JP3168346B2 - toner - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION The present invention relates to electrophotography, electrostatic recording,
The present invention relates to a dry electrophotographic toner for developing an electrostatic image in electrostatic printing or the like, and more particularly, to a color toner having significantly improved image quality.

[0002]

2. Description of the Related Art It is well known in the art to form and develop an image on the surface of a photoconductive material by electrostatic means.

That is, US Pat. No. 2,297,691, Japanese Patent Publication No. 42-23910, and Japanese Patent Publication No. 43-2
A number of methods are known, such as Japanese Patent No. 4748, but generally, a photoconductive substance is used to form an electric latent image on a photoreceptor by various means, and then the toner is called a toner on the latent image. A toner image corresponding to an electrostatic latent image is formed by attaching an extremely finely pulverized inspection material.

Then, if necessary, the toner is transferred to the surface of an image support such as paper, and then fixed by heating, pressurizing or solvent vapor to obtain a copy. When a step of transferring a toner image is provided, a step for removing the remaining toner is usually provided.

[0005] A developing method for visualizing an electric latent image by using a toner is described in, for example, a powder cloud method described in US Pat. No. 2,221,776, and US Pat. No. 2,618,55.
No. 2,874,063, a magnetic brush method, and a conductive property described in 3,909,258. A method using a magnetic toner is known.

As a toner applied to these developing methods, a toner obtained by mixing and dispersing a colorant in a thermoplastic resin and then pulverizing the same is used. As the thermoplastic resin, a polystyrene resin is the most common, but a polyester resin, an epoxy resin, an acrylic resin, a urethane resin, or the like is also used. As a coloring agent, carbon black is most widely used, and in the case of a magnetic toner, iron oxide black magnetic powder is often used. In the case of a system using a so-called two-component developer, the toner is usually used by being mixed with carrier particles such as glass beads and iron powder.

[0007] The toner image on the final copy image forming member such as paper is permanently fixed on the support by heat, pressure or the like. Conventionally, this fixing step has often been performed by heat.

When a step of transferring a toner image is provided, a step for removing the residual toner on the photosensitive member is usually provided.

In recent years, the development of monocolor copying to full-color copying in copying machines and the like has been rapidly progressing, and the study and commercialization of two-color copying machines and full-color copying machines have been greatly increased. For example, "Journal of the Society of Electrophotography" Vol.
22, no. 1 (1983) and "Journal of the Institute of Electrophotography" Vo
l 25, No. 1, P52 (1986).

However, for people who are not immediately compared with the real ones, such as televisions, photographs, and color prints, and who see color images that have been processed more beautifully than the real ones, full-color electronic devices currently in practical use are considered. Photographic images are not always satisfactory.

[0011] Color image formation by full-color electrophotography generally reproduces all colors using three primary color toners of yellow, magenta, and cyan.

In the method, first, an electrostatic latent image is formed on a photoconductive layer by passing light from a document through a color separation light transmitting filter having a complementary color relationship with the color of the toner, and then the toner is developed and transferred. Hold on the support. This process is sequentially performed a plurality of times, and while the registration is being performed, the toner is overlaid on the same support, and the final full-color image is obtained by one-time fixing.

Generally, in the case of a so-called two-component developing system in which a developer is composed of a toner and a carrier, the developer charges the toner to a required charge amount and charge polarity by friction with the carrier, and utilizes electrostatic attraction. Therefore, in order to obtain a good visible image, it is necessary for the toner to have good triboelectric charging properties mainly determined by the relationship with the carrier.

In order to solve the above-mentioned problems, search for a carrier core agent and a carrier coating agent, optimization of the coating amount, investigation of a charge control agent and a fluidity imparting agent to be added to the toner, and further, Many studies have been made to achieve excellent triboelectricity in all materials constituting the developer, including improvements.

For example, Japanese Patent Publication No. 52-32256 and Japanese Patent Application Laid-Open No. 56-64352 disclose a technique for adding a charge auxiliary agent such as chargeable fine particles to a toner. JP-A-61-160760 discloses that a fluorine-containing compound is added to each developer,
Techniques for obtaining stable triboelectric charging properties have been proposed, and many charging aids have been developed today.

Further, various techniques have been devised as a method for adding the above-mentioned charging aid. For example, a method of attaching the toner particles to the surface of the toner particles by electrostatic force or van der Waals force between the toner particles and the charge auxiliary agent is generally used, and a stirrer, a mixer or the like is used. However, in this method, it is not easy to uniformly disperse the additive on the surface of the toner particles. It is difficult to avoid. This tendency becomes more conspicuous as the specific electrical resistance of the charging aid increases and as the particle size decreases. In such a case, the performance as a developer is affected. For example, the amount of triboelectricity of the toner becomes unstable, so that the image density is not constant and the image has a lot of fog.

Alternatively, if continuous copying is performed, the content of the charging aid changes, and it is not possible to maintain the initial image quality.

As another addition method, there is a method in which a charging auxiliary is added in advance together with a binder resin and a colorant at the time of manufacturing a toner. However, the fact that it is not easy to make the charge control agent uniform, and that it substantially contributes to the chargeability,
Since it is near the surface of the toner particles and the charge auxiliary and charge control agent present inside the particles do not contribute to the charging property, it is not easy to control the amount of the charge auxiliary and the amount of dispersion on the surface. Even with the toner obtained by such a method, the amount of triboelectric charge of the toner is unstable, and it is not easy to obtain a toner satisfying the developer characteristics as described above. The fact is that high quality products have not been obtained.

Further, in recent years, the demand for higher definition and higher image quality of copying machines has been increasing in the market, and in this technical field, attempts have been made to achieve high image quality and color by reducing the particle size of toner. However, as the particle size becomes smaller, the surface area per unit weight tends to increase, and the amount of charge of the toner tends to increase. In addition, since the charged amount of the toner is large, the adhesion between the toners is strong, the fluidity is reduced, and problems occur in the stability of toner supply and in the application of tribo to the supplied toner.

In the case of a color toner, a magnetic material,
Since it does not contain a conductive substance such as carbon black, there is no portion that leaks charge, and the amount of charge generally tends to increase. This tendency is more remarkable especially when a polyester binder having high charging performance is used.

Particularly, in the case of color toners, the following characteristics are strongly desired. (1) In order that the fixed toner does not diffusely reflect light and hinder color reproduction, it is necessary that the toner is in a state close to almost complete melting such that the shape of the toner particles cannot be determined. (2) It must be a colored toner having transparency that does not interfere with the toner layers of different colors under the toner layer. (3) Each of the constituent toners must have balanced hue and spectral reflection characteristics and sufficient saturation.

From this point of view, many binder resins have been studied, but a toner satisfying all the above characteristics has not yet been developed. Today, polyester resins are widely used as binder resins for color in the technical field. However, toners made of polyester resins are generally easily affected by temperature and humidity, and have an excessive charge amount under low humidity and high humidity. Under such circumstances, there arises a problem such as insufficient charge amount, and there is an urgent need to develop a color toner having a stable charge amount even in a wide range of environments.

[0023]

SUMMARY OF THE INVENTION An object of the present invention is to provide a color toner which has solved the above-mentioned problems.

That is, an object of the present invention is to provide a color toner which is hardly influenced by the environment such as temperature and humidity and has always stable triboelectricity.

It is a further object of the present invention to provide a color toner which has clear image characteristics without fog and has excellent durability stability.

[0026]

Means for Solving the Problems and effects a feature of the toner of the present invention, hydrophobic fatty acid compounds in the aqueous and inorganic fine particles A having a hydrophobic treatment with hydrolysis, in an aqueous SILICON over N'oiru or silicone over Nwanisu processing or a coupling agent in an aqueous a toner containing an inorganic fine particles B obtained by hydrophobic treatment with hydrolyzed, inorganic fine particles
A and B have a particle size of 0.01 to 0.2 μm,
Degree is 20 to 80% .

[0027]

The present inventors have conducted intensive studies on the image characteristics of the color toner. As a result, the inclusion of two types of inorganic fine particles subjected to a hydrophobic treatment in an aqueous system stabilizes charging,
They have found that they are extremely effective in imparting fluidity.

This cannot be achieved with hydrophobic silica as a generally known flow improver.

The reason for this is that silica fine particles themselves have strong negative chargeability, whereas inorganic fine particles have almost neutral chargeability. Conventionally, JP 60
No. 136755 proposes to add hydrophobic titanium oxide. However, titanium oxide fine particles originally have a smaller surface activity than silica, and thus have not been sufficiently hydrophobized. In addition, when a large amount of a treating agent or the like is used or a highly viscous treating agent is used, the degree of hydrophobicity is certainly increased, but the coalescence of the particles occurs and the ability to impart fluidity is reduced. The balance between the stabilization and the provision of liquidity has not always been achieved. Therefore, in the above example, the combined use with silica is proposed.

However, in the present invention, in order to perform surface treatment while mechanically dispersing inorganic fine particles such as titanium oxide fine particles or alumina fine particles so as to have a primary particle size in an aqueous system,
Particles are less likely to coalesce than in the gas phase,
In addition, it was found that the surface of the titanium fine particles was substantially treated in the state of primary particles by the repulsion between particles caused by the treatment.

[0032] Inorganic fine particles A in the present invention, B is the particle size thereof in terms of fluidity 0. 0.01 to 0.2 μm , preferably 0.01 to 0.1 μm , and the degree of hydrophobicity is 2 in terms of storage stability and prevention of image density change due to charge fluctuation.
0-80%, good Mashiku is 30 to 70%.

When the particle size is larger than 0.2 μm, toner charging due to poor fluidity becomes non-uniform, and as a result, toner scattering, fogging and the like occur. On the other hand, when the thickness is smaller than 0.01 μm, the toner is easily embedded on the surface of the toner, so that the toner deteriorates quickly and the image deteriorates. This tendency is more remarkable in the sharp melt color toner used in the present invention.

If the degree of hydrophobicity is less than 20%, the amount of charge is greatly reduced particularly after long-term storage under high humidity, and a mechanism for accelerating charging on the hard side is required. If the degree exceeds 80%, it is difficult to control the charging of the inorganic fine particles themselves, and as a result, the toner is charged up particularly under low humidity.

The inorganic fine particles usable in the present invention include:
Anything can be used as long as it has low chargeability itself,
As the inorganic fine particles A, titanium oxide fine particles or alumina fine particles which are easily positively hydrophobized, and inorganic fine particles B
Titanium oxide fine particles which are easily negatively charged and are easily subjected to a hydrophobic treatment can be preferably used. The production method and crystal form are not particularly limited, but titanium oxide fine particles are rutile type,
An amorphous type is desirable in terms of photostability.

The present invention is characterized in that the inorganic fine particles are subjected to a hydrophobic treatment in an aqueous system. At this time, a mechanical force is applied to disperse the inorganic fine particles into the primary particles. It is not necessary to use a coupling agent with excellent reactivity such as by-product gas,
Further, a high-viscosity treating agent, which could not be used together with inorganic fine particles in the gas phase, can be used, and the effect of hydrophobization is enormous.

The treating agent that can be used in the present invention may be any of a coupling agent, oil, varnish, organic compound and the like.

Examples of the coupling agent preferably used as a treating agent for the inorganic fine particles B of the present invention include a silane coupling agent and a titanium coupling agent, and a silane coupling agent is particularly preferably used. Formula R _m SiY _n R: alkoxy group m: an integer of 1 to 3 Y: alkyl group Hydrocarbon group containing vinyl group, glycidoxy group, methacryl group n: an integer of 1 to 3, for example, vinyl tri Methoxysilane, vinyltriethoxysilane, γ-methacryloxypropyltrimethoxysilane, vinyltriacetoxysilane, methyltrimethoxysilane, methyltriethoxysilane, isobutyltrimethoxysilane, dimethyldimethoxysilane, dimethyldiethoxysilane, trimethylmethoxysilane, Hydroxyp Pills trimethoxysilane, phenyltrimethoxysilane, n- hexadecyl trimethoxy silane, can be mentioned n- octadecyl trimethoxysilane.

The treatment amount is 1 to 40 parts by weight, preferably 3 to 30 parts by weight, based on 100 parts by weight of titanium fine particles.

[0040] Also as silicone over N'oiru is not particularly limited, but the general formula

[0041]

Embedded image R ₁ and R ₂ are dimethylpolysiloxane types represented by CH ₃ or OH;

[0042]

Embedded image A methylhydrogenpolysiloxane type represented by the general formula

[0043]

Embedded image And a methylphenylpolysiloxane type represented by Further, if necessary, alkyl modification,
Amino modification, epoxy modification, epoxy / polyether modification, carboxyl modification, mercapto modification, alcohol modification, fluorine modification and the like may be performed.

[0044] The silicone over N'oiru is preferably a viscosity of 50 to 1000 centistokes at 25 ° C.. If it is less than 50 centistokes, the volatile component is large, and the treatment effect is not long lasting. If it exceeds 1,000 centistokes, it is difficult to perform uniform treatment in an aqueous system, and the treatment efficiency is extremely deteriorated.

The silicone over Nwanisu used in the present invention also, a viscosity at 25 ° C. is may no if 50 to 1000 centistokes.

The throughput of silicone over N'oiru or sheet <br/> Ricoh Nwanisu in the present invention is a solid content ratio, with respect to 100 parts by weight of titanium, 1 to 40 wt%, a good preferably 2 to 30 wt% .

As the fatty acid compound used as a treating agent for the inorganic fine particles A of the present invention, a stearic acid compound, an oleic acid compound, a palmitic acid compound and the like can be used.

In order to make the present invention more effective, it is effective that after treatment in an aqueous system, surface treatment is further performed in a gas phase with a low-viscosity surface treatment agent so that the particles do not coalesce. This was intended to seal the functional groups of the inorganic fine particles remaining in the treatment in an aqueous system with a coupling agent,
Surprisingly, its reactivity was found to be very high, once it had been treated in an aqueous system. The reason for this is not clear yet, but since the organic treatment has been carried out in an aqueous system in advance, the affinity between the hydrophobic groups of the treating agent and the lipophilic groups of the inorganic fine particles is good, and the reaction efficiency is improved. It is speculated that there is. Therefore, in the present invention,
The treatment agent can be selected in a very wide range from low viscosity to high viscosity, and is very effective in terms of charging ability and fluidity-imparting ability.

In the present invention, the silane coupling agent used for treating the inorganic fine particles treated in an aqueous system in the gas phase is a general formula R _m SiY _n R: an alkoxy group or a chlorine atom m: an integer of 1 to 3 Y: an alkyl group, a hydrocarbon group containing a vinyl group, a glycidoxy group, and a methacryl group. N: an integer of 1 to 3, for example, typically dimethyldichlorosilane, trimethylchlorosilane, allyldimethylchlorosilane, hexamethyl Disilazane, allylphenyldichlorosilane, benzyldimethylchlorosilane, vinyltriethoxysilane, γ-methacryloxypropyltrimethoxysilane, vinyltriacetoxysilane, divinylchlorosilane, dimethylvinylchlorosilane and the like can be mentioned.

The silane coupling agent treatment of the fine powder may be a dry treatment in which the vaporized silane coupling agent is reacted with a cloud of fine powder by stirring or the like. The silane coupling agent is used in an amount of 1 to 20 parts by weight, preferably 3 to 1 part by weight, per 100 parts by weight of the fine powder.
It is better to use 0 parts by weight.

[0051]

[0052]

[0053]

[0054]

The toner of the present invention may contain a charge control agent for stabilizing the charge characteristics. At that time, a colorless or light-colored charge control agent that does not affect the color tone of the toner is preferable. Examples of the negative charge control agent in this case include an organic metal complex such as a metal complex of an alkyl-substituted salicylic acid (for example, a chromium complex or a zinc complex of di-tert-butylsalicylic acid). When the negative charge control agent is added to the toner, it is added in an amount of 0.1 to 10 parts by weight, preferably 0.5 to 8 parts by weight, based on 100 parts by weight of the binder resin.

When a two-component developer is prepared by mixing with the toner of the present invention, the mixing ratio is preferably 2 to 10% by weight, and more preferably 3 to 9% by weight, as the toner concentration in the developer. The result is obtained. If the toner concentration is less than 2% by weight, the image density is too low to be practical. If it exceeds 10% by weight, fog and scattering in the machine are increased, and the useful life of the developer is shortened.

As the coloring agent used in the present invention, known dyes and pigments, for example, phthalocyanine blue, indaslen blue, peacock blue, permanent red, lake red, rhodamine lake, Hanza yellow, permanent yellow, benzine yellow and the like are widely used. can do. The content thereof is 12 parts by weight or less, preferably 0.5 to 9 parts by weight, based on 100 parts by weight of the binder resin so as to reflect sensitively on the permeability of the OHP film.

Additives may be added to the toner of the present invention, if necessary, as long as the properties of the toner are not impaired. Examples of such additives include Teflon, zinc stearate and polyvinylidene fluoride. And a fixing aid (eg, low molecular weight polyethylene, low molecular weight polypropylene, etc.), and a charging aid such as organic resin particles.

In the production of the toner of the present invention, the constituent materials are kneaded well by a hot kneader such as a hot roll, kneader, extruder or the like, and then are obtained by mechanical pulverization and classification, or in a binder resin solution. A method in which a material such as a colorant is dispersed and obtained by spray drying, or a method in which a predetermined material is mixed with a monomer to constitute a binder resin, and then the emulsified suspension is polymerized to form a toner. Each method such as a method for producing a polymerized toner to be obtained can be applied.

As the binder used in the toner of the present invention, various material resins conventionally known as toner binder resins for electrophotography are used.

For example, styrene-based copolymers such as polystyrene, styrene-butadiene copolymer and styrene-acrylic copolymer, and ethylene-based copolymers such as polyethylene, ethylene-vinyl acetate copolymer and ethylene-vinyl alcohol copolymer Copolymer, phenolic resin, epoxy resin, acrylic phthalate resin, polyamide resin, polyester resin, maleic acid resin and the like. In addition, the production method of any resin is not particularly limited.

The effect of the present invention is remarkable when a polyester resin having a high negative chargeability is used among these resins. That is, the polyester-based resin has excellent fixability and is suitable for a color toner, but on the other hand, the negative charging ability is strong and the charging is liable to be excessively large. A toner is obtained.

In particular, the following equation

[0064]

Embedded image (Wherein R is an ethylene or propylene group, x and y are each an integer of 1 or more, and the average value of x + y is 2
10 to 10. A) a carboxylic acid component consisting of a divalent or higher carboxylic acid or an acid anhydride thereof or a lower alkyl ester thereof (for example, fumaric acid, maleic acid,
A polyester resin obtained by co-condensation polymerization of maleic anhydride, phthalic acid, terephthalic acid, trimellitic acid, pyromellitic acid, etc.) is more preferable since it has sharp melting properties.

When the toner of the present invention is used as a two-component developer, an electrically insulating resin is used as a coating resin on the carrier surface, and is appropriately selected depending on the toner material and the carrier core material. In order to improve the adhesiveness with the carrier core material surface, it is necessary to contain at least one monomer selected from acrylic acid (or ester thereof) monomer and methacrylic acid (or ester thereof) monomer. is necessary. In particular, when a polyester resin particle having a high negative chargeability is used as the toner material, it is preferable to further form a copolymer with a styrene monomer for the purpose of stabilizing the charge, and the copolymerization weight ratio of the styrene monomer is preferable. 5 to 70
It is preferable to set the weight%.

Examples of the monomer for the coating resin of the toner carrier core material of the present invention include styrene monomers such as styrene monomer, chlorostyrene monomer, α-methylstyrene monomer, and styrene-chlorostyrene monomer. Examples thereof include acrylate monomers (methyl acrylate monomer, ethyl acrylate monomer, butyl acrylate monomer, octyl acrylate monomer, phenyl acrylate monomer, 2-ethylhexyl acrylate monomer) and the like, and methacrylate monomer (methacrylic ester). Methyl methacrylate monomer, ethyl methacrylate monomer, butyl methacrylate monomer, phenyl methacrylate monomer).

The carrier core material (magnetic particles) used in the present invention includes, for example, metals such as iron, nickel, copper, zinc, cobalt, manganese, chromium, rare earth and the like, and their alloys or oxides, which are not oxidized or surface oxidized. Things can be used.
In addition, there is no particular limitation on the manufacturing method. Preferably, it contains 98% by weight or more of a ferrite carrier having a metal composition ratio of 5 to 20: 5 to 20:30 to 80 (weight ratio).

Hereinafter, the measurement method of the present invention will be described. (1) Measurement of triboelectric charge amount The measurement method will be described in detail with reference to the drawings.

FIG. 1 is an explanatory view of an apparatus for measuring a triboelectric charge amount of a toner. First, in a metal measuring container 2 having a 500-mesh screen 3 at the bottom, a mixture of toner and carrier in a weight ratio of 1:19 to be measured for triboelectric charge, or 1:99 in the case of an external additive, is used. 50 ~
Put into a 100 ml polyethylene bottle,
Shake by hand for ~ 40 seconds and mix the mixture (developer)
1.5 g is put and the metal lid 4 is closed. At this time, the weight of the entire measurement container 2 is weighed and defined as W ₁ (g). Next, in the suction device 1 (at least a portion in contact with the measurement container 2 is an insulator), the pressure of the vacuum gauge 5 is adjusted to 250 mmAq by adjusting the air volume control valve 6 by suctioning from the suction port 7. In this state enough
Preferably, suction is performed for 2 minutes to remove toner by suction. The potential of the electrometer 9 at this time is set to V (volt). Here, reference numeral 8 denotes a capacitor, whose capacity is C (μF). or,
The weight of the whole measurement container after suction is weighed and is defined as W ₂ (g).
The triboelectric charge (μc / g) of this toner is calculated as in the following equation.

Amount of triboelectric charge of toner (μc / g) = C × V / (W ₁ −W ₂ ) (however, measurement conditions are 23 ° C. and 60% RH). The carrier used for measurement is 250 mesh pass. The coated ferrite carrier of the present invention having 70 to 90% by weight of 350, mesh-on carrier particles is used. (2) Hydrophobicity Measurement The methanol titration test is an experimental test for confirming the hydrophobicity of inorganic fine particles having a hydrophobic surface.

0.2 g of the inorganic fine particles to be tested is 250 ml in capacity.
To 50 ml of water in an Erlenmeyer flask. Methanol is titrated from the burette until all of the titanium oxide is wetted. At this time, the solution in the flask is constantly stirred with a magnetic stirrer. The end point is observed by the suspension of the entire amount of the inorganic fine particles in the liquid, and the degree of hydrophobicity is expressed as the percentage of methanol in the liquid mixture of methanol and water when the end point is reached. (3) Particle Size Measurement Method for Inorganic Fine Particles Apparatus A Coulter Counter N4 type is used as a measuring apparatus, and TOMY SEIKO UD-200 type is used as an ultrasonic generator for dispersion. Method An appropriate amount of a sample was put in 30 to 50 ml of distilled water to which a trace amount of surfactant was added, and the output was 2 to 2 using the ultrasonic generator.
6. Disperse for about 2 to 5 minutes. The suspension in which the sample is dispersed is transferred to a cell, and after the air bubbles are released, the suspension is set on the above-mentioned coulter counter in which the measurement temperature is set to 50 ° C. in advance. Measurement is started after elapse of 10 to 20 minutes to bring the sample to a constant temperature, and the volume average particle size distribution is determined.

[0072]

EXAMPLES Examples of the present invention will be described below, but "%" and "part" all indicate "% by weight" and "part by weight".

Synthetic Example 1 of Inorganic Fine Particles Using hydrophilic titanium oxide fine particles, while stirring and mixing in an aqueous system, dimethylpolysiloxane having a viscosity of 500 centistokes at 25 ° C. as a treating agent was converted into a solid component. The mixture was added to 10%, mixed, dried and crushed to obtain inorganic fine particles I having a hydrophobicity of 40%. Particle size 0.05 μm, BET 90 m ² / g Charge amount -2.0 μc / g

Synthetic Example 2 of Inorganic Fine Particles Inorganic fine particles II having a hydrophobicity of 50% were obtained in the same manner as in Synthetic Example 1 except that the treatment was carried out with 20% of sodium stearate. Particle size 0.05 μm, BET 85 m ² / g Charge amount +21 μc / g

Synthesis Example 3 of Inorganic Fine Particles Inorganic fine particles III having a degree of hydrophobicity of 50% were obtained in the same manner as in Synthetic Example 1, except that 20% treatment with nC ₆ H ₁₃ Si (OCH ₃ ) ₃ was performed. Particle size 0.05 μm, BET 80 m ² / g Charge amount -18.5 μc / g

Synthesis Example 4 of Inorganic Fine Particles 500 centistokes of dimethylpolysiloxane 30
% In the same manner as in Synthesis Example 1 except that the degree of hydrophobicity was 7%.
0% of inorganic fine particles IV were obtained. Particle size 0.06 μm, BET 80 m ² / g Charge amount -35 μc / g

Synthesis Example 5 of Inorganic Fine Particles Inorganic fine particles V having a hydrophobicity of 40% were obtained in the same manner as in Synthetic Example 1, except that hydrophilic alumina fine particles were used and treated with 10% of aluminum stearate. Particle size 0.04 μm, BET 100 m ² / g Charge amount +41 μc / g

Synthesis Example 6 of Inorganic Fine Particles Inorganic fine particles VI having a degree of hydrophobicity of 50% in the same manner as in Synthetic Example 1 except that hydrophilic titanium oxide fine particles having a large particle diameter were used.
I got Particle size 0.4 μm, BET 12 m ² / g Charge amount -5.6 μc / g

Synthesis Example 7 of Inorganic Fine Particles 5000 centistokes of dimethylpolysiloxane 3
Except that the treatment was performed at 0%, inorganic fine particles VII having a hydrophobicity of 85% were obtained in the same manner as in Synthesis Example 1. Particle size 0.05 μm, BET 60 m ² / g Charge amount -40 μc / g

Example 1 Production Example of Toner A polyester resin obtained by condensing 100 parts of a propoxylated bisphenol and fumaric acid 4 parts A phthalocyanine pigment 4 parts A chromium complex of di-tert-butylsalicylic acid 2 parts After mixing, the mixture was melt-kneaded with a twin-screw extruder, cooled, coarsely pulverized to about 1 to 2 mm using a hammer mill, and then finely pulverized by an air jet pulverizer. Further, the obtained finely pulverized product was classified and selected from 2 to 10 μm to obtain colorant-containing resin particles.

To 100 parts of the above colorant-containing resin particles, 0.5 part of inorganic fine particles I and 0.3 part of inorganic fine particles II were added to obtain a cyan toner.

A copolymer composed of 75% of methyl methacrylate and 25% of butyl acrylate was added to 5 parts of the cyan toner, and had a weight average particle size of 45 μm and 35 μm or less.
2%, 35 to 40 µm 9.5%, 34 µm or more 0.2%
0.5% coated Cu—Zn—Fe ferrite carrier having a particle size distribution of
To obtain a developer.

Using this developer, a commercial plain paper color copying machine (manufactured by Color Laser Copier 500 Canon) was used to set the development contrast to 300 V, and an image was formed at 23 ° C./65%. The image is as high as 1.51,
It was clear without fog. After that, 10,0
00 copies were made, and the density fluctuation during that time was 0.1
2 and the same fog and sharpness as in the initial stage were obtained.

Table 1 shows the results of image formation at 20 ° C./10% and 30 ° C./80%.

Examples 2 to 4 and Comparative Examples 1 to 4
Tables 1 and 2 show the results of image formation in the same manner.

[0086]

[Table 1]

[0087]

[Table 2]

[0088]

As described above, when the toner of the present invention is used, a stable image density and high quality image can be provided for a long time in various environments.

[Brief description of the drawings]

FIG. 1 is a schematic diagram of an apparatus for measuring a triboelectric charge amount of a toner.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Suction machine 2 Measurement container 3 Conductive screen 4 Lid 5 Vacuum gauge 6 Air flow control valve 7 Suction port 8 Condenser 9 Electrometer

──────────────────────────────────────────────────続 き Continued on the front page (58) Field surveyed (Int.Cl. ⁷ , DB name) G03G 9/08

Claims (1)

(57) [Claims] 1. A hydrolyzing the coupling agent fatty acid compounds in an aqueous hydrolysis while the inorganic fine particle A treated hydrophobic, or an aqueous hydrophobic treatment with silicone over N'oiru or silicone over Nwanisu in an aqueous a toner containing an inorganic fine particle B was hydrophobized while, the particle size of the inorganic fine particles a and B is 0.01~0.2μm der
A toner having a hydrophobicity of 20 to 80% .