JP2000010333A - Dry toner and image forming method - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a dry toner stably realizing a high grade image over a long period and exerting no adverse influence on a developer carrier and a photoreceptor, and an image forming method using this toner. SOLUTION: In a dry toner having toner particles containing at least a binding resin, a coloring agent and a wax component, a circle corresponding number average diameter D1 of the toner is 2 to 10 μm in a circle corresponding diameter-circularity scattergram of a number reference measured by a flow type particle image measuring device, and the dry toner contains particulates having circularity less than 0.950 by 5 to 40 number % in a particle group of a range where a circle corresponding diameter is 1 to 3 μm.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a dry toner (hereinafter referred to as "toner") used in a recording method utilizing an electrophotographic method, an electrostatic recording method, a magnetic recording method, a toner jet method, and the like. The present invention relates to an image forming method used. More specifically, the present invention relates to a toner used in an image recording apparatus that can be used in a copying machine, a printer, a facsimile, a plotter, and the like, and an image forming method using the toner.

[0002]

2. Description of the Related Art Conventionally, many methods have been known as electrophotography. In general, a photoconductive substance is used to form an electric latent image on a photoreceptor by various means.
The latent image is developed with a toner to make it a visible image, and if necessary, the toner image is transferred to a transfer material such as paper, and then the toner image is fixed on the transfer material by heat / pressure to obtain a final image. Things.

Various developing methods for visualizing an electrostatic latent image using toner have been known. For example, U.S. Pat.
The magnetic brush method described in U.S. Pat. No. 4,063, the cascade developing method described in U.S. Pat. No. 2,618,552 and the U.S. Pat. No. 2,221,776. Many developing methods such as a powder cloud method, a fur brush developing method, and a liquid developing method are known. Among these developing methods, in particular, a magnetic brush method, a cascade method, a liquid developing method and the like using a developer mainly composed of a toner and a carrier have been put to practical use. All of these methods are excellent methods for obtaining a good image relatively stably, but have the problems associated with the two-component developer such as deterioration of the carrier and fluctuation of the mixing ratio of the toner and the carrier.

In order to solve such a problem, various developing methods using a one-component developer consisting only of toner have been proposed.

In recent years, such copying apparatuses have begun to be used not only as office work copying machines for simply copying original documents, but also as printers as personal computer outputs or personal copies for individuals. .

[0006] Therefore, miniaturization, weight reduction and speeding up,
High reliability has been rigorously pursued, and machines have become simpler in various respects.

Particularly, in a printer or a facsimile, since it is desired to reduce the size of the image forming apparatus, a developing apparatus using one-component toner is often used.

[0008] Under these circumstances, demands for high resolution are increasing in printers and facsimile machines as described above. For example,
Initially 200-300 dpi (dot per inc
h) was 400 to 800 dpi, and 1
It is becoming 200 dpi. Similarly, copiers have advanced in function by digitalization, and there is a strong demand for a high-resolution and high-definition developing method.

Therefore, in particular, in a digital printer, a copying machine, and the like, the photosensitive layer has been made thinner in order to increase the definition of an electrostatic latent image. When such a thin film photoreceptor is used, the potential contrast of the electrostatic latent image is reduced.
As the toner used for development, a toner having higher developability is desired.

In the one-component developing method, the toner is developed in a chain state (generally called "spikes") at the time of development, so that the resolution in the horizontal direction of the image is likely to be worse than that in the vertical direction. In addition, the flying amount of the toner on the line image becomes excessive as compared with the solid black image, so that the toner consumption increases and the faithful reproducibility of the image and the economy tend to be inferior. On the other hand, when a visible image is formed by the toner, tailing development in which the toner runs out of the image portion in a spike state and toner scattering to the peripheral portion of the image occur, which causes a reduction in resolution.

Therefore, as a method for further improving the image reproducibility, it is necessary to make the toner application on the toner carrier (developing sleeve) extremely thin and to shorten the spike of the toner. However, in the case of the conventional toner, this method causes the frictional charging between the toner and the developing sleeve to be excessive, so that the toner charged more than necessary increases the Coulomb force with the developing sleeve, making the development difficult and, in addition, excessively charging. Blotting, which causes uneven application of the toner on the developing sleeve due to aggregation of the toner particles, and sleeve ghost development, which is caused by inhibiting charging of other toners, are likely to occur. Particularly, as described in Japanese Patent Application Laid-Open No. 2-28415, the sleeve ghost phenomenon causes an increase in the amount of triboelectric charge of the toner fine powder particles having a relatively small particle diameter in the toner, and the strong reflection force causes It is believed that the toner adheres and is generated to form a toner fine powder particle layer.

In response to the demand for a high-resolution and high-definition developing method,
JP-A-1-112253, JP-A-1-19115
No. 6, JP-A-2-214156, JP-A-2-214156
284158, JP-A-3-181952,
Japanese Patent Application Laid-Open No. 4-162048 and the like have proposed a small particle size toner exhibiting a specific particle size distribution. However, the smaller the particle size of the toner, the larger the triboelectric charge amount.
As described above, the sleeve ghost phenomenon and the blotch phenomenon caused by the unevenness of the toner coat on the surface of the toner carrier easily occur.

On the other hand, in Japanese Patent Application Laid-Open No. 9-160283, the average particle size is 6 to 10 μm and the average circularity is 0.85 to 0.85.
A toner having a content of 0.98 and a particle having a circularity of 0.85 or less and a content of 10% by weight or less has been proposed. However, no consideration has been given to the control of the releasability of the toner particles from the toner carrier and the control of the amount of triboelectric charge due to the reduction in the particle size of the toner, and the high-definition development has not been achieved.

In Japanese Patent Application Laid-Open No. 9-197714,
Ratio of 50% average diameter A and 10% average diameter B of developer particles B /
A is 40 to 80% and the average circularity is 0.93 to 1.0
A developer has been proposed that comprehensively considers the toner shape by controlling the toner shape so that the ratio of the circularity of 0.85 or less is 3.0% or less. However, although the stability of the image density of the developer is improved to some extent, the average circularity exceeds 0.96 and the 50% average diameter is 8%.
No consideration is given to toner having a particle diameter of less than μm, and there is still room for improvement in the reproducibility and transferability of fine dots and in matching with an image forming apparatus.

On the other hand, in recent years, from the viewpoint of environmental protection, the primary charging and transfer process using a corona discharge, which has been conventionally used, to the primary charging and transfer process using a photosensitive member contact member are becoming mainstream.

For example, JP-A-63-149669 and JP-A-2-123385 have been proposed. These are related to a contact charging method and a contact transfer method. However, a conductive elastic roller is brought into contact with an electrostatic latent image carrier, and the electrostatic latent image carrier is pressed while applying a voltage to the conductive roller. Then, a toner image is obtained by an exposure and development process, and then, while pressing another conductive roller to which a voltage is applied to the electrostatic latent image carrier, a transfer material is passed therebetween while the electrostatic latent image carrier is pressed. After the toner image on the image carrier is transferred to a transfer material, a transferred image is obtained through a fixing process.

However, in such a roller transfer method that does not use corona discharge, the transfer member is brought into contact with the photosensitive member via the transfer material at the time of transfer, so that the toner image formed on the photosensitive member is transferred to the transfer material. When the toner image was transferred, the toner image was pressed against the toner image, and a partial transfer failure called so-called “missing during transfer” occurred.

Further, as the particle size of the toner becomes smaller, the adhesion force (mirror image force, van der Waals force, etc.) of the toner particles to the photoreceptor becomes larger than the Coulomb force applied to the toner particles in the transfer. As a result, the transfer residual toner tends to increase.

Further, in the roller charging system, the physical and chemical action on the surface of the electrostatic latent image carrier due to the discharge generated between the charging roller and the electrostatic latent image carrier is larger than in the corona charging system. In particular, in the combination with the organic photoreceptor / blade cleaning, abrasion due to deterioration of the photoreceptor surface is liable to occur, and there is a problem in life.

Therefore, it is required that the toner and the photoreceptor used in such an image forming method have excellent releasability.

By the way, the untransferred toner remaining on the photoreceptor without being transferred so far is cleaned and removed by various methods, and then collected and discharged as so-called “waste toner”. Did not. Since the waste toner is treated as waste (waste plastic), the waste toner is reused from the viewpoints of effective use of resources, reduction of waste, and consideration of living environment, so-called toner reuse. Considerations have been widely conducted. If the waste toner can be reused, other merits such as not only effective use of the toner as described above but also downsizing of the image forming apparatus can be considered.

However, in practice, when the waste toner is reused, the image quality is adversely affected due to a reduction in image density or a fogging phenomenon, or a problem occurs in matching with an image forming apparatus.

Therefore, the toner applicable to the toner reuse as described above includes the developing property, environmental stability, low-temperature fixing property, anti-offset property, and developing property conventionally desired for the toner.
In addition to various properties such as storability, it is also required to have excellent mechanical strength and durability against external force, and also excellent transportability of waste toner to a developing portion.

The various properties required for the above-mentioned toners are often contradictory to each other, and it is increasingly desired in recent years to satisfy both of them with high performance. Under such circumstances, each toner constituent material plays a large role, and it is required to have high functionality, and it is important to design an image forming system that brings out excellent characteristics of the toner. However, there is not yet enough comprehensive response to comprehensively address the above issues.

[0025]

SUMMARY OF THE INVENTION An object of the present invention is to significantly improve the disadvantages of the prior art, improve the developability and transferability, and stably realize high-quality images for a long period of time. Another object of the present invention is to provide a dry toner which can be highly applied to an electrophotographic process which does not adversely affect a developer carrier and a photoreceptor, and an image forming method using the toner.

[0026]

Means for Solving the Problems The present invention provides at least:
A dry toner containing a binder resin, a colorant, and a wax component, wherein the number of circles equivalent to the number of circles of the toner in a number-based circle equivalent diameter-circularity scattergram measured by a flow-type particle image measuring device of the toner. Average diameter D1 is 2-10μ
m, and 5 to 40% by number of fine particles having a circularity of less than 0.950 in a particle group having an equivalent circle diameter of 1 to 3 μm.

Further, the present invention relates to an image forming method using the toner.

As a result of intensive studies, the present inventors have found that by precisely controlling the shape distribution of the toner, it is possible to impart desirable developability and transferability to the toner.

That is, the circle-equivalent diameter based on the number of toners−
In the circularity scattergram, particles having a circularity of less than 0.950 among particles having a toner-equivalent number average diameter of 2 to 10 μm and a circular equivalent diameter of 1 to 3 μm are included.
By precisely controlling the particle shape of the toner so as to be about 40% by number, the developing property and the transfer property can be improved in a well-balanced manner.

The toner has a circle-equivalent number average diameter of 2 to 10 μm.
By doing so, a good image can be obtained. In particular, by reducing the average particle diameter of the circle-equivalent number to 2 to 5 μm, the reproducibility of the contour portion of the image, particularly, the development of a character image or a line pattern becomes good. However, conventionally, when the particle size of the toner particles is reduced, the existence ratio of the toner having a small particle size is inevitably increased, so that it is difficult to uniformly charge the toner, causing not only image fogging but also the toner carrier. The adhesion to the surface was increased, resulting in the sleeve ghost phenomenon as described above.

However, in the toner according to the present invention, in the circle-equivalent diameter-circularity scattergram, the proportion of fine particles having a circularity of less than 0.950 in the particle group having an equivalent circle diameter of 1 to 3 μm is 5 to 40. By setting the number%, the problem relating to the developability can be significantly improved. The reason is that when a thin layer of toner is formed on the toner carrier in the developing step, a sufficient amount of toner coating can be maintained even if the regulating force of the toner layer thickness regulating member is made stronger than usual. Thus, the charge amount of the toner on the toner carrier can be made higher than usual without damaging the toner carrier. As a result, the uniform chargeability of the toner having a small particle size, which has been difficult in the related art, is greatly improved. Further, by controlling the shape of the fine particles, the mobility and the releasability of the toner on the toner carrier are improved, so that the sleeve ghost can be prevented beforehand, and at the same time, the chargeability of the toner is synergistically improved. And developability is remarkably improved. In particular, the circle equivalent diameter is 1-3 μm
By developing 5 to 25% by number of fine particles having a circularity of less than 0.950 in the particle group in the range of 2, the developing ability for a low-potential latent image is remarkably improved. It is effective in the case.

When the particles having a circularity of less than 0.950 in a group of fine particles having an equivalent circle diameter of 1 to 3 μm contain more than 40% by number, not only the chargeability of the toner becomes non-uniform, but also the toner becomes non-uniform. Since the releasability from the carrier is significantly reduced, a sleeve ghost phenomenon occurs. In addition, since the transferability of the toner on the toner carrier deteriorates, image fogging occurs and a blotch phenomenon, which is a rippled image unevenness, occurs.

When particles having a circularity of less than 0.950 in particles having an equivalent circle diameter of 1 to 3 μm are less than 5% by number,
The deterioration of the toner surface becomes remarkable, causing a problem in durability and the like, and causes a decrease in transferability and the like.

Further, the average circularity of the toner is 0.960 to
By setting the ratio to 0.995, the surface properties of the toner become uniform and the developability is improved. If the average circularity is less than 0.960, the shape of the toner surface is not uniform, which adversely affects the chargeability of the toner. On the other hand, when the average circularity exceeds 0.995, the surface of the toner deteriorates remarkably, causing a problem in durability and the like.

The circle equivalent diameter, circularity, and frequency distribution of the toner used in the present invention are used as a simple method for quantitatively expressing the shape of the toner. The measurement was performed using an apparatus FPIA-1000 (manufactured by Toa Medical Electronics Co., Ltd.) and calculated using the following equation.

Circle equivalent diameter = (projected area of particle / π) ^1/2 × 2

[0037]

[Outside 1]

Here, the "particle projection area" is the area of the binarized toner image, and the "perimeter of the particle projection image" is the length of a contour line obtained by connecting the edge points of the toner image. Is defined.

The circularity in the present invention is an index indicating the degree of unevenness of the toner. The circularity is 1.000 when the toner is perfectly spherical, and the circularity decreases as the surface shape becomes more complicated. Become.

In the present invention, the circle-equivalent number average diameter D1, which means the average value of the particle size frequency distribution based on the number of toners, is:
Assuming that the particle size (central value) at the dividing point i of the particle size distribution is di and the frequency is fi, it is calculated from the following equation.

[0041]

[Outside 2]

The average circularity C, which means the average value of the circularity frequency distribution, is calculated from the following equation, where the circularity (center value) at the dividing point i of the particle size distribution is ci and the frequency is fci.

[0043]

[Outside 3]

As a specific measuring method, 10 ml of ion-exchanged water from which impurity solids and the like have been removed in advance is prepared in a container, and a surfactant, preferably an alkylbenzenesulfonate, is added as a dispersant thereto. Further, 0.02 g of the measurement sample is added and uniformly dispersed. As a means for dispersing, an ultrasonic disperser UH-50 type (manufactured by SMT Co., Ltd.) equipped with a titanium alloy chip of 5φ as a vibrator is used for a dispersion treatment for 5 minutes to prepare a dispersion for measurement. At this time, the dispersion is appropriately cooled so as not to reach a temperature of 40 ° C. or higher.

The shape of the toner is measured by using the above-mentioned flow type particle image measuring device, and the toner concentration at the time of measurement is 3000 to 1
The concentration of the dispersion is readjusted so as to be 10,000 / μl, and 1,000 or more toners are measured. After the measurement, a two-dimensional frequency distribution diagram (scattergram) of the circle equivalent diameter and the circularity of the toner is obtained using this data.

Examples of the binder resin used in the toner of the present invention include commonly used styrene- (meth) acrylic copolymers, polyester resins, epoxy resins, and styrene-butadiene copolymers. In a method of directly obtaining toner particles by a polymerization method, a monomer for forming them is used. Specifically, styrene; o
Styrene-based monomers such as (m-, p-)-methylstyrene and m (p-)-ethylstyrene; methyl (meth) acrylate, ethyl (meth) acrylate, propyl (meth) acrylate, (meth) ) Butyl acrylate, octyl (meth) acrylate, dodecyl (meth) acrylate, stearyl (meth) acrylate, behenyl (meth) acrylate, 2-ethylhexyl (meth) acrylate, (meth)
(Meth) acrylate monomers such as dimethylaminoethyl acrylate and diethylaminoethyl (meth) acrylate; ene monomers such as butadiene, isoprene, cyclohexene, (meth) acrylonitrile and acrylamide are preferably used. Can be These can be used alone or generally in the published Polymer Handbook, 2nd Edition, III-P 139-192 (John Wiley).
& Sons Corporation) theoretical glass transition temperature (Tg)
However, it is used by appropriately mixing monomers so as to show a temperature of 40 to 75 ° C. If the theoretical glass transition temperature is lower than 40 ° C., problems tend to occur in terms of the storage stability and durability stability of the toner, while if it exceeds 75 ° C., the fixing point of the toner increases. In particular, in the case of a color toner for forming a full-color image, it is not preferable because the color mixing property of each color toner at the time of fixing is deteriorated and the color reproducibility is poor, and further the transparency of the OHP image is deteriorated.

The molecular weight of the binder resin is measured by gel permeation chromatography (GPC). In the case of a toner having a core-shell structure, specific GPC
The method of measurement is to extract the toner in advance using a Soxhlet extractor with a toluene solvent for 20 hours and then distill off the toluene with a rotary evaporator to obtain an extract. An organic solvent that does not dissolve the resin (for example, chloroform or the like) is added to the extract, washed sufficiently, and the residue is washed with tetrahydrofuran (TH
Sample (THF solution) obtained by filtering the solution dissolved in F) through a solvent-resistant membrane filter having a pore diameter of 0.3 μm.
Is measured using Waters 150C. The column configuration is A-801, 802, 803, 80 manufactured by Showa Denko
4, 805, 806, 807 can be linked and the molecular weight distribution can be measured using a standard polystyrene resin calibration curve. The main peak molecular weight of the binder resin according to the present invention is 5,000 to 100.
It is preferable in the present invention that the ratio (Mw / Mn) of the weight average molecular weight (Mw) to the number average molecular weight (Mn) is 2 to 100.

The coloring agents used in the present invention include the following yellow coloring agents, magenta coloring agents and cyan coloring agents. As black coloring agents, carbon black, magnetic substances or the following yellow coloring agents / magenta coloring agents / A mixture of a cyan colorant and a black color is used.

Examples of the yellow colorant include condensed azo compounds, isoindolinone compounds, anthraquinone compounds,
A compound represented by an azo metal complex, a methine compound or an allylamide compound is used. Specifically, C.I. I. Pigment Yellow 12, 13, 14, 15, 17, 6
2, 74, 83, 93, 94, 95, 109, 110,
111, 128, 129, 147, 168, 180 and the like are preferably used.

Examples of the magenta colorant include condensed azo compounds, diketopyrrolopyrrole compounds, anthraquinones, quinacridone compounds, basic dye lake compounds, naphthol compounds, benzimidazolone compounds, thioindico compounds and perylene compounds. Specifically, C.I.
I. Pigment Red 2, 3, 5, 6, 7, 23, 4
8; 2, 48; 3, 48; 4, 57; 1, 81; 1, 1
44, 146, 166, 169, 177, 184, 18
5, 202, 206, 220, 221, 254 are particularly preferred.

As the cyan coloring agent, copper phthalocyanine compounds and derivatives thereof, anthraquinone compounds, basic dye lake compounds and the like can be used. Specifically, C.I. I.
Pigment Blue 1, 7, 15, 15: 1, 15: 2,
15: 3, 15: 4, 60, 62, 66, etc. can be particularly preferably used.

These colorants can be used alone or as a mixture or in the form of a solid solution. The colorant is a hue,
It is selected from the viewpoints of chroma, lightness, weather resistance, OHP transparency, and dispersibility in toner particles. The amount of the coloring agent is preferably 1 to 20 parts by weight based on 100 parts by weight of the resin component.

When a magnetic material is used as a black colorant, unlike other colorants, 40 parts by weight with respect to 100 parts by weight of resin.
It is preferred to use up to 150 parts by weight.

The wax component according to the present invention includes petroleum waxes such as paraffin wax, microcrystalline wax and petrolactam and derivatives thereof, montan wax and derivatives thereof, hydrocarbon waxes and derivatives thereof by the Fischer-Tropsch method, and polyethylene. Representative polyolefin waxes and derivatives thereof,
Carnauba wax, candelilla wax, etc., natural waxes and their derivatives, and derivatives include oxides, block copolymers with vinyl monomers, graft-modified products, and alcohols such as higher aliphatic alcohols; stearin Fatty acids such as acid and palmitic acid or compounds thereof;
Any acid amide, ester, ketone, hydrogenated castor oil and derivatives thereof, vegetable wax, animal wax, and the like can be used as long as they have a dissolution temperature in styrene monomer of 40 to 80 ° C.

Among these, when polyolefin, hydrocarbon wax, petroleum wax, higher alcohol or higher ester by Fischer-Tropsch method is used, the effect of improving developability and transferability is further enhanced.

The above-mentioned wax component is used as the binder resin 100
It is preferable to use 1 to 30 parts by weight based on parts by weight.

An antioxidant may be added to the wax component as long as the chargeability of the toner is not affected.

The wax component according to the present invention can be used in a tomographic observation of a toner using a transmission electron microscope (TEM).
In a state where the wax component is not compatible with the binder resin, the wax component is dispersed in a substantially spherical and / or spindle-shaped island shape.

In the present invention, the dispersion state of the wax component as described above is defined as follows. In other words, the circle-equivalent weight average diameter D means the average value of the weight-based particle size frequency distribution of the toner measured by the above-mentioned flow type particle image measuring apparatus.
4 (μm), D4 × 0.9 or more, and D4 × 1.
Ten tomographic planes of toner particles having a major axis of 1 or less are selected. Then, the largest major axis r in the phase separation structure caused by the major axis R of the tomographic plane of each toner particle and the wax component existing in the major plane R of the toner particle in the tomographic plane.
Is measured, and the average value of r / R is determined. When the average value of r / R is in a dispersed state that satisfies the average value of 0.05 ≦ r / R ≦ 0.95, the spherical component and / or the spindle shape are substantially in a state where the wax component is not compatible with the binder resin. Have an island-like dispersion state.

As a specific method for measuring the tomographic plane of the toner in the present invention, the toner particles are sufficiently dispersed in a room-temperature-curable epoxy resin and then cured in an atmosphere at a temperature of 40 ° C. for 2 days. The cured product is stained with ruthenium tetroxide and, if necessary, osmium tetroxide, and then sliced using a microtome with diamond teeth. Measure morphology. In the present invention,
It is preferable to use a ruthenium tetroxide dyeing method in order to provide a contrast between materials by utilizing a slight difference in crystallinity between the low softening point substance used and the resin constituting the outer shell. FIG. 7 shows a typical example. In the toner particles obtained in Examples described later, it was observed that the low softening point substance was included in the outer shell resin.

The charge control agents used in the present invention include:
Known ones can be used, but the charging speed is fast, and
A charge control agent capable of stably maintaining a constant charge amount is preferable. Further, when the toner particles are directly polymerized,
A charge control agent having no polymerization inhibition and having no solubilized substance in an aqueous dispersion medium is particularly preferred. Specific compounds include metal compounds of aromatic carboxylic acids such as salicylic acid, naphthoic acid and dicarboxylic acid as negative charge control agents; high molecular compounds having sulfonic acid or carboxylic acid groups in side chains; boron compounds; urea Compound; silicon compound; curryxarene and the like. Examples of the positive charge control agent include a quaternary ammonium salt; a polymer compound having the quaternary ammonium salt in a side chain; a guanidine compound; and an imidazole compound. The charge control agent is preferably used in an amount of 0.5 to 10 parts by weight based on 100 parts by weight of the resin. However, in the present invention, the addition of a charge control agent is not essential, and in the case of using a two-component developing method, utilizing triboelectric charging with a carrier, and in the case of using a non-magnetic-component blade coating developing method, By positively utilizing frictional charging with the blade member and the sleeve member, it is not always necessary to include a charge control agent in the toner particles.

The addition of an inorganic fine powder to the toner of the present invention is a preferred embodiment for improving developability, transferability, charging stability, fluidity, and durability. Known inorganic fine powders can be used.
It is preferable to be selected from alumina, titania or a composite oxide thereof. Furthermore, silica is more preferable. For example, as the silica, both a so-called dry method produced by vapor phase oxidation of a silicon halide and an alkoxide, and a so-called wet silica produced from an alkoxide, a water glass and the like, and a dry silica called a fumed silica can be used. However, there are few silanol groups on the surface and inside the silica fine powder, and Na ₂ O,
Towards less dry silica of manufacture residues of SO ₃ ^2-like. In the case of fumed silica, it is also possible to obtain a composite fine powder of silica and another metal oxide by using another metal halide such as aluminum chloride and titanium chloride together with a silicon halide in the manufacturing process. Is also included.

[0063] Inorganic fine powder used in the present invention is the specific surface area by nitrogen adsorption measured by BET method is 30 m ² / g or more, particularly given good results in the range of 50 to 400 m ² / g, the toner 100 mass It is particularly preferable to use 0.1 to 8 parts by mass, preferably 0.5 to 5 parts by mass, more preferably more than 1.0 to 3.0 parts by mass of the silica fine powder based on parts.

The inorganic fine powder used in the present invention comprises:
Silicon varnish, various modified silicone varnishes, silicone oil, various modified silicone oils, silane coupling agents, silane coupling agents having functional groups, other organosilicon compounds, organic It is possible and preferable to use a treating agent such as a titanium compound or a combination of various treating agents.

The specific surface area was determined according to the BET method by adsorbing nitrogen gas on the sample surface using a specific surface area measuring device, Auto Soap 1 (manufactured by Yuasa Ionics), and calculating the specific surface area using the BET multipoint method.

In order to maintain a high charge amount and achieve a low consumption and a high transfer rate, it is more preferable that the inorganic fine powder is treated with at least a silicone oil.

In the toner of the present invention, other additives such as lubricant powders such as Teflon powder, zinc stearate powder and polyvinylidene fluoride powder; cerium oxide powder, silicon carbide Powder,
Abrasives such as strontium titanate powder; fluidity imparting agents such as titanium oxide powder and aluminum oxide powder; anti-caking agents; or conductivity imparting agents such as carbon black powder, zinc oxide powder and tin oxide powder, Organic and inorganic fine particles of opposite polarity can also be used in small amounts as a developer improver.

The method for producing the toner of the present invention includes:
After uniformly dispersing the release agent, colorant, charge control agent, etc. made of resin, low softening point substance using a pressure kneader, extruder, or media disperser, it is made to collide with the target mechanically or under a jet stream. After finely pulverizing the toner to a desired toner particle diameter (if necessary, a step of smoothing and spheroidizing the toner particles is added), and further passing through a classification step, the particle size distribution is sharpened to obtain a toner. In addition to the production method, a method of atomizing a molten mixture into air using a disk or a multi-fluid nozzle described in Japanese Patent Publication No. 56-13945 to obtain a spherical toner, and a method of producing a spherical toner,
No. 0231, JP-A-59-53856, JP-A-59-61842, a method of directly producing a toner by using a suspension polymerization method, and a method in which a toner is soluble in a monomer. Either a dispersion polymerization method of directly producing a toner using an aqueous organic solvent in which the resulting polymer is insoluble, or an emulsion polymerization method typified by a soap-free polymerization method of producing a toner by directly polymerizing in the presence of a water-soluble polar polymerization initiator. It is possible to produce a toner.

In a method of producing a toner using a pulverization method, it is difficult to keep the shape of toner particles in a desired range of circularity frequency distribution. However, the resulting toner tends to have a wide particle size distribution, and it is difficult to control the surface condition of the toner.
On the other hand, in the dispersion polymerization method, the obtained toner has an extremely sharp particle size distribution, but the production equipment is not suitable from the viewpoints of narrow selection of materials to be used and utilization of organic solvents in terms of treatment of waste solvents and flammability of solvents. It is complicated and easy to be complicated. Emulsion polymerization methods typified by soap-free polymerization are effective because the particle size distribution of the toner is relatively uniform, but when the used emulsifier or polymerization initiator terminal is present on the surface of the toner particles, the environmental characteristics tend to deteriorate.

In the present invention, it is possible to control the circularity frequency distribution of the toner, and to carry out the emulsion polymerization method or the suspension polymerization method under normal pressure or under pressure at which a toner having a small particle diameter can be obtained relatively easily. By using a medium to the polymer obtained in advance, using a medium, or directly hitting a heavy pressure body against a pressure collision plate, or further, the obtained polymer is frozen in an aqueous system, An aggregation method in which particles having opposite surface charges are united, aggregated and united in consideration of conditions such as pH is particularly preferable. Further, a seed polymerization method in which a monomer is further adsorbed on the polymer particles once obtained and then polymerized using a polymerization initiator can also be suitably used in the present invention.

When a direct polymerization method is used as a method for producing a toner, the control of the circularity frequency distribution and the particle size distribution of the toner is performed by changing the type and amount of a poorly water-soluble inorganic salt or a dispersing agent acting as a protective colloid. It is possible to obtain predetermined toner particles by controlling the method and mechanical device conditions (for example, the peripheral speed of the rotor, the number of passes, the stirring conditions such as the shape of the stirring blades and the shape of the container), or the solid concentration in the aqueous solution. it can.

When a toner is produced by the direct polymerization method, examples of the polymerization initiator used include 2,2'-azobis- (2,4-dimethylvaletonitrile), 2,2'-azobisisobutyronitrile, 1,1'-azobis (cyclohexane-1-carbonitrile), 2,2'-azobis-4-methoxy-2,4-dimethylvaleronitrile,
Azo-based or diazo-based polymerization initiators such as azobisisobutyronitrile; peroxide-based polymerization initiators such as benzoyl peroxide, methyl ethyl ketone peroxide, diisopropyl peroxycarbonate, cumene hydroperoxide, 2,4-dichlorobenzoyl peroxide and lauroyl peroxide Agent is used. The amount of the polymerization initiator varies depending on the desired degree of polymerization, but is generally used in an amount of 0.5 to 20% by weight based on the polymerizable monomer. The type of the polymerization initiator varies slightly depending on the polymerization method, but is used alone or in combination with reference to the 10-hour half-life temperature.

For controlling the degree of polymerization, known crosslinking agents, chain transfer agents, polymerization inhibitors and the like may be further added and used.

When a suspension polymerization method using a dispersion stabilizer is used as a method for producing a toner, the dispersion stabilizer to be used includes:
Inorganic compounds include tricalcium phosphate, magnesium phosphate, aluminum phosphate, zinc phosphate, calcium carbonate, magnesium carbonate, calcium hydroxide, magnesium hydroxide, aluminum hydroxide, calcium metasilicate, calcium sulfate, barium sulfate, bentonite , Silica, alumina and the like. As organic compounds,
Polyvinyl alcohol, gelatin, methylcellulose,
Examples include methylhydroxypropylcellulose, ethylcellulose, sodium salts of carboxymethylcellulose, polyacrylic acid and salts thereof, and starch. These can be used by dispersing them in an aqueous phase. It is preferable to use 0.2 to 20 parts by weight of these dispersion stabilizers based on 100 parts by weight of the polymerizable monomer.

When an inorganic compound is used as the dispersion stabilizer, a commercially available one may be used as it is, but fine particles of the inorganic compound may be produced in a dispersion medium in order to obtain fine particles. For example, in the case of tricalcium phosphate,
It is preferable to mix an aqueous solution of sodium phosphate and an aqueous solution of calcium chloride under high-speed stirring.

For fine dispersion of these dispersion stabilizers,
0.001 to 0.1 parts by weight of a surfactant may be used in combination. This is to promote the intended action of the dispersion stabilizer, for example, sodium dodecylbenzene sulfate, sodium tetradecyl sulfate, sodium bentadecyl sulfate, sodium octyl sulfate, sodium oleate, sodium laurate, potassium stearate. ,
And calcium oleate.

When a direct polymerization method is used as a method for producing the toner used in the present invention, the following production methods are possible.

Into the polymerizable monomer, a releasing agent composed of a substance having a low softening point, a colorant, a charge control agent, a polymerization initiator and other additives are added and uniformly dissolved or homogenized by a homogenizer, an ultrasonic disperser or the like. The dispersed monomer composition is added to an aqueous phase containing a dispersion stabilizer by using an ordinary stirrer or a homomixer.
Disperse with a homogenizer or the like. Preferably, the granulation is performed by adjusting the stirring speed and the stirring time so that the droplets of the monomer composition have a desired size of the toner particles. Thereafter, by the action of the dispersion stabilizer, the particles may be stirred to such an extent that the particle state is maintained and the particles are prevented from settling. The polymerization is preferably performed at a polymerization temperature of 40 ° C. or higher, generally 50 to 90 ° C. The temperature may be raised in the second half of the polymerization reaction, and further, for the purpose of improving the durability in the image forming method of the present invention, the second half of the reaction to remove unreacted polymerizable monomers, by-products, or After the completion of the reaction, a part of the aqueous medium may be distilled off from the reaction system. After completion of the reaction, the generated toner particles are collected by washing and filtration, and dried. In the suspension polymerization method, it is usually preferable to use 300 to 3000 parts by weight of water as a dispersion medium with respect to 100 parts by weight of the monomer composition.

On the other hand, the use of an air-flow classifier in order to obtain a desired shape distribution of the toner is one of the preferred embodiments of the present invention.

Conventionally, various methods have been proposed for classifying powders, and air-flow classifiers using a rotating blade or those having no movable part are known.
Classifiers having no moving parts include a fixed-wall centrifugal classifier and a chronic force classifier, and Loffier. F. and K. Maly: Sy
mpon Powder Techn. 2 (198
1), an elbow jet classifier commercialized as Nippon Steel Mining, and an Okuda. S. andYas
ukuni. J. Proc. Inter. Symosi
um on Powder Techn '81, 77
1 (1981) is known as a chronic force classifier capable of classifying in the fine powder region,
Although it can be applied to the present invention, in order to precisely control the toner particles to a desired shape distribution and to achieve high productivity, the airflow classifier shown in FIGS. Preferably, it is used.

An air-flow classifier suitable for the present invention is described below.
This will be specifically described with reference to the drawings.

FIG. 11 shows an airflow classifier B suitable for the present invention.
13 is a schematic sectional view (including a horizontal sectional view of a high-pressure air swirl introduction path portion), FIG. 12 is a three-dimensional view of a classification section, and FIG.
Is an example of a classifier system incorporating the airflow classifier B.

The side walls 72, 73 of the airflow classifier B shown in FIGS. 11 and 12 form a part of the classifying chamber 82, and similarly, the classifying edge blocks 74, which form the right side of the classifying chamber 82, 75 has classification edges 67 and 68 each having a sharp tip, and the classification or 80 in the classification chamber 82 is divided into three fractions (8
2a to 80c). On the other hand, a block 83 provided on the left side of the classifying chamber 82 is provided with an inlet edge 69. A raw material supply nozzle 6 having an opening in a classification area 80 in a classification chamber 82 is used to supply toner particles as a raw material to be classified.
6 and a high-speed jet together with the airflow, the classification band 80 in the classification chamber 82 has a Coanda ribbon 7 which is a metal band-shaped member.
6, and the locus of the air supplied from the raw material supply nozzle 66 and the inlet pipes 64 and 65 and the air discharged from the outlets 61, 62 and 63 by the suction and pressure reducing means. Move in a curved line without disturbing. As a result, depending on the size of each particle and the magnitude of the inertial force, the large particles (coarse powder)
That is, to the first fraction 80a below the classification edge 68, the medium-sized particles (medium powder) to the second fraction 80b between the classification edges 68 and 67, and to the small particles (fine powder). ) Are classified into the third fractions 80c above the classification edge 67, and are suctioned and discharged to the outside together with air from the discharge ports 61, 62, and 63, respectively.

The air-flow type classification device B has classification edges 67 and 68.
And the rotation of the inlet edge 69 and the classification edge blocks 74 and 7
5 and the Coanda diameter can be changed by the deformation of the Coanda ribbon 76, and the shape distribution of fine particles in the toner particles, which hardly give an inertia force, can be controlled with high accuracy.

On the other hand, in the air-flow classifier B, a raw material supply port 90 for introducing the raw material powder is arranged at the most upstream part of the apparatus, and between the raw material supply port 90 and the raw material supply nozzle 66. A high-pressure air supply nozzle 91 and a raw material powder supply nozzle 92 are provided. At this time, an introduction passage 93 for swirling and inflowing the air is provided above the high-pressure air supply nozzle 91, and by applying the swirling flow to the high-pressure air, a sufficient dispersing force can be applied even to toner particles having high cohesion. It is possible to control the shape distribution with higher accuracy in a constantly stable state.

Normally, the airflow type classifier B is used by being incorporated in a classifier system in which mutual devices are connected by communication means such as pipes. FIG. 13 shows an airflow classifier B, a quantitative feeder 52, a vibration feeder 53, and a collecting cyclone 5.
A classifier system connected by communication means such as 4, 55, 56 is shown. By using the classification device system, the shape distribution of the toner can be appropriately adjusted.

Next, an image forming method to which the toner of the present invention is applied will be described below with reference to the accompanying drawings.

In the apparatus system shown in FIG. 1, the developing units 4-1, 4-2, 4-3, and 4-4 respectively include a developer having a cyan toner and a developer having a magenta toner.
A developer having a yellow toner and a developer having a black toner are introduced, and an electrostatic charge image formed on an electrostatic latent image carrier (for example, a photosensitive drum) 1 by a magnetic brush development method or a non-magnetic-component method is used. After development, toner images of each color are formed on the photosensitive drum 1.

The toner of the present invention is suitable for one-component development using, for example, a developing means as shown in FIG.

An example of an apparatus for developing an electrostatic image formed on an electrostatic latent image carrier is shown, but the invention is not necessarily limited thereto.

In FIG. 2, reference numeral 25 denotes an electrostatic latent image carrier (photosensitive drum), and a latent image is formed by an electrophotographic process means or an electrostatic recording means. Reference numeral 24 denotes a toner carrier (developing sleeve), which is formed of a non-magnetic sleeve made of aluminum, stainless steel, or the like.

The substantially right half peripheral surface of the developing sleeve 24 is always in contact with the toner reservoir in the toner container 21, and the toner near the developing sleeve surface is brought into contact with the developing sleeve surface by the magnetic force of the magnetic generating means in the sleeve and / or Adhered and held by electrostatic force.

In the present invention, the surface roughness Ra of the toner carrier is
(Μm) is set to 1.5 or less. Preferably it is 1.0 or less. More preferably, it is 0.5 or less.

By setting the surface roughness Ra to 1.5 or less, the ability of the toner carrier to transport toner particles is suppressed.
Since the toner layer on the toner carrier is made thinner and the number of times of contact between the toner carrier and the toner is increased, the chargeability of the toner is also improved, so that the image quality is synergistically improved.

When the surface roughness Ra of the toner carrier exceeds 1.5, it becomes difficult not only to reduce the thickness of the toner layer on the toner carrier but also to improve the image quality because the chargeability of the toner is not improved. Can not hope.

In the present invention, the surface roughness Ra of the toner carrier is measured using a surface roughness measuring device (Surfcoder SE-30H, manufactured by Kosaka Laboratories Co., Ltd.) based on JIS surface roughness "JIS B0601". It corresponds to the measured center line average roughness. Specifically, a 2.5 mm portion as the measurement length a is extracted from the roughness curve in the direction of the center line, the center line of the extracted portion is the X axis, the direction of the vertical magnification is the Y axis, and the roughness curve is the When y = f (x), the value obtained by the following equation is expressed in micrometers (μm).

[0097]

[Outside 4]

As the toner carrier used in the present invention, a cylindrical or belt-like member made of, for example, stainless steel, aluminum or the like is preferably used. If necessary, the surface may be coated with metal, resin, etc.
A resin in which fine particles such as a resin, metals, carbon black, and a charge controlling agent are dispersed may be coated.

According to the present invention, the surface moving speed of the toner carrier is set to be 1.05 to 3 times the surface moving speed of the electrostatic latent image carrier.
By setting it to be 0 times, the toner layer on the toner carrier receives an appropriate stirring effect, so that the faithful reproduction of the electrostatic latent image is further improved.

If the surface moving speed of the toner carrier is less than 1.05 times the surface moving speed of the electrostatic latent image carrier, the stirring effect of the toner layer becomes insufficient, and a good image is obtained. No formation can be expected. Also, when developing an image that requires a large amount of toner over a large area, such as a solid black image, the amount of toner supplied to the electrostatic latent image is insufficient and the image density is reduced. On the other hand, when it exceeds 3.0, in addition to the various problems caused by excessive charging of the toner as described above,
Deterioration of the toner due to mechanical stress and sticking of the toner to the toner carrier occur and are promoted, which is not preferable.

The toner T is stored in the hopper 21 and is supplied by the supply member 22 onto the developing sleeve. As the supply member, a supply roller made of a porous material such as a foamed material such as a flexible polyurethane foam is preferably used. The supply roller is moved with respect to the developing sleeve.
Rotate forward or backward at a non-zero relative speed,
Along with the supply of the toner onto the developing sleeve, the developing toner (undeveloped toner) on the sleeve is also stripped off. At this time, the contact width of the supply roller to the developing sleeve is 2.0 to 2.0 in consideration of the balance between toner supply and stripping.
10.0 mm is preferable, and 4.0 to 6.0 mm is more preferable. On the other hand, excessive stress is inevitably applied to the toner, and the aggregation of the toner due to the deterioration of the toner is increased, or the fusion and fixation of the toner to the developing sleeve and the supply roller are easily caused. Is excellent in fluidity and releasability, and has durability stability, so that it is also preferably used in a developing method having the supply member. Further, a brush member made of a resin fiber such as nylon or rayon may be used as the supply member. Although these supply members are extremely effective in a one-component developing method using a non-magnetic one-component toner that cannot utilize a magnetic binding force, they may be used in a one-component developing method using a magnetic one-component toner.

The toner supplied onto the developing sleeve is thinly and uniformly applied by the regulating member. The toner thinning regulating member is a doctor blade such as a metal blade or a magnetic blade disposed at a predetermined gap from the developing sleeve. Or, instead of a doctor blade, use metal,
Rigid rollers or sleeves made of resin, ceramic, or the like may be used, and a magnet generating means may be inserted inside them.

An elastic member such as an elastic blade or an elastic roller for applying the toner by pressure may be used as a regulating member for thinning the toner. For example, in FIG. 2, the elastic blade 23 has its base, which is the upper side, fixedly held on the developer container 21 side, and its lower side flexes in the forward or reverse direction of the developing sleeve 24 against the elasticity of the blade. In this state, the inner surface of the blade (the outer surface in the opposite direction) is brought into contact with the surface of the sleeve 24 with an appropriate elastic pressure. According to such an apparatus, a dense toner layer that is stable against environmental fluctuations can be obtained. Although the reason is not clear, it is presumed that the elastic body is forcibly rubbed against the surface of the developing sleeve, so that charging is always performed in the same state regardless of a change in behavior due to a change in toner environment.

On the other hand, the toner is apt to be excessively charged and the toner is easily fused to the developing sleeve or the elastic blade. However, the toner used in the present invention has excellent releasability and stable triboelectric charging. It is preferably used.

For the elastic body, it is preferable to select a material of a triboelectric series suitable for charging the toner to a desired polarity, and a rubber elastic body such as silicone rubber, urethane rubber or NBR; a synthetic material such as polyethylene terephthalate Resin elastic body: Metal elastic bodies such as stainless steel, steel, and phosphor bronze can be used. Further, a composite thereof may be used.

When the elastic body and the toner carrier are required to have durability, it is preferable that the elastic body and the resin are bonded to the sleeve or the rubber so as to hit the sleeve contact portion, or the metal elastic body is coated.

Further, an organic substance or an inorganic substance may be added to the elastic body, may be melted and mixed, or may be dispersed. For example, the chargeability of the toner can be controlled by adding a metal oxide, metal powder, ceramics, carbon allotrope, whisker, inorganic fiber, dye, pigment, surfactant or the like. Particularly, when the elastic body is a molded body such as rubber or resin, fine particles of metal oxide such as silica, alumina, titania, tin oxide, zirconia, and zinc oxide, carbon black, a charge control agent generally used for toner And the like.

Further, by applying a DC electric field and / or an AC electric field to the developing blade as the regulating member, the supply roller as the supplying member, and the brush member, the regulating portion on the developing sleeve due to the action of loosening the toner. In the above, the uniform thin layer coating property and the uniform charging property are further improved, and the supply / stripping of the toner is more smoothly performed at the supply portion, so that a sufficient image density can be achieved and a good quality image can be obtained.

The contact pressure between the elastic body and the toner carrier is:
The linear pressure in the generatrix direction of the toner carrier is 0.1 kg / m
Above, preferably 0.3 to 25 kg / m, more preferably 0.5 to 12 kg / m is effective. As a result, the aggregation of the toner can be effectively released, and the charge amount of the toner can be instantaneously increased. If the contact pressure is less than 0.1 kg / m, it becomes difficult to apply the toner uniformly, and the charge amount distribution of the toner becomes broad, causing fogging and scattering. On the other hand, when the contact pressure exceeds 25 kg / m, a large pressure is applied to the toner, and the toner is undesirably deteriorated and a toner aggregate is generated.
Further, a large torque is required to drive the toner carrier, which is not preferable.

A gap α between the electrostatic latent image carrier and the toner carrier
Is preferably set to 50 to 500 μm, and the gap between the doctor blade and the toner carrier is preferably set to 50 to 400 μm.

It is most preferable that the layer thickness of the toner layer on the toner carrier is smaller than the gap α between the electrostatic latent image carrier and the toner carrier. Among them, the layer thickness of the toner layer may be restricted to such an extent that a part of the toner layer contacts the electrostatic latent image carrier.

On the other hand, a bias power supply 2
By applying an alternating electric field between the toner carrying member and the electrostatic latent image carrying member, the transfer of the toner from the toner carrying member to the electrostatic latent image carrying member can be facilitated, and a higher quality image can be obtained.
Vpp of the alternating electric field is 100 V or more, preferably 200 to
3000V, more preferably 300-2000V. Further, f is 500 to 5000 Hz, preferably 1000 to 3000 Hz, and more preferably 1500
In this case, a waveform such as a rectangular wave, a sine wave, a sawtooth wave, and a triangular wave can be used as the waveform used in the range of 3000 Hz. Also, asymmetrical AC biases having different positive and reverse voltages and times can be used. It is also preferable to superimpose a DC bias.

Further, the toner of the present invention is mixed with a magnetic carrier and can be suitably used for two-component development using, for example, a developing means as shown in FIG. Specifically, it is preferable to perform development in a state where the magnetic brush is in contact with the photosensitive drum 13 while applying an alternating electric field. The distance between the developer carrier (developing sleeve) 11 and the photosensitive drum 13 (S
(Distance between D) B is preferably 100 to 1000 μm in terms of preventing carrier adhesion and improving dot reproducibility. If it is smaller than 100 μm, the supply of the developer tends to be insufficient and the image density is reduced. If it is larger than 1000 μm, the magnetic field lines from the magnet S1 are widened and the density of the magnetic brush is reduced, resulting in poor dot reproducibility or restrained carrier. And the carrier is likely to adhere.

The voltage (Vpp) between the peaks of the alternating electric field is 5
00 to 5000 V is preferable, and the frequency (f) is 500 to
It is 10,000 Hz, preferably 500 to 3000 Hz, and each can be appropriately selected and used for the process. In this case, the waveforms are triangular, rectangular, sine,
Alternatively, various types of waveforms such as a waveform with a changed duty ratio can be used. If the applied voltage is lower than 500 V, it is difficult to obtain a sufficient image density, and it may not be possible to satisfactorily collect fog toner in the non-image area. 5000
When the voltage exceeds V, the electrostatic image is disturbed via the magnetic brush, and the image quality may be deteriorated.

By using a two-component developer having a well-charged toner, the fog removal voltage (Vback) can be reduced.
And the primary charge of the photoconductor can be reduced, so that the life of the photoconductor can be extended. Vbac
k is preferably 150 V or less, more preferably 100 V or less, depending on the developing system.

The contrast potential is preferably from 200 V to 500 V so that a sufficient image density can be obtained.

When the frequency is lower than 500 Hz, although it depends on the process speed, charge injection into the carrier may occur, so that the image quality may be degraded by carrier adhesion or disturbing the latent image. If the frequency exceeds 10,000 Hz, the toner cannot follow the electric field, and the image quality is likely to deteriorate.

In order to obtain a sufficient image density, achieve excellent dot reproducibility, and perform development without carrier adhesion, the contact width (developing nip C) of the magnetic brush on the developing sleeve 11 with the photosensitive drum 13 is preferably set. 3 to 8 mm. If the developing nip C is narrower than 3 mm, it is difficult to sufficiently satisfy a sufficient image density and dot reproducibility.
If the width is larger than mm, packing of the developer occurs to stop the operation of the machine, and it is difficult to sufficiently suppress the adhesion of the carrier. As a method of adjusting the developing nip, the nip width is appropriately adjusted by adjusting the distance A between the developer regulating member 18 and the developing sleeve 11 or adjusting the distance B between the developing sleeve 11 and the photosensitive drum 13.

In the output of a full-color image in which halftone is particularly important, three or more developing devices for magenta, cyan, and yellow are used, and the developer and the developing method of the present invention are used. By combining with a developing system that forms a latent image, it is possible to develop the dot latent image faithfully without being affected by the magnetic brush and disturbing the latent image. In the transfer step, a high transfer rate can be achieved by using the toner of the present invention, so that high image quality can be achieved in both the halftone portion and the solid portion.

Further, by using the toner of the present invention together with the initial improvement of the image quality, the effect of the present invention without lowering the image quality can be sufficiently exerted even when copying a large number of sheets.

The electrostatic latent image carrier is a-Se, Cds, Zn
A photosensitive drum or a photosensitive belt having a photoconductive insulating material layer such as O ₂ , OPC, or a-Si. The electrostatic latent image carrier is rotated in the direction of the arrow by a driving device (not shown).

As the latent electrostatic image bearing member, a photosensitive member having an amorphous silicon photosensitive layer or an organic photosensitive layer is preferably used.

As the organic photosensitive layer, the photosensitive layer contains a charge generating substance and a substance having charge transporting ability in the same layer.
It may be a single-layer type or a function-separated type photosensitive layer having a charge transport layer as a component of the charge transport layer. A laminated photosensitive layer having a structure in which a charge generation layer and then a charge transport layer are laminated on a conductive substrate in this order is one of preferred examples.

The binder resin for the organic photosensitive layer is preferably a polycarbonate resin, a polyester resin, or an acrylic resin, particularly having good transferability and cleaning properties, poor cleaning, fusion of toner to a photoreceptor, and filming of external additives. Less likely.

In the charging step, there are a system that is not in contact with the electrostatic latent image carrier 1 using a corona charger, and a contact system that uses a roller or the like, and both systems are used. For efficient uniform charging, simplification and low ozone generation, a contact type as shown in FIG. 1 is preferably used.

The charging roller 2 basically has a core 2b at the center and a conductive elastic layer 2a forming the outer periphery thereof. The charging roller 2 is pressed against the surface of the electrostatic latent image carrier 1 with a pressing force, and is driven to rotate as the electrostatic latent image carrier 1 rotates.

A preferable process condition when the charging roller is used is that the contact pressure of the roller is 5 to 500 g / cm.
When a DC voltage with an AC voltage superimposed is used, the AC voltage is 0.5 to 5 kVpp and the AC frequency is 50 kVpp.
Hz to 5 kHz, the DC voltage is ± 0.2 to ± 1.5 kV, and when only the DC voltage is used, the DC voltage is ± 0.2 to ± 0.5 kV.
2 to ± 5 kV.

Other charging methods include a method using a charging blade and a method using a conductive brush. These contact charging means are effective in that high voltage is not required and generation of ozone is reduced.

The material of the charging roller and the charging blade as the contact charging means is preferably conductive rubber, and a release coating may be provided on the surface thereof. As the release coating, a nylon resin, PVDF (polyvinylidene fluoride), PVDC (polyvinylidene chloride) or the like can be applied.

The toner image on the electrostatic latent image carrier is transferred to the intermediate transfer body 5 to which a voltage (for example, ± 0.1 to ± 5 kV) is applied. The surface of the electrostatic latent image carrier is cleaned by cleaning means 9 having a cleaning blade 8.

The intermediate transfer member 5 is made of a pipe-shaped conductive core 5.
b and a medium resistance elastic layer 5a formed on the outer peripheral surface thereof. The metal core 5b may be formed by applying a conductive plating to a plastic pipe.

The medium resistance elastic layer 5a is made of silicone rubber, Teflon rubber, chloroprene rubber, urethane rubber,
EPDM (terpolymer of ethylene propylene diene)
A conductive material such as carbon black, zinc oxide, tin oxide, or silicon carbide is mixed and dispersed in an elastic material such as to adjust the electric resistance (volume resistivity) to a medium resistance of 10 ⁵ to 10 ¹¹ Ω · cm. It is a solid or foamed layer.

The intermediate transfer member 5 is arranged so as to be supported in parallel with the electrostatic latent image carrier 1 so as to be in contact with the lower surface of the electrostatic latent image carrier 1. And rotates in the same direction at the contact portion at the same peripheral speed as.

The first color toner image formed and carried on the surface of the electrostatic latent image carrier 1 passes through a transfer nip where the electrostatic latent image carrier 1 and the intermediate transfer body 5 are in contact with each other. The image is transferred to the outer surface of the intermediate transfer member 5 by an electric field formed in the transfer nip area by the transfer bias applied to the member 5,
The second color, the third color, and the fourth color are sequentially transferred.

If necessary, the surface of the intermediate transfer member 5 is cleaned by the detachable cleaning means 10 after the transfer of the toner image onto the transfer material. When there is a toner image on the intermediate transfer member, the cleaning unit 10 is separated from the surface of the intermediate transfer member so as not to disturb the toner image.

A transfer means is provided in parallel with the intermediate transfer member 5 and is brought into contact with the lower surface of the intermediate transfer member 5, and the transfer means 7 is, for example, a transfer roller or a transfer belt. It rotates clockwise with the same peripheral speed as the arrow. The transfer unit 7 may be disposed so as to directly contact the intermediate transfer member 5, or a belt or the like may be disposed so as to contact between the intermediate transfer member 5 and the transfer unit 7.

In the case of the transfer roller, the basic configuration is a core metal 7b at the center and a conductive elastic layer 7a formed on the outer periphery thereof.

For the intermediate transfer member and the transfer roller, general materials can be used. By setting the volume resistivity of the elastic layer of the transfer roller smaller than the volume resistivity of the elastic layer of the intermediate transfer body, the voltage applied to the transfer roller can be reduced, and a good toner image can be formed on the transfer material. In addition, it is possible to prevent the transfer material from being wound around the intermediate transfer member. In particular, it is particularly preferable that the volume resistivity of the elastic layer of the intermediate transfer member is at least 10 times the volume resistivity of the elastic layer of the transfer roller.

For example, the conductive elastic layer 7b of the transfer roller 7
Is polyurethane, ethylene-propylene-diene terpolymer (EPDM) in which conductive material such as carbon is dispersed
It is made of an elastic material having a volume resistance of about 10 ⁶ to 10 ¹⁰ Ω · cm. A bias is applied to the metal core 7a from a constant voltage power supply. The bias condition is ± 0.2 ~
± 10 kV is preferred.

The toner of the present invention has a high transfer efficiency in the transfer step, a small amount of untransferred toner, and an excellent cleaning property, so that filming hardly occurs on the electrostatic latent image carrier. Furthermore, even when a multi-sheet durability test is performed, the toner of the present invention has less embedding of the external additive on the surface of the toner particles and is less likely to deteriorate on the surface of the toner particles than the conventional toner. obtain. In particular, an image forming apparatus having a so-called reuse mechanism for removing transfer residual toner on an electrostatic latent image carrier or an intermediate transfer member as shown in FIG. 4 by a cleaning means such as a cleaning blade and reusing the collected transfer residual toner. It is preferably used.

Next, the toner image on the transfer material 6 is fixed by heating and pressing fixing means. As the heating and pressing fixing means, a heating roller with a built-in heating element such as a halogen heater and an elastic pressing roller pressed against the heating roller with a pressing force as a basic configuration, or a heating roller through a film. A method of heat fixing (FIGS. 5 and 6) can be mentioned. However, since the toner fixing property and offset resistance of the present invention are excellent, good matching with the heat and pressure fixing means as described above is shown.

[0142]

DESCRIPTION OF THE PREFERRED EMBODIMENTS The present invention will be described below with reference to specific examples, but the present invention is not limited to these examples.

[Production Examples of Toner and Comparative Production Examples]
Production examples of the toner of the present invention and comparative production examples will be described.

Toner Production Example 1 High-speed stirrer TK homomixer ( manufactured by Tokushu Kika Kogyo Co., Ltd.)
600 g of ion-exchanged water and 50 mol of 0.1 mol / l-Na ₃ PO ₄ aqueous solution in a two-liter four-necked flask equipped with
0 g, adjust the rotation speed to 12000 rpm,
Warmed to 0 ° C. Here, 1 mol / l-CaCl ₂
60 parts by weight of the aqueous solution was gradually added to prepare an aqueous dispersion medium containing a minute water-insoluble dispersion stabilizer Ca ₃ (PO ₄ ) ₂ .

On the other hand, dispersoids include:-82 parts by weight of styrene-18 parts by weight of 2-ethylhexyl acrylate-0.1 part by weight of divinylbenzene-5 parts by weight of carbon black (oil absorption = 70 cc / 100 g)-Polyester resin (peak molecular weight = 7300, hydroxyl value = 16 mg KOH / g) 2 parts by weight-Negative charge control agent (salicylic acid-based iron complex) 2 parts by weight-Ester wax (melting point = 72 ° C) 4 parts by weight

After the above mixture was dispersed for 3 hours using an attritor (manufactured by Mitsui Kinzoku Co., Ltd.), 5 parts by weight of 2,2'-azobis (2,4-dimethylvaleronitrile) was added, and a polymerizable monomer composition was added. Was prepared.

Next, the polymerizable monomer composition was charged into the aqueous dispersion medium, and the mixture was maintained at 12,000 rpm under an N ₂ atmosphere at an internal temperature of 60 ° C. while maintaining the rotation speed at 12,000 rpm.
After stirring for minutes, the polymerizable monomer composition was granulated. Thereafter, the stirring was changed to a propeller stirring blade, and the mixture was maintained at the same temperature for 10 hours while stirring at 50 rpm to complete the polymerization.

After completion of the polymerization, the suspension was cooled, and then dilute hydrochloric acid was added to remove the dispersion stabilizer. Further, after washing with water was repeated several times and drying was performed, a classification process was performed using an airflow classifier system shown in FIG.

The obtained polymer particles (A) have a circle-equivalent number average diameter of 5.5 μm and an average circularity of 0.990.
The content of fine particles having a circularity of less than 0.95 in particles having an equivalent circle diameter of 1 to 3 μm was 16% by number,
Peak molecular weight is 19,000, Mw / M
n exhibited 29.

100 parts by weight of the above polymer particles (A) and hydrophobic oil-treated silica fine powder (BET; 200 m ² / g)
2 parts by weight were dry-mixed with a Henschel mixer to prepare a toner (A).

The obtained toner (A) had the same particle size distribution and shape distribution as the polymer particles (A).
Further, the dispersion state of the wax component in the toner (A) is determined by TE
When observed with M, as shown in the schematic diagram of FIG. 7 (a), it was substantially spherical and dispersed without being compatible with the binder resin. At this time, r / R was 0.41.

Toner Production Examples 2-4 Preparation conditions of aqueous dispersion medium, setting conditions in the classification chamber such as the classification edge and Coanda diameter of the airflow type classification device system, air balance of intake and intake air, and high pressure to the raw material supply port Production Example 1 of the toner described above, except that the particle size and shape of the polymer particles were controlled by adjusting the air supply conditions.
After obtaining polymer particles (B) to (D) in the same manner as in, toners (B) to (D) were prepared.

Comparative Production Example 1 of Toner : 100 parts by weight of styrene-2-ethylhexyl acrylate-divinylbenzene terpolymer (peak molecular weight = 190000, Mw / Mn = 33, Tg = 60 ° C.) 5 parts by weight of carbon black used in Production Example 1-2 parts by weight of polyester resin used in Production Example 1 of toner-2 parts by weight of negative charge control agent used in Production Example 1 of Toner-Used in Production Example 1 of Toner 4 parts by weight of ester wax

The above mixture was melt-kneaded with a twin-screw extruder, and the cooled kneaded material was coarsely pulverized with a hammer mill, and the coarsely pulverized material was finely pulverized with a jet mill. After mixing with a Henschel mixer, the obtained mixed powder is poured into a container containing water, and further dispersed in water using a homomixer. The water temperature is gradually raised, and the mixture is heated at a temperature of 60 ° C. for 2 hours. Was. Thereafter, diluted hydrochloric acid was added to the container to sufficiently dissolve the calcium phosphate on the surface of the finely pulverized product particles. This was washed after filtration, dried, and then passed through a 400-mesh sieve to remove aggregates, and then classified to obtain a classified powder (a). Using the classified powder (a), the comparative toner (a) was prepared in the same manner as in Example 1.

The wax component in the comparative toner (a) was contained in a finely dispersed state. The r / R at that time was 0.01 or less.

Comparative Production Example 2 of Toner A classified powder (b) was obtained in the same manner as in Comparative Production Example 1 of the toner, except that the particle size and shape of the toner particles were controlled by the conditions of pulverization and heat treatment. Thereafter, a comparative toner (b) was prepared.

Production Example 5 of Toner Production Example 1 of the toner except that a modified polypropylene wax (melting point = 96 ° C.) was used instead of the ester wax, and the stirring conditions during granulation and the setting conditions of the airflow classification system were adjusted. After obtaining polymer particles (E) in the same manner as described above, toner (E) was prepared.

Comparative Production Example 3 of Toner A polymer particle (c) was obtained in the same manner as in Production Example 5 of the toner except that the air-flow classifier system was not used. Prepared.

Table 1 shows properties of the toners (A) to (E) obtained above and comparative toners (a) to (c).

[0160]

[Table 1]

[Examples and Comparative Examples] Examples 1 to 5 and Comparative Examples 1 to 3 The image forming apparatus used in this example will be described. FIG.
1 is a schematic explanatory view of a cross section of an image forming apparatus applied to the present embodiment.

The photosensitive drum 1 has a photosensitive layer 1b having an organic optical semiconductor on a substrate 1a, and rotates in the direction of the arrow to rotate in contact with and rotate against the conductive roller 2 (conductive elastic layer 2a, core metal 2b). ) To charge the photosensitive drum 1 to a surface potential of about -630V. The exposure 3 is turned on and off on the photoreceptor by a polygon mirror in accordance with digital image information, thereby forming an electrostatic image having an exposed portion potential of -100 V and a dark portion potential of -630 V. A plurality of developing units 4-1 and 4-2;
Using 4-3 and 4-4, a yellow toner, a magenta toner, a cyan toner or a black toner was obtained on the photoreceptor 1 by a reversal developing method to obtain a toner image. The toner image is
Intermediate transfer member 5 (elastic layer 5a, core metal 5b as support)
The image is transferred onto the intermediate transfer member 5 to form a four-color superimposed developed image. The transfer material toner on the photoreceptor 1 is collected in a residual toner container 9 by a cleaner member 8.

The intermediate transfer member 5 was formed by coating a pipe-shaped metal core 5b with an elastic layer 5b in which a carbon black conducting member was sufficiently dispersed in nitrile-butadiene rubber (NBR). The hardness of the coat layer 5b is determined according to “JIS K
−6301 ”and a volume resistivity of 30 °
It was 10 ⁹ Ω · cm. The transfer current required for the transfer from the photoreceptor 1 to the intermediate transfer member 5 was about 5 μA, which was obtained by applying +500 V from the power supply to the cored bar 5b.

The outer diameter of the transfer roller 7 is 20 mm and the diameter is 10 m.
An elastic layer 7a formed by coating a core material 7b having a carbon conductivity imparting member sufficiently dispersed in an ethylene-propylene-diene-based terpolymer (EPDM) foam on a metal core 7b having an elastic layer 7a. The elastic layer 7a used had a volume resistivity of 10 ⁶ Ω · cm and a standard hardness of 35 degrees according to “JIS K-6301”. A voltage was applied to the transfer roller, and a transfer current of 15 μA was passed.

As the heat fixing device H, a heat roll type fixing device having no oil application function was used. At this time, the upper roller,
The lower roller used had a surface layer of a fluorine-based resin, and the diameter of the roller was 55 mm. The fixing temperature was set at 170 ° C., and the nip width was set at 5 mm.

The developing device shown in FIG. 2 was used.
The toner carrier (developing sleeve) used here had a surface roughness Ra of 1.4, and the toner regulating blade adhered urethane rubber to a phosphor bronze base plate, and formed a contact surface with the toner carrier with nylon. And the moving speed of the toner carrier surface was set to be 2.8 times the moving speed of the electrostatic latent image carrier surface.

Under the above setting conditions, using the continuous mode in a single color (a mode in which the consumption of toner is promoted without stopping the developing device), at a printout speed of eight sheets (A4 size) per minute and at room temperature Perform printout test on 1000 sheets under normal humidity (25 ° C / 60% RH) environment.
Thereafter, a printout test of 9000 sheets was performed in a low-temperature and low-humidity (15 ° C./10% RH) environment.
During the printout test, the toners (A) to (E) and the comparative developers (a) to (c) were successively supplied. The obtained printout image and the image forming apparatus after the completion of the printout test were observed, and the following items were evaluated.

Table 2 shows the evaluation results.

[0169]

[Table 2]

Example 6 and Comparative Example 4 In this example, a commercially available laser beam printer LBP-
EX (manufactured by Canon Inc.) was fitted with a crown mechanism, modified, reset, and used. That is, in FIG. 4, after the untransferred toner on the photosensitive drum 40 is scraped off by the elastic blade 42 of the cleaner 41 in contact with the photosensitive drum, the toner is sent to the inside of the cleaner by the cleaner roller, and further passed through the cleaner screw 43. Then, the toner was returned to the developing device 46 via the hopper 45 by the supply pipe 44 provided with the conveying screw, and a system utilizing the collected toner was attached again. As the primary charging roller 47, the conductive carbon coated with the nylon resin was dispersed. rubber roller (diameter 14 mm, contact pressure 50 g / cm) using a dark portion potential V _D = -700 V, the light potential V _L = 150 V was formed by laser exposure (600 dpi) to the electrostatic latent image bearing member. A developing sleeve 48 having a surface roughness Ra of 1.1 coated with a resin in which carbon black is dispersed on the surface as a toner carrier is set to be 1.1 times the moving speed of the photosensitive drum surface, Next, the gap between the photosensitive drum and the developing sleeve (between S and D) was set to 250 μm, and a urethane rubber blade was used as a toner regulating member in contact therewith. An AC bias component was superimposed on a DC bias component as a developing bias. The fixing device shown in FIGS. 5 and 6 is used as the heat fixing device H. The surface temperature of the heating element 31 d of the heating element 31 is 150 ° C.
1- The total pressure between the sponge pressure roller 33 having a foam of silicon rubber in the lower layer is 8 kg, the nip between the pressure roller and the film is 4 mm, and the fixing film 32 has a PTEF (high A heat-resistant polyimide film having a thickness of 50 μm and having a low-resistance release layer in which a conductive substance is dispersed in a (molecular weight type) was used.

Under the above set conditions, room temperature and normal humidity (25 ° C., 6
0% RH), low temperature and low humidity (15 ° C, 10% RH) environment
At a printout speed of 12 sheets (A4 size) / minute, the toner (A) and the comparative toner (a) are sequentially replenished while the intermittent mode (that is, the developing unit is stopped for 10 seconds each time one sheet is printed out) Then, a printout test of 5,000 sheets was performed in a mode in which the deterioration of the toner is promoted by the preliminary operation at the time of restarting), and the printout image obtained was evaluated for the items described below.

The matching between the image forming apparatus used at the same time and the toner was also evaluated.

Table 3 shows the above evaluation results.

[0174]

[Table 3]

Example 7 The same procedure as in Example 5 was repeated, except that the toner reuse mechanism in FIG. 4 was removed and the printout speed was changed to 16 sheets (A4 size) / min. A printout test of 10,000 sheets was performed in the mode (that is, the mode in which the consumption of toner is promoted without stopping the developing device).

The obtained printout image was evaluated for the following items, and also for matching with the used image forming apparatus. As a result, all items were good.

The evaluation items described in the examples of the present invention and the comparative examples and the evaluation criteria will be described.

[Evaluation of Printout Image] <1> Image Density Image density was evaluated by maintaining the image density when a predetermined number of printouts were completed on ordinary paper for copying machines (75 g / m ² ). The image density was measured by using a "Macbeth reflection densitometer" (manufactured by Macbeth Co., Ltd.) with respect to a printout image of a white background portion having a document density of 0.00. A: 1.40 or more B: 1.35 or more and less than 1.40 C: 1.00 or more and less than 1.35 D: less than 1.00

<2> Image Density Uniformity After printing out a predetermined number of sheets, two solid black images are printed out continuously, and the density difference of the image density generated on the second solid black image is determined. Measured and evaluated. A: less than 0.05 B: 0.05 or more, less than 0.10 C: 0.10 or more, less than 0.30 D: 0.3 or more

<3> Image fog [0180] From the difference between the whiteness of the white background portion and the whiteness of the transfer paper measured by a "reflectometer" (manufactured by Tokyo Denshoku Co., Ltd.) using a printout image of a predetermined number of printouts after printout. ,
The fog density (%) was calculated, and the image fog was evaluated. A: less than 1.5% B: 1.5% or more, less than 2.5% C: 2.5% or more, less than 4.0% D: 4.0% or more

<4> Image Missing After a predetermined number of printouts are completed, the character missing when printing the "amazing" character pattern shown in FIG. 9A on thick paper 128 g / m ² (FIG. 9). (State (b)) was visually evaluated. A: Almost no occurrence. B: Slight hollowing is observed. C: A slight hollow is seen. D: A noticeable hollow is observed.

<5> Dot Reproducibility After a predetermined number of printouts are completed, the electric field is easily closed by the latent image electric field, and the small diameter (5
(0 μm) was printed out, and the dot reproducibility was evaluated. A: 2 or less defects / 100 B: 3 to 5 defects / 100 C: 6 to 10 defects / 100 D: 11 or more defects / 100 defects

<6> Sleeve Ghost After a predetermined number of printouts are completed, a solid black belt-shaped image X having a width a and a length 1 shown in FIG. 10A is printed out, and then shown in FIG. Length 1 with width b (> a) shown
When the halftone image Y is printed out, the grayscale difference appearing on the halftone image Y (A in FIG. 10C).
B and C) were visually evaluated. A: No difference in shading is observed. B: A slight difference in shading is observed between B and C. C: A slight difference in shading is observed in each of A, B, and C. D: A remarkable density difference is observed.

[Evaluation of Matching of Image Forming Apparatus] <1> Matching with Developing Sleeve After completion of the printout test, the state of toner coating on the surface of the developing sleeve and the effect on the printout image were visually evaluated. A: Not generated. B: Slight unevenness in toner coating occurred. C: The toner coating unevenness is observed, but the influence on the image is small. D: The toner coating unevenness is remarkable, and horizontal stripe-like image unevenness is generated.

<2> Matching with Photoreceptor Drum After the printout test, the occurrence of scratches on the surface of the photoreceptor drum and sticking of residual toner and the effect on the printout image were visually evaluated. A: Not generated. B: Slight residual toner is observed, but there is no effect on the image. C: There is sticking or damage, but there is little effect on the image. D: There is also sticking, and a vertical streak-like image defect occurs.

<3> Matching with Intermediate Transfer Body After the print-out test was completed, the surface of the intermediate transfer body was scratched and the state of fixation of residual toner was visually evaluated. A: Not generated. B: The presence of residual toner on the surface is recognized, but there is no effect on the image. C: There is sticking or damage, but there is little effect on the image. D: Many adhesions cause image defects.

<4> Matching with Fixing Device After the completion of the printout test, the surface of the fixing film and the state of fixation of residual toner were visually evaluated. A: Not generated. B: Slight adhesion is observed, but there is no effect on the image. C: There is sticking or damage, but there is little effect on the image. D: Many adhesions cause image defects.

[0188]

As described above, according to the present invention,
By precisely controlling the particle shape of the toner particles, it is possible to impart desirable developability and transferability to the toner.
That is, in the particle group having a circle equivalent number average diameter of 2 to 10 μm and a circle equivalent diameter of 1 to 3 μm, the circularity is 0.950.
By containing less than 5 to 40% by number of fine particles,
Since the coated state of the toner on the toner carrier becomes good, the occurrence of image fogging and sleeve ghost is suppressed,
It has excellent dot reproducibility and can form high-quality images for a long period of time. Further, matching with the image forming apparatus is also preferable.

[Brief description of the drawings]

FIG. 1 is a schematic explanatory view of an image forming apparatus suitable for the present invention.

FIG. 2 is an enlarged cross-sectional view of a main part of a developing device for a one-component developer.

FIG. 3 is an enlarged cross-sectional view of a main part of a developing device for a two-component developer.

FIG. 4 is a schematic explanatory diagram of an image forming apparatus that reuses untransferred toner.

FIG. 5 is an exploded perspective view of a main part of the fixing device used in the embodiment of the present invention.

FIG. 6 is an enlarged cross-sectional view of a main part showing a film state when the fixing device used in the embodiment of the present invention is not driven.

FIG. 7 is a schematic diagram illustrating an example of a cross section of toner particles including a wax component.

FIG. 8 is an explanatory diagram of an isolated dot pattern for checking development characteristics of toner.

FIG. 9 is a schematic diagram showing a state where a character image is hollow;

FIG. 10 is an explanatory diagram of a sleeve ghost.

FIG. 11 is a schematic cross-sectional view (including a horizontal cross-sectional view of a high-pressure air swirling introduction path portion) of an airflow classifier suitable for the present invention.

FIG. 12 is a three-dimensional view of a main part of the airflow classifier.

FIG. 13 is a schematic explanatory diagram of a pneumatic classifier system suitable for the present invention.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Photoconductor (electrostatic latent image carrier) 2 Charging roller 3 Exposure 4 4-color developing device (4-1, 4-2, 4-3, 4-4) 5 Intermediate transfer body 6 Transfer material 7 Transfer roller 11 Development Agent carrier 13 Photoreceptor drum 30 Stay 31 Heater 31a Heater substrate 31b Heater 31c Surface protection layer 31d Temperature sensor 32 Fixing film 33 Pressure roller 34 Coil spring 35 Film end regulating flange 36 Power supply connector 37 Disconnecting member 38 Inlet Guide 39 Exit guide (separation guide)

──────────────────────────────────────────────────の Continued on the front page (51) Int.Cl. ⁷ Identification symbol FI Theme court ゛ (Reference) G03G 21/00 326 (72) Inventor Keiji Kawamoto 3-30-2 Shimomaruko, Ota-ku, Tokyo Canon Inc. (72) Inventor Satoshi Handa 3-30-2 Shimomaruko, Ota-ku, Tokyo Canon Inc. (72) Inventor Michihisa Magome 3-30-2, Shimomaruko 3-chome, Ota-ku, Tokyo F-term (Reference) 2H003 BB11 CC05 2H005 AA06 AA15 CA14 DA06 EA05 EA10 2H033 BB01 BE03 2H034 BA00 CB01 2H077 AA37 AD02 AD06 AD13 AD36 AE03 FA01 FA19 FA21

Claims (30)

[Claims] 1. A dry toner having toner particles containing at least a binder resin, a colorant and a wax component, wherein the toner has a circle-based diameter-circle based on the number measured by a flow type particle image measuring apparatus. In the scattergram, the toner has a circle-equivalent number average diameter D1 of 2 to 10 μm, and 5 to 40% by number of fine particles having a circularity of less than 0.950 in a particle group having a circle-equivalent diameter of 1 to 3 μm. Dry toner characterized by containing. 2. The toner according to claim 2, wherein the toner has a circle-equivalent number average diameter D1 of 2
5 μm, the average circularity is 0.960 to 0.995,
2. The dry toner according to claim 1, wherein the toner particles having an equivalent circle diameter of 1 to 3 [mu] m contain 5 to 25% by number of fine particles having a circularity of less than 0.950. 3. In a tomographic observation of the toner particles using a transmission electron microscope (TEM) of the toner, a circle-equivalent weight average diameter D4 based on the weight of the toner measured by the flow type particle image measuring device is defined as: Twenty tomographic planes of toner particles exhibiting a long diameter R satisfying the relationship of 0.9 ≦ R / D4 ≦ 1.1 were selected, and among the phase separation structures caused by the wax component present in the tomographic planes of the toner particles, The major axis r of the largest one is measured for the tomographic plane of each toner particle,
The obtained arithmetic mean value of r / R satisfies the arithmetic mean value of 0.05 ≦ r / R ≦ 0.95, and the wax component is substantially spherical and / or spindle-shaped in the binder resin. The dry toner according to claim 1, wherein the dry toner is dispersed in an island shape. 4. The arithmetic mean of r / R is 0.25 ≦
The wax component is dispersed in the binder resin in a substantially spherical and / or spindle-shaped island shape so as to satisfy an arithmetic average value of r / R ≦ 0.90. 3
The dry toner according to any one of the above. 5. A charging step of applying a voltage to a charging member from the outside to charge an electrostatic latent image carrier, and a latent image forming an electrostatic latent image on the charged electrostatic latent image carrier. A forming step, a developing step of developing the electrostatic image with toner to form a toner image on the electrostatic latent image carrier, and a transfer step of transferring the toner image on the electrostatic latent image carrier to a transfer material, A fixing step of heating and fixing a toner image on a transfer material, wherein the toner is a dry toner having toner particles containing at least a binder resin, a colorant, and a wax component. In the number-based circle equivalent diameter-circularity scattergram measured by the flow type particle image measurement device,
The toner is characterized in that the toner has a circle-equivalent number average diameter D1 of 2 to 10 μm and a particle group having an equivalent circle diameter of 1 to 3 μm contains 5 to 40% by number of fine particles having a circularity of less than 0.950. Image forming method. 6. The toner has a toner-equivalent number average diameter D1 of 2 to 6.
5 μm, the average circularity is 0.960 to 0.995,
In the particle group having an equivalent circle diameter of 1 to 3 μm, the degree of circularity is 0.
The image forming method according to claim 5, wherein 5 to 25% by number of fine particles having a particle size of less than 950 are contained. 7. In a tomographic observation of the toner particles using a transmission electron microscope (TEM) of the toner, a circle-equivalent weight average diameter D4 based on the weight of the toner measured by the flow type particle image measuring device is defined as: Twenty tomographic planes of toner particles exhibiting a long diameter R satisfying the relationship of 0.9 ≦ R / D4 ≦ 1.1 were selected, and among the phase separation structures caused by the wax component present in the tomographic planes of the toner particles, The major axis r of the largest one is measured for the tomographic plane of each toner particle,
The obtained arithmetic mean value of r / R satisfies the arithmetic mean value of 0.05 ≦ r / R ≦ 0.95, and the wax component is substantially spherical and / or spindle-shaped in the binder resin. The image forming method according to claim 5, wherein the image is dispersed in an island shape. 8. The arithmetic mean of the r / R of the toner is:
The wax component is substantially dispersed in the binder resin into spherical and / or spindle-shaped islands so as to satisfy an arithmetic mean value of 0.25 ≦ r / R ≦ 0.90. The image forming method according to claim 5. 9. In the developing step, the moving speed of the toner carrier surface in the developing area is 1.05 to 3.0 times the moving speed of the electrostatic latent image carrier. 9. The image forming method according to claim 5, wherein the surface roughness Ra (μm) of the carrier is 1.5 or less. 10. The image forming method according to claim 5, wherein a ferromagnetic metal blade is opposed to said toner carrier at a very small interval. 11. The image forming method according to claim 5, wherein a blade made of an elastic material is brought into contact with said toner carrier. 12. The image according to claim 5, wherein the electrostatic latent image carrier and the toner carrier have a certain distance, and are developed while applying an alternating electric field. Forming method. 13. In the charging step, the charging member is brought into contact with the electrostatic latent image carrier, and a voltage is externally applied to the charging member to charge the electrostatic latent image carrier. 13. The image forming method according to any one of 5 to 12. 14. In a transfer step of electrostatically transferring a toner image on an electrostatic latent image carrier to a transfer material using a transfer device, the electrostatic latent image carrier and the transfer device are contacted via the transfer material. 14. The image forming method according to claim 5, wherein the image forming method is in contact with the image forming apparatus. 15. The method according to claim 5, wherein in the heat fixing step, the toner image is heat-fixed to the transfer material by a heat fixing device having no supply of an offset preventing liquid or having no fixing device cleaner. 15. The image forming method according to any one of claims 1 to 14. 16. The heat fixing step, wherein a toner image is heat-fixed to a transfer material by a fixedly supported heating member and a pressing member which is pressed against the heating member and brought into close contact with the heating member via a film. 16. The image forming method according to claim 5, wherein: 17. A method for cleaning and collecting untransferred residual toner on an electrostatic latent image carrier after a transfer step, and having a toner reuse mechanism used for development in the developing step again in the recovered toner. Claims 5 to 1 characterized in that:
7. The image forming method according to any one of 6. 18. A charging step of applying a voltage to a charging member from the outside to charge an electrostatic latent image carrier, and a latent image forming an electrostatic latent image on the charged electrostatic latent image carrier. A forming step, a developing step of developing the electrostatic image with toner to form a toner image on the electrostatic latent image carrier, and a first step of transferring the toner image on the electrostatic latent image carrier to the intermediate transfer material A transfer step, and a second step of transferring the toner image on the intermediate transfer body to a transfer material.
And a fixing step of heating and fixing the toner image on the transfer material, wherein the toner is a dry type having at least a binder resin, a colorant, and toner particles containing a wax component. A toner, wherein in a number-based circle equivalent diameter-circularity scattergram of the toner measured by a flow-type particle image measuring device, the circle-equivalent number average diameter D1 of the toner is 2 to 10 μm; An image forming method, wherein 5 to 40% by number of fine particles having a circularity of less than 0.950 are contained in a particle group having a particle size of 1 to 3 μm. 19. The toner has a circle-equivalent number average diameter D1 of 2
5 to 25 μm, an average circularity of 0.960 to 0.995, and 5 to 25% by number of fine particles having a circularity of less than 0.950 in a particle group having an equivalent circle diameter of 1 to 3 μm. The image forming method according to claim 18, wherein: 20. A transmission electron microscope (TEM) of the toner.
In the tomographic plane observation of the toner particles using the method, the relationship of 0.9 ≦ R / D4 ≦ 1.1 with respect to the weight-based circle equivalent weight average diameter D4 of the toner measured by the flow type particle image measuring device is described. The tomographic plane of the toner particles having the major axis R that satisfies
Locations are selected, and the longest diameter r of the largest phase separation structure among the phase separation structures caused by the wax component existing in the tomographic plane of the toner particles is measured for each of the tomographic planes of the toner particles. The average value is 0.05 ≦ r /
20. The method according to claim 18, wherein an arithmetic mean value of R ≦ 0.95 is satisfied, and the wax component is dispersed in the binder resin in a substantially spherical and / or spindle-shaped island shape. Image forming method. 21. The wax component in the binder resin such that the arithmetic average of r / R of the toner satisfies the arithmetic average of 0.25 ≦ r / R ≦ 0.90. 21. The image forming method according to claim 18, wherein the particles are dispersed in a spherical and / or spindle-shaped island shape. 22. In the developing step, the moving speed of the toner carrier surface in the developing area is 1.05 to 3.0 times the moving speed of the electrostatic latent image carrier. 22. The image forming method according to claim 18, wherein the surface roughness Ra (μm) is 1.5 or less. 23. The image forming method according to claim 18, wherein a ferromagnetic metal blade is opposed to said toner carrier at a small interval. 24. The image forming apparatus according to claim 1, wherein a blade made of an elastic material is opposed to and abuts on the toner carrier.
23. The image forming method according to any one of 8 to 22. 25. The image according to claim 18, wherein said electrostatic latent image carrier and said toner carrier have a certain distance, and are developed while applying an alternating electric field. Forming method. 26. In the charging step, the charging member is brought into contact with the electrostatic latent image carrier, and a voltage is externally applied to the charging member to charge the electrostatic latent image carrier. 26. The image forming method according to any one of 18 to 25. 27. In a transfer step of electrostatically transferring a toner image on an electrostatic latent image carrier to a transfer material using a transfer device, the electrostatic latent image carrier and the transfer device are contacted via the transfer material. The image forming method according to claim 18, wherein the image forming apparatus is in contact with the image forming apparatus. 28. The method according to claim 18, wherein in the heat fixing step, the toner image is heat-fixed to the transfer material by a heat fixing device which does not supply an offset preventing liquid or does not have a fixing device cleaner. 28. The image forming method according to any one of the above items. 29. In the heat fixing step, a toner image is heat-fixed to a transfer material by a fixedly supported heating member and a pressing member which is pressed against the heating member and brought into close contact with the heating member via a film. The image forming method according to any one of claims 18 to 28, wherein: 30. A toner reuse mechanism used for development in the developing step in which the untransferred residual toner on the electrostatic latent image carrier after the first transfer step is collected by cleaning. 2. The method according to claim 1, wherein
30. The image forming method according to any one of items 8 to 29.