JP2003122047A - Toner kit and image forming method - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a toner kit which is hardly influenced by environment, has a stable chargeability, high in image density even in a long time use, suppressive in the occurrence of fogging and excellent in an image reproducibility, and to provide an image forming method which reduces the amount of toner left after a transfer process such as transfer void, because of the high transfer performance, and hardly causes a defective image even in a long time use. SOLUTION: In the toner kit having a magnetic toner and a non-magnetic toner, the magnetic toner is constituted of such toner having a (B/A) of <0.001, and the toner satisfying the relation of D/C<=0.02 is >=50 number %, and the average circularity is >=0.970, and as for the non-magnetic toner including coloring agent selected out of a group constituted of yellow coloring agent, magenta coloring agent and cyan coloring agent, the average circularity is >=0.970.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an image forming method and a toner used in a recording method utilizing electrophotography, electrostatic recording, magnetic recording, toner jet recording, and the like. After using a combination of black and white toner and color toner to form a toner image on the electrostatic latent image carrier in advance,
The present invention relates to a toner and an image forming method used for a copying machine, a printer, a fax, etc., which forms an image by transferring onto a transfer material.

[0002]

2. Description of the Related Art Conventionally, a large number of electrophotographic methods are known, but in general, a photoconductive material is used, and an electrostatic charge image carrier (hereinafter referred to as "photoreceptor") is formed by various means.
An electrical latent image is formed on the upper surface of the latent image, and then the latent image is developed with toner to form a visible image. If necessary, the toner image is transferred to a transfer material such as paper, and then the transfer material is applied by heat or pressure. It is a product in which a toner image is fixed on the top 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.

Unlike the two-component system, the one-component developing system does not require carrier particles such as glass beads and iron powder, and therefore the developing device itself can be made compact and lightweight. Further, since the two-component developing system needs to keep the toner concentration in the developer constant, an apparatus for detecting the toner concentration and supplying a required amount of toner is required. Therefore, also in this case, the developing device becomes large and heavy. Since such a device is not necessary in the one-component developing method,
It is preferable because it can be made small and light.

However, a considerable amount of fine powdery magnetic material is mixed and dispersed in the insulating magnetic toner used in the one-component developing method, and a part of the magnetic material is exposed on the surface of the toner particles. There is a problem 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 changed or deteriorated.

When the conventional magnetic toner containing a magnetic substance is used, it is considered that the above-mentioned problems are caused largely by the fact that the magnetic substance is exposed on the surface of the magnetic toner. That is, by exposing the magnetic fine particles having a resistance relatively lower than that of the resin forming the toner on the surface of the magnetic toner, the toner charging performance is deteriorated, the toner fluidity is deteriorated, and further, the In use, deterioration of the developer is caused, such as a decrease in image density due to the peeling of the magnetic material due to rubbing between toners or a regulating member, occurrence of uneven density called a sleeve ghost, and the like.

Under the circumstances described above, various proposals have been made for magnetic iron oxide contained in magnetic toners, but there are still some points to be improved.

On the other hand, although the toner has been manufactured by the conventional pulverization method, the pulverization method has a limit to the fineness of the toner required for high definition and high image quality.
In particular, the uniform chargeability and fluidity of the toner are significantly reduced.

In order to overcome the problems of the toner by the pulverization method, a method for producing the toner by the suspension polymerization method has been proposed.

A toner by suspension polymerization (hereinafter referred to as a polymerized toner) can be easily made into fine particles, and since the obtained toner has a spherical shape, it has excellent fluidity and high image quality. It is advantageous for However, by containing a magnetic material in the polymerized toner, its fluidity and charging characteristics are significantly reduced. This is because the magnetic substance is generally hydrophilic and therefore easily present on the toner surface, and in order to solve this problem, it is important to modify the surface characteristics of the magnetic substance.

A number of proposals have been made regarding surface modification for improving the dispersibility of the magnetic material in the polymerized toner. For example,
JP-A-59-200254, JP-A-59-200
256, JP-A-59-200257, JP-A-59-224102 and the like have proposed various silane coupling agent treatment techniques for magnetic materials.
-250660 discloses a technique of treating silicon-containing magnetic particles with a silane coupling agent, and JP-A-7-72654 discloses a technique of treating magnetic iron oxide with an alkyltrialkoxysilane. Has been done.

However, although the dispersibility in the toner is improved to some extent by these treatments, there is a problem in that it is difficult to uniformly make the surface of the magnetic material uniform. The generation of non-hydrophobicized magnetic particles cannot be avoided, and is insufficient to improve the dispersibility in the toner to a good level.

Further, a special toner in which magnetic particles are contained only in a specific portion inside the particles is also disclosed in Japanese Patent Laid-Open No. Hei 7 (1998)
It has already been disclosed in JP-A-209904. However, JP-A-7-209904 does not mention the circularity of the toner disclosed.

On the other hand, in printers and copiers, 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 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 the process of developing color toners other than black toner, non-magnetic color toners are often used in order to reproduce colors vividly. These non-magnetic color toners do not have a magnetic component that is excellent in charge imparting in terms of electrostatic properties that occupy an important part in electrophotography, and thus are generally referred to as carrier particles. Often mixed with the body and used as a two-component developer.

An image forming means using a magnetic toner and a non-magnetic color toner is proposed in JP-A-5-088412. According to this publication, a developer that outputs a black and white image has high maintainability, and by using a magnetic toner conventionally used in the market, an image texture (glossiness) similar to that of a black and white copier or a black and white printer is obtained. It has been achieved that a user can obtain a clear color image mainly by outputting a black and white image that does not cause discomfort. However, as mentioned above, when a higher-speed center machine will become mainstream in the office environment in the future, the output image amount will increase, and the following concerns are expected in obtaining a black and white image using magnetic toner. . That is, as the electrophotographic process becomes faster, the untransferred transfer residual magnetic toner is pressed against the surface of the photoconductor, and the abrasion or the scraped portion due to the scraping of the photoconductor surface becomes a nucleus to easily cause toner fusion. It is a point. Particularly in the magnetic toner, 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.

Specializing in the cleaning property of the transfer residual toner, Japanese Patent Laid-Open Nos. 11-24358, 11-52599, and 2000-112203.
The tandem type color electrophotography was proposed in the Japanese publication.
One set of each of a photoreceptor corresponding to the toner type, a charger, an exposure device, and a cleaning device is required. The publications and the like can be used under optimum conditions for each of them, but there is a point that the size of the device becomes large and costs are high.

Further, in Japanese Patent Laid-Open No. 8-137119,
An example is disclosed in which a developer having an average particle diameter of 4.5 to 9.0 μm is used, and the surface of the photoconductor is provided with irregularities having a curvature that is at least twice the average curvature of the developer to reduce “fog”. Has been done. However, in this publication, the surface shape of the photoconductor is defined as a macroscopic shape of a developer level (μm order) or more, and particularly when a magnetic developer and a non-magnetic developer are used. The cleaning property is not disclosed.

Further, in a system using a plurality of colors on the same photoconductor, particularly a magnetic toner and a non-magnetic toner, when the cleaning device alone is used, the characteristics of the magnetic toner and the non-magnetic toner are different. The conditions such as contact pressure required for are different.

On the other hand, when there is a magnetic black toner remaining after transfer as seen above when outputting a full-color image in which a non-magnetic color toner and a magnetic black toner are mixed, the non-magnetic color toner unit is used during continuous output. The magnetic black toner remaining after the transfer may be mixed in, and it is easily conceivable that the tint of the non-magnetic color toner for which clear color reproducibility is required is impaired.

The problems of abrasion of the photosensitive member and defective transfer are likely to occur when a developer containing 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 particle easily scratches the surface of the photoconductor. Further, the problem of shaving becomes particularly noticeable when a magnetic developer in which a magnetic material is exposed on the surface of toner particles is used as described above. This is easily understandable considering that the exposed magnetic body is directly pressed against the photoconductor.

In a developing / cleaning constitution essentially having no cleaning device, the surface of the photoconductor is rubbed with the toner and the toner carrier, the toner of the non-image area is collected by the toner carrier, and the toner of the image area is removed. It is necessary to have a structure for developing with. At the time of this rubbing, if the oppositely charged toner such as the transfer residual toner or the fog toner can be easily reversed to the positive charge, the electric potential can be easily collected.

Conventionally, when a toner containing a magnetic material is used in a developing / cleaning structure, the magnetic material is exposed on the surface of the toner. Therefore, it is difficult to obtain a high-definition image because the electrostatic charge image on the photoconductor is disturbed.
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, if the pressing force of the cleaning member is weakened in order to prolong the life of the photosensitive member, the amount of transfer residual toner that slips through the cleaning member increases by that amount, but the toner that slips through can be reduced as much as possible in the developing process. It can be said that it is very important in the system for recovering.

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 conventional magnetic toner. It is a big 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.

[0029]

SUMMARY OF THE INVENTION An object of the present invention is to provide an image forming method and a toner kit which solve the above-mentioned problems of the prior art, and more specifically, it is difficult to be influenced by the environment and has stable charging performance. It is to provide a toner kit which has a high image density even when used for a long time, suppresses fogging, and has excellent image reproducibility.

An object of the present invention is to provide an image forming method which has less transfer residual toner such as voids in transfer due to having a high transfer property and is less likely to cause image defects even in long-term use. There is a thing.

An object of the present invention is to provide an image forming method 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. It is in.

[0032]

The present invention is as follows. (1) In a toner kit including a magnetic toner containing at least a binder resin and iron oxide, and a non-magnetic toner containing at least a binder resin and a colorant, the magnetic toner is i) X-ray photoelectron. The ratio (B / A) of the content (B) of the iron element to the content (A) of the carbon element present on the toner surface measured by spectroscopic analysis is less than 0.001, and ii) the projected area of the magnetic toner When the equivalent diameter is C and the minimum value of the distance between the iron oxide and the toner surface in the cross section observation of the toner using a transmission electron microscope (TEM) is D, D
50% by number or more of the toner satisfying the relationship of /C≦0.02, iii) the average circularity of the magnetic toner is 0.970 or more, and the non-magnetic toner is iv) yellow colorant and magenta coloring. Containing a colorant selected from the group consisting of agents and cyan colorants, v)
A toner kit in which the average circularity of the non-magnetic toner is 0.970 or more. (2) A charging step of charging the electrostatic image carrier with a charging member to which a voltage is applied from the outside; an exposure step of forming an electrostatic latent image on the electrostatic image carrier by exposure; the electrostatic latent image Magnetic toner of a toner kit having magnetic toner and non-magnetic toner
Or a developing step of forming a toner image of a monochrome image or a color image with a non-magnetic toner; a transferring step of transferring the developed toner image to a transfer material; and the toner kit is the toner kit of the present invention. Image forming method.

[0033]

BEST MODE FOR CARRYING OUT THE INVENTION The present invention is described in detail below. <1> Toner Kit of the Present Invention The present invention is a toner kit including a magnetic toner containing at least a binder resin and iron oxide, and a non-magnetic toner containing at least a binder resin and a colorant. (1) Magnetic toner In the toner kit of the present invention, the magnetic toner is i) the ratio of the iron element content (B) to the carbon element content (A) present on the toner surface measured by X-ray photoelectron spectroscopy. (B / A) is less than 0.001, ii) the projected area equivalent diameter of the magnetic toner is C, and the distance between the iron oxide and the toner surface in the cross-sectional observation of the toner using a transmission electron microscope (TEM) When the minimum value is D, D
The toner satisfying the relationship of /C≦0.02 is 50% by number or more, and iii) the average circularity of the magnetic toner is 0.970 or more.

The inventors of the present invention have earnestly studied the homogenization and stabilization of the charging of the magnetic toner so far, and as a result, the content of the carbon element existing on the surface of the magnetic toner measured by X-ray photoelectron spectroscopy ( The ratio (B / A) of the iron element content (B) to A) is less than 0.001 and the average circularity of the toner calculated from the circularity calculated by the following formula is 0.970 or more. However, it has been found that it is extremely effective for uniforming and stabilizing the chargeability of the toner.

[0035]

[Equation 1] (In the formula, L ₀ represents the perimeter of a circle having the same projected area as the particle image, and L represents the perimeter of the projected image of the particle.) By using the above magnetic toner, toner recovery failure In the image forming method in which a cleanerless structure that easily causes a ghost image or contact charging is combined, or in an image forming method including a contact charging step, a one-component non-contact developing step, and a contact transfer step, It was found that shaving, charging failure and transfer failure were significantly suppressed, and a high-definition image free from fog and other image defects could be stably obtained even after long-term use. This is difficult to achieve with a magnetic toner using magnetic iron oxide that is generally used in the past.
The reason is that the magnetic iron oxide used was not sufficiently and uniformly made hydrophobic.

When the magnetic toner of the present invention is manufactured, by using iron oxide having a surface subjected to hydrophobic treatment,
The dispersibility of iron oxide particles in the toner binder resin can be improved. Further, even when a large amount of iron oxide is exposed on the surface of the toner particles, it is difficult to impair the charging performance of the toner under any environment if the surface of the iron oxide is uniformly subjected to the hydrophobic treatment.

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

Generally, since the untreated iron oxide surface has hydrophilicity, it is necessary to make the hydrophilic iron oxide hydrophobic in order to obtain hydrophobic iron oxide. According to the method, the uniformity of hydrophobicity is insufficient, and the conventional toner using such iron oxide has a lack of stability because its chargeability varies depending on humidity and the like.

On the other hand, the iron oxide used as a magnetic substance in the magnetic toner of the present invention has a very high level of uniformity of hydrophobization, and is, for example, hydrophobized. At this time, it is an iron oxide obtained by hydrolyzing the coupling agent and surface-treating it in an aqueous medium while stirring so that the iron oxide has a primary particle size. Compared to the treatment in the gas phase, the hydrophobic treatment method in an aqueous medium is less likely to cause coalescence of iron oxide particles with each other, and the electrostatic repulsion action between the iron oxide particles due to the hydrophobic treatment works, resulting in iron oxide. Since the particles are surface-treated 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 or silazanes that generate a gas. 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 which can be used for the surface treatment of iron oxide in the present invention include silane coupling agents and titanium coupling agents.
More preferably used is a silane coupling agent, which is represented by the general formula (I).

[0042]

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. Specifically, for example, vinyltrimethoxysilane, vinyltriethoxysilane, γ-methacryloxypropyltrimethoxysilane, vinyltri. Acetoxysilane, methyltrimethoxysilane, methyltriethoxysilane,
Examples thereof include isobutyltrimethoxysilane, dimethyldimethoxysilane, dimethyldiethoxysilane, trimethylmethoxysilane, hydroxypropyltrimethoxysilane, phenyltrimethoxysilane, n-hexadecyltrimethoxysilane, and n-octadecyltrimethoxysilane.

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

[0044]

## STR2 ## _{C p H 2p + 1 -Si- (} OC q H 2q + 1) 3 (II) ( wherein, p represents an integer of 2 to 20, q is an integer of 1-3.) When p in the above formula (II) is less than 2, hydrophobic treatment is easy, but it is difficult to impart sufficient hydrophobicity, and when p is greater than 20, hydrophobicity is sufficient. However, the coalescence of iron oxide particles increases, and it becomes difficult to sufficiently disperse the iron oxide particles in the toner. On the other hand, when q is larger than 3, the reactivity of the silane coupling agent is lowered and it becomes difficult to sufficiently hydrophobize.

Particularly, 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 weight, preferably 0.1 to 10 parts by weight, based on 100 parts by weight of iron oxide.

In the present invention, the aqueous medium used for hydrophobizing iron oxide is a medium containing water as a main component. Specific examples of the aqueous medium include water itself, water to which a small amount of a surfactant has been added, water to which a pH adjuster has been added, and water to which an organic solvent has been 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, by a mixer having stirring blades (specifically, a high shear mixing device such as an attritor or TK homomixer) so that the iron oxide fine particles become primary particles in an aqueous medium. It is good to do enough.

Since the surface of the iron oxide particles thus obtained is uniformly subjected to the hydrophobic treatment, when used as a magnetic toner material, the dispersibility in the magnetic toner is very good,
Moreover, there is no exposure from the surface of the magnetic toner. Therefore, by using such iron oxide, the ratio (B) 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 (B)
It is possible to obtain the magnetic toner according to the present invention in which / A) is less than 0.001. By using a magnetic toner having a ratio (B / A) of less than 0.001, uniformity and stabilization of charging can be achieved, and high image quality and high durability stability can be achieved.
Furthermore, by setting the (B / A) to less than 0.0005, the charging property and stability are further improved.

The 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 equivalent amount or an equivalent amount or more of an alkali such as sodium hydroxide to the ferrous sulfate aqueous solution. 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 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 iron oxide particles are dried as they are, coalescence due to agglomeration of the particles cannot be avoided, and even if wet-hydrophobicizing treatment is performed on such powder in the agglomerated state, uniform hydrophobizing treatment is performed. This is because it is difficult for the toner using such surface-treated iron oxide to
This is because it is difficult to achieve B / A <0.001 like the toner according to the present invention.

As ferrous sulfate used in the production of iron oxide, iron sulfate generally produced as a by-product of 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.

In the method for producing magnetic iron oxide by the aqueous solution method, generally, an iron concentration of 0.5 to 2 mol / liter is used in view of preventing the viscosity from increasing during the reaction and 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 thus produced hydrophobic iron oxide particles in the magnetic toner, it is possible to obtain the magnetic toner of the present invention which is excellent in image characteristics and stability.

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. Sho 60-3181 describes a wet powder surface treatment of a dry powdery untreated magnetic material with a silane coupling agent.
In such an untreated dry magnetic powder, it is inevitable that the particles are united with each other due to primary aggregation during drying, so that even if wet surface treatment is performed, it is difficult to make the individual magnetic particles uniform and hydrophobic. . Therefore, even if a polymerized toner is produced using such a surface-treated magnetic material, the characteristic B /
It is difficult to achieve A <0.001.

The iron oxide used in the magnetic toner of the present invention may contain elements such as phosphorus, cobalt, nickel, copper, magnesium, manganese, aluminum, and silicon, and contains triiron tetraoxide and γ-iron oxide as main components. And these are used alone or in combination of two or more.
These iron oxides preferably have a BET specific surface area by the nitrogen adsorption method of ² to 30 m ² / g, particularly 3 to 28 m ² / g, and more preferably a Mohs hardness of 5 to 7.

The shape of iron oxide includes octahedron, hexahedron, sphere, needle, scale, etc., but octahedron, hexahedron,
A substance having a small anisotropy such as a spherical shape or an amorphous shape is preferable in order to increase the image density. The shape described above can be confirmed by SEM or the like. The particle size of iron oxide is 0.03
In measuring the particle size of particles having a particle size of μm or more, the volume average particle size is 0.1 to 0.3 μm, and the particles having a particle size of 0.03 to 0.1 μm are 40% by number or less. Something is preferable.

When an image is obtained from a magnetic toner using iron oxide having a volume average particle size of less than 0.1 μm, the tint of the image shifts to reddish, the blackness of the image is insufficient, and in a halftone image. For example, the tendency to feel reddish color becomes stronger.
Generally not preferred. Further, since the surface area of iron oxide increases, the dispersibility decreases, and the energy required for production increases, which is not efficient. Further, the effect of iron oxide as a coloring agent becomes weak, and the density of an image may be insufficient, which is not preferable.

On the other hand, the volume average particle diameter of iron oxide is 0.3 μm.
If it exceeds, the mass per particle becomes large, the probability of being exposed to the surface of the magnetic toner increases due to the difference in specific gravity with the binder resin during manufacturing, and the possibility that wear of the manufacturing equipment may increase significantly However, the sedimentation stability of the dispersion is reduced, which is not preferable.

In the magnetic toner, the iron oxide of 0.
If the number of particles of 03 to 0.1 μm or less exceeds 40% by number,
The surface area of iron oxide increases and the dispersibility decreases, and aggregates are likely to occur in the toner, impairing the chargeability of the toner,
It is preferably 40% by number or less because the coloring power is likely to decrease. Further, when the content is 30% by number or less, the tendency becomes smaller, which is more preferable.

Iron oxide having a particle size of less than 0.03 μm has a small stress due to its small particle size during toner production, and therefore has a low probability of appearing on the surface of 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, particles of 0.3 μm or more in iron oxide are 1
If it exceeds 0% by number, the coloring power tends to decrease, and the image density tends to decrease. In addition, even if the amount used is the same, the number is small, so that the magnetic toner particles are present near the surface of the toner particles. It is probabilistically difficult to include a uniform number in each toner particle, which is not preferable. More preferably, it is 5% by number or less.

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

The volume average particle size and particle size distribution of iron oxide are determined by the following measuring methods.

With the particles sufficiently dispersed, the projected areas of 100 iron oxide particles in the visual field were measured with a transmission electron microscope (TEM) at a magnification of 30,000 times to measure the projected areas. 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 iron oxide in the magnetic toner particles are determined by the following measuring method.

After the magnetic toner particles to be observed are sufficiently dispersed in the epoxy resin, the cured product obtained by curing for 2 days in an atmosphere at a temperature of 40 ° C. is used as a flaky sample with a microtome to obtain a transmission electron. The projected area of the particle size of 100 iron oxide particles in the field of view 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 projected area of each measured particle. Is determined as the particle size of iron oxide.

Further, 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 diameter of the projected area of the toner is C and the minimum value of the distance between the iron oxide and the toner surface in the cross-section observation of the toner using a transmission electron microscope (TEM) is D, D / The fact that the number of toners satisfying the relationship of C ≦ 0.02 is 50% or more 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, and more preferably 75% or more.

When the number of magnetic toners satisfying the relation of D / C ≦ 0.02 is less than 50%, magnetic particles are present at least outside the boundary line of D / C = 0.02 in the majority of the magnetic toners. Will not exist at all. Assuming that such particles are spherical, at least 11.5% of the space where iron oxide does not exist is present on the surface of the magnetic toner when one magnetic toner is used as the entire space.

In practice, iron oxide does not exist so as to be uniformly aligned at the closest position to form an inner wall inside the magnetic toner, so it is clear that the amount is 12% or more. In the magnetic toner composed of such particles, the various problems described above are likely to occur.

In the present invention, specific D by TEM
The method of measuring / C is as follows. First, the particles to be observed are sufficiently dispersed in a room temperature curable epoxy resin and then cured for 2 days in an atmosphere at a temperature of 40 ° C. to obtain a cured product, which is directly or frozen to prepare a diamond tooth. Observe as a thin sample with a microtome.

Next, the ratio of the corresponding number of particles is determined as follows.

Particles for determining D / C by TEM are
The equivalent circle diameter is calculated from the cross-sectional area in the micrograph, and the value is within the range of ± 10% of the number average particle diameter (D1) measured by the Coulter counter described later. , The minimum value (D) of the distance from the iron oxide particle surface 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 (Hitachi H-600 type) is used as an apparatus and an accelerating voltage of 1
Observe at 00 kV and observe and measure using a micrograph with a magnification of 10,000 times.

B / A <0.001 is satisfied, and D / C ≦
The magnetic toner in which the number of toners satisfying the relationship of 0.02 is 50% or more means that iron oxide is localized on the surface of the magnetic toner, or conversely, it is extremely encapsulated and unevenly distributed inside the magnetic toner. The magnetic toner is not a magnetic toner that appears to be worn, but is a magnetic toner in which iron oxide is substantially evenly dispersed in the magnetic toner and the exposure of the magnetic material to the surface of the magnetic toner is suppressed. If the dispersed state of iron oxide is non-uniform, it is difficult to satisfy the requirements of the present invention.

Further, in the image forming method, when the magnetic toner in which the iron oxide is barely exposed on the surface of the toner particles is used, the magnetic toner is pressed against the surface of the electrostatic image carrier by the charging member or the transfer member. However, the surface of the electrostatic image carrier is scarcely scraped, and it is possible to significantly reduce the scraping of the electrostatic image carrier and the fusion of the magnetic toner over a long period of time.

As described above, the iron oxide is hardly exposed on the surface of the magnetic toner particles, but in order to create a state in which the iron oxide is concentrated on the outermost surface layer of the magnetic toner particles, the surface of the iron oxide is subjected to a hydrophobic treatment. Thus, it is considered possible to prepare a magnetic toner satisfying the relationship of D / C ≦ 0.02 as described above. When magnetic toner is manufactured by a polymerization method using iron oxide that has not been subjected to a hydrophobic treatment, it is easily exposed on the surface of the magnetic toner particles. It is possible to suppress the exposure of the iron oxide and to concentrate the magnetic iron oxide on the outermost surface layer inside the magnetic toner particles.

The iron oxide used in the magnetic toner of the present invention is preferably used in an amount of 10 to 200 parts by mass, more preferably 20 to 180 parts by mass, based on 100 parts by mass of the binder resin. When the content of iron oxide is less than 10 parts by mass, the coloring power of the magnetic toner is poor and it is difficult to suppress fog. On the other hand, when it exceeds 200 parts by mass, the coercive force due to the magnetic force on the toner carrier is increased and the developability is improved. Not only does this decrease, it becomes difficult to uniformly disperse iron oxide in the individual magnetic toner particles, but also the fixability deteriorates.

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

Next, the circularity of the toner, which is another feature of the present invention, will be described. In order to reduce the toner adhesion to the non-image area on the electrostatic image carrier and the amount of transfer residual toner, it is necessary that the chargeability of the toner particles is sufficient and uniform. Furthermore, when a toner having a small particle size is used from the viewpoint of high image quality, the adhesive force of the toner particles increases, so the shape of the toner particles also greatly affects the toner adhesion to the non-image area on the electrostatic image carrier. Exert. That is, as the toner particles are closer to a sphere, and the more uniform the shape is, the smaller the particle adhesion area is, the less toner adhesion to the non-image area on the electrostatic image carrier and the transfer residual toner amount are reduced, and high image quality and durability are achieved. Stability is achieved.

In addition, since the magnetic toner particles according to the present invention have sufficient chargeability and the adhesive force of the toner particles is reduced as described above, a transfer material such as paper from the electrostatic image carrier is obtained. The transfer efficiency of the toner to the toner is also greatly improved.
It can be said that this is an important toner performance for achieving high resolution as well as reproducibility of minute dot images.

Therefore, in the toner of the present invention, both the magnetic toner and the non-magnetic toner need to have an average circularity of 0.970 or more, and thereby high image quality and high stability are achieved.

Therefore, when a toner kit having such a magnetic toner and a non-magnetic toner is used, the transfer residual toner is greatly reduced, so that the photoconductor is prevented from being scraped and the toner is fused, and the image defects are remarkably suppressed. It is considered to be a thing.

Further, since the toner having an average circularity of 0.970 or more has almost no edge portion on the surface, even if there is 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.

Further, since the toner remaining after transfer is reduced, the black magnetic toner remaining after transfer is transferred to the toner carrier for the color non-magnetic toner, especially when outputting a full-color image in which color non-magnetic toner and black magnetic toner are mixed. It has been found that there is no possibility of being mixed and hindering the charging property of the color non-magnetic toner and causing the hue variation.

Further, these effects also become prominent even in an image forming method including a contact transfer step in which voids in transfer are likely to occur.

The magnetic toner in the present invention preferably has a volume average particle diameter of 2 to 10 μm. When the volume average particle diameter of the magnetic toner exceeds 10 μm, the reproducibility of the fine dot image is deteriorated, so that the charging stability of the magnetic toner in the severe environment obtained by the present invention cannot be sufficiently exhibited.

On the other hand, the volume average particle diameter of the magnetic toner is 2 μm.
When it is smaller, the fluidity of the magnetic toner is remarkably lowered even if the iron oxide of the present invention is used, and problems such as fog due to charging failure and low density are likely to occur.

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

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

The magnetic toner of the present invention can be manufactured by a pulverizing method, but in the pulverizing method, a mechanical, thermal or some special treatment is performed in order to adjust the average circularity of the magnetic toner to 0.970 or more. Since it is necessary to carry out the above, it is preferable to manufacture by the suspension polymerization method.

In particular, when a black magnetic toner is produced, even if a magnetic toner is produced by suspension polymerization using ordinary iron oxide, iron oxide is inferior in dispersibility and iron oxide is unevenly distributed on the toner surface. It is difficult to obtain a magnetic toner having an average circularity of 0.970 or more because iron oxide moves randomly during granulation in an aqueous medium and is dragged by it to distort the particle shape. In the present invention, in order to easily obtain a magnetic toner having an average circularity of 0.970 or more, it is preferable that the iron oxide used is subjected to uniform hydrophobicization at a high level.

The following are examples of the polymerizable monomer that constitutes the polymerizable monomer system serving as the binder resin, which is 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 monomers may be used alone or in combination. Among the above-mentioned monomers, it is preferable to use styrene or a styrene derivative alone or in combination with other monomers, from the viewpoints of developing characteristics and durability of the magnetic toner.

Further, it is one of the preferable usage forms that the magnetic toner in the present invention contains 0.5 to 50 parts by mass of the releasing agent to 100 parts by mass of the binder resin. If it is less than 0.5 parts by mass, the effect of suppressing the low temperature offset is poor, and if it exceeds 50 parts by mass, the long-term storage property is deteriorated and the dispersibility of other magnetic toner materials is deteriorated, so that the fluidity of the magnetic toner is deteriorated. This leads to deterioration and deterioration of image characteristics.

Usually, the toner image is transferred onto the transfer material in the transfer step, and then the toner image is fixed onto the transfer material by energy such as heat and pressure, and a semi-permanent image is obtained. As a fixing method at this time, a heat roll type fixing is generally often used, but as described above, when a toner having a volume average particle diameter of 10 μm or less is used, a very high-definition image can be obtained. When the transfer material such as paper is used, the toner particles having a small diameter enter the gap between the fibers of the paper, the heat is not sufficiently received from the heat fixing roller, and the low temperature offset is likely to occur. However, by including an appropriate amount of wax as a release agent in the magnetic toner, it is possible to prevent abrasion of the photoconductor while achieving both high resolution and offset resistance.

Examples of waxes usable in the magnetic toner of the present invention include petroleum waxes such as paraffin wax, microcrystalline wax and petrolactam and their derivatives, montan wax and its derivatives, hydrocarbon wax and its derivatives by the Fischer-Tropsch method,
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, in the DSC curve measured by a differential scanning calorimeter, 40 to 40
Those having a maximum endothermic peak in the region of 110 ° C are preferable, and those having a maximum endothermic peak in the region of 45 to 90 ° C are more preferable. By having a 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
If the temperature is less than 0 ° C, 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 deposition of wax 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 present invention, when the magnetic toner is produced by a polymerization method, a resin may be added to the polymerizable monomer system to perform polymerization. For example, since the polymerizable monomer is water-soluble, it cannot be used because it dissolves in an aqueous suspension to cause emulsion polymerization, and thus cannot be used. For example, amino group, carboxylic acid group, hydroxyl group, sulfonic acid group, glycidyl group, nitrile group When it is desired to introduce a hydrophilic functional group-containing monomer component into the toner, a copolymer such as a random copolymer, a block copolymer, or a graft copolymer of the monomer component and a vinyl compound such as styrene or ethylene. It can be used in the form of a polymer or in the form of a polycondensate such as polyester or polyamide, or a polyaddition polymer such as polyether or polyimine. When such a resin containing a polar functional group is allowed to coexist in the toner, the wax described above is phase-separated, the inclusion becomes stronger, and a toner having good offset resistance, blocking resistance, and low-temperature fixability can be obtained. .

The amount of the resin used is 10
1 to 20 parts by mass is preferable with respect to 0 parts by mass. If the amount used is less than 1 part by mass, the effect of addition is small, whereas if it exceeds 20 parts by mass, it becomes difficult to design various physical properties of the polymerized toner. The average molecular weight of the resin containing these polar functional groups is preferably 3000 or more. When the molecular weight is less than 3,000, particularly 2000 or less, the polymer is likely to concentrate near the surface, which is not preferable because the developability, blocking resistance and the like are likely to be adversely affected.
Further, if a resin having a molecular weight different from the molecular weight range of the toner obtained by polymerizing the monomer is dissolved in the monomer and polymerized,
It is possible to obtain a toner having a wide molecular weight distribution and high offset resistance.

The magnetic toner of the present invention may contain a charge control agent in order to stabilize the charging characteristics. As the charge control agent, known materials can be used, but a charge control agent having a high charging speed and capable of stably maintaining a constant charge amount is particularly preferable.

When the magnetic toner is produced by a direct polymerization method, a charge control agent having a low polymerization inhibitory property and substantially free of a solubilized product in an aqueous dispersion medium is particularly preferable.

Specific examples of the charge control agent include, as negative charge control agents, metal compounds of aromatic carboxylic acids such as salicylic acid, alkylsalicylic acid, dialkylsalicylic acid, naphthoic acid and dicarboxylic acid, and metal salts of azo dyes or azo pigments. Alternatively, a metal complex, a high molecular compound having a sulfonic acid or carboxylic acid group in a side chain, a boron compound, a urea compound, a silicon compound, a calixarene, or the like can be given. Examples of the positive charge control agent include a quaternary ammonium salt, a polymer type compound having the quaternary ammonium salt in its side chain, a guanidine compound, a nigrosine compound, an imidazole compound, and the like.

These charge control agents are the polymerizable monomers 10
It is preferable to use 0.5 to 10 parts by mass relative to 0 parts by mass. However, in the magnetic toner of the present invention, the addition of the charge control agent is not essential, and the charge control agent is not necessarily added to the magnetic toner by positively utilizing the triboelectric charging of the magnetic toner with the layer pressure regulating member and the toner carrier. Need not include.

The polymerization initiator used when the magnetic toner of the present invention is produced by the polymerization method is a polymerization initiator having a half-life of 0.5 to 30 hours at the time of the polymerization reaction.
When the polymerization reaction is carried out with an addition amount of 20% by mass, the molecular weight is 10,000 to
A polymer having a maximum value in the range of 100,000 can be obtained, and the toner can be provided with desired strength and proper melting characteristics.

Examples of the polymerization initiator include 2,2'-azobis- (2,4-dimethylvaleronitrile) and 2,2 '.
-Azobisisobutyronitrile, 1,1'-azobis (cyclohexane-1-carbonitrile), 2,2'-
Azo- or diazo-type polymerization initiators such as azobis-4-methoxy-2,4-dimethylvaleronitrile and azobisisobutyronitrile; benzoyl peroxide, methyl ethyl ketone peroxide, diisopropyl peroxycarbonate, cumene hydroperoxide, 2 , 4
Examples thereof include peroxide type polymerization initiators such as dichlorobenzoyl peroxide and lauroyl peroxide.

In the present invention, a crosslinking agent may be added when the magnetic toner is produced by a polymerization method, and the preferable addition amount is 0.001 to 15 with respect to 100 parts by mass of the polymerizable monomer.
Parts by mass.

In the production of a toner by the suspension polymerization method, generally, a magnetic toner such as iron oxide, a colorant, a release agent, a charge control agent and a crosslinking agent is added to the above-mentioned toner composition, that is, the polymerizable monomer. Necessary components and other additives, such as an organic solvent and a dispersant, which are added to reduce the viscosity of the polymer produced by the polymerization reaction, are added as appropriate, and a homogenizer, a ball mill, a colloid mill, an ultrasonic disperser or the like is dispersed. The monomer system uniformly dissolved or dispersed by a machine is suspended in an aqueous medium containing a dispersion stabilizer. At this time, the particle size of the obtained toner particles becomes sharper by using a high-speed disperser such as a high-speed stirrer or an ultrasonic disperser to quickly make the size of the desired toner particles. 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, an ordinary stirrer may be used to stir the particles to such an extent that the particle state is maintained and the particles are prevented from floating and settling.

In the suspension polymerization method of the present invention, known surfactants and organic / inorganic dispersants can be used as dispersion stabilizers. Among them, the inorganic dispersant hardly produces harmful ultrafine powder,
Since the dispersion stability is obtained due to the steric hindrance, the stability is not easily deteriorated even when the reaction temperature is changed, the cleaning is easy, and the toner is not adversely affected.

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.

These inorganic dispersants are used as the polymerizable monomer 10
0.2 to 20 parts by mass with respect to 0 parts by mass, or 2
It is preferable to use a combination of more than one kind. In the case of aiming at a finer toner, 0.001 to
You may use together 0.1 mass part surfactant.

Examples of the surfactant include sodium dodecylbenzenesulfate, sodium tetradecylsulfate, sodium pentadecylsulfate, sodium octylsulfate,
Examples thereof include 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, it is preferable to generate the inorganic dispersant particles in an aqueous medium. For example, in the case of calcium phosphate, a more uniform and fine dispersion can be achieved by mixing a sodium phosphate aqueous solution and a calcium chloride aqueous solution under high-speed stirring to generate water-insoluble calcium phosphate. 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 is carried out at a polymerization temperature of 40 ° C. or higher, generally 50 to 90 ° C. When the polymerization is carried out within this temperature range, the wax as a 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, the reaction temperature is 90 to 150 at the end of the polymerization reaction.
It is possible to raise it to ℃.

In the magnetic toner of the present invention, it is preferable that the magnetic toner particles obtained by a polymerization method or the like be mixed with an inorganic fine powder, particularly a hydrophobized inorganic fine powder, as a fluidity improving agent. For example, as the inorganic fine powder, it is preferable to add titanium oxide fine powder, 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 silica fine powder used in the present invention is a so-called dry method produced by vapor phase oxidation of a silicon halogen compound, or a so-called wet silica produced from water glass or the like, which is a so-called dry method or fumed silica. Both fine powders can be used, but dry silica, which has few silanol groups on the surface and inside and has no production residue, is preferably used.

Further, the silica fine powder used in the present invention is preferably subjected to a hydrophobic treatment.

The hydrophobic treatment of the fine silica powder is performed by treating it with an organic silicon compound or the like which reacts with or physically adsorbs 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. 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 silicone oil, for example, silica fine powder treated with a silane coupling agent and silicone oil may be directly mixed using a mixer such as a Henschel mixer, or silica fine powder as a base. Alternatively, a method of spraying silicone oil may 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, external additives other than the fluidity improver may be added to the magnetic toner of the present invention.
For example, the primary particle size exceeds 30 nm (preferably the specific surface area is 50 m) for the purpose of improving the cleaning property.
² / g) Fine particles, more preferably having a primary particle size of 50 n
It is also one of the preferable modes to further add inorganic fine particles or organic fine particles having a diameter of m or more (preferably a specific surface area of less than 30 m ² / g) and having a nearly spherical shape. For example spherical silica particles,
It is preferable to use 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 abrasive 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 0.1 to 5 parts by mass (preferably 0.1 to 3 parts) with respect to 100 parts by mass of the magnetic toner particles.
Mass part) It is better to use.

When the magnetic 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, iron oxide, a release agent,
After sufficiently pre-mixing the charge control agent, in some cases components necessary for the magnetic toner such as a colorant, and other additives in a mixer such as a Henschel mixer or a ball mill, the pre-mixture is heated with a heating roll, kneader or ext. Melt and knead using a heat kneader such as a ruder, with the above resins,
Other toner constituent materials are dispersed or dissolved, cooled and solidified, pulverized, classified, and if necessary surface-treated to obtain magnetic toner particles, and if necessary, fine powder as an external additive is added. A magnetic toner can be obtained by mixing. 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 carried out using a known crushing device such as a mechanical shock type or jet type. In order to obtain the magnetic toner 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 (and if necessary classified) magnetic toner particles are dispersed in hot water, a method of passing through a hot air stream, or the like may be used.

As a method of applying a mechanical impact force, for example, there is a method of using a mechanical impact type crusher such as a Kryptron system manufactured by Kawasaki Heavy Industries, Ltd. or a turbo mill manufactured by Turbo Kogyo Co., Ltd. Also, using a device such as Hosokawa Micron's mechano-fusion system or Nara Machinery's hybridization system, the toner is pressed against the inside of the casing by centrifugal force with a blade that rotates at high speed, and the compression force,
A method of applying a mechanical impact force to the toner by a force such as a friction force 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 atmosphere temperature during the treatment to a temperature near the glass transition point Tg of the magnetic toner (that is, a temperature within the range of ± 30 ° C. of the glass transition point Tg). More preferably, the glass transition point T of the magnetic toner is
Performing the treatment at a temperature within the range of ± 20 ° C. of g is particularly effective for improving the transfer efficiency.

The binder resin used when the magnetic toner of the present invention is produced by a pulverization method is a homopolymer of styrene such as polystyrene or polyvinyltoluene, or a substitution product thereof; a styrene-propylene copolymer or a styrene-vinyltoluene copolymer. Polymer, styrene-vinylnaphthalene copolymer, styrene-methyl acrylate copolymer, styrene-
Ethyl acrylate copolymer, styrene-butyl acrylate copolymer, styrene-octyl acrylate copolymer,
Styrene-dimethylaminoethyl acrylate copolymer,
Styrene-methyl methacrylate copolymer, styrene-
Ethyl methacrylate copolymer, styrene-butyl methacrylate copolymer, styrene-dimethylaminoethyl methacrylate copolymer, styrene-vinyl methyl ether copolymer, styrene-vinyl ethyl ether copolymer, styrene-vinyl Styrene-based copolymers such as methyl ketone copolymers, styrene-butadiene copolymers, styrene-isoprene copolymers, styrene-maleic acid copolymers, styrene-maleic acid ester copolymers; polymethylmethacrylate, polybutyl Methacrylate, polyvinyl acetate, polyethylene, polypropylene, polyvinyl butyral, silicone resin, polyester resin, polyamide resin, epoxy resin, polyacrylic acid resin, rosin, modified rosin, temper resin, phenol resin, aliphatic or alicyclic carbonization Containing resins, aromatic petroleum resins, paraffin wax, carnauba wax can be used alone or in combination with. In particular, styrene-based copolymers and polyester resins are preferable in terms of development characteristics, fixability and the like.

The magnetic toner used in the present invention is, for example, JP-B-56.
A method of atomizing a molten mixture into air using a disk or a multi-fluid nozzle described in JP-A-13945 to obtain a spherical toner, or an aqueous organic solvent in which a monomer is soluble and the obtained polymer is insoluble. A magnetic toner is produced by a dispersion polymerization method in which a toner is directly produced by using it or an emulsion polymerization method typified by a soap-free polymerization method in which a toner is produced by directly polymerizing in the presence of a water-soluble polar polymerization initiator. It is also possible to manufacture by the method.

(2) Non-Magnetic Toner The non-magnetic toner of the toner kit of the present invention contains iv) a colorant selected from the group consisting of yellow colorants, magenta colorants and cyan colorants, and v) non-magnetic toner. Has an average circularity of 0.970 or more. In the present invention, as the colorant used for each color of the yellow toner, the cyan toner, and the magenta toner, a dye-based colorant or a pigment-based colorant may be used alone, or a dye and a pigment may be used in combination. Absent. Especially when a dye-based coloring agent is used, 1
The color reproducibility of the next color is dramatically improved, and red, green,
The color reproducibility of the secondary color typified by blue becomes good, and the color reproduction range is widened, so that good light transmittance is achieved even in an OHP image.

However, when the dye-based colorant is used alone, the weather resistance is poor and the color may disappear due to long-term storage. Therefore, when the color reproducibility is increased by using the dye-based colorant, 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 12,
13, 14, 15, 17, 62, 74, 83, 93, 9
4, 95, 109, 110, 111, 128, 129,
147, 168, 180 and the like are preferably used. Further, as the dye-based colorant, solvent yellow 9, 17, 2
4, 31, 35, 58, 93, 100, 102, 10
3, 105, 112, 162, 163, Disperse Yellow 3, 42, 64, 82, 160, 201 and the like are preferably used.

As the pigment-based colorant used as the magenta colorant, condensed azo compounds, diketorolopyrrole compounds, anthraquinones, quinacridone compounds, basic dye lake compounds, naphthol compounds, benzimidazole compounds, thioindigo compounds, perylene compounds, etc. are used. To be Specifically, C.I. I. Pigment Red 2, 3,
5, 6, 7, 23, 48: 2, 48: 3, 48: 4,5
7: 1, 81: 1, 122, 144, 146, 166,
169, 177, 184, 185, 202, 206, 2
20, 221, 254 and Pigment Violet 19 are particularly preferable.

As the dye-based colorant, a condensed azo compound, anthraquinone compound or the like is 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 Neopen
Magenta 525, Bayer Macrolex RED H is particularly preferred.

As the cyan colorant used in the present invention, a copper phthalocyanine compound and its derivative, an anthraquinone compound, a basic dye lake compound 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 used particularly preferably. Further, as the dye-based coloring agent, Solvent Blue 36, 63, 6
4,67,68,70,97, Neopen Cya manufactured by BASF
n742, Bayer Macrolex Blue 3R is particularly preferred.

In the case of color toners, the above colorants are selected from the viewpoints of hue angle, saturation, brightness, weather resistance, OHP transparency and dispersibility in the toner. Is preferably used by adding 1 to 20 parts by mass to 100 parts by mass of the binder resin. When the addition amount is less than the lower limit, the transparency is improved, but the coloring power is extremely reduced, and it tends to be impossible to obtain an image density that maintains good visible image quality. When the value exceeds the upper limit, the light transmissivity is remarkably lowered, and thus the color reproducibility of the projected image by the OHP is hindered, or the fixing peeling easily occurs.

The binder resin, wax, charge control agent, external additives and the like used in the non-magnetic toner of the present invention may be the same as those used in ordinary non-magnetic toner. Specifically, the same binder resin, wax, charge control agent, and external additive as those used in the magnetic toner of the present invention can be used. Further, the non-magnetic toner can be manufactured in the same manner as the magnetic toner, and in order to satisfy the average circularity of 0.970, the suspension polymerization method is preferable. The particle size of the non-magnetic toner is 2 to 2 as in the magnetic toner.
It is preferably 10 μm.

The non-magnetic toner of the present invention can be used as a non-magnetic one-component developer in an electrophotographic process, but is prepared by mixing it with magnetic particles for development (hereinafter referred to as "carrier particles") called a carrier. It may be used as a two-component developer.

The carrier particles used in this case include, for example, surface-oxidized or unoxidized metals such as iron, nickel, copper, zinc, cobalt, manganese, chromium and rare earths, their alloys or oxides and ferrites. Further, a resin carrier in which a magnetic oxide, a metal magnetic oxide and the like are dispersed in a binder resin for carrier can be used. In addition, there is no particular restriction on the manufacturing method thereof.

A structure having a coating layer in which the surface of the carrier particles is coated with a resin or the like for the purpose of charge adjustment and the like is also preferable.
As a method thereof, a coating material such as a resin is dissolved or suspended in a solvent and applied to form a coating layer by adhering to a carrier particle, or a coating layer is formed by simply mixing resin powder with a resin powder. Any conventionally known method such as a forming method can be applied, but a method of dissolving the coating material in a solvent is preferable for the stability of the coating layer.

The coating material used for the carrier particles varies depending on the toner material, but is preferably, for example, an amino acrylate resin, an acrylic resin, or a copolymer of these resins and a styrene resin. As the negatively charged resin, silicone resin, polyester resin, fluororesin, polytetrafluoroethylene, monochlorotrifluoroethylene polymer, polyvinylidene fluoride, etc. are located on the negative side in the charging series and are preferable, You are not limited to this. The coating amount of these compounds may be appropriately determined so that the charge imparting property of the carrier particles is satisfied, but generally, the total amount is 0.1 to 30% by mass of the carrier particles.
(Preferably 0.3 to 20% by mass).

The carrier particles used in the present invention include a phenolic resin or the like on the surface of a spherical composite core particle obtained by binding a ferromagnetic iron compound and non-magnetic iron compound particles with a phenolic resin or the like as a binding component. Preferred examples include resin carriers made of spherical composite particles having a mean particle size of 1 to 1000 μm formed by forming a coating layer.
There is no restriction as long as it does not impair its performance. 98%
The above Cu-Zn-Fe (composition ratio [5-20]: [5-2]
0]: [30 to 80]) in the form of a carrier such as a ferrite particle.

These carrier particles have a volume average particle diameter of 3
The thickness is preferably 5 to 65 μm, more preferably 40 to 60 μm. Further, when the volume distribution of 26 μm or less is 2 to 6%, the volume distribution of 35 to 43 μm is 5% or more and 25% or less, and 74 μm or more is 2% or less, a good image can be maintained.

The volume average particle size of the carrier particles is 100% randomly extracted by an optical microscope or a scanning electron microscope, and the volume particle size distribution is calculated with the maximum chord length in the horizontal direction. The average particle size may be determined by the diameter, or a laser diffraction particle size distribution measuring device HEROS
(Manufactured by JEOL Ltd.), the range of 0.05 μm to 200 μm is divided into 32 logarithms and measured, and the 50% average particle size may be used as the average particle size.

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 a lipophilic treatment as the magnetic iron compound dispersed in the carrier core particles.

When a non-magnetic toner is used together with the above carrier to form a two-component developer, the mixing ratio of the carrier and the non-magnetic toner is 2.0 to 1.0 as the toner concentration in the two-component developer.
When the content is 9.0% by mass, preferably 3.0 to 8.0% by mass, generally good results are obtained. When the toner concentration is 2.0% by mass or less, the image density is low and it becomes unpractical, and when it is 9.0% or more, fog and in-machine scattering tend to increase, and the useful life of the developer tends to be shortened. (3) Toner Kit The present invention is a toner kit including the above-described magnetic toner and the above-mentioned non-magnetic toner, and the non-magnetic toner of the toner kit may be used together with a carrier as a two-component developer, if necessary.

When an image is formed using the toner kit of the present invention, the surface of the photoconductor is less likely to be scraped, and image defects are less likely to occur even after long-term use.

Further, when an image is formed using the toner kit of the present invention, the residual toner after transfer is reduced, so that the black magnetic toner remaining after transfer is mixed in the toner carrier for the color non-magnetic toner to prevent the color non-transfer. It does not hinder the chargeability of the magnetic toner or cause a hue change.

<2> Image Forming Method of the Present Invention An image forming method using the toner kit of the present invention will be described.

In the image forming method of the present invention, a charging step of charging the electrostatic image carrier with a charging member to which a voltage is applied from the outside; forming an electrostatic latent image on the electrostatic image carrier by exposure. Exposure step; developing step of forming a toner image of a black-and-white image or a color image by the magnetic toner and / or non-magnetic toner of the toner kit of the present invention carrying the electrostatic latent image on a toner carrier; developed toner image And a transfer step of transferring to a transfer material.

First, the developing process, particularly the system in which the toner carrier and the electrostatic image carrier are not in contact with each other, will be described. In the non-contact developing method, the toner is formed on the toner carrier with a layer thickness smaller than the closest distance (between SD) between the toner carrier (developing sleeve) and the photoconductor (electrostatic image carrier). Apply and apply alternating bias to develop. That is, the layer thickness regulating member for regulating the toner on the toner carrier is set so that the closest gap between the photoconductor and the toner carrier is wider than the toner layer thickness on the toner carrier. At this time,
It is particularly preferable that the layer thickness regulating member that regulates the toner on the toner carrier is an elastic blade and is in contact with the toner carrier via the toner from the viewpoint of uniformly charging the toner.

As the material of the elastic blade as the regulating member, it is preferable to select a friction charging series material suitable for charging the toner to a desired polarity. A rubber elastic body such as silicone rubber, urethane rubber or NBR , Synthetic resin elastic body such as polyethylene terephthalate, stainless steel,
An elastic metal such as copper or phosphor bronze can be used. Further, it may be a complex thereof.

When durability is required for the elastic blade and the toner carrying member, as the elastic regulating member,
It is preferable that the metal elastic body is laminated with resin or rubber so as to abut on the contact portion of the toner carrier, or is coated.

Further, an organic substance or an inorganic substance may be added to the elastic blade, and may be melt-mixed or dispersed. For example, metal oxide, metal powder, ceramics,
The chargeability of the toner can be controlled by adding a carbon allotrope, whiskers, inorganic fibers, dyes, pigments and surfactants. In particular, when the elastic blade is a molded body such as rubber or resin, silica, alumina, titania, tin oxide, zirconia, fine powder of metal oxide such as zinc oxide, carbon black, a charge control agent generally used for toner are used. It is also preferable to contain it.

By applying a DC electric field and / or an AC electric field to the regulating member, the uniform thin layer coating property and the uniform charging property are further improved due to the loosening effect on the toner, and the achievement of sufficient image density and You can get good quality images.

The toner carrier is 100 to 5 relative to the photoconductor.
It is preferable that they are installed facing each other with a separation distance of 00 μm, and it is more preferable that they are installed facing each other with a separation distance of 120 to 500 μm. If the separation distance of the toner carrier from the photoconductor is smaller than 100 μm, the change in the developing characteristics of the toner due to the deviation of the separation distance becomes large, which makes it difficult to mass-produce an image forming apparatus satisfying a stable image property. . When the distance between the toner carrier and the photoconductor is larger than 500 μm, the collectability in the case of performing the simultaneous development cleaning method for recovering the transfer residual toner by the developing means is deteriorated and the fog is apt to occur due to the defective recovery.
Further, since the ability of the toner to follow the latent image on the photoconductor is lowered, the resolution is lowered, and the image density is lowered.

In the present invention, 5 to 5 are formed on the toner carrier.
It is preferable to stack them so as to form a toner layer of 30 g / m ² . When the amount of toner on the toner carrier is less than 5 g / m ^2, it is difficult to obtain a sufficient image density, and the toner layer becomes uneven due to excessive charging of the toner. When the amount of toner on the toner carrier is more than 30 g / m ² , toner scattering easily occurs.

The surface roughness Ra (JIS center line average roughness) of the toner carrier used in the non-contact developing method is 0.2 to.
It is preferably in the range of 3.5 μm. Ra is 0.2μ
If it is less than m, the amount of charge on the toner carrier becomes high and the developability becomes insufficient. On the other hand, when Ra exceeds 3.5 μm, unevenness occurs in the lamination of the toner on the toner carrier, resulting in uneven density on the image. Surface roughness Ra is 0.5 to 3.0 μm
It is even more preferable that it is within the range.

In the present invention, the surface roughness Ra of the toner carrier is based on JIS surface roughness "JISB 0601" and is a surface roughness measuring device (Surfcoder SE-30H, manufactured by Kosaka Laboratory Ltd.). Corresponds to the centerline average roughness measured using. Specifically, a 2.5 mm portion as the measurement length a is extracted from the roughness curve in the direction of the center line,
The center line of this extracted portion is the X axis, and the vertical magnification direction is Y.
When the axis and roughness curve are represented by y = f (x), the value obtained by the following equation is represented by micrometers (μm).

[0170]

[Equation 2]

The surface roughness is adjusted by blasting the toner carrier with spherical particles. Spherical blast abrasive grains (smooth surface, spherical or spherical flat particles are good) are used as the treating agent, and the number is # 100 to # 80.
0 glass beads are selected and used.

Further, since the toner according to the present invention has a high charging ability, it is preferable to control the total charge amount of the toner during development. The surface of the toner carrier according to the present invention is preferably coated with a resin layer in which conductive fine particles and / or a lubricant are dispersed.

As the conductive fine particles contained in the resin layer coating the surface of the toner carrier, conductive metal oxides such as carbon black, graphite, conductive zinc oxide, etc. and metal complex oxides may be used alone or in combination of two or more kinds. It is preferable to use them in combination. As the resin of the resin layer in which the conductive fine particles and / or the lubricant are dispersed, a phenol resin,
Epoxy resin, polyamide resin, polyester resin, polycarbonate resin, polyolefin resin,
Known resins such as silicone-based resins, fluorine-based resins, styrene-based resins, and acrylic-based resins are used. Phenol-based resins and acrylic-based resins are particularly preferable as the thermosetting or photocurable resin.

In the non-contact developing method, it is preferable that the moving speed of the toner carrying member carrying the toner in the developing step and conveyed to the developing section has a speed difference with respect to the moving speed of the photosensitive member. By providing the speed difference, the toner can be sufficiently supplied from the toner carrier side to the photoconductor side, and a good image can be obtained.

The surface of the toner carrying member carrying the toner may move in the same direction as the moving direction of the photosensitive member surface,
It may be moving in the opposite direction. As the speed at that time,
It is preferable that one of the surfaces of the toner carrier and the surface of the photosensitive member moves 1.02 to 3.0 times as fast as the other, rather than moving at the same speed.

In the developing section, an AC bias is applied in order to transfer the magnetic toner to an electrostatic latent image for development, and the AC bias at this time has at least a peak-to-peak electric field strength. It is preferably 3 × 10 ⁶ to 1 × 10 ⁷ V / m and a frequency of 100 to 5000 Hz.
It is also a preferable mode to further superimpose a DC bias.

On the other hand, a system in which development is carried out by bringing the toner carrier and the electrostatic charge image carrier into contact with each other in the developing step will be described.

In the contact development method, it is preferable to use reversal development.

Further, it is also preferable to use a cleanerless process of collecting the transfer residual toner remaining on the photoconductor after the transfer step by the toner carrier, and the size of the apparatus can be greatly reduced. During development or during blanking before and after development, a bias of direct current or alternating current component is applied to the toner carrier, and the potential is controlled so that development and recovery of transfer residual toner on the photoconductor can be performed. It is located between the light potential and the dark potential.

It is preferable to use an elastic roller as the toner carrier. In the developing process, the surface of the elastic roller is coated with toner and brought into contact with the surface of the photoreceptor. In this case, since development is performed by an electric field acting between the photoconductor and the elastic roller facing the photoconductor surface via the toner, the elastic roller surface or the vicinity of the surface has a potential, and the photoconductor surface and the toner carrier surface are narrow. It is necessary to have an electric field in the gap. Therefore, the elastic rubber of the elastic roller is resistance-controlled in the medium resistance region to prevent conduction with the surface of the photoconductor to maintain an electric field, or a method of providing a thin insulating layer on the surface layer of the elastic roller can be used. Further, it is also possible to adopt a structure in which the side facing the surface of the photoconductor is covered with an insulating material on the elastic roller, or a conductive layer is provided on the side not facing the photoconductor with an insulating developing sleeve. It is also possible to use a rigid roller as the toner carrier and use a flexible material such as a belt for the photoconductor. The resistance of the elastic roller as the toner carrier is preferably in the range of 10 ² to 10 ⁹ Ω · cm. When it is lower than 10 ² Ω · cm, for example, when there is a pinhole or the like on the surface of the photoconductor 1, an overcurrent may flow. On the other hand, when it is higher than 10 ⁹ Ω · cm, toner charge-up due to triboelectric charging is likely to occur and the image density is apt to decrease.

The surface shape of the toner carrying member in the contact developing method has a surface roughness Ra (μm) of 0.2 to
If it is set to 3.0 μm, both high image quality and high durability can be achieved. The surface roughness Ra correlates with the toner conveying ability and the toner charging ability. Surface roughness R of the toner carrier
If a exceeds 3.0 μm, it is difficult to make the toner layer on the toner carrier thin, and the chargeability of the toner is not improved, so that improvement in image quality cannot be expected. When the thickness is 3.0 μm or less, the toner carrying ability on the surface of the toner carrier is suppressed, the toner layer on the toner carrier is thinned, and
Since the number of contact between the toner carrier and the toner is increased, the chargeability of the toner is also improved, and the image quality is synergistically improved. On the other hand, when the surface roughness Ra is less than 0.2 μm, it becomes difficult to control the toner coating amount.

In the contact developing method, the toner carrier may rotate in the same direction as the peripheral speed of the photosensitive member or may rotate in the opposite direction. When the rotations are in the same direction, the peripheral speed of the toner carrier is 1.05 to 3.
It is preferable to set it to be 0 times.

If the peripheral speed of the toner carrying member is less than 1.05 times the peripheral speed of the photosensitive member, the stirring effect of the toner on the photosensitive member is insufficient, and good image quality cannot be expected.
Further, when developing an image requiring a large amount of toner over a wide area such as a solid black image, the amount of toner supplied to the electrostatic latent image tends to be insufficient and the image density tends to be low. The higher the peripheral speed ratio, the larger the amount of toner supplied to the developing portion, the more frequently toner is desorbed from the electrostatic latent image, and the unnecessary portion is collected and applied to the necessary portion. By repeating, an image faithful to the latent image is obtained. However, if the peripheral speed ratio exceeds 3.0 times, conversely, in addition to the above-mentioned various problems caused by excessive charging of the toner (such as reduction in image density due to excessive toner charge-up), mechanical Deterioration of the toner due to stress and adhesion of the toner to the toner carrier are generated and promoted, which is not preferable.

Next, the charging step will be described.

In the present invention, a non-contact charging process using a charging means using corona discharge may be used, but a contact charging method of bringing a charging member into contact with a photosensitive member is a preferable charging method. In this case, it is preferable to use a charging roller as the contact charging member.

A preferable process condition when the charging roller is used is that the contact pressure of the roller is 4.9 to 490 N / m.
(5 to 500 g / cm), a DC voltage or a DC voltage superposed with an AC voltage is used. When the one in which the AC voltage is superimposed on the DC voltage is used, the AC voltage = 0.5 to
5 kVpp, AC frequency = 50 to 5 kHz, DC voltage =
± 0.2 to ± 5 kV is preferable.

As another charging process, there is a method of using a contact charging member such as a charging blade or a conductive brush. Even when these contact charging members are used, there is an effect that a high voltage is unnecessary and ozone generation is reduced.

As a material of the charging roller and the charging blade as the contact charging member, a conductive elastic layer such as conductive rubber is preferable, and a releasing film may be provided on the surface thereof. As the release coating, nylon resin, PVdF (polyvinylidene fluoride), PVdC (polyvinylidene chloride),
Fluoro acrylic resin can be applied.

Next, the transfer process will be described.

In the present invention, a non-contact transfer process using a transfer means using corona discharge may be used, but the transfer means is a contact transfer in which the transfer is carried out by contacting the photoreceptor with a transfer material. It is better to use the method.

The contact pressure of the transfer means is a linear pressure of 2.9 N.
/ M (3 g / cm) or more, more preferably 19.6 N / m (20 g / cm) or more. If the linear pressure as the contact pressure is less than 2.9 N / m (3 g / cm), the transfer deviation of the transfer material and the transfer failure are likely to occur, which is not preferable.

Next, the photoconductor used in the present invention will be described below.

As the photoconductor, a-Se, CdS, Zn
A photosensitive drum or photosensitive belt having a photoconductive insulating material layer such as O ₂ , OPC (organic photoconductor), and a-Si is preferably used.

Particularly in the present invention, it is preferable to use a photoconductor whose surface is composed mainly of a polymer binder. For example, a protective film (protective layer) mainly composed of a resin is provided on an inorganic photoreceptor such as selenium or amorphous silicon, or a charge transport material and a resin are used as a charge transport layer of a function-separated type organic photoreceptor. And a protective layer composed mainly of resin is provided on the surface layer.

It is preferable that these surface layers (or protective layers) have releasability. As a means for actually imparting releasability, a resin having a low surface energy is used as the resin itself constituting the film. Examples thereof include a method of using, adding an additive that imparts water repellency and lipophilicity, and dispersing a material having a high releasability into a powder form. For example, the introduction of a functional group such as a fluorine-containing group or a silicon-containing group into the structure of the structural unit of the resin can be mentioned. Examples of the additive that imparts water repellency and lipophilicity include a surfactant. Examples of the material having a high releasability include a compound containing a fluorine atom, that is, polytetrafluoroethylene, polyvinylidene fluoride, carbon fluoride and the like.

By these means for imparting releasability,
The contact angle of water on the surface of the photoconductor can be 85 degrees or more, and the transferability of the toner and the durability of the photoconductor can be further improved. The contact angle of water on the surface of the photoconductor is 9
It is preferably 0 degrees or more. In the present invention, among the above-mentioned means (1) to (4), it is preferable to disperse the fluorine-containing resin in the outermost surface layer of the releasable powder as described below. Particular preference is given to using ethylene oxide.

In order to contain these powders on the surface,
A layer in which a release powder is dispersed in a binder resin is provided on the outermost surface of the photoconductor, or a new surface layer is provided if the photoconductor itself is an organic photoconductor composed mainly of resin. Even if it is not necessary, the releasable powder may be dispersed in the uppermost layer. The amount of release powder added is 1 to the total amount of the surface layer.
60% by mass is preferable, and 2 to 50% by mass is more preferable. If the amount of the release powder added is less than 1% by mass, the effect of improving the transferability of the toner and the durability of the photoconductor is insufficient, and if it exceeds 60% by mass, the strength of the protective film is lowered,
This is not preferable because the amount of light incident on the photoconductor is significantly reduced.

In the present invention, the charging method is preferably the contact charging method in which the charging member is brought into contact with the photosensitive member. The charging method is, for example, corona discharge in which the charging member does not contact the photosensitive member. Since the load on the surface of the photoconductor is larger than that of the method, providing a protective layer (protective film) on the surface of the photoconductor has a remarkable effect of improving durability, and is one of preferred application modes.

Further, in the present invention, it is preferable to apply the contact charging method and the contact transfer method, so that the diameter is 50 mm.
It is particularly effectively used for an image forming apparatus having a photoreceptor having the following small diameter.

That is, when the diameter of the photosensitive member used in image formation is small, the curvature with respect to the same linear pressure is large and the pressure is likely to concentrate at the contact portion.
Although it is considered that the same phenomenon occurs with the belt photosensitive member, the present invention is also effective for an image forming apparatus having a radius of curvature at the transfer portion of 25 mm or less.

One of the preferable modes of the photoconductor used in the present invention will be described below. A charge generation layer on a conductive substrate,
Next, a laminated type photoreceptor having a structure in which photosensitive layers such as a charge transport layer are laminated is one of the preferable examples.

As the conductive substrate, metals such as aluminum and stainless steel; aluminum alloys, indium oxide-
Cylindrical cylinders and films such as plastic having a coating layer of tin oxide alloy; paper impregnated with conductive particles; plastic; plastic having conductive polymer; and the like are used.

On these conductive substrates, the adhesion of the photosensitive layer is improved, the coatability is improved, the substrate is protected, defects on the substrate are covered, the charge injection from the substrate is improved, and the electrical properties of the photosensitive layer are improved. An undercoat layer may be provided for the purpose of protection against breakage.
The subbing layer is polyvinyl alcohol, poly-N-vinylimidazole, polyethylene oxide, ethyl cellulose, methyl cellulose, nitrocellulose, ethylene-
It is formed of a material such as acrylic acid copolymer, polyvinyl butyral, phenol resin, casein, polyamide, copolymerized nylon, glue, gelatin, polyurethane and aluminum oxide. The thickness of the undercoat layer is usually 0.
It is 1 to 10 μm, preferably about 0.1 to 3 μm.

The charge generation layer comprises azo pigments, phthalocyanine pigments, indigo pigments, perylene pigments, polycyclic quinone pigments, squarylium dyes, pyrylium salts, thiopyrylium salts, triphenylmethane dyes, selenium,
The charge generation material, which is an inorganic material such as amorphous silicon, is dispersed in a suitable binder resin and applied, or formed by vapor deposition. Examples of the binder resin include polycarbonate resin, polyester resin, polyvinyl butyral resin, polystyrene resin, acrylic resin, methacrylic resin, phenol resin, silicone resin, epoxy resin, vinyl acetate resin, and the like. The binder resin can be arbitrarily selected. The amount of the binder resin contained in the charge generation layer is preferably 80% by mass or less, and 0 to 60% by mass with respect to the entire charge generation layer.
Is more preferable. The thickness of the charge generation layer is preferably 5 μm or less, and particularly preferably 0.05 to 2 μm.

The charge transport layer has a function of receiving charge carriers from the charge generation layer in the presence of an electric field and transporting them. The charge transport layer is formed by dissolving a charge transport material in a solvent together with a binder resin as necessary and coating the solution. The thickness of the charge generation layer is generally 5-4.
It is 0 μm. As the charge transporting material, a polycyclic aromatic compound having a structure such as biphenylene, anthracene, pyrene, or phenanthrene in the main chain or a side chain, a nitrogen-containing cyclic compound such as indole, carbazole, oxadiazole, or pyrazoline, a hydrazone compound, Examples thereof include styryl compounds, selenium, selenium-tellurium, amorphous silicon, and cadmium sulfide.

As the binder resin in which these charge-transporting substances are dispersed, polycarbonate resin, polyester resin, polymethacrylic acid ester, polystyrene resin,
Examples thereof include resins such as acrylic resins and polyamide resins, and organic photoconductive polymers such as poly-N-vinylcarbazole and polyvinylanthracene.

Further, as the surface layer, a separate protective layer may be provided. As the resin of the protective layer, polyester, polycarbonate, acrylic resin, epoxy resin, phenol resin, or a curing agent of these resins can be used alone or in combination of two or more kinds.

Also, conductive fine particles may be dispersed in the resin of the protective layer. Examples of the conductive fine particles include metals and metal oxides, preferably zinc oxide, titanium oxide,
Examples thereof include ultrafine particles of tin oxide, antimony oxide, indium oxide, bismuth oxide, tin oxide coated titanium oxide, tin coated indium oxide, antimony coated tin oxide, and zirconium oxide.

These conductive fine particles may be used alone or in combination of two or more. Generally, when the particles are dispersed in the protective layer, it is necessary that the particle size of the particles is smaller than the wavelength of the incident light in order to prevent scattering of the incident light by the dispersed particles. The particle diameter of the conductive fine particles dispersed in is preferably 0.3 μm or less. The content of the conductive fine particles in the protective layer is preferably 2 to 90% by mass, more preferably 5 to 80% by mass, based on the total mass of the protective layer. The thickness of the protective layer is 0.1 to 10 μm.
m is preferable, and 1 to 7 μm is more preferable.

The surface layer can be coated by spray coating, beam coating or dipping coating of the resin dispersion liquid.

Next, the image forming method of the present invention will be described below with reference to FIGS. FIG. 1 shows an outline of an image forming apparatus using an intermediate transfer member.
The photoconductor 10, the transfer material (transfer material) P such as paper, the intermediate transfer body 12, the fixing roller 23, and the primary charging unit 8 using corona discharge that is non-contact with the photoconductor 10 are provided. A bias power source is connected to the primary charging means 8 so as to uniformly charge the surface of the photoconductor 10.

The developing means 11 uses the toner kit of the present invention having a magnetic toner and a non-magnetic toner, and a toner carrier (developing sleeve) which rotates in contact with the photoconductor 10.
It is equipped with.

A transfer bias having a polarity opposite to that of the photoconductor 10 is connected to the intermediate transfer body 12.

Here, in FIG. 1, the photoconductor 10 and the toner carrier show non-contact development, and the gap between the photoconductor 10 and the toner carrier is maintained at about 300 μm. The toner carrier used in the non-contact developing method of FIG. 1 is preferably made of a non-magnetic metal such as aluminum or stainless steel. In this case, the amount of toner coating on the toner carrier is preferably 5 to 30 g / m ² . When the amount of toner on the toner carrier is less than 5 g / m ^2, it is difficult to obtain a sufficient image density, and the toner layer becomes uneven due to excessive charging of the toner. The amount of toner on the toner carrier is 30g
If it is more than / m ² , toner scattering tends to occur.

The image forming apparatus shown in FIG. 2 is a roller charging device in which the primary charging means 8 shown in FIG.

In FIG. 3, contact development is shown, and the length in the rotational direction at the contact portion between the photoconductor 10 and the toner carrier, the so-called development contact width, is preferably 0.2 to 8.0 mm. . If it is less than 0.2 mm, the amount of development is insufficient to obtain a satisfactory image density, and the transfer residual toner is not sufficiently collected.
If it exceeds 8.0 mm, the toner supply amount becomes excessive, the fog suppression is likely to be deteriorated, and the abrasion of the photoconductor 10 is also adversely affected.

A so-called elastic roller having an elastic layer on its surface is preferably used as the toner carrier used in the contact developing method shown in FIG. As the material of the elastic layer used, those having a degree of 20 to 65 degrees (JIS A) are preferably used.

The toner coat amount on the toner carrier is 0.
1 to 2.0 mg / cm ² is preferable. 0.1 mg / cm ²
If it is less than 2.0, it is difficult to obtain sufficient image density, and 2.0 mg /
When it is more than cm ^2, it becomes difficult to uniformly triboelectrically charge all the individual toner particles, which causes deterioration of fog suppression. Furthermore, 0.2-1.2 mg / cm < ² > is more preferable.

In the contact developing method as well, the toner coating amount is controlled by the regulating member, but it is preferable that the regulating member is in contact with the toner carrier via the toner layer. The contact pressure at this time is preferably 5 to 50 g / cm. If it is less than 5 g / cm, uniform triboelectric charging becomes difficult in addition to the control of the toner coat amount, which causes deterioration of fog suppression. On the other hand, if it is more than 50 g / cm, the toner particles are excessively loaded, and the deformation of the particles and the fusion of the toner to the regulation member or the toner carrier are likely to occur, which is not preferable. In this case, it is particularly preferable to use an elastic blade, a roller or the like for applying the toner under pressure as the regulating member in terms of prolonging the life of the member.

In the image forming apparatus shown in FIGS. 2 and 3, the primary charging means 8 uniformly charges the photoconductor 10 rotating in the arrow direction. The primary charging means used here is a charging roller having a central core metal and a conductive elastic layer forming the outer periphery thereof as a basic configuration. The charging roller is brought into contact with the entire surface of the electrostatic latent image carrier with a pressing force, and is driven to rotate as the photoconductor 10 rotates.

Following the primary charging step, an electrostatic latent image corresponding to the information signal is formed on the photoconductor 10 by exposure from the image reading light source 3, and electrostatically charged by the toner at the position where it comes into contact with the toner carrier. The latent image is developed and visualized. Furthermore, in the image forming method of the present invention, in particular, by combining with a developing system in which a digital latent image is formed on a photoconductor, it is possible to faithfully develop a dot latent image so as not to disturb the latent image. It will be possible.

Next, the visible image is transferred onto the transfer target by the intermediate transfer member 12, and the toner is transferred to the transfer target together with the fixing means 22 having the fixing roller 23 by the transport system 21.
It is transported to and fixed in to obtain a permanent image. The heating / pressurizing fixing means is not limited to the heat roller method, which basically has a heating roller having a heating element such as a halogen heater and an elastic pressing roller pressed against the heating roller with a pressing force. A method of heating and fixing with a heater through a film is also used.

On the other hand, the transfer residual toner remaining on the photoconductor 10 without being transferred passes between the photoconductor 10 and the primary charging means 8 and reaches the developing contact portion again, and is developed by the toner carrier. It is collected in the container.

<3> Method for Measuring Physical Properties in the Present Invention A method for measuring various physical property data in the present invention will be described in detail below. (1) Method for measuring ratio (B / A) of iron element content (B) to carbon element content (A) present on toner surface Content of carbon element present on toner surface in the present invention Ratio of iron element content (B) to (A) (B / A)
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 (400W) Spectral region 8
00 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. 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, and the external additive is removed before measurement. I do.

(2) Method of Measuring Circularity Distribution In the present invention, the circularity distribution of the equivalent circle diameter of the toner is measured by the following method using a flow type particle image distribution apparatus FPIA-1000 (manufactured by Toa Medical Electronics Co., Ltd.). Measured as Further, as shown by the following formula, 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.

[0228]

[Equation 3] In addition, the measuring device "FPIA-1" used in the present invention is used.
000 ”means that the circularity of each particle is calculated, and then the average circularity is calculated. According to the obtained circularity, the circularity is 0.400 to 1.000 at 0.010 intervals and 0.40.
0 or more and less than 0.410, 0.410 or more and less than 0.420 ... 0.990 or more and less than 1.000 and 1.000 divided into 61 divided ranges and using the center value and frequency of the divided points A calculation method for calculating the average circularity 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 which directly uses the circularity of each particle is very small and substantially Therefore, in the present invention, for the reason of data handling such as shortening of calculation time and simplification of calculation calculation formula, calculation using the circularity of each particle directly is carried out. Using the concept of the formula, a partially modified calculation method like this is used.

The circularity in the present invention is an index showing the degree of unevenness of particles, and when the particles are perfectly spherical, 1.
The circularity has a smaller value as the surface shape becomes more complicated.

As a specific method for measuring 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). Strobe and C to form an optical path that crosses the thickness of the flow cell.
The CD cameras are mounted so that they are located on opposite sides of the flow cell. While the sample dispersion is flowing,
Strobe light is emitted at 1/30 second intervals to obtain an image of particles flowing through the flow cell, and as a result, each particle is captured as a two-dimensional image having a certain range parallel to the flow cell.

From the area of the two-dimensional image of each particle,
The diameter of a circle having the same area is calculated as the circle equivalent diameter. From the projected area of the two-dimensional image of each particle and the perimeter of the projected image, the circularity of each particle is calculated using the above circularity calculation formula.

(3) Method for Measuring Toner Particle Size The average particle size and particle size distribution of the 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)
Is connected to an interface (manufactured by Nikkaki Co., Ltd.) that outputs the number distribution and volume distribution, and a PC9801 personal computer (manufactured by NEC) is used, and a 1% NaCl aqueous solution is prepared using primary sodium chloride as an electrolytic solution. For example IS
OTON R-II (manufactured by Coulter Scientific Japan) can be used. As a measuring method, a surfactant, preferably an alkylbenzene sulfonate, as a dispersant in 100 to 150 ml of the electrolytic aqueous solution is added in an amount of 0.1.
Add ~ 5 ml, and then add 2 to 20 mg of the measurement sample. 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 A standard volume distribution of 12.7 μm or more is obtained.

(4) Method for measuring molecular weight distribution In the present invention, the resin tetrahydrofuran (THF) is used.
The molecular weight distribution of the chromatogram by GPC (gel permeation chromatography) using the soluble component THF as a solvent is measured as follows. The measurement sample is measured as follows.

About 0.5 to 5.0 mg / sample of THF and
Mix at a concentration of ml (eg 5.0 mg / ml), leave it at room temperature for several hours (eg 5 to 6 hours), shake it well, and mix THF and sample well (the combination of samples disappears. Still) for 12 hours or more (for example, 24 hours) at room temperature. At this time, the time from the start of mixing the sample and THF to the end of the standing should be 24 hours or more. After that, a sample processing filter (pore size 0.4 to 0.5 μm, for example, Mysholydisk h-25-2
[Tosoh Corporation], Liquid Chlodisc 25CR [German Science Japan Ltd.] and the like can be preferably used. ) Is used as a GPC sample. The sample concentration is adjusted so that the resin component is 0.5 to 5.0 mg / ml.

In the GPC measuring apparatus, the column was stabilized in a heat chamber column at 40 ° C., THF as a solvent was flowed through the column at a flow rate of 1 ml / min, and a THF sample solution of about 100 μl was injected. And measure. In measuring the molecular weight of a sample, the molecular weight distribution of the sample is calculated from the relationship between the logarithmic value and the count number of a calibration curve prepared using several kinds of monodisperse polystyrene standard samples. A standard polystyrene sample for preparing a calibration curve has a molecular weight of 10 ² manufactured by Tosoh Corporation or Showa Denko KK, for example.
Used of about 10 ^7, it is appropriate to use at least about 10 standard polystyrene samples. An RI (refractive index) detector is used as the detector. As the column, it is preferable to combine a plurality of commercially available polystyrene gel columns, for example, Shodex GPC manufactured by Showa Denko KK
KF-801, 802, 804, 805, 806, 80
Combination of 7,800P and TSKge manufactured by Tosoh Corporation
lG1000H (Hxl), G2000H (Hxl),
G3000H (Hxl), G4000H (Hxl), G
5000H (Hxl), G6000H (Hxl), G7
A combination of 000H (Hxl) and TSKguardcolumn can be mentioned.

(5) Method of measuring specific surface area The specific surface area is measured according to the BET formula in ASTM method D3037-78. Specifically, a mixed gas of N ₂ and He is caused to flow through carbon black to adsorb N ₂ ,
The amount 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 the adsorption equilibrium is reached, the liquid N ₂ is removed and exposed to the air for 30 seconds, and then the U-shape is immersed in water at room temperature to desorb N ₂ . 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, a predetermined P / P was determined from the area obtained for the above sample.
Determine the N ₂ adsorption amount at ₀ .

The surface area is obtained by applying the following equation.

[0241]

[Number 4] _{P / ν (P 0 -P)} = 1 / νmC + C-1 / ν
mC · P / P ₀ (where P ₀ is the saturated vapor pressure of the adsorbate at the measurement temperature, P ₀
Is the pressure in the adsorption equilibrium, ν is the adsorption amount in the adsorption equilibrium, and C is a constant. ) The relationship between P / P ₀ and P / ν (P ₀ −P) is a straight line, and νm is obtained from the gradient and the intercept. If νm is obtained, the specific surface area S is calculated by the following equation.

[0242]

S = A × νm × N × W (In the formula, S is a specific surface area, A is a cross-sectional area of adsorbed molecules, N is Avogadro's number, and W is a sample amount.)

[0243]

EXAMPLES The present invention will be specifically described 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.

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

Then, the slurry solution was added with 0.9-1. To the initial amount of alkali (sodium component of caustic soda).
After adding ferrous sulfate aqueous solution to 2 equivalents, the slurry liquid is maintained at pH 8 to advance the oxidation reaction while blowing air, and the pH is adjusted to about 6 at the end of the oxidation reaction, and the silane coupling agent is added. _{[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 2 of Hydrophobic Iron Oxide) The oxidation reaction was carried out in the same manner as in Production Example 1, and the magnetic iron oxide particles produced after the oxidation reaction were washed, filtered, taken out once, and dried in another water without drying. after redispersion, to adjust the pH of the redispersion liquid, sufficiently stirring a silane coupling agent _{[n-C 6 H 13 Si} (O
CH _{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.

Production Example 3 of Hydrophobic Iron Oxide Hydrophobic oxidation was performed 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

Production Example 4 of Hydrophobic Iron Oxide Hydrophobic iron oxide 4 was obtained in the same manner as in Production Example 2 except that [γ-glycidyltrimethoxysilane] was used as the silane coupling agent.

(Production Example 5 of Hydrophobic Iron Oxide) Aqueous ferrous sulfate solution was 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.

Then, the slurry liquid was added with 0.9-1..1 to the initial alkali amount (sodium component of caustic soda).
After adding a ferrous sulfate aqueous solution so as to be 2 equivalents, the oxidation reaction was promoted while maintaining the pH of the slurry liquid at 8 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).

Production Example 6 of Hydrophobic Iron Oxide The iron oxide particles a obtained in Production Example 5 of hydrophobic iron oxide are dispersed in water, the pH of the iron oxide dispersion aqueous solution is adjusted, and the silane coupling agent is prepared. _{[n-C 6 H 13 Si} (OCH 3) 3] was added 0.5 parts of
The mixture 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.

Production Example 7 of Hydrophobic Iron Oxide In Production Example 1 of hydrophobic iron oxide, except that the ferrous sulfate aqueous solution at the time of synthesizing the magnetic iron oxide particles is reduced and the blowing amount of air is increased. In the same manner, hydrophobic iron oxide 7 was obtained.

Production Example 8 of Hydrophobic Iron Oxide In Production Example 5 of hydrophobic iron oxide, 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.

Production Example 9 of Hydrophobic Iron Oxide In Production Example 1 of hydrophobic iron oxide, 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. In the same manner, hydrophobic iron oxide 9 was obtained.

Production Example 10 of Hydrophobic Iron Oxide In Production Example 5 of hydrophobic iron oxide, except that the ferrous sulfate aqueous solution at the time of synthesizing the magnetic iron oxide particles is increased and the blowing amount of air is decreased. Similarly, hydrophobic iron oxide 10 was obtained.

Production Example 11 of Hydrophobic Iron Oxide In Production Example 3 of hydrophobic iron oxide, 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.

Production Example 12 of Hydrophobic Iron Oxide Hydrophobic iron oxide was produced in the same manner as in Production Example 5 of hydrophobic iron oxide except that the amount of air blown during the synthesis of magnetic iron oxide particles was increased. I got 12.

Table 1 shows the physical properties of the above hydrophobic iron oxides 1 to 12.
Shown in.

[0259]

[Table 1]

<2> Production of Magnetic Toner (Production Example 1 of Magnetic Toner) 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 mol. / Liter-CaCl ₂ aqueous solution 6
7.7 parts was 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 is heated to 60 ° C. After heating, 20 parts of ester wax (mp. 70 ° C.) was mixed and dissolved therein, and a polymerization initiator 2,2′-azobis (2,4-dimethylvaleronitrile [t1 / 2 = 140 minutes, 60 ° C. was added thereto. Conditions] 8 parts and dimethyl-2,2'-azobisisobutyrate [t1 / 2 = 2
70 minutes, 60 ° C; t1 / 2 = 80 minutes, 80 ° C]
Two parts were dissolved.

The above polymerizable monomer system was put into the above aqueous medium, and the mixture was fed at 60 ° C. under N ₂ atmosphere using a TK homomixer (Tokushu Kika Kogyo Co., Ltd.) at 10,000 rpm for 15 minutes.
It was stirred for a minute and granulated. After that, increase the liquid temperature to 80 ° C and further 1
Stirring was continued for 0 hours. After the reaction was completed, the suspension was cooled, hydrochloric acid was added to dissolve Ca ₃ (PO ₄ ) ₂ , and the magnetic toner particles were obtained by filtration, washing with water and drying. The magnetic toner particles 100
Parts and hexamethyldisilazane and then treated with silicone oil to give a BET specific surface area of 120 m ² /
1.4 parts of hydrophobic silica fine powder of g was mixed and externally added using a Henschel mixer (Mitsui Miike Kakoki Co., Ltd.) to obtain a magnetic toner 1. Table 2 shows the physical properties of the magnetic toner 1.

The volume average particle diameter was 6.2 μm, and the average circularity was 0.976.

(Production Example 2 of Magnetic Toner) The same procedure as in Production Example 1 of magnetic toner was carried out except that the hydrophobic iron oxide 1 in Production Example 1 of the magnetic toner was replaced with 100 parts of the hydrophobic iron oxide 2 and the stirring speed during granulation was changed. Magnetic toner particles were obtained. 100 parts of the 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 Kako Co., Ltd.). Mixing and external addition using a machine (trade name) to obtain a magnetic toner 2. At this time, the volume average particle diameter was 4.9 μm, and the average circularity was 0.977. Table 2 shows the physical properties of the magnetic toner 2.

(Magnetic Toner Production Example 3) Magnetic toner particles were obtained in the same manner except that the hydrophobic iron oxide 1 in the magnetic toner production example 1 was replaced with 150 parts of the hydrophobic iron oxide 3. 100 parts of the magnetic toner particles and 0.7 part 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 Kako Co., Ltd.). Mixing and external addition using a machine (trade name) to obtain a magnetic toner 3. At this time, the volume average particle diameter was 9.7 μm, and the average circularity was 0.981. Table 2 shows the physical properties of the magnetic toner 3.

(Production Example 4 of Magnetic Toner) Magnetic toner particles were obtained in the same manner except that the hydrophobic iron oxide 1 in Production Example 1 of magnetic toner was replaced with 190 parts of hydrophobic iron oxide 4. 100 parts of the magnetic toner particles and 2.0 parts by mass 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 magnetic toner 4 was obtained by mixing and externally adding it using Kakoki Co., Ltd. At this time, the volume average particle diameter was 7.1 μm, and the average circularity was 0.977. Table 2 shows the physical properties of the magnetic toner 4. (Production Examples 5 and 6 of magnetic toner) The amount of the hydrophobic iron oxide 3 used in Production Example 3 of the magnetic toner 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. Other than the above, magnetic toner particles were obtained in the same manner. 100 parts of each magnetic toner particle was treated with hexamethyldisilazane and then treated with silicone oil, and 1.0 part and 3.0 parts of hydrophobic silica fine powder having a BET specific surface area of 120 m ² / g after the treatment, A magnetic toner 5 and a magnetic toner 6 were obtained by mixing and externally adding each using a Henschel mixer (Mitsui Miike Kakoki Co., Ltd.). At this time, the magnetic toner particles 5 have a volume average particle diameter of 10.5 μm and an average circularity of 0.971, and the magnetic toner particles 6 have a volume average particle diameter of 2.4.
The average circularity in μm was 0.977. Table 2 shows the physical properties of the magnetic toners 5 and 6.

(Production Example 7 of Magnetic Toner) Ion-exchanged water 7
09 parts of 0.1 mol / liter -Na ₃ PO ₄ aqueous 4
After adding 51 parts and humidifying to 60 ° C., 67.7 parts of a 1.0 mol / 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 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-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 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 for 15 minutes.
It was stirred for a minute and granulated. After that, increase the liquid temperature to 80 ° C and further 1
Stirring was continued for 0 hours. After the reaction was completed, the suspension was cooled, hydrochloric acid was added to dissolve Ca ₃ (PO ₄ ) _2, and the mixture was filtered, washed with water and dried to obtain iron oxide-containing resin powder.

Next, the following materials were mixed and melt-kneaded with a twin-screw extruder heated to 140 ° C. to obtain a kneaded product. -205 parts of the iron oxide-containing resin powder-0.8% of negative charge control agent (iron compound of monoazo dye type) -3 parts of ethylene-propylene copolymer (Mw = 6000)

After cooling the kneaded product, it was roughly pulverized with a hammer mill, the coarsely pulverized product was finely pulverized with a jet mill, and the obtained finely pulverized product was subjected to air classification to obtain magnetic toner particles. 100 parts of the magnetic toner particles and 1.2 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 Kako Co., Ltd.). Mixing and external addition using a machine (trade name) to obtain a magnetic toner 7. At this time, the volume average particle diameter was 7.4 μm, and the average circularity was 0.981. Table 2 shows the physical properties of the magnetic toner 7.

(Production Example 8 of Magnetic Toner) The magnetic toner particles obtained in Production Example 7 of magnetic toner were surface-treated with a mechanical impact force to obtain magnetic toner particles. 100 parts of the magnetic toner particles are treated with hexamethyldisilazane and then with silicone oil, and the BET specific surface area after treatment is 120.
and mixed externally added using m ² / g of hydrophobic silica fine powder 1.2 parts of a Henschel mixer (Mitsui Miike Engineering Corporation) was a magnetic toner 8. The volume average particle size at this time is 7.
At 6 μm, the average circularity was 0.978. Table 2 shows the physical properties of the magnetic toner 8.

(Production Example 9 of Magnetic Toner) Magnetic toner particles were obtained in the same manner except that the hydrophobic iron oxide 1 in Production Example 1 of magnetic toner was replaced with 100 parts of the hydrophobic iron oxide 5. 100 parts of magnetic toner particles and 1.2 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 Henschel mixer (Mitsui Miike Kakoki Co., Ltd.). Magnetic toner 9 was mixed and externally added. At this time, the volume average particle diameter was 6.9 μm, and the average circularity was 0.977. Table 2 shows the physical properties of the magnetic toner 9.

(Production Example 10 of magnetic toner) 150 parts of the hydrophobic iron oxide 1 prepared in Production Example 1 of the magnetic toner was replaced with 6 parts of the hydrophobic iron oxide.
Magnetic toner particles were obtained in the same manner except that the above was changed. 100 parts of 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 Kakoki Co., Ltd.). Magnetic toner 10 was obtained by mixing and externally adding. At this time, the volume average particle diameter was 4.8 μm, and the average circularity was 0.980. Table 2 shows the physical properties of the magnetic toner 10.

(Production Example 11 of magnetic toner) 150 parts of the hydrophobic iron oxide 1 prepared in Production Example 1 of the magnetic toner was used.
Magnetic toner particles were obtained in the same manner except that the above was changed. 100 parts of magnetic toner particles and 1.2 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 Henschel mixer (Mitsui Miike Kakoki Co., Ltd.). Magnetic toner 11 was mixed and externally added. At this time, the volume average particle diameter was 6.9 μm, and the average circularity was 0.976. Table 2 shows the physical properties of the magnetic toner 11.

(Production Example 12 of magnetic toner) 100 parts of the hydrophobic iron oxide 1 obtained in Production Example 1 of magnetic toner was used.
Magnetic toner particles were obtained in the same manner except that the above was changed. 100 parts of magnetic toner particles and 1.2 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 Henschel mixer (Mitsui Miike Kakoki Co., Ltd.). Magnetic toner 12 was obtained by mixing and adding externally. At this time, the volume average particle diameter was 7.2 μm, and the average circularity was 0.981. Table 2 shows the physical properties of the magnetic toner 12.

(Production Example 13 of magnetic toner) 190 parts of hydrophobic iron oxide 9 was added to the hydrophobic iron oxide 1 of Production Example 1 of magnetic toner.
Magnetic toner particles were obtained in the same manner except that the above was changed. 100 parts of magnetic toner particles and 2.0 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 Henschel mixer (Mitsui Miike Kakoki Co., Ltd.). Magnetic toner 13 was mixed and externally added. At this time, the volume average particle diameter was 6.3 μm, and the average circularity was 0.969. Table 2 shows the physical properties of the magnetic toner 13.

(Production Example 14 of Magnetic Toner) 40 parts of hydrophobic iron oxide 9 prepared in Production Example 13 of magnetic toner was used.
Magnetic toner particles were obtained in the same manner except that 0 was used instead.
100 parts of magnetic toner particles and 2.0 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 Henschel mixer (Mitsui Miike Kakoki Co., Ltd.). Magnetic toner 14 was added and mixed externally to obtain a magnetic toner 14. At this time, the volume average particle diameter was 6.6 μm, and the average circularity was 0.971. Table 2 shows the physical properties of the magnetic toner 14.

(Manufacturing Example 15 of Magnetic Toner) The hydrophobic iron oxide 5 of Manufacturing Example 5 of the magnetic toner was replaced with 150 parts of the hydrophobic iron oxide 1.
Magnetic toner particles were obtained in the same manner except that 1 was used.
100 parts of magnetic toner particles and 1.2 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 Henschel mixer (Mitsui Miike Kakoki Co., Ltd.). Magnetic toner 15 was mixed and externally added to obtain a magnetic toner 15. At this time, the volume average particle diameter was 6.4 μm, and the average circularity was 0.962. Table 2 shows the physical properties of the magnetic toner 15.

(Manufacturing Example 16 of Magnetic Toner) 40 parts of hydrophobic iron oxide 12 of the hydrophobic iron oxide 1 of Manufacturing Example 1 of magnetic toner was used.
Magnetic toner particles were obtained in the same manner except that the above was changed. 100 parts of magnetic toner particles and 1.0 part 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 Kakoki Co., Ltd.). Magnetic toner 16 was mixed and externally added. At this time, the volume average particle diameter was 7.1 μm, and the average circularity was 0.983. Table 2 shows the physical properties of the magnetic toner 16.

(Production Example 17 of Magnetic Toner) 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 mol / liter.
67.7 parts of 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 formulation was uniformly dispersed and mixed using an attritor (Mitsui Miike Kakoki Co., Ltd.). -Styrene 80 parts-n-butyl acrylate 20 parts-Unsaturated polyester resin 2 parts-Negatively charged control agent (monoazo dye-based Fe compound) 2 parts-Hydrophobic iron oxide 1 100 parts This monomer composition 60 The mixture was heated to 0 ° 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, Under 60 ° C.] 8 parts and dimethyl-2,2′-azobisisobutyrate [t1 / 2 = 2
70 minutes, 60 ° C; t1 / 2 = 80 minutes, 80 ° C]
Two parts were dissolved.

The above polymerizable monomer system was added to 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 for 15 minutes.
It was stirred for a minute and granulated. After that, increase the liquid temperature to 80 ° C and further 1
Stirring was continued for 0 hours. After the reaction was completed, the suspension was cooled, hydrochloric acid was added to dissolve Ca ₃ (PO ₄ ) ₂ , and the magnetic toner particles were obtained by filtration, washing with water and drying. The magnetic toner particles 100
Parts and hexamethyldisilazane and then treated with silicone oil to give a BET specific surface area of 120 m ² /
1.2 parts of hydrophobic silica fine powder (g) was mixed and externally added using a Henschel mixer (Mitsui Miike Kakoki Co., Ltd.) to obtain a magnetic toner 17. The magnetic toner 17 had a volume average particle diameter of 6.3 μm and an average circularity of 0.988. Table 7 shows the physical properties of the magnetic toner 17.

(Production Example 18 of magnetic toner) In the same manner as in Production Example 17 of magnetic toner, except that the hydrophobic iron oxide 1 in Production Example 17 was replaced with 100 parts of the hydrophobic iron oxide 2 and the stirring speed during granulation was changed. Magnetic toner particles were obtained. 100 parts of the 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 1.2 parts of the hydrophobic silica fine powder of No. 1 were mixed and externally added using a Henschel mixer (Mitsui Miike Kakoki Co., Ltd.) to obtain a magnetic toner 18. Volume average particle size at this time is 5.2 μm
The average circularity was 0.991. Magnetic toner 18
The physical properties of are shown in Table 7.

(Production Example 19 of Magnetic Toner) Magnetic toner particles were obtained in the same manner as in Production Example 17 of magnetic toner except that the hydrophobic iron oxide 1 was replaced with 150 parts of the hydrophobic iron oxide 3.
100 parts of the magnetic toner particles are treated with hexamethyldisilazane and then treated with silicone oil, and BET after the treatment
Hydrophobic silica fine powder with a specific surface area of 120 m ² / g 0.7
Was mixed and externally added using a Henschel mixer (Mitsui Miike Kakoki Co., Ltd.) to obtain a magnetic toner 19. The magnetic toner 19 had a volume average particle diameter of 9.5 μm and an average circularity of 0.979. Table 7 shows the physical properties of the magnetic toner 19.

(Production Example 20 of Magnetic Toner) Magnetic toner particles were obtained in the same manner as in Production Example 17 of magnetic toner except that the hydrophobic iron oxide 1 was replaced with 190 parts of the hydrophobic iron oxide 4.
100 parts of the magnetic toner particles are treated with hexamethyldisilazane and then treated with silicone oil, and BET after the treatment
Hydrophobic silica fine powder with a specific surface area of 120 m ² / g 2.0
Was mixed and externally added using a Henschel mixer (Mitsui Miike Kakoki Co., Ltd.) to obtain a magnetic toner 20. The volume average particle diameter of the magnetic toner 20 was 4.3 μm, and the average circularity was 0.976. Table 7 shows the physical properties of the magnetic toner 20.

(Production Examples 21 and 22 of Magnetic Toner) The amount of the hydrophobic iron oxide 3 used in Production Example 19 of the magnetic toner was changed to 10 parts or 200 parts, and the amounts of the Na ₃ PO ₄ aqueous solution and the CaCl ₂ aqueous solution were added. Magnetic toner particles were obtained in the same manner except that was changed. Each magnetic toner particle 100
Part was treated with hexamethyldisilazane and then treated with silicone oil, and the BET specific surface area after treatment was 120 m ² /
2.0 parts or 3.0 parts of the hydrophobic silica fine powder of g was mixed and externally added using a Henschel mixer (Mitsui Miike Kakoki Co., Ltd.) to obtain a magnetic toner 21 and a magnetic toner 22. The magnetic toner 21 and the magnetic toner 22 had a volume average particle diameter of 10.7 μm and an average circularity of 0.979, and the magnetic toner particles 22 had a volume average particle diameter of 2.8 μm and an average circularity of 0.980. . Table 7 shows the physical properties of the magnetic toners 21 and 22.

(Production Example 23 of Magnetic Toner) 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 mol / liter.
67.7 parts of 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 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-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 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 for 15 minutes.
It was stirred for a minute and granulated. After that, increase the liquid temperature to 80 ° C and further 1
Stirring was continued for 0 hours. After the reaction was completed, the suspension was cooled, hydrochloric acid was added to dissolve Ca ₃ (PO ₄ ) _2, and the mixture was filtered, washed with water and dried to obtain iron oxide-containing resin powder.

Next, the following formulations were mixed and melt-kneaded with a twin-screw extruder heated to 140 ° C. to obtain a kneaded product. -205 parts of the above iron oxide-containing resin powder-Negatively charged property control agent (monoazo dye-based iron compound) 0.8 part-Ethylene-propylene copolymer (Mw = 6000) 3 parts Hammer mill after cooling the kneaded product Coarsely pulverized with, and the coarsely pulverized material was finely pulverized with a jet mill, and the obtained finely pulverized material was subjected to air classification to obtain magnetic toner particles. The magnetic toner particles 1
00 parts, treated with hexamethyldisilazane and then treated with silicone oil, and the BET specific surface area after treatment is 120 m
Magnetic toner particles 23 were obtained by externally mixing 1.2 parts of ² / g hydrophobic silica fine powder with a Henschel mixer (Mitsui Miike Kakoki Co., Ltd.). The magnetic toner particles 23
Has a volume average particle diameter of 7.6 μm and an average circularity of 0.88.
It was 6. Table 7 shows the physical properties of the magnetic toner 23.

(Production Example 24 of Magnetic Toner) The magnetic toner particles 23 obtained in Production Example 23 of magnetic toner were subjected to a surface treatment by mechanical impact to obtain magnetic toner particles. 100 parts of the magnetic toner particles and 1.2 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 Kako Co., Ltd.). And added externally by using a machine to make a magnetic toner 24. The magnetic toner 24
Has a volume average particle diameter of 7.4 μm and an average circularity of 0.95.
It was 3. Table 7 shows the physical properties of the magnetic toner 24.

(Production Example 25 of magnetic toner) Magnetic toner particles were obtained in the same manner as in Production Example 17 of magnetic toner except that the hydrophobic iron oxide 1 was replaced with 100 parts of the hydrophobic iron oxide 5.
100 parts of the magnetic toner particles are treated with hexamethyldisilazane and then treated with silicone oil, and BET after the treatment
Hydrophobic silica fine powder with a specific surface area of 120 m ² / g 1.2
Was mixed and externally added using a Henschel mixer (Mitsui Miike Kakoki Co., Ltd.) to obtain a magnetic toner 25. The magnetic toner 25 had a volume average particle diameter of 7.1 μm and an average circularity of 0.968. Table 7 shows the physical properties of the magnetic toner 25.

(Production Example 26 of Magnetic Toner) Magnetic toner particles were obtained in the same manner as in Production Example 17 of magnetic toner except that the hydrophobic iron oxide 1 was replaced with 150 parts of the hydrophobic iron oxide 6.
100 parts of the magnetic toner particles are treated with hexamethyldisilazane and then treated with silicone oil, and BET after the treatment
Hydrophobic silica fine powder 1.7 having a specific surface area of 120 m ² / g
Was mixed and externally added using a Henschel mixer (Mitsui Miike Kakoki Co., Ltd.) to obtain a magnetic toner 26. The volume average particle diameter of the magnetic toner 26 was 4.5 μm, and the average circularity was 0.977. Table 7 shows the physical properties of the magnetic toner 26.

<3> Production of non-magnetic toner (Production Example 1 of non-magnetic toner) 0.1 mol / liter
And Na ₃ PO ₄ aqueous solution, 1.0 mol / l -CaC
Prepare an l ₂ aqueous solution. 710 parts of ion-exchanged water and 0.1 mol / liter-Na were placed in a 2-liter four-necked flask equipped with a TK type homomixer (Tokushu Kika Kogyo Co., Ltd.).
550 parts of ₃ PO ₄ aqueous solution was added to adjust the number of rotations to 10,000, and the mixture was heated to 65 ° C.

1.0 mol / liter-CaCl
68 parts of ₂ aqueous solution was gradually added to prepare a dispersion medium system containing a fine water-soluble dispersant Ca ₃ (PO ₄ ) ₂ .

On the other hand, the following mixture was mixed with an attritor 3
After dispersing for 2 hours, 2 parts of 2,2′-azobis (2,4-dimethylvaleronitrile), which is a polymerization initiator, was added to prepare a dispersion. -Styrene 160 parts-n-butyl acrylate 40 parts-Colorant (phthalocyanine pigment) 6 parts-Saturated polyester 10 parts (terephthalic acid-propylene oxide-modified bisphenol A) -Di-tert-butylsalicylic acid aluminum compound 3 parts-Ester wax 20 parts of the dispersion was put into the dispersion medium system and granulated for 8 minutes while maintaining the rotation speed. After that, change the stirrer from the high speed stirrer to the propeller stirrer blade, and stir at 50 rpm while adjusting the internal temperature to 6
Polymerization was continued for a total of 8 hours at 0 ° C. for 4 hours and then to 80 ° C. for 4 hours. After the polymerization was completed, the slurry was cooled, diluted hydrochloric acid was added to remove the dispersant, and non-magnetic toner particles were obtained. Hydrophobic titanium oxide fine powder having a BET specific surface area of 100 m ² / g per 100 parts of the non-magnetic toner particles.
Cyan-colored non-magnetic toner 1 was mixed with 7 parts of hydrophobic silica fine powder having a BET specific surface area of 40 m ² / g using 0.7 part of Henschel mixer.
Got The volume average particle diameter of the non-magnetic toner 1 is 7.8 μm.
The average circularity was 0.974.

(Production Example 2 of non-magnetic toner) Non-magnetic toner particles were obtained in the same manner as Production Example 1 of non-magnetic toner except that 12 parts of quinacridone pigment was used instead of the phthalocyanine pigment. With respect to 100 parts of the non-magnetic toner particles,
0.7 parts of hydrophobic titanium oxide fine powder having a BET specific surface area of 100 m ² / g and 0.7 part of hydrophobic silica fine powder having a BET specific surface area of 40 m ² / g were mixed using a Henschel mixer, A magenta non-magnetic toner 2 was obtained.
The non-magnetic toner 2 had a volume average particle diameter of 7.7 μm and an average circularity of 0.975.

(Production Example 3 of non-magnetic toner) Instead of the phthalocyanine pigment, C.I. I. Non-magnetic toner particles were obtained in the same manner except that 6 parts of Pigment Yellow 180 and 4 parts of Solvent Yellow 93 were used. BET specific surface area is 100 m ² / g based on 100 parts of the non-magnetic toner particles
0.7 parts of the hydrophobic titanium oxide fine powder which is the above and 0.7 part of the hydrophobic silica fine powder having a BET specific surface area of 40 m ² / g are mixed using a Henschel mixer to obtain a yellow non-magnetic toner 3. Obtained. The non-magnetic toner 3 had a volume average particle diameter of 7.6 μm and an average circularity of 0.980.

(Production Example 4 of non-magnetic toner) The non-magnetic toner particles obtained in Production Example 1 of non-magnetic toner are further added.
After surface treatment with a hybridizer (manufactured by Nara Machinery Co., Ltd.),
BET for 100 parts of surface-treated non-magnetic toner particles
0.7 parts of hydrophobic titanium oxide fine powder having a specific surface area of 100 m ² / g and 0.7 part of hydrophobic silica fine powder having a BET specific surface area of 40 m ² / g were mixed using a Henschel mixer, and cyan A color non-magnetic toner 4 was obtained. The non-magnetic toner 4 had a volume average particle diameter of 7.7 μm and an average circularity of 0.983.

(Production Example 5 of non-magnetic toner) The non-magnetic toner particles obtained in Production Example 2 of non-magnetic toner were further added.
After surface treatment with a hybridizer (manufactured by Nara Machinery Co., Ltd.),
BET for 100 parts of surface-treated non-magnetic toner particles
0.7 parts of hydrophobic titanium oxide fine powder having a specific surface area of 100 m ² / g and 0.7 part of hydrophobic silica fine powder having a BET specific surface area of 40 m ² / g were mixed using a Henschel mixer to obtain magenta. A color non-magnetic toner 5 was obtained. The non-magnetic toner 5 had a volume average particle diameter of 7.6 μm and an average circularity of 0.984.

(Production Example 6 of non-magnetic toner) The non-magnetic toner particles obtained in Production Example 3 of non-magnetic toner were further added.
After surface treatment with a hybridizer (manufactured by Nara Machinery Co., Ltd.),
BET for 100 parts of surface-treated non-magnetic toner particles
0.7 parts of hydrophobic titanium oxide fine powder having a specific surface area of 100 m ² / g and 0.7 part of hydrophobic silica fine powder having a BET specific surface area of 40 m ² / g were mixed using a Henschel mixer, and yellow A color non-magnetic toner 6 was obtained. The non-magnetic toner 6 had a volume average particle diameter of 7.5 μm and an average circularity of 0.983.

(Production Example 7 of non-magnetic toner) 100 parts of polyester resin (consisting of terephthalic acid / fumaric acid / trimellitic anhydride / bisphenol A derivative) Colorant (phthalocyanine pigment) 4 parts di-tert -Butylsalicylic acid aluminum compound 4 parts

The above materials were sufficiently premixed with a Henschel mixer, melt-kneaded with a twin-screw extruder,
After cooling, it was roughly pulverized to about 1 to 2 mm using a hammer mill, and then finely pulverized by a fine pulverizer by a mechanical pulverization system (Kawatetsu Heavy Industries Co., Ltd.). Further, the finely pulverized product thus obtained was classified to obtain non-magnetic toner particles. Non-magnetic toner particles per 100 parts, BET specific surface area of 100 m ² / g of hydrophobic titanium oxide fine powder 0.7 parts of BET specific surface area of 40 m ² /
0.7 parts of hydrophobic silica fine powder (g) was mixed using a Henschel mixer to obtain a cyan non-magnetic toner 7. The non-magnetic toner 7 had a volume average particle diameter of 6.8 μm and an average circularity of 0.957.

(Production Example 8 of non-magnetic toner) 100 parts of polyester resin (obtained by polycondensation of propoxylated bisphenol and fumaric acid) Red pigment (Pigment Red 152) 4 parts 5-tert-octyl Aluminum compound of salicylic acid 5 parts The above materials are sufficiently premixed by a Henschel mixer, melt-kneaded at a temperature of about 140 ° C. by a twin-screw extruder, and after cooling, roughly crushed to about 1-2 mm using a hammer mill, Then, it was pulverized by an air jet pulverizer. Further, the obtained finely pulverized product was classified to obtain non-magnetic toner particles. For 100 parts of the non-magnetic toner particles, BE
0.7 parts of hydrophobic titanium oxide fine powder having a T specific surface area of 100 m ² / g and 0.7 part of hydrophobic silica fine powder having a BET specific surface area of 40 m ² / g were mixed using a Henschel mixer, A magenta non-magnetic toner 8 was obtained. The non-magnetic toner 8 had a volume average particle diameter of 6.3 μm and an average circularity of 0.912.

(Nonmagnetic toner production example 9) Nonmagnetic toner particles were prepared in the same manner as in nonmagnetic toner production example 8 except that 4 parts of yellow pigment (Pigment Yellow 17) was used in place of the red pigment. Obtained. The non-magnetic toner particles 10
With respect to 0 part, 0.7 part of hydrophobic titanium oxide fine powder having a BET specific surface area of 100 m ² / g and a BET specific surface area of 40 parts
0.7 parts of hydrophobic silica fine powder of m ² / g was mixed using a Henschel mixer to obtain a yellow non-magnetic toner 9. The volume average particle diameter of the non-magnetic toner 9 is 6.9.
μm, the average circularity was 0.904.

(Production Example 10 of non-magnetic toner) 0.1 mo
A 1 / liter-Na ₃ PO ₄ aqueous solution and a 1.0 mol / liter-CaCl ₂ aqueous solution are prepared. In a 2-liter four-necked flask equipped with a TK homomixer (Tokushu Kika Kogyo Co., Ltd.), 710 parts of ion-exchanged water and 0.1 mol /
L-Na ₃ PO ₄ aqueous solution (550 parts) was added to adjust the number of revolutions to 10,000, and the mixture was heated to 65 ° C.

Here, 1.0 mol / liter-CaCl
68 parts of ₂ aqueous solution was gradually added to prepare a dispersion medium system containing a fine water-soluble dispersant Ca ₃ (PO ₄ ) ₂ .

On the other hand, the following mixture was mixed with an attritor 3
After dispersing for 2 hours, 2 parts of 2,2′-azobis (2,4-dimethylvaleronitrile), which is a polymerization initiator, was added to prepare a dispersion. -Styrene 170 parts-n-butyl acrylate 30 parts-Colorant (disazo yellow pigment) 6 parts-Saturated polyester 10 parts (terephthalic acid-propylene oxide modified bisphenol A) -Di-tert-butylsalicylic acid chromium compound 3 parts- 30 parts of diester wax

The dispersion was put into the dispersion medium system and granulated for 8 minutes while maintaining the rotation speed. After that, the agitator was changed from the high-speed agitator to the propeller agitator blade, and while stirring at 50 rpm, the internal temperature was raised to 60 ° C for 4 hours and then to 80 ° C.
Polymerization was continued for a total of 8 hours. After the polymerization was completed, the slurry was cooled, diluted hydrochloric acid was added to remove the dispersant, and non-magnetic toner particles were obtained. For 100 parts of the non-magnetic toner particles, B
0.7 parts of hydrophobic titanium oxide fine powder having an ET specific surface area of 100 m ² / g and 0.7 part of hydrophobic silica fine powder having a BET specific surface area of 40 m ² / g were mixed using a Henschel mixer, A yellow non-magnetic toner 10 was obtained.
The non-magnetic toner 10 had a volume average particle diameter of 7.1 μm and an average circularity of 0.981.

(Production Example 11 of non-magnetic toner) Magenta non-magnetic toner particles were obtained in the same manner as in Production Example 10 of non-magnetic toner except that 12 parts of quinacridone pigment was used instead of the disazo yellow pigment. It was BET specific surface area is 100 m ² / g based on 100 parts of the non-magnetic toner particles
0.7 parts by mass of hydrophobic titanium oxide fine powder and 0.7 parts of hydrophobic silica fine powder having a BET specific surface area of 40 m ² / g
The parts were mixed using a Henschel mixer to obtain a magenta non-magnetic toner 11. The non-magnetic toner 11 had a volume average particle diameter of 7.2 μm and an average circularity of 0.979.

(Production Example 12 of non-magnetic toner) A phthalocyanine pigment was used in place of the disazo yellow pigment,
Production Example 10 of non-magnetic toner except that 30 parts of paraffin wax was used instead of 30 parts of diester wax
In the same manner as described above, cyan non-magnetic toner particles were obtained. The BET specific surface area is 10 with respect to 100 parts of the non-magnetic toner particles.
0.7 parts of hydrophobic titanium oxide fine powder of 0 m ² / g and B
0.7 parts of hydrophobic silica fine powder having an ET specific surface area of 40 m ² / g was mixed using a Henschel mixer to obtain a cyan non-magnetic toner 12. The volume average particle diameter of the non-magnetic toner 12 is 7.5 μm, and the average circularity is 0.983.
Met.

<4> Production of Carrier (Production Example 1 of Carrier Particles) -Phenol 7.5 parts-Formalin solution 11.25 parts (folimaldehyde about 40%, methanol about 10%, the rest is water) -Lipophilization Treated magnetite fine particles 53 parts (average particle size 0.24 μm, specific resistance 5 × 10 ⁵ Ω · cm) -Lipophilization-treated α-Fe ₂ O ₃ fine particles 35 parts (average particle size 0.60 μm, specific resistance 2 × 10 ⁹ Ω · cm) The lipophilic treatment of the magnetite and α-Fe ₂ O ₃ used here was carried out by adding 1.0 part of γ − to 99 parts of magnetite and 99 parts of α-Fe ₂ O ₃ , respectively. Add glycidoxypropyltrimethoxysilane and mix in a Henschel mixer for 10
It was carried out by premixing and stirring at 0 ° C. for 30 minutes.

While maintaining the above materials and 11 parts of water at 40 ° C., they were mixed for 1 hour. To this slurry, 2.0 parts of 28% ammonia water as a basic catalyst and 11 parts of water were placed in a flask, heated to and maintained at 85 ° C. for 40 minutes while stirring and mixing, and reacted for 3 hours. Produced and cured. Then, after cooling to 30 ° C. and adding 100 parts of water, the supernatant was removed, the precipitate was washed with water and air-dried. Then, this was dried under reduced pressure (5 mmHg or less) at 180 ° C. to obtain spherical magnetic carrier core particles containing magnetite fine particles using a phenol resin as a binder resin.

Coarse particles were removed from the particles through a 60-mesh and 100-mesh sieve, and then a multi-division wind classifier (Labojet EJ) utilizing the Coanda effect was used.
-L-3, manufactured by Nittetsu Mining Co., Ltd.) was used to remove fine powder and coarse powder to obtain carrier core particles having a volume average particle diameter of 50 μm and a particle diameter of 35 μm. The specific resistance of the obtained carrier core is 2.2.
It was × 10 ¹² Ω · cm.

[0316] To the obtained carrier core particles, 0.3% of γ-aminopropyltrimethoxysilane diluted with a toluene solvent was continuously applied with shear stress to treat the core surface. At that time, 40 ° C, 39.
It was carried out while evaporating the solvent under 9 kPa (300 torr). Subsequently, a mixture of 0.5% straight silicone resin having all methyl groups as substituents and 0.015% γ-aminopropyltrimethoxysilane was coated with toluene as a solvent. At that time, 40 ℃, 39.9kP
It was carried out while evaporating the solvent under a (300 torr). Further, this magnetic coated carrier was baked at 140 ° C., coarse particles aggregated with a 100-mesh sieve were cut, and then fine powder and coarse powder were removed by a multi-division air classifier to adjust the particle size distribution.

Then, the humidity was adjusted for 24 hours in a hopper kept at 23 ° C. and 60% to obtain magnetic coated carrier particles 1.

(Production Example 2 of carrier particles) In molar ratio, F
e ₂ O ₃ = 50 mol%, CuO = 27 mol%, ZnO = 2
It was weighed so as to be 3 mol% and mixed using a ball mill. After calcining this at a temperature of 1000 ° C., the burnable material was crushed by a ball mill. Obtained powder 10
0 parts, sodium polymethacrylate 0.5 parts and water 50
Parts were put in a wet ball mill and mixed to obtain a slurry.

The obtained slurry was granulated with a spray dryer. Sinter this at 1200 ° C,
Carrier core particles were obtained. When the resistance of the obtained carrier core particles was measured, it was 4.0 × 10 ⁸ Ω · cm.

The surface of the carrier core particles was coated with a thermosetting silicone resin by the following method. A 10% carrier coating solution was prepared using toluene as a solvent so that the coating resin amount was 1.2%. Shear stress was continuously applied to this coating solution to volatilize the solvent to coat the carrier core particles. The magnetic coated carrier particles were cured at 250 ° C. for 1 hour, crushed, and then classified with a 100 mesh screen to obtain magnetic coated carrier particles 2.
The magnetic coated carrier particles 2 thus obtained had a 50% volume average particle diameter of 47 μm. The specific resistance is 1.1 × 10 ^10.
It was Ω · cm.

79.6 kA / m (1 kilo Oersted)
Strength of magnetization (σ1000) = 20600 kA /
It was m ² (206 emu / cm ³ ). (Sample packing density 3.46 / cm ³ )

<5> Evaluation of Image Forming Method (1) The image forming apparatus used in Examples 1 to 11 and Comparative Examples 1 to 9 will be described.

Examples 1 to 10 and Comparative Examples 1 to 4 of the present invention
As the evaluation machine for performing the image evaluation, a modified machine of Canon Color Laser Copier 700 was used. As the developing means, the photoconductor was modified into a rotary type developing means. The distance between the developing sleeve as the toner carrier and the photoconductor is about 480 μm, and the developing sleeve is 1.75 relative to the photoconductor.
It was rotated at a double peripheral speed ratio, and the AC bias had a peak-to-peak electric field strength of 4.8 × 10 ⁶ V / m and a frequency of 2000 Hz. A stainless steel sleeve was used as the developing sleeve, and blasting treatment was performed for each example, and the sleeve surface roughness was changed and evaluated.

As the charging means, a non-contact type corona charging type charging means is used.
The DC voltage is set to 1.8 kVpp and the DC voltage is set to −680 Vdc, and the voltage value is used in the range of ± 0.2 to ± 5 kV.

As the transfer means, an intermediate transfer belt was used, and a means for forming a multi-layered toner image on the intermediate transfer member and transferring it collectively onto the transfer material was used. Specifically, the color image forming apparatus having the configuration shown in FIG. 1 is used. Table 2 shows combinations of toners used in Examples 1 to 11 and Comparative Examples 1 to 9.

[0326]

Example 1 A magnetic toner 1 and non-magnetic toners 1 to 3 are shown in FIG.
The image was put into the color image forming apparatus shown in (1), and an image output test of 5,000 sheets was performed under normal temperature and normal humidity environment (23 ° C., 65% RH). As a result, a good image without scattering was obtained even after the continuous output of 5000 sheets. Further, after the black magnetic toner on the developing sleeve was removed with air, visual observation was carried out, but no toner adhered to the developing sleeve at all. The color toner also showed good charging characteristics and exhibited clear color reproducibility.

The evaluation results of the image density, fog value, dot reproducibility and transfer efficiency by the evaluation method described later are shown in Tables 3 to 6.
Shown in. Surface roughness R on the developing sleeve surface at this time
a was 1.2. Similarly, under high temperature and high humidity environment (3
2.5 ℃, 85% RH) and low temperature and low humidity environment (10 ℃,
Table 4 shows the results of the image formation test at 15% RH).
It shows in Table 5.

[0328]

Example 2 The same image forming test as in Example 1 was conducted except that the magnetic toner 1 in Example 1 was replaced with the magnetic toner 2.
The evaluation results are shown in Tables 3 to 6. At this time, the surface roughness Ra on the surface of the developing sleeve was 1.1.

[0329]

Example 3 The same image forming test as in Example 1 was conducted except that the magnetic toner 1 in Example 1 was replaced with the magnetic toner 3.
The evaluation results are shown in Tables 3 to 6. At this time, the surface roughness Ra on the surface of the developing sleeve was 1.2.

[0330]

Fourth Embodiment The magnetic toner 1 of the first embodiment is replaced with the magnetic toner 4, and the nonmagnetic toner 1, the nonmagnetic toner 2 and the nonmagnetic toner 3 are replaced with the nonmagnetic toner 4, the nonmagnetic toner 5 and the nonmagnetic toner 6. An image drawing test was conducted in the same manner except that the image was replaced.
The evaluation results are shown in Tables 3 to 6. At this time, the surface roughness Ra on the surface of the developing sleeve was 1.2.

[0331]

[Example 5] The same image forming test as in Example 4 was conducted except that the magnetic toner 4 in Example 4 was replaced with the magnetic toner 5.
The evaluation results are shown in Tables 3 to 6. At this time, the surface roughness Ra on the surface of the developing sleeve was 1.5.

[0332]

Example 6 The same image forming test as in Example 4 was performed except that the magnetic toner 4 in Example 4 was replaced with the magnetic toner 6.
The evaluation results are shown in Tables 3 to 6. At this time, the surface roughness Ra on the surface of the developing sleeve was 1.3.

[0333]

Comparative Example 1 The same image forming test as in Example 1 was conducted except that the magnetic toner 1 in Example 1 was replaced with the magnetic toner 7.
The evaluation results are shown in Tables 3 to 6. At this time, the surface roughness Ra on the surface of the developing sleeve was 1.1.

[0334]

Comparative Example 2 The same image forming test as in Example 1 was conducted, except that the magnetic toner 1 used in Example 1 was replaced with the magnetic toner 8. The evaluation results are shown in Tables 3 to 6. At this time, the surface roughness Ra on the surface of the developing sleeve was 1.1.

[0335]

Comparative Example 3 The same image forming test as in Example 1 was conducted, except that the magnetic toner 1 used in Example 1 was replaced with the magnetic toner 9. The evaluation results are shown in Tables 3 to 6. At this time, the surface roughness Ra on the surface of the developing sleeve was 1.2.

[0336]

Comparative Example 4 The magnetic toner 1 used in Example 1 was replaced with the magnetic toner 10, the non-magnetic toner 1 was replaced with the non-magnetic toner 7, the non-magnetic toner 2 was replaced with the non-magnetic toner 8 and the non-magnetic toner 3 was replaced with the non-magnetic toner. The same image development test as in Example 1 was performed except that the toner 9 was used instead. The evaluation results are shown in Tables 3 to 6. At this time, the surface roughness Ra on the surface of the developing sleeve was 1.6.

[0337]

[Embodiment 7] In Embodiment 1, for each 7 parts of non-magnetic toner 1, non-magnetic toner 2 and non-magnetic toner 3,
93 parts of carrier particles 1 are weighed, and each is mixed with a YS-L mixer.
The same image-forming test was performed except that D (manufactured by Yayoi Co., Ltd.) was mixed for 2 minutes and used as a two-component developer. The evaluation results are shown in Tables 3 to 6. At this time, the surface roughness Ra on the surface of the developing sleeve was 1.4.

[0338]

[Embodiment 8] The non-magnetic toner 4, the non-magnetic toner 5 and the non-magnetic toner 6 used in the embodiment 4 are 7 respectively.
93 parts of the carrier particles 1 were weighed, and each of them was mixed for 2 minutes using a mixer YS-LD (manufactured by Yayoi Co., Ltd.) and used as a two-component developer. went. The evaluation results are shown in Tables 3 to 6. At this time, the surface roughness Ra on the surface of the developing sleeve was 1.1.

[0339]

[Embodiment 9] In Embodiment 4, each of the non-magnetic toner 4, the non-magnetic toner 5 and the non-magnetic toner 6 used is 7
93 parts of carrier particles 2 were weighed, and each of them was mixed for 2 minutes using a mixer YS-LD (manufactured by Yayoi Co., Ltd.) and used as a two-component developer. went. The evaluation results are shown in Tables 3 to 6. At this time, the surface roughness Ra on the surface of the developing sleeve was 1.7.

[0340]

COMPARATIVE EXAMPLE 5 Magnetic toner 1 of Example 1 was replaced with magnetic toner 11
The same image development test as in Example 1 was performed except that the above was replaced with. Although the fog value and the image density remained unchanged, it was confirmed that the photoconductor was scratched and the image quality was deteriorated after the durability test (especially in the halftone image). It is considered that the reason is that the dispersibility of iron oxide was significantly reduced and the iron oxide was exposed on the surface of the toner particles. The evaluation results are shown in Tables 3 to 6. At this time, the surface roughness Ra on the surface of the developing sleeve was 1.3.

[0341]

Comparative Example 6 Magnetic toner 1 of Example 1 is replaced with magnetic toner 12
The same image forming test as in Example 1 was performed except that the above was replaced with, and it was confirmed that the same image quality deterioration as in Comparative Example 5 was performed. The evaluation results are shown in Tables 3 to 6. At this time, the surface roughness Ra on the surface of the developing sleeve was 1.3.

[0342]

Comparative Example 7 An image output test was conducted in the same manner as in Example 4 except that the magnetic toner 4 was replaced with the magnetic toner 13. As a result, the image density after endurance was decreased and the black color of the entire image was reduced. The degree also decreased. The evaluation results are shown in Tables 3 to 6.
At this time, the surface roughness of the developing sleeve surface was 1.2.

[0343]

Comparative Example 8 An image output test was conducted in the same manner as in Example 4 except that the magnetic toner 4 was replaced with the magnetic toner 14, and as in Comparative Example 7, the image density after endurance decrease. However, the blackness of the entire image also decreased. The evaluation results are shown in Tables 3 to 6. At this time, the surface roughness of the developing sleeve surface was 1.2.

[0344]

[Comparative Example 9] Magnetic toner 1 of Example 1 was replaced with magnetic toner 15
The same image development test as in Example 1 was performed except that the above was replaced with. The image density was low from the beginning of the durability, and the image density never recovered even after the durability. In addition, the fog value after endurance was also high. The evaluation results are shown in Tables 3 to 6. At this time, the surface roughness Ra on the surface of the developing sleeve was 1.3.

[0345]

[Embodiment 10] Magnetic toner 4 of Embodiment 4 is replaced with magnetic toner 1
An image drawing test similar to that in Example 4 was performed except that 6 was replaced. The evaluation results are shown in Tables 3 to 6. At this time, the surface roughness Ra on the surface of the developing sleeve was 1.5.

Evaluation methods in Examples 1 to 11 and Comparative Examples 1 to 9 are as follows. Measurement of Image Density Image density was measured with a Macbeth densitometer RD918 (manufactured by Macbeth). Measurement of fog value The fog value is measured by REFLECT M made by Tokyo Denshoku
It was measured using an ETER MODEL TC-6DS. For the filter, a green filter was used for black magnetic toner and magenta toner, an amber filter was used for cyan toner, and a blue filter was used for yellow toner.

[0347]

[Equation 6] Fog value (reflectance) (%) = reflectance (%) on standard paper
-Reflectance of non-image part of sample (%) The fog value is 2.
If it is 0% or less, a good image is obtained. Dot reproducibility of black magnetic toner The dot reproducibility was evaluated by performing an image-examination test using a checker pattern of 80 μm × 50 μm shown in FIG. 4 and observing the presence or absence of a black portion defect with a microscope. A: 2 or less defects in 100 B: 3 to 5 defects in 100 C: 6 to 10 defects in 100 D: 11 or more defects in 100 Initial transfer efficiency durability (at 100 sheets) ) Transfer efficiency of solid image (F
F) After transfer, the transfer residual toner on the photoconductor was taped off with Mylar tape and peeled off, and the Macbeth density value of what was pasted on the paper was C, and the Mylar tape was pasted on the toner-laden paper after transfer. Macbeth concentration of thing is E,
When the Macbeth density of the Mylar tape stuck on the unused paper is D, it was approximately calculated by the following formula.

[0348]

## EQU00007 ## Transfer efficiency (%) = E-C / E-D.times.100 If the transfer efficiency is 90% or more, there is no problem.

[0349]

[Table 2]

[0350]

[Table 3]

[0351]

[Table 4]

[0352]

[Table 5]

[0353]

[Table 6] (2) Image forming apparatuses used in Examples 12 to 17 and Comparative Examples 10 to 13 will be described.

Examples 12 to 17 of the present invention and Comparative Example 10
The color laser copier 700 modified by Canon was used as an evaluation machine for performing image evaluation of Nos. 13 to 13. As the developing means, the photoconductor was modified into a rotary type developing means. The distance between the developing sleeve and the photoconductor is about 480 μm
The AC bias is the peak-to-peak field strength.
The frequency was 8 × 10 ⁶ V / m and the frequency was 2000 Hz. A stainless steel sleeve was used as the developing sleeve, and blasting treatment was performed for each example, and the sleeve surface roughness was changed and evaluated. The charging means was a contact charging type charging means in which a rubber roller was brought into contact, and the applied voltage was used as a direct current component (-1200 V) only.

The transfer means was a means for forming a multi-layered developed image on the intermediate transfer member by using an intermediate transfer belt and transferring it collectively onto the transfer material. Specifically, the color image forming apparatus having the configuration shown in FIG. 2 was used. Incidentally, as in FIG. 1, the developing sleeve rotates at a peripheral speed ratio of 1.75 times that of the photoconductor. Example 1
Table 7 shows combinations of toners used in Examples 1 to 16 and Comparative Examples 10 to 13.

[0356]

[Embodiment 11] Magnetic toner 17 and non-magnetic toners 1 to 3 are put into the color image forming apparatus shown in FIG. 2 and an image output test of 5000 sheets is continuously made under normal temperature and normal humidity environment (23 ° C., 65% RH). I went. As a result, a good image without scattering was obtained even after the continuous output of 5,000 sheets, and the contamination of the charging member confirmed on the halftone image and the solid white image was not observed.

After the black magnetic toner on the developing sleeve was removed by air, visual observation was conducted, but no toner adhered to the developing sleeve at all. The color non-magnetic toner also showed good charging characteristics and exhibited clear color reproducibility.
Tables 8 and 9 show the evaluation results of the contamination of the charging member, the fog value, the transfer efficiency, and the resolution at the initial stage of durability by the evaluation method described later. At this time, the surface roughness Ra on the surface of the developing sleeve was 1.3.

[0358]

Twelfth Embodiment An image forming test similar to that of the eleventh embodiment is performed except that the magnetic toner 17 of the eleventh embodiment is replaced with the magnetic toner 18. The evaluation results are shown in Tables 8 and 9. At this time, the surface roughness Ra on the surface of the developing sleeve was 1.2.

[0359]

[Embodiment 13] The magnetic toner 17 of Embodiment 11 is replaced with the magnetic toner 19, and the non-magnetic toner 1, the non-magnetic toner 2 and the non-magnetic toner 3 are replaced with the non-magnetic toner 12, the non-magnetic toner 11.
And the same image development test as in Example 11 was performed except that the non-magnetic toner 10 was used instead. The evaluation results are shown in Tables 8 and 9. Surface roughness Ra of the developing sleeve surface at this time
Was 1.4.

[0360]

[Embodiment 14] The magnetic toner 17 of Embodiment 11 is replaced with the magnetic toner 20, and the non-magnetic toner 1, the non-magnetic toner 2 and the non-magnetic toner 3 are replaced with the non-magnetic toner 4, the non-magnetic toner 5 and the non-magnetic toner 6. The same image-drawing test as in Example 11 was performed except that it was replaced. With the black magnetic toner, good results were obtained except that a slight contamination of the charging member was observed on the halftone image at about 4K sheets. The evaluation results are shown in Tables 8 and 9. At this time, the surface roughness Ra on the surface of the developing sleeve was 1.5.

[0361]

Example 15 The magnetic toner 20 of Example 14 was replaced with the magnetic toner 21, and 93 parts of the carrier particles 1 were weighed with respect to 7 parts of each of the non-magnetic toner 4, the non-magnetic toner 5 and the non-magnetic toner 6. The same image-forming test was conducted except that was used as a two-component developer by mixing for 2 minutes using a mixer YS-LD (manufactured by Yayoi Co., Ltd.).

The evaluation results are shown in Tables 8 and 9. At this time, the surface roughness Ra on the surface of the developing sleeve was 1.1.

[0363]

Example 16 The magnetic toner 20 of Example 14 was replaced with the magnetic toner 22, and 93 parts of the carrier particles 2 were weighed with respect to 7 parts of each of the non-magnetic toner 4, the non-magnetic toner 5 and the non-magnetic toner 6, respectively. The same image-forming test was conducted except that was used as a two-component developer by mixing for 2 minutes using a mixer YS-LD (manufactured by Yayoi Co., Ltd.).

With the black magnetic toner, a slight contamination of the charging member was observed on the halftone image at about 4K sheets, and good results were obtained except that the toner recoverability was lowered. The evaluation results are shown in Tables 8 and 9. At this time, the surface roughness Ra on the surface of the developing sleeve was 1.3.

[0365]

Comparative Example 10 The magnetic toner 17 of Example 11 was replaced with the magnetic toner 23, and the non-magnetic toner 1, the non-magnetic toner 2 and the non-magnetic toner 3 were replaced with the non-magnetic toner 12, the non-magnetic toner 11 and the non-magnetic toner 10. Example 11 except that
The same image drawing test was performed. In the case of about 300 sheets of black magnetic toner, the contamination level of the charging member on the halftone image was NG, and on the solid white image, the contamination level of the charging member became NG at about 3K sheets, and the transfer efficiency was low. . The evaluation results are shown in Tables 8 and 9. At this time, the surface roughness Ra on the surface of the developing sleeve was 1.2.

[0366]

Comparative Example 11 The magnetic toner 17 used in Example 11 was replaced with the magnetic toner 24, and the non-magnetic toner 1, the non-magnetic toner 2 and the non-magnetic toner 3 were replaced with the non-magnetic toner 7, the non-magnetic toner 8 and the non-magnetic toner. Example 11 except that the toner 9 was used instead
The same image drawing test was performed. In the case of about 1K sheets of black magnetic toner, the contamination level of the charging member on the halftone image was NG, and on the solid white image, the contamination level of the charging member became NG at about 4K sheets, and the transfer efficiency was also low. . The evaluation results are shown in Tables 8 and 9. At this time, the surface roughness Ra on the surface of the developing sleeve was 1.7.

[0367]

Comparative Example 12 An image output test was conducted in the same manner except that the magnetic toner 17 used in Example 11 was replaced with the magnetic toner 25. In the case of about 1K sheets of black magnetic toner, the contamination level of the charging member on the halftone image was NG, and on the solid white image, the contamination level of the charging member became NG at about 4K sheets, and the transfer efficiency was also low. . The evaluation results are shown in Tables 8 and 9. At this time, the surface roughness Ra on the surface of the developing sleeve was 1.6.

[0368]

Comparative Example 13 The magnetic toner 17 used in Example 11 is replaced with the magnetic toner 26, and the non-magnetic toner 1, the non-magnetic toner 2 and the non-magnetic toner 3 are replaced by the non-magnetic toner 7, the non-magnetic toner 8 and the non-magnetic toner. Example 11 except that the toner 9 was used instead
The same image drawing test was performed. With black magnetic toner, the contamination level of the charging member on the halftone image is NG when the sheet is about 2K, and the contamination level of the charging member is NG on the solid white image when the sheet is about 4.5K, and the transfer efficiency is low. there were. The evaluation results are shown in Tables 8 and 9. At this time, the surface roughness Ra on the surface of the developing sleeve was 2.2.

The evaluation methods in Examples 11 to 16 and Comparative Examples 10 to 13 are as follows. Evaluation of Contamination of Charging Member The contamination of the charging member of the developer was judged by the number of durable sheets in which uneven charging due to the contamination of the charging member occurred on the halftone image and the solid white image where image defects due to poor charging were likely to appear. The larger the number of generated sheets, the better the durability of the toner. Transfer efficiency The method of measuring the transfer efficiency at the initial stage of durability is described in Examples 1 to 10 above.
It is similar to the case shown in. Evaluation of resolution The resolution at the initial stage of durability (at the time of 100 sheets) was evaluated by the reproducibility of small-diameter isolated dots (diameter 60 μm) at 600 dpi, which is difficult to reproduce because the electric field is easily closed by the latent image electric field. A: 5 or less defects in 100 B: 6 to 10 defects in 100 C: 11 to 20 defects in 100 D: 21 or more defects in 100: measurement of fog value The measurement of the fog value is the same as in the cases shown in Examples 1 to 10 above. Measurement of Image Density Image density was measured with a Macbeth densitometer RD918 (manufactured by Macbeth).

[0370]

[Table 7]

[0371]

[Table 8]

[0372]

[Table 9] (3) As a machine for evaluating images of Examples 17 to 22 and Comparative Examples 14 to 17, a modified machine of Canon color laser copier 700 shown in FIG. 3 was used. As the developing means, the photoconductor was modified into a rotary type developing means. Instead of the stainless sleeve which is the toner carrier of the image forming apparatus shown in FIG. 2, a medium resistance rubber roller (diameter 16 mm, made of silicone rubber in which carbon black is dispersed,
Hardness ASKER C 45 degrees, resistance 10 ⁵ Ω · cm) was used to contact the photoreceptor. Development contact width at this time is about 3m
I made it m. The rotational peripheral speed of the toner carrier is in the same direction at the contact portion with the photoconductor, and is driven so as to be 140% of the rotational peripheral speed of the photoconductor.

As a means for applying toner to the toner carrier, an application roller made of foamed urethane rubber was provided in the developing unit and brought into contact with the toner carrier. For the coating roller,
A voltage of about -550V is applied. Further, in order to control the coating layer of the toner on the toner carrier, a resin-coated stainless steel blade was attached so that the contact pressure with the toner carrier was about 20 g / cm linear pressure. Further, the applied voltage at the time of development was limited to the direct current component (-450V). The surface roughness R of the medium resistance rubber roller used as the toner carrier is
a is shown in Table 10.

As the charging means, a contact charging means for contacting with a rubber roller is used, and the applied voltage is DC component (-120).
0V).

The transfer means was a means for forming a multi-layered developed image on the intermediate transfer member by using an intermediate transfer belt and transferring it collectively onto the transfer material.

[0376]

Examples 17 to 22 Using the toner combinations used in Examples 11 to 16 and using the above-described color image forming apparatus shown in FIG. 3 as an evaluation machine, evaluations were performed in the same manner as in Examples 11 to 16.

However, the color non-magnetic toners in Examples 21 and 22 were used as a one-component developer as they were without forming a two-component developer by mixing with the carrier particles. The evaluation results are shown in Tables 11 and 12.

[0378]

Comparative Examples 14 to 17 Evaluations were performed in the same manner as Comparative Examples 10 to 13 using the toner combinations used in Comparative Examples 10 to 13 and using the color image forming apparatus shown in FIG. The evaluation results are shown in Tables 11 and 12.

[0379]

[Table 10]

[0380]

[Table 11]

[0380]

[Table 12]

[0382]

According to the present invention, a toner kit which does not cause abrasion of the photosensitive member or toner fusion and can stably obtain an image of high quality and excellent resolution for a long period of time even under low humidity, and An image forming method can be provided.

By using the toner kit of the present invention, it is possible to reduce the transfer residual toner on the photoconductor, and not only the life of the photoconductor is extended even when multiple images are output, but also the toner carrier for color toner is provided. It is possible to significantly improve the color tone variation and the like due to the incorporation of the magnetic toner.

[Brief description of drawings]

FIG. 1 is a diagram showing an example of an image forming apparatus using a non-contact type corona charging method and a non-contact type developing method.

FIG. 2 is a diagram showing an example of an image forming apparatus using a contact type charging roller system and a non-contact type developing system.

FIG. 3 is a diagram showing an example of an image forming apparatus using a contact type charging roller system and a medium resistance rubber roller sleeve as a toner carrier which is a contact type developing system.

FIG. 4 is an explanatory diagram of a checkered pattern for testing a toner developing characteristic.

[Explanation of symbols]

1 Manuscript table 2 manuscripts 3 Image reading light source 4 scanner 5 Image signal light source 6 mirror 7 Internal electrometer 8 charging means 9 Cleaning means 10 photoconductor 11 Developing means (A) Magnetic one-component developing device (B), (c), (d) Two-component developing device 12 Intermediate transfer body 13 Intermediate transfer cleaning blade 14 Intermediate transfer material cleaning means 15 Drive system 16 paper feed path 17 Registration roller 18 Paper feed system 19 Transferring means 20 Separation means 21 Transport system 22 Fixing means 23 Fixing roller 24 Medium resistance rubber roller sleeve

─────────────────────────────────────────────────── ─── Continuation of front page (51) Int.Cl. ⁷ Identification code FI theme code (reference) G03G 9/09 G03G 15/01 113A 15/01 113Z 15/06 101 113 15/08 501C 501D 15/06 101 501Z 15/08 501 503A 504Z 506A 503 9/08 101 504 301 506 302 384 361 (72) Inventor Takehiko Chiba 3-30-2 Shimomaruko, Ota-ku, Tokyo Canon Inc. (72) Inventor Keiji Kawamoto Tokyo 3-30-2 Shimomaruko, Ota-ku, Tokyo Canon Inc. (72) Akira Hashimoto Akira Hashimoto 3-30-2 Shimomaruko, Ota-ku, Tokyo Canon Inc. (72) Michihisa Magome Ota-ku, Tokyo Shimomaruko 3-30-2 Canon Inc. (72) Inventor Takeshi Kaburagi Tokyo 3-30-2 Shimomaruko, Ota-ku Canon Inc. (72) Inventor Eriko Yanase 3-30-2 Shimomaruko, Ota-ku, Tokyo Canon Inc. F-term (reference) 2H005 AA01 AA02 AA03 AA06 AA08 AA15 AA21 AB06 CA04 CA08 CA14 CA26 CB03 CB13 DA10 EA05 EA07 EA10 FA02 FA06 FA07 2H030 AD01 AD03 BB24 BB34 BB63 2H073 AA03 BA03 BA13 BA43 CA03 CA22 2H077 AA37 AC16 AD02 AD06 AD13 AD15 AD08 EA03 FA01 FA01 EA03 FA01 FA03 FA01 FA01 FA01 FA01 FA03 FA01 FA03 FA01 FA01 FA01 FA03

Claims (34)

[Claims] 1. A toner kit comprising a magnetic toner containing at least a binder resin and iron oxide, and a non-magnetic toner containing at least a binder resin and a colorant, wherein the magnetic toner is i) X. The ratio (B / A) of the content (B) of the iron element to the content (A) of the carbon element present on the toner surface measured by line photoelectron spectroscopy is less than 0.001, and ii) the magnetic toner When the diameter equivalent to the projected area is C and the minimum value of the distance between the iron oxide and the toner surface in the cross-section observation of the toner using a transmission electron microscope (TEM) is D, D
50% by number or more of the toner satisfying the relationship of /C≦0.02, iii) the average circularity of the magnetic toner is 0.970 or more, and the non-magnetic toner is iv) a yellow colorant and a magenta color. A toner kit containing a colorant selected from the group consisting of a colorant and a cyan colorant, and v) the non-magnetic toner having an average circularity of 0.970 or more. 2. The ratio (B / A) of the magnetic toner is 0.0
The toner kit according to claim 1, wherein the toner kit is less than 005. 3. The toner kit according to claim 1, wherein the toner satisfying the relationship of D / C ≦ 0.02 of the magnetic toner is 65% by number or more. 4. The toner kit according to claim 1, wherein the toner satisfying the relationship of D / C ≦ 0.02 of the magnetic toner is 75% by number or more. 5. The iron oxide of the magnetic toner is a binder resin 1
The toner kit according to any one of claims 1 to 4, wherein the toner kit is contained in an amount of 10 to 200 parts by mass with respect to 00 parts by mass. 6. The iron oxide of the magnetic toner is a binder resin 1
The toner kit according to any one of claims 1 to 4, wherein the toner kit is contained in an amount of 20 to 180 parts by mass with respect to 00 parts by mass. 7. The magnetic toner has a volume average particle diameter of 2 to
The toner kit according to claim 1, wherein the toner kit has a thickness of 10 μm. 8. The magnetic toner has a volume average particle diameter of 3.
The toner kit according to claim 1, wherein the toner kit has a thickness of 5 to 8 μm. 9. The toner kit according to claim 1, wherein the magnetic toner contains silica fine powder. 10. The iron oxide of the magnetic toner is a product surface-treated with a surface-treating agent.
9. The toner kit according to any one of 9. 11. The toner kit according to claim 10, wherein the surface treatment agent is an alkyltrialkoxysilane coupling agent. 12. The iron oxide of the magnetic toner has a volume average particle diameter of 0.1 to 0.3 μm, and 0.03 to 0.1 μm.
The toner kit according to any one of claims 1 to 11, wherein the number of particles of m is 40% by number or less. 13. The iron oxide of the magnetic toner is 0.03.
Contains 30% by number or less of particles of 0.1 μm,
13. The toner kit according to claim 12, containing 10% by number or less of particles of 0.3 μm or more. 14. The iron oxide of the magnetic toner is 0.03.
Contains 30% by number or less of particles of 0.1 μm,
13. The toner kit according to claim 12, which contains 5% by number or less of particles of 0.3 μm or more. 15. The toner kit according to claim 1, wherein the magnetic toner contains wax. 16. The magnetic toner is a toner produced by a suspension polymerization method.
5. The toner kit according to any one of 5. 17. A charging step of charging an electrostatic charge image carrier by a charging member to which a voltage is applied from the outside; an exposure step of forming an electrostatic latent image on the electrostatic charge image carrier by exposure; A developing step of forming a toner image of a black-and-white image or a color image by the magnetic toner and / or the non-magnetic toner of the toner kit having the magnetic toner and the non-magnetic toner in which the latent image is carried on the toner carrier; A transfer step of transferring to a transfer material; and, wherein the magnetic toner is i) iron with respect to the content (A) of the carbon element present on the surface of the magnetic toner measured by X-ray photoelectron spectroscopy analysis. The ratio (B / A) of the element contents (B) is less than 0.001, ii) the magnetic toner using a transmission electron microscope (TEM), where C is the projected area equivalent diameter of the magnetic toner. When the minimum value of the distance between the iron oxide and magnetic toner surface in cross-sectional observation is D, the magnetic toner satisfies a relationship of D / C ≦ 0.02 5
0 number% or more, iii) the average circularity of the magnetic toner is 0.970 or more, and the non-magnetic toner is iv) a coloring selected from the group consisting of a yellow colorant, a magenta colorant and a cyan colorant. And (v) an average circularity of the non-magnetic toner is 0.960 or more. 18. The contact developing process, wherein the developing process is a contact developing process in which the electrostatic charge image on the electrostatic charge image carrier is brought into contact with the magnetic toner carried on the toner carrier. 17. The image forming method according to item 17. 19. The image forming method according to claim 18, wherein the toner carrier is an elastic roller. 20. In the developing step, the moving speed of the surface of the toner carrier in the developing area is 1.05 to 3.0 times the moving speed of the surface of the electrostatic image carrier. 20. The image forming method according to claim 18, which is characterized in that. 21. The toner carrier according to claim 18, wherein the surface roughness Ra is 0.2 to 3.0 μm.
21. The image forming method according to any one of 20. 22. In the developing step, the transfer residual toner remaining on the electrostatic image carrier after the transfer step is collected by the toner carrier. The image forming method described. 23. In the developing step, an electrostatic charge image carrier and a toner carrier are arranged with a constant space, and a toner layer is formed on the surface of the toner carrier with a thickness smaller than the space, and an alternating current is formed. 18. The image forming method according to claim 17, which is a step of transferring the toner to an electrostatic latent image and developing the toner in a developing portion to which a bias is applied. 24. The gap between the electrostatic image carrier and the toner carrier is 100 to 500 μm.
The image forming method according to item 3. 25. In the developing step, the speed difference between the surface of the electrostatic image carrier and the surface of the toner carrier in the developing region is 1.02 to 3.0 times. Item 2
The image forming method as described in 3 or 24. 26. The toner carrier according to claim 23, wherein the surface roughness Ra is 0.2 to 3.5 μm.
26. The image forming method according to any one of 25. 27. The AC bias has a peak-to-peak electric field strength of 3 × 10 ⁶ to 1 × 10 ⁷ V / m and a frequency of 1.
24 to 23, wherein the frequency is 0 to 5000 Hz.
27. The image forming method according to any one of 26. 28. The image forming method according to claim 17, wherein the charging step is a step of charging by charging a charging member with an electrostatic image carrier. 29. The transfer step is a step of transferring a toner image to a transfer material by a transfer member which is in contact with the electrostatic charge image carrier via the transfer material.
29. The image forming method according to any one of 28. 30. The charging step is a step of charging by charging a charging member to the electrostatic charge image carrier, and the developing step provides a constant space between the electrostatic charge image carrier and the toner carrier. Is a step of forming a toner layer on the surface of the toner carrier with a thickness smaller than the above interval, and transferring the toner to an electrostatic latent image in a developing section to which an AC bias is applied to perform development. 18. The image forming method according to claim 17, wherein: 31. The layer thickness of the toner carried on the toner carrying member is regulated by a toner layer thickness regulating member,
31. The image forming method according to claim 30, wherein the toner layer thickness regulating member is in contact with the toner carrier via the toner. 32. The image forming method according to claim 31, wherein the toner layer thickness regulating member is an elastic member. 33. The image forming method according to claim 17, further comprising a fixing step of fixing the toner image transferred to the transfer material on the transfer material. 34. A charging step of charging an electrostatic charge image carrier by a charging member to which a voltage is applied from the outside; an exposure step of forming an electrostatic latent image on the electrostatic charge image carrier by exposure; A developing step of forming a toner image of a black-and-white image or a color image by the magnetic toner and / or the non-magnetic toner of the toner kit having the magnetic toner and the non-magnetic toner in which the latent image is carried on the toner carrier; An image forming method comprising: a transfer step of transferring to a transfer material; and the toner kit according to any one of claims 2 to 17.