JPH04194867A - Developer for electrostatic latent image development, image forming device and device unit - Google Patents

Abstract

PURPOSE:To prevent fading phenomenon from generating to enable formation of uniform developed image by using developer holding body forming the surface layer under a constant condition and developer of specified composition. CONSTITUTION:The surface of a developing sleeve 2 is formed into a coated layer 10 containing conductive fine particle or/and solid lubricant having a thickness of about 0.5-30mum. As conductive fine particle, carbon fine particle is desirable, and as the solid lubricant graphite is desirable. Cutting depth Cv at the time of being 5% relative load length t is determined to be Cv<=5mum in a relative load curve. Developer 5 used is those containing fine particles treated with silicon oil or silicon varnish. Besides, a form sticking the fine particles to the surface of toner particle is desirable. It is possible thereby to prevent fading phenomenon from generating even in high temperature and humidity circumstances and to form uniform developed image.

Description

Detailed Description of the Invention (Technical Field) The present invention relates to a developing device for forming a latent image on an image bearing member such as an electrophotographic photoreceptor or an electrostatic recording dielectric material, and for making the latent image visible. Developers for developing electrostatic latent images, image forming devices,
The present invention relates to a device unit and a facsimile device.

[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 using magnetic toner as a one-component developer has been developed using friction between magnetic toner particles and the developer. A charge of opposite polarity is applied to the magnetic toner particles with respect to the electrostatic image charge and developing group 4 potential formed on the photosensitive drum due to friction between the sleeve as a carrier and the magnetic toner particles, and the magnetic toner is transferred onto the sleeve. The toner is applied in a thin layer and transported to a developing area formed by a photosensitive drum and a sleeve, where the electrostatic latent image on the photosensitive drum is developed by causing the magnetic toner to fly due to the action of a magnetic field from a magnet fixed inside the sleeve. It is known that

However, in the conventional example described above, there is a problem in that when the same image pattern is repeatedly printed, striped areas with low density occur. FIG. 2 shows a schematic diagram of the image. This is a phenomenon in character images where the characters become thinner and the halftone, solid black image texture and density decrease. This phenomenon will be referred to as fading hereinafter.

Further, the above-mentioned fading phenomenon is particularly noticeable in high-temperature environments where the charge of the developer tends to decrease, and a solution to this problem is eagerly awaited.

[Purpose of the invention]

An object of the present invention is to provide a developer for developing an electrostatic latent image, an image forming apparatus, an apparatus unit, and a facsimile apparatus as described above.

The purpose of the present invention is to prevent the occurrence of fading phenomenon,
An object of the present invention is to provide a developer, an image forming apparatus, an apparatus unit, and a facsimile apparatus that can form a uniform developed image.

An object of the present invention is to provide a developer, an image forming apparatus, an apparatus unit, and a facsimile apparatus that can prevent the occurrence of fading in a high-temperature environment and form a uniform developed image.

[Summary of the invention]

The present invention has a surface layer formed of a resin layer containing at least conductive fine particles and/or a solid lubricant,
Relative load curve of the surface of the surface layer (Abbott load curve)
Used in an image forming method in which a developer for developing an electrostatic latent image is conveyed by a developer carrier having a cutting depth Cv of 5 μm or less when the relative load length tp is 5%, and the electrostatic latent image is developed. A developer for developing an electrostatic latent image, characterized in that the developer for developing an electrostatic latent image contains a toner and a fine powder treated with silicone oil or silicone varnish. It relates to a developer for development.

Further, the present invention provides an electrostatic latent image carrier, and a carrier that carries an electrostatic latent image developer for developing the electrostatic latent image and conveys the electrostatic latent image developer to a development area. In an image forming apparatus, the image forming apparatus includes a developing device having a developer carrier for developing an electrostatic latent image, and a developer storage chamber containing a developer for developing an electrostatic latent image. It has a surface layer formed of a resin layer containing at least a lubricant, and the relative load curve of the surface layer (Abbott's load curve)
The cutting depth C52 when the relative load length 1F is 5% is 5 μm or less, and the developer for developing an electrostatic latent image contains toner and fine powder treated with silicone oil or silicone varnish. The present invention relates to an image forming apparatus characterized in that:

Furthermore, the present invention includes an electrostatic latent image carrier and a developing device for developing the electrostatic latent image, and the developing device includes a developer storage chamber containing a developer for developing the electrostatic latent image. and a developer carrier for carrying a developer for developing an electrostatic latent image and transporting the developer for developing an electrostatic latent image to a development area, and the developer carrier includes conductive fine particles or/and and a surface layer formed of a resin layer containing a small amount of solid lubricant, and when the relative load length of the surface layer is 1.5% in the relative load curve (Abbott's load curve). The cutting depth Cv is 5 μm or less, the developer for developing the electrostatic latent image contains toner and fine powder treated with silicone oil or silicone varnish, and the developing device is capable of carrying the latent image. The present invention relates to a device unit characterized in that it is integrally supported with a body to form a unit, and forms a single unit that is detachably attached to the device body.

Further, the present invention provides a facsimile apparatus having a receiving means for receiving image information from an electrophotographic apparatus and a remote terminal, wherein the electrophotographic apparatus includes an electrostatic latent image carrier and a facsimile apparatus for developing an electrostatic latent image. The developing device has a developer storage chamber that stores a developer for developing an electrostatic latent image, and a developer that supports the developer for developing an electrostatic latent image and has a developing area for developing an electrostatic latent image. a developer carrier for transporting a developer, the developer carrier having a surface layer formed of a resin layer containing at least conductive fine particles and/or a solid lubricant; In the relative load curve (Abbott's load curve) of the surface layer, when the relative load length tP is 5%, the cutting depth CV is 5 μm or less, and the developer for developing the electrostatic latent image is composed of toner and silicone oil. or a fine powder treated with silicone varnish.

[Detailed description of the invention]

A developing device used in the image forming apparatus of the present invention will be described.

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

1 in the figure is a photosensitive drum as an electrostatic latent image carrier that carries an electrostatic latent image and rotates in the direction of arrow A. Either one with or without an insulating layer on the surface can be used. Of course, the shape is not limited to a drum shape, but also a sheet shape or a belt shape. Reference numeral 2 denotes a developing sleeve as a developer carrier that carries a developer 5 containing toner on its surface and rotates in the direction of arrow B. A multipolar permanent magnet 3 is fixed inside the sleeve 2 so as not to rotate. has been done. Further, the surface of the developing sleeve 2 is coated with conductive fine particles or/
and the coating layer 10 containing a solid lubricant has a thickness of about 0.5 μm or more
The thickness is 30 μm, preferably 2 μm to 20 μm. Reference numeral 4 denotes a developer storage chamber that stores the developer 5 and brings the developer 5 into contact with the surface of the developing sleeve 2 . 6
is a talker blade as a member that regulates the layer of developer 5 on the surface of the developing sleeve 2 carried in the developer storage chamber 4 to a predetermined thickness, and the gap between the surface of the developing sleeve 2 and the doctor blade 6 is The thickness is approximately 50 μm to 500 μm.

When the developing device configured as described above is started and the developing sleeve 2 rotates in the direction of arrow B, the reference potential for development is reached within the developer storage chamber 4 mainly due to the contact friction between the surface of the developing sleeve 2 and the toner. On the other hand, a charge having a polarity opposite to that of the electrostatic latent image on the photosensitive tram 1 is applied to the toner, and the toner is applied to the surface of the developing sleeve 2.

The developer layer applied to the sleeve surface is further coated into a uniform and thin layer (the layer thickness is approx. 30 μm to 300 μm),
The photosensitive drum 1 and the developing sleeve 2 are conveyed to a developing area.

Furthermore, by applying a bias such as an AC bias or a pulse bias between the developing sleeve 2 and the surface of the photosensitive drum in the developing area, the toner in the developer on the developing sleeve 2 is caused to fly toward the photosensitive drum. You can do it like this.

Here, the coating layer 10 formed on the surface of the developing sleeve
I will explain about it.

The coating 10 used is one in which the coating layer-forming polymer material contains conductive fine particles and/or a solid lubricant.

The conductive fine particles preferably have a resistance value of 05 Ω·cm or less after being pressurized at 120 kg/C.

The conductive fine particles are preferably carphone fine particles, and the solid lubricant is preferably graphite (more preferably crystalline graphite).

Crystalline graphite preferably used in the present invention can be broadly classified into natural graphite and artificial graphite. Artificial graphite is made by hardening pitch coke with tar pitch etc.
After firing at about 00℃, put it in a graphitization furnace and heat it at 2300℃.
By processing at a high temperature of about °C, carbon crystals grow and turn into graphite. Natural graphite is produced from underground after being completely graphitized by natural geothermal heat and high underground pressure over a long period of time. These graphites have various excellent properties and have a wide range of industrial uses.

Graphite is a dark gray to black lustrous, extremely soft and slippery crystalline mineral that is heat resistant and chemically stable.
Excellent lubricity.

The crystal structure is hexagonal and rhombohedral, and has a completely layered structure. Regarding electrical properties, free electrons exist between carbon and carbon bonds, making it a good conductor of electricity. Note that the graphite used in the present invention may be either natural or artificial.

Furthermore, the graphite used in the present invention has a particle size of 0°5 μm.
~10 μm is preferred.

Conductive amorphous carbon is generally defined as "an aggregate of crystallites resulting from the combustion or thermal decomposition of carbon-hydrogen or carbon-containing compounds in the presence of insufficient air supply." In particular, it has excellent electrical conductivity, and is widely used because it can be filled into polymeric materials to impart electrical conductivity, and it is possible to obtain a desired electrical conductivity to some extent by controlling the amount added.

The conductive amorphous carphone used in the present invention preferably has a particle diameter of 5 to 100 mμ, more preferably 10 to 80 mμ, and still more preferably 15 to 4 mμ.
One with a diameter of 0 mμ is good.

The conductive fine particles and/or the solid lubricant have a resin component of 10
It is preferable to use 3 to 20 parts by weight per part by weight.

When using a combination of carphone fine particles and graphite particles, it is preferable to use 1 to 50 parts by weight of carphone fine particles per 10 parts by weight of graphite.

The volume resistivity of the resin coat layer of the sleeve in which conductive fine powder and/or solid lubricant is dispersed is 10-6 to 1.
06Ω·cm is preferable.

Examples of resin components that are coating-forming polymeric materials include:
Styrene resin, vinyl resin, polyether sulfone resin, polycarbonate resin, polyphenylene oxide resin, polyamide resin, fluororesin, cellulose resin,
Use thermoplastic resins such as acrylic resins, epoxy resins, polyester resins, alkyd resins, phenolic resins, melamine resins, polyurethane resins, urea resins, silicone resins, thermosetting resins such as polyimide resins, or photocurable resins. be able to. Among them, those with mold release properties such as silicone resins and fluorocarbon resins, and those with excellent mechanical properties such as polyethersulfone, polycarbonate, polyphenyl oxide, polyamide, phenol, polyester, polyurethane, and styrene resins. is more preferable. In particular, phenolic resins are preferred. Next, the fading phenomenon, which is a problem to be solved by the present invention, will be explained.

If you observe the sleeve when the fading phenomenon occurs, you will find that the toner layer is uniformly formed, so it is a different phenomenon from white spots due to toner shortage or the like. When we measured the amount of charge on the toner on the sleeve (hereinafter referred to as "tribo"), we found that the value was lower than normal. That is, in addition to normally charged toner particles, toner particles that are not sufficiently charged pass through the concentrated magnetic field formed by the plate 6 and magnet 3 in FIG. 1 due to the frictional force received from the sleeve surface, and form a toner layer on the sleeve. form. As a result, the triboelectricity of the toner layer decreases, and even if the photosensitive drum receives an alternating electric field between the photosensitive drum and the sleeve, a portion where the toner does not transfer occurs on the photosensitive drum, resulting in a fade phenomenon. In order to prevent this, it is necessary to increase the triboelectricity of the toner in the developer layer.

That is, when the toner passes through the concentrated magnetic field formed by the magnetic plate 6 and the magnet 3, the toner passes through the concentrated magnetic field only by the reflection force acting between the toner and the sleeve, regardless of the frictional force received from the sleeve surface. The developer layer can be formed using toner having a normal trigonometric force with a large mirroring force, and the problem of fade phenomenon can be prevented.

In order to reduce the friction on the sleeve surface and increase the slipperiness, it has been used to define the sleeve surface roughness. Center line average roughness Ra (JIS standard (BO601)
Reducing the value of Ra (hereinafter referred to as Ra) alone cannot be expected to have a reliable effect; rather, reducing Ra causes problems such as insufficient coating amount of toner in the developer on the sleeve.

The sleeve of the present invention is produced by coating the surface of a drawn aluminum pipe (surface roughness 2S) with a prepared solution such as the following formulation example to a thickness of about 05 to 30 μm by spraying, and then drying it in a drying oven. The coating treatment can be carried out by heat curing at 150 degrees Celsius or the like.

(Formulation Example 1) (Formulation Example 2) A resin coated sleeve is created through the steps described above. However, using only the above steps, it is difficult to reduce the cutting depth Cv to 5 μm or less when the relative load length tP is 5%. Therefore, a surface polishing process is added to the sleeve on the surface of the resin coating layer at the end. This is effective. For example, one may include a surface polishing process using felt. This polishing process will be explained by giving an example. After the drying process, the coated sleeve is
The felt is brought into contact with a pressure of about 1 to 3 kg while rotating at about r, p, and m. Polishing is completed by moving this felt in the longitudinal direction of the covering sleeve at a speed of 1 to 5 cm/sec from one end to the other. The polishing method is not limited to this, and it is also possible to use cloth, rags, etc., and it is also possible to polish directly by hand without rotating the sleeve. The covering sleeve used in the present invention is prepared in the manner described above.

Next, the relative load curve on the sleeve surface will be explained.

FIG. 3 shows the profile (cross-sectional curve) of the sleeve surface per reference length and the corresponding relative load curve (Abbott load curve). The relative load curve is the standard length L
(2.5 mm), the average line of this standard length section is parallel to the standard length by a straight line at a certain level (the distance from the highest peak of the standard length section to this level is called the cutting depth Cv). When a section is cut, the ratio of the length of the cut line segment r, +Z2...+la and the reference length is called the relative load length tP at that level (cut depth), A relative load curve is a graph of the relationship between the cuttic depth and the relative load length.

In Fig. 3, relative load length tp is 5%, e++
l12 jp': -X 100=5%, and the cutting depth at that time is C1.5.

In this example, the surface roughness measuring device 5E-30HKosak
a Laboratory Ltd.

Made in Japan. In the present invention, focusing on the cut and ink depth C1 when the relative load length tp is 5% in the relative load curve, C1, ≦5 μm (preferably 0.5 μm).
5 to 5 μm) to prevent fading from occurring.

Here, while the cutting depth Cv value when the relative load length is tp5% is related to the occurrence rate of fading, the center line average roughness Ra is not unconditionally related to the occurrence rate of fading. Explain why.

FIG. 4 is a profile schematically showing a part of the surface of coated sleeve A (comparative example), and Cv5 is 10 μm.
and Ra is 2.5 μm. - On the other hand, the surface of the coated sleeve is polished and the Cv5 is 1.0μ.
m, and Ra is 20 μm. Coated sleeve B (invention) was prepared.

A profile schematically showing a portion of the surface of the covering sleeve B is shown in FIG.

Comparing sleeves A and B, the value of C1 is 10μ
There was a large change from m to 1.0μm, but Ra was 2.5μm.
m to 20 μm, which does not change much. The difference between the covering sleeves A and B is obvious when looking at their profiles. Coated sleeve A has a sharp profile with large roughness, so both Cv5 and Ra take large values, but coated sleeve B has small protrusions on its profile because it is rounded by surface polishing, so C1 and 5 have small values. becomes.

However, since the concave portion of the covering sleeve B remains as it is, Ra remains at a relatively large value. Concerning the fading phenomenon, the covering sleeve A has a sharp protrusion, and the sleeve surface is slippery (the fading phenomenon occurred).The covering sleeve B has a rounded protrusion, so the sleeve surface is slippery. No fading phenomenon occurred.

As described above, it has been found that by defining the CVS value of the surface of the covering sleeve, it is possible to improve the slipperiness of the surface of the covering sleeve and prevent the occurrence of fading.

The data for Covering Sleeve A and Covering Sleeve B are shown in the foot table.

(Hereinafter, blank space) As described above, by setting the Cvs value to CV≦5 μm, it is possible to prevent the occurrence of fading. Also,
Set the C1,5 value to 01. It is effective to polish the sleeve surface to make it ≦5 μm.

As mentioned above, Ra is not a reliable means of suppressing the occurrence of fading, but if Ra<0.4μ
In the case of m, there is a tendency for problems such as a light density of the image due to an insufficient amount of toner coating on the sleeve and uneven coating of the developer due to non-uniform charging of the developer. Therefore, the value of Ra is preferably Ra≧0.4 μm, more preferably Ra≧0.5 μm.

It is also possible to blast the sleeve coating surface after drying in order to make the CVS value of the sleeve surface 5 μm or less. For example, blasting can be performed using a blasting machine manufactured by Fuji Seisakusho Co., Ltd., using abrasive grains such as Alundum #400. Further, in order to remove the fine powder of the coating film ground by the blasting process, alcohol cleaning or the like may also be carried out at the same time.

Next, the developer of the present invention will be explained.

The developer of the present invention contains fine powder treated with silicone oil or silicone varnish, and preferably has a form in which the fine powder is attached to the surface of the toner particles.

Since the developer according to the present invention has the above-mentioned configuration, it is possible to prevent the occurrence of fading phenomenon, especially under high temperature and high humidity conditions, and to fully utilize the original performance of the coat sleeve according to the present invention. It became. That is, the developer according to the present invention is a developer that is extremely well matched with the image forming apparatus according to the present invention and can fully utilize the development apparatus, and the developer according to the present invention and the image forming apparatus are compatible. By using this method, an image forming method that provides good images was established.

The present inventors believe that the reason for this is that the developer of the present invention, which has a high chargeability and the ability to maintain it even in a high temperature and high humidity environment, has good slipperiness due to the regulation of CV6 on the surface of the coated sleeve. We devised a sleeve that satisfies the requirements for a sleeve that suppresses the ability to mechanically transport the developer while increasing the chance of contact charging due to developer slipping, and can form a uniform charging layer. be done.

The particle size of the fine powder used in the present invention is 0.001 to 2μ
It is preferably in the range of 0.005 to 0.2μ, especially
is preferred. The material of the fine powder used in the present invention is preferably an inorganic compound. For example, metal oxides of groups 3 and 4, such as silicic acid, alumina, and titanium oxide, are preferred.

Particularly preferred is silicic acid fine powder, and as silicic acid fine powder,
Both the so-called dry process or fumed silica produced by vapor phase oxidation of silicon halide compounds, and the so-called wet process silica produced from hydraulic lath etc. can be used, but the surface and interior of the silicic acid fine powder can be used. There are few silanol groups in Na2O, So3'-
It is preferable to use dry silica which does not leave manufacturing residues such as silica.

In addition, in the manufacturing process of dry silica, for example,
It is also possible to obtain a composite fine powder of silica and other metal oxides by using other metal halokene compounds such as aluminum chloride or titanium chloride together with a silicon halokene compound, and these are also included.

In the silicone oil treatment of the fine powder used in the present invention, by applying the silicone oil to the surface of the fine powder, the silanol groups can be completely covered and hidden, and moisture resistance is dramatically improved.

The silicone oil or silicone varnish solid content used in the present invention is generally represented by the following formula, R I (R: C1-3 alkyl group LR' + C1-3 alkyl group or alkoxy group Examples include dimethyl silicone oil, alkyl-modified silicone oil, α-methylstyrene-modified silicone oil, chlorphenyl silicone oil, fluorine-modified silicone oil, etc. The silicone oil preferably has a viscosity of about 50 at 25°C.
~1000 centistokes is used. A silicone oil with a molecular weight that is too low may generate volatile matter when subjected to heat treatment, etc., and a silicone oil with a molecular weight that is too high may have too high a viscosity, making it difficult to perform treatment operations.

Known techniques are used for silicone oil treatment.
For example, the fine powder and silicone oil may be directly mixed using a mixer such as a Henschel mixer, or the silicone oil may be sprayed onto the base fine powder. Alternatively, it may be created by mixing the varnish with the base fine powder and then removing the solvent.

Further, it is more preferable that the 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, if silicone oil treatment alone is used, the amount of silicone oil that coats the surface of the fine powder is large, making it easy for fine powder aggregates to form during the treatment, and if it is applied to a developer, the fluidity of the developer may deteriorate. , it is necessary to be careful about the silicone oil treatment process. Therefore, in order to remove aggregates of fine powder while maintaining good moisture resistance, it is better to treat the fine powder with a silane coupling agent and then with silicone oil to fully demonstrate the treatment effect of silicone oil. It is.

The silane coupling agent used in the present invention has the general formula % R: alkoxy group or chlorine atom m: an integer of 1 to 3 Y: a hydrocarbon group including an alkyl group, a vinyl group, a glycidoxy group, and a methacrylic group n, Representative examples include dimethylcyclosilane, trimethylchlorosilane, allyldimethylchlorosilane, hexamethyldisilane, allyl phenyldichlorosilane, benzyldimethylchlorosilane, and vinyltriethoxy. Examples include silane, γ-methacryloxypropyltrimethoxysilane, vinyltriacetoxysilane, divinylchlorosilane, and dimethylvinylchlorosilane.

The above fine powder can be treated with a silane coupling agent by a dry process in which a vaporized silane coupling agent is reacted with the fine powder made into a cloud by stirring, or by dispersing the fine powder in a solvent and dropping the silane coupling agent. The treatment can be carried out by a generally known method such as a wet reaction method.

The silane coupling agent is used for 100 parts by weight of fine powder.
It is preferable to use 1 to 50 parts by weight, more preferably 5 to 40 parts by weight.

The processing amount of silicone oil or silicone varnish solid content in the present invention is 1 to 35 parts by weight per 100 parts by weight of fine powder.
It is preferably 2 to 30 parts by weight, more preferably 2 to 30 parts by weight. The reason for limiting the above treatment amount is that if the amount of silicone oil treated is too small, the result will be the same as that of silane coupling agent treatment alone, and the moisture resistance will not improve and the fine powder will absorb moisture under high humidity, resulting in a high quality product. Copy images cannot be obtained. Furthermore, if the amount of silicone oil processed is too large, the above-mentioned fine powder aggregates are likely to form, or even free silicone oil is formed, making it impossible to improve fluidity when applied to a developer. Problems such as this arise.

The amount of these treated fine powders to be applied to the developer is 0.01 to 20 parts by weight, more preferably 0.61 to 5 parts by weight, per 100 parts by weight of toner.

As the binder resin of the toner according to the present invention, monopolymers of styrene and its substituted products such as polystyrene and polyvinyltoluene; styrene-propylene copolymers, styrene-propylene copolymers, etc.
Vinyltoluene copolymer, styrene-vinylnaphthalene copolymer, styrene-methyl acrylate copolymer, styrene-ethyl acrylate copolymer, styrene-butyl acrylate copolymer, styrene-octyl acrylate copolymer, Styrene-dimethylaminoethyl acrylate copolymer, styrene-methyl methacrylate copolymer, styrene-ethyl methacrylate copolymer, styrene-butyl methacrylate copolymer, styrene-dimethylaminoethyl methacrylate copolymer Copolymer, styrene-hinyl methyl ether copolymer, styrene-hinyl ethyl ether copolymer, styrene-hinyl methyl ketone copolymer, styrene-butadiene copolymer, styrene-isoprene copolymer, styrene-maleic acid Copolymers, styrenic copolymers such as styrene-maleate ester copolymers: polymethyl methacrylate, polybutyl methacrylate,
Polyvinyl acetate, polyethylene, polypropylene, polyvinyl butyral 1, polyacrylic acid resin, rosin, modified rosin, terpene resin, phenolic resin, aliphatic or alicyclic hydrocarbon resin, aromatic petroleum resin, paraffin wax, carnauba wax, etc. These can be used alone or in combination.

Further, as the coloring material that can be further added to the developer according to the present invention, conventionally known carbon black, copper phthalocyanine, and the like can be used.

As the magnetic fine particles contained in the magnetic toner of the present invention, a substance that is magnetized by being placed in a magnetic field is used, such as powder of a ferromagnetic metal such as iron, cobalt, or nickel, or macnetite or γ-Fe2O3. , alloys and compounds with ferrite can be used.

These magnetic fine particles preferably have a BET specific surface area of 1 to 20 rn'/g, particularly 2°5 to 12 m
'/g, and preferably a magnetic powder having a Mohs hardness of 5 to 7. The content of this magnetic powder is 10 to 70% based on the weight of the developer.
Good weight percentage.

Further, the toner of the present invention may contain a charge control agent if necessary, such as metal complex salts of monoazo dyes, salicylic acid,
A negative charge control agent such as a metal complex salt of alkyl salicylic acid, dialkyl salicylic acid or naphthoic acid is used.

The developer of the present invention may further include other additives, such as Teflon, lubricants such as zinc stearate, fixing aids (such as low molecular weight polyethylene), or conductivity imparting agents, as long as they do not have a substantial adverse effect. Alternatively, a metal oxide such as tin oxide may be added.

In producing the toner of the present invention, the constituent materials are thoroughly kneaded using a thermal kneader such as a hot roll, kneader, or extruder, and then mechanically crushed or classified, or the materials are mixed in a binder resin solution. A method of producing a toner by dispersing and then spray drying, or a polymerization method of obtaining a toner by mixing a specified material with a monomer to constitute a binder resin to form an emulsified suspension and then polymerizing the resulting toner. , each method can be applied.

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

The surface of the OPC photoreceptor is negatively charged with a primary charger 217, and a digital latent image is formed by image scanning through exposure 705 with laser light, which includes a magnetic plate 6 and a magnet, and conductive fine particles or/and solid lubricant. A developing device 21 comprising a developing sleeve 2 in which C V 5 containing an agent is coated with a resin coating layer of 5 μm or less
The latent image is reversely developed using the one-component magnetic developer 5 of No. 1. In the developing section, an alternating bias, a pulse bias and/or a DC bias is applied between the conductive substrate of the photosensitive tram 1 and the developing sleeve 2 by a bias applying means 712. When the transfer paper P is conveyed and reaches the transfer section, the transfer means 702 charges the transfer paper P from the back side (the opposite side to the photosensitive drum side) with a voltage application means, thereby transferring the developed image (toner) on the surface of the photosensitive drum. image) is electrostatically transferred onto the transfer paper P.

The transfer paper P separated from the photosensitive drum 1 is subjected to a fixing process to fix the toner image on the transfer paper P by a heating and pressure roller fixing device 707.

The one-component developer remaining on the photosensitive drum after the transfer process is
It is removed by a cleaning device 708 having a cleaning plate. After cleaning, the photosensitive drum 2 is neutralized by erase exposure 706, and then charged again by the negative charger 217.
The process starting with the charging process is repeated.

The electrostatic 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 serving as a toner carrier rotates in the developing section so as to move in the same direction as the surface of the electrostatic image holder. Inside the nonmagnetic cylindrical sleeve 2, a multipolar permanent magnet (Macnet roll) serving as a magnetic field generating means is arranged so as not to rotate. The one-component insulating magnetic developer 5 in the developer storage chamber 212 of the developing device 211 is coated on a non-magnetic cylindrical surface, and due to the friction between the toner particles and the surface of the sleeve 2 having a coating layer, the toner particles are For example, a negative tribocharge is given. Furthermore, by arranging an iron magnetic doctor blade 6 close to the cylindrical surface (with an interval of 50 μm to 500 μm) and facing one magnetic pole position of the multipolar permanent magnet, the thickness of the developer layer can be reduced (30 μm to 50 μm). 300 μm) and uniformly regulate the electrostatic charge image carrier 1 and the developing station I in the developing section.
A developer layer thinner than the gap between the J-bums 2 is formed in a non-contact manner. By adjusting the rotational speed of the developing sleeve 2, the surface speed of the sleeve is made to be substantially the same speed as the speed of the electrostatic image holding surface, or a speed close to it. As the magnetic doctor blade 6, a permanent magnet may be used instead of iron to form opposing magnetic poles. 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. This AC bias has an f of 200 to 4°00.
It is sufficient if 0H2Xvpp is 500 to 3,000OV.

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

Instead of the magnetic doctor blade 6, an elastic plate made of an elastic material such as silicone rubber may be used to control the thickness of the developer layer by pressing, and the developer may be applied onto the developer carrier.

When the image forming apparatus of the present invention is used as a facsimile printer, the optical image exposure is exposure for printing received data. FIG. 7 is a block diagram showing an example of this case.

The controller 511 controls the image reading unit 510 and the printer 5.
Controls 19. The entire controller 511 is CPU5
17. The read data from the image reading section is transmitted to the partner station through the transmitting circuit 513. Data received from the partner station is sent to a printer 519 through a receiving circuit 512. Predetermined image data is stored in the image memory. A printer controller 518 controls a printer 519. 514 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 decodes the image information and sequentially stores it in the image memory 516. Ru. Then, once at least l pages of images are stored in the memory 516,
Record an image of that page. CPU 517 is memory 5
One page of image information is read out from 16 and the decoded one page of image information is sent to the printer controller 518. When the printer controller 518 receives one page of image information from the CPU 518, it controls the printer 519 to record the image information of the vane.

The CPU 517 receives the next page while the printer 519 is recording.

As described above, images are received and recorded.

As an electrophotographic apparatus, a plurality of components such as an electrostatic latent image carrier such as the above-mentioned photosensitive drum, a developing device, and a cleaning means are combined together as an apparatus unit, and this unit is attached to the main body of the apparatus. However, it may be configured to be detachable. For example, at least one of the charging means, the developing device, and the cleaning means may be integrally supported with the photosensitive drum to form a single unit that can be attached to and detached from the apparatus main body, and using guide means such as rails on the apparatus main body. It may be configured to be detachable. At this time, the above-mentioned device unit may include a charging means and/or a developing device.

Specific examples will be described below, but the present invention is not limited to the following examples. Note that all parts on each side are parts by weight.

3 parts of low molecular weight polypyrene The above materials were uniformly mixed, then kneaded, pulverized and classified to obtain a negatively charged magnetic toner having a weight average particle size of about 12 μm.

Next, 100 parts of silicic acid fine powder Aerosil #200 (manufactured by Nippon Aerosil Co., Ltd.) with a specific surface area of 200 rff/g was treated with 20 parts of hexamethyldisilazane (HMDS), and then dimethyl silicone oil KF-96100cS (
Negatively charged hydrophobic silicic acid fine powder prepared by diluting 10 parts of (Shin-Etsu Chemical System) with a solvent, drying, heating at about 250°C, treating with hexamethyldisilane, and then treating with dimethyl silicone oil. Get the body and the aforementioned toner 100
A developer was obtained by externally adding 0.6 parts to 1.0 parts.

Next, a commercially available Lasapeem printer LBP-3X (manufactured by Canon) was modified, and the surface of the developing sleeve (developer carrier) was prepared using Formulation 2 according to the method described above. : A synthetic resin containing a ratio of 1:1 was coated with a coating layer thickness of 8 μm).Furthermore, the surface was polished by bringing felt into contact as described above. A covered sleeve was prepared and installed in the equipment unit to serve as an evaluation device for imaging.

The developing bias is AC bias V, 160
The voltage was 0 V, the frequency was 1800 Hz, and the distance between the developer carrier of the present invention and the photosensitive tram serving as the electrostatic latent image carrier was approximately 300 microns.

The above developer is put into the above evaluation machine, and a negative electrostatic latent image is reversely developed with a magnetic toner having a negative triboelectric charge.
When continuous images were produced, uniform images without fading were obtained. Also, high temperature and high humidity (32,5
When a similar test was conducted under the following conditions (°C, 85% RH), similarly good results were obtained.

Kyoho±l Silicic acid fine powder Aerosil # with a specific surface area of 200rrf/g
200 (manufactured by Nippon Aerosil Co., Ltd.) was treated with 20 parts of dimethyl silicone oil KF-96100cS diluted with a solvent, dried, and then heat-treated at about 280°C to obtain dimethyl silicone oil-treated silica. When the same developer as in Example 1 was obtained and image output evaluation was performed, it was found that it could print 3,000 sheets at room temperature and 2 sheets at high temperature.
Good results were obtained up to 000 sheets.

Fuho U The silicic acid fine powder of Example 2 was mixed with α-alumina (average particle size: 0.
020μ, BET 100 crrf/g), and after performing the same treatment, a developer was obtained in the same manner as in Example 1.

In addition, as an evaluation machine, the degree of surface polishing of Example 1 was changed and
A sample with V5=0.6 μm and R=0.5 μm was prepared, and the same test as in Example I was conducted by adding the above developer. Although the overall image reflection density was somewhat low, good images free of faded were obtained up to 2,000 sheets at room temperature and up to 1,000 sheets at high temperature and high humidity.

Silicic acid fine powder Aerosil # with a specific surface area of 130rrf/g
100 parts of 130 (manufactured by Nippon Aerosil Co., Ltd.) were treated with 30 parts of dimethyl silicone oil KF-96100cS diluted with a solvent, dried, and then heat-treated at about 280°C to obtain shime silicone oil-treated silica. A developer was obtained in the same manner as in 1.

In addition, an evaluation machine was prepared in which the degree of surface polishing of Example 1 was changed to Cv5 = 2.5 μm Ta. Although some images showed a slight fading phenomenon that was not a practical problem, good results were obtained up to 3,000 sheets at normal temperature and 2,000 sheets at high temperature.

``1retsu'' - Silicic acid fine powder Aerosil # with a specific surface area of 300rn'/g
A developer was prepared in the same manner as in Example 4, except that 100 parts of 300 (manufactured by Nippon Aerosil Co., Ltd.) was treated with 2 parts of fluorine-modified silicone oil, and image formation was performed in the same manner as in Example 4. Although there was a slight fading phenomenon, good results were obtained up to 2,000 sheets at room temperature and humidity, and up to 1,000 sheets at high temperature.

The developer prepared in Example 4 was supplied to the image forming apparatus shown in FIG. 6, and an image reproduction test was conducted in the same manner as in Example 1. Good results were obtained at room temperature and at high temperature and high humidity.

The image output conditions are shown below.

(a) The surface of the aluminum developing sleeve used in the laser beam printer (LBP-3X) was coated with a composition consisting of 9 parts of graphite fine particles (volume average particle diameter 5 μrn), 1 part of conductive carbon fine particles, and 10 parts of phenol resin. A coated developing sleeve was used as the developer carrier 2, with C, 5=0.9 μm and Ra=1.5 μm coated with L (film thickness: about 6 μm) and surface polished with felt.

(b) A laminated PC photosensitive drum with a diameter of 30 mm was used as the electrostatic latent image carrier 1.

('c) A steel plate is used as the plate 6, and the gap between the covering sleeve and the steel plate is set to approximately 250 μm.

(d) The closest distance between the covering sleeve and the PC photosensitive tram in the development area is set to approximately 300 μm.

(e) AC bias (Vp, 1600V, frequency 180
0 Hz) and a DC bias of -400 cm was applied to the coated sleeve as a developing bias.

(f) Developing the electrostatic latent image using a reversal development method.

(g) Others are laser beam printers (LBP-S
Set the image output conditions similar to X).

As mentioned above, when the surface has a resin layer containing at least conductive fine particles and/or solid lubricant, and the relative load length tp = 5% in the relative load curve (Abbott's load curve) of the surface, cutting, depth cv
−cv<s μm.

By using the developer according to the present invention in an image forming apparatus using a developing device having a developer carrier for supporting and transporting developer, the occurrence of so-called fading phenomenon can be prevented not only at room temperature and humidity. This can be prevented even under high temperature and high humidity conditions.

[Brief explanation of the drawing]

FIG. 1 is a diagram showing a schematic cross-sectional view of a developing device of the present invention. FIG. 2 is a diagram showing a toner image for explaining the fading phenomenon. FIG. 3 is a diagram for explaining the relative load curve. 4 and 5 are diagrams schematically showing the profile of the surface of the covering sleeve. FIG. 6 is a diagram schematically showing a specific example of an image forming apparatus having the apparatus unit of the present invention. FIG. 7 is a block diagram showing a specific example of a facsimile device. 1... Electrostatic latent image carrier (photosensitive tram) 2... Developer carrier (sleeve) 3... Multipolar permanent magnet 4 - Developer storage chamber 6... Doctor blade 7... Sleeve base 10.・・Coating layer relative dismissal tF-

Claims (1)

[Scope of Claims] (1) It has a surface layer formed of a resin layer containing at least conductive fine particles and/or a solid lubricant, and has a relative load curve (Abbot's load curve) on the surface of the surface layer. ), an image forming method in which a developer for developing an electrostatic latent image is conveyed with a developer carrier having a cutting depth C_v of 5 μm or less when the relative load length t_p is 5%, and the electrostatic latent image is developed. A developer for developing an electrostatic latent image, which is characterized in that the developer for developing an electrostatic latent image contains a toner and a fine powder treated with silicone oil or silicone varnish. Developer for image development. (2) An electrostatic latent image carrier, and a developer for carrying an electrostatic latent image developing developer for developing the electrostatic latent image and transporting the electrostatic latent image developing developer to a development area. In an image forming apparatus having a developing device having a developer carrier and a developer storage chamber containing a developer for developing an electrostatic latent image, the developer carrier may contain conductive fine particles or/and a solid lubricant. It has a surface layer formed of at least a resin layer containing a resin layer, and has a relative load length t_
The cutting depth C_v when p is 5% is 5 μm or less, and the developer for developing an electrostatic latent image contains toner and fine powder treated with silicone oil or silicone varnish. image forming apparatus. (3) It has an electrostatic latent image carrier and a developing device for developing the electrostatic latent image, and the developing device includes a developer storage chamber containing a developer for developing the electrostatic latent image, and and a developer carrier for carrying a developer for developing an electrostatic latent image and transporting the developer for developing an electrostatic latent image to a development area, the developer carrier comprising conductive fine particles or/and solid lubricant. cutting depth C_v when the relative load length t_p is 5% in the relative load curve (Abbott's load curve) of the surface of the surface layer is 5 μm or less, the developer for developing an electrostatic latent image contains toner and fine powder treated with silicone oil or silicone varnish, and the developing device is integrated with the electrostatic latent image carrier. 1. A device unit characterized in that the unit is supported by a unit, and forms a single unit that can be freely attached to and detached from a device main body. (4) In a facsimile device having a receiving means for receiving image information from an electrophotographic device and a mode terminal, the electrophotographic device has an electrostatic latent image carrier and a developing device for developing the electrostatic latent image. The developing device includes a developer storage chamber that stores a developer for developing an electrostatic latent image, and a developer that supports the developer for developing an electrostatic latent image and has a developer for developing an electrostatic latent image in a development area. a developer carrier for transporting the developer; the developer carrier has a surface layer formed of a resin layer containing at least conductive fine particles and/or a solid lubricant; Relative load curve (Abbott load curve)
The cutting depth C_v when the relative load length t_p is 5% is 5 μm or less, and the electrostatic latent image developing developer contains toner and fine powder treated with silicone oil or silicone varnish. A facsimile device characterized in that it is an image forming device.