JPH0812444B2 - Electrostatic image developing method and apparatus - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION (Industrial Field of Application) The present invention relates to an electrostatic image developing method using an improved non-magnetic one-component toner and an apparatus therefor.

(Prior Art) In recent years, electrophotography, electrostatic recording method, electrostatic printing method and the like (hereinafter, abbreviated as electrophotographic method) have made remarkable progress, but these technologies are based on Electrophotography (RMSc
As described in Haffert, Focal press, etc.), the surface of the photoconductor is uniformly charged, and then the image corresponding to the original is exposed to eliminate or reduce the charge in the exposed area, and electrostatic Form a latent image. Next, electrostatic charge developing toner (hereinafter abbreviated as toner) is electrostatically adhered to the electrostatic latent image to develop the electrostatic latent image, thereby developing the electrostatic latent image.

In this case, the amount of adhered toner changes according to the magnitude of the amount of charge on the surface of the photoconductor, and as a result, a toner image with light and shade is formed. This toner image is made of paper, cloth,
It is transferred to a support such as a polymer film and generally heated directly or indirectly to be fixed on the surface of the support.

Although many methods are known as developing methods in electrophotography, they are roughly classified into two components using a mixture of carrier and toner composed of fine particles (50 to 300 μm) of iron powder, ferrite, glass, etc. as a developer. There are a developing method and a one-component developing method using a developer composed of only toner. In either method, generally, the electric charge is triboelectrically injected into the toner.

As a typical example of the two-component developing method, US Pat.
Method described in U.S. Pat.
There is a magnetic brush method described in the specification of 4,063. According to these methods, a relatively stable and good image can be obtained, but on the other hand, the image quality of the image due to the change of the triboelectric charging property due to the contamination of the carrier surface by the toner or the like and the change of the mixing ratio of the carrier and the toner, etc. The problems inherent to the two-component development method, such as deterioration, are inherently present.

The one-component developing method avoids the problems of such a two-component developing method. For example, US Pat. No. 4,336,31
No. 8 describes a method of developing using an electrically insulating magnetic toner, and British Patent No. 1,503,560 describes a developing method using a toner in which a magnetic material is exposed on the surface. ing. In these methods, the toner is charged by triboelectrification between the toner particles and the toner carrier and / or the toner thinning member, or by triboelectrification of the toner particles, and electrostatic charges on the photoreceptor are generated. Electrostatically adheres to the latent image. Such a one-component developing method has a great advantage that the developing device can be downsized because no carrier is used and a device for controlling the mixing ratio of the carrier and the toner is unnecessary. Since the insulating toner used is inferior in fluidity, triboelectrification is not sufficient, so that uniform development is difficult to perform, and scumming is likely to occur.

In order to avoid such a problem of the one-component developing method, a method of improving the fluidity of the toner by supporting hydrophobic silica on the toner surface (JP-A-58-132757), the toner is brought into contact with the photoreceptor. A so-called jumping developing method (Japanese Patent Publication No. 59-8831) is proposed in which the material is made to fly and developed without using it. However, these methods use magnetic action to convey the toner, and thus the toner necessarily contains a large amount (usually 30-70%) of magnetic material. As a result, due to the hygroscopicity of the magnetic material, a good image cannot be obtained under high humidity, and a clear and transparent color toner cannot be obtained due to the dark color of the magnetic material. It was still there.

In order to solve such an essential problem of the one-component developing method using a magnetic toner, a one-component developing method using no magnetic material has been proposed. For example, Japanese Patent Publication No. 60-45270, 5
No. 9-228271, No. 62-19884, No. 62-89975 and the non-magnetic one-component non-contact developing method described in Electrophotographic Society Journal, Vol. 26, No. 2, pp. 107-114. According to these methods,
It has been found that since the toner does not contain a magnetic material, a clear and transparent color toner can be obtained, and high image quality can be obtained relatively stably even under high humidity.

However, according to these developing methods, it has been found that triboelectric charging of the toner becomes unstable due to toner contamination on the toner carrier and / or the toner thinning member, and it is difficult to obtain a good image. It was also found that this tendency becomes remarkable under high humidity and low humidity.

(Problems to be Solved by the Invention) An object of the present invention is to provide a non-magnetic one-component non-contact development type electrostatic charge image developing method capable of obtaining a good image under high humidity and low humidity for a long period of time. To provide.

Another object of the present invention is to provide an electrostatic charge image developing device used in such an electrostatic charge image developing method.

[Structure of the Invention] As a result of intensive studies on the influence of the toner material on the image quality in the non-magnetic one-component non-contact developing method, the present inventors have found that by using a non-magnetic toner containing a magnetic agent powder, It has been found that the above-mentioned problems of the non-magnetic one-component non-contact developing method can be solved, and the present invention has been accomplished.

That is, according to the present invention, the powder toner for electrostatic image development is conveyed and supplied to the toner carrying roller without using magnetic action, and the toner thinning member forms a thin layer of the toner on the toner carrying roller. A method of developing the electrostatic latent image by causing the toner to fly from a thin layer of the toner to the electrostatic latent image that opposes the toner carrying roller with a certain gap. Provided is a method for developing an electrostatic charge image, which comprises 10% by weight of a magnetic agent powder and has a capacitance of 6.0 to 11.0 pF (pi kpf arad).

As the magnetic agent powder contained in the electrostatic charge image developing powder toner used in the electrostatic charge image developing method of the present invention, when contained in the toner, the electrostatic capacity of the toner becomes 6.0 to 11.0 pF. Then, there is no particular limitation. Usually, ferrous metals such as ferrite and magnetite, metals exhibiting ferromagnetism such as cobalt, nickel, alloys or compounds containing these elements; manganese-copper-aluminum, manganese-copper-tin etc. manganese-copper Heusler. An alloy, such as an alloy called an alloy, which does not contain a ferromagnetic element but exhibits ferromagnetism when subjected to an appropriate heat treatment; or chromium dioxide can be used. In particular, ferrite and magnetite having a particle size of 0.01 to 2.0 μm are preferable from the viewpoint of dispersibility and economy.

The content of the magnetic agent powder in the toner is 0.
It is 5 to 10% by weight. If it is less than 0.5% by weight, the effect of the present invention is not exhibited, while if it exceeds 10% by weight, the electrostatic capacity becomes too large, and the image tends to become unstable especially under high humidity. It is also economically disadvantageous.

The magnetic agent powder oxides may be used alone or in combination of two or more.

The electrostatic capacity of the toner used in the present invention is 6.0 to 11.0 pF.

If it is less than 6.0 pF, the image density becomes low, and if it exceeds 11.0 pF, the image becomes unstable especially under high humidity, which is not preferable.

The electrostatic capacity was measured by pressing the sample with a tablet press at 10 kg / cmm ² and using a model 4194A Impedance / Gain Phase Analyzer (Yokogawa Hewlett Packard) to sample the toner with a diameter of 10 mm and a thickness of 1 mm. , 20
It was obtained by measuring the sample in the thickness direction in a constant temperature and humidity room at 60 ° C and 60% RH.

The binder contained in the toner used in the method of the present invention is not particularly limited, but the following resins are preferably used.

Polystyrene system; Copolymer system of styrene and acrylic acid ester, acrylonitrile, maleic acid or maleic acid ester, etc .; Polyacrylic acid ester system; Polymethacrylic acid ester system; Polyester system; Polyamide system; Polyurethane system; Polyvinyl acetate system Polyvinyl chloride-based; polyvinyl butyral-based; epoxy-based; phenol-based; aliphatic or alicyclic hydrocarbon-based; rosin-based; terpene-based; petroleum-based; paraffin-based and the like. They are,
They can be used alone or as a mixture. Of these, polystyrene resins, styrene / acrylic acid ester resins, styrene / methacrylic acid ester resins, and polyester resins are particularly preferable in terms of developability and durability.

In the toner according to the present invention, if it is possible to secure a capacitance of 6.0 to 11.0 pF, if necessary, various additives such as a colorant, a charge control agent, and an offset preventive agent are added inside the particles.
Alternatively, it can be added to the outside and used.

Coloring agents include zinc yellow, yellow iron oxide, fast yellow, disazo yellow, red iron oxide, and watchchan red Ca.
It can be appropriately selected from various pigments such as salt, phthalocyanine blue, metal-free phthalocyanine, quinacridone red, titanium white, and carbon black in terms of hue and resistance according to the purpose. The amount of the colorant used is about 0 to 20% with respect to the toner.

As the charge control agent, for example, an azine-based nigrosine derivative, a quaternary ammonium salt compound, specifically, nigrosine base EX, Bontron N-01, N-07, P-51 (trade name, manufactured by Orient Chemical Co., Ltd.) , A positive charge control agent such as TP-302 (trade name, manufactured by Hodogaya Chemical Co., Ltd.); and an electron-accepting organic complex such as a metal-containing azo dye or a non-pigment metal complex.
Chlorinated paraffin, chlorinated polyester, copper phthalocyanine derivative, specifically Bontron E-82, E-84, S-34
(Trade name, manufactured by Orient Chemical Co., Ltd.), Kayaset Black T-2, Kayacharge N-1 (trade name, manufactured by Nippon Kayaku Co., Ltd.),
A negative charge control agent such as Spyron Black TRH (trade name, manufactured by Hodogaya Chemical Co., Ltd.) can be used. The amount of these charge control agents used is usually 0.1 to 5% by weight with respect to the toner.

As the offset preventing agent, for example, a polyolefin-based wax, an amide-based wax, an ester-based wax having a softening point of 70 to 170 ° C. according to the ring and ball method can be used. Examples thereof include polyethylene, polypropylene, dibasic acid bisamide, carnauba wax and the like. These can be used alone or in combination. The addition amount of the offset preventing agent is preferably 1 to 7% by weight.

Further, in the toner according to the present invention, if necessary, a fluidity improving agent such as hydrophobic silica; a higher fatty acid metal salt typified by zinc stearate, a cleaning agent such as a fine powder of fluoropolymer. Improver: Cerium oxide, strontium titanate, etc. Photoreceptor surface polishing agent: Alumina, tin oxide, molybdenum disulfide, copper oxide, developing / transferability adjusting agent such as fine powder of polymethylmethacrylate, etc. It is also possible to add the functional agent of (4) to the surface of particles.
The addition amount of these functional agents is preferably 0.1 to 3% by weight with respect to the toner.

In the case of developing a negative electrostatic image with the toner of the present invention, positively chargeable silica is preferably used as the hydrophobic silica. When negatively charged silica is used, fog increases in continuous copying when a small amount is used, and the image density is low in the initial stage when a large amount is used.
The hydrophobic silica preferably used is fine silica powder surface-treated with a silane compound represented by the following general formula.

Formula X _m S _i Y _n (wherein, X represents an alkoxy group or a chlorine atom, Y is 1 to 3
An organic group having a primary amino group, m and n are integers of 1 to 3, and the total thereof is 4. ) The positively charged hydrophobic silica treated with the silane compound of the above general formula can be prepared by referring to Japanese Patent Publication No. 53-22447.
It can be easily synthesized by those skilled in the art. The following can be mentioned as specific examples of the compound represented by the above general formula.

H ₂ NCONHCH ₂ CH ₂ CH ₂ Si (OC ₂ H ₅ ) ₃ H ₂ NCH ₂ CH ₂ CH ₂ Si (OCH ₂ CH ₃ ) ₃ H ₂ NCH ₂ CH ₂ NHCH ₂ CH ₂ CH ₂ Si (OCH ₃ ) ₃ H ₂ NCH ₂ CH ₂ CH ₂ Si (OCH ₃ ) ₃ H ₂ NCH ₂ CH ₂ NHCH ₂ CH ₂ NHCH ₂ CH ₂ CH ₂ Si (OCH ₃ ) ₃ H ₅ C ₂ OCOCH ₂ CH ₂ NHCH ₂ CH ₂ CH ₂ Si (OCH ₃ ) ₃ H ₅ C ₂ OCOCH ₂ CH ₂ NHCH ₂ CH ₂ NHCH ₂ CH ₂ CH ₂ Si (OCH ₃ ) ₃ H ₅ C ₂ OCOCH ₂ CH ₂ NHCH ₂ CH ₂ NHCH ₂ CH ₂ NHCH ₂ CH ₂ NHCH ₂ CH ₂ CH ₂ Si
(OCH ₃ ) ₃ NH ₂ C ₆ H ₄ Si (OCH ₃ ) ₃ C ₄ H ₉ NHCH ₂ CH ₂ CH ₂ Si (OCH ₃ ) ₃ The toner used in the method of the present invention includes a heat roll, a kneader, an extruder, etc. It is preferable that the above-mentioned toner constituent materials are well melt-kneaded by the hot melt kneader, and then mechanically pulverized and classified to produce the toner.

In addition, in order to add the above-mentioned various functional agents to the surface of the toner particles, a known mixer, for example, a V type mixer, a rotary container type mixer such as a turbula mixer, a ribbon type, a screw type, a rotary blade type, Other fixed container type mixers can be appropriately used.

Also, the mixing of various components, even if all at once,
You may mix in order considering the property of a toner.

Further, according to the present invention, a toner carrying roller, a supply roller for carrying powder toner for electrostatic image development without using magnetic action to the toner carrying roller, and a thin layer of toner formed on the toner carrying roller. A toner thinning member for holding the toner, and an image holding member that faces the toner carrying roller with a constant gap therebetween and holds an electrostatic latent image developed by the toner flying from the thin layer of the toner. In the electrostatic charge image developing device, the toner is 0.5 to 10
The present invention provides an electrostatic charge image developing device characterized by using a magnetic agent powder in an amount of 6.0% by weight and having a capacitance of 6.0 to 11.0 pF.

According to the electrostatic image developing device of the present invention, the toner is first
The supply roller conveys and supplies the toner to the toner carrying roller without using magnetic action. The supply roller is usually 2 to
Made of neoprene rubber foam with a hardness of 15 degrees. Hardness 2
If it is less than 15 degrees, the supply roller is deformed, and if it exceeds 15 degrees, the torque becomes too large and the durability of the image deteriorates. The toner carrying roller and the supply roller rotate in the same direction, but the peripheral speed ratio thereof is 1: 0.2 to 2.0, usually 1: 0.5. If the peripheral speed of the supply roller is slower than this, the image density becomes low, and if the peripheral speed of the supply roller is fast, the torque is too large to be suitable for the developing system.

The toner supplied to the toner carrying roller is thinned to a constant thickness on the toner carrying roller by the toner thinning member (coating blade). The coating blade is usually made of a stainless steel plate, and 0.
It is pressed against the toner carrying roller at a portion of 1 to 2 mm. The pressure is usually 40-120 g / cm. The toner is charged by the friction between the toner and the coating blade when forming the thin toner layer. The thickness of the toner thin layer formed on the toner carrying roller by the coating blade is 5 to 80 μm, preferably 10 to 40 μm. If the thickness of the thin toner layer is less than 5 μm, the image density will be low,
If it exceeds m, the toner consumption increases, which is not economical, and toner scattering and fog occur.

The toner carrying roller is usually made of a low resistance material such as Al, SUS, and a conductive rubber roller, and the surface thereof is sandblasted with an abrasive of 200 to 1000 #. When the grain size of the abrasive is coarser than 200 #, the toner thin layer becomes too thick, and when it exceeds 1000 #, it becomes too thin, resulting in the above-mentioned problems. The surface of the toner carrying roller is electroless nickel plated.

An image holding member (photoreceptor) that holds the electrostatic latent image is provided so as to face the toner carrying roller with a certain gap. Toner-carrying roller and coating blade have a DC voltage of −100 to −300V, usually −200V, and 2 to 4KH
z and an AC voltage of 1 to 3 KV are superimposed and applied, and the surface potential of the photoconductor is set to 500 to 1000V. The toner charged on the toner carrying roller flies in the space between the toner carrying roller and the photoconductor and adheres to the electrostatic latent image,
Develop the electrostatic latent image. When the DC voltage applied to the toner carrying roller is lower than -300 V, the AC voltage is lower than 1 KV, and the frequency is lower than 2 KHz, the toner does not fly and the image is liable to be defective. On the other hand, when the DC voltage applied to the toner carrying roller is higher than −100 V, the AC voltage is higher than 3 KV, and the frequency is higher than 4 KHz, a leak image is likely to occur.

The gap between the toner bearing roller and the photoconductor is 200-400.
μm is preferable, and more preferably 250 to 330 μm.
Is. If it is less than 200 μm, a leak image is likely to occur, and if it exceeds 330 μm, the toner is less likely to fly,
Image defects are likely to occur.

The photoconductor and the toner carrying roller rotate in opposite directions,
The peripheral speed ratio is 1: 0.5 to 3.0, usually 1: 1.2. If the peripheral speed of the toner carrying roller is slower than this, the image density becomes low, and if the peripheral speed is fast, the toner consumption increases, which is not economical, and toner scattering and fog occur.

(Action) The action mechanism of the magnetic agent powder in the toner used in the method of the present invention has not been completely clarified yet, but is presumed to be as follows. That is, in the non-magnetic one-component non-contact developing method as in the present invention, not all the toner on the toner carrying roller is transferred to the photoconductor at the time of development. Triboelectricity with the coating blade will be weighted over time. as a result,
The toner charge amount increases and the image density decreases. On the other hand, when the magnetic agent powder is present as in the toner used in the present invention, the accumulated electric charge leaks through the magnetic agent powder, so that the electrical characteristics of the toner are considered to be stable for a long period of time. To be

(Example) Hereinafter, the electrostatic image developing device according to the present invention will be specifically described with reference to the drawings.

FIG. 1 is a schematic diagram showing an electronic copying machine according to an embodiment of the present invention. A photoconductor 2 as an image holding member is provided at a substantially central portion of the copying machine main body 1 so as to be rotatable in an arrow direction. Around the photoconductor 2, a charger 3, an imaging lens array 4, a developing device 5, a developing device 5,
The transfer charger 6, the cleaner 7, and the static eliminator 8 are sequentially arranged. An optical system 9 for exposing a document is provided on the upper part of the main body 1, and a paper feed cassette 10 is mounted on the lower part of the main body 1. Paper is supplied from the paper feed cassette 10, and the paper is transported along the transport path 11. A register roller 12, a fixing device 13, and a paper discharge roller 14 are arranged in the conveyance path 11 along the paper conveyance direction. In addition, 15 is a discharge tray,
16 is a manuscript table.

The copying process in the copying apparatus described above is as follows. First, the optical system 9 irradiates a document on the document table 16 with light, and the reflected light is imaged on the photoconductor 2 via the imaging lens array 4, and an electrostatic latent image is formed on the photoconductor 2. It is formed. Toner supplied from the developing device 5 adheres to the electrostatic latent image, and the electrostatic latent image is visualized. On the other hand, the paper supplied from the paper feed cassette 10 is the photoconductor 2 and the transfer charger 6.
And the visible image on the photoconductor 2 is transferred to the paper. After that, the sheet is conveyed to the fixing device 13 along the conveying path 11, where it is fixed, and then is ejected onto the sheet ejection tray 15 via the sheet ejection roller 14.

Next, the developing device 5 in the above copying apparatus will be described in detail. As shown in FIG. 2, the developing device 5 includes a developing unit 21, and inside the developing unit 21,
A non-magnetic one-component toner 22 is contained as a developer, and a mixer 23, a toner supply roller 24 and a toner carrying roller 25 are arranged. Toner carrier roller 25
Are opposed to the photoconductor 2 through a gap of 200 to 400 μm, and can be rotated in a shift law at a peripheral speed of 1 to 3 times that of the photoconductor 2 by a driving unit (not shown). Further, in the developing unit 21, the upper end thereof is held in a conductive state by the holder 26, and the vicinity of the lower end thereof contacts the toner carrying roller 25. A coating blade 27 is provided as a toner thinning member. Further, a collecting blade 28 is in contact with the lower side of the toner carrying roller 25.

At the time of development, the toner is supplied to the carrying roller 25 by the rotation of the supply roller 24, is thinned by the coating blade 27, and is triboelectrically charged. The toner charged on the toner carrying roller 25 flies in the space between the toner carrying roller 25 and the photoconductor 2 and adheres to the electrostatic latent image to develop the electrostatic latent image. The toner remaining on the toner carrying roller 25 is collected in the developing unit by the collecting blade 28.

 Hereinafter, production examples of the toner used in the present invention will be shown.

Production Example 1. A mixture having the following composition was obtained.

Styrene / butyl methacrylate / methacrylic acid N, N-dimethylethyl ester copolymer (weight ratio = 65/34/1, _Mw =
131,000; _Mn = 11,000) 85 parts Magnetic agent powder MG-RF (manufactured by Mitsui Kinzoku Co., Ltd.) 5 parts Carbon black Raven 1250 (manufactured by Columbia Carbon Co.) 5 parts Nigrosine dye Bontron N-01 3 parts Polypropylene viscol 660P (manufactured by Sanyo Kasei Co., Ltd.) ... 4 parts After preliminarily dispersing the above mixture, a twin-screw kneader PCM-30
(Made by Ikegai Tekko Co., Ltd.). Next, the kneaded product was rolled and cooled, coarsely pulverized with a hammer mill, and finely pulverized with Lab Jet (manufactured by Nippon Pneumatic Co., Ltd.). This is classified with a zigzag classifier (Albine Co., Ltd.), and the average particle size is 10.2μ.
m toner was obtained. The electrostatic capacity of this toner was measured and found to be 9.39 pF.

Production Example 2. Using Mapico Black BL-100 (manufactured by Titanium Industry Co., Ltd.) as the magnetic agent powder, and using a quaternary salt charge control agent TP-302 (manufactured by Hodogaya Chemical Co., Ltd.) instead of the nigrosine dye. A toner having an average particle size of 9.8 μm was obtained in the same manner as in Production Example 1 except for. When the electrostatic capacity of this toner was measured,
It was 8.03 pF.

Production Example 3. A mixture having the following composition was obtained.

Styrene / butyl methacrylate copolymer (weight ratio = 65/3
5, M _w = 150,000, M _n = 7,900) 87 parts Magnetic agent powder KBC200 (manufactured by Kanto Denka Co., Ltd.) 3 parts Carbon black # 40 (manufactured by Mitsubishi Kasei) 5 parts Nigrosine dye Bontron N-07 2 Part Quaternary salt charge control agent P-51 2 parts Polypropylene VISCOL 550P (manufactured by Sanyo Chemical Co., Ltd.) 2 parts Polyethylene high wax 1140H (manufactured by Mitsui Petrochemical Co., Ltd.) 2 parts The above mixture was prepared in the same manner as in Preparation Example 1. Toner was obtained to obtain a toner having an average particle size of 10.1 μm. The electrostatic capacity of this toner was measured and found to be 8.21 pF.

Production Example 4. A mixture having the following composition was obtained.

Styrene / butyl acrylate / N, N-diethylethyl methacrylate copolymer (weight ratio = 79/20/1, M _w = 110,000; M _n
= 10,000)… 85 parts Magnetic agent powder EPT-500 (manufactured by Toda Kogyo Co., Ltd.)… 3 parts Conductive carbon black Vulcan WC-72R (manufactured by Cabot)… 3 parts Carbon black # 44… 2 parts Quaternary salt charge control Agent TP-302 3 parts Polypropylene Viscole 550P 2 parts Carnaupa wax (manufactured by Noda Wax Co., Ltd.) 2 parts The above mixture was made into a toner in the same manner as in Production Example 1 to obtain a toner having an average particle size of 10.2 μm. The electrostatic capacity of this toner was measured and found to be 7.93 pF.

Production Example 5. A toner having an average particle size of 10.3 μm was obtained in the same manner as in Production Example 1 except that Spiron Black TRH was used in place of the Nigrosine dye Bontron N-01. The electrostatic capacity of this toner was measured and found to be 10.01 pF.

Comparative Production Example 1 A toner having an average particle size of 10.4 μm was obtained in the same manner as in Production Example 1 except that the magnetic agent powder was excluded and the binder resin was changed to 88 parts. When the electrostatic capacity of this toner was measured,
It was 5.23 pF.

Comparative Production Example 2 A toner having an average particle size of 10.4 μm was obtained in the same manner as in Production Example 3, except that the magnetic agent powder was excluded and the binder resin was 87 parts. When the electrostatic capacity of this toner was measured,
It was 4.93 pF.

The following is a test example for evaluating the performance of the toner obtained in the above production example.

Test Example Each toner was used in a copying machine BD-3110 (manufactured by Toshiba Corp.) in which the developing device was modified as shown in FIG. 2, and a running test was carried out for copying 10,000 sheets. The results are shown in the table below. In the case of positively chargeable toner, positively chargeable silica RA-200H (manufactured by Nippon Aerosil Co., Ltd.) is used as the toner.
A negatively chargeable organic photoconductor was used as the photoconductor, using 3% by weight of external addition. In the case of a negatively chargeable toner, 0.3% by weight of negatively chargeable silica R-972 (manufactured by Nippon Aerosil Co., Ltd.) is externally added as a toner, and a Se / Te photoreceptor is used as a positively chargeable photoreceptor. I was there.

From the table below, it can be seen that according to the method of the present invention, a good image can be stably obtained even under high humidity and low humidity over a long period of time and is superior to the conventional method using the conventional toner.

In the table, "environment" indicates the temperature and relative humidity of the running test place, "run" indicates after copying 10,000 sheets, and "fog" indicates the non-image area and the blank sheet. The difference in reflectance is shown.

[Effects of the Invention] As described above, according to the present invention, it is possible to stably obtain a good image under high humidity and low humidity for a long period by using the non-magnetic one-component non-contact developing method. is there.

[Brief description of drawings]

FIG. 1 is a diagram schematically showing a copying machine according to an embodiment of the present invention, and FIG. 2 is a diagram showing the structure of a developing device in the copying machine of FIG. 1 ... Copier body, 2 ... photoreceptor, 5 ... developing device, 24
...... Toner supply roller, 25 …… Toner carrying roller, 27 ・ ・ ・
… Coating blade.

─────────────────────────────────────────────────── ─── Continuation of the front page (51) Int.Cl. ⁶ Identification code Internal reference number FI Technical indication location G03G 15/08 D 504 A 507 L G03G 13/08 (72) Inventor Shin Takagi Kyobashi, Chuo-ku, Tokyo 2-33 Toyo Inki Manufacturing Co., Ltd. (72) Inventor Yoshifumi Ishikawa 2-33 Kyobashi, Chuo-ku, Tokyo Toyo Inki Manufacturing Co., Ltd. (56) Reference JP-A-62-184473 ( JP, A) JP 61-88277 (JP, A) JP 60-229035 (JP, A) JP 60-217370 (JP, A) JP 62-70862 (JP, A) JP JP-A-60-12556 (JP, A) JP-A-59-200276 (JP, A) JP-A-55-88070 (JP, A) JP-A-55-73059 (JP, A)

Claims (2)

[Claims] 1. A non-magnetic one-component toner containing 0.5 to 10% by weight of magnetic powder contained in an accommodating portion and having a capacitance of 6.0 to 11.0 pF is a neoprene having a hardness of 2 to 15 degrees. The toner supply roller made of rubber foam rotates in the same direction as the toner supply roller at a peripheral speed ratio of 1: 0.5 to 5,
The step of transporting to the toner carrying roller, which is made of low resistance metal and whose surface is sandblasted with an abrasive of 200 to 1000 #, and the toner transported by this toner transport step,
It is pressed at a pressure of 40 to 120 g / cm against the toner carrying roller at a portion of 0.1 to 2 mm from its tip, and -100
A step of thinning to a thickness of 5 to 80 μm by a stainless steel toner thinning member to which a DC voltage of −300 V and an AC voltage of 2 to 4 kHz and 1 to 3 kV are superimposed and applied; The toner thinned by the layering step is separated from the toner carrying roller by a space of 200 to 400 μm and
A step of facing an image bearing member having an electrostatic latent image with a surface potential of 500 to 1000 V and rotating at a peripheral speed ratio of 1: 0.5 to 3.0 in the direction opposite to the toner bearing roller; While the layered toner and the electrostatic latent image are opposed to each other, a DC voltage of −100 to −300 V, 2 to 4 kHz, 1 to 3 is applied to the toner carrying roller.
a step of causing toner to fly to the electrostatic latent image by applying an alternating voltage of kV to the electrostatic latent image, and a step of collecting the toner remaining on the toner carrying roller after the flying step in the containing portion by a collecting blade. A non-magnetic one-component electrostatic charge image developing method comprising: 2. An accommodating portion for accommodating a non-magnetic one-component toner containing 0.5 to 10% by weight of magnetic powder and having a capacitance of 6.0 to 11.0 pF, and the toner disposed in this accommodating portion. And a toner supply roller made of neoprene rubber foam having a hardness of 2 to 15 degrees, and a low resistance metal rotating in the same direction as the toner supply roller at a peripheral speed ratio of 1: 0.5 to 5. The toner carrying roller whose surface is sandblasted with an abrasive of 200 to 1000 #, and the toner conveyed to the toner carrying roller by the toner supply roller are By pressing it against the carrier roller at a pressure of 40 to 120 g / cm, the layer is thinned to a thickness of 5 to 80 μm.
A stainless toner thinning member to which a direct current voltage of 0 to −300 V and an alternating voltage of 2 to 4 kHz and 1 to 3 kV are superposed and applied, and a toner thinned by the thinning member is A space of 200-400 μm is separated from the toner carrying roller and
An image bearing member having an electrostatic latent image with a surface potential of 500 to 1000 V and rotating at a peripheral speed ratio of 1: 0.5 to 3.0 in a direction opposite to the toner bearing roller, and −100 to the toner bearing roller. Means for causing toner to fly to the electrostatic latent image by superimposing and applying a DC voltage of −300 V and an alternating voltage of 2 to 4 kHz and 1 to 3 kV; and A non-magnetic one-component electrostatic charge image developing device, comprising: a collecting blade that collects the toner remaining on the toner carrying roller into the accommodating portion.