JPH0158500B2 - - Google Patents

Description

[Detailed description of the invention]

The present invention relates to a method of developing an electrostatic image formed on the surface of an electrostatic image carrier, and particularly to a method of forming and developing a thin and uniform insulating nonmagnetic toner layer on a toner carrier. Conventionally, the following methods are known as developing methods using a one-component non-magnetic toner. a movable developer carrying means that carries and conveys the developer and supplies it to the latent image carrier; a developer replenishing means; and a movable developer carrying means that receives the developer from the developer replenishing means and supplies the developer to the movable developer carrying means. A movable applicator for coating, which has a fiber brush that carries a developer on its surface, contacts the movable developer carrier, and moves a movable developer in the same direction as the movable developer carrier at this abutting portion. A method in which toner is uniformly applied to the surface of the movable developer carrying means using a movable coating means that moves at a higher speed than the developer carrying means, and development is carried out by bringing this coated layer close to the electrostatic latent image area, or a one-component system. A rotatable magnetic roller that attracts a magnetic carrier to form a magnetic brush for charging non-magnetic toner particles, and a rotatable magnetic roller that transfers the toner particles from the roller to develop an electrostatic image on an electrostatic image carrier. The electrostatic image is developed by maintaining a gap between the electrostatic image holder and the developing roller in the developing section, and setting the gap length to be larger than the thickness of the toner coating layer on the developing roller. Method/An electrostatic image developing method in which an electrostatic image carrier holding a developer on its surface is opposed to an electrostatic image carrier and an electrostatic image on the surface of the carrier is developed. When pumping up the developer under the developer holder stored in the means onto the developer holder, vibration is applied to only the pumped up portion of the developer to activate it, and a predetermined thickness is applied to the surface of the developer holder. There is a developing method in which a developer layer is formed and then subjected to development. However, in the method of developing these insulating non-magnetic toners by supporting them on a carrier using non-magnetic force in the developing section, the forces that cause the non-magnetic toner to be supported on the toner carrier around the developing section are mainly electrostatic attraction and physical force. The magnetic adhesion force is predominant, and various disadvantages arise compared to the conventional developing method using insulating magnetic toner, in which the toner is supported on the carrier by the point magnetic force, electrostatic force, etc. for example,
This results in development in which much of the toner is spread relatively thinly and unevenly on the carrier. Furthermore, for example, so-called background fog occurs in which toner adheres to non-image areas even though the toner is applied relatively uniformly. Furthermore, even though the toner is applied thinly and uniformly, the amount of toner adhering to the image area is insufficient, resulting in an image with low density. Additionally, many toners have low fidelity even though they are thinly and evenly applied, resulting in very poor images with low resolution. Furthermore, repeated use of more toner results in decreased image density and lower quality images. Furthermore, many toners have the disadvantage that they sometimes cause a decrease in image density when subjected to environmental changes such as high temperature and high humidity, low temperature and low humidity, and sometimes cause background fog. In addition, in the development method using one-component magnetic toner, since the magnetic toner particles contain a large amount of magnetic powder, it is not only more expensive than non-magnetic toner, but also produces beautiful colors. was difficult. An object of the present invention is to provide a new developing method using an insulating non-magnetic toner, which improves the above-mentioned drawbacks. That is, an object of the present invention is to provide a developing method with high fidelity and stable image quality. Another object of the present invention is to provide a developing method that eliminates the background fog phenomenon and provides a high-resolution image that is uniform and has sufficient density in the image area. Another object of the present invention is to provide a developing method with excellent durability such as continuous use characteristics. Another object of the present invention is to provide a developing method that is stable against environmental changes such as high temperature and high humidity, and low temperature and low humidity. Another object of the present invention is to provide a developing method that provides images with sharp hues. Specifically, the present invention uses an electrostatic image carrier that holds an electrostatic image on its surface, and an inorganic fine powder treated with silicone oil having an amine in its side chain (excluding silicic acid fine powder). A toner carrier carrying a positively charged insulating nonmagnetic toner in the toner particles or on the surface of the toner particle is arranged with a certain gap in the developing section, and the toner supports the positively charged insulating nonmagnetic toner. The present invention relates to a developing method characterized in that the toner is supported on a body to a thickness thinner than the gap, and the toner is transferred to the electrostatic image holder in a developing section for development. The present inventors have studied various developing methods using conventionally known non-magnetic toners, and found that in order to solve the above-mentioned drawbacks, compared to developing methods using magnetic toners, it is necessary to use a toner carrier in the developing section. We have found that more precise control of the amount of electrostatic charge that the above toner has is necessary. For example, if the amount of charge is low, a phenomenon occurs in which the toner is not evenly applied onto the carrier, and development is of course impossible. Next, even if the amount of charge is increased to create a state in which the toner is evenly applied, if the value is not appropriate, background fogging will likely occur, and conversely, if the value is too high, electrostatic interaction with the toner carrier will occur. If the attractive force is too strong, it becomes difficult for the toner to transfer to the electrostatic image carrier, resulting in a decrease in image density and the appearance of a low-quality image. Furthermore, for the same reason, these developing methods have an extremely large effect on the image due to changes in the toner charge amount during repeated use or environmental changes, and ensuring the stability of the charge amount is more important than ever before. In this development method, the physical adhesion between the toner and the toner carrier clearly affects the transfer of the toner from the toner carrier. It has been found that when the toner particle packing density is high, the image density is low, resulting in a low-quality image with low resolution, and that it is extremely important to prevent the physical adhesion from increasing. In the present invention, insulating non-magnetic toner is supported on a carrier by non-magnetic force in a developing section, and these characteristic requirements resulting from the developing method are applied to specific inorganic fine powder (excluding silica fine powder). This is achieved by using a positively charged insulating non-magnetic toner having this in the toner particles or on the surface of the toner particles. In the developing method of the present invention, the inorganic fine powder constituting a component of the developer is an inorganic powder having a particle size of 10μ or less (more preferably 1μ or less) that is poorly water-soluble and thermally stable at a temperature of 300°C or lower. It is a fine powder of a compound. Examples of such inorganic fine powders include alumina, titanium dioxide, barium titanate, magnesium titanate, calcium titanate, strontium titanate, zinc oxide, clay, mica, wollastonite, diatomaceous earth, and various inorganic oxides. Pigment, chromium oxide, cerium oxide, red iron,
Examples include powders and particles of various ferrites such as iron oxide, iron sand, γ-ferrite, barium ferrite, strontium ferrite and rare earth ferrite, antimony trioxide, magnesium oxide, zirconium oxide, barium sulfate, and calcium carbonate. As the silicone oil having an amine in its side chain, silicone oil containing a structural unit represented by the formula () can generally be used. (Here, R ₁ is hydrogen, alkyl group, aryl group,
It represents an alkoxy group, R ₂ represents an alkylene group or a phenylene group, and R ₃ and R ₄ represent hydrogen, an alkyl group, or an aryl group. However, the above alkyl group, aryl group, alkylene group, and phenylene group may contain an amine, or may have a substituent such as a halogen within a range that does not impair chargeability. ) Preferred commercially available silicone oils having an amine in their side chains include, for example, amino-modified silicone oils represented by the following structural formula. it is (Here, R ₁ and R ₂ represent an alkyl group or an aryl group, R ₂ represents an alkylene group, a phenylene group, or an alkyl group containing an amine, and R ₃ represents hydrogen, an alkyl group, or an aryl group. m, n is a number of 1 or more.) Specifically, the following are preferred, and these may be used alone or in a mixed system of two or more.

【table】

[Table] Manufactured by the company)
The amine equivalent in the above table is the equivalent per amine (g/eqiv), which is the value obtained by dividing the molecular weight by the number of amines per molecule. A silicone oil having an amine in the side chain having a molecular weight of 320 to 8800 is preferred from the viewpoint of positive charge control, environmental stability, and development characteristics. Furthermore, a silicone oil having an amine in its side chain and having a viscosity of 20 to 3500 cps at 25°C is preferred. These may be used alone or in a mixed system of two or more. The treatment of the inorganic fine powder with the modified silicone oil containing amino groups can be carried out, for example, as follows. If necessary, the inorganic fine powder is violently agitated while being heated, and the above-mentioned modified silicone oil containing an amino group or its solution is sprayed or vaporized, or the inorganic fine powder is made into a slurry. This can be easily treated by dropping a modified silicone oil containing an amino group or a solution thereof while stirring the mixture. Furthermore, it is also preferable to perform a heat treatment thereafter at a temperature of about 50 to 400°C. The desired toner is obtained by melt-kneading the inorganic fine powder treated with modified silicone oil containing amino groups as described above with other constituent components of the toner, such as a resin as a binder and a coloring agent, followed by crushing and classification. It will be done. Alternatively, the above-mentioned modified silicone oil-treated inorganic fine powder containing an amino group may be added by mixing together with a toner formed from a resin, a colorant, or the like. The preferred processing amount ratio of the modified silicone oil containing amino groups to the inorganic fine powder is 0.1 to 50% by weight. Furthermore, the amount of the modified silicone oil containing amino groups added to the toner is preferably 0.01 to 50% by weight. According to the present invention, in which the inorganic fine powder treated with the above-mentioned modified silicone oil containing an amino group is used as a component of the developer, an electrical latent image can be developed and transferred into a clear image without fog. That is, when the developer according to the present invention is used, the toner exhibits strong and uniform positive chargeability. In addition, the modified silicone oil containing amino groups of the present invention is stable and has a heat resistance temperature of about 300°C, so it is extremely unlikely to decompose or change in quality due to thermal or mechanical shock, and it can be used for charge control. There are no problems such as a decrease in properties, and toner deterioration during durability is significantly reduced. Furthermore, the modified silicone oil containing amino groups of the present invention has strong positive chargeability and also has high humidity stability, so it has good positive chargeability even under high humidity, and clear images can be obtained. Furthermore, since the modified silicone oil containing amino groups is colorless or pale white, when white inorganic fine powder is treated according to the present invention, a positively chargeable color developer can be obtained. Note that the inorganic fine powder used in the present invention may be treated with a compound other than the modified silicone oil containing an amino group, if necessary. Other compounds that can treat the inorganic fine powder include coupling agents such as silane coupling agents, titanium coupling agents, and aluminum coupling agents, and fatty acid metal salts. Examples of the toner binder resin that can be used in the developing method of the present invention include monopolymers of styrene and substituted products thereof such as polystyrene, polyP-chlorostyrene, and polyvinyltoluene; styrene-P-chlorostyrene copolymers, and styrene-P-chlorostyrene copolymers; Propylene copolymer, styrene-vinyltoluene copolymer, styrene-vinylnaphthalene copolymer, styrene-methyl acrylate copolymer, styrene-ethyl acrylate copolymer, styrene-butyl acrylate copolymer, styrene- Octyl acrylate copolymer, styrene-methyl methacrylate copolymer, styrene-ethyl methacrylate copolymer, styrene-butyl methacrylate copolymer, styrene-alpha chloromethyl methacrylate copolymer, styrene-acrylonitrile copolymer Copolymer, styrene-vinyl methyl ether copolymer, styrene-vinyl ethyl ether copolymer, styrene-vinyl methyl ketone copolymer, styrene-butadiene copolymer, styrene-isoprene copolymer, styrene-acrylonitrile-indene copolymer Styrenic copolymers such as styrene-maleic acid copolymers, styrene-maleic acid ester copolymers; polymethyl methacrylate, polybutyl methacrylate, polyvinyl chloride, polyvinyl acetate, polyethylene, polypropylene, polyester, polyurethane, Polyamide, polyvinyl butyral, polyacrylic acid resin, rosin, modified rosin, terpene resin, phenolic resin, aliphatic or alicyclic hydrocarbon resin,
Aromatic petroleum resins, chlorinated paraffin, paraffin wax, etc. can be used alone or in combination. Coloring materials used in toner include known dyes and pigments such as carbon black, phthalocyanine blue, indanthrene blue, peacock blue,
Permanent red, lake red, rhodamine lake, Hansa yellow, permanent yellow, benzidine yellow, etc. can be widely used. The present invention will be explained in detail below using figures and examples. FIG. 1 is an explanatory diagram showing an example of an embodiment of an electrostatic latent image developing method using an insulating nonmagnetic toner.
In the figure, 1 is a cylindrical electrostatic image holder;
For example, the Carlson method, which is a known electrophotographic method, or
An electrostatic latent image is formed on this using the NP method,
The insulating non-magnetic toner 5 in the hopper 3, which is a toner supply means, is applied onto the toner carrier 2 by the application means 4 with the thickness of the toner layer regulated.
Develop it with The toner carrier 2 is a cylindrical developing roller made of stainless steel. Aluminum may be used as the material for this developing roller, or other metals may be used. Alternatively, a metal roller coated with resin or the like may be used in order to triboelectrically charge the toner to a desired polarity. Further, the toner applying means 4 may be a blade as shown in FIG. 1, or may be an elastic roller. When the application means 4 is an elastic roller, the amount of toner charge on the carrier can be changed by changing the pressing pressure of the elastic roller against the toner carrier. Moreover, the electrostatic image carrier 1
It is preferable that the distance between the toner carrier 2 and the toner carrier 2 is set to be greater than or equal to the thickness of the toner layer coated on the toner carrier 2. Further, it is preferable that a bias power source as shown in 6 is provided and a developing bias is applied between the electrostatic image carrier 1 and the toner carrier 2. FIG. 2 is an explanatory diagram of another example. In the figure, 1 is an electrostatic image carrier, 2 is a toner carrier, 5 is a toner, 3 is a hopper, 16 is a vibration member, 17 is a vibration generating means, 16a is a permanent magnet, 19 is a cleaning blade, and 10 is a toner. A supply member is shown. That is, the vibrating member 16 is vibrated with an appropriate amplitude and frequency to form a uniform toner coating layer on the toner carrier 2 rotating at a constant speed, and the toner carrier 2 and the electrostatic image carrier 1 are The electrostatic image is developed by facing the electrostatic image with a gap larger than the thickness of the toner coating layer, and causing the non-magnetic toner to fly onto the electrostatic image. The vibration of the vibrating member 16 may be at any level as long as it does not come into direct contact with the toner carrier 2. It is also possible to apply an AC and/or DC developing bias voltage between the toner carrier 2 and the electrostatic image holder 1. FIG. 3 is an explanatory diagram of another example. In the figure, 1 is an electrostatic image carrier, 2 is a toner carrier,
35 is a coating roller, 36 is a fiber brush fixed to its surface, 6 is a developing bias power source, 38 is a developing device, 9 is a toner cleaning member, and 40 is a coating bias source. That is, the toner No. 5 is uniformly applied onto the toner carrier 2 by rotating the application roller 35 and conveyed by the brush No. 36, and is caused to fly onto the electrostatic image No. 1 to be developed. The gap between the toner carrier 2 and the application roller 35 may be adjusted so as to form a uniform toner layer on the toner carrier 2, and a bias voltage indicated by 40 may be applied to uniformly apply the toner. The gap between the electrostatic image carrier 1 and the toner carrier 2 may be made larger than the above-mentioned toner layer thickness, and a developing bias of 6 may be applied during development. FIG. 4 is an explanatory diagram of another example. In the figure, 1 is an electrostatic image carrier, 2 is a toner carrier, and 4 is a toner carrier.
3 is a developing device, 5 is a one-component non-magnetic toner, 6 is a bias power supply, 48 is a magnetic roller, 49 is a non-magnetic sleeve, 50 is a magnet, 52 is a magnetic brush, 53
represents a one-component non-magnetic toner or a two-component developer in which a non-magnetic toner and a magnetic carrier are mixed. That is, a magnetic carrier is magnetically held on a non-magnetic sleeve 49 to form a brush, and by rotating 49, the carrier brush 53 draws up the toner or developer 53 and contact-coats it onto the toner carrier 2. This forms a uniform toner layer. At this time, since the carrier is held on the toner carrier 48 by magnetic force, it does not move onto the toner carrier 2. Next, the non-magnetic toner is transferred to the toner carrier 2.
The image is transferred from above onto the electrostatic image holder 1 and developed. The gap between the toner carrier 2 and the electrostatic image carrier 1 is made larger than the toner layer thickness, and the gap between the toner carrier 2 and the electrostatic image carrier 1 is made larger than the toner layer thickness.
A developing bias voltage may be applied between the image carrier 1 and the electrostatic image holder 1 . FIG. 5 is an explanatory diagram of another example. In the figure, 1 is an electrostatic image carrier, 2 is a toner carrier, and 3 is a toner carrier.
is a hopper, 52 is a magnetic brush using a carrier toner mixture, 58 is a blade for regulating toner thickness,
50 is a fixed magnet, 6 is a developing bias, and 5 is a one-component non-magnetic toner. That is, the magnetic brush 52 formed on the toner carrier 2 is circulated by rotating the toner carrier 2, and the toner in the hopper 3 is taken in and uniformly coated on the hopper 2 in a thin layer. Next, the toner carrier 2 and the electrostatic image carrier 1 are made to face each other with a gap larger than the toner layer thickness, and the one-component non-magnetic toner 5 on the toner carrier 2 is
The image is developed by flying onto the electrostatic charge image above. The total amount of charge in the toner layer can be controlled by the size or carrier amount of the magnetic brush 52 and the regulating blade 58. The gap between 1 and 2 may be made larger than the toner layer thickness, and a developing bias of 6 may be applied. Example 1 Styrene-butyl methacrylate (weight ratio 7:
3) 100 parts by weight of copolymer, 10 parts by weight of phthalocyanine blue pigment, 3 parts by weight of polyethylene wax,
Amino-modified silicone oil (viscosity at 25℃
Calcium carbonate treated with 70cps (amine equivalent: 830) (oil content 20% by weight, specific surface area 18m ² /g)
Mix 15 parts by weight and melt-knead with a roll mill. After cooling, it is roughly pulverized in a hammer mill, and then finely pulverized in a jet pulverizer. The mixture was then classified using an air classifier to obtain a fine powder having a particle size of approximately 5 to 20 μm as a positively charged toner. A toner was prepared by adding 0.4 parts by weight of colloidal silica to 100 parts by weight of this fine powder. Meanwhile, a mixture consisting of 100 parts by weight of zinc oxide, 20 parts by weight of styrene-butadiene copolymer, 40 parts by weight of n-butyl methacrylate, 120 parts by weight of toluene, and 4 parts by weight of 1% rose bengal methanol solution was dispersed in a ball mill for 6 hours. Mixed. This is 0.05
The coating was applied to a mm-thick aluminum plate with a wire bar to a dry coating thickness of 40 μm, and the solvent was evaporated with hot air to create a zinc oxide binder-based photoreceptor in the form of a drum. This photoreceptor was subjected to -6 KV corona discharge to uniformly charge the entire surface, and then an original image was irradiated to form an electrostatic latent image. The above toner was put into a developing device as shown in FIG. 1, and the electrostatic latent image described above was developed. Here, the toner carrier is a stainless steel cylindrical sleeve with an outer diameter of 50 mm, and the distance between the photosensitive drum surface and the sleeve surface is
0.25 mm, and 400 Hz, 1000 V AC and -150 V DC bias were applied to the sleeve. Next, the powder image was transferred while irradiating -7 KV direct current corona from the back side of the transfer paper to obtain a copied image. Fixing was carried out using a commercially available plain paper copying machine (trade name, NP-5000; manufactured by Canon). The resulting transferred image has a sufficiently high density of 1.5.
A good blue image with high resolution was obtained with no fog or toner scattering around the image. Durability was continuously investigated using the above developer.
The transferred image after 50,000 copies was also completely dull compared to the initial image. In addition, when the environmental conditions were set to 35℃ and 85%, the image density was 1.40, a value that was almost unchanged from normal temperature and humidity, and a clear blue image was obtained without fogging or scattering, and the durability was almost 1.40 up to 50,000 sheets. There was no change. Next, when a transferred image was obtained at a low temperature and low humidity of 10°C and 10%, the image density was as high as 1.40, solid black was developed and transferred extremely smoothly, and the image was excellent with no scattering or hollow spots. When durability tests were carried out under these environmental conditions, the density fluctuation was ±0.2 up to 50,000 sheets, which was sufficient for practical use even though continuous and intermittent copying was performed. Example 2 Styrene-butyl methacrylate (weight ratio 7:
3) 100 parts by weight of copolymer, 5 parts by weight of phthalocyanine blue pigment, 4 parts by weight of polyethylene wax,
Amino-modified silicone oil (viscosity at 25℃
Titanium oxide treated with 3500cps, amine equivalent 3800) (specific surface area 10m ² /g, oil amount 10wt%)
The same procedure as in Example 1 was carried out except that 20 parts by weight was used, and a clear blue image without fogging was obtained. Good images were also obtained under high temperature and high humidity conditions as well as under low temperature and low humidity conditions. Example 3 Styrene-butyl methacrylate (weight ratio 7:
3) 80 parts by weight of copolymer, 20 parts by weight of styrene-butadiene (weight ratio 85:15) copolymer, 5 parts by weight of phthalocyanine blue, 4 parts by weight of low molecular weight polypropylene
Part by weight, cerium oxide treated with amino-modified silicone oil (viscosity 3500 cps at 25°C, amine equivalent 3800) (specific surface area 27 m ² /g, oil amount 12
13 parts by weight (% by weight) were mixed in substantially the same manner as in Example 1 to obtain a toner having a particle size of approximately 5 to 20 μm. When an image was obtained in the same manner as in Example 1, a clear blue image without fog was obtained. Examples 4 to 6 Amine equivalent and viscosity at 25°C are 2000, respectively.
Good results were obtained in the same manner as in Example 1, except that amino-modified silicone oils of 3500 cps, 8800, 90 cps, 22500, and 60 cps were used. Example 7 When the toner of Example 1 is put into the apparatus shown in FIG. 2, the vibrating member 16 is vibrated at a frequency of about 50 Hz and an amplitude of 0.2 mm, and the toner carrier 2 is rotated at a circumferential speed of 120 mm/sec. A uniform toner coating layer with a thickness of about 50 μm was formed on the toner carrier. The toner carrier 2 and the electrostatic image holder 1 are placed facing each other with a gap of about 300μ maintained, and the toner carrier 2 has a frequency of 100 to several kilohertz.
Similar good results were obtained when development was carried out by applying a bias AC electric field with a negative peak value of -600 to -1200V and a positive peak value of +400 to +800V. Example 8 The toner shown in Example 1 was applied using a fiber brush 36 with a gap of about 2 mm between the toner carrier 2 and the application roller 35.
The toner was placed in the developing device shown in Figure 3 whose length was set to approximately 3 mm, the gap between the developing roller and the electrostatic image holder was maintained at 300 μ, and a toner layer of approximately 80 μ was formed on the developing roller. The waveform has a frequency of 200Hz and a DC component of 250V is added to the voltage peak value ±450V.
Similar good results were obtained when developing at peak voltages of +700V and -200V. Example 9 The toner of Example 1 was put into the developing device shown in FIG. 4, which was set so that the gap between the toner carrier 2 and the magnetic roller 48 was about 2 mm, and the maximum thickness of the magnetic brush 52 was about 3 mm. The gap between the developing roller and the electrostatic image holder is maintained at 300μ, a toner layer of approximately 80μ is formed on the developing roller, and the frequency is expressed as an AC waveform.
200Hz, voltage peak value ±450V and DC component 250V
Similar good results were obtained by applying peak voltages of +700V and -200V. Example 10 20g of the toner of Example 1 was placed in an iron powder carrier in advance.
20g, and the mixture is passed through the regulation blade 58.
The toner is placed in the developing device shown in Fig. 5, which is set so that the gap between the toner and the electrostatic image holder 2 is approximately 250μ, and the gap between the developing roller and the electrostatic image holder 2 is maintained at 300μ.
A toner layer of 80μ is formed on the developing roller, and the frequency is 200Hz as an AC waveform, and the voltage peak value ±
Similar good results were obtained when developing by adding a direct current component of 250 V to 450 V to give voltage peak values of +700 V and -200 V. Comparative Examples 1-3 Examples 1-3 except that they do not contain inorganic fine powder treated with amino-modified silicone oil
When I did the same thing, the image I got was poor. Comparative Example 4 Same as Example 1 except that calcium carbonate treated with aminosilane (H ₂ N (CH ₂ ) ₄ Si (OC ₂ H ₅ ) ₃ ) was used instead of treated with amino-modified silicone oil. Although good images were obtained, the images became poor under high temperature and high humidity conditions. Comparative Example 5 An insulating non-magnetic toner was produced in the same manner as in Example 1, except that calcium carbonate treated with dimethyl silicone oil (viscosity 50 cps at 25°C) was used instead of silicone oil having an amine in the side chain. It was prepared and imaged in the same manner as in Example 1. Image density 0.17 at normal temperature and humidity
I could only get a poor image of it. Example 11 Styrene-butyl methacrylate (weight ratio 7:
3) 100 parts by weight of copolymer, 10 parts by weight of phthalocyanine blue pigment and 3 parts by weight of polyethylene wax were mixed and melt-kneaded in a roll mill. After cooling, it was coarsely pulverized in a hammer mill, and then finely pulverized in a jet pulverizer. Next, it was classified using an air classifier to obtain a fine powder toner having a particle size of approximately 5 to 20 μm. 100 parts by weight of this fine powder and amino-modified silicone oil (viscosity 70 cps at 25°C, amine equivalent
830) treated alumina (oil treatment amount: 20% by weight, specific surface area: 100 m ² /g) and 1 part by weight of alumina (oil treatment amount: 20% by weight, specific surface area: 100 m 2 /g) to prepare a positively charged insulating nonmagnetic toner. Using the obtained positively charged insulating non-magnetic toner, an image was produced in the same manner as in Example 1, and the image density was
A good image of 1.35 was obtained. Comparative Example 6 Dimethyl silicone oil (viscosity 50 cps at 25°C) instead of amino-modified silicone oil
A toner having treated alumina on the surface of the toner particles was prepared in the same manner as in Example 11, except for using alumina treated with . Compared to Example 11, only a poor image with an image density of 0.41 was obtained.

[Brief explanation of drawings]

1 to 5 are explanatory views showing examples of embodiments of a developing method using insulating nonmagnetic toner. 1... Electrostatic image holder. 2...Toner carrier. 4
...Applying means. 5... Toner. 6...Bias power supply.

Claims (1)

[Claims] 1. An electrostatic image carrier that holds an electrostatic image on its surface and an inorganic fine powder treated with silicone oil having an amine in its side chain (excluding silicic acid fine powder) are contained in toner particles or A toner carrier carrying positively charged insulating non-magnetic toner on the surface of the toner particles is arranged with a certain gap in a developing section,
A developing method comprising: supporting a positively charged insulating non-magnetic toner on a toner carrier to a thickness thinner than the gap, and transferring the toner to the electrostatic image carrier in a developing section for development. 2. The developing method according to claim 1, wherein an alternating current and/or direct current bias is applied between the toner carrier and the electrostatic image carrier surface in the developing section. 3 Silicone oil with amine in the side chain is
The following structural units [In the formula, R ₁ represents hydrogen, an alkyl group, an aryl group, or an alkoxy group, R ₂ represents an alkylene group or a phenylene group, and R ₃ and R ₄ represent hydrogen, an alkyl group, or an aryl group. ] The developing method according to claim 1 or 2, which has the following. 4 Silicone oil with amine in the side chain is
Amine equivalent 320~8800 and viscosity at 25℃ 20~
Claims 1 to 3 having 3500 cps
The developing method described in any of the paragraphs.