JPH02287365A - Image forming method - Google Patents

Abstract

(57) [Summary] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

Detailed Description of the Invention [Industrial Application Field] The present invention has a step of developing an electrostatic latent image formed by electrophotography, electrostatic printing, etc. using a one-component nonmagnetic toner. The present invention relates to an image forming method.

[Conventional technology 1] Conventionally, as a method for forming an electrostatic latent image, there have been two methods: an analog method in which a document is irradiated with a halogen lamp, etc., and the reflected light is imaged on an electrostatic latent image holder, a laser beam, and an LED light. There is a digital method in which a latent image is formed by directly irradiating a latent image onto an electrostatic latent image carrier.

A developing method using a one-component non-magnetic toner for developing these electrostatic latent images involves uniformly applying a thin layer of non-magnetic toner onto the sleeve using a coating member, and bringing this into contact with an adjacent latent image carrier. The image is developed by facing the image without any problem. During development, a low frequency alternating voltage is applied between the toner carrier and the substrate conductor of the latent image carrier to cause the toner to reciprocate between the toner carrier and the latent image carrier, thereby eliminating background fog. In addition, it is possible to perform good development without thinning at the edges of the image. In this development method, since the toner is an insulator, electrostatic transfer is easy.

Analog latent images and digital latent images are formed in completely different ways, and the appropriate areas for developing these latent images are also different. There are many problems in the method of doing both that are not known in the past.

These will be explained below, and the circumstances leading to the present invention will be described.

A digital latent image is created by charging an electrostatic latent image carrier and lowering its surface potential using a light source such as a laser beam to form a potential contrast. In order to visualize this latent image, it is sufficient to develop only one of the potentials. Incidentally, developing the high potential area is called normal development, and developing the low potential area is called reverse development, and below, the case of normal development will be described.

When development is performed with the low potential area set to the bright area potential (VL) and the high potential area set to the dark area potential (Vo), the VL area is visualized as a white image and the VO area is visualized as a black image. During this development, it is sufficient to develop only the VD portion, but if the VL portion is developed, a fog appears. Although the surface potential of the VL portion is lowered by a laser spot or the like, in reality, the potential between the spots is not lowered sufficiently, and variations occur in the surface potential of the VL portion. In other words, there is a risk that a high-potential portion will occur in the VL portion, and this portion will be developed and visualized as a sliver-like fog. On the other hand, since intermediate tones in digital latent images are expressed by dot and line density, there is no need to develop intermediate potentials to visualize intermediate tones (halftones).

In order to visualize a digital latent image using the development method described above, the gradation reproducibility of the intermediate potential is not a problem, and the area near the VD area is sufficiently developed, and the low potential area near the area . A non-magnetic toner that does not develop is required.

In the conventional developing method using non-magnetic toner, there is a problem in that the curve of image density versus surface potential has a small slope near the VL and VD areas (FIGS. 2 and 3).

When developing a digital latent image, areas with high potential near the VL area are developed and toner remains. To avoid this, the slope of the curve of image density versus surface potential is adjusted as shown in Figure 2. It was necessary to use a developing method in which the developing conditions were set so as not to affect the density curve. (Development method A is used.) On the other hand, an analog latent image is formed by charging an electrostatic latent image carrier, using reflected light from the original as a light source, lowering the surface potential according to the density of the original, and setting the potential contrast. It is something.

When developing is performed with the low potential area as vL and the high potential area as VD% and the intermediate potential area as halftone potential (V□), the VL area will be a white image,
The Vr5 portion is visualized as a black image, and the V□ portion is visualized as a halftone image.

Since the visualization of intermediate tones is determined by the surface potential, it is necessary to develop each potential with good gradation.

In order to visualize an analog latent image using the above-mentioned developing method, the gradation reproducibility of the intermediate potential is also important.

Therefore, when developing an analog latent image, the slope of the image density curve with respect to the surface potential should be made small, as shown in Figure 3.
A developing method is used in which developing conditions are set so that gradation is obtained. (Development method B is used.) In addition, in order to improve tone reproducibility, if the slope of potential-density is made smaller, the skirt will extend toward the VL and VO areas, but in the case of an analog latent image, the reflected light will appear in the VL area. Since the light is uniformly irradiated and the potential is constant, fogging does not occur.

However, when developing method B is applied to a digital latent image, a trailing occurs near V of the potential-density slope, resulting in fogging in the VL portion. On the other hand, if developing method A is applied to an analog latent image, the gradient of potential-density is large, so a slight change in potential will greatly change the density, resulting in poor reproduction of halftones and the gradation of halftones cannot be obtained. .

Conventionally, in order to form an analog latent image, 400
Since this is carried out using visible light of ~700 nm, a photosensitive drum having spectral sensitivity in this wavelength range is used.

On the other hand, when forming a digital latent image using a semiconductor laser or the like, a photosensitive drum having spectral sensitivity in the infrared region around 80 Onm is used.

It has both of these spectral sensitivities and charging characteristics.

There was no photosensitive drum with sufficient electrophotographic properties such as residual potential and dark decay, and there was also no toner that could be applied to it, so it was difficult to develop digital latent images and analog latent images in the same image forming device. This was not possible using conventional methods.

Further, in order to use for multicolor development, a toner that can provide vivid colors is required, but since it is difficult to obtain this with a magnetic toner, a nonmagnetic toner that can develop the above-mentioned latent image is required.

[Problems to be Solved by the Invention] An object of the present invention is to provide an image forming method using a developing method using a single-component non-magnetic toner that solves the above-mentioned problems and visualizes a digital latent image and an analog latent image. This is what we provide.

Another object of the present invention is to provide an image forming method that can simultaneously visualize a digital latent image and an analog latent image.

Still another object of the present invention is to provide an image forming method that can produce a brightly colored image with high image density, no fog, and excellent dot and line expression when visualizing a digital latent image or an analog latent image. It is something to do.

Still another object of the present invention is to provide an image forming method with excellent gradation in visualizing an analog latent image.

The applicant has discovered that it is possible to obtain a photosensitive drum that has uniform spectral sensitivity from white light to long wavelength light, which is necessary for forming digital latent images and analog latent images, and has high sensitivity and excellent electrophotographic characteristics. This makes it possible to provide an image forming device that incorporates the combined functions of both a copier and a laser printer.
There is a need for an image forming method that can develop a digital latent image without fogging, develop an analog latent image with good gradation, and visualize each latent image, and as a result of study, the present invention was developed. .

[Means and effects for solving the problems] The present invention provides an organic photoreceptor for electrophotography that contains a small amount (of two or more charge generating substances and retains a digital electrostatic charge image and an analog electrostatic charge image) and a one-component system. A toner carrier carrying non-magnetic toner on its surface is arranged with a certain gap in the developing section, and the one-component non-magnetic toner is regulated on the toner carrier to a thickness thinner than the gap. In the image forming method, the one-component non-magnetic toner contains 5) 12 to 60 number % of non-magnetic toner particles having a particle size of zm or less;
1 to 33 non-magnetic toner particles with a particle size of 8 to 12.7 μm
% by number, contains 2.0 volume % or less of non-magnetic toner particles having a particle size of 16 μm or more, and has a particle size distribution in which the volume average particle size of the one-component non-magnetic toner is 4 to 10 μm. It is characterized by

The non-magnetic toner in the present invention has a saturation magnetization of 0 to 10, em in an external magnetic field of 5000 oersted (Oe).
g/g toner.

The electrostatic image carrier of the present invention is an organic photoreceptor having a photosensitive layer containing at least a charge generating substance and a charge transporting substance on a conductive substrate.
f! It is characterized by using a photoreceptor containing a compound of

The ionization potential and electrical potential of multiple charge-generating substances, which are compounds that have spectral sensitivity in the visible light region (400 nm to 700 nm) and compounds that have spectral sensitivity in the infrared region (700 r+m to 900 nm), match, and the sensitivity, By using an organic photoreceptor using a charge transport material with excellent residual potential and charging characteristics, an electrostatic image carrier having spectral sensitivity ranging from visible light to semiconductor laser light can be obtained.

By using such an electrostatic image holder, it is possible to form an analog latent image using white reflected light from the document table and a digital latent image using a laser spot from a semiconductor laser or the like on the electrostatic image holder. can.

For example, as a charge generating substance, the following structural formulas (1) and (2) are used.
There is a compound that has

...(1) R1:F, CR, Br, IIh: CHs, -C)lzc)Is Also, as the charge transport substance, there is a compound having the following structural formula (3).

H3 Non-magnetic toner particles of the present invention having a particle size of 5 μm or less
Contains 60% by number, 1 to 33% by number of non-magnetic toner particles with a particle size of 8 to 12.7 μm, and 2.0% by volume or less of non-magnetic toner particles with a particle size of 16 μI or more. A toner carrier carrying a non-magnetic toner on its surface having a particle size distribution in which the volume average particle diameter of the magnetic toner is 4 to 10 μI is disposed at a constant gap in a developing section, and the non-magnetic toner is Using a developing method in which the toner carrier is regulated to a thickness thinner than the gap and transported to the developing section for development, the digital latent image and analog latent image described above can be faithfully visualized and a high-density image without fogging can be created. Images can be given.

The non-magnetic toner having the particle size distribution characteristic of the present invention is
It is possible to faithfully reproduce down to the fine lines of the latent image formed on the photoreceptor, and it is also excellent in reproducing halftone dots and digital dot latent images, and has excellent gradation and resolution. give an image. Furthermore, it maintains high image quality even when copying or printing is continued, and even in the case of high-density images, it is possible to perform good development with less toner consumption than conventional non-magnetic toner, making it economical. This has advantages in terms of flexibility and miniaturization of the copying machine or printer body.

In the non-magnetic toner according to the present invention, it is not necessarily clear how such an effect can be achieved, but it is estimated as follows.

That is, one of the characteristics of the nonmagnetic toner of the present invention is that the number of nonmagnetic toner particles having a particle size of 5 μm or less is 12 to 60% by number. Conventionally, in non-magnetic toner, non-magnetic toner particles with a particle diameter of 5 μI or less are difficult to control the amount of charge, and impair the fluidity of the non-magnetic toner.
In addition, as a component that scatters toner and stains the machine,
It was thought that it was necessary to actively reduce this component, which causes image fog.

However, according to the inventors' study, 5tLII
It has been found that non-magnetic toner particles of 4 or less are an essential component for forming high quality images.

For example, using a non-magnetic toner with a particle size distribution ranging from 0.5 μm to 30 μm, the surface potential on the photoreceptor is changed from a large development potential contrast where large numbers of toner particles are likely to be developed, to halftone, and The latent image is developed by changing the surface potential on the photoreceptor, down to a small development potential contrast where only a few toner particles are developed.
When the developed toner particles on the photoreceptor were collected and the toner particle size distribution was measured, it was found that there were many non-magnetic toner particles with a size of 8 μm or less, and in particular, there were many non-magnetic toner particles with a size of 5 μm or less. In other words, when non-magnetic toner particles with a particle size of 5 μm or less, which is the most suitable for development, are smoothly supplied to develop the latent image on the photoreceptor, the latent image is faithful to the latent image, does not protrude from the latent image, and is truly reproduced. Images with excellent quality can be obtained.

Further, in the non-magnetic toner of the present invention, 8 to 12.7
One of the characteristics is that the number of particles in the μm range is 1 to 33% by number. As mentioned above, this is related to the necessity of the presence of non-magnetic toner particles with a particle size of 5 μm or less.
Non-magnetic toner particles with a particle size of m or less have the ability to strictly cover the latent image and reproduce it faithfully, but in the latent image itself,
The electric field strength at the surrounding edge portions is higher than that at the center, and therefore the toner particles may be thinner inside the latent image than at the edge portions, and the image density may appear to be thinner. In particular, 5
Non-magnetic toner particles of μm or less have a strong tendency to do so. However, the present inventors have found that this problem can be solved and the image can be made even clearer by containing toner particles in the range of 8 to 12.7 μm in an amount of 1% to 33% by number. In other words, it is thought that this is because toner particles in the particle size range of 8 to 12.7 μm have a suitably controlled amount of charge compared to non-magnetic toner particles with a particle size of 5 μm or less, but the edge portion of the latent image The toner is supplied to the inner side, where the electric field strength is lower, to compensate for the lack of adhesion of the inner toner particles to the edge areas, and a uniformly developed image is formed, resulting in high density and excellent resolution and gradation. This provides a sharp image.

Furthermore, the amount of non-magnetic toner particles having a particle size of 16 μm or more is preferably 2.0% by volume or less, and is preferably as small as possible.

By adopting a completely different approach from the conventional viewpoint, the non-magnetic toner according to the present invention solves the conventional problems and makes it possible to withstand the recent strict demands for high image quality.

The configuration of the present invention will be explained in more detail.

Non-magnetic toner particles with a particle size of 5μ or less account for 17 of the total number of particles.
~60% by number, preferably 25~50%
17% by number of non-magnetic toner particles with a particle size of 5 μm or less, preferably 30 to 50% by number.
If it is below, there are few non-magnetic toner particles effective for high image quality, and in particular, as the toner is used by continuing copying or printing, the effective non-magnetic toner particle component decreases, and as shown in the present invention, The particle size distribution of the non-magnetic toner becomes unbalanced, and the image quality gradually deteriorates. In addition, if the content is 60% or more, non-magnetic toner particles tend to aggregate with each other, resulting in toner lumps larger than the original particle size, resulting in rough image quality, lowering resolution, or reducing latent images. The difference in density between the edges and the inside becomes large, and the image tends to appear hollow.

In addition, the number of particles in the range of 8 to 12.7 μm is 1 to 33%.
%, preferably 8 to 20% by number.

When the amount is more than 33% by number, image quality deteriorates and more development than necessary occurs, that is, too much toner is applied, leading to an increase in toner consumption. On the other hand, if it is less than 1% by number,
It becomes difficult to obtain high image density.

In addition, non-magnetic toner particles with a particle size of 16 μm or more are 2.0 μm or more.
It is preferably less than or equal to volume %, more preferably 1.0
It is not more than 0.5% by volume, more preferably not more than 0.5% by volume. If the amount is more than 2.0% by volume, it not only hinders fine line reproduction, but also causes coarse toner particles of 16 μm or more to protrude on the thin layer surface of toner particles developed on the photoreceptor during transfer. This makes the delicate state of close contact between the photoreceptor and the transfer paper via the toner layer irregular, causing fluctuations in transfer conditions and causing a defective transfer image. In addition, the volume average diameter of the non-magnetic toner is 4~
The thickness is 10 .mu.m, preferably 4 to 9 .mu.m, and this value cannot be considered separately from the above-mentioned components. When the volume average particle diameter is less than 4 μm, in applications with a high image area ratio such as graphic images, the amount of toner applied on the transfer paper is small, which tends to cause problems such as low image density. This is considered to be due to the same reason as the reason why the density inside the edge portion of the latent image decreases as described above. If the volume average particle diameter exceeds 10 μm, the resolution will not be good, and even if copying is good at the beginning, image quality will tend to deteriorate with continued use.

FIG. 4 shows the slope of image density with respect to surface potential obtained by a developing method using a non-magnetic toner having a specific particle size distribution, which is a feature of the present invention.

As is clear from Figure 4, it has a moderate slope, so
Since an analog latent image is faithfully visualized according to the potential, an image with Il tonality in halftone reproduction can be obtained. Also vL club karari. It has good cutting ability and does not cause fogging even in digital latent images. The sharpness from the VH part to the VO part is good, and sufficient image density can be obtained in analog latent images and digital latent images, and density unevenness does not occur. As will be described later, the non-magnetic toner having a specific particle size distribution as in the present invention adheres well to the latent image, and it adheres uniformly to the latent image, and a constant amount of non-magnetic toner is always developed depending on the potential of the latent image. Therefore, it is possible to obtain an image in which the change from vL to VHl or from VH to v.

The particle size distribution of the toner can be measured by the fm method, but in the present invention it was measured using a Coulter counter.

In other words, the measuring device is Coulter counter TA.
- An interface (manufactured by Nikkaki) that outputs number distribution 1 volume distribution using type II (manufactured by Coulter) and CX-
1 A personal computer (manufactured by Canon) is connected, and a 1% NacR* solution is prepared using primary sodium chloride as the electrolyte. As a measurement method, the electrolytic aqueous solution 100-1
50mj of dispersant and surfactant, preferably alkylbenzene sulfonate, 0.1 to 5m! ! In addition, 2 to 20 mg of the measurement sample is added. The electrolytic solution in which the sample was suspended was subjected to a dispersion treatment for about 1 to 3 minutes using an ultrasonic dispersion device, and then particles with a size of 2 to 40 μm based on the number of particles were dispersed using the Coulter Counter TA-II model using a 100 μm aperture as an aperture. The particle size distribution of the sample was measured and the values according to the present invention were determined therefrom.

As the binder resin used in the non-magnetic toner according to the present invention, the following toner binder resins can be used when a heating and pressure roller fixing device having an oil coating device is used.

For example, 4! of styrene and its substituted products such as polystyrene, poly-p-chlorostyrene, and polyvinyltoluene.
Coalescence: Styrene-p-chlorostyrene copolymer, styrene-vinyltoluene copolymer, styrene-vinylnaphthalene copolymer, styrene-acrylic acid ester copolymer, styrene-methacrylic acid ester copolymer, styrene-α-chlor Methyl methacrylate copolymer, styrene
Acrylonitrile copolymer, styrene-vinyl methyl ether copolymer, styrene-vinyl ethyl ether copolymer, styrene-vinyl methyl ketone copolymer, styrene-butadiene copolymer, styrene-isoprene copolymer, styrene-acrylonitrile- Styrenic copolymers such as indene copolymers; polyvinyl chloride, phenolic resin, naturally modified phenolic resin, natural resin-modified maleic acid resin, acrylic resin, methacrylic resin, polyvinyl acetate, silicone resin, polyester resin, polyurethane, polyamide Resin, furan resin, epoxy resin, xylene resin, polyvinyl butyral, terpene resin, coumaron indene resin, petroleum resin, etc. can be used.

In the heating and pressure roller fixing method in which little oil is applied, the so-called offset phenomenon, in which a part of the toner image on the toner image support member is transferred to the roller, and the adhesion of the toner to the toner image support member are important issues. be. Toners that are fixed with less thermal energy usually tend to block or cake during storage or in a developing device, so these problems must also be taken into consideration. The physical properties of the binder resin in the toner are most significantly involved in these phenomena. Therefore, when using the heated pressure roller fixing method in which little oil is applied in the present invention, the selection of the binder resin is more important. Preferred binding materials include crosslinked styrenic copolymers or crosslinked polyesters.

Examples of comonomers for the styrene monomer in the styrenic copolymer include acrylic acid, methyl acrylate, ethyl acrylate, butyl acrylate, dodecyl acrylate, octyl acrylate, 2-ethylhexyl acrylate, phenyl acrylate, and methacrylate. acids, monocarboxylic acids having a double bond such as methyl methacrylate, ethyl methacrylate, butyl methacrylate, octyl methacrylate, acrylonitrile, methacrinitrile, acrylamide, etc., or substituted products thereof: for example, maleic acid, butyl maleate, Dicarboxylic acids with double bonds and substituted products thereof such as methyl maleate, dimethyl maleate, etc.; vinyl esters such as vinyl chloride, vinyl acetate, vinyl benzoate, etc.; e.g. ethylene, propylene, butylene, etc. vinyl monomers such as ethylene olefins; vinyl ketones such as vinyl methyl ketone, vinyl hexyl ketone; vinyl ethers such as vinyl methyl ether, vinyl ethyl ether, vinyl isobutyl ether; More than one is used.

As the crosslinking agent, compounds having two or more polymerizable double bonds are mainly used, such as aromatic divinyl compounds such as divinylbenzene and divinylnaphthalene; for example, ethylene glycol diacrylate,
Carboxylic acid esters having two double bonds such as ethylene glycol dimethacrylate and 1,3-butanediol dimethacrylate; divinyl compounds such as divinylaniline, divinyl ether, divinyl sulfide, and divinyl sulfone; and three or more vinyl Compounds having groups can be used alone or as a mixture.

In addition, when using a pressure fixing method, it is possible to use a binder resin for pressure fixing toner, such as polyethylene,
Examples include polypropylene, polymethylene, polyurethane elastomer, ethylene-ethyl acrylate copolymer, ethylene-vinyl acetate copolymer, ionomer resin, styrene-butadiene copolymer, styrene-isoprene copolymer, linear saturated polyester, and paraffin.

In addition, in the non-magnetic toner of the present invention, a charge control agent is added to the toner particles (internal addition) or mixed with the toner particles (external addition).
It is preferable to use it as The charge control agent makes it possible to optimally control the amount of charge depending on the developing system, and in particular, in the present invention, it is possible to further stabilize the balance between particle size distribution and charge. As a positive charge control agent, modified products such as nigrosine and fatty acid metal salts; tributylbenzylammonium-1-hydroxy-
Quaternary ammonium salts such as 4-naphthosulfonate, tetrabutylammonium tetrafluoroborate; diorganotin oxides such as dibutyltin oxide, dioctyltin oxide, dicyclohexyltin oxide; dibutyltinborate, dioctyltinborate, dicyclohexyltinborate, etc. These diorganostin borates can be used alone or in combination of two or more. Among these, charge control agents such as nigrosine and quaternary ammonium salts are particularly preferably used.

In addition, - format [wherein Ro represents H or CH3, R2 and R1 are substituted or unsubstituted alkyl groups (preferably 01 to C
4) is shown. ]; or copolymers with polymerizable monomers such as styrene, acrylic esters, and methacrylic esters as described above can be used as positive charge control agents; in this case, these The charge control agent also functions as (all or part of) a binder resin.

The above-mentioned charge control agent (one that does not function as a binder resin) is preferably used in the form of fine particles. In this case, the number average particle size of this charge control agent is specifically:
The thickness is preferably 4 μm or less (more preferably 3 μm or less).

When internally added to the toner, such a charge control agent is added in an amount of 0.1 to 20 parts by weight (or even 0.1 to 20 parts by weight) per 100 parts by weight of the binder resin.
．． 2 to 10 parts by weight) is preferably used.

The non-magnetic toner of the present invention preferably contains a colorant, if necessary. As the colorant, conventionally known dyes and pigments can be used, such as nigrosine, carbon black, phthalocyanine blue, peacock blue, permanent red, lake red, rhodamine lake, Banzai Niro, permanent yellow benzidine yellow, etc. Can be widely used.

Its content is 0.5 parts per 101) parts of the binder resin.
~20 parts by weight, roughly 0) In order to improve the permeability of the IP film, the amount is preferably 12 parts by weight or less, and more preferably 0.5 to 9 parts by weight.

Further, other additives may be used as necessary. As other additives, for example, if 0.1 to 5 wt % of a conductivity imparting agent such as carbon black or tin oxide is added, excessive charging on the sleeve can be suppressed and a stable charging state can be maintained. Further, the addition of spherical fine particle resin powder having an average particle diameter of O, OS ~ 3 μm, preferably 0.1 to 1 μm can also achieve the same effect and is also effective in increasing the sharpness of image quality. The amount added is 0.01 to 10 wt%, preferably 0.05 to 5 wt%, more preferably 0.05 to 2 wt%.
t% is good).

It is preferable that the spherical fine particle resin powder having a polarity opposite to that of the non-magnetic toner is charged in the opposite direction or weakly in the same polarity.

Other additives include, for example, lubricants such as zinc stearate, or abrasives such as cerium oxide or silicon carbide, or flow agents such as colloidal silica or aluminum oxide, and anti-caking agents.

In addition, in order to improve mold releasability during hot roll fixing, waxy substances such as low molecular weight polyethylene, low molecular weight polypropylene, microcrystalline wax, carnauba wax, Sasol wax, paraffin wax, etc.
It is also one of the preferred embodiments of the present invention to add about 5 wt% to the non-magnetic toner.

To prepare the non-magnetic toner for developing electrostatic images according to the present invention, a vinyl or non-vinyl thermoplastic resin, a pigment or dye as a coloring agent, a charge control agent, other additives, etc. are added as necessary. After thorough mixing using a mixer such as a ball mill, the mixture is melted using a heat kneader such as a heated roll, kneader, or extruder. The non-magnetic toner according to the present invention can be obtained by dispersing or dissolving pigments or dyes in the resins that have been kneaded and kneaded, and then cooling and solidifying, followed by pulverization and strict classification. I can do it.

Another method is to obtain a toner by dispersing the constituent materials in a binder resin solution and then spray-drying; or by mixing a predetermined material with the monomers that constitute the binder resin to form an emulsified suspension. A polymerization toner production method in which the toner is then polymerized to obtain a toner; or a method in which a so-called microcapsule toner consisting of a core material and a shell material contains a predetermined material in the core material, the shell material, or both; etc. This method can be applied.

Further, fine silica powder may be added internally or externally to the non-magnetic toner according to the present invention, but it is more preferable to mix it externally. A non-magnetic toner having a particle size distribution characteristic of the present invention has a larger specific surface area than conventional toners. When non-magnetic toner particles are brought into contact with the surface of a cylindrical conductive sleeve that has a magnetic field generating means inside for triboelectric charging, the number of times the toner particle surface contacts the sleeve increases compared to conventional non-magnetic toner. , the non-magnetic toner according to the present invention, which tends to cause abrasion of toner particles;
When fine silica powder is used in combination, the fine silica powder is interposed between the toner particles and the sleeve surface, thereby significantly reducing wear. This makes it possible to prolong the life of the non-magnetic toner, maintain stable charging properties, and provide a developer containing non-magnetic toner that is more excellent even in long-term use.

As the silica fine powder, both silica fine powder produced by a dry method and a wet method can be used, but from the viewpoint of filming resistance and durability, it is preferable to use a silica fine powder produced by a dry method.

The dry method mentioned here is a method for producing fine silica powder produced by vapor phase oxidation of a silicon halide compound. For example, this method utilizes the thermal decomposition oxidation reaction of silicon tetrachloride gas in oxygen and hydrogen, and the basic reaction formula is as follows.

5iCj'4+ 2 )+2 + 02→5i02+
4 HCl2 Also, in this manufacturing process, it is also possible to obtain a composite fine powder of silica and other metal oxides by using other metal halide compounds such as aluminum chloride or titanium chloride together with a silicon halide compound. Also includes.

Commercially available fine silica powder produced by vapor phase oxidation of a silicon halogen compound used in the present invention includes, for example, those commercially available under the following trade names.

AERO5IL (Japan Aerosil) QQ x50 T600 0X80 0X170 0X84) MS-7 S-75 Ca-0-5iL (f; ABOTO S-5 E) l-5 Wacker HDK N 20
V 15 (WACKER-CI (EMI)
E GMB) 1 company) N20ED-CFine
5ilica (Dow Corning, Inc.) Fransol (Fransi 1, Inc.) On the other hand, various conventionally known methods can be applied to the method of producing the silica fine powder used in the present invention by a wet method.

For example, the general reaction formula for the decomposition of sodium silicate with an acid is shown below.

Na1O'X5102+ )ICj + H2O-5i
Oz'nthO+ NaC11 Other methods include decomposition of sodium silicate with ammonia salts or alkali salts, generation of alkaline earth metal silicate from sodium silicate, and then decomposition with acid to produce silicic acid, method of decomposing sodium silicate solution with There are methods of converting silicic acid into silicic acid using an ion exchange resin, and methods of using natural silicic acid or silicate.

The silica fine powder referred to herein can be any of anhydrous silicon dioxide (silica) and other silicates such as aluminum silicate, sodium silicate, potassium silicate, magnesium silicate, and zinc silicate.

Commercially available fine silicic acid powders synthesized by a wet method include those sold under the following trade names, for example.

Carplex Shionogi & Co., Ltd. 21 Bu Seal Nippon Silica Tora Seal. Fine Seal Tokuyama Sodavita Seal Multi-Wooden Hijiruton, Silnex Mizusawa Chemical Star Seal Kamishima Chemical Himeji Le Ehime Pharmaceutical Products Lloyd Fuji Davison Chemical Formerly 5it (High Seal) Plttsburgh Plate Glass, G
.

(Pittsburgh Plate Glass) Durosil Ultrasil FiLIL
stoff-Gesellschaft Marqua
rt (Fürstzuf Gesellschaft Markorth) Manosll (Manosill) Hardman and I (olden (Hardman and Holden) ) 1 oesch (:hemische Fabrik Hoesc
h ni-G (Hiemische Fabric Herras) Sll-5tone (Sil-stone) Stone
er Rubber Co, (Stoner Rubber) Nalco (Nalco) Nalco Chell, Co, (Nalco Chemical) Quso (Shoes) Philadelphia Quartz (Philadelphia Co.

quartz) Insil 1111nois Minerals Co.

(Illinois Mineral) Calcium 5ilikat (Calcium Silicate) Chemfsche Fabrtk Hoe
sch, Ni-G (Hiemische Fabrik Hetsch) Ca1s11. (Kargil) Fiilistoff-Gesellschaft
Marquart Fortafil () Alterfil In+perial Chemical Industry
ries. Ltd.

(Imperial Chemical Industries) Microcal Joseph Crosflels & Son
s Ltd.

(Joseph Crosfield & Sons) Vulkasil Farbenfabriken Dryer, ^
．． -G.

(Falpenfabriken Bayer) Tufkntt
(Toughknit) Durham Chemicals. Ltd.

(Durham Chemicals) Sil Moss White Masonry
Among the silica fine powders mentioned above, the specific surface area due to nitrogen adsorption measured by the BET method is 3 om"/g or more (especially 50 to 400
m27g) gives good results. Silica fine powder 0.01 to 100 parts by weight of non-magnetic toner
It is good to use 8ffi parts, preferably 0.1 to 5 parts by weight.

In addition, when used as a positively charged nonmagnetic toner like the nonmagnetic toner of the present invention, the silica fine powder added to prevent toner abrasion may also be used as a positively charged nonmagnetic toner rather than a negatively charged one. It is better to use fine silica powder! It is preferable because it does not impair stability.

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

In the present invention, positively charged silica refers to silica that has a positive triboelectric charge relative to the iron powder carrier when measured by a blow-off method.

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

(In the formula, R represents hydrogen, an alkyl group, an aryl group, or an alkoxy group, % R2 represents an alkylene group or a phenylene group, R3 and R4 represent hydrogen, an alkyl group, or an aryl group, and R8 represents a nitrogen-containing hetero In addition, the above-mentioned alkyl group, aryl group, alkylene group. The phenylene group may have an organo group having a nitrogen atom, and may also have a substituent such as a halogen within a range that does not impair chargeability.

Furthermore, the nitrogen-containing silane coupling agent used in the present invention is
It generally has a structure shown by the following formula.

R, - Si- Yn (R represents an alkoxy group or a halogen, Y represents an amino group or an organo group having at least one nitrogen atom, m and n are integers of 1 to 3, and m+n=
It is 4. ) Examples of the organo group having at least one nitrogen atom include an amino group having an organic group as a substituent, a nitrogen-containing heterocyclic group, or a group having a nitrogen-containing heterocyclic group. Examples of the nitrogen-containing heterocyclic group include unsaturated heterocyclic groups and saturated heterocyclic groups, and known ones can be used. Examples of the unsaturated heterocyclic group include the following.

(The following is a blank space) Examples of the saturated heterocyclic group include the following.

(2) The heterocyclic group used in the present invention is preferably a five-membered ring or a six-membered ring in consideration of stability.

Examples of such treatment agents include aminopropyltrimethoxysilane, aminopropyltriethoxysilane, dimethylaminopropyltrimethoxysilane, diethylaminopropyltrimethoxysilane, dipropylaminopropyltrimethoxysilane, dibutylaminopropyltrimethoxysilane, Monobutylaminopropyltrimethoxysilane, dioctylaminopropyltrimethoxysilane, dibutylaminopropyldimethoxysilane, dibutylaminopropyl monomethoxysilane, dimethylaminophenyltriethoxysilane, trimethoxysilyl-γ
-Propylphenylamine, trimethoxysilyl-γ-
Propylbenzylamine, etc. Furthermore, as the nitrogen-containing heterocycle, those having the above-mentioned structure can be used. Examples of such compounds include trimethoxysilyl-γ-propylpiperidine, trimethoxysilyl-γ-propyl sulfoline, etc. , trimethoxysilyl-γ-propylimidazole, and the like.

The application amount of these treated positively charged silica fine powders is
0,0 for 100 II parts of positively charged magnetic toner
The effect is exhibited when the amount is 1 to 8 parts by weight, and particularly preferably 0.
．． A preferred form of addition is that when added in an amount of 1 to 5 parts by weight, it exhibits positive chargeability with excellent stability.
It is preferable that 1 to 3 parts by weight of lA treated silica fine powder be attached to the surface of the toner particles. Note that the untreated fine silica powder described above can also be used in the same amount.

Furthermore, the silica fine powder used in the present invention has been treated with a silane coupling agent, a treatment agent such as silicone oil, an organosilicon compound for the purpose of hydrophobization, or a combination of various treatment agents, if necessary. It may also be treated with the above-mentioned treatment agent that reacts with or physically adsorbs the silica fine powder. Examples of such treatment agents include hexamethyldisilazane, trimethylsilane, trimethylchlorosilane, trimethylethoxysilane, dimethyldichlorosilane, methyltrichlorosilane, allyldimethylchlorosilane, allyl phenyldichlorosilane, and benzyldimethylchlorosilane. , bromomethyldimethylchlorosilane, α-chloroethyltrichlorosilane, β-chloroethyltrichlorosilane, chloromethyldimethylchlorosilane, triorganosilylmercaptan, trimethylsilylmercaptan, triorganosilylacrylate, vinyldimethylacetoxysilane, dimethylethoxysilane, dimethyl dimethoxysilane, diphenyljethoxysilane, hexamethyldisiloxane, 1,3-divinyltetramethyldisiloxane, 1,3-diphenyltetramethyldisiloxane, and having from 2 to 12 siloxane units per molecule, with terminal There are dimethylpolysiloxanes and the like containing hydroxyl groups bonded to one SL in each located unit.

Further, silicone oil is generally represented by the following formula.

Preferred silicone oils include those having a viscosity of approximately 5 to 5000 cSt at 25°C, such as methyl silicone oil, dimethyl silicone oil, phenylmethyl silicone oil, chlorphenylmethyl silicone oil, alkyl-modified silicone oil, and fatty acid-modified silicone oil. , polyoxyalkylene-modified silicone oil, etc. are preferred. These are t f
i or a mixture of two or more.

Further, in the non-magnetic toner according to the present invention, a fine powder of a fluorine-containing polymer may be added internally or externally. Examples of fluorine-containing polymer powders include fine powders of polytetrafluoroethylene, polyvinylidene fluoride, etc., and tetrafluoroethylene-vinylidene fluoride copolymers. In particular, fine powders of polyvinylidene fluoride are fluid. It is preferable in terms of polishability and polishability.

The amount added to the toner is 0.01 to 2. Owt%, especially 0.02-1. Owt% is preferred.

Particularly, in non-magnetic toners in which silica fine powder is combined with the above-mentioned fine powders and mixed with external additives, the reason is not clear, but
Stabilizes the state of existence of silica attached to the toner, for example, prevents the attached silica from being released from the toner and reducing the effect on toner abrasion and sleeve staining, and further increases charging stability. It is possible to do so.

An example of a specific apparatus that can be used to carry out the developing step in the present invention is shown in FIG. 5, but this is not intended to limit the present invention in any way.

The nonmagnetic toner of the present invention is preferably applicable to an image forming method in which a latent image is developed while flying the toner from a toner carrier such as a cylindrical sleeve to a latent image carrier such as a photoreceptor. That is, the non-magnetic toner is applied to the sleeve in a thin layer by the application member, and at this time, a triboelectric charge is applied mainly through contact with the sleeve surface, and the non-magnetic toner is applied in a thin layer onto the sleeve surface. The thickness of the thin layer of non-magnetic toner is formed to be thinner than the gap between the photoreceptor and the sleeve in the development area. When developing a latent image on the photoreceptor, it is preferable to apply an alternating electric field between the photoreceptor and the sleeve and cause the magnetic toner having triboelectric charges to fly from the sleeve to the photoreceptor.

Examples of the alternating electric field include a pulsed electric field, an alternating current bias, or a combination of alternating current and direct current bias.

FIG. 5 shows an example of an embodiment of an electrostatic latent image developing method and a developing device using the one-component developer non-magnetic toner of the present invention.
In the figure, reference numeral 1 denotes a cylindrical electrostatic image holder, on which an electrostatic latent image is formed by, for example, a known electrophotographic method such as the Carlson method or the NP method. The magnetic non-magnetic toner 5 is applied onto the toner carrier 2 by a coating means 4 that controls the thickness of the toner layer and is used for development. The toner carrier 2 is a cylindrical developing roller made of stainless steel.

The developing roller may be made of aluminum or other metals. Alternatively, a metal roller coated with resin or the like may be used in order to triboelectrically charge the toner to a desired polarity. Additionally, the developer roller may be made of an electrically conductive non-metallic material. Although not shown in the drawings, spacer rollers made of high-density polyethylene are inserted into the shafts of both ends of the toner carrier 2. By abutting these spacer rollers against both ends of the electrostatic image holder 1 and fixing the developing device, the distance between the electrostatic image holder 1 and the toner carrier 2 is adjusted so that the toner coated on the toner carrier 2 Set and maintain the layer thickness or higher. For example, this interval is 10
0-500ttII+1 preferably 150-30041
It is 11. If this distance is too large, the electrostatic force exerted by the electrostatic latent image on the electrostatic image carrier 1 on the non-magnetic toner coated on the toner carrier 2 will be weak, resulting in a decrease in image quality, especially in the visualization of fine lines during development. becomes difficult. Furthermore, if this distance is too narrow, there is a great risk that the toner applied on the toner carrier 2 will be compressed and aggregated between the toner carrier 2 and the electrostatic image holder 1. 6 is a developing bias power supply;
A voltage can be applied between the toner carrier 2 and the back electrode of the electrostatic holder 1. This developing bias voltage is a developing bias voltage as described in Japanese Patent Publication No. 58-32375.

An example of a specific apparatus that can be used to carry out the image forming method of the present invention is shown in FIG. 6, but this is not intended to limit the present invention in any way.

The process of forming an electrostatic latent image on the photoreceptor 30 will be explained. −
After the photoreceptor 30 is charged by the charger 29, the original 21
irradiated with a halogen lamp 24 and its reflected light! .

The photoreceptor 30 is
An analog latent image is formed. Further, the electrical signals output from the keyboard, external equipment, or image information obtained from the original are processed by the image processing unit 39 and input to the laser scanner 27, and the laser beam I
D is irradiated onto the photoreceptor 30 to form a digital latent image.

The latent images formed in this manner are simultaneously developed in the developing device 31 using the above-described developing process to form a secondary image. Photoreceptor 3
The toner image formed on the toner image is transferred to a transfer material 38 by a transfer separation charger 35, and then the transfer material 38 is separated from the photoreceptor 30 and fixed by a fixing device 37 to obtain an image.

Further, the photoreceptor 30 is cleaned of residual toner after transfer in a cleaner section 33, and electricity is removed by a pre-exposure lamp z8, and the photoreceptor 30 is used repeatedly.

[Examples] The present invention will be specifically explained below with reference to Examples, which do not limit the present invention in any way. All parts in the following formulations are parts by weight.

An image forming apparatus used for image formation will be described with reference to FIG.

First, the photosensitive drum 30 used will be explained.

100 parts of conductive powder coated with tin oxide containing 10% antimony oxide so that titanium oxide is 75%, 100 parts of resol type phenolic resin, 30 parts of methanol
In addition to a solution consisting of 100 parts of methyl cellosolve and a paint that was sufficiently dispersed with a ball mill, a 80φ x 360m
It was coated by dip coating onto a substrate, which is an aluminum cylinder, and was cured by heating at 140° C. for 30 minutes to form a 20 μl conductive undercoat layer. Polyamide resin (B-66-6
1 part of 10-124 element-nylon) and 8-nylon resin (methoxymethylated 6-nylon, methoxylation rate 30%)
) in a solvent consisting of 50 parts of methanol and 40 parts of butanol was applied by dip coating to form an intermediate layer having a thickness of 0.5 μm.

Next, 2.5 parts of the disazo pigment shown in formula (4) and (5)
1.0 part of disazo pigment shown in the formula ((blank below) Polyvinyl benzal resin R...(4) (M n = 85,000. Degree of benzalization 80) 2
and 100 parts of cyclohexanone were dispersed in a sand mill for 2 hours using 1φ glass beads. Add 40 to 80 parts of tetrahydrofuran and 40 parts of methyl ethyl ketone to this dispersion.
Appropriately add ~80 parts and dilute to make a coating solution, apply it on the intermediate layer and dry at 80°C for 10 minutes to obtain 250 mg/n+"
A charge generation layer having a film thickness calculated by weight was formed.

Next, bisphenol 2 type polycarbonate resin (Mn
22,000) 5 parts of polytetrafluoroethylene powder as fluorine-containing resin powder was dispersed for 50 hours in a stainless steel ball mill with 40 parts of monochlorobenzene and 15 parts of THF. A solution containing 10 parts of the stilbene compound represented by formula (6) as a transport substance was applied onto the charge generation layer and heated at 120°C.
The charge transport layer was dried with hot air for 1 hour to form a charge transport layer with a thickness of 25 μI.

The photoreceptor 30 thus obtained was mounted on an image forming apparatus.

Incidentally, the spectral sensitivity of this photoreceptor is shown in FIG.

The measurement was carried out using Paper Analyzer 5P-428 (newly manufactured by Kawaguchi Denki). The laser scanner 27 uses a 780 nm semiconductor laser to place a spot diameter of 100 μI on the photoreceptor.
The scanning line density was set to 254-DPI.

In addition, the potential of the 70th copy was set to -700V using the negative charger 29, and the amount of reflected light IA from the white part of the original was set to 1.5RuX-5e.
As c, the potential of the vL portion was set to -200V.

Further, the laser output was set to 1.2 μJ/cm' and the average potential of the vL portion was set to 1200V. Through the above steps, an analog latent image and a digital latent image can be formed on the photoreceptor 30.

The developing conditions will be explained with reference to FIG.

- The component developer 5 was applied in a thin layer by the application member 4 onto the surface of the stainless steel cylindrical sleeve 2 rotating in the direction of the arrow 7. The closest distance between the photosensitive drum 1 comprising an organic photoconductive layer having a negatively charged latent image rotating in the direction of arrow 7 and the sleeve 2 was set to about 250 μm. In addition, between the photosensitive drum 1 and the sleeve 2, the AC bias and DC bias are combined at 2000 Hz/1300 V, (7) )<
(DC bias is -100
V).

The above-described latent image was visualized using the above-described developing device, and the toner image on the photoreceptor 30 was transferred onto a transfer material and fixed, thereby obtaining an image.

Next, the image evaluation method according to the present invention will be described.

In analog images, fine line reproducibility was measured using the following method. That is, exactly 100μ in width
The measurement sample is an image of an original document with fine lines rated m, copied under appropriate copying conditions, and a Luzex 450 particle analyzer is used as the measurement device to measure the line width using an indicator from the enlarged monitor image.

At this time, since the line width measurement position has irregularities in the width direction of the fine line image of the toner, the average line width of the irregularities is taken as the measurement point. From this, the value (%) of fine line reproducibility is calculated using the following formula.

The resolution was measured by the following method. In other words, it is a pattern consisting of 5 thin lines with equal line widths and intervals, and 1
Between mm 2.8.3.2.3.6.4.04.5.
5. Create an original image that appears to have 0.5.6.8.3.7.1 or 8.0 lines. Observe with a magnifying glass the image copied from the original document with these 10 types of line images under appropriate copying conditions, and calculate the resolution value by calculating the number of images (wood/mm) in which thin lines are clearly separated. do.

The larger this number, the higher the resolution.

Line representation and resolution of digital images were measured using the following method.

A latent image was created on the photoreceptor with a laser so that five lines (100 um) of one dot and one space were formed, and the resulting image was used as a measurement sample. The resolution is 5 lines/mm
Evaluation was made based on line resolution.

Also, the line expression is a line with 1 dot and 2 spaces (1
00u+11) formed into a 4-tree tree, the value is calculated using the following formula in the same manner as in the case of analog images.

An image with an analog part and a digital part was obtained.

On the other hand, non-magnetic toner was prepared as follows.

The dot representation was measured using the method shown below. A checkered latent image consisting of 1 dot, 2 dots, 3 dots, and 4 dots was formed on a photoreceptor using a laser, and the resulting image was used as a measurement sample.

This sample is observed with a magnifying glass, and the number of dots in the image that clearly shows the checkered pattern is expressed as a dot representation. The smaller this number is, the better the dot representation is.

In the image formation test, a digital image and an analog image could be obtained simultaneously using the following method. A solid black area was provided in the original document, and a digital latent image was formed using a laser on the solid black area formed on the photoreceptor. The analog latent image and digital latent image obtained in this way are developed,
After visualization and mixing the above materials well with a blender,
The mixture was kneaded using a twin-screw kneading extruder set at 150°C.

The obtained mixed material was cooled, coarsely pulverized with a cutter mill, and then finely pulverized with a pulverizer using a jet stream.
The obtained finely pulverized powder was classified using a fixed wall type wind classifier to produce classified powder. Furthermore, the obtained classified powder is strictly classified and removed at the same time to remove ultra-fine powder and coarse powder using a multi-division classifier that utilizes the Coanda effect (Nippon Steel Mining Co., Ltd.'s Elbow Jet Classifier), resulting in blue fine powder (non-magnetic toner). I got it. Table 1 shows the particle size distribution of this non-magnetic toner.

Positively charged hydrophobic dry silica (BET specific surface area 200 m2/g) was added to 100 parts of the obtained blue fine powder non-magnetic toner.
．． 8 parts were added and mixed in a Henschel mixer.

This non-magnetic toner was put into the image forming apparatus described above and an image reproduction test was carried out. This test was repeated 5000 times, and the results are shown in Table 2 for the analog image portion and Table 3 for the digital image portion.

As is clear from these tables, good blue images with no fogging were obtained in both the analog and digital sections, and the line expression and halftone dot expression were excellent in single gradation.

The multi-division classifier used in this example and the classification process using the classifier will be explained with reference to FIGS. 1a and 1b. The multiple division vLm51 is shown in FIG. 1a.

In b, the sidewall has a shape shown at 72.74;
The lower wall has a shape shown by 75, and the side wall 73 and the lower wall 75 are provided with knife-type classification edges 67 and 68, respectively, and the classification edges 137 and 68 divide the classification zone into three parts. . The upper wall 77 of the classification chamber is provided with a raw material supply nozzle 66 that opens into the classification chamber at the lower part of the side wall 72, and a Coanda block 76 that is bent downward with respect to the extension direction of the bottom tangent of the nozzle to draw an elongated arc. ,
A knife-shaped edge 69 is provided at the bottom of the classification chamber, and a tube 84 opening into the classification chamber is provided at the top of the classification chamber.
．． 65 is provided. In addition, the popular tubes 64 and 65 are equipped with first and second gas introduction adjusting means 70 and 71 such as dampers, and static pressure gauges 78 and 79, respectively. A discharge pipe 81.62.83 having a discharge port opening into the chamber is provided.The 0-class powder is introduced under reduced pressure from the supply nozzle BIi into the classification area, and due to the Coanda effect of the Coanda block 76, the inflow is caused by the Coanda effect. Due to the action of high-speed air, the curved line 8
Draw 0 and fin! It was classified into coarse powder (discharge pipe 61), black fine powder (discharge pipe 62) having a predetermined volume average particle diameter and particle size distribution, and ultrafine powder (discharge pipe 63).

FIG. 8 shows the relationship between the surface potential of the drum and the image density. This uses a gray scale to adjust the illuminance of a halogen lamp, places various charges on the drum, and measures the surface potential of that area. Then, each potential was developed and the image density was determined.

An image was produced in the same manner as in Example 1, except that instead of the non-magnetic toner used in Example 1, a toner having a particle size distribution as shown in Table 1 was used by controlling the fine pulverization and classification conditions. A test was conducted. However, as a coloring agent, 1985 parts of perilin scar was used in Example 2, and 4 parts of carbon black was used in Example 3. The results are shown in Tables 2 and 3, and both analog and digital images have a clear red color.
A black image was obtained.

Example using the above materials! Table 1 shows the particle size distribution of the non-magnetic toner obtained in the same manner as above.

Furthermore, the same external addition as in Example 1 was applied, and the same image formation test as in Example 1 was conducted.

The results are shown in Tables 2 and 3.

As is clear from this table, a clear green image with no fogging was obtained, the image was sharp, and the image quality was also excellent.

The above raw materials were used, and in Example 6, C8 was used as the colorant.
! , 4 parts of Pigment Red 6 were used. An imaging test was conducted in the same manner as in Example 4, except that a toner having a particle size distribution as shown in Table 1 was used by controlling the fine pulverization and classification conditions.

The results are shown in Tables 2 and 3, and both analog and digital images were excellent and clear cyan and magenta colored images.

A non-magnetic toner having a particle size distribution shown in Table 1 was obtained in the same manner as the non-magnetic toner used in Example 1. Here, an image reproduction test was conducted in the same manner as in Example 1 except that 0.4 parts of positively charged hydrophobic dry silica (BET 200127 g) was added to 100 parts of this non-magnetic toner and mixed in a Henschel mixer. It is shown in Table 2 and Table 3.

Line expression, dot expression, and resolution were poor, and there was fog in the digital image area, and halftones were rough in the analog image area.

Yomi” Shishiji A Same as Example 6 except that the coarsely crushed product obtained in Example 1 was used and a toner having a particle size distribution as shown in Table 1 was used by controlling the fine pulverization and classification conditions. We conducted an image rendering test.

The results are shown in Tables 2 and 3.

In Comparative Example 2, fogging in the digital section, In Comparative Example 3, lines and dots were crushed due to excessive application. In Comparative Example 4, there was fog; A good image could not be obtained due to such reasons.

Concealment ■1 In the image forming apparatus of Example 3, the following was installed as a photosensitive drum. A photosensitive drum was prepared in the same manner as in Example 3 except that the compound represented by formula (1) was removed. Tables 2 and 3 show the results of an image reproduction test in which the non-magnetic toner used in Example 4 was immersed in this image forming apparatus.

I was unable to obtain good images due to lack of sensitivity in the analog section, but there were no problems with the digital section.

(The following is a blank space) [Effects of the Invention] Since the present invention is an image forming method comprising a non-magnetic toner having a specific particle size distribution, an organic photoreceptor, and a developing method, it exhibits the following excellent effects. .

(1) Simultaneously visualize digital latent image and analog latent image,
This is an image forming method that provides a clear image consisting of an analog part and a digital part.

(2) It is an image forming method that can produce brightly colored images with high image density, no fog, and excellent dot and line expressions.

(3) Gradation by halftone expression of analog images,
This is an image forming method with excellent gradation through dot representation of digital images.

[Brief explanation of the drawing]

Among the accompanying drawings, FIG. 1 shows an explanatory view and a schematic cross-sectional view of the classification process using a multi-division classification means, and FIGS. 2, 3, and 4 show the image density and the potential of the photoreceptor surface. FIG. 5 shows a schematic explanatory diagram of the developing device according to the present invention, and FIG. 6 shows a specific apparatus that can be used to carry out the image forming method according to the present invention. An example is shown, FIG. 7 shows the spectral sensitivity of the photosensitive drum according to the present invention, and FIG. 8 plots the relationship between the image density and the surface potential of the photosensitive drum obtained in the image forming apparatus according to the present invention. The following graph is shown below. 1... Electrostatic image holder 2... Toner carrier 3.
... Hopper 4 ... Application member 5 ... Non-magnetic toner 6 ... Bias power supply 21 ... Original
23... Optical system reflection plate 24... Optical system halogen lamp 25... Reflection mirror 26... Lens group 27
... Laser scanner 28 ... Pre-exposure lamp 29
...-Charger 30...Photoreceptor 31...
Developing device 33...Cleaner part 35...
Transfer/separation charger 37... Fixing device 38... Transfer material 39... Image processing section 40... Electric signal human power section 51... Multi-division classification device 61... Coarse powder (
Discharge pipe) 62...Powder having a predetermined particle size (discharge pipe) 63...
・Fine powder (discharge tube) 64.65...Popular tube 66・
... Supply nozzle 67, 88 ... Classification edge 6
G...Popular edge 70...First gas introduction adjustment means 71...Second gas introduction adjustment means

Claims (1)

[Claims] An electrophotographic organic photoreceptor containing at least two or more charge-generating substances and holding a digital electrostatic charge image and an analog electrostatic charge image, and a toner carrier carrying a one-component non-magnetic toner on its surface are fixed in a developing section. In an image forming method, the one-component non-magnetic toner is arranged with a gap, and the one-component non-magnetic toner is regulated to a thickness thinner than the gap on a toner carrier, and then conveyed to a developing section and developed. Toner is 5μm
Contains 12 to 60% by number of nonmagnetic toner particles with the following particle sizes, and contains 1 to 60% of nonmagnetic toner particles with a particle size of 8 to 12.7 μm.
33% by number, contains 2.0% by volume or less of non-magnetic toner particles with a particle size of 16 μm or more, and has a particle size distribution in which the volume average particle size of the one-component non-magnetic toner is 4 to 10 μm. Characteristic image forming method.