JP2000352844A - Black toner, its manufacturing method and image forming method - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a black toner high in coloring performance and good in chargeability and small in a weight average particle diameter and sharp in a particle diameter distribution. SOLUTION: The black toner has a weight average particle diameter of 3-10 μm, and an average primary particle diameter of a carbon black of 13-60 mμ and in the dispersion of the black toner, the agglomerated particle number (a) containing <10 primary particles and that (b) containing >10 satisfy the following expression: a<=b. The charge controller is an azo type metal compound represented by the formula in which M is a metal atom; each of R1 and R3 is an H atom or an C1 to C18 alkyl group or the like; each of (n) and (n') is 1, 2, or 3; each of R2 and R4 is an H atom or a nitro group or the like; each of R5 and R6 is an H or halogen atom or the like; and A+ is an H ion or a Na ion or the like.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a black toner used in electrophotography, a method for producing the same, and an image forming method using the toner.

[0002]

2. Description of the Related Art Conventionally, a developer using an electrophotographic process is prepared by adding a colorant, a charge control agent, and a release agent to a binder resin such as a polyester resin, a styrene-acrylic resin, or an epoxy resin, and melt-kneading the mixture. , And then pulverized to a predetermined particle size, and further, a pulverization method in which excess fine powder and coarse powder are removed using a classifier. However, with the recent trend toward higher image quality, it has become necessary to further sharpen the particle size distribution of the toner.

[0003] As the weight average particle size measured by a Coulter counter becomes 8 µm or less, the toner is classified into a uniform particle dispersibility, a highly efficient pulverizability, and a sharp particle size distribution which have not been a problem in the past. Tends to be extremely difficult.

In order to overcome the problems of the toner caused by these pulverizing methods, Japanese Patent Publication No. 36-10231 and Japanese Patent Publication No. 43
JP-A-10-10799 and JP-B-51-14895 propose a method for producing toner particles by a suspension polymerization method. In the suspension polymerization method, a monomer composition is prepared by uniformly dissolving or dispersing a polymerizable monomer, a colorant and a polymerization initiator, and further, if necessary, a crosslinking agent, a charge control agent, and other additives. After that, the monomer composition is dispersed in a continuous phase containing a dispersion stabilizer, for example, an aqueous phase using a suitable stirrer, and simultaneously subjected to a polymerization reaction, thereby obtaining toner particles having a desired particle size. How to get.

[0005] In this production method, there is no need to impart brittleness to the toner particles since it does not pass through a pulverizing step, and it is also possible to use a large amount of a low softening point substance which has been difficult to use in the conventional pulverization method. The range of materials that can be used is expanded. The release agent and the coloring agent, which are hydrophobic materials, are hardly exposed on the surface of the toner particles, and therefore have a feature that the toner carrying member, the photoconductor, the transfer roller, and the fixing device are less contaminated, Recently, it has attracted attention.

In recent years, digital full-color copying machines and printers have been put into practical use.
It has become necessary to further improve properties such as releasability / color reproducibility.

As the required quality required for image fidelity,
Digital full-color copiers require a larger amount of toner to be transferred from the photoconductor to the transfer material than black-and-white copiers, and the fine particles of toner that correspond to fine dots in order to support higher image quality in the past. From this point, it is expected that the diameter should be increased, and from this point too, the polymerization method capable of producing toner particles having a sharp particle size distribution and a fine particle diameter has excellent characteristics.

However, when toner particles are produced by the above polymerization method, when carbon black is used as a coloring agent,
Many problems occurred.

First, carbon black has a functional group such as a quinone group on the surface that inhibits the polymerizability of the polymerizable monomer, so that the polymerization rate is reduced and the degree of polymerization is not increased. Becomes unstable, causing aggregation and coalescence, making it difficult to take out as particles.

Second, when carbon black is dispersed in a polymerizable monomer, carbon black has a small primary particle size, a large specific surface area, is very difficult to disperse, and is free from other pigments. Carbon black is easily generated.

Third, since carbon black is conductive, charges on the toner surface are liable to leak, and problems such as fogging and toner scattering are likely to occur during development.

In order to solve these problems, for example, for the inhibition of polymerization, a method using a carbon black having a surface grafted as disclosed in Japanese Patent Application Laid-Open No. As described in JP-A-210849, there is a method using carbon black surface-treated with an aluminum coupling agent. However, in these methods, the process for surface-treating carbon black is complicated and troublesome, the production cost is high, and it is difficult to employ industrially.

Regarding dispersibility, see JP-A-64-3545.
No. 7, JP-A-1-145664 and JP-A-1-145664 propose a method of using a specific dispersant to improve the dispersibility, but the situation has not been sufficiently solved.

[0014]

SUMMARY OF THE INVENTION An object of the present invention is to provide a black toner which solves the above-mentioned problems, a method for producing the same, and a method for forming an image.

An object of the present invention is to provide a black toner having high coloring power and good chargeability, and an image forming method using the same.

[0016] An object of the present invention is to reduce the weight average particle size,
Another object of the present invention is to provide a black toner having a sharp particle size distribution and an image forming method using the same.

An object of the present invention is to provide a method for producing a black toner, which can provide stable particles when producing a toner by a polymerization method, has high coloring power, and has good chargeability.

An object of the present invention is to provide a black toner which can obtain stable particles, has high coloring power, and has good chargeability when a toner is produced by a polymerization method.

An object of the present invention is to reduce the weight average particle size,
Another object of the present invention is to provide a method for producing a black toner having a sharp particle size distribution.

[0020]

According to the present invention, there is provided a black toner containing at least a binder resin, a solid wax, carbon black and a charge control agent, wherein the weight average particle diameter of the toner is 3 to 10 μm. The average primary particle diameter of the carbon black is 13 to 60 mμ.
In the dispersion state in the black toner particles, the number of agglomerates having less than 10 primary particles is a
The present invention relates to a black toner, wherein a ≦ b when the number of particles of the aggregates is at least b, and the charge control agent is an azo-based metal compound represented by the following formula (1).

[0021]

Embedded image [M represents a metal element. R ₁ and R ₃ are a hydrogen atom, C ₁
To ₁₈ alkyl groups, C ₂ to ₁₈ alkenyl groups, sulfonamide groups, mesyl groups, sulfonic acid groups, carboxyester groups, hydroxy groups, C ₁ to ₁₈ alkoxy groups, acetylamino groups, benzoylamino groups or halogen atoms Wherein R ₁ and R ₃ are the same or different, and n and n ′
Represents an integer of 1 to 3, R ₂ and R ₄ represent a hydrogen atom or a nitro group, R ₂ and R ₄ are the same or different,
R ₅ and R ₆ are a hydrogen atom, a halogen atom, a nitro group, a carboxyl group, an anilide group, an alkyl group of C ₁ ~ _18, an alkenyl group, an aralkyl group, an alkoxy group, an aryl group, carboxy ester group, or

[0022]

Embedded image X represents a hydrogen atom, a lower alkyl group, a lower alkoxy group, a nitro group or a halogen atom, m represents an integer of 1 to 3, R ₅ and R ₆ are the same or different,
A ⁺ represents a hydrogen ion, a sodium ion, a potassium ion, an ammonium ion or a mixture thereof. ]

The present invention also relates to a method for mixing at least a first polymerizable monomer, carbon black and an azo metal compound, and dispersing the carbon black and the azo metal compound in the polymerizable monomer. Preparing a polymerizable monomer by mixing at least the obtained dispersion, a second polymerizable monomer and a solid wax; and preparing a polymerizable monomer. A method of producing black toner particles by polymerizing a body composition in an aqueous medium, wherein the azo-based iron compound is a compound represented by the formula (1), The carbon black has an average primary particle diameter a of 13 to 60 μm, and relates to a method for producing black toner particles, wherein the dispersion state of the carbon black in the toner is set to the above value.

Further, the present invention provides a process for developing a latent image held by a latent image holding member with a black toner to form a toner image; Transferring the toner image onto a recording material with or without an intermediate transfer member; and fixing the toner image transferred onto the recording material, wherein the black toner is used as the black toner. The present invention relates to an image forming method characterized by using.

As a result of intensive studies, the present inventors have found that the use of carbon black having specific physical properties and a specific azo metal compound in the presence of a solid wax suppresses the agglomeration of carbon black and reduces The release of carbon black is dramatically suppressed, and coloring power and production stability are improved. Further, since the dispersibility of the carbon black is controlled, it is possible to use a carbon black having a small DBP oil absorption and a small amount of toluene extraction. Accordingly, polymerization inhibition can be prevented when toner particles are manufactured, and a toner having a sharp particle size distribution can be manufactured by uniformly controlling the dispersion of carbon black having a small DBP adsorption amount. In addition, the inclusion of carbon black in the toner particles is achieved,
Until now, we have solved the problem of the toner charging performance degradation due to the increase in the toner surface conductivity, which is a problem due to the release of carbon black, and found that superior charging performance can be obtained compared to the conventional use of carbon black. It is. JP-A-7-064337 also discloses a combination of carbon black having a small DBP adsorption amount and a metal-containing compound having a specific structure. However, when applied to the polymerization method toner of the present invention, release of carbon black can be suppressed. Was not always satisfactory.

[0026]

DESCRIPTION OF THE PREFERRED EMBODIMENTS A feature of the present invention is that a black toner has black toner particles obtained by polymerizing a polymerizable monomer composition containing at least a polymerizable monomer and a colorant in an aqueous medium. A carbon black having an average primary particle diameter of 13 to 60 μm is used as a colorant, and a specific azo metal compound and a solid wax are used as a dispersant to control the dispersion state of the carbon black in the toner. is there.

As described above, carbon black is a pigment that is more difficult to disperse than other pigments. In particular, when dispersing in a polymerizable monomer, a sufficient shearing force is not applied, so that carbon black is liberated. Was very difficult to control. The present inventors have solved this problem by using a specific azo metal compound and carbon black having a small oil absorption in the presence of a solid wax.

Carbon black having a small oil absorption, such as carbon black used in the present invention, is difficult to disperse, and it is difficult to achieve both improvement in coloring power and charging characteristics of the toner.

However, the present inventor has found that when a specific azo metal compound is used as a dispersant, a more uniform dispersion in particles can be achieved in the presence of solid wax than in the case of conventionally used carbon black. In addition, it has been found that the toner does not easily exist on the surface of the toner and, on the contrary, has better charging characteristics than the conventional toner containing carbon black.

In producing the suspension polymerization toner, at least the above specific carbon black and the above specific azo iron compound are contained in the polymerizable monomer used in order to sufficiently disperse the pigment. By performing a pre-dispersion master batch process, the carbon black can be dispersed at a higher concentration with respect to the polymerizable monomer, so that a shearing force is more easily applied to the dispersion, and the dispersion effect of the carbon black is improved. It is particularly preferable because it becomes large.

One characteristic of the carbon black of the present invention is that the DBP oil absorption is 3 to 100 ml / 100 g. When the oil absorption exceeds 100 ml / 100 g, carbon black tends to be present on the toner surface, and it is particularly difficult to improve the transferability of the toner under high humidity and the coloring power of the toner. On the other hand, when the oil absorption is less than 30 ml / 100 g, the dispersibility of the carbon black in the toner particles is not sufficient, and the coloring power and the charge amount of the toner are likely to decrease.

The oil absorption of the carbon black is preferably 30 to 70 ml / 100 g, and more preferably 35 to 70 ml / 100 g.
It is good to be ~ 55ml / 100g.

Further, the carbon black used in the present invention has a smaller specific surface area and a smaller amount of toluene extraction than those used for ordinary toners. Carbon black having a small specific surface area and a small amount of toluene extracted has an advantage of low polymerization inhibition since the wettability with the polymerizable monomer is reduced but the number of functional groups having polymerization inhibition is small.

Accordingly, the carbon black used in the present invention has a specific surface area by nitrogen adsorption of 100 m ² / g or less, preferably 90 to 30 m ² / g, more preferably 90 to 40 m ² / g. Further, the amount of toluene extracted is 0.5% or less, preferably 0.001 to 0.
The content is preferably 3%, more preferably 0.01 to 0.15%.

If the specific surface area of carbon black due to nitrogen adsorption is larger than 100 m ² / g, polymerization inhibition is likely to occur. Furthermore, if the amount of toluene extracted from carbon black exceeds 0.50%, it is not suitable for use because a large number of polymerization inhibiting groups are present on the surface of carbon black.

The carbon black used in the present invention is:
The average primary particle diameter a is 13 to 60 μm, preferably 25 to
The thickness is preferably 55 mμ, more preferably 25 to 45 mμ.

The average primary particle diameter of carbon black is 13
When it is smaller than mμ, even if a specific azo metal compound used in the present invention and a solid wax having a long-chain branched structure are used in combination, uniform dispersion is difficult, it is difficult to manage, and furthermore, the average primary particle size is small. Because the diameter is very fine,
It is easily released on the toner surface. Further, when the average primary particle diameter of the carbon black is larger than 60 mμ, the coloring power of the toner becomes too low even if dispersed well, and when used in a large amount to increase the coloring power, the charge of the toner is reduced. It is not suitable for use.

In the present invention, in the dispersed state in the toner, the number of agglomerates having less than 10 primary particles is represented by a,
When a number of particles of 10 or more agglomerates is b, a ≦ b, preferably a ≦ b ≦ 3a is characterized. a> b
In this case, the conductivity of the toner is increased, the charging under high humidity becomes unstable, and fog, toner scattering, and the like are easily caused.

According to the study of the present inventors, the content of the carbon black A [wt.
%] And the content B [wt] of the azo metal complex compound.
%] Preferably satisfies the following relationship 3 ≦ A / B ≦ 40, and more preferably satisfies the following relationship 3 ≦ A / B ≦ 30.

If the amount of the azo-based metal compound is too small relative to the carbon black, the dispersion state is unstable even in the presence of a solid wax, and the coloring power tends to decrease. Further, carbon black is easily released on the toner surface.

If the amount of the azo-based metal compound is too large relative to the carbon black, the azo-based metal compound is liable to cause secondary aggregation, dispersibility is reduced, and the secondary aggregate is liable to inhibit polymerization. It is difficult to take out.

In the present invention, the content A [% by weight] of the carbon black with respect to the weight of the toner particles is preferably 2 to 20% by weight, more preferably 3 to 15% by weight, and still more preferably 5 to 13% by weight. This is advantageous in terms of high image density, toner charging stability, and uniform dispersion of carbon black.

When the content A of the carbon black is less than 2% by weight, the coloring power as a toner is low, and a high image density cannot be achieved. Even if a solid wax having a structure is used, encapsulation of carbon black is not achieved, and as a result, suppression of fog, toner scattering, and the like deteriorate.

In the present invention, the content B [% by weight] of the azo metal compound with respect to the weight of the toner particles is preferably 0.1 to 3.0% by weight, more preferably 0.3 to 2.0%.
0% by weight, more preferably 0.5 to 1.5% by weight is preferable in that the viscosity of the dispersion is maintained in an appropriate state and the uniform dispersibility of carbon black is improved.

When the content B of the azo metal compound is less than 0.1% by weight, the effect of improving the dispersibility of the carbon black is not exhibited because the viscosity of the dispersion does not increase, and 3.0% by weight.
If it exceeds, the viscosity of the dispersion liquid will decrease,
After all, the effect of improving the dispersibility of carbon black disappears.

As described above, the present inventor has proposed that carbon black having a small oil absorption, which has not been usually used, is used in combination with a specific azo metal compound in the presence of a solid wax having a long-chain branched structure. Thus, the present invention succeeded in obtaining electrophotographic characteristics superior to those of the suspension polymerization toner using carbon black.

The azo metal compound used in the present invention has a structure represented by the following formula (1).

[0048]

Embedded image [M represents a metal element. R ₁ and R ₃ are a hydrogen atom, C ₁
To ₁₈ alkyl groups, C ₂ to ₁₈ alkenyl groups, sulfonamide groups, mesyl groups, sulfonic acid groups, carboxyester groups, hydroxy groups, C ₁ to ₁₈ alkoxy groups, acetylamino groups, benzoylamino groups or halogen atoms Wherein R ₁ and R ₃ are the same or different, and n and n ′
Represents an integer of 1 to 3, R ₂ and R ₄ represent a hydrogen atom or a nitro group, R ₂ and R ₄ are the same or different,
R ₅ and R ₆ are a hydrogen atom, a halogen atom, a nitro group, a carboxyl group, an anilide group, an alkyl group of C ₁ ~ _18, an alkenyl group, an aralkyl group, an alkoxy group, an aryl group, carboxy ester group, or

[0049]

Embedded image X represents a hydrogen atom, a lower alkyl group, a lower alkoxy group, a nitro group or a halogen atom, m represents an integer of 1 to 3, R ₅ and R ₆ are the same or different,
A ⁺ represents a hydrogen ion, a sodium ion, a potassium ion, an ammonium ion or a mixture thereof. ]

Among the compounds represented by the above general formula (1), particularly, an iron compound represented by the following general formula (2) is dispersible in the polymerizable monomer of the present invention and is present on the toner surface in an aqueous medium. This is preferable in that the toner particle size distribution becomes sharp.

[0051]

Embedded image [M represents a metal element. X ₁ and X _{2 each} represent a hydrogen atom, a lower alkyl group, a lower alkoxy group, a nitro group or a halogen atom; X ₁ and X ₂ are the same or different;
And m 'is an integer of 1 to 3, R ₁ and R ₃ is a hydrogen atom, an alkyl group of C ₁ ~ _18, an alkenyl group of C ₂ ~ _18, a sulfonamide group, a mesyl group, a sulfonic acid group, carboxy ester group, hydroxy group, an alkoxy group of C ₁ ~ _18,
An acetylamino group, a benzoylamino group or a halogen atom; R ₁ and R ₃ are the same or different; n and n ′ each represent an integer of 1 to 3; R ₂ and R ₄ represent a hydrogen atom or a nitro group; A ⁺ represents a hydrogen ion, a sodium ion, a potassium ion, an ammonium ion or a mixture thereof. ]

The azo metal compound is also used as a negative charge control agent in the toner. This azo-based iron compound can be synthesized by known means.

According to the study of the present inventors, the mechanism by which the azo metal compound represented by the above general formula (1) improves the dispersibility of a specific carbon black in a polymerizable monomer is as follows. I believe.

That is, the azo metal compound of the present invention comprises
It has a moderate wettability to the polymerizable monomer, and there is no problem such as foaming, so that the dispersion viscosity of carbon black can be controlled stably, so the manufacturing latitude for dispersing carbon black is A wide and uniform dispersion state is achieved in a short time.

Typical specific examples of the azo metal complex compound represented by the general formula (2) include the following compounds.

[0056]

Embedded image

[0057]

Embedded image

[0058]

Embedded image

[0059]

Embedded image

In the present invention, the content of the solid wax with respect to the weight of the toner particles is preferably 0.1 to 5.0.
% By weight, more preferably 0.3 to 3.0% by weight, and still more preferably 0.3 to 2.0% by weight can stabilize the dispersion state of carbon black and thoroughly incorporate the carbon black.

When the content is less than 0.1% by weight, the inclusion of carbon black is insufficient, so that poor charging is apt to occur, and fog and toner scattering are liable to occur. On the other hand, when the content exceeds 5% by weight, the fluidity of the toner deteriorates, and as a result, fog and toner scattering easily occur due to durability.

In the present invention, the weight average particle diameter (D ₄ ) of the toner particles is preferably 3 to 10 μm, and more preferably _{4 to 9} μm, in order to achieve both high image density and high image quality.

When the weight average particle diameter of the toner particles is less than 3 μm, defects such as toner scattering and fog occur, and
If m exceeds m, the reproducibility of fine dots is reduced, or scattering occurs during transfer, which hinders high image quality.

Further, in the present invention, toner particles are produced by a polymerization method. In this polymerization process, since carbon black hardly causes polymerization inhibition as described above,
The generated toner particles also have a small content ratio of ultrafine powder or coarse powder in which toner particles are aggregated, and have a sharp particle size distribution.

The number of toner particles having a particle size distribution of 4 μm or less is 20% by number or less, preferably 5 to 15%.
2.0% by volume of toner particles of 10.1 μm or more
Hereinafter, preferably 0.1 to 1.3% by volume,
This is preferable because the charge of the toner is made uniform.

If toner particles having a particle size of 4 μm or less are more than 20% by number, fogging is likely to occur due to toner reuse, particularly when the toner particles are applied to a cleaner-less system as an example of the present invention.

On the other hand, if the amount of toner particles having a particle size of 10.1 μm or more is more than 2.0% by volume, scattering tends to occur particularly when applied to an intermediate transfer member system which is an example of the present invention.

Further, in the present invention, the dispersion state of carbon black in the toner particles is such that when the cross section of the toner is observed with a transmission microscope, the carbon black is more present in the binder resin toward the center of the toner. It is desirable that the toner does not exist much on the toner surface layer.

In the present invention, non-magnetic toner and non-magnetic toner particles refer to toner and toner particles having a saturation magnetization of 20 Am ² / kg or less.

In the present invention, the volume resistivity of the non-magnetic toner is preferably 10 ¹⁰ to 10 ¹⁶ Ωcm, more preferably 10 ¹² to 10 ¹⁶ Ωcm, and further preferably 10 ¹³
Over a long period it is to 10 ¹⁶ [Omega] cm, or in that to stabilize the charging of toner.

The non-magnetic toner has a volume resistance of 10 ¹⁰ Ωcm
If it is less than 10%, the charge of the toner is apt to decrease particularly under high humidity. If it exceeds 10 ¹⁶ Ωcm, the image density is particularly low when the original document having an image area ratio of 2% or less is continuously printed under low humidity. Tends to decrease, which is not preferable.

In the present invention, when forming the toner, the dispersion liquid in the masterbatch step in which the carbon black and the azo-based metal compound are pre-dispersed in the polymerizable monomer to be used, especially the dispersion of the carbon black, The effect of improving the performance is remarkable. This is because carbon black is dispersed at a higher concentration with respect to the polymerizable monomer, so that the viscosity can be increased and the dispersion effect is large. Furthermore, even if the second wax is diluted with the second polymerizable monomer in the presence of the solid wax, the carbon black hardly re-aggregates.

The polymerizable monomers used in the toner of the present invention include styrene monomers such as styrene, o (m-, p-)-methylstyrene and m (p-)-ethylstyrene; ) Methyl acrylate, ethyl (meth) acrylate, propyl (meth) acrylate, butyl (meth) acrylate, octyl (meth) acrylate, dodecyl (meth) acrylate, stearyl (meth) acrylate, (meth) (Meth) acrylate monomers such as behenyl acrylate, 2-ethylhexyl (meth) acrylate, dimethylaminoethyl (meth) acrylate, and diethylaminoethyl (meth) acrylate; butadiene; isoprene; cyclohexene; ) Acrylonitrile; acrylamide is preferred. These may be used alone or as a mixture. When used in a mixture, the publication Polymer Handbook 2nd edition III-P139-19
2 (manufactured by John Wiley & Sons), and the monomers are used in an appropriate combination so that the theoretical glass temperature (Tg) indicates 40 to 75 ° C. If the theoretical glass transition temperature is less than 40 ° C., it is not preferable from the viewpoint of the storage stability of the toner and the durability stability of the developer. If the glass transition temperature exceeds 75 ° C., the fixing point is increased. However, the color mixing of each color toner is insufficient and the color reproducibility is poor, and the transparency of the OHP image is remarkably reduced, which is not preferable from the viewpoint of high image quality.

In the present invention, the GP of the resin component of the toner
In the molecular weight distribution by C (gel permeation chromatography), the weight average molecular weight (Mw) is preferably 5,000 to 1,000,000, and more preferably 7,000 to 500,000. The ratio (Mw) between the average molecular weight (Mw) and the number average molecular weight (Mn)
/ Mn) is preferably 2 to 100, more preferably 3
A value of from 50 to 50 is suitable for preventing the contamination of the toner charging member with a wide fixing latitude.

The weight average molecular weight (M
When w) is less than 5,000, the non-offset region on the high-temperature side becomes narrower, and at the same time, the toner charging member is easily contaminated, and the toner is poorly charged. 1,
When the amount exceeds 1,000,000, the fixing property is deteriorated.

Further, when Mw / Mn of the resin component of the toner is less than 2, the fixable temperature region becomes extremely narrow, and when it exceeds 100, the black image sinks when applied to a full-color image. The feeling is uncomfortable, which is not preferable.

The azo metal compound used in the present invention is
Although it also has a function as a charge control agent, another charge control agent may be used in combination. Known charge control agents that can be used in combination can be used. Specific examples of the negative compound include salicylic acid, naphthoic acid, a metal compound of dicarboxylic acid, a sulfonic acid, a polymer compound having a carboxylic acid in a side chain, a boron compound, a urea compound,
Examples of the positive compound include a quaternary ammonium salt, a polymer compound having the quaternary ammonium salt in a side chain, a guanidine compound, and an imidazole compound.

In the present invention, in order to improve the releasability of the fixing member at the time of heat fixing, a solid wax component, which is a hydrocarbon compound, is further used in the toner particles also as a releasing agent. preferable. Examples of the wax component preferably used as a mold release agent in the present invention include ester waxes and modified products thereof (for example, oxides and grafted products), higher fatty acids and metal salts thereof, and amide waxes. These waxes are used in the ring and ball method (JIS
Those having a softening point according to K 2531) of 40 to 130 ° C, preferably 50 to 120 ° C, are good. When the softening point of the wax component is less than 40 ° C., the blocking resistance and shape retention of the toner are insufficient, and when it exceeds 130 ° C., the effect of the releasability is insufficient.

In the present invention, an ester wax having a long-chain alkyl group can be preferably used.
An ester wax satisfying the following general formula is preferred.

[0080]

Embedded image [In the above formula, R ₁ and R ₂ each represent a hydrocarbon group having 15 to 45 carbon atoms.]

Further, in the present invention, an ester wax containing an ester compound represented by the above formula and containing 50 to 95% by weight of an ester compound having the same total number of carbon atoms is used. It is particularly preferred to use a wax composition.

In the present invention, the content of the ester compounds having the same total number of carbon atoms was measured by a gas chromatography method (GC method) described below.

In the present invention, a gas chromatogram was measured using GC-17A (manufactured by Shimadzu Corporation). At this time, a solution previously dissolved at a concentration of 1% by weight in toluene is used as a measurement sample, and 1 microliter of the solution is injected into a GC device equipped with an on-column injector. The column is
Ultra Alloy-1 with 0.5mm diameter x 10m length
(HT) was used. The column has an initial temperature of 40 ° C,
From there, 40 ° C / min. At a heating rate of 200 ° C., and further at 15 ° C./min. At 350 ° C., and then at 7 ° C./min. The temperature was raised up to 450 ° C. at the temperature raising speed. As a carrier gas, He gas was flowed under a pressure condition of 50 kPa. When identifying the compound species, an alkane with a known carbon number is separately injected, measured at the same effluent time as above, and the obtained gas chromatograms are compared with each other. The structure was identified by methods such as incorporation into chromatography. The content of the ester compound having the same carbon number was calculated by calculating the ratio of each peak area to the total peak area of the chromatogram.

In the present invention, an ester wax particularly preferably used as an ester wax having a long-chain alkyl group is generally synthesized from a higher carboxylic acid component, similarly to a higher alcohol component. These higher alcohol and higher carboxylic acid components are usually obtained from natural products in many cases, and are generally composed of a mixture having an even number of carbon atoms. When these mixtures are esterified as they are, by-products having various similar structures are produced as by-products in addition to the intended ester compound, so that each property of the toner is likely to be adversely affected. For this reason, in the present invention, it is preferable to use an ester wax obtained by purifying raw materials or products using a solvent extraction or vacuum distillation operation.

In the measurement by the gas chromatography method described above, when the content of the ester compound having the same total number of carbon atoms is less than 50% by weight, complicated crystal polymorphism and freezing point drop are caused. When it is contained in the toner, it tends to be one of the causes mainly having an adverse effect on the anti-blocking property and the developing property of the toner. Further, in the present invention, when the ester compound as described above is used, it is difficult to obtain a predetermined fluidity of the toner, and filming due to the ester wax is easily generated on the carrier particles and the photoreceptor surface. In addition, the frictional charge amount of the toner decreases, and it is difficult to continuously obtain a sufficient frictional charge amount.

Therefore, in the present invention, the ester compound having the same total carbon number in the ester wax is preferably 55 to 95% by weight, more preferably 6 to 95% by weight.
It is good to use what is contained in the range of 0 to 95% by weight. Further, in the present invention, the ester compound having the same total number of carbon atoms contained most in the ester wax, and the total number of carbon atoms is ±
The total content of the ester compound including the ester compound in the range of 2 is preferably 80 to 95% by weight, more preferably 90 to 95% by weight.

The most preferred ester wax for constituting the toner in the present invention is an ester wax represented by the following general formula, particularly an ester compound having a carbon number of 44: 50 to 95% by weight in the ester wax. The degree is included.

[0088]

Embedded image [Wherein R ₁ ′ and R ₂ ′ represent a linear long-chain alkyl group having 15 to 45 carbon atoms]

Further, the ester compound represented by the above formula may be a compound wherein R ₁ ′ and R ₂ ′ are a saturated hydrocarbon group, more preferably an alkyl group, further preferably a linear alkyl group. preferable. In particular, when R ₁ ′ has 1 carbon atom
An ester compound having a linear alkyl group of 5 to 45 and R ₂ 'being a linear alkyl group of 16 to 44 carbon atoms is preferable. Specific examples of such compounds include the following ester compounds.

[0090]

Embedded image

As the ester wax having the above ester compound used in the toner of the present invention, when the endothermic curve is measured according to ASTM D3418-8, the main maximum peak (main peak) value of the endothermic curve is measured. (Hereinafter referred to as “melting point”) is 40 to 90
C, more preferably in the range of 55-85 C,
It is preferable for improving the low-temperature fixability and the offset resistance of the toner.

That is, an ester wax having a melting point of less than 40 ° C. has a weak self-cohesive force of the ester wax.
As a result, there is a tendency that the high-temperature offset resistance of the toner is reduced. On the other hand, an ester wax having a melting point higher than 90 ° C. performs good granulation and polymerization in an aqueous medium when toner particles are obtained by a direct polymerization method. This tends to make it difficult to form granules having a sharp particle size distribution.

In the present invention, ASTM D3418-
The measurement according to 8 was performed using Perkin-Elmer DSC-7. The temperature of the detector was corrected using the melting points of indium and zinc, and the calorific value was corrected using the heat of fusion of indium. For the sample, an aluminum pan was used, an empty pan was set as a control, and the temperature was raised at a rate of 10 ° C./mi.
n. Was measured.

The ester wax used in the present invention preferably has a hardness of 0.5 to 5.0. The hardness of this ester wax is 20 mm in diameter.
After preparing a cylindrical sample having a thickness of 5 mm by using a dynamic ultra-micro hardness tester (DUH-20) manufactured by Shimadzu Corporation
0) is a value obtained by measuring Vickers hardness. As the measurement conditions, the load speed was 9.67 m with a load of 0.5 g.
After displacing 10 μm under m / sec and holding for 15 seconds, the resulting dent shape was measured to determine the Vickers hardness. According to the study of the present inventors, when an ester wax having a hardness measured by the above method of less than 0.5 is used, the pressure dependency and the process speed dependency of the fixing device become large, and the hot offset resistance is increased. The sexual effect tends to decrease. On the other hand, when the hardness exceeds 5.0, the storage stability of the toner decreases, and the self-cohesive force of the ester wax itself is small, so that the high-temperature offset resistance tends to decrease.

The ester wax used in the present invention preferably has a weight average molecular weight (Mw) of 200 to 2,000 and a number average molecular weight (Mn) of 150 to 2,000, more preferably 300 to 2,000. Those having 1,000 and Mn of 250 to 1,000 are preferred. That is, Mw
Is less than 200 and Mn is less than 150, the blocking resistance of the toner is reduced, and a low molecular weight component is easily present on the surface, and the fluidity of the toner is reduced. On the other hand, when Mw is 2,000
When an ester wax exceeding 0 and Mn exceeding 2,000 is used, granulation properties are inhibited in the production of toner, and coalescence of the toner is likely to occur.

In the present invention, the molecular weight distribution of the wax was measured by GPC under the following conditions.

(GPC measurement conditions) Apparatus: GPC-150C (manufactured by Waters) Column: GMH-HT 30 cm double (manufactured by Tosoh Corporation) Temperature: 135 ° C. Solvent: o-dichlorobenzene (addition of 0.1% ionol) Flow rate: 1 0.0 ml / min sample: Inject 0.4 ml of 0.15% sample

The measurement was performed under the above conditions, and the molecular weight of the sample was calculated using a molecular weight calibration curve prepared from a monodisperse polystyrene standard sample. Furthermore, Mark-Hou
It was calculated by converting into polyethylene using a conversion formula derived from the win viscosity formula.

In the present invention, the black toner may contain another resin in addition to the resin synthesized by the polymerization of the polymerizable monomer.

The black toner particles further containing such another resin may be added with at least a polymerizable monomer, carbon black and an azo metal compound during the production process of the black toner particles by the polymerization method. To prepare a polymerizable monomer composition, and polymerize the polymerizable monomer composition thus prepared.

For example, hydrophilic groups such as amino group, carboxylic acid group, hydroxyl group, sulfonic acid group, glycidyl group, and nitrile group which cannot be used because they dissolve in an aqueous suspension to cause emulsion polymerization due to water solubility. When a polymerizable monomer component containing a functional group is introduced into toner particles, a copolymer such as a random copolymer, a block copolymer, or a graft copolymer of these and a vinyl compound such as styrene or ethylene is used. Or in the form of a polycondensation product such as polyester or polyamide, or a polyaddition product such as polyether or polyimine. The coexistence of such a high molecular polymer containing a polar functional group in the toner particles makes it possible to phase-separate the above-mentioned wax component during polymerization of the polymerizable monomer composition in an aqueous medium, thereby making the toner particles more encapsulated. This is a preferred embodiment, since it makes the toner more powerful and can improve the performance of the toner targeted by the present invention.

The content of the high molecular polymer containing a polar functional group with respect to the weight of the toner particles is preferably 1 to
The content is preferably 20% by weight, more preferably 2 to 16% by weight.

If the content of the high molecular polymer containing a polar functional group is less than 1% by weight, the amount of the encapsulated wax is too small for the toner to appear on the toner surface and exhibit the releasing effect.
If the content exceeds 0% by weight, it becomes difficult to incorporate the wax, and as a result, the contamination of the toner charging member is accelerated, which is not preferable.

The weight average molecular weight of the high molecular polymer containing a polar functional group is preferably 5,000 or more.
When the weight average molecular weight is less than 5,000, particularly less than 4,000, the high molecular polymer containing a polar functional group tends to be concentrated near the surface, so that adverse effects on developability and blocking resistance are likely to occur, which is not preferable. .

When a polymer having a molecular weight different from the molecular weight range of the toner obtained by polymerizing the polymerizable monomer is dissolved in the polymerizable monomer composition and polymerized, a polymer having a broad molecular weight distribution can be obtained. A toner having high offset resistance can be obtained.

In the present invention, examples of the polymerization initiator used for producing toner particles by the polymerization method include 2,2′-azobis- (2,4-dimethylvaleronitrile) and 2,2′-azobis Isobutyronitrile,
1,1′-azobis (cyclohexane-1-carbonitrile), 2,2′-azobis-4-methoxy-2,4-
Azo or diazo polymerization initiators such as dimethyl valeronitrile and azobisisobutyronitrile; peroxides such as benzoyl peroxide, methyl ethyl ketone peroxide, diisopropyl peroxycarbonate, cumene hydroperoxide, 2,4-dichlorobenzoyl peroxide and lauroyl peroxide A system polymerization initiator is used.

The amount of the polymerization initiator to be added varies depending on the desired degree of polymerization, but is generally from 0.5 to 20% by weight based on the polymerizable monomer, which controls the molecular weight distribution of the toner. In addition, it is preferable to increase the latitude of the reaction conditions. The type of the polymerization initiator varies slightly depending on the polymerization method, but may be used alone or in combination with reference to the 10-hour half-life temperature.

When the toner particles are produced by a polymerization method, it is also possible to produce a toner particle by further adding a known crosslinking agent, chain transfer agent and polymerization inhibitor in order to control the degree of polymerization.

In the present invention, as a dispersant used in the polymerization step, for example, inorganic oxides such as tricalcium phosphate, magnesium phosphate, aluminum phosphate, zinc phosphate, hydroxyapatite, calcium carbonate, magnesium carbonate, and calcium hydroxide , Magnesium hydroxide,
Examples include aluminum hydroxide, calcium metasilicate, calcium sulfate, barium sulfate, bentonite, silica, alumina, magnetic material, and ferrite. Examples of the organic compound include polyvinyl alcohol, gelatin, methylcellulose, methylhydroxypropylcellulose,
Ethyl cellulose, sodium salt of carboxymethyl cellulose, starch and the like are used by being dispersed in an aqueous phase.
It is preferable to use 0.2 to 10 parts by weight of these dispersants with respect to 100 parts by weight of the polymerizable monomer since a sharp particle size distribution is achieved and toner particles are united.

As these dispersants, commercially available ones may be used as they are. However, in order to obtain finely dispersed particles having a uniform particle size, the inorganic compound may be formed under high-speed stirring in a dispersion medium. it can. For example, in the case of tricalcium phosphate, a dispersant suitable for a suspension polymerization method can be obtained by mixing an aqueous solution of sodium phosphate and an aqueous solution of calcium chloride under high-speed stirring. A surfactant may be used in an amount of 0.001 to 0.1 part by weight to make these dispersants finer. Specifically, commercially available nonionic, anionic, and cationic surfactants can be used, and examples thereof include sodium dodecyl sulfate, sodium tetradecyl sulfate, sodium pentadecyl sulfate, sodium octyl sulfate, sodium oleate, sodium laurate, potassium stearate, and olein. Calcium acid is preferably used.

The black toner particles according to the present invention can be specifically manufactured by the following manufacturing method.

Carbon black and an azo metal compound, and if necessary, a charge control agent, a polymerization initiator, and other additives are added to the polymerizable monomer, and the mixture is uniformly mixed with a mixing device such as a homogenizer or a media disperser. The polymerizable monomer composition is prepared by dissolving or dispersing. The polymerizable monomer composition thus prepared is dispersed in an aqueous phase containing a dispersion stabilizer using a conventional mixer or a mixing device such as a homomixer or a homogenizer. Preferably, the stirring speed and time are adjusted such that the droplets of the polymerizable monomer composition have the desired size of the toner particles, and the granulation is performed.
Thereafter, by the action of the dispersion stabilizer, the particles may be stirred to such an extent that the particle state is maintained and the particles are prevented from settling. The polymerization is performed at a polymerization temperature of 40 ° C. or higher, generally 50 to 90 ° C. The temperature may be raised in the latter half of the polymerization reaction. Further, in order to improve durability in the image forming method using the toner of the present invention, the polymerization reaction is performed to remove unreacted polymerizable monomers and by-products. The aqueous medium may be partially distilled off in the second half or after the end of the polymerization reaction. After completion of the polymerization reaction, the generated toner particles are washed, collected by filtration,
dry. In the suspension polymerization method, the monomer system 100
It is preferable to use 300 to 3000 parts by weight of water as a dispersion medium with respect to parts by weight.

In the method for producing black toner particles of the present invention, as described above, a polymerizable monomer composition is prepared through a masterbatch process in order to improve the dispersibility of carbon black in the toner particles. .

Specifically, based on 100 parts by weight of the first polymerizable monomer, preferably 10 to 40 parts by weight, more preferably 10 to 25 parts by weight of carbon black and preferably 0.2 to 5 parts by weight. By mixing and dispersing the azo metal compound in an amount of 0.5 parts by weight, more preferably 0.5 to 3 parts by weight, carbon black can be mixed at a very high concentration with respect to the polymerizable monomer. Of the azo-based metal compound can significantly improve the dispersibility of carbon black.

When the mixing amount of carbon black is less than 10 parts by weight, even if an azo-based metal compound is used, the viscosity of the dispersion is small and sufficient dispersion is difficult to achieve. On the other hand, if it exceeds 40 parts by weight, it becomes difficult to control the viscosity of the dispersion, and as a result, the dispersion tends to be uneven.

When the amount of the azo-based metal compound is less than 0.2 part by weight, the effect of increasing the viscosity of the dispersion is insufficient, while when the amount exceeds 5 parts by weight, the viscosity increases. And dispersion tends to be non-uniform.

The viscosity of the (masterbatch) dispersion containing the first polymerizable monomer, carbon black and an azo metal compound, and if necessary, a wax component and / or a charge control agent, is preferably 100 to 100. It is good to be 2000 centipoise, more preferably 150-1600 centipoise.

When the viscosity of the dispersion is less than 100 centipoise, the viscosity is too low and the dispersion share is not applied.
Uniform dispersion of carbon black becomes difficult. On the other hand, 20
When the viscosity exceeds 00 centipoise, the viscosity is too high, and it is difficult to maintain a uniform dispersion state, and at the same time, the dischargeability is deteriorated and the productivity is reduced.

This dispersion was mixed with the second polymerizable monomer and the first wax component of the present invention, a high molecular polymer containing a polar functional group, a charge control agent, a polymerization initiator and a second solid wax. And a polymerizable monomer composition by mixing with other additives.

The mixing amount of the second polymerizable monomer with respect to 100 parts by weight of the dispersion is preferably 20 to 100 parts by weight, more preferably 30 to 70 parts by weight. Is good in terms of uniform dispersibility in a polymerizable monomer.

When the mixing amount of the second polymerizable monomer is less than 20 parts by weight, it takes time to disperse uniformly, and when it exceeds 100 parts by weight, re-agglomeration of carbon black is required. Etc. are likely to occur, and it also takes time for uniform dispersion.

The content ratio of carbon black in the polymerizable monomer composition relative to the weight of the polymerizable monomer composition is preferably 2 to 20% by weight, more preferably 3 to 1%.
An amount of 5% by weight is good in terms of the coloring power of the toner and the stabilization of the charging of the toner.

When the content of carbon black in the polymerizable monomer composition is less than 2% by weight, it becomes difficult to achieve a high image density. The charge of the toner under high humidity tends to be low.

The content ratio of the azo-based metal compound in the polymerizable monomer composition relative to the weight of the polymerizable monomer composition is preferably 0.1 to 3.0% by weight, more preferably 0.1 to 3.0% by weight. The content of 2 to 2.0% by weight is preferable in that the viscosity of the dispersion is maintained in an appropriate state and the uniform dispersibility of carbon black is improved.

When the content of the azo metal compound in the polymerizable monomer composition is less than 0.1% by weight, the effect of improving the dispersibility of carbon black is exhibited without increasing the viscosity of the dispersion. On the other hand, when the content exceeds 3.0% by weight, the viscosity of the dispersion liquid is reduced, and the effect of improving the dispersibility of carbon black is also lost.

Next, various measuring methods according to the present invention will be described.

(1) Measurement of DBP Oil Absorption of Carbon Black It is measured according to JIS 4656/1.

(2) Measurement of Specific Surface Area of Carbon Black by Nitrogen Adsorption It is measured according to JIS 4652.

(3) Measurement of Volatile Content of Carbon Black Measured according to JIS 1126.

(4) Method for Measuring Average Primary Particle Diameter and Aggregated Particle Diameter of Carbon Black A cross section of the toner was taken with a transmission microscope at a magnification of 50,000 times, and 100 primary particles and aggregated particles 3 were taken.
Zero is randomly selected, the average primary particle size is calculated, and the aggregated particle size is measured.

(5) Weight average particle diameter (D ₄ ) of toner and the number% of toner particles having a particle size of 4.0 μm or less and 10.1 μm
Measurement of Volume% of Toner Particles Above average particle size and particle size distribution of toner are measured using Coulter Counter T
It can be measured using A-II or Coulter Multisizer II (manufactured by Coulter), but in the present invention, Coulter Multisizer II (manufactured by Coulter) is used.
And an interface (manufactured by Nikkaki) for outputting a number distribution and a volume distribution and a PC9801 personal computer (manufactured by NEC) are connected, and a 1% aqueous NaCl solution is prepared using primary-grade sodium chloride as an electrolytic solution. For example, I
SOTON R-II (manufactured by Coulter Scientific Japan) can be used. As a measurement method, 0.1 to 5 ml of a surfactant, preferably an alkylbenzene sulfonate, is added as a dispersant to 100 to 150 ml of the electrolytic aqueous solution, and 2 to 20 mg of a measurement sample is further added. The electrolyte in which the sample was suspended was mixed with an ultrasonic
After a dispersion treatment for a minute, the volume and the number of toner particles having a size of 2 μm or more were measured using the Coulter Multisizer with an aperture of 100 μm as an aperture to calculate a volume distribution and a number distribution. Then, the weight average particle diameter (D ₄ ) obtained from the volume distribution according to the present invention (the representative value of each channel is taken as the representative value of each channel) and the toner particles having a particle size of 4.0 μm or less obtained from the number distribution. Number%
And the volume% of toner particles of 10.1 μm or more determined from the volume distribution.

(6) GPC Molecular Weight Distribution of Polymer Component Containing Polar Component and Resin Component of Toner Particles As a specific method for measuring GPC of resin component of polymer component and polymer containing polar functional group, Is to extract the toner particles in advance with a toluene solvent using a Soxhlet extractor for 20 hours, then distill off the toluene with a rotary evaporator, and if necessary, dissolve the wax added to the toner particles but dissolve the resin component. After adding an organic solvent that cannot be used, for example, chloroform, and washing well,
A solution obtained by dissolving a solution dissolved in HF (tetrahydrofuran) was filtered through a solvent-resistant membrane filter having a pore diameter of 0.3 μm, and a sample was formed using 150C manufactured by Waters Corporation.
805, 806 and 807 are connected, and the molecular weight distribution is measured using a standard polystyrene resin calibration curve.

From the obtained molecular weight distribution, a weight average molecular weight (Mw) and a number average molecular weight (Mn) are calculated.

The image forming method using the toner of the present invention will be described below with reference to the accompanying drawings.

As a developing method using the toner of the present invention, for example, development can be performed using a developing means as shown in FIG. Specifically, it is preferable to perform development in a state where the magnetic brush is in contact with the latent image carrier, for example, the photosensitive drum 1 while applying an alternating electric field. The distance (S-D distance) B between the developer carrier (developing sleeve) 11 and the photosensitive drum 1 is preferably 100 to 800 [mu] m in order to prevent carrier adhesion and improve dot reproducibility. 1
If it is smaller than 00 μm, the supply of the developer tends to be insufficient, and the image density becomes low.
_The lines of magnetic force from ₁ widen and the density of the magnetic brush decreases,
The dot reproducibility is poor, and the force for restraining the magnetic coated carrier is weakened, and carrier adhesion is likely to occur.

The voltage between the peaks of the alternating electric field is 300 to 30.
00V is preferable, the frequency is 500 to 10000 Hz,
Preferably, it is 1000-7000 Hz, and each can be appropriately selected and used depending on the process. In this case, the waveform may be triangular, rectangular, sine, or D
Various waveforms with different duty ratios, intermittent alternating superposed electric fields, and the like can be selected and used. If the applied voltage is lower than 300 V, it may be difficult to obtain a sufficient image density, and it may not be possible to satisfactorily collect fog toner in the non-image area. If the voltage exceeds 5000 V, the latent image may be disturbed via the magnetic brush, which may cause deterioration in image quality.

By using a two-component developer having a well-charged toner, the fog removal voltage (Vback)
And the primary charge of the photoconductor can be reduced, so that the life of the photoconductor can be extended. Vbac
k is preferably 200 V or less, more preferably 150 V or less, depending on the developing system.

The contrast potential is preferably from 100 V to 400 V so that a sufficient image density can be obtained.

When the frequency is lower than 500 Hz, although it depends on the process speed, when the toner in contact with the electrostatic image carrier is returned to the developing sleeve, sufficient vibration is not given and fog is liable to occur. When the frequency exceeds 10,000 Hz, the toner cannot follow the electric field, and the image quality is liable to be deteriorated.

What is important in the developing method of the present invention is that the magnetic brush on the developing sleeve 11 and the photosensitive drum 1 are used to develop a sufficient image density, have excellent dot reproducibility, and perform development without carrier adhesion. The contact width (development nip C) is preferably set to 3 to 8 mm. Development nip C is 3
If it is smaller than 8 mm, it is difficult to sufficiently satisfy sufficient image density and dot reproducibility. If it is larger than 8 mm, packing of the developer occurs, which stops the operation of the machine and sufficiently suppresses carrier adhesion. It becomes difficult. As a method of adjusting the developing nip, the distance A between the developer regulating member 15 and the developing sleeve 11 may be adjusted, or the developing sleeve 1 may be adjusted.
The nip width is appropriately adjusted by adjusting the distance B between the photosensitive drum 1 and the photosensitive drum 1.

The image forming method of the present invention uses the developer and the developing method of the present invention, particularly when outputting an image in which halftone is emphasized, and particularly, in combination with a developing system for forming a digital latent image, There is no influence of the charge injection through the dot and the latent image is not disturbed, so that the dot latent image can be developed faithfully. Also in the transfer step, a high transfer rate can be achieved by using a fine-particle-cut toner having a sharp particle size distribution, so that high image quality can be achieved in both the halftone portion and the solid portion.

In addition to the initial improvement in image quality, the use of the two-component developer of the present invention minimizes the change in the amount of charge of the toner in the developing device, and the image quality of the present invention does not deteriorate even when copying a large number of sheets. The effect of can be fully exhibited.

In order to obtain a tighter full-color image, it is preferable to have developing units for magenta, cyan, yellow and black, and to exhibit a tighter image by performing black development last. be able to.

An image forming method according to the present invention will be described with reference to the accompanying drawings.

In FIG. 1, a magnetic brush composed of magnetic particles 23 is formed on the surface of the transfer sleeve 22 by the magnetic force of the magnet roller 21, and this magnetic brush contacts the surface of the electrostatic image carrier (photosensitive drum) 1. Then, the photosensitive drum 1 is charged. A charging bias is applied to the transport sleeve 22 by a bias applying unit (not shown). By irradiating the charged photosensitive drum 1 with laser light 24 by an exposure device (not shown), a digital electrostatic charge image is formed. The electrostatic charge image formed on the photosensitive drum 1 includes a magnet roller 12 and a developer 19 carried on a developing sleeve 11 to which a developing bias is applied by a bias applying device (not shown).
It is developed by the toner 19a inside.

The developing device 4 is provided with a developer chamber R by a partition wall 17.
_1, is divided into the stirring chamber R _2, respectively developer conveying screw 13, 14 is installed. Above the stirring chamber R _2, a toner storage chamber R ₃ containing a replenishing toner 18 is installed, supply opening 20 is provided in a lower portion of the storage chamber R _3.

The developer transport screw 13 rotates to transport the developer in the developer chamber R1 in _one direction along the longitudinal direction of the developing sleeve 11 while stirring. The partition 17 is provided with openings (not shown) on the near side and the back side in the drawing, and the developer conveyed to _one of the developer chambers R1 by the screw 13 passes through the opening of the partition 17 on one side. The developer is sent to the stirring chamber R ₂ and transferred to the developer transport screw 14. In the direction of rotation the screw 13 opposite the screw 14, the developer in the stirring chamber R _2, the developer chamber R ₁
Stirring the toner supplied from the passed developer and toner storage chamber R ₃ from, with mixing, the screw 13 and conveyed in the stirring chamber R ₂ in the opposite direction, through the other opening of the partition wall 17 sent into the developer chamber R _1.

[0148] To develop the electrostatic latent image formed on the photosensitive drum 1, the developer 19 in the developer chamber R ₁ is drawn up by the magnetic force of the magnet roller 12, the developing sleeve 1
1 is carried on the surface. The developer carried on the developing sleeve 11 is conveyed to the regulating blade 15 with the rotation of the developing sleeve 11, where it is regulated to a thin developer layer having an appropriate layer thickness. To the development area opposed to it. The portion corresponding to the developing area of the magnet roller 12, the magnetic poles are (developing pole) N ₁ is positioned, the developing pole N ₁ forms a developing magnetic field in the developing area,
This developer magnetic field causes the developer to spike, and a magnetic brush of the developer is generated in the development area. Then, the magnetic brush contacts the photosensitive drum 1, and the toner adhered to the magnetic brush and the toner adhered to the surface of the developing sleeve 11 are transferred to the electrostatic image area on the photosensitive drum 1 by the reversal developing method. Then, the electrostatic image is developed to form a toner image.

The developer that has passed through the developing area is returned to the developing device 4 as the developing sleeve 11 rotates, and the magnetic pole S
Due to the repelling magnetic field between S ₁ and S ₂ , it is peeled off from the developing sleeve 11 and falls into the developer chamber R ₁ and the stirring chamber R ₂ to be collected.

By the above development, the developer 1 in the developing device 4
T / C ratio of 9 (toner and mixing ratio of the carrier, i.e., toner concentration in the developer) When decreases is, the agitation chamber R in an amount that was seen from the toner storage chamber R ₃ to the amount consumed toner 18 in the developing ₂ and the T / C of the developer 19 is maintained at a predetermined amount. To detect the T / C ratio of the developer 19 in the container 4,
A toner concentration detection sensor that measures a change in the magnetic permeability of the developer using the inductance of the coil is used. The toner concentration detection sensor has a coil (not shown) therein.

The regulating blade 15 which is disposed below the developing sleeve 11 and regulates the layer thickness of the developer 19 on the developing sleeve 11 is a non-magnetic blade 15 made of a non-magnetic material such as aluminum or SUS316. The distance between the end and the surface of the developing sleeve 11 is 300 to 1000 μm.
m, preferably 400 to 900 μm. If the distance is less than 300 μm, the magnetic carrier is clogged during this time, and the developer layer is likely to be uneven, and it is difficult to apply the developer necessary for good development, and a developed image having a low density and many unevenness is formed. Easy to be. This distance is preferably 400 μm or more in order to prevent non-uniform application (so-called blade jam) due to unnecessary particles mixed in the developer. If it is larger than 1000 μm, the amount of the developer applied on the developing sleeve 11 increases, and it is difficult to regulate a predetermined thickness of the developer layer. As a result, the adhesion of the magnetic carrier particles to the photosensitive drum 1 increases and the circulation and regulation of the developer. The regulation of development by the blade 15 is weakened, so that toner tribo is reduced and fogging is likely to occur.

Even when the developing sleeve 11 is driven to rotate in the direction of the arrow, the magnetic carrier particle layer moves away from the sleeve surface due to the balance between the restraining force based on magnetic force and gravity and the conveying force in the moving direction of the developing sleeve 11. Movement slows down. Some fall under the influence of gravity.

Accordingly, by appropriately selecting the arrangement positions of the magnetic poles N and N and the fluidity and magnetic characteristics of the magnetic carrier particles, the closer the magnetic carrier particle layer is to the sleeve, the more the magnetic pole N ₁ becomes.
To form a moving layer. Due to the movement of the magnetic carrier particles, the developer is conveyed to the developing area with the rotation of the developing sleeve 11 and is used for development.

Further, the developed toner image is transferred onto a transfer material (recording material) 25 conveyed by a bias applying means 2.
The toner image transferred by the transfer blade 27 as a transfer unit to which a transfer bias is applied by 6 and transferred onto the transfer material is fixed to the transfer material by a fixing device (not shown). In the transfer step, the transfer residual toner remaining on the photosensitive drum 1 without being transferred to the transfer material is adjusted in charge in the charging step, and is collected during development.

FIG. 3 is a schematic diagram in which the image forming method of the present invention is applied to a full-color image forming apparatus.

The main body of the full-color image forming apparatus includes a first image forming unit Pa, a second image forming unit Pb,
An image forming unit Pc and a fourth image forming unit Pd are provided side by side, and images of different colors are formed on a transfer material through a process of forming, developing, and transferring a latent image.

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

The first image forming unit Pa includes an electrophotographic photosensitive drum 6 having a diameter of 30 mm as an electrostatic image carrier.
1a, the photosensitive drum 61a is rotated in the direction of arrow a. Reference numeral 62a denotes a primary charger as a charging unit, and a magnetic brush formed on the surface of a sleeve having a diameter of 16 mm is arranged so as to contact the surface of the photosensitive drum 61a. Reference numeral 67a denotes a laser beam for forming an electrostatic charge image on the photosensitive drum 61a, the surface of which is uniformly charged by the primary charger 62a, and is irradiated by an exposure device (not shown). 63a is the photosensitive drum 6
The developing device is a developing device as a developing unit for forming a color toner image by developing the electrostatic charge image carried on 1a, and holds a color toner. Reference numeral 64a denotes a transfer blade as transfer means for transferring the color toner image formed on the surface of the photosensitive drum 61a to the surface of a transfer material (recording material) conveyed by a belt-shaped transfer material carrier 68. The transfer blade 64a can apply a transfer bias by contacting the back surface of the transfer material carrier 68.

The first image forming unit Pa uniformly and primary charges the photosensitive drum 61a by the primary charger 62a, forms an electrostatic image on the photosensitive member by the exposure device 67a, and forms the electrostatic image by the developing device 63a. Is developed using a color toner, and the developed toner image is transferred to a back surface side of a belt-shaped transfer material carrier 68 which carries and conveys the transfer material at a first transfer portion (a contact position between the photoconductor and the transfer material). A transfer bias is applied from a transfer blade 64a that comes into contact with the transfer member to transfer the image onto the surface of the transfer material.

When the toner is consumed by the development and the T / C ratio decreases, the decrease is detected by a toner concentration detection sensor 85 which measures the change in the magnetic permeability of the developer by using the inductance of the coil, and the toner is consumed. The supply toner 65 is supplied according to the toner amount. The toner density detection sensor 85 has a coil (not shown) therein.

The present image forming apparatus has the same configuration as the first image forming unit Pa, and has a second image forming unit Pb, a third image forming unit Pc, and a second image forming unit Pc having different colors of the color toner held in the developing device. Four image forming units of the fourth image forming unit Pd are provided side by side. For example, yellow toner is used for the first image forming unit Pa, magenta toner is used for the second image forming unit Pb, cyan toner is used for the third image forming unit Pc, and black toner is used for the fourth image forming unit Pd. The transfer of each color toner onto the transfer material is sequentially performed in the transfer section of each image forming unit. In this step, while the registration is being performed, each color toner is superimposed on the same transfer material by one transfer of the transfer material, and when the transfer is completed, the transfer material is separated from the transfer material carrier 68 by the separation charger 69. The sheet is sent to the fixing device 70 by a conveying means such as a conveying belt, and the final full-color image is obtained by a single fixing.

The fixing device 70 has a pair of a fixing roller 71 having a diameter of 40 mm and a pressure roller 72 having a diameter of 30 mm. The fixing roller 71 has heating means 75 and 76 inside.

The unfixed color toner image transferred onto the transfer material passes through a pressure contact portion between the fixing roller 71 and the pressure roller 72 of the fixing device 70, and is applied to the transfer material by the action of heat and pressure. Is established.

In FIG. 3, the transfer material carrier 68 is an endless belt-shaped member, which is moved in the direction of arrow e by a driving roller 80. 7
9 is a transfer belt cleaning device, 81 is a belt driven roller, and 82 is a belt static eliminator. 8
Reference numeral 3 denotes a pair of registration rollers for conveying the transfer material in the transfer material holder to the transfer material carrier 68.

The transfer means is a contact transfer in which a transfer bias can be directly applied by contacting the back surface of a transfer material carrier such as a roller-shaped transfer roller instead of the transfer blade contacting the back surface of the transfer material carrier. Means can be used.

Further, in place of the above-mentioned contact transfer means, a non-contact type in which a transfer bias is applied from a corona charger arranged in a non-contact manner on the back side of a generally used transfer material carrier to perform transfer. May be used.

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

Next, an example of another image forming method of the present invention will be described with reference to FIG.

FIG. 4 is a schematic diagram showing an example of an image forming apparatus capable of performing the image forming method of the present invention.

This image forming apparatus is configured as a full-color copying machine. As shown in FIG. 4, the full-color copying machine has a digital color image reader unit 35 at the upper part and a digital color image printer unit 36 at the lower part.

In the image reader section, the original 30 is placed on an original platen glass 31, and is exposed and scanned by an exposure lamp 32, so that a reflected light image from the original 30 is condensed on a full color sensor 34 by a lens 33, and a color Obtain a decomposed image signal. The color-separated image signal is processed by a video processing unit (not shown) through an amplifier circuit (not shown) and sent to a digital image printer unit.

In the image printer section, the photosensitive drum 1, which is an electrostatic image carrier, is a photosensitive body such as an organic photoconductor, and is rotatably carried in the direction of the arrow. Around the photosensitive drum 1, a pre-exposure lamp 11, a corona charger 2 as a primary charging member, a laser exposure optical system 3 as a latent image forming means, a potential sensor 12, and four developing devices 4Y and 4C of different colors. , 4M, 4K, on-drum light amount detecting means 1
3. The transfer device 5A and the cleaning device 6 are arranged.

In the laser exposure optical system 3, an image signal from the reader unit is converted into an image scan exposure light signal by a laser output unit (not shown), and the converted laser light is reflected by the polygon mirror 3a. Is projected on the surface of the photosensitive drum 1 via the lens 3b and the mirror 3c.

[0174] The printer unit is provided with a photosensitive drum 1 for forming an image.
Is rotated in the direction of the arrow, and after the charge is eliminated by the pre-exposure lamp 11, the photosensitive drum 1 is uniformly negatively charged by the charger 2 to irradiate a light image E for each separation color, and the latent image is formed on the photosensitive drum 1. To form

Next, the latent image on the photosensitive drum 1 is developed by operating a predetermined developing device, and a visible image, that is, a toner image is formed on the photosensitive drum 1 by using a resin-based negatively chargeable toner. I do. The developing units 4Y, 4C, 4M, and 4K alternately approach the photosensitive drum 1 in accordance with the respective separation colors and perform development by the operation of the eccentric cams 24Y, 24C, 24M, and 24K.

The transfer device 5A includes a transfer drum 5, a transfer charger 5b, a suction charger 5c for electrostatically attracting a recording material and a suction roller 5g opposed thereto, an inner charger 5d, an outer charger 5e, It has a separation charger 5h.
The transfer drum 5 is rotatably supported so as to be rotatable, and a transfer sheet 5f, which is a recording material carrier for supporting a recording material (transfer material) in an opening area around the transfer drum 5, is integrally adjusted in a cylindrical shape. A polycarbonate film or the like is used for the transfer sheet 5f.

The recording material is conveyed from the recording material cassette 7a, 7b or 7c to the transfer drum 5 through the recording material conveyance system, and is carried on the transfer sheet 5f. Transfer drum 5
The recording material carried thereon is repeatedly conveyed to a transfer position facing the photosensitive drum 1 as the transfer drum 5 rotates, and is transferred onto the photosensitive material by the action of the transfer charger 5b while passing through the transfer position. 1 is transferred.

In the above image forming step, yellow (Y)
By repeating the process for magenta (M), cyan (C), and black (K), a color image in which four color toner images are superimposed and transferred on the recording material on the transfer drum 5 is obtained.

In the case of single-sided image formation, the recording material onto which the toner images of four colors have been transferred in this manner is separated by the action of the separation claw 8a, the separation push-up roller 8b, and the separation charger 5h.
The sheet is separated from the transfer drum 5 and sent to the heat fixing device 9.
The heat fixing device 9 includes a heat fixing roller 9a having a heating unit therein and a pressure roller 9b. The full-color image carried on the recording material is fixed on the recording material by passing the recording material through the pressure contact portion between the heat fixing roller 9a and the pressure roller 9b as a heating member. That is, in this fixing step, toner color mixing, color development, and fixing to the recording material are performed to form a full-color permanent image, which is then discharged to the tray 10 to complete one full-color copy. On the other hand, the photosensitive drum 1 is subjected to the image forming process again after the residual toner on the surface is cleaned and removed by the cleaning device 6.

In the image forming method of the present invention, a toner image obtained by developing the electrostatic image formed on the latent image carrier can be transferred to a recording material via an intermediate transfer member.

That is, in this image forming method, the toner image formed by developing the electrostatic image formed on the electrostatic image carrier is transferred to the intermediate transfer member, and the toner image transferred to the intermediate transfer member is developed. Is transferred to a recording material.

An example of an image forming method using an intermediate transfer member will be specifically described with reference to FIG.

In the apparatus system shown in FIG. 5, the cyan developing device 54-1, the magenta developing device 54-2, the yellow developing device 54-3, and the black developing device 54-4 are respectively provided with a cyan developer having a cyan toner and a magenta developing device. A magenta developer having a toner, a yellow developer having a yellow toner, and a black developer having a black toner have been introduced. An electrostatic latent image is formed on a photosensitive member 51 as a latent image holding member by a latent image forming means 53 such as a laser beam. By a developing method such as a magnetic brush developing method, a non-magnetic one-component developing method or a magnetic jumping developing method,
The electrostatic charge image formed on the photoconductor 51 is developed with these developers, and a toner image of each color is formed on the photoconductor 51.
The photosensitive member 51 is a photosensitive drum or a photosensitive belt having a conductive substrate 51b and a photoconductive insulating material layer 51a such as amorphous selenium, cadmium sulfide, zinc oxide, an organic photoconductor, and amorphous silicon formed on the conductive substrate 51b. is there. The photoconductor 51 is rotated in a direction indicated by an arrow by a driving device (not shown). As the photoconductor 51, a photoconductor having an amorphous silicon photosensitive layer or an organic photosensitive layer is preferably used.

The organic photosensitive layer may be a single layer type in which the photosensitive layer contains a charge generating substance and a substance having charge transporting ability in the same layer, or a functional separation type in which the charge transporting layer is composed of the charge generating layer as a component. It may be a photosensitive layer. A laminated photosensitive layer having a structure in which a charge generation layer and then a charge transport layer are laminated on a conductive substrate in this order is one of preferred examples.

As the binder resin for the organic photosensitive layer, a polycarbonate resin, a polyester resin or an acrylic resin has good cleaning properties, and poor cleaning, fusion of the toner to the photosensitive member, and filming of the external additive hardly occur.

In the charging step, there are a non-contact type with the photoreceptor 51 using a corona charger and a contact type with a contact charging member such as a roller, and both types are used. For efficient uniform charging, simplification, and low ozone generation, a contact type as shown in FIG. 5 is preferably used.

The charging roller 52 as a primary charging member is
Conductive elastic layer 5 having central core 52b and outer periphery thereof
2a as a basic configuration. Charging roller 52
Is pressed against the surface of the photoconductor 51 with a pressing force, and the photoconductor 5
The rotation follows the rotation of 1.

The preferable process conditions when the charging roller is used are that the contact pressure of the roller is 5 to 500 g / cm
In the case where a DC voltage with an AC voltage superimposed thereon is used, an AC voltage = 0.5 to 5 kVpp and an AC frequency = 50
Hz to 5 kHz, DC voltage = ± 0.2 to ± 5 kV.

Other contact charging members include a method using a charging blade and a method using a conductive brush. These contact charging members are effective in that high voltage is not required and generation of ozone is reduced.

The material of the charging roller and the charging blade as the contact charging member is preferably a conductive rubber, and a release coating may be provided on the surface thereof. As the release coating, a nylon resin, PVDF (polyvinylidene fluoride), PVDC (polyvinylidene chloride), or a fluorine acrylic resin can be used.

The voltage of the toner image on the photosensitive member (for example, ±
(0.1 to ± 5 kV). The intermediate transfer member 55 includes a pipe-shaped conductive core 55b and a medium-resistance elastic layer 55 formed on the outer peripheral surface thereof.
a. The cored bar 55b may be provided with a conductive layer (for example, conductive plating) on the surface of plastic.

The medium resistance elastic layer 55a is made of silicone rubber, Teflon rubber, chloroprene rubber, urethane rubber,
EPDM (terpolymer of ethylene propylene diene)
A conductive material such as carbon black, zinc oxide, tin oxide, and silicon carbide is mixed and dispersed in an elastic material such as to adjust the electric resistance (volume resistance) to a medium resistance of 10 ⁵ to 10 ¹¹ Ω · cm. It is a solid or foamed layer.

The intermediate transfer member 55 is provided in parallel with the photosensitive member 51 so as to be in contact with the lower surface of the photosensitive member 51, and is arranged at the same peripheral speed as the photosensitive member 51 in the counterclockwise direction indicated by the arrow. Rotate.

The first color toner image formed and carried on the surface of the photosensitive member 51 is transferred by the transfer bias applied to the intermediate transfer member 55 in the process of passing through the transfer nip where the photosensitive member 51 and the intermediate transfer member 55 are in contact with each other. The intermediate transfer is sequentially performed on the outer surface of the intermediate transfer body 55 by the electric field formed in the nip area.

The untransferred toner on the photosensitive member 51 that has not been transferred to the intermediate transfer member 55 is removed by the photosensitive member cleaning member 5.
8 and is collected in the photoconductor cleaning container 59.

A transfer means is disposed in parallel with the intermediate transfer body 55 and is brought into contact with the lower surface of the intermediate transfer body 55. The transfer means 57 is, for example, a transfer roller or a transfer belt. It rotates clockwise with the same peripheral speed as the arrow. The transfer means 57 may be provided so as to directly contact the intermediate transfer body 55, or a belt or the like may be provided so as to contact between the intermediate transfer body 55 and the transfer means 57.

In the case of the transfer roller, the transfer roller is basically composed of a central core bar 57b and a conductive elastic layer 57a formed on the outer periphery thereof.

For the intermediate transfer member and the transfer roller, general materials can be used. By setting the volume resistivity of the elastic layer of the transfer roller smaller than the volume resistivity of the elastic layer of the intermediate transfer body, the voltage applied to the transfer roller can be reduced, and a good toner image can be formed on the transfer material. In addition, it is possible to prevent the transfer material from being wound around the intermediate transfer member. In particular, it is particularly preferable that the volume resistivity of the elastic layer of the intermediate transfer member is at least 10 times the volume resistivity of the elastic layer of the transfer roller.

The hardness of the intermediate transfer member and the transfer roller is determined by JI
It is measured according to SK-6301. The intermediate transfer member used in the present invention is preferably composed of an elastic layer belonging to the range of 10 to 40 degrees. On the other hand, the hardness of the elastic layer of the transfer roller is higher than the hardness of the elastic layer of the intermediate transfer member.
Those having a value of from -80 degrees are preferred in order to prevent the transfer material from winding around the intermediate transfer member. When the hardness of the intermediate transfer member and that of the transfer roller are reversed, a concave portion is formed on the transfer roller side, and the winding of the transfer material around the intermediate transfer member is likely to occur.

The transfer means 57 rotates the intermediate transfer member 55 at a constant speed or at a different peripheral speed. The transfer material 56 is conveyed between the intermediate transfer body 55 and the transfer means 57,
The toner image on the intermediate transfer body 55 is transferred to the surface of the transfer material 56 by applying a bias having a polarity opposite to the frictional charge of the toner to the transfer unit 57 from the transfer bias unit.

The untransferred toner on the intermediate transfer member that has not been transferred to the transfer material 56 is removed by the cleaning member 6 for the intermediate transfer member.
0 and is collected in the intermediate transfer body cleaning container 62. The toner image transferred to the transfer material 56 is fixed on the transfer material 56 by the heat fixing device 61.

As the material of the transfer roller, the same material as that of the charging roller can be used. The preferable transfer process condition is that the contact pressure of the roller is 2.94 to 490.
N / m (3 to 500 g / cm) (more preferably, 19.
6 to 294 N / m), DC voltage = ± 0.2 to ± 10 k
V.

When the linear pressure as the contact pressure is less than 2.94 N / m, the transfer of the transfer material and the occurrence of transfer failure tend to occur, which is not preferable.

For example, the conductive elastic layer 5 of the transfer roller 57
7b is an elastic material such as polyurethane rubber or EPDM (ethylene propylene diene terpolymer) mixed with a conductivity-imparting agent such as carbon black, zinc oxide, tin oxide, and silicon carbide to disperse the electric resistance (volume resistance). ) From 10 ⁶
It is a solid or foamed layer adjusted to have a medium resistance of 10 ¹⁰ Ω · cm.

As a contact one-component developing method, it is possible to develop using a non-magnetic toner, for example, using a developing device 90 as shown in FIG.

The developing device 90 carries a developing container 91 containing a one-component developer 98 having a magnetic or non-magnetic toner, and carries the one-component developer 98 contained in the developing container 91, and transports it to the developing area. Roller 92 for supplying developer to developer carrier 92 for supplying toner to developer carrier
5. Elastic blade 96 as a developer layer thickness regulating member for regulating the thickness of the developer layer on the developer carrier, and developing container 9
1 has a stirring member 97 for stirring the developer 98.

As the developer carrying member 92, an elastic layer 9 formed on a roller base 93 by an elastic member such as rubber or resin having elasticity such as foamed silicone rubber.
It is preferred to use an elastic roller having 4.

The elastic roller 92 is pressed against the surface of a photosensitive drum 99 as a latent image holding member, and electrostatically formed on the photosensitive member by a one-component developer 98 applied to the surface of the elastic roller. While developing the latent image, an unnecessary one-component developer 98 existing on the photoreceptor after transfer is collected.

In the present invention, the developer carrying member is substantially in contact with the photosensitive member surface. This means that the developer carrier is in contact with the photoconductor when the one-component developer is removed from the developer carrier. At this time, an image having no edge effect can be obtained by an electric field acting between the photoconductor and the developer carrier via the developer, and at the same time, cleaning is performed. There is a need to have an electric potential between the surface of the elastic roller or the vicinity of the surface as a developer carrier and an electric field between the surface of the photosensitive member and the surface of the elastic roller. For this reason,
It is also possible to use a method in which the elastic rubber of the elastic roller is resistance-controlled in the medium resistance region to keep the electric field while preventing conduction with the photoreceptor surface, or a method of providing a thin dielectric layer on the surface layer of the conductive roller. Further, a configuration in which a conductive layer is provided on a surface of the conductive roller which is in contact with the surface of the photoreceptor with a conductive resin sleeve having a surface in contact with the surface of the photoreceptor covered with an insulating material, or a surface of the insulating roller which is not in contact with the photoreceptor. It is possible.

The elastic roller carrying the one-component developer may rotate in the same direction as the photosensitive drum or in the opposite direction. When the rotation is in the same direction, it is preferable that the peripheral speed ratio is greater than 100% with respect to the peripheral speed of the photosensitive drum. If it is less than 100%, problems tend to occur in image quality such as poor line clarity. As the peripheral speed ratio increases, the amount of the developer supplied to the development site increases, and the frequency of desorption of the developer from the electrostatic latent image increases.
An unnecessary portion of the developer is scraped off, and the necessary portion is repeatedly supplied with the developer, whereby an image faithful to the electrostatic latent image is obtained. More preferably, the peripheral speed ratio is 100
% Or more is good.

The developer layer thickness regulating member 96 is not limited to an elastic blade, and may be an elastic roller as long as it is in pressure contact with the surface of the developer carrying member 92 by elastic force.

As the elastic blade and the elastic roller, rubber elastic bodies such as silicone rubber, urethane rubber and NBR; synthetic resin elastic bodies such as polyethylene terephthalate; metal elastic bodies such as stainless steel and steel can be used. Further, even a complex thereof can be used.

In the case of an elastic blade, the base on the upper side of the elastic blade is fixed and held on the developer container side, and the lower side is bent in the forward or reverse direction of the developing sleeve against the elasticity of the blade. In this state, the inner surface of the blade (the outer surface in the case of the opposite direction) is brought into contact with the sleeve surface with moderate elastic pressure.

[0214] The supply roller 95 is made of a foam material such as polyurethane foam.
The developer rotates in a forward or reverse direction at a relative speed other than 0, and supplies the one-component developer and also peels off the developed developer (undeveloped developer) on the developer carrier.

When the electrostatic latent image on the photosensitive member is developed by the one-component developer on the developer bearing member in the developing area, the direct and / or alternating current is applied between the developer bearing member and the photosensitive drum. It is preferred to apply a developing bias of to develop.

Next, the non-contact jumping development system will be described.

The non-contact jumping development method includes a development method using a one-component magnetic developer having a non-magnetic toner.

Here, a developing method using a one-component non-magnetic developer having a non-magnetic toner will be described with reference to a schematic configuration diagram shown in FIG.

The developing device 170 includes a developing container 17 containing a non-magnetic one-component developer 176 having a non-magnetic toner.
1. A developer carrier 172 for carrying the one-component non-magnetic developer 176 contained in the developing container 171 and transporting it to the development area, and supplying the one-component non-magnetic developer on the developer carrier Roller 173 for controlling the thickness, the elastic blade 174 as a developer layer thickness regulating member for regulating the thickness of the developer layer on the developer carrier, and the one-component non-magnetic developer 176 in the developing container 171 are stirred. Stirring member 175 for the purpose.

Reference numeral 169 denotes an electrostatic latent image holding member, and the latent image is formed by an electrophotographic process means or an electrostatic recording means (not shown). Reference numeral 172 denotes a developing sleeve as a developer carrier, which is made of a non-magnetic sleeve made of aluminum or stainless steel.

As the developing sleeve, a rough tube of aluminum or stainless steel may be used as it is, but preferably the surface is uniformly roughened by spraying glass beads,
A mirror-finished one or a resin-coated one is preferred.

The one-component non-magnetic developer 176 is contained in the developing container 1
The developer is supplied to the developer carrier 172 by a supply roller 173. Supply roller 173
Is made of foam material such as polyurethane foam,
The developer carrier is rotated in a forward or reverse direction at a relative speed other than 0, and the developer is supplied and the developer (undeveloped developer) on the developer carrier 172 after the development is peeled off. ing. The one-component non-magnetic developer supplied onto the developer carrier 172 is uniformly and thinly applied by an elastic blade 174 as a developer layer thickness regulating member.

The contact pressure between the elastic coating blade and the developer carrier is 0.3 to 2 as a linear pressure in the developing sleeve generatrix direction.
5 kg / m, preferably 0.5 to 12 kg / m is effective. When the contact pressure is less than 0.3 kg / m, it is difficult to uniformly apply the one-component non-magnetic developer, and the charge amount distribution of the one-component non-magnetic developer becomes broad, which causes fogging and scattering. When the contact pressure exceeds 25 kg / m, a large pressure is applied to the one-component non-magnetic developer, and the one-component non-magnetic developer is deteriorated. Absent. Further, a large torque is required to drive the developer carrier, which is not preferable. That is, by adjusting the contact pressure to 0.3 to 25 kg / m, it becomes possible to effectively loosen the aggregation of the one-component non-magnetic developer using the toner of the present invention. It is possible to instantly raise the charge amount of the non-magnetic developer.

As the developer layer thickness regulating member, an elastic blade or an elastic roller can be used, and it is preferable to use a material of a triboelectric series suitable for charging the developer to a desired polarity.

In the present invention, silicone rubber, urethane rubber and styrene butadiene rubber are preferred. Furthermore, polyamide, polyimide, nylon, melamine, melamine cross-linked nylon, phenolic resin, fluororesin,
An organic resin layer such as a silicone resin, a polyester resin, a urethane resin, and a styrene resin may be provided. Uses conductive rubber and conductive resin, and further disperses fillers and charge control agents such as metal oxides, carbon black, inorganic whiskers, and inorganic fibers in the rubber and resin of the blade to achieve appropriate conductivity and charging. It is preferable because it gives imparting properties and can appropriately charge the one-component non-magnetic developer.

In this non-magnetic one-component developing method, in a system in which a one-component non-magnetic developer is thinly coated on the developing sleeve by a blade, the one-component non-magnetic developer on the developing sleeve is required to obtain a sufficient image density. It is preferable that the thickness of the non-magnetic developer layer is made smaller than the opposing gap length β between the developing sleeve and the latent image holding member, and an alternating electric field is applied to this gap.
That is, by applying an alternating electric field or a developing bias in which a DC electric field is superimposed on the alternating electric field between the developing sleeve 172 and the latent image holder 169 by the bias power supply 177 shown in FIG. The transfer of the one-component non-magnetic developer to the non-magnetic developer can be facilitated, and a higher quality image can be obtained.

[0227]

EXAMPLES Hereinafter, a specific method for producing a toner, an example,
The present invention will be described in more detail with reference to comparative examples. "Department"
Means "parts by weight".

(Production Example 1 of Toner) Styrene monomer 10
For 0 parts, 16 parts of carbon black (1) [DBP oil absorption 42 ml / 100 g, specific surface area 6.5 m ² / g, average particle diameter 31 mμ, volatile matter 0.5%, pH value 9],
A combination of 1 part of the azo-based iron compound (1) and 1 part of the aluminum compound of di-tert-butylsalicylic acid was prepared. This was added to an attritor (manufactured by Mitsui Mining Co., Ltd.) and stirred at 200 rpm for 180 minutes at 25 ° C. using 2 mm zirconia beads to prepare a master batch dispersion liquid 1 (A / B = 16).

On the other hand, 0.1M
-Na ₃ PO ₄ aqueous solution 450 parts was charged, followed by heating to 60 ° C., and stirred at 12,000rpm using Claire mixer (manufactured by M Technique Co., Ltd.). 1.0MCa
68 parts of a Cl ₂ aqueous solution was gradually added to obtain an aqueous medium containing a calcium phosphate compound.

Next, 117 parts of master batch dispersion liquid, 66 parts of styrene monomer, 34 parts of n-butyl acrylate, 25 parts of ester wax (1), 10 parts of saturated polyester resin, and 0.5 parts of divinylbenzene The mixture was heated to 60 ° C., stirred and uniformly dissolved and dispersed. Into this, 5 parts of a polymerization initiator 2,2′-azobis (2,4-dimethylvaleronitrile) was dissolved to prepare a polymerizable monomer composition.

Then, while maintaining the pH in the aqueous medium at pH 6, the polymerizable monomer composition was charged, and the mixture was subjected to a Clear mixer (manufactured by M Technique) at 10,000 rpm for 10 minutes at 60 ° C. in an N ₂ atmosphere. After stirring, the polymerizable monomer composition was granulated. Thereafter, the mixture is transferred to a reaction vessel, the pH of the aqueous medium is maintained at 6, and the mixture is stirred with a paddle stirring blade.
The temperature was raised to 60 ° C., and the reaction was performed for 5 hours. Further, a water-soluble initiator was added, the temperature was raised to 80 ° C., and the reaction was performed for 5 hours. After completion of the polymerization reaction, the remaining monomer was distilled off under reduced pressure, and after cooling, hydrochloric acid was added to dissolve the calcium phosphate compound, followed by filtration, washing with water, drying under vacuum, and classification using a multi-stage classifier. Thus, black toner particles were obtained.

To 98.5 parts by weight of the obtained black toner particles, 0.7 part by weight of hydrophobic titanium oxide having a specific surface area of 100 m ² / g by the BET method, and 40 m ² / g by the BET method. Was added externally with a Henschel mixer, and coarse particles were removed with a turbo screener. 1 was obtained. a = 9,
b = 21. 8.2% by number is 4 μm or less,
0.8 volume% was 12.7 μm or more.

As the saturated polyester resin to be added when preparing the polymerizable monomer composition, Mw = 1 obtained by condensing propoxylated bisphenol and terephthalic acid was used.
1000, Mw / Mn = 2.1, acid value 10 mgKOH /
g of polyester resin was used.

(Production Example 2 of Toner)
DBP oil absorption 95ml / 100g, specific surface area 300m ²
/ G, average particle diameter 14 mμ, volatile matter 1%, pH value 9 except that carbon black was used. 2 was obtained. a = 13 and b = 17. In addition, 18.2% by number was 4 μm or less, and 1.4% by volume was 12.7 μm or more.

(Production Example 3 of Toner)
DBP oil absorption 123ml / 100g, specific surface area 80m ²
/ G, average particle diameter 27 mμ, volatile matter 0.9%, pH value 9.5 except that carbon black was used. 3 was obtained. a = 18, b = 12, and many carbon blacks were present on the toner surface layer. Also, 17.3% by number is 12.7 μm when 4 μm or less.
m or more was 1.3% by volume.

(Production Example 4 of Toner)
Except not using an azo-based iron compound, black toner no. 4 was obtained. a = 12, b = 18,
It was observed that carbon black was released from the toner surface layer. In addition, 15.2% by number is 4 μm or less;
7% or more was 1.0% by volume.

(Production Example 5 of Toner)
Except that no wax is used, black toner N
o. 5 was obtained. a = 20, b = 10, and many carbon blacks were present on the toner surface layer. Also, 4
μm or less is 21.3% by number, and 12.7 μm or more is 1.7.
% By volume.

(Production Example 6 of Toner)
DBP oil absorption of 52ml / 100g, a specific surface area of 85m ² /
g, an average particle diameter of 70 mμ, a volatile content of 1%, and a pH value of 9 except that carbon black was used. 6 was obtained. a = 17 and b = 13. Also,
10.5% by number is 4 μm or less, and 0.
It was 9% by volume.

(Production Example 7 of Toner)
Black toner No. 1 was prepared in the same manner except that an azo chromium compound was used instead of the azo iron compound. 7 was obtained. a =
14, b = 16. In addition, 20.8 or less is 20.8
The number%, 12.7 μm or more was 1.6% by volume.

(Production Example 8 of Toner)
Except not using a master batch, black toner No. 8 was obtained. a = 6, b = 24. Further, 21.2% by number was 4 μm or less, and 1.8% by volume was 12.7 μm or more.

(Production Example 9 of Toner)
Black toner No. 1 was prepared in the same manner except that the aluminum compound of di-tert-butylsalicylic acid was not used. 9 was obtained. a = 11 and b = 19. In addition, 11.3% by number was 4 μm or less, and 1.7% by volume was 12.7 μm or more.

(Toner Production Example 10) In the same manner as in Production Example 1, except that a saturated polyester resin was not used, black toner No. 10 was obtained. a = 10, b = 20
Met. 16.5% by number is 4 μm or less;
7% or more was 2.1% by volume.

(Toner Production Examples 11, 12, and 13) In Production Example 4, magenta toner No. 1 was prepared by using 16 parts of a quinacridone pigment instead of carbon black. 11
And cyan toner No. 1 using 12 parts of a phthalocyanine pigment. 12 as C.I. I. Pigment Yellow 180
5 parts of yellow toner no. 13 was obtained.

(Toner Production Example 14) Black toner No. 1 was produced in the same manner as in Production Example 1 except that 6 parts of an azo-based iron compound (A / B = 2.67) was used. 14 was obtained.
a = 5, b = 25. Also, 10 μm or less is 10.
8% by volume and 12.7 μm or more were 1.8% by volume.

(Toner Production Example 15) Black toner No. 1 was produced in the same manner as in Production Example 1, except that 0.3 parts (A / B = 53.3) of an azo-based iron compound was used. 15 was obtained. a = 7 and b = 23. In addition, 4 μm or less is 2
1.5% by volume and 12.7 μm or more were 1.1% by volume.

(Toner Production Example 16) In the same manner as in Production Example 1, except that paraffin wax was used instead of ester wax, black toner No. 16 was obtained. a = 10 and b = 20. Also, 12.3% by number was 4 μm or less, and 1.8% by volume was 12.7 μm or more.

(Production Example 1 of Magnetic Carrier) ・ 50 parts of phenol (hydroxybenzene) ・ 80 parts of 37 wt% formalin aqueous solution ・ 50 parts of water ・ 280 parts of silane coupling agent having epoxy group KBM403 280 parts (Shin-Etsu Chemical Co., Ltd. ))-Treated alumina-containing magnetite fine particles (number-average particle diameter 0.24 μm, specific resistance value 5 × 10 ⁵ Ω · cm) ・ 120 parts of α-Fe ₂ O ₃ fine particles surface-treated with KBM403 (Average particle size 0.40 μm, specific resistance value 8 × 10 ⁹ Ω · cm) ・ 25 parts by weight of aqueous ammonia 15 parts The above-mentioned materials were placed in a four-necked flask and mixed while stirring.
The temperature was raised to 85 ° C. in 0 minutes, and the reaction and curing were performed for 120 minutes. After cooling to 30 ° C. and addition of 500 parts by weight of water, the supernatant was removed, and the precipitate was washed with water and air-dried. Then, this was reduced to 150 to 180 under reduced pressure (5 mmHg).
After drying at 24 ° C. for 24 hours, a magnetic carrier core (A) using a phenol resin as a binder resin was obtained. The magnetic carrier core (A) has a temperature of 30 ° C./80% for 24 hours, and
t% of adsorbed water was present.

The surface of the obtained magnetic carrier core (A) was coated with γ-aminopropyltrimethoxysilane.

[0249]

Embedded image Of a 5% by weight toluene solution was applied.

The surface of the magnetic carrier core (A) was 0.2
It had been treated with γ-aminopropyltrimethoxysilane by weight. During the application, the toluene was volatilized while applying while continuously applying shear stress to the magnetic carrier core (A). On the surface of the magnetic carrier core (A)

[0251]

Embedded image Was confirmed to be present.

While stirring the magnetic carrier (A) treated with the silane coupling agent in the processing machine at 70 ° C.,
Silicone resin KR-221 (Shin-Etsu Chemical Co., Ltd.)
) Was added with 3% of γ-aminopropyltrimethoxysilane based on the solid content of the silicone resin, diluted with toluene so as to have a silicone resin solid content of 20%, and then added under reduced pressure. Resin coating was performed. Thereafter, after stirring for 2 hours, heat treatment was performed at 140 ° C. for 2 hours in an atmosphere of nitrogen gas to loosen aggregation, and coarse particles of 200 mesh or more were removed to obtain a magnetic carrier I.

The average particle size of the obtained magnetic carrier I was 3
5 μm, magnetization strength (σ ₁₀₀₀ ) 42 Am ² / k at 1 × 10 ¹³ Ω · cm, 1 Oe
g, the residual magnetization (σ _r ) was 3.1 Am ² / kg, the true specific gravity was 3.71, and the bulk density was 1.87 g / cm ³ .

(Production Example 2 of Magnetic Carrier) A silicone resin coating was carried out in the same manner as in Production Example 1 except that a core material having an Mg—Mn—Sn—Fe composition was used. The average particle diameter was 38 μm. Resistance value 5 × 10 ¹¹ Ω · cm,
σ ₁₀₀₀ is 45 Am ² / kg, σ _r is 0.8 Am ² / kg, and a magnetic carrier II having a true specific gravity of 4.6 and a bulk density of 1.98 g / cm ³ was obtained.

Example 1 92 parts by weight of magnetic carrier I and black toner no. 18 parts by weight were mixed with a V-type mixer to obtain a two-component developer.

Using this two-component developer, a commercially available digital copying machine GP55 (manufactured by Canon) as an image forming apparatus
Was modified so that the developing device and charging device shown in Fig. 1 could be inserted, and the fixing device was changed to a roller whose surface layer was covered with PFA by 1.2 µm for both the heating roller and the pressure roller using the developing bias shown in Fig. 2. Then, the structure was modified to remove the oil application mechanism, and the original manuscript with an image area of 20% was used, and 23 ° C / 60% (N / N) and 23 ° C /
In each environment of 5% (N / L) and 32.5 ° C./90% (H / H), a paper passing test of 10,000 sheets was performed, and the evaluation was performed based on the following evaluation method. The results are shown in Table 1. As can be seen from Table 1, good results were obtained. Here, the photoconductor is
An organic photoreceptor having a diameter of 30 mm and having a surface layer having a volume resistance of 3 × 10 ¹² Ω · cm so as to be easily charged was used.

(1) Image Density: The image density was measured using a Macbeth Densitometer PD918 type (Macbeth Densitometer) equipped with an SPI filter.
ETER RD918manufacturd by
Macbeth Co. ) Was measured as the relative density of the image formed on plain paper.

(2) Solid Uniformity An original document having five circles each having a diameter of 20 mm and having an image density of 1.5 as measured by a reflection densitometer RD918 (manufactured by Macbeth) was copied, and the image density of the image portion was copied. Was measured with a reflection densitometer RD918, and the difference between the maximum value and the minimum value at that time was determined. ◎: 0.04 or less ○: More than 0.04 0.08 or less △: More than 0.08 0.12 or less ×: More than 0.12

(3) Fog suppression The average reflectance Dr (%) of plain paper before image output was measured using a reflectometer (“REFECTOM” manufactured by Tokyo Denshoku Co., Ltd.).
ETER ODEL TC-6DS "). On the other hand, a solid white image was formed on plain paper, and the reflectance Ds (%) of the solid white image was measured. Fog (%)
Is calculated from the following equation: Fog (%) = Dr (%)-Ds (%) A: Less than 0.4% B: 0.4% to less than 0.8% C: 0.8% to less than 1.2% D: 1.2% or more

Example 2 In Example 1, the black toner No. When we went in the same way except using 2,
Although the fog suppression slightly deteriorated, the results shown in Table 1 were obtained. This is presumed to be because the amount of carbon black present on the toner surface slightly increased due to the small particle size of the carbon black.

Comparative Example 1 In Example 1, the black toner No. When we went in the same way except using 3,
Under H / H, solid uniformity deteriorated. This is presumed to be because a> b because the DBP oil absorption is large, a large number of carbon blacks are present in the toner surface layer, and charges have been injected from the toner surface.

Comparative Example 2 In Example 1, the black toner No. When we went in the same way except using 4,
Under H / H, fog suppression and solid uniformity deteriorated. This is presumably because the dispersion of carbon black became non-uniform because no azo-based metal compound was used.

Comparative Example 3 In Example 1, the black toner No. When we went in the same way except using 5,
Evaluation was stopped because fog suppression deteriorated from the beginning under H / H. This is presumed to be because carbon black was released because no wax was used.

[Comparative Example 4] In Example 1, the black toner No. After using the same procedure except using 6,
The evaluation was stopped because the image density decreased under N / L. This is presumed to be due to insufficient coloring power due to the large primary particle diameter of carbon black.

[Embodiment 3] In the embodiment 1, the black toner No. After using the same method except using 7,
Under N / L, the image density slightly decreased due to durability, and under H / H, solid uniformity deteriorated due to durability, but good results were obtained.

Example 4 In Example 1, the black toner No. When we went in the same way except using 8,
Although the image density decreased and fog increased, it was at a level at which there was no practical problem. This is presumed to be because the dispersion of the carbon black became slightly non-uniform because the master batch was not used.

Example 5 In Example 1, the black toner No. When we went in the same way except using 9,
Fog slightly increased under H / H, and good results were obtained although solid uniformity was reduced.

Example 6 In Example 1, the black toner No. The same procedure was carried out except that No. 10 was used. As a result, although fog increased, the level was practically no problem.

[Embodiment 7] GP5 is used as an image forming apparatus.
Commercial full color copier CLC-2400 instead of 5
(Manufactured by Canon Inc.), as shown in FIG. 3, the cleaning unit was eliminated, and the primary charging was replaced with a contact charging unit. When images were formed in the same manner except that toners / developers of four colors 1, 11, 12, and 13 were used, good results were obtained.

Example 8 In Example 7, a developing device of CLC-700 (manufactured by Canon) was used as an image forming apparatus.
When the image was formed in the same manner as in Example 7 except that the fixing device was modified, good results were obtained.

[Embodiment 9] As shown in FIG. 5, an intermediate transfer drum was used as an image forming apparatus. 1, 1
As shown in FIG. 7, when images were formed in the same manner except that the toners of four colors 1, 12, and 13 were used in the non-magnetic one-component developing system, good results were obtained.

Embodiment 10 As shown in FIG. 6, the developing device of GP55 was modified for non-magnetic contact development as shown in FIG. When 1,500 sheets were used to endure 5,000 sheets, good results were obtained.

[Embodiment 11] In the embodiment 1, the toner no. After using the same method except using 14,
Although fog slightly increased under H / H, good results were obtained. This is presumed to be because the value of A / B became small and the dispersion state of carbon black became non-uniform.

[Example 12] In Example 1, the toner No. When we went in the same way except using 15,
Under H / H, solid uniformity deteriorated and image density decreased, but good results were obtained.

Example 13 The same procedure as in Example 1 was carried out except that ferrite carrier II was used. As a result, good results were obtained although the fog was slightly increased.

[Example 14] In Example 1, the black toner No. When the same procedure was performed except that No. 16 was used, good results were obtained although the uniformity of the solid was slightly lowered. This is presumably because the use of paraffin wax slightly reduced the fluidity of the toner.

[0277]

[Table 1]

[0278]

According to the present invention, it is possible to obtain a high-definition black image with a high image density regardless of the development method, regardless of the temperature and humidity, and further as a full-color black toner. Can also be suitably used.

[Brief description of the drawings]

FIG. 1 is a schematic view illustrating a preferred example of an image forming method of the present invention.

FIG. 2 is a diagram showing an alternating electric field used in Example 1.

FIG. 3 is a schematic explanatory view showing an example of a full-color image forming method.

FIG. 4 is a schematic explanatory view showing another example of the image forming apparatus for performing the image forming method of the present invention.

FIG. 5 is a schematic explanatory view showing another example of the image forming apparatus for performing the image forming method of the present invention.

FIG. 6 is a schematic explanatory view showing another example of an image forming apparatus for performing the image forming method of the present invention.

FIG. 7 is a schematic explanatory view showing another example of the image forming apparatus for performing the image forming method of the present invention.

[Explanation of symbols]

 REFERENCE SIGNS LIST 1 electrostatic image carrier (photosensitive drum) 4 developing device 11 developer carrier (developing sleeve) 12 magnet roller 13, 14 developer transport screw 15 regulating blade 17 partition 18 replenishing toner 19 developer 19 a toner 19 b carrier 20 replenishing Port 21 Magnet roller 22 Transport sleeve 23 Magnetic particles 24 Laser beam 25 Transfer material (recording material) 26 Bias applying means 27 Transfer blade 28 Toner density detection sensor 61a Photosensitive drum 62a Primary charger 63a Developing device 64a Transfer blade 65a Replenishing toner 67a Laser light 68 Transfer material carrier 69 Separation charger 70 Fixer 71 Fixing roller 72 Pressure roller 73 Web 75, 76 Heating means 79 Transfer belt cleaning device 80 Driving roller 81 Belt driven roller 82 Bell G Static eliminator 83 Registration roller 85 Toner density detection sensor

 ──────────────────────────────────────────────────続 き Continuing on the front page (72) Ryoichi Fujita, Inventor 3-30-2 Shimomaruko, Ota-ku, Tokyo Inside Canon Inc. (72) Inventor Shinya Yanagi 3-30-2 Shimomaruko, Ota-ku, Tokyo Canon (72) Inventor Yuji Mikituri 3-30-2 Shimomaruko, Ota-ku, Tokyo F-term (reference) 2H005 AA06 AA21 AB06 CA14 CA21 CA22 CB18 DA02 EA05 EA07 EA10

Claims (33)

[Claims] 1. A black toner having black toner particles containing at least a binder resin, a solid wax, carbon black, and a charge control agent, wherein the weight average particle diameter of the toner is 3 to 10 μm. Average primary particle size of 13-60 mμ
In the dispersion state in the black toner particles, the number of agglomerates having less than 10 primary particles is a
A black toner, wherein a ≦ b, where b is the number of agglomerates or more, and the charge control agent is an azo-based metal compound represented by the following formula (1). Embedded image [M represents a metal element. R ₁ and R ₃ are a hydrogen atom, C ₁
To ₁₈ alkyl groups, C ₂ to ₁₈ alkenyl groups, sulfonamide groups, mesyl groups, sulfonic acid groups, carboxyester groups, hydroxy groups, C ₁ to ₁₈ alkoxy groups, acetylamino groups, benzoylamino groups or halogen atoms Wherein R ₁ and R ₃ are the same or different, and n and n ′
Represents an integer of 1 to 3, R ₂ and R ₄ represent a hydrogen atom or a nitro group, R ₂ and R ₄ are the same or different,
R ₅ and R ₆ are a hydrogen atom, a halogen atom, a nitro group, a carboxyl group, an anilide group, an alkyl group of C ₁ ~ _18, an alkenyl group, an aralkyl group, an alkoxy group, an aryl group, carboxy ester group or ## STR2 ] X represents a hydrogen atom, a lower alkyl group, a lower alkoxy group, a nitro group or a halogen atom, m represents an integer of 1 to 3, R ₅ and R ₆ are the same or different,
A ⁺ represents a hydrogen ion, a sodium ion, a potassium ion, an ammonium ion or a mixture thereof. ] 2. The dispersion state of the carbon black is a ≦ b.
The black toner according to claim 1, wherein ≤ 3a. 3. The carbon black according to claim 1, wherein the carbon black has an average primary particle diameter of 25 to 55 mμ.
3. The black toner according to 1. 4. The carbon black having a DBP oil absorption of 3
The black toner according to any one of claims 1 to 3, wherein the amount is 0 to 100 ml / 100 g. 5. The carbon black having a DBP oil absorption of 3
The black toner according to any one of claims 1 to 3, wherein the amount is 0 to 70 ml / 100 g. 6. The carbon toner content A (% by weight) and the azo metal compound content B (% by weight) in the black toner particles satisfy the following relationship: 3 ≦ A / B ≦ 50. The black toner according to any one of claims 1 to 5, wherein 7. The black toner according to claim 1, wherein the content A of the carbon black in the black toner particles is 2 to 20% by weight. 8. The black toner according to claim 1, wherein the content B of the azo metal compound in the black toner particles is 0.1 to 3.0% by weight. 9. The compound according to claim 1, wherein X in the general formula (1) represents a hydrogen atom, an alkyl group having 1 to 18 carbon atoms, an alkoxy group having 1 to 18 carbon atoms, a nitro group or a halogen atom. 9. The black toner according to any one of 1 to 8. 10. The black toner according to claim 1, wherein the azo metal compound contains a compound represented by the following general formula (2). Embedded image [M represents a metal element. X ₁ and X _{2 each} represent a hydrogen atom, a lower alkyl group, a lower alkoxy group, a nitro group or a halogen atom; X ₁ and X ₂ are the same or different;
And m 'is an integer of 1 to 3, R ₁ and R ₃ is a hydrogen atom, an alkyl group of C ₁ ~ _18, an alkenyl group of C ₂ ~ _18, a sulfonamide group, a mesyl group, a sulfonic acid group, carboxy ester group, hydroxy group, an alkoxy group of C ₁ ~ _18,
An acetylamino group, a benzoylamino group or a halogen atom; R ₁ and R ₃ are the same or different; n and n ′ each represent an integer of 1 to 3; R ₂ and R ₄ represent a hydrogen atom or a nitro group; A ⁺ represents a hydrogen ion, a sodium ion, a potassium ion, an ammonium ion or a mixture thereof. ] 11. The method according to claim 1, wherein X in the general formula (2) represents a hydrogen atom, an alkyl group having 1 to 18 carbon atoms, an alkoxy group having 1 to 18 carbon atoms, a nitro group or a halogen atom. 11. The black toner according to 10. 12. The black toner particles contain 20% by number or less of toner particles having a particle size of 4 μm or less.
The black toner according to any one of claims 1 to 11, further comprising 1.5 vol% or less of toner particles having a size of 2.7 µm or more. 13. The black toner according to claim 1, wherein the solid wax contains an ester wax component having a long-chain alkyl group. 14. The black toner according to claim 1, wherein the black toner particles further contain a polymer having a polar functional group. 15. The black toner according to claim 1, wherein the black toner particles further contain a charge control agent other than the azo metal compound. 16. The black toner according to claim 1, wherein the black toner is obtained by polymerizing a composition with a polymerizable monomer in an aqueous medium. 17. A dispersion wherein at least a first polymerizable monomer, carbon black and an azo metal compound are mixed, and the carbon black and the azo metal compound are dispersed in the polymerizable monomer. Preparing a polymerizable monomer by mixing at least the obtained dispersion, the second polymerizable monomer and the solid wax; and preparing the polymerizable monomer composition. A method for producing black toner particles having a step of producing black toner particles by polymerizing in an aqueous medium, wherein the azo-based metal compound has a compound represented by the following formula (1): Formula 4 [M represents a metal element. R ₁ and R ₃ are a hydrogen atom, C ₁
To ₁₈ alkyl groups, C ₂ to ₁₈ alkenyl groups, sulfonamide groups, mesyl groups, sulfonic acid groups, carboxyester groups, hydroxy groups, C ₁ to ₁₈ alkoxy groups, acetylamino groups, benzoylamino groups or halogen atoms Wherein R ₁ and R ₃ are the same or different, and n and n ′
Represents an integer of 1 to 3, R ₂ and R ₄ represent a hydrogen atom or a nitro group, R ₂ and R ₄ are the same or different,
R ₅ and R ₆ are a hydrogen atom, a halogen atom, a nitro group, a carboxyl group, an anilide group, an alkyl group of C ₁ ~ _18, an alkenyl group, an aralkyl group, an alkoxy group, an aryl group, carboxy ester group or embedded ] X represents a hydrogen atom, a lower alkyl group, a lower alkoxy group, a nitro group or a halogen atom, m represents an integer of 1 to 3, R ₅ and R ₆ are the same or different,
A ⁺ represents a hydrogen ion, a sodium ion, a potassium ion, an ammonium ion or a mixture thereof. The carbon black has an average primary particle diameter of 13 to 60 m.
μ, and in the dispersed state in the black toner particles, the number of agglomerates having less than 10 primary particles is a, 1
A method for producing black toner particles, wherein a ≦ b when the number of particles of 0 or more aggregates is b, and the weight average particle diameter of the toner is 3 to 10 μm. 18. The method according to claim 1, wherein X in the general formula (1) represents a hydrogen atom, an alkyl group having 1 to 18 carbon atoms, an alkoxy group having 1 to 18 carbon atoms, a nitro group or a halogen atom. 18. The method for producing black toner particles according to item 17. 19. The method according to claim 17, wherein the azo metal compound includes a compound represented by the following general formula (2). Embedded image [M represents a metal element. X ₁ and X _{2 each} represent a hydrogen atom, a lower alkyl group, a lower alkoxy group, a nitro group or a halogen atom; X ₁ and X ₂ are the same or different;
And m 'is an integer of 1 to 3, R ₁ and R ₃ is a hydrogen atom, an alkyl group of C ₁ ~ _18, an alkenyl group of C ₂ ~ _18, a sulfonamide group, a mesyl group, a sulfonic acid group, carboxy ester group, hydroxy group, an alkoxy group of C ₁ ~ _18,
An acetylamino group, a benzoylamino group or a halogen atom; R ₁ and R ₃ are the same or different; n and n ′ each represent an integer of 1 to 3; R ₂ and R ₄ represent a hydrogen atom or a nitro group; A ⁺ represents a hydrogen ion, a sodium ion, a potassium ion, an ammonium ion or a mixture thereof. ] 20. The compound according to claim 2, wherein X in the general formula (2) represents a hydrogen atom, an alkyl group having 1 to 18 carbon atoms, an alkoxy group having 1 to 18 carbon atoms, a nitro group or a halogen atom. 20. The method for producing black toner particles according to item 19. 21. The dispersion liquid comprises the first polymerizable monomer 1
21. The composition according to claim 17, further comprising 10 to 40 parts by weight of the carbon black and 0.2 to 5 parts by weight of the azo-based metal compound based on 00 parts by weight. Production method of black toner particles. 22. The polymerizable monomer composition, the dispersion 1
20 parts by weight of the second polymerizable monomer per 100 parts by weight.
22. The method for producing black toner particles according to any one of claims 17 to 21, comprising 00 parts by weight and 0.1 to 5 parts by weight of a solid wax. 23. The polymerizable monomer composition comprises 2 to 20% by weight of the carbon black and 0.2 to 2% by weight of a solid wax.
% By weight and 0.1 to 3.0% by weight of the azo metal compound
The method for producing black toner particles according to claim 17, wherein the black toner particles are contained. 24. The method for producing black toner particles according to claim 17, wherein the carbon black has a DBP oil absorption of 30 to 100 ml / 100 g. 25. The method for producing black toner particles according to claim 17, wherein the carbon black has a DBP oil absorption of 30 to 70 ml / 100 g. 26. The method for producing black toner particles according to claim 17, wherein the carbon black has an average primary particle size of 25 to 55 mμ. 27. The method for producing black toner particles according to claim 17, wherein the solid wax contains a solid wax component having a long-chain alkyl group. 28. The black toner particles according to claim 17, wherein the polymerizable monomer composition further contains a polymer having a polar functional group. Production method. 29. The black toner particles according to claim 17, wherein the polymerizable monomer composition further contains a charge control agent other than the azo metal compound. Manufacturing method. 30. An electrostatic latent image held by a latent image holding member,
Developing with a black toner to form a toner image; transferring the toner image formed on the latent image holding member onto a recording material with or without an intermediate transfer member; and on the recording material. 30. An image forming method comprising the step of fixing a toner image transferred to a black toner, wherein the black toner is the black toner according to claim 1. 31. The image forming method according to claim 30, wherein the toner image is a color toner image including the black toner particles and a chromatic color toner. 32. The image forming method according to claim 30, wherein the toner image is a full-color toner image including the black toner particles, cyan toner, magenta toner, and yellow toner. 33. The image forming method according to claim 30, wherein the latent image holding member is formed of a photoconductor for electrophotography.