JP3021260B2 - Developer for developing electrostatic image and image forming method - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an image forming method for forming a latent image by using an electrophotographic photosensitive member as a latent image holding member, visualizing the latent image with a developer, and transferring and forming the latent image. The present invention relates to a developer for developing an electrostatic image and an image forming method used in the method.

[0002]

2. Description of the Related Art Electrophotography is disclosed in U.S. Pat.
As described in, for example, US Pat. No. 691 and the like, a number of methods are known. Generally, a photoconductive substance is used to form an electric latent image on a photoreceptor by various means, and then the latent image is formed. The image is developed using toner, and if necessary, the toner image is transferred to a transfer member such as paper, and then fixed by heating, pressure, or solvent vapor to obtain a copy. Further, as a method of developing using a toner or a method of fixing a toner image, various methods have been conventionally proposed, and a method suitable for each image forming process is adopted.

Conventionally, toners used for these purposes are generally prepared by melt-mixing a coloring agent composed of a dye and a pigment in a thermoplastic resin, uniformly dispersing the same, and then using a pulverizer or a classifier to obtain a toner having a desired particle size. Has been manufactured.

[0004] Although this process can produce fairly good toners, it does have certain limitations, namely the range of choice of toner materials. For example, the resin colorant dispersion must be sufficiently brittle and capable of being pulverized in economically feasible manufacturing equipment. However, when the resin colorant dispersion is made brittle to satisfy these requirements, the particle size range of the particles formed when actually pulverized at a high speed tends to be widened, and in particular, a relatively large proportion of the fine particles The problem of inclusion occurs. Further, such a highly brittle material is susceptible to further pulverization or pulverization when used for development in a copying machine or the like. Further, in this method, it is difficult to completely and uniformly disperse solid fine particles such as a colorant in a resin,
Depending on the degree of the dispersion, fog may be increased, the image density may be reduced, and the color mixture / transparency may be poor. Further, exposure of the coloring agent to the fracture surface may cause fluctuations in development characteristics.

On the other hand, in order to overcome the problems of the toner by these pulverization methods, production of a toner by a suspension polymerization method is disclosed in Japanese Patent Publication Nos. 36-10231, 43-10799 and 51-14895. A method has been proposed. In the suspension polymerization method, a polymerizable monomer, a colorant, a polymerization initiator and a crosslinking agent, if necessary, a charge control agent,
After the other additives are uniformly dissolved or dispersed into a monomer composition, the monomer composition is dispersed in a continuous phase containing a dispersion stabilizer, for example, an aqueous phase using a suitable stirrer. Simultaneously, a polymerization reaction is carried out to obtain toner particles having a desired particle size.

This method does not include a pulverizing step at all, so that the toner does not need to be brittle, and a soft material can be used. There is an advantage of having a triboelectric charging property. Further, since the classification step can be omitted, the cost reduction effect is large, such as saving energy, shortening the time, and improving the process yield.

As described above, the polymerization method toner has many advantages, but from the viewpoint of further improving the image quality and durability of electrophotography in recent years, sufficient toner has not yet been obtained.

[0008] Polymerized toner is characterized by its manufacturing method.
Among the various additives added to the monomer composition, those having polarity tend to be unevenly distributed on the toner surface and in the vicinity thereof. This feature can reduce the amount of additives used to impart various toner properties, but on the other hand, when considered from the viewpoint of improving image quality, especially maintaining high image quality, it can be used with sleeves, carriers, etc. There is a problem that the deterioration of the toner surface due to the rubbing of the toner greatly affects the toner characteristics.

Further, the polymerized toner has such characteristics, so that it is generally susceptible to the effects of temperature and humidity, causing problems such as excessive charge under low humidity and insufficient charge under high humidity. There is an urgent need to develop a toner having a stable charge amount even in the environment.

In general, a carrier constituting a two-component developer is mainly classified into a conductive carrier represented by iron powder and a so-called insulating carrier in which the surface of iron powder, nickel, ferrite or the like is coated with an insulating resin. Separated. When an alternating electric field is applied to improve the image quality, if the resistance of the developer carrier is low, the carrier leaks the latent image potential and a good image cannot be obtained. When the carrier core is conductive, it is preferable to use the carrier core after coating, and ferrite having a relatively high resistance is preferably used as the core material.

In addition, since iron powder has a high magnetic force, the developer brush becomes hard in the developing area where the developer toner is developed, so that the brush is likely to be creased or rough, so that a high quality image is formed. Is difficult to obtain. Therefore,
Ferrite is also preferably used to reduce the magnetic force of the carrier to achieve high image quality.

For the purpose of forming a high quality image, Japanese Patent Application Laid-Open No.
No. 04663 discloses that the saturation magnetization value of a carrier is 50 em.
It has been proposed that a good image without nicks can be obtained by setting the ratio to u / g or less. However, when a carrier having a gradually decreased saturation magnetization value is used, the reproducibility of the fine wire becomes better, As the distance from the carrier increases, the phenomenon that the carrier adheres to the electrostatic image carrier (so-called photosensitive drum) (carrier adhesion) becomes more remarkable.

Japanese Patent Publication No. 4-3868 proposes to use a so-called hard ferrite having a coercive force of 300 gauss or more as a carrier. However, this is a system for using the hard ferrite having a high coercive force to make full use of the carrier. In order to realize a small high-quality color copier,
It is preferable to use a developer carrier using a fixed magnetic core. In this case, a hard carrier having a high coercive force has a problem that transportability is rather deteriorated due to its self-aggregating property.

Further, Japanese Patent Application Laid-Open No. 2-88429 proposes to use a hard ferrite composed of a spinel phase and a magnet plumbite phase containing a lanthanoid element as a carrier. In a system in which development is performed by an alternating electric field for obtaining a higher quality image because of having conductivity, it is not preferable in that the charge leaks through the carrier to disturb the development.

Therefore, in a system for developing by an alternating electric field, it is necessary that the carrier has a certain resistance.

As described above, a sufficient developer carrier which satisfies high image quality, particularly, reproducibility of highlight while preventing carrier adhesion has not yet been obtained.

On the other hand, as a matter of course, the electrophotographic photoreceptor is required to have predetermined sensitivity, electrical characteristics, and optical characteristics according to the applied electrophotographic process. However, not only that, the durability of the photoreceptor is also an important property. Even if the photosensitive member has excellent electrophotographic characteristics at low humidity, it is difficult to obtain a stable and clear image on a photosensitive member whose surface potential is significantly reduced at high humidity. Also, in the electrophotographic process for transferring,
Usually, the photoreceptor is used repeatedly, so that the corona discharge destroys the chemical bond of the surface-forming substance, and as a result, the surface acts to react with ionized oxygen, ozone, moisture, nitric oxide, etc. In many cases, the electrostatic charge retention force in moisture is reduced and the sharpness of an image is impaired. In addition, adhering matter such as paper dust often lowers the charge holding ability of the photoreceptor and causes image deletion.

Since the surface of the photoreceptor is coated with a resin, the performance of the resin is particularly important, and a resin having excellent durability has been demanded. Recently, a polycarbonate resin having bisphenol A as a skeleton (hereinafter, referred to as bisphenol A type polycarbonate) has been studied as a binder for the surface layer as a resin satisfying these requirements.

First, a polycarbonate resin as an engineering plastic generally has a large surface free energy, and a developer (hereinafter abbreviated as a toner) tends to adhere to the surface. When an image is displayed in this situation, a phenomenon in which many white dots appear on the entire black image (hereinafter, abbreviated as solid black) easily occurs.

Second, when a photoreceptor is prepared, a film is formed by dissolving the binder resin and the charge transport material in a solvent, coating and drying. A resin formed under such conditions has a residual strain stress in its internal structure, and a polycarbonate resin has a particularly strong tendency, and has a drawback that a so-called solvent crack is easily generated. When handling the photoreceptor thus created or mounting it on an electrophotographic device, for example,
When the photosensitive member comes into contact with various oils or the like used in the apparatus, cracks easily occur on the photosensitive member. When the cracks occur, they appear as defective images.

Third, since the friction coefficient of the surface is large, there is a problem that the cleaning amount is increased when cleaning with urethane rubber or the like, and it is difficult to increase the number of durable sheets.

[0022]

SUMMARY OF THE INVENTION An object of the present invention is to provide a developer for developing an electrostatic image and an image forming method which solve the above problems.

That is, an object of the present invention is to provide a developer for developing an electrostatic image and an image forming method, which are hardly influenced by environmental fluctuations such as temperature and humidity and have a stable triboelectric charging property in each environment. .

Another object of the present invention is to provide a developer for developing an electrostatic image and an image forming method which has clear image characteristics without fog and has excellent durability stability.

Another object of the present invention is to provide a developer for developing an electrostatic image and an image forming method having excellent fixability.

It is a further object of the present invention to provide a developer for developing an electrostatic image and an image forming method which are excellent in high resolution, high highlight reproducibility and high fine line reproducibility.

It is a further object of the present invention to provide an image forming method which is excellent in transferability and cleaning performance and can obtain excellent images even after running many sheets without causing cleaning defects. I do.

[0028]

The present invention attains the above object by the following constitutions.

The present invention relates to a developer for developing an electrostatic image having a toner and a carrier, wherein the toner has toner particles and titanium oxide, and the toner particles are directly obtained by a suspension polymerization method. A toner component having at least a colorant and a resin component, wherein at least one of the molecular weight peaks of the resin component constituting the toner particle has a molecular weight range of 5,000 to 50,000 in a molecular weight distribution by GPC. And at least one polar component, the titanium oxide has an average particle size of 0.01 to 0.2 μm and a hydrophobicity of 20 to 98%, and the carrier is Having an average particle size of 5 to 100 μm and a bulk density of 3.0 g / cm ³ or less,
The magnetic properties of the carrier are as follows: (i) the magnetization intensity (σ ₁₀₀₀ ) at 1000 Oe after magnetic saturation is 30 to 150 emu / cm ³ ;
(Ii) the magnetization intensity (residual magnetization: σ _r ) at a magnetic field of 0 Oe is 25 emu / cm ³ or more, and (ii)
i) the coercivity is less than 300 Oersteds and (i)
v) The following formula

[0030]

[Outside 3] (Wherein σ ₁₀₀₀ and σ ₃₀₀ indicate the magnetization intensity (emu / cm ³ ) at 1000 Oe and 300 Oe, respectively, after magnetic saturation.) The present invention relates to a developer for developing a charge image.

According to the present invention, a latent image is formed by using an electrophotographic photosensitive member having at least a conductive support and a photosensitive layer having a laminated structure of a charge generation layer and a charge transport layer. In an image forming method in which an image is visualized using a developer and transferred to a transfer material, a substance having a fluorine atom and / or a silicon atom is present in a surface layer of the electrophotographic photosensitive member, and the XPS The ratio of the fluorine atom and the silicon atom to the carbon atom measured is as follows: fluorine atom / carbon atom (F / C) = 0.01 to 1.00 silicon atom / carbon atom (Si / C) = 0.03 1.00, the developer has a toner and a carrier having toner particles and titanium oxide, and the toner particles are obtained by a suspension polymerization method. With toner particles containing resin component Ri, the resin component constituting the toner particles, the molecular weight distribution by GPC, at least one molecular weight peak, molecular weight 5,
000 to 50,000, and contains at least one or more polar components.
Average particle size of 0.01 to 0.2 μm and 20 to 98%
And the carrier has a hydrophobicity of 5 to 100.
It has an average particle size of μm and a bulk density of 3.0 g / cm ³ or less, and the magnetic properties of the carrier are as follows: (i) Magnetization intensity at 1000 Oe after magnetic saturation (σ ₁₀₀₀ ) Is 30 to 150 emu / cm ³ ,
(Ii) the magnetization intensity (residual magnetization: σ _r ) at a magnetic field of 0 Oe is 25 emu / cm ³ or more, and (ii)
i) the coercivity is less than 300 Oersteds and (i)
v) The following formula

[0032]

[Outside 4] (Wherein σ ₁₀₀₀ and σ ₃₀₀ indicate the magnetization intensity (emu / cm ³ ) at 1000 Oe and 300 Oe, respectively, after being magnetically saturated.) It relates to a forming method.

Hereinafter, the present invention will be described in detail.

The present inventors have conducted intensive studies in order to solve the above-mentioned problems of the prior art, and as a result, by setting the carrier magnetization intensity to 30 to 150 emu / cm ³ in the magnetic field at the developing pole, a latent image can be formed. It has been found that it is possible to form a clear image without fog which is faithful to the image. This is because the strength of the magnetic field at the developing pole is generally about 1000 Oersted, and the magnetic strength of the carrier at that time is weak, so that the magnetic brush of the developer is short and dense, and the brush is soft. Thus, it is considered that development faithful to the latent image could be achieved. It is considered that such a magnetic brush is short, dense, and soft, so that the development efficiency is improved, and higher-fidelity development can be performed, particularly in the development in which an alternating electric field for oscillating the developer is applied. Further, another effect of the present invention is to prevent the deterioration of the image quality and maintain the initial high-quality image because such a carrier having a low magnetic force is used to coat the developing sleeve with the developer. In this case, the magnetic coupling force of the carrier brush near the regulating member is weak, and the ears are soft, so it does not take much share of the toner, making it difficult for the polar substances on the toner surface to be scraped off. It is thought that the image can be maintained for a long time.

In addition, a detailed investigation has revealed that carrier adhesion tends to occur when the magnetic field strength is 0 to 300 Oersted, and does not occur when the carrier magnetization strength at that time is high to some extent. Carrier adhesion also depends on the bias condition of development. Particularly in the case of development using an alternating electric field, compared to a DC electric field, the carrier is more likely to be developed if it has an electric charge. Is required. Therefore, it is considered that the intensity of magnetization in the above-mentioned magnetic field is necessary to suppress carrier adhesion. Therefore, according to the present invention, as shown in the hysteresis curve of FIG. 1, the magnetization intensity σ ₁₀₀₀ at 1000 Oe is 30 to 150 emu / c.
m ³ , which is smaller than the conventional carrier, but is 0 to 30
It is considered that by increasing the intensity of magnetization at 0 Oe, it is possible to prevent carrier adhesion while improving image quality.

Generally, a magnetic material having a large residual magnetization is a magnetic material such as a so-called permanent magnet having a large coercive force, such as a hard ferrite, as described above. Poor transportability occurs, and the developer carrier is like a rotating magnetic core applicator,
A large and special developing device is required.

The present invention uses a carrier having a coercive force of less than 300 Oersteds instead of using such a general hard magnetic material. But the miscibility with toner,
It is considered that a developer having good developer transportability can be achieved.

The carrier used in the present invention needs to have the following magnetic properties of the carrier particles.

(I) It is necessary that the magnetization intensity (σ ₁₀₀₀ ) at 1000 Oe after magnetic saturation is 30 to 150 emu / cm ³ . In order to further improve the image quality, preferably 30 to 12
0 emu / cm ³ is good. If it is larger than 150 emu / cm ^3, the density of the developer brush at the developing pole is not so different from the conventional one, and it is difficult to obtain a high quality image as in the present invention. If it is less than ³⁰ emu / cm ³ , the magnetic binding force at 0 to 300 Oe is also reduced, so that carrier adhesion occurs.

(Ii) It is necessary that the intensity of magnetization (residual magnetization) at a magnetic field of 0 Oe is 25 emu / cm ³ or more. When it is less than 25 emu / cm ³ ,
In particular, in a developing system that uses a large contrast potential for high image quality, or an alternating electric field having a large amplitude, carrier adhesion is likely to occur, and in the transfer process after development, a carrier attached portion causes transfer failure, and the like. High quality images cannot be obtained. (Iii) The coercive force must be less than 300 Oersted. If the coercive force is 300 Oe or more, the carrier itself will self-aggregate, resulting in poor mixing with the toner, and particularly, the carrier cannot move easily in the developing sleeve containing the fixed magnet, and the And the coated state of the developer is deteriorated, so that a high quality image cannot be obtained.

(Iv) What is important in the present invention is the intensity of magnetization near a magnetic field of 0 to 300 Oe. Therefore, the following equation

[0042]

[Outside 5] [Wherein σ ₁₀₀₀ and σ ₃₀₀ indicate the magnetization intensity (emu / cm ³ ) at 1000 Oe and 300 Oe, respectively, after magnetic saturation. ] Must be satisfied. More preferably, this value is 0.30 or less. Here, a description will be given using the hysteresis curve of FIG. If this value exceeds 0.40, the effect of preventing carrier adhesion while achieving high image quality of the present invention cannot be achieved. That is, although the image quality is worn Taking a value that satisfies sigma _1000, is likely to occur the carrier deposition. Further, if a value that satisfies σ ₃₀₀ is taken, carrier adhesion can be prevented, while σ ₁₀₀₀
Increases, it becomes impossible to obtain a high quality image as in the present invention.

Accordingly, the carrier having the above-described magnetic characteristics is unlikely to cause carrier adhesion, and is excellent in high resolution, high highlight reproducibility, and high fine line reproducibility.

The measurement of the magnetic characteristics of the carrier in the present invention was performed using a DC magnetization BH characteristic automatic recording device BHH-50 manufactured by Riken Denshi Co., Ltd. Since the magnetic material is generally saturated by a magnetic field of 10 kOe, the saturation magnetization of the carrier is set to a value of 10 kOe in the present invention. Therefore, the magnetic characteristic value is ± 1.
A magnetic field of 0 kOe was created, and the value was obtained from a hysteresis curve at that time. The magnetic properties in the present invention, after loosely placing the sample in a cylindrical plastic container,
Packing was performed strongly in a magnetized state by applying a magnetic field of 10 km, and the magnetic properties in that state were measured. This was used as the magnetic characteristic of the present invention. The volume of the sample holder at that time was 0.332 cm ³ , and the intensity of magnetization per unit volume was determined from this.

The carrier particles used in the present invention preferably have an average particle size of 5 to 100 μm, more preferably 20 to 80 μm. When the thickness is smaller than 5 μm, carrier adhesion to the photoreceptor is likely to occur.
If it exceeds 0 μm, the magnetic brush at the developing pole becomes coarse, and a high quality image cannot be obtained. In the present invention, the particle size of the carrier is randomly extracted by 300 or more by an optical microscope, and the image processing and analysis apparatus Luzex3 manufactured by Nireco Co., Ltd.
As a result, the carrier diameter is determined by the ferrite diameter in the horizontal direction.
It was measured.

The carrier used in the present invention is 3.0 g.
/ Cm ³ or less. 3.0
If it exceeds g / cm ³ , the rotation of the developing sleeve causes a large centrifugal force on one carrier as compared with the force of magnetically holding the carrier on the sleeve, so that the carrier is easily scattered. In addition, the measurement of the bulk density of the carrier in the present invention was performed according to the method described in JIS Z2504.

The carrier used in the present invention is substantially spherical, and the sphericity is preferably 2 or less. If the sphericity exceeds 2, the fluidity of the developer becomes poor, and the shape of the magnetic brush at the developing pole becomes poor, so that a high-quality image cannot be obtained. The sphericity of the carrier in the present invention was measured by randomly extracting 300 or more carriers using a field emission scanning electron microscope S-800 manufactured by Toshiba Corporation and using an image processing analyzer Luzex3 manufactured by Nireco. , By calculating a shape factor derived by the following equation.

[0048]

[Outside 6] MX LNG: Maximum diameter of carrier AREA: Projected area of carrier Here, SF1 is closer to 1 means closer to a sphere.

The carrier used in the present invention is 10 ³ to 10
It is preferable to have a specific resistance of 10 ¹³ Ω · cm. 10
^If it is less than ³ Ω · cm, current leaks from the sleeve to the surface of the photoreceptor in the developing area in a developing method in which a bias voltage is applied, and a good image cannot be obtained. Also, 10 ¹³
If it exceeds Ω · cm, a charge-up phenomenon is caused under conditions such as low humidity, which causes image deterioration such as density loss, transfer failure and fog. In the present invention, the measurement method as shown in FIG. 3 was used for measuring the specific resistance of the carrier.
That is, the cell A is filled with a carrier, the lower electrode and the upper electrodes 1 and 2 are arranged so as to be in contact with the filled carrier, a voltage is applied between the electrodes, and a current flowing at that time is measured to measure the specific resistance. Was used. In the above-mentioned measuring method, since the carrier is a powder, a change occurs in the filling rate, and accordingly, the specific resistance may change. The measurement condition of the specific resistance in the present invention is such that the contact area S between the filled carrier and the electrode is about 2.3 cm.
^{2. The} thickness d was about 1 mm, the load on the upper electrode 2 was 275 g, and the applied voltage was 100 V.

In FIG. 3, 3 is an insulator, 4 is an ammeter, 5 is a voltmeter, 6 is a constant voltage device, 7 is a carrier, 8
Indicates a guide ring.

In order to achieve the above-mentioned magnetic characteristics, which is the most important feature of the carrier used in the present invention, a metal oxide magnetic material or an iron-based alloy, for example, carbon steel, chromium steel, cobalt-chromium steel , Baicaloy, alnico alloy, and the like. Preferably, the periodic table IA
Group, IIA, IIIA, IVA, VA, VIA
Group, IB, IIB, IVB, VB, VIB,
Ferrite particles containing at least one element selected from the group consisting of Group VIIB and Group VIII and containing other elements at less than 1% by weight are preferred. When other elements are contained, it is difficult to obtain a carrier having desired magnetic properties used in the present invention, and the resistance tends to decrease.

The carrier used in the present invention is a single phase having a spinel structure, a single phase having a magnet plumbite structure, a composite phase having at least a spinel structure or a magnet plumbite structure, or a composite phase having a spinel structure and a magnet plumbite structure. In this case, the molar ratio of the spinel phase to the magnet plumbite phase is preferably 1: 1 to 10: 1. Further, it is preferable that magnetic particles having a spinel structure and a magnet plumbite structure do not significantly react with each other.

By adopting such a composition form, the magnetization intensity (σ ₁₀₀₀ ) at 1000 Oe after magnetic saturation is 30 to 150 emu / cm ³ , and the residual magnetization σ _r is 25 emu / cm ^3. As described above, a carrier having a magnetic characteristic with a coercive force of less than 300 Oe can be obtained.

In the present invention, the measurement of the crystal constituting the carrier was carried out by using an X-ray diffraction method and X-ray fluorescence.

The carrier used in the present invention is a sintering method,
It can be manufactured by a manufacturing method such as the atomizing method,
If necessary, a carrier having the above specific magnetic properties can be produced by a method such as mixing and sintering two or more kinds of crystal fine powders.

By using the carrier used in the present invention after being magnetically saturated, it is easy to achieve the characteristic magnetic characteristics of the present invention. As a method of magnetic saturation, there is a method in which carrier particles are exposed to a magnetic field of ± 10 kOe by a DC electromagnet.

The carrier of the present invention can be used by coating the surface of the carrier particles with an optional resin, if necessary, in order to control the specific resistance as described above or to improve the durability. As the coating resin, a known appropriate resin can be used, for example, an acrylic resin,
Fluorine-based resin, silicon-based resin, epoxy-based resin, and the like can be given.

On the other hand, in order to obtain a toner having excellent fixability, which is one of the objects of the present invention, at least one of the peaks of the molecular weight distribution by GPC of the resin component constituting the toner particles has a molecular weight of 5,000. To 50,000 and it has been found that it is effective to contain at least one or more polar components.

That is, by adding a resin having a good affinity for paper, the adhesion to paper is increased.

It has been found that the toner particles are preferably obtained as a means for achieving the object of the present invention by being obtained directly by a suspension polymerization method.

It is considered that, when the toner is produced in an aqueous system, the internally added polar component is more likely to be present on the surface of the toner particles, and therefore, one of the objects of the present invention can be achieved more effectively.

In the present invention, when at least one of the peaks of the molecular weight distribution of the resin component constituting the toner particles by GPC is in the range of 5,000 to 50,000, low-temperature fixability can be exhibited.

When the peak of the molecular weight distribution in GPC of the resin component for achieving the toner particles is less than 5,000, the blocking resistance becomes poor,
50,000 with no peak in the range specified in the present invention
If the peak exists beyond the range, the low-temperature fixability is inferior.

Further, preferably, the molecular weight is 100,00
When the content of 0 or less component is 50% or less, good fixability can be exhibited.

In the present invention, the molecular weight distribution of a chromatogram by GPC using THF (tetrahydrofuran) as a resin component constituting toner particles as a solvent is measured under the following conditions.

The column was stabilized in a heat chamber at 40 ° C., THF was passed through the column at this temperature as a solvent at a flow rate of 1 ml per minute, and the THF sample solution was poured into the column at about 100 μm.
Inject and measure. When measuring the molecular weight of a sample,
The molecular weight distribution of the sample was calculated from the relationship between the logarithmic value of the calibration curve prepared from several types of monodisperse polystyrene standard samples and the count number. As a standard polystyrene sample for preparing a calibration curve, for example, a molecular weight of about 10 ² to 10 ⁷ manufactured by Tosoh Corporation or Showa Denko KK is used, and it is appropriate to use a standard polystyrene sample of at least about 10 points. is there. The detector has a RI (refractive index)
Use a detector. As the column, it is preferable to combine a plurality of commercially available polystyrene gel columns. For example, showex GPC KF-80 manufactured by Showa Denko KK
1, 802, 803, 804, 805, 806, 80
7,800P combination or TSKge manufactured by Tosoh Corporation
_{1 G1000H (H XL), G2000H} (H XL), G
_{3000H (H XL), G4000H (} H XL), G500
0H (H _XL ), G6000H (H _XL ), G7000H
(H _XL ) and a combination of TSKguard columns.

A sample is prepared as follows. Place the sample in THF, leave it for several hours, shake
Mix well with F (until the sample is no longer united) and add 1 more
Leave for at least 2 hours. At this time, the time of being left in THF is set to be 24 hours or more. After that, a filter passed through a sample processing filter (pore size: 0.45 to 0.5 μm, for example, available from Maishoridisc H-25-5 Tosoh Corporation, Exiclodisc 25CR Germanman Sysense Japan Ltd.) can be used. GPC
Sample. The sample concentration is 0.5 to 5 for the resin component.
Adjust to be mg / ml.

Further, in the toner of the present invention, it is preferable to use titanium oxide as an additive for the toner particles. The following can be considered as a reason for this. That is, the polar substance tends to be unevenly distributed on the surface of the polymerized toner particles as described above. For this reason, the hygroscopicity fluctuates with the fluctuation of the environment, and the environmental stability of the charging property is still insufficient.

On the other hand, the titanium oxide fine particles used in the present invention have a substantially neutral charging property as compared with the hydrophobic silica, so that a constant fluidity can be obtained without being affected by the charging of the toner particles. it is conceivable that.

The titanium oxide used in the present invention has a hydrophobicity of 20 to 98%, preferably 30 to 90%, more preferably 40 to 80%.

When the degree of hydrophobicity is less than 20%, the amount of charge is greatly reduced due to long-term storage under high humidity, a mechanism for accelerating charging on the hard side is required, and the apparatus becomes complicated, and the degree of hydrophobicity is reduced. If it exceeds 98%, it is difficult to control the charging of titanium oxide itself, and as a result, the toner is charged up under low humidity.

The average particle size of the titanium oxide is preferably 0.01 to 0.2 μm from the viewpoint of imparting fluidity. If the average particle size is larger than 0.2 μm, toner charging due to poor fluidity becomes non-uniform, resulting in toner scattering and fogging. On the other hand, when the average particle size is smaller than 0.01 μm, the toner is easily embedded on the toner surface, the toner is quickly deteriorated, and the durability is reduced. As a means for hydrophobizing titanium oxide, it is preferable to perform treatment using a coupling agent.

The coupling agents usable in the present invention include silane coupling agents, titanium coupling agents and the like.
All that can be subjected to a hydrophobic treatment can be used. Particularly preferably used is a silane coupling agent,
R _m SiY _n R: alkoxy group m: an integer of 1 to 3 Y: alkyl group Hydrocarbon group containing vinyl group, glycidoxy group, methacryl group n: an integer of 1 to 3 For example, vinyltrimethoxysilane, vinyltriethoxysilane, γ-methacryloxypropyltrimethoxysilane, vinyltriacetoxysilane, methyltrimethoxysilane, methyltriethoxysilane, isobutyltrimethoxysilane, dimethyldimethoxysilane, dimethyldiethoxysilane, trimethyl Methoxysilane, hydroxypropyltrimethoxysilane, phenyltrimethoxysilane, n-hexadecyltrimethoxysilane, n-octadecyltrimethoxysilane and the like can be mentioned.

[0074] More preferably, the following formula _{CaH 2a + 1 -Si (OC b} H 2b + 1) 3 a: 4~12 integer b: those represented by good an integer from 1 to 3.

When a in the above general formula is smaller than 4,
Although the treatment is easy, it is difficult to sufficiently achieve the hydrophobicity. If a is larger than 12, the hydrophobicity is sufficient, but coalescence between the titanium oxide particles increases, and the ability to impart fluidity is reduced. .

If b in the above general formula is larger than 3, the reactivity is lowered and the hydrophobic treatment is not sufficiently performed.

Therefore, in the above general formula, a is 4-1.
2, preferably 4 to 8, and b is 1 to 3, preferably 1 to 2.

The method for measuring the degree of hydrophobicity in the present invention is described below.

Method for Measuring Hydrophobicity The methanol titration test is an experimental test for confirming the hydrophobicity of a titanium oxide fine powder having a hydrophobized surface.

The "methanol titration test" defined herein for evaluating the degree of hydrophobicity of the treated fine titanium oxide powder is carried out as follows. 0.2 g of the test titanium oxide fine powder was added to 50 m of water in a 250 ml Erlenmeyer flask.
Add to l. Methanol is titrated from the burette until all of the titanium oxide is wetted. At this time, the solution in the flask is constantly stirred with a magnetic stirrer. The end point is observed as the entire amount of titanium oxide fine powder is suspended in the liquid, and the degree of hydrophobicity is expressed as the percentage of methanol in the liquid mixture of methanol and water when the end point is reached.

Further, in the present invention, the treated titanium oxide has a light transmittance of 40% or more at a light length of 400 nm when dispersed in an ethanol solvent at a solid concentration of 0.1%. Is another feature.

That is, the titanium oxide used in the present invention has a very small primary particle size of 0.01 to 0.2 μm. However, when the titanium oxide is actually mixed with the toner particles, it is not necessarily a primary particle. , And may exist in the form of secondary particles. Therefore, even if the primary particle diameter is small, it is difficult to sufficiently obtain the effects of the present invention if the effective diameter acting as secondary particles is large. However, 400 mm which is the lower limit wavelength in the visible region when dispersed in the liquid phase
The higher the light transmittance is, the smaller the secondary particle diameter is, and good results such as the sharpness of the projected image of the fluidity imparting ability OHP can be expected.

The method for measuring the transmittance in the present invention will be described below.

[0086] Transmittance measuring method Sample 0.10 g Alkyd resin 13.20 * 1 Melamine resin 3.30 * 2 Thinner 3.50 * 3 Glass media 50.00 * 1 Bekkosol 1323-60- manufactured by Dainippon Ink and Chemicals, Inc.
EL * 2 Super Beckamine J-820 manufactured by Dainippon Ink and Chemicals, Inc.
-60 * 3 Amirac thinner manufactured by Kansai Paint Co. The above formulation is collected in a 150 cc mayonnaise bottle, and dispersed for 1 hour by a paint conditioner manufactured by Red Devil. 2. After the dispersion, the PET film is coated with a 2 mil doctor blade. 3.2. Is heated at 120 ° C. for 10 minutes to perform baking. 4.3. The transmittance of the sheet is measured by U-BEST 50 manufactured by JASCO Corporation in the range of 320 to 800 nm and compared.

In the present invention, the following additives may be used in addition to the above titanium oxide fine particles.

The additive for imparting various toner properties should have a particle diameter of 1/10 or less of the volume average diameter of the toner particles from the viewpoint of durability when added to the toner or when added to the toner. Is preferred. The particle size of this additive
The average particle diameter obtained by observing the surface of the toner particles with an electron microscope is meant. As additives for imparting these properties, for example, the following are used.

1) Fluidity imparting agents: metal oxides (such as silicon oxide and aluminum oxide), carbon black, and carbon fluoride. Those subjected to a hydrophobic treatment are more preferable.

2) Abrasives: metal oxides (strontium titanate, cerium oxide, aluminum oxide, magnesium oxide, chromium oxide, etc.), nitrides (silicon nitride, etc.), carbides (silicon carbide, etc.) metal salts (calcium sulfate, Barium sulfate, calcium carbonate, etc.).

3) Lubricants: fluororesin powder (vinylidene fluoride, polytetrafluoroethylene, etc.), fatty acid metal salts (zinc stearate, calcium stearate, etc.).

4) Charge controllable particles: metal oxides (tin oxide, zinc oxide, silicon oxide, aluminum oxide, etc.)
Such as carbon black.

These additives are used in an amount of 0.1 to 10 parts by weight based on 100 parts by weight of the toner particles.
0.1 to 5 parts by weight are used. These additives may be used alone or in combination of two or more.

In the toner used in the present invention, the polar component contained in the resin component constituting the toner particles may be a polymer of a nitrogen-containing monomer such as dimethylaminoethyl methacrylate and diethylaminoethyl methacrylate, or a styrene / non-polymer. Copolymers with saturated carboxylic esters, nitrile monomers such as acrylonitrile, halogenated monomers such as vinyl chloride, unsaturated carboxylic acids such as acrylic acid and methacrylic acid, and other unsaturated dibasic acids. Examples thereof include polymers such as unsaturated dibasic acid anhydrides and nitro monomers, copolymers with styrene monomers, polyesters, epoxy resins and the like.

The following method is used as a method for incorporating the polar component into the toner particles.

Polymerized toner particles may be prepared by dissolving the above-mentioned polar component as a polymer or copolymer in another monomer component and adding it by polymerization, or by adding the above-mentioned polar component as a monomer. And a method of mixing with the monomer component and polymerizing and adding the mixture.

The polymerizable monomer that can be used in the other polymerization-processed toner particles that can be used in the present invention includes styrene o
Styrene monomers such as methyl styrene, m-methyl styrene, p-methyl styrene, p-methoxy styrene, p-ethyl styrene, methyl acrylate, ethyl acrylate, n-butyl acrylate, isobutyl acrylate;
Acrylic esters such as n-propyl acrylate, n-octyl acrylate, dodecyl acrylate, 2-ethylhexyl acrylate, stearyl acrylate, 2-chloroethyl acrylate, phenyl acrylate, methyl methacrylate, ethyl methacrylate. Monomers of methacrylates such as n-propyl methacrylate, n-butyl methacrylate, isobutyl methacrylate, n-octyl methacrylate, dodecyl methacrylate, 2-ethylhexyl methacrylate, stearyl methacrylate, phenyl methacrylate, etc. No. These monomers alone,
Alternatively, they can be used in combination. Among the above-mentioned monomers, it is preferable to use styrene or a styrene derivative alone or in a mixture with another monomer, from the viewpoint of the developing characteristics and durability of the toner.

As the coloring agent used in the present invention, known coloring agents can be used. For example, carbon black, iron black, C.I. I. Direct Red 1, C.I. I. Direct Red 4, C.I. I. Acid Red 1, C.I. I. Basic Red 1, C.I. I. Modant Red 30, C.I.
I. Direct Blue 1, C.I. I. Direct Blue 2, C.I. I. Acid Blue 9, C.I. I. Acid Blue 15, C.I. I. Basic Blue 3, C.I. I. Basic Blue 5, C.I. I. Modant Blue 7, C.I. I.
Direct Green 6, C.I. I. Basic Green 4, C.I. I. Dyes such as Basic Green 6, graphite, cadmium yellow, mineral fast yellow, navel yellow, naphthol yellow S, Hanza yellow G, permanent yellow NCG, tartrazine lake, molybdenum orange, permanent orange GT
R, Benzidine Orange G, Cadmium Red, Permanent Red 4R, Watching Ledge Calcium Salt,
Brilliantamine 3B, Fast Violet B, Methyl Violet Lake, Navy Blue, Cobalt Blue, Alkaline Blue Lake, Victoria Blue Lake, Quinacridone, Rhodamine Lake, Phthalocyanine Blue, Fast Sky Blue, Pigment Green B, Malachite Green Lake, Final Yellow Green G, etc. There are pigments. In the present invention, in order to obtain a toner using a polymerization method, it is necessary to pay attention to the polymerization inhibitory property and the aqueous phase migration property of the colorant, preferably, surface modification, for example, hydrophobicity by a substance without polymerization inhibition It is better to have a chemical treatment. In particular, attention must be paid to the use of dyes and carbon black since many of them have polymerization inhibitory properties. As a preferable method for surface-treating the dye system, there is a method in which a polymerizable monomer is polymerized in the presence of these dyes in advance, and the obtained colored polymer is added to the monomer system. The carbon black may be treated with a substance that reacts with the surface functional group of the carbon black, such as polyorganosiloxane, in addition to the same treatment as the above-described dye.

When the toner is used as a magnetic toner, it may contain a magnetic powder. As such magnetic powder, a substance that is magnetized when placed in a magnetic field is used.
There are powders of ferromagnetic metals such as iron, cobalt and nickel, or compounds such as magnetite and ferrite. In particular, in the present invention, in order to obtain a toner using the polymerization method, it is necessary to pay attention to the polymerization inhibitory properties and aqueous phase migration properties of the magnetic substance, preferably, surface modification, for example, a substance without polymerization inhibition Should be subjected to a hydrophobic treatment.

In the present invention, for the purpose of improving the releasability at the time of heat roll fixing property, waxes generally used as a releasing agent such as a hydrocarbon compound may be blended in the toner particles. Examples of the waxes used in the present invention include paraffin / polyolefin waxes and modified products thereof, for example, oxides and grafted products, higher fatty acids, metal salts thereof, and amide waxes.
These waxes have a softening point of 40 to 130 ° C, preferably 50 to 120 ° C, according to a ring and ball method (JIS K 2531).
When the softening point is 40 ° C. or less, the toner has insufficient blocking resistance and shape retention, and has a softening point of 13%.
At a temperature of 0 ° C. or higher, the effect of the releasability becomes insufficient.

These release agents may be used alone or in combination. The amount of addition is preferably 0.1 to 50% by weight.

In the present invention, it is desirable to add a charge control agent to the toner material in order to control the chargeability of the toner. As these charge control agents, those having little polymerization inhibition and water phase transfer among known ones are used. For example, as positive charge control agents, nigrosine dyes, triphenylmethane dyes, quaternary ammonium salts, guanidines Derivatives, imidazole derivatives, amine-based and polyamine-based compounds, and the like, as negative charge control agents, metal-containing salicylic acid-based compounds, metal-containing monoazo-based dye compounds, urea derivatives, styrene-acrylic acid copolymers, styrene-methacrylic Acid copolymers and the like can be mentioned.

The charge control agent may be added in an amount of 0.1.
1-10% by weight is preferred.

As the polymerization initiator, any suitable polymerization initiator, for example, 2,2'-azobis- (2,4-dimethylvaleronitrile), 2,2'-azobisisobutyronitrile, 1'-azobis (cyclohexane-1-
Azo or diazo polymerization initiators such as carbonitrile), 2,2'-azobis-4-methoxy-2,4-dimethylvaleronitrile, azobisisobutyronitrile, benzoyl peroxide, methyl ethyl ketone peroxide, diisopropyl peroxy carbonate, Peroxide-based polymerization initiators such as cumene hydroperoxide, 2,4-dichlorobenzoyl peroxide and lauroyl peroxide are exemplified. These polymerization initiators are preferably added in an amount of 0.5 to 20% by weight of the polymerizable monomer, and may be used alone or in combination.

In the present invention, known crosslinking agents and chain transfer agents may be added in order to control the molecular weight. The preferred amount is 0.001 to 15% by weight.

In the dispersion medium used in the present invention, any suitable stabilizer is used. For example, as inorganic compounds, tricalcium phosphate, magnesium phosphate, aluminum phosphate, zinc phosphate, calcium carbonate, magnesium carbonate, calcium hydroxide, magnesium hydroxide, aluminum hydroxide, calcium metasilicate, calcium sulfate, barium sulfate -Bentonite, silica, alumina and the like. As an organic compound, polyvinyl alcohol, gelatin, methylcellulose, methylhydroxypropylcellulose, ethylcellulose, sodium salt of carboxymethylcellulose, polyacrylic acid and its salts, starch and the like can be used by dispersing them in an aqueous phase.
These stabilizers are based on 100 parts of the polymerizable monomer.
It is preferred to use 0.2 to 20 parts by weight.

When an inorganic compound is used among these stabilizers, a commercially available one may be used as it is, but in order to obtain fine particles, the inorganic compound may be formed in a dispersion medium. For example, in the case of tricalcium phosphate, it is preferable to mix an aqueous solution of sodium phosphate and an aqueous solution of calcium chloride under high stirring.

For the fine dispersion of these stabilizers,
0.001 to 0.1 parts by weight of a surfactant may be used. This is to promote the desired action of the dispersion stabilizer, and specific examples thereof include sodium dodecylbenzene sulfate, sodium tetradecyl sulfate, sodium pentadecyl sulfate, sodium octyl sulfate, sodium oleate, and lauryl acid. Sodium / potassium stearate / calcium oleate;

The polymerized toner particles used in the present invention are obtained by the following method. That is, a monomer system in which a mold release agent, a coloring agent, a charge control agent, a polymerization initiator, and other additives are added to the polymerizable monomer, and the monomer system is uniformly dissolved or dispersed by a homogenizer, an ultrasonic disperser, or the like, It is dispersed in an aqueous phase containing a dispersion stabilizer by using a conventional stirrer or a homomixer / homogenizer. Preferably, the stirring speed and time are adjusted so that the monomer droplets have a desired toner particle size, generally a particle size of 30 μm or less, and granulation is performed. After that, by the action of the dispersion stabilizer, stirring may be performed to such an extent that the particle state is maintained and the particles are prevented from settling. The polymerization temperature is 40 ° C. or higher, generally 50 to 90 ° C.
The polymerization is carried out at a temperature set to. In addition, the temperature may be raised in the latter half of the polymerization reaction, and further, in the latter half of the reaction or after the end of the reaction in order to remove unreacted polymerizable monomers and by-products that cause odor during toner fixing. Later, a part of the aqueous medium may be distilled off. After completion of the reaction, the generated toner particles are collected by washing and filtration, and dried. In the suspension polymerization method, it is generally preferable to use 300 to 3000 parts by weight of water as a dispersion medium with respect to 100 parts by weight of the monomer system.

In the image forming method of the present invention, an image is formed by forming a latent image using an electrophotographic photosensitive member, visualizing the latent image using a developer, and transferring and forming the latent image on a transfer material. Is what you do.

As the developer used in this image forming method, the above-mentioned developer for developing an electrostatic image can be used.

Further, the electrophotographic photosensitive member used in the image forming method of the present invention preferably has at least a conductive support and a photosensitive layer having a laminated structure of a charge generation layer and a charge transport layer.

The surface layer of the electrophotographic photosensitive member, that is,
When the protective layer is provided on the charge transport layer or the photosensitive layer, the protective layer contains a substance having a fluorine atom and / or a silicon atom, and the fluorine atom and the silicon atom and the carbon atom are measured by XPS measurement. When the ratio satisfies the following condition: fluorine atom / carbon atom (F / C) = 0.01 to 1.00 silicon atom / carbon atom (Si / C) = 0.03 to 1.00, higher image quality can be obtained. We found that an image could be obtained.

Here, the reason for defining F / C and Si / C is that when the surface of the photoreceptor is combined with the present invention,
It is configured so as to achieve the object of the present invention.

That is, the fluorine atom and the silicon atom reduce the surface energy of the photoreceptor, improve the transferability,
In addition, the adhesiveness is reduced. On the other hand, the presence of carbon atoms increases its surface energy. The present inventors have found that by defining this ratio, the toner surface has a large amount of polar components and the transferability is good even in a toner structure having a strong adhesive force and does not cause a cleaning failure. .

Here, the F / C and the Si / C of the surface layer of the photoreceptor are each 0.01 with respect to the toner used in the present invention.
If it is less than 0.03, the surface energy of the photoreceptor is high, and the transferability of the toner is deteriorated. If F / C and Si / C each exceed 1.00, the coefficient of friction with the cleaning member decreases, and conversely This results in poor cleaning through the toner.

A still more preferred configuration is that the surface layer of the electrophotographic photosensitive member contains polycarbonate, and even more preferred is that the polycarbonate is synthesized from an asymmetric diol.

As a result, an electrophotographic photosensitive member having excellent durability and good productivity can be obtained. Further, as a preferable configuration, it is preferable that a protective layer is provided on the photosensitive layer of the electrophotosensitive member, and the protective layer contains polycarbonate.

Thus, the stability of the durability characteristic is further increased.

Further, a more preferable constitution for attaining the object of the present invention is that the surface layer of the electrophotographic photosensitive member of the present invention has a X
The ratio of fluorine atom and / or silicon atom to oxygen atom by PS measurement is as follows: Fluorine atom / oxygen atom (F / O) = 0.01 or more Silicon atom / oxygen atom (Si / O) = 0.03 or more It is preferable to satisfy.

By regulating the amount of oxygen atoms to fluorine atoms and silicon atoms as described above, the adhesion to the toner containing the resin having a polar component of the present invention can be more preferably controlled.

The method for measuring the XPS of the surface of the electrophotographic photosensitive member according to the present invention is described below.

As the XPS measuring device, ES manufactured by VG is used.
The measurement was performed using a CALAB200-X type X-ray photoelectron spectrometer.

The measurement conditions were as follows: X-ray source: Mg Kα (300 W); analysis area: 2 × 3 mm.

The components used in the present invention will be specifically described below.

The structure of the electrophotographic photosensitive member used in the present invention will be described.

The photoreceptor used in the present invention has a photosensitive layer having a laminated structure having a charge generation layer and a charge transport layer on a conductive substrate. Further, in the present invention, a configuration in which a protective layer is provided on the charge transport layer may be used.

The present invention is characterized in that the charge transport layer and / or the protective layer serving as the surface layer of the photoreceptor contain a fluorine compound and / or a silicon compound.

Further, as a means for more effectively achieving the object of the present invention, it is preferable that the charge transport layer and / or the protective layer contain polycarbonate.

In the present invention, the polycarbonate preferably contains a polycarbonate synthesized using an asymmetric diol.

The materials used for the photoreceptor of the present invention are described below.

As specific examples of the fluorine-based compound, a known fluorine-based resin may be used, and ethylene tetrafluoride, ethylene trifluoride chloride, ethylene tetrafluoride hexafluoropropylene, vinyl fluoride, vinylidene fluoride, One or more selected from ethylene dichloride and copolymers thereof are appropriately selected.

Also, carbon fluoride and the like can be used.

In the present invention, a block containing a fluorine-containing segment synthesized from polymerization or copolymerization with a fluorine-based polymerizable monomer or a non-fluorine-based polymerizable monomer,
A graft polymer, a surfactant, a macromonomer and the like can be used alone or in combination with the above-mentioned fluororesin.

In particular, the combined use with a fluorine-based graft polymer having a continuous fluorine-based segment is also preferable from the viewpoint of facilitating the dispersion of the fluorine-based resin and the control of the surface F / C ratio characteristic of the present invention.

Preferred specific examples of the above-mentioned fluorine-based polymerizable monomer are shown below, but the range of usable compounds is not limited to the above-mentioned ranges.

[0135]

[Outside 7] (In the above compounds, R ₁ represents a hydrogen atom, a halogen atom or a methyl group, R ₂ represents a hydrogen atom, a halogen atom, an alkyl group, an alkoxy group or a nitrile group, and may be a combination of several kinds thereof; An integer of 4 and m is 1 to 5
K + m = 5, and Rf is at least 1
It represents an alkyl group substituted with at least two fluorine atoms. Non-fluorinated polymerizable monomers include low-molecular-weight linear unsaturated hydrocarbons, vinyl halides, organic acid vinyl esters, vinyl aromatic compounds, acrylic and methacrylic esters, N-vinyl compounds, vinyl Silicon compounds,
One or more of maleic anhydride, esters of maleic acid and fumaric acid can be used, but the charge transport layer and / or protective layer to which the formed fluorine-based graft polymer is added can be used. Compatible with the resin layer,
Alternatively, it is preferable to select one having a similar structure even if they are not completely compatible with each other and having a little affinity between them.

Specific examples of the silicon-based compound include three-dimensionally crosslinked monomethylsiloxane, dimethylsiloxane-
Monomethylsiloxane three-dimensional crosslinked products, ultrahigh molecular weight polydimethylsiloxane, block polymers containing polydimethylsiloxane segments, graft polymers, surfactants, macromonomers, terminal-modified polydimethylsiloxane, and the like are used. In the case of a three-dimensional crosslinked product, the particle size used in the form of fine particles or the like can be used in the range of 0.01 to 5 μm. In the case of a polydimethylsiloxane compound, its molecular weight can be used in the range of 3000 to 5,000,000. The fine particles are dispersed as a photosensitive layer composition together with a binder resin. As a dispersion method, a sand mill, a ball mill, a roll mill, a homogenizer, a nanomizer, a paint shaker, an ultrasonic wave, or the like is used. At the time of dispersion, it is preferable to use the above-mentioned graft, block polymer and surfactant as a dispersing aid, and it is also preferable to use them together for controlling the Si / C ratio which is a feature of the present invention.

The polycarbonate soluble in the aromatic hydrocarbon solvent or the halogenated aromatic hydrocarbon solvent used in the charge transport layer and / or the protective layer of the present invention can be obtained by lowering the crystallinity. . Specifically, for example, 1) bisphenol A and one or two or more asymmetric diol compounds 2) a general polycarbonate synthesis method such as a phosgene method using one or two or more asymmetric diol compounds Can be obtained by Further, it can also be obtained by using a diol compound having a substituent having 3 or more carbon atoms in a side chain.

The typical examples of the asymmetric diol compound used in the present invention are shown below, but the present invention is not limited thereto.

[0139]

[Outside 8]

[0140]

[Outside 9]

[0141]

[Outside 10]

[0142]

[Outside 11]

[0143]

[Outside 12]

The proportion of the asymmetric diol compound in the above-mentioned polycarbonate copolymer with bisphenol A is preferably at least 20% by weight, more preferably at least 50% by weight in the diol compound. 20% by weight of the asymmetric diol compound
If it is below, the solubility in the aromatic hydrocarbon solvent or the halogenated aromatic hydrocarbon solvent becomes insufficient, and the temporal stability of the coating liquid also deteriorates. The solubility (the number of grams of polycarbonate in 100 g of the solution at a temperature of 25 ° C.) of the polycarbonate soluble in the above-mentioned aromatic hydrocarbon solvent or halogenated aromatic hydrocarbon solvent is 1 g or more,
Particularly, 5 g or more is preferable. When the solubility is 1 g or less,
For example, when a coating solution for a charge transport layer is prepared, the viscosity of the coating solution is so low that an appropriate film thickness required for the charge transport layer cannot be obtained.

The effect of the polycarbonate used in the present invention can be enhanced particularly when used as a binder resin for a charge generation layer or a charge transport layer.

Examples of aromatic hydrocarbon solvents include benzene, toluene, xylene and the like, and examples of halogenated aromatic hydrocarbon solvents include monochlorobenzene and dichlorobenzene.

When the electrophotographic photosensitive member used in the present invention is manufactured, a cylindrical cylinder or a film of metal such as aluminum or stainless steel, paper, plastic or the like is used as the conductive substrate. On these substrates,
An undercoat layer (adhesive layer) having a barrier function and an undercoat function can be provided.

The undercoat layer is used for improving the adhesion of the photosensitive layer, improving the coating property, protecting the substrate, covering defects on the substrate, improving the charge injection property from the substrate, protecting the photosensitive layer against electrical breakdown, and the like. It is formed. Examples of the material of the undercoat layer include polyvinyl alcohol, poly-N-vinyl imidazole, polyethylene oxide, ethyl cellulose, methyl cellulose, ethylene-acrylic acid copolymer, casein, polyamide,
Copolymerized nylon, glue, gelatin and the like are known. These are dissolved in a suitable solvent and applied onto a substrate. Its film thickness is about 0.2 to 2 μm.

In the function-separated type photoreceptor, selenium-tellurium, pyrylium, thiapyrylium dye, phthalocyanine pigment, anthantrone pigment, dibenzopyrenequinone pigment, pyranthrone pigment, trisazo pigment, diazo pigment, azo pigment , Indigo pigment,
Quinacridone pigments, asymmetric quinocyanines, quinocyanines or amorphous silicon described in JP-A No. 54-143645 can be used. Examples of the charge transporting substance include pyrene, N-ethylcarbazole, N-isopropylcarbazole, and N-isopropylcarbazole. Methyl-N-phenylhydrazino-3-methylidene-9-ethylcarbazole, N,
N-diphenylhydrazino-3-methylidene-9-ethylcarbazole, N, N-diphenylhydrazino-3-
Methylidene-10-ethylphenothiazine, N, N-diphenylhydrazino-3-methylidene-10-ethylphenoxazine, P-diethylaminobenzaldehyde-
N, N-diphenylhydrazone, P-diethylaminobenzaldehyde-N-α-naphthyl-N-phenylhydrazone, P-pyrrolidinobenzaldehyde-N, N-diphenylhydrazone, 1,3,3-tramethylindolenine-ω-aldehyde Hydrazones such as -N, N-diphenylhydrazone, P-diethylbenzaldehyde-3-methylbenzthiazolinone-2-hydrazone, 2,
5-bis (P-diethylaminophenyl) -1,3,4
-Oxadiazole, 1-phenyl-3- (P-diethylaminostyryl) -5- (P-diethylaminophenyl) pyrazoline, 1- [quinolyl (2)]-3- (P-
Diethylaminostyryl) -5- (P-diethylaminophenyl) pyrazoline, 1 [pyridyl (2)]-3-
(P-diethylaminostyryl) -5- (P-diethylaminophenyl) pyrazoline, 1- [6-methoxy-pyridyl (2)]-3- (P-diethylaminostyryl)
-5- (P-diethylaminophenyl) pyrazolin, 1
-[Pyridyl (3)]-3- (P-diethylaminostyryl) -5- (P-diethylaminophenyl) pyrazolin, 1- [repidyl (2)]-3- (P-diethylaminostyryl) -5- (P- Diethylaminophenyl) pyrazolin, 1- [pyridyl (2)]-3-3 (P-diethylaminostyryl) -4-methyl-5- (P-diethylaminophenyl) pyrazolin, 1- [pyridyl (2)]-3- ( α-methyl-P-diethylaminostyryl) -5- (P-diethylaminophenyl) pyrazoline, 1-phenyl-3- (P-diethylaminostyryl) -4-methyl-5- (P-diethylaminophenyl) pyrazoline, 1-phenyl -3- (α-benzyl-
Pyrazolines such as P-diethylaminostyryl) -5- (P-diethylaminofail) pyrazoline and spiropyrazoline, 2- (P-diethylaminostyryl) -6-
Oxazole compounds such as diethylaminobenzoxazole, 2- (P-diethylaminophenyl) -4- (P-dimethylaminophenyl) -5- (2-chlorophenyl) oxazole, 2- (P-diethylaminostyryl) -6-diethylaminobenzo A thiazole compound such as thiazole, a triarylmethane compound such as bis (4-diethylamino-2-methylphenyl) -phenylmethane, 1,1-bis (4-N, N-diethylamino-
Polyarylalkanes such as 2-methylphenyl) heptane and 1,1,2,2-tetrakis- (4-N, N-dimethylamino-2-methylphenyl) ethane can be used.

The charge generation layer was prepared by adding the above-mentioned charge generation pigment to 0.1%.
With 3 to 4 times the amount of binder resin and solvent, well dispersed by a method such as homogenizer, ultrasonic wave, ball mill, vibrating ball mill, sand mill, attritor, roll mill, etc.
It is formed by coating and drying. Its thickness is 0.1-1μ
It is about.

When the above-mentioned polycarbonate resin is used for the charge generation layer, the charge generation material is dissolved together with the polycarbonate in an aromatic hydrocarbon solvent or a halogenated aromatic hydrocarbon solvent alone or in a mixed solvent thereof. ,
It is formed by applying a coating liquid obtained by dispersing a charge generating substance in a solution in which the above-mentioned polycarbonate resin is dissolved in the above-mentioned solvent. The proportion of the charge generation material in the charge generation layer can be 30% by weight or more, preferably 80% by weight or more. As solvents, toluene, xylene or monochlorobenzene are particularly useful. As a method of applying the coating solution, for example, a dip coating method, a spray coating method, a spinner coating method, a curtain coating method, or the like can be used.

When the above-mentioned polycarbonate resin is used for the charge transporting layer, the charge transporting substance and the above-mentioned polycarbonate are used alone or in a mixture of the above-mentioned aromatic hydrocarbon solvent or halogenated aromatic hydrocarbon solvent. It is obtained by applying a coating solution prepared by dissolution. The mixing ratio of the charge transport material and the above-described polycarbonate resin used as a binder is about 2: 1 to 1: 2 by weight. Particularly useful solvents are toluene, xylene or monochlorobenzene.

As a method of applying this solution, for example, a dip coating method, a spray coating method, a spinner coating method, a curtain coating method and the like are known. The dip coating method is the best for efficient and accurate production of electrophotographic photoreceptors and mass production. Especially, the pot life in the dip coating method can be greatly improved by using the above-mentioned polycarbonate. The productivity of manufacturing using the coating method can be greatly improved. After applying and forming the charge transport layer, air drying or still drying is performed at a temperature of 10 ° C to 200 ° C, preferably 20 ° C to 150 ° C for 5 minutes to 5 hours, preferably 10 minutes to 2 hours. A charge transport layer of 20 μ is obtained.

[0154]

The present invention will be specifically described below with reference to examples. They do not limit the invention in any way.

[Production Example A of Polymerized Toner Particles] 450 g of a 0.1 M Na ₃ PO ₄ aqueous solution was added to 710 g of ion-exchanged water.
And heated to 60 ° C., and then stirred at 12000 rpm using a TK homomixer (manufactured by Tokushu Kika Kogyo). 68 g of a 1.0 M CaCl ₂ aqueous solution was gradually added thereto to obtain an aqueous medium containing Ca ₃ (PO ₄ ) ₂ .

Styrene 180 g 2-ethylhexyl acrylate 20 g Phthalocyanine pigment 10 g Di-t-butylsalicylic acid metal compound 1 g Styrene-methacrylic acid copolymer (molar ratio 95: 5, M
_W 50,000) 10 g Paraffin wax 40 g

The above-mentioned formulation was heated to 60 ° C., and was subjected to 12000 rpm using a TK homomixer (manufactured by Tokushu Kika Kogyo).
To dissolve and disperse uniformly. In addition, polymerization initiator 2,
2'-azobis (2,4-dimethylvaleronitrile) 1
0 g was dissolved to prepare a polymerizable monomer composition.

The polymerizable monomer composition was charged into the aqueous medium, and the mixture was stirred at 10,000 rpm for 20 minutes at 60 ° C. in a N ₂ atmosphere using a TK homomixer to obtain a polymerizable monomer composition. Was granulated. Thereafter, while stirring with a paddle stirring blade, the temperature was raised to 80 ° C., and the reaction was performed for 10 hours.

After the completion of the polymerization reaction, a part of the aqueous medium was distilled off under reduced pressure, the mixture was cooled, hydrochloric acid was added to dissolve the calcium phosphate, followed by filtration, washing with water and drying to give a weight average diameter of about 8 μm.
m of colored suspension particles A (toner particles A).

[Production Example B of Polymerized Toner Particles] A toner particle B was obtained in the same manner as in Production Example A of Polymerized Toner Particles, except that the phthalocyanine pigment used in Production Example A of Polymerized Toner Particles was changed to carbon black.

[Production Examples C and D of Polymerized Toner Particles] By adjusting the amount of the polymerization initiator and the polymerization temperature used in Production Example A of the polymerized toner particles, toner particles C and D having different molecular weight peaks in the molecular weight distribution were obtained. .

Table 1 shows the molecular weight peaks of the toner particles A to D obtained in the polymerized toner particle production examples A to D.

[0163]

[Table 1] Note that the toner particles C were slightly blocked during drying during the production process and were not evaluated.

[Carrier Production Example A] Fe ₂ O in molar ratio
₃ = 60 mol%, CuO = 20 mol%, were weighed so that ZnO = 20 mol%, whereas, Fe ₂ O ₃ = 82 mol%, SrCO ₂ = 10 mol%, so that the ZnO = 8 mol% , And mixed using a ball mill. After calcining each of them, pulverize them by a ball mill, mix the above formulations at a ratio of 2: 1 respectively, add polyvinyl alcohol, an antifoaming agent and a dispersing agent to form a slurry, and granulate and dry using a spray drier. Then, sintering was performed. Further classification results in an average particle size of 55 μm
Was obtained. The shape of the carrier obtained at that time was almost spherical. X-ray diffraction and fluorescence X
As a result of the line analysis, the ratio between the spinel phase (Cu-Zn-ferrite) and the magnet plumbite phase (Sr ferrite) was 2: 1, which is almost the same as the charged amount. The bulk density was 2.32 g / cm ³ . When the resistance of the carrier particles was measured, it was 6.2 × 10 ⁹ Ω · cm. After saturating the carrier with a magnetic field of ₁₀ kOe, a magnetic measurement was performed. As a result, the magnetic characteristics at that time were σ ₁₀₀₀ = 142 emu / cm ³ and σ _r = 104 em.
u / cm ³ , σ ₃₀₀ = 122 emu / cm ³ ,

[0165]

[Outside 13] Met. Then, | σ ₁₀₀₀ −σ ₃₀₀ | / σ ₁₀₀₀ =
0.14.

Further, the surface of the carrier was coated with a copolymer of styrene and 2-ethylhexyl methacrylate (45/55) by a fluidized bed coating method to obtain Carrier A. The specific resistance of the carrier A at that time is 9.5
× 10 ¹² Ω · cm.

[Carrier Production Example B] Fe ₂ O
₃ = 50 mol%, CuO = 20 mol%, were weighed so that ZnO = 30 mol%, whereas, Fe ₂ O ₃ = 85 mol%, BaO = 12 mol%, so that ZnO = 3 mol% The mixture was weighed and mixed using a ball mill.

After calcining each of them, pulverizing them by a ball mill, mixing the above-mentioned formulations at a ratio of 1.5: 1, adding polyvinyl alcohol, an antifoaming agent and a dispersing agent to form a slurry, and using a spray drier The mixture was granulated and dried, and then sintered. By further classification, carrier particles having an average particle size of 45 μm were obtained. The shape of the carrier obtained at that time was almost spherical. As a result of X-ray diffraction measurement and X-ray fluorescence measurement, the molar ratio of the spinel phase to the magnet plumbite phase (Ba ferrite) was almost the same as the charged amount (1.6: 1). The bulk density is 2.30
g / cm ³ . When the resistance of the carrier particles was measured, it was 9.2 × 10 ⁹ Ω · cm. After saturating this carrier with a magnetic field of 10 kOe, a magnetic measurement was performed. As a result, the magnetic characteristic at that time was σ ₁₀₀₀ = 67.
_{^{emu / cm 3, σ r =}} 36emu / cm 3, σ 300 =
52 emu / cm ³ ,

[0169]

[Outside 14] Met. Then, | σ ₁₀₀₀ −σ ₃₀₀ | / σ ₁₀₀₀ =
0.22.

Further, the surface of this carrier was coated with a copolymer of styrene and 2-ethylhexyl methacrylate (45/55) by a fluidized bed coating method to obtain Carrier B. The specific resistance of the carrier B at that time is 1.3
× 10 ¹² Ω · cm.

[Carrier Production Example C] Fe ₂ O in molar ratio
₃ = 62 mol%, ZnO = 16 mol%, CuO = 22 mol%, and the mixture was mixed using a ball mill. The mixed powder was calcined and then pulverized. The pulverized sample was formed into a slurry, the slurry was granulated in a spray dryer, and the granulated powder was sintered. The obtained sintered powder was classified by an air classifier to obtain carrier particles having an average particle size of 50 μm. The shape of the carrier obtained at that time was almost spherical. The bulk density was 2.77 g / cm ³ . When the resistance of the carrier particles was measured, 4.0 ×
It was 10 ⁹ Ω · cm. This carrier was subjected to magnetic measurement in a magnetic field of ₁₀ kOe. As a result, the magnetic properties at that time were σ ₁₀₀₀ = 214 emu / cm ³ , σ _r
= 2 emu / cm ³ , σ ₃₀₀ = 113 emu / cm ³ ,

[0172]

[Outside 15] Met. At this time, | σ ₁₀₀₀ −σ ₃₀₀ | σ ₁₀₀₀ = 0.
47.

The obtained carrier was surface-coated in the same manner as in Carrier Production Example A to obtain Carrier C. At this time, the specific resistance of the carrier C was 3.2 × 10 ¹² Ω · cm.

[Carrier Production Example D] Fe ₂ O in molar ratio
₃ = 60 mol%, SrCO ₃ = 3 mol%, ZnO = 21
The mixture was weighed so that mol% and CuO = 16 mol%, and mixed using a ball mill. This is Carrier Manufacturing Example C
In the same manner as in the above, carrier particles having an average particle size of 52 m were obtained. The shape of the carrier obtained at that time was almost spherical. As a result of the X-ray diffraction measurement and the fluorescent X-ray measurement, the molar ratio of the spinel phase (Cu-Zn ferrite) to the magnet plumbite phase (Sr ferrite) was approximately 15: 1. The bulk density was 2.32 g / cm ³ . When the resistance of the carrier particles was measured, it was 1 × 10 ⁹ Ω · cm. As a result of the magnetic measurement of this carrier, the magnetic characteristics at that time were as follows: σ ₁₀₀₀ = 58 emu / cm ³ , σ _r =
6 emu / cm ³ , σ ₃₀₀ = 20 emu / cm ³ ,

[0175]

[Outside 16] Met. Then, | σ ₁₀₀₀ −σ ₃₀₀ | / σ ₁₀₀₀ =
0.66.

The obtained carrier was surface-coated in the same manner as in Carrier Production Example A to obtain Carrier D. At this time, the specific resistance of the carrier D was 1.5 × 10 ¹² Ω · cm.

Table 2 shows the physical properties of the carriers A to D.

[0178]

[Table 2]

[Titanium Oxide Treatment Example A] Hydrophilic titanium oxide fine particles (particle size: 0.05 μm) were added to an aqueous system, and mixed and stirred by a mechanical method. Titanium oxide 1
A processing amount of 30% by weight based on 00 parts by weight of vinyltriethoxysilane as a coupling agent is added and dispersed,
Surface treatment was performed while hydrolyzing.

At this time, the titanium oxide was not united.
Thereafter, drying and crushing were performed to obtain titanium oxide A having an average particle size of 0.05 μm, a degree of hydrophobicity of 60%, and a light transmittance of 81% at 400 nm.

[Titanium Oxide Treatment Example B] Hydrophilic titanium oxide fine particles (particle size: 0.04 μm) were added to an aqueous system, and mixed and stirred by a mechanical method. Titanium oxide 1
A vinyltriethoxysilane coupling agent having a treatment amount of 41% by weight based on 00 parts by weight was added and dispersed,
Surface treatment was performed while hydrolyzing.

At this time, the titanium oxide was not united.
Thereafter, drying and crushing were performed to obtain titanium oxide B having an average particle diameter of 0.08 μm, a hydrophobicity of 55%, and a light transmittance of 35% at 400 nm.

[Titanium Oxide Treatment Example C] Hydrophilic titanium oxide fine particles (particle size: 0.04 μm) were added to an aqueous system, and mixed and stirred by a mechanical method. Titanium oxide 1
A coupling agent, vinyltriethoxysilane, having a processing amount of 60% by weight based on 00 parts by weight was added and dispersed,
Surface treatment was performed while hydrolyzing. At this time, the titanium oxide particles were not united. After this, it is dried and crushed,
Titanium oxide C having an average particle size of 0.30 μm, a hydrophobicity of 99%, and a light transmittance of 8% at 400 nm was obtained.

Table 3 shows the physical properties of the titanium oxides A to C.

[0185]

[Table 3]

[Photoconductor Production Example A] 10 parts by weight of conductive titanium oxide (tin oxide coating, average primary particle size 0.4 μm), 10 parts by weight of phenol resin precursor (resole type), 10 parts by weight of methanol, and 10 parts by weight of butanol The portion was sand-milled and then dip-coated on an aluminum cylinder having an outer diameter of 80 mm and a length of 360 mm, cured at 140 ° C., and provided with a conductive layer having a volume resistance of 5 × 10 ⁹ Ωcm and a thickness of 20 μm.

Next, 10 parts by weight of the following methoxymethylated nylon (methoxymethylation degree: about 30%)

[0188]

[Outside 17] And 150 parts by weight of isopropanol were mixed and dissolved, and then dip-coated on the conductive layer to provide a 1 μm undercoat layer.

Next, 10 parts by weight of the following azo pigment:

[0190]

[Outside 18] The following polycarbonate resin (bisphenol A molecular weight 3
0000) 5 parts by weight,

[0191]

[Outside 19] And 700 parts by weight of cyclohexanone were dispersed in a sand mill, and this dispersion was applied by dip coating on the undercoat layer.
A charge generation layer of 0.05 μ was obtained.

Next, 10 parts by weight of the following triphenylamine:

[0193]

[Outside 20] Polycarbonate resin of the following structure (Bisphenol Z
Mold, molecular weight 20,000) 10 parts by weight

[0194]

[Outside 21] 50 parts by weight of monochlorobenzene and dichloromethane 1
After stirring and mixing 5 parts by weight, dip coating was performed on the charge generation layer. The coated cylinder was dried with hot air to form a 20 μm charge transport layer.

Next, 1 part by weight of carbon fluoride fine powder (average particle size: 0.23 μm, manufactured by Central Glass Co., Ltd.) and the following polycarbonate resin (bisphenol Z, molecular weight: 800
00) 6 parts by weight,

[0196]

[Outside 22] The following perfluoroalkyl acrylate-methyl methacrylate block copolymer (molecular weight 30,000) 0.1
Parts by weight

[0197]

[Outside 23] Monochlorobenzene (120 parts by weight) and dichloromethane (80 parts by weight) were dispersed and mixed in a sand mill. 3 parts by weight of the following triphenylamine

[0198]

[Outside 24] Was added and mixed and dissolved, and the mixture was applied in the form of a charge transport layer by spray coating.

[F / C Ratio XPS Measurement] After the surface of the photoconductor A was peeled off, the surface elements were quantified using an ESCALAB200-X type X-ray photoelectron spectrometer manufactured by VG. X
Using MgCa (300 W) as a radiation source, the measurement was performed at a depth of several Å over a 2 × 3 mm area. The surface of the photoconductor A of Production Example A had 5, 2% of F atoms and 81.3% of C atoms, and the F / C ratio was 0.064.

[Photoconductor Production Example B] 10 parts by weight of conductive titanium oxide (tin oxide coating, average primary particle size 0.4 μm), 10 parts by weight of phenol resin precursor (resole type), 10 parts by weight of methanol, and 10 parts by weight of butanol After the weight part was dispersed in a sand mill, it was applied by dip coating to an aluminum cylinder having an outer diameter of 80 mm and a length of 360 mm, cured at 140 ° C., and provided with a conductive layer having a volume resistance of 5 × 10 ⁹ cm and a thickness of 20 μm.

Next, 10 parts by weight of the following methoxymethylated nylon (methoxymethylation degree: about 30%)

[0202]

[Outside 25] And 150 parts by weight of isopropanol were mixed and dissolved, and then dip-coated on the conductive layer to provide a 1 μm undercoat layer.

Next, 10 parts by weight of the following azo pigment:

[0204]

[Outside 26] The following polycarbonate resin (bisphenol A molecular weight 3
0000) 5 parts by weight,

[0205]

[Outside 27] And 700 parts by weight of cyclohexanone were dispersed in a sand mill, and this dispersion was applied by dip coating on the undercoat layer.
A charge generation layer of 0.05 μ was obtained.

Next, 10 parts by weight of the following triphenylamine:

[0207]

[Outside 28] Polycarbonate resin of the following structure (Bisphenol Z
Mold, molecular weight 20,000) 10 parts by weight

[0208]

[Outside 29] 50 parts by weight of monochlorobenzene and dichloromethane 1
After stirring and mixing 5 parts by weight, dip coating was performed on the charge generation layer. The coated cylinder was dried with hot air to form a 20 μm charge transport layer.

Next, 1 part by weight of fine spherical three-dimensionally crosslinked polysiloxane fine particles (average particle size: 0.29 μm, manufactured by Toshiba Silicone Co., Ltd.) and the following polycarbonate resin (bisphenol Z,
(Molecular weight: 80000) 6 parts by weight,

[0210]

[Outside 30] The following polydimethylsiloxane methacrylate-methyl methacrylate block copolymer (molecular weight 50,000, S
i amount 12 wt%) 0.1 part by weight

[0211]

[Outside 31] Monochlorobenzene (120 parts by weight) and dichloromethane (80 parts by weight) were dispersed and mixed in a sand mill. 3 parts by weight of the following triphenylamine

[0212]

[Outside 32] Was added and mixed and dissolved, and the mixture was applied in the form of the charge transport layer by spray coating.

[Measurement of Si / C Ratio XPS] After the surface of the photoconductor B was peeled off, ESCALAB200-X manufactured by VG was used.
The surface elements were quantified using a type X-ray photoelectron spectrometer.
2 x 3 mm using MgCa (300 W) as X-ray source
Area was measured at a depth of several square centimeters. The surface of the photoreceptor B of Production Example B has 10.2% Si atoms and 69.3% C atoms
And the Si / C ratio was 0.147.

[Photoreceptor Production Example C] In the photoreceptor A of photoreceptor production example A, a photoreceptor C was obtained by coating the charge transport layer without the protective layer.

Table 4 shows the F / C ratio and the F / O ratio of the surface layers of the photoconductors A and C.
Table 5 shows the / C ratio and the Si / O ratio.

[0216]

[Table 4]

[0219]

[Table 5]

[Preparation of Toner] A toner was prepared by externally adding 0.2 parts by weight of titanium oxide to 100 parts by weight of toner particles.

[Preparation and Evaluation Method of Developer] After the carrier was saturated and magnetized by a magnetic field of 10 kOe, the carrier and the toner were mixed at a toner concentration of 5% by weight to obtain a developer. This was modified from a Canon full color laser copying machine CLC-500, and an image was displayed using the drum of the present invention. FIG. 4 is a schematic diagram of the developing device and the developing area of the photosensitive drum at this time. The distance between the developing sleeve and the developer regulating member is 400 μm, the peripheral speed ratio between the developing sleeve and the photosensitive drum is 1.3: 1, and
The developing conditions were as follows: the magnetic field strength of the developing pole was 1000 Oersted, the alternating electric field was 2000 V _pp , the frequency was 3000 Hz, and the distance between the sleeve and the photosensitive drum was 500 μm.
At this time, spikes of the developing brush near the developing pole on the developing sleeve were observed under a microscope to evaluate image formation. Furthermore, idle rotation of the developing device is performed at a speed of 200 rpm for 30 minutes.
Image evaluation was performed. The idle rotation test was performed at normal temperature and normal humidity (23 ° C., 60% RH) and at low temperature and low humidity (15 ° C., 10% RH).
RH) and the image quality was evaluated.

Next, a method for evaluating the fixing property in Examples of the present invention will be described.

As a recording material, commercially available copier paper Canon New Dry Paper (Canon sales company 54 g / m 2)
² ) to obtain an unfixed image, and use a commercially available copier Cano.
The fixing device of nFC-1 (manufactured by Canon Inc.) was modified, and the fixing temperature was modulated every 5 ° C. (120 to 200 ° C.), and the fixing start temperature and the offset temperature were observed.

Here, the fixing start temperature was determined by rubbing the obtained fixed image with silbon paper 10 times in a reciprocating manner at a load of about 100 g, and removing the image peeling by a reduction rate (%) of the reflection density by 10%.
% Or less.

[Examples 1 to 5 and Comparative Examples 1 to 5] The above toners A to D, titanium oxides A to C, and carrier A
To D and the photoconductors A to C were used in combinations shown in Table 6 to prepare toners and developers, and the image output was evaluated according to the above evaluation method.

Table 6 shows the evaluation results.

[0225]

[Table 6]

[0226]

According to the present invention, there is provided a developer for developing an electrostatic image having a toner and a carrier, wherein the toner has toner particles and titanium oxide, and the toner particles are directly formed by a suspension polymerization method. Is a toner particle having at least a colorant and a resin component, and the resin component constituting the toner particle has a molecular weight distribution determined by GPC,
At least one of the molecular weight peaks is in the range of 5,000 to 50,000, and contains at least one or more polar components.
The carrier has an average particle size of 5 to 100 μm and a bulk density of 3.0 g / cm ³ or less. And the magnetic properties of the carrier are as follows: (i) the magnetization intensity (σ) at 1000 Oe after magnetic saturation;
₁₀₀₀ ) is 30 to 150 emu / cm ³ , and (i)
i) The magnetization intensity (residual magnetization: σ _r ) at a magnetic field of 0 Oe is 25 emu / cm ³ or more, and (ii)
i) the coercivity is less than 300 Oersteds and (i)
v) The following formula

[0227]

[Outside 33] (In the formula, σ ₁₀₀₀ and σ ₃₀₀ indicate the magnetization intensity (emu / cm ³ ) at 1000 Oe and 300 Oe after magnetic saturation, respectively). It is hardly affected by fluctuations, has stable triboelectric charging under each environment, and has excellent fog-free clear image characteristics with high resolution, high highlight reproducibility, and high fine line reproducibility even after durability. Thus, excellent fixability can be obtained.

Further, a latent image is formed using an electrophotographic photosensitive member having at least a conductive layer and a photosensitive layer having a laminated structure of a charge generation layer and a charge transport layer. In an image forming method in which an image is formed using a developer and transferred to a transfer material, the surface layer of the electrophotographic photosensitive member contains a substance having a fluorine atom and / or a silicon atom, and the fluorine atom determined by XPS measurement. The ratio of the silicon atom to the carbon atom is as follows: fluorine atom / carbon atom (F / C) = 0.01 to 1.00 silicon atom / carbon atom (Si / C) = 0.03 to 1.00. Since the above-mentioned developer is used in a satisfactory image forming method, even if the toner has a relatively strong adhesive force because the resin component constituting the toner particles has a polar component, The surface layer of the photoreceptor Due to the presence of a specific amount of silicon atoms, the surface of the photoreceptor has a low surface energy, so that a good transferability can be obtained, and the cleaning performance is excellent, and excellent image quality can be obtained even after the endurance. And can be obtained well.

[Brief description of the drawings]

FIG. 1 is a schematic diagram schematically showing a magnetic characteristic curve (hysteresis curve). The horizontal axis indicates the external magnetic field (Oersted), and the vertical axis indicates the intensity of magnetization per unit volume of the carrier.

FIG. 2 is a schematic diagram schematically showing a magnetic characteristic curve (hysteresis curve). The numerical value shown in the box is (σ
₁₀₀₀₋ σ ₃₀₀ ) / σ ₁₀₀₀ .

FIG. 3 is a schematic diagram schematically showing an electric resistance measuring device.

[Explanation of symbols]

 A cell d Thickness 1 Lower electrode 2 Upper electrode 3 Insulator 4 Ammeter 5 Voltmeter 6 Constant voltage device 7 Carrier 8 Guide ring

Continuation of the front page (51) Int.Cl. ⁷ Identification symbol FI G03G 13/08 G03G 9/08 384 13/09 9/10 321 13/08 Z (72) Inventor Kasugani Rare 3-30 Shimomaruko, Ota-ku, Tokyo No. 2 Canon Inc. (56) References JP-A-2-88429 (JP, A) JP-B-4-3868 (JP, B2) (58) Fields surveyed (Int. Cl. ⁷ , DB name) ) G03G 9/08-9/113

Claims (17)

(57) [Claims] 1. A developer for developing an electrostatic charge image having a toner and a carrier, wherein the toner has toner particles and titanium oxide,
The toner particles were directly obtained by a suspension polymerization method,
Toner particles having at least a colorant and a resin component, wherein the resin component constituting the toner particles has a molecular weight distribution in which at least one of the molecular weight peaks is in the range of 5,000 to 50,000 in the molecular weight distribution by GPC;
And at least one or more polar components; the titanium oxide has an average particle size of 0.01 to 0.2 μm and a hydrophobicity of 20 to 98%; Average particle size of ~ 100 μm and 3.0
g / cm ³ or less, and the magnetic properties of the carrier are as follows: (i) the magnetization intensity (σ ₁₀₀₀ ) at 1000 Oe after magnetic saturation is 30 to 1;
(Ii) the magnetization intensity (residual magnetization: σ _r ) at a magnetic field of 0 Oe is 25 emu / cm ^3;
/ Cm ³ or more; (iii) the coercive force is less than 300 Oersted; and (iv) the following formula: (Wherein σ ₁₀₀₀ and σ ₃₀₀ indicate the magnetization intensity (emu / cm ³ ) at 1000 Oe and 300 Oe after magnetic saturation, respectively). A developer for developing a charge image. 2. The developer according to claim 1, wherein the carrier is substantially spherical and has a sphericity of 2 or less. 3. The carrier according to claim 1, wherein the carrier is Group IA or IIA of the periodic table.
Group, group IIIA, group IVA, group VA, group VIA, IB
Group, IIB, IVB, VB, VIB, VIIB
2. A ferrite particle comprising at least one element selected from the group consisting of Group III and Group VIII, and having a content of other elements of less than 1% by weight. The developer for developing an electrostatic image according to the above. 4. The carrier is a single phase having a spinel structure, a single phase having a magnet plumbite structure, a composite phase having at least a spinel structure or a magnet plumbite structure, and a composite phase having a spinel structure and a magnet plumbite structure. 2. The developer according to claim 1, wherein the molar ratio of the spinel phase to the magnet plumbite phase is 1: 1 to 10: 1. 5. The carrier according to claim 5, wherein the carrier has a density of 10 ^{8 to} 10 ¹³ Ω · c.
2. The developer according to claim 1, wherein the developer has a specific resistance of m. 6. The developer for developing an electrostatic image according to claim 1, wherein said titanium oxide is surface-treated by hydrolysis of a coupling agent. 7. The developer for developing an electrostatic charge image according to claim 1, wherein the titanium oxide has a light transmittance of 40% or more at a light length of 400 nm. 8. A latent image is formed by using an electrophotographic photosensitive member having at least a conductive support and a photosensitive layer having a laminated structure of a charge generation layer and a charge transport layer, wherein the latent image is formed. Image forming method using a developer to transfer and form a transfer material on a transfer material, wherein the surface layer of the electrophotographic photoreceptor contains a substance having a fluorine atom and / or a silicon atom, and is measured by XPS. The ratio of the fluorine atom and the silicon atom to the carbon atom is as follows: fluorine atom / carbon atom (F / C) = 0.01 to 1.00 silicon atom / carbon atom (Si / C) = 0.03 to 1 Wherein the developer has a toner and a carrier having toner particles and titanium oxide, and the toner particles are at least a colorant and a resin component directly obtained by a suspension polymerization method. Toner particles having the formula: Resin component constituting the toner particles, the molecular weight distribution by GPC, at least one molecular weight peak molecular weight of 5,000 to 5
The titanium oxide has an average particle diameter of 0.01 to 0.2 μm and a degree of hydrophobicity of 20 to 98%. The carrier has an average particle size of 5 to 100 μm and 3.0
g / cm ³ or less, and the magnetic properties of the carrier are as follows: (i) the magnetization intensity (σ ₁₀₀₀ ) at 1000 Oe after magnetic saturation is 30 to 1;
(Ii) the magnetization intensity (residual magnetization: σ _r ) at a magnetic field of 0 Oe is 25 emu / cm ^3;
/ Cm ³ or more; (iii) the coercive force is less than 300 Oersted; and (iv) the following formula: (Wherein σ ₁₀₀₀ and σ ₃₀₀ indicate the magnetization intensity (emu / cm ³ ) at 1000 Oe and 300 Oe, respectively, after magnetic saturation.) Forming method. 9. The image forming method according to claim 8, wherein the surface layer of the electrophotographic photosensitive member contains polycarbonate. 10. The image forming method according to claim 8, wherein the surface layer of the electrophotographic photosensitive member contains a polycarbonate synthesized using an asymmetric diol. 11. The image forming method according to claim 8, wherein said electrophotographic photoreceptor has a protective layer on said photosensitive layer, and said protective layer contains polycarbonate. 12. The image forming method according to claim 8, wherein said carrier is substantially spherical and has a sphericity of 2 or less. 13. The carrier of the periodic table IA, II
Group A, Group IIIA, Group IVA, Group VA, Group VIA, IB
Group, IIB, IVB, VB, VIB, VIIB
9. A ferrite particle containing at least one element selected from the group consisting of Group III and Group VIII, and having a content of other elements of less than 1% by weight. Image forming method. 14. The carrier according to claim 1, wherein the carrier is a single phase having a spinel structure, a single phase having a magnet plumbite structure, a composite phase having at least a spinel structure or a magnet plumbite structure,
9. The image forming method according to claim 8, wherein the composite phase has a spinel structure and a magnet plumbite structure, and a molar ratio of the spinel phase to the magnet plumbite phase is 1: 1 to 10: 1. . 15. The carrier according to claim ⁸ , wherein the carrier has a resistance of 10 ^{8 to} 10 ¹³ Ω ·
9. The image forming method according to claim 8, wherein the image forming apparatus has a specific resistance of about 0.1 cm. 16. The image forming method according to claim 8, wherein said titanium oxide is surface-treated by hydrolysis of a coupling agent. 17. The image forming method according to claim 8, wherein the titanium oxide has a light transmittance of 40% or more at a light length of 400 nm.