JP2002123037A - Dry toner, image forming method and process cartridge - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a dry toner which can be prevented from sticking to members of a fixing device regardless of the configuration of the fixing device, can obtain stable high image quality even when the toner is used under high humidity or low humidity condition, and does not cause image defects with time. SOLUTION: In the dry toner having toner particles containing at least a binder resin and magnetic iron oxide, particles containing liberated iron elements exist by 100 to 350 pieces per 10,000 toner particles. The weight average particle size of the toner is 5 μm to 12 μm. In particles of >=3 μm particle size contains such particles by >=90%, by number, having >=0.90 circularity (a) calculated by formula (1): a=L0/L, wherein L0 is the circumference length of a circle having the same projected area as that of the particle image and L is the circumference length of the particle image. The cut rate Z and the weight average particle size X of the toner, and the cumulative value Y of the particles having >=0.950 circularity, by number, and the toner weight average particle size X satisfy specified relations.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an image forming method for visualizing an electrophotographic image and an electrostatic image, a toner used for a toner jet, an image forming method using the toner, and a process cartridge having the toner. About.

[0002]

2. Description of the Related Art Conventionally, electrophotography has been disclosed in U.S. Pat. No. 2,297,691, Japanese Patent Publication No. 42-23910.
Numerous methods are known as described in Japanese Patent Publication No. JP-B-43-24748 and Japanese Patent Publication No. 43-24748. Generally, a photoconductive substance is used to form an electric latent image on a photoreceptor by various means, and then the latent image is developed with a toner to form a visible image. After the toner is transferred to such a transfer material, the toner image is fixed on the transfer material by heat, pressure, and heat and pressure to obtain a copy or print. The toner remaining on the photoreceptor without being transferred is cleaned by various methods, and the above-described steps are repeated.

A jumping development method has been proposed in Japanese Patent Application Laid-Open No. 55-18656. This involves applying a very thin layer of magnetic toner on a sleeve, triboelectrically charging it, and then developing it in close proximity to the electrostatic image. This method is an excellent method in that the magnetic toner is applied thinly on the sleeve to increase the chance of contact between the sleeve and the toner, thereby enabling sufficient triboelectric charging.

However, in the developing method using the insulating magnetic toner, there are unstable factors related to the insulating magnetic toner to be used. The reason is that a considerable amount of a fine powdered magnetic substance is mixed and dispersed in the insulating magnetic toner, and a part of the magnetic substance is released from the toner particles or is exposed on the surface. In addition, it affects the triboelectrification property, and as a result, causes fluctuation or deterioration of various characteristics such as development characteristics and durability of the magnetic toner. This is considered to be caused by the presence of magnetic fine particles having relatively lower resistance than the resin constituting the toner on the surface of the magnetic toner particles. Further, the chargeability of the toner has a great influence on development and transfer, and is closely related to image quality. Therefore, a magnetic toner capable of stably obtaining a high charge amount has been desired.

Further, in recent years, devices using such electrophotography have begun to be used not only for copying machines for copying original documents, but also for printers and facsimile machines for computer output. As a result, smaller, lighter, faster, and more reliable devices are being sought, and machines are becoming simpler in various respects. As a result, the performance required of the toner becomes higher, and if the performance of the toner cannot be improved, a better machine cannot be realized.

[0006] JP-A-7-230182 and JP-A-8-230182
Japanese Patent Application No. 286421 proposes stabilizing the charging property by externally adding a magnetic powder. According to this method, it is possible to obtain a toner having a stable chargeability and a high cleaning property. However, in a printer having a high-speed and simpler configuration required in recent years, there is a problem that adhesion to a contact charging member easily occurs. is there.

Further, when a toner image is transferred from a photoreceptor to a transfer material, there is toner left untransferred on the photoreceptor. In order to obtain a good toner image even after continuous copying and printing, it is necessary to clean the residual toner on the photoconductor. The collected residual toner is discarded or recycled after being put in a container or a collection box installed in the main body.

[0008] As a waste tonerless system, it is necessary to design a recycling mechanism provided inside the main body. However, in order to achieve the multifunctional, high-speed, and high-quality copy images required for the copiers, printers, and facsimile machines required in the market, a fairly large-scale recycling system is required inside the main unit. It becomes large and goes against the miniaturization required in the market. The same applies to a method of storing waste toner in a container or a collection box installed in the main body, or a method of integrating a photosensitive member and a portion for collecting the above-mentioned waste toner.

In order to cope with these problems, it is necessary to improve the transfer rate when transferring a toner image from a photoreceptor onto a transfer material.

Japanese Patent Application Laid-Open No. 9-26672 discloses that a toner containing a transfer efficiency improver having an average particle diameter of 0.1 to 3 μm and a hydrophobic silica fine powder having a BET specific surface area of 50 to 300 m ² / g are contained. It is disclosed that the volume resistivity is reduced and the transfer efficiency is improved by forming a thin film layer with a transfer efficiency enhancer on the photoreceptor. However, since the toner produced by the pulverization method generally has a wide particle size distribution, it is difficult to uniformly improve the transfer rate on all toner particles, and further improvement is required.

As a method of improving the transfer efficiency, there is a method of making the shape of the toner close to a sphere. As the method, toners produced by a production method such as a spray granulation method, a solution dissolution method, and a polymerization method are disclosed in JP-A-3-84558 and JP-A-3-2558.
29268, JP-A-4-1766, JP-A-4-10
No. 2,862. However, the production of these toners requires not only a large-scale facility but also a problem of poor cleaning due to the toner approaching a true sphere.

In general, a method for producing a toner includes a binder resin for fixing the toner to a transfer material, a colorant or a magnetic material for giving a color as a toner, and a charge control agent for giving a charge to toner particles. After dry-mixing, etc., then roll mill, melt-kneading in a kneading device such as an extruder, after cooling and solidification, the kneaded product is jet-powder pulverizer, finely pulverized by a pulverizer such as a mechanical collision pulverizer,
The obtained finely pulverized product is introduced into an air classifier and classified to obtain toner particles, and if necessary, a fluidizing agent or a lubricant is externally added to the toner particles. In the case of a two-component developer, it is formed of a magnetic carrier and the toner.

FIG. 7 shows an example of a flow for obtaining toner particles.
Shown in

The coarsely crushed toner is continuously or sequentially supplied to the first classifying means, and the classified coarse powder having a coarse particle group having a specified particle size or more as a main component is sent to the crushing means and crushed. It is circulated to the classifier.

[0015] The finely pulverized toner mainly composed of particles within the other specified particle size range and particles smaller than the specified particle size is sent to the second classifying means, and the medium powder mainly composed of particles having the specified particle size is used. Body, a fine powder mainly composed of particles smaller than the specified particle size,
It is classified into a coarse powder mainly composed of particles exceeding a specified particle size.

As the pulverizing means, various pulverizing apparatuses are used. For pulverizing a coarsely pulverized toner mainly composed of a binder resin,
As shown in FIG. 8, a collision type air flow pulverizer using a jet air flow is used.

An impingement type air current pulverizer using a high-pressure gas such as a jet air stream conveys a powder raw material by a jet air stream, injects the powder raw material from an outlet of an acceleration tube, and opposes the powder raw material to an opening surface of an outlet of the acceleration tube. Then, the powder material is crushed by the impact force of the collision surface of the collision member provided.

For example, in the collision type air flow pulverizer shown in FIG. 9, an acceleration tube 162 connected to a high-pressure gas supply nozzle 161 is used.
A collision member 164 is provided opposite to the outlet 163 of the, and the high-pressure gas supplied to the acceleration pipe 162 sucks the powder raw material into the acceleration pipe 162 from the powder raw material supply port 165 communicated in the middle of the acceleration pipe 162. Then, the powder raw material is ejected together with the high-pressure gas to collide with the collision surface 166 of the collision member 164, crushed by the impact, and the crushed material is discharged from the crushed material discharge port 167.

However, since the above-mentioned collision type air-flow pulverizer is configured to eject the powder raw material together with the high-pressure gas to collide with the collision surface of the collision member and pulverize by the impact, the pulverized toner is indefinite in shape. , And the release agent and the magnetic substance powder are likely to fall off from the toner particles.

JP-A-2-87157 discloses that a toner produced by a pulverization method is subjected to mechanical shock (hybridizer).
Discloses a method for improving the transfer efficiency by modifying the shape and surface properties of particles. However, in this method, a further processing step is performed after the pulverization, so that the productivity of the toner particles and the surface of the toner particles are close to a state without unevenness, and it is necessary to improve the development surface, which is not a preferable method.

In addition, a large amount of air is required to produce a toner having a small particle diameter by the above-mentioned impingement airflow pulverization. Therefore, power consumption is extremely large, and there is a problem in terms of energy cost. In particular, in recent years, energy saving of a toner manufacturing apparatus has been demanded in response to environmental problems.

As for the classification means, various airflow classifiers and methods have been proposed. Among these, there are a classifier using a rotary wing and a classifier without a movable part. Among them, a classifier without a movable part includes a fixed wall centrifugal classifier and an inertial force classifier. Classifiers utilizing such inertia are disclosed in JP-B-54-24745 and JP-B-55-64.
No. 33, and JP-A-63-101858.

As shown in FIG. 10, these air-flow classifiers blow out powder into the classifying region at high speed from a supply nozzle having an opening in a classifying region of a classifying room with a gas stream. The coarse powder, the medium powder, and the fine powder are separated by the centrifugal force of the curved airflow flowing along the block 145, and the coarse powder is separated by the narrowed edges 146 and 147.
Classifying medium powder and fine powder.

In the classifier 127, the finely pulverized raw material is introduced from the raw material supply nozzle, and the powder particles flowing inside the pyramidal cylinders 148, 149 tend to flow straight and parallel to the pipe wall with a propulsive force. However, when the raw material is introduced from the upper part in the raw material supply nozzle, the raw material is divided into an upper flow and a lower flow, and the upper flow contains a lot of light fine powders, and the lower flow easily contains a lot of heavy coarse powders, Since each particle flows independently, different trajectories are drawn depending on the site of introduction into the classifier, and coarse powder disturbs the trajectory of fine powder, so there is a limit in improving the classification accuracy.

In general, a toner requires many different properties, and in order to obtain such required properties, the raw materials to be used as well as the production method are often determined. In the toner classification process, the classified particles are required to have a sharp particle size distribution. It is also desired to efficiently and stably produce high quality toner at low cost.

Furthermore, in recent years, toner particles have been gradually miniaturized in order to improve image quality in copying machines and printers. In general, as the material becomes finer, the function of the interparticle force increases, but the same applies to resin and toner.

In particular, when trying to obtain a toner having a sharp particle size distribution with a weight average diameter of 10 μm or less, the conventional apparatus and method cause a reduction in classification yield. Further, when trying to obtain a toner having a sharp particle size distribution with a weight average diameter of 8 μm or less, not only the conventional apparatus and method cause a reduction in classification yield, but also a large amount of ultrafine powder. Tend to be.

Even if a desired product having a fine particle size distribution can be obtained under the conventional method, the process becomes complicated, the classification yield is lowered, the production efficiency is poor, and the cost tends to be high. is there. This tendency becomes more pronounced as the predetermined particle size becomes smaller.

Further, in the case of a magnetic toner having a particle diameter smaller than the normal particle diameter, the amount of the magnetic substance contained in the toner particles increases in order to suppress fog, and the amount of the magnetic substance released increases accordingly. Therefore, when the speed is increased, the low-temperature fixability of the toner is reduced, and the developability tends to be more strict than before.

[0030]

SUMMARY OF THE INVENTION An object of the present invention is to provide a dry toner, a process cartridge and an image forming method which solve the above problems.

It is an object of the present invention to provide a dry toner, a process cartridge, and an image forming method which can maintain good developability even when fine particles are formed.

An object of the present invention is to provide a dry toner, a process cartridge, and an image forming method with high transfer efficiency, which generate little waste toner.

[0033]

According to the present invention, there is provided a dry toner having toner particles having at least a binder resin and magnetic iron oxide, wherein particles having free iron element are contained in an amount of 100 to 350 particles per 10,000 toner particles. Exist,
The toner has a weight average particle diameter of 5 μm to 12 μm,
In addition, in the toner particles having a particle diameter of 3 μm or more, the circularity a obtained by the following formula (1) has 90% by number or more based on the number of particles having a circularity of 0.900 or more, and circularity a = L ₀ / L (1) [Where L ₀ represents the circumference of a circle having the same projected area as the particle image, and L represents the circumference of the particle image. And a) the relationship between the cut rate Z and the toner weight average diameter X satisfies the following expression (2), and the cut rate Z ≦ 5.3 × X (2) [However, the cut rate Z is the particle of all the measured particles. When the concentration A (number / μl) and the measured particle concentration B (number / μl) having a circle-equivalent diameter of 3 μm or more are represented by the following equation (3). Z = (1−B / A) × 100 (3)] and the number-based cumulative value Y of particles having a circularity of 0.950 or more
And the toner weight average diameter X satisfy the following formula (4); the number-based cumulative value of particles having a circularity of 0.950 or more Y ≧ exp 5.51 × X ^−0.645 (4) [However, the toner weight average particle Diameter X: 5.0-12.0μ
m] or b) the relationship between the cut ratio Z and the toner weight average diameter X satisfies the following expression (5), and the cut ratio Z> 5.3 × X (5) and the particles having a circularity of 0.950 or more Number-based cumulative value Y
And the toner weight average diameter X satisfy the following expression (6); the number-based cumulative value of particles having a circularity of 0.950 or more Y ≧ exp 5.37 × X ^−0.545 (6) [However, toner weight average particles Diameter X: 5.0-12.0μ
m].

Further, according to the present invention, an electrostatic image is formed on an electrostatic image holder, and the electrostatic image is developed with a dry toner held in a developing means to form a toner image. Is transferred to a transfer material with or without an intermediate transfer agent, and a toner image on the transfer material is fixed to the transfer material by a heat and pressure fixing unit. Toner particles having a resin and magnetic iron oxide, and particles having a free iron element are the toner particles 1
There are 100 to 350 particles per 0000 particles, the weight average particle diameter of the toner is 5 μm to 12 μm, and the circularity a obtained from the following formula (1) is 0. 90% by number or more based on the number of particles of 900 or more, and circularity a = L ₀ / L (1) [where L ₀ represents the circumference of a circle having the same projected area as the particle image, and L represents Indicates the perimeter of the particle image. And a) the relationship between the cut rate Z and the toner weight average diameter X satisfies the following expression (2), and the cut rate Z ≦ 5.3 × X (2) [However, the cut rate Z is the particle of all the measured particles. When the concentration A (number / μl) and the measured particle concentration B (number / μl) having a circle-equivalent diameter of 3 μm or more are represented by the following equation (3). Z = (1−B / A) × 100 (3)] and the number-based cumulative value Y of particles having a circularity of 0.950 or more
And the toner weight average diameter X satisfy the following formula (4); the number-based cumulative value of particles having a circularity of 0.950 or more Y ≧ exp 5.51 × X ^−0.645 (4) [However, the toner weight average particle Diameter X: 5.0-12.0μ
m] or b) the relationship between the cut ratio Z and the toner weight average diameter X satisfies the following expression (5), and the cut ratio Z> 5.3 × X (5) and the particles having a circularity of 0.950 or more Number-based cumulative value Y
And the toner weight average diameter X satisfy the following expression (6); the number-based cumulative value of particles having a circularity of 0.950 or more Y ≧ exp 5.37 × X ^−0.545 (6) [However, toner weight average particles Diameter X: 5.0-12.0μ
m].

Further, the present invention provides an electrostatic image carrier, developing means for developing the electrostatic image formed on the electrostatic image carrier with dry toner, and a container for holding the dry toner. A process cartridge having a configuration in which the electrostatic image carrier, the developing means, and the container are integrally supported, and the process cartridge is detachable from an image forming apparatus main body, and the toner Comprises toner particles having at least a binder resin and magnetic iron oxide, and particles having free iron elements are
100 to 350 particles per 000 particles, the weight average particle diameter of the toner is 5 μm to 12 μm, and the circularity a determined by the following formula (1) is 0.900 or more in particles of 3 μm or more of the toner. 90 particles based on the number
% Or more, circularity a = L ₀ / L (1) [where L ₀ indicates the circumference of a circle having the same projected area as the particle image, and L indicates the circumference of the particle image. And a) the relationship between the cut rate Z and the toner weight average diameter X satisfies the following expression (2), and the cut rate Z ≦ 5.3 × X (2) [However, the cut rate Z is the particle of all the measured particles. When the concentration A (number / μl) and the measured particle concentration B (number / μl) having a circle-equivalent diameter of 3 μm or more are represented by the following equation (3). Z = (1−B / A) × 100 (3)] and the number-based cumulative value Y of particles having a circularity of 0.950 or more
And the toner weight average diameter X satisfy the following formula (4); the number-based cumulative value of particles having a circularity of 0.950 or more Y ≧ exp 5.51 × X ^−0.645 (4) [However, the toner weight average particle Diameter X: 5.0-12.0μ
m] or b) the relationship between the cut rate Z and the toner weight average diameter X satisfies the following formula (5), the cut rate Z> 5.3 × X (5), and the particles having a circularity of 0.950 or more Number-based cumulative value Y
And the toner weight average diameter X satisfy the following expression (6); the number-based cumulative value of particles having a circularity of 0.950 or more Y ≧ exp 5.37 × X ^−0.545 (6) [However, toner weight average particles Diameter X: 5.0-12.0μ
m].

[0036]

BEST MODE FOR CARRYING OUT THE INVENTION The present inventors have studied the amount and shape of a free magnetic substance in a toner produced by a pulverization method and the constituent materials of a toner, and have determined the amount of a free magnetic substance in a toner, It has been found that transferability and developability are closely related.

The toner of the present invention has improved transfer efficiency without impairing the fixability, can stably provide high image quality even when used under high and low humidity, and does not cause image defects over time. I found that.

The dry toner of the present invention contains at least a binder resin and a magnetic iron oxide, and particles having a free iron element are present in an amount of 100 to 10,000 per 10,000 toner particles.
350, preferably 100 to 300, preferably 12
The number is preferably 0 to 250, more preferably 120 to 200.

The number of particles having the free iron element is 30
If the number is more than 0, the charge leakage of the toner tends to occur through the released particles, and as a result, the charge amount of the toner is reduced. In addition, a toner having a low charge amount causes an increase in fog, a low transfer efficiency, and poor charging, which adversely affects the developability. further,
Adhesion of toner to the toner carrier increases, and frictional charging and charging ability are impaired to cause poor charging, with the result that the developability is adversely affected. On the other hand, when the number of particles having the released iron element is less than 100, it indicates that the magnetic iron oxide particles in the toner are not substantially released. Although the toner that has almost no separation has a high charge amount, charge-up is likely to occur when a large number of images are formed by a high-speed machine, particularly when a large number of images are formed under low temperature and low humidity. Tends to decrease. By controlling the number of particles having the liberated iron element to be in the range of 100 to 300, it is possible to obtain a toner which is easy to control the charging, makes the charging uniform, and has stable charging durability.

Next, a method for measuring the number of particles having a free iron element in the present invention will be described.

Here, the “number of particles having a free iron element” means a particle analyzer (PT1000:
Yokogawa Electric Corp.), and the particle analyzer was Japan Hardcopy 9
The measurement is performed according to the principle described on pages 65 to 68 of the collection of seven papers. Specifically, the device introduces toner fine particles one by one into the plasma, and from the emission spectrum of the fine particles, the element of the luminescent substance,
It is a device that can know the number of particles and the particle size of the particles. For example, consider the case where toner particles are introduced into the plasma.
Light emission of carbon, which is a constituent element of the binder resin, and light emission of iron atoms in the magnetic iron oxide particles are observed. Since one light emission is obtained for one toner particle, the number of toner particles can be obtained from the number of times of light emission. At that time, iron atoms emitted within 2.6 msec from emission of carbon atoms were regarded as iron atoms that simultaneously emitted light, and subsequent emission of iron atoms was assumed to be emission of only iron atoms.

Since the toner of the present invention contains magnetic iron oxide particles, simultaneous emission of carbon atoms and iron atoms means that magnetic iron oxide particles are dispersed in the toner particles. The emission of only atoms can be said to be that the magnetic iron oxide particles are separated from the toner particles. As a specific method, the toner sample conditioned by leaving it overnight in an environment of a temperature of 23 ° C. and a humidity of 60% is subjected to 0.1% in the above environment.
It is measured using helium gas containing oxygen. Channel 1 measures carbon atoms (measuring wavelength 247.86 nm, K factor uses recommended values) and channel 2 measures iron atoms (measuring wavelength 239.56 nm, K factor 3.33764). Emission number of 1000-1
Sampling is performed so that the number becomes 400, the scan is repeated until the total number of emitted carbon atoms becomes 10,000 or more, and the number of emitted light is integrated. At this time, it is important that the particle size distribution curve has one maximum and the valley does not exist, the particle size distribution curve having the number of light emission of the element on the vertical axis and the cube root voltage representing the particle diameter of the particle on the horizontal axis. . Then, the emission number of only iron atoms at that time was counted to determine the number of particles having the iron element liberated. The noise cut level at this time is 1.50V. In addition, an azo-based iron compound which is a charge control agent contained in the toner may also contain an iron atom, but since these control agents are organometallic compounds, it is impossible to emit light only from the iron atom. .

Further, it is conceivable that the charge control agent is released, but it can be ignored because it is very small at 1 to 3% as compared with the amount of the binder resin and the magnetic iron oxide particles in the toner particles. . Therefore, it can be considered that the emission of carbon atoms and iron atoms measured by this apparatus is emission of only the binder resin and the magnetic iron oxide particles.

Further, the toner of the present invention is manufactured by, for example, a toner manufacturing method described below to reduce the circularity of toner particles of 3 μm or more and the number of free magnetic iron oxide particles to 10 μm.
It can be controlled in the range of 0 to 300.

The average circularity in the present invention is used as a simple method for quantitatively expressing the shape of particles. In the present invention, the average circularity is measured using a flow particle image analyzer FPIA-1000 manufactured by Toa Medical Electronics. And the circularity of the measured particles is determined by the following equation (1), and the value obtained by dividing the sum of the circularities of all the particles measured by the following equation (8) by the total number of particles is used as the average circularity. Defined as degrees.

Circularity a = L ₀ / L (1) [where L ₀ indicates the circumference of a circle having the same projected area as the particle image, and L indicates the circumference of the particle image. ]

[0047]

(Equation 1)

[0048]

[0049]

(Equation 2)

The degree of circularity used in the present invention is an index of the degree of unevenness of the toner particles. The degree of circularity is 1.00 when the toner is perfectly spherical, and the circularity becomes smaller as the surface shape becomes more complicated. In addition, the SD of the circularity distribution in the present invention
Is an index of the variation, and the smaller the numerical value, the smaller the variation of the toner shape.

The measuring device used in the present invention, "FP"
IA-1000 "is a class obtained by calculating the circularity of each particle, and then calculating the average circularity and the circularity standard deviation. And a calculation method of calculating the average circularity and the circularity standard deviation using the center value and the frequency of the division points. However, each value of the average circularity and circularity standard deviation calculated by this calculation method, and the error of the average circularity and circularity standard deviation calculated by the above-described calculation formula that directly uses the circularity of each particle, Very small and substantially negligible. In the present invention, the circularity of each particle described above is directly calculated for data handling reasons such as shortening of calculation time and simplification of calculation formula. Such a calculation method partially modified using the concept of the calculation formula to be used may be used.

Conventionally, it has been known that the shape of the toner affects various characteristics of the toner. However, the present inventors have made various studies to determine the shape of the toner of 3 μm or more and the amount of the magnetic iron oxide particles released. Has greatly affected transferability and developability. In addition, the present inventors have found that when a group of particles having a circle equivalent diameter of less than 3 μm exceeds a certain amount, transferability,
It has also been found that this is a factor that lowers the developability. Particle size 3
When the amount of the fine powder of the toner having a particle diameter of less than 3 μm or the amount of the external additive having a particle diameter of less than 3 μm is more than a certain amount, it is apparent that the desired performance is difficult to obtain unless the circularity of the toner having the particle diameter of 3 μm or more is further increased. .

Therefore, in the present invention, the degree of circularity of a group of particles having a circle equivalent diameter of 3 μm or more is important for exhibiting the effects of the present invention. However, in the present invention, transferability and developability are greatly affected. In order to more effectively exert the effect of the circularity of the toner particles having a size of 3 μm or more, it is necessary to use 3
It is necessary to control the degree of circularity of toner particles having a size of 3 μm or more based on the amount of fine particles having a size of not more than μm.

By controlling the circularity of toner particles having a size of 3 μm or more by controlling the amount of fine particles having a size of 3 μm or less, a toner having excellent transferability and developability can be obtained.

In the measurement of the circularity in the FPIA-1000, the smaller the particle diameter, the closer the particle image is to a point, so that the circularity tends to increase. For this reason,
When a large amount of particles having a small particle diameter are present in the toner, the circularity of the toner increases. Conversely, when only a small amount of particles having a small particle diameter are present in the toner, the circularity of the toner is reduced. Therefore, as calculated by the following equation (3), the cut rate Z expressed by subtracting the ratio of the particle concentration of the particle group having a circle equivalent diameter of 3 μm or more to the particle concentration of all the measured particles from 100% is calculated.
And the relationship between the weight average particle size X and the weight average particle diameter X are divided into two cases of Expression (2) or Expression (5).
The relationship between the circularity of the toner and the weight-average particle size required to satisfy the desired performance was derived as in the equation (4) or (6).

Cut ratio Z = (1−B / A) × 100 (3) [where A represents the particle concentration of all the measured particles, and B represents 3 μm.
The particle concentration of the particle group having the above-mentioned circle equivalent diameter is shown.]

In a toner containing a small amount of particles having a particle size of less than 3 μm, the circularity of the particles having a particle size of 3 μm or more is 0.9.
The cumulative value Y based on the number of particles of 50 or more is a weight average diameter X
Exp 5.51 × X ^−0.645 (≒ 247.15
1 × X ^−0.645 ) or more, but in a toner containing a large amount of particles of less than 3 μm, the number-based cumulative value Y of the particles having a circularity of 0.950 or more in the particles of 3 μm or more is Larger ex than weight average diameter X
p 5.37 × X ^−0.545 or more.

The toner of the present invention contains 90% or more of particles having a circularity a of 0.900 or more in particles having a particle size of 3 μm or more of 0.900 or more, and has a circularity a of 0.9 or more.
50 or more particles are the cumulative value based on the number, and a) Cut ratio Z
And the toner weight average diameter X, the cut rate Z ≦ 5.3 × X
(Preferably 0 <cut ratio Z ≦ 5.3 × X), the number-based cumulative value Y ≧ exp5.51 × X− ^0.645.
Is preferably satisfied.

Alternatively, the toner of the present invention has a 3 μm
The particles having a circularity a of 0.900 or more in particles of m or more contain 90% or more in terms of the number-based cumulative value, and the circularity a
Is a cumulative value based on the number, and b) the relationship between the cut rate Z and the toner weight average diameter X is the cut rate Z>
5.3 × X (preferably 95 ≧ cut ratio Z> 5.3 ×
X), the number-based cumulative value Y ≧ exp5.
It is preferable to satisfy 37 × X ^−0.545 . [However, the cut rate Z is determined by the flow particle image analyzer F manufactured by Toa Medical Electronics.
Particle concentration A of all measured particles measured by PIA-1000
(Number / μl), measurement particle concentration B with a circle equivalent diameter of 3 μm or more
When expressed as (number / μl), it is represented by the following equation (3): Z = (1−B / A) × 100 (3) The toner weight average particle diameter X is 5.0 to 12.0 μm. ]

When the toner has such a circularity,
The toner is easy to control charging, and can achieve uniform charging and stable charging durability. Further, it has been found that when the circularity is as described above, the transfer efficiency is increased.
This is because, in the case of the toner having the circularity as described above, the contact area between the toner particles and the photoconductor is reduced, and the adhesion of the toner particles to the photoconductor due to van der Waals force or the like is reduced. It is believed that there is. Furthermore, since the specific surface area of such toner particles is smaller than that of the toner pulverized by a conventional impingement air-flow pulverizer, the contact area between the toner particles is reduced, and the bulk density of the toner powder is increased. In addition, heat conduction at the time of fixing can be improved, and an effect of improving fixability can be obtained.

Further, when the number of particles having a circularity a of 0.900 or more in particles having a particle size of 3 μm or more is less than 90% as a cumulative value on a number basis, the magnetic oxide having released the charge leakage of the toner is released. It easily occurs through iron particles, and even if the amount of free magnetic iron oxide particles is controlled, the charge amount of the toner may decrease as a result. Also,
Since the contact area between the toner particles and the photoreceptor increases, and the adhesion of the toner particles to the photoreceptor increases, it becomes difficult to obtain sufficient transfer efficiency.

Further, the particles having a circularity a of 0.950 or more among the particles having a particle size of 3 μm or more are cumulative values based on the number. A) The relationship between the cut rate Z and the toner weight average diameter X is as follows. 0.3 × X (preferably 0 <cut ratio Z ≦ 5.
3 × X), and the number-based cumulative value Y ≧ exp5.
51 × X ^−0.645 is not satisfied, that is, the number-based cumulative value Y <exp 5.51 × X ^−0.645 is satisfied; or the circularity a of the toner particles of 3 μm or more is 0.950 or more. Is the cumulative value based on the number, b
> The relationship between the cut rate Z and the toner weight average diameter X is the cut rate Z
> 5.3 × X (preferably 95 ≧ cut ratio Z> 5.3 × X
X), and the number-based cumulative value Y ≧ exp5.37
If the value does not satisfy × X ^−0.545 , for example, if the number-based cumulative value Y <exp 5.37 × X ^−0.545 is satisfied, not only sufficient transfer efficiency cannot be obtained but also the fluidity of the toner decreases. And the desired fixing performance is hardly obtained.

When producing a toner having a specific circularity, the weight average diameter is preferably 5 to 12 μm.

More preferably, the weight average diameter is 5 to 10 μm.
m, 40% by number or less of particles having a particle size of 4.0 μm or less, and 25% by volume or less of particles having a particle size of 10.1 μm or more.

To obtain a toner having a weight average diameter of more than 12 μm, it is possible to cope with the particle size by reducing the load in the pulverizer as much as possible or by increasing the amount of processing, but the shape is square. Therefore, it is difficult to obtain a desired circularity, and it is difficult to obtain a desired circularity distribution.

In order to obtain a toner having a weight average diameter of less than 5 μm, it is possible to cope with the problem by increasing the load in the pulverizer or by extremely reducing the processing amount. It is not only difficult to obtain a desired circularity distribution, but also it is difficult to suppress the generation of fine powder and ultrafine powder.

The toner of the present invention contains particles having a circularity a of 0.900 or more in particles having a particle size of 3 μm or more of 90% or more in terms of the number-based cumulative value.
50 or more particles are the cumulative value based on the number, and a) Cut ratio Z
And the toner weight average diameter X, the cut rate Z ≦ 5.3 × X
(Preferably, 0 <cut ratio Z ≦ 5.3 × X) The number-based cumulative value Y ≧ exp5.51 × X ^−0.645 is satisfied, and more preferably the number-based cumulative value ex
p4.85 × X ^−0.187 ≧ Y <exp 5.51 × X ^−0.645
It is. Alternatively, in the toner of the present invention, particles having a circularity a of 0.950 or more in particles having a particle size of 3 μm or more are cumulative values based on the number. B) The relationship between the cut rate Z and the toner weight average diameter X is represented by the cut rate Z. > 5.3 × X (preferably 95 ≧
When the formula of cut rate Z> 5.3 × X) is satisfied, the number-based cumulative value exp 4.85 × X ^−0.187 ≧ Y ≧ exp 5.37
× X ^-0.545 . When the toner has such a circularity, it is possible to obtain a toner which is easy to control charging, has uniform charging, and has stable charging durability. Further, when the circularity is as described above, the transfer efficiency can be increased. This is because, in the case of the toner having the circularity as described above, the contact area between the toner particles and the photoconductor is reduced, and the adhesion of the toner particles to the photoconductor due to van der Waals force or the like is reduced. it is conceivable that. further,
Since the specific surface area of the toner particles is reduced as compared with the toner pulverized by the conventional collision type air pulverizer,
The contact area between the toner particles is reduced, the bulk density of the toner powder is increased, the heat conduction at the time of fixing can be improved, and the effect of improving the fixing property can be obtained.

When a toner having a particle size of 4.0 μm or less exceeding 40% by number can be obtained, it is possible to cope by increasing the load in the pulverizer or by extremely reducing the processing amount. It is difficult to obtain a desired circularity by approximating a spherical shape, and it is also difficult to obtain a desired circularity distribution.

25% by volume of particles having a particle size of 10.1 μm or more
In order to obtain a toner having a particle size exceeding that of the above, it is possible to cope with the particle size by reducing the load in the pulverizer as much as possible or by increasing the processing amount, but the shape becomes angular and the desired circularity cannot be obtained. It is difficult to achieve a desired circularity distribution.

As one measure of such variation of the particles having each circularity, the circularity standard deviation SD can be used. In the present invention, there is no problem if the circularity standard deviation SD is 0.030 to 0.045.

As a specific measuring method, 0.1 to 0.5 ml of a surfactant (preferably an alkylbenzene sulfonate) is added as a dispersant to 100 to 150 ml of water from which impurities have been removed in a container in advance, and Set the measurement sample to 0.
Add about 1-0.5 g. The suspension in which the sample was dispersed was irradiated with ultrasonic waves (50 kHz, 120 W) for 1 to 3 minutes, the concentration of the dispersion was adjusted to 1.2 to 20 thousand / μl, and the above-mentioned flow type particle image measuring apparatus was used. 0.60 μm or more 159.2
The circularity distribution of particles having a circle equivalent diameter of less than 1 μm is measured. By setting the concentration of the dispersion liquid to 12 to 20 thousand particles / μl, it is possible to maintain a particle concentration that can maintain the accuracy of the apparatus even when the cut rate increases.

The outline of the measurement is described in the catalog of FPIA-1000 (June 1995 version) issued by Toa Medical Electronics Co., Ltd., the operation manual of the measuring apparatus, and Japanese Patent Application Laid-Open No. 8-136.
No. 439. The measuring method will be described below.

The sample dispersion liquid is passed through a flow path (spread along the flow direction) of a flat and flat flow cell (about 200 μm thick). The strobe and the CC are connected so as to form an optical path that intersects with the thickness of the flow cell.
The D cameras are mounted so as to be located on opposite sides of the flow cell. While the sample dispersion is flowing,
Strobe light is applied at 1/30 second intervals to obtain an image of the particles flowing through the flow cell, so that each particle is captured as a two-dimensional image having a range parallel to the flow cell. The diameter of a circle having the same area is calculated as the equivalent circle diameter from the area of the two-dimensional image of each particle. The circularity of each particle is calculated from the projected area of the two-dimensional image of each particle and the perimeter of the projected image using the above-described circularity calculation formula.

Next, the binder resin used in the toner of the present invention will be described.

The binder resin used in the present invention has an acid value of from 1 to 1.
It is preferably 100 mgKOH / g, more preferably 1 to 50 mgKOH / g, and particularly preferably 2 to 4 mgKOH / g.
It is preferably 0 mgKOH / g.

When the acid value is not in such a range, the dispersion state of the toner raw materials, particularly the magnetic iron oxide particles, is deteriorated in the kneading step in the production of the toner, and the free magnetic iron oxide particles are likely to increase in the pulverizing step.

If the acid value of the binder resin is less than 1 mgKOH / g, the chargeability of the toner particles decreases, and the developability and durability stability decrease. On the other hand, if it exceeds 100 mgKOH / g, the binder resin has a high hygroscopicity, the image density tends to decrease, and the fog tends to increase.

In the present invention, the acid value of the binder resin is determined by the following method.

The basic operation of measuring the acid value is in accordance with JIS K-0070. 1) 0.5-2.0 (g) of the crushed binder resin is precisely weighed,
The weight of the binder resin is W (g). 2) The sample is placed in a 300 (ml) beaker, and 150 (ml) of a mixed solution of toluene / ethanol (4/1) is added and dissolved. 3) Titration using a 0.1N KOH methanol solution using a potentiometric titrator (for example, a potentiometric titrator AT-400 manufactured by Kyoto Electronics Co., Ltd. (win wor)
kstation) and automatic titration with an ABP-410 motorized burette. 4) At this time, the used amount of the KOH solution was defined as S (ml), and at the same time, a blank was measured.
(Ml). 5) Calculate the acid value by the following equation. f is a factor of KOH.

Acid value (mgKOH / g) = ((S−B) ×
f × 5.61) / W

As the binder resin, a vinyl polymer having a carboxyl group or an acid anhydride group, a polyester resin or the like can be used.

The following are examples of monomers for forming the vinyl polymer used as the binder resin.

For example, unsaturated dibasic acids such as maleic acid, citraconic acid, dimethyl maleic acid, itaconic acid, alkenyl succinic acid, fumaric acid, metaconic acid, dimethyl fumaric acid and anhydrides thereof. Further, monoesters of the above unsaturated dibasic acids. Α, β-unsaturated acids such as acrylic acid, methacrylic acid, crotonic acid, and cinnamic acid and anhydrides thereof; and the α, β-unsaturated dibasic acid and the α, β-unsaturated monoacid. Anhydrides and anhydrides of the above unsaturated acids and lower fatty acids. Alkenyl malonic acid, alkenyl glutaric acid, alkenyl adipic acid and their anhydrides and their monoesters. Among these, maleic acid, maleic acid half ester and maleic anhydride are particularly preferably used as monomers for obtaining the binder resin of the present invention.

Further, examples of the comonomer for producing the vinyl polymer include the following.

For example, styrene; o-methylstyrene, m
-Methylstyrene, p-methylstyrene, p-methoxystyrene, p-phenylstyrene, p-chlorostyrene, 3,4-dichlorostyrene, p-ethylstyrene,
2,4-dimethylstyrene, pn-butylstyrene,
Styrene derivatives such as p-tert-butylstyrene, pn-hexylstyrene, pn-octylstyrene, pn-nonylstyrene, pn-decylstyrene, pn-dodecylstyrene; ethylene, propylene, Ethylenically unsaturated monoolefins such as butylene and isobutylene; unsaturated polyenes such as butadiene; vinyl halides such as vinyl chloride, vinylidene chloride, vinyl bromide and vinyl fluoride; vinyl acetate, vinyl propionate;
Vinyl esters such as vinyl benzoate; methyl methacrylate, ethyl methacrylate, propyl methacrylate, n-butyl methacrylate, isobutyl methacrylate, n-octyl methacrylate, dodecyl methacrylate, 2-ethylhexyl methacrylate, methacrylic acid Α-methylene aliphatic monocarboxylic esters such as stearyl, phenyl methacrylate, dimethylaminoethyl methacrylate, diethylaminoethyl methacrylate;
Methyl acrylate, ethyl acrylate, acrylic acid n-
Butyl, isobutyl acrylate, propyl acrylate,
Acrylic esters such as n-octyl acrylate, dodecyl acrylate, 2-ethylhexyl acrylate, stearyl acrylate, 2-chloroethyl acrylate and phenyl acrylate; vinyl ethers such as vinyl methyl ether, vinyl ethyl ether and vinyl isobutyl ether Vinyl ketones such as vinyl methyl ketone, vinyl hexyl ketone and methyl isopropenyl ketone; N-vinyl pyrrole, N-vinyl carbazole, N
N- such as vinylindole and N-vinylpyrrolidone
Vinyl compound; vinyl naphthalene; acrylonitrile,
Acrylic acid derivatives such as methacrylonitrile and acrylamide or methacrylic acid derivatives; esters of the aforementioned α, β-unsaturated acids and diesters of dibasic acids. These vinyl monomers are used alone or in combination of two or more.

Among these, a combination of monomers that results in a styrene-based copolymer or a styrene-acrylic-based copolymer is preferred.

As the crosslinkable monomer, mainly 2
A monomer having two or more polymerizable double bonds is used.

The binder resin used in the present invention may be a polymer cross-linked with a cross-linkable monomer as exemplified below, if necessary.

Aromatic divinyl compounds (eg, divinylbenzene, divinylnaphthalene, etc.); diacrylate compounds linked by an alkyl chain (eg, ethylene glycol diacrylate, 1,3-butylene glycol diacrylate, 1,4-butane) Diol diacrylate,
1,5-pentanediol diacrylate, 1,6-hexanediol diacrylate, neopentyl glycol diacrylate and acrylates of the above compounds replaced with methacrylate); diacrylate linked by an alkyl chain containing an ether bond Compounds (eg,
Diethylene glycol diacrylate, triethylene glycol diacrylate, tetraethylene glycol diacrylate, tetraethylene glycol diacrylate, polyethylene glycol # 400 diacrylate,
Polyethylene glycol # 600 diacrylate, dipropylene glycol diacrylate and acrylates of the above compounds replaced with methacrylate); diacrylate compounds linked by a chain containing an aromatic group and an ether bond (for example, polyoxyethylene (2) -2,
2-bis (4-hydroxydiphenyl) propane diacrylate, polyoxyethylene (4) -2,2-bis (4
-Hydrodiphenyl) propane diacrylate and
Polyacrylate diacrylate compounds (for example, trade name MANDA (Nippon Kayaku)) in which the acrylate of the above compound is replaced with methacrylate).
Examples of polyfunctional crosslinking agents include pentaerythritol triacrylate, trimethylolethane triacrylate,
Trimethylolpropane triacrylate, tetramethylol methanetetraacrylate, oligoester acrylate and those obtained by replacing the acrylate of the above compound with methacrylate; triallyl cyanurate and triallyl trimellitate.

These cross-linking agents can be used in combination with other monomer components 10
It is preferable to use about 0.01 to 5 parts by mass (more preferably about 0.03 to 3 parts by mass) with respect to 0 parts by mass.

As the type of the agent and the polymerization initiator for polymerizing the vinyl monomer, benzoyl peroxide,
1,1-di (t-butylperoxy) -3,3,5-trimethylcyclohexane, n-butyl-4,4-di (t
-Butylperoxy) valerate, dicumyl peroxide, α, α'-bis (t-butylperoxydiisopropyl) benzene, t-butylperoxycumene, di-t
Organic peroxides such as -butyl peroxide; azo and diazo compounds such as azobisisobutyronitrile and diazoaminoazobenzene.

As a method for synthesizing the binder resin, a bulk polymerization method, a solution polymerization method, a suspension polymerization method, and an emulsion polymerization method can be used.

The toner of the present invention preferably has a main peak in the molecular weight distribution of 2,000 to 25,000 in the molecular weight distribution of THF-soluble components by GPC, more preferably 5,000 to 20,000, It is preferable that the main peak exists in the region of 000. Further, the soluble component of THF contains 50 to 90% of components having a molecular weight of 100,000 or less.
Is preferred. Main peak molecular weight 20
If it is less than 00, the toner cannot have appropriate elasticity, so that the fixing property is improved, but the durability as the toner is reduced. Therefore, as the end of the durability increases, the magnetic iron oxide particles are likely to be missing from the toner particles,
As a result, developability tends to decrease in the latter half of durability. When the molecular weight of the main peak is less than 2,000, the storage stability of the toner is also reduced. Main peak molecular weight 25,000
If it is larger, the fixability decreases.

Thus, the GP content of the THF soluble portion of the toner
In the molecular weight distribution due to C, the toner having such peaks has a good balance of fixing property, anti-offset property and storage stability.

In order to produce a toner having a desired molecular weight distribution, the binder resin has a molecular weight of 2,000 to 25,000.
It is preferable to have a main peak in the region of 0.

If the molecular weight distribution does not have such a peak, the resin cannot have appropriate elasticity, so that kneading shear cannot be applied during melt-kneading in the production of toner, and the dispersibility of the raw materials decreases. In the pulverizing step, the magnetic iron oxide particles are easily released from the toner particles. Further, the lowering of the dispersibility of the raw materials lowers both the fixing property and the durability stability.

In the present invention, the T of the toner and the binder resin
The molecular weight distribution of the HF-soluble component by GPC using THF as a solvent is measured under the following conditions.

The column was cooled in a heat chamber at 40 ° C.
And the column at this temperature was treated with THF as solvent.
At a flow rate of 1 ml per minute, and the THF sample solution is
Inject μl and measure. When measuring the molecular weight of a sample
The molecular weight distribution of the sample was measured using several monodisperse polystyrene standards.
The body value and the count value of the calibration curve created by the quasi sample
It calculated from the relationship. Standard polystyrene for creating calibration curves
As the sample, for example, Tosoh Corporation or Showa Denko Corporation
Has a molecular weight of 10^Two-10⁷Use something at least,
It is appropriate to use about 10 standard polystyrene samples.
is there. As the detector, an RI (refractive index) detector is used. column
Set of multiple commercially available polystyrene gel columns
It is good to match, for example, showex made by Showa Denko
 GPCKF-801,802,803,804,80
5,806,807,800P combination and Tosoh Corporation
TSKgel G1000H (H_XL), G2000
H (H_XL), G3000H (H_XL), G4000H (H
_XL), G5000H (H _XL), G6000H (H_XL),
G7000H (H_XL), TSKguard column
Can be mentioned.

A sample is prepared as follows.

After placing the sample in THF and leaving it to stand for several hours, it is shaken well, mixed well with THF (until the sample is no longer united), and left still for 12 hours or more. Then TH
The time of leaving in F is set to 24 hours or more. After that, sample processing filter (pore size 0.2 ~
0.5 μm, for example, Mysholi Disc H-25-2
(Made by Tosoh Corporation). ) Is used as a GPC sample. In addition, the sample concentration was 0.1% for the resin component.
Adjust to 5-5 mg / ml.

The toner has a glass transition temperature (Tg) of from 45 to 75 ° C., preferably from 50 to 70 ° C., from the viewpoint of the storage stability of the toner. Is easily deteriorated, and an offset is easily generated at the time of fixing. Also, the Tg of the toner is 75 ° C.
If the ratio exceeds the range, the fixability tends to decrease.

Next, the magnetic iron oxide particles will be described.

Examples of the magnetic iron oxide particles used in the present invention include magnetic iron oxides such as magnetite, maghemite, and ferrite having a surface containing iron or an oxide or hydroxide of a different element, and mixtures thereof. As described above, by containing an oxide or a hydroxide, preferably an oxide or a hydroxide of a non-ferrous element, on the surface of the magnetic iron oxide particles, the affinity for the binder resin is good and the dispersibility is very high. Therefore, free magnetic iron oxide particles are less likely to be generated in the pulverizing step in the production of toner particles. As a result, transfer efficiency is improved, and high image quality is stably obtained even when used under high and low humidity. As a result, it is possible to obtain a toner which does not cause image defects over time, and it also contributes to controlling the charge of the free magnetic iron oxide particles. Among them, lithium, beryllium, boron, magnesium, aluminum, silicon, phosphorus, germanium, titanium, zirconium, tin, lead, zinc, calcium, barium, scandium, vanadium, chromium, manganese, cobalt,
Copper, nickel, gallium, cadmium, indium,
Magnetic oxide containing oxide or hydroxide of at least one element selected from silver, palladium, gold, mercury, platinum, tungsten, molybdenum, niobium, osmium, strontium, yttrium, technetium, ruthenium, rhodium, bismuth It is preferably iron particles.

In the present invention, the abundance of the oxide or hydroxide of iron or a different element on the surface of the magnetic iron oxide particles can be represented by the degree of hydrophobicity of the magnetic iron oxide particles. In the case of magnetic iron oxide particles, it can be said that iron or oxides or hydroxides of iron or a different element, which can maintain the above performance, exist on the surface.

The degree of hydrophobicity of the magnetic iron oxide particles in the present invention is measured by the following method.

The degree of hydrophobicity of the magnetic iron oxide particles was measured by a methanol titration test. The measurement of the degree of hydrophobicity using methanol is performed as follows. 0.1 g of magnetic iron oxide particles are added to a 250 ml beaker containing 50 ml of distilled water. Then, methanol was poured 1.3 m from the bottom of the liquid.
Feed at a rate of 1 / min. At this time, it is preferable to supply the solution with gentle stirring. The end of sedimentation of the magnetic iron oxide particles is defined as the time when no suspended matter of the magnetic iron oxide particles is observed on the liquid surface, and the degree of hydrophobicity is determined by the volume of methanol in the methanol and water mixture at the time when the sedimentation ends. Expressed as a percentage.

When the magnetic iron oxide particles have a uniform particle size distribution, the dispersibility in the binder resin is improved, and the chargeability of the toner can be stabilized. In recent years, the toner particle diameter has been reduced, and even when the weight average particle diameter is 10 μm or less, charging uniformity is promoted, toner cohesion is reduced, and image density and fog are improved. Developability is improved. In particular, the effect is remarkable in a toner having a weight average particle diameter of 6.0 μm or less, and an extremely high-definition image can be obtained. It is preferable that the weight average particle diameter is 5 μm or more, since sufficient image density can be obtained.

The content of these different elements is preferably 0.05 to 10% by mass based on the iron element of the magnetic iron oxide particles. More preferably, it is 0.1 to 7% by mass, particularly preferably 0.2 to 5% by mass, further preferably 0.3 to 7% by mass.
4% by mass. If the content is less than 0.05% by mass, the effect of containing these elements cannot be obtained, and good dispersibility and uniform charging cannot be obtained. On the other hand, when the content is more than 10% by mass, the discharge of electric charge is increased and insufficient charging is caused, so that the image density may be lowered or fog may increase.

In the content distribution of these dissimilar elements, it is preferable that a large amount of the dissimilar elements be present closer to the surface of the magnetic particles. For example, the ratio (B / A) × the content B of the foreign element present when the iron element dissolution rate of the magnetic iron oxide particles is up to 20% by mass and the total content A of the foreign element in the magnetic iron oxide particles.
100 is preferably 40% or more. And 4
It is preferably from 0 to 80%, particularly preferably from 60 to 80%.
By increasing the surface abundance, the dispersion effect and the electric diffusion effect can be further improved. Further, the amount contained in the toner particles is preferably 20 to 200 parts by mass, more preferably 1 to 100 parts by mass of the binder resin.
40 to 150 parts by mass relative to 00 parts by mass is preferred.

In the toner of the present invention, the content of the silicon element in the magnetic iron oxide particles is 0.4 to 2.0 based on the iron element.
% By mass (more preferably 0.5 to 0.9% by mass), and Fe / Si on the outermost surface of the magnetic iron oxide particles.
Has an atomic ratio of 1.2 to 7.0, more preferably 1.2 to 7.0.
It is preferably 4.0.

Fe / S on the outermost surface of magnetic iron oxide particles
The atomic ratio of i is measured by X-ray photoelectron spectroscopy (XPS).

When the silicon element content is less than 0.4% by mass or the Fe / Si atomic ratio exceeds 7.0, the effect of improving the magnetic toner, particularly the degree of improvement in the fluidity of the magnetic toner, is reduced. Low. When the content of the silicon element is more than 2.0% by mass or the Fe / Si atomic ratio is less than 1.2, the chargeability is deteriorated in environmental characteristics, particularly in long-term storage under high humidity. Further, the durability of the magnetic toner and the dispersibility of the magnetic iron oxide particles in the binder resin are reduced, which causes the magnetic iron oxide particles to be released from the toner at the time of pulverization.

The amount of silicon atoms on the outermost surface of the magnetic iron oxide particles has a correlation with the fluidity and water absorption of the magnetic iron oxide particles, and affects the physical properties of the magnetic toner containing the magnetic iron oxide particles.

More preferably, the smoothness of the magnetic iron oxide particles satisfies 0.3 to 0.8, preferably 0.45 to 0.7, and more preferably 0.5 to 0.7. The smoothness is related to the amount of pores on the surface of the magnetic iron oxide particles. When the smoothness is less than 0.3, there are many pores on the surface of the magnetic iron oxide, and the adsorption of water is promoted. As described above, the adsorption site where the adsorbed water is difficult to desorb is more present, so that in the magnetic toner containing the magnetic iron oxide particles,
In particular, the charging characteristics are degraded during long-term storage under high humidity, and the recovery of the charging characteristics is delayed.

More preferably, the magnetic iron oxide particles have a bulk density of 0.8 g / cm ³ or more, preferably 1.0 g / cm ^3.
m ³ or more.

The magnetic iron oxide particles have a bulk density of 0.8 g / cm.
^When the ratio is less than ³ , the physical miscibility with other toner materials during the production of the toner is reduced, the dispersibility of the magnetic iron oxide particles is reduced, and the magnetic iron oxide particles are easily released from the toner particles during the production.

More preferably, B of the magnetic iron oxide particles
ET specific surface area of 15.0 m ² / g or less, preferably 1
2.0 m ² / g or less. When the BET specific surface area of the magnetic iron oxide particles exceeds 15.0 m ² / g, the water adsorption of the magnetic iron oxide particles increases, and the magnetic toner containing the magnetic iron oxide particles has high hygroscopicity and low chargeability. descend.

Further, the magnetic iron oxide particles used in the present invention have an aluminum hydroxide content of 0.01 to 2.0% by mass (more preferably 0.05 to 1.0% by mass) in terms of aluminum element. It is preferably treated with an aluminum compound such as a substance.

Although the reason is not clear, it has been confirmed that the treatment of the surface of the magnetic iron oxide particles with an aluminum compound can further stabilize the charging of the magnetic toner.

Further, the outermost surface of the magnetic iron oxide particles used in the present invention has an Fe / Al atomic ratio of 0.3 to 1
It is preferably 0.0 (more preferably 0.3 to 5.0, even more preferably 0.3 to 2.0). Fe / Al atomic ratio at the outermost surface of the magnetic iron oxide particles is 0.3 to 1
When the ratio is 0.0, the charging characteristics of the toner can be favorably maintained even under high humidity.

The magnetic iron oxide particles used in the present invention have an average particle size of 0.1 to 0.4 μm, preferably 0.1 to 0.4 μm.
It preferably has a thickness of about 0.3 μm.

The method for measuring various physical property data in the present invention will be described in detail below.

(1) Particle Size Distribution of Magnetic Toner The particle size distribution of the magnetic toner can be measured by various methods. In the present invention, the particle size distribution is measured using a Coulter counter. As a measuring device, Coulter Multisizer II
E (manufactured by Coulter) is used. As the electrolyte, about 1% NaCl aqueous solution is prepared using primary sodium chloride.
For example, ISOTON®-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 electrolytic solution in which the sample was suspended was subjected to a dispersion treatment for about 1 to 3 minutes by an ultrasonic disperser, and the volume and the number of toner particles were measured by using the measuring device, using a 100 μm aperture as an aperture, and the volume distribution. Calculate the number distribution. At this time, the measured data is obtained in a channel obtained by dividing the particle diameter of 1.59 to 64.0 μm into 256. The data obtained in 256 channels is 16
The weight-average particle diameter (D4) based on the weight obtained from the volume distribution according to the present invention, which is processed by the division (the median of each channel is a representative value for each channel), and the number based on the number obtained from the number distribution The number average particle size (D1), the weight-based coarse powder amount (10.1 μm or more) determined from the volume distribution, and the number-based fine powder number (4.00 μm or less) determined from the number distribution are determined.

(2) Half-width y of peak particle size x in number particle size distribution of magnetic toner 2 obtained by Coulter Multisizer IIE (manufactured by Coulter Corporation) measured by the particle size distribution of the magnetic toner.
The frequency% A at the time of the peak particle size x is calculated from the particle size distribution of 56 channels (see FIG. 23).

The frequency% A at the peak particle size x is half value A /
The particle size taking 2 is calculated from the particle size distribution, and is set as x1, x2.

At this time, the half value width can be obtained by y = x2-x1.

According to the Coulter counter, 256 channels
In the number-based particle size distribution measured in the above, it is preferable that the relationship of the half value width Y with respect to the peak particle size X satisfies 2.06x−9.113 ≦ y ≦ 2.06x−7.341 (7).

According to the coulter counter, 256 ch
In the number-based particle size distribution measured in the above, the relationship of the half width Y to the peak particle size X is Y> 2.06X−7.34.
In the case of 1, it means that this toner is a broad toner having a so-called particle size distribution in which the cumulative number of other particle sizes is larger than the cumulative number of peak particle sizes X. In the case of such a toner, the charge distribution of the toner varies, thereby deteriorating the developability, particularly the durability. Also, in the number-based particle size distribution measured at 256 ch by a Coulter counter,
The relation of the half value width Y to the peak particle size X is Y <2.06X
In the case of -9.113, this toner has a very sharp particle size distribution. To obtain a toner with a sharp particle size distribution, it is possible to manufacture by sharply cutting the fine powder and coarse powder in the classification process. Not realistic.

(3) Fe / Si atomic ratio, Fe / Al atomic ratio The Fe / Si atomic ratio and the Fe / Al atomic ratio on the outermost surface of the magnetic iron oxide particles are determined by XPS measurement. The conditions are as follows: XPS measuring apparatus: ESCALAB, 200-X manufactured by VG
Type X-ray photoelectron spectrometer X-ray source: Mg Kα (300 W) Analysis area: 2 × 3 mm

(4) Bulk Density The bulk density of the magnetic iron oxide particles is measured according to the pigment test method of JIS-K-5101.

(5) Smoothness The smoothness D of the magnetic iron oxide particles is determined as follows.

[0132]

(Equation 3)

(6) BET Specific Surface Area The BET specific surface area of the magnetic iron oxide particles is measured as follows.

The BET specific surface area was measured by Yuasa Ionics Co., Ltd., fully automatic gas adsorption amount measuring apparatus: Autosoap 1
And BET multipoint method using nitrogen as the adsorption gas. As pretreatment of the sample, degassing is performed at 50 ° C. for 10 hours.

(7) Average Particle Size and Surface Area of Magnetic Iron Oxide Particles The measurement of the average particle size and the calculation of the surface area of the magnetic iron oxide particles are performed as follows.

A transmission electron micrograph of the magnetic iron oxide particles was taken, and after arbitrarily selecting 250 particles of a 40,000-fold magnification, the Martin diameter of the projected diameters (the projected area in the fixed direction was divided into two equal parts) The length of a line segment to be measured) is measured, and this is represented by a number average diameter.

For the calculation of the surface area, it is assumed that the magnetic iron oxide is spherical with the average particle diameter being the diameter, and the density of the magnetic iron oxide is measured by an ordinary method to determine the value of the surface area.

[0138]

(Equation 4)

(8) Amount of Foreign Element The amount of the foreign element in the magnetic iron oxide particles of the present invention can be determined by using a fluorescent X-ray analyzer SYSTEM3080 (manufactured by Rigaku Corporation).
JIS K0119 "General rules for X-ray fluorescence analysis"
Is measured by performing fluorescent X-ray analysis according to the above.

The magnetic iron oxide particles having different elements are produced, for example, by the following method when they are silicon elements.

An aqueous solution of ferrous salt and F in the aqueous solution of ferrous iron
By passing an oxygen-containing gas through a ferrous salt reaction aqueous solution containing a ferrous hydroxide colloid obtained by reacting 0.90 to 0.99 equivalents of an aqueous alkali hydroxide solution with respect to e ²⁺ In producing the magnetite particles, either the aqueous alkali hydroxide solution or the ferrous salt containing the ferrous hydroxide colloid, the water-soluble silicate is previously contained in total in terms of silicon element with respect to iron element. Amount (0.
4 to 2.0% by mass), and 85 to 1%.
While heating in a temperature range of 00 ° C., an oxygen-containing gas is passed to cause an oxidation reaction, whereby magnetic iron oxide particles containing a silicon element are generated from the ferrous hydroxide colloid. Then, the Fe remaining in the suspension after the completion of the oxidation reaction
2.00 equivalents or more of alkali hydroxide aqueous solution and the remaining water-soluble silicate relative to ²⁺ [total content (0.4 to 2.0
Mass%) of 1 to 50%].
An oxidation reaction is performed while heating in a temperature range of ° C. to produce magnetic iron oxide particles containing silicon element. In the case of other elements, they can be obtained in the same manner by using a water-soluble salt of the corresponding element.

Next, in the case of treatment with aluminum hydroxide, a water-soluble aluminum salt is added to the alkaline suspension in which the magnetic iron oxide particles have been formed in an amount of 0.01 to 2 in terms of aluminum element. After the addition, the pH is adjusted to a range of 6 to 8 to precipitate aluminum hydroxide on the surface of the magnetic iron oxide particles. Then, the particles are filtered, washed with water, dried and crushed to obtain the magnetic iron oxide particles according to the present invention. Further, as a method for adjusting the smoothness and the specific surface area to a preferable range, it is preferable to perform compression, shearing, and spatula using a mix muller or a grinder.

Examples of the silicate compound to be added to the magnetic iron oxide particles used in the present invention include silicates such as commercially available sodium silicate and silicic acids such as sol silicic acid generated by hydrolysis.

Examples of the water-soluble aluminum salt to be added include aluminum sulfate.

As the ferrous salt, it is generally possible to use iron sulfate produced as a by-product in the production of titanium sulfate and iron sulfate produced as a by-product of cleaning the surface of a steel sheet. It is also possible to use iron chloride.

Other colorants that can be used in the magnetic toner include any suitable pigments or dyes.

For example, pigments include carbon black, aniline black, acetylene black, naphthol yellow, hansa yellow, rhodamine lake, alizarin lake, bengalah, phthalocyanine blue and indanthrene blue. These are used in an amount sufficient to maintain the optical density of the fixed image. It is preferable to use 0.1 to 20 parts by mass, preferably 1 to 10 parts by mass of the pigment based on 100 parts by mass of the resin. A dye is further used for the same purpose. For example, there are azo dyes, anthraquinone dyes, xanthene dyes, and methine dyes, and 0.1 to 20 parts by mass, preferably 0.3 to 10 parts by mass of the dye is preferably used for 100 parts by mass of the resin. .

The waxes used in the toner of the present invention include the following. For example, oxidation of aliphatic hydrocarbon wax such as low molecular weight polyethylene, low molecular weight polypropylene, polyolefin copolymer, polyolefin wax, microcrystalline wax, paraffin wax, Fischer-Tropsch wax; and aliphatic hydrocarbon wax such as polyethylene oxide wax. Or a block copolymer thereof; plant wax such as candelilla wax, carnauba wax, wood wax, jojoba wax; animal wax such as beeswax, lanolin, whale wax; minerals such as ozokerite, ceresin, petrolactam Waxes mainly containing fatty acid esters such as montanic acid ester wax and caster wax; and those obtained by partially or completely deoxidizing fatty acid esters such as deoxidized carnauba wax. That. Further, unsaturated linear fatty acids such as palmitic acid, stearic acid, montanic acid, or long-chain alkyl carboxylic acids having a longer-chain alkyl group; unsaturated fatty acids such as brassic acid, eleostearic acid, and barinaric acid; stearyl alcohol; Eicosyl alcohol, behenyl alcohol,
Saturated alcohols such as carnaubavir alcohol, seryl alcohol, melisyl alcohol, or long-chain alkyl alcohol having a longer-chain alkyl group; polyhydric alcohols such as sorbitol; linoleamide, oleic amide, lauric amide Aliphatic amides; saturated fatty acid bisamides such as methylenebisstearic acid amide, ethylenebiscapric acid amide, ethylenebislauric acid amide, hexamethylenebisstearic acid amide; ethylenebisoleic acid amide, hexamethylenebisoleic acid amide, N, N Unsaturated fatty acid amides such as' -dioleyl adipamide, N, N'-dioleyl sebacamide; aromatic bisamides such as m-xylene bis stearamide, N, N'-distearyl isophthalic amide ; Fatty acid metal salts such as calcium stearate, calcium laurate, zinc stearate, and magnesium stearate (commonly referred to as metal soaps); grafted onto aliphatic hydrocarbon waxes with vinyl monomers such as styrene and acrylic acid Waxes; partially esterified products of fatty acids such as behenic acid monoglyceride and polyhydric alcohols; and methyl ester compounds having a hydroxyl group obtained by hydrogenating vegetable oils and fats.

The wax preferably used is a polyolefin obtained by radical polymerization of an olefin under high pressure;
A polyolefin obtained by purifying a low-molecular-weight by-product obtained during polymerization of a high-molecular-weight polyolefin; a polyolefin polymerized under low pressure using a catalyst such as a Ziegler catalyst or a metallocene catalyst; a polyolefin polymerized by using radiation, electromagnetic waves or light; Low molecular weight polyolefin obtained by pyrolysis of polyolefin; paraffin wax, microcrystalline wax, Fischer-Tropsch wax; synthetic hydrocarbon wax synthesized by the gindol method, hydrocoll method, Aage method, etc .; A synthetic wax, a hydrocarbon wax having a functional group such as a hydroxyl group or a carboxyl group;
A mixture of a hydrocarbon wax and a wax having a functional group; a wax obtained by graft-modifying a vinyl monomer such as styrene, maleic ester, acrylate, methacrylate, or maleic anhydride using these waxes as a base.

Further, these waxes are used in a press sweating method,
Solvent method, recrystallization method, vacuum distillation method, supercritical gas extraction method or liquid crystal method using sharpened molecular weight distribution,
Those from which low molecular weight solid fatty acids, low molecular weight solid alcohols, low molecular weight solid compounds, and other impurities have been removed are also preferably used.

The wax used in the present invention has a melting point of 65 to 16 in order to balance the fixing property and the offset resistance.
The temperature is preferably 0 ° C, more preferably 65 to 130 ° C, and particularly preferably 70 to 120 ° C. If the temperature is lower than 65 ° C., the blocking resistance decreases, and if the temperature exceeds 160 ° C., the offset resistance effect is hardly exhibited.

In the toner of the present invention, the total content of these waxes is 0.2 to 100 parts by mass of the binder resin.
It is effective to use at 20 to 20 parts by mass, preferably 0.5 to 10 parts by mass. Further, other waxes may be used in combination as long as they do not adversely affect.

The melting point of the wax is defined as the temperature at the peak top of the maximum endothermic peak of the wax measured by DSC.

In the present invention, in the DSC measurement of the wax or the toner by the differential scanning calorimeter, for example, DSC-7 manufactured by PerkinElmer can be used.

The measuring method is as described in ASTM D3418-82.
Perform according to. The DSC curve used in the present invention is obtained by taking a pre-history by raising the temperature once, and then measuring the temperature by 10 ° C./min.
After the temperature is lowered in the range of 0 to 200 ° C., a DSC curve measured when the temperature is raised is used.

The toner of the present invention is preferably used by adding a charge control agent.

Examples of the negative charge control agent include JP-B-41-20.
No. 153, JP-B-42-27596, JP-B-44-6397, and JP-B-45-26478; metal complexes of monoazo dyes; and further described in JP-A-50-133838. Nitrohumic acid and its salts or C.I. I. Dyes and pigments such as 14645; JP-B-55-42752;
No. 1508, JP-B-58-7384, JP-B-59-7385, and Zn, Al, Co, Cr of salicylic acid, naphthoic acid and dicarboxylic acid.
Metal complexes of Fe or Zr; sulfonated copper phthalocyanine pigments; styrene oligomers having introduced nitro groups and halogens; chlorinated paraffins. In particular, an azo metal complex represented by the general formula (I) or a basic organic acid metal complex represented by the general formula (II), which has excellent dispersibility and is effective in stabilizing image density and reducing fog, preferable.

[0158]

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[0159]

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Among them, the azo-based metal complex represented by the above formula (I) is more preferable, and the azo-based iron complex represented by the following formula (III) or (IV) in which the central metal is Fe is most preferable.

[0161]

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[0162]

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Next, specific examples of the azo type iron complex represented by the above formula (III) are shown below.

[0164]

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[0165]

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[0166]

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The above formulas (I), (II) and (IV)
Specific examples of the charge control agent represented by are shown below.

[0168]

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[0169]

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[0170]

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These metal complex compounds can be used alone or in combination of two or more.

The amount of the charge control agent used is 0.1 to 100 parts by mass of the binder resin in terms of the charge amount of the toner.
5.0 parts by mass is preferred.

On the other hand, the following substances control the toner to be positively charged.

Modified product of nigrosine with nigrosine and a fatty acid metal salt; tributylbenzylammonium-1-
Onium salts of quaternary ammonium salts such as hydroxy-4-naphthosulfonate and tetrabutylammonium tetrafluoroborate, and their analogs, phosphonium salts and their lake pigments; triphenylmethane dyes and their lake pigments ( As a rake agent,
Phosphotungstic acid, phosphomolybdic acid, phosphotungsten molybdic acid, tannic acid, lauric acid, gallic acid, ferricyanide, ferrocyanide, etc.); metal salts of higher fatty acids; such as dibutyltin oxide, dioctyltin oxide, dicyclohexyltin oxide Diorganotin oxide; dibutyltin borate;
Diorganotin borates such as dioctyltin borate and dicyclohexyltin borate. These can be used alone or in combination of two or more.

It is preferable that an inorganic fine powder or a hydrophobic inorganic fine powder be externally added to the toner particles of the present invention. For example, it is preferable to add silica fine powder for use.

As the silica fine powder used in the present invention, both a dry method produced by vapor phase oxidation of a silicon halide and a dry silica called fumed silica and a wet silica produced from water glass can be used. It is. Dry silica with few silanol groups on the surface and inside and no production residue is preferred.

The silica fine powder used in the present invention is preferably subjected to a hydrophobic treatment. The hydrophobization treatment is provided by chemically treating with an organosilicon compound that reacts or physically adsorbs with the silica fine powder.
A preferred method is to treat the dry silica fine powder produced by the vapor phase oxidation of the silicon halide compound with a silane coupling agent or simultaneously with the silane coupling agent and an organic silicon compound such as silicone oil. Is mentioned.

Examples of the silane coupling agent used for the hydrophobizing treatment include hexamethyldisilazane, trimethylsilane, trimethylchlorosilane, trimethylethoxysilane, dimethyldichlorosilane, methyltrichlorosilane, allyldimethylchlorosilane, and allylphenyldisilane. Chlorosilane, benzyldimethylchlorosilane, bromomethyldimethylchlorosilane, α-chloroethyltrichlorosilane, β-chloroethyltrichlorosilane, chloromethyldimethylchlorosilane, triorganosilanemercaptan, trimethylsilylmercaptan, triorganosilyl acrylate, vinyldimethylacetoxy Silane, dimethylethoxysilane, dimethyldimethoxysilane, diphenyldiethoxysilane, hexamethyldisiloxane, 1,3-di Vinyltetramethyldisiloxane,
1,3-diphenyltetramethyldisiloxane is exemplified.

Examples of the organosilicon compound include silicone oil. Preferred silicone oils have a viscosity at 25 ° C. of about 3 × 10 ⁻⁵ to 1 × 10 ^5
-3 m ² / s is used. Dimethyl silicone oil, methylphenyl silicone oil, α-methylstyrene-modified silicone oil, chlorophenyl silicone oil, and fluorine-modified silicone oil are preferred.

The silicone oil treatment may be carried out by directly mixing the silica fine powder treated with the silane coupling agent with the silicone oil using a mixer such as a Henschel mixer, or adding the silicone to the base silica. A method of injecting oil may be used. Alternatively, the silicone oil may be dissolved or dispersed in an appropriate solvent, mixed with a base silica fine powder, and the solvent may be removed.

An external additive other than the silica fine powder may be used in the toner of the present invention, if necessary.

For example, a charge auxiliary agent, a conductivity-imparting agent, a fluidity-imparting agent, an anti-caking agent, a release agent for fixing a hot roll,
Resin fine particles and inorganic fine particles that function as a lubricant or an abrasive.

For example, lubricants such as fluororesin, zinc stearate, and polyvinylidene fluoride, among which polyvinylidene fluoride are preferred. Abrasives such as cerium oxide, silicon carbide and strontium titanate, among which strontium titanate are preferred. Fluidity-imparting agents such as titanium oxide and aluminum oxide, particularly hydrophobic ones, are preferred. Anti-caking agent. Conductivity-imparting agents such as carbon black, zinc oxide, antimony oxide, and tin oxide. A small amount of white fine particles and black fine particles having a polarity opposite to that of the toner particles can be used as a developing property improver.

The amount of the inorganic fine powder or the hydrophobic inorganic fine powder mixed with the toner is 0.1 to 100 parts by mass of the toner.
It is good to use 5 parts by mass (preferably 0.1 to 3 parts by mass).

Further, the magnetic toner of the present invention preferably has a Carr jetting index of greater than 80, more preferably a Carr flowing index of greater than 60.

The magnetic toner of the present invention preferably has a Carr jetting index of 81 to 89. Further, the magnetic toner of the present invention has a Carr fluidity index of 61.
More preferably, it is -79.

The fluidity index and jetness index of the magnetic toner are measured by the following methods. Powder tester P-1
Using 00 (manufactured by Hosokawa Micron Corporation), parameters of repose angle, collapse angle, difference angle, degree of compression, degree of cohesion, degree of spatula, degree of dispersion are measured. The values obtained for each are applied to the Carr's liquidity index table and jettable index table, converted into respective indexes of 25 or less, and the sum of the indexes obtained from each parameter is used as the liquidity index and jettable index. Calculated. The measurement method of each parameter is shown below.

Angle of repose 150 g of the toner is deposited on a circular table having a diameter of 8 cm through a mesh having an opening of 710 μm.
At this time, the toner is accumulated to such an extent that the toner overflows from the end of the table. At this time, the angle formed between the ridge line of the toner deposited on the table and the circular table surface was measured with a laser beam to obtain the angle of repose.

Compressibility The degree of compression can be determined from the loosely filled bulk density (loose apparent specific gravity A) and the tapping bulk density (solid apparent specific gravity P). Compressibility (%) = 100 (PA) / P * Loose apparent specific gravity measurement method 5cm in diameter, 5.2c in height
m, gently pour 150 g of toner into a cup having a capacity of 100 cc. When the toner is filled into the measuring cup at the peak, the surface of the toner is wiped, and the apparent specific gravity of the looseness is calculated from the amount of toner filled in the cup. ○ Measurement method for apparent bulk specific gravity Add the attached cap to the measuring cup used for loose apparent specific gravity. Fill the cup with toner and tap the cup 180 times. When the tapping is completed, remove the cap and wipe off excess toner piled up in the cup. The apparent apparent specific gravity is calculated from the amount of toner filled in the cup. Both apparent specific gravity values are inserted into the expression of the degree of compression to determine the degree of compression.

Spatula angle The bat with a size of 10 cm × 15 cm is placed so that the bottom thereof is in contact with a spatula with a size of 3 cm × 8 cm. The toner is deposited on the spatula. At this time, the toner is deposited so as to rise on the spatula. Thereafter, only the bat is gently lowered, and the inclination angle of the side surface of the toner remaining on the spatula is measured by a laser beam.

Thereafter, an impact is applied once with a shocker attached to the spatula, and the spatula angle is measured again. The average of the measured value and the measured value before giving an impact was calculated as a spatula angle.

Aggregation degree On a vibrating table, openings 250 μm, 150 μm,
Set sieves in order of 75 μm. 1m vibration amplitude
m, the vibration time is 20 seconds, and 5 g of the toner is gently placed and vibrated. After stopping the vibration, the weight remaining on each sieve is measured. (Amount of toner remaining on upper sieve) ÷ 5 (g) × 100... A (Amount of toner remaining on middle sieve) ÷ 5 (g) × 100 × 0.6... B (Lower sieve Is calculated as (amount of toner remaining) ｇ5 (g) × 100 × 0.2... Ca + b + c = aggregation degree (%).

The value obtained from the parameter is represented by Carr
Table of Fluidity Index and Spouting Index of Chemicals (Chemical E
ngineering. Jan. 18.1965) to convert to an index of 25 or less, and sum of those values ++
+ = Carr's fluidity index.

Collapse Angle After measuring the angle of repose, a shocker is applied to the bat on which the circular table for measurement is placed three times with a shocker. Thereafter, the angle of the toner remaining on the table is assumed using a laser beam, and is set as a collapse angle.

Difference Angle The difference between the angle of repose and the angle of collapse is the difference angle.

Dispersion 10 g of toner is dropped from a height of about 60 cm onto a watch glass having a diameter of 10 cm. Then, the toner remaining on the watch glass is measured, and the degree of dispersion is determined by the following equation. Dispersion degree (%) = ((10− (toner amount remaining on plate))
× 10

The sum of the index which can be converted from the value of and the index corresponding to the fluidity index value obtained above can be obtained as the jetness index from the above-mentioned Carr table.

As a result of the above measurement, the jettability index was 8
A value larger than 0 (more preferably, 81 to 89);
More preferably, if the magnetic toner has a Carr fluidity index of a value greater than 60 (more preferably, 61 to 79), even if the magnetic toner is filled into the cartridge at a high filling rate, the stirring member may be used. Because high fluidity is reproduced during agitation, magnetic toner is easily conveyed from the toner container in the cartridge to the developing sleeve, and is stable even when charged into a high-speed printer or a large-capacity cartridge. Developing characteristics can be obtained. In the magnetic toner of the present invention, appropriate jetness index and fluidity index can be achieved by changing the particle size and shape of the magnetic toner particles, the amount of the external additive, and the adhesion state. As described above, in the magnetic toner, by controlling the number of particles having the free iron element to 100 to 350 per 10,000 toner particles, a decrease in fluidity due to aggregation of the free magnetic iron oxide particles is achieved. In addition, the jetting index and the fluidity index can be achieved by changing the stirring state by changing the shape of the stirring blade used at the time of external addition, the filling amount in the mixing device, and the stirring mode. Can be.

When the jetting index of the magnetic toner is 80 or less, high fluidity can be obtained, but once it is clogged, it is difficult to flow even if a force is applied. , Is not easily transported.
As a result, the magnetic toner is difficult to be conveyed to the developing sleeve, and is charged in a state where the magnetic toner is unevenly placed on the developing sleeve. Therefore, the charging of the magnetic toner is also likely to be uneven and an image is likely to be uneven.

When the jetting index of the magnetic toner is 80 or less and the fluidity index of the toner is 60 or less, the magnetic toner easily aggregates and hardly flows, so that the magnetic toner Fusion is likely to occur.

Furthermore, the magnetic toner of the present invention preferably satisfies 70 ≧ | Qd | ≧ 20 μC / g, where | Qd | is the absolute value of the triboelectric charge amount with respect to the iron powder carrier. Since the value of the triboelectric charge greatly changes depending on the surface shape of the magnetic toner and the state of exposure of the magnetic iron oxide particles to the surface of the magnetic toner particles, in order to obtain a desired triboelectric charge in the present invention, as described above, the circular charge is obtained. The degree of release of magnetic iron oxide particles from toner particles is controlled, the type and amount of external additives are changed, and the shape of the stirring blade used for external addition, the filling amount in the mixing device, and the stirring mode are changed. It is important to change the stirring state.

The method for measuring Qd is shown below.

For the measurement, a charge amount measuring device shown in FIG. 19 is used. Under an environment of a temperature of 23 ° C. and a relative humidity of 60%, as an iron powder carrier, 50 to 70% by mass in a particle size range of 106 to 150 μm, and 20 to 50% by mass in a particle size range of 75 to 106 μm.
Powder carrier such as DSP138
(Manufactured by Dowa Iron Powder Co., Ltd.)), and a mixture of 9.0 g of iron powder carrier and 1.0 g of magnetic toner is placed in a polyethylene bottle having a volume of 50 to 100 ml, and shaken by hand 50 times.

Next, the mixture 1. was placed in a metal measuring container 902 having a 500-mesh screen 903 at the bottom.
0 to 1.2 g is put, and a metal lid 904 is formed. At this time, the weight of the entire measurement container 902 is weighed and set as W1 (g). Next, in the suction device 901 (at least the portion in contact with the measurement container 902 is at least an insulator), the air is suctioned from the suction port 907 and the air volume control valve 906 is adjusted to reduce the pressure of the vacuum gauge 905 by 2 k.
Pa.

In this state, suction is performed for one minute to remove the developer by suction. The potential of the electrometer 909 at this time is set to V (volt). Here, 8 is a capacitor whose capacity is C
(ΜF). Further, the weight of the entire measuring machine after suction is weighed and is defined as W2 (g). The triboelectric charge amount Qd (μ
C / g) is calculated as follows. Qd = CV / (W1-W2)

When the absolute value of the triboelectric charge amount of the magnetic toner with respect to the iron powder carrier is 70 μC / g ≦ | Qd |, the developing property is deteriorated due to the charge-up particularly under low humidity. When | Qd | ≦ 20 μC / g, an appropriate electrostatic cohesive force of the magnetic toner on the developer carrier and an appropriate magnetic binding force to the developer carrier cannot be obtained due to a low charge amount. In addition, the magnetic toner cannot be faithfully transferred to the electrostatic latent image, resulting in a decrease in developability.

The magnetic toner of the present invention preferably has a maximum endothermic peak in a DSC curve of the toner measured by a differential scanning calorimeter at 60 to 120 ° C. When the maximum endothermic peak is less than 60 ° C., the offset resistance and the blocking resistance decrease. Maximum endothermic peak is 120
When the temperature exceeds ℃, the fixing property is lowered.

Further, the toner of the present invention has a DSC endothermic peak of 6 as measured by a differential scanning calorimeter.
0 to 120 ° C., and the endothermic subpeak is 60 to 160 ° C.
It is more preferable that the distance between the endothermic peaks is 20 ° C. or more.

If the difference between the endothermic peaks is less than 20 ° C., it becomes difficult to exhibit the function-separating effect of the fixing property and the releasability. Thus, the presence of the endothermic peak as described above allows the effect of plasticizing the magnetic toner and the effect of giving the releasing action to be appropriately adjusted, so that the balance between the fixing property, the offset resistance, and the blocking resistance can be achieved. Become. Furthermore,
By having the circularity of the present invention, the plasticizing effect can be exhibited more effectively, and the releasing effect can be exhibited in a wide temperature range.

Hereinafter, preferred embodiments of the method for producing the toner of the present invention will be specifically described with reference to the accompanying drawings. FIG. 1 is an example of a flowchart showing the outline of the toner manufacturing method of the present invention. As shown in the flowchart, the production method of the present invention does not require a classification step before the pulverization treatment, and it is preferable that the pulverization step and the classification step be performed in one pass.

In the method for producing a toner, the number of free magnetic iron oxides and the circularity of the toner can be controlled by producing the toner by using a specific toner constituent material and selecting various production conditions. . In general, a mixture containing at least a binder resin, a colorant and a wax is melt-kneaded, and the obtained kneaded material is cooled. Used as A rotor comprising a rotating body having at least a predetermined amount of the pulverized raw material attached to a central rotating shaft, and a stator disposed around the rotor while maintaining a constant distance from the rotor surface In addition, the annular space formed by maintaining the interval is introduced into a mechanical crusher configured to be in an airtight state, and the crushed material is crushed by rotating the rotor of the mechanical crusher at a high speed. Finely pulverize things. Next, the pulverized raw material is introduced into a classification step and classified to obtain toner particles composed of particles having a preferred particle size. At this time, in the classification step, a multi-split airflow classifier having at least a coarse powder region, a medium powder region, and a fine powder region is preferably used. For example, when a three-division airflow classifier is used, the powder raw material is classified into at least three types of fine powder, medium powder and coarse powder. In the classification process using such a classifier, the coarse powder composed of a group of particles having a larger particle size than the preferred particle size and the ultrafine powder composed of a group of particles having a particle size smaller than the preferred particle size are removed, and the intermediate powder is used as toner particles. The toner is used as it is, or after being mixed with an external additive such as hydrophobic colloidal silica, is used as a toner.

The ultrafine powder composed of particles having a particle size smaller than the preferred particle size classified in the above-mentioned classification step is generally used in a melt-kneading step for producing a powder raw material composed of a toner material introduced into the pulverization step. To be reused or discarded.

FIG. 2 shows an example of a toner production system. As a powder raw material which is a toner raw material introduced into this device system, a binder resin, a colored resin particle powder containing at least a colorant and a wax is used, and the powder raw material is, for example, a binder resin, A mixture composed of a magnetic iron oxide and a wax is melt-kneaded, the obtained kneaded product is cooled, and the cooled product is roughly pulverized by a pulverizing means.

In this apparatus system, the pulverized raw material serving as the toner powder raw material is supplied to a mechanical pulverizer 301 as pulverizing means.
A predetermined amount is introduced through the first metering device 315. The introduced pulverized raw material is instantaneously pulverized by the mechanical pulverizer 301 and is introduced into the second constant feeder 2 via the collection cyclone 229. Next, it is supplied into the multi-split airflow classifier 1 as a classifying means via the vibrating feeder 3 and further through the raw material supply nozzle 16.

In this apparatus system, the first fixed-quantity feeder 315 sends a mechanical pulverizer 301 as a pulverizing means.
The relationship between the predetermined amount introduced into the second constant feeder 2 and the predetermined amount introduced into the multi-split airflow type classifier 1 as the classification means from the second constant supply device 2 to the mechanical pulverizer 301 from the first constant supply device 315 Assuming that the predetermined amount to be introduced is 1, the predetermined amount to be introduced from the second fixed-quantity feeder 2 to the multi-split airflow classifier 1 is preferably 0.7 to 1.7, more preferably 0.7 to 1.7. And more preferably from 1.0 to 1.2 from the viewpoint of toner productivity and production efficiency.

In general, the air-flow classifier of the present invention is used by connecting mutual devices by a communication means such as a pipe, and is incorporated in an apparatus system. FIG. 2 shows a preferred example of such an apparatus system. The integrated device system shown in FIG. 2 is a means for communicating the multi-divided classifier 1 (the classifier shown in FIG. 6), the fixed-quantity feeder 2, the vibration feeder 3, the collection cyclone 4, the collection cyclone 5, and the collection cyclone 6. Are connected by

In this apparatus system, the powder is fed into the quantitative feeder 2 by an appropriate means, and then introduced into the three-division classifier 1 through the vibrating feeder 3 by the raw material supply nozzle 16. For introduction, 10-3
The powder is introduced into the classifier 1 at a flow rate of 50 m / sec. Since the size of the classifying chamber of the three-segment classifier 1 is usually [10 to 50 cm] × [10 to 50 cm], the powder is instantaneously divided into three or more types of particles in 0.1 to 0.01 seconds or less. Can be classified. Then, the particles are classified into large particles (coarse particles), intermediate particles, and small particles by the three-division classifier 1. Thereafter, the large particles pass through the discharge conduit 11a, are sent to the collection cyclone 6, and are returned to the mechanical grinder 301. The intermediate particles are discharged out of the system via the discharge conduit 12a, collected by the collection cyclone 5, and collected as toner. The small particles are discharged out of the system via the discharge conduit 13a, collected by the collection cyclone 4, and supplied to a melt-kneading process for producing a powder material composed of the toner material, and are reused or discarded. Is done. Collection cyclone 4,
5 and 6 can also function as suction pressure reducing means for sucking and introducing the powder into the classification chamber via the raw material supply nozzle 16. In addition, it is preferable that the large particles to be classified at this time are re-introduced into the first quantitative feeder 315, mixed into the powder raw material, and pulverized again by the mechanical pulverizer 301.

The reintroduction amount of large particles (coarse particles) reintroduced from the multi-split air classifier 1 to the mechanical pulverizer 301 depends on the mass of the finely pulverized product supplied from the second quantitative feeder 2. It is preferably 0 to 10.0% by mass, more preferably 0 to 5.0% by mass, based on the toner production. If the reintroduction amount of large particles (coarse particles) reintroduced from the multi-split air classifier 1 into the mechanical pulverizer 301 exceeds 10.0% by mass, the dust concentration in the mechanical pulverizer 301 increases. ,
At the same time as the load on the apparatus itself increases, it is excessively pulverized at the time of pulverization, and the surface of the toner deteriorates due to heat, the magnetic iron oxide is easily released from the toner particles, and the inside of the apparatus is easily fused.

In this apparatus system, the particle size of the powder raw material is 95 mass% or more in the 18 mesh pass (ASTME-11-61) and 100 mesh on (ASTM).
E-11-61) is preferably 90% by mass or more.

Further, in this apparatus system, in order to obtain a toner having a sharp particle size distribution having a weight average particle diameter of 10 μm or less (more preferably 8 μm or less), a finely pulverized material pulverized by a mechanical pulverizer is used. Weight average particle size is 5-10μ
m, 4.0 μm or less, 70% by number or less, further, 65% by number or less, 10.1 μm or more, 25% by volume or less,
It is preferably 0% by volume or less. The particle size of the classified medium powder has a weight average particle size of 5 to 10 μm.
0 μm or less is 40 number% or less, further 35 number% or less,
25% by volume or less for 10.1 μm or more, further 20% by volume
The following is preferred.

In the above-described apparatus system to which the method for producing a toner according to the present invention is applied, the pulverizing step and the classifying step can be performed in one pass without requiring the first classifying step before the pulverizing treatment.

A mechanical pulverizer preferably used as a pulverizing means used in the method for producing a toner of the present invention will be described. Examples of the mechanical pulverizer include a pulverizer KTM manufactured by Kawasaki Heavy Industries, Ltd. and a turbo mill manufactured by Turbo Kogyo. It is preferable to use these devices as they are or after appropriately improving them.

Of these, the production of toner by using a mechanical pulverizer as shown in FIGS. 3, 4 and 5 and using specific raw materials as the toner constituent material depends on the shape of the toner particles and the looseness of the toner. This is preferable as a method capable of controlling the number of magnetic iron oxide particles for production. Further, since the pulverization of the powder raw material can be easily performed, the efficiency can be improved, which is preferable.

In the conventional collision-type airflow pulverization, free magnetic iron oxide particles are easily generated at the time of collision because toner particles collide with the collision surface of the collision member and are pulverized by the impact. Further, since the pulverized toner becomes irregular and angular, the magnetic iron oxide particles are likely to fall off from the toner particles. Further, it is possible to modify the shape and surface properties of the toner particles produced by the collision type air pulverization by mechanical impact (hybridizer). However, in the collision type pulverization, the toner particles are applied to the collision surface of the collision member. Are caused to collide with each other and pulverized by the impact, so that free magnetic iron oxide particles are easily generated at the time of collision.
Then, by changing the shape of the particles by mechanical impact and making the shape close to a spherical shape, the magnetic iron oxide particles are less likely to fall off from the toner than the amorphous toner, but the toner using a mechanical pulverizer is used. It is difficult to control the shape of the toner and the number of free magnetic iron oxide particles as compared with the production method of the above.

Hereinafter, the mechanical crusher shown in FIGS. 3, 4 and 5 will be described. FIG. 3 is a schematic cross-sectional view of an example of a mechanical crusher, and FIG.
FIG. 5 shows a schematic cross-sectional view taken along the plane D ′, and FIG. 5 shows a perspective view of the rotor 314 shown in FIG. The device is shown in FIG.
, The casing 313, the jacket 316, the distributor 220, the casing 313
A rotor 314 in which a number of grooves are provided on a high-speed rotating surface composed of a rotating body attached to a central rotating shaft 312, and a surface arranged at a constant interval on the outer periphery of the rotor 314. Stator 310 having a large number of grooves formed therein, and a raw material inlet 3 for introducing a raw material to be processed.
11, a raw material discharge port 302 for discharging the powder after the treatment.

The pulverizing operation with a mechanical pulverizer is performed, for example, as follows. That is, when a predetermined amount of powder raw material is introduced from the powder inlet 311 of the mechanical pulverizer shown in FIG. 3, the particles are introduced into the pulverization processing chamber, and the surface is rotated at a high speed in the pulverization processing chamber. Rotor 314 provided with multiple grooves
And the stator 310 having a large number of grooves formed on the surface thereof, instantaneously pulverized by a large number of ultra-high-speed vortices generated by the impact, and high-frequency pressure vibrations generated by this. After that, it is discharged through the raw material discharge port 302. The air (air) carrying the toner particles passes through the pulverization processing chamber, and is supplied to the raw material outlet 302, the pipe 219, the collection cyclone 229, and the bag filter 22.
2, and is discharged out of the system of the apparatus system through the suction filter 224. In the present invention, since the powder raw material is pulverized, a desired pulverization process can be easily performed without increasing fine powder and coarse powder.

Further, when the pulverized raw material is pulverized by a mechanical pulverizer, cold air is blown into the mechanical pulverizer together with the powder raw material by the cool air generating means 321, and the mechanical pulverizer has a jacket structure 316. By having a structure and passing cooling water (preferably an antifreeze such as ethylene glycol), the atmospheric temperature in the crusher is 0 ° C or lower, more preferably -5 to -15 ° C, further preferably -7 to -12 ° C. Is preferred from the viewpoint of toner productivity. The room temperature of the vortex chamber in the crusher is 0 ° C. or lower, more preferably −5 to −1.
By setting the temperature to 5 ° C., more preferably −7 to −12 ° C., it is possible to suppress the surface deterioration of the toner particles due to heat, in particular, the release of magnetic iron oxide particles present on the toner particle surface, and to efficiently pulverize the raw material. can do. When the ambient temperature in the pulverizer exceeds 0 ° C., it is preferable from the viewpoint of toner productivity because the surface of the toner particles deteriorates due to heat during the pulverization, and in particular, the magnetic iron oxide particles present on the surface of the toner particles are easily released or fused in the apparatus. Absent. In addition, if an attempt is made to operate at an ambient temperature lower than −15 ° C. in the crusher, the refrigerant (alternative Freon) used in the cold air generating means 321 must be changed to Freon.

At present, elimination of CFCs is being promoted from the viewpoint of protection of the ozone layer. It is not preferable to use chlorofluorocarbon as the refrigerant of the cold air generating means 321 from the viewpoint of global environmental problems.

The cooling water (preferably an antifreeze such as ethylene glycol) is supplied into the jacket from a cooling water supply port 317 and discharged from a cooling water discharge port 318.

When the pulverized raw material is pulverized by a mechanical pulverizer, the room temperature T1 of the spiral chamber 212 and the rear chamber
The temperature difference ΔT (T2−T1) of the room temperature T2 of 21 to 30 to 8
The temperature is preferably 0 ° C, more preferably 35 to 75.
C., more preferably 37-72 ° C., it is possible to suppress the deterioration of the surface of the toner particles due to heat, particularly the release of magnetic iron oxide particles present on the surface of the toner particles, and it is possible to efficiently pulverize the raw material. it can. ΔT between temperature T1 (inlet temperature) and temperature T2 (outlet temperature) of mechanical pulverizer
Is less than 30 ° C., a short path may occur without being pulverized, which is not preferable in terms of toner performance. If the temperature is higher than 80 ° C., it may be excessively pulverized at the time of pulverization, whereby the magnetic iron oxide particles are liberated, and the surface of the toner particles is deteriorated by heat, particularly, the magnetic iron oxide particles present on the toner particle surface are released. Also, it is not preferable from the viewpoint of toner productivity because the toner tends to fuse in the apparatus.

When the pulverized raw material is pulverized by a mechanical pulverizer, the inlet temperature of the mechanical pulverizer is 0 ° C. or less with respect to the glass transition point (Tg) of the binder resin and is 6 ° C. or less than Tg.
It is preferable to lower the temperature by 0 to 75 ° C. from the viewpoint of toner productivity. By setting the inlet temperature of the mechanical pulverizer to 0 ° C. or lower and lowering the Tg by 60 to 75 ° C., it is possible to suppress the surface alteration of the toner particles due to heat, in particular, the release of magnetic iron oxide present on the toner particle surface. It is possible to efficiently pulverize the raw material. The outlet temperature is T
It is preferably 5 to 30 ° C, more preferably 10 to 20 ° C lower than g. By lowering the outlet temperature of the mechanical pulverizer by 5 to 30 ° C. lower than Tg, it is possible to suppress the surface deterioration of the toner particles due to heat, in particular, the release of the magnetic iron oxide particles present on the toner particle surface, and to efficiently pulverize the toner particles. Raw materials can be crushed.

Further, the peripheral speed of the tip of the rotating rotor 314 is preferably 80 to 180 m / s, more preferably 90 to 170 m / s, and further preferably 10 to 170 m / s.
It is preferably from 0 to 160 m / s from the viewpoint of toner productivity. The peripheral speed of the rotating rotor 314 is set to 80 to 18
0 m / s, more preferably 90 to 90 m / s.
By controlling the particle diameter to 170 m / s, more preferably 100 to 160 m / s, insufficient pulverization of the toner particles, excessive pulverization, and release of magnetic iron oxide particles due to excessive pulverization can be suppressed.
The pulverized raw material can be efficiently pulverized. If the peripheral speed of the rotor is lower than 80 m / s, it is not preferable from the viewpoint of toner performance because a short path is easily generated without being pulverized. When the peripheral speed of the rotor 314 is higher than 180 m / s, the load on the device itself is increased, and at the same time, the magnetic iron oxide particles are easily pulverized during the pulverization and liberated. Further, excessive pulverization is not preferable in terms of toner productivity because the surface of the toner particles is deteriorated by heat, particularly, the magnetic iron oxide particles existing on the surface of the toner particles are easily released or fused in the machine.

The minimum distance between the rotor 314 and the stator 310 is preferably 0.5 to 10.0 mm, more preferably 1.0 to 5.0 mm, and still more preferably 1.0 to 5.0 mm. It is preferably 3.0 mm. Rotor 3
0.5 to 10.0 m between the stator 14 and the stator 310
m, more preferably 1.0 to 5.
By setting the thickness to 0 mm, more preferably 1.0 to 3.0 mm, insufficient pulverization of the toner, excessive pulverization, and release of magnetic iron oxide particles due to excessive pulverization can be suppressed, and the pulverized raw material can be efficiently pulverized. it can. Rotor 314 and stator 3
If the distance between the particles is more than 10.0 mm, a short path is likely to occur without being pulverized, which is not preferable in terms of toner performance. When the distance between the rotor 314 and the stator 310 is smaller than 0.5 mm, the load on the apparatus itself is increased and, at the same time, the magnetic iron oxide particles are liable to be loosened due to excessive pulverization during pulverization. Further, excessive pulverization is liable to cause surface deterioration of the toner particles due to heat and fusing in the apparatus, which is not preferable in terms of toner productivity.

Further, the pulverizer controls the generation of free magnetic iron oxide particles by controlling the surface roughness of the pulverized surfaces of the rotor and the stator to an appropriate state. A magnetic toner having chargeability can be obtained. That is, the center line average roughness Ra of the crushed surfaces of the rotor 314 and the stator 310 is 10.0 μm or less, more preferably 2.0 to 10.0 μm, and the maximum roughness Ry is 60.0 μm or less, more preferably. Is 25.0 to 60.0 μm, and
The ten-point average roughness Rz is preferably 40.0 μm or less, more preferably 20.0 to 40.0 μm. The center line average roughness Ra of the crushed surfaces of the rotor and the stator is 10.0 μm.
If the maximum roughness Ry is more than 60.0 μm and the ten-point average roughness Rz is more than 40.0 μm, the magnetic iron oxide particles are liable to be released by over-grinding during grinding. Further, excessive pulverization is not preferable in terms of toner productivity because the surface of the toner particles is deteriorated by heat, particularly, the magnetic iron oxide particles existing on the surface of the toner particles are easily released or fused in the machine.

The value of each analysis parameter of the surface roughness is measured by a laser focus displacement meter L which can be measured in a non-contact manner.
Measurement was performed using T-8100 (manufactured by Keyence Corporation) and surface shape measurement software Tres-Vale Lite (manufactured by Mitani Shoji Co., Ltd.). Calculate from the value. At this time, the reference length was set to 8 mm, the cutoff value was set to 0.8 mm, and the moving speed was set to 90 μm.
/ Sec.

Among the analysis parameters of the surface roughness, the center line roughness Ra is obtained by extracting a portion of the reference length L from the roughness curve in the direction of the center line, and defining the center line of the extracted portion as X.
Axis, the direction of the vertical magnification is the Z axis, and the roughness curve is Z = f (x)
Is determined by obtaining the following equation.

[0237]

(Equation 5)

The maximum roughness Ry is obtained by extracting a reference length from the roughness curve in the direction of the average line, and measuring the distance between the top and the bottom of the extracted portion in the direction of the vertical magnification of the roughness curve. Decide by doing. The ten-point average roughness Rz is obtained by extracting a reference length from the roughness curve in the direction of the average line and measuring the average length of the extracted portion in the direction of the vertical magnification from the highest peak to the fifth peak. It is determined by calculating the sum of the average of the absolute values of the altitudes and the average of the absolute values of the valley bottom altitudes from the lowest valley to the fifth.

As the roughening treatment of the crushed surface of the rotor and / or the stator, a known method is used.

However, in a mechanical crusher in which only the base material of the crushed surface of the rotor and / or the stator is roughened, abrasion of the crushed surface of the rotor and / or the stator occurs in a short time. The rotor and / or
Alternatively, abrasion resistance treatment of the crushed surface of the stator is required.

The base material of the crushed surface of the rotor and / or the stator is subjected to a roughening treatment as a pre-process and a wear-resistant treatment of the base material as a post-process, thereby easily suppressing the generation of free magnetic iron oxide. A toner capable of maintaining good developability can be obtained, and wear of the crushing surfaces of the rotor and the stator can be reduced, and the toner can be stably crushed for a long period of time.

As the abrasion-resistant treatment of the crushed surface of the rotor and / or the stator, a known method is used, and among these, treatment by nitriding is most preferable.

The above-mentioned nitriding is a surface hardening method intended to improve the wear resistance and fatigue resistance of a work material.
This is a heat treatment of heating at an appropriate temperature for an appropriate time to diffuse nitrogen on the entire or partial surface of the processing material to form a nitrided layer.

The generation of free magnetic iron oxide particles can be easily suppressed by roughening the base material of the crushed surface of the rotor and / or the stator as a pre-treatment and nitriding the base material as a post-process. And a toner capable of maintaining good developability can be obtained, and the wear of the crushing surfaces of the rotor and the stator can be reduced, and the kneaded material can be crushed stably for a long period of time. preferable.

The method of pulverizing the kneaded material does not require the first classifying step before the pulverizing step. Therefore, the toner particles are made finer, so that the electrostatic aggregation between the particles is increased. The toner particles to be recycled are circulated again to the first classifying means, so that excessively pulverized fine powder and ultrafine powder are not generated. Furthermore, in addition to the simple configuration, since a large amount of air is not required to pulverize the pulverized raw material, power consumption is low and energy cost can be reduced.

Next, an air-flow classifier that is preferably used as a classifying means constituting the toner manufacturing method will be described.

As an example of a preferred multi-split air classifier used in the present invention, an apparatus of the type shown in FIG. 6 (cross-sectional view) will be exemplified as a specific example.

In FIG. 6, the side wall 22 and the G block 2
3 forms part of the classification chamber, the classification edge blocks 24 and 25 are provided with classification edges 17 and 18. The installation position of the G block 23 can be slid right and left. Further, the classification edges 17 and 18 correspond to the shaft 17a.
And 18a can be rotated, and the classification edge can be rotated to change the classification edge tip position.
Each of the classification edge blocks 24 and 25 can be slid left and right, and accordingly, the respective knife-edge classification edges 17 and 18 also slide right and left. The classification area 30 of the classification chamber 32 is divided into three by the classification edges 17 and 18.

A raw material supply port 40 for introducing the raw material powder is provided at the rearmost end of the raw material supply nozzle 16, and a high pressure air nozzle 41 and a raw material powder introduction nozzle 42 are provided at the rear end of the raw material supply nozzle 16. And a raw material supply nozzle 16 having an opening in the classifying chamber 32 is provided on the right side of the side wall 22, and the Coanda block 26 is installed so as to draw an oblong arc with respect to the extension direction of the lower tangent of the raw material supply nozzle 16. Have been. The left block 27 of the classifying chamber 32 has a knife-edge type air inlet edge 19 on the right side of the classifying chamber 32, and further, on the left side of the classifying chamber 32, the inlet pipes 14 and 1 that open to the classifying chamber 32.
5 is provided. In addition, as shown in FIG.
And 15 include a first gas introduction adjusting means 2 such as a damper.
Zero and second gas introduction adjusting means 21 and static pressure gauges 28 and 29
Is provided.

The positions of the classification edges 17 and 18, the G block 23, and the inlet edge 19 are adjusted according to the type of the toner to be classified and the desired particle size.

The upper surfaces of the classifying chambers 32 are provided with discharge ports 11, 1 opening into the classifying chambers corresponding to the respective dividing areas.
Each of the outlets 11, 12 and 13 is connected to a communicating means such as a pipe, and each of the outlets may be provided with an opening / closing means such as a valve means.

The raw material supply nozzle 16 is composed of a right-angled cylinder and a pyramidal cylinder. The ratio of the inner diameter of the right-angled cylinder to the inner diameter of the narrowest part of the pyramidal cylinder is 20: 1 to 1: 1, preferably 10: 1. : 1
If the ratio is set to 2: 1 from, a good introduction speed can be obtained.

The classification operation in the multi-division classification region configured as described above is performed, for example, as follows. That is, the outlet 1
The pressure in the classification chamber is reduced through at least one of 1, 12, and 13, and the material supply nozzle 16 having an opening in the classification chamber is provided.
The powder is injected into the classifying chamber through the raw material supply nozzle 16 at a flow rate of preferably 10 to 350 m / s by the ejector effect of the air flow flowing through the inside by the reduced pressure and the compressed air injected from the high pressure air supply nozzle 41. And disperse.

The particles in the powder introduced into the classifying chamber move on a curved surface due to the action of the Coanda effect of the Coanda block 26 and the action of gas such as air flowing in at that time. Depending on the particle size and the magnitude of the inertial force, large particles (coarse particles) are outside the airflow, ie, the first fraction outside the classification edge 18, and intermediate particles are the second fraction between the classification edges 18 and 17. Classification edge 1 for small particles
7, the classified large particles are discharged from the outlet 11, the classified intermediate particles are discharged from the outlet 12, and the classified small particles are discharged from the outlet 13. Is discharged.

In the above-mentioned classification of the powder, the classification point is mainly determined by the edge tip positions of the classification edges 17 and 18 with respect to the lower end portion of the Coanda block 26 where the powder jumps into the classification chamber 32. Further, the classification point is affected by the suction flow rate of the classification airflow, the powder ejection speed from the raw material supply nozzle 16, and the like.

In the method and system for producing a toner, the weight average diameter is 5 to 12 μm (particularly 5 to 10 μm) by controlling the pulverization and classification conditions.
m), a toner having a sharp particle size distribution having a particle size of m) can be efficiently produced.

As a mixing machine, a Henschel mixer (manufactured by Mitsui Mining); a super mixer (manufactured by Kawata); a ribocorn (manufactured by Okawara Seisakusho); a Nauta mixer, a turbulizer, a cyclomix (manufactured by Hosokawa Micron); Pin mixers (manufactured by Taiheiyo Kiko Co., Ltd.); Ledige mixers (manufactured by Matsubo), and kneading machines include KRC kneader (manufactured by Kurimoto Tekkosho);
Co-kneader (manufactured by Buss); TEM extruder (manufactured by Toshiba Machine); TEX twin-screw kneader (manufactured by Nippon Steel Works); PCM kneader (manufactured by Ikegai Iron Works); three-roll mill; mixing roll mill , Kneader (manufactured by Inoue Seisakusho); Kneedex (manufactured by Mitsui Mining); MS type pressure kneader, kneader router (manufactured by Moriyama Seisakusho); Banbury mixer (manufactured by Kobe Steel); , Counter Jet Mill, Micron Jet, Inomaizer (manufactured by Hosokawa Micron); IDS Mill, PJ
M jet crusher (manufactured by Nippon Pneumatic Industries); cross jet mill (manufactured by Kurimoto Iron Works); ulmax (manufactured by Nisso Engineering); SK Jet O.
Mills (manufactured by Seishin Enterprises); Kryptron (manufactured by Kawasaki Heavy Industries); Turbo Mills (manufactured by Turbo Kogyo). Classifiers include Crasheal, Micron Classifier, and Spedd Classifier (manufactured by Seishin Company). Turbo Classifier (Nisshin Engineering); Micron Separator, Turboplex (ATP), TSP Separator (Hosokawa Micron); Elbow Jet (Nisshin Mining), Dispersion Separator (Nihon Pneumatic) ; Y
M microcut (manufactured by Yasukawa Shoji Co., Ltd.) is mentioned. As a sieving device used for sifting coarse particles, etc.,
Ultrasonic (made by Koei Sangyo Co., Ltd.); resonator sieve, gyro shifter (made by Tokuju Kogyo Co., Ltd.); Vibrasonic system (made by Dalton); Sonic Clean (made by Shinto Kogyo); turbo screener (made by Turbo Kogyo); Micro shifter (manufactured by Makino Sangyo Co., Ltd.);

In producing the toner of the present invention, it is preferable to use the apparatus system having the above-described configuration in the pulverizing step and the classifying step.

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

The surface of the photosensitive drum 1 is negatively charged by the primary charger 702, a digital latent image is formed by image scanning by exposure to laser light 705, and a developing sleeve 704 containing a magnetic blade 711 and a magnet 714 is included. The latent image is reversal-developed by a dry magnetic toner (one-component magnetic developer) 710 of a developing device 709 provided with In the developing section, the conductive base of the photosensitive drum 1 is grounded, and an alternating bias, a pulse bias, and / or a DC bias are applied to the developing sleeve 704 by bias applying means 712. When the transfer paper P is conveyed and reaches the transfer portion, the transfer paper P is charged by the voltage application means 723 from the back surface (the surface opposite to the photosensitive drum side) of the transfer paper P by the roller transfer means 702, so that the toner on the surface of the photosensitive drum 701 is charged. The image is transferred onto transfer paper P by contact transfer means 702. The transfer paper P separated from the photosensitive drum 701 is subjected to a fixing process by a heating and pressing roller fixing device 707 to fix a toner image on the transfer paper P. The toner image is transferred to the photosensitive drum 7
01 may be transferred to the transfer paper P via the intermediate transfer member, or may be transferred to the transfer paper P without the intermediate transfer member.

The dry magnetic toner remaining on the photosensitive drum 701 after the transfer step is removed by cleaning means 708 having a cleaning blade. If the remaining dry magnetic toner is small, the cleaning step can be omitted. After the cleaning, the photosensitive drum 701 is de-charged by the erase exposure 706, and is again charged in the primary charger 702.
The step starting from the charging step is repeated.

A photosensitive drum 701 (that is, an electrostatic image carrier) has a photosensitive layer and a conductive substrate, and moves in the direction of the arrow. Non-magnetic cylindrical developing sleeve 70 as a toner carrier
Reference numeral 4 rotates in the developing section so as to advance in the same direction as the surface of the photosensitive drum 701. Inside the developing sleeve 704, a multi-pole permanent magnet (magnet roll) as a magnetic field generating means is arranged so as not to rotate. The insulating dry magnetic toner 710 in the developing device 709 is applied on a non-magnetic cylindrical surface, and the magnetic toner is given, for example, a negative triboelectric charge by friction between the surface of the developing sleeve 704 and the magnetic toner. Furthermore, a magnetic doctor blade 711 made of iron is placed close to the cylindrical surface (at an interval of 50 μm to 500 μm).
μm), and the thickness of the magnetic toner layer is reduced (30 μm) by disposing the multi-pole permanent magnet so as to face one magnetic pole position.
(.About.300 .mu.m) and uniformly regulated to form a magnetic toner layer thinner than the gap between the photosensitive drum 701 and the developing sleeve 704 in the developing section. By adjusting the rotation speed of the developing sleeve 704, the sleeve surface speed is substantially equal to or close to the speed of the photosensitive drum surface. The opposed magnetic poles may be formed by using permanent magnets instead of iron as the magnetic doctor blade 711. In the developing unit, an AC bias or a pulse bias may be applied to the developing sleeve 704 by the bias unit 712. This AC bias is f 200 to 4,000.
It suffices if 0 Hz and Vpp are 500 to 3,000 V.

When transferring the magnetic toner in the developing section,
The magnetic toner particles are transferred to the electrostatic image side by the electrostatic force on the surface of the photosensitive drum and the action of an AC bias or a pulse bias.

Instead of the magnetic doctor blade 711,
The thickness of the magnetic toner layer may be regulated by pressing using an elastic blade formed of an elastic material such as silicone rubber to apply the magnetic toner on the developing sleeve.

FIG. 12 shows an image forming apparatus having a contact charging means 742 to which a voltage is applied from a bias applying means 743 and a corona transfer means 733.

FIG. 13 shows an image forming apparatus having the contact charging means 742 and the contact transfer means 702.

In FIG. 14, reference numeral 702 denotes a transfer roller, which is basically composed of a core 702a at the center and a conductive elastic layer 702b forming the outer periphery thereof. The transfer roller 702 presses the transfer material against the surface of the photosensitive drum 701 with a pressing force, and rotates the photosensitive drum 701 at a constant speed or at a different circumferential speed. The transfer material passes through the guide 744 and the photosensitive drum 701 and the transfer roller 7
The toner image on the photosensitive drum 701 is transferred to the surface of the transfer material by applying a bias having a polarity opposite to that of the toner to the transfer roller 702 from the transfer bias applying unit 723. Next, the transfer material is the guide 7
45.

The conductive elastic layer 702b is made of a polyurethane or an ethylene-propylene-diene terpolymer (EPDM) in which a conductive material such as carbon is dispersed.
It is made of an elastic body ^{6 ~10 10 Ωcm.}

As preferable transfer process conditions, the contact pressure of the roller is 0.16 × 10 ^{-2 to} 24.5 × 10 ^-2 M
In Pa, the DC voltage is ± 0.2 to ± 10 kV.

On the other hand, FIG. 15 shows a contact charging means.
5, reference numeral 701 denotes a rotating drum type electrostatic image carrier (hereinafter, referred to as a photosensitive drum).
Reference numeral 1 designates a basic structure of a conductive base layer 701a of aluminum or the like and a photoconductive layer 701b formed on its outer surface, and is rotated at a predetermined peripheral speed (process speed) clockwise in the drawing.

Reference numeral 742 denotes a charging roller, which is basically composed of a core 742a at the center, a conductive elastic layer 742b forming the outer periphery thereof, and a surface layer 742c. The charging roller 742 is pressed against the surface of the photosensitive drum 701 with a pressing force, and rotates following the rotation of the photosensitive drum 701. A voltage is applied to the charging roller 742 by the bias applying unit E, and a bias is applied to the charging roller 742 so that the surface of the photosensitive drum 701 has a predetermined polarity.
It is charged to a potential. Next, an electrostatic image is formed by image exposure, and the electrostatic image is sequentially visualized as a toner image by a developing unit.

A preferable process condition when the charging roller is used is that the contact pressure of the roller is 0.49 × 10 ^−2.
When a voltage obtained by superimposing an AC voltage on a DC voltage at a pressure of up to 98 × 10 ⁻² MPa is used, the AC voltage is 0.5 to 5 kVp.
p, AC frequency = 50-5 kHz, DC voltage = ± 0.2
When the DC voltage is used, the DC voltage is ± 0.2 to ± 5 kV.

The material of the charging roller and the charging blade is preferably conductive rubber, and a release coating may be provided on the surface thereof. Nylon resin, P
VDF (polyvinylidene fluoride) and PVDC (polyvinylidene chloride) are applicable.

FIG. 16 shows a specific example of the process cartridge of the present invention. The process cartridge at least integrates the developing unit and the electrostatic image carrier into a cartridge, and the process cartridge is formed so as to be detachable from a main body of the image forming apparatus (for example, a copying machine or a laser beam printer).

In FIG. 16, a process cartridge 750 integrally includes a developing means 709, a drum-shaped electrostatic image carrier (photosensitive drum) 701, a cleaner 708 having a cleaning blade 708a, and a temporary charger (charging roller) 742. Is exemplified.

In the present embodiment, the developing means 709 has a magnetic blade 711 and a magnetic toner 710 in a toner container 760, and uses the magnetic toner 710 to perform development with the photosensitive drum 701 by a bias from a bias applying means. The distance between the photosensitive drum 701 and the developing sleeve 704 is very important so that a predetermined electric field is formed between the photosensitive drum 701 and the developing sleeve 704 so that the developing step is suitably performed.

In FIG. 17, the developing means 709 has an elastic blade 711a and a magnetic toner 710 in a toner container 760. The magnetic toner 710 is used. The distance between the photosensitive drum 1 and the developing sleeve 704 is very important so that a predetermined electric field is formed between the photosensitive drum 1 and the developing sleeve.

FIG. 18 shows one specific example of a process cartridge having an injection charging step used. This is an example of an image forming apparatus of non-contact development in which a magnetic toner is used as a developer and a developer layer on a developer carrier and an image carrier are arranged so as to be in non-contact. Reference numeral 801 denotes a rotating drum type OPC photoconductor as an image carrier, which is driven to rotate clockwise (in the direction of the arrow). Reference numeral 802 denotes a charging roller as a contact charging member. The charging roller 802 is a photosensitive member 801
Are pressed against each other with a predetermined pressing force against the elasticity. n is a charging nip portion which is a nip portion between the photosensitive member 801 and the charging roller 802. In this embodiment, the charging roller 802 faces the charging nip n, which is the contact surface with the photoconductor 801 (the direction opposite to the moving direction of the photoconductor surface).
Is driven to rotate. Further, the conductive fine powder m is applied to the surface of the charging roller 802 such that the amount of application is substantially uniform.

A core metal 802a of the charging roller 802 is connected to a charging bias application power source S1 (not shown) by -700.
A DC voltage of V is applied as a charging bias. In this embodiment, the surface of the photoconductor 801 is uniformly charged to a potential (−680 V) substantially equal to the voltage applied to the charging roller 802 by the direct injection charging method.

Reference numeral 803 denotes a laser beam scanner (exposure device) including a laser diode, a polygon mirror and the like. This laser beam scanner outputs laser light (wavelength 740 nm) intensity-modulated in accordance with a time-series electric digital pixel signal of target image information, and the laser light L
Is scanned and exposed. By this scanning exposure, an electrostatic latent image corresponding to the target image information is formed on the rotating photoconductor 801.

Reference numeral 804 denotes a developing device. The electrostatic latent image on the surface of the photoconductor 804 is developed as a toner image by this developing device. The developing device 804 of the embodiment is a non-contact reversal developing device using an insulating negatively charged magnetic toner. The magnetic toner 4d contains magnetic toner particles (t) and conductive fine powder (m).

Reference numeral 804a denotes a developer carrying conveyance member.
A non-magnetic developing sleeve having a diameter of 16 mm and including a magnet roll 804b. This developing sleeve 804a
Is disposed opposite to the photoconductor 1 at a distance of 320 μm, and the photoconductor is moved in the forward direction with respect to the rotation direction of the photoconductor 801 at a developing unit (development area) a which is a portion facing the photoconductor 801. 801 is rotated at a peripheral speed ratio of 120% of the peripheral speed.

On this developing sleeve 804a, a magnetic toner 804d is coated in a thin layer by an elastic blade 804c. The magnetic toner 804d is
The thickness of the layer on the developing sleeve 804a is regulated by c and an electric charge is applied.

[0284] The magnetic toner 804d coated on the developing sleeve 804a is conveyed to the developing section a, which is the opposing portion of the photosensitive member 801 and the developing sleeve 804a, by the rotation of the developing sleeve 804a.

A developing bias voltage is applied to the developing sleeve 804a by a developing bias applying power source S2. The developing bias voltage is obtained by superimposing a DC voltage of −420 V and a rectangular AC voltage having a frequency of 1500 Hz and a peak-to-peak voltage of 1600 V (electric field intensity of 5 × 10 ⁶ V / m). One-component jumping development is performed between 801. In the present invention, the conductive fine powder m is not only applied to the charging roller but may be externally added to the magnetic toner.

The presence of the conductive fine powder m can maintain the close contact property and contact resistance of the charging roller 802 with the photosensitive member 801.
For direct injection charging.

The charging roller 802 comes into close contact with the photosensitive member 801 via the conductive fine powder m, and the conductive fine powder m rubs the surface of the photosensitive member 801 without any gap. This makes it possible for the charging of the photoconductor 801 by the charging roller 802 to be dominated by stable and safe direct injection charging without using a discharge phenomenon, and high charging that cannot be obtained by conventional roller charging or the like. Efficiency is obtained. Therefore, a potential substantially equal to the voltage applied to the charging roller 802 can be given to the photoconductor 801.

The toner image on the photosensitive drum 801 is transferred to the transfer portion b
Is transferred to the transfer material P by the transfer roller 805 to which the transfer bias is applied by the transfer bias application power source S3. The transfer roller 805 applies a linear pressure of 1 to
Pressing at 80 g / cm.

[0289]

Although the basic configuration and features of the present invention have been described above, the present invention will be specifically described below based on the embodiments. However, this does not limit the embodiment of the present invention at all. Parts in the examples are parts by mass.

The resins used in the examples are shown in Table 1, the waxes are shown in Table 2, and the magnetic iron oxide particles are shown in Table 3. Styrene resin was synthesized by solution polymerization or suspension polymerization, and polyester resin was synthesized by dehydration condensation. Hereinafter, a method for producing magnetic iron oxide particles will be described.

Production Example 1 of Magnetic Iron Oxide Particles An aqueous solution of sodium hydroxide in an amount of 0.95 equivalent to Fe ²⁺ was mixed with a ferrous sulfate solution, and then ferrous iron containing Fe (OH) ₂ was added. An aqueous salt solution was produced. Then, sodium silicate was added in an amount of 1.0 mass% in terms of silicon element with respect to iron element.
Was added so that Then, air was passed through the aqueous ferrous salt solution containing Fe (OH) ₂ at a temperature of 90 ° C. to adjust the pH.
By performing an oxidation reaction under the conditions of 6 to 7.5, magnetic iron oxide particles containing a silicon element were produced. Further, to this suspension, an aqueous sodium hydroxide solution in which 0.1% by mass of sodium silicate (in terms of silicon element with respect to iron element) was dissolved was added in an amount of 1.05 equivalent to the remaining Fe ²⁺ , and the temperature was further increased. While heating at 90 ° C., an oxidation reaction was performed under conditions of pH 8 to 11.5 to produce magnetic iron oxide particles containing silicon element. Wash the generated magnetic iron oxide particles by the usual method.
Filtered and dried.

Since the obtained primary particles of the magnetic iron oxide particles are aggregated to form an aggregate, they are compressed into an aggregate of the magnetic iron oxide particles using a mix muller (manufactured by Shinto Kogyo Co., Ltd.). By applying force and shearing force, the aggregates are crushed to make the magnetic iron oxide particles primary particles, and the surface of the magnetic iron oxide particles is smoothed, and the magnetic iron oxide particles have the properties shown in Table 3. Particle 1 was obtained. The average particle size of the magnetic iron oxide particles was 0.21 μm. The surface of the magnetic iron oxide particles 1 was formed of iron oxide and silicon oxide.

[0293] Magnetic same manner as in Example 2 Production Example 1 of the iron oxide particles, to obtain magnetic iron oxide particles 2 of Preparation 2 instead of silicon element content. The surface of the magnetic iron oxide particles 2 was formed of iron oxide and silicon oxide.

Production Examples 3 and 4 of Magnetic Iron Oxide Particles Before the filtration step of the magnetic iron oxide particles obtained in Production Example 2, a predetermined amount of aluminum sulfate was added to the slurry to adjust the pH to 6
The surface treatment of the magnetic iron oxide particles was performed as aluminum hydroxide to adjust the magnetic iron oxide particles 3 and 4 of Production Examples 3 and 4 as aluminum hydroxide. The magnetic iron oxides of Production Examples 3 and 4 were subjected to consolidation and disintegration treatment by a mix muller as in Production Example 1. The surfaces of the magnetic iron oxide particles 3 and 4 were formed of iron oxide, silicon oxide, aluminum oxide, and aluminum hydroxide.

Production Examples 5 and 6 of Magnetic Iron Oxide Particles At the time of the first stage reaction of Production Example 1, a predetermined total silicon content was charged, and the aqueous sodium hydroxide solution to be charged was
Magnetic iron oxide particles 5 and 6 of Production Examples 5 and 6 were obtained by changing the pH adjustment to an amount exceeding 1 equivalent to e ²⁺ and changing the pH adjustment.
The surfaces of the magnetic iron oxide particles 5 and 6 were formed of iron oxide and silicon oxide.

Production Example 7 of Magnetic Iron Oxide Particles Sodium silicate was added to an aqueous solution of ferrous sulfate so that the content ratio of silicon element to iron element was 1.8%. On the other hand, 1.0 to 1.1 equivalents of an aqueous alkali hydroxide solution were mixed to produce an aqueous ferrous salt solution containing Fe (OH) ₂ . Then, while maintaining the pH of the aqueous solution at 9, air was passed through at a temperature of 85 ° C. to cause an oxidation reaction, thereby producing magnetic iron oxide particles containing a silicon element. Further, an aqueous solution of ferrous sulfate was added to the suspension so as to have an equivalent amount of 1.1 equivalents to the initial amount of alkali (the sodium component of sodium silicate and the sodium component of alkali hydroxide). Was maintained at 8, and the oxidation reaction was promoted while blowing air in. At the end of the oxidation reaction, the pH was adjusted to a slightly alkaline side to obtain magnetic iron oxide particles.

The produced magnetic iron oxide particles were washed, filtered and dried by a conventional method, and then the aggregated magnetic iron oxide particles were subjected to ordinary crushing treatment to obtain magnetic iron oxide particles 7. The surface of the magnetic iron oxide particles 7 was formed of iron oxide and silicon oxide.

Example 1-100 parts of binder resin A-90 parts of magnetic iron oxide particles 3-4 parts of wax c-2 parts of azo-based iron complex compound A 2 parts of the above materials were premixed with a Henschel mixer, and then 130 parts.
The mixture was melt-kneaded by a twin-screw kneading extruder set at a temperature of ° C.

The obtained kneaded material was cooled and coarsely pulverized to 1 mm or less with a cutter mill to obtain a coarsely pulverized material. The obtained coarsely pulverized product is finely pulverized by a mechanical pulverizer 301 shown in FIG. 2, and the obtained finely pulverized product is classified by using a multi-segment classifier shown in FIG. 2, and has a weight average particle size of 6.5 μm. Magnetic toner particles were obtained.
In the present embodiment, the rotor 314 of the mechanical pulverizer 301 and the pulverized surfaces of the stator 310 that have been subjected to a wear-resistant treatment by nitriding are used. As for the surface roughness after the treatment, the center line roughness Ra was 1.1 μm, the maximum roughness Ry was 20.6 μm, and the ten-point average roughness was 12.3 μm. The peripheral speed of the rotor 314 is set to 11
7 m / s, the gap between the rotor 314 and the stator 310 is 1.3
mm. At this time, the inlet temperature T1 is -10
° C and outlet temperature T2 was 42 ° C.

With respect to 100 parts of the obtained magnetic toner particles,
1.2 parts of negatively chargeable hydrophobic silica fine powder having a methanol wettability of 80% and a BET specific surface area of 120 m ² / g treated with 15% by mass of hexamethyldisilazane and 15% by mass of dimethyl silicone, and strontium titanate 1 0.0 parts of the magnetic toner was filled with a Henschel mixer FM10C / l (manufactured by Mitsui Mining Co., Ltd.) so that the apparent volume filling ratio of the dry magnetic toner was 12%, and the Y0 blade and the S0 blade shown in FIG. Using the number of rotations 45.00
Stir for 1 minute at s ^-1 and then continue at 50.00 s ^-1 for 2 minutes.
The toner particles are stirred for about 1 minute. 1 was prepared.

Table 4 shows the toner internal additive formulation, grinding conditions and physical properties. FIG. 20 shows the relationship between the circularity of No. 1 and the average particle size, and FIG. 22 shows the relationship between the half-width with respect to the weight average size X and the peak particle size.

The magnetic toner No. 1 was modified from a commercially available LBP printer of the type shown in FIG. 13 (LBP-930, manufactured by Canon Inc.) to a print speed 1.5 times equivalent to a process speed of 235 mm / sec.
Temperature, low humidity (15 ° C, 10% RH)
A print test of 15,000 sheets was performed in an environment of H) and in an environment of high temperature and high humidity (30 ° C., 80% RH).

The image density was measured with a Macbeth densitometer (manufactured by Macbeth) using a SPI filter to measure the reflection density to measure a 5 mm square image. Fogging is performed using a reflection densitometer (reflectometer model TC-6DS, manufactured by Tokyo Denshoku Co., Ltd.), and the worst value of the reflection density of the white background after image formation is Ds, and the average reflection density of the transfer material before image formation is Dr.
The fog was evaluated using Ds-Dr as the fog amount. The smaller the value, the better the fog suppression.

These evaluations were initially performed at 15,000 sheets.
I went after leaving it outside the machine for a day.

Regarding the evaluation of the transfer efficiency, commercially available LBP
23 with a printer (LBP-950, manufactured by Canon Inc.)
In an environment of 65 ° C. and 65% RH, a change in transferability at the initial stage and after the endurance of 10,000 sheets was evaluated. Plain paper of 75 g / cm ² was used as the transfer paper. The transferability is calculated from the value obtained by tapping off the untransferred toner and untransferred toner on the solid black 6PC photoreceptor with a polyester tape, and subtracting the Macbeth density of the tape-only tape from the Macbeth density of the tape. Was evaluated.

The evaluation of the consumption amount of the magnetic toner and the line width was performed using a Canon laser beam printer LBP-.
A normal temperature and normal humidity environment (23 ° C., 65% RH) using an image forming apparatus obtained by modifying 1760 from 16 sheets / min to 24 sheets / min.
After printing 1000 sheets, the latent image line width is set to about 420 μm in a 600 dpi 10-dot horizontal line pattern, 5000 images of 4% printing rate are output on A4 size paper, The amount of consumption was determined from the change in the amount of toner. Further, a solid black image was output, and the image density at this time was confirmed.

Further, a latent image of a 10-dot horizontal line pattern of 600 dpi (latent image line width: about 420 μm) was written at 1 cm intervals, developed, transferred to a PET OHP,
Established. The obtained horizontal line pattern image was obtained by using a surface roughness meter surf coder SE-30H (manufactured by Kosaka Laboratories) as a method of applying the toner on the horizontal line as a surface roughness profile, and the line width was determined from the width of this profile. Was.
When the line width is slightly thicker than the latent image line width, an image with the highest sharpness is obtained, and as the line width becomes narrower than the latent image line width, the reproducibility of a thin line decreases.

A magnetic toner having a high image density, an appropriate line width, and a small amount of toner consumption is preferable. A magnetic toner having a low image density and a small amount of toner consumption, and a magnetic toner having a small line width and a small amount of toner consumption are preferable. Magnetic toner is not a preferred form.

Regarding the evaluation of the image quality, an isolated one-dot pattern was formed using the above-described image forming tester, and the image was observed with an optical microscope to evaluate the dot reproducibility. A: The magnetic toner does not protrude from the latent image at all, and the dots are completely reproduced. B: The magnetic toner protrudes from the latent image in some places. C: The magnetic toner slightly protrudes from the latent image D: The magnetic toner protrudes much from the latent image

Regarding the evaluation of the tailing, a pattern of about 20 cm in length, in which a 4-dot horizontal line was printed in a 175 dot space, was formed using the above-described image forming tester.
The number of lines that were visually trailed on the lines among 0 lines was counted. A: No occurrence B: 2 or less C: 3 to 6 D: 7 to 14 E: 15 or more

The evaluation results are shown in Tables 8 to 12.

Example 2 In the same manner as in Example 1 except that the magnetic toner No.
2 was produced. However, the peripheral speed of the rotor 314 is 125 m /
s, grinding was performed with the gap between the rotor 314 and the stator 310 set to 1.3 mm. At this time, the inlet temperature T1 was −10 ° C., and the outlet temperature T2 was 37 ° C. The obtained magnetic toner No.
Table 4 shows the physical property values of Magnetic Toner No. 2 in Table 4. FIG. 20 shows the relationship between the circularity of No. 2 and the average particle diameter, and FIG. 22 shows the relationship between the weight average diameter X and the half-value width with respect to the peak particle size. Tables 8 to 12 show the results of the same test as in Example 1.

Example 3 In the same manner as in Example 1 except that the magnetic toner No.
3 was produced. However, the peripheral speed of the rotor 314 is set to 150 m /
s, grinding was performed with the gap between the rotor 314 and the stator 310 set to 1.3 mm. At this time, the inlet temperature T1 was −10 ° C., and the outlet temperature T2 was 53 ° C. The obtained magnetic toner No.
Table 4 shows the physical property values of Magnetic Toner No. 3 in Table 4. FIG. 20 shows the relationship between the circularity of No. 3 and the average particle diameter, and FIG. 22 shows the relationship between the weight average diameter X and the half value width with respect to the peak particle size. Tables 8 to 12 show the results of the same test as in Example 1.

Example 4 In the same manner as in Example 1 except that the magnetic toner No.
4 was produced. However, the peripheral speed of the rotor 314 is 114 m /
s, grinding was performed with the gap between the rotor 314 and the stator 310 set to 1.3 mm. At this time, the inlet temperature T1 was −10 ° C., and the outlet temperature T2 was 45 ° C. The obtained magnetic toner No.
Table 4 shows the physical property values of Magnetic Toner No. 4 in Table 4. FIG. 21 shows the relationship between the circularity of No. 4 and the average particle diameter, and FIG. 22 shows the relationship between the weight average diameter X and the half-value width with respect to the peak particle size. Tables 8 to 12 show the results of the same test as in Example 1.

Example 5 In the same manner as in Example 1 except that the magnetic toner No.
5 was produced. However, the peripheral speed of the rotor 314 is 115 m /
s, grinding was performed with the gap between the rotor 314 and the stator 310 set to 1.3 mm. At this time, the inlet temperature T1 was −10 ° C., and the outlet temperature T2 was 40 ° C. The obtained magnetic toner No.
Table 4 shows the physical property values of Magnetic Toner No. 5 in Table 4. FIG. 20 shows the relationship between the circularity of No. 5 and the average particle size, and FIG. 22 shows the relationship between the weight average size X and the half-width with respect to the peak particle size. Tables 8 to 12 show the results of the same test as in Example 1.

Example 6 In the same manner as in Example 1 except that the magnetic toner No.
No. 6 was produced. However, the peripheral speed of the rotor 314 is set to 144 m /
s, grinding was performed with the gap between the rotor 314 and the stator 310 set to 1.3 mm. At this time, the inlet temperature T1 was −10 ° C., and the outlet temperature T2 was 55 ° C. The obtained magnetic toner No.
Table 4 shows the physical property values of Magnetic Toner No. 6. FIG. 21 shows the relationship between the circularity of No. 6 and the average particle diameter, and FIG. 22 shows the relationship between the weight average diameter X and the half width with respect to the peak particle size. Tables 8 to 12 show the results of the same test as in Example 1.

Example 7 In the same manner as in Example 1 except that the magnetic toner No.
7 was produced. However, before the pulverizing step, medium pulverization was performed by a mechanical pulverizer 301 shown in FIG. The grinding conditions at this time were the same as those in the grinding step. However, pulverization was performed with the gap between the rotor 314 and the stator 310 set to 2.0 mm. Then, the peripheral speed of the rotor 314 is set to 144 m / s,
And the stator 310 were crushed with a gap of 1.3 mm. At this time, the inlet temperature T1 is −10 ° C., and the outlet temperature T2 is 55 ° C.
Met. The obtained magnetic toner No. Table 4 shows the physical property values of No. 7.
And the magnetic toner No. The relationship between the circularity of 7 and the average particle diameter is shown in FIG. 20, and the relationship between the weight average diameter X and the half-width with respect to the peak particle size is shown in FIG. Tables 8 to 12 show the results of the same test as in Example 1.

Example 8 In the same manner as in Example 7 except that the magnetic toner No.
No. 8 was produced. The obtained magnetic toner No. Table 4 shows the physical property values of Magnetic Toner No. 8 for Magnetic Toner No. 8. FIG. 20 shows the relationship between the circularity of No. 8 and the average particle size, and FIG. 22 shows the relationship between the half-width with respect to the weight average size X and the peak particle size. Tables 8 to 12 show the results of the same test as in Example 1.

Example 9 In the same manner as in Example 7 except that the magnetic toner No.
9 was produced. The obtained magnetic toner No. Table 4 shows the physical property values of Magnetic Toner No. 9. FIG. 21 shows the relationship between the circularity of No. 9 and the average particle diameter, and FIG. 22 shows the relationship between the weight average diameter X and the half value width with respect to the peak particle size. Tables 8 to 12 show the results of the same test as in Example 1.

Example 10 In the same manner as in Example 7 except that the magnetic toner No.
10 was produced. The obtained magnetic toner No. Table 5 shows the physical property values of Magnetic Toner No. 10 in Table 5. The relationship between the circularity of 10 and the average particle diameter is shown in FIG. 21, and the relationship between the weight average diameter X and the half width with respect to the peak particle size is shown in FIG. Tables 8 to 12 show the results of the same test as in Example 1.

Example 11 In the same manner as in Example 1 except that the magnetic toner No.
11 was produced. However, the peripheral speed of the rotor 314 is 90 m /
s, grinding was performed with the gap between the rotor 314 and the stator 310 set to 1.3 mm. At this time, the inlet temperature T1 was −10 ° C., and the outlet temperature T2 was 30 ° C. The obtained magnetic toner No.
Table 5 shows the physical property values of Magnetic Toner No. 11 in Table 5. The relationship between the circularity of No. 11 and the average particle size is shown in FIG.
FIG. 22 shows the relationship between the peak width and the half-value width. Tables 8 to 12 show the results of the same test as in Example 1.

Example 12 In the same manner as in Example 1 except that the magnetic toner No.
No. 12 was produced. However, the peripheral speed of the rotor 314 is 120 m
/ S, the gap between the rotor 314 and the stator 310 is 1.3 mm
As crushed. At this time, the inlet temperature T1 was −10 ° C., and the outlet temperature T2 was 50 ° C. Obtained magnetic toner N
o. Table 5 shows the physical property values of Magnetic Toner No. 12. 12
FIG. 20 shows the relationship between the circularity and the average particle diameter, and FIG. 22 shows the relationship between the weight average diameter X and the half width with respect to the peak particle size. Tables 8 to 12 show the results of the same test as in Example 1.

Example 13 In the same manner as in Example 1 except that the magnetic toner No.
13 was produced. However, the surface roughness, center line roughness Ra
Was 1.7 μm, the maximum roughness Ry was 35.6 μm, and the ten-point average roughness was 21.3 μm. Set the peripheral speed of the rotor 314 to 15
5 m / s, the gap between the rotor 314 and the stator 310 is 1.3
mm. At this time, the inlet temperature T1 is -10
° C and the outlet temperature T2 was 46 ° C. The obtained magnetic toner No. Table 5 shows the physical property values of Magnetic Toner No. 13 in Table 5.
The relationship between the circularity of No. 13 and the average particle size is shown in FIG. 20, and the relationship between the weight average size X and the half width with respect to the peak particle size is shown in FIG. Tables 8 to 12 show the results of the same test as in Example 1.

Example 14 In the same manner as in Example 1 except that the magnetic toner No.
14 was produced. However, the peripheral speed of the rotor 314 is 135 m
/ S, the gap between the rotor 314 and the stator 310 is 1.3 mm
As crushed. At this time, the inlet temperature T1 was −10 ° C., and the outlet temperature T2 was 33 ° C. Obtained magnetic toner N
o. Table 5 shows the physical property values of Magnetic Toner No. 14 in Table 5. 14
FIG. 21 shows the relationship between the circularity and the average particle diameter, and FIG. 22 shows the relationship between the weight average diameter X and the half-width with respect to the peak particle size. Tables 8 to 12 show the results of the same test as in Example 1.

Example 15 In the same manner as in Example 1 except that the magnetic toner No.
No. 15 was produced. However, the peripheral speed of the rotor 314 is 115 m
/ S, the gap between the rotor 314 and the stator 310 is 1.3 mm
As crushed. At this time, the inlet temperature T1 was −10 ° C., and the outlet temperature T2 was 48 ° C. Obtained magnetic toner N
o. Table 5 shows the physical property values of Magnetic Toner No. 15 in Table 5. Fifteen
FIG. 21 shows the relationship between the circularity and the average particle diameter, and FIG. 22 shows the relationship between the weight average diameter X and the half-width with respect to the peak particle size. Tables 8 to 12 show the results of the same test as in Example 1.

Comparative Example 1 A comparative magnetic toner (i) was prepared in the same manner as in Example 1 with the formulation shown in Table 5. However, the rotor and the stator used were mirror-finished and then abrasion-resistant by nitriding. The roughness of the crushed surface after the treatment has a center line roughness Ra of 0.9μ.
m, maximum roughness Ry is 9.0 μm, and ten-point average roughness is 6.4.
μm. The crushing was performed by setting the peripheral speed of the rotor 314 to 150 m / s and the gap between the rotor 314 and the stator 310 to 1.3 mm. At this time, the inlet temperature T1 is −10 ° C. and the outlet temperature T1 is
2 was 53 ° C. Table 5 shows the physical property values of the obtained comparative magnetic toner (i), and FIG. 20 shows the relationship between the circularity and the average particle diameter of the comparative magnetic toner (i). FIG. 22 shows the relationship. Example 1
Tables 8 to 12 show the results of the same tests.

Comparative Example 2 A comparative magnetic toner (ii) was prepared in the same manner as in Example 1 with the formulation shown in Table 5. However, the rotor and the stator were subjected to a blasting treatment, and then subjected to an abrasion resistance treatment by nitriding. The roughness of the ground surface after the treatment was such that the center line roughness Ra was 3.2.
μm, maximum roughness Ry is 43.5 μm, and ten-point average roughness is 3
5.4 μm, the peripheral speed of the rotor 314 is 90 m / s,
Grinding was performed with the gap between the rotor 314 and the stator 310 set to 1.0 mm. At this time, the inlet temperature T1 was −10 ° C., and the outlet temperature T2 was 31 ° C. The obtained comparative magnetic toner (i
The physical property values of i) are shown in Table 5, the relationship between the circularity and the average particle size of the comparative magnetic toner (ii) is shown in FIG. 21, and the relationship between the weight average size X and the half width with respect to the peak particle size is shown in FIG.
Tables 8 to 12 show the results of the same test as in Example 1.

Comparative Example 3 A comparative magnetic toner (iii) was prepared according to the formulation shown in Table 5. In the pulverizing step, the powder was pulverized with a fine pulverizer using an impinging air current pulverization, and the obtained finely pulverized powder was classified using a multi-part classifier utilizing the Coanda effect. Table 5 shows the physical property values of the obtained comparative magnetic toner (iii).
FIG. 20 shows the relationship between the circularity and the average particle size in ii), and FIG. 22 shows the relationship between the half-width with respect to the weight average size X and the peak particle size.
Shown in Tables 8 to 12 show the results of the same test as in Example 1.
Shown in

Comparative Example 4 A comparative magnetic toner (iv) was prepared according to the formulation shown in Table 5. In the pulverization process, the powder is pulverized by a pulverizer using an impinging airflow pulverizer, and the obtained pulverized powder is classified using a multi-segment classifier utilizing the Coanda effect. Was modified. Table 5 shows the physical property values of the comparative magnetic toner (iv) obtained. Tables 8 to 12 show the results of the same test as in Example 1.

Examples 16 to 20 The magnetic toner N used in Examples 1, 2, 12, 13, and 15
o. Using 1, 2, 12, 13 and 15 and commercially available LB
Image output was evaluated using a cartridge used for a P printer (LBP-250, manufactured by Canon Inc.) which was modified into a cartridge having the injection charging step described in FIG. The remodeling contents are as follows. A zinc oxide fine powder containing aluminum element with a resistance of 100 Ω · cm is uniformly coated with conductive fine powder on the charging roller, and the charging roller is charged with a DC voltage of -700 V from the charging bias applying power source S1. A bias was applied.

In this embodiment, the surface of the OPC photosensitive member 1 has a potential (−680) substantially equal to the voltage applied to the charging roller 2.
V) was uniformly charged by the direct injection charging method. The developing bias voltage is obtained by superimposing a DC voltage of −420 V and a rectangular AC voltage having a frequency of 1500 Hz and a peak-to-peak voltage of 1600 V (electric field intensity of 5 × 10 ⁶ V / m). One component jumping development was performed between body 1.

Using this cartridge, a commercially available LBP printer (LBP-250, manufactured by Canon Inc.) was modified so as to have a process speed of 120 mm / sec, and the toner consumption, image density, line width, dot Reproducibility and tailing were evaluated. Table 13 shows the results.

[0333]

[Table 1]

[0334]

[Table 2]

[0335]

[Table 3]

[0336]

Embedded image

[0337]

[Table 4]

[0338]

[Table 5]

[0339]

[Table 6]

[0340]

[Table 7]

[0341]

[Table 8]

[0342]

[Table 9]

[0343]

[Table 10]

[0344]

[Table 11]

[0345]

[Table 12]

[0346]

[Table 13]

Example 21 Binder resin B 100 parts Magnetic iron oxide particles 3 90 parts Wax c 4 parts Azo-based iron complex compound A 2 parts After the above materials were premixed with a Henschel mixer, 130
The mixture was melt-kneaded by a twin-screw kneading extruder set at a temperature of ° C.

The obtained kneaded material was cooled and coarsely pulverized to 1 mm or less with a cutter mill to obtain a coarsely pulverized material as a powder material for toner production. The obtained powdery raw material is finely pulverized by a mechanical pulverizer 301 shown in FIG. 2, and the obtained finely pulverized product is classified using a multi-divider classifier shown in FIG.
m of magnetic toner particles were obtained. In the present embodiment, the crushed surfaces of the rotor 314 and the stator 310 of the mechanical crusher 301 are subjected to surface roughening treatment to reduce the surface roughness to a center line roughness R.
a = 5.9 μm, maximum roughness Ry = 32.4 μm, ten-point average roughness = 21.4 μm, and abrasion resistance treatment was performed by nitriding. In addition, grinding was performed with the peripheral speed of the rotor 314 being 117 m / s and the gap between the rotor 314 and the stator 310 being 1.3 mm. At this time, the inlet temperature T1 is −10 ° C., and the outlet temperature T2
Was 42 ° C.

With respect to 100 parts of the obtained magnetic toner particles,
80 parts of methanol wettability hydrophobized by 15% by mass of hexamethyldisilazane and 15% by mass of dimethyl silicone, 1.2 parts of hydrophobic silica fine powder having a BET specific surface area of 120 m ² / g, and 1.0 part of strontium titanate were added. After external addition and mixing, the magnetic toner No. 16 were prepared.

Tables 14 and 15 show the toner internal addition formulation, grinding conditions and physical properties. FIG. 25 shows the relationship between the circularity of No. 16 and the average particle diameter.

The magnetic toner No. 16 was converted to a 1.5 times print speed of a commercially available LBP printer (LBP-930, manufactured by Canon Inc.) of the type shown in FIG.
65% RH environment, 15 ℃, 10% RH environment and 30%
A print test of 15,000 sheets was performed in an environment of 80 ° C. and 80% RH. The evaluation results are shown in Tables 16 to 18.

The image density was measured by using a Macbeth densitometer (manufactured by Macbeth) using an SPI filter to measure the reflection density, and an image of 5 mm square was measured. Fogging is performed using a reflection densitometer (reflectometer model TC-6DS, manufactured by Tokyo Denshoku Co., Ltd.), and the worst value of the reflection density of the white background after image formation is Ds, and the average reflection density of the transfer material before image formation is Dr.
The fog was evaluated using Ds-Dr as the fog amount. The smaller the value, the better the fog suppression.

[0353] These evaluations were initially performed at 15,000 sheets.
I went after leaving it outside the machine for a day.

For evaluation of the transfer efficiency, a commercially available LBP
23 with a printer (LBP-930, manufactured by Canon Inc.)
In an environment of 65 ° C. and 65% RH, a change in transferability at the initial stage and after the endurance of 10,000 sheets was evaluated. Plain paper of 75 g / cm ² was used as the transfer paper. The transferability is calculated from the value obtained by subtracting the Macbeth density of the tape-only tape from the Macbeth density of the tape-only tape, from the residual toner and the pre-transfer toner on the solid black photoreceptor by taping with a polyester tape and peeling off. Was evaluated. Table 19 shows the evaluation results.

Example 22 In the same manner as in Example 21 except that the magnetic toner N
o. 17 was produced. However, the peripheral speed of the rotor 314 is set to 12
5 m / s, the gap between the rotor 314 and the stator 310 is 1.3
mm. At this time, the inlet temperature T1 is -10
° C and outlet temperature T2 was 37 ° C. The obtained magnetic toner No. Table 14 and Table 15 show the physical property values of Magnetic Toner No. 17, respectively. FIG. 25 shows the relationship between the circularity of No. 17 and the average particle diameter.
Shown in Tables 16 to 19 show the results of the same test as in Example 21.

Example 23 In the same manner as in Example 21 except that the magnetic toner N
o. 18 were produced. However, the peripheral speed of the rotor 314 is set to 15
0 m / s, the gap between the rotor 314 and the stator 310 is 1.3
mm. At this time, the inlet temperature T1 is -10
° C and outlet temperature T2 was 63 ° C. The obtained magnetic toner No. Table 14 and Table 15 show the physical property values of Magnetic Toner No. 18 for Magnetic Toner No. 18. FIG. 25 shows the relationship between the circularity of 18 and the average particle diameter.
Shown in Tables 16 to 19 show the results of the same test as in Example 21.

Example 24 In the same manner as in Example 21 except that the magnetic toner N
o. 19 were produced. However, the peripheral speed of the rotor 314 is set to 11
4 m / s, the gap between the rotor 314 and the stator 310 is 1.3
mm. At this time, the inlet temperature T1 is -10
° C and the outlet temperature T2 was 45 ° C. The obtained magnetic toner No. Table 14 and Table 15 show the physical property values of Magnetic Toner No. 19, respectively. FIG. 26 shows the relationship between the circularity of 19 and the average particle diameter.
Shown in Tables 16 to 19 show the results of the same test as in Example 21.

Example 25 A magnetic toner N was prepared in the same manner as in Example 21 with the formulation shown in Table 14.
o. 20 were produced. However, the peripheral speed of the rotor 314 is set to 11
5 m / s, the gap between the rotor 314 and the stator 310 is 1.3
mm. At this time, the inlet temperature T1 is -10
° C and the outlet temperature T2 was 40 ° C. The obtained magnetic toner No. Table 14 and Table 15 show the physical property values of the magnetic toner No. 20. FIG. 25 shows the relationship between the circularity of No. 20 and the average particle diameter.
Shown in Tables 16 to 19 show the results of the same test as in Example 21.

Example 26 In the same manner as in Example 21 except that the magnetic toner N
o. 21 was produced. However, the peripheral speed of the rotor 314 is set to 14
4 m / s, the gap between the rotor 314 and the stator 310 is 1.3
mm. At this time, the inlet temperature T1 is -10
° C and the outlet temperature T2 was 60 ° C. The obtained magnetic toner No. Table 14 and Table 15 show the physical property values of Magnetic Toner No. 21. FIG. 26 shows the relationship between the circularity of No. 21 and the average particle diameter.
Shown in Tables 16 to 19 show the results of the same test as in Example 21.

Example 27 In the same manner as in Example 21 except that the magnetic toner N
o. No. 22 was produced. However, if the peripheral speed of the rotor 314 is 90
m / s, the gap between the rotor 314 and the stator 310 is 1.3 m
pulverized as m. At this time, the inlet temperature T1 is −10 ° C.
The outlet temperature T2 was 30 ° C. Obtained magnetic toner N
o. Table 14 and Table 15 show the physical property values of Magnetic Toner No. 22. FIG. 26 shows the relationship between the circularity of No. 22 and the average particle diameter. Table 16 shows the results of the same test as in Example 21.
To 19.

Comparative Example 5 A comparative magnetic toner (v) was prepared in the same manner as in Example 21 with the formulation shown in Table 14. However, the surface roughness of the pulverized surface was determined as follows: center line roughness Ra = 1.8 μm, maximum roughness Ry = 13.5 μm.
m, ten-point average roughness = 9.8 μm, and abrasion resistance treatment was performed by nitriding. The crushing was performed by setting the peripheral speed of the rotor 314 to 150 m / s and the gap between the rotor 314 and the stator 310 to 1.3 mm. At this time, the inlet temperature T1 is −10 ° C. and the outlet temperature T1 is
2 was 63 ° C. The physical properties of the obtained comparative magnetic toner (v) are shown in Tables 14 and 15, and the relationship between the circularity and the average particle diameter of the comparative magnetic toner (v) is shown in FIG. Tables 16 to 19 show the results of the same test as in Example 21.
Shown in

Comparative Example 6 A comparative magnetic toner (vi) was produced in the same manner as in Example 21 with the formulation shown in Table 14. However, the surface roughness of the pulverized surface was determined as follows: center line roughness Ra = 12.3 μm, maximum roughness Ry = 70.8
μm, ten-point average roughness = 41.3 μm, and abrasion resistance treatment was performed by nitriding. The peripheral speed of the rotor 314 is 90 m / s,
Grinding was performed with the gap between the rotor 314 and the stator 310 set to 1.3 mm. At this time, the inlet temperature T1 was −10 ° C., and the outlet temperature T2 was 31 ° C. The obtained comparative magnetic toner (v
Tables 14 and 15 show the physical property values of i), and FIG. 26 shows the relationship between the circularity and the average particle diameter of the comparative magnetic toner (vi). Table 16 shows the results of the same test as in Example 21.
To 19.

Comparative Example 7 A comparative magnetic toner (vii) was prepared according to the formulation shown in Table 14. In the pulverizing step, the powder was pulverized with a fine pulverizer using an impinging air current pulverization, and the obtained finely pulverized powder was classified using a multi-part classifier utilizing the Coanda effect. The physical properties of the obtained comparative magnetic toner (vii) are shown in Tables 14 and 15, and the relationship between the circularity and the average particle diameter of the comparative magnetic toner (vii) is shown in FIG.
It is shown in FIG. Tables 16 to 19 show the results of the same test as in Example 21.

Comparative Example 8 A comparative magnetic toner (viii) was prepared according to the formulation shown in Table 14. In the pulverization process, the powder is pulverized by a pulverizer using an impinging airflow pulverizer, and the obtained pulverized powder is classified using a multi-segment classifier utilizing the Coanda effect. Was modified. Table 14 and Table 15 show the physical property values of the obtained comparative magnetic toner (viii).
FIG. 25 shows the relationship between the circularity and the average particle diameter of the comparative magnetic toner (viii). Tables 16 to 19 show the results of the same test as in Example 21.

[0365]

[Table 14]

[0366]

[Table 15]

[0367]

[Table 16]

[0368]

[Table 17]

[0369]

[Table 18]

[0370]

[Table 19]

[0371]

According to the present invention, a toner having a specific number of magnetic iron oxides is prevented from adhering to a fixing device member irrespective of the configuration of the fixing device, and is used under high and low humidity. In addition, high image quality can be stably obtained, image defects do not occur over time, and transfer efficiency can be improved without impairing fixability.

[Brief description of the drawings]

FIG. 1 is a flowchart illustrating an example of a method for manufacturing a toner according to the present invention.

FIG. 2 is a schematic view showing a specific example of an apparatus system for carrying out an example of the toner manufacturing method of the present invention.

FIG. 3 is a schematic sectional view of an example of a mechanical pulverizer used in a pulverizing step of the toner of the present invention.

FIG. 4 is a schematic cross-sectional view taken along a line DD ′ in FIG. 3;

FIG. 5 is a perspective view of the rotor shown in FIG. 3;

FIG. 6 is a schematic cross-sectional view of a multi-split airflow classifier used in the toner classifying step of the present invention.

FIG. 7 is a flowchart for explaining a conventional manufacturing method.

FIG. 8 is a system diagram showing a conventional manufacturing method.

FIG. 9 is a schematic sectional view of a conventional collision-type airflow pulverizer.

FIG. 10 is a schematic sectional view of a multi-split airflow classifier used in a conventional second classifier.

FIG. 11 is a schematic diagram illustrating an example of an image forming apparatus suitable for forming an image using the magnetic toner of the present invention.

FIG. 12 is a schematic diagram illustrating an example of a suitable image forming apparatus.

FIG. 13 is a schematic diagram illustrating another example of a suitable image forming apparatus.

FIG. 14 is a diagram schematically illustrating a transfer device.

FIG. 15 is a diagram schematically illustrating a charging roller.

FIG. 16 is an explanatory diagram illustrating an example of the process cartridge of the present invention.

FIG. 17 is an explanatory diagram illustrating an example of a process cartridge using the elastic blade of the present invention.

FIG. 18 is an explanatory diagram illustrating an example of a process cartridge having an injection charging step used in an embodiment of the present invention.

FIG. 19 is an explanatory diagram of an apparatus used for measuring a charge amount of toner.

FIG. 20 is a diagram for explaining the relationship between circularity and average particle size.

FIG. 21 is a diagram for explaining the relationship between circularity and average particle size.

FIG. 22 shows a half-width Y with respect to a weight average diameter X and a peak particle size.
FIG. 4 is a diagram for explaining the relationship of FIG.

FIG. 23 shows a half-width Y with respect to a weight average diameter X and a peak particle size.
Is the data of the particle size distribution representing the relationship.

FIG. 24 is an explanatory diagram of a stirring blade during addition mixing used in an example of the present invention.

FIG. 25 is a diagram for explaining the relationship between circularity and average particle size.

FIG. 26 is a diagram for explaining the relationship between circularity and average particle size.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Multi-divider classifier 2 2nd fixed-quantity feeder 3 Vibration feeder 4,5,6 Collection cyclone 11,12,13 Discharge port 11a, 12a, 13a Discharge conduit 14,15 Intake pipe 16 Raw material supply nozzle 17,18 Classification edge DESCRIPTION OF SYMBOLS 19 Inlet edge 20 1st gas introduction adjustment means 21 2nd gas introduction adjustment means 22, 23 Side wall 24, 25 Classification edge block 26 Coanda block 27 Left block 28, 29 Static pressure gauge 30 Classification area 32 Classification chamber 40 Raw material supply port 41 High-pressure air nozzle 42 Raw material powder introduction nozzle 122 First classifier 123 Collection cyclone 124 Second quantitative feeder 125 Vibration feeder 127 Multi-divider classifier (second classifier) 128 Air flow crusher 129, 130, 131 Supplement Cyclone 135 Injection feeder 141,142 Side wall 14 , 144 Classification edge block 145 Coanda block 146, 147 Classification edge 148, 149 Raw material supply pipe 150 Classification chamber upper wall 151 Inlet edge 153, 153 Inlet pipe 154, 155 Gas introduction control means 156, 157 Static pressure gauge 158, 159, 160 Outlet 161 High-pressure gas supply nozzle 162 Acceleration tube 163 Acceleration tube outlet 164 Collision member 165 Raw material supply 166 Collision surface 167 Crushed material discharge 212 Swirl chamber 219 Pipe 220 Distributor 222 Bag filter 224 Suction filter 229 Collection cyclone 301 Mechanical grinding Machine 302 Powder outlet 310 Stator 311 Powder inlet 312 Rotary shaft 313 Casing 314 Rotor 315 First metering device 316 Jacket 317 Cooling water supply port 318 Cooling water discharge 320 Back chamber 321 Cold air generating means 331 Third constant supply device 701 Latent image carrier (photoconductor) 702 Transfer roller 702a Core 702b Conductive elastic layer 704 Developing sleeve (developer carrier) 705 Exposure 709 Developing device 711 Magnetic blade 723 constant voltage power supply 742 charging roller

──────────────────────────────────────────────────続 き Continued on the front page (51) Int.Cl. ⁷ Identification code FI Theme coat ゛ (Reference) G03G 15/02 101 G03G 9/08 301 15/08 504 325 507 346 346 21/18 381 15/08 507L 15 / 00556 (72) Inventor Tsutomu Konuma 3-30-2 Shimomaruko, Ota-ku, Tokyo Inside Canon Inc. (72) Inventor Tsuneo Nakanishi 3-30-2 Shimomaruko 3-chome, Ota-ku, Tokyo Inside Canon Inc. (72 ) Inventor Kaori Hiratsuka 3-30-2 Shimomaruko, Ota-ku, Tokyo F-term within Canon Inc. (reference) 2H005 AA01 AA02 AA06 AB04 CA05 CA14 CA22 CB01 CB02 CB03 CB06 DA02 EA01 EA03 EA05 EA06 EA10 FA01 2H071 BA05 DA06 DA09 DA15 2H077 AD06 AD13 AD23 EA13 2H200 FA12 GA23 GA46 GB41 HA03 HA28 JC00

Claims (45)

[Claims] 1. A dry toner having toner particles having at least a binder resin and magnetic iron oxide, wherein the particles having a free iron element are contained in the toner particles.
The toner has a weight average particle diameter of 5 μm to 12 μm,
In addition, in the toner particles having a particle diameter of 3 μm or more, the circularity a obtained by the following formula (1) has 90% by number or more based on the number of particles having a circularity of 0.900 or more, and circularity a = L ₀ / L (1) [Where L ₀ represents the circumference of a circle having the same projected area as the particle image, and L represents the circumference of the particle image. And a) the relationship between the cut rate Z and the toner weight average diameter X satisfies the following expression (2), and the cut rate Z ≦ 5.3 × X (2) [However, the cut rate Z is the particle of all the measured particles. When the concentration A (number / μl) and the measured particle concentration B (number / μl) having a circle-equivalent diameter of 3 μm or more are represented by the following equation (3). Z = (1−B / A) × 100 (3)] and the number-based cumulative value Y of particles having a circularity of 0.950 or more
And the toner weight average diameter X satisfy the following formula (4); the number-based cumulative value of particles having a circularity of 0.950 or more Y ≧ exp 5.51 × X ^−0.645 (4) [However, the toner weight average particle Diameter X: 5.0-12.0μ
m] or b) the relationship between the cut rate Z and the toner weight average diameter X satisfies the following formula (5), the cut rate Z> 5.3 × X (5), and the particles having a circularity of 0.950 or more Number-based cumulative value Y
And the toner weight average diameter X satisfy the following expression (6); the number-based cumulative value of particles having a circularity of 0.950 or more Y ≧ exp 5.37 × X ^−0.545 (6) [However, toner weight average particles Diameter X: 5.0-12.0μ
m]. 2. The dry toner according to claim 1, wherein the magnetic iron oxide particles are contained in an amount of 20 to 200 parts by mass with respect to 100 parts by mass of the binder resin. 3. The dry method according to claim 1, wherein the magnetic iron oxide particles are magnetic iron oxide fine particles containing 0.05 to 10% by mass of a different element based on iron element. toner. 4. The magnetic iron oxide particles contain Fe on the outermost surface.
The dry toner according to claim 3, wherein the / Si atomic ratio is from 1.2 to 7.0. 5. The magnetic iron oxide particles have a smoothness of 0.3 to 0.3.
The dry toner according to any one of claims 1 to 4, wherein the ratio is 0.8. 6. The magnetic iron oxide particles having a specific surface area of 15.0.
The dry toner according to claim 1, wherein m ² / g or less. 7. The method according to claim 1, wherein the magnetic iron oxide particles contain 0.01 to 2.0% by mass of an aluminum compound in terms of aluminum element. Dry toner. 8. Fe on the outermost surface of the magnetic iron oxide particles
The dry toner according to claim 7, wherein the / Al atomic ratio is 0.3 to 10.0. 9. The dry toner according to claim 1, wherein the binder resin has a carboxyl group or an acid anhydride group, and has an acid value of 1 to 100 mgKOH / g. . 10. The method according to claim 1, wherein the carboxyl group or the acid anhydride group of the binder resin is formed from an acid monomer selected from at least one of maleic acid, maleic acid half ester and maleic anhydride. The dry toner according to any one of claims 1 to 9, wherein: 11. The dry toner according to claim 1, wherein the binder resin is a styrene copolymer. 12. The dry toner according to claim 1, wherein the toner contains an azo metal complex compound represented by the following formula (I) as a charge control agent. Embedded image 13. The dry toner according to claim 1, wherein the toner contains a basic organometallic compound represented by the following formula (II) as a charge control agent. Embedded image 14. The dry toner according to claim 1, wherein the toner contains an azo-based iron complex compound represented by the following formula (III) as a charge control agent. Embedded image 15. The dry toner according to claim 1, wherein the toner contains an azo iron complex compound represented by the following formula (IV) as a charge control agent. Embedded image 16. The dry toner according to claim 1, wherein the toner contains 0.2 to 20 parts by mass of a release agent based on 100 parts by mass of the binder resin. 17. The dry toner according to claim 16, wherein the melting point of the release agent is 65 to 160 ° C. 18. The dry toner according to claim 1, wherein the surface of the magnetic iron oxide particles is formed of an oxide and / or a hydroxide. 19. The magnetic iron oxide particles have a hydrophobicity of 20%.
The dry toner according to any one of claims 1 to 18, wherein: 20. The magnetic iron oxide particles have a silicon content of 0.4 to 2.0% by mass based on the iron element, and have an Fe / Si atomic ratio of 1 on the outermost surface of the magnetic iron oxide particles. 2 to 4.0.
10. The dry toner according to any one of items 9 to 9. 21. 100 to 300 toner particles having free iron element per 10,000 toner particles, and the surface of the magnetic iron oxide particles is formed of an oxide and / or a hydroxide. The dry toner according to any one of claims 1 to 20, wherein: 22. The toner tetrohydrofuran (TH)
The soluble component of F) has a molecular weight of 2,000 in the molecular weight distribution measured by gel chromatography (GPC).
22. The dry toner according to claim 1, which has a main peak in a range of 0 to 25,000. 23. The toner has a Carr jetting index of 80.
The dry toner according to any one of claims 1 to 22, wherein the dry toner is larger than the toner. 24. A toner having a Carr fluidity index of 60.
24. The dry toner according to claim 1, wherein the toner is larger than the toner. 25. A toner having a Carr jetting index of 81.
The dry toner according to any one of claims 1 to 24, wherein the number is from 90 to 89. 26. A toner having a Carr fluidity index of 61.
26. The dry toner according to claim 1, wherein 27. The toner according to claim 1, wherein a half-width y with respect to a peak particle size x satisfies the following expression (7) in a number-based particle size distribution measured by a Coulter counter at 256 ch. The dry toner according to any one of the above. 2.06x-9.113≤y≤2.06x-7.341 (7) 28. When the absolute value of the triboelectric charge amount with respect to the iron powder carrier is | Qd |
28. The dry toner according to claim 1, wherein d│ ≧ 20 μC / g. 29. The toner is as follows: a) The relationship between the cut ratio Z and the toner weight average diameter X satisfies the expression 0 <cut ratio Z ≦ 5.3 × X, and the toner has a circularity of 0.950 or more. Number-based cumulative value Y
The dry toner according to any one of claims 1 to 28, wherein a relationship between the toner and the toner weight average diameter X satisfies the following expression. exp 4.85 × X ^−0.187 ≧ Y ≧ exp 5.51 × X
^-0.645 30. The toner: b) the relationship between the cut rate Z and the toner weight average diameter X satisfies the expression 95 ≧ cut rate Z> 5.3 × X, and the toner has a circularity of 0.950 or more. Number-based cumulative value Y
The toner according to any one of claims 1 to 28, wherein a relationship between the toner and the toner weight average diameter X satisfies the following expression. exp 4.85 × X ^-0.187 ≧ Y ≧ exp 5.37 × X
^-0.545 31. The dry toner according to claim 1, wherein the DSC curve of the toner measured by a differential scanning calorimeter has a maximum endothermic peak at 60 to 120 ° C. 32. The DSC curve measured by a differential scanning calorimeter of a toner has a maximum endothermic peak at 60 to 120 ° C., a sub-endothermic peak at 60 to 160 ° C., a maximum endothermic peak temperature T _max and a sub-endothermic peak. _32. The difference between the peak temperature T _sub and 20 ° C. or more.
The dry toner according to any one of the above. 33. The toner has a weight average particle size of 5 to 10 μm.
The dry toner according to any one of claims 1 to 32, wherein: 34. The particles having the free iron element are magnetic iron oxide particles, and the magnetic iron oxide particles have an average particle diameter of 0.1.
34. The apparatus according to claim 1, wherein the thickness is about 0.4 μm.
The dry toner according to any one of the above. 35. The magnetic toner particles are obtained by melt-kneading a mixture containing at least a binder resin, magnetic iron oxide particles and wax, cooling the kneaded material, coarsely pulverizing the cooled product, and obtaining the coarsely pulverized product. 35. It is obtained by finely pulverizing with a mechanical pulverizer.
The dry toner according to any one of the above. 36. An electrostatic image formed on an electrostatic image holder,
The electrostatic charge image is developed with dry toner held in the developing means to form a toner image, and the formed toner image is transferred to a transfer material with or without an intermediate transfer member, on the transfer material. An image forming method of fixing the toner image of (1) to a transfer material by a heat and pressure fixing means, wherein the toner has toner particles having at least a binder resin and magnetic iron oxide, and particles having a free iron element are 100 to 350 particles per 10,000 toner particles, the weight average particle diameter of the toner is 5 μm to 12 μm,
In addition, in the toner particles having a particle diameter of 3 μm or more, the circularity a obtained by the following formula (1) has 90% by number or more based on the number of particles having a circularity of 0.900 or more, and circularity a = L ₀ / L (1) [Where L ₀ represents the circumference of a circle having the same projected area as the particle image, and L represents the circumference of the particle image. And a) the relation between the cut rate Z and the toner weight average diameter X satisfies the following formula (2), and the cut rate Z ≦ 5.3 × X (2) [However, the cut rate Z is the particle of all the measured particles. When the concentration A (number / μl) and the measured particle concentration B (number / μl) having a circle-equivalent diameter of 3 μm or more are represented by the following equation (3). Z = (1−B / A) × 100 (3)] and the number-based cumulative value Y of particles having a circularity of 0.950 or more
And the toner weight average diameter X satisfy the following formula (4); the number-based cumulative value of particles having a circularity of 0.950 or more Y ≧ exp 5.51 × X ^−0.645 (4) [However, the toner weight average particle Diameter X: 5.0-12.0μ
m] or b) the relationship between the cut ratio Z and the toner weight average diameter X satisfies the following expression (5), and the cut ratio Z> 5.3 × X (5) and the particles having a circularity of 0.950 or more Number-based cumulative value Y
And the toner weight average diameter X satisfy the following expression (6); the number-based cumulative value of particles having a circularity of 0.950 or more Y ≧ exp 5.37 × X ^−0.545 (6) [However, toner weight average particles Diameter X: 5.0-12.0μ
m]. 37. The electrostatic image holder is charged by a contact charging unit to which a bias is applied, and a digital latent image is formed by exposing the charged electrostatic image holder to a developing unit. A magnetic toner image is formed by developing with a dry magnetic toner held in the printer, and the magnetic toner image is transferred by an abutting transfer unit to which a bias is applied to a transfer material via an intermediate transfer member or without the intermediate transfer member. 37. The image forming method according to claim 36, wherein: 38. The developing means has a developing sleeve enclosing a magnetic field generating means, and has an elastic blade for forming a magnetic toner layer on the developing sleeve. Or the image forming method according to 37. 39. The image forming apparatus according to claim 36, wherein the electrostatic image holding member is injected and charged by a contact charging means, and a conductive fine powder is externally added to the magnetic toner particles. Image forming method. 40. The dry toner according to claim 2, wherein the toner is a dry toner.
40. The image forming method according to any one of 6 to 39. 41. At least an electrostatic image carrier, a developing means for developing an electrostatic image formed on the electrostatic image carrier with dry toner, and a container for holding dry toner A process cartridge having a configuration in which the electrostatic image carrier, the developing means, and the container are integrally supported; the process cartridge is detachable from an image forming apparatus main body; A toner having toner particles having a coloring resin and magnetic iron oxide, wherein 100 to 350 particles having a free iron element exist per 10,000 toner particles, and the weight average particle diameter of the toner is 5 μm to 12 μm. ,
In addition, in the toner particles having a particle diameter of 3 μm or more, the circularity a obtained by the following formula (1) has 90% by number or more based on the number of particles having a circularity of 0.900 or more, and circularity a = L ₀ / L (1) [Where L ₀ represents the circumference of a circle having the same projected area as the particle image, and L represents the circumference of the particle image. And a) the relationship between the cut rate Z and the toner weight average diameter X satisfies the following formula (2), and the cut rate Z ≦ 5.3 × X (2) [However, the cut rate Z is the particle of all the measured particles. When the concentration A (number / μl) and the measured particle concentration B (number / μl) having a circle equivalent diameter of 3 μm or more are expressed by the formula (3). Z = (1−B / A) × 100 (3)] and the number-based cumulative value Y of particles having a circularity of 0.950 or more
And the toner weight average diameter X satisfy the following formula (4); the number-based cumulative value of particles having a circularity of 0.950 or more Y ≧ exp 5.51 × X ^−0.645 (4) [However, the toner weight average particle Diameter X: 5.0-12.0μ
m] or b) the relationship between the cut ratio Z and the toner weight average diameter X satisfies the following expression (5), and the cut ratio Z> 5.3 × X (5) and the particles having a circularity of 0.950 or more Number-based cumulative value Y
And the toner weight average diameter X satisfy the following expression (6); the number-based cumulative value of particles having a circularity of 0.950 or more Y ≧ exp 5.37 × X ^−0.545 (6) [However, toner weight average particles Diameter X: 5.0-12.0μ
m]. 42. The process cartridge according to claim 41, wherein the electrostatic image carrier is a photosensitive drum. 43. The process cartridge according to claim 41, wherein the process cartridge further includes a contact charging unit. 44. The process cartridge according to claim 41, wherein the process cartridge further has an intermediate transfer member. 45. The toner according to claim 2, wherein the toner is a dry toner according to claim 2. Description:
45. The process cartridge according to any one of 1 to 44.