JPH0667460A - Image forming method, image forming device, and device unit - Google Patents

Abstract

PURPOSE:To produce no void in an image during transfer in an image forming device having a contact electrifying means and contact transfer means, to obtain picture images excellent in low temp. fixing property and off set resistance, to hardly contaminate the surface of an electrostatic latent image holding body having an org. photoconductive layer, and to hardly cause filming. CONSTITUTION:This image forming means has a contact electrifying means 2 and contact transfer means 6. The electrostatic latent image holding body 1 having an org. photoconductive layer contains fluororesin particles on the surface. The magnetic toner to develop an electrostatic latent image contains magnetic toner particles containing at least a binder resin and a magnetic material. The binder resin contains >=50 pts.wt. polymer synthesized from vinyl monomers in the presence of an aromatic org. solvent to 100 pts.wt. of the binder resin. The magnetic toner particles contain <=500ppm aromatic org. solvent to the weight of the magnetic toner particles.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an image forming method for visualizing an electrostatic charge image in electrophotography, electrostatic recording and electrostatic printing, and more specifically, a charging member externally applied with a voltage is used as an electrostatic latent image. An image forming method and image used in an electrophotographic method having a contact charging step of contacting an image bearing member to perform charging and a contact transfer step of electrostatically transferring a transfer member applied with a voltage from the outside onto a transfer material. The present invention relates to a forming apparatus and an apparatus unit.

[0002]

2. Description of the Related Art Conventionally, US Pat.
Many methods are known as described in Japanese Patent Publication No. 297691, Japanese Patent Publication No. 42-23910 and Japanese Patent Publication No. 43-24748, but generally, a photoconductive substance is used and various methods are used. After forming an electrical latent image on the photoconductor, developing the latent image with a toner, and optionally transferring the toner image to a transfer material such as paper, heating,
The toner is fixed by pressure, heat and pressure, or solvent vapor to obtain a copy, and the toner left untransferred on the photoreceptor is removed by various methods, and the above steps are repeated.

In recent years, such a copying apparatus is not an office processing copying machine for simply copying an original, but as an information output device linked to another information processing device by the introduction of digital technology, or as a multifunctional device. By making it easier to process and edit image information, it has begun to be used as a copier for creating new original manuscripts and as a personal copy for individuals.

Therefore, higher speed, higher image quality, smaller size and lighter weight have been pursued, and higher reliability has been strictly pursued.

Under such circumstances, in a printer or a copying machine using electrophotography, (i) as a means for uniformly charging the surface of a photoconductor (electrostatic image carrier), and (ii) photoconductivity. As a means to transfer the developer developed image on the body surface,
Although the corona discharger has been widely used in general, a method of directly charging and transferring a charging member by directly applying a voltage to the surface of the photoconductor while contacting or pressing it has been researched and developed, and is being put to practical use. .

[0006] As such a method, for example, Japanese Patent Laid-Open No. 63-63
JP-A-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 charge image carrier, and the electrostatic charge image carrier is uniformly applied while applying a voltage to the conductive roller. After being charged, an electrostatic charge image is formed by exposure, and a toner image is obtained by a developing process, and then a transfer material is applied to the electrostatic charge image carrier while pressing another conductive elastic roller to which a voltage is applied. After passing, the toner image on the electrostatic image carrier is transferred to a transfer material, and then a fixing image is obtained through a fixing process.

Further, an example of an image forming method having the contact charging method and the contact transfer method will be described with reference to the schematic configuration diagram of FIG.

Reference numeral 101 denotes a rotary drum type electrostatic charge image bearing member (hereinafter referred to as a photosensitive member). The photosensitive member 101 includes a conductive base layer 101b such as aluminum and a photoconductive layer 101a formed on the outer surface thereof. It is a basic constituent layer and is rotated clockwise in the drawing at a predetermined peripheral speed (process speed).

Reference numeral 102 denotes a charging roller, which has a basic structure including a central cored bar 102b and a conductive elastic layer forming the outer periphery thereof. The charging roller 102 is the photoreceptor 1.
It is pressed against the surface with a pressing force, and is rotated by the rotation of the photoconductor 101. A charging bias power source 103 applies a voltage to the charging roller 102. By applying a bias to the charging roller 103, the surface of the photoconductor 101 is charged to a predetermined polarity and potential. Image exposure 1
An electrostatic latent image is formed by 04, and the developing unit 105 sequentially visualizes it as a toner image.

Reference numeral 106 denotes a transfer roller, which has a basic structure of a cored bar 106b at the center and a conductive elastic layer 106a forming the outer periphery thereof. The transfer roller 106 is
The photosensitive member 101 is pressed against the surface of the photosensitive member 101 with a pressing force,
The peripheral speed of 1 is rotated at a constant speed or a different peripheral speed. The transfer material 108 includes the photoconductor 101 and the transfer roller 106.
At the same time when the toner image is conveyed to the transfer roller 106, a toner image on the photoconductor 101 is transferred to the surface side of the transfer material 108 by applying a bias having a reverse polarity to the toner from the transfer bias power source 107 to the transfer roller 106.

Next, the transfer material 112 is conveyed to a fixing device 111 which is basically composed of a heating roller 111a having a halogen heater built therein and an elastic pressure roller 111b pressed against the heating roller 111a by a pressing force, and 111a and 111b.
By passing through the space, the toner image is fixed on the transfer material 108 and is discharged as an image-formed product.

After the transfer of the toner image, the surface of the photosensitive member 1 after transfer is cleaned by a cleaning device equipped with an elastic cleaning blade that is pressed against the photosensitive member 101 in the counter direction to clean the surface of the adhered contaminated material such as toner. The exposure apparatus 110 removes the electric charge and repeatedly forms an image.

In the image forming apparatus having such a contact charging system and the transfer system, the photosensitive member can be uniformly charged and sufficiently transferred with a relatively low voltage bias as compared with the corona charging and the corona transfer. It is excellent in reducing the size of the discharger itself and suppressing corona discharge products such as ozone.

However, in the image forming apparatus as described above, the outer peripheral surface of the photoconductor is scraped by the cleaning blade of the cleaning means or the developer as the number of times of image formation is increased. Then, the charging characteristic changes due to a change in equivalent capacitance due to a decrease in the thickness (layer thickness, film thickness) of the photoconductor.

When the number of times image formation is used and the film thickness of the photoconductor decreases, the direct current flowing through the charging roller increases and the surface potential of the outer peripheral surface of the photoconductor rises. When the film thickness of the photoconductor decreases and the surface potential rises, the development contrast increases and the density of the developed image rises, and at the same time, sufficient reverse contrast cannot be obtained with respect to the potential of the white image and the developer becomes thin. There was an obstacle to a "fog" image when developed.

Poor mechanical durability such as reduction in film thickness of the photoconductor is a major factor in determining the life of the photoconductor.

To solve this problem, in order to reduce the abrasion of the surface layer of the photoreceptor and prevent the deterioration of the charging characteristics, Japanese Patent Laid-Open No. 63-30850 discloses a fluorine resin fine powder for the surface layer. Organic photoreceptors containing such lubricants have been proposed and obtained.

On the other hand, it is known that the relationship between the voltage applied to the transfer roller and the current flowing through the transfer roller greatly changes depending on the environment. Further, in this type of device, the maximum size transfer which can be used is achieved. It is usually possible to use a small-sized transfer material within the range below the material.When using a small-sized transfer material, the photoconductor and the transfer roller come into direct contact with each other even when the paper is being passed. Since there is a non-sheet passing portion that does not exist, unevenness in the flow of current may occur, causing a drop in voltage.

That is, in the contact transfer method, it is difficult to give good transferability to all transfer materials in all environments by either constant voltage control or constant current control. However, if the decrease occurs, it is not possible to meet various needs such as postcards that are unfavorable for transfer and OHP films. Further, in a portion where the developer is likely to concentrate (edge developing portion) such as a contour portion and a line drawing portion of the image, "transfer void", which is a part of transfer failure, occurs. This is considered to be because the amount of developer in the edge developing area is larger than that in the normal area, developer aggregation is likely to occur, and the response to transfer electrolysis is lowered.
Therefore, there is a problem that it is difficult to obtain a high-quality image that is true to the latent image.

On the other hand, JP-A-63-276106
Although the control methods proposed in Japanese Patent Laid-Open No. 2-264278 and Japanese Patent Laid-Open No. 2-264278 have been improved, they have not been sufficiently satisfactory.

Regarding the process of fixing a toner image to a transfer material such as a transfer paper, the most popular method at present is a heating and pressing method using a heat roller, which is a so-called heat roll fixing method. The heat roll fixing requires a wait time for the heat roller to reach a predetermined time. With the shortening of the wait time and the speeding up of the apparatus, the transfer material is instantaneously fixed and the transfer material passes through. As a result, the fixing failure is likely to occur due to the temperature drop of the heating roller. Further, since the surface of the heat roller and the toner image are in contact with each other in a molten state of the toner,
A part of the toner image adheres to and transfers to the surface of the fixing roller and retransfers to the next transfer material, so that a so-called offset phenomenon easily occurs.

Therefore, the fixing property of the developer used has been improved, and Japanese Patent Publication No. Sho 63-32182 has been proposed for the purpose of improving the low temperature fixing property of the toner. This publication proposes a toner containing a vinyl-based polymer having at least one local maximum in each specific region of a low molecular weight and a high molecular weight as a binder resin component of the toner, and contains a relatively large amount of the low molecular weight component. By doing so, the low temperature fixability is improved. Further, in JP-A-2-235069, there are two maximum values in the molecular weight distribution of the binder resin, and the respective dispersion ratios of the low molecular weight region and the high molecular weight region are set with the minimum value between the two maximum values as a base point. By making it small, low-temperature fixability and offset resistance are improved.

However, although the above-mentioned toners are improved in fixing property, when the magnetic toners are used in an image forming apparatus having a contact charging system and a contact transfer system, a void in transfer is likely to occur. This is because a large amount of the solvent during the solution polymerization remains in the magnetic toner, so that the toner aggregation is promoted by the pressure during the transfer process.

However, it is conceivable that the vinyl resin is produced by a polymerization method other than the solution polymerization method.
As disclosed in Japanese Patent No. 72459, a solution polymerization method is more preferable in order to obtain sufficient (low temperature) fixability as a binder resin. As a polymerization method of a vinyl resin for obtaining (low temperature) fixability, a solution polymerization method is used. Is considered essential.

Further, an organic photoconductor (organic photoconductor) is generally used as a photoconductor used in a medium-to-low speed machine in order to reduce the size and cost of the copying machine, and in particular, a surface layer of the organic photoconductor. JP-A-63-30850 proposes an organic photoreceptor containing a lubricant such as a fluororesin fine powder in its surface layer for the purpose of reducing the wear of the toner and preventing the deterioration of the charging characteristics. However, in the organic photoreceptor containing the lubricant, a binder resin synthesized by using a vinyl monomer in the presence of an aromatic organic solvent preferably used in the solution polymerization method although the life of the photoreceptor itself is certainly extended. When a toner image is formed by developing with a magnetic toner using, a large amount of aromatic organic solvent remains in the magnetic toner, so this aromatic organic solvent contaminates the resin on the surface of the photoconductor. By doing so, the resin component of the magnetic toner is likely to adhere to the surface of the photoconductor, and filming is likely to occur. Further, when the surface layer of the organic photoconductor contains fine fluororesin powder, the amount of abrasion of the surface of the photoconductor by the cleaning blade and the magnetic toner is small. However, there is a problem in that filming is more likely to occur and filming is more likely to occur.

[0026]

SUMMARY OF THE INVENTION It is an object of the present invention to provide an image forming method, an image forming apparatus and an apparatus unit which solves the above problems.

According to the present invention, when an electrostatic latent image carrier having an organic photoconductive layer is contacted with a contact charging means and a contact transfer means to form an image, a hollow portion during transfer does not occur. Alternatively, it is an object of the present invention to provide an image forming method, an image forming apparatus and an apparatus unit that are hard to cause.

According to the present invention, when an electrostatic latent image carrier having an organic photoconductive layer is brought into contact with a contact charging means and a contact transfer means to form an image, the charging characteristics are good and the toner is still in use. It is an object of the present invention to provide an image forming method, an image forming apparatus, and an apparatus unit that always have stable chargeability, are clear, have no fog, and can obtain an image without a decrease in density.

According to the present invention, the magnetic toner used for image formation is excellent in storage stability and is unlikely to cause agglomeration, the toner image to be fixed is excellent in low-temperature fixing property and anti-offset property, and has a wide fixing temperature range. An image forming method, an image forming apparatus and a unit having the same are provided.

An object of the present invention is to form an electrostatic latent image carrier having an organic photoconductive layer when an image is formed by contacting the latent image carrier having the organic photoconductive layer with a contact charging means and a contact transfer means. An object of the present invention is to provide an image forming method, an image forming apparatus, and an apparatus unit in which the surface of an image carrier is less likely to be contaminated and filming does not occur or does not occur easily.

[0031]

Means and Actions for Solving the Problems The present invention has achieved the above object by the following constitutions.

According to the present invention, a contact charging member is brought into pressure contact with the surface of an electrostatic latent image bearing member having an organic photoconductive layer to apply a bias voltage to charge the electrostatic latent image bearing member, and the electrostatic latent image bearing member is charged. A latent image forming means forms a charged latent image on the electrostatic latent image carrier, the electrostatic latent image carried by the electrostatic latent image carrier is developed with magnetic toner, and a toner image formed by the development is developed. In the image forming method, in which the toner image on the transfer material is fixed by the fixing means, the electrostatic latent image carrier is transferred to the transfer material by a contact transfer member that contacts the electrostatic latent image carrier via the transfer material. The surface contains fluorine-containing resin fine particles, and the magnetic toner has magnetic toner particles containing at least a binder resin and a magnetic material, and the binder resin is
The polymer synthesized by using a vinyl-based monomer in the presence of an aromatic organic solvent is contained in an amount of 50 parts by weight or more based on 100 parts by weight of a binder resin, and the magnetic toner particles have the aromatic organic solvent. To 500 ppm or less based on the weight of the magnetic toner particles.

Further, according to the present invention, an electrostatic latent image carrier having an organic photoconductive layer for carrying an electrostatic latent image, and a bias voltage is applied by pressing the surface of the electrostatic latent image carrier. Thereby, a latent image forming means for forming an electrostatic latent image on the electrostatic latent image carrier, a developing means for developing the electrostatic latent image carried by the electrostatic latent image carrier, A contact transfer member for contacting the electrostatic latent image carrier via a transfer material to transfer the toner image formed by the developing means to the transfer material, and a fixing means for fixing the toner image on the transfer material. In the image forming apparatus having, the electrostatic latent image bearing member contains fluorine-containing resin fine particles on the surface, and the magnetic toner is
It has magnetic toner particles containing at least a binder resin and a magnetic substance, and the binder resin is a binder resin obtained by synthesizing a polymer synthesized using a vinyl monomer in the presence of an aromatic organic solvent. 50 parts by weight or more with respect to 100 parts by weight, and the magnetic toner particles contain the aromatic organic solvent in an amount of 500 ppm or less based on the weight of the magnetic toner particles. .

Further, according to the present invention, (i) an electrostatic latent image carrier having an organic photoconductive layer for carrying an electrostatic latent image and (ii) a surface of the harmful electrostatic latent image carrier are brought into pressure contact with each other. At least one of the contact charging means for charging the electrostatic latent image carrier by applying a bias voltage to develop the electrostatic latent image carried on the electrostatic latent image carrier. A unit is supported integrally with the developing unit, and the unit includes (iii) latent image forming means for forming an electrostatic latent image on a charged electrostatic latent image carrier, and (iv) A device removably attached to a device main body having a latent image forming unit for forming an electrostatic latent image on the electrostatic latent image carrier and (v) a fixing unit for fixing the toner image of the transfer material. In the unit, the electrostatic latent image bearing member contains fluorine-containing resin fine particles on the surface. In addition, the magnetic toner has magnetic toner particles containing at least a binder resin and a magnetic material, and the binder resin contains a vinyl-based monomer in the presence of an aromatic organic solvent. The synthesized polymer is contained in an amount of 50 parts by weight or more based on 100 parts by weight of the binder resin, and the magnetic toner particles contain the aromatic organic solvent in an amount of 500 ppm or less based on the weight of the magnetic toner particles. The present invention relates to an apparatus unit.

The present invention can achieve the above-mentioned object in that the binder resin used for the magnetic toner contains 50 parts by weight or more of a polymer synthesized by using a vinyl monomer in the presence of an aromatic organic solvent. Since it is contained in parts by weight,
A molecular weight component contributing to (low temperature) fixability can be secured, and further, since the content of the aromatic organic solvent in the magnetic toner particles is 500 ppm or less based on the weight of the magnetic toner particles, the aggregation of the toners can occur. This is because it has an effect of preventing the occurrence of voids in the transfer, the storage stability of the toner is improved, and the surface of the electrostatic latent image carrier having the organic photoconductive layer is less likely to be contaminated by the solvent.

Examples of the aromatic organic solvent for synthesizing the polymer used as the binder resin in the present invention include benzene, toluene, xylene, cyclohexane, and tetrahydrofuran, but xylene is taken into consideration when considering the polymerization temperature and the desolvation temperature. Is most preferred.

In the present invention, the method of synthesizing the vinyl monomer in the presence of the aromatic organic solvent includes, for example, a solution polymerization method in an aromatic organic solvent.

In the present invention, the binder resin used for the magnetic toner is a low molecular weight component having a peak molecular weight (Mp) of 4000 to 30,000 and a high molecular weight component having a peak molecular weight (Mp) of 200,000 to 1,000,000 in a chromatogram in GPC measurement. A resin containing a molecular weight component is preferable in that the low temperature fixability and the offset resistance are improved.

The resin containing such a low molecular weight component and a high molecular weight component is a low molecular weight polymer and a high molecular weight polymer when melt-kneading a toner constituent material containing a binder resin during toner production. Can be prepared by melt-kneading.

This low molecular weight polymer has a peak molecular weight (Mp) in the chromatogram in GPC measurement of preferably 4000 to 30,000, more preferably 7000 to 2
In terms of good low temperature fixability, the high molecular weight polymer preferably has a peak molecular weight (Mp) of 2
From the viewpoint of good offset resistance, it is preferable that it has a range of 0,000 to 1,000,000, more preferably 300,000 to 700,000.

The low molecular weight polymer can be synthesized by a known polymerization method such as a solution polymerization method, a suspension polymerization method and an emulsion polymerization method. Particularly, in view of synthesizing a low molecular weight polymer, the solution polymerization method is used. Is preferred.

Further, the high molecular weight polymer is a solution polymerization method,
Although it can be synthesized by a known polymerization method such as a suspension polymerization method and an emulsion polymerization method, a suspension polymerization method is preferable in terms of synthesizing a polymer having a high molecular weight and producing a polymer having a preferable particle size. .

As the solvent used in the solution polymerization, aromatic solvents such as benzene, toluene, xylene, cyclohexane and tetrahydrofuran; ketone solvents such as acetone, methyl ethyl ketone, methyl isobutyl ketone and cyclohexanone, dimethyl formamide and dimethyl acetamide are used. An amide solvent may be used.

Examples of the polymerization initiator for polymerizing a low molecular weight monomer include t-butylperoxy-2-ethylhexanoate, t-butylperoxylaurate, benzoyl peroxide, lauroyl peroxide and octanoyl peroxide. Oxide, di-t-butyl peroxide, t-butyl cumyl peroxide, diisopropylbenzene hydroperoxide, p-menthane hydroperoxide, 2,2'-azobisisobutyronitrile, 2,2azobis (2-methyl) Butyronitrile) and 2,2′-azobis (4-methoxy-2,4-dimethylvaleronitrile) such as monofunctional radical initiators may be used alone or in combination. The amount of the radical polymerization initiator used is 0.1 with respect to the monomers constituting the low molecular weight polymer.
-15 wt%, preferably 1-10 wt% is suitable.

As a preferred polymerization initiator for polymerizing a high molecular weight monomer, a polyfunctional radical initiator is preferably used, for example, 1,1-bis (t-butylperoxy) 3,3,5. -Trimethylcyclohexane, 1,1-
Bis (t-butylperoxy) cyclohexane, 1,4
-Bis (t-butylperoxycarbonyl) cyclohexane, 2,2-bis (t-butylperoxy) octane, n-butyl 4,4-bis (t-butylperoxy)
Valylate, 2,2-bis (t-butylperoxy) butane, 1,3-bis (t-butylperoxy-isopropyl) benzene, 2,5-dimethyl-2,5-di (t-butylperoxy) hexane , 2,5-dimethyl-2,5
-Di (t-butylperoxy) hexane-3,2,5-
Dimethyl-2,5-di (benzoylperoxy) hexane, di-t-butylperoxyisophthalate, 2,2
-Bis (4,4-di-t-butylperoxycyclohexyl) propane, di-t-butylperoxy-α-methylsuccinate, di-t-butylperoxydimethylglutarate, di-t-butylperoxy Hexahydroterephthalate, di-t-butylperoxyazelate,
2,5-dimethyl-2,5- (t-butylperoxy)
A difunctional radical polymerization initiator such as -hexane, diethylene glycol bis (t-butyl peroxycarbonate), di-t-butyl peroxytrimethyl adipate; for example, tris (t-butyl peroxy) triazine, vinyl tris (t-butyl) Trifunctional radical polymerization initiators such as peroxy) silane, 2,2-bis (4,4)
-Di-t-butylperoxycyclohexyl) propane, a copolymerization compound of t-butylperoxyallyl carbonate (for example, Hyper B and Hyper G series manufactured by NOF CORPORATION), a copolymerization compound of t-butylperoxymaleic acid Examples of the radical polymerization initiator having 4 or more functional groups such as those described above are used alone or in combination, and if necessary, used in combination with a monofunctional radical initiator.

The amount of these polyfunctional radical polymerization initiators used is 0.05 to 5% by weight, preferably 0.1 to 3% by weight, based on the monomers constituting the high molecular weight polymer. Is.

As the resin which can be used in combination with the polymer synthesized by using the vinyl monomer in the presence of the aromatic organic solvent constituting the binder resin applied to the present invention, a vinyl (based) resin is used. , Polyester resin, phenolic resin,
Epoxy resins can be mentioned, but vinyl resins and polyester resins are particularly preferable.

The polymer using the vinyl monomer used in the present invention, which is synthesized in the presence of the aromatic organic solvent, and the vinyl monomer constituting the vinyl resin that can be used in combination with the polymer, , For example:

For example, styrene, o-methylstyrene,
m-methylstyrene, p-methylstyrene, p-phenylstyrene, p-ethylstyrene, 2,4-dimethylstyrene, pn-butylstyrene, p-tert-butylstyrene, pn-hexylstyrene, p- n-octylstyrene, pn-nonylstyrene, pn-decylstyrene, pn-dodecylstyrene, p-methoxystyrene, p-chlorostyrene, 3,4-dichlorostyrene, m-nitrostyrene, o -Nitrostyrene, p-
Styrene and styrene derivatives such as nitrostyrene; Ethylene and unsaturated monoolefins such as ethylene, propylene, butylene and isobutylene; Unsaturated diolefins such as butadiene and isoprene; Vinyl chloride, vinylidene chloride, vinyl bromide, vinyl fluoride Vinyl halides such as; vinyl acetates such as vinyl acetate, vinyl propionate, vinyl benzoate; methacrylic acid and methyl methacrylate, ethyl methacrylate, propyl methacrylate, n-butyl methacrylate, isobutyl methacrylate, methacrylic acid α-Methylene aliphatic monocarboxylic acid esters such as n-octyl, dodecyl methacrylate, 2-ethylhexyl methacrylate, stearyl methacrylate and phenyl methacrylate; acrylic acid and methyl acrylate Ethyl acrylate, n-
Butyl, isobutyl acrylate, propyl acrylate,
Acrylic esters such as n-octyl acrylate, dodecyl acrylate, 2-ethylhexyl acrylate, stearyl acrylate, 2-chloroethyl acrylate, phenyl acrylate; vinyl ethers such as vinyl methyl ether, vinyl ethyl ether, vinyl isobutyl ether Vinyl ketones such as vinyl methyl ketone, vinyl hexyl ketone and methyl isopropenyl ketone; N-vinyl pyrrole, N-vinyl carbazole, N
-N- such as vinylindole and N-vinylpyrrolidone
Vinyl compounds such as vinyl compounds, vinyl naphthalene compounds, acrylic acid or methacrylic acid derivatives such as acrylonitrile, methacrylonitrile and acrylamide; acrolein compounds; and vinyl monomers used alone or in combination are used.

As the polyester resin, for example, 45 to 55 mol% is an alcohol component and 55 to 45 mol% is an acid component in all components of the polyester resin.

As the alcohol component, ethylene glycol, propylene glycol, 1,3-butanediol, 1,4-butanediol, 2,3-butanediol, diethylene glycol, triethylene glycol,
1,5-Pentanediol, 1,6-hexanediol, neopentyl glycol, 2-ethyl-1,3-hexanediol, hydrogenated bisphenol A, the following (A)
Bisphenol derivative represented by the formula

[0052]

[Outer 1] (In the formula, R is an ethylene or propylene group, x and y are each an integer of 1 or more, and the average value of x + y is 2
It is -10. ) Diols represented by the following formula (B)

[0053]

[Outside 2] And polyhydric alcohols such as glycerin, sorbit and sorbitan.

Examples of the acid component include benzenedicarboxylic acids such as phthalic acid, terephthalic acid, isophthalic acid and phthalic anhydride or their anhydrides as divalent carboxylic acids; succinic acid, adipic acid, sebacic acid and azelaic acid. Alkyl dicarboxylic acids or their anhydrides; C6-18
The succinic acid substituted with an alkyl group or its anhydride; and the trivalent or higher carboxylic acid include trimellitic acid, pyromellitic acid, benzophenonetetracarboxylic acid and its anhydride.

Further, those having an unsaturated double bond include unsaturated dicarboxylic acids such as fumaric acid, maleic acid, citraconic acid, itaconic acid and dodecenylsuccinic acid, or anhydrides thereof.

The alcohol component of the polyester resin particularly preferred in the practice of the present invention is a bisphenol derivative represented by the above formula (A), and the acid component is phthalic acid, terephthalic acid, isophthalic acid or its anhydride, and succinic acid. Trimellitic acid or its tricarboxylic acid anhydride, and examples of those having an unsaturated double bond include fumaric acid, maleic acid, and maleic anhydride. The content having an unsaturated double bond is preferably 1 in the total amount of acid.
It is good that the content is at least wt%, more preferably at least 5 wt%.

In the present invention, among the resins which can be used in combination with the polymer synthesized by using the vinyl monomer in the presence of the aromatic organic solvent, the polymer in which the vinyl monomer is synthesized is generally generally Known methods include, for example, a method of obtaining by a solvent polymerization method or a suspension polymerization method using a peroxide as an initiator. Polyester resins are also usually obtained by commonly known polycondensation.

The glass transition point (Tg) of the binder resin used in the magnetic toner of the present invention is preferably 45 to 80 ° C.
More preferably, it is 50 to 70 ° C.

The magnetic toner of the present invention further contains a magnetic material which may also serve as a colorant.

The magnetic substance contained in the magnetic toner of the present invention includes iron oxides such as magnetite, γ-iron oxide ferrite and iron-excessive ferrite; metals such as iron, cobalt and nickel; or metals such as aluminum and aluminum; cobalt,
Examples thereof include alloys with metals such as copper, lead, magnesium, tin, zinc, antimony, beryllium, bismuth, cadmium, calcium, manganese, selenium, titanium, tungsten, vanadium, and mixtures thereof.

These magnetic materials have an average particle size of 0.1 to 1 μm.
m, preferably about 0.1 to 0.5 μm, and the amount contained in the magnetic toner is the resin component 1
The amount is preferably 60 to 110 parts by weight, more preferably 65 to 100 parts by weight, relative to 00 parts by weight.

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. The charge control agent enables optimum charge control according to the developing system, and particularly in the present invention, the balance between the binder resin and the charge can be further stabilized.

As the positive charge control agent, a modified product of nigrosine and a fatty acid metal salt; tributylbenzylammonium-1-hydroxy-4-naphthosulfonate,
Quaternary ammonium salts such as tetrabutylammonium tetrafluoroborate; diorganotin oxides such as dibutyltin oxide, dioctyltin oxide and dicyclohexyltin oxide; diorganotin borates such as dibutyltin borate, dioctyltin borate and dicyclohexyltin borate alone or Is 2
A combination of more than one type can be used.

Of these, charge control agents such as nigrosine and quaternary ammonium salts are particularly preferably used. Further, a homopolymer of a monomer represented by the following general formula;

[0065]

[Outside 3] [In the formula, R ₁ represents H or CH ₃ , and R ₂ and R ₃ are substituted or unsubstituted alkyl groups (preferably C _{1 to} C ₄ ).
], A copolymer with a polymerizable monomer such as styrene, an acrylic acid ester, or a methacrylic acid ester as described above can be used as a positive charge control agent. In this case, these charge control agents can be used as a binder resin ( (All or part of)).

As the negative charge control agent which can be used in the present invention, for example, an organometallic complex and a chelate compound are effective, and examples thereof include aluminum acetyl acetate, iron (II) acetyl acetate and 3,5-di- Examples include sali-butyl chromium salicylate. Acetylacetone metal complex, salicylic acid-based metal complex or salt is preferable, more preferably salicylic acid-based metal complex (including monoalkyl group-substituted or dialkyl group-substituted) or salicylic acid-based metal salt (monoalkyl group-substituted or dialkyl group) Including a substitution product) is preferable.

The above-mentioned charge control agent (which does not act as a binder resin bet) is preferably used in the form of fine particles. In this case, the number average particle size of this charge control agent is
Specifically, 4 μm or less (more preferably 3 μm or less)
Is preferred.

When internally added to the toner particles, such a charge control agent is preferably used in an amount of 0.1 to 20 parts by weight (more preferably 0.2 to 10 parts by weight) with respect to 100 parts by weight of the binder resin. Is good.

In order to solve the problem of offset phenomenon, the magnetic toner particles according to the present invention may contain a polyolefin as a release agent.

The polyolefin applicable to the present invention is, for example, a homopolymer of α-olefin such as ethylene, propylene, 1-butene, 1-hexene and 4-methyl-1-pentene, and a copolymer of two or more α-olefins. Examples thereof include polymers or oxides of polyolefins, and these polyolefins may be vinyl-based graft modified polyolefins.

The vinyl-based graft modified polyolefin comprises the above-mentioned polyolefin component and modifying component, and the modifying component is grafted to the polyolefin component. As the modifying component, vinyl-based monomers such as aliphatic vinyl-based monomers and aromatic vinyl-based monomers are used. For example, aliphatic vinyl monomers include methacrylic acid and methyl methacrylate, ethyl methacrylate, propyl methacrylate, n-butyl methacrylate, isobutyl methacrylate, n-octyl methacrylate, 2-ethylhexyl methacrylate, lauryl methacrylate, stearyl methacrylate, dodecyl methacrylate, phenyl methacrylate. , Dimethylaminoethyl methacrylate, diethylaminoethyl methacrylate, 2-hydroxyethyl methacrylate, 2,2,2-trifluoroethyl methacrylate, methacrylates such as glycidyl methacrylate, acrylic acid and methyl acrylate, ethyl acrylate, propyl acrylate, n -Butyl acrylate, isobutyl acrylate, n-octyl Acrylate, lauryl acrylate, stearyl acrylate,
Dodecyl acrylate, 2-ethylhexyl acrylate, phenyl acrylate, 2-chloroethyl acrylate, 2-hydroxyethyl acrylate, cyclohexyl acrylate, dimethylaminoethyl acrylate,
Diethylaminoethyl acrylate, dibutylaminoethyl acrylate, 2 ethoxy acrylate, 1,4-
Acrylates such as butanediol diacrylate,
Maletanic acid, fumaric acid, itaconic acid, citraconic acid, monoethylmalate, diethylmalate, monopropylmalate, dibutylmalate, monobutylmalate, dibutylmalate, di-2ethylhexyl fumarate, monoethylfumarate , Di-ethyl fumarate, dibutyl fumarate, di-2 ethylhexyl fumarate, monoethyl itaconate, diethyl itaconate, monoethyl citracone, diethyl citracone, and one or two of these may be mentioned. More than one species can be used simultaneously.

Styrene as the aromatic vinyl monomer,
o-methylstyrene, m-methylstyrene, p-methylstyrene, α-methylstyrene, 2,4-dimethylstyrene, p-ethylstyrene, pn-butylstyrene,
It is possible to increase p-tert-butylstyrene, pn-dodecylstyrene, p-phenylstyrene, p-chlorostyrene and the like, and one or more of these can be used simultaneously.

As a method for graft modification, a conventionally known method can be used. For example, a graft-modified polyolefin is obtained by reacting the above-mentioned polyolefin with an aromatic vinyl monomer and an aliphatic vinyl monomer in a solution state or a molten state under heating in the atmosphere or under pressure in the presence of a radical initiator. The grafting with the aromatic vinyl monomer and the aliphatic vinyl monomer may be carried out both at the same time or individually.

The polyolefin used in the present invention has a weight average molecular weight (Mu) in GPC measurement of preferably 2000 to 30000, more preferably 5000.
A low molecular weight of ˜18,000 is preferable.

In the magnetic toner of the present invention, the addition amount of polyolefin to the binder resin is 10
The amount is preferably 0.1 to 20 parts by weight, more preferably 0.1 to 10 parts by weight, based on 0 parts by weight. If the amount is less than 0.1 parts by weight, the effect on offset resistance cannot be exhibited, and if the amount is more than 20 parts by weight, the polyolefin particles precipitated in the binder resin become large and toner blocking is caused. The property is likely to deteriorate.

In order to produce the magnetic toner particles used in the present invention, a binder resin comprising the resin composition of the present invention containing magnetic iron oxide, a pigment or a dye as a colorant, and a charge control if necessary. The agents and other additives were thoroughly mixed by a mixer such as a ball mill, and then melted, kneaded, and kneaded using a heat kneader such as a heating roll, kneader, or extruder to make the resins compatible with each other. A magnetic toner particle of the present invention can be obtained by dispersing or dissolving a pigment or a dye therein, cooling and solidifying, and then pulverizing and classifying.

In the present invention, the content of the aromatic organic solvent in the magnetic toner particles is 5 with respect to the weight of the magnetic toner particles.
As a means for reducing the amount to 00 ppm or less, for example, after completion of solution polymerization using a vinyl-based monomer in the presence of an aromatic organic solvent, a dryer is used, and the temperature is preferably 30 at normal pressure.
~ 50 ° C for 5 to 48 hours, more preferably temperature 35 to 4
After drying and desolvating the polymer at 5 ° C. for 8 to 36 hours,
Using a vacuum dryer, preferably under reduced pressure (absolute pressure: 1
0 to 500 mmHg) at a temperature of 30 to 50 ° C. for 5 to 48 hours, more preferably under reduced pressure (absolute pressure 50 to 400 mm).
Hg), using a polymer obtained by drying and desolvating the polymer at a temperature of 35 to 45 ° C. for 8 to 36 hours, the above-mentioned melting, kneading,
The magnetic toner particles may be prepared by a method for producing toner particles including a pulverization and classification step.

In the magnetic toner according to the present invention, it is more preferable that silica fine powder is internally added to the magnetic toner particles or externally mixed with the magnetic toner particles. When the magnetic toner particles are brought into contact with the surface of a cylindrical conductive sleeve having a magnetic field generating means for frictional charging,
Generally, when the number of contact between the surface of the toner particles and the sleeve increases, abrasion of the toner particles easily occurs. On this occasion,
When the magnetic toner particles and the silica fine powder are combined, the silica fine powder is present between the magnetic toner particles and the surface of the conductive sleeve, and such abrasion is remarkably reduced. Therefore, the life of the magnetic toner can be extended and
It is possible to prepare a developer having a magnetic toner that can exhibit more excellent properties even when used for a long period of time.

As the silica fine powder used at this time, silica fine powder produced by a dry method or a wet method can be used. However, from the viewpoint of filming resistance and durability, silica produced by the dry method is used. It is preferable to use fine powder.

The dry method mentioned here is a manufacturing method in which silica fine powder is produced by vapor phase oxidation of a silicon halogen compound. For example, it is a method utilizing a thermal decomposition oxidation reaction of silicon tetrachloride gas in oxygen hydrogen, and a basic reaction formula is as follows.

SiCl ₄ + 2H ₂ + O ₂ → SiO ₂ + 4HCl In this manufacturing process, for example, aluminum chloride,
Alternatively, by using another metal halogen compound of titanium chloride together with a silicon halogen compound, it is possible to obtain a composite fine powder of silica and another metal oxide, which is also included.

Commercially available silica fine powders produced by vapor phase oxidation of a silicon halogen compound used in the present invention include, for example, those commercially available under the following trade names. AEROSIL (Japan Aerosil Co., Ltd.) 130 200 300 380 OX50 TT600 MOX80 MOX170 COK84 Ca-O-SiL (CABOTO Co., Ltd.) M-5 MS-7 MS-75 HS-5 EH-5 Wacker HDK N 20-CHE (WACKER). GMBH) N20E T30 T40 D-C Fine Silica (Dow Corning Co.) Francol (Fransil)

Further, as a method for producing the silica fine powder used in the present invention by a wet method, various conventionally known methods can be applied. For example, decomposition of sodium silicate represented by the following general reaction formula by an acid can be mentioned.

Na ₂ O · xSiO ₂ + HCl + H ₂ O → SiO ₂ · nH ₂ O + NaCl In addition, decomposition of sodium silicate with ammonia salts or alkali salts, and generation of an alkaline earth metal silicate from sodium silicate, There are a method of decomposing with an acid to silicic acid, a method of converting a sodium silicate solution into silicic acid by an ion exchange resin, and a method of utilizing natural silicic acid or silicate.

As the silica fine powder referred to herein, anhydrous silicon dioxide (colloidal silica) and other silicates such as aluminum silicate, sodium silicate, potassium silicate, magnesium silicate and silicic acid should be applied. Can be done.

Examples of commercially available silicic acid fine powders synthesized by the wet method include those commercially available under the following trade names.・ Carplex (Shionogi Pharmaceutical Co., Ltd.) ・ Kneepseal (Nippon Silica) ・ Tokuseal and Fineseal (Sokutoku Soda) ・ Vitaseal (Taki Manure) ・ Shilton and Sinex (Mizusawa Chemical) ・ Stasil (Kamishima Chemical) ・ Himezir (Ehime Pharmaceutical) -Syloid (Fuji Davison Chemicals) -Hi-Sil (high seal) Pittsburgh Plate Glass. Co
(Pittsburgh plate glass) -Durosil (Durosil) -Ultrasil (Ultraseal) Filmstoff-Gesellschaft M
arquart (Furstoff Gezer shaft Marquardt) Manosil (Manosir) Hardman and Holden (Hardman
And Holden) Hoesch Chemische Fabrik Hoesch K
-G (Hemische Fabry Hech) -Sil-Stone (Stone Stone) Stoner Rubber Co. (Stoner rubber) Nalco Nalco Chem. Co. (Nalco Chemical) -Quso Philadelphia Quartz Co. (Philadelphia Quartz) Imsl Illinois Minerals Co. (Illinois Minerals) -Calcium Silikat Chemische Fabrik Hoesch. K
-G (Chemish Fabry Heche) -Calsil (Still) -Fillstoff-Gesellschaft M
arquart (furstoff-gezel shaft
Marquart) Fortafil (Fortafil) Imperial Chemical Industr
ies. Ltd. (Imperial Chemical Industries) -Microcal Joseph Crossfields & Sons. L
td. (Joseph Crossfield and Sons) Manosil (Manosir) Hardman and Holden (Hardman
And Holden) Vulkasil Farbenfabriken Bryer, A .; −
G. (Farben Fabry Ken Bayer) -Tufknit (Tough Knit) Durham Chemicals. Ltd. (Durham Chemicals) ・ Sirumos (Shiraishi Industry) ・ Star Rex (Kamishima Chemical) ・ Furicosyl (many wooden fertilizer) Of the above silica fine powders, the specific surface area by nitrogen adsorption measured by the BET method is 30 m ² / g or more (especially 50-40
Those in the range of 0 m ² / g) give good results. The fine silica powder is preferably 0.01 to 8 parts by weight, more preferably 0.1 to 8 parts by weight, based on 100 parts by weight of the toner.
It is preferable to use 1 to 5 parts by weight.

When the magnetic toner according to the present invention is used as a positively chargeable magnetic toner, in order to prevent abrasion of the toner,
It is preferable to use positively chargeable silica fine powder rather than negatively chargeable silica fine powder to be added, since the charge stability is not impaired.

As a method for obtaining a positively chargeable silica fine powder, the above-mentioned untreated silica fine powder is treated with a silicone oil having an organo group having at least one nitrogen atom in its side chain, and a nitrogen-containing silica fine powder. There is a method of treating with a silane coupling agent, or a method of treating with both of them.

In the present invention, the positively chargeable silica is one having a positive triboelectric charge to the iron powder carrier when measured by the blow-off method.

As the silicone oil having a nitrogen atom in the side chain used for treating the silica fine powder, a silicone oil having at least a partial structure represented by the following formula can be used.

[0091]

[Outside 4] (In the formula, R ₁ represents hydrogen, an alkyl group, an aryl group or an alkoxy group, R ₂ represents an alkylene group or a phenylene group, R ₃ and R ₄ represent hydrogen, an alkyl group or an aryl group, and R ₅ Represents a nitrogen-containing heterocyclic group.) In the above formula, the alkyl group, the aryl group, the alkylene group, and the phenylene group may have an organo group having a nitrogen atom, and may have a halogen atom within a range not impairing the charging property. It may have such a substituent.

The nitrogen-containing silane coupling agent used in the present invention generally has a structure represented by the following formula.

R _m —Si—Y _n (R represents an alkoxy group or halogen, Y represents an amino group or an organo group having at least one nitrogen atom, and m and n are integers of 1 to 3. And m + n = 4.) Examples of the organo group having at least one nitrogen atom include an amino group having an organic group as a substituent, a nitrogen-containing heterocyclic group, or a group having a nitrogen-containing heterocyclic group.

The nitrogen-containing heterocyclic group includes an unsaturated heterocyclic group and a saturated heterocyclic group, each of which is publicly known. Examples of the unsaturated heterocyclic group include the followings.

[0095]

[Outside 5]

Examples of the saturated heterocyclic group are shown below.

[0097]

[Outside 6]

The above-mentioned heterocyclic group used in the present invention is preferably a 5-membered ring or a 6-membered ring in view of stability.

Examples of such treating agents include aminopropyltrimethoxysilane, aminopropyltriethoxysilane, dimethylaminopropyltrimethoxysilane,
Diethylaminopropyltriethoxysilane, dipropylaminopropyltrimethoxysilane, dibutylaminopropyldimethoxysilane, monobutylaminopropyltriethoxysilane, dioctylaminopropyltriethoxysilane, dibutylaminopropyltrimethoxysilane, dibutylaminopropylmonomethoxysilane, dimethyl Examples thereof include aminophenyltriethoxysilane, trimethoxysilyl-γ-propylphenylamine and trimethoxysilyl-γ-propylbenzylamine. Further, as the nitrogen-containing heterocyclic group, those having the above-mentioned structure can be used, and examples of such a compound include trimethoxysilyl-γ-propylpiperidine, trimethoxysilyl-γ-propylmorpholine and trimethoxy. Cyril-
γ-Propylimidazole may be mentioned.

When the amount of the positively charged silica fine powder treated with these is 0.01 to 8 parts by weight with respect to 100 parts by weight of the positively charged magnetic toner, the effect is exerted, and particularly preferably 0. When added in an amount of 1 to 5 parts by weight, it exhibits positive stability and excellent stability.

A preferred mode of addition is as follows: 0.1 part with respect to 100 parts by weight of the positively chargeable magnetic toner.
It is preferable that about 3 parts by weight of the treated silica fine powder is attached to the surface of the toner particles. The untreated silica fine powder described above can also be used in the same application amount.

The silica fine powder used in the present invention may be treated with a treating agent such as a silane coupling agent or an organic silicon compound for the purpose of making it hydrophobic, if necessary, by reacting with the silica fine powder or by physical adsorption. Is treated with the above-mentioned treating agent.

Examples of the organic silicon compound include hexamethylsilane, trimethylsilane, trimethylchlorosilane, trimethylethoxysilane, dimethyldichlorosilane, methyltrichlorosilane, allyldimethylchlorosilane, allylphenyldichlorosilane, and benzyldimethylchlorosilane. , Prommethyldimethylchlorosilane, α-chloroethyltrichlorosilane, β-chloroethyltrichlorosilane, chloromethyldimethylchlorosilane, triorganosilylmercaptan, trimethylsilylmercaptan, triorganosilylacrylate,
Vinyldimethylacetoxysilane, dimethylethoxysilane, dimethyldimethoxysilane, diphenyldiethoxysilane, hexamethyldisiloxane, 1,3-divinyltetramethyldisiloxane, 1,3-diphenyltetramethyldisiloxane, and 2 to 12 per molecule. There is a dimethylpolysiloxane having siloxane units, each of which has a hydroxyl group bonded to Si in each of the terminal units. These are used alone or in a mixture of two or more.

The methods for measuring various values in the present invention will be described below.

(1) Measurement of glass transition temperature Tg In the present invention, measurement is carried out using DSC-7 (manufactured by Perkin Elmer Co., Ltd.) which is a differential thermal analysis measuring device (DSC measuring device).

The measurement data is 5 to 20 mg, preferably 10
Precisely weigh mg. This is placed in an aluminum van, and an empty aluminum pan is used as a reference, and measurement is performed at a temperature rising rate of 10 ° C./min at a measurement temperature range of 30 to 200 ° C. under normal temperature and normal humidity.

In this temperature rising process, an endothermic peak of the main peak in the temperature range of 40 to 100 ° C. is obtained. At this time, the intersection of the line at the midpoint of the baseline before and after the appearance of the endothermic peak and the differential heat curve is taken as the glass transition temperature Tg in the present invention.

(2) Measurement of molecular weight In the present invention, the molecular weight of the chromatogram by GPC (gel permeation chromatography) is measured under the following conditions.

That is, the column was stabilized in a heat chamber at 40 ° C., and THF (tetrahydrofuran) as a solvent was passed through the column at this temperature at a flow rate of 1 ml / min to obtain a sample concentration of 0.05 to 0.6% by weight. 50-200 μl of a THF sample solution of the resin adjusted to 1 is injected and measured.

In measuring the molecular weight of the sample, the molecular weight distribution of the sample was calculated from the relationship between the logarithmic value and the count number of the calibration curve prepared from several kinds of monodisperse polystyrene standard samples. As a standard polystyrene sample for preparing a calibration curve, for example, Pressure Chemica
l Co. Manufactured by Toyo Soda Kogyo Co., Ltd. has a molecular weight of 6
× 10 ² , 2.1 × 10 ³ , 4 × 10 ³ , 1.75 × 1
0 ⁴ , 5.1 × 10 ⁴ , 1.1 × 10 ⁵ , 3.9 × 1
0 ⁵ , 8.6 × 10 ⁵ , 2 × 10 ⁶ , 4.48 × 10 ⁶
It is suitable to use a standard polystyrene sample of at least 10 points. An RI (refractive index) detector is used as the detector.

As the column, it is preferable to combine a plurality of commercially available polystyrene gel columns in order to accurately measure the molecular weight region of 10 ³ to 2 × 10 ⁶ , and for example, Watt
ers manufactured by the μ-styragel 500,10 ^3,
A combination of 10 ⁴ and 10 ⁵ or a shod made by Showa Electric Co.
ex KF-80M and KF-801, 803, 804
And 805, KA-802, 803, 804,
Combination of 805 or TSKgel G made by Toyo Soda
1000H, G2000H, G2500H, G3000
H, G4000H, G5000H, G6000H, G7
A combination of 000H and GMH is preferred.

(3) The residual solvent in the developer is quantitatively determined by the following method using a gas chromatograph.

2.55 mg of DMF was used as an internal standard, and 1
Make a solvent containing an internal standard by adding 00 ml of acetone. Next, 400 mg of the developer is made into a 10 ml solution with the above solvent. After ultrasonically shaking for 30 minutes, leave it for 1 hour. Then, it is filtered with a 0.5 μm filter. The amount of sample to be implanted is 4 μl.

The conditions for the gas chromatograph are: Capillary column (30 m × 0.249 mm, DBW
AX, film thickness 0.25 μm) ・ Detector FID, nitrogen pressure 0.45 kg / cm ²・ Injection concentration 200 ° C, detector temperature 2
The column temperature is raised from 50 ° C. to 5 ° C./1 minute for 30 minutes. -Preparation of calibration curve A standard sample prepared by adding the same amount of DMF and acetone solution as the sample solution to the solvent of interest is subjected to gas chromatograph measurement in the same manner to determine the weight ratio / area ratio of the solvent to the internal standard DMF.

The electrostatic latent image carrier used in the present invention will be described.

The electrostatic latent image carrier having the organic photoconductive layer used in the present invention contains fluorine-containing resin fine particles on at least the surface thereof in order to reduce the friction resistance of the surface.

Even if the surface of the electrostatic latent image carrier is formed of an organic photoconductive layer containing an organic photoconductive substance,
A protective layer may be further formed on this organic photoconductive layer.

The fluorine-containing resin fine particles used in the electrostatic latent image bearing member of the present invention are polytetrafluoroethylene, polychlorotrifluoroethylene, polyvinylidene fluoride,
Polydichlorodifluoroethylene, tetrafluoroethylene-perfluoroalkyl vinyl ether copolymer,
Tetrafluoroethylene-hexafluoropyrene copolymer, tetrafluoroethylene-ethylene copolymer, and tetrafluoroethylene-hexafluoropropylene-
It is composed of one or more selected from perfluoroalkyl vinyl ether copolymers. It is possible to use the commercially available fluorine-containing resin fine particles as they are. Those having a weight average molecular weight of 30,000 to 5,000,000 can be used, and those having a particle diameter of 0.01 to 10 μm, preferably 0.05 to 2.0 μm can be used.

The organic photoconductive layer of the electrostatic latent image carrier of the present invention contains at least a charge generating material and a charge transporting material as the organic photoconductive substance. Examples of the charge generating material include phthalocyanine pigment, polycyclic quinone pigment, trisazo pigment, disazo pigment, azo pigment, perylene pigment, indigo pigment, quinacridone pigment, azurenium salt dye, squalium dye, cyanine dye, pyrylium dye, thiopyrylium dye, Examples include xanthene dyes, quinoneimine dyes, triphenylmethane dyes, styryl dyes, selenium, selenium-tellurium alloys, amorphal silicon, and cadmium sulfide.

Examples of the charge transport material include pyrene compounds, N-alkylcarbazole compounds, hydrazone compounds, N, N-dialkylaniline compounds, diphenylamine compounds, triphenylamine compounds, triphenylmethane compounds, pyrazoline compounds, styryl compounds, Examples include stilbene compounds, polynitro compounds, polycyano compounds, and pendant polymers in which these compounds are fixed on a polymer.

In some cases, the protective layer and the organic photoconductive layer are formed by dispersing and containing the above-mentioned fluorine-containing resin fine particles, charge generating material, charge transporting material and the like in a binder resin having film forming properties. Many. Examples of such binder resin include polyester, polyurethane, polyacrylate, polyethylene, polystyrene, polybutadiene, polycarbonate, polyamide, polypropylene, polyimide, phenol resin, acrylic resin, silicone resin, epoxy resin, urea resin, allyl resin, alkyd resin. , Polyamide-imide, nylon, polysulfone, polyallyl ether, polyacetal, butyral resin.

Next, the layer structure of the electrostatic latent image carrier used in the present invention will be described. Conductive supports are iron, copper, gold, silver,
Metals and alloys such as aluminum, zinc, titanium, lead, nickel, tin, antimony and indium, or oxides of the above metals, carbon and conductive polymers can be used. The shape includes a drum shape such as a cylindrical shape and a cylindrical shape, a belt shape, and a sheet shape. The conductive material may be molded and processed as it is, used as a paint, vapor-deposited, or processed by etching or plasma treatment. In the case of paint, not only the metals and alloys mentioned above but also paper and plastic are used as the support.

An example of layer formation of the electrostatic latent image carrier used in the present invention is shown in FIG.

The organic photoconductive layer 23 in the electrostatic latent image carrier 20 used in the present invention may be formed on the conductive support 21 and may have a single layer structure or a laminated structure. In the case of the laminated structure, it is composed of at least the charge generation layer 23a and the charge transport layer 23b. However, when the charge generation layer 23a is provided on the conductive support 21 side and in the charge transport layer 2
The charging polarity and the polarity of the toner used are different from when 3b is provided. The thickness of the charge generation layer 23a is preferably 0.001 to 6 μm, more preferably 0.
It is 01 to 2 μm. The content of the charge generating material contained in the charge generating layer 23a is preferably 10 to 100% by weight, and more preferably 50 to 100% by weight, based on the total weight of the charge generating layer. The thickness of the charge transport layer is determined from the thickness of the organic photoconductive layer 23 to the charge generation layer 2
It is obtained by subtracting the film thickness of 3a. Charge transport layer 23b
The content of the charge transport material contained therein is preferably 20 to 80% by weight, and more preferably 30 to 70% by weight, based on the total weight of the charge generation layer.

An undercoat layer 22 may be provided between the conductive support 21 and the organic photoconductive layer 23. The undercoat layer 22 functions as a charge injection control at the interface and as an adhesive layer. The undercoat layer 22 is mainly composed of a binder resin, but may contain the above-mentioned metals or alloys, or their oxides, salts, surfactants and the like. As the binder resin forming the undercoat layer 22,
As the binder resin for the organic photoconductive layer 23, those mentioned as the binder resin can be used, and the thickness of the undercoat layer is preferably 0.05 to 7 μm, more preferably 0.1 to 2 μm.

The content of the fluorine-containing resin fine particles contained on the surface of the electrostatic latent image carrier used in the present invention is such that when the surface is the charge transport layer 23b of the organic photoconductive layer 23, the entire charge transport layer is included. It is preferably 5 to 30% by weight, more preferably 10 to 25% by weight based on the weight, and when the surface is a protective layer, preferably 5 to 30% by weight based on the total weight of the protective layer. 40% by weight, more preferably 10
It is preferably about 40% by weight.

The thickness of this protective layer is preferably 0.05.
The range is from 0.8 μm to 8.0 μm, and more preferably 0.0.
The range of 5 μm to 6.0 μm is preferable.

Further, the film thickness of the organic photoconductive layer of the electrostatic latent image bearing member is preferably 10 to 35 μm, more preferably 1
5 to 30 μm is preferable, and the film thickness of this organic photoconductive layer is the total thickness with the film thickness of the protective layer when the protective layer is provided.

As a method for producing the electrostatic latent image carrier used in the present invention, a method such as vapor deposition or coating is used. The coating method can form a wide range of films from thin films to thick films, and can form films of various compositions. Specifically, bar coater, knife coater, dip coating, spray coating,
Coating is carried out using a coating method such as beam coating, electrostatic coating, roll coater, attritor, or powder coating.

The coating material used for forming the surface layer forming the surface of the electrostatic latent image bearing member is obtained by dispersing the fluorine-containing resin fine particles in at least a binder resin and a solvent. As a dispersion method, a ball mill,
Methods such as ultrasonic, paint shaker, red devil, sand mill are used. The same dispersion method can be used when the conductive fine powder, the pigment, and the charge generation material are pigments.

An example of a specific image forming apparatus that can be used to carry out the image forming method in the present invention will be described with reference to FIG.

Reference numeral 1 is a rotary drum type photosensitive member as an electrostatic latent image bearing member, and the photosensitive member 1 is basically composed of a conductive base layer 1b such as aluminum and a photoconductive layer 1a formed on the outer surface thereof. The surface portion of the photoconductive layer 1a is composed of a polycarbonate resin containing 8% by weight of a charge-transporting substance and a fluorine-based resin fine powder. It is rotationally driven in the clockwise direction on the drawing at a peripheral speed of 200 mm / s.

Reference numeral 2 denotes a charging roller as a contact charging means, which is a conductive elastic layer 2 having a central core metal 2b and an outer periphery thereof made of epichlorohydrin rubber containing carbon black.
The basic configuration is a.

The charging roller 2 has a linear pressure of 40 on the surface of the photoreceptor 1.
The photosensitive member 1 is pressed with a pressing force of g / cm and is driven to rotate as the photosensitive member 1 rotates. Further, a felt pad as a cleaning member 12 is in contact with the charging roller 2.

Reference numeral 3 is a charging bias power source for applying a voltage to the charging roller 2, and a DC voltage is applied to the charging roller 3.
By applying a bias of 1.4 kV, the surface of the photoconductor 1 is charged to a polarity and potential of about -700V.

Next, an electrostatic latent image is formed by the image exposure 4 as a latent image forming means, and the electrostatic latent image is developed by the developer held in the developing means 5 and sequentially visualized as a toner image. Reference numeral 6 denotes a transfer roller as a contact transfer member, which basically has a core metal bar 6b and a conductive elastic layer 6a whose outer periphery is formed of an ethylene-propylene-butadiene copolymer containing carbon black. .

The transfer roller 6 has a linear pressure of 20 on the surface of the photoreceptor 1.
g. They are pressed against each other with a pressing force of cm, and rotate or rotate at the same speed as the peripheral speed of the photoconductor 1. Further, a felt pad as a cleaning member 13 is in contact with the transfer roller 6.

As the transfer material 8, A4 size paper is used.
At the same time as this is conveyed between the photoconductor 1 and the transfer roller 6, the transfer roller 6 has a direct current of -5 kV having a polarity opposite to that of the toner.
The toner image on the photoconductor 1 is transferred to the surface side of the transfer material 8 by applying the bias of 1 from the transfer bias power source 7. Therefore, at the time of transfer, the transfer roller 6 is pressed against the photoconductor 1 via the transfer material 8.

Next, the transfer material 8 is conveyed to a fixing device 11 as a fixing means having a fixing roller 11a containing a halogen heater and an elastic pressure roller 11b pressed against the fixing roller 11a as a fixing means. By passing between the fixing roller 11a and the pressure roller 11b, the toner image is fixed on the transfer material 8 and discharged as an image-formed product.

After the transfer of the toner image, the surface of the photosensitive member 1 is provided with an elastic cleaning blade made of polyurethane rubber as a basic material, which is brought into contact with adherent contaminants such as transfer residual toner on the photosensitive member 1 at a linear pressure of 25 g / cm in the counter direction. The surface is cleaned by the cleaning device 9 described above, and the charge is removed by the charge removing exposure device 10 to repeatedly form an image.

The image forming apparatus is constructed by integrally combining a plurality of constituent elements such as the electrostatic image carrier, the developing means, the charging means, and the cleaning means as an apparatus unit. May be detachably attached to the apparatus body. For example, at least one of a group consisting of a charging unit, an electrostatic latent image carrier, and a cleaning unit is integrally supported together with a developing unit to form a unit, which is a device unit that is detachably attached to the device body. It may be configured to be detachably attached using the guide means as described above. At this time, the apparatus main body may be configured with a component not selected from the above group, for example, a charging unit and / or a cleaning unit.

When the image forming apparatus of the present invention is used as a printer for a facsimile, the image exposure 4 as a latent image forming means is digital exposure by laser light for printing received data. A specific example of this case is shown in the block diagram of FIG.

The controller 211 is the image reading unit 210.
And control the printer 219. Controller 211
Is controlled by the CPU 217. The read data from the image reading unit is transmitted to the partner station via the transmission circuit 213. The data received from the partner station is the receiving circuit 21.
2 to the printer 219. Predetermined image data is stored in the image memory. The printer control 218 controls the printer 219. 214 is a telephone.

The image received from the line 215 (the image information from the remote terminal contacted via the line) is demodulated by the receiving circuit 212, and then the CPU 217 carries out the image information decoding process, and sequentially the image memory 216. Stored in. When the image of at least one page is stored in the memory 216, the image recording of that page is performed. CPU217
Reads out one page of image information from the memory 216 and sends the decoded one page of image information to the printer controller 218. Printer controller 218
When receiving the image information of one page from the CPU 218, the printer 21
Control 9

The CPU 217 is receiving the next page while the printer 219 is recording.

The basic structure and features of the present invention have been described above. The present invention will be specifically described below with reference to examples. However, this does not limit the invention in any way. Parts in the following formulations are parts by weight.

[0147]

【Example】

(Synthesis example 1) Nitrogen gas inlet tube, condenser, stirrer,
Into a four-necked flask equipped with a thermometer, 800 parts of xylene was charged, and the temperature was increased by stirring under a nitrogen gas stream to maintain the temperature at 90 ° C.
Styrene 85 parts, butyl acrylate copolymer 15 parts, di-t-butyl peroxide (DTBP) as an initiator
4 parts of the mixture was added dropwise using a continuous dropping device over 8 hours to carry out solution polymerization. Then, it was dried under normal pressure at 40 ° C. for 12 hours and desolvated to obtain a polymer (A) having a peak at a molecular weight of 10 thousand in GPC. The amount of residual solvent in this polymer (A) was 2300 p as determined by gas chromatogram measurement.
It was pm.

(Synthesis example 2) Synthesis example 1 was prepared using a polymerization apparatus.
A polymer (B) having a peak at a molecular weight of 13,000 in GPC was obtained in the same manner as in Synthesis Example 1 except that 83 parts of styrene and 17 parts of butyl acrylate copolymer were used.
The amount of residual solvent in this polymer (B) was 2700 ppm as determined by gas chromatogram measurement.

(Synthesis Example 3) With respect to the polymer (A) obtained in Synthesis Example 1, the polymer after completion of solution polymerization was treated under normal pressure at 40 ° C.
After drying at 12 ° C for 12 hours and solvent removal treatment, the residual solvent treatment was performed using a vacuum dryer under reduced pressure (absolute pressure: 1
60 mmHg), dried at 40 ° C. for 24 hours and desolvated to reduce the amount of residual solvent to 1100 ppm (C)
Got

(Synthesis Example 4) The polymer (B) obtained in Synthesis Example 2 was treated with the same residual solvent as in Synthesis Example 3 to obtain a polymer (D) in which the residual solvent amount was reduced to 1300 ppm. It was

(Synthesis Example 5) In a four-necked flask equipped with a nitrogen gas introduction tube, a condenser, a stirrer, and a thermometer, 200 parts of ion-exchanged water, 81 parts of styrene, 19 parts of n-butyl acrylate, and initiators 1 and 4 were used. 0.4 parts of -bis (t-butylperoxycarbonyl) cyclohexane (HTP) was charged, and suspension polymerization was carried out at a polymerization temperature of 90 ° C for 24 hours. Then, it was cooled, washed with water and dried to obtain a polymer (E) having a peak at a molecular weight of 700,000 in GPC.

(Synthesis Example 6) Using the polymerization apparatus of Synthesis Example 5,
G was prepared in the same manner as in Synthesis Example 5 except that suspension polymerization was carried out at a polymerization temperature of 90 ° C. for 24 hours using 83 parts of styrene, 17 parts of n-butyl acrylate and 6 parts of DTBP as an initiator.
A polymer (F) having a peak at a molecular weight of 20,000 in PC was obtained.

(Synthesis Example 7) In a pressure autoclave, a mixture of 86 parts of styrene and 14 parts of butadiene, 1 part of calcium carbonate, and 30 parts of benzoyl peroxide as an initiator.
Parts of polyvinyl alcohol having a silicidation degree of 85 mol%.
The dispersion was dispersed in 1500 parts of a 1% aqueous solution, and suspension polymerization was performed at about 80 ° C. for 6 hours. Then, cool, wash with water, dry, GP
Polymer having a peak at a molecular weight of 21,000 in C (G)
Got

These are shown in Table 1.

[0155]

[Table 1]

(Magnetic Toner Production Example I) Binder Resin 1 was prepared by mixing the following polymer prepared by the synthesis example: Polymer (C) 56 parts Polymer (E) 24 parts Polymer (G) 20 parts Binder resin 1 100 parts Low molecular weight polypropylene 4 parts Magnetic iron oxide 90 parts Nigrosine 2 parts After premixing the above materials with a Henschel mixer, 150
Melt kneading was carried out at a temperature of ° C by a twin-screw kneading extruder. The kneaded product was allowed to cool, coarsely pulverized and finely pulverized, and further, using a wind classifier, black fine powder (magnetic toner particles) having a volume average particle diameter of 8.5 μm was obtained.

100 parts of the obtained black fine powder was charged with positively charged hydrophobic silica (BET specific surface area; 200 m ² / g) of 0.
Six parts were added and mixed with a Henschel mixer to obtain a positively chargeable insulating magnetic toner (I).

The residual amount (content) of the solvent at the time of solution polymerization of the obtained magnetic toner particles was 380 ppm as shown in the following Table 2 from the measurement of the gas chromatogram.

(Magnetic Toner Production Examples II to VII) Magnetic toner production examples I to II except that the binder resin I used in the magnetic toner production example I was changed to binder resins 2 to 7 as shown in Table 2 below. In the same manner as in Example 1, positively chargeable insulating magnetic toners II to VII were obtained.

The residual amount (content) of the aromatic organic solvent in the obtained magnetic toner particles is shown in Table 2 below.

[0161]

[Table 2]

[Production Example of Electrostatic Latent Image Bearing Member] An aluminum cylinder of 30φ × 360 mm is used as a base, on which a polyamide resin (trade name: Amilan CM-8) is provided.
000, manufactured by Toray) was applied by a dipping method to form an undercoat layer having a thickness of 1 μm.

Next, 10 parts (parts by weight) of the following structural formula disazo pigment was used.

[0164]

[Outside 7] The same applies hereinafter), 6 parts of polyvinyl butyral resin (trade name: S-REC BXL, manufactured by Sekisui Chemical Co., Ltd.) and 100 parts of cyclohexane were dispersed for 20 hours in a sand mill using 1φ glass beads. Tetrahydrofuran 5 was added to this dispersion.
0-100 (appropriately) parts are added and coated on the undercoat layer, and 1
It was dried at 00 ° C. for 5 minutes to form a charge generation layer having a thickness of 0.15 μm.

Next, 20 parts of bisphenol Z type polycarbonate resin (manufactured by Teijin Chemicals) as a binder and 20 parts of p-diethylaminobenzaltodehyde-N-β-naphthyl-N-phenylhydrazone as a charge transport material. Was dissolved in 100 parts of cyclohexane, and 7 parts of polytetrafluoroethylene resin fine powder (trade name: Lubron L-2, manufactured by Daikin Industries, Ltd.) was added as fine particles of fluorine-containing resin, and dispersed for 50 hours with a stainless steel ball mill. Then, 20 parts of dichloroethane was further added to prepare a charge transport layer coating solution.

This solution was applied onto the charge generation layer, and 10
It was dried in hot air at 0 ° C. for 90 minutes to form a charge transport layer having a thickness of 25 μm, and an electrostatic latent image carrier I was obtained.

(Embodiment 1) The electrostatic latent image carrier 1 is used in the image forming apparatus shown in FIG. 1, and the following conditions are applied: Contact pressure of the charging roller to the electrostatic latent image carrier: 50 g / c
m Applied voltage: -1400 V (DC) Contact pressure of the transfer roller to the electrostatic latent image carrier: 20 g / c
m (Linear pressure) Applied voltage: -6000 V (DC) Peripheral speed difference with respect to the electrostatic latent image carrier: 1.5% (0.5,
1.5, 3.0, 5.0, -0.5, -1.5, -3.
0, -5.0%) Contact pressure of cleaning blade: 20 g / cm Development bias condition Vpp: 1300 V (AC) Vf: 1800 Hz Vdc: -210 V (DC) Electrostatic latent image carrier and developer carrier In the electrophotographic copying machine in which the distance was 300 μm and the process speed was 200 mm / sec, the magnetic toner I was put into a remodeling machine with the fixing device removed to obtain an unfixed image on the transfer material. The fixing device removed from the electrophotographic copying machine GP55 (manufactured by Canon Inc.) was remodeled to be a heat roller external fixing device with variable temperature, and a fixing test and an offset test of an unfixed image were performed under the following conditions.

The nip of the external fixing device is set to 5.0 mm, the process speed is set to 200 mm / s, and 100 ° C. to 25 ° C.
The temperature is adjusted every 5 ° C in the temperature range of 0 ° C, and the unfixed image is fixed at each temperature.
Rubbing was performed with sillbon paper applied with a load of / cm ² , and the fixing temperature at which the image density reduction rate before and after rubbing was 5% or less was determined as the fixing start temperature.

As a result, an excellent fixing temperature range was obtained in which the fixing start temperature was 170 ° C. and the offset start temperature was 250 ° C.

Using A4 size paper as the transfer material,
A that has 10 0.2 x 20 mm lines as a document
When an image forming test was carried out by using an electrophotographic copying machine using the above image forming apparatus using the 4 size chart, a good line image having no voids in the transfer was obtained.

Furthermore, an A4 image of a line image having an image area ratio of 10% is obtained by an electrophotographic copying machine using the above image forming apparatus.
After 20,000 sheets of continuous printing test were performed on an A4 size transfer paper using the original document, the surface of the photoconductor (electrostatic latent image bearing member) was observed, and filming was not observed at all. In addition, the obtained image was good, and no omission of lines occurred. The results are shown in Table 3 below.

(Example 2) A fixing, offset test and an image forming test were conducted in the same manner as in Example 1 except that the magnetic toner II was used instead.

The results are shown in Table 3 below.

(Comparative Examples 1 to 5) In Example 1, the fixing and offset test and the image forming test were performed in the same manner as in Example 1 except that the magnetic toners III to VII were used instead.

The results are shown in Table 3 below.

[0176]

[Table 3] * 1 Missing transfer o: 0 to 1 out of 10 line images occurred. Δ: 2 to 5 out of 10 line images occurred. ×: 6 to 10 out of 10 line images occurred. * 2 Filming ○: Filming does not occur on the photoconductor at all △: Filming occurs on a part of the photoconductor ×: Filming occurs on the entire photoconductor

According to the present invention, the binder resin of the magnetic toner particles is made of a vinyl-based monomer in the presence of an aromatic organic solvent, and the synthesized polymer is 50 parts by weight or more.
And the magnetic toner particles contain the aromatic organic solvent in an amount of 50 parts by weight based on the weight of the magnetic toner particles.
Since the content is 0 ppm or less, the electrostatic latent image bearing member is contacted with the contact charging means to charge the electrostatic latent image bearing member,
Moreover, when the toner image is transferred onto the transfer material by bringing the contact transfer means into contact with the electrostatic latent image carrier through the transfer material, and the image is formed, the toner image has excellent low-temperature fixing property and offset resistance, No void occurs during transfer or is unlikely to occur, and it also has stable charging characteristics at all times during use, is clear and free from fog, and is less likely to reduce image density. Since it is as small as 500 ppm or less with respect to the weight of the magnetic toner particles, it is difficult to contaminate the surface of the electrostatic latent image carrier, and filming does not occur or is unlikely to occur.

[Brief description of drawings]

FIG. 1 is a schematic configuration diagram for explaining an image forming method and an image forming apparatus using a contact charging method and a contact transfer method of the present invention.

FIG. 2 is a block diagram of a facsimile machine when the image forming apparatus of the present invention is used as a printer of the facsimile machine.

FIG. 3 is an explanatory view showing a specific example of the layer structure of the electrostatic latent image carrier used in the present invention.

FIG. 4 is a schematic configuration diagram of an image forming apparatus using a conventionally known contact charging method and a contact transfer method.

[Explanation of symbols]

 1 Electrostatic Latent Image Holder (Photoreceptor) 2 Charging Roller 3 Charging Bias Applying Power Supply 4 Image Exposure 5 Developing Means 6 Transfer Roller 7 Transfer Bias Applying Power Supply 8 Transfer Material 9 Cleaning Means 10 Electrification Exposure 11 Fixing Means

─────────────────────────────────────────────────── ─── Continuation of the front page (51) Int.Cl. ⁵ Identification number Reference number within the agency FI Technical indication location G03G 9/08 384 (72) Inventor Kazuyoshi Hagiwara 3-30-2 Shimomaruko, Ota-ku, Tokyo Canon Incorporated (72) Inventor Toshiaki Nakahara 3-30-2 Shimomaruko, Ota-ku, Tokyo Canon Inc.

Claims (6)

[Claims] 1. A static charge image bearing member having an organic photoconductive layer is brought into contact with a surface of a contact charging member under pressure to apply a bias voltage to charge the static latent image carrier, and the electrostatic latent image carrier is charged. A charged latent image is formed on the electrostatic latent image carrier by the latent image forming means, the electrostatic latent image carried by the electrostatic latent image carrier is developed with magnetic toner, and the toner image formed by the development is transferred. In the image forming method, in which the toner image of the transfer material is transferred to the transfer material by the contact transfer member that is in contact with the electrostatic latent image support through the material, and the toner image of the transfer material is fixed by the fixing means, The magnetic toner contains fluorine-containing resin fine particles, and the magnetic toner has magnetic toner particles containing at least a binder resin and a magnetic material,
The binder resin has a polymer synthesized using a vinyl monomer in the presence of an aromatic organic solvent in an amount of 50 parts by weight or more based on 100 parts by weight of the binder resin, and the magnetic toner particles are An image forming method comprising the aromatic organic solvent in an amount of 500 ppm or less based on the weight of magnetic toner particles. 2. The image forming method according to claim 1, wherein the binder resin has a polymer synthesized by solution polymerization using a vinyl monomer in the presence of an aromatic organic solvent. 3. An electrostatic latent image carrier having an organic photoconductive layer for carrying an electrostatic latent image, wherein a bias voltage is applied to the surface of the electrostatic latent image carrier by applying a bias voltage thereto. Latent image forming means for forming an electrostatic latent image on the electrostatic latent image carrier, developing means for developing the electrostatic latent image carried by the electrostatic latent image carrier, the electrostatic latent image Image formation having a contact transfer member for contacting the carrier through the transfer material to transfer the toner image formed by the developing means to the transfer material, and a fixing means for fixing the toner image of the transfer material In the apparatus, the electrostatic latent image carrier contains fluorine-containing resin fine particles on its surface, and the magnetic toner has magnetic toner particles containing at least a binder resin and a magnetic material. ,
The binder resin is synthesized by using a vinyl monomer in the presence of an aromatic organic solvent and has a polymer in an amount of 50 parts by weight or more based on 100 parts by weight of the binder resin. An image forming apparatus comprising the aromatic organic solvent in an amount of 500 ppm or less based on the weight of magnetic toner particles. 4. The image forming apparatus according to claim 3, wherein the binder resin has a polymer synthesized by solution polymerization using a vinyl monomer in the presence of an aromatic organic solvent. 5. (i) an electrostatic latent image bearing member having an organic photoconductive layer for carrying an electrostatic latent image; and (ii) a bias voltage applied by pressure contact with the surface of the electrostatic latent image bearing member. When applied, at least one of the contact charging means for charging the electrostatic latent image carrier is integrated with the developing means for developing the electrostatic latent image carried on the electrostatic latent image carrier. Are supported by the unit to form a unit, and the unit is (ii)
i) latent image forming means for forming an electrostatic latent image on a charged electrostatic latent image carrier, (iv) latent image forming for forming an electrostatic latent image on the electrostatic latent image carrier And (v) an apparatus unit detachably mounted on an apparatus body having a fixing means for fixing the toner image of the transfer material, wherein the electrostatic latent image carrier contains fluorine-containing resin fine particles on its surface. And the magnetic toner has magnetic toner particles containing at least a binder resin and a magnetic material,
The binder resin is synthesized by using a vinyl monomer in the presence of an aromatic organic solvent and has a polymer in an amount of 50 parts by weight or more based on 100 parts by weight of the binder resin. An apparatus unit comprising the aromatic organic solvent in an amount of 500 ppm or less based on the weight of magnetic toner particles. 6. The apparatus unit according to claim 5, wherein the binder resin has a polymer synthesized by solution polymerization using a vinyl monomer in the presence of an aromatic organic solvent.