JPH0869125A - Electrostatic developing method - Google Patents

Abstract

PURPOSE: To obtain an electrostatic developing method to transfer a developer on a carrier body to an electrostatic latent image holding member in the area where the carrier body faces the image holding member so that melt sticking of a toner or pulverization into a fine powder is hardly caused, good quantitative stability for formation of layers and good stability against environments can be obtd. without losing thermal fixing property, and that an image having a long life and high quality can be obtd. without voids, by incorporating particles of fatty acid metal salt into the developer. CONSTITUTION: The developer contains particles of fatty acid metal salt. As for the fatty acid for the particles of fatty acid metal salt, polyvalent satd. fatty acids such as butyric acid, valeric acid and lauric acid, univalent unsatd. fatty acids such as crotonic acid and oleic acid, and polyvalent unsatd. fatty acids such as maleic acid and citraconic acid are used. Usually, particles of fatty acid metal salt having 0.2 to 30μm average particle size before addition are used. The amt. of the fatty acid metal salt added depends on the particle size, and usually 0.01 to 5 pts.wt. of the powder to 100 pts.wt. of toner particles, more preferably 0.03 to 1.5 pts.wt., is enough to obtain a significant effect.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an electrostatic developing method used in electrophotography, electrostatic recording and the like.

[0002]

2. Description of the Related Art Generally, in the electrophotographic system, an electrostatic latent electric image is formed by various means on a photoconductor (usually a photosensitive drum processed into a drum shape) containing various photoconductive substances, and the electrostatic latent image is formed. The electrostatic latent image is developed with a developer made of powder, and if necessary, the powder is transferred onto a substrate such as paper or film, and then fixed by a method such as pressing or heating. As the developer, a two-component developer composed of a carrier such as iron powder or ferrite powder and a toner and a one-component developer (non-magnetic or magnetic toner) not requiring a carrier are known.

As a developing method using a one-component developer,
A developer layer is adhered and formed on the surface of a developer carrier, and the developer is transferred by contacting it with an electrostatic latent image holding member such as a photoconductor, or by transferring the developer in a non-contact manner. Flying development methods are known. The electrostatic force control method at the time of transferring the developer includes a method of forming a DC electric field between the developer carrying member and the latent image holding member, a direction toward the latent image holding member by applying an AC bias, and a developer carrying method. A method of applying an electrostatic force alternately with the direction toward the body is known.

As a method of forming a developer layer on the developer carrying member, the developer carrying member is made to move relative to the developer layer thickness regulating member so that the developer moves when passing through the facing area. A general method is to regulate the amount and form a developer layer on the developer carrier. In the two-component method using magnetic carrier particles or the method using magnetic toner, the developer is magnetically adsorbed to a developer carrier (magnet roller) having a magnetic field generating means arranged on the back surface of the developer carrier to develop the developer. A general method is to form a developer layer by passing it through a gap maintaining an appropriate distance between the carrier and the developer layer thickness regulating member.

When a non-magnetic developer such as a non-magnetic one component is used or a magnetic restraining force is not used, it is necessary to form the developer layer by Coulomb force due to frictional charge. In these cases, a sufficient amount of electrostatic charge cannot be secured just by passing through the gap as in the above, and the developer layer may become non-uniform or the developer may be scattered to the periphery. Therefore, in the case of a method that does not use magnetic force, the developer layer thickness regulating member is generally pressed against the developer carrier. That is, the developer is conveyed by the developer carrier and passes while pressing the pressing portions of the developer layer thickness regulating member and the developer carrier to form an appropriate developer layer thickness and at the same time press the pressing portion. Sufficient frictional charge can be obtained by the frictional energy at the time of spreading and a stable developer layer can be formed.

On the other hand, as a method for producing a toner, a method for producing a pulverized toner in which a binder raw material and other components are mixed and kneaded, cooled, and solidified to obtain toner particles having a desired particle size There is known a method for producing a polymerized toner in which various components and a monomer of a binder resin raw material are dispersed to carry out a polymerization reaction to synthesize toner particles. As a pulverization method for pulverized toner production, a coarsely pulverized toner raw material is jetted together with a gas from a nozzle and pulverized by collision of raw material particles with each other or collision with a collision plate, or crushing with a high-speed impact member. A mechanical crushing method and the like are known.

From the pulverized toner raw material, only particles having a desired particle diameter are selected by a classification step to obtain toner particles. The toner of the developer for dry electrostatic image development has an average particle size of 5 to 20 μm.
Those of about m are usually used.

[0008]

In recent years, personalization,
With market demands such as space saving, downsizing of copiers, printers, etc. tends to be promoted. In order to further reduce the size of the electrophotographic apparatus, it is necessary to reduce the diameter of the photosensitive member, for example, the photosensitive drum, and further reduce the size of the developing tank.

However, the two-component developing method which has been most commonly used conventionally requires a developing chamber for agitating a mixture of carrier particles and toner particles and a replenishment toner chamber for replenishing consumed toner. In addition, the function of controlling the mixing ratio of the toner and the carrier in the developing chamber is also required, and there are many problems from the viewpoint of downsizing and simplification.

In order to avoid these problems, the magnetic one-component method which does not use carrier particles has been widely used for personal use. However, when further simplification is attempted, there is a limit to the number of parts and cost reduction in the magnet roller system used for holding the developer. In addition, the ferromagnetic component contained in the toner particles is generally metal oxide particles, which is an obstacle to recycling printed paper.

Under such circumstances, a non-magnetic one-component developing system using neither a ferromagnetic component nor a magnet roller has been attracting attention. The non-magnetic one-component developing method includes a flying developing method and a contact developing method, but these methods are generally unsuitable for analog image expression that requires gradation expression of photographs and the like.
There are few edge effects peculiar to electrophotography (a phenomenon in which toner is excessively developed on the black and white boundary of a printed image), and thickening of printed characters does not easily occur, so it is said to be suitable for digital binary representation of laser printers. ing. Further, with the development of digital image information processing technology in recent years, a non-magnetic one-component system has been attracting attention as an output unit of a digital full-color copying machine or a monochrome digital copying machine.

A problem with the non-magnetic one-component system occurs when the above-mentioned pressed developer layer thickness regulating member is used.
That is, when a sufficient pressing force is applied to the developer layer thickness regulating member so that the toner does not scatter around and a uniform layer is formed,
The frictional energy causes a fatal problem that the toner is fused to the developer carrier or the developer layer thickness regulating member or is finely pulverized. If a hard toner having a high glass transition point or a high softening point is used to avoid these problems, the heat fixing performance is deteriorated, and a high temperature and a large amount of energy are required to sufficiently fix the toner on paper or the like. Further, as a means for solving these problems, a method of adding fine particle silica to the toner as a fluidizing agent can be considered, but they decrease the charge amount of the toner particles or increase the reverse charged particles, and An unfavorable phenomenon in image quality such as white background fogging in which a white background portion is contaminated with toner occurs.

Another problem is the stability of the amount of the developer layer formed. When image formation with a large amount of toner consumption is continuously performed, the amount of the layer-forming developer decreases, and there arises a problem that a sufficient image density cannot be obtained. This is because the developer carried by the developer carrying member and passing through the developer layer thickness regulating member while spreading the pressing portion cannot continuously form a stable layer.

In addition, the non-magnetic one component is more likely to cause "middle void" than the two components. In order to solve these problems, a method of using a toner having a shape close to a sphere so that the rolling of the toner is improved and the frictional force is not concentrated on a part of the toner particles or a part of the toner particles (JP-A-4-4).
No. 4056, Japanese Patent Application Laid-Open No. 5-142857, etc.) and a method using polymerized toner having a nearly spherical shape (Japanese Patent Application Laid-Open No. 3-259).
No. 161, Japanese Patent Laid-Open No. 4-225368, Japanese Patent Laid-Open No. 5-165253, etc.) are known. Since the toner particles are triboelectrically charged with the developer carrier while rotating in the developing device, the surface of the toner that has a substantially spherical shape and a smooth surface can actually come into contact with the toner that has a non-uniform shape and unevenness. It becomes wider and is advantageous in terms of triboelectrification.

However, the polymerized toner often uses various additives in order to control the shape, the molecular weight, the dispersion of the pigment to be added, etc. in the manufacturing process, which is not preferable in terms of the charge control ability. In particular, environmental stability often causes problems such as deterioration of image quality due to high temperature and high humidity and low temperature and low humidity. On the other hand, the toner manufactured by the pulverization method is superior to the polymerized toner in terms of environmental stability, but has a non-uniform shape and is not preferable because of stability of layer formation. A method of producing a toner having a nearly spherical shape by a pulverization method (method using Kryptron: powder and industrial volume 25, No. 5 (199
3) p59 etc.) are also known, but they are still insufficient.

In order to realize the non-magnetic one-component developing system without impairing the fixing property at low temperature, high triboelectric charging property with weak friction energy is essential. As means for obtaining high chargeability even with weak friction energy, there is a method of increasing the chance of friction by contacting a contact member such as a sponge roller that supplies toner to the developer carrier, or a developer carrier and developer layer thickness regulation. It is known that a potential difference is applied between members or between the developer carrying member and the contact member, and the charge is injected into the developer passing between them, but as described above, the low cost of the electrophotographic apparatus is used. Nowadays, it is urgently required to eliminate these auxiliary members as much as possible, and to charge them only with a very weak friction energy between the developer layer thickness regulating member and the developer carrier. At that level, it is not possible to improve the composition simply or to make it spherical.

[0017]

The present inventors have solved the above problems by obtaining sufficient charge with weak friction energy, and (1) toner fusion and pulverization are less likely to occur.
(2) The heat fixing property is not sacrificed, (3) the layer formation amount stability and the environmental stability are good, and (4) there are no hollow defects, and as a result of diligent study, a result of earnest study was obtained. The present invention has been accomplished by using certain specific additives. Furthermore, the present invention exerts its effect even when used in a simple developing method.

That is, the gist of the present invention is that the developer layer thickness regulating member is pressed against the developer carrying member and the carrying member moves relatively to the regulating member, so that the developer passes through the pressing portion. In the step of forming a developer layer on the carrier, and transferring the developer on the carrier to the electrostatic latent image holding member in the area facing the electrostatic latent image holding member. And the fatty acid metal salt particles are contained in the developer.

The present invention will be described in detail below. The toner used in the present invention is a fine powder obtained by melt-kneading a thermoplastic binder resin, a colorant, and if necessary, a charge control agent, a release agent, and other substances, pulverizing and classifying. Among the above-mentioned toner constituent components, various known binder materials suitable for the toner can be used as the binder resin. For example,
Polystyrene, polychlorostyrene, poly-α-methylstyrene, styrene-chlorostyrene copolymer, styrene-propylene copolymer, styrene-butadiene copolymer, styrene-vinyl chloride copolymer, styrene-vinyl acetate copolymer , Styrene-maleic acid copolymer, styrene-acrylic acid ester copolymer (styrene-methyl acrylate copolymer, styrene-ethyl acrylate copolymer, styrene-butyl acrylate copolymer, styrene-
Octyl acrylate copolymer and styrene-phenyl acrylate copolymer, etc.), styrene-methacrylic acid ester copolymer (styrene-methyl methacrylate copolymer,
Styrene-ethyl methacrylate copolymer, styrene-butyl methacrylate copolymer, styrene-octyl methacrylate copolymer, styrene-phenyl methacrylate copolymer, etc.), styrene-α-methyl chloroacrylate copolymer and Styrene-based resins such as styrene-acrylonitrile-acrylic acid ester copolymers (homopolymers or copolymers containing styrene or styrene substitution products), vinyl chloride resins, rosin-modified maleic acid resins, phenol resins, epoxy resins, saturated polyesters. Resin, unsaturated polyester resin, low molecular weight polyethylene resin, low molecular weight polypropylene resin, ionomer resin, polyurethane resin, silicone resin, ketone resin, ethylene-ethyl acrylate copolymer resin, xylene resin, polyvinyl butyral resin, etc. There is, as the preferred resin for use in the present invention include a styrene resin, saturated or unsaturated polyester resins and epoxy resins.

Further, the cross-linking binder resins described in JP-B-50-23354 and JP-A-50-44836, or JP-B-55-6895 and JP-B-63-32180 are described. A non-crosslinked binder resin can also be used. It is more preferable to use a crosslinkable polyester resin from the viewpoint of achieving both low temperature fixability to some extent and difficulty in fusion and fine pulverization in a developing device. The crosslinkable polyester resin is obtained by polycondensation of a divalent carboxylic acid monomer, a divalent alcohol monomer and a trivalent or higher polyvalent carboxylic acid monomer or a polyvalent alcohol monomer. Examples of the dihydric alcohol monomer include ethylene glycol, diethylene glycol, triethylene glycol, 1,2
-Propylene glycol, 1,3-propylene glycol, 1,4-butanediol, neopentyl glycol, 1,4-butenediol and other diols, bisphenol A, polyoxyethylenated bisphenol A, polyoxypropyleneated bisphenol A, etc. Bisphenols and other dihydric alcohol monomers. As the divalent carboxylic acid monomer, isophthalic acid,
Terephthalic acid, adipic acid, sebacic acid, diphenic acid,
Examples thereof include naphthalenedicarboxylic acid, cyclohexanedicarboxylic acid, and anhydrides or lower alkyl esters of these acids as main components. Examples of the trivalent or higher polycarboxylic acid include trimellitic acid, cyclohexanetricarboxylic acid, naphthalenetricarboxylic acid, butanetricarboxylic acid, hexanetricarboxylic acid, octanetetracarboxylic acid, and anhydrides of these acids. As the trihydric or higher polyhydric alcohol monomer,
Trimethylolethane, trimethylolpropane, glycerin, pentaerythritol and the like can be mentioned.

The above resins are not limited to being used alone, but two or more kinds may be used in combination. The softening point of the binder resin for toner is preferably 100 to 160 ° C. as measured by a flow tester method. If the softening point is less than 100 ° C., stains (so-called “hot offset” phenomenon) during fixing tend to occur, and if it exceeds 160 ° C., the fixing strength tends to deteriorate, which is not preferable. The glass transition temperature of the binder resin is such that the transition start (inflection point) is 50 when measured with a differential thermal analyzer.
It is preferably at least ° C. When the glass transition temperature is lower than 50 ° C., the thermal stability during long-term storage is poor and toner aggregation and solidification are caused, which is a problem in use.

As the colorant, any suitable pigment or dye can be used so far as it is a conventionally used one. For example, titanium oxide, zinc white, alumina white, calcium carbonate, navy blue, carbon black, phthalocyanine blue, phthalocyanine green, Hansa yellow G, rhodamine dyes and pigments, chrome yellow, quinacridone, benzidine yellow, rose bengal, triallyl methane dyes. , Anthraquinone dye, monoazo and diazo dyes and pigments are used alone or in an appropriate mixture according to the color of the corresponding toner. The content of the colorant may be an amount sufficient to color the toner so that a visible image can be formed by development, and is, for example, 3 to 20 parts by weight with respect to 100 parts by weight of the binder resin. preferable.

As the charge control agent used in the present toner, measures such as composition control of the binder resin used and composition control of the surface of the developer carrier can be considered, but normally, in order to obtain positive chargeability. A positive charge control agent may be used, and a negative charge control agent may be used to obtain negative chargeability. These may be appropriately selected from various known ones. Examples of the positive charge control agent include various nigrosine dyes, quaternary ammonium compounds described in Japanese Patent Publication No. 1-54694, Japanese Patent Publication No. 1-54695, Japanese Patent Publication No. 1-54696, and the like. -455, Japanese Patent Publication No. 63
-57787, Japanese Patent Publication No. 2-501506, etc., and triphenylmethane compounds described in JP-A-3-11.
Examples thereof include imidazole derivatives and metal complexes of imidazoles described in JP-A-9364, JP-A-3-202856 and JP-A-3-217851. Examples of the negative charge control agent include metal-containing azo dyes described in JP-B-3-37183 and JP-B-2-16916, and salicylic acid metal complexes described in JP-B-55-42752. Examples include salicylic acid metal salts described in JP-A-63-163374, and calixarene compounds containing no metal element described in JP-A-5-119535. As a method of incorporating the above charge control agent into the toner, there are a method of adding it inside the toner and a method of adding it externally. When internally added, the amount of these compounds used is usually 0.05 to 20 parts by weight, preferably 0.1 to 10 parts by weight, based on 100 parts by weight of the binder resin. If externally added, the resin 10
0.01 to 10 parts by weight is preferable with respect to 0 parts by weight.

In addition, known auxiliary agents that can be internally added to the toner for the purpose of improving thermal characteristics and physical characteristics can be used. For example, polyalkylene wax or paraffin wax can be used as a releasing agent. , Higher fatty acids, fatty acid amides, metal soaps and the like. The addition amount is preferably 0.1 to 10 parts by weight with respect to 100 parts by weight of the binder resin.

The toner may be manufactured by kneading the above components with a kneader, cooling, pulverizing and classifying. The average particle size of the toner is preferably 5 to 20 μm. Generally, a method using a Coulter counter is widely used for the particle size of the toner. The average particle size of the toner used in this invention is 1 for Coulter Counter TA-II type.
Toner particles were dispersed in Isoton using an aperture of 00 μm, and the toner particle size distribution was measured using channels 3 to 16 and determined by volume averaging.

The fatty acid of the fatty acid metal salt particles used in the present invention includes monovalent saturated fatty acids such as butyric acid, valeric acid, lauric acid, myristic acid, palmitic acid, stearic acid and montanic acid, adipic acid, pimelic acid, Suberic acid, polyvalent saturated fatty acids such as azelaic acid and sebacic acid, monovalent unsaturated fatty acids such as crotonic acid and oleic acid, and polyvalent unsaturated fatty acids such as maleic acid and citraconic acid, In the present invention, a metal salt of a saturated or unsaturated fatty acid having 8 to 35 carbon elements can be preferably used. As the metal salt, lithium, sodium, potassium, copper, rubinium, silver, magnesium,
Includes, but is not limited to, calcium, zinc, strontium, cadmium, barium, mercury, aluminum, chromium, tin, titanium, zirconium, lead, manganese, iron, cobalt, nickel salts and mixtures thereof.
The average particle size of the fatty acid metal salt powder before addition is 0.2.
The particle size of about 30 μm is usually used, but it is not particularly limited because it has a crushing effect when mixed with toner particles. However, it is more preferable that the amount of coarse powder is small and the particle size is small because uniform dispersion is easy at the time of mixing. The amount of the fatty acid metal salt added depends on the particle size and the like, but is 0.01 to 5 parts by weight, more preferably 0.03 to 1.5 parts by weight, based on 100 parts by weight of the toner particles. Exert.

The electrostatic developer used in the present invention may contain inorganic oxide fine particles having a specific surface area of 45 m ² / g or more, and the inorganic oxide fine particles include silicon, titanium, aluminum, magnesium, iron, Oxides such as zinc and cerium and their composite oxides can be used. The surface of these may be surface-treated with a silane coupling agent, a titanium coupling agent, silicone, or other resin. Conventionally known fine particle inorganic oxides include silica (R972 from Nippon Aerosil Co., Ltd., Taranox 5 from Gunze Sangyo Co., Ltd.).
00), titania (IT-S manufactured by Idemitsu Kosan Co., Ltd.), alumina (aluminum oxide C manufactured by Nippon Aerosil Co., Ltd.),
Magnesia (Ube Industries gas phase method high-purity ultrafine powder magnesia 100A, etc.), iron oxide (BASF made Sicopur F
Inorganic oxide fine particles such as F4098) are known.

In the present invention, in addition to the toner particles, the fatty acid metal salt, and the fine particles of inorganic oxide having a specific surface area of 45 m ² / g or more, it is more preferable to add auxiliary particles that help improve the image quality. The auxiliary particles added in the present invention have a particle size smaller than the toner particle size, a specific surface area of 20 m ² / g or less, and more preferably a specific surface area of 10 m ^2.
/ G or less particles are used. The purpose of using these auxiliary particles is to adjust the chargeability and fluidity of the developer, and by adding them, the "following property is poor" (when the image with a large printing area is continuously printed, the developer is It is possible to improve the phenomenon that it does not adhere sufficiently to the carrier. Regarding the composition of the auxiliary particles,
Although not limited, it is easy to procure inorganic oxides. As the inorganic oxide, oxides of silicon, titanium, aluminum, magnesium, iron, zinc, chromium and the like, and complex oxides thereof are not limited to magnetic and non-magnetic substances, and can be used. Among them, composite oxides are preferable, and as composite oxides, inorganic pigments such as magnetite, various ferrites, various chromites are preferable. It is considered that these complex oxides are in the region where the charging order and the electric conductivity are appropriate.
The amount of the auxiliary particles added was 100 parts by weight per 100 parts by weight of the toner particles.
2 to 12 parts by weight are suitable.

The specific surface area measured by the nitrogen adsorption method was Shimadzu Micromeritics Flowsorb 2300, and an appropriate amount of the sample was put into the cell and degassing was performed at 200 ° C. for 10 to 20 minutes to obtain the specific surface area (m ² / g). taking measurement. If degassing at 200 ° C is not possible due to possible decomposition of the sample, degas at a temperature below that value and repeat the measurement on the same sample. Use the measured value when the value is stable. .

The electrostatic developer used in the present invention may be a one-component, two-component, magnetic or non-magnetic developer, but the effect of the present invention is remarkable when it is a non-magnetic one-component developer. FIG.
The developing method will be described by taking the developing device of No. 1 as an example. The developer carrying member 1 used in the present invention usually has a cylindrical or cylindrical surface as a carrying surface. The material may be either an elastic body or a rigid body, but a method using an elastic body is generally used in the contact developing method. Surface is electrostatic developer 6
An appropriate surface roughness may be given for the purpose of improving the transportability of the. In addition, it is necessary to consider a material that can obtain appropriate frictional charging with the toner particles. In the case of non-magnetic one-component contact type development, a conductive rubber roller (such as NBR rubber or silicone rubber in which conductive particles are dispersed and contained) is used as a general form of the elastic developer carrier.
A dielectric layer may be provided on the surface layer of the conductive rubber.

Developer layer thickness regulating member 2 used in the present invention
Examples include various types such as a rectangular rod-shaped rigid body, a protrusion-shaped elastic body, a leaf spring that uses the surface or tip of a leaf spring, a roller, or a combination thereof. The developer layer thickness regulating member 2 is linearly pressed against the developer carrying member 1 by its own elastic force, the elastic force of the developer carrying member 1, an external force, or a combined force thereof. Regarding the electrical characteristics of the developer layer thickness regulating member 2, when a voltage is applied to an insulating material or an electrically conductive material, or when it is an electrically conductive material, it is electrically connected to nothing and floats. There are various types of materials such as an insulator, but in the case of an insulator or an electrically conductive substance that is electrically floating, that is, when a voltage is not applied between the developer layer thickness regulating member 2 and the developer carrier 1, reverse charging is performed. The "white background fog" due to the toner easily occurs, and in such a case, the present invention exerts a remarkable effect.
By electrostatically moving the developer carrying member 1 relative to this linear pressing so as to slide in a direction perpendicular to the pressing direction, the electrostatic developer particles pass while spreading the pressing portion, and are uniformly applied onto the developer carrying member 1. To form a developer layer. The form of this pressing part,
The developer layer thickness and the toner charge amount are controlled by the pressure, composition, and applied voltage. Globally, the higher the pressure, the smaller the developer layer thickness applied and the higher the amount of charge, but the morphology, composition, and applied voltage are complicated physical and chemical phenomena and cannot be generally discussed.

Electrostatic latent image holding member 3 used in the present invention
Uses a photoreceptor with a layer of selenium, an organic photosensitive material, etc. on the surface of a conductive base material, or a master with an insulator layer on the surface of a conductive base material. Form a latent image pattern. A general form used in a copying machine or a laser printer uses a cylindrical surface made of a metal such as aluminum coated with a photosensitive material. When an organic photosensitive material is used as the photosensitive material, the relative dielectric constant of the photosensitive layer is 1 to 5
The thickness is about 10 to 50 μm, and is generally used.

In the image forming step, a latent image having an electrostatic charge distribution is formed on the electrostatic latent image holding member 3 by a procedure of uniform charging and exposure according to the generally used principle of xerography. At this time, the maximum potential on the electrostatic latent image holding member 3 is
About 100 to 1200 V in absolute value based on the conductive base material,
More preferably, it is controlled to be about 300 to 900V.

On the other hand, as described above, the developer carrying member 1 has
The electrostatic developer 6 is applied by the developer layer thickness regulating member 2. Between the developer carrier 1 and the developer layer thickness regulating member 2,
Especially when no voltage is applied, when short-circuiting to the same potential,
There are cases where a voltage of about 500 V or less is applied. Further, the contact member 4 may be provided on the upstream side of the developer layer thickness regulating member 2 in the relative movement direction of the developer carrier 1. Contact member 4
For this, in addition to the force of the electrostatic developer 6 adhering to the developer carrying member 1 due to its own weight and fluidity, the electrostatic developer 6 positively moves toward the developer carrying member 1. For example, a method in which a sponge-like or brush-like member contains the electrostatic developer 6 and is rubbed against the developer carrying member 1 is used. The friction at this time may be used to accelerate the triboelectrification of the electrostatic developer 6. A conductive material may be used for the contact member 4 and a voltage may be applied between the electrostatic developer 6 and the developer carrying member 1 so as to apply an electrostatic force toward the developer carrying member 1. Further, since the roller-shaped endless developer carrying member 1 is generally used, the developer carrying member 1 to which the remaining developer which has finished development on the electrostatic latent image holding member 3 is attached is the contact member 4. Since it returns to the part, it can also serve as a cleaning means.
On the contrary, when it is desired to positively utilize the effect, the electrostatic developer 6 is used.
A voltage may be applied so that a force is applied in a direction away from the developer carrying member 1. Alternatively, an alternating electric field may be applied for the purpose of both cleaning and supply, or for the purpose of increasing the charging of the electrostatic developer 6.

However, in order to reduce the cost of the apparatus, it is preferable to apply no voltage between the developer carrying member 1 and the contact member 4, and it is more preferable not to use the contact member 4. In this case, the chances of charging due to friction of toner particles and charge injection are reduced, so that a bad phenomenon such as "white background fog" due to the oppositely charged toner is likely to occur. In such a case, the present invention exerts a remarkable effect.

When the developing device having the configuration shown in FIGS. 1 to 3 is used, the electrostatic developer 6 is introduced from the lower gap of the developer carrying member 1.
It is common to attach the developer leakage seal member 5 because there is a risk of leakage. By the above steps, the developer carrying member 1 having the developer layer formed thereon and the electrostatic latent image holding member 3 having the latent image formed thereon face each other, and at least toner particles in the electrostatic developer 6 are transferred to visualize the latent image. Turn into.

At this time, in flight development, 50 to 50
A gap of 0 μm is formed and transferred by electrostatic force. In the case of contact development, the toner particles corresponding to the latent image pattern are transferred by electrostatic force by being pressed through the developer layer. A general method is to keep the potential of the developer carrier 1 at a potential between the latent image potential to which the toner is to be transferred and the latent image potential to be the white background.

According to the present invention, the member which comes into contact with the developer carrying member 1 directly or through the developer layer is the developer layer thickness regulating member 2, the electrostatic latent image holding member 3, and the developer leakage if necessary. In the case where only the prevention seal member 5 is used, the problem such as the above-mentioned "middle-out" is solved, and it works particularly effectively. The toner transferred to the latent image pattern is further transferred to a transfer material such as paper or film in the case of an ordinary copying machine or laser printer. In this transfer step, a method in which a transfer material is brought into contact with an electrostatic latent image carrier and a charge is applied from the back surface by corona discharge, or a method in which a conductive transfer roller is pressed to apply a voltage is generally used. In the case of a transfer process that applies pressure such as roller transfer, the above-mentioned "middle-out"
Is likely to occur. In addition, the one-component developing method is also more likely to cause "middle voids" than the two-component developing method. In such a case, the present invention exerts a remarkable effect. In the fixing step, the toner transferred to the transfer material is generally fused and fixed by heat.

[0039]

The present invention will be described in more detail with reference to the following examples, but the present invention is not limited to the following examples as long as the gist thereof is not exceeded. In addition, in the following Examples and Comparative Examples, simply saying “part” means “part by weight”.

Three types of toner raw materials having the following compounding ratios were kneaded by a twin-screw kneading extruder, pulverized and classified to obtain toner particles. The glass transition point, softening point and average particle size of the toner particles are also described together with the compounding ratio.

[0041]

[Table 1] Toner particles A Styrenic resin 100 parts (monomer weight ratio: styrene / n-butyl acrylate = 82/18) Charge control agent Chromium-containing azo dye 2 parts (Spiron Black TRH, Hodogaya Chemical Co., Ltd.) Carbon black 6 parts (Mitsubishi carbon black MA100, manufactured by Mitsubishi Kasei) Low molecular weight polypropylene 3 parts (Viscor 550P, manufactured by Sanyo Kasei) Glass transition point 62 ° C Softening point 130 ° C Average particle size 8.8 μm

[0042]

[Table 2] Toner particles B Polyester-based cross-linking resin 100 parts (Constituent monomers: ethylene glycol, polyoxypropylene bisphenol A, isophthalic acid, terephthalic acid, trimellitic acid) Charge control agent Chromium-containing azo dye 1 part (Bontron S -34, manufactured by Orient Chemical Co., Ltd. Carbon black 6 parts (Mitsubishi Carbon Black MA100, manufactured by Mitsubishi Kasei) Low molecular weight polypropylene 2 parts (Viscor 550P, manufactured by Sanyo Kasei) Glass transition point 61 ° C Softening point 131 ° C Average particle size 9. 1 μm

[0043]

[Table 3] Toner particles C Polyester-based cross-linking resin 100 parts (Constituent monomers: ethylene glycol, polyoxypropylene bisphenol A, terephthalic acid, trimellitic acid) Charge control agent Chromium-containing azo dye 1 part (Bontron S-34, Orient Chemical Co., Ltd.) Carbon black 4 parts (Mitsubishi Carbon Black MA100, manufactured by Mitsubishi Kasei) Low molecular weight polypropylene 3 parts (Number average molecular weight Mn = 8,000) Glass transition point 72 ° C. Softening point 147 ° C. Average particle size 9.1 μm

Example 1 To 100 parts of toner particles A, 1 part of aluminum stearate and silica fine powder (R972 manufactured by Nippon Aerosil Co., specific surface area 120 m ² / g, surface treated with dimethylsilane group for hydrophobic treatment) 0 .2 parts and mixed with a Henschel mixer to obtain a developer. This developer is equipped with an IBM laser printer 4019 (developing device corresponding to the developing device A shown in FIG. 1), and a voltage-applied rectangular rod-shaped developer layer thickness regulating member and a voltage-applied sponge roller-shaped contact. When a print test was performed using a member), there was almost no "middle-out" or "fog", and "solid followability" was good, and high-quality image formation was possible.

Example 2 To 100 parts of toner particles A, 1 part of magnesium stearate and silica fine powder (R972 manufactured by Nippon Aerosil Co., Ltd., specific surface area: 120 m ² / g, surface hydrophobized with dimethylsilane group) 0 .2 parts and mixed with a Henschel mixer to obtain a developer. This developer was subjected to a print test with an IBM laser printer 4019 in the same manner as in Example 1. As a result, "medium void" and "fog" were observed.
There was almost no such thing, and the "solid following ability" was also good, and high-quality image formation was possible.

Example 3 To 100 parts of toner particles A, 1 part of zinc stearate and silica fine powder (R972 manufactured by Nippon Aerosil Co., Ltd., specific surface area 120)
m ² / g, the surface of which is hydrophobized with dimethylsilane groups) 0.2 part, and mixed with a Henschel mixer to procure a developer. This developer is used in Example 1.
Similarly, when a print test was carried out with an IBM laser printer 4019, there were almost no "blanks" and "fogs", and "solid followability" was good, and high-quality image formation was possible.

Example 4 To 100 parts of toner particles A, 2.5 parts of zinc stearate and silica fine powder (R972 manufactured by Nippon Aerosil Co., Ltd., specific surface area 1)
20 m ² / g, the surface of which is hydrophobized by dimethylsilane groups) 0.2 part, and mixed with a Henschel mixer to procure a developer. When this developer was subjected to a print test with an IBM laser printer 4019 in the same manner as in Example 1, there was almost no "blurring" or "fog", and the "solid followability" was also good, resulting in high quality image formation. I was able to do it.

Example 5 To 100 parts of toner particles A, 0.5 parts of small particle size zinc stearate (DLG-20 manufactured by SYNPRO, USA) and silica fine powder (R972 manufactured by Nippon Aerosil Co., Ltd., specific surface area 120 m ² / g, 0.3 parts whose surface has been hydrophobized by dimethylsilane groups) and mixed with a Henschel mixer to obtain a developer. When this developer was subjected to a print test with an IBM laser printer 4019 in the same manner as in Example 1, there was almost no "blurring" or "fog", and the "solid followability" was also good, resulting in high quality image formation. I was able to do it.

Example 6 Toner particles A (100 parts) had a small particle size of zinc stearate (DLG-20 manufactured by SYNPRO, USA), 0.1 parts, and fine silica powder (R972, manufactured by Nippon Aerosil Co., Ltd., specific surface area: 120 m ² / g). 0.1 parts whose surface has been hydrophobized with dimethylsilane groups) and mixed with a Henschel mixer to obtain a developer. When this developer was subjected to a print test with an IBM laser printer 4019 in the same manner as in Example 1, there was almost no "blurring" or "fog", and the "solid followability" was also good, resulting in high quality image formation. I was able to do it.

Example 7 To 100 parts of toner particles A, 1 part of zinc stearate and 1 part of silica fine powder (having a specific surface area of 50 m ² / g, the surface of which is treated to be hydrophobic with silicone) were added, and a Henschel mixer was used. And mixed to obtain a developer. When this developer was subjected to a print test with an IBM laser printer 4019 in the same manner as in Example 1, there was almost no "blurring" and little "fog", but there was almost no problem. Was also good, and high-quality image formation was possible.

Comparative Example 1 To 100 parts of toner particles A, fine silica powder (R972 manufactured by Nippon Aerosil Co., Ltd., specific surface area: 120 m ² / g, surface of which is hydrophobized by dimethylsilane group) 0.2
Only a part was added and mixed with a Henschel mixer to obtain a developer. When a print test was performed on this developer with an IBM laser printer 4019 as in Example 1,
There was almost no "fog" and the "solid followability" was good, but a lot of "holes" occurred and the image was of low quality.

Example 8 To 100 parts of toner particles B, 1 part of magnesium stearate and silica fine powder (R972 manufactured by Nippon Aerosil Co., specific surface area of 120 m ² / g, surface of which is hydrophobized by dimethylsilane group) 0 .2 parts and mixed with a Henschel mixer to obtain a developer. This developer is modified from the electrical connection method of the IBM laser printer 4019 (equipped with a developing device corresponding to the developing device A shown in FIG. 1) so that the rectangular rod-shaped developer layer thickness regulating member and the sponge roller-shaped contact member are When I did a print test in an electrically floating state without electrically connecting to anything, there was almost no "middle-out" or "fog", and the "solid followability" slightly diminished in the latter half of the image. Almost no problem, and high quality image formation was possible.

Example 9 To 100 parts of toner particles B, 0.5 parts of calcium laurate and fine silica powder (specific surface area 180 m ² / g, surface of which is hydrophobized by trimethylsilane group)
0.1 part was added and mixed with a Henschel mixer to obtain a developer. This developer was modified in the same manner as in Example 8 by changing the electric connection method of the IBM laser printer 4019, and the square rod-shaped developer layer thickness regulating member and the sponge roller-shaped contact member were not electrically connected to each other, but electrically. When a print test was performed in a floating state, there was almost no "blurring" or "fog", and "solid followability" was a level that was not a problem although it slightly faded in the latter half of the image, and high quality. Image formation was possible.

Example 10 To 100 parts of Toner Particle B was added aluminum stearate 0.
5 parts and fine silica powder (specific surface area 180 m ² / g,
0.1 parts (the surface of which has been hydrophobized by trimethylsilane group) and 10 parts of MnZn ferrite having a specific surface area of 1.5 m ² / g as auxiliary particles were added and mixed with a Henschel mixer to obtain a developer. This developer was used in Example 8.
Similarly, by modifying the electrical connection method of the IBM laser printer 4019, the square rod-shaped developer layer thickness regulating member and the sponge roller-shaped contact member are electrically connected to nowhere and printed in an electrically floating state. After testing,
There was almost no "middle-out" and there was a slight "fogging", but there was no problem, "solid following ability" was good, and high-quality image formation was possible.

Example 11 To 100 parts of Toner Particle B was added aluminum stearate 0.
5 parts and fine silica powder (specific surface area 180 m ² / g,
0.1 parts (the surface of which is hydrophobized by trimethylsilane group) and 5 parts of MnZn ferrite having a specific surface area of 1.5 m ² / g as auxiliary particles were added and mixed with a Henschel mixer to obtain a developer. This developer was modified in the same manner as in Example 8 by changing the electric connection method of the IBM laser printer 4019, and the square rod-shaped developer layer thickness regulating member and the sponge roller-shaped contact member were not electrically connected to each other, but electrically. When a print test was performed in a floating state, there was almost no "blank" or "fog", and "solid followability" was good, and high-quality image formation was possible.

Example 12 To 100 parts of toner particles B, 1 part of calcium sebacate and silica fine powder (R972 manufactured by Nippon Aerosil Co., Ltd., specific surface area 1)
Magnetite having a surface area of 20 m ² / g, the surface of which is hydrophobized by dimethylsilane groups) and a specific surface area of 3.5 m ² / g as auxiliary particles (Kanto Denka Kogyo KBC)
100 parts) and 1 part, and mixed with a Henschel mixer to obtain a developer. This developer was applied to IBM in the same manner as in Example 8.
By modifying the electrical connection method of the laser printer 4019 manufactured by
The square bar-shaped developer layer thickness regulating member and the sponge roller-shaped contact member were electrically connected to nowhere, and a print test was performed in an electrically floating state. And the "solid followability" is good,
High quality image formation was possible.

Example 13 To 100 parts of toner particles B, 0.5 parts of zinc stearate and fine silica powder (specific surface area 180 m ² / g, surface of which is hydrophobized by trimethylsilane group) 0.1
Parts and 1 part of copper chromite having a specific surface area of 4.0 m ² / g as auxiliary particles (Dainippon Seika's dipyrroxite # 9510, which does not stick to a magnet at room temperature), and mixed with a Henschel mixer to prepare a developer. Procured. This developer was modified in the same manner as in Example 8 by changing the electric connection method of the IBM laser printer 4019, and the square rod-shaped developer layer thickness regulating member and the sponge roller-shaped contact member were not electrically connected to each other, but electrically. When a print test was performed in a floating state, there was almost no "blank" or "fog", and "solid followability" was good, and high-quality image formation was possible.

Example 14 To 100 parts of Toner particles B, 0.5 parts of zinc stearate, 0.3 parts of silica fine powder (specific surface area: 50 m ² / g, surface of which is hydrophobized with silicone) and auxiliary particles As a Henschel mixer, 1 part of a complex oxide of zinc, nickel, aluminum, and iron having a specific surface area of 8.1 m ² / g (Dairo Seika's Daipyroxite # 9270, which does not attach to a magnet at room temperature) is added. And mixed to obtain a developer. This developer was modified in the same manner as in Example 8 by changing the electric connection method of the IBM laser printer 4019, and the square rod-shaped developer layer thickness regulating member and the sponge roller-shaped contact member were not electrically connected to each other, but electrically. When a print test was performed in a floating state, there was almost no "blank" or "fog", and "solid followability" was good, and high-quality image formation was possible.

Comparative Example 2 To 100 parts of toner particles B, fine silica powder (specific surface area 180
m ² / g, the surface of which is hydrophobized by trimethylsilane group) was added, and mixed with a Henschel mixer to obtain a developer. This developer was modified in the same manner as in Example 8 by changing the electric connection method of the IBM laser printer 4019, and the square rod-shaped developer layer thickness regulating member and the sponge roller-shaped contact member were not electrically connected to each other, but electrically. When a print test was performed in a floating state, the "solid followability" was practically acceptable as it became slightly lighter in the second half of the image, but "fog" and "blank" occurred. The image was of low quality.

Example 15 To 100 parts of toner particles C, 0.5 parts of zinc montanate and aluminum oxide fine powder (aluminum oxide C manufactured by Nippon Aerosil Co., Ltd., specific surface area 100 m ² / g) 0.1
Parts and 1 part of copper chromite having a specific surface area of 4.0 m ² / g as auxiliary particles (Dainippon Seika's dipyrroxite # 9510, which does not stick to a magnet at room temperature), and mixed with a Henschel mixer to prepare a developer. Procured. This developer is electrophotographic printer CP500U manufactured by Casio, and the developer layer thickness regulating member of the rigid plate is electrically floated, and the sponge roller-shaped contact member is removed (corresponding to the developing device B shown in FIG. 2). Equipped with a developing device that can be used.), A print test showed that there was almost no "blank" or "fog", and "solid followability" was good, and high-quality image formation was possible.

Example 16 To 100 parts of Toner Particles C was added small particle size zinc stearate 0.0
5 copies (DLG-20 manufactured by SYNPRO, USA)
And 0.1 part of silica fine powder (R972 manufactured by Nippon Aerosil Co., Ltd., specific surface area: 120 m ² / g, the surface of which is hydrophobized by dimethylsilane group) and a specific surface area of 3.8 m ² / g as auxiliary particles. 1.5 parts of zinc ferrite (Daipiro Seika # 9211, manufactured by Dainichiseika Co., Ltd., which does not attach to a magnet at room temperature) was added and mixed with a Henschel mixer to obtain a developer. This developer was used in the same manner as in Example 15 by using an electrophotographic printer CP500U manufactured by Casio, and the developer layer thickness regulating member on the rigid plate was electrically floated.
When the print test was conducted after removing the sponge roller-shaped contact member, there was almost no "middle-out" and a slight "fogging", but there was no problem in practical use.
"Solid followability" was good, and high-quality image formation was possible.

Example 17 To 100 parts of Toner Particles C was added small particle size zinc stearate 0.0
5 copies (DLG-20 manufactured by SYNPRO, USA)
And 0.1 part of silica fine powder (R972 manufactured by Nippon Aerosil Co., Ltd., specific surface area: 120 m ² / g, the surface of which is hydrophobized by a dimethylsilane group) are mixed with a Henschel mixer to prepare a developer. Procured. This developer is used for the electrophotographic printer CP manufactured by Casio as in Example 15.
When 500 U was used, the rigid flat plate developer layer thickness regulating member was electrically floated, the contact member in the form of a sponge roller was removed, and a print test was carried out. As a result, there was almost no "middle void" and "fog". "Solid followability" is a level that is practically no problem as it becomes slightly lighter in the latter half of the image,
High quality image formation was possible.

Comparative Example 3 Toner particles C (100 parts) by silica fine powder (R972 manufactured by Nippon Aerosil Co., Ltd., specific surface area: 120 m ² / g, surface treated with dimethylsilane group for hydrophobicity) 0.1
Only a part was added and mixed with a Henschel mixer to obtain a developer. Using the electrophotographic printer CP500U manufactured by Casio as in Example 15, this developer was electrically floated to the developer layer thickness regulating member of the rigid plate, and the sponge roller-shaped contact member was removed to perform a print test. As a result, "middle-out" and "fogging" occurred, and "solid followability" was at a poor level, and the image was of low quality.

Example 18 To 100 parts of toner particles C, 0.1 parts of zinc stearate having a small particle size was added.
Part (DLG-20 manufactured by SYNPRO, USA) and silica fine powder (having a specific surface area of 180 m ² / g and having a surface hydrophobized with trimethylsilane group).
0.3 parts by weight of 4 parts and a composite oxide of zinc, nickel, aluminum and iron having a specific surface area of 8.1 m ² / g as auxiliary particles (Dainippon Kasei's Daipyrroxite # 9270, which does not attach to magnets at room temperature) And were mixed with a Henschel mixer to obtain a developer. Using the laser printer LP1500 made by Epson (equipped with a developing device corresponding to the developing device C shown in FIG. 3), this developer is adjusted so that the leaf spring-shaped developer layer thickness regulating member has the same potential as the developing sleeve. After modifying the wiring and conducting a print test, there was almost no "blank" or "fog", and "solid followability" was good,
High quality image formation was possible.

Example 19 To 100 parts of Toner Particles C, 1 part of zinc stearate, 0.4 parts of silica fine powder (specific surface area 180 m ² / g, surface of which is hydrophobized by trimethylsilane group) and auxiliary particles As a composite oxide of zinc, nickel, aluminum and iron having a specific surface area of 8.1 m ² / g (Daipyroxite # 9270 manufactured by Dainichiseika Co., Ltd., which does not attach to a magnet at room temperature), 0.3 part is added, A Henschel mixer was used for mixing and a developer was procured. Using this Epson laser printer LP1500 as in Example 18, the developer was subjected to a print test by modifying the wiring so that the leaf spring-shaped developer layer thickness regulating member has the same potential as the developing sleeve. There was almost no "middle-out" or "fog", and "solid followability" was good, and high-quality image formation was possible.

Example 20 To 100 parts of Toner Particles C was added aluminum stearate 0.
3 parts and silica fine powder (specific surface area 180 m ² / g,
0.4 parts (the surface of which has been hydrophobized by trimethylsilane groups) and 3 parts of MnZn ferrite having a specific surface area of 1.5 m ² / g as auxiliary particles were added and mixed with a Henschel mixer to obtain a developer. This developer was used in Example 18.
Similarly, using an Epson laser printer LP1500, the wiring was modified so that the leaf spring-shaped developer layer thickness regulating member had the same potential as the developing sleeve, and a print test was performed. There was almost no fog, and the "solid followability" was good, and high-quality image formation was possible.

Comparative Example 4 To 100 parts of toner particles C, fine silica powder (specific surface area 180
m ² / g, the surface of which is hydrophobized by trimethylsilane group), and 0.4 parts thereof were added and mixed by a Henschel mixer to obtain a developer. This developer was used in the same manner as in Example 18 to prepare a laser printer LP1500 manufactured by Epson.
Using a paper, the leaf spring-shaped developer layer thickness regulating member was modified to have the same potential as the developing sleeve and the wiring was modified, and a print test was conducted. As a result, "fog" and "solid followability" can be practically used. Although it was at the level, "middle-out" occurred and the image quality was low.

[0068]

EFFECTS OF THE INVENTION According to the present invention, toner fusion and pulverization are unlikely to occur, heat fixing property is not sacrificed, layer formation amount stability and environmental stability are good, no hollow defects occur, and long life image quality is high. It is possible to obtain various developing methods.

[Brief description of drawings]

FIG. 1 is a diagram showing an example of a developing method that can be used in the present invention.

FIG. 2 is a diagram showing another example of a developing method that can be used in the present invention.

FIG. 3 is a diagram showing another example of a developing method that can be used in the present invention.

[Explanation of symbols]

 1 developer carrier 2 developer layer thickness regulating member 3 electrostatic latent image holding member 4 contact member 5 developer leakage prevention seal member 6 electrostatic developer

─────────────────────────────────────────────────── ─── Continuation of the front page (51) Int.Cl. ⁶ Identification code Office reference number FI technical display location G03G 15/08 507 L G03G 9/08 374

Claims (13)

[Claims] 1. A developer layer thickness regulating member is pressed against a developer carrier, and the carrier moves relative to the regulating member, so that the developer passes through the pressing portion. An electrostatic development method in which a developer layer is formed on the carrier, and the developer on the carrier is transferred to the electrostatic latent image holding member in an area facing the electrostatic latent image holding member. An electrostatic development method characterized in that fatty acid metal salt particles are contained therein. 2. The electrostatic developing method according to claim 1, wherein the developer contains inorganic oxide fine particles having a specific surface area of 45 m ² / g or more as measured by a nitrogen adsorption method. 3. The electrostatic developing method according to claim 1, wherein the content of the fatty acid metal salt particles is 0.01 to 5 parts by weight with respect to 100 parts by weight of the toner particles. 4. The developer according to claim 1, wherein the developer contains auxiliary particles having a specific surface area of 10 m ² / g or less by a nitrogen adsorption method and having a particle size smaller than the toner particle size. The electrostatic developing method according to any one of 1. 5. The electrostatic developing method according to claim 4, wherein the auxiliary particles are inorganic oxides. 6. A voltage is not applied between the developer layer thickness regulating member and the developer carrying member.
The electrostatic developing method according to any one of 1. 7. The method according to claim 1, wherein no voltage is applied between the contact member that contacts the developer carrier and supplies and / or removes the developer, and the developer carrier. Item 1. The electrostatic developing method according to item 1. 8. The member which comes into contact with the developer bearing member directly or through the developer layer is only the developer layer thickness regulating member, the electrostatic latent image holding member, and, if necessary, the developer leakage preventing seal member. 7. The electrostatic development method according to claim 1, wherein the electrostatic development method is present. 9. The electrostatic developing method according to claim 1, wherein the developer is a non-magnetic one-component developer. 10. Toner particles containing a resin and a colorant, fatty acid metal salt particles, and a specific surface area of 4 by a nitrogen adsorption method.
Electrostatics characterized by containing inorganic oxide fine particles of 5 m ² / g or more and auxiliary particles having a specific surface area of 10 m ² / g or less by a nitrogen adsorption method and having a particle size smaller than the toner particle size. Developer. 11. The electrostatic developer according to claim 10, wherein the content of the fatty acid metal salt particles is 0.01 to 5 parts by weight with respect to 100 parts by weight of the toner particles. 12. The electrostatic developer according to claim 10, wherein the auxiliary particles are an inorganic oxide. 13. The electrostatic developer according to claim 10, which is a non-magnetic one-component developer.