JPH0812440B2 - Toner for electrostatic image development - Google Patents

Description

The present invention relates to an electrostatic image developing toner used in electrophotography, electrostatic printing, electrostatic recording and the like.

[Background of the Invention]

For example, in electrophotography, generally, an electrostatic latent image is formed on a latent image carrier made of a photoconductive photoreceptor by charging and exposure, and then this electrostatic latent image is coated with a colorant in a binder resin. The toner image obtained is developed with fine particle toner contained therein, and the obtained toner image is transferred onto a support such as transfer paper and fixed to form a visible image.

Therefore, in order to form a good image many times, it is necessary that the electric characteristics of the photoconductor are stably exhibited for a long period of time. Particularly, in the developing process, since the toner particles come into contact with the surface of the photoconductor, a so-called filming phenomenon occurs in which the surface of the photoconductor is covered with the toner constituent substance, and the characteristics of the photoconductor are likely to deteriorate. Alternatively, it is necessary to impart a filming resistance property to the toner, or to impart a property of polishing the deteriorated portion of the photoreceptor to the toner.

The following techniques have been conventionally proposed as techniques for imparting such filming resistance and polishing properties.

(1) Add alkylated silane (silica) (see JP-A-46-5782).

(2) A lubricant such as a polyhydric alcohol ester is deposited on the surface of the toner particles (see JP-A-48-47345).

(3) Fatty acid metal salt and colloidal silica 0.1 each
-1% is added (see Japanese Patent Laid-Open No. 48-47346).

(4) Add phthalic acid and its salt (JP-A-49-6)
(See JP 0229).

(5) Add cross-linked polyvinylidene fluoride powder (see Japanese Patent Application Laid-Open No. 50-99143).

(6) A non-adhesive polymer such as polyvinylidene fluoride and an abrasive such as colloidal silica are added (Japanese Patent Laid-Open No. 50-120).
631 publication).

(7) An organic polymer such as a fluorine-based resin having a surface free energy and a particle size smaller than that of the toner particles is added (see JP-A-48-8141).

(8) A thin layer of boron nitride is attached to the surface of the photoconductor (see Japanese Patent Application Laid-Open No. 49-31657).

(9) A network of polytetrafluoroethylene fibers is formed on the toner particles (see JP-A-52-23941).

(10) An abrasive such as cerium oxide is used to clean the residual toner (see Japanese Patent Laid-Open No. 53-81127).

(11) A fluorine-based surfactant is added to the toner particles (JP-A-52-138982, JP-A-52-107337, JP-A-53-1).
(See Japanese Patent No. 24428).

(12) Add metal oxide powder treated with aminosilane (see Japanese Patent Laid-Open No. 52-135739).

(13) Add polystyrene smaller than the toner particles (see JP-A-53-84741).

(14) Add a few inorganic powders having a BET specific surface area of 0.2 to 30 m ² / g (see JP-A-60-32060 and JP-A-60-136752).

(15) Acrylic polymer fine powder smaller than toner particles is contained (see JP-A-60-186851).

[Problems to be solved by the invention]

However, in the technique of adding the organic fine powder, the polishing property for polishing the surface of the photoconductor is not obtained, and as the image formation is repeated, the toner constituent substances are deposited and deposited on the surface of the photoconductor, and the characteristics of the photoconductor are reduced. There is a problem of early deterioration.

Further, in the technique of adding the inorganic fine powder, the polishing property can be obtained, but when the particle size is large, the polishing property becomes excessive, so that the surface of the photoconductor is scratched and dot-like stains are generated on the image. On the contrary, when the particle size is small, it is necessary to increase the addition amount in order to obtain effective polishing property or cleaning property, and as a result, the triboelectric charging property of the toner becomes unstable and image defects are caused. There is a problem that occurs.

Further, in the technique of adding the resin acid metal salt, there are problems that the surface of the carrier particles is easily contaminated, so that the triboelectric charging property is deteriorated, toner scattering and fog occur, and the image density is lowered.

[Object of the Invention]

The present invention has been made under the circumstances described above, and an object thereof is to provide a stable image capable of stably forming a good image many times without causing damage to a photoreceptor and contamination by toner constituents. It is to provide a toner for developing an image.

[Means for solving problems]

The present invention comprises a binder resin powder and resin fine powder particles having a smaller diameter than the particles of the binder resin powder, wherein the resin fine powder particles have the resin fine powder particles on the surface thereof. 1/2
It is characterized in that it holds inorganic fine particles having the following sizes.

In a preferred embodiment, the resin fine powder particles and the inorganic fine particles are mixed, and a mechanical impact force is applied to the mixture, whereby the inorganic fine particles are retained on the surface of the resin fine powder particles. To do.

[Effects of the Invention]

According to the toner of the present invention, it is possible to stably form a good image many times without damaging the photoconductor and contaminating the toner constituents.

That is, since the specific inorganic fine particles are held on the surface of the resin fine powder particles, not on the surface of the binder resin powder particles, the binder resin powder has a small diameter and a small amount of inorganic particles without impairing the triboelectric chargeability. The fine particles exhibit suitable polishing properties, and as a result, the surface of the photoconductor can be satisfactorily polished without being scratched, and the surface can always be in a good state without contamination. The presence of the toner improves the fluidity of the toner, so that good developability can be obtained.

Further, since a small amount of inorganic fine particles is required, the triboelectric chargeability of the toner is not adversely affected, and when the two-component type developer is combined with a carrier, specific inorganic fine particles are formed on the surface of the resin fine powder particles. Since it is held, the toner constituent substances are prevented from transferring and adhering to the surface of the carrier particles, and as a result, stable triboelectric charging properties can be obtained for a long period of time.

Further, since the specific inorganic fine particles are held on the surface of the resin fine powder particles, in the cleaning process,
The inorganic fine particles can be reliably cleaned together with the resin fine powder particles, and the toner constituent substances remaining on the surface of the photoconductor can be satisfactorily cleaned.

Further, since the resin fine powder particles having a smaller diameter than the particles of the binder resin powder and having the inorganic fine particles held on the surface are contained, the resin fine powder particles are present around the particles of the binder resin powder. Therefore, when a soft resin is used as the binder resin powder, the so-called blocking resistance, which can stably exist as a powder, is excellent.

Further, by holding the inorganic fine particles on the surface of the resin fine powder particles by a mechanical impact force, there is no fear that the inorganic fine particles will be embedded in the resin fine powder particles or released from the resin fine powder particles. The characteristics of the fine particles and the resin fine powder particles are reliably exhibited, and the durability of the toner is significantly improved.

After all, according to the toner of the present invention, the surface of the photoconductor can always be maintained in a good state, and the triboelectric charging property becomes stable for a long period of time, and further, the good cleaning property is exhibited. It is possible to form a stable image many times without causing scattering and image defects.

[Specific configuration of the invention]

 Hereinafter, the present invention will be specifically described.

As the inorganic fine particles retained on the surface of the resin fine powder particles, inorganic fine particles such as oxides, carbides and nitrides can be preferably used. Specifically, for example, silica, alumina, titania, barium titanate, aluminum titanate, magnesium titanate, calcium titanate, strontium titanate, zinc oxide, chromium oxide, cerium oxide, antimony trioxide, zirconium oxide, tungsten oxide. Examples thereof include fine particles of copper oxide, tin oxide, tellurium oxide, manganese oxide, boron oxide, silicon carbide, titanium carbide, boron carbide, silicon nitride, titanium nitride, and boron nitride.

The inorganic fine particles must be smaller than the resin fine powder particles, that is, the particle size of the inorganic fine particles must be 1/2 or less of the particle diameter of the resin fine powder particles. When the particle size of the inorganic fine particles is excessively large, it becomes difficult to hold them on the surface of the resin fine powder particles. Specifically, the average particle size of the inorganic fine particles is 0.01 to
It is preferably in the range of 0.15 μm.

The addition amount of the inorganic fine particles differs depending on the size addition amount of the resin fine powder particles and cannot be specified unconditionally, but is the amount necessary to cover 10% or more of the total surface area of the resin fine powder particles. I wish I had it.

The resin constituting the resin fine powder particles is not particularly limited as long as it is a resin capable of holding the inorganic fine particles on the surface thereof, and various resins can be used. Specifically, for example, an acrylic polymer (for example, JP-A-60-186851
Acrylic polymer described in JP-A No. 1994-101), an acrylic / styrene-based polymer (for example, an acrylic-styrene-based polymer described in JP-A-60-186852), a polymer of a nitrogen-containing addition polymerizable monomer, or Copolymers (for example, polymers or copolymers of nitrogen-containing addition-polymerizable monomers described in JP-A-60-186853), polymers or copolymers of addition-polymerizable carboxylic acids (for example, JP-A-60-186853) Addition-polymerizable carboxylic acid polymers or copolymers described in JP-A-60-186868), fluororesins (for example, fluororesins described in Japanese Patent Application No. 62-67997), silicone resins (for example, Japanese Patent Application No. 62-67997). -131258, the silicone resin) and the like can be preferably used.

The average particle size of the resin fine powder particles is, for example, 0.05 to 3 μm,
In particular, it is preferably within the range of 0.15 to 0.5 μm. If the average particle size is too small, the blocking resistance becomes poor,
On the other hand, if it is too large, the image quality tends to deteriorate.

The content ratio of the resin fine powder particles is 0.1 to the total amount of the toner.
3% by weight is preferred. When the content ratio is too large, the fluidity of the toner is lowered and the image density is lowered. On the other hand, when it is too small, the cleaning property is deteriorated.

The shape of the resin fine powder particles is particularly preferably spherical. By using a spherical one, the fluidity of the toner is improved and the cleaning property is also improved.

In the present invention, resin fine powder particles (hereinafter, also referred to as “composite fine powder”) that holds inorganic fine particles on the surface are used. Specifically, for example, the resin fine powder particles are mixed with the inorganic fine powder. Mixing and electrostatically adhering the inorganic fine particles to the resin fine powder particles by light agitation, etc., and then introducing this into an impact type pulverizer etc. to give mechanical impact force to it,
It is preferable to hold the inorganic fine particles on the surface of the resin fine powder particles by utilizing a very small amount of frictional heat and impact force generated at this time. Here, "holding" refers to a state in which the length ratio of the portion of the inorganic fine particles embedded in the resin fine powder particles is 5 to 95%. It should be noted that such a state can be easily confirmed by observing the surface of the resin fine powder particles with a transmission electron microscope or an ordinary electron microscope.

In order to obtain such a state, in a system in which both the powder of resin fine powder particles and the powder of inorganic fine particles are present, an impact force of a magnitude that does not crush the resin fine powder particles may be applied.

The time for which the impact force is applied is selected based on the characteristics of the resin of the resin fine powder particles, the operating conditions of the crusher used, and the like.

In the present invention, it is preferable that the inorganic fine particles are retained in 50% or more of the whole resin fine powder particles, and the surface area of the resin fine powder particles is 10
It is preferable that at least% of the portion is covered with the retained inorganic fine particles. The specific treatment means for holding the inorganic fine particles on the surface of the resin fine powder particles is not particularly limited, and the treatment may be performed plural times.

The particles of the binder resin powder are particles made of only the binder resin,
Alternatively, the particles may be particles in which a toner component is dispersed and contained in a binder resin. Examples of such toner components include colorants, charge control agents, fixability improvers, magnetic particles, and other property improvers.

The average particle diameter of the binder resin powder particles is 1 to 30 μm.
Are preferable, and spherical particles are preferable from the viewpoint of developability, but irregular particles may be used.
By using a binder resin powder having a small diameter, it is possible to form an image with high resolution.

The binder resin that constitutes the binder resin powder is not particularly limited, and various resins can be used.

Examples of the thermoplastic resin suitable for a heat fixing method such as a heat roller fixing method or a flash fixing method include styrenes such as styrene, parachlorostyrene, α-methylstyrene; methyl acrylate, ethyl acrylate, acrylic acid n- Propyl, lauryl acrylate, acrylic acid 2
-Α-methylene aliphatic monocarboxylic acid esters such as ethylhexyl, methyl methacrylate, ethyl methacrylate, n-butyl methacrylate, lauryl methacrylate, 2-ethylhexyl methacrylate; acrylonitrile,
Vinyl nitriles such as methacrylonitrile; vinyl pyridines such as 2-vinyl pyridine and 4-vinyl pyridine;
Vinyl ethers such as vinyl methyl ether and vinyl isobutyl ether; vinyl ketones such as vinyl methyl ketone, vinyl ethyl ketone and methyl isopropenyl ketone; unsaturated hydrocarbons such as ethylene, propylene, isoprene and butadiene and their halides, chloroprene and the like Polymer of halogen-based unsaturated hydrocarbon monomer of, or rosin-modified phenol formalin resin,
Examples thereof include non-vinyl condensation resins such as oil-modified epoxy resins, polyester resins, polyurethane resins, polyimide resins, cellulose resins, and polyether resins, and mixtures of these with the vinyl resins.

As the binder resin for pressure fixing that is compatible with the pressure fixing method, for example, polyolefins such as polyethylene, polypropylene, polytetrafluoroethylene, ethylene-vinyl acetate copolymer, ethylene-acrylic acid ester copolymer,
Polyethylene copolymer polyesters such as polyethylene-methacrylic acid ester copolymers, styrene-butadiene copolymers, waxes such as beeswax, carnauba wax, microcrystalline wax, higher fatty acids such as stearic acid and palmitic acid, and salts thereof, and Examples thereof include esters, epoxy resins, isobutylene rubber, cyclized rubber, rubbers such as nitrile rubber, polyamide, chlorone-indene resin, maleic acid-modified phenol resin, phenol-modified terpene resin, and silicone resin.

Other toner components include colorants, charge control agents,
There are various additives such as a fixability improver and a lubricant, which can be used if necessary.

Examples of colorants include carbon black, nigrosine dye (CINo.50415B), aniline blue (CINo.5040).
5), Calco Oil Blue (CINo.azoic Blue3), Chrome Yellow (CINo.14090), Ultramarine Blue (CINo.77103), DuPont Oil Red (CINo.261)
05), Quinoline Yellow (CINo.47005), Methylene Blue Chloride (CINo.52015), Phthalocyanine Blue (CINo.74160), Malachite Green Oxalate (CINo.42000), Lamp Black (CINo.77266),
Rose Bengal (CI No.45435), magnetic materials, mixtures thereof, and the like can be used.

As the charge control agent, for example, a nigrosine dye, a metal-containing azo dye, a metal complex, or the like can be used.

Examples of the fixability improver include polyolefin, aliphatic metal salt, fatty acid ester and fatty acid ester wax, partially saponified fatty acid ester, higher fatty acid, higher alcohol, liquid or solid paraffin wax, amide wax, polyhydric alcohol ester. , Silicon varnish, aliphatic fluorocarbon, etc. can be used.

Examples of the lubricant include zinc stearate, lithium stearate, sodium stearate, stearic acid,
Hardened castor oil and the like can be used. It is preferable that these lubricants are externally added to and mixed with the binder resin powder.

When the toner of the present invention is a magnetic toner, magnetic fine particles are contained in the particles of the binder resin powder. Examples of such magnetic fine particles include ferromagnetic metals such as iron, nickel and cobalt, alloys containing these metals, ferrite,
A compound of a ferromagnetic metal such as magnetite, an alloy containing no ferromagnetic element but exhibiting ferromagnetism when appropriately heat-treated, for example, a type called a Heusler alloy such as manganese-copper-aluminum or manganese-copper-tin. The alloy of or the fine particles such as chromium dioxide can be used. The average particle size of the magnetic fine particles is preferably about 0.1 to 2 μm. The amount of the magnetic fine particles added is usually about 20 to 70% by weight of the total toner.

To give an example of a suitable method for producing a toner according to the present invention, first, a binder resin material resin is pulverized and classified to produce a binder resin powder having a desired particle diameter as a toner. The toner component as described above can be contained in the particles of the binder resin powder.

On the other hand, the material of the resin fine powder particles is crushed and classified,
A powder of resin fine powder particles having a predetermined particle size is produced, powder of inorganic fine particles is added to the powder of the resin fine powder particles, and the mixture is stirred by, for example, a V-type mixer. The inorganic fine particles are electrostatically adhered, and then this is put into an impact type fine pulverizer and an impact is applied. By such treatment, composite fine particles in which the inorganic fine particles are held on the surface of the resin fine powder particles can be obtained.

Then, the composite fine powder is mixed and stirred with the binder resin powder, for example, and the particles of the composite fine powder are electrostatically attached to the particles of the binder resin powder to manufacture a toner.

When toner components such as colorants, fixability improvers, magnetic fine particles, and other property improvers are dispersedly contained in the particles of the binder resin powder, they are uniformly dispersed in advance by an extruder or the like. After mixing, the powder may be pulverized and classified into powder having a predetermined particle size. When an external additive such as a fluidizing agent or a lubricant is used, it may be mixed with the binder resin powder together with the composite fine powder.

〔Example〕

Examples of the present invention will be specifically described below, but the present invention is not limited thereto.

<Resin fine powder particles> (1) Resin fine powder particles 1 Acrylic polymer particles (MP-100, manufactured by Soken Chemical Co., Ltd.)
0, average particle size = 0.4 μm, true sphere (2) Resin fine powder particles 2 Acrylic polymer particles (manufactured by Soken Chemical Industry Co., Ltd., MP-140)
0, average particle size = 1 to 2 μm, true sphere (3) Resin fine powder particles 3 Acrylic polymer particles (manufactured by Soken Chemical Industry Co., Ltd., MP-145)
1, average particle size = 0.15 μm, true sphere (4) Resin fine powder particles 4 Fluororesin particles (Neotron VDF VP-850 manufactured by Daikin Industries, Ltd., average particle size = 0.25 μm, true sphere) (5) Resin Fine powder particles 5 Silicone resin particles (Toshiba Silicone Co., Ltd., Tospearl 120, average particle size = 2 μm, true sphere) (6) Resin fine powder particles 6 Acrylic polymer particles (Soken Chemical Co., Ltd., MP-120)
1, average particle size = 0.4 μm, true sphere <Inorganic particles> (1) Inorganic particles 1 Silicon carbide particles (Fujimi Abrasives Industry Co., Ltd., GC
# 10.000 crushed product, average particle size = 0.05 μm) (2) Inorganic fine particles 2 Zirconium oxide fine particles (manufactured by Daiichi Rare Elements Co., EP,
(Average particle size = 0.04 μm) (3) Inorganic fine particles 3 Strontium titanate fine particles (Fuji Titanium Industry Co., Ltd., pulverized product of ST, average particle size = 0.1 μm) <Production of composite fine powder> Shown in Table 1 below. The combination and proportions of the resin fine powder particles and the inorganic fine particles are sufficiently stirred and mixed by a V-type mixer to electrostatically attach the inorganic fine particles to the resin fine powder particles, and then the mixture is subjected to normal impact pulverization. The mixture was charged into an improved apparatus, and an impact force was applied to the mixture to obtain each composite fine powder in which the inorganic fine particles were held on the surface of the resin fine powder particles.

Each of the composite fine powders obtained here is the inorganic fine particles electrostatically attached to the surface of the resin fine powder particles by the surface observation and the transmission electron microscope observation by an electron microscope,
It was confirmed that the resin fine powder particles were embedded and retained on the surface.

<Example 1> 100 parts by weight of a binder resin (polyester resin), 10 parts by weight of carbon black "Mogal L" (manufactured by Cabot), and 3 parts by weight of polypropylene "Viscor 660 P" (manufactured by Sanyo Kasei Co., Ltd.) Was mixed with a V-type blender, melt-kneaded with two rolls, then cooled, coarsely pulverized with a hammer mill, finely pulverized with a jet mill, and then classified with an air classifier to obtain an average particle size of 1
A 1.0 μm non-magnetic binder resin powder 1 was obtained.

Hydrophobic silica fine powder "Aerosil R-805" (manufactured by Nippon Aerosil Co., Ltd.) was added to this binder resin powder 1 at a ratio of 0.8% by weight and composite fine powder 1 at a ratio of 0.7% by weight, and mixed by a Henschel mixer. To obtain Toner 1 according to the present invention.

Example 2 A toner 2 according to the present invention was obtained by the same procedure as in Example 1, except that the composite fine powder 2 (0.3 wt%) was used instead of the composite fine powder 1.

Example 3 A toner 3 according to the present invention was obtained in the same manner as in Example 1, except that the composite fine powder 3 (1.0 wt%) was used instead of the composite fine powder 1.

Example 4 A toner 4 according to the present invention was obtained in the same manner as in Example 1, except that the composite fine powder 4 (0.5% by weight) was used instead of the composite fine powder 1.

Example 5 A toner 5 according to the present invention was obtained by the same process as in Example 1, except that the composite fine powder 5 (0.7% by weight) was used instead of the composite fine powder 1.

<Example 6> 60 parts by weight of a binder resin (polyester resin), 35 parts by weight of magnetite "BL-100" (manufactured by Titanium Industry Co., Ltd.),
3 parts by weight of polypropylene "Viscor 660 P" (manufactured by Sanyo Kasei Co., Ltd.) were treated in the same manner as in Example 1 to obtain an average particle size.
11.0 μm of magnetic binder resin powder 2 was obtained.

To the binder resin powder 2, 0.4% by weight of hydrophobic silica fine powder "Aerosil R-812" (manufactured by Nippon Aerosil Co., Ltd.) and 0.5% by weight of the composite fine powder 6 were added and mixed by a Henschel mixer. To obtain Toner 6 according to the present invention.

<Comparative Example 1> Comparative Example 1 was obtained in the same manner as in Example 1, except that the composite fine powder was not used.

Comparative Example 2 A comparative toner 2 was obtained in the same manner as in Example 1 except that the resin fine powder particles 1 (0.7% by weight) were used instead of the composite fine powder 1.

Comparative Example 3 A comparative toner 3 was obtained in the same manner as in Example 1 except that inorganic fine particles (2% by weight) made of silicon carbide having an average particle size of 1.0 μm were used instead of the composite fine powder 1. .

Comparative Example 4 Comparative Toner 4 was obtained in the same manner as in Example 6, except that the composite fine powder was not used.

<Preparation of Developer> 5 parts by weight of each of Toners 1 to 5 and Comparative Toners 1 to 3 and a carrier 100 whose surface is coated with a styrene-acrylic resin (styrene: methyl methacrylate = 3: 7).
A two-component developer was prepared by mixing with a part by weight.

Toner 6 and comparative toner 4 were used as they were as a one-component developer.

<Real-life test> (1) For the two-component type developer, a real-life test was conducted using an electrophotographic copying machine "U-Bix 5000" (manufactured by Konishi Rokusha Kogyo Co., Ltd.) equipped with a selenium photoreceptor, and evaluated.

(2) With respect to the one-component type developer, an actual copying test was carried out by a prototype electrophotographic copying machine equipped with a non-contact type developing device for applying an oscillating electric field to the developing region, and the following items were evaluated respectively.

 The results are shown in Table 2 below.

Cleaning Property The surface of the photoconductor immediately after being cleaned by the cleaning blade was visually observed and judged by the presence or absence of the deposit on the surface of the photoconductor. The evaluation is "○" when there is almost no adhering matter and is good, "△" when there is a little adhering matter but at a practical level, and when there are many adhering matters and there is a practical problem Was designated as "x".

Damage to Photoreceptor The surface of the photoreceptor was visually observed to check for damage.

Triboelectric charge amount The initial charge amount of each toner and the charge amount after 290,000 times of copying were measured by a known blow-off method. This evaluation was performed only for the two-component developer.

Image density "Sakura Densitometer" (made by Konishi Rokusha Kogyo Co., Ltd.)
Was used to measure the relative concentration. The relative concentration is 1.
A value of 25 or more was marked as "○", a value of 1.1 or more and less than 1.25 was marked as "△", and a value of less than 1.1 was marked as "x".

Image quality The copied image was visually judged from three points: sharpness, image unevenness, and image loss. The evaluation was “Poor” when it was defective and practically problematic, “Δ” when it was slightly defective but at a practical level, and “◯” when it was good.

Fog "Sakura Densitometer" (made by Konishi Rokusha Kogyo Co., Ltd.)
Was used to measure and determine the relative density of a white background portion where the original density was 0.0. The white background reflection density was 0.0. In the evaluation, when the relative concentration was less than 0.01, it was evaluated as “◯”, when it was 0.01 or more and less than 0.03, it was evaluated as “Δ”, and when it was 0.03 or more, it was evaluated as “x”.

Toner scattering Visually observing the inside of the copying machine and the copied image. When toner scattering is hardly observed and is good, it is "○", when toner scattering is slightly observed but it is at the practical level, "△", many toner scattering The case where it was recognized and had a problem in practical use was marked with "x".

As can be understood from the results of the above-described actual copying test, the developer using the toner according to the present invention can always maintain the surface of the photoconductor in a good state, and the triboelectrification property can be improved. Is stable for a long period of time and good cleaning performance is exhibited, so a stable image with high image density can be obtained without causing toner scattering and image defects.
It can be formed over 200,000 times.

On the other hand, in the developer using the comparative toner 1, since the toner does not contain the composite fine powder, the cleaning property is poor, the photoconductor is damaged, and the triboelectrification property is unstable. The toner was scattered and the image was defective after the formation was performed 10,000 times.

In the developer using the comparative toner 2, since the resin fine powder particles contained in the toner do not hold the inorganic fine particles on the surface thereof, the cleaning property is poor, and the number of image formations is 100,000 times. Toner scattering and defective images occurred.

In the developer using the comparative toner 3, since the toner does not contain the resin fine powder particles, the surface of the photoconductor is greatly damaged, and the image formation is defective at 100,000 times.

In the developer using the comparative toner 4, since the toner does not contain the fine composite powder, the cleaning property is poor, the photoconductor is damaged, the triboelectric charging property is unstable, and the number of image formations is 10,000. The toner scatters and the image defect occurs during the operation.

 ─────────────────────────────────────────────────── ─── Continuation of front page (56) References JP-A-55-26588 (JP, A) JP-A-56-66856 (JP, A) JP-A-54-48241 (JP, A) JP-A-54- 2741 (JP, A)

Claims (3)

[Claims] 1. A binder resin powder, and resin fine powder particles having a smaller diameter than the particles of the binder resin powder, the resin fine powder particles having the resin fine powder particles on the surface thereof. 1/2 of
An electrostatic image developing toner, characterized in that it holds inorganic fine particles having the following sizes. 2. The fine resin particles are held on the surface of the fine resin particles by mixing the fine resin particles with the fine inorganic particles and applying a mechanical impact force to the fine particles. The electrostatic image developing toner according to claim 1. 3. The resin fine powder particles have an average particle diameter of 0.05 to 3 μm.
The electrostatic image developing toner according to claim 1 or 2, wherein