JPH0915901A - Magnetic toner and image forming method - Google Patents

Abstract

PURPOSE: To provide a magnetic toner faithful to an original, faithful to a signal, that is, faithful to a latent image, not practically causing fogging or tailing and having high resolution and high definition reproducibility. CONSTITUTION: Organically treated inorg. fine powder and a liq. lubricant are added to magnetic toner particles contg. at least a bonding resin and a magnetic substance and they are mixed to obtain the objective magnetic toner having 3 to <6μm vol. average particle diameter, 3.5 to <6.5μm wt. average particle diameter and a number-particle size distribution in which the percentage of particles of <=5μm is >60 to 90 number %. The ratio (Nr/Nv) of the percentage Nr of particles of <=3.17μm in the number-particle size distribution to the percentage Nv of particles of <=3.1μm in the vol.-particle size distribution is 2.0-8.0.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a magnetic toner used in electrophotography, electrostatic recording, magnetic recording and the like and an image forming method, and is applied to printers, copying machines, facsimiles and the like.

[0002]

2. Description of the Related Art Conventionally, a number of electrophotographic methods are known, but generally, a photoconductive material is used to form an electric latent image on a photoconductor by various means, and then the electrophotographic image is formed. The latent image is developed with toner to make it a visible image. If necessary, the toner image is transferred to a transfer material such as paper, and then the toner image is fixed on the transfer material by heat or pressure to obtain a copy. It is a thing.

As a method for visualizing an electric latent image, a cascade developing method, a magnetic brush developing method, a pressure developing method and the like are known. Further, a method is also used in which a magnetic toner is used and a rotating sleeve having a magnetic pole disposed at the center is used to fly between the photosensitive member and the sleeve by an electric field.

Unlike the two-component system, the one-component developing system does not require carrier particles such as glass beads and iron powder, so that the developing device itself can be made compact and lightweight. Further, since the two-component developing system needs to keep the toner concentration in the carrier constant, a device for detecting the toner concentration and supplying a required amount of toner is required. Therefore, the developing device also becomes large and heavy here. In the one-component developing system, such an apparatus is not required, so that the apparatus can be made small and light, which is preferable.

[0005] In recent years, LED and LBP printers have become the mainstream in the printer market, and the direction of technology has been increased to higher resolution, that is, from 240, 300 dpi to 400, 600, 800 dpi. ing. Accordingly, higher definition has been required for the developing system. In addition, the functions of the copying machine have been advanced, and the digital copying machine is moving toward digitalization. In this direction, a method of forming an electrostatic charge image with a laser is mainly used, so that the direction is also moving toward a higher resolution, and a high-resolution and high-definition developing method is required similarly to a printer. . For this reason, the particle size of the toner is being reduced, and it is disclosed in Japanese Patent Laid-Open Nos. 1-112253 and 1-1.
No. 91156, No. 2-214156, No. 2-284158, No. 3-181952.
And Japanese Patent Application Laid-Open No. 4-162048 propose a toner having a specific particle size distribution and a small particle size.

In copying machines, there is always a demand for higher speed and stabilization. Especially for medium speed machines and high speed machines, the two-component development method is the mainstream. This is because, with such a relatively large machine, the stability for long-term use at high speed becomes more important than the problem of the size and weight of the developing device. Generally, the toner of the two-component toner is colored with carbon black or the like, and the rest is composed of a polymer. For this reason, the toner particles are light and have no force other than electrostatic force to adhere to the carrier particles. Therefore, especially at high-speed development, the toner is scattered, and the lens, the original glass, the transport section, etc. are contaminated over a long period of time, which may cause image deterioration. May impair stability. Therefore, a two-component toner has been put into practical use in which a magnetic substance is contained in the toner to make the toner heavy, and at the same time, magnetic particles are attached to the magnetic carrier particles by magnetic force as well as electrostatic force to prevent scattering.

As described above, toner containing a magnetic material is becoming more and more important.

By the way, in the one-component magnetic developing system, since the toner is developed in a chain shape (generally called "brush") at the time of development, the resolution in the horizontal direction of the image is worse than that in the vertical direction. For example, the trailing phenomenon due to the protrusion of the ears is likely to occur in the non-image portion in the latter half of the developed image, and a rough image tends to occur as compared with the two-component developing method. Therefore, as a method of further improving the image reproducibility, it is possible to make the ears of the toner shorter and denser. Means such as abutting are considered. However, for example, when the amount of magnetic material is reduced, the charge amount of the toner is generally excessive and a so-called charge-up phenomenon occurs, resulting in deterioration of image quality such as decrease in image density and increase in fog. The relationship between the magnetic strength of the magnetic toner and the shape of the spikes is also qualitatively understood as follows. That is, when the magnetic toner has a large magnetization intensity, a strong attractive force along the magnetic field direction and a strong repulsive force in the direction perpendicular to the magnetic field are generated between the magnetic toner particles. Therefore, when the magnetization intensity is high, the ears formed by the magnetic toner are long, and the ears on the toner carrier have a low density, and the individual ears are thin. On the other hand, when the magnetic toner has a low magnetization strength, the ears are short and the ears on the toner carrier become dense, but the individual ears are thick because the binding between the magnetic toner particles is not broken. Becomes shorter,
It will be in an aggregated state. In this case, the magnetic toner particles existing inside the ears are less likely to come into contact with the surface of the toner carrier, resulting in poor charging. Such poorly charged toner particles cause fog on the image and deteriorate the image quality.

Further, in recent years, from the viewpoint of environmental protection, the primary charging and transfer processes using corona discharge, which have been conventionally used, are becoming mainstream, and the primary charging and transfer processes using a photoconductor contact member are becoming mainstream.

For example, JP-A-63-149669 and JP-A-2-123385 have been proposed. These are related to the contact charging method and the contact transfer method, but a conductive elastic roller is brought into contact with the electrostatic latent image carrier,
While electrostatically charging the electrostatic latent image carrier while applying a voltage to the conductive roller, another voltage was applied to the electrostatic latent image carrier after obtaining a toner image by exposure and development steps. While transferring the transfer material while pressing the conductive roller to transfer the toner image on the electrostatic latent image bearing member onto the transfer material, a transfer image is obtained through a fixing step.

However, in such a roller transfer system which does not use corona discharge, the transfer member is brought into contact with the photoconductor through the transfer member during the transfer, so that the toner image formed on the photoconductor is transferred to the transfer material. When the toner image is transferred to the toner image, the toner image is brought into pressure contact with the toner image, which causes a problem of partial transfer failure, which is so-called transfer void.

Further, in the roller charging system, the physical and chemical action on the surface of the electrostatic latent image bearing member due to the discharge generated between the charging roller and the electrostatic latent image bearing member is larger than that in the corona charging system. In particular, in the combination of organic photoreceptor / blade cleaning, there is a drawback that problems such as toner fusion on the photoreceptor and poor cleaning due to deterioration of the photoreceptor surface are likely to occur (direct charging / organic cleaning). The combination of photoconductor / single-component magnetic developing method / contact transfer / blade cleaning makes it easy to reduce the cost and size and weight of the image forming apparatus. This is the mainstream method for printers, facsimiles, etc.).

Therefore, the toner used in such an image forming method is required to have excellent releasability and lubricity. Therefore, Japanese Patent Publication No. 57-13868, Japanese Patent Laid-Open No. 54-58245, and Japanese Patent Laid-Open No. 59-19.
7048, JP 2-3073, JP 3
No. 63636, U.S. Pat. No. 4,517,272 and the like disclose methods of incorporating a silicone compound. However, in these methods, since the silicone compound is directly added to the toner, the silicone compound which is not compatible with the binder resin is poorly dispersed in the toner, resulting in uneven chargeability of the toner particles and long-term repeated use. Therefore, there is a problem that the developability is deteriorated.

In recent years, so-called recycled paper has become the mainstream as copy paper from the viewpoint of environmental protection. However, since recycled paper generates a large amount of paper powder and filler powder, problems such as cleaning failure and toner fusion are promoted by the use of recycled copy paper. These problems are small while clearing environmental problems.
This has been a problem that must be improved in order to obtain an image forming apparatus that can obtain high resolution and high definition images at light weight and low cost.

[0015]

SUMMARY OF THE INVENTION An object of the present invention is to provide a magnetic toner and an image forming method which solve the above problems of the prior art.

That is, the object of the present invention is to adhere to the original,
It is an object of the present invention to provide a magnetic toner having high resolution and high definition reproducibility, which is faithful to a signal, that is, substantially fogged to a latent image and has no toner tailing, and an image forming method.

Further, an object of the present invention is that the transferability is excellent, and whether voids in the transfer occur even in the roller transfer system.
Another object is to provide a magnetic toner and an image forming method in which these phenomena are suppressed.

Further, the object of the present invention is that the toner has excellent releasability and slipperiness, and these functions are maintained and maintained for a long period of time and after printing a large number of sheets, and toner fusion or cleaning failure does not occur, or these properties do not occur. It is an object to provide a magnetic toner in which the phenomenon is suppressed and an image forming method.

A further object of the present invention is to provide a magnetic toner and an image forming method in which abnormal charging or image defects due to contamination of a member pressed against an electrostatic latent image carrier does not occur, or these phenomena are suppressed. Especially.

[0020]

According to the present invention, an organically treated inorganic fine powder and a liquid lubricant are externally added to and mixed with magnetic toner particles containing at least a binder resin and a magnetic substance. In the magnetic toner, the volume average particle diameter D _v (μm) of the toner is 3 μm ≦ D _v <6 μm, and the weight average particle diameter D ₄ (μm) is 3.5 μm ≦ D ₄ <6.5 μm.
In the number particle size distribution, the ratio M _r of particles of 5 μm or less is 60 number% <M _r ≦ 90 number%, and the ratio N _r of particles of 3.17 μm or less in the number particle size distribution and the volume particle size distribution Ratio N of particles not larger than 3.17 μm
_{By v} ratio of (N _r / N _v) is used a magnetic toner and an image forming method using the same, characterized in that a 2.0 to 8.0, the toner on the toner carrying member suitable static The electrostatic cohesive force and the lubricity of each individual toner, as well as the appropriate magnetic binding force to the toner carrier, causes the toner in the developing area space to have a shape closer to that of individual toner particles, resulting in electrostatic discharge of the toner particles. Achieving a faithful flight to the latent image.

At the transfer site where the transfer material / magnetic toner / electrostatic latent image carrier is present, due to the adhesion of the liquid lubricant to the surface of the electrostatic latent image carrier and the good releasability of the toner. The toner particles can be uniformly transferred from the surface of the electrostatic latent image carrier to the transfer material.

At the cleaning portion where the cleaning blade / transfer residual toner / electrostatic latent image carrier exists, the electrostatic cohesive force between the toners and the electrostatic adhesion force to the electrostatic latent image carrier are reduced. It is possible to hold it down and to coat the surface of the electrostatic latent image bearing member and the cleaning blade with liquid lubricant. As a result, toner and paper dust are removed from the surface of the electrostatic latent image bearing member even with a slight blade contact pressure. To prevent fusion of toner on the surface of the electrostatic latent image bearing member damaged by discharge, and to prevent defective cleaning of the electrostatic latent image bearing member.

Since the electrostatic latent image carrier of the liquid lubricant and the surface of the cleaning blade are coated, and further, the electrostatic cohesive force between the magnetic toner particles is low and the lubricity is good, the toner is separated at the edge portion of the cleaning blade. The particles are easily dispersed in the particles, and the surface of the photoconductor is uniformly polished by a slight blade contact pressure. Etc. are achieved, and high resolution and high definition images that substantially prevent image contamination, scattering, background fog, and reverse fog when using fine particle toner, which has been a problem in the past, are obtained, and at the same time, defective cleaning and toner fusion occur. Adhesion was suppressed, and the life of the electrostatic latent image carrier was extended.

The following are used as the inorganic fine powder used in the present invention. For example, colloidal silica, titanium oxide, iron oxide, aluminum oxide, magnesium oxide, calcium titanate, barium titanate, strontium titanate, magnesium titanate,
Cerium oxide, zirconium oxide and the like can be used. These other types or two or more types can be mixed and used. Preferably, oxides or complex oxides such as titania, alumina and silica are preferable.

The toner used in the present invention is obtained by adding at least inorganic fine powder to toner particles, and in addition, organic fine powder, resin fine powder and the like having an average particle size smaller than the average particle size of the toner particles are added. What was done is one of the preferable forms.

Further, it is preferable that the toner particles also have the particle size distribution of the present invention.

60% by number or less of particles of 5 μm or less
And, there is almost no effect on the reduction of consumption, and the volume average particle size is
D_v(Μm) is 6 μm or more, weight average particle diameter D _Four(Μm)
In case of 6.5 μm or more, an isolated dot of about 50 μm
Resolution is not enough. At this time, you may be forced
When you try to make an image, line thickening and scattering occur,
This results in increased consumption. Furthermore, it must have the above particle size distribution.
With this, high productivity is maintained even for fine particle size toner.
Also, if the number of particles of 5 μm or less exceeds 90% by number, the image
Insufficient concentration. Preferably 62% <M_r≤
88% by number is good. For average particle size, further resolution
To improve, preferably 3.2 μm ≦ D_v≤
5.8 μm, 3.6 μm ≦ D_Four≦ 6.3 μm is preferable.

Further, in the number particle size distribution, 3.17 μm
The ratio N _r of the following particles and 3.17 in the volume particle size distribution
The ratio (N _r / N _v ) of the ratio N _v of particles of μm or less is 2.0 to
It is preferably 8.0 from the viewpoint of image quality. If it is less than 2.0, fog tends to occur, and if it exceeds 8.0, it is 50 μm.
The resolution of isolated dodds tends to deteriorate. Furthermore, 3.0-7.0 is preferable. Further, in this case, the ratio N _r of particles having a particle size distribution of 3.17 μm or less is 5 to 4
0%, preferably 7 to 35% is good.

Regarding the coefficient of variation, it is preferable that the coefficient of variation B of the number distribution is 20 ≦ B <40.

(B = S _v / D ₁ , D ₁ ; number average particle size,
S _v ; standard deviation of number distribution)

The absolute value of the charge amount of the toner (mC /
g or μC / g) is preferably 14 ≦ Q ≦ 80 (Q: triboelectricity with iron powder). Furthermore, 14 ≦ Q
≦ 60 is preferable, and 24 <Q ≦ 55 is particularly preferable. When Q <14, the charge amount is insufficient and the effect of reducing the consumption amount is not sufficient, and when 80 <Q, the charge amount is too high, and the concentration is likely to decrease.

Further, in the volume particle size distribution of the toner, 8
It is preferable that the volume ratio of particles having a size of μm or more is 10% by volume or less from the viewpoints of further reducing scattering, suppressing changes in the particle size distribution in the developing device through durability, and obtaining a stable density.

The toner of the present invention achieves higher image quality due to its small particle size, and has a high charge amount per unit mass.
Achieving low consumption by increasing the amount of fine powder below μm,
By containing a liquid lubricant, it is possible to prevent the void during transfer.

Concerning the consumption amount, the reason why a larger amount of toner is generally developed in the line image area than in the solid image area is considered as follows. In the electrostatic latent image of the line image portion on the photoconductor, unlike the solid image portion, the lines of electric force are closely wrapping around the line latent image from the outside of the line latent image. Since a large amount of toner is attracted to and pressed against the latent image surface of the photoconductor, more toner is easily developed on the line latent image surface.

Since the toner of the present invention contains a large amount of particles having a high charge amount of 5 μm or less, it is easy to fill the latent image potential.
Unnecessary toner particles once developed in the line image area on the photoconductor can return to the sleeve against the force due to the wraparound of the latent image electric lines of force, and can be properly transferred to the line image area. We believe that only a certain amount of toner will remain. That is, particles having a particle size of 5 μm or less reach the latent image on the photoconductor faster than particles having a large particle size because the charge amount per unit mass is high, and the lines of electric force of the latent image wrap around to weaken the developing electric field. This is because other particles are less likely to be affected by.

The magnetic material of the present invention includes a magnetic field of 79.6 k.
A magnetic substance formed of a metal oxide having a magnetization intensity at A / m (1000 oersteds) of more than 50 Am ² / kg (emu / g) is preferable, and iron, cobalt, nickel, copper, magnesium, manganese. , Metal oxides containing elements such as aluminum and silicon. The BET specific surface area of these magnetic particles by the nitrogen adsorption method is preferably 1 to 30 m ² / g, and particularly preferably 2.5 to 26 m ² / g.

The amount of magnetic material is 5 with respect to 100 parts by mass of the binder resin.
0 to 200 parts by mass, particularly 60 to 150 parts by mass are preferred. When the amount is less than 50 parts by mass, the transportability is insufficient and the toner layer on the toner carrier tends to be uneven, resulting in image unevenness, and further, the image density tends to be lowered due to the increase in toner tribo. On the other hand, if the amount exceeds 200 parts by mass, the fixing property tends to be problematic.

The average particle size of the magnetic material is 0.05 to 1.
0 μm is preferable, and 0.1 to 0.6 μm is more preferable.
m, more preferably 0.1 to 0.4 μm. Further, these magnetic particles are preferably magnetic powder having a Mohs hardness of 5 to 7.

In the present invention, the liquid lubricant is preferably contained in the toner by being carried on carrier particles by means such as adsorption, granulation, aggregation, impregnation, encapsulation and the like. As a result, the liquid lubricant can be uniformly and appropriately present on the toner surface, and the releasing property and lubricity of the toner can be stabilized.

Examples of liquid lubricants that impart releasability and lubricity to the toner of the present invention include animal oils, vegetable oils, petroleum-based lubricating oils,
A synthetic lubricating oil or the like is used, and a synthetic lubricating oil is preferably used because of its stability. Synthetic lubricating oils include silicones such as dimethyl silicone, methylphenyl silicone and various modified silicones; pentaerythritol ester,
Polyol ester such as trimethylolpropane ester; Polyolefin such as polyethylene, polypropylene, polybutene, poly α-olefin; Polyglycol such as polyethylene glycol and polypropylene glycol; Silicic acid ester such as tetradecyl silicate and tetraoctyl silicate; Di-2- Diesters such as ethylhexyl sebacate and di-2-ethylhexyl adipate; Phosphoric acid esters such as trikeresyl phosphate and propylphenyl phosphate; Fluorocarbonization such as polychlorotrifluoroethylene, polytetrafluoroethylene, polyvinylidene fluoride, and polyfluoroethylene Hydrogen compounds: polyphenyl ether, alkyl naphthenes, alkyl aromatics and the like. Of these, silicone and fluorohydrocarbon are preferable from the viewpoint of thermal stability and oxidation stability. As the silicone, reactive silicone such as amino modified, epoxy modified, carboxyl modified, carbinol modified, methacryl modified, mercapto modified, phenol modified, different functional group modified; polyether modified, methylstyryl modified, alkyl modified, fatty acid modified , Alkoxy-modified, fluorine-modified non-reactive silicone; dimethyl silicone,
Straight silicones such as methylphenyl silicone and methyl hydrogen silicone are used.

In the present invention, since the liquid lubricant on the surface of the carrier is partially released and exists on the surface of the toner particles, the effect is exerted, so that the curable silicone is less effective in nature. In addition, reactive silicones and silicones with polar groups may be less adsorbed depending on the degree, such as stronger adsorption to the liquid lubricant-carrying medium and compatibility with the binder resin. . In addition, even non-reactive silicone may show poor compatibility due to its compatibility with the binder resin depending on the structure of the side chain. Accordingly, dimethyl silicone, fluorine-modified silicone, fluorohydrocarbon, etc. are preferably used because they have low reactivity, low polarity, strong adsorption and no compatibility with the binder resin.

The liquid lubricant used in the present invention preferably has a viscosity at 25 ° C. of 100,000 to 200,000 cSt, more preferably 200 to 100,000 cSt, and particularly 50 to 50.
It is preferably 70,000 cSt. When it is less than 10 cSt, the amount of low molecular weight components is large, so that developability and storability tend to occur. If it exceeds 200,000 cSt,
The migration and dispersion in the toner particles become non-uniform, and problems easily occur in the developability, transferability, stain resistance, and the like. Viscosity measurement of the liquid lubricant in the present invention is performed by using Viscotester V.
T500 (made by Haake) is used.

One of several viscosity sensors for VT500 is arbitrarily selected, and a measurement material is put in the cell for the sensor for measurement. Viscosity (pas) displayed on the device
Is converted to cSt.

In the present invention, since the liquid lubricant is used by being carried on the lubricating particles, the dispersibility is superior to the case where the liquid lubricant such as silicone is simply added as it is. However, in the present invention, the purpose is not merely to improve the dispersibility, but to release the liquid lubricant from the carrier particles to exert its releasability and lubricity, and at the same time, to obtain an appropriate adsorption strength of the liquid lubricant. It is necessary to have it and prevent excessive liberation.

By holding the liquid lubricant on the surface of the carrier and allowing it to exist on or near the surface of the toner, the amount of the liquid lubricant on the surface of the toner can be adjusted appropriately.

As a specific method for supporting the liquid lubricant of the present invention on the surface of carrier particles, the liquid lubricant is directly used by using a mixer such as a Henschel mixer or a ball mill.
Alternatively, there may be used a method of diluting with a solvent or the like to directly mix and carry the carrier particles, or a method of directly spraying and carrying the carrier particles, or a wheel type kneading machine or a raking machine. As the wheel type kneader, a Simpson mix muller, Marutimaru, Stotsmill, Erich mill, backflow kneader, etc. can be preferably used.

As the lubricating particles containing a liquid lubricant used in the present invention, fine particles of an organic compound or an inorganic compound are granulated or agglomerated with a liquid lubricant to be used as the lubricating particles.

Examples of the organic compound include resin particles such as styrene resin, acrylic resin, silicone resin, polyester resin, urethane resin, polyamide resin, polyethylene resin and fluororesin. Inorganic compounds include SiO ₂ , GeO ₂ , TiO ₂ , SnO ₂ and Al.
Oxides of ₂ O ₃ , B ₂ O ₃ , P ₂ O ₅ etc., silicates, borates, phosphates, borosilicates, aluminosilicates, aluminoborates, aluminoborosilicates, tungstates , Metal oxide salts such as molybdates and tellurates, and composite compounds thereof, silicon carbide, silicon nitride, amorphous carbon and the like. These can be used alone or in combination.

As the inorganic compound fine powder, an inorganic compound fine powder produced by a dry method or a wet method can be used. The dry method mentioned here is a method for producing a fine powder of an inorganic compound produced by vapor-phase acid of a halide. For example, the basic reaction formula in the method utilizing the thermal decomposition oxidation reaction of a halide gas in oxygen-hydrogen is as follows.

MX_Four+2 H_Two+ ／ O_Two → MO_Two+4
HX (M: tetravalent)

In this formula, for example, M is a metal or metalloid element, X is a halogen element, and n is a reaction formula representing an integer. Specifically, AlCl ₃ , TiCl ₄ , GeCl ₄ ,
When SiCl ₄ , POCl ₃ , and BBr ₃ are used, Al ₂ O ₃ , TiO ₂ , GeO ₂ , SiO ₂ , P ₂ O ₅ , and B ₂ O are used, respectively.
₃ is obtained. At this time, if a mixture of halides is used, a composite compound can be obtained.

Alternatively, a dry fine powder can be obtained by applying a manufacturing method such as thermal CVD or plasma CVD. Among them, SiO ₂ , Al ₂ O ₃ , TiO _{2 and the} like are preferably used.

On the other hand, as a method for producing the inorganic compound fine powder used in the present invention by a wet method, various conventionally known methods can be applied. For example, a method of decomposing sodium silicate with an acid, a decomposition of sodium silicate with an ammonia salt or an alkali salt, and generating an alkaline earth metal silicate from sodium silicate, and then decomposing with an acid to obtain silicic acid. There are a method of converting a sodium acid solution into silicic acid by an ion exchange resin, a method of using natural silicic acid or a silicate, and the like. Other methods include hydrolysis of metal alkoxides. The general reaction formula is shown below.

M (OR) ₄ O + 2H ₂ O → MO ₂ + 4
ROH (M: tetravalent)

In this formula, for example, M is a metal or metalloid element, R is an alkyl group, and n is an integer. At this time, if two or more metal alkoxides are used, a composite can be obtained.

Among these, inorganic compounds are preferable, and metal oxides are particularly preferable because they have an appropriate electric resistance value. Especially,
Oxides and double oxides of Si, Al and Ti are preferred.

Further, the surface of which may be made hydrophobic by a coupling agent or the like may be used. However, some liquid lubricants tend to be overcharged when the surface of the toner particles is covered. When a non-hydrophobicized carrier is used as the carrier, an appropriate charge leak can be performed, and good developability can be maintained. Therefore, it is also one of the preferable modes to use a carrier which has not been subjected to a hydrophobic treatment.

The particle size of the carrier fine particles is preferably 0.001 to 20 μm, particularly 0.005 to 10 μm. The specific surface area by nitrogen adsorption measured by the BET method is 5 to 500 m ² / g, more preferably 10 to 400.
m ² / g, more preferably 20~350m ² / g is good. If it is less than 5 m ² / g, it tends to be difficult to retain the liquid lubricant of the present invention as lubricating particles having a suitable particle size.

The amount of liquid lubricant in the lubricating particles is
20 to 90% by mass, preferably 27 to 87% by mass, particularly preferably 40 to 80% by mass. If the amount of the liquid lubricant is less than 20% by mass, the toner particles are not provided with a good lubricant and releasability. Therefore, if a large amount of the lubricant particles is added to the toner, the developability tends to be unstable. 90 mass%
If it exceeds, it is difficult to uniformly obtain the lubricating particles containing the liquid lubricant.

Conventionally, methods of adsorbing silicone to SiO ₂ , Al ₂ O ₃ , TiO, etc. have been proposed, but these methods are so strongly adsorbed that the liquid lubricant does not easily appear on the surface of the toner particles and the toner particles do not appear on the toner particles. Sufficient lubricity and releasability cannot be imparted, and they do not serve as the lubricating particles of the present invention. In the present invention, the particle size of the lubricating particles is preferably 0.5 μm or more so that the liquid lubricant can be released while being retained.
Further, it is preferably 1 μm or more, and it is also preferable that the main component due to the volume standard distribution is larger than the particle diameter of the toner particles. Since these lubricating particles are fragile and contain a large amount of liquid lubricant, some of them collapse during the production of the toner and are evenly dispersed in the toner particles, and at the same time, the liquid lubricant is released and the toner particles have lubricity and release. Can give sexuality. On the other hand, since the lubricating particles are present in the toner particles while maintaining the liquid lubricant retaining ability, the particle size of the toner particles is not limited.

Therefore, the liquid lubricant is not excessively transferred to the surface of the toner particles, and the fluidity and developing property of the toner are not deteriorated. On the other hand, even if a part of the liquid lubricant is separated from the surface of the toner particles, the liquid lubricant can be replenished from the lubricant particles, so that the releasability and lubricity of the toner particles can be maintained for a long time. These lubricating particles can be granulated by a method in which droplets of a solution diluted with a liquid lubricant or an arbitrary solvent in a mixer are adsorbed on carrier fine particles, and the solvent is volatilized after granulation and further required. It may be crushed accordingly. Alternatively, a liquid lubricant or a diluent thereof may be added to the carrier particles and kneaded by using a kneader or the like, and, if necessary, pulverized and granulated, and then the solvent is volatilized. Lubricant particles as described above are 0.0 per 100 parts by mass of the binder resin.
The content is preferably 1 to 50 parts by mass, more preferably 0.05 to 50 parts by mass, and particularly preferably 0.1 to 20 parts by mass. If it is less than 0.01 parts by mass, the effects of lubrication and release cannot be obtained, and if it exceeds 50 parts by mass, problems in charge stability and productivity tend to occur.

As the lubricating particles of the present invention, porous powders impregnated with a liquid lubricant and contained therein can be used.

Examples of the porous powder used in the present invention include molecular sieves represented by zeolite, clay minerals such as bentonite, aluminum oxide, titanium oxide, zinc oxide, resin gel and the like. The particle size of the porous powder, such as resin gel, whose particles are disintegrated in the kneading step during toner production is not limited. On the other hand, the particle size of the porous powder that is difficult to disintegrate is 15 μm as the primary particle size.
m or less is preferable. If it exceeds 15 μm, the dispersion in the toner particles tends to be non-uniform. Further, it is preferable that the specific surface area of the porous powder before impregnation with the liquid lubricant is 10 to 50 m ² / g by nitrogen adsorption measured by the BET method. If it is less than 10 m ² / g, it is difficult to retain a large amount of liquid lubricant, and if it exceeds 50 m ² / g, the pore size is so small that the liquid lubricant cannot be sufficiently impregnated. As a method of impregnating the porous powder, it can be manufactured by a method of subjecting the porous powder to a pressure reduction treatment and immersing the porous powder in a liquid lubricant. The porous powder impregnated with the liquid lubricant is preferably mixed in the range of 0.1 to 20 parts by mass with respect to 100 parts by mass of the binder resin. If the amount is less than 0.1 parts by mass, there is no effect on improving lubricity and releasability, and if the amount is more than 20 parts by mass, problems may occur in the charging stability of the toner. In addition to these, it is also possible to use capsule-type lubricating particles containing a liquid lubricant, resin particles in which a liquid lubricant is dispersed, included, expanded or impregnated.

In the present invention, it is necessary to disperse the liquid lubricant as toner particles in the toner. However, since the lubricant particles and their disintegration particles are uniformly dispersed in the toner particles, the liquid lubricant is also uniformly dispersed in each toner. it can. Conventionally, since silicone is uniformly dispersed in the toner, it may be used by being adsorbed on various carriers, and is superior in uniform dispersibility to the method of directly adding silicone or the like. However, the purpose of the present invention is not merely to improve the dispersibility, but the liquid lubricant must be released from the carrier to effectively exert its lubricating effect and releasing effect.
It is important to provide an appropriate holding strength to prevent excessive release of the liquid lubricant. For that purpose, it is preferable to use lubricating particles in the present invention, and lubricating particles in which a liquid lubricant is supported on various carriers are used.

The presence of the lubricating particles on the surface of the toner particles makes it possible to properly adjust the amount of the liquid lubricant on the surface of the toner particles. Further, the liquid lubricant is released from the lubricating particles and migrates to the surface of the toner particles, but if the holding force of the carrier is strong, the liquid lubricant is less likely to be released, and therefore the migration to the surface of the toner particles is less and the lubricity of the toner particles is reduced. No releasability is obtained. On the contrary, if the holding power of the carrier is weak, the liquid lubricant is easily released, and therefore the migration to the surface of the toner particles becomes excessive, the charging property becomes unstable, and the developing property becomes a problem.
Further, the fluidity is deteriorated, and problems such as uneven image density are likely to occur. Furthermore, if the liquid lubricant is completely released from the carrier, the effects of lubricity and releasability are lost. In the present invention, since the holding force of the lubricating particles is appropriate, the liquid lubricant is appropriately released from the carrier, and therefore, even if the liquid lubricant is separated from the surface of the toner particles, the liquid lubricant is gradually replenished. Releasability is sustained. Further, since the carrier particles are present on the surface of the toner particles, the liquid lubricant transferred to the surface of the toner particles can be re-adsorbed, and excessive exudation of the liquid lubricant can be prevented. Therefore, the presence of the carrier on or near the surface of the toner particles is important for keeping the liquid lubricant on the surface of the toner particles in an appropriate amount. That is, the function of promptly replenishing the consumed liquid lubricant can be assisted while absorbing the excess liquid lubricant.

It is important and preferable to add the lubricating particles so that the amount of the liquid lubricant is 0.1 to 7 parts by mass with respect to 100 parts by mass of the binder resin, and more preferably 0.2. To 5 parts by mass, and particularly preferably 0.3 to 2 parts by mass.

The type of the binder resin used in the present invention is, for example, a homopolymer of styrene such as polystyrene, poly-p-chlorostyrene, polyvinyltoluene and the like, or a substitution product thereof; styrene-p-chlorostyrene copolymerization. Coal, styrene-vinyltoluene copolymer, styrene-vinylnaphthalene copolymer, styrene-acrylic acid ester copolymer, styrene-methacrylic acid ester copolymer, styrene-α-chloromethyl methacrylate copolymer, styrene- Acrylonitrile copolymer, styrene-vinyl methyl ether copolymer, styrene-vinyl ethyl ether copolymer, styrene-vinyl methyl ketone copolymer, styrene-butadiene copolymer, styrene-isoprene copolymer, styrene-acrylonitrile- Styrene-based copolymers such as indene copolymers Coalescence; polyvinyl chloride, phenolic resin, natural modified phenolic resin, natural resin modified maleic acid resin, acrylic resin, methacrylic resin, polyvinyl acetate, silicone resin, polyester resin, polyurethane, polyamide resin, furan resin, epoxy resin, xylene resin , Polyvinyl butyral, terpene resin, cumarone indene resin, petroleum resin and the like can be used. A crosslinked styrene resin is also a preferable binder resin.

Examples of the comonomer for the styrene monomer of the styrene copolymer include acrylic acid, methyl acrylate, ethyl acrylate, butyl acrylate, and the like.
Didecyl acrylate, octyl acrylate, 2-ethylhexyl acrylate, phenyl acrylate, methacrylic acid, methyl methacrylate, ethyl methacrylate, butyl methacrylate, octyl methacrylate, octyl methacrylate, acrylonitrile, methacrylonitrile, acrylamide, etc. A monocarboxylic acid having a heavy bond or a substituted product thereof;
For example, a dicarboxylic acid having a double bond such as maleic acid, butyl maleate, methyl maleate, dimethyl maleate, and the like; and vinyl chloride;
Vinyl esters such as vinyl acetate, vinyl benzoate and the like, for example, ethylene olefins such as ethylene, propylene, butylene and the like; vinyl ketones such as vinyl methyl ketone and vinyl hexyl ketone;
For example, vinyl monomers such as vinyl methyl ether, vinyl ethyl ether, and vinyl isobutyl ether; and the like, or a vinyl monomer such as vinyl monomers, may be used alone or in combination.

As the crosslinking agent, a compound having two or more polymerizable double bonds is mainly used. For example, an aromatic divinyl compound such as divinylbenzene, divinylnaphthalene, etc .; for example, ethylene glycol diacrylate. , Ethylene glycol dimethacrylate,
Carboxylic acid esters having two double bonds such as 1,3-butanediol dimethacrylate; divinyl compounds such as divinylaniline, divinyl ether, divinyl sulfide and divinyl sulfone; and compounds having three or more vinyl groups; Can be used alone or as a mixture.

In the bulk polymerization method, it is possible to obtain a low molecular weight polymer by polymerizing at a high temperature to accelerate the termination reaction rate, but there is a problem in that the reaction is uncontrollable. In the solution polymerization method, a low molecular weight polymer can be easily obtained under mild conditions by utilizing the difference in radical chain transfer depending on the solvent, and by adjusting the amount of the initiator and the reaction temperature. It is preferable when a low molecular weight compound is obtained from the resin composition.

As the solvent used in the solution polymerization, xylene, toluene, cumene, cellosolve acetate, isopropyl alcohol, benzene and the like can be used. In the case of a styrene monomer mixture, xylene, toluene or cumene is preferred. It is appropriately selected depending on the polymer to be polymerized.

As the binder resin for toner used for pressure fixing, low molecular weight polyethylene, low molecular weight polypropylene, ethylene-vinyl acetate copolymer, ethylene-acrylic acid ester copolymer, higher fatty acid, polyamide Resin and polyester resin may be used. These are preferably used alone or as a mixture.

Further, it is also preferable to include the following waxes in the toner from the viewpoint of improving the releasability from the fixing member during fixing and the fixing property. Paraffin wax and its derivatives, microcrystalline wax and its derivatives, Fischer-Tropsch wax and its derivatives, polyolefin wax and its derivatives, carnauba wax and its derivatives, etc., with derivatives including oxides and block copolymers with vinyl monomers , Graft-modified products.

In addition, alcohols, fatty acids, acid amides,
Esters, ketones, hydrogenated castor oil and derivatives thereof, vegetable waxes, animal waxes, mineral waxes, petrolactam and the like can also be used.

As the colorant, conventionally known inorganic / organic dyes / pigments can be used. Examples thereof include carbon black, aniline black, acetylene black,
Naphthol yellow, Hansa yellow, Rhodamun rake, Alizarin rake, red iron oxide, phthalocyanine blue, indanthrene blue and the like. These are usually used in an amount of 0.5 to 20 parts by mass with respect to 100 parts by mass of the binder resin.

In the magnetic toner of the present invention, a charge control agent is blended with toner particles (internal addition) or mixed with toner particles (external addition).
It is preferable to use them. The charge control agent makes it possible to control the amount of charge optimally according to the development system. In particular, in the present invention, the balance between the particle size distribution and the amount of charge can be further stabilized. The following substances control the toner to be negatively charged.

Organic metal complexes and chelate compounds are effective, for example, monoazo metal complexes, acetylacetone metal complexes, aromatic hydroxycarboxylic acids, and aromatic dicarboxylic acid type metal complexes. Other examples include aromatic hydroxycarboxylic acids, aromatic mono- and polycarboxylic acids and their metal salts, anhydrides, esters, and phenol derivatives such as bisphenol.

The following substances are used to control the positive chargeability.

Modified products of nigrosine and fatty acid metal salts and the like; quaternary ammonium salts such as tributylbenzylammonium-1-hydroxy-4-naphthosulfonate, tetrabutylammonium tetrafluoroborate, and phosphonium salts which are analogs thereof. Onium salts and lake pigments thereof, triphenylmethane dyes and lake pigments thereof (as a laker, phosphotungstic acid, phosphomolybdic acid, phosphotungstic molybdic acid, tannic acid, lauric acid, gallic acid, ferricyanide) Compounds, ferrocyanides, etc.), metal salts of higher fatty acids; diorganotin oxides such as dibutyltin oxide, dioctyltin oxide, dicyclohexyltin oxide; dibutyltin borate, dioctyltin borate, dicyclohexyl Diorgano tin borate such as Suzuboreto; can be used in combination singly or two or more kinds.

The above charge control agents are preferably used in the form of fine particles, and in this case, the number average particle diameter of these charge control agents is preferably 4 μm or less, more preferably 3 μm or less. When these charge control agents are internally added to the toner, it is preferable to use 0.1 to 20 parts by mass, particularly 0.2 to 10 parts by mass with respect to 100 parts by mass of the binder resin.

The magnetic toner of the present invention has environmental stability,
In order to improve charge stability, developability, fluidity, and storage stability, the inorganic toner finely treated with an organic material is stirred and mixed with a mixer such as a Henschel mixer to obtain the magnetic toner characterized by the present invention.

As the inorganic fine powder used in the present invention,
Inorganic fine powders such as silicic acid fine powder, titanium oxide, and aluminum oxide are preferable, and silicic acid fine powder is particularly preferable.
For example, both the so-called dry method produced by vapor phase oxidation of a silicon halide or the dry silica called fumed silica and the so-called wet silica produced from water glass can be used as the fine silica powder. But
Dry silica having less silanol groups on the surface and inside the fine silica powder and less production residues such as Na ₂ O and SO ₃ ^2- is preferable. Further, in the case of dry silica, in the manufacturing process, for example, aluminum chloride, titanium chloride,
By using other metal halogen compounds together with the silicon halogen compounds, it is possible to obtain composite fine powders of silica and other metal oxides, and these are also included.

The present invention is characterized in that an organically treated inorganic fine powder is used. Examples of such an organic treatment method include a method of treating with an organic metal compound such as a silane coupling agent or a titanium coupling agent which reacts with or physically adsorbs to the inorganic fine powder, or after treatment with a silane coupling agent, or silane. A method of treating with a coupling agent and at the same time treating with an organic silicon compound such as silicone oil can be mentioned. The silane coupling agent used in the organic treatment, for example, hexamethyldisilazane, trimethylsilane, trimethylchlorosilane, trimethylethoxysilane, dimethyldichlorosilane, methyltrichlorosilane, allyldimethylchlorosilane, allylphenyldichlorosilane, Benzyldimethylchlorosilane, bromomethyldimethylchlorosilane, α-chloroethyltrichlorosilane, β-chloroethyltrichlorosilane, chloromethyldimethylchlorosilane, triorganosilylmercaptan, trimethylsilylmercaptan, triorganosilylacrylate, vinyldimethylacetoxysilane, dimethyl Diethoxysilane, dimethyldimethoxysilane, diphenyldiethoxysilane,
Hexamethyldisiloxane, 1,3-divinyltetramethyldisiloxane, 1,3-diphenyltetramethyldisiloxane, and 2 to 12 siloxane units per molecule, one for each terminally located unit And dimethylpolysiloxane containing a hydroxyl group bonded to the silicon atom.

Also, aminopropyltrimethoxysilane, aminopropyltriethoxysilane, dimethylaminopropyltrimethoxysilane, diethylaminopropyltrimethoxysilane, dipropylaminopropyltrimethoxysilane, dibutylaminopropyltrimethoxysilane, mono having a nitrogen atom. Butylaminopropyltrimethoxysilane, dioctylaminopropyldimethoxysilane, dibutylaminopropyldimethoxysilane,
A silane coupling agent such as dibutylaminopropylmonomethoxysilane, dimethylaminophenyltriethoxysilane, trimethoxysilyl-γ-propylphenylamine and trimethoxysilyl-γ-propylbenzylamine may be used alone or in combination. A preferred silane coupling agent is hexamethyldisilazane (H
MDS). In addition, examples of the organic silicon compound include silicone oil. A preferred silicone oil has a viscosity of 0.5 to 10 at 25 ° C.
000 centistokes, preferably 1 to 1000 centistokes are used, and for example, dimethyl silicone oil, methylphenyl silicone oil, α-methylstyrene modified silicone oil, chlorophenyl silicone oil, fluorine modified silicone oil and the like are particularly preferable. As a method for treating silicone oil, for example, silica fine powder treated with a silane coupling agent and silicone oil may be directly mixed using a mixer such as a Henschel mixer, or silica fine powder as a base may be treated with silicone. A method of spraying oil may be used. Alternatively, a method of dissolving or dispersing a silicone oil in an appropriate solvent, adding a silica fine powder, mixing and removing the solvent may be used.

[0085] used in the present invention the organic-treated inorganic fine powder has a specific surface area by nitrogen adsorption measured by BET method is 30 m ² / g or more, in particular 50 to 400 m ² / g good results in the range of The inorganic fine powder which has been subjected to the hydrophobization treatment and used in the present invention is preferably used in an amount of 0.01 to 8 parts by mass, preferably 0.1 to 5 parts by mass, particularly preferably 0.1 to 5 parts by mass, relative to 100 parts by mass of the toner particles. It is preferably 0.2 to 3 parts by mass. If it is less than 0.01 part by mass, the effect of improving toner aggregation will be poor, and if it exceeds 8 parts by mass, problems such as toner scattering between fine lines, contamination inside the machine, scratches and abrasion of the photoconductor tend to occur. is there.

In the magnetic toner of the present invention, other additives are added within a range that does not have a substantially adverse effect, for example, lubricant powder such as Teflon powder, zinc stearate powder, polyvinylidene fluoride powder; cerium oxide powder, carbonization. Abrasives such as silicon powder and strontium titanate powder; fluidity imparting agents such as titanium oxide powder and aluminum oxide powder;
A small amount of an anti-caking agent or a conductivity-imparting agent such as carbon black powder, zinc oxide powder, tin oxide powder, or organic fine particles and inorganic fine particles having opposite polarities can be used as a developing property improver.

A known method is used for producing the toner according to the present invention. For example, a binder resin, a wax,
Metal salts or metal complexes, pigments and dyes as colorants,
Alternatively, a magnetic material, if necessary, a charge control agent, other additives and the like are sufficiently mixed by a mixer such as a Henschel mixer or a ball mill, and then melt-kneaded by using a heat kneader such as a heating roll, a kneader or an extruder. The metal compound, the pigment, the dye, and the magnetic substance are dispersed or dissolved in the resin to make them compatible with each other, and after solidification by cooling, pulverization and classification are performed to obtain the toner according to the present invention. In the classification step, it is preferable to use a multi-division classifier in terms of production efficiency.

Further, the toner of the present invention may be mixed with carrier particles and used as a two-component toner.

The present invention is also effective when the surface of the image bearing member is mainly composed of a polymer binder. For example, when a protective film mainly composed of a resin is provided on an inorganic image bearing member such as selenium or amorphous silicon, or as a charge transporting layer of a function separation type organic image bearing member, a surface layer comprising a charge transporting material and a resin. In some cases, the above-mentioned protective layer may be further provided on it. As means for imparting releasability to such a surface layer, a resin having a low surface energy is used as the resin forming the film, water repellency,
Examples thereof include adding an additive that imparts lipophilicity, dispersing a material having a high mold release property into a powder, and dispersing the powder. Is achieved by introducing a fluorine-containing group, a silicon-containing group, or the like into the structure of the resin. For this, a surfactant or the like may be used as an additive. Examples thereof include compounds containing a fluorine atom, that is, powders of polytetrafluoroethylene, polyvinylidene fluoride, carbon fluoride and the like. Among them, polytetrafluoroethylene is particularly preferable. In the present invention, it is particularly preferable to disperse the releasable powder such as the fluorine-containing resin in the outermost surface layer.

By these means, the contact angle of water on the surface of the image bearing member can be 85 degrees or more (preferably 90 degrees or more). If it is less than 85 degrees, deterioration of the toner and the toner carrier due to durability tends to occur.

In order to contain these powders on the surface, a layer in which the powders are dispersed in a binder resin is provided on the outermost surface of the image bearing member, or an organic material mainly composed of a resin is used. In the case of an image carrier, the powder may be dispersed in the uppermost layer without providing a new surface layer.

The amount of the powder added to the surface layer is preferably 1 to 60% by mass, more preferably 2 to 50% by mass, based on the total mass of the surface layer. If it is less than 1% by mass, the effect of improving the durability of the toner and the toner carrier is insufficient, and 60% by mass
If it exceeds, the strength of the film is lowered, or the amount of light incident on the image carrier is significantly lowered, which is not preferable.

The present invention is particularly effective when the charging means is the direct charging method in which the charging member is brought into contact with the image carrier. As compared with corona discharge or the like in which the charging means does not come into contact with the image carrier, the load on the surface of the image carrier is large, so that the improvement effect is remarkable in terms of the life of the image carrier.

One of the preferred embodiments of the image carrier used in the present invention will be described below.

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

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

The charge generation layer includes azo pigments, phthalocyanine pigments, indigo pigments, perylene pigments, polycyclic quinone pigments, squarylium dyes, pyrylium salts, thiopyrylium salts, triphenylmethane dyes, selenium,
It is formed by dispersing a charge generating substance such as an inorganic substance such as amorphous silicon in a suitable binder and coating or vapor depositing. The binder can be selected from a wide range of binder resins, for example, polycarbonate resin, polyester resin, polyvinyl butyral resin, polystyrene resin, acrylic resin, methacrylic resin, phenol resin, silicone resin, epoxy resin, vinyl acetate resin, etc. Is mentioned. The amount of the binder contained in the charge generation layer is 80% by mass.
Below, it is preferably selected to be 0 to 40% by mass. Further, the thickness of the charge generation layer is preferably 5 μm or less, particularly preferably 0.05 to 2 μm.

The charge transport layer has a function of receiving charge carriers from the charge generation layer in the presence of an electric field and transporting them. The charge transporting layer is formed by dissolving a charge transporting substance in a solvent together with a binder resin if necessary, and applying the solution. The film thickness is generally 5 to 40 μm. As the charge transport substance, biphenylene is added to the main chain or side chain,
Polycyclic aromatic compounds having a structure such as anthracene, pyrene and phenanthrene, nitrogen-containing cyclic compounds such as indole, carbazole, oxadiazole and pyrazoline,
Hydrazone compounds, styryl compounds, selenium, selenium-
Tellurium, amorphous silicon, cadmium sulfide, etc. may be mentioned.

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

A protective layer may be provided as the surface layer. As the resin for the protective layer, polyester, polycarbonate, acrylic resin, epoxy resin, phenol resin, or a curing agent of these resins may be used alone or in combination.
Used in combination of more than one species.

Also, conductive fine particles may be dispersed in the resin of the protective layer. Examples of the conductive fine particles include metals and metal oxides, and preferably zinc oxide, titanium oxide, tin oxide, antimony oxide, indium oxide, bismuth oxide, tin oxide coated titanium oxide, tin coated indium oxide, Antimony coating There are ultrafine particles such as tin oxide and zirconium oxide. These may be used alone or as a mixture of two or more. Generally, when the particles are dispersed in the protective layer, it is necessary that the particle size of the particles is smaller than the wavelength of the incident light in order to prevent scattering of the incident light by the dispersed particles, and the particles are dispersed in the protective layer in the present invention. The particle diameter of the conductive and insulating particles is preferably 0.5 μm or less. The content in the protective layer is preferably 2 to 90% by mass, more preferably 5 to 80% by mass, based on the total weight of the protective layer. The thickness of the protective layer is preferably from 0.1 to 10 μm, more preferably from 1 to 7 μm.

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

The contact transfer step applicable to the image forming method of the present invention will be specifically described below.

In the contact transfer step, the developed image is electrostatically transferred to the transfer material while the electrostatic charge image carrier and the transfer material are in contact with each other, and the contact pressure of the transfer means is linear pressure. It is preferably 2.9 N / m (3 g / cm) or more, more preferably 19.6 N / m (20 g / cm).
That is all. The linear pressure as the contact pressure is 2.9 N / m (3
If it is less than g / cm), transfer deviation of the transfer material and transfer failure are likely to occur, which is not preferable.

As the transfer means in the contact transfer step, a device having a transfer roller or a transfer belt is used. The transfer roller is composed of at least a core metal and a conductive elastic layer, and the conductive elastic layer is made of urethane having a conductive material such as carbon dispersed therein or EPDM and has a volume resistance of 10 ⁶ to 1 1.
It is made of an elastic body of about 0 ¹⁰ Ωcm.

The present invention is particularly effectively used in an image forming apparatus in which the surface of the latent image carrier (photoreceptor) is an organic compound. That is, when the organic compound forms the surface layer of the photoconductor, the adhesiveness to the binder resin contained in the toner particles is better than that of other photoconductors using an inorganic material, and the transferability is further reduced. This is because there is a tendency to

Further, the latent image carrier (photoreceptor) according to the present invention
Examples of the surface substance include, for example, silicone resin, vinylidene chloride, ethylene-vinyl chloride, styrene-acrylonitrile, styrene-methyl methacrylate, styrene, polyethylene terephthalate, and polycarbonate. Copolymers and blends between the above-mentioned binder resins can also be used.

Further, the present invention is particularly effectively used for an image forming apparatus having a photoconductor having a small diameter of 50 mm or less. That is, in the case of a small-diameter photoconductor, the curvature with respect to the same linear pressure is large, and the pressure is likely to concentrate at the contact portion. Although it is considered that the same phenomenon occurs in the belt photoreceptor, the present invention has a radius of curvature of 25 at the transfer portion.
It is also effective for an image forming apparatus having a size of less than or equal to mm.

The toner carrier carrying the magnetic toner of the present invention is preferably covered with a resin layer containing conductive fine particles.

The surface roughness of the toner carrier used in the present invention is from 0.2 to JIS center line average roughness (Ra).
It is preferably in the range of 3.0 μm. Ra is 0.2μ
If it is less than m, the amount of charge on the toner carrier becomes high and the developability becomes insufficient. When Ra exceeds 3.0 μm, unevenness occurs in the toner coat layer on the toner carrier, resulting in uneven density on the image.

As the conductive fine particles contained in the resin layer coating the surface of the toner carrier, conductive metal oxides such as carbon black, graphite and conductive zinc oxide, and metal complex oxides may be used alone or in combination of two or more. It is preferably used. Further, as the resin in which the conductive fine particles are dispersed, phenolic resin, epoxy resin, polyamide resin, polyester resin, polycarbonate resin,
Known resins such as polyolefin resins, silicone resins, fluorine resins, styrene resins, and acrylic resins are used. A thermosetting or photocurable resin is particularly preferable.

In the magnetic toner of the present invention, the magnetic toner on the toner carrier is regulated by the elastic member which is in contact with the toner carrier via the toner, so that the magnetic toner is uniformly charged. It is particularly preferable in terms of

The toner composition used in the present invention is characterized by the presence of inorganic fine powder on the surface. The effect is to improve the developing efficiency, the latent image reproducibility, and the transfer efficiency, and reduce the fog.

The average particle size and particle size distribution of the toner can be measured by various methods such as Coulter Counter TA-II type or Coulter Multisizer (manufactured by Coulter), but in the present invention, Coulter Multisizer (manufactured by Coulter). Connect a PC9801 personal computer (manufactured by NEC) and an interface (manufactured by Nikkaki) that outputs the number distribution and volume distribution using 1
A 1% NaCl aqueous solution is prepared using graded sodium chloride. For example, ISOTON R-II (manufactured by Coulter Scientific Japan) can be used. As a measuring method, 0.1 to 5 ml of a surfactant, preferably an alkylbenzene sulfonate, is added as a dispersant to 100 to 150 ml of the electrolytic aqueous solution, and further 2 to be measured sample.
Add ~ 20 mg. The electrolytic solution in which the sample is suspended is subjected to dispersion treatment for about 1 to 3 minutes by an ultrasonic disperser, and the volume and number of toner particles of 2 μm or more are measured by using the 100 μm aperture as an aperture by the Coulter Multisizer to obtain a volume distribution. The number distribution was calculated. Then, the volume-based volume average particle diameter (D _v : the median value of each channel is used as a representative value of the channels) and the volume variation coefficient (S _v ) obtained from the volume distribution according to the present invention, and the number obtained from the number distribution. Standard length average particle diameter (D ₁ ) and length variation coefficient (S ₁ ), and mass-based particle ratio (8.00 μm or more and 3.17 μm or less) obtained from volume distribution, number obtained from number distribution Standard particle ratio (5 μm or less and 3.1
7 μm or less).

A method of measuring the two-component tribo value of the toner according to the present invention will be described below with reference to FIG.

In an environment of 23 ° C. and relative humidity of 60%, EFV200 / 300 (manufactured by Powdertech Co., Ltd.) was used as a carrier, and a mixture of 9.0 g of carrier and 1.0 g of toner was added to a polyethylene bottle having a capacity of 50 to 100 ml. Shake by hand 50 times. Next, 1.0 to 1.2 g of the mixture is put into a metal measuring container 32 having a 500 mesh screen 33 on the bottom, and a metal lid 34 is placed on the container. At this time, the total mass of the measurement container 32 is weighed and designated as W ₁ (g). Next, in the suction device (at least the part in contact with the measurement container 32 is an insulator), suction is performed from the suction port 37 and the air volume control valve 36 is adjusted to adjust the pressure of the vacuum gauge 35 to 2450 Pa (25
0 mmAq). In this state, suction is performed for one minute to remove the toner by suction. The potential of the electrometer 39 at this time is V
(Volts). Here, 38 is a capacitor, and the capacitance is C (μF). The mass of the entire measuring container after suction is weighed and is W ₂ (g). The triboelectric charge amount (mC / kg) of this toner is calculated by the following formula.

Triboelectric charge amount (mC / kg) = CV / (W ₁ -W ₂ ).

In the present invention, the magnetic characteristics of the magnetic toner are as follows using VSM P-1-15 (manufactured by Toei Industry Co., Ltd.).
It was determined from the result of measurement at room temperature with an external magnetic field of 79.6 kA / m (1000 Oersted).

The specific surface area was determined according to the BET method by using a specific surface area measuring device Autosorb 1 (manufactured by Yuasa Ionics Co., Ltd.) to adsorb nitrogen gas on the sample surface and calculating the specific surface area using the BET multipoint method.

Next, the image forming method of the present invention will be specifically described with reference to the drawings.

In FIG. 1, a photosensitive drum 100 is provided with a primary charging roller 117, a developing device 140, a transfer charging roller 114, a cleaner 116, a register roller 124 and the like around the photosensitive drum. And the photosensitive drum 100
Is charged to −700 V by the primary charging roller 117 (applied voltage is AC voltage −2.0 kVpp, DC voltage −700 Vdc). Then, the laser light 123 is applied to the photosensitive drum 100 by the laser generator 121, so that the photosensitive drum 100 is exposed. The electrostatic latent image on the photosensitive drum 100 is developed with a one-component magnetic toner by the developing device 140,
Transfer roller 1 that is in contact with the photosensitive drum via the transfer material
It is transferred onto the transfer material by 14. The transfer material on which the toner image is placed is conveyed to the fixing device 126 by the conveyor belt 125 or the like and fixed on the transfer material. The toner partially left on the electrostatic latent image carrier is cleaned by the cleaning unit 116.

As shown in FIG. 2, the developing device 140 is provided with a cylindrical toner carrier 102 (hereinafter referred to as a developing sleeve) made of a non-magnetic metal such as aluminum or stainless steel in the vicinity of the photosensitive drum 100. The gap between the photosensitive drum 100 and the developing sleeve 102 is maintained at about 300 μm by a sleeve / drum gap holding member (not shown). A stirring rod 141 is arranged in the developing device. Inside the developing sleeve, a magnet roller 104 is fixed and disposed concentrically with the developing sleeve 102. However, the developing sleeve 102 is rotatable. The magnet roller 104 is provided with a plurality of magnetic poles as shown in the drawing. S ₁ influences development, N ₁ regulates toner coat amount, S ₂ influences toner intake / conveyance, and N ₂ influences toner blowout prevention. There is. The elastic blade 1 is used as a member for controlling the amount of magnetic toner attached to the developing sleeve 102 and conveyed.
03 is arranged and the developing sleeve 10 of the elastic blade 103
The amount of toner conveyed to the developing area is controlled by the contact pressure with respect to 2. In the developing area, a DC and AC developing bias is applied between the photosensitive drum 100 and the developing sleeve 102, and the toner on the developing sleeve flies on the photosensitive drum 100 according to the electrostatic latent image to become a visible image.

[0123]

EXAMPLES The present invention will be specifically described below with reference to production examples and examples, but the present invention is not limited thereto. In the following formulation, all parts are parts by mass.

(Photoreceptor Production Example 1) As a photoreceptor, 30
A φ, 254 mm Al cylinder was used as a base. A layer having a structure as shown in FIG. 5 was sequentially laminated thereon by dip coating to prepare a photoconductor.

(1) Conductive coating layer: Mainly composed of tin oxide and titanium oxide powder dispersed in a phenol resin. The thickness is 15 μm.

(2) Undercoat layer: Mainly composed of modified nylon and copolymer nylon. The film thickness is 0.6 μm.

(3) Charge generation layer: Mainly composed of an azo pigment having absorption in a long wavelength region dispersed in butyral resin. The film thickness is 0.6 μm.

(4) Charge transport layer: Mainly composed of a hole-transporting triphenylamine compound dissolved in a polycarbonate resin (molecular weight of 20,000 by Oswald viscosity method) at a mass ratio of 8:10, and further polytetrafluoroethylene. 10% by mass of powder (particle size: 0.2 μm) was added to the total solid content and uniformly dispersed. 25 μm thick. The contact angle with water was 95 degrees.

The contact angle was measured using pure water, and the apparatus used was a contact angle meter CA-DS type manufactured by Kyowa Interface Science Co., Ltd.

(Photoreceptor Production Example 2) A photoconductor was produced in the same manner as in Photoreceptor Production Example 1 without adding polytetrafluoroethylene powder. The contact angle with water was 74 degrees.

(Photoreceptor Production Example 3) A photoreceptor was produced according to Photoreceptor Production Example 1 up to the charge generation layer. As the charge transport layer, a material obtained by dissolving a hole transporting triphenylamine compound in a polycarbonate resin at a mass ratio of 10:10 was used. Film thickness 20 μm. Further, as a protective layer, a polytetrafluoroethylene powder (particle diameter: 0.2 μm) was added to a composition in which the same material was dissolved at a mass ratio of 5:10, and 30% of the total solid content was added thereto. Was spray-coated on the charge transport layer. Film thickness 5 μm. The contact angle with water was 102 degrees.

(Production Example of Lubrication Particles Bearing Liquid Lubricant) While the carrier particles carrying a liquid lubricant were stirred in a Henschel mixer, a liquid lubricant diluted with n-hexane was added dropwise. After completion of the dropping, the pressure was reduced with stirring to remove n-hexane, and then pulverization was performed with a hammer mill to obtain lubrication fine particles 1 carrying a liquid lubricant. Similarly, various liquid lubricants were supported on various carrier fine particles. Table 1 shows the physical property values of the lubricating particles 1 to 9 carrying the obtained liquid lubricant. In addition, the untreated product of silica used for manufacturing the lubricating particles 1 is referred to as particles 10.

[0133]

[Table 1]

Toner Production Example 1 Magnetic substance (spherical magnetite) 100 parts Styrene-n-butyl acrylate-maleic acid n-butyl half ester copolymer (copolymerization ratio 8: 2, M _w = 260,000) 100 parts Monoazo dye Iron complex (negative charge control agent) 2 parts Low molecular weight polyolefin (release agent) 4 parts

The above materials were mixed in a blender and mixed at 140
Melt and knead with a twin-screw extruder heated to ℃, and cool
The kneaded product was roughly crushed with a hammer mill, and
Finely pulverized with a mill and the resulting finely pulverized product is used as an air classifier.
And classified to obtain a black fine powder. For the obtained black fine powder
1.2% by mass of hydrophobic silica fine powder (hexamethyl
Disilazane treated BET specific surface area 200 m^Two/ G) and 0.
Add 4% by weight of lubricating particles and use a Henschel mixer
After stirring and mixing, remove coarse particles with a 150 mesh screen and
Toner 1 was obtained. Weight average particle of the obtained magnetic toner 1
The diameter was 5.1 μm. Table 2 shows the physical properties of the toner.

Toner Production Examples 2 and 3 Black fine powder was obtained in the same manner as in Production Example 1 except that the particle size and particle size distribution were changed. With respect to 100 parts of this black fine powder, 1.5% by mass of hydrophobic silica fine powder (Production Example 1
Same as the above) and 0.5 mass% of lubricating particles 2 were added to obtain a magnetic toner 2. Similarly, for 100 parts of black fine powder,
A magnetic toner 3 was obtained by adding 1.8% by mass of hydrophobic silica fine powder (the same as in Production Example 1) and 0.3% by mass of the lubricating particles 3. Table 2 shows the physical properties of the obtained magnetic toners 2 and 3.

Toner Production Example 4 Magnetic substance (spherical magnetite) 120 parts Styrene-n-butyl acrylate copolymer 100 parts (copolymerization ratio 8: 2, M _w = 260,000) Iron complex of monoazo dye (control of negative charging property) Agent) 2 parts Low molecular weight ethylene-propylene copolymer 3 parts

Using the same components as in Production Example 1, a black fine powder was obtained. For 100 parts of this black fine powder, 1.2
Mass% of hydrophobic silica fine powder (BET specific surface area treated with silicone oil and hexamethyldisilazane 120 m ² /
g) and 0.2% by mass of lubricating particles 4 are added, and magnetic toner 4 is added.
I got Table 2 shows the physical properties of the obtained magnetic toner 4.

Toner Production Example 5 Black fine powder was obtained in the same manner as in Production Example 1 except that the particle size and particle size distribution were changed. To 100 parts of this black fine powder, 1.8% by mass of hydrophobic silica fine powder (the same as in Production Example 4) and 0.3% by mass of lubricating particles 5 were added to obtain a magnetic toner 5. Table 2 shows the physical properties of the obtained magnetic toner 5.

Toner Production Examples 6 and 7 Black fine powder was obtained in the same manner as in Production Example 1 except that the particle size and the particle size distribution were changed. With respect to 100 parts of this black fine powder, 1.5% by mass of hydrophobic silica fine powder (Production Example 1
Same as the above) and 0.5 mass% of lubricating particles 6 were added to obtain a magnetic toner 6. Similarly, for 100 parts of black fine powder,
1.0% by mass of hydrophobic silica fine powder (same as in Production Example 1) and 0.3% by mass of lubricating particles 7 were added to obtain a magnetic toner 7.
I got Table 2 shows the physical properties of the obtained magnetic toners 6 and 7.

Toner Production Examples 8 and 9 In the same manner as in Production Example 1, black fine powder was obtained. With respect to 100 parts of this black fine powder, 1.5% by mass of hydrophobic silica fine powder (the same as in Production Example 1) and 0.5% by mass of lubricating particles 8
Was added to obtain a magnetic toner 8. Similarly, black fine powder 100
1.5 parts by mass of hydrophobic silica fine powder (the same as in Production Example 1) and 0.7 mass% of lubricating particles 9 were added to the parts,
Magnetic toner 9 was obtained. Table 2 shows the physical properties of the obtained magnetic toners 8 and 9.

Toner Comparative Production Example 1 A magnetic toner 10 was obtained in the same manner as in Toner Production Example 1 except that black fine powder having a changed particle size and particle size distribution was used and the lubricating particles 1 were not added. Table 2 shows the physical properties of the obtained magnetic toner.

Comparative toner production example 2 In the toner production example 1, the lubricating particles 1 were replaced by particles 10
A magnetic toner 11 was obtained in the same manner as in Toner Production Example 1 except that 0.5% by weight was used. Table 2 shows the physical properties of the obtained magnetic toner 11.

[0144]

[Table 2]

[Embodiment 1] An image forming apparatus shown in FIG. 1 was used.

As the electrostatic latent image carrier, the organic photoconductor (OPC) drum of Photoconductor Production Example 1 was used and the dark portion potential V _d = -70.
0 V and the bright portion potential V _L = −210 V. The gap between the photosensitive drum and the developing sleeve is 300 μm, a toner carrier having a layer thickness of about 7 μm and a JIS center line average roughness (Ra) of 0.8 μm is used as a toner carrier, and the surface is a mirror surface having a diameter of 12φ. Using a developing sleeve formed on an aluminum cylinder, a developing magnetic pole of 950 gauss and a urethane rubber blade having a thickness of 1.0 mm and a free length of 10 mm as a toner regulating member were brought into contact with each other at a linear pressure of 15 g / cm.

Phenolic resin 100 parts Graphite (particle size about 7 μm) 90 parts Carbon black 10 parts

Next, as a developing bias, a DC bias component V _dc = -500V and an AC bias component V to be superimposed
_PP = 1200V and f = 2000Hz were used. Also,
The peripheral speed of the developing sleeve is the peripheral speed of the photoconductor (48 mm / sec)
150% in the forward direction (reverse direction of rotation)
(72 mm / sec).

A transfer roller as shown in FIG. 4 (made of ethylene-propylene rubber in which conductive carbon is dispersed, volume resistance value of conductive elastic layer 10 ⁸ Ωcm, surface rubber hardness 24)
°, diameter 20 mm, contact pressure 49 N / m (50 g / cm)
Equal to the peripheral speed of the photoconductor (48 mm / sec),
+2000 V was applied as the transfer bias, the magnetic toner 1 was used as the toner, and the image was printed in the environment of 23 ° C. and 65% RH. 128 g / m ² of paper was used as the transfer paper.

As a result, as shown in Table 3, a good image having sufficient image density and high resolution with no voids in the transfer was obtained. Further, the resolution of the latent image of an isolated dot of 50 μm was at a sufficiently good level. Furthermore, no abnormalities such as fusion were observed on the surface of the photoreceptor even after printing 5000 sheets continuously.

In the present embodiment, the evaluation of splattering is splattering evaluation in fine fine lines relating to the image quality of a graphical image, and splattering evaluation in 100 μm lines, which is easier to scatter than in character lines. .

The resolving power was evaluated by the reproducibility of small-diameter isolated dots as shown in FIG. 7 in which the electric field is easily closed due to the latent image electric field and is difficult to reproduce.

Further, 500 sheets of a character pattern with an area ratio of 4% printed on A4 size paper were continuously printed out from the initial stage, and the toner consumption amount was calculated from the change of the toner amount in the developing device. As a result, it was 0.039 g / sheet. there were. Further, a 600-dpi 10-dot vertical line pattern latent image (line width of about 420 μm) was written on the photoconductor at 1 cm intervals by laser exposure, developed, and transferred and fixed on PET OHP. The obtained vertical line pattern image was obtained by using a surface roughness meter Surfcoder SE-30H (manufactured by Kosaka Laboratory Ltd.) as a profile of the surface roughness of the toner on the vertical line, and the line from the width of this profile was obtained. I asked for the width. As a result, it was confirmed that the line width was 430 μm, the line was reproduced with high density and clearly, and the low consumption was achieved while maintaining the reproducibility of the latent image.

[Comparative Example 1] Image formation was carried out under the same apparatus and conditions as in Example 1 except that Toner 10 was used as the toner and the organic photoreceptor of Photoreceptor Production Example 2 was used as the electrostatic latent image carrier. went. As a result, as shown in Table 3, an image in which there are many scatterings around the characters and character transfer voids are conspicuous (FIG. 6B).
See). Further, an image was obtained in which the resolution of the latent image of an isolated dot of 50 μm was insufficient and the sharpness was lacking. Further, fusion of toner was recognized on the surface of the photoconductor after printing 5000 sheets continuously, and white spots were generated on the printed image.

[Comparative Example 2] Toner 11 was used as the toner, and images were printed under the same apparatus and conditions as in Comparative Example 1.
As a result, as in the case of Comparative Example 1, the image was a large amount of scattering, in which character dropouts were noticeable. Toner fusion was required on the surface of the photosensitive member after continuous printing of 5000 sheets, and white spots occurred on the printed image. Also 100 μm
The resolution of the latent image of the isolated dot of No. 1 was also insufficient.

[Examples 2 to 9] Toner 2 as toner
9 was used, and image formation was performed using the same apparatus and conditions as in Example 1. Table 3 shows the results.

[Example 10] Image formation was carried out under the same apparatus and conditions as in Example 1 except that the organic photoconductor of Photoconductor production example 3 was used as the electrostatic latent image carrier. As a result, as shown in Table 3, it was good. Also, when a polyester OHP sheet was used as a transfer material, a good image with no voids in the transfer was obtained.

[Example 11] Image formation was carried out by using the same apparatus and conditions as in Example 1 except that the organic photoconductor of Photoconductor production example 2 was used as the electrostatic latent image carrier. As a result, the dropout in transfer when using 128 g / m ² of transfer paper was slightly inferior to that of Example 1, but it was at a level where there was no problem in practical use, and the transfer paper of 75 g / m ² was used. There was no dropout in the transfer when using, and it was very good.

[0159]

[Table 3]

[0160]

According to the present invention, the magnetic toner having the above-mentioned structure is obtained by externally mixing the organically treated inorganic fine powder and the liquid lubricant to the magnetic toner particles containing at least the binder resin and the magnetic substance. And an image forming method using the same,
It is possible to obtain a high-resolution, high-definition reproducible image having a good image density without fusion of toner to the photoconductor, poor cleaning, omission of transfer, and tailing.

[Brief description of the drawings]

FIG. 1 is an explanatory diagram of an example of an image forming apparatus used in the present invention.

FIG. 2 is an enlarged view of a main part of FIG.

FIG. 3 is an explanatory diagram of a toner triboelectric charge amount measuring method of the present invention.

FIG. 4 is a schematic view of a transfer unit having a transfer roller used in the present invention.

FIG. 5 is a schematic view showing a layer structure of a photoconductor of photoconductor manufacturing example 1.

FIG. 6 is a diagram showing a good image (a) having no “transfer defects” and a defective image (b) having “transfer defects”.

FIG. 7 is an example of an isolated dot pattern used for resolution evaluation.

[Explanation of symbols]

 100 photosensitive drum 102 developing sleeve (toner carrier) 103 contact blade 104 magnet roller 114 transfer charging roller 116 cleaner 117 primary charging roller 140 developing device 141 stirring rod 401 photosensitive drum 403 transfer roller 403a core metal 403b conductive elastic layer 414 power supply

─────────────────────────────────────────────────── ─── Continuation of the front page (51) Int.Cl. ⁶ Identification number Internal reference number FI Technical indication location G03G 9/08 374 21/00 312 (72) Inventor Motoki Hisaki 3-30 Shimomaruko, Ota-ku, Tokyo No. 2 Canon Inc.

Claims (34)

[Claims] 1. A magnetic toner obtained by externally mixing an organically treated inorganic fine powder and a liquid lubricant to a magnetic toner particle containing at least a binder resin and a magnetic substance. D _v (μm) is 3 μm ≦ D _v <6
and the weight average particle diameter D ₄ (μm) is 3.5 μm ≦
D ₄ <6.5 μm and 5 μ in the number particle size distribution
The ratio M _r of particles of m or less is 60% by number <M _r ≦ 90% by number
And the ratio (N _r / N _v ) of the ratio N _r of particles of 3.17 μm or less in the number particle size distribution to the ratio N _v of particles of 3.17 μm or less in the volume particle size distribution is 2.0 to 8.0.
The magnetic toner is characterized by: 2. The liquid lubricant is in the form of lubricating particles supported on carrier particles, and the liquid lubricant is contained in an amount of 20 to 90% by mass based on the total mass of the lubricating particles. 1. The magnetic toner according to 1. 3. The viscosity of the liquid lubricant at 25 ° C. is 1.
The magnetic toner according to claim 1 or 2, wherein the magnetic toner has a viscosity of 0 to 200,000 cSt. 4. The magnetic toner according to claim 1, wherein the carrier particles carrying the liquid lubricant are inorganic fine powders. 5. The magnetic toner according to claim 1, wherein the carrier particles carrying the liquid lubricant are organic fine powders. 6. A ratio of a ratio N _r of particles of 3.17 μm or less in the number particle size distribution of the magnetic toner to a ratio N _v of particles of 3.17 μm or less in the volume particle size distribution (N _r /
A magnetic toner according to any one of claims 1 to 5 N _v) is characterized in that 3.0 to 7.0. 7. The volume particle size distribution of the magnetic toner is 8
7. The magnetic toner according to claim 1, wherein the volume ratio of particles having a size of μm or more is 10% by volume or less. 8. The inorganic fine powder to be mixed with the magnetic toner particles is selected from titania, alumina, silica, or a complex oxide thereof, according to any one of claims 1 to 7. The magnetic toner described. 9. The absolute value Q (mC) of the charge amount of the magnetic toner
/ G) is 14 ≦ Q ≦ 80 mC / kg (Q; triboelectric charge amount with iron powder). 9. The magnetic toner according to claim 1, wherein 10. An absolute value Q (m) of the charge amount of the magnetic toner
C / g) is 14 ≦ Q ≦ 60 mC / kg (Q; triboelectric charge amount with iron powder), The magnetic toner according to claim 1. 11. An absolute value Q (m) of the charge amount of the magnetic toner
The magnetic toner according to claim 1, wherein C / g) is 24 <Q ≦ 55 mC / kg (Q; triboelectric charge amount with iron powder). 12. The magnetic toner according to claim 1, wherein the surface of the fine particles mixed with the magnetic toner particles is treated with at least silicone oil or varnish. 13. The magnetic powder has a magnetic field of 79.6 kA / m.
The magnetization intensity at (1000 Oersted) is 50 A
The magnetic toner according to any one of claims 1 to 12, which is a magnetic substance formed of a metal oxide exceeding m ² / kg (emu / g). 14. At least an electrostatic latent image bearing member is charged,
An electrostatic latent image is formed by exposure, the visible image obtained by developing the electrostatic latent image with toner is transferred onto a transfer material, and then the surface of the electrostatic latent image carrier is cleaned with a cleaning member. In the image forming method, the member that comes into pressure contact with the electrostatic latent image carrier is a charging process, a developing process,
In at least two steps of the transfer step and the cleaning step, the toner is formed by externally mixing magnetic toner particles containing at least a binder resin and a magnetic substance, organically treated inorganic fine powder and a liquid lubricant. A magnetic toner having a volume average particle diameter D _v (μm) of 3 μm ≦ D _v <6 μm and a weight average particle diameter D ₄ (μm) of 3.5 μm ≦ D ₄ <6.
A 5 [mu] m, the number particle size _ratio, M _r 60% by number or less of particles 5 [mu] m in the distribution <a M _r ≦ 90% by number, and the number particle size ratio N _r and the volume particle size distribution of 3.17μm or smaller particles in the distribution The ratio (N _r / N _v ) of the ratio N _v of particles having a particle size of 3.17 μm or less in (2) is 2.0 to 8.0. 15. The liquid lubricant is in the form of lubricating particles supported on carrier particles, and the liquid lubricant is contained in an amount of 20 to 90% by mass based on the total mass of the lubricating particles. 14. The image forming method according to item 14. 16. A liquid lubricant having a viscosity at 25 ° C. of 1
The image forming method according to claim 14 or 15, wherein the image forming method is 0 to 200,000 cSt. 17. The image forming method according to claim 14, wherein the carrier particles carrying the liquid lubricant are inorganic fine powders. 18. The image forming method according to claim 14, wherein the carrier particles carrying the liquid lubricant are organic fine powders. 19. A ratio of a ratio N _r of particles of 3.17 μm or less in the number particle size distribution of the magnetic toner to a ratio N _v of particles of 3.17 μm or less in the volume particle size distribution (N _r /
The image forming method according to any one of claims 14 to 18 N _v) is characterized in that 3.0 to 7.0. 20. The image forming method according to claim 14, wherein the volume ratio of particles of 8 μm or more in the volume particle size distribution of the magnetic toner is 10% by volume or less. 21. The inorganic fine powder to be mixed with the magnetic toner particles is selected from titania, alumina, silica, or a complex oxide thereof, according to any one of claims 14 to 20. The image forming method described. 22. The absolute value Q (m) of the charge amount of the magnetic toner
22. The image forming method according to claim 14, wherein C / g) is 14 ≦ Q ≦ 80 mC / kg (Q: frictional charge amount with iron powder). 23. The absolute value Q (m) of the charge amount of the magnetic toner
23. The image forming method according to claim 14, wherein C / g) is 14 ≦ Q ≦ 60 mC / kg (Q: triboelectric charge amount with iron powder). 24. The absolute value Q (m of the charge amount of the magnetic toner
24. The image forming method according to claim 14, wherein C / g) is 24 <Q ≦ 55 mC / kg (Q: triboelectric charge amount with iron powder). 25. The surface of the inorganic fine particles to be mixed with the magnetic toner particles is treated with at least silicone oil or varnish.
The image forming method according to any one of the above. 26. The magnetic powder has a magnetic field of 79.6 kA / m.
The magnetization intensity at (1000 Oersted) is 50 A
26. A magnetic body formed of a metal oxide exceeding m ² / kg (emu / g).
The image forming method according to any one of the above. 27. A developing method, wherein an electrostatic latent image bearing member and a toner bearing member are disposed in a developing unit with a constant gap,
The magnetic toner is regulated to a thickness thinner than the gap on the toner carrier and conveyed to the developing unit, and an alternating electric field is applied in the developing unit to develop the latent image on the electrostatic latent image carrier. The image forming method according to any one of claims 14 to 26. 28. The image forming method according to claim 27, wherein the member for regulating the magnetic toner of the toner carrier is in contact with the toner carrier via the toner. 29. The toner carrier is coated with a resin layer containing conductive fine particles.
The image forming method as described in 7 or 28. 30. The image forming method according to claim 14, wherein the electrostatic latent image carrier is an organic photoconductor. 31. The image forming method according to claim 14, wherein a contact angle of water on the surface of the electrostatic latent image bearing member is 85 degrees or more. 32. The image forming method according to claim 14, wherein the surface of the electrostatic latent image bearing member contains a substance containing fluorine. 33. The image forming method according to claim 14, wherein the transfer member is in contact with the electrostatic latent image carrier via the transfer material during transfer. 34. The image forming method according to claim 14, wherein a charging member for charging the electrostatic latent image carrier is in contact with the electrostatic latent image carrier.