JPH11194529A - Electrostatic image developing toner and developing method - Google Patents

Abstract

(57) [Problem] To provide a toner and a developing method which achieve a wide fixing temperature range and maintain a high image density for a long period of time. SOLUTION: Resin fine particles and hydrophobic inorganic fine particles are added and mixed, and the resin fine particles contain 5% by weight or more of chloroform-insoluble matter and the surface of the toner carrier has a dielectric part and a conductive part having a very small area. This is a developing method having a configuration that is mixed.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a toner used in an image forming method for developing an electrostatic latent image in electrophotography, electrostatic recording, electrostatic printing, and the like. And the toner carrier are arranged at a certain interval,
The present invention relates to a toner used in a developing method in which toner is held on the toner carrier at a thickness smaller than the above-mentioned interval, and the carried toner is caused to fly to an electrostatic latent image on an electrostatic latent image holder and developed.

[0002]

2. Description of the Related Art In an image forming apparatus such as an electronic copying machine, a printer, or a facsimile, which forms an electrostatic latent image on a latent image holding member and visualizes the latent image with a developer to obtain a recorded image, a powdery image is formed. Dry developing devices using a developer are widely used.

As such a powdery developer, a two-component developer having a toner and a carrier and a one-component developer not containing a carrier are known, and the former two-component developer is used. In the two-component developing method, a relatively stable and good recorded image can be obtained, but the deterioration of the carrier and the fluctuation of the mixing ratio of the toner and the carrier are apt to occur, the maintenance of the apparatus is complicated, and the structure of the entire apparatus is large. It has a disadvantage that it is easy to change. Therefore, a one-component developing method using a one-component developer which does not have such a drawback has attracted attention. One-component developers include those consisting of toner only and those to which an auxiliary agent is externally added as necessary.

In recent years, there has been an increasing demand for multi-color copying machines and printers such as two-color, multi-color and full-color printers, especially for copying machines and printers that are compact and inexpensive. As one means for reducing the size of the apparatus, superposition development of a multicolor toner on a latent image holding member (photoreceptor) has been proposed.

In the superposition development on the latent image holding member, a multi-color toner image is formed on the latent image holding member, so that the toner does not directly contact the toner image on the latent image holding member. The holding member and the toner holding member are arranged at a fixed interval, the toner is held on the toner holding member to a thickness smaller than the distance, and the held toner flies to the electrostatic latent image on the latent image holding member. Development method (hereinafter referred to as non-contact development)
Is preferred. Regarding this non-contact development,
No. 9475, however, to fly toner to an electrostatic latent image, toner particles must be charged to a desired polarity with certainty, particles can be easily separated individually, and static The ability to fly easily in accordance with the electric field is an important condition for obtaining good image quality.

The present inventors have found that a method of improving the flying of a toner to an electrostatic latent image in non-contact development greatly affects the adhesion between toners (Japanese Patent Application Laid-Open No. 6-258).
867, Japanese Patent Application Laid-Open No. 7-13386, etc., with the further miniaturization, low cost, and high speed of the machine, there has been a demand for a toner that can be fixed in a high temperature range from low to high temperatures. To reduce the fixing energy, the molecular weight of the fixing resin is reduced to lower the softening point and the molecular weight distribution is sharpened. Can be seen.

As a toner additive, Japanese Patent Publication No. 2-60
179, Japanese Patent Publication No. 4-9299, etc., which are used as a photoreceptor filming inhibitor using fine resin particles, but have no effect on improving the fixing property.

[0008]

As a method for improving the developing property of the toner, there is a method of applying an AC electric field or increasing the electric field intensity. However, these methods complicate the developing device,
There are problems such as an increase in size. In addition, a large amount of a high fluidity additive is used as an external additive, but there is a problem of filming of the additive to the electrostatic latent image holding member and deterioration of fixability. Further, the size of the machine has been reduced and the price has been reduced, and a toner capable of fixing the toner in a wide temperature range has been required.

That is, recently, the speed of a small printer has been increased, and the energy applied to a fixing unit for fixing toner on an image tends to increase. It is getting bigger. To improve fixing at low temperatures, various measures have been taken, such as lowering the glass transition temperature of the toner's fixing resin.However, conversely, the fixability in high-temperature areas deteriorates, causing toner to adhere to the fixing roller and causing image contamination. Be the source of An object of the present invention is to achieve a wide fixing temperature range and maintain a high image density for a long period of time.

[0010]

According to the present invention, a latent image holding member for holding an electrostatic latent image on a surface thereof and a toner carrying member are opposed to each other at a predetermined interval in a developing section, and the toner is carried on the toner carrying member. A toner used in an image forming method in which the toner is held on a body at a thickness smaller than the gap, and the carried toner is caused to fly on the surface of the latent image holding body in a developing unit to develop the toner. A toner for developing an electrostatic charge image, characterized by being mixed with inorganic fine particles, wherein the resin fine particles contain 5% by weight or more of a chloroform-insoluble component. The softening point of the resin fine particles is higher than the glass transition temperature of the fixing resin of the toner, and the number average particle diameter thereof is 0.1 μm to 1 μm.

In the present invention, by fixing resin fine particles containing chloroform-insoluble components locally outside the toner as a toner capable of fixing in a wide temperature range, fixability of the toner on a low temperature side is inhibited. It has been found that it is possible to improve the fixability on the high temperature side without any problem, and the present invention has been made. The thermal energy during fixing does not prevent the toner from reaching the toner matrix.In the event of overheating, the chloroform-insoluble matter localized on the surface of the fused toner prevents sticking between the toner and the fixing section, thereby maintaining the fixability in a wide temperature range. It is expected to be. If the chloroform-insoluble content is less than 5% by weight, the desired effect is hardly obtained. On the other hand, if the content exceeds 30% by weight, the viscosity of the resin solution during the production of the resin fine particles increases, and the handling during the production becomes worse.

Further, in one-component non-contact development, the fluidity of the toner greatly affects the image quality, and it is controlled by adding hydrophobic inorganic fine particles to improve the fluidity. Mechanical stress such as agitation in the developing machine is apt to be applied, and the inorganic fine particles adhering to the toner surface are buried in the toner or detached from the surface, causing the toner fluidity to decrease and the image density to decrease. Quality degradation occurs.

The effect of suppressing a decrease in fluidity by using resin fine particles in combination with inorganic fine particles was confirmed. Although details are unknown, it is presumed that the resin particles act as a shock absorber to reduce the stress applied to the toner. In addition, since sufficient fluidity cannot be ensured as a toner by using only resin fine particles, it is essential to use the resin in combination with hydrophobic inorganic particles.

The fine resin particles used preferably have a glass transition temperature higher than the glass transition temperature of the fixing resin used in the toner. When the temperature is lower than the glass transition temperature of the fixing resin, the offset resistance at the time of fixing on the high temperature side becomes insufficient. The number average particle diameter of the resin fine particles is 0.
1 μ to 1 μ is preferred. If it is less than 0.1 μm, the stress buffering effect in the developing machine is weakened, and the fluidity of the toner is reduced. On the other hand, if it is larger than 1 μm, the coverage of the toner surface becomes small, and a sufficient effect cannot be obtained. As the resin fine particles used as the toner of the present invention, a fixing resin generally used for a toner can be used, and resin fine particles can be obtained by making the resin fine particles. Fine particles can be formed by various general polymerization methods, mechanical pulverization methods, fine particles formed by dissolving in a solvent once and then spray-drying.

Adjustment of the softening point, glass transition point, and chloroform-insoluble content of the resin fine particles can be easily performed by adjusting the amount of the polymerization initiator or the catalyst in the raw material monomer mixture or selecting the reaction conditions. The amount of the resin fine particles added to the toner ranges from 0.1% by weight to 5% based on the toner.
% By weight is preferred. When the amount is less than 0.1% by weight, the fixing offset property in a high temperature part is insufficient, and when the amount exceeds 5% by weight, the fixing property on a low temperature side deteriorates.

The addition amount of the hydrophobic inorganic fine particles is preferably from 0.1% by weight to 3% by weight based on the toner.
When the amount is less than 10% by weight, sufficient fluidity as a toner cannot be obtained, and developability is reduced, and sufficient image quality cannot be obtained.
If the amount is more than 10% by weight, the fixability at low temperatures becomes poor. As examples of the type of the fixing resin used in the present invention, all of those which have been used as a binder resin for a toner can be applied.

Specifically, homopolymers of styrene such as polystyrene, polychloroethylene and polyvinyltoluene and their substituted products; 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-α-chloromethyl methacrylate copolymer, styrene-acrylonitrile copolymer, styrene-vinyl methyl ether copolymer, styrene-vinyl ethyl ether copolymer, Styrene-vinyl methyl ketone copolymer, styrene-butadiene copolymer, styrene-isoprene copolymer, styrene-acrylonitrile-
Styrene-based copolymers such as indene copolymer, styrene-maleic acid copolymer, styrene-maleic acid ester copolymer; polymethyl methacrylate, polybutyl methacrylate, polyvinyl chloride, polyvinyl acetate, polyethylene, polypropylene, polyester , Polyvinyl butyl butyral, polyacrylic acid resin, rosin, modified rosin, terpene resin, phenol resin and the like.

The electrostatic image developing toner of the present invention is an electrostatic image developing toner comprising at least a fixing resin and a colorant, and is characterized by using the above-mentioned binder resin. The toner of the present invention is produced by a known method such as melt-kneading, cooling, pulverizing, and classifying.
At this time, a charge control agent, a magnetic substance, and the like can be added as needed.

As the coloring agent, all of conventionally used pigments and dyes can be applied. Specifically, ultramarine blue, nigrosine dye, aniline blue, coco oil blue, Dupont oil red, quinoline yellow, methylene blue chloride, phthalocyanine blue, phthalocyanine green, rhodamine 6C lake, quinacridone, benzidine yellow, malachite green, hansa yellow G, malachite green Examples include hexalate, oil black, azo oil black, rose bengal, monoazo dyes and pigments, disazo dyes and pigments, and trisazo dyes and the like. Examples of the charge control agent include nigrosine, quaternary ammonium salts, metal-containing azo dyes, and salicylic acid complex compounds.

As the release agent, all of the release agents which have been used up to now as toner release agents can be applied. In addition to synthetic waxes such as polyethylene and polypropylene having a low molecular weight, candelilla wax, carnauba wax, rice wax, wood wax and the like. Plant waxes such as wax and jojoba oil; animal waxes such as beeswax, lanolin, and spermaceti; mineral waxes such as montan wax and ozokerite; hardened castor oil; hydroxystearic acid; fatty acid amides; And the like can be used.

The hydrophobic inorganic fine particles which can be used in the present invention include abrasives such as general hydrophobic silica, aluminum oxide, titanium oxide and silicon carbide as toner additives, and conductivity imparting materials such as carbon black and tin oxide. And the like are subjected to a hydrophobic treatment. 0.1% by weight based on toner
~ 5% by weight is preferred.

The average particle size of the toner used in the present invention is preferably 7 μm to 13 μm, which is preferable for ensuring the flying property of the toner. When the average particle size is smaller than 7 μm, the adhesion between toner particles, particularly the liquid crosslinking force between the particles is increased, so that the separation of the toner from the toner carrier is suppressed, and the flying to the electrostatic latent image is suppressed. On the other hand, if it is larger than 13 μm, the image clarity deteriorates (image blurring and bleeding occur).

FIG. 1 shows an outline of a typical developing device useful for carrying out an image forming method using the toner, focusing on a developing roller portion, but the present invention is not limited to the above. FIG.
In the above, the toner 6 of the present invention contained in the toner tank 7 is forcibly brought to a toner supply member (such as a sponge roller or a fur brush) 4 by a stirring blade (toner supply unit auxiliary member) 5, and the toner 6 is It is supplied to the supply member 4. On the other hand, the developing roller 2 having completed the development
Rotates in the direction of the arrow and reaches a contact portion with the toner supply member (sponge roller) 4. The toner supply member 4 rotates in a direction opposite to that of the developing roller 2, charges the developing roller 2 and the toner 6, and causes the toner 6 to adhere to the developing roller 2. Further, the developing roller 2 rotates, and the toner adhered on the developing roller 2 is removed by a toner layer thickness regulating member (elastic blade).
3, the charge is also stabilized while controlling the thickness, and reaches the developing zone 8. In the development area 8, the latent image is developed by non-contact development. Here, a DC voltage or the like is applied to the developing roller 2 and the toner supply member 4 to apply an electric field in a direction in which the toner is held on the developing roller, thereby suppressing the toner from flying to portions other than the electrostatic latent image portion and forming an optimal image. Can be controlled. In the figure, reference numeral 1 denotes an electrostatic latent image carrier.

Next, the mechanism of toner adhesion to the developing roller 2 of this type (electrode type) will be described.
As the developing roller, a developing roller of one-component toner is usually used. For example, a roller obtained by coating a cored roller with an insulating resin can be used. However, when the toner is recently used in a printer or the like, a high-density image is required, and it is necessary to increase the amount of toner to be attached on the roller.

According to the present invention, in the above-mentioned developing method using the toner of the present invention, the surface of the toner carrier has a structure in which a dielectric portion and a conductive portion are mixed in a very small area. It is a developing method. With this method, a desired amount of toner can be carried, and a high-density image can be obtained.

As an example of the developing roller, for example, as shown in FIG.
Are mixed in a very small area. The size of the area is 30 to 2 in diameter when the shape is circular.
Small areas with a size of 000 μm, preferably 100-400 μm, are dispersed randomly or according to certain regulations. As the area ratio, the area of the insulating portion is preferably in the range of 50 to 80%.

The toner adhesion is as follows. First, the developing roller 2 that has completed the development rotates in the direction of the arrow and comes into contact with the toner supply member 4. Here, the remaining toner in the non-image portion that has not been developed is mechanically and electrically scraped off by the toner supply member 4, and the dielectric portion 9 is charged by friction.
At this time, the charges of the developing roller 2 and the toner by the previous development are fixed and initialized by friction. Next, the toner carried by the supply member 4 is charged by friction and adheres to the dielectric portion 9 of the developing roller 2 electrostatically. At this time, the polarity of the toner is opposite to the charge of the photosensitive member, and the dielectric portion 9 of the developing roller 2 has the same polarity.

At this time, the electric field on the developing roller 2 is a microfield (closed electric field) 11 as shown in FIG.
Thus, the electric field has a large electric field gradient, and the toner can be adhered in multiple layers. Further, since the adhered toner has a closed electric field, it is strongly pulled toward the developing roller 2 and is hardly separated. The thickness of the toner layer is further controlled by the toner layer thickness regulating member 3 so that the developing area 8
The toner becomes an electric field that easily adheres to the photoreceptor, and is developed.

In order to prepare a developing roller in which the derivative portion 9 and the conductor portion 11 are mixed in a small area on the surface, for example, first, a metal roller having a groove formed on the surface by iris knurling or the like is used. The prepared and grooved metal surface is coated, for example, with a fluororesin, cured and dried, and then the surface of the roller is cut or polished so that the conductive portion is mixed in a small area, and the conductive portion area is 2
Grind to 0-50%.

Of course, instead of the developing roller shown here, a metal member subjected to a sandblast treatment or a metal member coated in a thin layer with a resin can be used. It is also used in a developing method in which a regulating member is provided by two-component magnetic brush development to perform non-contact development.

[0031]

DESCRIPTION OF THE PREFERRED EMBODIMENTS Hereinafter, the present invention will be described specifically with reference to examples. In addition, "part" in an example shows a weight part. In addition, the performance evaluation in the example was performed using the following method. Resin 5 in a 100 cc screw cap glass bottle with chloroform insoluble content
g and 100 ml of chloroform, and the mixture was stirred and dissolved in a ball mill at 25 ° C. for 5 hours. The filter paper after filtration was dried under vacuum, and the amount of the residue was divided by the amount of the initial resin (5 g) and expressed as a percentage.

Softening point 1 cm using an elevated flow tester (manufactured by Shimadzu Corporation)
While heating the sample of No. ³ at 6 ° C./min, a load of 20 kg / cm ² was applied by a plunger to give a diameter of 1 mm and a length of 1 m.
m, a plunger descent amount-temperature curve is drawn, and when the height of the S-shaped curve is h, the temperature corresponding to h / 2 (the temperature at which half of the resin flows out) is set to the softening point. And

Preparation of Resin Fine Particles A Polyoxypropylene (2,2) -2,2-bis (4-
(Hydroxyphenyl) propane 600 g, polyoxyethylene (2,2) -2,2-bis (4-hydroxyphenyl) propane 400 g, isododecenyl succinic acid 150
g, 300 g of fumaric acid and 5 g of dibutyltin oxide were placed in a flask and placed under a nitrogen stream in a mantle heater.
The temperature was raised to 0 ° C., and the reaction was carried out with stirring. Softening point 110 ° C
When the reaction reached, the reaction was terminated. The obtained resin A was a pale yellow solid, had a glass transition temperature by DSC of 70 ° C. and a chloroform-insoluble content of 5.3%.

Further, 300 parts of methyl ethyl ketone was charged into a reactor equipped with a stirrer, a thermometer, a falling condenser and a nitrogen introducing tube, 30 parts of the resin obtained above was added, the mixture was heated to 40 ° C., stirred, and 2 parts of triethylamine was stirred. After adding and neutralizing 100 parts of ion-exchanged water, 200 rpm
Methyl ethyl ketone was distilled off under reduced pressure at a stirring speed of m to obtain an aqueous dispersion of the polyester resin. The number average particle size of this dispersion was measured to be 1.1 μm. This aqueous dispersion was dried with a freeze dryer to obtain fine resin particles A. This aqueous dispersion was dried with a freeze dryer to obtain fine resin particles A.

Preparation of Resin Fine Particles B Polyoxypropylene (2,2) -2,2-bis (4-
(Hydroxyphenyl) propane 700 g, polyoxyethylene (2,2) -2,2-bis (4-hydroxyphenyl) propane 650 g, isododecenyl succinic acid 60
g, 160 g of terephthalic acid and 6 g of dibutyltin oxide were placed in a flask and placed under a nitrogen stream in a mantle heater.
The temperature was raised to 10 ° C. and the reaction was carried out with stirring. Softening point is 85 ℃
When the reaction reached, the reaction was terminated. The obtained resin was a pale yellow solid, and had a glass transition temperature by DSC of 68.5 ° C. and a chloroform-insoluble content of 3.5%.

Further, 300 parts of methyl ethyl ketone was put into a reactor equipped with a stirrer, a thermometer, a falling condenser and a nitrogen inlet tube, 30 parts of the resin obtained above was added, the mixture was heated to 40 ° C., stirred, and 2 parts of triethylamine was stirred. After adding and neutralizing, and adding 1000 parts of ion exchange water, 200 rpm
Methyl ethyl ketone was distilled off under reduced pressure at a stirring speed of m to obtain an aqueous dispersion of the polyester resin. The number average particle size of this dispersion was measured and found to be 1.2 μm. The aqueous dispersion was dried with a freeze dryer to obtain fine resin particles B.

Preparation of Resin Fine Particles C Polyoxypropylene (2,2) -2,2-bis (4-
(Hydroxyphenyl) propane 600 g, polyoxyethylene (2,2) -2,2-bis (4-hydroxyphenyl) propane 400 g, isododecenyl succinic acid 100
g, fumaric acid 320 g, and dibutyltin oxide 3 g were placed in a flask and placed in a mantle heater under a nitrogen stream.
The temperature was raised to 0 ° C., and the reaction was carried out with stirring. 120 ° C softening point
When the reaction reached, the reaction was terminated. The obtained resin C was a pale yellow solid and had a glass transition temperature of 83.5 ° C. by DSC.
And the chloroform-insoluble content was 8.5%.

Further, 300 parts of methyl ethyl ketone was charged into a reactor equipped with a stirrer, a thermometer, a falling condenser and a nitrogen inlet tube, 30 parts of the resin obtained above was added, the mixture was heated to 40 ° C., stirred, and 2 parts of triethylamine was stirred. After adding and neutralizing, and adding 1000 parts of ion exchange water, 200 rpm
Methyl ethyl ketone was distilled off under reduced pressure at a stirring speed of m to obtain an aqueous dispersion of the polyester resin. The number average particle size of this dispersion was measured and found to be 1.0 μm. The aqueous dispersion was dried with a freeze dryer to obtain fine resin particles C.

Preparation of Resin Fine Particles D To the resin C, 300 parts of methyl ethyl ketone was added to a reactor equipped with a stirrer, a thermometer, a falling condenser, and a nitrogen inlet tube, and 30 parts of the resin obtained above was added at 40 ° C. The mixture was heated and stirred, and 2 parts of triethylamine was added to neutralize the mixture, and 1000 parts of ion-exchanged water was added.
Methyl ethyl ketone was distilled off under reduced pressure at a stirring speed of m to obtain an aqueous dispersion of the polyester resin. The number average particle diameter of this dispersion was measured and found to be 0.4 μm. This aqueous dispersion was dried with a freeze dryer to obtain fine resin particles A.

Example 1 Binder resin Polyester resin (glass transition temperature 70 ° C.) 90 parts Release agent Carnauba wax 5 parts Colorant carbon black 15 parts Charge control agent Zinc salicylate 5 parts The mixture having the above composition was melt-kneaded. After cooling, the mixture was coarsely pulverized by a hammer mill, finely pulverized by a pulverizer using an air jet method, and classified to obtain a toner base having an average particle diameter of 10.5 μm. Further, 1.5 parts of hydrophobic silica (H-2000, manufactured by Hoechst) and 0.8 parts of fine resin particles A were added to 100 parts of the toner base, and the mixture was added and mixed to prepare a toner (A1).

COMPARATIVE EXAMPLE 1 Toner matrix prepared in Example 1
To 1.5 parts of hydrophobic silica 1.5 parts (Hechst H-
2000) was added to form a toner (B1). Comparative Example 2 Toner base 1 prepared in Example 1 was replaced with toner base 1
To 1.5 parts of hydrophobic silica 1.5 parts (Hechst H-
2000) and 0.8 parts of fine resin particles B were added and mixed to prepare a toner (B2).

Example 2 To 100 parts of the toner base material prepared in Example 1, 1.5 parts of hydrophobic silica (H-2000 manufactured by Hoechst) and 0.7 parts of fine resin particles C were added and mixed to prepare a toner (A2). Created.

Example 3 The toner base 1 prepared in Example 1 was replaced with the toner base 1
To 1.5 parts of hydrophobic silica 1.5 parts (Hechst H-
2000) and 0.8 parts of resin fine particles D were added and mixed to prepare a toner (B2).

In the examples and comparative examples obtained above,
Prepare a developing device equipped with a developing roller in which an aluminum core is coated with an epoxy-modified silicone resin on the entire surface of the roller and then dried and polished. The developing device is equipped with the toner of Example 1, and the developing device is developed with an IMAGIO MF530 (Ricoh). An image was printed by placing the sleeves at an interval of 200 microns. Further, running was performed continuously for 5000 sheets, and an image was formed again, and the image density was measured with a Macbeth densitometer. The fixing temperature of the fixing unit of the copying machine was modified so that the temperature could be varied, and the temperature was changed at intervals of 5 ° C. to measure the lower limit temperature of fixing and the upper limit temperature of fixing. The results are shown in Table 1.

[0045]

[Table 1]

Example 4 In the toner obtained in Example 3, the core was subjected to knurling on the roller surface, coated with an epoxy-modified silicone resin and polished, and the dielectric portion and the conductive portion were mixed in a small area (area ratio 50%). ) A developing roller was prepared and used as a developing roller. A developing device equipped with the prepared developing roller was prepared, and the toner (A3) of Example 3 was mounted thereon, and IMAGI was prepared.
It was mounted on OMF530 (manufactured by Ricoh), installed in the same manner as in Example 1, and an image was created and evaluated.

[0047]

According to the toner and the developing method of the present invention, there is provided a toner and a developing method which have less image density and image deterioration even when used for a long period of time and have a wide fixing temperature range, in comparison with non-contact development. It is possible.

[Brief description of the drawings]

FIG. 1 is an explanatory diagram of a typical developing device using the toner of the present invention.

FIG. 2 is an explanatory diagram of a developing roller used in the present invention.

[Explanation of symbols]

 REFERENCE SIGNS LIST 1 electrostatic latent image carrier 2 developing roller 3 toner layer thickness regulating member 4 toner supply member 5 stirring blade 6 toner 7 toner tank 8 development area

Claims (4)

[Claims] An image forming apparatus comprising: a latent image holding member for holding an electrostatic latent image on a surface thereof and a toner carrier which are opposed to each other at a predetermined interval in a developing section; A toner used in an image forming method in which the toner is held at a thickness and the developed toner is caused to fly to the surface of the latent image holding member in a developing section and developed. The toner is formed by adding and mixing resin fine particles and hydrophobic inorganic fine particles. 5% by weight of the resin fine particles
A toner for developing electrostatic images, characterized by containing a chloroform-insoluble component as described above. 2. The electrostatic image developing toner according to claim 1, wherein the softening point of the resin fine particles is higher than the glass transition temperature of the fixing resin of the toner. 3. A resin fine particle having a number average particle diameter of 0.1.
The toner for developing an electrostatic image according to claim 1, wherein the toner has a particle size of μ to 1 μ. 4. The developing method according to claim 1, wherein the surface of the toner carrier has a structure in which a dielectric portion and a conductor portion are mixed in a small area.