JP2001201893A - Two-component developer - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a durable two-component developer having satisfactory triboelectric chargeability, even if it comprises a spherical toner and a spherical carrier, stably keeping the quantity of triboelectric charges because the satisfactory triboelectric chargeability is not impaired, even after long-term use and capable of forming an superior image. SOLUTION: The two-component developer has at least a toner and a magnetic carrier. The toner consists of at least a bonding resin and a colorant and, having a coating layer formed by sticking granular agglomerates containing at least a silicon compound to one another on the surface of each of toner particles having a shape factor SF1 of 1.0-1.2. The magnetic carrier has carrier particles, having a shape factor SF1 of 1.0-1.2 and a shape factor SF2 of 1.1-2.5.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a two-component developer for developing an electrostatic latent image in electrophotography, electrostatic recording and the like.

[0002]

2. Description of the Related Art Electrophotography is described in, for example, U.S. Pat. No. 2,297,691, Japanese Patent Publication No. 42-239.
Various methods are described in Japanese Patent Publication No. 10 and Japanese Patent Publication No. 43-24748. Each of these methods forms an electrostatic latent image by irradiating a photoconductive layer with a light image corresponding to a document, and then has an opposite polarity to the latent image on the electrostatic latent image. Using a colored resin fine powder called a toner as a developer, developing the electrostatic latent image by attaching it to form a toner image, and transferring the toner image to a transfer material such as paper as necessary, The copy is obtained by fixing with heat, pressure, solvent vapor or the like. In the step of developing the electrostatic latent image, the charged toner particles are made visible by attaching the charged toner particles to the electrostatic latent image by utilizing the electrostatic interaction of the electrostatic latent image. Is formed. There are various methods for developing an electrostatic latent image using a toner.In general, as a developer, a method using a two-component developer in which a toner is dispersed in a particulate medium called a carrier, It is suitably used in full-color copying machines requiring high image quality and high-speed copying machines. Then, in order to enable formation of more precise and high-quality images, proposals have been made for optimizing the particle diameter of particles constituting the toner and the carrier.

For example, as means for facilitating control of the particle size of toner and carrier, Japanese Patent Application Laid-Open No. Sho 59-34538 and Japanese Patent Application Laid-Open No. Hei 22-220068
In the publications, a production method by a polymerization method is proposed,
Regarding the toner, JP-A-36-10231, JP-A-43-10799, and JP-A-51-148.
No. 95 proposes a production method using a polymerization method. The toner particles and carrier particles obtained by the polymerization method as described above are all spherical, so that the fluidity is far superior to that of a developer composed of amorphous particles obtained by a conventional pulverization method. , And developability, and high transfer efficiency can be obtained. However, in the case of a developer using spherical toner particles having a smooth surface and carrier particles having a smooth surface, friction between the toner and the carrier is low due to the slipperiness of each other and the low probability of contact between the toner and the carrier. There is a drawback that the chargeability is inferior, the rise of the triboelectric charge amount is slow, and the image characteristics are impaired.

To solve this problem, Japanese Patent Laid-Open Publication No. 1-1
No. 85653 proposes to increase the contact probability between the toner particles and the carrier particles by forming the developer inferior in sphericity to the spherical toner particles, that is, by combining the non-spherical carrier particles. Have been. However, when a non-spherical carrier having poor sphericity is used, the fluidity of the developer constituted by the non-spherical carrier is deteriorated, and the high fluidity, which is one of the effects of the spherical toner, is not exhibited. There is a disadvantage that. In addition, in the case of using toner particles that are spherical and have a very smooth surface, no matter how the contact probability between the toner particles and the carrier particles is increased by improving the shape of the carrier, sufficient triboelectrification and stable stability are obtained. There is a problem that a triboelectric charge cannot be obtained. In particular, this tendency is high when used in a high-speed machine for electrophotography.

[0005]

SUMMARY OF THE INVENTION Accordingly, an object of the present invention is to provide a two-component developer comprising a spherical toner and a spherical carrier, whereby a sufficient triboelectric charging property can be obtained.
It is another object of the present invention to provide a durable two-component developer capable of stably maintaining a triboelectric charge amount without impairing the sufficient triboelectric charging property even after printing a large number of sheets.

[0006]

The above objects can be achieved by the present invention described below. That is, the present invention
A two-component developer having at least a toner and a magnetic carrier, wherein the toner comprises at least a binder resin and a colorant, and has a shape factor SF1 of toner particles of 1.
0 to 1.2, having a coating layer formed by fixing at least particles of silicon containing particles on the surface of the toner particles, wherein the magnetic carrier has a shape factor of the carrier particles. SF1 is 1.0 to 1.2, and SF2 is 1.1 to 2.5. The shape factor SF1 of the toner particles and the magnetic carrier particles is an index indicating the sphericity of each particle. In the case of a true sphere, SF1 = 1. The shape factor SF2 is an index indicating the degree of fine irregularities on the surface of the particles.
= 1. Each calculation method will be described later.

[0007]

BEST MODE FOR CARRYING OUT THE INVENTION The inventors of the present invention have conducted intensive studies to solve the above-mentioned problems of the prior art, and as a result, have examined in detail the shapes of a carrier and a toner constituting a two-component developer. It has been found that when both are roughly spherical, excellent fluidity and developability are imparted to the developer, and the present invention has been accomplished. As a means for confirming that the shapes of the carrier and the toner are substantially spherical, the value of the shape factor SF1, which is an index indicating the sphericity, is used, and the value of SF1 is 1.0 to 1.2. It was found that excellent effects were obtained. That is, when one of the values of the shape factor SF1 of the toner and the magnetic carrier constituting the two-component developer is larger than 1.2, the excellent fluidity of the two-component developer as the object of the present invention is obtained. May not be achieved.

Further, according to a detailed study by the present inventors,
The shape factor SF1 of both the toner and the magnetic carrier is 1 to
Even in the range of 1.2, it was found that when the surfaces of both the toner particles and the magnetic carrier particles were too smooth, the triboelectric chargeability between the toner and the magnetic carrier tended to deteriorate. In this case, during print running, uncharged toner particles are likely to be generated, causing fogging and scattering of toner particles, and weak adhesion to magnetic carrier particles so that toner particles are not transported sufficiently. It was found that the image density could not be obtained in some cases. This is particularly noticeable in high-speed electrophotographic apparatuses that require rapid charging. On the other hand, the present inventors have studied using a toner and a magnetic carrier having fine irregularities on their respective surfaces, and found that a developer exhibiting extremely excellent charging characteristics can be obtained. Was. This is because, when the toner and the magnetic carrier are in contact with each other and the toner and the magnetic carrier are in contact with each other, if the toner and the magnetic carrier have appropriate irregularities formed on the particle surfaces of the toner and the magnetic carrier, the frictional charging is efficiently performed. It is thought that it becomes.

The fine irregularities on the surface of the toner constituting the two-component developer according to the present invention are such that at least a silicon compound is contained on the surface of the toner particles comprising at least the binder resin and the colorant constituting the toner. It is easily formed by the coating layer in a state where the granular mass is fixed. In the present invention, the coating layer in a state in which the granular lumps containing at least the silicon compound are fixed to each other, specifically, for example, on the surface of the toner particles by hydrolysis and polycondensation of a silicon compound represented by silane alkoxide. Some of them can be formed, and what is called a sol-gel film corresponds to this.

As a result of intensive studies by the present inventors, the surface of toner particles containing at least a binder resin and a colorant is
By providing a coating layer in which the above-mentioned granular lumps containing at least a silicon compound are fixed to each other, it is found that a toner having sufficient fluidity can be obtained without using a conventional external additive. The present invention has been reached. Thereby, it turned out that stable charging property can be maintained. Furthermore, since no external additive is used, even when the development is performed continuously, the external additive is not released or the external additive is not embedded in the toner particles, and the durability is excellent. all right.

The two-component developer of the present invention is composed of a magnetic carrier together with the toner having the above-mentioned characteristics. According to the studies made by the present inventors, the carrier further has a particle surface. It has been found that the shape factor SF2 indicating the degree of the unevenness needs to be in the range of 1.1 to 2.5. That is, the shape factor SF2 is 1.1
If the magnetic carrier has a particle size of less than 1, the surface becomes too smooth, and even when a toner having fine irregularities on the surface having the sol-gel film containing the metal atoms described above, excellent triboelectric charging characteristics cannot be obtained. On the other hand, fine irregularities on the surface of the magnetic carrier can be formed by exposing the surface of metal oxide fine particles containing a magnetic substance, resin fine particles, or the like. However, as the shape factor SF2 of the magnetic carrier becomes larger than 2.5, When the fine particles are exposed on the surface, these fine particles are easily detached from the surface of the magnetic carrier particles, so that not only the charging characteristics are changed but also the detached fine particles disturb the printed image.

In the present invention, when the shape factor SF2 is 1.
Any magnetic carrier can be used as long as it is within the range of 1 to 2.5. However, it is possible to use a magnetic material-dispersed resin magnetic carrier or a coated resin carrier that easily controls the surface characteristics. preferable. In the case of magnetic material-dispersed resin magnetic carrier particles, as a method of forming fine irregularities on the surface of the magnetic carrier, specifically, magnetic fine particles to be present inside the carrier or metal oxide fine particles containing a magnetic material Can be formed by exposing the surface. In the case of a coated resin carrier, metal oxide fine particles or resin fine particles are added to a coating resin for coating the surface of magnetic carrier particles of a magnetic substance alone such as ferrite magnetic carrier particles, and these are appropriately It can be formed by a method in which a projection is formed by being exposed to the surface in a state.

Hereinafter, the toner and carrier constituting the two-component developer of the present invention will be described in more detail. First, the “coating layer in a state where the granular lumps containing at least the silicon compound are fixed to each other” provided on the surface of the toner particles will be described in detail. Such a coating layer can be easily formed by a so-called sol-gel film manufacturing method described later.

The present inventors have studied the surface condition of the toner having the above-described excellent action, and
The following findings were obtained. First, by observing the cross section of the particles constituting the toner constituting the two-component developer of the present invention with a transmission electron microscope (TEM), the surface of the toner particles is formed of a granular mass having a diameter of several tens nm. It was possible to observe how the layered structure was formed.
Further, an electron probe microanalytical method using a scanning electron microscope (SEM) equipped with an X-ray microanalyzer.
ysis: EPMA), the result of examining the surface configuration of the toner particles before and after cleaning the toner with a surfactant showed that the reduction rate of the silicon element caused by the cleaning was small, and the granular mass containing the silicon compound was It was confirmed that instead of simply adhering to the surface of the toner particles, the granular masses were present on the surface of the toner particles in a state of being fixed to each other, forming a coating layer.

The method for confirming the layer structure of the coating layer formed by fixing the particulate masses containing at least the silicon compound, which is a constituent element of the toner constituting the two-component developer of the present invention, will be described below. I do. In the following procedure, a coating layer formed by fixing at least the granular lumps containing the silicon compound was confirmed.

<< Confirmation of coating layer formed by fixation of granular masses containing silicon compound >> Confirmation of presence / absence of layer structure by observation with a transmission electron microscope Embedding toner particles in epoxy resin After hardening with a microtome, an ultra-thin section of the toner particles is created and fixed in a measurement cell for a transmission electron microscope.
This was used as a sample. The above sample was observed at a magnification of 10,000 to 50,000 times with a Hitachi H-7500 type transmission electron microscope, and it was confirmed that a layer structure of a granular mass was present on the toner particle surface.

Confirmation of sticking of granular agglomerates by the reduction rate of the amount of silicon element on the surface of toner particles after washing with surfactant (1) Abundance of silicon atoms on the particle surface of toner by electron probe microscopic analysis Measurement of (mass%) The surface of the toner particles was measured using a S-4500 type field emission scanning electron microscope manufactured by Hitachi, Ltd. equipped with an X-ray microanalyzer X-5770W manufactured by Horiba, Ltd. Acceleration voltage 20 kV, absorption current value of sample 1.0 ×
Electron probe microscopic analysis was performed under the conditions of 10 ^-10 A and 25,000 times, and the abundance of silicon atoms when the total amount (% by mass) of carbon atoms, oxygen atoms, and silicon atoms was 100% Si ₁ (% by mass) was measured. The measurement was performed for 20 visual fields, and the average value was used as the measured value.

(2) Cleaning of Particle Surface of Toner with Surfactant 0.2 g of the toner is dispersed in 5 ml of a 5% aqueous solution of dodecylbenzenesulfonic acid, and the resulting mixture is subjected to an ultrasonic cleaner for 30 minutes to sufficiently clean the particle surface of the toner. Washed. Further, centrifugation and washing were repeated to completely remove dodecylbenzenesulfonic acid from the toner particle surface, and then dried under reduced pressure to isolate the toner.

(3) Measurement of abundance (% by mass) of silicon atoms on the particle surface of the toner after washing with a surfactant surfactant Abundance of silicon atoms detached from the particle surface of the toner by the above operation (2) In order to measure (mass%), an electron probe microscopic analysis of the surface of the particles of the toner after washing with the surfactant was performed in the same manner as in the above (1) to determine the abundance of silicon atoms Si ₂ (mass%). It was measured.

(4) Analysis of State of Coating Layer Formed by Granular Lumps Containing Silicon Compound Provided on Surface of Toner Particles Si ₁ and Si ₂ obtained by the above procedures (1) to (3) From the values, the reduction rate of the abundance of the silicon element on the surface of the toner particles caused by the surfactant washing was calculated by the following equation. When the rate of reduction of the abundance ratio of the silicon element on the surface of the toner particles is extremely small, the coating layer formed on the surface of the toner particles by the granular lumps containing the silicon compound adheres in a state where it is difficult to fall off the surface. It can be determined that there is. Therefore, the reduction rate of the abundance of the silicon element on the surface of the toner particles obtained by the following equation is 3%.
When the content is 0% or less, the coating layer formed on the surface of the toner particles is considered to be in a state in which the granular masses containing the silicon compound constituting the layer are firmly fixed to each other, and the silicon compound This is a means for confirming whether or not the granular lumps including the particles are in a fixed state.

[0021]

(Equation 1)

As described above, in the present invention,
Combine the visual confirmation of the layer structure with the granular mass by transmission electron microscopy observation and the measurement result of the reduction rate of the abundance of silicon element on the particle surface of the toner before and after washing with the surfactant. Coating layer formed by fixation of granular lumps containing silicon compound "
Confirmation means.

As confirmed by the above method, in the toner constituting the two-component developer of the present invention, the coating layer on the surface of the toner particles constituting the toner contains at least a silicon compound. Since the toner particles are formed by fixing the containing granular masses, fine irregularities are present on the surface of the toner particles, thereby realizing excellent charging characteristics. In the present invention, as a typical example of the production of a toner, a coating layer is formed on the surface of toner particles by a polycondensate of a silicon compound by a sol-gel method described below. It is in the form of a film, and is a film in which granular masses containing polycondensates of silicon compounds are chemically bonded to each other to form a coating layer covering the entire surface of the toner particles. For this reason, as in the case where a conventional fluidizing agent such as silica is adhered to the surface of the toner particles described above, there is room for generation of unattached free fine particles caused by the addition of the fluidizing agent and free fine particles due to deterioration in durability. There is no. Therefore, the toner constituting the two-component developer of the present invention has excellent durability.

According to a detailed study of the present inventors, the EPM
When the amount of silicon element present on the particle surface of the toner is measured by A, the amount is preferably 0.10 to 2
0.0 mass%, more preferably 0.1 to 10.0
Mass%, more preferably 0.10 to 4.0 mass%.
It has been found that a coating layer in a more preferable state can be obtained when it is within the range. That is, a case in which a coating layer formed by fixing particulate agglomerates containing a silicon compound such that the abundance of silicon atoms on the surface of the toner particles is 0.10% by mass or more is provided on the surface of the toner particles. Furthermore, it was confirmed that higher fluidity and better charging characteristics can be imparted to the toner. Further, when the amount of silicon atoms present on the surface of the toner particles provided with the coating layer formed by fixing the granular lumps containing the silicon compound is 0.10% by mass or more, the granular Since the surface of the toner particles is covered in a sufficient state by the coating layer formed by fixing the lumps, a higher fluidity can be imparted to the toner and a sufficient charge amount can be imparted to the toner. A toner is obtained. On the other hand, when the amount of silicon atoms on the surface of the toner particles is 2
By providing a coating layer that is 0.0% by mass or less,
It was found that the toner exhibited better fixability. This is because, in the case of a coating layer in which the amount of silicon atoms present on the surface of the toner particles satisfies the above conditions, the thermoplasticity of the binder resin constituting the toner particles is sufficiently exhibited. I think that the.

The method for measuring the abundance (% by mass) of silicon atoms in the particle cross section of the toner specified in the present invention will be described. << Method of Measuring Abundance of Silicon Atoms in Toner Section of Toner >> After embedding and solidifying the toner particles to be measured in an epoxy resin, an ultrathin section of the toner particles is prepared by a microtome to prepare a sample for measurement. This sample is placed on an aluminum sample stand for scanning electron micrographs, and fixed using a conductive carbon adhesive sheet.
For this sample, the amount of silicon atoms was quantified in the same manner as the above-described method for measuring the amount of silicon atoms present on the particle surface of the toner.

Further, as a result of a series of studies on the present invention, it was found that in the toner constituting the two-component developer of the present invention, the amount of silicon atoms present on the particle surface of the toner was 4.0% by mass.
It has been found that a more preferable effect can be obtained in the following cases. Such a configuration is easily achieved by using a compound having an organic substituent in the silicon compound in the coating layer formed by fixing the granular masses containing at least the silicon compound. It was also found that the durability of the toner could be further improved. This is probably due to the use of those having organic substituents in the silicon compound in the coating layer, which added the flexibility of the organic chains to the formed coating layer, resulting in excellent durability. Believe in things.

That is, when there is an organic substituent in the silicon compound in the coating layer formed by fixing the granular masses containing at least the silicon compound, the abundance of carbon atoms on the particle surface of the toner increases. In other words, when the total amount of carbon atoms, oxygen atoms and silicon atoms is assumed to be 100%, the amount of silicon atoms is considered to be reduced. As a result of comparing and examining the abundance of atoms and the durability of the toner, the abundance of silicon atoms on the particle surface of the toner was determined to be 100% of the total abundance of carbon, oxygen and silicon atoms.
When the content is 4.0% by mass or less, the durability of the coating layer formed becomes higher, thereby further improving the durability of the toner constituting the two-component developer of the present invention. Was found to be possible.

In the method for producing a toner constituting the two-component developer according to the present invention, toner particles comprising at least a binder resin and a colorant are prepared, and at least a silicon compound is formed on the surface thereof by a method described later. To form a coating layer formed by fixing the granular masses containing As the toner particles, conventionally known,
Any toner particles may be used as long as they contain at least a binder resin and a colorant, and if necessary, various additives. That is, the toner particles used in the present invention are:
After kneading the toner composition comprising the binder resin and other optional components, the kneaded product may be cooled and then pulverized. A so-called polymerization toner obtained by polymerizing a monomer may be used. However, in the toner constituting the two-component developer of the present invention, if the shape of the toner particles is irregular, the above-described coating layer formed on the surface of the toner is deteriorated due to friction between the toner particles. For ease of use, it is more preferable to use spherical toner particles as the toner particles. The spherical toner particles can be easily obtained by spheroidizing the toner particles produced by a pulverizing method or by producing the toner particles by a polymerization method.

As a typical production example of the coating layer formed by fixing the granular masses containing at least a silicon compound according to the present invention, an application of a method generally called a sol-gel method may be mentioned. it can. Hereinafter, a production example by the sol-gel method will be described. The sol-gel method is generally known as a technique for producing a planar metal compound polycondensation film or a solid metal compound polycondensate.
It is generally called a sol-gel film.

The sol-gel film is specifically formed by hydrolytic polycondensation of a silicon compound typified by silane alkoxide, and fine irregularities on the order of nm are observed on the surface thereof. The present inventors have conducted intensive studies, and as a result, by providing this sol-gel film on the surface of the toner particles, a sufficient charge amount can be imparted without using an external additive as in the conventional toner. ,and,
It has been found that a toner is obtained in which the performance of the toner hardly deteriorates due to durability.

A first method for forming a coating layer formed by fixing at least particles containing a silicon compound on the surface of toner particles is as follows. From outside the particle
There is a method in which a polycondensate of a silicon compound is deposited on the surface of the toner particles to form the coating layer on the surface of the toner particles. Specifically, a method of dispersing the base toner particles in water or an aqueous medium in which silane alkoxide is dissolved, and then dropping this dispersion solution into water or an aqueous medium to which an alkali has been added. is there. According to this method, the silane alkoxide dissolved in the dispersion solution containing the toner particles undergoes hydrolysis and polycondensation in the presence of an alkali, gradually insolubilizes, and further becomes hydrophobic. The interaction results in deposition on the surface of the toner particles. As a result, a coating layer is formed on the surfaces of the toner particles by fixing the granular lumps containing at least the silicon compound. Further, when the toner particles obtained by the dispersion polymerization described above are used, the reaction system after the completion of the polymerization of the parent toner particles may be cooled to room temperature, and then the silane compound may be dissolved therein and used as a toner dispersion. it can.

As the aqueous medium used above, for example, alcohols such as methanol, ethanol and isopropanol are used. When the organicity of these solvents is high, the solubility of the polycondensate of silane alkoxide increases. This makes it difficult for polycondensates of silane alkoxide to deposit on the surface of the toner particles. Therefore, it is preferable to use methanol or ethanol as the aqueous medium.

As a second method for forming a coating layer formed by fixing at least the granular mass containing a silicon compound on the surface of the toner particles, at least a binder resin and a colorant are contained. And, by dispersing the toner particles in which the silicon compound is contained, in water, or a mixed solvent of an aqueous solvent and water, hydrolysis and polycondensation of the silicon compound are performed on the surface of the toner particles, There is a method of forming the coating layer.

In the above method, the toner particles are
When dispersed in water or a mixed solvent of an aqueous solvent and water, the silicon compound contained in the toner particles comes into contact with water on the surface of the toner particles and undergoes hydrolysis. That is, the sol-gel reaction proceeds only near the surface of the toner particles. Further, after the reaction is completed, by washing with a solvent such as alcohol, unreacted silicon compounds remaining inside the toner particles can be removed. As a result, a polycondensate of the silicon compound is selectively present on the surface of the toner particles, and the coating layer is formed by fixing at least the granular lumps containing the silicon compound,
In addition, it is possible to form a coating layer in which the amount of silicon atoms present on the surface of the toner particles is larger than the amount present inside the toner particles.

Here, the aqueous solvent refers to a solvent that can be dissolved in water, and the aqueous solvent suitable for dispersing the toner particles in the above-mentioned method includes methanol,
Examples include alcohols such as ethanol and propanol, and mixed solvents thereof.

As a method of preliminarily incorporating the silicon compound in the toner particles, the silicon compound may be mixed at the time of the production of the toner particles, or the mother toner particles may be prepared by a conventional method and then added to the obtained particles. May be introduced. In this case, as a method of introducing the silicon compound into the toner particles after preparing the toner particles serving as the base, the silicon compound is swollen into the toner particles serving as the base in water or a mixed medium of water and an aqueous medium. Is effective. Specifically, the following methods are mentioned.

Specifically, for example, there is a method in which toner particles serving as a base and a silicon compound are dispersed in a liquid medium in which the silicon compound is not dissolved, typically in water. In this way, the silicon compound slightly dissolved in the liquid medium,
The silicon compound is absorbed into the toner particles due to physical contact between the dispersed silicon compound and the toner particles, or the silicon compound is absorbed into the toner particles by diffusing in the liquid medium, and the silicon compound is incorporated into the toner particles. Can be introduced. In this case, it is preferable to use a surfactant in order to stably disperse the silicon compound in the liquid medium.
As the surfactant, a conventionally known general agent can be used.

At this time, when a dispersion of the toner particles and a dispersion of the silicon compound are separately prepared and both are mixed,
It is not preferable to add the silicon compound dispersion to the toner particle dispersion because the toner particles tend to coalesce, resulting in a toner having a broader particle size distribution than the toner particles before the reaction. As a result, the obtained toner tends to have a problem that the distribution of the triboelectric charge amount becomes broad and the image is scattered. Therefore, in a case where a dispersion of toner particles and a dispersion of silicon compound are separately prepared and mixed, a method of adding the dispersion of toner particles to the dispersion of silicon compound is more preferable.

In order to maintain the particle size distribution of the toner particles before forming the coating layer after forming a coating layer on the surface of the toner particles to form the toner constituting the two-component developer of the present invention, silicon is required. In dispersing the compound in a liquid medium such as water, it is more preferable to disperse the silicon compound for the individual toner particles into as small droplets as possible. Further, as the method, it is preferable to use a method of mechanically stirring with a high-speed stirrer or the like, or a method of finely dispersing with an ultrasonic disperser or the like.

As described above, when the silicon compound is swelled and incorporated in the toner particles, the silicon compound and the other poorly water-soluble solvent are used in combination for the auxiliary purpose such as increasing the swelling speed. A silicon compound may be swelled therein. As the poorly water-soluble solvent used at this time, any solvent may be used as long as it is a solvent having a higher hydrophilicity than the silicon compound to be used and a solvent which is hardly soluble in water. Specific examples include isopentyl acetate, isobutyl acetate, methyl acetate, ethyl acetate and the like. When using these poorly water-soluble solvents, at any stage after the start of the polycondensation reaction of the silicon compound, by evaporating the poorly water-soluble solvent or by charging the toner particles into a hydrophobic medium, It is necessary to dissolve the poorly water-soluble solvent in the hydrophobic medium and remove it from the toner particles.
By performing the above operation, the unreacted silicon compound remaining in the toner particles can also be removed.

Further, as another method of swelling the silicon compound inside the toner particles serving as the base, the toner particles are dispersed in a liquid medium in which the silicon compound is dissolved, typically, alcohol, and the silicon compound is dispersed. There is a method of introducing a silicon compound into a toner by lowering the solubility. Examples of the method of lowering the solubility of the silicon compound include a method of lowering the temperature and gradually adding a liquid medium which is soluble in the liquid medium in which the silicon compound is soluble and which does not dissolve the silicon compound. As the latter method, specifically, for example, after dissolving a silicon compound in a low molecular weight alcohol such as methanol and dispersing the toner particles serving as a base, water is gradually added to lower the solubility of the silicon compound. And a method in which the silicon compound is swollen into toner particles and contained therein.

As described above, in the case where the method of dissolving the silicon compound and introducing the silicon compound into the interior of the toner particles is used, if the solubility of the silane alcohol after hydrolysis is high, the Since the silane alcohol dissolves into the medium from the surface and the dissolved silane alcohols may form particles alone, select a medium in which the silane alcohol obtained by hydrolyzing the silicon compound is hardly soluble. There is a need to.

When the polycondensation reaction of the silicon compound proceeds on the surface of the parent toner particles in which the silicon compound is swollen, the stirring speed depends on the particle concentration in the system, the size of the system, the swelling amount of the silicon compound, and the like. Although it depends on the particles, it is easy for the particles to coalesce if they are too slow or too fast,
Because it may cause the particle size distribution of the obtained toner to be disturbed,
The speed needs to be adjusted appropriately. In the above case, a general surfactant, a polymer dispersant, a solid dispersant, or the like may be used in order to stably disperse the base toner particles in the poorly water-soluble medium.

In the toner constituting the two-component developer of the present invention, the coating layer formed on the surface of the toner particles and formed by fixing the granular lumps containing at least the silicon compound is specifically described. And a coating layer comprising a polycondensate of a silicon compound obtained by hydrolyzing a silicon compound such as silane alkoxide by the above method and then subjecting the compound to polycondensation. The above reaction basically proceeds at room temperature.

To obtain a film-like polycondensate as described above,
It is necessary to use at least one silicon compound having at least two hydrolysis and polycondensation groups in one molecule. However,
Monofunctional compounds can be used in combination. Therefore, in the present invention, the following silicon compounds can be used when forming a coating layer formed by fixing at least the granular masses containing the silicon compound.

Examples of the bifunctional or higher silane alkoxide include tetramethoxysilane, methyltriethoxysilane, hexyltriethoxysilane, triethoxychlorosilane, di-tert-butoxydiacetoxysilane, hydroxymethyltriethoxysilane, tetraethoxysilane. Silane, tetra-n-propoxysilane, tetrakis (2-methacryloxyethoxysilane) silane, allyltriethoxysilane, allyltrimethoxysilane,
-Aminopropyltriethoxysilane, 3-aminopropyltrimethoxysilane, bis (triethoxysilyl) ethylene, bis (triethoxysilyl) methane, bis (triethoxysilyl) 1,7-octadiene, 2,2-
(Chloromethyl) allyltrimethoxysilane, ((chloromethyl) phenylethyl) trimethoxysilane, 1,
3-divinyltetraethoxydisiloxane, 2- (3,
4-epoxycyclohexyl) ethortrimethoxysilane, (3-glycidoxypropyl) methyldiethoxysilane, (3-glycidoxypropyl) methyldimethoxysilane, (3-glycidoxypropyl) trimethoxysilane, 3-mercapto Propyltriethoxysilane, methacrylamidopropyltriethoxysilane, methacryloxymethyltriethoxysilane, methacryloxymethyltrimethoxysilane, 3- (methacryloxypropyl) trimethoxysilane, 1,7-octadienyltriethoxysilane, 7- Octenyltrimethoxysilane,
Examples thereof include tetrakis (ethoxyethoxy) silane, tetrakis (2-methacryloxyethoxy) silane, vinylmethyldiethoxysilane, vinylmethyldimethoxysilane, vinyltriethoxysilane, and vinyltriphenoxysilane.

The monofunctional silane alkoxide which can be used in combination with the above-mentioned bifunctional or higher silane alkoxide includes, for example, (3-acryloxypropyl)
Dimethylmethoxysilane, o-Acryloxy (polyethyleneoxy) trimethylsilane, Acryloxytrimethylsilane, 1,3-Bis (methacryloxy) -2-trimethylsiloxypropane, 3-Chloro-2-trimethylsiloxypropene, (Cyclohexenyloxy) trimethyl Silane, methacryloxyethoxytrimethylsilane,
(Methacryloxymethyl) dimethylethoxysilane.

Further, as a sol-gel reactive compound other than silane alkoxide, for example, aminosilane such as 1,3,5,7-tetravinyl-1,3,5,7-tetramethylcyclotetrasilazane may be used. it can. These sol-gel reactive compounds can be used alone or
More than one type may be used in combination. In general, it is known that, in a sol-gel reaction, the bonding state of a sol-gel film generated varies depending on the acidity of a reaction medium. Specifically, when the medium is acidic, H ⁺ is electrophilically added to oxygen of the alkoxy group (（OR group) to be eliminated as an alcohol. The water then attacks nucleophilically and is replaced by a hydroxy group. At this time, when the content of water in the medium is low, the substitution reaction of the hydroxy group is particularly slow, so that a polycondensation reaction occurs before all of the alkoxy groups attached to the silane are hydrolyzed, so that the one-dimensional reaction can be performed relatively easily. Linear polymers and two-dimensional polymers are easily generated.

[0049] On the other hand, when the medium is an alkaline, OH ^-
The alkoxy group is easily changed to silane alcohol by the nucleophilic substitution reaction of In particular, when a silicon compound having three or more alkoxy groups in the same silane is used,
Polycondensation occurs three-dimensionally, and a polymer having many three-dimensional cross-links, that is, a sol-gel film having high strength is generated. In addition, the reaction is completed in a short time. Therefore, in order to form a sol-gel film on the surface of the toner particles serving as a base, it is preferable to carry out the sol-gel reaction under alkalinity, and specifically, it is preferable to carry out the reaction under alkaline conditions having a pH of 9 or more. Thereby, a sol-gel film having higher strength and excellent durability can be formed. Further, the above-mentioned sol-gel reaction basically proceeds even at room temperature, but since the reaction is accelerated by heating, heat may be applied to the reaction system as needed.

Next, the method of the present invention for producing toner particles serving as a base for forming a coating layer formed by fixing particulate masses containing at least a silicon compound to each other will be described.

Examples of the polymerizable monomer that can be used in the case of producing the parent toner particles by the polymerization method include styrene, o-methylstyrene, m-methylstyrene, p-methoxystyrene, and p-ethylstyrene. Styrene monomers such as styrene and pt-butylstyrene, acrylic acid, methyl acrylate, ethyl acrylate, n-butyl acrylate, n-propyl acrylate, isobutyl acrylate, octyl acrylate, dodecyl acrylate 2-ethylhexyl acrylate, stearyl acrylate, 2-chloroethyl acrylate, phenyl acrylate, methacrylic acid, methyl methacrylate, ethyl methacrylate, n-propyl methacrylate, n-butyl methacrylate, methacrylic acid Isobutyl, n-octyl methacrylate, Dodecyl methacrylate, 2-ethylhexyl methacrylate, stearyl methacrylate, phenyl methacrylate, diaminomethyl methacrylate, dimethylaminoethyl methacrylate, benzyl methacrylate, crotonic acid, isocrotonic acid, acid phosphoxyethyl methacrylate, acid phosphooxy Acrylic monomers such as propyl methacrylate, acroyl morpholine, 2-hydroxyethyl acrylate, 2-hydroxyethyl methacrylate, acrylonitrile, methacrylonitrile, acrylamide, methyl vinyl ether, ethyl vinyl ether, propyl vinyl ether, n-butyl ether, isobutyl Ether, β-chloroethyl vinyl ether, phenyl vinyl ether,
p-methylphenyl ether, p-chlorophenyl ether, p-bromophenyl ether, p-nitrophenyl vinyl ether, p-methoxyphenyl vinyl ether, vinyl ether monomers such as butadiene, itaconic acid, maleic acid, fumaric acid, itaconic acid Monobutyl, dibasic acid monomers such as monobutyl maleate, 2-vinylpyridine, 3-vinylpyridine, 4-vinylpyridine,
Heterocyclic monomers such as N-vinylimidazole can be exemplified. These monomers may be used alone or in combination of two or more, and a suitable polymer composition can be selected by arbitrarily combining them so as to obtain preferable characteristics.

Further, as a polymerization solvent (a solvent in which the polymerizable monomer is dissolved but the polymer is not dissolved) which can be used when preparing the base toner particles by the dispersion polymerization method, a solvent obtained by polymerization is used. A product (polymer) that precipitates as the polymerization proceeds can be used. Specifically, for example, methanol, ethanol, 1-propanol, 2-propanol, 1-butanol, 2-butanol, isobutyl alcohol, tertiary butyl alcohol, 1-pentanol, 2-pentanol, 3-pentanol, 2-methyl-1-butanol, isopentyl alcohol, tertiary pentyl alcohol, 1-
Hexanol, 2-methyl 1-pentanol, 4-methyl-2-pentanol, 2-ethylbutanol, 1-heptanol, 2-heptanol, 3-heptanol, 2
Linear or branched aliphatic alcohols such as -octanol and 2-ethyl 1-hexanol, butane, 2-methylbutane, n-hexane, cyclohexane, 2-methylpentane, 2,2-dimethylbutane, 2,3 -Dimethylbutane, heptane, n-octane, isooctane,
In addition to aliphatic hydrocarbons such as 2,2,3-trimethylpentane, decane, nonane, cyclopentane, methylcyclopentane, methylcyclohexane, ethylcyclohexane, p-menthane, and bicyclohexyl, aromatic hydrocarbons and halogenated carbons Examples include hydrogens, ethers, fatty acids, esters, sulfur-containing compounds, and mixtures thereof.

Further, as the polymer dispersant that can be used in the dispersion polymerization, specifically, for example, polystyrene,
Polyhydroxystyrene, polyhydroxystyrene-acrylate copolymer, hydroxylstyrene-vinyl ether or vinyl ester copolymer, polymethyl methacrylate, phenol novolak resin, cresol novolak resin, styrene-acryl copolymer, vinyl ether copolymer Specifically, for example, polymethyl vinyl ether, polyethyl vinyl ether,
Polybutyl vinyl ether, polyisobutyl vinyl ether, polyvinyl alcohol, polyvinyl pyrrolidone,
Polyvinyl acetate, styrene-butadiene copolymer, ethylene-vinyl acetate copolymer, vinyl chloride, polyvinyl acetal, cellulose, cellulose acetate, cellulose nitrate, alkylated cellulose, hydroxyalkylated cellulose, specifically, hydroxymethyl cellulose, Hydroxypropyl cellulose, a saturated alkyl polyester resin, an aromatic polyester resin, a polyamide resin, a polyacetal, a polycarbonate resin, or a mixture thereof, or can be formed using an arbitrary ratio of the monomers forming the polymer compound described above. Copolymers can be mentioned.

The toner constituting the two-component developer of the present invention contains a high molecular weight component or a gel component as a component of the toner to prevent offset or the like.
The melt viscosity characteristics can be adjusted as needed. The introduction of such a component is achieved by using a crosslinking agent having two or more polymerizable double bonds per molecule. Specific examples of the crosslinking agent include, for example, aromatic divinyl compounds such as divinylbenzene and divinylnaphthalene, ethylene glycol diacrylate, ethylene glycol dimethacrylate, triethylene glycol dimethacrylate, tetraethylene glycol dimethacrylate, and 1,3. -Butylene glycol dimethacrylate, trimethylolpropane triacrylate, trimethylolpropane trimethacrylate,
1,4-butanediol diacrylate, neopentyl glycol diacrylate, 1,6-hexanediol diacrylate, pentaerythritol triacrylate, pentaerythritol tetraacrylate, pentaerythritol dimethacrylate, pentaerythritol tetramethacrylate, glycerol acroxydimethacrylate, Examples include compounds of N, N-divinylaniline, divinyl ether, divinyl sulfide, and divinyl sulfone.

These can be used alone or in combination of two or more. In addition, these crosslinking agents can be mixed in advance with the polymerizable monomer, or can be appropriately added during the polymerization as needed. The concentration of these crosslinking agents used in the present invention can be appropriately adjusted in consideration of the molecular weight, molecular weight distribution, and the like of the polymer to be produced. It is preferable that the content be in the range of 01 to 5% by mass.

Examples of the binder resin that can be used when producing toner particles by a pulverization method include, for example, styrene-substituted homopolymers such as polystyrene, poly-p-chlorostyrene, and polyvinyltoluene; p-chlorostyrene copolymer, styrene-vinyltoluene copolymer, styrene-vinylnaphthalene copolymer, styrene-acrylate ester copolymer, styrene-methacrylic acid copolymer, styrene-α-chloromethyl methacrylate copolymer Polymer, styrene-acrylonitrile copolymer, styrene-vinyl methyl ether copolymer, styrene-vinyl ethyl ether copolymer, styrene-vinyl methyl ketone copolymer, styrene-butadiene copolymer, styrene-isoprene copolymer , Styrene-acrylonitrile-indene copolymer Such styrene copolymers, polyvinyl chloride, phenolic resin, natural modified phenolic resin,
Naturally modified maleic acid resin, acrylic resin, methacrylic resin, polyvinyl acetate, silicone resin, polyester resin, polyurethane, polyamide resin, furan resin, epoxy resin, xylene resin, polyvinyl butyral, terpene resin, cumarone indene resin, petroleum resin And the like. Crosslinked styrenic copolymers and crosslinked polyester resins are also preferred binder resins. In the toner constituting the two-component developer of the present invention, a gel component can be contained in the binder resin in order to prevent offset during melting.

As the colorant constituting the toner particles serving as the base, any pigment or dye can be used, and both can be used in combination. As the black colorant to be used, for example, carbon black, a magnetic substance, and a black color tone using a yellow / magenta / cyan colorant shown below are used. As the yellow colorant, compounds represented by condensed azo compounds, isoindolinone compounds, anthraquinone compounds, azo metal complexes, methine compounds and allylamide compounds are used. In particular,
C. I. Pigment Yellow 12, 13, 14, 15,
17, 62, 74, 83, 93, 94, 95, 97, 1
09, 110, 111, 120, 127, 128, 12
9, 147, 168, 174, 176, 180, 18
1, 191 are preferably used.

As the magenta coloring agent, condensed azo compounds, diketopyrrolopyrrole compounds, anthraquinones, quinacridone compounds, basic dye lake compounds, naphthol compounds, benzimidazolone compounds, thioindigo compounds, thioindigo compounds and perylene compounds are used. Specifically, C.I. I. Pigment Red 2, 3,
5, 6, 7, 23, 48: 2, 48: 3, 48: 4,5
7: 1, 81: 1, 144, 146, 166, 169,
177, 184, 185, 202, 206, 220, 2
21, 254 are particularly preferred.

As the cyan coloring agent, copper phthalocyanine compounds and derivatives thereof, anthraquinone compounds, basic dye lake compounds and the like can be used. Specifically, C.I. I.
Pigment Blue 1, 7, 15, 15: 1, 15: 2,
15: 3, 15: 4, 60, 62, 66 can be particularly preferably used.

These colorants can be used alone or as a mixture, or can be used in the form of a solid solution. The amount of the colorant added is preferably 40 to 150 parts by mass per 100 parts by mass of the binder resin when a magnetic material is used, and 100 parts by mass of the binder resin when another colorant is used. It is preferable to add 5 to 20 parts by mass per unit.

Further, a charge control agent may be added to the toner constituting the two-component developer of the present invention, if necessary. In this case, any known charge control agent can be used. However, it is preferable to use a charge control agent that can charge the toner quickly and stably maintain a constant charge amount. Specifically, as the negative charge control agent, for example, salicylic acid, alkyl salicylic acid, dialkyl salicylic acid, naphthoic acid, metal compounds such as dicarboxylic acid; sulfonic acid, a high molecular compound having a carboxylic acid in the side chain, It is preferable to use a boron compound, a urea compound, a silicon compound, calixarene and the like. As the positive charge control agent, for example, a quaternary ammonium salt, a polymer compound having the quaternary ammonium salt in a side chain, a guanidine compound, an imidazole compound, or the like is preferably used. These charge control agents are preferably added in the range of 0.5 to 10 parts by mass with respect to 100 parts by mass of the binder resin.

Next, a magnetic carrier which is another component of the two-component developer of the present invention will be described. As described above, in the present invention, a magnetic substance-dispersed resin carrier or a magnetic carrier of a magnetic substance alone such as ferrite whose surface is coated with a resin can be used. For this purpose, it is preferable to use a magnetic material-dispersed resin carrier produced by a polymerization method. Furthermore, in order to be able to permanently maintain the fine irregularities on the surface of the magnetic carrier, a thermosetting binder resin is used, the thermosetting binder resin is formed from a binder resin and a metal oxide, and a direct polymerization method is used. It is preferable to use the magnetic carrier obtained by the method described above. Hereinafter, this method will be described.

As a method for obtaining magnetic material-dispersed resin carrier particles, which are a preferred form of the above magnetic carrier particles, a method of mixing and polymerizing a monomer of a binder resin and a metal oxide containing at least a magnetic fine powder and directly polymerizing the same. A method for obtaining a magnetic carrier is exemplified. The monomers used for the polymerization at this time include, in addition to the vinyl monomers exemplified when forming the toner, bisphenols and epichlorohydrin as starting materials for epoxy resins, phenols and aldehydes as starting materials for phenol resins. ,
Urea and aldehydes as starting materials of urea resin, melamine and aldehydes as starting materials of melamine resin, and the like are used. For example, when using a thermosetting phenol resin as a binder resin to produce the magnetic carrier particles used in the present invention, in an aqueous medium, phenols and aldehydes as raw materials in the presence of a basic catalyst, It can be produced by mixing a metal oxide, preferably a metal oxide subjected to lipophilic treatment, and polymerizing the mixture.

Further, in the present invention, the magnetic carrier particles formed as described above are coated with a coating resin appropriately selected according to the charge amount of the toner, and the two-component developer of the present invention is optimally used. It is preferable to have a good chargeability and charge amount. The amount of the coating resin at this time is preferably in the range of 0.1 to 10% by weight, more preferably 0.3 to 5% by weight. However, in the present invention, the coating amount and the coating state are adjusted so that the shape factor SF1 of the magnetic carrier after resin coating is in the range of 1.0 to 1.2 and the shape factor SF2 is in the range of 1.1 to 2.5. Need to adjust. As the coating resin, a thermosetting silicone resin or the like can be used.

As the coating resin that can be used as described above, an insulating resin can be suitably used. The insulating resin may be a thermoplastic resin or a thermosetting resin.
Specifically, for example, as a thermoplastic resin, polystyrene, polymethyl methacrylate, acrylic resin such as styrene-acrylic acid copolymer, styrene-butadiene copolymer, ethylene-vinyl acetate copolymer, vinyl chloride, Vinyl acetate, polyvinylidene fluoride resin, fluorocarbon resin, perfluorocarbon resin, solvent-soluble perfluorocarbon resin, polyvinyl alcohol, polyvinyl acetal, polyvinylpyrrolidone, petroleum resin, cellulose, cellulose acetate, cellulose nitrate, methyl cellulose, hydroxymethyl cellulose, hydroxymethyl cellulose, hydroxy Cellulose derivatives such as propylcellulose, novolak resin, low molecular weight polyethylene, saturated alkyl polyester resin, polyethylene terephthalate, polybutane Terephthalate, aromatic polyester resins polyarylate, polyamide resins, polyacetal resins, polycarbonate resins, polyethersulfone resins, polysulfone resins, polyphenylene sulfide resins, polyether ketone resins.

As the curable resin, specifically, for example, a phenol resin, a modified phenol resin, a maleic resin, an alkyd resin, an epoxy resin, an acrylic resin, specifically, maleic anhydride-terephthalic acid-polyester Unsaturated polyester obtained by polycondensation of a polyhydric alcohol, urea resin, melamine resin, urea-melamine resin, xylene resin, toluene resin, guanamine resin, melamine-guanamine resin, acetoguanamine resin, gliptal resin, furan resin, silicone resin, Examples include polyimide, polyamide imide resin, polyether imide resin, and polyurethane resin. In addition, the above resin is
Although they can be used alone, they may be used in combination. Further, a curing agent or the like may be mixed with the thermoplastic resin and cured.

The magnetic fine particles used in producing the above-mentioned magnetic material-dispersed resin carrier include MO.Fe.
Magnetite, ferrite, and the like represented by the general formula of ₂ O ₃ or MFe ₂ O ₄ can be preferably used. Here, M is a divalent or monovalent metal, for example, M
n, Fe, Ni, Co, Cu, Mg, Zn, Cd, Li
And the like. M may be a single metal or a plurality of metals. Specific magnetic fine particles include, for example, magnetite, gamma iron oxide, Mn-Zn ferrite, Ni-Zn ferrite, Mn-Mg ferrite, Ca-Mg ferrite, Li ferrite, Cu
-Zn-based ferrite or the like can be used.

Further, in addition to the above-described magnetic metal oxides, as a material for producing a magnetic material-dispersed resin carrier, M
g, Al, Si, Ca, Sc, Ti, V, Cr, Mn,
Fe, Co, Ni, Cu, Zn, Sr, Y, Zr, N
A nonmagnetic metal oxide using a single metal or a plurality of metals such as b, Mo, Cd, Sn, Ba, and Pb can be used. Specifically, for example, as a non-magnetic metal oxide material, Al ₂ O ₃ , SiO ₂ , CaO, TiO ₂ , V
₂ O ₅ , CrO ₂ , MnO ₂ , Fe ₂ O ₃ , CoO, NiO,
CuO, ZnO, SrO, Y ₂ O ₃ , ZrO _{2 and the} like can be used.

In the present invention, there is no limitation on the particle size of the magnetic carrier formed from the above-mentioned materials.
In order to obtain a developer capable of forming a preferable image, the number average particle diameter is preferably in the range of 5 to 100 μm. There is no particular limitation on the magnetic force of the magnetic carrier particles.
It is preferably about 0 to 300 emu / cm ³ .

Hereinafter, a method of calculating the shape factors SF1 and SF2 of the respective particles constituting the toner and the magnetic carrier used in the two-component developer of the present invention will be described. The shape factor of these particles was measured by randomly photographing 100 enlarged photographs of toner particles and magnetic carrier particles with a field emission scanning electron microscope S-4500 manufactured by Hitachi, Ltd. Analysis is performed using an image processing and analysis device Luzex3 manufactured by the company, and further, a shape coefficient derived by the following equation is calculated, and an average thereof is obtained.

(Equation 2)

[0071]

The present invention will be described below in more detail with reference to examples and comparative examples of the present invention. First, the used toner and carrier will be specifically described. <Production of Toner> [Toner 1] 900 parts by weight of ion-exchanged water and 100 parts by weight of polyvinyl alcohol were charged into a four-necked flask equipped with a high-speed stirrer TK-Homomixer, and the number of rotation was 12
It was adjusted to 00 rpm and heated to 60 ° C. to produce an aqueous medium. On the other hand, the following composition (1) was mixed, heated to 60 ° C., and then stirred at 12,000 rpm using a TK homomixer (manufactured by Tokushu Kika Kogyo). In addition to this,
The polymerizable monomer composition in which 3 parts by weight of 2-azobisisobutyronitrile was dissolved was put into the aqueous medium prepared above, and the mixture was added at 60 ° C. with a TK homomixer under a nitrogen stream at 60 ° C.
The mixture was stirred at 000 rpm for 10 minutes, then heated to 80 ° C. while stirring with a paddle stirring blade, and reacted for 10 hours.
After the completion of the polymerization reaction, the remaining monomer was distilled off under reduced pressure. After cooling, hydrochloric acid was added to dissolve the calcium phosphate, followed by filtration, washing with water and drying to obtain a polymer toner (A). Composition (1) ・ Styrene monomer 90 parts by weight ・ n-butyl acrylate monomer 22 parts by weight ・ Carbon black 10 parts by weight ・ Salicylic acid metal compound 1 part by weight ・ Release agent 20 parts by weight

Subsequently, the above-mentioned polymer toner (A) 0.9
Parts by weight were dispersed in 5.0 parts by weight of methanol, and then 0.5 parts by weight of tetraethoxysilane and 0.3 parts by weight of methyltriethoxysilane were dissolved as silicon compounds, and then 50 parts by weight of methanol was added. did. Subsequently, a solution obtained by adding 100 parts by weight of methanol to 10 parts by weight of a 28% by weight aqueous NH ₄ OH solution was added dropwise thereto, and the mixture was stirred at room temperature for 48 hours, so that at least a polycondensate of a silicon compound was obtained. A film composed of the particles containing was deposited on the surface of the toner particles.

After completion of the reaction, the obtained particles are washed with purified water and then with methanol, and then the particles are separated by filtration and dried to obtain a coating composed of particles containing at least a polycondensate of a silicon compound. The toner covered by the layer is obtained. When the particle size of the obtained toner was measured by the above-described method, the number average particle size was 6.25 μm.
The shape factor SF1 was 1.06. Observation of the particle surface of the toner with a scanning microscope photograph revealed that a coating layer having fine granular irregularities having a diameter of about 40 nm was observed on the particle surface of the toner. Further, from observation of a cross section of the particles of the toner with a transmission electron microscope photograph, it was confirmed that a coating layer was formed on the surface of the particles of the toner.

The proportion of silicon atoms on the particle surface of the toner determined by EPMA was 3.31% by mass. Similarly, the proportion of silicon atoms in the cross section of the toner particles was 0.03%. Therefore,
The abundance ratio of silicon atoms on the surface of the toner particles is 11% of the abundance ratio of silicon atoms on the cross section of the toner particles.
The polycondensate of the silicon compound was hardly present inside the toner particles. Further, after the toner was washed with a 5% aqueous solution of dodecylbenzenesulfonic acid, the abundance ratio of silicon atoms on the surface of the toner particles was 2.99.
%Met. Therefore, the reduction rate of silicon atoms present on the particle surface of the toner before and after washing with the surfactant was 9.67%. Therefore, it was confirmed that the coating layer formed on the particle surface of the toner obtained above was a layer in which the granular lumps were fixed.

[Toner 2] After dispersing 0.6 parts by mass of the polymer toner (A) used in Toner 1 in 4.1 parts by mass of methanol, 2.5 parts by mass of tetraethoxysilane was used as a silicon compound. After dissolution, another 40 parts by mass of methanol was added. The solution is then combined with 28% by weight of NH ₄
Add dropwise to an alkaline solution obtained by mixing 100 parts by mass of methanol with respect to 10 parts by mass of the OH aqueous solution,
By stirring at room temperature for 48 hours, a film composed of particles containing at least a polycondensate of a silicon compound was deposited on the surface of the toner particles.

After completion of the reaction, the obtained particles are washed with purified water and then with methanol, and then the particles are separated by filtration and dried to obtain a coating comprising at least particles containing a polycondensate of a silicon compound. The toner covered by the layer is obtained. When the particle size of the obtained toner was measured by the above-mentioned method, the number average particle size was 6.23 μm.
The shape factor SF1 was 1.12. Observation of the particle surface of the toner with a scanning microscope photograph revealed that a coating layer having fine granular irregularities having a diameter of about 40 nm was observed on the particle surface of the toner. Further, from observation of a cross section of the particles of the toner with a transmission electron microscope photograph, it was confirmed that a coating layer was formed on the surface of the particles of the toner.

Further, the content of silicon atoms on the particle surface of the toner determined by EPMA was 9.52% by mass. Similarly, the proportion of silicon atoms present in the cross section of the toner particles was 0.07%. Therefore,
The abundance ratio of silicon atoms on the toner particle surface is 13% of the abundance ratio of silicon atoms on the toner particle cross section.
6.00 times, and almost no polycondensate of the silicon compound was present inside the toner particles. Further, after the toner was washed with a 5% aqueous solution of dodecylbenzenesulfonic acid, the ratio of silicon atoms on the surface of the toner particles was 7.68.
%Met. Therefore, the reduction rate of silicon atoms present on the particle surface of the toner before and after washing with the surfactant is 1%.
9.33%. Therefore, it was confirmed that the coating layer formed on the particle surface of the toner obtained above was a layer in which the granular lumps were fixed.

[Toner 3] As a monomer dispersion, 10 parts by mass of tetraethoxysilane as a silicon compound was further added to the composition of the monomer dispersion used in Toner 1, and an NH ₄ OH aqueous solution was added to the system. Was added to make the reaction temperature 77 ° C., and the polymerization was carried out in the same manner as the polymerization method of Toner 1, except that the monomer dispersion was made alkaline. As a result, the silicon compound contained in the toner particles during the production of the polymerized toner tends to cause a sol-gel reaction by heat. Thereafter, the film was washed with a large amount of ethanol to remove unreacted tetraethoxysilane inside the particles, and further filtered and dried to provide a film composed of particles containing at least a polycondensate of a silicon compound. A toner was obtained.

When the particle size of the toner was measured by the method described above, the weight average particle size was 6.51 μm. The shape factor SF1 was 1.08. Observation of the particle surface of the toner with a scanning microscope photograph revealed that a coating layer having fine granular irregularities having a diameter of about 40 nm was observed on the particle surface of the toner. Further, from observation of a cross section of the particles of the toner with a transmission electron microscope photograph, it was confirmed that a coating layer was formed on the surface of the particles of the toner.

Further, the content of silicon atoms on the particle surface of the toner determined by EPMA was 19.02.
% By mass. Similarly, the proportion of silicon atoms present in the toner particle cross section was 3.57%. Therefore, the abundance ratio of silicon atoms on the particle surface of the toner is 5.33 times the abundance ratio of silicon atoms on the cross section of the toner particles, and a polycondensate of the silicon compound exists inside the toner particles. It was confirmed that. Furthermore,
After this toner was washed with a 5% aqueous solution of dodecylbenzenesulfonic acid, the abundance ratio of silicon atoms on the particle surface of the toner was 18.10%. Therefore, the reduction rate of silicon atoms existing on the surface of the toner particles before and after the surfactant was washed was 4.84%. Therefore, it was confirmed that the coating layer formed on the particle surface of the toner obtained above was a layer in which the granular lumps were fixed.

[Toner 4] As a monomer dispersion, 5 parts by mass of tetraethoxysilane as a silicon compound was further added to the composition of the monomer dispersion used in Toner 1, and an NH ₄ OH aqueous solution was added to the system. , And the polymerization was carried out in the same manner as the polymerization method of Toner 1 except that the monomer dispersion was made alkaline. As a result, the silicon compound contained in the toner particles during the production of the polymerized toner tends to cause a sol-gel reaction by heat. Thereafter, the film was washed with a large amount of ethanol to remove unreacted tetraethoxysilane inside the particles, and further filtered and dried to provide a film composed of particles containing at least a polycondensate of a silicon compound. A toner was obtained.

When the particle size of the toner was measured by the method described above, the weight average particle size was 6.48 μm. The shape factor SF1 was 1.05. Observation of the particle surface of the toner with a scanning microscope photograph revealed that a coating layer having fine granular irregularities having a diameter of about 40 nm was observed on the particle surface of the toner. Further, from observation of a cross section of the particles of the toner with a transmission electron microscope photograph, it was confirmed that a coating layer was formed on the surface of the particles of the toner.

Further, the content ratio of silicon atoms on the particle surface of the toner determined by EPMA was 10.10.
% By mass. Similarly, the proportion of silicon atoms present in the cross section of the toner particles was 5.71%. Therefore, the abundance ratio of silicon atoms on the particle surface of the toner is 1.77 times the abundance ratio of silicon atoms on the cross section of the toner particle, and a polycondensate of the silicon compound exists inside the toner particle. It was confirmed that. Furthermore,
After the toner was washed with a 5% aqueous solution of dodecylbenzenesulfonic acid, the abundance ratio of silicon atoms on the particle surface of the toner was 9.01%. Therefore, the reduction rate of silicon atoms existing on the particle surface of the toner before and after the surfactant was washed was 10.79%. Therefore, it was confirmed that the coating layer formed on the particle surface of the toner obtained above was a layer in which the granular lumps were fixed.

[Toner 5] The polymer toner (A) used in the toner 1 was used as a toner 5 without forming a coating layer on the surface. When the particle size of the obtained toner was measured by the above-mentioned method, the number average particle size was 6.22 μm. The shape factor SF1 was 1.06.

[Toner 6] A weight average particle diameter of 40 nm was used with respect to 100 parts by mass of the polymer toner (A) used in Toner 1.
Was added and mixed with a Henschel mixer to obtain a toner obtained by externally adding the silica fine powder as a fluidizing agent. When the particle size of the toner obtained above was measured by the method described above, the weight average particle size was 6.32 μm. The shape factor SF1 is 1.0
It was 6. Observation of this toner with a scanning microscope photo revealed that, although particles were observed on the surface of the particles of the toner, many gaps existed between the particles and the particles were not formed into a film. Further, when the cross section of the toner was observed with a transmission electron microscope photograph, the presence of particles and a continuous layer were sometimes confirmed on the surface of the particles of the toner, but no continuous layer was confirmed.

The proportion of silicon atoms on the particle surface of the toner determined by EPMA was 0.44% by mass. Similarly, the proportion of silicon atoms in the cross section of the toner particles was 0.00%. Further, after this toner was washed with a 5% aqueous solution of dodecylbenzenesulfonic acid, the abundance ratio of silicon atoms on the particle surface of the toner was 0.3%.
It was 0%. Therefore, the reduction rate of the silicon atoms existing on the surface of the toner particles before and after the surfactant was washed was 31.
82%. Therefore, this toner was not recognized as a fixed layer because the rate of silicon reduction by washing with a surfactant was high.

[Toner 7] 180 parts by weight of nitrogen-substituted water and 20 parts by weight of an aqueous solution of 0.2 parts by weight of polyvinyl alcohol were charged into a four-necked flask, and the following formulation was added thereto, followed by stirring to form a suspension. . Then, after the inside of the flask was replaced with nitrogen, the temperature was raised to 80 ° C. and maintained at the same temperature for 10 hours to carry out a polymerization reaction. After washing the polymer with water,
The resin was dried in a reduced pressure environment while maintaining the temperature at 5 ° C. to obtain a resin. 88 parts by weight of the resin, 10 parts by weight of carbon black, 5 parts by weight of salicylic acid metal compound, and 3 parts by weight of a release agent were mixed by a fixed-tank type dry mixer, and the vent port was connected to a suction pump for suction. Melt kneading was performed with a shaft extruder.

The melt-kneaded product was crushed by a hammer mill to obtain a crushed toner composition of 1 mm mesh pass. Further, the coarsely crushed material is crushed by a mechanical crusher to a volume average diameter of 20 to 30 μm, and then crushed by a jet mill utilizing collision between particles in a swirling flow, and then classified by a multi-stage classifier. To obtain a pulverized toner (B). (Composition 2) ・ Styrene monomer 88 parts by weight ・ n-butyl acrylate monomer 22 parts by weight ・ Benzoyl peroxide 1.4 parts by weight ・ Divinylbenzene 0.2 parts by weight

Subsequently, the above-mentioned pulverized toner (B) 0.9
Parts by weight were dispersed in 5.0 parts by weight of methanol, and then 0.5 parts by weight of tetraethoxysilane and 0.3 parts by weight of methylethoxysilane were dissolved as silicon compounds, and 50 parts by weight of methanol were further added. . Subsequently, 10 parts by weight of a 28% by weight aqueous NH ₄ OH solution
A solution containing 0 parts by weight of methanol was added dropwise, and the mixture was stirred at room temperature for 48 hours to deposit a film composed of particles containing at least a polycondensate of a silicon compound on the surface of the toner particles.

After completion of the reaction, the obtained particles are washed with purified water and then with methanol, and then filtered and dried to obtain a coating composed of particles containing at least a polycondensate of a silicon compound. The toner covered by the layer is obtained. When the particle size of the obtained toner was measured by the above-described method, the number average particle size was 6.57 μm.
The shape factor SF1 was 1.36. Observation of the particle surface of the toner with a scanning microscope photograph revealed that a coating layer having fine granular irregularities having a diameter of about 40 nm was observed on the particle surface of the toner. Further, from observation of a cross section of the particles of the toner with a transmission electron microscope photograph, it was confirmed that a coating layer was formed on the surface of the particles of the toner.

Further, the abundance ratio of silicon atoms on the particle surface of the toner determined by EPMA was 3.40% by mass. Similarly, the proportion of silicon atoms present in the cross section of the toner particles was 0.07%. Therefore,
The ratio of silicon atoms present on the particle surface of the toner is 48.
The ratio was 57 times, and almost no polycondensate of the silicon compound was present inside the toner particles. Furthermore, this toner is
After washing with a 5% aqueous solution of dodecylbenzenesulfonic acid, the abundance ratio of silicon atoms on the surface of the toner particles was 3.00%. Accordingly, the reduction rate of silicon atoms present on the surface of the toner particles before and after washing with the surfactant is 11.
76%. Therefore, it was confirmed that the coating layer formed on the particle surface of the toner obtained above was a layer in which the granular lumps were fixed.

Table 1 summarizes the physical properties of each of the above toners (Toners 1 to 7).

[Table 1]

<Production of Magnetic Carrier Particles> [Magnetic Carrier 1] Magnetite powder (FeO.Fe ₂ O ₃ ), which is a ferromagnetic material having a number average particle size of 0.24 μm, and a nonmagnetic material having a number average particle size of 0.60 μm to α-Fe ₂ O ₃ powder body, respectively 5.5 wt% of silane coupling agent (3-
(2-Aminoethylaminopropyl) dimethoxysilane) was added, and the mixture was stirred at a high speed of 100 ° C. or higher in a container to perform lipophilic treatment of each metal oxide fine particle.

Next, the following composition (2) containing the above-mentioned metal oxide fine particles was placed in a flask containing an aqueous medium comprising water containing a 28% by weight aqueous NH ₄ OH solution, and stirred.
The temperature was raised to 85 ° C. in 40 minutes while mixing, and the reaction and thermal curing were performed for 3 hours while maintaining this temperature. Subsequently, at 30 ° C
Cool, add more water, remove the supernatant,
The precipitate was washed with water and air-dried. Then, under reduced pressure (5 mm
(Hg or less) at 50 to 60 ° C. to obtain a spherical magnetic resin carrier by a polymerization method. Composition (2) ・ Phenol 10 parts by weight ・ Formaldehyde solution (formaldehyde 40% by weight, methanol 10% by weight, water 5% by weight 0%) 6 parts by weight ・ Lipophilized magnetite powder 60 parts by weight ・ Lipophilized α-Fe ₂ O ₃ powder 40 parts by weight

Further, using the magnetic resin carrier obtained above as core particles, a thermosetting silicone resin was coated on the surface by the following method. A coating solution containing 10% by weight of a silicone resin material was prepared using toluene as a solvent so that the amount of the coating resin on the surface of the magnetic carrier was 1.0% by weight. The solvent was volatilized while continuously applying a shearing stress to the solution to coat the surface of the core particles. Next, the magnetic carrier coated with the coating solution is cured at 200 ° C. for 1 hour, crushed, classified by a 200-mesh sieve, and a magnetic material-dispersed magnetic resin coated on the surface with a silicone resin. Carrier 1 was obtained.

When the particle diameter of the magnetic resin carrier 1 obtained above was measured, the number average particle diameter measured by an image processing analyzer Luzex3 manufactured by Nireco was 28.3.
μm, shape factor SF1 is 1.04, SF2 is 1.
51. Further, the magnetization intensity at 1 kOe was 129 emu / cm ³ . The strength of the magnetization is
Oscillating magnetic field type magnetic characteristics automatic recording device B manufactured by RIKEN ELECTRONICS CO., LTD.
It measured using HV-30.

[Magnetic carrier 2] The above magnetic carrier 1
A spherical magnetic material produced by a polymerization method in the same manner as in the production of the magnetic carrier 1 using the following composition (3) containing the magnetite powder which is a ferromagnetic substance subjected to lipophilic treatment described in A resin carrier was obtained. Composition (3) ・ Phenol 10 parts by weight ・ Formaldehyde solution (formaldehyde 40% by weight, methanol 10% by weight, water 50% by weight) 6 parts by weight ・ Lipophilized magnetite powder 100 parts by weight

Further, the magnetic carrier obtained above was used as the core particles, and the same silicone resin was coated on the surface of the magnetic carrier 1 in the same manner as in the production of the magnetic carrier 1. Thus, a magnetic material-dispersed magnetic resin carrier 2 having a surface coated with a silicone resin was obtained. The number average particle diameter of the obtained magnetic carrier 2 is 30.5 μm, and the shape factor SF1 is 1.
10, SF2 was 1.15. The magnetization intensity at 1 kOe was 218 emu / cm ³ .

[Magnetic carrier 3] Number average particle size 1.02
To a μm magnetite powder, 4.5% by weight of a silane coupling agent (3- (2-aminoethylaminopropyl) dimethoxysilane) was added, and 100 ° C. in a container.
As described above, the lipophilic treatment of the magnetite powder was performed by high-speed mixing and stirring. Next, a spherical magnetic resin carrier produced by a polymerization method using the following composition (4) containing the lipophilic magnetite powder as core particles in the same manner as in the case of producing the magnetic carrier 1 was obtained. . Composition (4) ・ Phenol 10 parts by weight ・ Formaldehyde solution (formaldehyde 40% by weight, methanol 10% by weight, water 50% by weight) 6 parts by weight ・ Lipophilized magnetite 100 parts by weight

Subsequently, the amount of the coating resin on the surface of the magnetic carrier was 1.0
A silicone resin was coated so as to be a weight%, and a magnetic material-dispersed magnetic resin carrier 3 having a surface coated with the silicone resin was obtained. The number average particle diameter of the obtained magnetic carrier 3 is 29.5 μm, and the shape factor SF1 is 1.0.
04, SF2 was 1.95. The magnetization intensity at 1 kOe was 220 emu / cm ³ .

[Magnetic Carrier 4] The following composition (5) composed of a plurality of metal oxides was mixed using a ball mill, calcined, further pulverized by a ball mill, and then granulated by a spray drier. . By sintering the obtained granules, a magnetic carrier composed of Cu-Zn ferrite was obtained. Composition _{(5) · Fe 2 O 3} 50 parts · CuO 27 parts by weight · ZnO 23 parts by weight

Using the magnetic carrier obtained above as core particles, the same coating resin as used in the magnetic carrier 1 was coated on the surface of the particles with a coating resin amount of 1.0% by weight based on the core particles. Thus, a magnetic substance-dispersed magnetic carrier 4 coated with a silicone resin was obtained. The number average particle diameter of the obtained magnetic carrier 4 is 29.0.
μm, the shape factor SF1 is 1.21, and SF2 is 1.
12 and had an irregular shape with a smooth surface and a considerable distance from a sphere. The intensity of magnetization at 1 kOe was 280 emu / cm ³ .

[Magnetic carrier 5] The following composition (6) was
After sufficiently premixing with a Henschel mixer, the mixture was melt-kneaded twice with a three-roll mill, and after cooling the kneaded product, it was roughly pulverized to a particle size of about 2 mm using a hammer mill. Next, a particle size of about 30 was
It was pulverized to μm. Furthermore, this finely pulverized product is
M-10 (manufactured by Okada Seiko) and mechanically spheroidized. Further, by classifying the spheroidized finely pulverized particles, a magnetic substance-dispersed magnetic resin carrier was obtained by a pulverization method. Composition (6) ・ Styrene-butyl acrylate copolymer (70/30) 30 parts by weight ・ Magnetite (particle size 0.24 μm) 70 parts by weight

Further, using the magnetic resin carrier obtained above as core particles, the surface was coated with the same silicone resin as used in the case of magnetic carrier 1 by the following method. First, a coating solution containing 5% by weight of a silicone resin material was prepared using toluene as a solvent so that the amount of the coating resin on the surface of the magnetic carrier was 1.0% by weight. Using this solution, the surface of the core particles was coated with a spray-type fluidized bed coater. Further, within the device, 60
After drying at 1 ° C. for 1 hour, a magnetic material-dispersed magnetic resin carrier 5 whose surface was coated with a silicone resin was obtained. The number average particle diameter of the obtained magnetic resin carrier 5 was 30.3 μm, the shape factor SF1 was 1.09 and SF2 was 1.08, which was close to a true sphere and the surface was very smooth.
The magnetization intensity at 1 kOe is 150 e.
mu / cm ³ .

The physical properties of each of the above magnetic carriers are summarized in Table 2.

[Table 2]

Example 1 Toner 1 and magnetic carrier 1 were mixed so that the toner / magnetic carrier (weight ratio) was 8.0% by weight, and the mixture was placed in a glass bottle for 180 seconds (2.5 times / second). 2) A two-component developer was prepared by shaking. The triboelectric charge of this two-component developer was -23.5 μC / g. The obtained two-component developer is used with a copier NP manufactured by Canon Inc.
Using a modified machine of Model No. 6050, an image output durability test of 50,000 sheets was performed. When the obtained fixed image was observed with a microscope, it was found that the toner did not leave a particle shape and a good image was formed. Also, if you leave the image,
There was no peeling of the fixed toner particles when the image was rubbed. Further, when the characteristics of the obtained image were examined, a stable image was obtained from the initial stage to the end of outputting 50,000 sheets of images without fog or other deterioration of image stains and without any change in image density.

Table 3 shows the triboelectric charge of the two-component developer obtained as a result of the endurance test before the endurance test and the triboelectric charge after the endurance test. In addition, the initial stage of the durability test and 5
The occurrence of fog in each image at the end of the 10,000-sheet durability test was evaluated according to the following criteria by the following method.

Evaluation of image fogging First, using a densitometer TC-6MC manufactured by Tokyo Denshoku Co., Ltd., first, the average reflectance Dr (%) of plain paper before displaying an image.
Was measured. Then, an image of a solid white image was formed on the plain paper, and the reflectance Ds (%) of the obtained solid white image was measured. From these reflectances, fog at each stage was calculated by the following equation.

(Equation 3)

Based on the fog value calculated above, the occurrence of fog was evaluated according to the following criteria. The results are shown in Table 3.

[0110]

[Table 3]

Example 2 A two-component developer was prepared in the same manner as in Example 1 except that the toner 1 and the magnetic carrier 1 were used. The triboelectric charge of this two-component developer was -21.5 μC / g. This two-component developer was subjected to an image output durability test in the same manner as in Example 1. The results were good as shown in Table 3.

Example 3 A two-component developer was prepared in the same manner as in Example 1, except that the toner particles 3 and the magnetic carrier particles 1 were used. The triboelectric charge of this two-component developer was -25.3 μC / g.
This two-component developer was subjected to an image output durability test in the same manner as in Example 1. The results were good as shown in Table 3.

Example 4 A two-component developer was prepared in the same manner as in Example 1, except that the toner 4 and the magnetic carrier 1 were used. The triboelectric charge of this two-component developer was -22.4 μC / g. This two-component developer was subjected to an image output durability test in the same manner as in Example 1. As a result, the fixing property was slightly inferior to those of the other examples, but at a practically acceptable level.

Example 5 A two-component developer was prepared in the same manner as in Example 1, except that the toner 1 and the magnetic carrier 2 were used. The triboelectric charge of this two-component developer was -26.3 μC / g. This two-component developer was subjected to an image output durability test in the same manner as in Example 1. As a result, as shown in Table 3, although the occurrence of fog increased after the durability test, the level was not a problem and was generally good.

Example 6 A two-component developer was prepared in the same manner as in Example 1, except that the toner 1 and the magnetic carrier 3 were used. The triboelectric charge of this two-component developer was -26.1 μC / g. This two-component developer was subjected to an image output durability test in the same manner as in Example 1. As a result, as shown in Table 3, although the occurrence of fog increased after the durability test, the level was not a problem and was generally good.

Comparative Example 1 A two-component developer was prepared in the same manner as in Example 1, except that toner particles 5 having no coating layer containing a silicon compound on the surface of the toner particles and magnetic carrier particles 1 were used. The triboelectric charge of this two-component developer was -20.3 μC / g. This two-component developer was subjected to an image output durability test in the same manner as in Example 1. As a result, fog was observed from the beginning, and did not change even after the durability test.
Further, the charge amount after the durability was slightly reduced.

Comparative Example 2 Toner 6 having fine silica particles adhered to the surface of toner particles
And a magnetic carrier 1 to prepare a two-component developer in the same manner as in Example 1. The triboelectric charge of this two-component developer was -20.2 μC / g. This two-component developer was subjected to an image output durability test in the same manner as in Example 1. As a result, as shown in Table 3, good images were obtained in the early stage of the durability test, but the fog deteriorated at the end of the durability test of 50,000 sheets. Also, during the durability test, dropping of silica fine particles from the developing sleeve was observed. Further, the triboelectric charge amount of the image agent after running was considerably reduced.

Comparative Example 3 An example using a magnetic carrier 3 and a toner 7 having a coating layer formed by fixing granular particles containing a silicon compound on the surface of toner particles obtained by a pulverization method. A two-component developer was prepared in the same manner as in Example 1. The triboelectric charge of this two-component developer was -25.3 μC / g.
This two-component developer was subjected to an image output durability test in the same manner as in Example 1. As a result, as shown in Table 3, fogging was observed from the beginning, and the fog was further deteriorated at the end of the durability test of 50,000 sheets.

Comparative Example 4 Using the toner 1 and the irregular shaped magnetic carrier 4,
A two-component developer was prepared in the same manner as in Example 1. The triboelectric charge of this two-component developer was -23.5 μC / g. This two-component developer was subjected to an image output durability test in the same manner as in Example 1. As a result, as shown in Table 3, fog occurred in the image from the beginning, and the image was further deteriorated after the 50,000-sheet durability test. The triboelectric charge was significantly reduced after running.

Comparative Example 5 Using the toner 1 and the magnetic carrier 5 obtained by the pulverization method, a two-component developer was prepared in the same manner as in Example 1. The triboelectric charge of this two-component developer is -20.7 μC
/ G. Example 1 of this two-component developer
An image output durability test was performed in the same manner as described above. As a result, as shown in Table 3, fogging was observed from the initial stage, and carrier adhesion to a white background on paper was observed after about 5,000 sheets of durability. Further, fog was further deteriorated at the end of the durability test of 50,000 sheets.

[0121]

As described above, according to the present invention,
By forming both the toner and the magnetic carrier constituting the two-component developer into roughly spherical particles and having fine irregularities on the surface, excellent triboelectric charging characteristics can be obtained even in a high-speed image forming apparatus. It will be shown. As a result, when an image is formed using the two-component developer provided by the present invention, the formed image is free from fogging due to poor charging of the toner and has excellent triboelectric charging even in long-term durability. Since the characteristics do not change, a good image can be formed even in durability. Further, according to the present invention, a toner and a magnetic carrier having a specific shape and surface state capable of exhibiting the above-described excellent image characteristics can be easily obtained, and the two-component developer having the above-described excellent image characteristics can be obtained. Provided easily.

 ────────────────────────────────────────────────── ─── Continued on the front page (72) Inventor Yoshinobu Baba 3-30-2 Shimomaruko, Ota-ku, Tokyo F-term in Canon Inc. (reference) 2H005 AA13 AA15 AB02 AB06 AB07 BA03 BA06 BA11 BA15 CA12 CA15 CA26 CB03 EA07 FA02

Claims (14)

[Claims] 1. A two-component developer having at least a toner and a magnetic carrier, wherein the toner comprises at least a binder resin and a colorant, and has a toner particle shape factor SF1 of 1.0 to 1 2. The magnetic carrier has a coating layer formed by fixing particulate masses containing at least a silicon compound on the surface of the toner particles, and the magnetic carrier has a carrier particle shape factor SF1 of 1 0.02 to 1.2, and SF2 is 1.1 to 2.5. 2. The two-component developer according to claim 1, wherein the magnetic carrier is formed of a thermosetting binder resin and a metal oxide, and is obtained by a direct polymerization method. 3. The mass ratio of silicon atoms to the total amount of carbon atoms, oxygen atoms and silicon atoms measured by electron probe microanalysis on the particle surface of the toner is 0.1 to 20.0% by mass. Claim 1 or 2 which is
2. The two-component developer according to item 1. 4. The content ratio of silicon atoms to the total amount of carbon atoms, oxygen atoms and silicon atoms measured by an electron probe microanalysis on the particle surface of the toner is 0.1 to 10.0% by mass. Claim 1 or 2 which is
2. The two-component developer according to item 1. 5. The toner according to claim 1, wherein said silicon atom is present in an amount of 0.1 to 4.0% by mass based on the total amount of carbon atoms, oxygen atoms and silicon atoms measured by electron probe microanalysis on the particle surface. The two-component developer according to claim 1, wherein 6. The method according to claim 1, wherein the proportion of silicon atoms to the total amount of carbon atoms, oxygen atoms and silicon atoms measured by electron probe microanalysis on the particle cross section is 4.0% by mass or less. Item 2. The two-component developer according to Item 1 or 2. 7. The toner according to claim 1, wherein the proportion of silicon atoms, based on the total amount of carbon atoms, oxygen atoms, and silicon atoms, measured by electron probe microanalysis on the particle cross section is 0.1% by mass or less. Item 2. The two-component developer according to Item 1 or 2. 8. The toner according to claim 1, wherein the silicon atom is present in an amount of 0.1 to 20.0% by mass based on the total amount of carbon atoms, oxygen atoms and silicon atoms measured by electron probe microanalysis on the particle surface of the toner. And the content ratio of silicon atoms to the total amount of carbon atoms, oxygen atoms, and silicon atoms measured by electron probe microanalysis on the particle cross section of the toner is 4.0% by mass.
The two-component developer according to claim 1, wherein: 9. The mass ratio of silicon atoms to the total amount of carbon atoms, oxygen atoms and silicon atoms measured by electron probe microanalysis on the particle surface of the toner is 0.1 to 10.0% by mass. And the content ratio of silicon atoms to the total amount of carbon atoms, oxygen atoms, and silicon atoms measured by the electron probe microscopic analysis in the particle cross section of the toner is 0.1% by mass.
The two-component developer according to claim 1, wherein: 10. The ratio of silicon atoms to the total amount of carbon atoms, oxygen atoms and silicon atoms measured by electron probe micropartial analysis on the particle surface of the toner is 0.1 to 4.0% by mass. And the content ratio of silicon atoms to the total amount of carbon atoms, oxygen atoms, and silicon atoms measured by the electron probe microscopic analysis in the particle cross section of the toner is 0.1% by mass.
The two-component developer according to claim 1, wherein: 11. The toner according to claim 3, wherein the content of silicon atoms on the particle surface of the toner provided with the coating layer is at least twice the content of silicon atoms on the cross section of the toner particles. Item 2. The two-component developer according to Item 1. 12. The two-component developer according to claim 3, wherein the coating layer is formed by a polycondensate of a silicon compound. 13. The two-component developer according to claim 12, wherein the polycondensate of the silicon compound is formed by a sol-gel method. 14. The two-component developer according to claim 12, wherein the coating layer is in a state in which granular lumps containing a polycondensate of a silicon compound are chemically bonded to each other.