used alone or when mixed with non-magnetic metal compound particles, the number average particle size of the metal compound particles exhibiting magnetism is the same as that of the magnetic particle-dispersed resin carrier particles. Although it depends on the particle size, it is preferably 0.02 to 2 μm, more preferably 0.05 to 1 μm.

When the number average particle diameter of the metallic compound having magnetism is less than 0.02 μm, it is difficult to incorporate a large amount in the magnetic particle-dispersed resin carrier particles, and it becomes difficult to obtain preferable magnetic characteristics. When the number average particle diameter of the metal compound particles having magnetism exceeds 2 μm, the dispersion is likely to be non-uniform, and it becomes difficult to obtain the magnetic particle-dispersed resin carrier particles having a particle diameter in a preferable range with high strength.

When the metal compound particles having magnetism and the non-magnetic metal compound particles are mixed and used, the number average particle diameter of the non-magnetic metal compound particles is preferably 0.05 to 5 μm.
The particle size is more preferably 0.1 to 3 μm, and it is preferable that the particle size is larger than that of the metal compound particles having magnetism, because the preferred resistance can be easily obtained.

The number average particle diameter of the above metal compound particles is determined by using a photographic image magnified 5000 times to 20000 times by a transmission electron microscope H-800 manufactured by Hitachi Ltd. Image processing analysis device Luzex manufactured by Nicolet Co., Ltd. by extracting 300 or more particles
3, the Feret diameter in the horizontal direction is measured as the particle size of the metal oxide particles, and the number average particle size is calculated by averaging.

In the magnetic particle-dispersed resin carrier particles of the present invention, the content of the metal compound particles is preferably 80 to 9 relative to the magnetic particle-dispersed resin carrier particles.
It is preferably 9% by mass.

If the content of the metal compound particles is less than 80% by mass, the chargeability tends to be unstable, and the magnetic particle-dispersed resin carrier particles are charged, especially in a low temperature and low humidity environment, and the residual charge thereof is Since it easily remains, the fine powder toner and the external additive easily adhere to the surface of the magnetic particle-dispersed resin carrier particles, and an appropriate specific gravity cannot be obtained. When the content of the metal compound particles exceeds 99% by mass, the strength of the magnetic particle-dispersed resin carrier particles decreases, and problems such as carrier particle cracking due to durability tend to occur.

Further, as a preferred embodiment of the present invention, in the magnetic particle-dispersed resin carrier particles containing a mixture of magnetic metal compound particles and non-magnetic metal compound particles, the magnetic particles occupying the entire metal compound particles are contained. The content of the metal compound particles having a content of 50 to 95% by mass is preferable, and more preferably 60 to 95% by mass.

The binder resin of the magnetic particle-dispersed resin carrier particles used in the present invention is preferably a thermosetting resin, and further contains a partially or wholly three-dimensionally crosslinked resin, for example, a phenol resin. It is preferably a thermosetting resin. By using this resin, the dispersed metal compound particles can be firmly bound, so that the strength of the magnetic particle-dispersed resin carrier particles can be increased, and the detachment of the metal compound particles can be achieved even when copying a large number of sheets. Hard to get up. In the present invention, the magnetic particle-dispersed resin carrier particles preferably have a laminated structure in which the carrier core is covered with a resin layer.

The method for obtaining the magnetic particle-dispersed carrier core is not particularly limited to the method described below, but in the present invention, the monomer to be the binder resin, the metal compound particles and the solvent are used. By polymerizing the monomer in a solution that is uniformly dispersed or dissolved, a method for producing a polymerization method for forming a carrier core, particularly,
A method of obtaining a magnetic particle-dispersed resin carrier core having a sharp particle size distribution and a small amount of fine powder by subjecting the metal compound particles dispersed in the carrier core to a lipophilic treatment is preferably used.

As a monomer used for the binder resin of the carrier core, a radical polymerizable monomer can be used. For example, styrene; styrene derivatives such as o-methylstyrene, m-methylstyrene, p-methoxystyrene, p-ethylstyrene, p-tertiarybutylstyrene; acrylic acid, methyl acrylate, ethyl acrylate, n-butyl acrylate. , N-propyl acrylate,
Acrylic esters such as isobutyl acrylate, octyl acrylate, dodecyl acrylate, 2-ethylhexyl acrylate, stearyl acrylate, 2-chloroethyl acrylate, phenyl acrylate; methacrylic acid, methyl methacrylate, ethyl methacrylate, methacrylic acid n-propyl, n-butyl methacrylate, isobutyl methacrylate, n-octyl methacrylate, dodecyl methacrylate, 2-ethylhexyl methacrylate, stearyl methacrylate, phenyl methacrylate, dimethylaminomethyl methacrylate, diethylaminoethyl methacrylate, methacrylic acid Methacrylic acid esters such as benzyl acid ester; 2-hydroxyethyl acrylate, 2-hydroxyethyl methacrylate; acrylonitrile, methacrylonitrile, acetic acid Ruamido; methyl vinyl ether,
Ethyl vinyl ether, propyl vinyl ether, n-
Butyl ether, isobutyl ether, β-chloroethyl vinyl ether, phenyl vinyl ether, p-methylphenyl ether, p-chlorophenyl ether, p
-Bromphenyl ether, p-nitrophenyl vinyl ether, p-methoxyphenyl vinyl ether, and other vinyl ethers; and butadiene and other diene compounds.

These monomers can be used alone or as a mixture, and a suitable polymer composition can be selected so as to obtain preferable characteristics.

The most preferable binder resin is a phenol resin as a thermosetting resin. As the starting material,
Phenol, m-cresol, 3,5-xylenol,
p-alkylphenol, resorcil, p-tert-
Butylphenol and other phenolic compounds, formalin,
Examples thereof include aldehyde compounds such as paraformaldehyde and furfural. A combination of phenol and formalin is particularly preferable.

When using these phenolic resins, a basic catalyst can be used as a curing catalyst. As the basic catalyst, various kinds of catalysts commonly used in the production of resol resins can be used. Specifically, aqueous ammonia, hexamethylenetetramine, diethyltriamine,
Examples thereof include amines such as polyethyleneimine.

As described above, the metal compound particles contained in the carrier core are subjected to lipophilic treatment to sharpen the particle size distribution of the magnetic particle-dispersed resin carrier particles, and It is preferable for preventing the desorption of When forming the carrier core in which the lipophilicity-treated metal compound particles are dispersed, the polymerization reaction proceeds from the liquid in which the monomer and the solvent are uniformly dispersed or dissolved, and at the same time, the particles insolubilized in the solution are generated. At that time, it is considered that the metal compound particles have a function of being uniformly and densely incorporated inside the carrier core and a function of preventing aggregation of the carrier cores and sharpening the particle size distribution. Furthermore, when using metal compound particles subjected to lipophilic treatment,
It is not necessary to use a suspension stabilizer, and the suspension stabilizer remains on the surface of the carrier core to inhibit charging, nonuniformity of the coating resin when coating the carrier core, particularly reactivity of silicone resin, etc. It is possible to prevent reaction inhibition when coated with a resin. It also facilitates the absence of a suspension stabilizer on the surface and elimination of the harmful effects associated with it.

The lipophilic treatment is performed with an organic compound having one or more functional groups selected from an epoxy group, an amino group and a mercapto group, or a lipophilic treatment agent which is a mixture thereof. It is preferable that In particular, an epoxy group is preferably used in order to obtain carrier particles having a stable charge imparting ability according to the present invention.

The magnetic metal compound particles are preferably treated with 0.1 to 10 parts by mass, more preferably 0.2 to 6 parts by mass of the lipophilic treatment agent per 100 parts by mass of the magnetic metal compound particles. It is preferable for enhancing the lipophilicity and hydrophobicity of the magnetic metal compound particles. Further, when the non-magnetic metal compound particles are subjected to lipophilic treatment, it is 0.1 to 10 parts by mass, more preferably 0.2 parts by mass per 100 parts by mass of the non-magnetic metal compound particles.
It is preferable that the lipophilic treatment agent is up to 6 parts by mass.

Examples of the lipophilic treatment agent having an epoxy group include γ-glycidoxypropylmethyldiethoxysilane, γ-glycidoxypropyltrimethoxysilane and β
Examples thereof include-(3,4-epoxycyclohexyl) trimethoxysilane, epichlorohydrin, glycidol, and styrene-glycidyl methacrylate (meth) acrylate.

Examples of the lipophilic treatment agent having an amino group include γ-aminopropyltrimethoxysilane, γ-aminopropylmethoxydiethoxysilane, γ-aminopropyltriethoxysilane and N-β (aminoethyl)-
γ-aminopropyltrimethoxysilane, N-β (aminoethyl) -γ-aminopropylmethyldimethoxysilane, N-phenyl-γ-aminopropyltrimethoxysilane, ethylenediamine, ethylenetriamine, styrene-dimethylamino (meth) acrylate Ethyl copolymer and isopropyl tri (N-aminoethyl) titanate are used.

Examples of the lipophilic treatment agent having a mercapto group include mercaptoethanol, mercaptopropionic acid and γ-mercaptopropyltrimethoxysilane.

The resin used for the resin layer coating the surface of the carrier core is not particularly limited. Specifically, for example, polystyrene, acrylic resin such as styrene-acrylic copolymer, vinyl chloride, vinyl acetate, polyvinylidene fluoride resin, fluorocarbon resin, perfluorocarbon resin, solvent-soluble perfluorocarbon resin, polyvinyl alcohol, polyvinyl acetal, Polyvinylpyrrolidone, petroleum resin, cellulose, cellulose derivative, novolac resin, low molecular weight polyethylene, saturated alkyl polyester resin, aromatic polyester resin, polyamide resin, polyacetal resin, polycarbonate resin, polyether sulfone resin, polysulfone resin, polyphenylene sulfide resin, poly Ether ketone resin, phenol resin, modified phenol resin, malein resin, alkyd resin, epoxy resin, acrylic resin, anhydrous male Unsaturated polyester obtained by polycondensation of the terephthalic acid polyhydric alcohol, urea resins, melamine resins, urea - melamine resins, xylene resins, toluene resins, guanamine resins, melamine - guanamine resins, acetoguanamine resins, Guriputaru resin,
Furan resin, silicone resin, polyimide resin, polyamideimide resin, polyetherimide resin, polyurethane resin and the like can be mentioned.

Of these, fluorine-containing resins such as polyvinylidene fluoride resin, fluorocarbon resin, perfluorocarbon resin, solvent-soluble perfluorocarbon resin, and silicone resin are preferable because of their high releasability.

In the present invention, a silicone resin is particularly preferably used from the viewpoints of adhesion to the core, prevention of spent and film strength. Although the silicone resin can be used alone, it is preferably used in combination with a coupling agent in order to further increase the strength of the resin layer and control the charge to be preferable. Further, the coupling agent is preferably used as a so-called primer agent, in which a part of the coupling agent is treated on the surface of the carrier core before coating with the resin, and the subsequent resin layer is more closely attached with covalent bonds. It can be formed in a highly flexible state.

Aminosilane is preferably used as the coupling agent. As a result, an amino group having a positive charging property can be introduced on the surface of the carrier particles, and the toner can be favorably provided with the negative charging property. Further, the presence of the amino group activates both the lipophilic treatment agent which is preferably used for treating the metal compound particles and the silicone resin, so that the adhesion with the carrier core of the silicone resin is further increased, and at the same time, By promoting the curing of the resin layer, a stronger resin layer can be formed.

<3> Method for Measuring Various Physical Properties in the Present Invention The method for measuring various physical property data in the present invention will be described in detail below.

(1) The ratio of the iron element content (B) to the carbon element content (A) present on the toner surface (B /
A) Ratio (B / A) of iron element content (B) to carbon element content (A) present on the toner surface in the present invention
Is calculated by performing surface composition analysis by ESCA (X-ray photoelectron spectroscopy analysis). In the present invention, the ESCA device and measurement conditions are as follows. Equipment used: PHI (Physical Electronics Industrie)
s, Inc.) 1600S type X-ray photoelectron spectrometer Measurement conditions: X-ray source MgKα (400 W) Spectral region 800 μmφ In the present invention, from the measured peak intensity of each element, PH
The surface atomic concentration (atomic%) is calculated using the relative sensitivity factor provided by Company I.

A toner is used as a measurement sample, but when an external additive is added to the toner, the toner is washed with a solvent that does not dissolve the toner, such as isopropanol, to remove the external additive. The measurement will be performed later.

(2) Method of Measuring Circularity Distribution In the present invention, the circularity distribution particles having the equivalent circle diameter of the toner are as follows using a flow type particle image analyzer FPIA-1000 (manufactured by Toa Medical Electronics Co., Ltd.). To be measured. The toner particle shape is measured, and the circularity is calculated by the following formula (1). Further, as shown in the following formula (2), the value obtained by dividing the total sum of the measured circularity of all particles by the total number of particles is defined as the average circularity.

[0195]

[Equation 1] (In the formula, L ₀ represents the perimeter of a circle having the same projected area as the toner particle image, and L represents the perimeter of the projected image of the toner particles.)

[0196]

[Equation 2]

The measuring device "FPIA-1000" used in the present invention calculates the circularity of each toner particle, and then calculates the average circularity. 0.400 to 1.000 at 0.010 intervals, 0.400 or more and less than 0.410,
0.410 or more and less than 0.420 ... Dividing into 61 divided areas such as 0.990 to less than 1.000 and 1.000, and calculating the average circularity using the center value and frequency of the dividing points. The calculation method used is used.

The error between each value of the average circularity calculated by this calculation method and each value of the average circularity calculated by the above-mentioned calculation formula that directly uses the circularity of each particle is very small and substantially Therefore, in the present invention, a calculation formula that directly uses the circularity of each particle described above is used in the present invention for the reason of handling data such as shortening of calculation time and simplification of calculation calculation formula. The concept is used and a partially modified calculation method like this is used.

The circularity in the present invention is an index showing the degree of unevenness of the toner particles, and shows 1.000 when the toner particles are completely spherical, and the more complicated the surface shape, the more
The circularity has a small value.

As a concrete measuring method of the circularity, 10 m of water in which about 0.1 mg of a nonionic surfactant is dissolved.
Approximately 5 mg of the toner is dispersed in 1 to prepare a dispersion liquid, and the dispersion liquid is irradiated with ultrasonic waves (20 kHz, 50 W) for 5 minutes, and the dispersion liquid concentration is set to 5000 to 20000 particles / μl. The circularity distribution of particles having a circle equivalent diameter of 3 μm or more is measured.

The outline of the measurement is described in the catalog of FPIA-1000 issued by Toa Medical Electronics Co., Ltd. (June 1995 version), the operation manual of the measuring device and JP-A-8-136.
It is described in Japanese Patent No. 439, but is as follows.

The sample dispersion liquid is passed through the flow passage (which spreads along the flow direction) of a flat and flat transparent flow cell (thickness: about 200 μm). A strobe and a CCD camera are mounted on opposite sides of the flow cell so as to form an optical path that intersects and passes through the thickness of the flow cell. While the sample dispersion is flowing, stroboscopic light is irradiated at 1/30 second intervals to obtain an image of the toner particles flowing in the flow cell, so that each toner particle occupies a certain area parallel to the flow cell. The two-dimensional image is captured. From the two-dimensional image area of each particle, the diameter of a circle having the same area is calculated as the equivalent circle diameter. 2 of each toner particle
The circularity of each particle is calculated from the three-dimensional image projected area and the projected image perimeter using the above circularity calculation formula.

(3) Method for Measuring Toner Particle Size The average particle size and particle size distribution of toner can be measured by various methods such as Coulter Counter TA-II type or Coulter Multisizer (manufactured by Coulter Co.). Is a Coulter Multisizer (manufactured by Coulter)
The method using is used. An interface (manufactured by Nikkaki Co., Ltd.) that outputs a number distribution and a volume distribution is connected to a PC9801 personal computer (manufactured by NEC), and a 1% NaCl aqueous solution is prepared using primary sodium chloride as an electrolytic solution. For example, ISOTON R-II (manufactured by Coulter Scientific Japan Co.) can be used.

As the measuring method, the above-mentioned electrolytic aqueous solution 100 was used.
Add a surface active agent as a dispersant, preferably 0.1 to 5 ml of alkylbenzene sulfonate, to ~ 150 ml,
Further, 2 to 20 mg of the measurement sample is added. The electrolytic solution in which the sample is suspended is subjected to a dispersion treatment for about 1 to 3 minutes by an ultrasonic disperser, and the volume and number of the toner is measured by using a 100 μm aperture as an aperture by the Coulter Multisizer and particles of 2 to 40 μm are measured. Calculate the volume distribution and number distribution of. Then, the number average particle diameter (D1) obtained from the number distribution, the volume-based volume average particle diameter obtained from the volume distribution (D4: the median value of each channel is a representative value for each channel), and the volume obtained from the volume distribution Standard 12.7 μm
The above volume distribution is obtained.

(4) Method of measuring specific surface area The specific surface area is measured according to the BET formula in ASTM method D3037-78. That is, a mixed gas of N ₂ and He is caused to flow through carbon black to adsorb N ₂ , the amount thereof is detected by a thermal conductivity cell, and the specific surface area of the sample is calculated from the N ₂ adsorption amount. 1) The sample is dried at 105 ° C. for 1 hour, then 0.1 to 1 g is precisely weighed, put in a U-shaped officer and attached to the flow path. 2) Change the N ₂ / He mixture ratio by the flow rate controller and set it to a predetermined P / P 0. After introducing suction gas into the sample layer open the stopcock, to adsorb the N ₂ is immersed a U officer liquid N _2. After reaching the adsorption equilibrium, the liquid N ₂ was removed and exposed to the air for 30 seconds, and then the U-shaped member was immersed in water at room temperature for N ₂
Desorption. Draw the desorption curve on the recorder and measure the area. Using a calibration curve prepared by introducing a known amount of N ₂ prior to these operations, the N ₂ adsorption amount at a predetermined P / P 0 is determined from the area obtained for the above sample.

Below, the surface area is obtained by applying the following equation (3).

[0207]

## EQU00003 ## P / .nu. (P0-P) = 1 / .nu.mC + C-1 / .nu.mC.P / P0 (3) (where P0 is the saturated vapor pressure of the adsorbate at the measurement temperature,
P: pressure at adsorption equilibrium, ν: amount of adsorption at adsorption equilibrium, C: constant. )

The relationship between P / P0 and P / v (P0-P) is a straight line, and vm is obtained from the slope and intercept. νm
If is obtained, the specific surface area S is calculated by the following equation (4).

[0209]

## EQU4 ## S = A × νm × N × W (4) (In the formula, S: specific surface area, A: cross-sectional area of adsorbed molecule, N: Avogadro's number, and W: sample amount.)

(5) Measuring method of particle size of magnetic particle-dispersed resin carrier The average particle size and particle size distribution of the magnetic particle-dispersed resin carrier are measured by a laser diffraction particle size distribution measuring device HELOS (manufactured by JEOL Ltd.) in a dry dispersion unit RODOS. (Made by JEOL)
When used in combination, the lens focal length is 200 mm, the dispersion pressure (feed air pressure) is 3.0 bar, and the suction pressure is 0.1.
particle diameter 0.5 μm under the measurement conditions of bar and measurement time of 1 to 2 seconds
-350.0 μm range is divided into 31 channels for measurement, and 50% particle size (median size) of volume distribution is obtained as an average particle size, and volume% of particles in each particle size range is calculated from a volume-based frequency distribution. Ask for.

The laser diffraction type particle size distribution measuring device HELOS used for measuring the particle size distribution is a device for performing measurement using the Franhofer diffraction principle. The measurement principle will be briefly described. The particle size distribution of the measurement particles is calculated by forming the diffraction pattern on the lens focal plane on the opposite side of the laser light source and detecting the diffraction image by a detector.

<4> Color Image Forming Apparatus of the Present Invention Next, the color color replenishing developer of the present invention, the black one-component magnetic developer of the present invention and the color two-component developer of the present invention can be used. A color image forming apparatus including a developing device that forms and develops a visible image will be described.

The color image forming apparatus of the present invention uses a color two-component developer containing 1 to 12 parts by mass of carrier with respect to 1 part by mass of color non-magnetic toner to obtain a color image. As a replenishing developer, a color two-component developer can be used without being affected by the environment by using a compounding ratio of 2 to 50 parts by mass of a color non-magnetic toner to 1 part by mass of a carrier. The chargeability of is stable, and good image quality can be obtained for a long period of time.

FIG. 1 is a schematic block diagram of one embodiment of an electrophotographic full-color image forming apparatus equipped with a one-drum type rotary rotating type developing device 13.

First, the surface of the image carrier 1 is uniformly charged with the negative polarity by the charging device 15. Next, the exposure device 14 performs image exposure corresponding to the first color, for example, a yellow image, and an electrostatic latent image corresponding to the yellow image is formed on the surface of the image carrier 1.

The developing device 13 is of a rotational movement type, and the yellow developing device faces the image carrier 1 before the tip of the electrostatic latent image corresponding to the yellow image reaches the developing position, and then The magnetic brush rubs the electrostatic latent image to form a yellow toner image on the image carrier 1.

The developing device 13 used for the above-mentioned development is equipped with a developing device for each color. For example, as shown in FIG. 2, the developing device for a yellow two-component developer is provided with a developing sleeve 6, a magnet roller 8, a regulating member 7, developer conveying screws 10 and 11, a scraper 39, and the like. FIG. 2 shows the developing units 2, 3, 4 and 5 of FIG.
2 is a schematic configuration diagram of an apparatus used as a color developing device in FIG. Taking a yellow two-component developer as an example, the flow of conveyance until the yellow two-component developer in the developing device is developed will be described with reference to FIG.

The developing sleeve 6 contains the fixed magnet roller 8 therein, and is driven and rotated while maintaining a predetermined developing interval with the peripheral surface of the image carrier 1. The developing sleeve 6 and the image carrier 1 may be in contact with each other. The regulating member 7 has rigidity and magnetism, and keeps a predetermined space between the developing sleeve 6 and the object which is pressed against the developing sleeve 6 with a predetermined load without a two-component developer of yellow color. There are various things such as things to be distributed. Pair of screws 1
Nos. 0 and 11 are objects having a screw structure, in which the developer is conveyed and circulated in the opposite directions to sufficiently agitate and mix the yellow non-magnetic toner and carrier particles, and then the developer is sent to the developing sleeve 6. The magnet roller 8 is, for example,
A repulsive magnetic field is formed at a part that is in contact with a scraper or an object composed of four pole magnets of equal magnetic force in which N poles and S poles are alternately arranged at equal intervals, and peels off the yellow two-component developer. For ease of description, one pole may be omitted to make five poles, and the development sleeve 6 may be encapsulated in a fixed state.

The two developer conveying screws 10 and 1
Reference numeral 1 denotes a member that also functions as a stirring member that rotates in mutually opposite directions. The member 1 conveys the yellow color replenishment developer replenished from the yellow color replenishment developer accommodating device 9 by the thrust of the screw, and also the yellow non-magnetic material. By the mixing action of the toner and the carrier particles, a triboelectrically homogeneous two-component developer is obtained, and the yellow two-component developer is attached in layers on the peripheral surface of the developing sleeve 6. The yellow two-component developer on the surface of the developing sleeve 6 forms a uniform layer by the double-structure regulating member 7 made of a non-magnetic material and a magnetic material, which is provided so as to face the magnetic poles of the magnet roller 8. The uniformly formed yellow two-component developer layer develops the electrostatic latent image on the peripheral surface of the image carrier 1 in the developing area to form a yellow toner image.

In FIG. 1, the transfer material 12 such as paper or a transparent sheet is conveyed from the paper feed tray 26 or 27 by the delivery roller 28 or 29, and its front end is once blocked by the registration roller 25. After that, it is sent to the transfer drum 24 at a predetermined timing. The transferred transfer material 12 is electrostatically held on the transfer drum 24 by the suction device 32 and the counter roller 30, and is conveyed to a transfer area where the transfer drum 24 and the image carrier 1 face each other. Therefore, the transfer material comes into close contact with the yellow toner image on the image carrier 1 and the yellow toner image is transferred by the transfer device 31.
2 is transferred onto the transfer drum 24, and the transfer drum 24 is prepared for the next step while holding the transfer material 12.

Image carrier 1 after transfer of yellow toner
After that, after performing a cleaning pretreatment as required, the static electricity is removed by the static elimination corotron, and the cleaning device 1
The yellow toner remaining on the surface is scraped off by 8, and the charge remaining on the surface is removed by the charge removing device 16.

Next, for the image forming process of the second color, for example, magenta, the surface of the image carrier 1 is uniformly charged to the negative polarity by the charging device 15, and the laser exposure device 14 magenta. Image exposure corresponding to the image is made,
An electrostatic latent image corresponding to a magenta image is formed on the surface of the image carrier 1. Further, in the developing device 13, after the formation of the yellow toner image is completed, the developing device for the magenta two-component developer is switched so as to face the image carrier 1 and corresponds to the magenta image. The electrostatic latent image is developed with a magenta magnetic brush. Then, the transfer material held on the transfer drum is conveyed again to the transfer area, and by the action of the transfer device 31, the magenta toner is multi-transferred onto the yellow toner this time.

Image carrier 1 after transfer of magenta toner
After that, in the same manner as the yellow image forming step, the residual toner on the surface is cleaned and the residual charge is removed, while the transfer material after the transfer of the magenta toner is
While being held on the transfer drum 24, it is ready for the next step.

Thereafter, similarly to the magenta image forming step, an image forming step for the third color, for example, cyan is performed, and finally an image forming step for the fourth color, for example, black is performed. In the final black image forming step, the transfer material is conveyed differently from the steps up to the third color. That is, the transfer material that has finished the transfer of the fourth color is the static eliminator 19 and the conveyance guide member 2.
A separation finger (not shown) at the tip of 0 separates the transfer drum 24 from the transfer drum 24, and the fixing device 21 transfers the multi-toner image to a transfer material, and then carries the transfer toner out of the image forming apparatus.

As a developing device for forming a black toner image using a black one-component magnetic developer, a developing device for a normal one-component developer used in a rotary rotation system can be used.

Further, the transfer drum 24 which has completed the separation of the transfer material
After the surface thereof is destaticized by the destaticizing devices 22 and 33, the cleaning device 23 performs surface cleaning and waits for the next supply of the transfer material 12.

When the copying operation as described above is repeated, the color non-magnetic toner in the two-component developer for color colors stored in the developing tank 17 in the developing device of FIG. Ratio of color non-magnetic toner to particles,
That is, the toner density decreases. This change in toner concentration is feedback-controlled by a toner concentration sensor (not shown) provided in the developing tank 17 so that the toner concentration always falls within an appropriate range required for development. By the above control, the replenishment developer is supplied to the developing tank 17 in the developing device from the replenishment port of the color color replenishment developer replenishment section (color color replenishment developer accommodating device 9).

On the other hand, the carrier particles in the two-component developer in the developing tank 17 are not consumed by the development and are stirred together with the color non-magnetic toner in the developing tank 17,
Due to the influence of the magnetic force of the magnet roller and the contact with the image carrier 1, the surface is gradually contaminated and deteriorates. When the carrier particles deteriorate in this way, it becomes impossible to impart a predetermined charge amount to the color non-magnetic toner, resulting in deterioration of image quality. Therefore, it is necessary to replace the deteriorated carrier particles which are not consumed in the developing device with new carrier particles.

In FIG. 1, as means for replenishing the developing device with new carrier particles, a toner cartridge for replenishing the color non-magnetic toner consumed by the development (color replenishment developer accommodating device 9) ) Is filled with a non-magnetic toner for replenishment and a predetermined amount of the carrier particles mixed in a fixed ratio, and a replenishing developer for color color is put in the replenishing port of the replenishing developer accommodating device 9 for color color. Replenish each color toner developing device. The excessive developer is discharged from the developer discharge port on the developing device side as described below.

Replacement of the two-component developer by utilizing the rotational movement in the rotationally-moving developing device 13 shown in FIG. 1 will be described with reference to FIGS. 3 and 4. In a color image forming apparatus having a developing device 13 adopting a rotational movement system, the developing devices 2, 3, 4 and 5 are rotationally moved inside the developing device 13 and face the image carrier 1 during development. The image bearing member 1 is rotated and moved to a position for developing, and when not developing, it is rotated to a position not facing the image carrier 1.

At the position where the developing device 2 faces the image carrier 1 and is performing the developing operation, the developer overflowing from the developing device side developer discharge port 34 provided in the developing device 2 is connected by the rotating operation. It moves in the pipe 36 and is discharged from the developer recovery port 35 provided on the rotation center shaft of the rotary rotation type developing device.

As a method of developing a two-component developer using the carrier particles of the present invention, specifically, an AC voltage is applied to the developer carrying member to form an alternating electric field in the developing region while a magnetic brush is used. It is preferable to carry out the development in a state where the toner is in contact with the image carrier (photosensitive drum) 1. Distance between developer carrying member (developing sleeve) 6 and photosensitive drum 1 (distance between SD)
Is preferably 100 to 1000 μm in terms of preventing carrier particle adhesion and improving dot reproducibility. 10
If it is narrower than 0 μm, the supply of the developer is likely to be insufficient and the image density is lowered, and if it exceeds 1000 μm, the magnetic force lines from the magnetic pole S ₁ are expanded and the density of the magnetic brush is lowered, resulting in poor dot reproducibility and poor carrier particles. The restraining force is weakened and carrier particles are easily attached.

The voltage between the peaks of the alternating electric field is 300 to 30.
00V is preferable, the frequency is 500 to 10000 Hz,
The frequency is preferably 1000 to 7000 Hz, and can be appropriately selected and used depending on the process. In this case, examples of the waveform of the AC bias for forming the alternating electric field include a triangular wave, a rectangular wave, a sine wave, and a waveform in which the duty ratio is changed. At times, in order to cope with changes in the toner image forming speed, it is preferable to apply a developing bias voltage (intermittent alternating superposition voltage) having a discontinuous AC bias voltage to the developing sleeve to perform development. Applied voltage is 300
If it is lower than V, it may be difficult to obtain a sufficient image density, and it may not be possible to satisfactorily collect the fog toner in the non-image area. On the other hand, if the voltage exceeds 3000 V, the electrostatic latent image may be disturbed via the magnetic brush, and the image quality may be deteriorated.

By using a two-component developer having a well-charged non-magnetic toner, the fog removal voltage (Vbac
k) can be lowered and the primary charging of the photosensitive drum can be reduced, so that the life of the photosensitive drum can be extended. V
The back is preferably 200 V or less, more preferably 150 V or less, though it depends on the developing system. As the contrast potential, 100 to 400 V is preferably used so that a sufficient image density can be obtained.

Further, if the frequency is lower than 500 Hz, it depends on the process speed, but when the toner contacting the image bearing member is returned to the developing sleeve, sufficient vibration is not given and fogging is apt to occur. If the frequency exceeds 10000 Hz, the toner cannot follow the electric field and the image quality is apt to deteriorate.

What is important in the two-component developing method of the present invention is that the magnetic brush on the developing sleeve 11 is exposed to light so that sufficient image density can be obtained, dot reproducibility is excellent, and carrier particles do not adhere. The contact width with the drum 1 (developing contact portion) is preferably 3 to 8 mm. If the development contact area is narrower than 3 mm, it is difficult to satisfactorily satisfy the sufficient image density and dot reproducibility, and if it is wider than 8 mm, the packing of the developer occurs and the operation of the machine is stopped. It becomes difficult to suppress particle adhesion sufficiently. As a method of adjusting the developing contact portion, the contact width can be adjusted by adjusting the distance between the regulating member 7 and the developing sleeve 6 or the distance between the developing sleeve 6 and the photosensitive drum 1 (SD distance). Can be adjusted appropriately.

The constitution of the photosensitive drum may be the same as that of the photosensitive drum normally used in the image forming apparatus.
A photosensitive drum having a structure in which a conductive layer, an undercoat layer, a charge generation layer, a charge transport layer, and a charge injection layer, if necessary, are provided in this order on a conductive substrate such as aluminum or SUS is given.

The conductive layer, the undercoat layer, the charge generation layer and the charge transport layer may be those usually used for a photosensitive drum.

As the outermost surface layer of the photosensitive drum, for example, a charge injection layer or a protective layer may be used.

Further, in addition to the improvement in the initial image quality, the use of the replenishing developer of the present invention reduces the share of the developer in the developing device, and the color to the carrier particles can be obtained even when copying a large number of sheets. The spent of the non-magnetic toner or the external additive is suppressed, and the effect of the present invention that the deterioration of the image quality is small can be sufficiently exhibited even if the amount of the carrier particles to be replenished is small.

Examples of the charging device 15 in the color image forming apparatus of the present invention include a magnetic brush charging device in which a magnetic charging brush made of magnetic particles is formed on the surface of the conveying sleeve by the magnetic force of the magnet roller. The magnetic brush charging device is brought into contact with the surface of the photosensitive drum to charge the photosensitive drum.

The regulating member 7 for regulating the amount of developer on the developing sleeve is arranged below the developing sleeve, and the distance between the end portion and the developing sleeve surface is 150 to 800 μm, preferably 250 to 700 μm. This distance is 150 μm
When the particle size is smaller, carrier particles are aggregated and clogged during this time to easily cause unevenness in the developer layer, and it is difficult to apply the developer necessary for good development, and a developed image with thin density and unevenness is formed. easy. This distance is preferably 150 μm or more in order to prevent uneven coating (so-called blade clogging) due to unnecessary particles mixed in the developer. 800
If it is larger than .mu.m, the amount of the developer applied on the developing sleeve increases, and it is difficult to regulate the predetermined developer layer thickness, the magnetic carrier particles adhere to the photosensitive drum more, and the developer circulation and regulating member 7 As a result, the regulation of development is weakened, the toner tribo is reduced, and fogging is likely to occur. FIG. 5 is a schematic view of another form of the full-color image forming apparatus of the present invention. Also, FIG.
In the full-color image forming apparatus, the tandem system in which the image formation of each color is performed by using the photosensitive drum for each color is used.

Further, there is no independent cleaning means for collecting and storing the transfer residual toner remaining on the photosensitive drum, and the toner remaining on the photosensitive drum after the developing means transfers the toner image onto the transfer material is removed. The simultaneous developing and cleaning method for collecting is carried out, and it is also a preferable mode to use the simultaneous cleaning and developing method in the color image forming apparatus of the present invention.

The carrier particles increased by the carrier particles contained in the replenishment developer overflow the capacity UP, are taken into the developer recovery auger, and are conveyed to the replenishment developer accommodating device or another recovery container. . The main body of the full-color image forming apparatus shown in FIG. 5 is provided with a first image forming unit Pa, a second image forming unit Pb, a third image forming unit Pc, and a fourth image forming unit Pd, each of which has an image of a different color. Are formed on the transfer material through the processes of electrostatic latent image formation, development, and transfer.

The construction of each image forming unit provided in the image forming apparatus will be described by taking the first image forming unit Pa as an example.

The first image forming unit Pa includes a photosensitive drum 61a having a diameter of 30.6 mm as an image carrier, and the photosensitive drum 61a is rotationally moved in the direction of arrow a. The primary charger 62a as a charging means has a diameter of 16 m.
The magnetic brush charging device is arranged such that the charging magnetic brush formed on the surface of the sleeve m is in contact with the surface of the photoconductor 61a. The laser light 67a is supplied to the primary charger 6
Photosensitive drum 61 whose surface is uniformly charged by 2a
It is irradiated by an exposure device (not shown) to form an electrostatic latent image on a. The developing device 63a as a developing unit for developing the electrostatic latent image carried on the photosensitive drum 61a to form a color toner image holds the color toner.

The transfer blade 64a as the transfer means is
The color toner image formed on the surface of the photosensitive drum 61a is transferred onto the surface of the transfer material (recording material) conveyed by the belt-shaped transfer material carrier 68. This transfer blade 64
Reference numeral a is an object that can be applied to the transfer bias by contacting the back surface of the transfer material carrier 68.

In the first image forming unit Pa, after the photosensitive drum 61a is uniformly and primarily charged by the primary charger 62a, an electrostatic latent image is formed on the photosensitive drum by the exposure device 67a and the electrostatic latent image is generated by the developing device 63a. An image is developed using color toner, and the developed toner image is conveyed by a belt-shaped transfer material carrier 68 that carries and conveys the transfer material at the first transfer portion (contact position between the photoconductor and the transfer material). Transfer is applied to the surface of the transfer material by applying a transfer bias from the transfer blade 64a that is in contact with the back surface side.

When the color non-magnetic toner is consumed by the development and the color non-magnetic toner / carrier particle (T / C) ratio decreases, the decrease is utilized by utilizing the inductance of the coil to change the magnetic permeability of the two-component developer. Is detected by the toner concentration detection sensor 85, and the replenishment developer is replenished from the replenishment developer accommodating device 65a according to the amount of the consumed color non-magnetic toner. The toner concentration detection sensor 85
Has a coil (not shown) inside.

This image forming apparatus has the same structure as the first image forming unit Pa, and has the second image forming unit Pb, the third image forming unit Pc, and the third image forming unit Pc in which the colors of the color toners held in the developing device are different. The fourth image forming unit Pd is provided with four image forming units. For example,
A yellow toner is used for the first image forming unit Pa, a magenta toner is used for the second image forming unit Pb, a cyan toner is used for the third image forming unit Pc, and a black toner is used for the fourth image forming unit Pd. Transfer of each color toner onto the transfer material is sequentially performed at the transfer portion of the forming unit. In this step, while matching the registration, the color toners are superposed on the same transfer material by one movement of the transfer material, and when completed, the transfer material is separated from the transfer material carrier 68 by the separation charger 69. Then, it is sent to the fixing device 70 by a carrying means such as a carrying belt, and the final full-color image is obtained by only one fixing.

For the black image forming unit, a one-component magnetic developing method using a one-component developer is used.

The fixing device 70 includes, for example, a pair of diameters 40.
mm fixing roller 71 and 32 mm diameter pressure roller 72
The fixing roller 71 has a heating means 75 and 7 inside.
Have six.

The unfixed color toner image transferred onto the transfer material passes through the pressure contact portion between the fixing roller 71 and the pressure roller 72 of the fixing device 70, and is subjected to the action of heat and pressure on the transfer material. Is fixed in.

In FIG. 5, the transfer material carrier 68 is an endless belt-shaped member, and this belt-shaped member is moved by the drive roller 80 in the direction of arrow e. other,
Transfer belt cleaning device 79, belt driven roller 8
1. A pair of registration rollers 8 having a belt static eliminator 82
Reference numeral 3 is a member for conveying the transfer material in the transfer material holder to the transfer material carrier 68.

As the transfer means, a contact capable of directly applying a transfer bias by abutting the back side of the transfer material carrier such as a roller-shaped transfer roller, instead of the transfer blade contacting the back side of the transfer material carrier. It is possible to use transfer means.

Further, instead of the above contact transfer means, a contact bias is applied from a corona charger which is disposed in contact with the back surface of a transfer material carrier which is generally used. It is also possible to use the above transfer means.

However, it is more preferable to use the contact transfer means because the amount of ozone generated when the transfer bias is applied can be controlled.

[0258]

EXAMPLES The present invention will be described in detail below with reference to production examples and examples, but the present invention is not limited thereto. The number of parts or% described in the examples indicates parts by mass or% by mass.

(Production Example of Magnetic Iron Oxide 1) Ferrous Sulfate (F
eSO ₄ ) aqueous solution with 1.0 to 1.1 relative to iron ions
Add an equivalent amount of caustic soda (NaOH) solution and mix,
By reacting both at a temperature of ~ 100 ° C, ferrous hydroxide (F
An aqueous solution containing e (OH) ₂ ) was prepared. After that, the pH of the aqueous solution was adjusted to 12 to 13 by adjusting the alkali, and the oxidation reaction was advanced while blowing steam and air to obtain a magnetite slurry.

Next, this slurry was filtered, washed with water, kept at a drying temperature of 130 ° C./10 minutes in a nitrogen atmosphere using a warm air dryer, and then dried at a drying temperature of 80 ° C./2 hours.
After the drying was completed, a crushing process was performed to obtain magnetic iron oxide 1. The FeO content of magnetic iron oxide 1 is 26.1% and the specific surface area is 8.1.
The m ² / g and the bulk density were 0.44 g / cm ³ .

(Production Example of Magnetic Iron Oxide 2) The same as the production example of Magnetic Iron Oxide 1 except that the drying temperature is maintained at 120 ° C./15 minutes and then dried at 80 ° C./2 hours. Magnetic iron oxide 2 was obtained through the steps.

At this time, the FeO content was 28.1%, the specific surface area was 7.4 m ² / g, and the bulk density was 0.46 g / cm ³ .

(Production Example of Magnetic Iron Oxide 3) Magnetic Iron Oxide 3 was obtained through the same steps as in the Production Example of Magnetic Iron Oxide 1 except that the drying temperature was 65 ° C. for 15 hours.

At this time, the FeO content was 25.4%, the specific surface area was 7.6 m ² / g, and the bulk density was 0.45 g / cm ³ .

(Production Example of Magnetic Iron Oxide 4) Magnetic iron oxide 4 was obtained through the same steps as in the production example of magnetic iron oxide 1 except that the drying temperature was 70 ° C. for 10 hours.

At this time, the FeO content was 27.3%, the specific surface area was 7.2 m ² / g, and the bulk density was 0.47 g / cm ³ .

(Production Example of Magnetic Iron Oxide 5) As a drying condition, a nitrogen iron purge is not performed, and the magnetic iron oxide 5 is subjected to the same steps as in the production example of the magnetic iron oxide 1 except that drying is performed in a normal oxygen atmosphere. Got

At this time, the FeO content was 23.3%, the specific surface area was 6.9 m ² / g, and the bulk density was 0.45 g / cm ³ . (Production Example of Magnetic Iron Oxide 6) As a drying temperature condition, a drying temperature of 75 ° C./18 hours was maintained, and then a drying temperature of 50 ° C./5.
Magnetic iron oxide 6 was obtained through the same steps as in the production example of magnetic iron oxide 1 except that the material was dried for 0 hour and then left under H ₂ atmosphere for 15 hours.

At this time, the FeO content was 30.6%, the specific surface area was 7.2 m ² / g, and the bulk density was 0.47 g / cm ³ .

(Production Example of Hydrophobic Iron Oxide 1) An aqueous ferrous sulfate solution is mixed with 1.0 to 1.1 equivalents of caustic soda solution with respect to iron ions to prepare an aqueous solution containing ferrous hydroxide. did. Blow air while maintaining the pH of the aqueous solution at 9,
An oxidation reaction was carried out at 80 to 90 ° C to prepare a slurry liquid for generating seed crystals.

Then, the slurry liquid contained 0.9-1..1 with respect to the initial amount of alkali (sodium component of caustic soda).
After adding ferrous sulfate aqueous solution so as to be 2 equivalents, the pH of the slurry liquid is maintained at 8 and the oxidation reaction is advanced while blowing air, and the pH is adjusted to about 6 at the end of the oxidation reaction, and the silane coupling is performed. agent _{[n-C 4 H 9 Si} (OCH 3) 3] was added 0.5 parts per 100 parts of magnetic iron oxide was sufficiently stirred.
The produced hydrophobic iron oxide particles were washed, filtered, and dried by a conventional method, and then the aggregated particles were crushed to obtain hydrophobic iron oxide 1. Table 1 shows the physical properties of hydrophobic iron oxide 1.

(Production Example of Hydrophobic Iron Oxide 2) The oxidation reaction was carried out in the same manner as in the production example of the hydrophobic iron oxide 1, and the magnetic iron oxide particles produced after the oxidation reaction were washed, filtered, taken out once, and not dried. After redispersing it in another water, the pH of the redispersion is adjusted, and the silane coupling agent [n-
_{C 6 H 13 Si (OCH 3} ) 3] was added 0.5 parts subjected to coupling treatment. The produced hydrophobic iron oxide particles were washed, filtered, and dried by a conventional method, and then the aggregated particles were lightly crushed to obtain hydrophobic iron oxide 2. The physical properties are shown in Table 1.

(Production Example of Hydrophobic Iron Oxide ₃ ) Hydrophobic oxidation was conducted in the same manner as in Production Example 2 except that [nC ₁₀ H ₂₁ Si (OCH ₃ ) ₃ ] was used as the silane coupling agent. Iron 3
Got The physical properties are shown in Table 1.

(Production Example of Hydrophobic Iron Oxide 4) Hydrophobic iron oxide 4 was produced in the same manner as in Production Example of hydrophobic iron oxide 2 except that [γ-glycidyltrimethoxysilane] was used as the silane coupling agent. Got 4. The physical properties are shown in Table 1.

(Production Example of Hydrophobic Iron Oxide 5) A ferrous sulfate aqueous solution is mixed with 1.0 to 1.1 equivalents of caustic soda solution with respect to iron ions to prepare an aqueous solution containing ferrous hydroxide. Prepared.

[0276] Next, in this slurry liquid, 0.9-1. To the initial amount of alkali (sodium component of caustic soda) was added.
After adding a ferrous sulfate aqueous solution to 2 equivalents, the slurry liquid was maintained at pH 8 and the oxidation reaction was advanced while blowing air, and the pH was adjusted at the final stage of the oxidation reaction to complete the oxidation reaction. The produced particles are washed, filtered and dried by a conventional method, and then the aggregated particles are crushed to obtain iron oxide particles a.
Got The resulting iron oxide particles a 10-fold dilution with methanol at gas phase silane coupling agent [n-C ₆ H ₁₃ S
Hydrophobic iron oxide 5 was obtained by hydrophobizing with i (OCH ₃ ) ₃ ] (adjusting the coupling agent to be 0.5 part with respect to 100 parts of iron oxide). The physical properties are shown in Table 1.

(Production Example of Hydrophobic Iron Oxide 6) The iron oxide particles a obtained in Production Example 5 of hydrophobic iron oxide are dispersed in water,
By adjusting the pH of the iron oxide aqueous dispersion, a silane coupling agent _{[n-C 6 H 13 Si} (OCH 3) 3] 0.5 parts were added and was thoroughly mixed and stirred. The produced hydrophobic iron oxide particles were washed, filtered, and dried by a conventional method, and then the aggregated particles were crushed to obtain hydrophobic iron oxide 6. The physical properties are shown in Table 1.

(Production Example of Hydrophobic Iron Oxide 7) In the production example of the hydrophobic iron oxide 1, except that the ferrous sulfate aqueous solution at the time of synthesizing the magnetic iron oxide particles is reduced and the air blowing amount is increased. In the same manner, hydrophobic iron oxide 7 was obtained. The physical properties are shown in Table 1.

(Production Example of Hydrophobic Iron Oxide 8) In the production example of the hydrophobic iron oxide 5, except that the ferrous sulfate aqueous solution at the time of synthesizing the magnetic iron oxide particles is reduced and the amount of air blown in is increased. In the same manner, hydrophobic iron oxide 8 was obtained. The physical properties are shown in Table 1.

(Production Example of Hydrophobic Iron Oxide 9) In the production example of the hydrophobic iron oxide 1, except that the ferrous sulfate aqueous solution at the time of synthesizing the magnetic iron oxide particles is increased to reduce the air blowing amount. In the same manner, hydrophobic iron oxide 9 was obtained. The physical properties are shown in Table 1.

(Production Example of Hydrophobic Iron Oxide 10) In the production example of the hydrophobic iron oxide 5, except that the ferrous sulfate aqueous solution at the time of synthesizing the magnetic iron oxide particles is increased and the air blowing amount is decreased. Similarly, hydrophobic iron oxide 10 was obtained. The physical properties are shown in Table 1.

(Production Example of Hydrophobic Iron Oxide 11) In the production example of the hydrophobic iron oxide 3, except that the ferrous sulfate aqueous solution at the time of synthesizing the magnetic iron oxide particles is reduced and the amount of air blown in is increased. Similarly, hydrophobic iron oxide 11 was obtained. The physical properties are shown in Table 1.

(Production Example of Hydrophobic Iron Oxide 12) In the production example of the hydrophobic iron oxide 5, the hydrophobic iron oxide 12 was produced in the same manner except that the air blowing amount of the magnetic iron oxide particles was increased.
Got The physical properties are shown in Table 1.

[0284]

[Table 1]

<1> Production of Black Magnetic Toner <Production Example of Black Magnetic Toner 1> • Styrene-butyl acrylate-maleic acid 100 parts (monobutyl-divinylbenzene copolymer (Mw = 300,000)) • Magnetic iron oxide 1 80 parts-Negatively-charged charge control agent 2 parts-Low molecular weight polypropylene 3 parts After sufficiently premixing the above materials with a Henschel mixer, melt kneading with a twin-screw extruder, and after cooling, use a hammer mill to obtain a particle size of about It was roughly crushed to about 1 to 2 mm. Then, it was pulverized by an air jet pulverizer. Further, the obtained finely pulverized product was classified by a multi-division classifier to obtain black magnetic toner particles having a volume average particle size of 8.0 μm.

For 100 parts of the above black magnetic toner particles,
1. 5 parts of zinc oxide fine particles having an average particle diameter of 3 μm and oil-treated silica fine powder having an average particle diameter of 0.02 μm
0 part was added and dispersed and mixed by a Henschel mixer to obtain a black magnetic toner 1. The physical properties are shown in Table 2.

<Production Example of Black Magnetic Toner 2> A black magnetic toner 2 was obtained in the same manner as in the production example of the black magnetic toner 1 except that the magnetic iron oxide 2 was used in place of the magnetic iron oxide 1 used. The physical properties are shown in Table 2.

<Production Example of Black Magnetic Toner 3> A black magnetic toner 3 was obtained in the same manner as in the production example of the black magnetic toner 1 except that the magnetic iron oxide 3 was used instead of the magnetic iron oxide 1 used. The physical properties are shown in Table 2.

<Production Example of Black Magnetic Toner 4> A black magnetic toner 4 was obtained in the same manner as in the production example of the black magnetic toner 1 except that the magnetic iron oxide 4 was used in place of the magnetic iron oxide 1 used. The physical properties are shown in Table 2.

<Production Example of Black Magnetic Toner 5> A black magnetic toner 5 was obtained in the same manner as in the production example of the black magnetic toner 1 except that the magnetic iron oxide 5 was used in place of the magnetic iron oxide 1 used. The physical properties are shown in Table 2.

<Production Example of Black Magnetic Toner 6> A black magnetic toner 6 was obtained in the same manner as in the production example of the black magnetic toner 1 except that the magnetic iron oxide 1 was used instead of the magnetic iron oxide 1 used. The physical properties are shown in Table 2.

[0292]

[Table 2]

<Production Example of Black Magnetic Toner 7> To 709 parts of ion-exchanged water was added 451 parts of 0.1 mol / liter-Na ₃ PO ₄ aqueous solution, and after moistening at 60 ° C., 1.0 mol was added.
/ L-CaCl ₂ aqueous solution 67.7 parts gradually added to obtain an aqueous medium containing Ca ₃ (PO _{4) 2.}

On the other hand, the following formulation was uniformly dispersed and mixed using an attritor (Mitsui Miike Kakoki Co., Ltd.). -Styrene 82 parts-n-butyl acrylate 18 parts-Polyester resin 5 parts-Negatively charged control agent (monoazo dye-based Fe compound) 2 parts-Hydrophobic iron oxide 1 100 parts

This monomer composition was heated to 60 ° C., 20 parts of ester wax (mp. 70 ° C.) was mixed and dissolved therein, and the polymerization initiator 2,2′-azobis (2,4- Dimethylvaleronitrile [t1 / 2 = 140 minutes, at 60 ° C.] 8 parts and dimethyl-2,2′-azobisisobutyrate [t1 / 2 = 270 minutes, at 60 ° C .; t1 / 2 = 80 minutes ,
Under 80 ° C.] 2 parts were dissolved.

The above polymerizable monomer system was introduced into the above aqueous medium, and the mixture was mixed at 60 ° C. under N ₂ atmosphere with a TK homomixer (Tokushu Kika Kogyo Co., Ltd.) at 10,000 rpm at 1 rpm.
The mixture was stirred for 5 minutes and granulated. Then, the liquid temperature was adjusted to 80 ° C. and stirring was continued for 10 hours. After the reaction is completed, the suspension is cooled,
Hydrochloric acid was added to dissolve Ca ₃ (PO ₄ ) ₂ and filtered, washed with water,
It was dried to obtain black magnetic toner particles. 100 parts of the black magnetic toner particles are treated with hexamethyldisilazane and then with silicone oil, and the BET specific surface area after treatment is 1
A black magnetic toner 7 was prepared by externally mixing 1.4 parts of 20 m ² / g of hydrophobic silica fine powder with a Henschel mixer (Mitsui Miike Kakoki Co., Ltd.).

Here, the dispersion state of the hydrophobic iron oxide inside the magnetic toner particles was evaluated by observing the tomographic plane of the toner particles using a transmission electron microscope (TEM).

The volume average particle diameter was 6.4 μm and the average circularity was 0.977. The physical properties are shown in Table 3.

<Production Example of Black Magnetic Toner 8> In Production Example of Black Magnetic Toner 7, except that hydrophobic iron oxide 1 was replaced with 100 parts of hydrophobic iron oxide 2 and the stirring speed during granulation was changed. In the same manner, black magnetic toner particles were obtained. 100 parts of the black magnetic toner particles and 1.7 parts of hydrophobic silica fine powder having a BET specific surface area of 120 m ² / g after being treated with hexamethyldisilazane and then with silicone oil were mixed with a Henschel mixer (Mitsui Miike). A black magnetic toner 8 was obtained by mixing and externally adding with a chemical processor. At this time, the volume average particle diameter was 5.1 μm, and the average circularity was 0.976.
The physical properties are shown in Table 3.

<Production Example of Black Magnetic Toner 9> Black magnetic toner particles were produced in the same manner as in Production Example of black magnetic toner 7 except that the hydrophobic iron oxide 1 was replaced with 150 parts of the hydrophobic iron oxide 3. Got 100 parts of the black magnetic toner particles and 0.7 part of a hydrophobic silica fine powder having a BET specific surface area of 120 m ² / g after being treated with hexamethyldisilazane and then with silicone oil were mixed with Henschel mixer (Mitsui Miike). Black magnetic toner 9 mixed and externally added by Kakoki Co., Ltd.
And At this time, the volume average particle diameter was 9.3 μm, and the average circularity was 0.983. The physical properties are shown in Table 3.

<Production Example of Black Magnetic Toner 10> Black magnetic toner particles are produced in the same manner as in the production example of black magnetic toner 7 except that hydrophobic iron oxide 1 is replaced with 190 parts of hydrophobic iron oxide 4. Got 100 parts of the black magnetic toner particles,
Hexamethyldisilazane treatment followed by silicone oil treatment and mixing with 2.0 parts of the treated hydrophobic silica fine powder having a BET specific surface area of 120 m ² / g using a Henschel mixer (Mitsui Miike Kakoki Co., Ltd.) In addition, black magnetic toner 10 was obtained. At this time, the volume average particle diameter was 7.0 μm, and the average circularity was 0.981. The physical properties are shown in Table 3.

<Production Example of Black Magnetic Toners 11 and 12>
In the production example of the black magnetic toner 9, the amount of the hydrophobic iron oxide 3 used was changed to 40 parts or 200 parts, and the amounts of the Na ₃ PO ₄ aqueous solution and the CaCl ₂ aqueous solution added were changed in the same manner. Black magnetic toner particles were obtained respectively. 100 parts of each black magnetic toner particle was treated with hexamethyldisilazane and then treated with silicone oil, and the treated BE was treated.
Hydrophobic silica fine powder having T specific surface area of 120 m ² / g
0 parts and 3.0 parts were mixed and externally added with a Henschel mixer (Mitsui Miike Kakoki Co., Ltd.) to obtain a black magnetic toner 11
And black magnetic toner 12. At this time, the volume average particle diameter of the black magnetic toner 11 is 9.9 μm and the average circularity is 0.
975, the volume average particle diameter of the black magnetic toner 12 is 8.1μ.
The average circularity at m was 0.972. The physical properties are shown in Table 3.

<Production Example of Black Magnetic Toner 13> To 709 parts of ion-exchanged water was added 451 parts of 0.1 mol / liter-Na ₃ PO ₄ aqueous solution, and the mixture was humidified at 60 ° C., and then 1.0 mo.
67.7 parts of a 1 / liter CaCl ₂ aqueous solution was gradually added to obtain an aqueous medium containing Ca ₃ (PO ₄ ) ₂ .

On the other hand, the following formulations were uniformly dispersed and mixed using an attritor (Mitsui Miike Kakoki Co., Ltd.). -Styrene 82 parts-n-butyl acrylate 18 parts-Polyester resin 5 parts-Hydrophobic iron oxide 1 100 parts This monomer composition is heated to 60 ° C and the polymerization initiator 2,2'-azobis ( 2,4-dimethylvaleronitrile
[t1 / 2 = 140 minutes, at 60 ° C.] 8 parts and dimethyl-
2,2'-azobisisobutyrate [t1 / 2 = 270 minutes,
60 ° C. condition; t 1/2 = 80 minutes, 80 ° C. condition] 2 parts were dissolved.

The above polymerizable monomer system was added to the above aqueous medium, and the mixture was mixed with a TK homomixer (Tokushu Kika Kogyo Co., Ltd.) at 60 rpm and 1 rpm at 10,000 rpm under N ₂ atmosphere.
The mixture was stirred for 5 minutes and granulated. Then, the liquid temperature was adjusted to 80 ° C. and stirring was continued for 10 hours. After the reaction is completed, the suspension is cooled,
Hydrochloric acid was added to dissolve Ca ₃ (PO ₄ ) ₂ and filtered, washed with water,
It dried and the iron oxide containing resin powder was obtained.

Next, 205 parts of the above iron oxide-containing resin powder, 0.8 part of a negative charge controlling agent (iron compound of monoazo dye type), and 3 parts of ethylene-propylene copolymer (Mw = 6000) were mixed, Melt and knead with a twin-screw extruder heated to 140 ° C., cool the kneaded material, coarsely pulverize with a hammer mill, finely pulverize the coarsely pulverized material with a jet mill, and classify the obtained finely pulverized material with wind. , Black magnetic toner particles were obtained. 100 parts of the black magnetic toner particles are treated with hexamethyldisilazane, treated with silicone oil, and treated with BE.
Hydrophobic silica fine powder having T specific surface area of 120 m ² / g
Henschel mixer (Mitsui Miike Kakoki Co., Ltd.)
Then, the mixture was externally added to obtain a black magnetic toner 13. At this time, the volume average particle diameter is 7.6 μm, and the average circularity is 0.961.
Met. The physical properties are shown in Table 3.

<Production Example of Black Magnetic Toner 14> The iron oxide-containing resin powder obtained in the Production Example of Black Magnetic Toner 13 was surface-treated by mechanical impact to obtain black magnetic toner particles. 100 parts of the black magnetic toner particles and 1.2 parts of hydrophobic silica fine powder having a BET specific surface area of 120 m ² / g after treatment with hexamethyldisilazane and then with silicone oil were mixed with Henschel mixer (Mitsui Miike). A black magnetic toner 14 was obtained by mixing and externally adding with a chemical processor.
The volume average particle diameter is 7.3 μm, and the average circularity is 0.973.
Met. The physical properties are shown in Table 3.

<Production Example of Black Magnetic Toner 15> Black magnetic toner particles were produced in the same manner as in Production Example of black magnetic toner 7 except that hydrophobic iron oxide 1 was replaced with 100 parts of hydrophobic iron oxide 5. Got 100 parts of the black magnetic toner particles,
Hexamethyldisilazane treatment followed by silicone oil treatment and 1.2 parts of the treated hydrophobic silica fine powder having a BET specific surface area of 120 m ² / g were mixed with a Henschel mixer (Mitsui Miike Kakoki Co., Ltd.) In addition, black magnetic toner 15 was obtained. At this time, the volume average particle diameter was 7.2 μm, and the average circularity was 0.979. The physical properties are shown in Table 3.

<Production Example of Black Magnetic Toner 16> Black magnetic toner particles were produced in the same manner as in the production example of black magnetic toner 7 except that hydrophobic iron oxide 1 was replaced with 150 parts of hydrophobic iron oxide 6. Got 100 parts of the black magnetic toner particles,
After hexamethyldisilazane treatment and silicone oil treatment, 1.7 parts of the treated hydrophobic silica fine powder having a BET specific surface area of 120 m ² / g is mixed with a Henschel mixer (Mitsui Miike Kako Co., Ltd.) In addition, black magnetic toner 16 was obtained. The volume average particle diameter was 5.1 μm, and the average circularity was 0.977. The physical properties are shown in Table 3.

<Production Example of Black Magnetic Toner 17> Black magnetic toner particles were produced in the same manner as in Production Example of black magnetic toner 7 except that hydrophobic iron oxide 1 was replaced with 150 parts of hydrophobic iron oxide 7. Got 100 parts of the black magnetic toner particles,
Hexamethyldisilazane treatment followed by silicone oil treatment and 1.2 parts of the treated hydrophobic silica fine powder having a BET specific surface area of 120 m ² / g were mixed with a Henschel mixer (Mitsui Miike Kakoki Co., Ltd.) In addition, a black magnetic toner 18 was obtained. The volume average particle diameter was 7.0 μm, and the average circularity was 0.963. The physical properties are shown in Table 3.

<Production Example of Black Magnetic Toner 18> Black magnetic toner particles were produced in the same manner as in the production example of black magnetic toner 7 except that hydrophobic iron oxide 1 was replaced with 100 parts of hydrophobic iron oxide 8. Got 100 parts of the black magnetic toner particles,
Hexamethyldisilazane treatment followed by silicone oil treatment and 1.2 parts of the treated hydrophobic silica fine powder having a BET specific surface area of 120 m ² / g were mixed with a Henschel mixer (Mitsui Miike Kakoki Co., Ltd.) In addition, a black magnetic toner 18 was obtained. The volume average particle diameter was 6.9 μm, and the average circularity was 0.979. The physical properties are shown in Table 3.

<Production Example of Black Magnetic Toner 19> Black magnetic toner particles are produced in the same manner as in Production Example of black magnetic toner 7 except that hydrophobic iron oxide 1 is replaced with 190 parts of hydrophobic iron oxide 9. Got 100 parts of the black magnetic toner particles,
Hexamethyldisilazane treatment followed by silicone oil treatment and mixing with 2.0 parts of the treated hydrophobic silica fine powder having a BET specific surface area of 120 m ² / g using a Henschel mixer (Mitsui Miike Kakoki Co., Ltd.) In addition, black magnetic toner 19 was obtained. The volume average particle diameter was 6.9 μm, and the average circularity was 0.968. The physical properties are shown in Table 3.

<Production Example of Black Magnetic Toner 20> In the production example of the black magnetic toner 19, hydrophobic iron oxide 9 is added to 190
Black magnetic toner particles were obtained in the same manner except that the hydrophobic iron oxide 10 in part was replaced. 100 parts of the black magnetic toner particles are treated with hexamethyldisilazane and then treated with silicone oil, and the BET specific surface area after treatment is 120 m ² / g.
2.0 parts of the hydrophobic silica fine powder of No. 1 was mixed and externally added with a Henschel mixer (Mitsui Miike Kakoki Co., Ltd.) to obtain a black magnetic toner 20. The volume average particle diameter was 6.8 μm, and the average circularity was 0.972. The physical properties are shown in Table 3.

<Production Example of Black Magnetic Toner 21> In the production example of the black magnetic toner 15, 100 parts of the hydrophobic iron oxide 5 is added.
Black magnetic toner particles were obtained in the same manner except that the hydrophobic iron oxide 11 in part was replaced. 100 parts of the black magnetic toner particles are treated with hexamethyldisilazane and then treated with silicone oil, and the BET specific surface area after treatment is 120 m ² / g.
And 1.2 parts of the hydrophobic silica fine powder of No. 1 were mixed and added externally with a Henschel mixer (Mitsui Miike Kakoki Co., Ltd.) to obtain a black magnetic toner 21. The volume average particle diameter was 7.1 μm, and the average circularity was 0.970. The physical properties are shown in Table 3.

<Production Example of Black Magnetic Toner 22> Black magnetic toner particles are produced in the same manner as in the production example of black magnetic toner 7 except that hydrophobic iron oxide 1 is replaced with 100 parts of hydrophobic iron oxide 12. Got 100 parts of the black magnetic toner particles are treated with hexamethyldisilazane and then with silicone oil, and the BET specific surface area after treatment is 120 m ² / g.
And 1.0 part of the hydrophobic silica fine powder of No. 2 were mixed and externally added with a Henschel mixer (Mitsui Miike Kakoki Co., Ltd.) to obtain a black magnetic toner 22. The volume average particle diameter was 7.0 μm, and the average circularity was 0.981. The physical properties are shown in Table 3.

[0316]

[Table 3]

<2> Production of Yellow Color Toner, Magenta Color Toner and Cyan Color Toner <Production Example of Yellow Color Toner 1> Polyester resin obtained by condensing 100 parts of propoxylated bisphenol and fumaric acid (in this resin The molecular weight distribution of the THF-soluble component had a peak at 6300.) C. I. Pigment Yellow 17 3.5 parts / chromium complex salt of di-tert-butylsalicylic acid 4 parts After sufficiently premixing the above materials with a Henschel mixer, melt kneading with a twin-screw extruder, and after cooling, using a hammer mill Coarsely pulverized to a particle size of about 1 to 2 mm. Then, it was pulverized by an air jet pulverizer. Further, the obtained finely pulverized product was classified by a multi-division classifier to obtain yellow toner particles having a volume average particle size of 7.3 μm.

With respect to 100 parts of the yellow toner particles, 0.7 part of hydrophilic titanium oxide fine powder (BET 70 m ^{2 /} g) synthesized from titanium chloride and an average particle size of 0.8
Yellow toner 1 was prepared by combining 0.7 parts of spherical silica fine powder of μm.

<Production Example of Magenta Color Toner 1> In the production example of yellow color toner 1, C.I. I. A magenta toner 1 having a volume average particle diameter of 7.3 μm was obtained through the same steps except that 4 parts of rhodamine-based pigment was used instead of Pigment Yellow 17.

<Production Example of Cyan Color Toner 1> In the production example of yellow color toner 1, C.I. I. Pigment Yellow 17 was replaced with 5 parts of a phthalocyanine-based pigment represented by the following formula (V), and a cyan toner 1 having a volume average particle diameter of 7.4 μm was obtained through the same steps.

[0321]

[Chemical 4]

<Production Example of Yellow Color Toner 2> In the production example of Yellow color toner 1, polyester resin A shown below is used in place of the polyester resin obtained by condensing propoxylated bisphenol and fumaric acid. Was subjected to the same steps to obtain a yellow toner 2 having a volume average particle diameter of 7.6 μm.

(Production Example of Polyester Resin A) 2 mol terephthalic acid, dodecenyl succinic anhydride 1.09 mo
1, polyoxypropylene (2.2) -2,2-bis (4-hydroxyphenyl) propane (3.4 mol) and dibutyltin oxide (0.01 g) were placed in a glass four-necked flask, and a thermometer, a stirring rod, A condenser and a nitrogen inlet tube were attached and placed in the mantle heater.

Next, after replacing the inside of the flask with nitrogen gas,
The temperature was gradually raised with stirring and the reaction was carried out for 4 hours. Then, 0.2 mol of trimellitic anhydride and 0.08 g of dibutyltin oxide were added, and the reaction was continued at 190 ° C. for 3 hours, further heated to 200 ° C., reacted for 5 hours, and then the reaction was terminated. Resin A was obtained. At this time, the mass average molecular weight Mw is 16000, and the number average molecular weight M
n was 5900 and Mw / Mn was 2.7.

<Production Example of Magenta Color Toner 2> In the production example of yellow color toner 2, C.I. I. Pigment Yellow 17 was replaced with 4 parts of rhodamine-based pigment, and the same steps were followed except that the same steps were used to obtain magenta toner 2 having a volume average particle diameter of 7.2 μm.

<Production Example of Cyan Color Toner 2> In the production example of the yellow color toner 2, C.I. I. A cyan toner 2 having a volume average particle diameter of 6.8 μm was obtained through the same steps except that 5 parts of the phthalocyanine pigment was used instead of Pigment Yellow 17.

<Production Example of Yellow Color Toner 3> In the production example of Yellow color toner 1, polyester resin B shown below is used in place of the polyester resin obtained by condensing propoxylated bisphenol and fumaric acid. Was subjected to the same steps to obtain a yellow toner 3 having a volume average particle diameter of 7.7 μm.

(Production Example of Polyester Resin B) Isophthalic acid 1.8 mol, dodecenyl succinic anhydride 1.06 m
ol and 3.5 mol of polyoxypropylene (2.0) -2,2-bis (4-hydroxyphenyl) propane were reacted in the same manner as polyester resin A in a nitrogen atmosphere. Next, 0.16 mol of trimellitic anhydride and 0.09 g of dibutyltin oxide were added and the reaction was carried out at 180 ° C. for 5 hours to obtain a polyester resin B. At this time, the mass average molecular weight Mw is 17,000 and the number average molecular weight Mn is 5
It was 700 and Mw / Mn was 3.0.

<Production Example of Magenta Color Toner 3> In the production example of the yellow color toner 3, C.I. I. Pigment Yellow 17, C.I. I. 4.2 parts of Solvent Red 122, and C.I. I. Solvent Red 49 0.8
Part except that the toner is used through the same steps except that the magenta toner 3 having a volume average particle diameter of 6.9 μm is obtained.

<Production Example of Cyan Color Toner 3> In the production example of the yellow color toner 3, C.I. I. A cyan toner 3 having a volume average particle diameter of 7.4 μm was obtained through the same steps except that 5 parts of a phthalocyanine pigment was used instead of Pigment Yellow 17.

<Manufacturing Example of Yellow Color Toner 4> Yellow toner 4 having a volume average particle diameter of 5.2 μm is obtained through the same steps as in the manufacturing example of yellow color toner 3.

<Production Example of Cyan Color Toner 4> A volume average particle size of 1 is obtained through the same steps as in the production example of cyan color toner 3.
Cyan toner 4 having a size of 3.2 μm was used.

<3> Manufacture of Magnetic Carrier <Manufacture of Magnetic Carrier 1> 50 parts of phenol (hydroxybenzene), 80 parts of 37% by weight formalin aqueous solution, 50 parts of water, magnetite surface-treated with a silane coupling agent Fine particles 320 parts (50% particle size 0.25 μm, volume resistance value 3 × 10 ⁵ Ω · cm) -α-Fe ₂ O ₃ fine particles surface-treated with a silane coupling agent 80 parts (50% particle size 0. 35 μm, volume resistance value 6 × 10 ⁹ Ω · cm) ・ 15 parts by mass of 25 mass% ammonia water

The above materials were placed in a four-necked flask, heated and maintained at 85 ° C. for 50 minutes while stirring and mixing, and reacted and cured for 120 minutes. After cooling to 30 ° C. and adding 500 parts of water, the supernatant was removed, the precipitate was washed with water and air dried. Then, this is depressurized (665 Pa = 5 m
mHg) It dried at 160 degreeC for 24 hours, and obtained the magnetic carrier core (A) which uses a phenol resin as a binder resin.

A 3% methanol solution of γ-aminopropyltrimethoxysilane represented by the following general formula (VI) was coated on the surface of the obtained magnetic carrier core (A).

[0336]

[Chemical 5]

The surface of the magnetic carrier core (A) is 0.1
It had been treated with 2% γ-aminopropyltrimethoxysilane. During the coating, while continuously applying the shear stress to the magnetic carrier core (A), the methanol was volatilized while coating.

On the surface of the magnetic carrier core (A)

[0339]

[Chemical 6] Was confirmed to exist.

While stirring the magnetic carrier core (A) treated with the silane coupling agent in the above treatment machine at 50 ° C., silicone resin SR2410 (manufactured by Toray Dow Corning Co., Ltd.) was added as a silicone resin solid content of 20%. Diluted with toluene so that the total amount becomes 0.
A 5% resin coating was applied.

Thereafter, the toluene was volatilized while stirring in a nitrogen gas atmosphere for 2 hours, and then heat treatment was performed at 140 ° C. for 2 hours in an atmosphere of nitrogen gas to loosen the agglomerates, and then 200 mesh (75 μm The coarse particles above (opening) were removed to obtain magnetic carrier 1.

The magnetic carrier 1 thus obtained has a 50% particle size of 3
5 μm, volume resistance value 8 × 10 ¹³ Ω · cm, 79.6 k
The saturation magnetization at A / m (1000 Oersted) is 4
4 Am ² / kg, the residual magnetization is 5.1 Am ² / kg,
True specific gravity is 3.70, and bulk density is 1.86 g / cm ^3.
Met.

<Production of Magnetic Carrier 2> Magnetic Carrier 1
In the manufacture of B, instead of the magnetic carrier core (A)
50% particle diameter 38 μm, volume resistance value 5 in the same manner except that a ferrite core having an i-Ni-Zn-Fe composition is used.
× 10 ¹¹ Ω · cm, saturation magnetization 66 Am ² / kg, residual magnetization 2.5 Am ² / kg, true specific gravity 4.71 and bulk density 2.
35 g / cm ³ of magnetic carrier 2 was obtained.

[0344] <Manufacture of magnetic carrier 3> ・ Terephthalic acid trimellitic anhydride / propylene oxide 100 parts   Polyester resin consisting of derivative of bisphenol A ・ 500 parts of magnetite used in Production Example 1 ・ Quaternary ammonium salt compound 5 parts

The above materials were sufficiently premixed by a Henschel mixer, and melt-kneaded by a twin-screw extruder kneader.
After cooling, it was roughly pulverized to about 1 to 2 mm using a hammer mill, and then finely pulverized by an air jet type fine pulverizer. Furthermore, after classifying the obtained finely pulverized product, 0.02μ
m styrene / methyl methacrylate copolymer resin particles were dry-coated with a hybridizer (manufactured by Nara Machinery Co., Ltd.) to obtain a 50% particle diameter of 43 μm and a volume resistance value of 4 × 10 ⁹ Ω · c.
m, saturation magnetization 52 Am ² / kg, residual magnetization 4.5 Am ² /
kg, a true specific gravity of 4.05, a bulk density was obtained magnetic carrier 3 of 1.66 g / cm ^3.

<Production of Magnetic Carrier 4> Magnetic Carrier 1
0.02μ in the magnetic carrier core (A) in the manufacture of
m styrene / methylmethacrylate polymerized resin particles were coated in the same manner with a hybridizer (manufactured by Nara Machinery Co., Ltd.) in the same manner, but the 50% particle size was 38 μm and the volume resistance value was 9
× 10 ¹² Ω · cm, saturation magnetization 41 Am ² / kg, residual magnetization 5.2 Am ² / kg, true specific gravity 3.71, bulk density 1.
A magnetic carrier 4 of 83 g / cm ³ was obtained.

<Production of Magnetic Carrier 5> Magnetic Carrier 3
In the same manner as in the production of, except that the pulverization / classification conditions are changed, the 50% particle size is 23 μm, and the volume resistance value is 1 × 10 ⁹ Ω · c.
m, saturation magnetization 50 Am ² / kg, residual magnetization 4.6 Am ² /
A magnetic carrier 5 having a weight specific gravity of 4.02 and a bulk density of 1.52 g / cm ³ was obtained.

<Production of Magnetic Carrier 6> Magnetic Carrier 3
In the production of, except that the pulverization and classification conditions were changed, the 50% particle size was 53 μm and the volume resistance value was 3 × 10 ⁹ Ω · c.
m, saturation magnetization 51 Am ² / kg, residual magnetization 4.7 Am ² /
A magnetic carrier 6 having a weight specific gravity of 4.02 and a bulk density of 1.65 g / cm ³ was obtained.

[0349]

Example 1 Magnetic Carrier 1 (92 parts) obtained above
And yellow toner 1 (8 parts) with a V-type mixer,
The starting yellow color developer 1 was used. On the other hand, magnetic carrier 1 (1 part) and yellow toner 1 (19 parts) were mixed by a V-type mixer to obtain replenishing yellow developer 1.

Then, similarly, magenta toner 1 is used,
Magenta color developer 1 for start and magenta color developer 1 for replenishment were prepared with the same mixing ratio. Further, in the same manner, the cyan toner 1 was used and the starting cyan developer 1 and the replenishing cyan developer 1 were prepared with the same mixing ratio.

Furthermore, black magnetic toner 1 was prepared as the black magnetic toner. The combinations of developers used are shown in Table 4.

Next, the developing device of the commercially available copying machine GP55 (manufactured by Canon Inc.) was modified as shown in FIG. Specifically, as a developing sleeve, a SUS sleeve having a diameter of 16 mm is sandblasted to give a surface shape R
The one adjusted to z = 12.1 μm was used.

A magnetic brush charger is used as the charging member, iron oxide particles a obtained in the production of the hydrophobic iron oxide 5 are used as the magnetic particles, and the particles are exposed in the opposite direction to the contact portion of the photosensitive drum. DC / AC electric field (-700V, 1.5kHz /
1.2 kVpp) is superimposed and applied to charge the photosensitive drum. Also, the cleaning unit is removed, and the development contrast is 250V, the reverse contrast with the fog is -180.
V is set, a developing bias having a discontinuous AC voltage shown in FIG. 6 is applied from a developing bias applying unit (not shown), and the fixing device is a heating roller and a pressure roller, and the surface layer is PFA.
Change to a roller coated with 1.2 μm of (tetrafluoroethylene-perfluoroalkyl vinyl ether copolymer),
Moreover, the oil application mechanism was modified to remove the structure.

The yellow developer 1, the magenta developer 1, the cyan developer 1 and the black magnetic toner 1 shown above were placed in the developing device shown in FIG. 3 and evaluated.

Using an original document having an image area of 35%, 23 ° C./60% (hereinafter also referred to as “N / N”), 23 ° C./5% (hereinafter also referred to as “N / L”), In each environment of 32.5 ° C / 90% (hereinafter, also referred to as "H / H"), a paper passing test was performed at an image forming speed of 120 mm / sec using CLC80g paper (manufactured by Canon Sales Co.). It evaluated based on the following evaluation methods.

The results are shown in Tables 5 to 8. In this example, good results were obtained as can be seen from the tables. [Evaluation Methods / Standards] (1) Image Density Image density is based on Macbeth Densitometer RD918 type (Macbeth Desit
nsitometer RD918manufactured by Mcbeth Co.) was used to measure the average relative density of five points at the four corners and the center of an image formed on plain paper with an original image density of 1.5.

(2) Halftone Reproducibility Using the original image density of 0.3, the relative density was measured in the same manner as in (1). The evaluation criteria are as follows. ⊚: 0.3 to 0.4 ∘: 0.25 to less than 0.3 Δ: 0.20 to less than 0.25 x: less than 0.2

(3) The average reflectance Dr (%) of plain paper before the fog image is output is measured by a reflectometer (“REFLECTOMETER MODEL” manufactured by Tokyo Denshoku Co., Ltd.).
TC-6DS ”). On the other hand, a solid white image is printed on plain paper, and then the reflectance Ds (%) of the solid white image
Was measured. Fog (%) is calculated from the following formula.

Fog (%) = Dr (%)-Ds (%) The evaluation criteria are as follows. ◎: less than 0.4% ○: 0.4 to less than 0.8% Δ: 0.8 to less than 1.2% ×: 1.2% or more

(4) Solid Uniformity Using the original image density of 1.5, the relative density at 5 points was measured in the same manner as in (1), and the maximum density difference was measured. The evaluation criteria are as follows. ⊚: 0.0 to less than 0.05 ◯: 0.05 to less than 0.15 Δ: 0.15 to less than 0.25 ×: 0.25 or more

[0361]

[Table 4]

[0362]

[Table 5]

[0363]

[Table 6]

[0364]

[Table 7]

[0365]

[Table 8]

[0366]

Example 2 In Example 1, the magnetic carrier 1 mixed with the yellow color toner 1, the magenta color toner 1 and the cyan color toner 1 was changed to the magnetic carrier 2, and the black magnetic toner 1 was changed to the black magnetic toner 2. Same as above, except change
Similar evaluation was performed. The combinations of developers used are shown in Table 4. The results are shown in Tables 5 to 8.

[0367]

Third Embodiment In the first embodiment, the yellow toner 1, the magenta toner 1 and the cyan toner 1 are changed to the yellow toner 2, the magenta toner 2 and the cyan toner 2 and mixed with each toner. The magnetic carrier 1 is changed to the magnetic carrier 3, and the black magnetic toner 1 is replaced with the black magnetic toner 3.
The same evaluation was performed in the same manner except that the same was changed to. The combinations of developers used are shown in Table 4. The results are shown in Tables 5 to 8.

[0368]

Fourth Embodiment In the first embodiment, the magnetic carrier 1 mixed with the yellow toner 1, the magenta toner 1, and the cyan toner 1 is changed to the magnetic carrier 4, and the black magnetic toner 1 is changed to the black magnetic toner 4. Same as above, except change
Similar evaluation was performed. The combinations of developers used are shown in Table 4. The results are shown in Tables 5 to 8.

[0369]

Fifth Embodiment The magnetic carrier 1 mixed with the yellow toner 1, the magenta toner 1 and the cyan toner 1 in the first embodiment is changed to the magnetic carrier 2, and the black magnetic toner 1 is changed to the black magnetic toner 5. Same as above, except change
Similar evaluation was performed. The combinations of developers used are shown in Table 4. The results are shown in Tables 5 to 8.

As is clear from the results, although the fog was good in the magnetic toner, the image density after 20,000 sheets was decreased in all the environments. This is probably because the FeO content in the magnetic iron oxide was small and the charge amount increased.

[0371]

Sixth Embodiment In the first embodiment, the yellow toner 1,
The same evaluation was made in the same manner except that the magenta toner 1 and the cyan toner 1 were changed to the yellow toner 2, the magenta toner 2 and the cyan toner 2, and the black magnetic toner 1 was changed to the black magnetic toner 6. went. The combinations of developers used are shown in Table 4. The results are shown in Tables 5 to 8.

As is clear from the results, the image density and the like of the magnetic toner were stable and good, but the fog value was poor from the beginning and toner scattering occurred in the evaluation machine. It is considered that the reason for this is that since the FeO content in the magnetic iron oxide was large, the fluidity of the toner deteriorated and stable triboelectric charging characteristics could not be obtained.

[0373]

Seventh Embodiment In the first embodiment, the yellow toner 1 is changed to the yellow toner 4, the magenta toner 1 is changed to the magenta toner 3 and the cyan toner 1 is changed to the cyan toner 3, and the black magnetic toner 1 is changed. The same evaluation was performed in the same manner except that the black magnetic toner 2 was used. The combinations of developers used are shown in Table 4. The results are shown in Tables 5 to 8.

As is clear from the results, yellow toner 4
After passing 20,000 sheets of paper, the image density in each environment decreased and the fog worsened. It is presumed that this is because the toner particle size of the yellow toner 4 is small, and thus the triboelectric charging uniformity of the toner is impaired.

[0375]

[Embodiment 8] In the same manner as in Embodiment 4, except that the yellow color toner 1 is changed to the yellow color toner 2, the magenta color toner 1 is changed to the magenta color toner 2, and the cyan color toner 1 is changed to the cyan color toner 4. Similar evaluation was performed. The combinations of developers used are shown in Table 4. The results are shown in Tables 5 to 8.

As is clear from the results, under the H / H environment, the halftone reproducibility of the cyan toner 4 was lowered, and the fog was worsened. It is presumed that this is because the cyan toner 4 has a large particle size, and the triboelectric charging property of the toner is deteriorated, making it difficult to faithfully develop the latent image.

[0377]

COMPARATIVE EXAMPLE 1 In Example 2, the yellow toner 1 was changed to the yellow toner 3, the magenta toner 1 was changed to the magenta toner 3 and the cyan toner 1 was changed to the cyan toner 3, and replenishment magenta color development was carried out. Agent 1 to magnetic carrier 1 (1
Part) and magenta color toner 3 (1 part) are mixed by a V-type mixer to a replenishing magenta color developer 2, and the black magnetic toner 1 is changed to a black magnetic toner 2 in the same manner. Was evaluated. Table 4 shows the combinations of the developers used.
Shown in. The results are shown in Tables 5 to 8.

As is clear from the results, in the evaluation of magenta toner 3 under each environment, the image density was lowered and the solid uniformity was deteriorated at the time of 500 sheets, so the evaluation was stopped. It is presumed that this is because the toner amount in the replenishing magenta color developer 2 was small, so that the toner replenishment could not catch up in the solid image, resulting in non-uniformity.

[0379]

COMPARATIVE EXAMPLE 2 In Example 3, the magnetic carrier 3 was changed to the magnetic carrier 1, and the replenishing cyan developer 1 was magnetic carrier 1 (1 part) and cyan toner 2 (60 parts) was V-type. The same evaluation was performed in the same manner except that the cyan cyan developer 2 for replenishment mixed with a mixer was used. The combinations of developers used are shown in Table 4. The results are shown in Tables 5 to 8.

As is clear from the results, fog was aggravated in the evaluation of cyan toner 3 under each environment. It is presumed that this is because the amount of carrier in the replenishment developer was small, and the replacement of the toner spent toner could not catch up, resulting in non-uniform triboelectric charging of the toner.

[0380]

[Embodiment 9] To 100 parts of each of the yellow toner 1, the magenta toner 1 and the cyan toner 1 in the embodiment 1, 5 parts of ester wax is added to form each toner, and the black magnetic Evaluation was performed in the same manner except that the toner 1 was changed to the black magnetic toner 2, and the same evaluation was performed. The combinations of developers used are shown in Table 4. The results are shown in Table 5
It shows in Table 8.

[0382]

[Embodiment 10] The black magnetic toner 1 in Embodiment 1 is
The evaluation was performed in the same manner except that the black magnetic toner 7 was changed. The combinations of developers used are shown in Table 4. The results are shown in Table 5.
~ Shown in Table 8.

[0383]

[Embodiment 11] Black magnetic toner 7 in Embodiment 10
Was evaluated in the same manner except that the black magnetic toner 8 was changed to. The combinations of developers used are shown in Table 4. The results are shown in Tables 5 to 8.

[0384]

[Embodiment 12] Black magnetic toner 7 in Embodiment 10
Was evaluated in the same manner except that the black magnetic toner 9 was used. The combinations of developers used are shown in Table 4. The results are shown in Tables 5 to 8.

[0385]

[Embodiment 13] Black magnetic toner 7 in Embodiment 10
To black magnetic toner 10 and yellow toner 1
Was evaluated in the same manner except that the yellow toner 2, the magenta toner 1 were changed to the magenta toner 2 and the cyan toner 1 was changed to the cyan toner 2. The combinations of developers used are shown in Table 4. The results are shown in Tables 5 to 8.

[0386]

Example 14 Black magnetic toner 10 in Example 13
Was changed to the black magnetic toner 11 and the magnetic carrier 1 was changed to the magnetic carrier 3, and the same evaluation was performed. The combinations of developers used are shown in Table 4. The results are shown in Table 5
It shows in Table 8.

[0387]

[Embodiment 15] Black magnetic toner 10 in Embodiment 13
To black magnetic toner 12 and yellow toner 2
Was evaluated in the same manner except that the yellow toner 3, the magenta toner 2 were changed to the magenta toner 3 and the cyan toner 2 was changed to the cyan toner 3. The combinations of developers used are shown in Table 4. The results are shown in Tables 5 to 8.

[0388]

Example 16 The same evaluation as in Example 1 was carried out except that the magnetic carrier 1 was changed to the magnetic carrier 5. The combinations of developers used are shown in Table 4. The results are shown in Table 5
It shows in Table 8. As shown in Tables 5 to 8, although the characteristics of the two-component developer under each environment were slightly deteriorated, good results were obtained. This is because the particle size of the magnetic carrier 5 is small,
It is presumed that the circulation in the developing device was disturbed and coating unevenness on the developing sleeve was likely to occur.

[0389]

Example 17 The same evaluation as in Example 10 was performed except that the magnetic carrier 1 was changed to the magnetic carrier 5. The combinations of developers used are shown in Table 4. The results are shown in Table 5
As shown in Table 8, the same results as in Example 12 were obtained.

[0390]

Example 18 The same evaluation as in Example 3 was carried out except that the magnetic carrier 1 was changed to the magnetic carrier 6. The combinations of developers used are shown in Table 4. The results are shown in Table 5
It shows in Table 8. As shown in Tables 5 to 8, although the characteristics of the two-component developer under each environment were slightly deteriorated, good results were obtained. This is because the particle size of the magnetic carrier 6 is large,
It is presumed that the property of imparting triboelectrification to the toner was lowered, and the toner was likely to be unevenly charged.

[0391]

[Example 19] The same evaluation as in Example 12 was carried out except that the magnetic carrier 1 was changed to the magnetic carrier 6. The combinations of developers used are shown in Table 4. The results are shown in Table 5
As shown in Table 8, the same results as in Example 14 were obtained.

[0390]

Comparative Example 3 The same evaluation as in Example 10 was carried out except that the black magnetic toner 7 was changed to the black magnetic toner 13. The combinations of developers used are shown in Table 4. The results are shown in Table 5.
~ As shown in Table 8, black magnetic toner 1 in N / N environment
3 was poor in solid uniformity and was inferior in transfer efficiency.
It is presumed that the reason for this is that by melting the polymerizable magnetic monomer containing iron oxide again, the dispersibility of the hydrophobic magnetic iron oxide was deteriorated, and it was difficult to obtain uniform triboelectric charging characteristics.

[0393]

Comparative Example 4 The same evaluation as in Example 10 was conducted except that the black magnetic toner 7 was changed to the black magnetic toner 14. The combinations of developers used are shown in Table 4. The results are shown in Table 5.
As shown in Table 8, as in Comparative Example 3, the solid uniformity of the black magnetic toner 14 in the N / N environment was poor, and the transfer efficiency was also poor. It is presumed that the reason for this is that by melting the polymerizable magnetic monomer containing iron oxide again, the dispersibility of the hydrophobic magnetic iron oxide was deteriorated, and it was difficult to obtain uniform triboelectric charging characteristics.

[0394]

Comparative Example 5 The same evaluation as in Example 10 was carried out except that the black magnetic toner 7 was changed to the black magnetic toner 15. The combinations of developers used are shown in Table 4. The results are shown in Table 5.
~ As shown in Table 8, the fog of the black magnetic toner 15 worsened in each environment.

The reason for this is that the ratio (B / A) of the iron element content (B) to the carbon element content (A) on the surface of the black magnetic toner 15 is 0.0012, and the hydrophobic property used is 0.3μ in particle size distribution of magnetic iron oxide
Since the ratio of m or more was 11% by number, it is presumed that the frictional charge amount was decreased.

[0396]

Comparative Example 6 The same evaluation as in Example 10 was conducted except that the black magnetic toner 7 was changed to the black magnetic toner 16. The combinations of developers used are shown in Table 4. The results are shown in Table 5.
As shown in Table 8, the fog of the black magnetic toner 16 worsened in each environment as in Comparative Example 5. It is presumed that the reason for this is that (B / A) is 0.0012, and the triboelectric charge amount is decreased.

[0397]

Comparative Example 7 The same evaluation as in Example 10 was carried out except that the black magnetic toner 7 was changed to the black magnetic toner 19. The combinations of developers used are shown in Table 4. The results are shown in Table 5.
As shown in Table 8, the image density of the black magnetic toner 19 decreased after the endurance under the N / L environment. The reason is that the circularity of the black magnetic toner 19 is 0.968, the projected area equivalent diameter of the toner is C, and the transmission electron microscope (TE
D / C ≦ 0.02, where D is the minimum value of the distance between the iron oxide and the toner surface in the cross section observation of the toner using M).
Since 45% by number of toners satisfy the above relationship, it is presumed that the triboelectric charge amount of the black magnetic toner 19 increased and the image density decreased.

[0398]

Comparative Example 8 The same evaluation as in Example 13 was conducted except that the black magnetic toner 10 was changed to the black magnetic toner 20. The combinations of developers used are shown in Table 4. The results are shown in Tables 5 to 8, and the fog of the black magnetic toner 20 deteriorated under the N / L environment, and the image density decreased after the durability test. At this time, the circularity of the black magnetic toner 20 is 0.97.
Although it was 2, it is presumed that 47% by number of the toners satisfy the relationship of D / C ≦ 0.02, and the resistance of the toner surface is reduced, and a lot of toners with poor charging exist.

[0399]

Comparative Example 9 Evaluation was made in the same manner as in Example 14, except that the black magnetic toner 11 was changed to the black magnetic toner 17. The combinations of developers used are shown in Table 4. The results are shown in Tables 5 to 8, and in the N / N environment, the halftone reproducibility of the black magnetic toner 17 was poor. The reason is that the circularity of the black magnetic toner 17 is 0.96.
It is presumed that the transfer characteristics were impaired because the number of particles was 3 and the number of particles of 0.03 to 1 μm in the particle size distribution of the hydrophobic magnetic iron oxide used was 42% by number.

[0400]

[Embodiment 20] Black magnetic toner 12 in Embodiment 15
Was changed to the black magnetic toner 18 and the magnetic carrier 1 was changed to the magnetic carrier 2, and the same evaluation was performed. The combinations of developers used are shown in Table 4. The results are shown in Tables 5 to 8, and in each environment, the image density of the black magnetic toner 18 was low from the initial stage of the durability test, and the image concentration was not recovered even after the durability test. It is presumed that the reason is that the hydrophobic magnetic iron oxide has a large volume average diameter of 0.34 μm, and the dispersibility in the toner is not improved.

[0401]

Example 21 The same evaluation as in Example 19 was carried out except that the black magnetic toner 9 was changed to the black magnetic toner 21. The combinations of developers used are shown in Table 4. The results are shown in Tables 5 to 8, and the black magnetic toner 21 is used under each environment.
The image density was low from the beginning of the durability test, and the image density did not recover even after the durability test. In the particle size distribution of the hydrophobic iron oxide used for this reason, it is presumed that particles of 0.3 μm or more were present in an amount of 15% by number, and uniform triboelectric charging could not be performed.

[0402]

Example 22 The same evaluation as in Example 17 was carried out except that the black magnetic toner 7 was changed to the black magnetic toner 22. The combinations of developers used are shown in Table 4. The results are shown in Tables 5 to 8.

[0403]

Twenty-third Embodiment A full-color image was produced by using the image forming apparatus of FIG. 5, which is a modified CLC1000 (manufactured by Canon), in place of the image forming apparatus used in the first embodiment. The results were obtained. The combinations of developers used are shown in Table 4. The results are shown in Tables 5 to 8.

[0404]

Twenty-fourth Embodiment A full-color image is prepared by using the image forming apparatus of FIG. 5 in which CLC1000 (manufactured by Canon) is modified instead of the image forming apparatus used in the tenth embodiment.
Good results were obtained as in Example 1. The combinations of developers used are shown in Table 4. The results are shown in Tables 5 to 8.

[0405]

According to the present invention, by using the replenishment developer having the above-mentioned constitution, the chargeability of the toner is stabilized without being influenced by the environment, and good image quality can be obtained for a long period of time.

The present invention can be used for a long period of time by using the magnetic toner having the above-mentioned structure in which the surface of the photoconductor is hard to be scraped when using different kinds of toner such as magnetic toner and non-magnetic toner. It is possible to provide a magnetic toner that is less likely to cause image defects.

INDUSTRIAL APPLICABILITY The present invention can provide an image forming apparatus capable of stably forming an electrostatic latent image even in an environment of low humidity, and having few image defects such as fog due to a decrease in charging property during durability.

[Brief description of drawings]

FIG. 1 shows an embodiment of an image forming apparatus equipped with a rotary rotation type developing device in which a replenishing developer of the present invention is used.

2 shows an embodiment of a developing device used in the image forming apparatus of FIG.

FIG. 3 is an enlarged configuration diagram for explaining the developing device in FIG.

FIG. 4 shows an embodiment of the developing device of FIG.

FIG. 5 shows an embodiment of a full-color image forming apparatus of the present invention.

FIG. 6 shows a bias having a discontinuous AC electric field of a developing bias used in the image forming apparatus used in Example 1.

[Explanation of symbols]

1 photosensitive drum 2,3,4,5 developing unit 6 Development sleeve 7 Control member 8 magnet roller 9 Color Replenishment Developer Storage Device 10, 11 developer transport screw 12 Transfer material 13 Rotary rotation type developing device 14 Laser exposure device 15 Charging device 17 Development tank 18,23 Cleaning device 19, 22, 33 Static eliminator 20 Transport guide member 21 Fixing device 24 Transfer drum 25 Registration Roller 26,27 paper feed tray 28,29 Sending roller 30 Opposing roller 31 Transfer device 32 Adsorption device 34 Developer outlet 35 developer recovery port 37 Developer Primary Storage Section 38 Developer Recovery Auger 39 scraper 61 Photosensitive drum 62 Primary charger 63 developing device 65 Replenishment developer device 85 Toner concentration detection sensor

─────────────────────────────────────────────────── ─── Continuation of front page (51) Int.Cl. ⁷ Identification code FI theme code (reference) G03G 9/087 G03G 9/10 352 9/107 9/08 101 9/113 301 384 (72) Inventor Chiba Tatehiko 3-30-2 Shimomaruko, Ota-ku, Tokyo Canon Inc. (72) Inventor Yoshi ▲ Saki ▼ Kazumi 3-30-2 Shimomaruko, Ota-ku, Tokyo Canon Inc. F-term (reference) 2H005 AA03 AA08 AA15 AA21 AB06 BA03 BA06 BA11 CA12 CA14 CA15 CA17 CB13 EA02 EA05 EA07 EA10 FA06

Claims (26)

[Claims] 1. A black one-component magnetic developer, a yellow two-component developer, a magenta two-component developer and a cyan two-component developer, and a yellow replenishment developer, a magenta color replenishment developer and cyan. Color replenishing developer Color replenishing developer used in a color image forming apparatus having a developing device that contains a color replenishing developer of the developer and forms a visible image by using the developer. A developer for use, which is contained in an amount of 2 to 50 parts by mass of a non-magnetic toner selected from the group consisting of a yellow non-magnetic toner, a magenta non-magnetic toner and a cyan non-magnetic toner with respect to 1 part by mass of carrier particles. A replenishing developer for color color, which is characterized in that 2. The color color replenishment developer according to claim 1, wherein the carrier particles are magnetic particle-dispersed resin carrier particles containing at least inorganic compound particles and a binder resin. 3. The color color replenishment developer according to claim 2, wherein the binder resin is a thermosetting resin. 4. The color color replenishment developer according to claim 3, wherein the thermosetting resin contains at least a phenol resin. 5. The color color according to claim 2, wherein the magnetic particle-dispersed resin carrier particles are a coated carrier having a carrier core and a resin layer coating the carrier core. Replenishing developer. 6. The color color replenishment developer according to claim 5, wherein the resin layer is made of a silicone resin. 7. The color color replenishment developer according to claim 2, wherein the magnetic particle-dispersed carrier particles have a volume average particle diameter of 15 to 60 μm. 8. The magnetic particle-dispersed carrier particles have a true specific gravity of 2.5 to 4.5 and 1000 / 4π (kA /
The strength of magnetization at m) is 20 to 65 (Am ² / kg),
The replenishment developer for color color according to any one of claims 2 to 7, wherein the residual magnetization (σr) is 0.1 to ²⁰ Am ² / kg. 9. The magnetic particle-dispersed resin carrier particles are polymerized carriers.
The replenishing developer for color color according to any one of 1. 10. A black one-component magnetic developer, a yellow two-component developer, a magenta two-component developer and a cyan two-component developer, and a yellow color replenishment developer,
Magenta color replenishment developer and cyan color replenishment developer A color image provided with a developing device for accommodating the color color replenishment developer of the developer and forming a visible image using the developer to develop the visible image. A black one-component magnetic developer used in a forming apparatus, the black one-component magnetic developer having black magnetic toner particles containing at least a binder resin and magnetic iron oxide, i) X-ray photoelectron spectroscopy analysis The ratio (B / A) of the content (B) of the iron element to the content (A) of the carbon element existing on the surface of the black magnetic toner particles measured by the method (B / A) is less than 0.001, and ii) black one-component magnetism C is the projected area equivalent diameter of the developer,
When the minimum value of the distance between the magnetic iron oxide and the surface of the black magnetic toner particles in the cross-sectional observation of the black one-component magnetic developer using a transmission electron microscope (TEM) is D, D / C ≦ 0.
50% by number or more of the developers satisfying the relationship of 02, and iii) the average circularity of the black one-component magnetic developer is 0.9.
A black one-component magnetic developer having a content of 70 or more. 11. The black one-component magnetic developer according to claim 10, wherein the ratio (B / A) is less than 0.0005. 12. The developer satisfying the relationship of D / C ≦ 0.02 is 65% by number or more.
Or the black one-component magnetic developer according to item 11. 13. The developer satisfying the relationship of D / C ≦ 0.02 is 75% by number or more.
Or the black one-component magnetic developer according to item 11. 14. The black one-component magnetic developer according to claim 10, wherein the magnetic iron oxide is contained in an amount of 10 to 200 parts by mass with respect to 100 parts by mass of the binder resin. Agent. 15. The black one-component magnetic development according to claim 10, wherein the magnetic iron oxide is contained in an amount of 20 to 180 parts by mass with respect to 100 parts by mass of the binder resin. Agent. 16. The black one-component magnetic developer has a volume average particle diameter of 2 to 10 μm.
The black one-component magnetic developer according to any one of 0 to 15. 17. The black one-component magnetic developer according to claim 10, wherein the black one-component magnetic developer has a volume average particle size of 3.5 to 8 μm. 18. The black one-component magnetic developer according to claim 10, wherein the black one-component magnetic developer contains silica. 19. The magnetic iron oxide is surface-treated with a surface treating agent, according to claim 10.
9. The black one-component magnetic developer according to any of 8. 20. The black one-component magnetic developer according to claim 19, wherein the surface treatment agent is an alkyltrialkoxysilane coupling agent. 21. The magnetic iron oxide has a volume average particle diameter of 0.
1 to 0.3 μm and 4 particles of 0.03 to 0.1 μm
21. The number is 0 or less, and the number is 0 or less.
The black one-component magnetic developer according to any one of 1. 22. The magnetic iron oxide is 0.03 to 0.1.
22. The black one-component magnetic developer according to claim 21, containing 30% by number or less of particles of .mu.m and 10% or less of particles of 0.3 .mu.m or more. 23. The magnetic iron oxide is 0.03 to 0.1.
22. The black one-component magnetic developer according to claim 21, which contains 30% by number or less of particles of .mu.m and 5% or less of particles of 0.3 .mu.m or more. 24. The black one-component magnetic developer according to claim 10, wherein the black magnetic toner particles contain a release agent. 25. The black one-component magnetic developer according to claim 10, wherein the black magnetic toner particles are toner particles manufactured by a polymerization method. 26. At least a black one-component magnetic developer, a yellow two-component developer, a magenta two-component developer and a cyan two-component developer, and a yellow replenishment developer,
Magenta color replenishing developer and cyan color replenishing developer A color containing at least a developing device that contains the color replenishing developer of the developer and forms a visible image using these developers to develop the image. An image forming apparatus, wherein the black one-component magnetic developer is the black one-component magnetic developer according to any one of claims 10 to 25, the yellow color replenishment developer, and the magenta color replenishment developer. A color image forming apparatus, wherein the cyan color replenishing developer is the color color replenishing developer according to claim 1.