JPS61182055A - Process for spreading toner - Google Patents

Abstract

PURPOSE:To form a uniform thin layer of a toner on the surface of a toner carrying sleeve and to stabilize triboelectrification amt. by incorporating, in the toner, fine particles treated with a polymer prepared from a specified monomer. CONSTITUTION:The toner is triboelectrified with the sleeve 2 or magnetic particles, and spread uniformly and thinly on the surface of the sleeve 2 by the reflection force with a magnetic brush formed near a magnetic blade 6, and brought to a position facing a photosensitive drum. As the fine particles, those of pigments or the like treated with the polymer prepared by the monomer represented by formula I, each of R1-R3 being H, optionally substd. hydrocarbon, but R1, R2 being not simultaneously H, and n being an integer >=1, are used in an amt. of 1-80wt%, preferably, 2-50wt% of the fine particles.

Description

Detailed Description of the Invention [Technical Field to which the Invention Pertains] The present invention relates to a toner application method for developing an electrostatic latent image formed by electrophotography using a substantially non-magnetic toner. Regarding. More particularly, the present invention relates to a method of forming a uniform thin layer of a substantially non-magnetic toner and magnetic toner particles.

[Description of prior art]

As the electrophotographic method, US Pat.
Various methods are described in Japanese Patent No. 24748, etc., but all of these methods apply electrostatic charges to the surface of a photoreceptor having a photoconductive layer by means such as corona discharge, and remove the charged photoconductive layer. An electrostatic latent image is formed by irradiating a light image corresponding to the original, and then colored fine powder called toner having the opposite polarity is deposited on the electrostatic latent image to remove the electrostatic latent image. After developing the image and transferring the toner image to a transfer material such as paper as necessary, it is fixed by heat, pressure, solvent vapor, etc. to obtain a copy.

The process of developing the electrostatic latent image involves attracting toner particles charged with a polarity opposite to that of the latent image by electrostatic attraction and making them adhere to the electrostatic latent image. Methods for developing images using toner can be roughly divided into:
There is a method using a so-called two-component developer in which a small amount of toner is dispersed in a medium called a carrier, and a method using a so-called one-component developer in which the toner is used alone without using a carrier.

The method using a two-component developer involves stirring and rubbing the toner and carrier to charge each to a different polarity.The cascade method uses glass beads as the carrier, and the cascade method uses iron powder as the carrier. There are magnetic brush methods, etc. In either case, the toner in the developer maintains its charged state during the development process and is sequentially consumed during image formation, so if the toner content falls below the optimum content, the image density will decrease and the image will become faint and faded. In addition, the carrier may adhere to the photoreceptor or paper surface, causing various defects. In addition, if an excessive amount of toner is contained, the amount of toner adhesion will increase, resulting in a higher image density, but this will not cause problems such as "roughness", "fogging" in non-image areas, and "poor cleaning". Further, electrostatic repulsion between excess toner particles tends to cause scattering and contamination inside the device. Therefore, during development, it is necessary to replenish toner and maintain the developer content within a constant range.

In order to eliminate these problems with two-component developers, development methods using various one-component developers have been proposed and put into practical use. However, in any of these methods, it is difficult to form a uniform thin layer of toner using a one-component developer, and for this reason, most of the methods form a relatively thick single layer of toner. Nowadays, there is a need to improve the clarity and resolution of developed images, and there is an urgent need to develop a method and apparatus for forming a uniform thin layer of toner.

As a conventionally known method for forming a thin layer of toner, there is a method described in JP-A-43037 using a -component developer, and this method has also been put into practical use. . This method uses a magnetic developer (so-called magnetic toner) as a developer and forms a thin layer with a magnetic brush, but in order to make magnetic toner magnetic, a magnetic substance must be added to the toner. . Since magnetic materials generally have a black or blackish-brown color, it is difficult to obtain clear color images using magnetic toners containing such materials, resulting in the problem of poor color quality in color electrophotography. Further, the internal addition of a magnetic material has a negative effect on the fixing performance when a developed toner image is transferred to a transfer paper and thermally fixed, resulting in poor fixing performance.

In order to avoid these problems, various methods have been proposed in which thin layers are formed using non-magnetic toner. For example, B.
2- A method in which toner is applied using a cylindrical brush made of soft bristles, or a method in which the toner is applied to a developing roller whose surface is made of fibers such as velvet using a doctor blade, etc. etc. However, if an elastic blade is used as a doctor blade for the fiber brush, it is possible to control the amount of toner, but it is difficult to apply it uniformly, and simply rubbing the fiber brush on the developing roller will cause damage between the fibers of the brush. Since the existing toner is not sufficiently charged by frictional charging, there is a problem in that ghosts and the like are likely to occur. Furthermore, in systems using these non-magnetic toners, it is difficult to prevent developer from leaking from the device.

[Object of the Invention] The main object of the present invention is to provide a new toner application method that overcomes the problems of the conventional methods described above.

Another object of the present invention is to provide a toner application method that forms a uniform thin layer of toner on the surface of a toner carrier.

Still another object of the present invention is to stabilize the amount of triboelectric charge of a thin toner layer formed on a toner carrier.

Still another object of the present invention is to make the distribution of triboelectric charge of a thin toner layer formed on a toner carrier uniform.

Another object of the present invention is to obtain a good developed image that does not cause problems such as fog or a decrease in one-plane image density.

Yet another object of the present invention is to obtain sharp color images using substantially non-magnetic toner.

The primary object of the present invention is achieved by carrying out the toner application method described below. .

That is, the toner application method of the present invention is a toner application method using a substantially non-magnetic toner and toner application magnetic particles. Specifically, the developing device includes at least a developer container that stores toner and magnetic particles for toner application, a toner carrier that conveys the toner to the latent image carrier, and an upstream side of the toner outlet of the developer container. A toner coating method in which a thin layer of toner is formed on the toner carrier by arranging a magnet forming a magnetic brush made of toner coating magnetic particles in contact with the toner carrier; This is a toner application method characterized by containing fine particles treated with a polymer synthesized from a monomer represented by the formula (l).

vinegar. However, R and & are never hydrogen atoms at the same time. ) In the toner application method of the present invention, the toner used has a function of stabilizing the friction and the amount of electric charge of the toner thin layer formed on the toner carrier, and the toner is made of the above-mentioned specific polymer. It is characterized by having treated fine particles as its constituent components.

The latent image carrier used in the present invention is a drum-shaped or belt-shaped member having a photoreceptor layer and an insulating layer, and the magnetic pole is a member having the same polarity or different polarity in the axial direction of the magnetic roller. It is possible to use one in which magnetic poles are magnetized or one in which a plurality of rod-shaped magnets are adhered to a fixed support member. Furthermore, as the rotating toner carrier, it is possible to use a sleeve made of non-magnetic metal such as aluminum, copper, stainless steel, brass, etc. or a synthetic resin material, or an endless belt made of resin or metal, and the circumferential surface of the sleeve is made of a non-magnetic metal such as aluminum, copper, stainless steel, brass, etc. In order to improve charging characteristics, a roughened surface or an uneven pattern may be provided. Further, as the regulating member provided on the outlet side of the developer container as required, a blade plate or wall made of a magnetic material such as iron or a non-magnetic material such as aluminum, copper, or resin may be used.

Hereinafter, specific contents of the present invention will be explained using example drawings as necessary.

FIG. 1 shows a sectional view of a developing device for explaining the developing principle to which the coating method of the present invention is applied.

In FIG. 1, an electrophotographic photosensitive drum 1 holds a latent image formed by a latent image forming means (not shown), and rotates in the direction of arrow a to pass through a developing position shown in the drawing. A non-magnetic sleeve 2, which is a toner carrier that carries toner, faces the photosensitive drum 1 with a predetermined gap therebetween, and this sleeve 2 rotates in the direction indicated by the arrow. A container 3 made of a non-magnetic material such as resin or aluminum is located above the sleeve 2 and stores the toner 4 and a mixture of the toner 4 and magnetic particles 5, and downstream of the container 3 in the rotation direction of the sleeve, Screw the magnetic blade 6.

On the other hand, a magnet 7 is provided on the opposite side of the sleeve 20 to the magnetic blade 6. The mounting position of this magnet is determined by the relationship between the position of the magnetic pole and the magnetic blade 6, but preferably the magnetic pole is provided slightly upstream of the position of the magnetic blade 6.

Due to the action of the magnetic field thus formed, better results are obtained in terms of preventing magnetic particles from flowing out onto the sleeve 2 through the magnetic blade 6 and uniform application of toner.

In the present invention, in the above configuration, the magnetic particles 5 in the container 3 are
A magnetic brush 8 is formed by a magnetic field generated between the S pole of the magnet 7 and the magnetic blade 6. And sleeve 2
By rotating, the magnetic particles and toner are stirred and mixed while the magnetic brush 8 is held. In this state, on the magnetic blade side of the container 3, due to the presence of the blade 6, the mixture of magnetic particles and toner is prevented from moving by the blade, rises, and circulates in the direction of arrow C.

As a result, the toner is triboelectrically charged by the sleeve 2 or the magnetic particles by mixing with the magnetic particles. The charged toner is uniformly and thinly applied to the surface of the sleeve 2 by mirror force by a magnetic brush 8 formed near the magnetic blade 6, and reaches a position facing the photoreceptor drum.

By the way, the magnetic particles 5 constituting the magnetic brush 8 do not flow onto the sleeve 2 by setting the restraining force due to the magnetic field of the magnet 7 to be stronger than the conveying force caused by the frictional force. If there is toner within the area of the magnetic brush 8, the ratio of the magnetic particles of the magnetic brush 8 to this toner is
The rotation of the sleeve 2 keeps the value almost constant. Thereby, even if the toner on the sleeve is consumed due to development, toner is automatically supplied to the area of the magnetic brush 8. Therefore,
A constant amount of toner can always be applied onto the sleeve 2.

In order to achieve the above-mentioned object of the present invention in the toner application method of the present invention carried out in this manner, the toner used constantly stabilizes the amount of charging friction of the toner thin layer formed on the toner carrier, In addition, it is required to have a function of making the distribution of the amount of charging friction uniform.

Generally, a toner is made by mixing a colored dye/pigment (coloring agent) with a binder resin, and adding auxiliary agents such as a charge control agent as necessary.
As fine particles of pigment, fine particles treated with a polymer synthesized from a monomer represented by the following general formula (I) are used, and these are mixed with a binder resin.

It is never an elementary atom.

Here, as the hydrocarbon group, an alkyl group and an aryl group are preferable. In addition, R and U may be a group that takes an alkylene group together and bonds to an N atom to form a ring.

The substituted or unsubstituted hydrocarbon group is preferably a group having 1 to 10 carbon atoms. In particular, & is a hydrogen atom,
A methyl group or an ethyl group is preferable, and R and & are preferably a hydrogen atom, a methyl group, an ethyl group, an n-propyl group, an isopropyl group, a cyclohexyl group, or a phenyl group.

The above polymer may be not only a homopolymer of the monomer represented by the general formula (I), but also a copolymer of the monomer represented by the general formula (T) and a monomer or polymer copolymerizable therewith. .

Preferred specific examples of the compound represented by the general formula (I) include dimethylaminoethyl acrylate dimethylaminoethyl methacrylate diethylaminoethyl methacrylate C ratio) -n-propylaminoethyl methacrylate diethylaminoethyl acrylate monomethylaminoethyl methacrylate C monoethylaminoethyl Methacrylate H3, monophenylaminoethyl methacrylate H5, diphenylamine ethyl methacrylate, and the like.

As the fine particles used in the present invention, all fine particles conventionally used as constituent components of toner can be used.
Examples of these include conventionally known pigments such as anthraquinone series, quinacridone series, phthalocyanine series, anthraquinone series, perinone series, azo series, and other organic pigments, as well as titanium oxide, iron oxide, yellow lead, ultramarine, and navy blue. Various inorganic pigments such as various metal oxides, metal chlorides, or mixtures thereof, metal compounds such as metal complexes, etc., and the BET specific surface beak measured by the nitrogen adsorption method is 0.1 m2/II to 300 m2/I.
It is something that is.

A specific method for treating fine particles used in the present invention is as follows:
For example, a method in which a polymer emulsion obtained by adding a hexamer represented by the general formula CI) to an aqueous solution containing a surfactant and carrying out emulsion polymerization is added to an aqueous slurry of fine particles and heat-treated; A method of dispersing fine particles, a monomer represented by general formula (1), and a solvent system that dissolves the monomer but not the polymer using a ball mill or the like, and then precipitating the polymer on the surface of the fine particles using a polymerization initiator or the like; There are various methods such as

In the microparticles treated in this manner, I<IJ is particularly preferably 3 to 30 folds.

As the binder resin of the toner used in the present invention, polyp
-Chlorstyrene, : N +7 Monopolymers of styrene and its substituted products such as vinyltoluene; styrene-p-chlorostyrene copolymer, styrene-propylene copolymer, styrene-vinyltoluene copolymer, styrene-vinylnaphthalene Copolymer, styrene-methyl acrylate copolymer, styrene-ethyl acrylate copolymer, styrene-butyl acrylate copolymer, styrene-octyl acrylate copolymer, styrene-methyl methacrylate copolymer, styrene -Ethyl methacrylate copolymer, styrene-butyl methacrylate copolymer, styrene-alpha chloromethyl methacrylate copolymer, styrene-acrylonitrile copolymer, styrene rubinyl methyl ether copolymer, styrene-vinylethyl ether copolymer Polymer, styrene-vinyl methyl ketone copolymer, styrene-butadiene copolymer, styrene-isoprene copolymer, styrene-acrylonitrile-indene copolymer, styrene/-maleic acid copolymer, styrene-maleic acid ester copolymer Styrenic copolymers such as polymers; polymethyl methacrylate, polybutyl methacrylate, polyvinyl chloride, polyvinyl acetate, polyethylene, 4+)-)'ropyrene
, J Realester, polyurethane, polyamide, epoxy resin, polyvinyl butyral, polyacrylic acid resin,
Rosin, modified rosin, terpene m fat, phenolic resin, aliphatic or alicyclic hydrocarbon resin, aromatic petroleum resin,
Chlorinated Noq Rough In, No Q Rough In wax, etc. can be used alone or in combination.

It is synthesized from monomers represented by the general formula (1) of the present invention. T? The amount of IJ mom-treated fine particles contained in the toner varies depending on the material used and the purpose, but generally KO, 2 to 80% by weight, preferably 0.5 to 7%.
0% by weight, especially 1 to 50% by weight is good.

As the method for manufacturing the toner used in the present invention, all commonly used methods can be adopted, and specific examples thereof include:
The binder resin and the fine particles treated with the above polymer are melted and mixed, cooled, crushed and classified, ■ melt-kneaded, dispersed in a liquid, and granulated, ■ melt-kneaded, sprayed into a gas, A method of granulating, or a method of polymerizing a material in which the fine particles are pre-dispersed in a monomer constituting the binder resin.
There is a method of granulation, and a method of coating the outside of the fine particles with a binder resin to form so-called microcapsule-like fine particles.

The magnetic particles for toner application used in the present invention include, for example, surface oxidized or unoxidized iron, nickel, cobalt,
Metals such as manganese, chromium, rare earths, and their alloys or oxides, etc., or their surfaces, can be treated with polytetrafluoroethylene, monochlorotrifluoroethylene polymer, polyvinylidene fluoride, silicone resin, polyester resin, ditertiary-butylsalicylic acid, etc. Those coated with metal complexes, styrene resins, acrylic resins, polyamides, polyvinyl butyral nigrosine, aminoacrylate resins, basic dyes and lakes thereof, fine silica powder, fine alumina powder, etc. can be used.

〔Example〕

Hereinafter, the present invention will be explained in more detail using Examples 1 to 3 and Comparative Example 1. All parts shown on each side are parts by weight. First, the developing device used in each of the following Examples and Comparative Examples will be explained with reference to FIG. Figure 2 (cross section)
The developing device shown in FIG. 1 is a modification of the developing device shown in FIG. 1, and in FIG. 2, the same members as in FIG. 1 are given the same reference numerals. In the embodiment apparatus, the photosensitive drum 1 rotates in the direction of arrow a at a circumferential speed of 60 mm/sec. 2 is an outer diameter 32 that rotates at a circumferential speed of 66 mm/sec in the direction of the arrow.
Stainless steel (SUS 304), thickness o, smm
The sleeve is made of aluminum, and its surface is subjected to irregular sandblasting using ≠60007 random abrasive grains, and the roughness of the circumferential surface is 0.8 μm (Rz=) KL.

On the other hand, a sintered ferrite type magnet 7 is fixedly disposed inside the rotating sleeve 2, and the N pole of the first magnetic pole is a line connecting the center 0 of the sleeve 2 and the tip of the blade with respect to the magnetic blade 6. The relationship (θ shown in the figure) is taken into consideration.

The magnetic plate P6 is made of iron and has nickel plating applied to the surface to prevent rust. The distance between the blade 6 and the surface of the sleeve 2 was set to 200 μm.

Next, a method for measuring the amount of triboelectric charge of a toner according to the present invention will be explained in detail with reference to the drawings. FIG. 3 is an explanatory diagram showing an apparatus for measuring the amount of triboelectric charge used in each example.

In FIG. 3, 11 is a suction device, 12 is a measuring container, and 13 is a suction device.
14 is a conductive screen, 14 is a metal lid, 15 is a vacuum gauge, 16 is an air volume control valve, 17 is a suction port, 18 is a condenser, and 19 is an electrometer.

First, a metal measurement container 12 with a conductive screen 13 of 400 meshes (however, the size can be changed as appropriate so that toner particles do not pass through) on the bottom is filled with the toner particles whose frictional charge amount is to be measured and the particles. A weight ratio of 1 to amorphous iron powder with a diameter between 200 and 300 mesh (the surface is untreated and has almost no triboelectrification property like the toner carrier)
: Add about 4 g of the mixture from step 9 and cover with a metal lid 14.

At this time, the entire weight of the measurement container 12 is weighed, and Wl (1
). Next, in the suction device 11 (at least the part in contact with the measurement container 12 is made of an insulator), the suction port 1
7 and adjust the air volume control valve 16 to set the pressure on the vacuum gauge 15 to 70 mmHg. In this state, suction is performed sufficiently (for about 1 minute) to remove the toner. The potential of the electrometer 19 at this time is assumed to be V (volt). Further, the capacitance of the capacitor 18 used here is assumed to be C (μF). Next, the weight of the entire measuring container after suction is weighed and is set as W2 (,9). At this time, the amount of triboelectric charge T (μcr/#) is calculated as shown in the following equation.

However, the measurement conditions are 23'C150.

Example 1 (a) Production of toner (A) In a flask equipped with a stirrer, a thermometer, a dropping funnel, a Dimroth condenser, and an Ar inlet tube, 1 (5 parts) of a nonionic surfactant having an LB of 18 dissolved in water; 150 parts Add to 80℃
heated to. Thereafter, while passing Ar gas, 100 parts of dimethylamine ethyl methacrylate (the above compound (b)) and 100 parts of a 1% aqueous solution of potassium persulfate were added dropwise from separate dropping funnels. After the dropwise addition was completed, heating was continued for ω minutes, and then cooled to room temperature to obtain a milky white polymer emulsion.

(B) Commercially available copper-phthalonanine M material (c, I.

Pigment blue 15) Listen to 100 copies =
After adding HC1 aqueous solution (4), 5 parts of the nonionic polymer emulsion synthesized in (A) was added and heated to 80% while stirring vigorously.
The temperature was raised to .degree. C., and NaOH was added to adjust the pH to 11, followed by repeated filtration and water washing, followed by drying to obtain a treated product.

(C) Copper-phthalocyanine pigment obtained in (B) toner treatment 5
and 40 parts of styrene-butadiene copolymer, and a mixture containing these components was mixed with 15 parts of styrene-butadiene copolymer using a roll mill.
After heating and kneading at 0° C. for 15 minutes, the mixture was cooled, coarsely crushed using a hammer mill, and then finely pulverized using an air jet type pulverizer. Furthermore, perform wind classification and select 5 to 25μ,
A toner was prepared by adding 1% by weight of colloidal silica.

(b) Development using the above toner 5 parts by weight of the above toner and magnetic particles (EFV-
After thoroughly mixing 50 parts by weight of iron powder C), the mixture was placed in a container 3. Next, 100 parts by weight of toner was added thereon,
I put it in container 3. The mixture of toner and magnetic particles in the container 3 was observed to move in circulation as the magnetic particles were conveyed by the sleeve under the magnetic field, especially when the amount of toner was low.

In the developing device having the above configuration, as the sleeve rotated, a thin layer of only toner having a thickness of about 5 μm was formed on the surface of the sleeve 2.

The charge potential of this toner layer is set to 1f (I) by blow-off method.
It was confirmed that the battery was uniformly charged at a potential of +9.7 μc/I.

Opposing this sleeve 2! On the surface of photoreceptor drum 1,
A charge pattern of -50 V in the dark part and -200 V in the bright part was formed as an electrostatic latent image, and the distance from the sleeve surface was set to 300 μm. Then, the above sleeve was powered by power source E at a frequency of 1600 Hz and a peak-to-peak value of 1.4 KV.
When a voltage with a center value of -300 V was applied, a clear blue developed image of high quality with no uneven development, ghost images, or any other appearance could be obtained.

The image density at this time was 1.38, which was sufficient, and even after repeated development equivalent to 1500 sheets, the image density was 1.33, which was sufficient, and the fog was as good as the initial image. Met. Further, the charge potential of the first layer of the toner at this time was +9.6 μc/.9, which was maintained at the initial value.

In addition, good images were obtained even under special environments of high temperature and high humidity, and low temperature and low humidity.

Furthermore, regarding the mixture in container 3, only the toner was consumed for development, with almost no magnetic particles being consumed.

However, the developing function remained unchanged until almost all of the toner was consumed.

Comparative Example 1 Copper-phthalocyanine pigment (C, 1, Pigment b
When the same procedure as in Example 1 was carried out except that lue 15) was not processed, an image with a lot of ground blur was obtained, and the image density at this time was 0.96, which was insufficient.

Furthermore, as the number of copies increased, the soil strength increased.

Example 2 (A) Production of toner (A) In Example 1-(A)-(A), 100 parts of dimethylamine ethyl methacrylate was replaced with diethylamine ethyl methacrylate (the above compound example (C)).
A nonionic polymer emulsion was obtained in the same manner as in Example 1-(a)-(A) except that the amount was 100 parts.

(B) In Example 1-(a)-(B), copper-phthalocyanine pigment (C,1, Pigment blue1
5) 100 parts of another copper-phthalocyanine pigment (C,
1, PigonentGreen 7) The polymer emulsion obtained using Al was treated in the same manner as in Example 1-(a)-(B) except that the amount was 100 parts.

(C) Toner treatment (C obtained with Bl, 1. Pigment Green
7 15 parts styrene-butadiene copolymer
Example 1-(a)-(
Obtained in the same manner as C).

(b) Development using the above toner When copying was carried out in the same manner as in Example 1-(o) using the above toner, a clear green image without capris could be obtained.

The image density at this time was 1.29, which was sufficient.

Example 3 (A) Production of toner (A) In Example 1-(A)-(A), 100 parts of dimethylamine ethyl methacrylate was added with 1 part of di-n-propylaminoethyl methacrylate. (Said Compound Example (a)) A nonionic polymer emulsion was obtained in the same manner as in Example 1-@I-(A) except that 40 parts of methyl methacrylate and 60 parts of methyl methacrylate were used.

(B) Example 1-(A) -(Copper-7 in Bl
Tarociani/Pigment (C, 1, Pigment blue
15) 100 parts of monoazo pigment (C, 1, Pi
The polymer emulsion obtained in (A) was treated in the same manner as in Example 1-(a)-(Bl) except that the amount of gment Red 170) was 100 parts.

(C) Toner treatment obtained in (B) C, 1. Pigrnent Red
170 2 parts styrene/-diethylamino methacrylate copolymer A toner was obtained in the same manner as in Example 1-@1-(c) except that the amount was changed to 100 parts.

Middle) Development using the above toner When copying was carried out in the same manner as in Example 1-(b) using the above toner, a clear red image without fogging could be obtained.

The image density at this time was 1.43, which was sufficient.

[Summary of effects of the invention]

In the toner application method of the present invention, it is possible to apply a uniform thin layer of toner to a toner carrier, and in particular, it is possible to apply a thin layer of toner uniformly to a toner carrier. Since it is treated with +O remer, which is synthesized from -, the amount of triboelectric charge of the thin toner layer formed on the sleeve, which is the toner carrier, is stable, and the distribution of the amount of triboelectricity is uniform, making it optimal. The amount of charge can be controlled.

One - b. However, R and R2 are never hydrogen atoms at the same time. )

[Brief explanation of the drawing]

FIG. 1 is a sectional view of a developing device for explaining the principle of the present invention;
FIG. 2 is a sectional view of a developing device used in an embodiment of the present invention, and FIG. 3 is an explanatory diagram showing a triboelectric charge amount measuring device in the present invention. In the figure, l is a photosensitive drum which is a latent image holding member, 2 is a sleeve which is a toner carrier, 3 is a container, 4 is a toner, and 5
are magnetic particles, 6 is a magnetic blade which is a regulating member, 7 is a magnet, 8 is a magnetic brush, 11 is a suction device, 12 is a measurement container,
13 is a conductive screen, 14 is a metal lid, 15 is a vacuum gauge, 16 is an air volume control valve, 17 is a suction port, 18 is a condenser, and 19 is an electrometer.

Claims (1)

[Scope of Claims] A developing device includes at least a developer container that stores toner and magnetic particles for toner application, a toner carrier that conveys the toner to a latent image carrier, and a toner outlet of the developer container. A toner coating method in which a thin layer of toner is formed on the toner carrier by disposing a magnet forming a magnetic brush made of toner coating magnetic particles in contact with the toner carrier on the upstream side, wherein the toner is A toner application method comprising fine particles treated with a polymer synthesized from a monomer represented by the following general formula (I). ▲There are mathematical formulas, chemical formulas, tables, etc.▼ (I) (In the formula, R_1, R_2, and R_3 are each a hydrogen atom or a substituted or unsubstituted hydrocarbon group, and n represents an integer of 1 or more. However, , R_1 and R_2 are never hydrogen atoms at the same time.)