JP2886952B2 - Image forming apparatus, apparatus unit and facsimile apparatus - Google Patents

Description

Description: TECHNICAL FIELD The present invention is used in the field of a technique of developing an electrostatic latent image with a developer, and in particular, an image forming apparatus and an apparatus that perform development by restraining the developer with a magnetic force The present invention relates to a unit and a facsimile machine.

(Background technology)

Conventionally, for example, a developing device that visualizes a latent image formed on the surface of a photosensitive drum as an electrostatic latent image carrier with a magnetic toner has been developed by friction between magnetic toner particles, a sleeve as a developer carrier and a magnetic toner. A charge having a polarity opposite to that of the electrostatic image formed on the photosensitive drum due to the friction of the particles is applied to the magnetic toner particles, and the magnetic toner is applied very thinly on the sleeve, so that the magnetic toner is applied to the developing area formed by the photosensitive drum and the sleeve. It is known that the toner is conveyed, and the magnetic toner is caused to fly by the action of a magnetic field by a magnet fixed in a sleeve in a developing area to visualize an electrostatic latent image on a photosensitive drum.

However, in any of the developing devices described above, a relatively thin uniform toner layer must be formed on the sleeve, but the uniform toner layer depends on environmental conditions, toner physical properties, and the state of the sleeve surface. Cannot be obtained, and unevenness often occurs particularly in a low humidity environment.

As the copy or printout is repeated, the developer is repeatedly rubbed against the sleeve, so that additives for improving the fluidity of the toner and non-developing substances such as carriers in the two-component toner are deposited on the sleeve, or The surface condition of the sleeve changes because the binder resin in the developer forms a film on the sleeve, so that the developability of the developer becomes unstable or the developer is not transported to the electrostatic latent image surface. There was a problem of stabilization.

In order to prevent such a change in the surface state of the sleeve, for example, a coating layer containing an inorganic high-molecular fluorocarbon is formed (JP-A-57-66443). Forming a good resin (JP-A-58-17)
No. 8380), an organic silicone polymer, an aliphatic fluorine-containing compound, or a film formed of at least one substance selected from styrene resins and polyferralene oxide (Japanese Patent Laid-Open No. 57-76558) In addition, there has been proposed a technique in which a material having high releasability is coated on the sleeve surface to prevent a change in the surface state.

However, a coated sleeve in which these synthetic resins are coated on the surface of the sleeve is relatively softer than a conventionally used aluminum or SUS sleeve. Therefore, the developer is pressed down during the repeated developing operation, and the surface of the developer carrier is unevenly polished or scratched, or a part of the developer adheres, and the coating is originally performed. There is a problem that the performance of the sleeve tends to deteriorate. In particular, when a magnetic toner containing a magnetic material is used, the above-mentioned problem becomes remarkable.

The toner is fixed to the transfer material by hot-melt fixing using a hot-press roller or radiant heating or pressure fixing using a pressure roller. It is preferable that the heat quantity and pressure be small in consideration of economy, safety in terms of device structure, and ease of design. Accordingly, the components of the toner tend to include soft components having a low melt viscosity, a low melting point, a small pressure yield point, and a soft component. Conversely, in terms of toner durability, fixability, and anti-offset, it is important that the toner contains a hard component.

In order to satisfy such conflicting factors, the binder resin constituting the toner has a molecular weight distribution of:
It is often advantageous to include both a soft part and a hard part.

Such a tendency of the developer is likely to make the above-mentioned problem of the developer carrier more prominent.

[Object of the invention]

An object of the present invention is to provide an image forming apparatus, an apparatus unit, and a facsimile apparatus which have solved the above-mentioned problems.

SUMMARY OF THE INVENTION It is an object of the present invention to provide an image forming apparatus, an apparatus unit, and a facsimile apparatus that can uniformly carry toner on a developing sleeve.

An object of the present invention is to provide an image forming apparatus, an apparatus unit, and a facsimile apparatus having a small sleeve memory.

An object of the present invention is to provide an image forming apparatus, an apparatus unit, and a facsimile apparatus which are excellent in environmental stability.

[Summary of the Invention]

The present invention relates to an electrostatic latent image carrier for carrying an electrostatic latent image, a developing device for developing the electrostatic latent image carried on the electrostatic latent image carrier, and a developing device for developing. In an image forming apparatus having a bias applying unit for applying an AC bias or a pulse bias, the developing device includes: a one-component developer; a developer storage chamber that stores the one-component developer; A developer carrying member for carrying the one-component developer housed in the developer accommodating chamber and transporting the developer to a developing area; and a layer of the one-component developer carried on the developer carrying body. A developer layer thickness regulating member for regulating the thickness, wherein the developer carrier has a rotatable aluminum developing sleeve, a magnet fixed in the developing sleeve so as not to rotate, and Film formation on the surface of the developing sleeve A coating layer containing a polymer material and conductive fine particles, wherein the developer layer thickness regulating member has a layer thickness of the one-component developer carried on the rotating developer carrier. Is formed to be thinner than the gap between the electrostatic latent image carrier and the developer carrier in the development area.The one-component developer has a THF insoluble content of 10% as a binder resin. G content of up to 70% by weight and soluble in THF
It has a resin composition containing a component having a molecular weight of 10,000 or less in a molecular weight distribution by PC and 10 to 50% by weight based on the binder resin, and a magnetic toner containing a magnetic substance. And an externally-added hydrophobic silica fine powder treated with silicone oil or silicone varnish.

The present invention relates to an apparatus unit detachably mounted to an image forming apparatus main body, the apparatus unit comprising: an electrostatic latent image carrier for carrying an electrostatic latent image; and an image carrier carried by the electrostatic latent image carrier. A developing device for developing the electrostatic latent image, and the developing device is integrally supported with the electrostatic latent image carrier to form a unit, and an AC bias or a pulse is applied to the developing device during development. The developer device is mounted on an image forming apparatus main body having a bias applying unit for applying a bias, and the developer device contains a one-component developer and the one-component developer. A developer carrying chamber, a developer carrying body for carrying the one-component developer housed in the developer containing chamber, and transporting the developer to a developing area; and a developer carrying body carried by the developer carrying body. Development to regulate layer thickness of one-component developer A layer thickness regulating member, wherein the developer carrier is formed on a rotatable aluminum developing sleeve, a magnet fixed in the developing sleeve so as not to rotate, and formed on the surface of the developing sleeve. A coating layer containing a film-forming polymer material and conductive fine particles, wherein the developer layer thickness regulating member is the one-component developer carried on the rotating developer carrier. Is formed to be thinner than the gap between the electrostatic latent image carrier and the developer carrier in the development area. The one-component developer includes a THF-insoluble component as a binder resin. GPC containing 10-70% by weight and soluble in THF
And a magnetic toner containing a magnetic material and a resin composition in which a component having a molecular weight of 10,000 or less in the molecular weight distribution with respect to the binder resin is contained in the magnetic toner, The present invention relates to an apparatus unit to which hydrophobic silica fine powder treated with silicone oil or silicone varnish is externally added.

The present invention relates to a facsimile apparatus having an electrophotographic apparatus and a receiving means for receiving image information from a remote terminal, wherein the electrophotographic apparatus comprises: an electrostatic latent image carrier for carrying an electrostatic latent image; A developing device for developing the electrostatic latent image carried on the latent image carrier and a bias applying unit for applying an AC bias or a pulse bias to the developing device during development; A one-component developer, a developer storage chamber storing the one-component developer, and carrying the one-component developer stored in the developer storage chamber and transporting the one-component developer to a development area. And a developer layer thickness regulating member for regulating the layer thickness of the one-component developer carried on the developer carrier. Is a rotatable aluminum developing sleeve, A magnet layer fixed so as not to rotate in the developing sleeve, and a coating layer containing a film-forming polymer material and conductive fine particles formed on the surface of the developing sleeve; The thickness of the layer of the one-component developer carried on the rotating developer carrier is smaller than the gap between the electrostatic latent image carrier and the developer carrier in the development area. The one-component developer contains 10 to 70% by weight of a THF-insoluble component as a binder resin, and has a THF-soluble component of G
It has a resin composition containing a component having a molecular weight of 10,000 or less in a molecular weight distribution by PC and 10 to 50% by weight based on the binder resin, and a magnetic toner containing a magnetic substance. Facsimile apparatus, wherein hydrophobic silica fine powder treated with silicone oil or silicone varnish is externally added.

[Specific description of the invention]

The developing device used in the present invention will be described with reference to the accompanying drawings.

 FIG. 1 is a sectional view of an example of the developing device of the present invention.

In FIG. 1, reference numeral 1 denotes a photosensitive drum as an electrostatic latent image carrier that carries an electrostatic latent image and rotates in the direction of arrow A. The photosensitive drum 1 may or may not have an insulating layer on the surface. Not only the drum shape but also a sheet shape or a belt shape photoreceptor can be used.

For photosensitive drums, small-diameter (40 mm or less in diameter) stacked type
OPC photosensitive drums are preferred in terms of weight reduction of the apparatus and sensitivity to laser beams.

The developing device is a one-component developer (hereinafter simply referred to as “toner”).
A multi-pole permanent magnet 3 inside the developer carrier (development sleeve) 2 that carries a developer carrier 2 (for example, a development sleeve) that carries the surface 5 and rotates in the direction of arrow B.
Is fixed so that it does not rotate. On the surface of the developer carrier 2, a coating layer 10 containing conductive fine particles described later is formed. The thickness of the coating layer 10 is 0.5 μm to 30 μm
(Preferably, 2 to 20 μm). Further, the developing device has a developer accommodating chamber 4 for accommodating the toner 5 and bringing the toner 5 into contact with the surface of the developing sleeve 2. Further, the developing device includes a doctor blade 6 as a member (developer layer thickness regulating member) for regulating the layer of the toner 5 on the surface of the sleeve 2 carried in the developer accommodating chamber 4 to a predetermined thickness. . It is preferable that the distance between the surface of the sleeve 2 and the doctor blade 6 is about 50 μm to 500 μm.

When the developing device configured as described above is activated and the sleeve 2 rotates in the direction of arrow B, the contact friction between the surface of the sleeve 2 and the toner 5 mainly occurs in the developer storage chamber 4.
In the case of normal development, a charge having a polarity opposite to that of the electrostatic latent image on the photosensitive drum 1 is given to the toner 5 and applied to the surface of the sleeve 2. In the case of reversal development, a charge having the same polarity as the electrostatic latent image is applied to the toner 5. The toner layer applied to the surface of the sleeve further has a doctor blade 6 disposed opposite to one magnetic pole (S pole in the figure) of the multipolar permanent magnet 3.
More uniform and thin layer (toner layer thickness is about 30μm ~ 300μ)
m), the photosensitive drum 1 and the sleeve 2
And is transported to the developing area formed by

In the developing area, the toner 5 on the sleeve 2 is moved toward the photosensitive drum while applying a bias such as an AC bias or a pulse bias between the sleeve 2 and the surface of the photosensitive drum 1.

Here, the coating layer 10 formed on the surface of the sleeve 2 will be described.

As the coating layer 10, a film-forming polymer material containing conductive fine particles is used. 120Kg /
It is preferable that the resistance after pressurizing with cm ² be 0.5 Ω · cm or less.

As the conductive fine particles, carbon fine particles, a mixture of carbon fine particles and crystalline graphite, or crystalline graphite is preferable. The conductive fine particles have a particle size of 0.005 to 1
Those having 0 μm are preferred.

The crystalline graphite used in the present invention can be roughly classified into natural graphite and artificial graphite. Artificial graphite is obtained by solidifying pitch coke with a binder such as tar pitch.
After firing at about 1200 ° C, put it in a graphitization furnace. 2300 ℃
It is prepared by growing at high temperatures to grow carbon crystals to graphite. Natural graphite is produced from underground, completely graphitized by natural geothermal heat and underground high pressure for a long time. Since these graphites have various excellent properties, they have wide industrial applications. Graphite is a very soft, lubricious crystalline mineral with a dark gray to black luster,
Has heat resistance and chemical stability. The crystal structure includes a hexagonal crystal and others belonging to a rhombohedral system, and has a layered structure. Regarding electrical properties, free electrons exist between carbon and carbon bonds, and have good electrical conductivity. The graphite used in the present invention may be natural or artificial.

The graphite used in the present invention has a particle size of 0.5 μm to 10 μm.
m is preferred.

The film-forming polymer material is, for example, a thermoplastic resin such as a styrene resin, a vinyl resin, a polyether sulfone resin, a polycarbonate resin, a polyphenylene oxide resin, a polyamide resin, a fluororesin, a cellulose resin, and an acrylic resin; A thermosetting resin such as a resin, a polyester resin, an alkyd resin, a phenol resin, a melamine resin, a polyurethane resin, a urea resin, a silicone resin, and a polyimide resin or a photocurable resin can be used. Among them, silicone resins, those with release properties such as fluororesins, or polyether sulfone,
Polycarbonate, polyphenylene oxide, polyamide, phenolic resin, polyester, polyurethane,
Those having excellent mechanical properties such as styrene resins are more preferable. Particularly, a phenol resin is preferable.

Amorphous carbon, such as conductive carbon black, is generally defined as an aggregate of crystallites formed by burning or pyrolyzing a compound containing hydrocarbons or carbon in an insufficient air supply. Have been. In particular, it is excellent in electric conductivity, and can be filled with a polymer material to impart conductivity, or a certain degree of conductivity can be obtained by controlling the amount of addition.

The conductive amorphous carbon used in the present invention has a particle diameter of 5 to 100 μm, preferably 10 to 80 mμ, and more preferably 15 to 40 mμ.

It is preferable to use 3 to 20 parts by weight of the conductive fine particles per 10 parts by weight of the resin component.

When carbon fine particles and graphite particles are used in combination, it is preferable to use 1 to 50 parts by weight of carbon fine particles per 10 parts by weight of graphite.

The deposition resistivity of the resin coat layer of the sleeve in which the conductive fine powder is dispersed is preferably 10 ^{−6 to} 10 ⁶ Ω · cm.

Next, the developer used in the above-described developing device will be described.

Next, the toner used in the developer of the present invention will be described.
It is necessary to precisely control the molecular weight distribution of the binder resin used in the toner used in the present invention.

The THF-insoluble content is preferably 10 to 70 wt%, and the ratio of the component having a molecular weight of 10,000 or less in the GPC of the THF-soluble component is 10%.
~ 50 wt% is good, preferably 20-39 wt%. In order to obtain sufficient performance, the molecular weight should be 2,000 or more to 15,000
Less than 0, preferably 2,000 to 10,000 (more preferably 2,
000-8,000) and a molecular weight of 15,0
It is preferable that there is a peak or shoulder in the region of 100 to 100,000 (preferably 20,000 to 70,000).

When the ratio of the component having a molecular weight of 10,000 or less exceeds 50% by weight,
In the step of applying the toner on the developer carrying member, the toner tends to adhere to the device, and the tendency is more remarkable when the THF-insoluble content is less than 10% by weight.

When the THF-insoluble content exceeds 70% by weight, the strength of the developer itself becomes too large, and the surface of the developer carrier may be damaged, and as a result, adhesion to the apparatus may be promoted. The tendency is that when the proportion of components with a molecular weight of 10,000 or less is less than 10 wt%,
It gets even bigger.

As described above, the molecular weight distribution of the binder resin as described above is preferable in order not to cause a problem due to fusing as a toner for hot-melt fixing.

The THF-insoluble component in the present invention indicates the weight ratio of the polymer component (substantially crosslinked polymer) insoluble in the THF solvent in the resin composition in the toner, and indicates the weight ratio of the resin composition containing the crosslinkable component. It can be used as a parameter indicating the degree of crosslinking. The THF-insoluble matter is defined by a value measured as follows.

0.5 to 1.0 g of the toner sample is weighed (W ₁ g), placed in a cylindrical filter paper (for example, No.86R made by Toyo Filter Paper), subjected to a Soxhlet extractor, extracted with 100 to 200 ml of THF as a solvent for 6 hours, and extracted with a THF solvent. After evaporating the extracted soluble component, it is vacuum-dried at 100 ° C. for several hours, and the amount of the THF-soluble resin component is weighed (W ₂ g). The weight of a component other than the resin component such as a magnetic substance or a pigment in the toner is defined as (W ₃ g). The THF-insoluble content is obtained from the following formula.

In the present invention, the peak or / and shoulder molecular weight of a chromatogram by GPC (gel permeation chromatography) are measured under the following conditions.

The column was stabilized in a heat chamber at 40 ° C., and THF (tetrahydrofuran) was passed through the column at this temperature as a solvent at a flow rate of 1 ml / min.
~ 0.6% by weight of the resin THF sample solution adjusted to 50-200μ
Inject and measure. When measuring the molecular weight of a sample,
The molecular weight distribution of the sample was calculated from the relationship between the logarithmic value of the calibration curve prepared from several types of monodisperse polystyrene standard samples and the count number. Examples of the standard polystyrene sample for the action of the calibration curve include those manufactured by Pressure Chemical Co. or Toyo Soda Kogyo having a molecular weight of 6 × 10 ² , 2.1 × 10 ³ , 4 × 10 ³ , 1.
75 × 10 ⁴ , 5.1 × 10 ⁴ , 1.1 × 10 ⁵ , 3.9 × 10 ⁵ , 8.6 × 10 ⁵ ,
It is suitable to use 2 × 10 ⁶ and 4.48 × 10 ⁶ , and to use at least about 10 standard polystyrene samples. An RI (refractive index) detector is used as the detector.

As a column, a plurality of commercially available polystyrene gel columns are preferably combined in order to accurately measure a molecular weight region of 10 ³ to 4 × 10 ⁶ . For example, μ-styragel 5 manufactured by Waters
00, 10 ³ , 10 ⁴ , 10 ⁵ combinations and Showa Denko shod
exKF-80M or a combination of KF-802, 803, 804, 805, or TSKgel G1000H, G2000H, G2500H, G3000 manufactured by Toyo Soda
Preferred are combinations of H, G4000H, G5000H, G6000H, G7000H, and GMH.

The weight% of the binder resin having a molecular weight of 10,000 or less according to the present invention is obtained by cutting out the molecular weight of 10,000 or less in the chromatogram by GPC, calculating the weight ratio with the cutting weight having a molecular weight of 10,000 or more, and using the above-described weight% of the THF-insoluble portion, The weight% based on the binder resin is calculated.

In the present invention, a magnetic toner containing a magnetic material is used as the toner. As the magnetic substance contained in the magnetic toner, it is preferable to select a magnetic substance having a good dispersion with respect to a binder resin having a THF-insoluble component. The high density value of the magnetic material is preferably 0.35 g / ml or more, preferably 0.6 g / ml or more, preferably 0.8 g / ml or more, more preferably 0.9 g / ml to 1.5 g.
/ ml range. When the bulk density is less than 0.35 g / ml, the dispersion of the magnetic material in the magnetic toner is not sufficient, causing the magnetic material to be unevenly distributed, and the effect of the binder resin, which has strictly controlled the molecular weight distribution, is sufficient. May not be able to demonstrate.

When the magnetic material is a cubic system, there is a concern that the coating layer on the surface of the developing sleeve and the surface of the photoreceptor may be damaged because the shape is angular, and a spherical magnetic material is preferable.

As a method for increasing the bulk density of the magnetic material, a method of treating with a device such as a fret mill is exemplified.

In this specification, the bulk density (g / cc) refers to a value measured according to JIS (Japanese Industrial Standard) K = 5101.

The spherical magnetic material preferably has a remanence (σγ) of 5 emu / g or less and a coercive force (Hc) of 100 oersted (Oe) or less.

The content of the magnetic substance is preferably from 10 to 70% by weight based on the weight of the magnetic toner.

Resin composition in the toner of the present invention, styrenes,
Those obtained by polymerizing one or more monomers selected from acrylic acids, methacrylic acids and derivatives thereof are preferred from the viewpoint of developing characteristics and charging characteristics. Examples of monomers that can be used include styrenes such as styrene, α-methylstyrene, vinyltoluene, and chlorostyrene. Examples of acrylic acids, methacrylic acids and derivatives thereof include acrylic acid, methyl acrylate, ethyl acrylate, propyl acrylate, butyl acrylate, octyl acrylate, 2-ethylhexyl acrylate, n-tetradecyl acrylate, and n-acrylate. Acrylates such as hexadecyl, lauryl acrylate, cyclohexyl acrylate, diethylaminoethyl acrylate, dimethylaminoethyl acrylate; methacrylic acid, methyl methacrylate, ethyl methacrylate, propyl methacrylate, butyl methacrylate, methacrylic Amyl acrylate, hexyl methacrylate, 2-ethylhexyl methacrylate, octyl methacrylate, decyl methacrylate, dodecyl methacrylate, lauryl methacrylate,
Cyclohexyl methacrylate, phenyl methacrylate,
2-hydroxyethyl methacrylate, 2-methacrylic acid 2-
Examples include methacrylates such as hydroxypropyl, dimethylaminoethyl methacrylate, glycidyl methacrylate, and stearyl methacrylate. In addition to the above-mentioned monomers, a small amount of acrylonitrile, 2-vinylpyridine, 4-vinylpyridine, vinylcarbazole, vinylmethylether, as long as it does not adversely affect the present invention,
Monomers such as butadiene, isoprene, maleic anhydride, maleic acid, maleic acid monoesters, maleic acid diesters, and vinyl acetate may be used.

As the crosslinking agent used in the toner of the present invention, divinylbenzene, bis (4-acryloxypolyethoxyphenyl) propane, ethylene glycol diacrylate, 1,3-butylene glycol diacrylate, 4-butanediol diacrylate, 1,5
-Pentanediol diacrylate, 1,6-hexanediol diacrylate, neopentyl glycol diacrylate, diethylene glycol diacrylate, triethylene glycol diacrylate, tetraethylene glycol diacrylate, polyethylene glycol # 20
0, # 400, # 600 diacrylate, dipropylene glycol diacrylate, polypropylene glycol diacrylate, polyester type diacrylate (MANDA
Nippon Kayaku) and those obtained by replacing the above diacrylate with methacrylate.

Pentaerythritol triacrylate, trimethylolethane triacrylate, trimethylolpropane triacrylate, tetramethylolmethanetetraacrylate, oligoester acrylate and its methacrylate, 2,2-bis (4-methacryloxy, polyethoxyphenyl) as polyfunctional crosslinking agents Examples include propane, diallyl phthalate, trialcyanurate, triallyl isocyanurate, triallyl trimellitate, and diarylchlorendate.

In the present invention, an uncrosslinked or crosslinked first vinyl (preferably styrene) polymer or copolymer,
It is preferable to use a resin composition containing a crosslinked second vinyl (preferably styrene) polymer or copolymer as a binder resin.

The method for synthesizing the binder resin according to the present invention is basically preferably a method for synthesizing two or more polymers or copolymers.

In this method, a first polymer or copolymer soluble in THF and soluble in a polymerizable monomer is dissolved in the polymerizable monomer, and the monomer is polymerized to obtain a resin composition. In this case, a composition is formed in which the former and the latter polymers or copolymers are uniformly mixed.

The first polymer or copolymer soluble in THF is preferably solution polymerization or ionic polymerization. The second polymer or copolymer for producing a component insoluble in THF may be a suspension polymerized or bulk polymerized in the presence of a crosslinkable monomer under conditions in which the first polymer or copolymer is dissolved. It is preferable to synthesize with. The first polymer or copolymer is a second polymer or copolymer.
Polymerizable monomer for producing a polymer or copolymer of
It is preferable to use 10 to 120 (preferably 20 to 100 parts by weight) parts by weight based on 100 parts by weight.

Examples of the magnetic substance contained in the magnetic toner of the present invention include a compound of iron oxide or a divalent metal such as magnetite, hematite, and ferrite with iron oxide; iron, cobalt, a metal such as nickel, or a metal such as these and aluminum; Cobalt copper, lead, magnesium, tin, zinc, antimony,
Alloys with metals such as perylium, bismuth, cadmium, calcium, manganese, selenium, titanium, tungsten, vanadium and mixtures thereof.

The following substances control the chargeability of the toner.

Nitrohumic acid and its salt described in JP-A-50-133338 or a face wash such as CI14645;
-42752, JP-B-58-41508, JP-B-58-73
No. 84, salicylic acid, naphthoic acid, dicarboxylic acids described in JP-B-59-7384, Zn, Al, Co, C
r, metal complex of Fe, sulfonated copper phthalocyanine pigment, styrene oligomer into which nitrile group and halogen are introduced, chlorinated paraffin, etc. In particular, from the viewpoint of dispersibility, a metal complex salt of a monoazo dye, a metal complex of salicylic acid, a metal complex of alkylsalicylic acid, a metal complex of naphthoic acid, and a metal complex of dicarboxylic acid are preferable.

The toner of the present invention can provide good results even when additives are mixed as necessary. Examples of the additives include a lubricant, an abrasive, a fluidity-imparting agent, an anti-caking agent, a conductivity-imparting agent, a fixing aid, and an anti-offset agent.

Examples of the lubricant include fine powders of materials such as Teflon, zinc stearate, and polyvinylidene fluoride, and among them, fine powder of polyvinylidene fluoride is preferable.

Examples of the abrasive include fine powder of a material such as cerium silicon carbide and strontium titanate. Among them, strontium titanate fine powder is preferable.

Examples of the fluidity-imparting agent include fine powders of materials such as colloidal silica, hydrophobic colloidal silica, and aluminum oxide. Among them, hydrophobic colloidal silica is preferable.

Examples of the conductivity-imparting agent include fine powders of materials such as carbon black, zinc oxide, antimony oxide, and tin oxide.

Examples of the fixing aid or the anti-offset agent contained in the toner particles include low molecular weight polyethylene, low molecular weight polypropylene, and various waxes.

A small amount of white fine particles and black fine particles having a polarity opposite to that of the toner particles with respect to the triboelectricity can be used as a developing property improver.

As the above-mentioned hydrophobic colloidal silica, hydrophobic colloidal silica treated with silicone oil or silicone varnish is preferable.

The silicone oil or silicone varnish used in the present invention is generally represented by the following formula, [R: C _1-3 alkyl group R ′: Silicon oil modified group such as alkyl, halogen-modified alkyl, phenyl, modified phenyl R ″: C _1-3 alkyl group or alkoxy group] For example, dimethyl silicone oil, alkyl Modified silicone oil, α-methylstyrene-modified silicone oil, chlorophenyl silicone oil, and fluorine-modified silicone oil are exemplified.

The above silicone oil preferably has a viscosity at 25 ° C. of about 50 to 1000 centistokes. Silicone oil having a molecular weight that is too low may generate volatile components due to heat treatment or the like. If the molecular weight is too high, the viscosity becomes too high and the processing operation becomes difficult.

A known technique can be used for the method of treating the silicone oil. For example, the colloidal silica fine powder and the silicone oil may be directly mixed using a mixer such as a Henschel mixer, or a method of spraying a base silica hen silicone oil. After dissolving or dispersing the silicone oil in a suitable solvent,
After mixing with the base silica fine powder, the solvent may be removed to form hydrophobic silica.

It is more preferable that the inorganic fine powder used in the present invention is first treated with a silane coupling agent and then treated with silicone oil or silicone varnish.

In general, only the silicone oil treatment requires a large amount of silicone oil to cover the surface of the fine powder, which tends to cause agglomeration of the fine powder during processing, and that when applied to a developer, the fluidity of the developer may be deteriorated. It is necessary to pay close attention to the processing steps of silicone oil. Therefore, in order to remove the aggregates of the fine powder while maintaining good moisture resistance, it is better to treat the fine silica powder with a silane coupling agent and then treat it with silicone oil, so that the effect of treating the silicone oil can be sufficiently exhibited. That's what it means.

The silane coupling agent used in the present invention is hexamethyldisilazane or a general formula For example, typically represented by dimethyldichlorosilane, trimethylchlorosilane, allyldimethylchlorosilane, allylphenyldichlorosilane, benzyldimethylchlorosilane, vinyltriethoxysilane, γ-methacryloxypropyltrimethoxysilane, Vinyl triacetoxysilane, divinylchlorosilane, dimethylvinylchlorosilane and the like can be mentioned.

The silane coupling agent treatment of the fine powder is performed by a dry process in which a vaporized silane coupling agent is reacted with a cloud of the fine powder by stirring, or a drop reaction of the silane coupling agent by dispersing the fine powder in a solvent. It can be treated by a wet method.

The treatment amount of the silicone oil or silicone varnish in the present invention is preferably 1 to 35 parts by weight, more preferably 2 to 30 parts by weight, based on 100 parts by weight of the inorganic fine powder. If the treatment amount of silicone oil or silicone varnish is too high, the moisture resistance is not improved, and the fine powder may absorb moisture under high humidity, and a high-quality copy image may not be obtained. If the processing amount of silicone oil or silicone varnish is too large, aggregates of inorganic fine powders are likely to be formed, and moreover, free silicone oil or silicone varnish is formed, so that when applied to a developer, fluidity is improved. May not be possible.

The hydrophobic colloidal silica is preferably used in an amount of 0.1 to 3.0 (preferably 0.6 to 1.6) parts by weight based on 100 parts by weight of the toner.

As a method for producing the toner, a method in which the constituent materials are thoroughly kneaded by a hot kneader such as a hot roll kneader or an extruder, and then obtained by mechanical pulverization and classification: after dispersing the materials in a binder resin solution, spray drying A method of obtaining a toner by mixing a predetermined material with a monomer to form a binder resin to form an emulsion suspension and then polymerizing the emulsion.

Further, the image forming method and apparatus of the present invention will be described with reference to FIG.

A primary charger 217 charges the surface of the OPC photosensitive member to a negative polarity, forms a digital electrostatic latent image by image scanning by exposure to a laser beam 705, includes a magnetic blade 6 and a magnet, and contains conductive fine particles. Developing device 21 having a developing sleeve 2 covered with a resin coating layer
The latent image is reversely developed with one one-component magnetic developer 5. In the developing section, the conductive base of the photosensitive drum 1 and the developing sleeve 2
Between, alternate bias by the bias applying means 712,
A pulse bias and / or a DC bias is applied. When the transfer paper P is conveyed and reaches the transfer section, the transfer means 70
The developing image (toner image) on the surface of the photosensitive drum is electrostatically transferred onto the transfer paper P by charging the transfer paper P from the back surface (the surface opposite to the photosensitive drum side) by the voltage applying means in Step 2. The transfer paper P separated from the photosensitive drum 1 is subjected to a fixing process to fix a toner image on the transfer paper P by a heating / pressing roller fixing device 707.

The one-component developer remaining on the photosensitive drum after the transfer process is transferred to a cleaning device 708 having a cleaning blade.
Is removed by After the cleaning, the photosensitive drum 2 is gradually charged by the erase exposure 706, and the process starting from the charging process by the primary charger 217 is repeated again.

The electrostatic latent image carrier (photosensitive drum) has a photosensitive layer and a conductive substrate, and moves in the direction of the arrow. A non-magnetic cylindrical developing sleeve 2 as a developer carrier rotates in the developing section so as to advance in the same direction as the surface of the electrostatic latent image carrier. Inside the non-magnetic cylindrical sleeve 2, a multi-pole permanent magnet (magnet roll) as a magnetic field generating means is arranged so as not to rotate. The one-component insulating magnetic developer 5 in the developer accommodating chamber 212 of the developing device 211 is applied on a non-magnetic cylindrical surface, and the toner particles are formed by friction between the surface of the sleeve 2 having the coating layer and the toner particles. For example, a negative tribo charge is provided. Further, the thickness of the developer layer is reduced (30 μm to 30 μm) by disposing an iron magnetic doctor blade 6 close to the cylindrical surface (interval: 50 μm to 500 μm) and opposed to one magnetic pole position of the multipole permanent magnet. 300 μm) and uniformly regulated, and the electrostatic image carrier 1 and the developing sleeve 2 in the developing section
Is formed so as to be non-contact. By adjusting the rotational speed of the developing sleeve 2, the surface speed of the sleeve is substantially equal to or close to the speed of the electrostatic image holding surface. A counter electrode may be formed by using a permanent magnet instead of iron as the magnetic doctor blade 6. In the developing section, an AC bias or a pulse bias may be applied between the developing sleeve 2 and the electrostatic latent image carrier by the bias means 712. As for this AC bias, f is 200 ~ 4,000Hz, Vpp is 500 ~
3,000V is fine.

When the toner particles are transferred in the developing section, the toner particles are transferred to the electrostatic image side due to the electrostatic force of the electrostatic image holding surface and the action of the AC bias or the pulse bias.

Instead of the magnetic doctor blade 6, an elastic blade made of an elastic material such as silicone rubber is used as a developer layer thickness regulating member to regulate the layer thickness of the developer layer by pressing, so that the developer is placed on the developer carrier. May be applied.

When the image forming apparatus of the present invention is used as a facsimile printer, the light image exposure L is an exposure for printing received data. FIG. 3 is a block diagram showing an example of this case.

The controller 511 controls the image reading unit 510 and the printer 519. The whole controller 511 is controlled by the CPU 517. The read data from the image reading unit is sent to the transmission circuit
It is transmitted to the partner station through 513. Data received from the partner station is sent to the printer 519 through the receiving circuit 512.
Predetermined image data is stored in the image memory. The printer controller 518 controls the printer 519. 51
4 is a telephone.

The image received from the line 515 (image information from a remote terminal connected via the line) is demodulated by the receiving circuit 512, and then the CPU 517 performs a decoding process of the image information and is sequentially stored in the image memory 516. You. When at least one page of the image is stored in the memory 516, the image of the page is recorded. The CPU 517 reads out one page of image information from the memory 516 and sends out the decoded one page of image information to the printer controller 518. When receiving the image information of one page from the CPU 518, the printer controller 518 prints out the image information of the page.
Control 9

The CPU 517 is receiving the next page during recording by the printer 519.

 As described above, image reception and recording are performed.

As an electrophotographic apparatus, a plurality of components, such as an electrostatic latent image carrier such as the above-described photosensitive drum, a developing device, and a cleaning unit, are integrally connected as a device unit, and the unit is configured as a device main body. May be configured to be detachable with respect to. For example, a unit is formed by integrally supporting at least one of the charging unit, the developing device, and the cleaning unit together with the photosensitive drum, and the unit is detachably attached to the apparatus main body. It may be configured to be detachable. At this time, the above-described device unit may be provided with a charging unit and / or a developing device.

Hereinafter, synthesis examples of the binder resin according to the present invention will be described.

(Synthesis Example 1) 200 parts by weight of cumene was charged into a reactor and heated to a reflux temperature. A mixture of 100 parts by weight of styrene monomer and 6.5 parts by weight of benzoyl peroxide was added dropwise thereto over 4 hours under reflux of cumene. Furthermore, under cumene reflux (146 ° C-1
(56 ° C.) to complete the solution polymerization and remove cumene. The obtained polystyrene is soluble in THF, the molecular weight at which the main peak of GPC is located is 4,000, and the glass transition point (Tg) is 57 ° C.
Met.

30 parts by weight of the above polystyrene was dissolved in the following monomer mixture to prepare a mixed solution.

Polyvinyl alcohol partially saponified in the above mixed solution 0.
170 parts by weight of water in which 1 part by weight was dissolved was added to obtain a suspension dispersion. The above suspension dispersion was added to a reactor filled with 15 parts by weight of water and purged with nitrogen, and a suspension polymerization reaction was performed at a reaction temperature of 70 to 95 ° C. for 6 hours. After completion of the reaction, the mixture was filtered off, dehydrated and dried to obtain a composition of polystyrene and styrene-n-butyl acrylate copolymer. In the composition, the THF-insoluble component and the THF-soluble component were uniformly mixed, and the polystyrene and the styrene-n-butyl acrylate copolymer were uniformly mixed. The obtained resin composition was made into a powder of 24 mesh pass, 60 mesh on, and about 0.5 g was precisely weighed and cylindrical filter paper No.86R made by Toyo Filter Paper (diameter 28).
mm, 100 mm in length), and 200 ml of THF was refluxed once every about 4 minutes to measure the insoluble matter in THF. THF in resin composition
The insoluble content was 24% by weight.

When the molecular weight distribution of the THF-soluble component was measured, the GPC chart had peaks at about 4500 and about 41,000,
The molecular weight was less than 10,000 and 28% by weight. Further, the glass transition point (Tg) of the resin composition was 56 ° C.

Characteristics relating to the molecular weight of each resin and resin composition were measured by the following method.

Using Shodex KF-80M as a column for GPC measurement, the GPC measurement device (150CALC / GPC manufactured by Waters Corporation) was incorporated into a heat chamber at 40 ° C and the THF flow rate was 1 ml / min. Concentration of about 0.1% by weight)
GPC was measured by injection. As the calibration curve of the molecular weight measurement, the molecular weight is 0.5 × 10 ³ , 2.35 × 10 ³ , 10.2 × 10 ³ , 35 × 10
³ , 110 × 10 ³ , 200 × 10 ³ , 470 × 10 ³ , 1200 × 10 ³ , 2700 ×
A THF solution of 10 ³ and 8420 × 10 ³ monodisperse polystyrene standard substances (manufactured by Waters) was used.

(Synthesis Example 2) According to the same production method as in Synthesis Example 1, only the polymerization temperature was adjusted to obtain TH.
The peaks in the GPC chart of the F-insoluble content of 32 wt% and the THF-soluble content are at about 4,800 and about 52,000, and the molecular weight of 10,000 or less is 32%.
, A homogeneous mixture of polystyrene and styrene-n-butyl acrylate copolymer was obtained. Tg of homogeneous mixture is 60
° C.

(Synthesis Example 3) 150 parts by weight of cumene was charged into a reactor and heated to a reflux temperature. The following mixture was added dropwise over 4 hours under cumene reflux.

Further, the polymerization was completed under cumene reflux (146-156 ° C),
Cumene was removed. The obtained styrene-acrylic acid n-
The butyl copolymer had a main peak at a position of a molecular weight of 2,200, and had a Tg of 56 ° C.

35 parts by weight of the styrene-n-butyl acrylate copolymer was dissolved in the following monomer mixture to prepare a mixture.

Polyvinyl alcohol partially saponified 0.1 to the above mixture
170 parts by weight of water in which parts by weight were dissolved were added to obtain a suspension dispersion.

The above dispersion was added to a reactor filled with 15 parts by weight of water and purged with nitrogen, and reacted at a reaction temperature of 70 to 95 ° C. for 6 hours. After completion of the reaction, the mixture was filtered, dehydrated and dried, and styrene-acrylic acid n-
A homogeneous mixed composition of a butyl copolymer and a styrene-n-butyl methacrylate copolymer was obtained.

The obtained resin composition has a THF insoluble content of 18 wt% and a THF soluble content of
The peak in the GPC chart is about 3200 and about 28,000,
The molecular weight of 10,000 or less was 35 wt% and Tg was 54 ° C.

(Comparative synthesizer 1) By adjusting only the polymerization temperature in the same production method as in Synthesis example 3, THF
The peak positions in the GPC chart of the insoluble content 8wt% and the THF soluble content are about 1700 and about 22,000, and the molecular weight of 10,000 or less is 57wt.
%, And a resin composition having a Tg of 51 ° C. was obtained.

Hereinafter, specific examples will be described. Parts in each example are parts by weight.

Reference Example 1-100 parts of the resin composition of Synthesis Example 1-60 parts of spherical magnetite (bulk density: 1.0 g / ml)-1 part of monoazo Cr-based complex-3 parts of low molecular weight polypropylene 3 parts are uniformly mixed, then kneaded and crushed And classified to obtain a negatively chargeable magnetic toner having a weight average particle diameter of 12 μm.

0.4 part of hydrophobic colloidal silica fine powder was added to and mixed with 100 parts of the magnetic toner to prepare a developer having a magnetic toner to which hydrophobic colloidal silica fine powder was externally added.

Laser beam printer made by Canon (trade name LBP-S
X) The aluminum developing sleeve of the developing device is applied to the surface of the aluminum developing sleeve by a volume average particle diameter of 7 μm.
1 part by weight of conductive graphite particles and phenolic resin 1
It created a laser beam printer modified machine and replace the cover the developing sleeve having a coating layer comprising a composition of the weight portion (thickness 6.5 [mu] m, a volume resistivity of 10~10 ³ Ω · cm). Note that, similarly to the LBP-SX, a multi-pole permanent magnet 3 as shown in FIG. 1 is fixed in the developing sleeve so as not to rotate.

The developer was placed in a developer storage chamber of a developing device of a laser beam printer modified machine, and an image output test of 3,000 sheets was performed.

 The development conditions are shown below.

・ The closest gap between the laminated OPC photosensitive drum and the coated developing sleeve (including the fixed magnet): about 300 μm ・ The gap between the magnetic blade and the coated developing sleeve: about 250 μ
m ・ Thickness of magnetic toner layer on coated developing sleeve: about 130μ
m ・ Developing bias: AC bias (Vpp1600V, frequency 1800
Hz) and DC bias (-390V) room temperature room temperature (20 ℃, 60%
RH), high temperature and high humidity (32.5 ℃, 90% RH), low temperature and low humidity (15 ℃,
10% RH) environment-free, and
A good toner image without sleeve memory could be obtained.

Further, while image replenishment was performed on 5,000 sheets while replenishing the developer, a satisfactory image without any problem was obtained. No toner sticking or scratching was observed on the surface of the coated developing sleeve.

Reference Example 2 A developer was obtained in the same manner as in Reference Example 1 except that the resin composition obtained in Synthesis Example 2 was used instead of the resin composition in Synthesis Example 1, and an image formation test similar to that in Reference Example 1 was performed. Done.

A good image without any problem could be obtained. When the coated developing sleeve was observed after 5,000 sheets of image were formed, slight damage was observed on the surface of the sleeve, but it did not appear in the toner image and was at a level that was no problem.

Reference Example 3 A developer was obtained in the same manner as in Reference Example 1 except that the resin composition obtained in Synthesis Example 3 was used instead of the resin composition of Reference Example 1, and an image formation test similar to that of Reference Example 1 was performed. Done.

Good development without problems could be obtained. When the coated developing sleeve was observed after 5,000 sheets of image were formed, a slight amount of the developer was adhered to the surface of the sleeve, but at a level that did not appear in the toner image.

Comparative Example 1 A developer was obtained in the same manner as in Reference Example 1 except that the resin composition obtained in Comparative Synthesis Example 1 was used instead of the resin composition of Reference Example 1, and an image formation test was performed in the same manner as in Reference Example 1. Was performed.

Image defects due to uneven application of the developer on the sleeve occurred after 3,000 sheets in an environment of normal temperature and normal humidity. When the surface of the developing sleeve was observed, a large amount of the developer was fixed.

In a high-temperature and high-humidity environment, an image-defect test was performed. After about 1,500 sheets, image defects due to uneven coating of the developer on the sleeve occurred.

Example 1 Colloidal silica having a specific surface area of 200 m ² / g (Aerosil # 2
100 parts of Nippon Aerosil Co., Ltd.) were treated with 20 parts of hexamethyldisilazane (HMDS), and then treated with 10 parts of dimethyl silicone oil (KF-96 100cS, Shin-Etsu Chemical) diluted with a solvent. After drying, a heat treatment was performed at about 250 ° C. to prepare hydrophobic colloidal silica treated with hexamethyldisilazane and then treated with dimethylsilicone oil.

0.7 part of the prepared hydrophobic colloidal silica and 100 parts of the negatively chargeable magnetic toner prepared in the same manner as in Reference Example 1 were mixed to obtain a developer.

Using the obtained developer, an image output test was performed in the same manner as in Reference Example 1. Due to the lubricating properties of the silicone oil contained in the hydrophobic colloidal silica, the durability on multiple sheets was further improved as compared with the image forming apparatus of Reference Example 1.

Example 2 The developer prepared in Example 1 was supplied to the image forming apparatus shown in FIG. 2, and an image-drawing test was performed in the same manner as in Reference Example 1. The same good results as in Example 1 were obtained.

 The image forming conditions are shown below.

(A) A composition consisting of 8 parts of graphite fine particles (volume average particle diameter 5 μm), 2 parts of conductive carbon fine particles, and 10 parts of phenol resin on the surface of an aluminum developing sleeve used for a laser beam printer (LBP-SX). The coated developing sleeve coated with (approximately 6 μm) is used as the developer carrier 2.

(B) A laminated OPC photosensitive drum having a diameter of 30 mm is used as the electrostatic latent image carrier 1.

(C) An iron blade is used as the blade 6, and the gap between the coating sleeve and the iron blade is set to about 250 μm.

(D) The closest distance between the covering sleeve and the OPC photosensitive drum in the developing area is set to about 300 μm.

(E) An AC bias (Vpp 1600 V, frequency 1800 Hz) and a DC bias of -400 V were applied to the coating sleeve as a developing bias.

(F) The electrostatic latent image is developed by the reversal developing method.

(G) Other settings are the same as those of the laser beam printer (LBP-SX).

〔The invention's effect〕

As described above, in the present invention, in a specific image forming apparatus using a developing device having a developer carrying member on which a coating layer containing a film forming polymer material and conductive fine particles is formed, the specific image forming apparatus according to the present invention is used. By using a one-component developer having a magnetic toner containing a resin composition as a binder resin, generation of scratches on the surface of the developer carrier can be prevented, and the life of the developer carrier can be further maintained. It is possible to provide a good visible image that does not depend on the environment.

[Brief description of the drawings]

FIG. 1 is a schematic sectional view of a developing device according to the present invention. FIG. 2 is a schematic sectional view of the image forming apparatus of the present invention. FIG. 3 is a block diagram showing a specific example of the facsimile apparatus. DESCRIPTION OF SYMBOLS 1 ... Electrostatic latent image carrier 2 ... Developer carrier 3 ... Multipolar permanent magnet 5 ... Toner 10 ... Coating layer containing conductive fine particles

──────────────────────────────────────────────────続 き Continuation of the front page (72) Inventor Manabu Oono 3-30-2 Shimomaruko, Ota-ku, Tokyo Inside Canon Inc. (56) References JP-A-63-100482 (JP, A) JP-A-64 -37574 (JP, A) JP-A-63-223014 (JP, A) (58) Fields investigated (Int. Cl. ⁶ , DB name) G03G 15/08 G03G 9/08

Claims (9)

(57) [Claims] An electrostatic latent image carrier for carrying an electrostatic latent image, a developing device for developing the electrostatic latent image carried on the electrostatic latent image carrier, and the developing device during development An image forming apparatus having a bias applying unit for applying an AC bias or a pulse bias to the image forming apparatus, wherein the developing device includes a one-component developer, a developer storage chamber that stores the one-component developer, A developer carrying member for carrying the one-component developer housed in the developer accommodating chamber and transporting the developer to a developing area; and a one-component developer carried by the developer carrying member. A developer layer thickness regulating member for regulating a layer thickness, wherein the developer carrier is a rotatable aluminum developing sleeve, a magnet fixed in the developing sleeve so as not to rotate, and Coating formed on the surface of the developing sleeve A coating layer containing a synthetic polymer material and conductive fine particles, wherein the developer layer thickness regulating member is a layer of the one-component developer supported on the rotating developer carrier. The one-component developer has a thickness of less than a gap between the electrostatic latent image carrier and the developer carrier in the development area. GPC containing 10-70% by weight and soluble in THF
And a magnetic toner containing a magnetic material and a resin composition in which a component having a molecular weight of 10,000 or less in the molecular weight distribution with respect to the binder resin is contained in the magnetic toner, An image forming apparatus, wherein hydrophobic silica fine powder treated with silicone oil or silicone varnish is externally added. 2. The coating layer contains (i) a phenolic resin as the film-forming polymer material, and (ii) carbon fine particles, graphite fine particles or a mixture of carbon fine particles and graphite fine particles as the conductive fine particles. The image forming apparatus according to claim 1, wherein: 3. The magnetic toner according to claim 1, wherein the magnetic toner contains a magnetic substance having a density of 0.35 g / ml or more based on the weight of the magnetic toner. An image forming apparatus according to claim 1. 4. An apparatus unit detachably mounted on a main body of an image forming apparatus, wherein the apparatus unit carries an electrostatic latent image carrier for carrying an electrostatic latent image and a carrier carried on the electrostatic latent image carrier. A developing device for developing the electrostatic latent image that has been formed, and the developing device is integrally supported together with the electrostatic latent image carrier to form a unit. The developer device is mounted on an image forming apparatus main body having a bias applying unit for applying a pulse bias. The developer device contains a one-component developer and the one-component developer. Developer carrying chamber, a developer carrying body for carrying the one-component developer housed in the developer accommodating chamber and transporting the developer to the developing area, and carried by the developer carrying body. A current method for regulating the layer thickness of the one-component developer An agent layer thickness regulating member, wherein the developer carrier is formed on a rotatable aluminum developing sleeve, a magnet fixed in the developing sleeve so as not to rotate, and a surface of the developing sleeve. A coating layer containing a film-forming polymer material and conductive fine particles, wherein the developer layer thickness regulating member is a one-component type developer supported on the rotating developer carrier. A layer thickness of the developer, which is smaller than a gap between the electrostatic latent image carrier and the developer carrier in the development area, wherein the one-component developer is THF as a binder resin. GPC containing 10-70% by weight of insolubles and soluble in THF
And a magnetic toner containing a magnetic material and a resin composition in which a component having a molecular weight of 10,000 or less in the molecular weight distribution with respect to the binder resin is contained in the magnetic toner, An apparatus unit to which hydrophobic silica fine powder treated with silicone oil or silicone varnish is externally added. 5. The coating layer contains (i) a phenol resin as the film-forming polymer material, and (ii) carbon fine particles, graphite fine particles or a mixture of carbon fine particles and graphite fine particles as the conductive fine particles. The device unit according to claim 4, wherein: 6. The magnetic toner according to claim 4, wherein the magnetic toner contains a magnetic material having a bulk density of 0.35 g / ml or more by 10 to 70% by weight based on the weight of the magnetic toner. An apparatus unit according to item 1. 7. A facsimile apparatus having an electrophotographic apparatus and a receiving means for receiving image information from a remote terminal, wherein the electrophotographic apparatus comprises: an electrostatic latent image carrier for carrying an electrostatic latent image; A developing device for developing the electrostatic latent image carried on the electrostatic latent image carrier; and a bias applying unit for applying an AC bias or a pulse bias to the developing device during development. Is a one-component developer, a developer storage chamber that stores the one-component developer, and carries the one-component developer stored in the developer storage chamber and transports the developer to a development area. And a developer layer thickness regulating member for regulating the layer thickness of the one-component developer carried on the developer carrier. Is a rotatable aluminum developing sleeve, A magnet layer fixed so as not to rotate in the developing sleeve, and a coating layer containing a film-forming polymer material and conductive fine particles formed on the surface of the developing sleeve; The layer thickness of the one-component developer carried on the rotating developer carrier is smaller than the gap between the electrostatic latent image carrier and the developer carrier in the development area. The one-component developer contains 10 to 70% by weight of a THF-insoluble component as a binder resin, and has a GPC of THF-soluble component.
And a magnetic toner containing a magnetic material and a resin composition in which a component having a molecular weight of 10,000 or less in the molecular weight distribution with respect to the binder resin is contained in the magnetic toner, A facsimile machine, wherein hydrophobic silica fine powder treated with silicone oil or silicone varnish is externally added. 8. The coating layer contains (i) a phenol resin as the film forming polymer material, and (ii) carbon fine particles, graphite fine particles or a mixture of carbon fine particles and graphite fine particles as the conductive fine particles. The facsimile apparatus according to claim 7, wherein: 9. The magnetic toner according to claim 7, wherein the magnetic toner contains a magnetic material having a bulk density of 0.35 g / ml or more based on the weight of the magnetic toner. A facsimile apparatus according to claim 1.