JP2000039741A - Magnetic fine particle dispersion type resin carrier, two- component developer and image forming method - Google Patents

Abstract

PROBLEM TO BE SOLVED: To obtain a magnetic carrier that does not cause its sticking, suppresses the occurrence of fog and can form a toner image having high image quality. SOLUTION: The surfaces of carrier cores contg. magnetic fine particles dispersed in a 1st resin are coated with a 2nd resin to obtain the objective magnetic fine particle dispersion type resin carrier having a true specific gravity of 2.5-4.5, 15-60 Am2/kg (emu/g) intensity of magnetization, 0.1-20 Am2/kg (emu/g) residual magnetization and 5×1011-5×1015 Ω.cm specific resistance. The 1st resin forming the carrier cores has methylene units, the 2nd resin coating the surfaces of the carrier cores has fluoroalkyl units, methylene units, etc., and the surfaces of the carrier cores are coated with a mixture of the 2nd resin and a coupling agent having a methylene unit or the surfaces are coated with the 2nd resin after surface treatment with the coupling agent.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a magnetic carrier for developing an electrostatic image in electrophotography, electrostatic recording, and the like, a two-component developer using the magnetic carrier, and an image forming method.

[0002]

2. Description of the Related Art U.S. Pat.
7, 691, JP-B-42-23910 and JP-B-43-24748 describe various methods. These methods form an electrostatic image by irradiating the photoconductive layer of the electrostatic image carrier with a photo image, and then apply toner to the electrostatic image to develop the electrostatic image, After the transfer of the toner image onto a transfer material such as paper, the toner image is fixed by heat, pressure, heat and pressure, or a solvent vapor to obtain a copy or print.

In the step of developing the electrostatic image, a toner image is formed on the frictionally charged toner by utilizing the electrostatic interaction of the electrostatic image. In general, of the methods for developing an electrostatic image using toner, a two-component developer in which toner is mixed with a carrier is suitably used in a full-color copying machine or a printer that requires high image quality.

In this developing method, the carrier imparts an appropriate amount of positive or negative charge to the toner by triboelectric charging, and carries the toner on the surface by the electrostatic attraction of the triboelectric charging.

A developer having a toner and a carrier is coated on a developing sleeve containing a magnet to a predetermined layer thickness by a developer layer thickness regulating member, and by utilizing a magnetic force, an electrostatic image carrier (photosensitive material) is formed. Body) and the developing sleeve are transported to a developing area formed between the developing sleeve and the developing sleeve.

A predetermined developing bias voltage is applied between the photosensitive member and the developing sleeve, and the toner is developed on the photosensitive member in the developing area.

There are various characteristics required for the carrier, and particularly important characteristics include appropriate charging properties, pressure resistance to an applied electric field, impact resistance, abrasion resistance, spent resistance, developability, and the like. Can be

For example, when a developer is used for a long time,
A toner which does not contribute to the development called a spent toner is fused to the surface of the carrier, and toner filming occurs. As a result, the developer is deteriorated and the image quality of the developed image is deteriorated accordingly.

In general, if the true specific gravity of the carrier is too large, the developer may be used when the developer is brought into a predetermined layer thickness on the developing sleeve by the developer layer thickness regulating member, or when the developer is stirred in a developing device. In this case, the load on the developer increases. In the long-term use of the developer, (a) toner filming,
(B) Carrier destruction and (c) toner deterioration are likely to occur. As a result, deterioration of the developer and accompanying image quality deterioration of the developed image are likely to occur.

Further, when the particle size of the carrier is large, the load on the developer is increased similarly to the above, so that the above (a) to (c) tend to occur, and as a result, the deterioration of the developer occurs It will be easier. In addition, (d) the reproducibility of the fine line of the developed image is likely to be reduced.

Therefore, in a carrier in which the above (a) to (c) are likely to occur, it takes time and effort to replace the developer periodically and is uneconomical, so that the load on the developer is reduced. Alternatively, it is preferable to improve the impact resistance and spent resistance of the carrier to prevent the above (a) to (c) and extend the life of the developer.

When the particle size of the carrier is reduced, (e) the carrier easily adheres to the electrostatic image carrier. Further, reducing the particle diameter of the carrier only with a constant toner particle diameter results in (f) the distribution of the charge amount of the toner being broadened, and the toner flies to a non-image portion due to charge-up particularly in a low humidity environment ( Hereinafter, this phenomenon will be referred to as “fog”).

As a carrier for solving the above problems (a) to (f), a magnetic fine particle-dispersed resin carrier can be mentioned. This carrier is relatively easy to be formed into a sphere having a small particle shape distortion and a high particle strength, and is excellent in fluidity. Since the particle size can be controlled in a wide range, it is suitable for a high-speed copying machine in which the number of rotations of a developing sleeve or a magnet in the sleeve is large, a high-speed laser beam printer of a general-purpose computer, and the like.

A magnetic fine particle-dispersed resin carrier has been proposed in JP-A-54-66134 and JP-A-61-9659. However, when the magnetic particle carrier does not contain a large amount of a magnetic substance, the saturation magnetization is small with respect to the particle diameter, carrier adhesion easily occurs on the electrostatic image carrier during development, and the developer Replenishment,
Alternatively, it may be necessary to provide a mechanism for collecting the attached carrier in the image forming apparatus.

In addition, when a magnetic substance is contained in a large amount in a magnetic fine particle-dispersed resin carrier, the impact resistance becomes weak because the amount of the magnetic substance increases with respect to the binder resin, so that the developer is not used. When a predetermined layer thickness is formed on the sleeve by the developer layer thickness regulating member, (g) the magnetic material is easily dropped from the carrier, and as a result, the developer is easily deteriorated.

In the above-mentioned magnetic fine particle-dispersed resin carrier, when a magnetic substance is contained in a large amount, the specific resistance of the carrier decreases due to an increase in the amount of the magnetic substance having a low specific resistance. h) Image defects due to leakage of bias voltage applied during development are also likely to occur.

JP-A-58-21750 proposes a technique for coating a carrier core with a resin. Carrier coated with resin, spent resistance, impact resistance,
The withstand voltage with respect to the applied voltage can be improved. In addition, since the charging characteristics of the toner can be controlled by the charging characteristics of the resin to be coated, a desired charge can be imparted to the toner by selecting the resin to be coated.

However, also in the above resin-coated carrier, when the amount of the coating resin is large and the specific resistance of the carrier is high, the charge-up phenomenon of the toner easily occurs in a low humidity environment. Further, when the amount of the coating resin is small, the specific resistance of the carrier becomes too low, so that an image defect easily occurs due to a leak of the developing bias voltage.

Further, depending on the coating resin, even if the specific resistance of the carrier coated with the resin is considered to be an appropriate specific resistance in measurement, an image defect is likely to occur due to a leakage of a developing bias voltage, or in a low humidity environment. In some cases, the charge-up phenomenon easily occurs.

Further, as a carrier having improved surface contamination resistance, impact resistance, charging environment dependency, charging rising property, charge exchange property, etc., a silane coupling agent is used for the inner layer, and a fluororesin is used for the outer layer. The carrier used is disclosed in
-198946, JP-A-5-72815,
It is proposed in Japanese Patent Application Laid-Open No. 7-319218. In JP-A-4-198946 and JP-A-5-72815, there is a limitation in the production method, and a high coverage cannot be obtained. Have left. In addition, Japanese Patent Application Laid-Open No. 7-31921
No. 8 discloses that the electric resistance of a carrier is 1.5 × 10 ^{9 to} 3.0 × 10 ¹⁰ Ω · when a voltage of 10 ^3.5 V / cm is applied.
cm, a carrier with a relatively medium resistance is used, especially when a low-magnetization carrier or a low-resistance electrostatic image carrier is used, charge injection from the developer carrier to the electrostatic image carrier occurs in the development area. The carrier easily adheres to the electrostatic image carrier, and the electrostatic image tends to be disturbed or image defects.
Further, in the proposed developer, when a large number of large image areas that consume a large amount of toner are copied many times, the toner tends to be spent on the carrier, and the charge amount of the toner tends to change.

As described above, it is possible to satisfy today's strict quality requirements, for example, various objects such as fine lines, small letters, photographs, and color originals, and also to achieve high image quality, high quality, high speed, and high durability. There is a long-awaited demand for magnetic carriers.

[0022]

SUMMARY OF THE INVENTION An object of the present invention is to provide a magnetic carrier which has solved the above-mentioned problems and a two-component developer using the magnetic carrier.

An object of the present invention is to provide a magnetic carrier capable of forming a high-quality toner image by preventing or suppressing the occurrence of fog without carrier adhesion and a two-component developer using the magnetic carrier. It is in.

An object of the present invention is to provide a magnetic carrier capable of forming a high-definition color toner image with a high image density without being affected by temperature and humidity, and a two-component developer using the magnetic carrier. It is in.

An object of the present invention is to provide a magnetic carrier which is excellent in durability without causing image deterioration even when a large number of images are formed, and a two-component developer using the magnetic carrier.

An object of the present invention is to provide an image forming method using the two-component developer.

[0027]

Specifically, the present invention provides:
A magnetic fine particle-dispersed resin carrier in which the surface of a carrier core in which magnetic fine particles are dispersed in a first resin is coated with a second resin. (A) The magnetic fine particle-dispersed resin carrier has a true specific gravity of 2 0.5 to 4.5, and 1000 ×
The magnetization intensity (σ ₁₀₀₀ ) measured under a magnetic field of (10 ³ / 4π) · A / m (1000 Oe) is 15 to 60.
Am ² / kg (emu / g), residual magnetization (σ _r ) of 0.1 to ²⁰ Am ² / kg (emu / g), and specific resistance of 5 × 10 ^{11 to} 5 × 10 ¹⁵ Ω · cm,
(B) the first resin forming the carrier core has a methylene unit (—CH ₂ —) in a polymer chain;
(C) The second resin covering the surface of the carrier core comprises a fluoroalkyl unit and a methylene unit (−
CH ₂ —) and an ester unit,
(D) The surface of the carrier core is coated with a mixture of (i) a second resin and a coupling agent having at least a methylene unit (excluding a coupling agent having a methylene unit and an amino group). Or (ii) coated with a second resin after being surface-treated with a coupling agent having at least a methylene unit (excluding a coupling agent having a methylene unit and an amino group). And a magnetic fine particle-dispersed resin carrier.

Further, the present invention provides a two-component developer having at least a negatively chargeable toner having toner particles and an external additive and a magnetic fine particle-dispersed resin carrier, wherein the magnetic fine particle-dispersed resin carrier has the above constitution. And a two-component developer.

Further, according to the present invention, the electrostatic image carrier is charged by a charging means, and the charged electrostatic image carrier is exposed to form an electrostatic image on the electrostatic image carrier. A toner image is formed on an electrostatic image carrier by development using a developing means having a two-component developer, and the toner image on the electrostatic image carrier is transferred to a transfer material with or without an intermediate transfer member. The present invention relates to an image forming method for transferring and fixing a toner image on a transfer material by a heating / pressing fixing means, wherein the two-component developer having the above-mentioned configuration is used.

[0030]

BEST MODE FOR CARRYING OUT THE INVENTION The present inventors have conducted various studies and studies to improve the above-mentioned problems. As a result, the resin coated on the magnetic fine particle-dispersed resin carrier contains at least a fluorine-containing resin, Before or simultaneously with the surface of the core material being coated with the fluorine-containing resin, the specific resistance was 5 × 10 ¹¹ to 5 × 10 5 which was treated with a specific coupling agent.
The inventors have found that a magnetic fine particle-dispersed resin carrier of ¹⁵ Ω · cm is effective in improving various characteristics, and have reached the present invention.

The magnetic fine particle-dispersed resin carrier of the present invention (hereinafter referred to as “magnetic resin carrier”) has a true specific gravity of 2.5 to 4.5 (preferably 3.0 to 4.3), When the true specific gravity is within this range, the load on the toner during stirring and mixing of the magnetic resin carrier and the toner is small,
It is preferable because contamination of the carrier surface by the toner is suppressed, and carrier adhesion to a non-image portion on the electrostatic image carrier is suppressed.

The magnetic resin carrier of the present invention has a size of 1000 ×
The magnetization intensity (σ ₁₀₀₀ ) measured under a magnetic field of (10 ³ / 4π) · A / m (1000 Oe) is 15 to 60.
Am ² / kg (emu / g) (preferably 20 to 5
5 Am ² / kg) and the residual magnetization (σ _r ) is 0.1 to 2
0 Am ² / kg (emu / g) (preferably 0.3 to 10 Am ² / kg). When the magnetic properties of the magnetic resin carrier are within this range, the magnetic resin carrier is enclosed in the developer carrier (developing sleeve). Under a magnetic field generated by a magnetic field generating means (for example, a fixed magnet), carrier adhesion of the magnetic resin carrier to the electrostatic image carrier is prevented, and the compressive force of the two-component developer on the toner in the magnetic brush is reduced. This is preferable because carrier contamination due to external additives and toner particles is suppressed. The residual magnetization (σ _r ) of the magnetic resin carrier is 20 Am ² /
If the weight exceeds kg, the two-component developer on the developer carrier and the two-component developer in the developing device are not smoothly exchanged,
The charge-up of the toner and the charge amount of the toner tend to vary.

The magnetic resin carrier of the present invention has a specific resistance of 5 × 10 ^{11 to} 5 × 10 ¹⁵ Ω · cm. When the specific resistance of the magnetic resin carrier is within this range, the magnetic resin carrier has an electrostatic charge. It is difficult for the carrier to adhere to the image carrier, and the charge-up of the toner can be suppressed well.

The specific resistance of the magnetic resin carrier is 5 × 10 ¹¹
If the resistance is less than Ωcm, charge injection from the developer carrier to the electrostatic image carrier tends to occur in the developing region, causing carriers to adhere to the electrostatic image carrier, causing disturbance of the electrostatic image and image defects. Cheap. Further, when the specific resistance value of the magnetic resin carrier exceeds 5 × 10 ¹⁵ Ω · cm, the charge generated by frictional charging with the toner hardly leaks, and the charge amount of the toner tends to be excessively high. In particular, it tends to cause a decrease in image density due to charge-up of the toner under low humidity and fog. Further, in a solid image, a problem that the image density in the central portion is lower than the image density in the edge portion is likely to occur.

In the magnetic resin carrier of the present invention,
(1) The first resin forming the carrier core has a methylene unit (—CH ₂ —) in a polymer chain;
(2) The second resin covering the surface of the carrier core includes a fluoroalkyl unit and a methylene unit (−
CH ₂ —) and an ester unit,
(3) The surface of the carrier core is coated with a mixture of (i) a second resin and a coupling agent having at least a methylene unit, or (ii) is coated with a coupling agent having at least a methylene unit. After the treatment, it is covered with a second resin.

By coating a carrier core composed of a first resin having a methylene unit in a polymer chain and magnetic fine particles with a second resin having at least the above three types of units, a positively chargeable toner can be obtained. And carrier contamination by toner and external additives is suppressed while maintaining a positive triboelectric charge-imparting ability. When coating the carrier core with the second resin, the carrier core is treated with a coupling agent having at least a methylene unit before the carrier core is coated with the second resin, or the carrier resin is coated with the second resin. It is preferable that the surface of the carrier core is coated with a mixture obtained by mixing the coupling agent with the coupling agent, because the adhesion between the carrier core and the second resin is enhanced and the ability to impart a positive triboelectric charge to the positively chargeable toner is also improved.

The first resin constituting the carrier core is a vinyl resin having a methylene unit in a polymer chain, a polyester resin, an epoxy resin, a phenol resin, a urea resin, a polyurethane resin, a polyimide resin, a cellulose resin and a polyether resin. Is mentioned. These resins may be used as a mixture.

As the vinyl monomer for forming the vinyl resin, styrene; o-methylstyrene, m-
Methyl styrene, p-methyl styrene, p-phenyl styrene, p-ethyl styrene, 2,4-dimethyl styrene, pn-butyl styrene, p-tert-butyl styrene, pn-hexyl styrene, pn- Octyl styrene, pn-nonyl styrene, pn-decyl styrene, pn-dodecyl styrene, p-methoxy styrene, p-chlorostyrene, 3,4-dichlorostyrene, m-nitrostyrene, o-nitro Styrene derivatives such as styrene and p-nitrostyrene; ethylene and unsaturated monoolefins such as ethylene, propylene, butylene and isobutylene; unsaturated diolefins such as butadiene and isoprene; vinyl chloride, vinylidene chloride, vinyl bromide and vinyl fluoride Vinyl halide such as vinyl acetate; propionic acid Alkenyl, such as vinyl esters of benzoate vinyl, methacrylate, methyl methacrylate, ethyl methacrylate, propyl methacrylate, n- butyl methacrylate, isobutyl methacrylate, n- octyl, dodecyl methacrylate, -
Α-methylene aliphatic monocarboxylic acid esters such as 2-ethylhexyl, stearyl methacrylate, phenyl methacrylate; acrylic acid; methyl acrylate, ethyl acrylate, n-butyl acrylate, isobutyl acrylate, propyl acrylate, acrylic acid Acrylic esters such as n-octyl, dodecyl acrylate, 2-ethylhexyl acrylate, stearyl acrylate, 2-chloroethyl acrylate, phenyl acrylate; maleic acid, maleic half-ester; vinyl methyl ether, vinyl ethyl ether, vinyl Vinyl ethers such as isobutyl ether; vinyl ketones such as vinyl methyl ketone, vinyl hexyl ketone and methyl isopropenyl ketone; N-vinyl pyrrole, N-vinyl carbazole, N-vinyl in And N-vinyl compounds such as N-vinylpyrrolidone; vinyl naphthalene; acrylic acid or methacrylic acid derivatives such as acrylonitrile, methacrylonitrile, and acrylamide; acrolein, and the like. And polymerized.

As a method for producing magnetic fine particle-dispersed resin core particles, there is a method in which a monomer and magnetic fine particles are mixed and the monomer is polymerized to obtain carrier core particles. At this time, in addition to the above-mentioned vinyl monomers, bisphenols and epichlorohydrin for forming an epoxy resin; phenols and aldehydes for forming a phenol resin; Urea and aldehydes, and melamine and aldehydes are used. For example, as a method for producing a carrier core using a curable phenol resin, magnetic fine particles are added to phenols and aldehydes in an aqueous medium in the presence of a basic catalyst, and polymerized to obtain core particles.

As another method for producing the magnetic fine particle-dispersed resin core particles, a vinyl or non-vinyl thermoplastic resin, magnetic fine particles, and other additives are sufficiently mixed by a mixer, and then heated roll, kneader, or the like is used. , Melting and kneading using a kneading machine such as an extruder, after cooling this,
Carrier core particles can be obtained by pulverization and classification. At this time, it is preferable that the obtained magnetic fine particle-containing resin particles are thermally or mechanically spherical and used as a core. The carrier preferably has a shape factor SF-1 to be described later of 100 to 130 in order to improve the developability of the two-component developer.

Among them, thermosetting resins such as phenolic resins, melamine resins, and epoxy resins are preferred because of their excellent durability, impact resistance, and heat resistance. In order to make the characteristics of the present invention more suitable, a phenol resin is more preferable.

In order to keep the specific resistance value and the magnetic characteristics of the magnetic resin carrier within a predetermined range, it is preferable to mix a nonmagnetic inorganic compound in the carrier core in addition to the magnetic fine particles. The fact that the magnetic fine particles and the nonmagnetic inorganic compound fine particles are contained in a total amount of 70 to 99% by weight (based on the carrier) (more preferably, 80 to 99% by weight) can adjust the true specific gravity of the carrier, This is preferable in relation to the adjustment of the specific resistance value and the mechanical strength of the carrier core.

Furthermore, the specific resistance of the nonmagnetic inorganic compound fine particles is larger than that of the magnetic fine particles, and the larger the number average particle diameter of the nonmagnetic inorganic compound fine particles than the number average particle diameter of the magnetic fine particles, the higher the specific resistance of the carrier. This is preferable for increasing the value and reducing the true specific gravity of the carrier.

The fact that the magnetic fine particles are contained in an amount of 30 to 95% by weight based on the total amount of the magnetic fine particles and the non-magnetic inorganic compound fine particles prevents the carrier from adhering by adjusting the magnetic force of the carrier, It is preferable for adjusting the specific resistance.

In the present invention, the magnetic fine particles are preferably magnetite fine particles or magnetic ferrite fine particles containing at least an iron element and a magnesium element, and the nonmagnetic inorganic compound fine particles are preferably hematite (α-Fe ₂ O). The fine particles of ₃ ) are more preferable for adjusting the magnetic properties, the true specific gravity and the specific resistance of the carrier.

The carrier has a number average particle size of 15 to 60.
μm, and the magnetic fine particles have a number average particle size (r _a ) of 0.
The thickness is preferably from 02 to 2 μm from the viewpoint of the uniformity of the carrier particle surface. Nonmagnetic inorganic compound fine particles is the number average particle diameter (r _b) 0.05 to 5 [mu] m, r _b is the larger 1.5 times or more r _a, in terms of enhancing the surface resistance of the carrier core preferable.

The magnetic fine particles used in the present invention include ferromagnetic iron oxide particles such as magnetite and maghemite;
A spinel ferrite particle powder containing one or more metals (Mn, Ni, Zn, Mg, Cu, etc.) other than iron;
Magnetoplumbite type ferrite particles such as barium ferrite, and fine particles of iron or iron alloy having an oxide film on the surface can be used. Preferably, it is fine particles of magnetite. The number average particle diameter of the magnetic fine particles is
It is preferably from 0.02 to 3 μm, and more preferably from 0.05 to 1 μm in consideration of the dispersion in the aqueous medium and the strength of the resulting spherical carrier core particles. The shape may be any of a granular shape, a spherical shape, and a needle shape.

The nonmagnetic inorganic compound fine particles used in the present invention preferably have an electric resistance of 10 ^{8 to} 10 ¹⁵ Ω · cm. For example, fine particles such as titanium oxide, silica, alumina, zinc oxide, magnesium oxide, hematite, goethite, and ilmenite can be used. Hematite, zinc oxide, titanium oxide, etc., which have little difference in specific gravity from the magnetic fine particles, are more preferable. The number average particle diameter of the nonmagnetic inorganic compound fine particles used for producing the spherical carrier core particles is preferably 0.05 to 5 μm, and considering the dispersion in an aqueous medium and the strength of the generated carrier core particles, 0 It is more preferable that the thickness be from 1 to 3 μm.

The phenols for producing the phenol resin include phenol itself, m-cresol,
Alkylphenols such as p-tert-butylphenol, o-propylphenol, resorcinol and bisphenol A and phenolic hydroxyl groups such as halogenated phenols in which part or all of the benzene nucleus or alkyl group is substituted with a chlorine atom or a bromine atom. Compounds. Among them, phenol (hydroxybenzene)
Is more preferred.

Examples of the aldehyde include formaldehyde and furfural in either form of formalin or paraaldehyde. Among them, formaldehyde is particularly preferred.

The molar ratio of the aldehyde to the phenol is preferably from 1 to 4, particularly preferably from 1.2 to 3. The molar ratio of aldehydes to phenols is 1
If the particle size is smaller, particles are difficult to be generated, and even if the particles are generated, the curing of the resin is difficult to progress, so that the strength of the generated particles tends to be weak. On the other hand, when the molar ratio of aldehydes to phenols is greater than 4, unreacted aldehydes remaining in the aqueous medium after the reaction tend to increase.

Examples of the basic catalyst used in the condensation polymerization of phenols and aldehydes include those used in the production of ordinary resol resins. For example,
Examples include aqueous ammonia, hexamethylenetetramine and alkylamines such as dimethylamine, diethyltriamine and polyethyleneimine. The molar ratio of these basic catalysts to phenols is preferably from 0.02 to 0.3.

The second resin covering the surface of the carrier core has at least a fluoroalkyl unit, a methylene unit and an ester unit.

[0054]

Embedded image [In the formula, m represents an integer of 0 to 20. Is preferable in order to prevent the external additive from adhering to the surface of the carrier particles.
The fluoroalkyl unit and the methylene unit are

[0055]

Embedded image [Wherein, m represents an integer of 0 to 20, and n represents 1 to 15
Indicates an integer. ] Is preferable in order to enhance the adhesion to the surface of the carrier core.

To maintain the adhesion to the carrier core surface and the ability to impart a positive triboelectric charge to the positively chargeable toner,

[0057]

Embedded image [Wherein, m represents an integer of 0 to 20, and n represents 1 to 15
Indicates an integer. Having a unit represented by
More preferred.

The second resin is a polymer or copolymer of methacrylic acid or its ester having a fluoroalkyl unit, or a polymer or copolymer of acrylic acid or its ester having a fluoroalkyl unit. Preferably, there is. For example, the second resin is

[0059]

Embedded image [Wherein, m represents an integer of 0 to 20, and n represents 1 to 15
Indicates an integer. A unit represented by

[0060]

Embedded image [Wherein, m represents an integer of 0 to 20, and n represents 1 to 15
Indicates an integer. ].

The second resin is preferably a graft copolymer having a fluoroalkyl unit, from the viewpoint of making the surface characteristics of the carrier particles more uniform. For example,

[0062]

Embedded image [In the formula, R ₁ has hydrogen or a methyl group, R ₂ represents hydrogen or an alkyl group having 1 to 20 carbon atoms, and k represents an integer of 1 or more. ] Unit,

[0063]

Embedded image And a graft copolymer having a unit represented by the following formula:

The second resin is tetrahydrofuran (TH
In the gel permeation chromatography (GPC) of the soluble component of F), the weight average molecular weight is 20,000 to 30.
It is preferable in terms of the strength of the coating layer, the adhesion to the carrier core, and the applicability.

The second resin is GPC of a soluble component of THF.
In the chromatogram, the molecular weight is 2,000 to 10
It preferably has a main peak in the region of 10,000, and more preferably has a sub-peak or shoulder in the region of molecular weight of 2,000 to 100,000.

Most preferably, the second resin has a molecular weight of 2 in the GPC chromatogram of the soluble component of THF.
It has a main peak in the region of 10,000 to 100,000,
It is desirable to have subpeaks or shoulders in the region of 000 to 19,000.

By satisfying the above-mentioned molecular weight distribution, the magnetic resin carrier coated with the second resin has a durability of a large number of sheets, a stable charge to the toner, and prevents the external additive from adhering to the surface of the carrier particles. The performance is further improved.

The weight average molecular weight of the trunk of the graft polymer is 3
It is preferably from 000 to 200,000, and the weight average molecular weight of the branch is preferably from 3,000 to 10,000.

Here, in the present invention, the molecular weight distribution of the resin coating is measured by gel permeation chromatography under the following conditions.

Apparatus: GPC-150C (manufactured by Waters) Column: KF801 to 7 (manufactured by Shodex) Seven consecutive temperature: 40 ° C Solvent: THF flow rate: 1.0 ml / min Sample: concentration 0 0.05 to 0.6% by weight under the condition of 0.1 ml or more, and in calculating the molecular weight of the sample,
A molecular weight calibration curve generated from a monodisperse polystyrene standard sample is used.

Further, as a preferable configuration for the present invention,
In the graft polymer, the content of the α, β-unsaturated carboxylic acid ester having a fluorine-containing ester group may be 5 to 80% by weight, but if it is less than 5%, sufficient releasability is obtained. If it exceeds 80% by weight, the adhesiveness is reduced.

The α, β-unsaturated carboxylic acid esters include alkyl acrylates and alkyl methacrylates. As the ester group, a hydrophilic group such as a hydroxyl group can be included. Preferably, alkyl methacrylate, especially methyl methacrylate, is preferred.

The α, β-unsaturated carboxylic acid ester having a fluorine-containing ester group used in the present invention includes fluoroalkyl acrylate and fluoroalkyl methacrylate. To give a specific example, CHR = CH ₂ —COO—CXX ^* —CYY ^* — (CF ₂ )
It is represented by m-CF ₂ Z. R represents hydrogen or a methyl group,
X and X ^* are hydrogen or fluorine, Y and Y ^* are hydrogen or fluorine, m is an integer of 0 to 10, and z is hydrogen or fluorine.

Of these monomers, at least three of X, X ^* , Y and Y ^* are preferably hydrogen, more preferably all four are hydrogen. This is because if the proportion of fluorine is large, the flexibility of the fluorine-containing ester group tends to be insufficient and the fluorine-containing ester group tends to be brittle. Further, R is preferably a methyl group. This is because the toughness at the time of coating is relatively greater when R is a methyl group than when it is hydrogen. Further, m is preferably 4 to 9. If m is too small, the releasing effect of fluorine decreases.

The graft polymer can be produced by reacting a macromer having an ethylenically unsaturated group at a terminal with an ethylenically unsaturated monomer. There is also a method of obtaining a graft polymer using a macromer having a functional group capable of condensation reaction or a terminal group capable of condensation in the presence of a chain transfer agent. These macromers are obtained by ionic polymerization,
It is produced by a radical polymerization method.

Examples of the coupling agent used for the surface treatment of the carrier core or the mixture with the second resin include a silane coupling agent and a titanium coupling agent.

Preferred silane coupling agents include
γ-methacryloxypropyl trialkoxysilane, β
-(3,4-epoxycyclohexyl) ethyl trialkoxysilane, γ-glycidoxypropyl trialkoxysilane, γ-glycidoxypropylmethyl dialkoxysilane, γ-mercaptopropyl trialkoxysilane, γ-chloropropyl trialkoxysilane Is mentioned. Further, as a preferable titanium coupling agent,
Isopropyl triisostearoyl titanate, isopropyl trialkylbenzenesulfonyl titanate having a methylene unit and isopropyl tris (dialkylpyrophosphate) titanate having a methylene unit.

Preferably, the binder resin of the core particles is a phenol resin and the coating resin is a fluorine-containing graft polymer, so that fluorine can be better oriented on the surface due to the polarity of the hydroxyl group of the phenol resin. Release properties can be obtained. Further, it exerts an effect on the control of adhesion and chargeability.

The second resin is 0.0
The coating of 1 to 5% by weight (based on carrier) and the coating of 0.01 to 5% by weight (based on carrier) stabilize the triboelectric charge imparting property to the negatively chargeable toner, From the standpoint of durability of multiple sheets and suppressing contamination by external additives and toner.

The bulk density of the magnetic resin carrier of the present invention is:
3.0 g / cm ³ or less (more preferably 2.0 g / c 3
m ³ ) is preferred. If it exceeds 3.0 g / cm ³ , the share of the carrier in the developer becomes large, and the toner tends to be spent or the coating resin is easily peeled. The bulk density of the carrier is measured according to the method described in JIS K5101.

The shape of the magnetic resin carrier is appropriately selected so as to be suitable for a predetermined system. However, the sphericity of the magnetic resin carrier is 100 to 130.
(More preferably 100 to 120). When the magnetic resin carrier has a sphericity of more than 130, the fluidity as a developer becomes inferior, and the frictional charging ability to the toner is lowered, and the shape of the magnetic brush becomes uneven at the developing pole. It becomes difficult to obtain a high-quality image.

The sphericity of the carrier was measured by using a field emission scanning electron microscope S-manufactured by Hitachi, Ltd.
This is performed by extracting 300 or more carriers at random using 800, and using a Luzex3 image processing / analysis device manufactured by Nireco to determine the sphericity derived by the following equation.

[0083]

(Equation 1) [Where MXLNG indicates the maximum diameter of the carrier, and ARE
A indicates the projected area of the carrier. Here, SF-1 closer to 100 means closer to a sphere.

As the core material of the magnetic resin carrier, magnetite, ferrite or the like represented by a general formula of MO.Fe ₂ O ₃ or M.Fe ₂ O ₄ exhibiting magnetism can be preferably used. Here, M is a divalent or monovalent metal ion (Mn, Fe, Ni, Co, Cu, Mg, Zn, Cd,
Li or the like, and M may be a single metal or a plurality of metals. For example, magnetite, gamma iron oxide,
Mn-Zn ferrite, Ni-Zn ferrite, M
n-Mg ferrite, Li ferrite, Cu-Zn
And iron-based oxides such as ferrite.
Among them, inexpensive magnetite can be more preferably used.

Further, as other metal oxides, Mg, Al,
Si, Ca, Sc, Ti, V, Cr, Mn, Fe, C
o, Ni, Cu, Zn, Sr, Y, Zr, Nb, Mo,
Single or multiple metals such as Cd, Sn, Ba, Pb
Non-magnetic metal oxide and metal oxide exhibiting the above magnetism
Things can be used. For example, a nonmagnetic metal oxide such as Al
_TwoO_Three, Si O_Two, CaO, TiO_Two, V_TwoO_Five, CrO_Two,
MnO_Two, Fe_TwoO_Three, CoO, NiO, CuO, Zn
O, SrO, Y_TwoO_Three, ZrO_TwoSystem can be used
Wear.

When the phenols and aldehydes are reacted in the presence of a basic catalyst, the amount of the coexisting magnetic fine particles and nonmagnetic inorganic compound fine particles is preferably 0.5 to 200 times the weight of the phenols. . Further, considering the strength of the generated carrier core particles, 4 to 10
More preferably, it is 0 times.

The magnetic fine particles and the non-magnetic inorganic compound fine particles can be used as they are without surface treatment, but may be subjected to lipophilic treatment in advance. When using magnetic fine particles and non-magnetic inorganic compound fine particles that have not been subjected to lipophilic treatment, a hydrophilic organic compound such as carboxymethyl cellulose or polyvinyl alcohol or a fluorine compound such as calcium fluoride is added as a suspension stabilizer. By doing so, spherical particles are easily generated.

The lipophilic treatment is carried out by a method of adding and mixing a coupling agent such as a silane coupling agent or a titanate coupling agent to magnetic fine particles or nonmagnetic inorganic compound fine particles, or applying a surfactant. There is a method in which magnetic fine particles and non-magnetic inorganic compound fine particles are dispersed in an aqueous solvent containing the particles, and a surfactant is adsorbed on the surface of the particles. The magnetic fine particles and the nonmagnetic inorganic compound fine particles may be subjected to a lipophilic treatment at the same time or may be treated separately. Alternatively, only one of the lipophilic treatments may be performed.

As the surfactant, a commercially available surfactant can be used. Magnetic fine particles, non-magnetic inorganic compound fine particles and those having a functional group capable of binding to a hydroxyl group on the surface of the fine particles are preferable, and cationic in terms of ionicity,
Alternatively, an anionic compound is preferable.

An example of manufacturing the magnetic resin carrier core of the present invention will be described.

In the reaction, first, phenols, formalins, water, magnetic fine particles and non-magnetic inorganic compound fine particles are charged into a reaction vessel, and the mixture is sufficiently stirred. The reaction temperature is adjusted to 70 to 90 ° C. to cure the phenol resin. At this time, it is preferable to slowly raise the temperature in order to obtain spherical composite particles having a high sphericity. The heating rate is preferably 0.5 to 1.5.
C / min, more preferably 0.8 to 1.2 C / min.

After the cured reaction product is cooled to 40 ° C. or lower, the obtained aqueous dispersion is separated into solid and liquid by a conventional method such as filtration and centrifugation, and then washed and dried to obtain magnetic fine particles. Spherical carrier core particles obtained by combining nonmagnetic inorganic compound fine particles with a phenol resin as a binder resin are obtained. The production of the carrier core particles may be a batch type or a continuous type.

Further, as a method of coating the surface of the carrier core with a resin, there is a method of applying a coating solution prepared by dissolving or suspending the resin in a solvent to the surface of the carrier core.

In the present invention, when a two-component developer is prepared by mixing a toner and a carrier, the mixing ratio is 2 to 15% by weight as the toner concentration in the developer.
Good results are obtained when the content is preferably 4% to 13% by weight. If the toner concentration is less than 2% by weight, the image density tends to be low, and if it exceeds 15% by weight, fogging and scattering in the machine are liable to occur, and the useful life of the developer tends to decrease.

The ratio a / b of the weight average particle diameter a of the toner to the number average particle diameter b of the magnetic carrier is preferably 0.1 to 0.3. If the ratio is less than 0.1, it becomes difficult to appropriately charge the toner, and fog or toner scattering in a high humidity environment is likely to occur. On the other hand, if it exceeds 0.3, the charge amount of the toner particularly under low humidity becomes too high,
This tends to cause a decrease in image density and fog.

The toner according to the present invention has a weight average particle diameter of 3 to 3.
It is 9.9 μm, preferably 4.5 to 8.9 μm. In addition, it is determined that the cumulative value of the distribution not more than 1/2 times the number average particle diameter is 20% by number or less, and the cumulative value of the distribution not less than twice the diameter of the weight average particle diameter is 10% by volume or less. This is preferable for improving good charging and improving the reproducibility of latent image dots. Further, in order to improve the triboelectric charging property of the toner and to improve the dot reproducibility, it is necessary to use 1/2 of the number average particle diameter.
It is more preferable that the cumulative value of distribution below the double diameter is 15% by number or less, and the cumulative value of distribution over twice the weight average particle diameter is 5% by volume or less. Further, it is more preferable that the cumulative value of the distribution not more than 1/2 times the number average particle diameter is 10% by number or less, and the cumulative value of the distribution not less than twice the diameter of the weight average particle diameter is 2% by volume or less.

The toner has a weight average particle size (D4) of 9.9 μm.
If m exceeds m, the toner particles for developing the electrostatic image become large, so that even if the magnetic force of the magnetic coat carrier is reduced, development faithful to the electrostatic image is difficult to be performed, and electrostatic transfer is performed. And the toner is easily scattered. On the other hand, a toner having a weight average particle diameter of less than 3 μm has poor powder handling properties.

If the cumulative value of the distribution of less than half the number average particle diameter exceeds 20% by number, the toner charge cannot be properly applied to the fine toner particles, and the tribo distribution of the toner becomes wide. Due to poor charging (generation of a reversal component) and uneven distribution of the particle diameter of the developed toner, a problem of a change in particle diameter during durability is likely to occur. On the other hand, if the distribution cumulative value of the diameter twice or more the weight average particle diameter exceeds 10% by volume, it becomes difficult to satisfactorily perform triboelectric charging with the magnetic resin carrier, and it is difficult to faithfully reproduce an electrostatic charge image. The particle size distribution of the toner can be measured by, for example, a method using a Coulter counter.

As the binder resin used for the toner, the following binder resins can be used.

For example, homopolymers of styrene and its substituted substances such as polystyrene, poly-p-chlorostyrene and polyvinyl toluene; styrene-p-chlorostyrene copolymer, styrene-vinyltoluene copolymer, styrene-
Vinyl naphthalene copolymer, styrene-acrylate copolymer, styrene-methacrylate copolymer, styrene-α-chloromethyl methacrylate copolymer, styrene-acrylonitrile copolymer, styrene-
Styrene such as vinyl methyl ether copolymer, styrene-vinyl ethyl ether copolymer, styrene-vinyl methyl ketone copolymer, styrene-butadiene copolymer, styrene-isoprene copolymer, styrene-acrylonitrile-indene copolymer -Based copolymer; polyvinyl chloride; phenolic resin; natural modified phenolic resin; natural resin modified maleic acid resin; acrylic resin; methacrylic resin; polyvinyl acetate; silicone resin; polyester resin; A xylene resin; a polyvinyl butyral; a terpene resin; a cumarone indene resin; Preferred binder resins include styrene copolymers and polyester resins. Further, a crosslinked styrene resin is also a preferable binder resin.

Examples of the comonomer for the styrene monomer of the styrene copolymer include acrylic acid, methyl acrylate, ethyl acrylate, butyl acrylate, and the like.
Double such as dodecyl acrylate, octyl acrylate, 2-ethylhexyl acrylate, phenyl acrylate, methacrylic acid, methyl methacrylate, ethyl methacrylate, butyl methacrylate, octyl methacrylate, acrylonitrile, methacrylonitrile, acrylamide A monocarboxylic acid having a bond or a substituted product thereof; for example, a dicarboxylic acid having a double bond such as maleic acid, butyl maleate, methyl maleate, or dimethyl maleate and a substituted product thereof; for example, vinyl chloride, vinyl acetate, Vinyl esters such as vinyl benzoate, for example, ethylene olefins such as ethylene, propylene, butylene; for example, vinyl ketones such as vinyl methyl ketone and vinyl hexyl ketone; for example, vinyl methyl ether Vinyl ethyl ether, vinyl ethers such as vinyl isobutyl ether; such vinyl monomers are used alone or in combination.

In the present invention, the TH of the binder resin of the toner is
The number average molecular weight of the F-soluble component is preferably 3,000 to 1,000,000 (more preferably, 6,000 to 200,000).

The styrene-based polymer or styrene-based copolymer may be cross-linked, or may be a mixed resin of a cross-linked resin and a non-cross-linked resin.

As the crosslinking agent for the binder resin, a compound having two or more polymerizable double bonds may be mainly used. For example, divinylbenzene, aromatic divinyl compounds such as divinylnaphthalene; ethylene glycol diacrylate, ethylene glycol dimethacrylate,
Carboxylic acid esters having two double bonds such as 1,3-butanediol dimethacrylate; divinyl compounds such as divinylaniline, divinylether, divinylsulfide and divinylsulfone; and compounds having three or more vinyl groups. Can be These are used alone or as a mixture.

The amount of the crosslinking agent to be added may be as follows.
0.001 to 10 parts by weight based on 00 parts by weight is preferred.

The toner may contain a charge control agent.

As a substance which controls the toner to be positively charged, a colorless control agent is preferable so as not to adversely affect a color image. Examples include quaternary ammonium salts and resin control agents containing amino groups. When producing the toner of the present invention with a polymerized toner, a monomer containing an amino group as a control agent, for example,

[0108]

Embedded image It is also preferable to incorporate a compound such as 2- (dimethylamino) ethyl methacrylate or 2- (dimethylamino) ethyl acrylate represented by the following structural formula (R ₁ : H or an alkyl group, R ₂ , R ₃ : an alkyl group). Used.

These charge control agents are used in an amount of 0.01 to 20 parts by weight, preferably 0.1 to 10 parts by weight, more preferably 0.2 to 4 parts by weight, based on 100 parts by weight of the resin component of the toner. Good to do.

As the colorant of the toner used in the present invention, carbon black, a magnetic substance, and those toned to black using the following yellow / magenta / cyan colorants are used.

Examples of yellow colorants include condensed azo compounds, isoindolinone compounds, anthraquinone compounds,
Compounds represented by azo metal complexes, methine compounds and allylamide compounds are used. Specifically, C.I. I. Pigment Yellow 12, 13, 14, 15, 17, 6
2, 74, 83, 93, 94, 95, 109, 110,
111, 128, 129, 147, 168 or 180 are preferably used.

Examples of the magenta colorant include condensed azo compounds, diketopyrrolopyrrole compounds, anthraquinones, quinacridone compounds, basic dye lake compounds, naphthol compounds, benzimidazolone compounds, thioindigo compounds and perylene compounds. Specifically, C.I.
I. Pigment Red 2, 3, 5, 6, 7, 23, 4
8: 2, 48: 3, 48: 4, 57: 1, 81: 1, 1
44, 146, 166, 169, 177, 184, 18
5, 202, 206, 220, 221 or 254 are preferably used.

As the cyan coloring agent, copper phthalocyanine compounds and derivatives thereof, anthraquinone compounds, basic dye lake compounds and the like can be used. Specifically, C.I. I.
Pigment Blue 1, 7, 15, 15: 1, 15: 2,
15: 3, 15: 4, 60, 62, 66 can be particularly preferably used.

These colorants can be used alone or as a mixture or in the form of a solid solution. The colorant of the present invention is selected from the viewpoints of hue angle, saturation, brightness, weather resistance, OHP transparency, and dispersibility in toner. The colorant is used in an amount of 1 to 20 parts by weight based on 100 parts by weight of the resin.

The toner particles may contain a wax if necessary. A preferred wax has a weight average molecular weight (Mw) / number average molecular weight (Mn) of 1.45 or less and a solubility parameter of 8.4 to 10 in a molecular weight distribution measured by gel permeation chromatography (GPC). By using the wax of No. 5, the toner is excellent in fluidity, a uniform fixed image without gloss unevenness can be obtained, and furthermore, the heating member of the fixing device is hardly contaminated and the storage stability is not reduced, and the fixing property and the fixed image are reduced. When a full-color OHP with excellent transparency and excellent transparency is produced by melting the toner, a part or all of the wax covers the heating member moderately, and the toner is not offset. In addition to being able to form and exhibit good low-temperature fixing properties, it is possible to achieve a longer life of the press-contact member.

The wax contained in the toner used in the present invention has a weight average molecular weight (Mw) / number average molecular weight (Mn) of 1.45 or less, and preferably 1.45 or less, in the molecular weight distribution by GPC using a double column. A value of 30 or less is more preferable in terms of uniformity of a fixed image, good transferability of toner, and prevention of contamination of a contact charging unit for charging by contacting the photoreceptor.

When the value of Mw / Mn of the wax exceeds 1.45, the fluidity of the toner decreases,
Gloss unevenness of the fixed image is apt to occur, and further, the transferability of the toner is deteriorated and the contact charging means is likely to be contaminated.

In the present invention, the molecular weight distribution of the wax is
It is measured under the following conditions by GPC using a double column.

(GPC measurement conditions) Apparatus: GPC-150C (manufactured by Waters) Column: GMH-HT 30 cm double (manufactured by Tosoh Corporation) Temperature: 135 ° C. Solvent: o-dichlorobenzene (addition of 0.1% ionol) Flow rate: 1 0.0 ml / min sample: 0.4 ml of 0.15% sample is injected

Measurement is performed under the above conditions, and the molecular weight of the sample is calculated using a molecular weight calibration curve prepared from a monodispersed polyurethane standard sample. In addition, Mark-Hou
The molecular weight is calculated by converting to polyethylene using a conversion formula derived from the win viscosity formula.

The melting point of the wax used in the present invention is 3
The temperature is preferably from 0 to 150 ° C, more preferably from 50 to 120 ° C. The melting point of the wax is 3
When the temperature is lower than 0 ° C., the blocking resistance of the toner, the suppression of sleeve contamination at the time of copying a large number of sheets, and the prevention of contamination of the photoreceptor are likely to deteriorate. If the melting point of the wax exceeds 150 ° C., excessive energy is required for uniform mixing with the binder resin in the production of the toner by the pulverization method, and the homogenization of the binder resin in the production of the toner by the polymerization method is also required. In addition, since the size of the apparatus is increased due to the increase in viscosity or the amount of compatibility is limited, it is not preferable because it becomes difficult to contain a large amount.

The melting point of the wax was determined according to ASTM D3418.
The temperature was the main peak value in the endothermic curve measured according to −8.

The measurement according to ASTM D3418-8 is performed using, for example, DSC-7 manufactured by PerkinElmer. The temperature correction of the device detection unit uses the melting points of indium and zinc, and the heat quantity correction uses the heat of fusion of indium. An aluminum pan was used as a sample, an empty pan was set as a control, and the temperature was raised at a rate of 10 ° C./min. At a temperature in the range of 20 to 200 ° C.

The wax used in the present invention preferably has a melt viscosity at 100 ° C. of 1 to 50 mPas · sec, more preferably 3 to 30 mPas · s.
A wax compound having ec is particularly preferred.

The melt viscosity of the wax is 1 mPas · sec.
If it is lower, when the toner layer is thinly coated on the sleeve by a toner layer thickness regulating member that regulates the toner layer thickness by an elastic force such as an elastic blade in a one-component developing method, the sleeve is contaminated by mechanical shearing force. In addition, in a two-component developing method, when a toner is developed using a carrier, the toner tends to be damaged due to a shear force between the toner and the carrier, and the external additive is easily buried or the toner is crushed. When the melt viscosity of the wax exceeds 50 mPas · sec, when producing the toner using the polymerization method, the viscosity of the dispersoid is too high, and it is easy to obtain a toner having a fine particle diameter having a uniform particle diameter. And the toner tends to have a wide particle size distribution.

The measurement of the melt viscosity of the wax was performed using HAAKE.
Cone-plate type rotor (PK
-1).

Further, the wax used in the present invention is:
The molecular weight distribution measured by GPC has two or more peaks or one or more peaks and one or more shoulders, and in the molecular weight distribution, weight average molecular weight (Mw)
Is 200 to 2000, and the number average molecular weight (Mn) is 150
It is preferably from 2000 to 2000. It has been found that the above-mentioned molecular weight distribution can be achieved with either a single wax or a plurality of waxes, and as a result, crystallinity can be inhibited and transparency can be further improved. The method of blending two or more waxes is not particularly limited. For example, a media-type dispersing machine (ball mill, sand mill, attritor, apex mill, Koball mill, handy mill) is used at a temperature higher than the melting point of the wax to be blended. Melt blending, or dissolving the wax to be blended in a polymerizable monomer and blending with a media type disperser. At this time,
Pigments, charge control agents, and polymerization initiators may be used.

The weight average molecular weight (Mw) of the wax was 20.
0 to 2000, number average molecular weight (Mn) is 150 to 2
00 is preferred. More preferably, Mw is 20
0 to 1500, more preferably 300 to 100
0, Mn is 200 to 1500, more preferably 25.
It is preferably 0 to 1000. Mw of wax is 2
If it is less than 00 and Mn is less than 150, the blocking resistance of the toner is reduced. Mw of wax is 2000
If the Mn is more than 2,000, the crystallinity of the wax itself is exhibited, and the transparency is reduced.

The wax is used in an amount of 1 to 40 parts by weight, preferably 2 to 30 parts by weight, based on 100 parts by weight of the binder resin of the toner.

In the production of a pulverized toner in which a mixture containing a binder resin, a colorant and a wax is melt-kneaded, cooled, pulverized, and classified to obtain toner particles, the amount of wax added is 100 parts by weight of the binder resin. It is preferable to use 1 to 10 parts by weight, more preferably 2 to 7 parts by weight.

In a polymerization toner production method in which toner particles are directly obtained by polymerizing a mixture having a polymerizable monomer, a colorant and a wax, the amount of the wax added is determined by the amount of the polymerizable monomer or polymerizable monomer. 2 to 40 parts by weight, more preferably 5 to 30 parts by weight, even more preferably 10 to 2 parts by weight per 100 parts by weight of the resin synthesized by polymerization of the monomer.
It is preferred to use 0 parts by weight.

Since the wax used in the polymerization toner production method is lower in polarity than the binder resin as compared with the pulverized toner production method, a large amount of wax is easily encapsulated in the toner particles by the polymerization method in an aqueous medium. In comparison, a large amount of wax can be used, which is particularly effective for the effect of preventing offset during fixing.

When the amount of the wax is less than the lower limit, the effect of preventing offset tends to decrease, and when the amount exceeds the upper limit, the anti-blocking effect is reduced and the anti-offset effect is liable to be adversely affected. In particular, in the case of a polymerization toner production method, a toner having a wide particle size distribution tends to be produced.

Examples of the wax that can be used in the present invention include paraffin wax, polyolefin wax, modified products thereof (for example, oxides and graft-treated products), higher fatty acids, metal salts thereof, amide waxes, and the like. And ester waxes.

Among them, higher quality full color OH
Ester wax is particularly preferred in that a P image can be obtained.

As a method for producing the ester wax preferably used in the present invention, for example, a synthesis method by an oxidation reaction, a synthesis from a carboxylic acid or a derivative thereof, and an ester group introduction reaction represented by a Michael addition reaction are used.

A particularly preferable method for producing the wax used in the present invention is a method using a dehydration condensation reaction of a carboxylic acid compound and an alcohol compound represented by the following formula (1), because of the variety of raw materials and the ease of reaction, Or the following formula (2)
The reaction of a halide with an alcohol compound is particularly preferred.

[0138]

Embedded image

In the formula, R ₁ and R _{2 each} represent an organic group such as an alkyl group, an alkenyl group, an aralkyl group and an aromatic group, and n represents an integer of 1 to 4. The organic group preferably has 1 to 50, preferably 2 to 45, and more preferably 4 to 30 carbon atoms, and further preferably has a straight chain.

In order to transfer the above-mentioned ester equilibrium reaction to the production system, the reaction is carried out using a large excess of alcohol or in a Dean-Stark water separator in an aromatic organic solvent capable of azeotropic distillation with water. . A method of synthesizing a polyester by adding a base as an acceptor of an acid by-produced in an aromatic organic solvent using an acid halide compound can also be used.

Next, a method for producing the toner used in the present invention will be described. The toner used in the present invention can be manufactured using a pulverized toner manufacturing method and a polymerized toner manufacturing method.

In the present invention, a method for producing a pulverized toner includes a binder resin, a wax, a pigment as a colorant, a dye or a magnetic substance, a charge control agent, and other additives as necessary. The resulting mixture is melt-kneaded using a heat kneader such as a heating roll, kneader, extruder and the like, and the metal components, pigments, dyes, and magnetic materials are mixed while the resin components are mutually mixed. The kneaded product is cooled and solidified, and then pulverized and classified to obtain a toner.

Further, if necessary, the toner and the desired additive are sufficiently mixed by a mixer such as a Henschel mixer.
The toner used in the present invention can be obtained.

A method for producing a polymerized toner is described in JP-B-56-13.
No. 945, etc., a method of atomizing a molten mixture into air using a disk or a multi-fluid nozzle to obtain a spherical toner, Japanese Patent Publication No. Sho 36-10231, and Japanese Patent Application Laid-Open No. Sho 59-53.
No. 856, JP-A-59-61842, a method of directly producing a toner using a suspension polymerization method, an aqueous organic solvent which is soluble in a monomer and insoluble in a polymer obtained. An emulsion polymerization method typified by a dispersion polymerization method in which a toner is directly produced using a water-soluble polar polymerization initiator or a soap-free polymerization method in which a toner is produced by directly polymerizing in the presence of a water-soluble polar polymerization initiator, or a method in which primary polar emulsion polymerization particles are previously prepared. It is possible to produce a toner using a hetero-aggregation method in which polar particles having opposite charges are added and associated.

Among these, a method in which toner particles are produced by directly polymerizing a monomer composition containing at least a polymerizable monomer, a colorant and a wax is preferred.

However, in the dispersion polymerization method, the obtained toner shows an extremely sharp particle size distribution, but the selection of materials to be used is narrow, and the use of an organic solvent is disadvantageous from the viewpoints of waste solvent treatment and solvent flammability. The manufacturing equipment is complicated and easily complicated. Therefore, a method of directly polymerizing a monomer composition containing at least a polymerizable monomer, a colorant and a wax in an aqueous medium to form toner particles is more preferable. However, the emulsion polymerization method represented by soap-free polymerization is effective because the particle size distribution of the toner is relatively uniform, but when the used emulsifier and the terminal of the initiator are present on the surface of the toner particles, the environmental characteristics are likely to deteriorate.

Therefore, in the present invention, the suspension polymerization method under normal pressure or under pressure, which can easily obtain a fine particle toner having a sharp particle size distribution, is particularly preferable. A so-called seed polymerization method in which a monomer is further adsorbed on the polymer particles once obtained and then polymerized using a polymerization initiator can also be suitably used in the present invention.

In a preferred embodiment of the toner used in the present invention, wax is encapsulated in an outer shell resin layer by a tomographic plane measurement method of the toner using a transmission electron microscope (TEM). From the viewpoint of fixability, it is necessary to incorporate a large amount of wax into the toner, and it is preferable to include the wax in the outer shell resin layer from the viewpoints of storage stability and fluidity of the toner. If the toner is not encapsulated, the wax cannot be dispersed uniformly, resulting in a broad particle size distribution, and
It is easy for toner fusion to occur. As a specific method of encapsulating the wax, the polarity of the material in the aqueous medium is set to be smaller for the wax than for the main monomer, and a small amount of a polar resin or monomer is further added. A toner having a so-called core-shell structure in which wax is coated with an outer shell resin can be obtained. To control the particle size distribution and particle size of the toner, the method of changing the type and amount of the hardly water-soluble inorganic salt and the dispersant that acts as a protective colloid and the mechanical device conditions, such as the peripheral speed of the rotor, the number of passes, and stirring The predetermined toner of the present invention can be obtained by controlling the stirring conditions such as the shape of the blades, the shape of the container, and the solid content concentration in the aqueous solution.

In the present invention, a specific method for measuring the tomographic plane of the toner is as follows. A toner obtained by sufficiently dispersing a toner in a room-temperature curable epoxy resin and then curing it in an atmosphere at a temperature of 40 ° C. for 2 days. The product is stained with ruthenium tetroxide and, if necessary, osmium tetroxide, and then sliced using a microtome equipped with diamond teeth. The morphology of the toner is measured using a transmission electron microscope (TEM). did. In the present invention, it is preferable to use a ruthenium tetroxide dyeing method in order to give a contrast between materials by utilizing a slight difference in crystallinity between the wax used and the resin constituting the outer shell.

In the case where the direct polymerization method is used in the toner production method of the present invention, the toner can be specifically produced by the following production method. A wax, a coloring agent, a charge control agent, a polymerization initiator and other additives are added to the monomer, and a monomer system uniformly dissolved or dispersed by a homogenizer, an ultrasonic disperser or the like, and a dispersion stabilizer is contained. It is dispersed in the aqueous phase by a conventional stirrer or a stirrer such as a homomixer or a homogenizer. Preferably, the stirring speed and time are adjusted so that the monomer droplets have the desired size of the toner particles, and the granulation is performed. Thereafter, by the action of the dispersion stabilizer, the particles may be stirred to such an extent that the particle state is maintained and the particles are prevented from settling. The polymerization is performed at a polymerization temperature of 40 ° C. or higher, generally 50 to 90 ° C. Further, the temperature may be raised in the latter half of the polymerization reaction, and further, in order to remove unreacted polymerizable monomers, by-products and the like which cause odor at the time of fixing the toner, the second half of the reaction, or
After the completion of the reaction, a part of the aqueous medium may be distilled off. After completion of the reaction, the generated toner particles are collected by washing and filtration, and dried. In the suspension polymerization method, it is generally preferable to use 300 to 3000 parts by weight of water as a dispersion medium with respect to 100 parts by weight of the monomer system.

When a toner is directly obtained by a polymerization method, the polymerizable monomer may be a styrene-based monomer such as styrene, o (m-, p-)-methylstyrene or m (p-)-ethylstyrene. Methyl (meth) acrylate, ethyl (meth) acrylate, propyl (meth) acrylate, butyl (meth) acrylate, octyl (meth) acrylate,
(Meth) such as dodecyl (meth) acrylate, stearyl (meth) acrylate, behenyl (meth) acrylate, 2-ethylhexyl (meth) acrylate, dimethylaminoethyl (meth) acrylate, and diethylaminoethyl (meth) acrylate ) Acrylic ester monomers: Enene monomers such as butadiene, isoprene, cyclohexene, (meth) acrylonitrile and acrylamide are preferably used.

Examples of the polar resin include a polymer of a nitrogen-containing monomer such as dimethylaminoethyl methacrylate and diethylaminoethyl methacrylate or a copolymer of a nitrogen-containing monomer and a styrene-unsaturated carboxylic acid ester; Nitrile monomers such as vinyl chloride; halogen-containing monomers such as vinyl chloride; unsaturated carboxylic acids such as acrylic acid and methacrylic acid; unsaturated dibasic acids; unsaturated dibasic acid anhydrides; A polymer or a copolymer of the polymer and a styrene monomer; a polyester; an epoxy resin. More preferred are a copolymer of styrene and (meth) acrylic acid, a maleic acid copolymer, a saturated polyester resin, and an epoxy resin.

Examples of the polymerization initiator include, for example, 2,2′-
Azobis- (2,4-dimethylvaleronitrile), 2,
2′-azobisisobutyronitrile, 1,1′-azobis (cyclohexane-1-carbonitrile), 2,2 ′
Azo or diazo polymerization initiators such as azobis-4-methoxy-2,4-dimethylvaleronitrile and azobisisobutyronitrile; benzoyl peroxide, methyl ethyl ketone peroxide, diisopropyl peroxycarbonate, cumene hydroperoxide, t-butylhydro Peroxide, di-t-butyl peroxide, dixyl peroxide, 2,4-dichlorobenzoyl peroxide, lauroyl peroxide, 2,2-bis (4,4-t-butylperoxycyclohexyl) propane, tris- (t-butylperoxy) A peroxide initiator such as triazine; a polymer initiator having a peroxide in a side chain; a persulfate such as potassium persulfate and ammonium persulfate; and hydrogen peroxide are used. These can be used alone or in combination of two or more.

The polymerization initiator is preferably added in an amount of 0.5 to 20 parts by weight based on 100 parts by weight of the polymerizable monomer.

In order to control the molecular weight, known crosslinking agents and chain transfer agents may be added. A preferable addition amount is 0.001 to 100 parts by weight of the polymerizable monomer.
１５15 parts by weight.

A dispersion medium used for producing a polymerized toner by a polymerization method using emulsion polymerization, dispersion polymerization, suspension polymerization, seed polymerization, or hetero-aggregation method can be prepared by stabilizing an appropriate inorganic compound or organic compound. It is preferred to use agents. Examples of the inorganic compound stabilizer include, for example, tricalcium phosphate, magnesium phosphate, aluminum phosphate, zinc phosphate, calcium carbonate, magnesium carbonate,
Examples include calcium hydroxide, magnesium hydroxide, aluminum hydroxide, calcium metasilicate, calcium sulfate, barium sulfate, bentonite, silica, and alumina. Examples of organic compound stabilizers include polyvinyl alcohol, gelatin, methylcellulose, methylhydroxypropylcellulose, ethylcellulose, sodium salts of carboxymethylcellulose, polyacrylic acid and salts thereof, starch, polyacrylamide, polyethylene oxide, and poly (hydroxystearic acid). -G-methyl methacrylate-eu-methacrylic acid) copolymer and a nonionic or ionic surfactant.

When the emulsion polymerization method and the heteroaggregation method are used, an anionic surfactant, a cationic surfactant,
Zwitterionic surfactants and nonionic surfactants are used. It is preferable to use 0.2 to 30 parts by weight of these stabilizers based on 100 parts by weight of the polymerizable monomer.

When an inorganic compound is used among these stabilizers, a commercially available one may be used as it is, but in order to obtain fine particles, the inorganic compound may be formed in a dispersion medium.

For finely dispersing these stabilizers, a surfactant may be used in an amount of 0.001 to 0.1 part by weight based on 100 parts by weight of the polymerizable monomer. This surfactant is for promoting the stabilizing action of the dispersion stabilizer. Specific examples thereof include sodium dodecylbenzene sulfate, sodium tetradecyl sulfate, sodium pentadecyl sulfate, sodium octyl sulfate, sodium oleate, sodium laurate, potassium stearate, calcium oleate, and the like.

As the colorant used in the polymerization method toner in the present invention, it is necessary to pay attention to the polymerization inhibitory property and the water phase migration property of the colorant. It is better to perform a hydrophobic treatment without any. In particular, many dyes and carbon blacks have polymerization inhibitory properties, so care must be taken when using them.
As a preferable method for surface-treating the dye system, a method in which a polymerizable monomer is previously polymerized in the presence of these dyes is mentioned, and the obtained colored polymer is added to the monomer system. The carbon black may be treated with a substance that reacts with the surface functional groups of the carbon black, such as polyorganosiloxane, in addition to the same treatment as the above dye.

Further, the melting point of the wax of the toner is higher than the glass transition temperature of the binder resin, and the temperature difference is preferably 100 ° C. or less, more preferably 75 ° C. or less, and further preferably 50 ° C. or less. .

When this temperature difference exceeds 100 ° C.,
The low-temperature fixability decreases. Furthermore, if this temperature difference is too close, the temperature range in which the storage stability of the toner can be compatible with the high-temperature offset resistance becomes narrow, and therefore it is preferably 2 ° C. or more. The glass transition temperature of the binder resin is preferably 40 ° C to 90 ° C, more preferably 5 ° C to 90 ° C.
The temperature is preferably 0 to 85 ° C.

When the glass transition temperature of the binder resin is lower than 40 ° C., the storage stability of the toner is lowered and the fluidity is deteriorated, so that a good image cannot be obtained.

When the glass transition temperature of the binder resin exceeds 90 ° C., the low-temperature fixability is inferior and the transparency of full-color transparency is deteriorated. In particular, the halftone portion tends to be dull and a projection image without saturation is likely to be obtained.

The glass transition temperature (Tg) of the binder resin is A
It performed by the measurement according to STM D3418-8.
For example, this is performed using Perkin Elmer DSC-7.
The temperature correction of the device detection unit uses the melting points of indium and zinc, and the heat quantity correction uses the heat of fusion of indium. An aluminum pan was used as a sample, an empty pan was set as a control, and the temperature was raised at a rate of 10 ° C./min. At a temperature in the range of 20 to 200 ° C.

Next, the external additives externally added to the toner particles will be described.

The toner used in the present invention comprises fine particles of inorganic fine particles such as silica, alumina, and titanium oxide; and fine organic fine particles such as polytetrafluoroethylene, polyvinylidene fluoride, polymethyl methacrylate, polystyrene and silicone. It is preferable that it is done. By externally adding the above-mentioned fine powder to the toner, the fine powder exists between the toner and the carrier or between the toner particles, the fluidity of the developer is improved, and the life of the developer is also increased. improves. The average particle size of the fine powder described above is preferably 3 to 100 nm. When the average particle size exceeds 100 nm, the effect of improving the fluidity decreases,
In some cases, image quality is degraded due to a defect during development or transfer. If it is smaller than 3 nm, it is difficult to maintain fluidity during durability. The measurement of the average particle size of these fine powders will be described later.

The surface area of these fine powders is BET
Specific surface area by nitrogen adsorption 30 m ² / g or more by law, is excellent particularly in the range of 5~400m ² / g. The addition amount of the fine powder is preferably 0.1 to 20 parts by weight based on 100 parts by weight of the toner.

The silica is preferably subjected to a hydrophobic treatment in order to maintain the chargeability under high humidity. An example of the hydrophobic treatment is shown below.

One of the hydrophobizing agents is silicone oil. In general, it is preferable to be represented by the following formula.

[0171]

Embedded image [Wherein, R _{1 to} R ₁₀ may be the same or different,
Hydrogen, hydroxyl group, nitrogen-containing organic group, alkyl group, halogen,
A phenyl group, a phenyl group having a substituent, a fatty acid group, a polyoxyalkylene group or a perfluoroalkyl group, and m and n each represent an integer.

Preferred silicone oils include 25
Those having a viscosity at 5 ° C. of 5 to 2000 mm ² / s are preferably used. A silicone oil having a low molecular weight and a low viscosity is not preferable because a volatile component may be generated by heat treatment. On the other hand, a silicone oil having a high molecular weight and a high viscosity makes it difficult to perform a surface treatment operation. Silicone oils include methyl silicone oil, dimethyl silicone oil, phenyl methyl silicone oil, chlorophenyl methyl silicone oil, alkyl-modified silicone oil, fatty acid-modified silicone oil, polyoxyalkyl-modified silicone oil, fluorine-modified silicone oil, and amino-modified silicone oil. Is preferred.

As the above-mentioned silicone oil, in order to enhance the chargeability of the toner, it is preferable to use a positive charge having the same polarity as the toner particles, and an amino-modified silicone oil is particularly preferable.

As a method of treating the inorganic fine powder with silicone oil, a known technique is used.

For example, the inorganic fine powder and the silicone oil may be directly mixed using a mixer such as a Henschel mixer, or a method of spraying the silicone oil onto the inorganic fine powder may be used. Alternatively, it may be prepared by dissolving or dispersing silicone oil in an appropriate solvent, mixing with an inorganic fine powder, and then removing the solvent.

The silicone oil is used in an amount of 1.5 to 60 parts by weight, preferably 3.5 to 40 parts by weight, based on 100 parts by weight of the inorganic fine powder to be treated. 1.5 to 6
When the amount is 0 part by weight, the surface treatment with the silicone oil can be performed uniformly, filming and dropout can be suitably prevented, the toner charging property can be prevented from lowering due to moisture absorption under high humidity, and the image density in durability can be reduced. A fall can be prevented. Also,
It is possible to prevent the occurrence of image defects such as scattering of fixing. It can prevent a decrease in the fluidity of the toner and can also prevent the occurrence of fog. As another hydrophobic treatment method, treatment with a silane coupling agent is also preferable.

The silane coupling agent is used in an amount of 1 to 100 parts by weight of the inorganic fine powder before the coupling treatment.
It is good to use 40 parts by weight, preferably 2 to 35 parts by weight. When the amount is 1 to 40 parts by weight, moisture resistance is improved and aggregates are hardly generated.

Examples of the silane coupling agent used in the present invention include those represented by the following general formula.

R _m SiY _{n wherein} R represents an alkoxy group or a chlorine atom, and m represents 1
Y represents a hydrocarbon group (for example, an alkyl group, a vinyl group, a glycidoxy group, and a methacryl group), and n is an integer of 3-1. ]

For example, aminosilane, dimethyldichlorosilane, trimethylchlorosilane, allyldimethylchlorosilane, hexamethyldisilazane, allylphenyldichlorosilane, benzyldimethylchlorosilane, vinyltriethoxysilane, γ-methacryloxypropyltrimethoxysilane , Vinyltriacetoxysilane, divinylchlorosilane, dimethylvinylchlorosilane, and the like.

As the above silane coupling agent, in order to enhance the charging characteristics of the toner, it is preferable to use a positively chargeable silane coupling agent having the same polarity as the toner particles, and particularly preferably an aminosilane coupling agent. When these external additives having a high positive chargeability are used, the external additives that have been partially released tend to migrate to the carrier. Even in such a case, the fluorine-containing resin-coated carrier of the present invention can suppress adhesion of a fluidizing agent due to low surface energy.

The silane coupling agent treatment of the inorganic fine powder includes a dry treatment in which the vaporized silane coupling agent is reacted with a cloud of the inorganic fine powder by stirring.
Alternatively, the treatment can be carried out by a generally known method such as a wet method in which fine silica powder is dispersed in a solvent and a silane coupling agent is dropped. The above-mentioned hydrophobizing treatment can be appropriately used in combination.

Additives for imparting various toner properties may have a particle size of not more than 1/5 of the volume average particle size of the toner particles from the viewpoint of durability in the toner or when added to the toner. preferable. The particle size of the additive means an average particle size obtained by observing the surface of the toner particles with an electron microscope. As additives for the purpose of imparting these properties, for example, the following are used.

Examples of the fluidity-imparting agent include metal oxides such as silicon oxide, aluminum oxide and titanium oxide;
Carbon black; and carbon fluoride.
Each of these is preferably subjected to a hydrophobic treatment.

Examples of the abrasive include metal oxides such as strontium titanate, cerium oxide, aluminum oxide, magnesium oxide and chromium oxide; nitrides such as silicon nitride; carbides such as silicon carbide; and calcium sulfate and sulfuric acid. Metal salts such as barium and calcium carbonate are mentioned.

Examples of the lubricant include fluorine resin powders such as vinylidene fluoride and polytetrafluoroethylene; and fatty acid metal salts such as zinc stearate and calcium stearate.

Examples of the charge control particles include tin oxide,
Metal oxides such as titanium oxide, zinc oxide, silicon oxide and aluminum oxide; and carbon black.

These additives are preferably used in an amount of 0.1 to 10 parts by weight, more preferably 0.1 to 5 parts by weight, based on 100 parts by weight of the toner particles. These additives may be used alone or in combination of two or more.

The positively chargeable toner preferably has a triboelectric charge of +15 to +40 mC / kg (more preferably, +20 to +35 mC / kg) when mixed with the magnetic resin carrier.

The negatively chargeable toner has a shape factor SF-1 of 1
It is preferably from 00 to 140, and at least hydrophobic silica fine powder is used as an external additive in order to further improve developability.

As a developing method using the magnetic resin carrier of the present invention, for example, development can be performed using a developing means as shown in FIG. Specifically, the magnetic brush is applied to the latent image carrier, for example, the photosensitive drum 1 while applying an alternating electric field.
It is preferable to carry out development in a state where it is in contact with the surface. The distance (S-D distance) B between the developer carrier (developing sleeve) 11 and the photosensitive drum 1 is preferably 100 to 1000 [mu] m in order to prevent carrier adhesion and improve dot reproducibility. Narrower than 100μm tends to become insufficient supply of the developer, the image density is lowered, the lower the density of the magnetic brush field lines spread from pole S ₁ exceeds 1000 .mu.m, or poor dot reproducibility, magnetic coating The force for restraining the carrier is weakened, and carrier adhesion is likely to occur.

The voltage between the peaks of the alternating electric field is 300 to 30.
00V is preferable, the frequency is 500 to 10000 Hz,
Preferably, it is 1000-7000 Hz, and each can be appropriately selected and used depending on the process. In this case, the waveform may be triangular, rectangular, sine, or D
Various waveforms with different duty ratios, intermittent alternating superposed electric fields, and the like can be selected and used. If the applied voltage is lower than 300 V, it may be difficult to obtain a sufficient image density, and it may not be possible to satisfactorily collect fog toner in the non-image area. If the voltage exceeds 5000 V, the latent image may be disturbed via the magnetic brush, which may cause deterioration in image quality.

By using a two-component developer having a well-charged toner, the fog removal voltage (Vback)
And the primary charge of the photoconductor can be reduced, so that the life of the photoconductor can be extended. Vbac
k is preferably 200 V or less, more preferably 150 V or less, depending on the developing system.

As the contrast potential, 100 V to 400 V is preferably used so that a sufficient image density can be obtained.

When the frequency is lower than 500 Hz, although it depends on the process speed, when the toner in contact with the electrostatic image carrier is returned to the developing sleeve, sufficient vibration is not given and fog is liable to occur. When the frequency exceeds 10,000 Hz, the toner cannot follow the electric field, and the image quality is liable to be deteriorated.

What is important in the developing method of the present invention is that the magnetic brush on the developing sleeve 11 and the photosensitive drum 1 are used to develop a sufficient image density, have excellent dot reproducibility, and perform development without carrier adhesion. The contact width (development nip C) is preferably set to 3 to 8 mm. Development nip C is 3
If it is smaller than 8 mm, it is difficult to sufficiently satisfy sufficient image density and dot reproducibility. If it is larger than 8 mm, packing of the developer occurs, which stops the operation of the machine and sufficiently suppresses carrier adhesion. It becomes difficult. As a method of adjusting the developing nip, the distance A between the developer regulating member 15 and the developing sleeve 11 may be adjusted, or the developing sleeve 1 may be adjusted.
The nip width is appropriately adjusted by adjusting the distance B between the photosensitive drum 1 and the photosensitive drum 1.

The image forming method of the present invention uses three or more developing units for magenta, cyan, and yellow, especially in outputting a full-color image in which halftone is emphasized. By using the developing method, particularly in combination with a developing system that forms a digital latent image, it is possible to develop the dot latent image faithfully without being affected by the magnetic brush and disturbing the latent image. Also in the transfer step, a high transfer rate can be achieved by using a fine-particle-cut toner having a sharp particle size distribution, so that high image quality can be achieved in both the halftone portion and the solid portion.

Furthermore, by using the two-component developer of the present invention together with the initial improvement of the image quality, the share of the developer in the developing device is small, and the image quality of the present invention does not deteriorate even when copying a large number of sheets. The effect of can be fully exhibited.

In order to obtain a tighter image, it is preferable to have a developing device for magenta, cyan, yellow, and black, and to exhibit a tighter image by performing black development last. Can be.

The image forming method of the present invention will be described with reference to the accompanying drawings.

In FIG. 1, a magnetic brush made of magnetic particles 23 is formed on the surface of the transfer sleeve 22 by the magnetic force of the magnet roller 21, and the magnetic brush contacts the surface of the electrostatic image carrier (photosensitive drum) 1. Then, the photosensitive drum 1 is charged. A charging bias is applied to the transport sleeve 22 by a bias applying unit (not shown). By irradiating the charged photosensitive drum 1 with laser light 24 by an exposure device (not shown), a digital electrostatic charge image is formed. The electrostatic charge image formed on the photosensitive drum 1 includes a magnet roller 12 and a developer 19 carried on a developing sleeve 11 to which a developing bias is applied by a bias applying device (not shown).
It is developed by the toner 19a inside.

The developing device 4 is configured such that the developer chamber R
_1, is divided into the stirring chamber R _2, respectively developer conveying screw 13, 14 is installed. Above the stirring chamber R _2, a toner storage chamber R ₃ containing a replenishing toner 18 is installed, supply opening 20 is provided in a lower portion of the storage chamber R _3.

The developer transport screw 13 rotates to transport the developer in the developer chamber R1 in _one direction along the longitudinal direction of the developing sleeve 11 while stirring. The partition 17 is provided with openings (not shown) on the near side and the back side in the drawing, and the developer conveyed to _one of the developer chambers R1 by the screw 13 passes through the opening of the partition 17 on one side. The developer is sent to the stirring chamber R ₂ and transferred to the developer transport screw 14. In the direction of rotation the screw 13 opposite the screw 14, the developer in the stirring chamber R _2, the developer chamber R ₁
Stirring the toner supplied from the passed developer and toner storage chamber R ₃ from, with mixing, the screw 13 and conveyed in the stirring chamber R ₂ in the opposite direction, through the other opening of the partition wall 17 sent into the developer chamber R _1.

[0204] To develop the electrostatic latent image formed on the photosensitive drum 1, the developer 19 in the developer chamber R ₁ is drawn up by the magnetic force of the magnet roller 12, the developing sleeve 1
1 is carried on the surface. The developer carried on the developing sleeve 11 is conveyed to the regulating blade 15 with the rotation of the developing sleeve 11, where it is regulated to a thin developer layer having an appropriate layer thickness. To the development area opposed to it. The portion corresponding to the developing area of the magnet roller 12, the magnetic poles are (developing pole) N ₁ is positioned, the developing pole N ₁ forms a developing magnetic field in the developing area,
This developer magnetic field causes the developer to spike, and a magnetic brush of the developer is generated in the development area. Then, the magnetic brush contacts the photosensitive drum 1, and the toner adhered to the magnetic brush and the toner adhered to the surface of the developing sleeve 11 are transferred to the electrostatic image area on the photosensitive drum 1 by the reversal developing method. Then, the electrostatic image is developed to form a toner image.

The developer that has passed through the developing area is returned into the developing device 4 as the developing sleeve 11 rotates, and the magnetic pole S
Due to the repelling magnetic field between S ₁ and S ₂ , it is peeled off from the developing sleeve 11 and falls into the developer chamber R ₁ and the stirring chamber R ₂ to be collected.

By the development described above, the developer 1 in the developing device 4
T / C ratio of 9 (toner and mixing ratio of the carrier, i.e., toner concentration in the developer) When decreases is, the agitation chamber R in an amount that was seen from the toner storage chamber R ₃ to the amount consumed toner 18 in the developing ₂ and the T / C of the developer 19 is maintained at a predetermined amount. To detect the T / C ratio of the developer 19 in the container 4,
A toner concentration detection sensor that measures a change in the magnetic permeability of the developer using the inductance of the coil is used. The toner concentration detection sensor has a coil (not shown) therein.

The regulating blade 15 disposed below the developing sleeve 11 and regulating the layer thickness of the developer 19 on the developing sleeve 11 is a non-magnetic blade 15 made of a non-magnetic material such as aluminum or SUS316. The distance between the end and the surface of the developing sleeve 11 is 300 to 1000 μm.
m, preferably 400 to 900 μm. If the distance is less than 300 μm, the magnetic carrier is clogged during this time, and the developer layer is likely to be uneven, and it is difficult to apply the developer necessary for good development, and a developed image having a low density and many unevenness is formed. Easy to be. This distance is preferably 400 μm or more in order to prevent non-uniform application (so-called blade jam) due to unnecessary particles mixed in the developer. If it is larger than 1000 μm, the amount of the developer applied on the developing sleeve 11 increases, and it is difficult to regulate a predetermined thickness of the developer layer. As a result, the adhesion of the magnetic carrier particles to the photosensitive drum 1 increases and the circulation and regulation of the developer. The regulation of development by the blade 15 is weakened, so that toner tribo is reduced and fogging is likely to occur.

Even when the developing sleeve 11 is rotationally driven in the direction of the arrow, the magnetic carrier particle layer is separated from the surface of the sleeve by the balance between the restraining force based on magnetic force and gravity and the conveying force in the moving direction of the developing sleeve 11. Movement slows down. Some fall under the influence of gravity.

Therefore, by appropriately selecting the arrangement positions of the magnetic poles N and N and the fluidity and magnetic characteristics of the magnetic carrier particles, the magnetic carrier particle layer becomes closer to the sleeve so that the magnetic pole N ₁ becomes closer to the sleeve.
To form a moving layer. Due to the movement of the magnetic carrier particles, the developer is conveyed to the developing area with the rotation of the developing sleeve 11 and is used for development.

Further, the developed toner image is transferred onto a transfer material (recording material) 25 conveyed by a bias applying means 2.
The toner image transferred by the transfer blade 27 as a transfer unit to which a transfer bias is applied by 6 and transferred onto the transfer material is fixed to the transfer material by a fixing device (not shown). In the transfer step, the transfer residual toner remaining on the photosensitive drum 1 without being transferred to the transfer material is adjusted in charge in the charging step, and is collected during development.

FIG. 3 is a schematic diagram in which the image forming method of the present invention is applied to a full-color image forming apparatus.

The main body of the full-color image forming apparatus includes a first image forming unit Pa, a second image forming unit Pb,
An image forming unit Pc and a fourth image forming unit Pd are provided side by side, and images of different colors are formed on a transfer material through a process of forming, developing, and transferring a latent image.

The configuration of each image forming unit provided in the image forming apparatus will be described by taking the first image forming unit Pa as an example.

The first image forming unit Pa includes an electrophotographic photosensitive drum 6 having a diameter of 30 mm as an electrostatic image carrier.
1a, the photosensitive drum 61a is rotated in the direction of arrow a. Reference numeral 62a denotes a primary charger as a charging unit, and a magnetic brush formed on the surface of a sleeve having a diameter of 16 mm is arranged so as to contact the surface of the photosensitive drum 61a. Reference numeral 67a denotes a laser beam for forming an electrostatic charge image on the photosensitive drum 61a, the surface of which is uniformly charged by the primary charger 62a, and is irradiated by an exposure device (not shown). 63a is the photosensitive drum 6
The developing device is a developing device as a developing unit for forming a color toner image by developing the electrostatic charge image carried on 1a, and holds a color toner. Reference numeral 64a denotes a transfer blade as transfer means for transferring the color toner image formed on the surface of the photosensitive drum 61a to the surface of a transfer material (recording material) conveyed by a belt-shaped transfer material carrier 68. The transfer blade 64a can apply a transfer bias by contacting the back surface of the transfer material carrier 68.

In the first image forming unit Pa, after the photosensitive drum 61a is uniformly and primarily charged by the primary charger 62a, an electrostatic image is formed on the photosensitive member by the exposure device 67a, and the electrostatic image is formed by the developing device 63a. Is developed using a color toner, and the developed toner image is transferred to a back surface side of a belt-shaped transfer material carrier 68 which carries and conveys the transfer material at a first transfer portion (a contact position between the photoconductor and the transfer material). A transfer bias is applied from a transfer blade 64a that comes into contact with the transfer member to transfer the image onto the surface of the transfer material.

When the toner is consumed by the development and the T / C ratio decreases, the decrease is detected by a toner concentration detection sensor 85 for measuring a change in the magnetic permeability of the developer by using the inductance of the coil, and the toner is consumed. The supply toner 65 is supplied according to the toner amount. The toner density detection sensor 85 has a coil (not shown) therein.

The present image forming apparatus has the same configuration as the first image forming unit Pa, and has the second image forming unit Pb, the third image forming unit Pc, and the third image forming unit Pc having different colors of the color toner held in the developing device. Four image forming units of the fourth image forming unit Pd are provided side by side. For example, yellow toner is used for the first image forming unit Pa, magenta toner is used for the second image forming unit Pb, cyan toner is used for the third image forming unit Pc, and black toner is used for the fourth image forming unit Pd. The transfer of each color toner onto the transfer material is sequentially performed in the transfer section of each image forming unit. In this step, while the registration is being performed, each color toner is superimposed on the same transfer material by one transfer of the transfer material, and when the transfer is completed, the transfer material is separated from the transfer material carrier 68 by the separation charger 69. The sheet is sent to the fixing device 70 by a conveying means such as a conveying belt, and the final full-color image is obtained by a single fixing.

The fixing device 70 has a pair of a fixing roller 71 having a diameter of 40 mm and a pressure roller 72 having a diameter of 30 mm. The fixing roller 71 has heating means 75 and 76 therein.

The unfixed color toner image transferred onto the transfer material passes through a pressure contact portion between the fixing roller 71 and the pressure roller 72 of the fixing device 70, and is applied to the transfer material by the action of heat and pressure. Is established.

In FIG. 3, the transfer material carrier 68 is an endless belt-shaped member, which is moved in the direction of arrow e by a driving roller 80. 7
9 is a transfer belt cleaning device, 81 is a belt driven roller, and 82 is a belt static eliminator. 8
Reference numeral 3 denotes a pair of registration rollers for conveying the transfer material in the transfer material holder to the transfer material carrier 68.

The transfer means is a contact transfer in which a transfer bias can be directly applied by contacting the back surface of a transfer material carrier such as a roller-shaped transfer roller instead of the transfer blade contacting the back surface of the transfer material carrier. Means can be used.

Further, in place of the above-mentioned contact transfer means, a non-contact type in which transfer is performed by applying a transfer bias from a corona charger arranged in a non-contact manner on the back side of a generally used transfer material carrier. May be used.

However, it is more preferable to use the contact transfer means in that the amount of ozone generated when the transfer bias is applied can be controlled.

Next, an example of another image forming method of the present invention will be described with reference to FIG.

FIG. 4 is a schematic diagram showing an example of an image forming apparatus capable of performing the image forming method of the present invention.

This image forming apparatus is configured as a full-color copying machine. As shown in FIG. 4, the full-color copying machine has a digital color image reader unit 35 at the upper part and a digital color image printer unit 36 at the lower part.

In the image reader section, the original 30 is placed on an original platen glass 31 and is exposed and scanned by an exposure lamp 32 so that a reflected light image from the original 30 is condensed on a full-color sensor 34 by a lens 33 to produce a color image. Obtain a decomposed image signal. The color-separated image signal is processed by a video processing unit (not shown) through an amplifier circuit (not shown) and sent to a digital image printer unit.

In the image printer section, the photosensitive drum 1, which is an electrostatic image carrier, is, for example, an amorphous silicon or amorphous silicon photosensitive body, and is rotatably carried in the direction of the arrow. Around the photosensitive drum 1, a pre-exposure lamp 11, a corona charger 2 as a primary charging member, a laser exposure optical system 3 as a latent image forming means, a potential sensor 12,
The four developing devices 4Y, 4C, 4M, and 4K having different colors, the on-drum light amount detecting means 13, the transfer device 5A, and the cleaning device 6 are arranged.

In the laser exposure optical system 3, an image signal from the reader unit is converted into an image scan exposure light signal by a laser output unit (not shown), and the converted laser light is reflected by the polygon mirror 3a. Is projected on the surface of the photosensitive drum 1 via the lens 3b and the mirror 3c.

[0230] At the time of forming an image, the printer unit operates the photosensitive drum 1
Is rotated in the direction of the arrow, and after the charge is eliminated by the pre-exposure lamp 11, the photosensitive drum 1 is uniformly positively charged by the charger 2 to irradiate a light image E for each separation color, and the latent image is formed on the photosensitive drum 1. To form

Next, the latent image on the photosensitive drum 1 is developed by operating a predetermined developing device to form a visible image, that is, a toner image, on the photosensitive drum 1 using a resin-based positively chargeable toner. I do. The developing units 4Y, 4C, 4M, and 4K alternately approach the photosensitive drum 1 in accordance with the respective separation colors and perform development by the operation of the eccentric cams 24Y, 24C, 24M, and 24K.

The transfer device 5A includes a transfer drum 5, a transfer charger 5b, a suction charger 5c for electrostatically attracting a recording material and a suction roller 5g opposed thereto, an inner charger 5d, an outer charger 5e, It has a separation charger 5h.
The transfer drum 5 is rotatably supported so as to be rotatable, and a transfer sheet 5f, which is a recording material carrier for supporting a recording material (transfer material) in an opening area around the transfer drum 5, is integrally adjusted in a cylindrical shape. A polycarbonate film or the like is used for the transfer sheet 5f.

The recording material is conveyed from the recording material cassette 7a, 7b or 7c to the transfer drum 5 through the recording material conveyance system, and is carried on the transfer sheet 5f. Transfer drum 5
The recording material carried thereon is repeatedly conveyed to a transfer position facing the photosensitive drum 1 as the transfer drum 5 rotates, and is transferred onto the photosensitive material by the action of the transfer charger 5b while passing through the transfer position. 1 is transferred.

In the above image forming step, yellow (Y),
By repeating the process for magenta (M), cyan (C), and black (K), a color image in which four color toner images are superimposed and transferred on the recording material on the transfer drum 5 is obtained.

In the case of one-sided image formation, the recording material onto which the toner images of four colors have been transferred in this manner is separated by the action of the separation claw 8a, the separation push-up roller 8b and the separation charger 5h.
The sheet is separated from the transfer drum 5 and sent to the heat fixing device 9.
The heat fixing device 9 includes a heat fixing roller 9a having a heating unit therein and a pressure roller 9b. The full-color image carried on the recording material is fixed on the recording material by passing the recording material through the pressure contact portion between the heat fixing roller 9a and the pressure roller 9b as a heating member. That is, in this fixing step, toner color mixing, color development, and fixing to the recording material are performed to form a full-color permanent image, which is then discharged to the tray 10 to complete one full-color copy. On the other hand, the photosensitive drum 1 is subjected to the image forming process again after the residual toner on the surface is cleaned and removed by the cleaning device 6.

In the image forming method of the present invention, it is also possible to transfer a toner image developed from the electrostatic charge image formed on the latent image carrier to a recording material via an intermediate transfer member.

That is, in this image forming method, the toner image formed by developing the electrostatic image formed on the electrostatic image carrier is transferred to an intermediate transfer member, and the toner image transferred to the intermediate transfer member is Is transferred to a recording material.

An example of an image forming method using an intermediate transfer member will be specifically described with reference to FIG.

In the apparatus system shown in FIG. 5, the cyan developing device 54-1, the magenta developing device 54-2, the yellow developing device 54-3, and the black developing device 54-4 have a cyan developer and a A magenta developer having a toner, a yellow developer having a yellow toner, and a black developer having a black toner have been introduced. An electrostatic latent image is formed on a photosensitive member 51 as a latent image holding member by a latent image forming means 53 such as a laser beam. By a developing method such as a magnetic brush developing method, a non-magnetic one-component developing method or a magnetic jumping developing method,
The electrostatic charge image formed on the photoconductor 51 is developed with these developers, and a toner image of each color is formed on the photoconductor 51.
The photosensitive member 51 is a photosensitive drum or a photosensitive belt having a conductive substrate 51b and a photoconductive insulating material layer 51a such as amorphous selenium, cadmium sulfide, zinc oxide, an organic photoconductor, and amorphous silicon formed on the conductive substrate 51b. is there. The photoconductor 51 is rotated in a direction indicated by an arrow by a driving device (not shown). As the photoconductor 51, a photoconductor having an amorphous silicon photosensitive layer is preferably used.

In the charging step, there are a non-contact type with the photosensitive member 51 using a corona charger and a contact type with a contact charging member such as a roller, and both types are used. For efficient uniform charging, simplification, and low ozone generation, a contact type as shown in FIG. 5 is preferably used.

A charging roller 52 as a primary charging member is
Conductive elastic layer 5 having central core 52b and outer periphery thereof
2a as a basic configuration. Charging roller 52
Is pressed against the surface of the photoconductor 51 with a pressing force, and the photoconductor 5
The rotation follows the rotation of 1.

Preferred process conditions when a charging roller is used include a contact pressure of the roller of 5 to 500 g / cm.
In the case where a DC voltage with an AC voltage superimposed thereon is used, an AC voltage = 0.5 to 5 kVpp and an AC frequency = 50
Hz to 5 kHz, DC voltage = ± 0.2 to ± 5 kV.

Other examples of the contact charging member include a method using a charging blade and a method using a conductive brush. These contact charging members are effective in that high voltage is not required and generation of ozone is reduced.

As the material of the charging roller and the charging blade as the contact charging member, conductive rubber is preferable, and a release coating may be provided on the surface thereof. As the release coating, a nylon resin, PVDF (polyvinylidene fluoride), PVDC (polyvinylidene chloride), or a fluorine acrylic resin can be used.

The toner image on the photosensitive member is applied with a voltage (for example, ±
(0.1 to ± 5 kV). The intermediate transfer member 55 includes a pipe-shaped conductive core 55b and a medium-resistance elastic layer 55 formed on the outer peripheral surface thereof.
a. The cored bar 55b may be provided with a conductive layer (for example, conductive plating) on the surface of plastic.

The medium resistance elastic layer 55a is made of silicone rubber, Teflon rubber, chloroprene rubber, urethane rubber,
EPDM (terpolymer of ethylene propylene diene)
A conductive material such as carbon black, zinc oxide, tin oxide, or silicon carbide is mixed and dispersed in an elastic material such as to adjust the electric resistance (volume resistivity) to a medium resistance of 10 ⁵ to 10 ¹¹ Ω · cm. It is a solid or foamed layer.

The intermediate transfer member 55 is provided in parallel with the photoreceptor 51 so as to be in contact with the lower surface of the photoreceptor 51, and is arranged in the counterclockwise direction indicated by an arrow at the same peripheral speed as the photoreceptor 51. Rotate.

The first color toner image formed and carried on the surface of the photosensitive member 51 is transferred by a transfer bias applied to the intermediate transfer member 55 while passing through a transfer nip portion where the photosensitive member 51 and the intermediate transfer member 55 are in contact with each other. The intermediate transfer is sequentially performed on the outer surface of the intermediate transfer body 55 by the electric field formed in the nip area.

The untransferred toner on the photosensitive member 51 that has not been transferred to the intermediate transfer member 55 is removed by the photosensitive member cleaning member 5.
8 and is collected in the photoconductor cleaning container 59.

A transfer means is provided in parallel with the intermediate transfer body 55 and is brought into contact with the lower surface of the intermediate transfer body 55. The transfer means 57 is, for example, a transfer roller or a transfer belt. It rotates clockwise with the same peripheral speed as the arrow. The transfer means 57 may be provided so as to directly contact the intermediate transfer body 55, or a belt or the like may be provided so as to contact between the intermediate transfer body 55 and the transfer means 57.

In the case of the transfer roller, it has a basic structure including a central core bar 57b and a conductive elastic layer 57a formed on the outer periphery thereof.

A general material can be used for the intermediate transfer member and the transfer roller. By setting the volume resistivity of the elastic layer of the transfer roller smaller than the volume resistivity of the elastic layer of the intermediate transfer body, the voltage applied to the transfer roller can be reduced, and a good toner image can be formed on the transfer material. In addition, it is possible to prevent the transfer material from being wound around the intermediate transfer member. In particular, it is particularly preferable that the volume resistivity of the elastic layer of the intermediate transfer member is at least 10 times the volume resistivity of the elastic layer of the transfer roller.

The hardness of the intermediate transfer member and the transfer roller is determined by JI
It is measured according to SK-6301. The intermediate transfer member used in the present invention is preferably composed of an elastic layer belonging to the range of 10 to 40 degrees. On the other hand, the hardness of the elastic layer of the transfer roller is higher than the hardness of the elastic layer of the intermediate transfer member.
Those having a value of from -80 degrees are preferred in order to prevent the transfer material from winding around the intermediate transfer member. When the hardness of the intermediate transfer member and that of the transfer roller are reversed, a concave portion is formed on the transfer roller side, and the winding of the transfer material around the intermediate transfer member is likely to occur.

The transfer means 57 rotates the intermediate transfer member 55 at a constant speed or at a different peripheral speed. The transfer material 56 is conveyed between the intermediate transfer body 55 and the transfer means 57,
The toner image on the intermediate transfer body 55 is transferred to the surface of the transfer material 56 by applying a bias having a polarity opposite to the frictional charge of the toner to the transfer unit 57 from the transfer bias unit.

The untransferred toner remaining on the intermediate transfer member that has not been transferred to the transfer material 56 is removed by the cleaning member 6 for the intermediate transfer member.
0 and is collected in the intermediate transfer body cleaning container 62. The toner image transferred to the transfer material 56 is fixed on the transfer material 56 by the heat fixing device 61.

As the material of the transfer roller, the same material as that of the charging roller can be used. As a preferable transfer process condition, the contact pressure of the roller is 2.94 to 490.
N / m (3 to 500 g / cm) (more preferably, 19.
6 to 294 N / m), DC voltage = ± 0.2 to ± 10 k
V.

When the linear pressure as the contact pressure is less than 2.94 N / m, it is not preferable because the transfer of the transfer material and the occurrence of transfer failure are likely to occur.

For example, the conductive elastic layer 5 of the transfer roller 57
7b is an elastic material such as polyurethane rubber or EPDM (ethylene propylene diene terpolymer), and a conductive agent such as carbon black, zinc oxide, tin oxide or silicon carbide mixed and dispersed in the material to obtain an electric resistance value (volume resistivity). ) From 10 ⁶
It is a solid or foamed layer adjusted to have a medium resistance of 10 ¹⁰ Ω · cm.

The methods for measuring the properties are described below.

The particle size of the magnetic resin carrier of the present invention was determined by randomly extracting 300 or more carrier particles having a particle size of 0.1 μm or more using an optical microscope (100 to 5,000 times) and analyzing the image by Nireco Co., Ltd. The horizontal Feret diameter was measured as the carrier particle diameter by a device Luzex3,
The number average particle size is calculated. Based on the number-based particle size distribution measured under these conditions, the cumulative ratio of the number average particle size smaller than 1/2 times the diameter cumulative distribution is determined, and the cumulative value equal to or smaller than the 1/2 size diameter cumulative distribution is calculated.

The magnetic properties of the magnetic resin carrier were measured using an oscillating magnetic field type automatic magnetic property recording apparatus BHV-3 manufactured by Riken Denshi Co., Ltd.
Measure using 0. The magnetic characteristic value of the magnetic coated carrier powder is determined by creating an external magnetic field of 1 kOe and determining the intensity of magnetization at that time. The magnetic resin carrier is manufactured in a state of being packed in a cylindrical plastic container having a volume of about 0.07 cm ³ so as to be sufficiently dense. In this state, the magnetization moment is measured, the actual volume when the sample is put in is measured, and the magnetization intensity per unit volume is obtained.

The specific resistance of the magnetic resin carrier or the carrier core is measured using a measuring device shown in FIG. In cell E,
A magnetic resin carrier or core is filled, electrodes 121 and 122 are arranged so as to be in contact with the magnetic resin carrier or core filled as sample 127, a voltage is applied between the electrodes, and a current flowing at that time is measured. Find the specific resistance. In the above-mentioned measuring method, since the magnetic resin carrier or the core is a powder, a change occurs in the filling rate, and the specific resistance may change with the change. The measurement conditions of the specific resistance were as follows: the contact area S between the filled magnetic resin carrier or core and the electrode was about 2.3 cm ² , and the thickness d was about 2
mm, load 180 g on the upper electrode 22, applied voltage 100V
And

The method for measuring the particle size of the magnetic fine particles and the non-magnetic inorganic compound fine particles will be described below. The number-average particle diameter of the fine particles is determined by using a transmission electron microscope H- manufactured by Hitachi, Ltd.
Using a photographic image magnified 5000 to 20000 times by 800, 3 particles having a particle size of 0.01 μm or more
More than 00 particles are extracted, and the particle size of the fine particles is measured with the Feret diameter in the horizontal direction using an image processing analyzer Luzex3 manufactured by Nireco Co., Ltd., and averaged to calculate the number average particle size.

The measurement of the specific resistance of the fine particles conforms to the method of the specific resistance of the carrier. The cell E of FIG. 6 is filled with fine particles, and the electrode 1 is placed in contact with the fine particles filled as a sample 127.
21 and 122 are arranged, a voltage is applied between the electrodes, and a current flowing at that time is measured to obtain a specific resistance.
When the fine particles are filled, the filling is performed while rotating the upper electrode 121 right and left so that the electrode uniformly contacts the sample. In the above measurement method, the specific resistance measurement conditions are as follows: the contact area S between the filled fine particles and the electrode is about 2.3 cm ² , the thickness d is about 2 mm, the load on the upper electrode 122 is 180 g, and the applied voltage is 100 V.

A specific example of the measurement of the toner particle size will be described below.

A surfactant (alkylbenzenesulfonate) is added in an amount of 0.1 to 5 ml to 100 to 150 ml of the electrolyte solution.
And 2 to 20 mg of a measurement sample is added thereto. The electrolytic solution in which the sample was suspended was subjected to dispersion treatment for 1 to 3 minutes by an ultrasonic disperser, and the above-mentioned Coulter counter multisizer was used to adjust the volume of the electrolyte to a value of 0.1 μm based on the volume using an aperture appropriately adjusted to a toner size of 17 μm or 100 μm. 3 ~
A particle size distribution of 40 μm is to be measured. The number average particle diameter and the weight average particle diameter measured under these conditions are obtained by computer processing, and the cumulative ratio of the number average particle diameter smaller than 1/2 times the diameter cumulative distribution is calculated from the number-based particle diameter distribution,
A cumulative value equal to or smaller than the 1/2 diameter cumulative distribution is obtained. Similarly, a cumulative ratio equal to or larger than the double diameter cumulative distribution of the weight average particle diameter is calculated from the volume-based particle size distribution, and a cumulative value equal to or larger than the double diameter cumulative distribution is obtained.

A method for measuring the triboelectric charge amount will be described.

1.6 g of toner and 18.4 g of magnetic carrier
Is placed in a 50 cc polyethylene container and left open for one day under each environment. In a high-temperature and high-humidity environment, the sample is sealed after standing and the apparatus is further left for 2 hours so that the sample does not dew. Mix the powder (developer) in a metal container equipped with a 625 mesh conductive screen at the bottom, suction with a suction machine, and mix the powder with the weight difference before and after suction. The amount of triboelectric charge is determined from the potential stored in the connected capacitor. On this occasion,
The suction pressure is 250 mmHg. With this method, the triboelectric charge amount is calculated using the following equation.

Q (mC / kg) = (C × V) × (W ₁ −W ₂ ) ⁻¹ (where W ₁ is the weight before suction, W ₂ is the weight after suction, and C Is the capacity of the capacitor, and V is the potential accumulated in the capacitor.) The amount of triboelectricity of the toner in the developer at the time of durability is determined by sampling 1 g of the developer on the developing sleeve and mixing without stirring. The measurement was performed using a measuring device.

[0270]

EXAMPLES Preparation Example 1 of Coating Resin 10 parts by weight of methyl methacrylate macromer having an ethylenically unsaturated group at one end and having a weight average molecular weight of 5,000, 60 parts by weight of 2- (perfluorooctyl) -ethyl methacrylate, methyl 30 parts by weight of methacrylate is added to a four-necked flask equipped with a reflux condenser, a thermometer, a nitrogen suction tube and a stirrer, and 100 parts by weight of methyl ethyl ketone and 2.0 parts by weight of azobisisovaleronitrile are further added. 10 at 70 ° C under nitrogen flow
The graft copolymer (A) was obtained while keeping for a time. Gel Permeation Chromatogram (G
PC) has a weight average molecular weight of 70,000;
It had a main peak at a molecular weight of 40,000 and a shoulder at a molecular weight of 4,000.

In the graft copolymer A, methyl methacrylate macromer was graft-polymerized to a copolymer of 2- (perfluorooctyl) -ethyl methacrylate and methyl methacrylate.

Preparation Example 2 of Coating Resin 20 parts by weight of methyl methacrylate macromer having an ethylenically unsaturated group at one end and having a weight average molecular weight of 2,000, 60 parts by weight of 2- (perfluorooctyl) -ethyl methacrylate, methyl methacrylate 20 parts by weight were added to a four-necked flask equipped with a reflux condenser, a thermometer, a nitrogen suction tube and a stirrer, and 100 parts by weight of methyl ethyl ketone and 7.0 parts by weight of azobisisovaleronitrile were further added. 10 at 70 ° C under nitrogen stream
The graft copolymer (B) was obtained while keeping for a while. The weight average molecular weight by GPC is 10,000, and the molecular weight is 10,000.
000 and a molecular weight of 20,000
No peak was observed at 0 to 100,000.

Preparation Example 3 of Coating Resin 10 parts by weight of methyl methacrylate macromer having an ethylenically unsaturated group at one terminal and having a weight average molecular weight of 8,000, 70 parts by weight of 2- (perfluorooctyl) -ethyl methacrylate, methyl methacrylate 20 parts by weight were added to a four-necked flask equipped with a reflux condenser, a thermometer, a nitrogen suction pipe and a stirrer, and 100 parts by weight of methyl ethyl ketone and 0.7 part by weight of azobisisovaleronitrile were further added. 15 at 65 ° C under nitrogen stream
The graft copolymer (C) was obtained while keeping the time. The weight average molecular weight by GPC was 320,000, and had a main peak at a molecular weight of 80,000 and a shoulder at a molecular weight of 9,000.

Production Example 4 of Coating Resin 90 parts by weight of 2- (perfluorooctyl) -ethyl methacrylate and 10 parts by weight of methyl methacrylate were mixed with a reflux condenser, a thermometer, a nitrogen suction pipe and a stirrer with a stirrer. 100 parts by weight of methyl ethyl ketone and 2.0 parts by weight of azobisisovaleronitrile were further added, and the mixture was kept at 70 ° C. for 10 hours under a nitrogen stream to obtain a graft copolymer (D). The weight average molecular weight by GPC was 70,000, and had a main peak at a molecular weight of 40,000, but no peak or shoulder was found at a molecular weight of 2,000 to 20,000.

Example 1-50 parts by weight of phenol (hydroxybenzene)-80 parts by weight of a 37 wt% formalin aqueous solution-50 parts by weight of water-280 parts by weight of magnetite fine particles surface-treated with a titanium coupling agent (number average particle diameter of 0) .24 μm, specific resistance value 5 × 10 ⁵ Ω · cm) 120 parts by weight of α-Fe ₂ O ₃ fine particles surface-treated with a titanium coupling agent (number average particle size 0.60 μm, specific resistance value 8 × 10 ⁹⁾ 15% by weight of 28% by weight of aqueous ammonia The above materials were placed in a four-necked flask, and stirred and mixed.
The temperature was maintained at 85 ° C. for 0 minutes, and the reaction and curing were performed for 180 minutes. After cooling to 30 ° C. and addition of 500 parts by weight of water, the supernatant was removed, and the precipitate was washed with water and air-dried. Next, this was dried at 60 ° C. for 24 hours under reduced pressure (5 mmHg) to obtain a magnetic carrier core (A) using a phenol resin having a methylene unit as a binder resin. Hydroxyl groups were present on the surface of the magnetic carrier core (A).

On the surface of the obtained magnetic carrier core (A), γ-methacryloxypropyltrimethoxysilane

[0277]

Embedded image Of a 5% by weight toluene solution was applied.

The surface of the magnetic carrier core (A) is 0.1
It had been treated with weight percent of gamma-methacryloxypropyltrimethoxysilane. During the application, the toluene was volatilized while applying while continuously applying shear stress to the magnetic carrier core (A). On the surface of the magnetic carrier core (A)

[0279]

Embedded image Was confirmed to be present.

A 10% by weight toluene coating solution of the graft copolymer (A) was applied to the magnetic carrier core (A) surface-treated with γ-methacryloxypropyltrimethoxysilane. The surface of the magnetic carrier core (A) is 0.7
It was coated with the graft copolymer (A) by weight. When applying the surface of the magnetic carrier core (A) with the coating solution, the toluene was volatilized while applying while continuously applying a shearing force.

Thereafter, the mixture was cured at a temperature of 140 ° C. for 2 hours to disperse the aggregates, and then classified with a 200-mesh sieve to obtain a magnetic resin carrier (I). SF-1 of the obtained magnetic resin carrier (I) is 109, and the number average particle diameter is 33.
μm, the specific resistance value is 7.2 × 10 ¹³ Ω · cm, and the magnetization intensity at 1 kOe (σ ₁₀₀₀ )
Is 41 Am ² / kg (emu / g), the residual magnetization (σ _r ) is 3.3 Am ² / kg (emu / g), the true specific gravity is 3.71, and the bulk density is 1.87 g / g. cm ³ . Table 1 shows the physical properties of the obtained magnetic resin carrier (I).
Shown in

Comparative Example 1 The surface of the magnetic carrier core (A) not surface-treated with γ-methacryloxypropyltrimethoxysilane was directly coated with a 10% by weight toluene coating solution of the graft copolymer (A). A comparative magnetic resin carrier (i) having a carrier core surface coated with 0.7% by weight of the graft copolymer (A) was prepared. Table 1 shows the physical properties of Comparative Magnetic Resin Carrier (i).

Comparative Example 2 The surface of a magnetic carrier core (A) not surface-treated with γ-methacryloxypropyltrimethoxysilane was coated with a 10% by weight toluene coat solution of polytetrafluoroethylene (weight average molecular weight 32,000). 0.7% by weight
The comparative magnetic resin carrier (ii) in which the carrier core surface was coated with the polytetrafluoroethylene was prepared. Table 1 shows the physical properties of Comparative Magnetic Resin Carrier (ii).

Comparative Example 3 The surface of the magnetic carrier core (A) was treated with a toluene solution of γ-methacryloxypropyltrimethoxysilane in the same manner as in Example 1, and then treated with a toluene coat solution of polytetrafluoroethylene. A comparative magnetic resin carrier (iii) coated in the same manner as in Example 2 and coated with the carrier core surface with 0.7% by weight of polytetrafluoroethylene was prepared. Comparative magnetic resin carrier (ii
Table 1 shows the physical properties of i).

Comparative Example 4 A silicone resin (SR241, manufactured by Dow Corning Toray Co., Ltd.) was applied to the surface of a magnetic carrier core (A) which had not been surface-treated with γ-methacryloxypropyltrimethoxysilane.
A comparative magnetic resin carrier (iv) having a carrier core surface coated with 0.7% by weight of a silicone resin was prepared by applying the toluene solution of 0). Table 1 shows the physical properties of the comparative magnetic resin carrier (iv).

Comparative Example 5 The surface of a magnetic carrier core was treated with a toluene solution of γ-methacryloxypropyltrimethoxysilane in the same manner as in Example 1, and then coated with a toluene solution of a silicone resin in the same manner as in Comparative Example 4. And a comparative magnetic resin carrier (v) having a carrier core surface coated with 0.7% by weight of a silicone resin. Table 1 shows the physical properties of the comparative magnetic resin carrier (v).

Comparative Example 6 The surface of a ferrite core particle having a number average particle size of 34 μm was treated in the same manner as in Example 1 with 0.1% by weight of γ-methacryloxypropyltrimethoxysilane and 0.7% by weight of a graft copolymer ( A comparative magnetic ferrite carrier (vi) coated with A) was prepared. The comparative magnetic ferrite carrier (vi) had a true specific gravity of 4.90. Table 1 shows the physical properties of the comparative magnetic ferrite carrier (vi).

Comparative Example 7 The surface of iron core particles having a number average particle diameter of 34 μm was treated in the same manner as in Example 1 by using 0.1% by weight of γ-methacryloxypropyltrimethoxysilane and 0.7% by weight of a graft copolymer ( Comparative magnetic iron carrier coated with A) (vii)
Was prepared. The comparative magnetic iron carrier (vii) had a true specific gravity of 5.00. Table 1 shows the physical properties of the comparative magnetic iron carrier (vii).

Comparative Example 8 The number average particle size was 0.19 μm and the specific resistance was 3 × 1.
0 ⁴ Omega · cm magnetic carrier core except using magnetite particles is surface-treated with a titanium coupling agent in the same manner as in Example 1 (a) was prepared, further,
In the same manner as in Example 1, a comparative magnetic resin carrier (viii) coated with 0.1% by weight of γ-methacryloxypropyltrimethoxysilane and 0.7% by weight of the graft copolymer (A) was prepared. . Comparative magnetic resin carrier (v
In iii), the specific resistance was 1.0 × 10 ⁹ Ω · cm. Table 1 shows the physical properties of the comparative magnetic resin carrier (viii).

Comparative Example 9 The number average particle diameter was 0.35 μm, and the specific resistance was 3 × 1.
0 ⁸ Ω · cm of the magnetite fine particles that are treated with a titanium coupling agent used 200 parts by weight, except that the α-Fe ₂ O ₃ which has been treated with a titanium coupling agent used 200 parts by weight of exemplary A magnetic carrier core (b) was prepared in the same manner as in Example 1, and 0.1% by weight of γ-methacryloxypropyltrimethoxysilane and 0.7% by weight of a graft copolymer were obtained in the same manner as in Example 1. A comparative magnetic resin carrier (ix) coated with (A) was prepared. The specific resistance value of the comparative magnetic resin carrier (ix) is 7.0.
× 10 ¹⁵ Ω · cm. Comparative magnetic resin carrier (i
Table 1 shows the physical properties of x).

Comparative Example 10 The surface of the magnetic carrier core (A) was treated with a 5% by weight solution of vinylmethoxysilane in toluene, and treated with 0.1% by weight of vinyltrimethoxysilane. ) Is prepared, and then coated with a toluene solution of the graft copolymer (A) in the same manner as in Example 1 to obtain a comparative magnetic resin coated with 0.7% by weight of the graft copolymer (A). A carrier (x) was prepared. Table 1 shows the physical properties of the comparative magnetic resin carrier (x).

Example 2 Using 350 parts by weight of magnetite fine particles surface-treated with a titanium coupling agent, and using 50 parts by weight of α-Fe ₂ O ₃ treated with a titanium coupling agent A magnetic carrier core (B) was prepared in the same manner as in Example 1 except that
A magnetic resin carrier (II) coated with methacryloxypropyltrimethoxysilane and a graft copolymer (A) was prepared. The obtained magnetic resin carrier (I
Table 1 shows the physical properties of I).

Example 3 Using 385 parts by weight of magnetite fine particles surface-treated with a titanium coupling agent, and using 15 parts by weight of α-Fe ₂ O ₃ treated with a titanium coupling agent A magnetic carrier core (C) was prepared in the same manner as in Example 1 except that
A magnetic resin carrier (III) coated with methacryloxypropyltrimethoxysilane and the graft copolymer (A) was prepared. The obtained magnetic resin carrier (I
Table 1 shows the physical properties of II).

Example 4 Using 200 parts by weight of magnetite fine particles surface-treated with a titanium coupling agent and 200 parts by weight of α-Fe ₂ O ₃ treated with a titanium coupling agent A magnetic carrier core (D) was prepared in the same manner as in Example 1 except that
Preparation of a magnetic resin carrier (IV) coated with methacryloxypropyltrimethoxysilane and a graft copolymer (A). The obtained magnetic resin carrier (I
Table 1 shows the physical properties of V).

Example 5 Using 150 parts by weight of magnetite fine particles surface-treated with a titanium coupling agent, and using 250 parts by weight of α-Fe ₂ O ₃ treated with a titanium coupling agent A magnetic carrier core (E) was prepared in the same manner as in Example 1 except that
-A magnetic resin carrier (V) coated with methacryloxypropyltrimethoxysilane and the graft copolymer (A) was prepared. Table 1 shows the physical properties of the obtained magnetic resin carrier (V).

Example 6 Using 110 parts by weight of magnetite fine particles surface-treated with a titanium coupling agent and 290 parts by weight of α-Fe ₂ O ₃ treated with a titanium coupling agent A magnetic carrier core (F) was prepared in the same manner as in Example 1 except that
-A magnetic resin carrier (VI) coated with methacryloxypropyltrimethoxysilane and the graft copolymer (A) was prepared. The obtained magnetic resin carrier (V
Table 1 shows the physical properties of I).

Example 7 Magnetic Cu—Zn ferrite fine particles treated with a titanium coupling agent instead of magnetite fine particles (number-average particle diameter 0.35 μm, specific resistance 2.0 × 10 ⁷ Ω · cm)
Except for using 280 parts by weight, a magnetic carrier core (G) was prepared in the same manner as in Example 1 and further treated with γ-methacryloxypropyltrimethoxysilane and the graft copolymer (A) in the same manner as in Example 1. A coated magnetic resin carrier (VII) was prepared. Table 1 shows the physical properties of the magnetic resin carrier (VII) obtained.

Example 8 Magnetic Mn—Mg ferrite fine particles treated with a titanium coupling agent instead of magnetite fine particles (number-average particle diameter 0.42 μm, specific resistance 6.0 × 10 ⁷ Ω · cm)
A magnetic carrier core (H) was prepared in the same manner as in Example 1 except that 280 parts by weight were used, and γ-methacryloxypropyltrimethoxysilane and a graft copolymer (A) were further prepared in the same manner as in Example 1. A coated magnetic resin carrier (VIII) was prepared. Table 1 shows the physical properties of the obtained magnetic resin carrier (VIII).

Example 9 Nickel microparticles treated with a titanium coupling agent instead of magnetite microparticles (number average particle diameter 0.47 μm)
m, specific resistance value 2.5 × 10 ⁶ Ω · cm) Except for using 280 parts by weight, a magnetic carrier core (I) was prepared in the same manner as in Example 1; Magnetic resin carrier (I) coated with methacryloxypropyltrimethoxysilane and graft copolymer (A)
X) was prepared. Table 1 shows the physical properties of the obtained magnetic resin carrier (IX).

Example 10 Fine alumina powder treated with a titanium coupling agent instead of α-Fe ₂ O ₃ (number average particle size 0.37 μm,
A magnetic carrier core (J) was prepared in the same manner as in Example 1 except that 120 parts by weight of the specific resistance value (2 × 10 ¹⁰ Ω · cm) was used, and γ-methacryloxypropyltriethyl was prepared in the same manner as in Example 1. A magnetic resin carrier (X) coated with methoxysilane and the graft copolymer (A) was prepared. Table 1 shows the physical properties of the obtained magnetic resin carrier (X).

Example 11 γ-methacryloxypropyltrimethoxysilane and graft copolymer were prepared in the same manner as in Example 1 except that the graft copolymer (B) was used instead of the graft copolymer (A). A magnetic resin carrier (XI) coated with the combination (B) was prepared. The obtained magnetic resin carrier (X
Table 1 shows the physical properties of I).

Example 12 γ-methacryloxypropyltrimethoxysilane and graft copolymer were prepared in the same manner as in Example 1 except that the graft copolymer (C) was used instead of the graft copolymer (A). A magnetic resin carrier (XII) coated with the union (C) was prepared. Table 1 shows the physical properties of the obtained magnetic resin carrier (XII).

Example 13 γ-methacryloxypropyltrimethoxysilane and graft copolymer were prepared in the same manner as in Example 1 except that the graft copolymer (D) was used instead of the graft copolymer (A). A magnetic resin carrier (XIII) coated with the union (D) was prepared. Table 1 shows the physical properties of the obtained magnetic resin carrier (XIII).

Example 14 50 parts by weight of styrene monomer 12 parts by weight of 2-ethylhexyl acrylate 280 parts by weight of magnetite fine particles surface-treated with a titanium coupling agent (number average particle diameter 0.24 μm, specific resistance 5 × 10 5 ^{5 Ω} · cm) · titanium coupling α-Fe ₂ O ₃ fine particles 120 parts by weight of surface-treated with agent (number average particle diameter 0.60 .mu.m, the specific resistance value 8 × 10 ⁹ Ω · cm) above materials after mixing The mixture was heated to 70 ° C., and the monomer composition prepared by adding 0.7 parts by weight of azobisisobutyronitrile was dispersed in a 1% by weight aqueous solution of polyvinyl alcohol, followed by forming with a homogenizer (4500 rpm) for 10 minutes. Then, polymerization was carried out at 70 ° C. for 10 hours while stirring with a paddle stirrer to produce a magnetic carrier core (K). The generated magnetic carrier core (K) was filtered from the aqueous polyvinyl alcohol solution, washed, and dried.

A magnetic resin carrier (XIV) coated with γ-methacryloxypropyltrimethoxysilane and the graft copolymer (A) was prepared in the same manner as in Example 1 using the magnetic carrier core (K). . Table 1 shows the physical properties of the obtained magnetic resin carrier (XIV).

Example 15 Styrene-butyl acrylate copolymer crosslinked with divinylbenzene (copolymerization weight ratio = 83: 17: 0.
5; weight average molecular weight 350,000) 50 parts by weight, 280 parts by weight of magnetite fine particles treated with the titanium coupling agent used in Example 1, and 120 parts by weight of α-Fe ₂ O ₃ treated with the titanium coupling agent Were melt-kneaded at a temperature of 135 ° C., and the kneaded material was cooled and pulverized, and the pulverized material was classified to produce a magnetic carrier core (L). Using the magnetic carrier core (L), a magnetic resin carrier (XV) coated with γ-methacryloxypropyltrimethoxysilane and the graft copolymer (A) was prepared in the same manner as in Example 1. Table 1 shows the physical properties of the obtained magnetic resin carrier (XV).

Example 16 A toluene solution in which γ-methacryloxypropyltrimethoxysilane and the graft copolymer (A) were dissolved was applied to the magnetic carrier core (A), and γ-methacryloxypropyltriethoxysilane was applied. A magnetic resin carrier (XVI) coated with 0.1% by weight and 0.7% by weight of the graft copolymer (A) was prepared. Table 1 shows the physical properties of the obtained magnetic resin carrier (XVI).

[0308]

[Table 1]

[0309]

[Table 2]

Toner Production Example 1 450 parts by weight of a 0.1 M Na ₃ PO ₄ aqueous solution was added to 710 parts by weight of ion-exchanged water, and heated to 60 ° C.
1300 using a homo homomixer (manufactured by Tokushu Kika Kogyo)
Stirred at rpm. To this, 68 parts by weight of a 1.0 M CaCl ₂ aqueous solution was gradually added to obtain an aqueous medium containing Ca ₃ (PO ₄ ) ₂ . 160 parts by weight of styrene 34 parts by weight of n-butyl acrylate 12 parts by weight of copper phthalocyanine pigment 2 parts by weight of a quaternary ammonium salt represented by the following formula

[0311]

Embedded image ・ Styrene-aminoacryl copolymer 10 parts by weight (peak molecular weight 8500, Mw 220,000) ・ Monoester wax 20 parts by weight (Mw: 500, Mn: 400, Mw / Mn: 1.25, melting point: 69 ° C., viscosity: 6.5 mPa · s, Vickers hardness: 1.1, SP value: 8.6)

The above-mentioned material was heated to 60 ° C., and 2,000 rpm using a TK homomixer (manufactured by Tokushu Kika Kogyo).
To dissolve and disperse uniformly. In addition, polymerization initiator 2,
2'-azobis (2,4-dimethylvaleronitrile) 1
0 g was dissolved to prepare a polymerizable monomer composition. The polymerizable monomer composition was charged into the aqueous medium, and the mixture was heated at 60 ° C. and N ₂
Under an atmosphere, the mixture was stirred at 10,000 rpm for 10 minutes with a CLEAR MIXER (manufactured by M Technique Co., Ltd.) to granulate the polymerizable monomer composition. Thereafter, the temperature was raised at 80 ° C. while stirring the aqueous medium with a paddle stirring blade, and a polymerization reaction was carried out for 10 hours while maintaining the pH at 6.

After completion of the polymerization reaction, the mixture was cooled, hydrochloric acid was added to dissolve calcium phosphate, and then filtered, washed with water and dried to obtain polymer particles (toner particles).

The obtained polymer particles contained 8.4 parts by weight of a monoester wax per 100 parts by weight of the binder resin, and the wax was removed by a tomography of the polymer particles using a transmission electron microscope (TEM). A core-shell structure encapsulated in the shell resin layer was confirmed.

The binder resin of the polymer particles obtained was S
The P value was 19 and the Tg was 60 ° C.

To 100 parts by weight of the obtained polymer particles (toner particles), the following three external additives were externally added, and after the external addition, coarse particles were removed with a 330-mesh sieve, and then positively charged. Cyan toner No. 1 was obtained. Cyan toner No. Table 3 shows the physical properties of No. 1.

(1) First hydrophobic silica fine powder 0.3 part by weight: BET specific surface area 200 m ² / g Number average particle diameter 12 nm 20 parts by weight of γ-aminopropyltrimethoxysilane with respect to 100 parts by weight of silica fine powder Part, then treated with 10 parts by weight of amino-modified silicone oil.

(2) Second hydrophobic silica fine powder 0.7 parts by weight: BET specific surface area 50 m ² / g Number average particle diameter 30 nm 10 parts by weight of γ-aminopropyltrimethoxysilane with respect to 100 parts by weight of silica fine powder Hydrophobized part.

(3) Hydrophobic titanium oxide fine powder 0.4 part by weight: BET specific surface area 100 m ² / g Number average particle diameter 45 nm Hydrophobized with 10 parts by weight of isobutyltrimethoxysilane to 100 parts by weight of titanium oxide fine powder What was processed.

Toner Production Example 2 An aqueous medium having a higher Ca (PO ₄ ) ₂ content than that of Toner Production Example 1 was used, and the rotational speed of the Clare mixer was set at 15.0.
Polymer particles (toner particles) were prepared in the same manner as in Production Example 1 of the toner except that the rotation speed was changed to 00 rpm, and an external additive was externally added in the same manner as in Production Example 1 of the toner. No. 2 was prepared. Cyan toner No. Sample No. 2 had a weight average particle size of 2.8 μm. Cyan toner No.
Table 3 shows the physical properties of No. 2.

Toner Production Example 3 An aqueous medium having a lower content of Ca (PO ₄ ) ₂ than in Production Example 1 of the toner was used, and the rotational speed of the Clare mixer was set at 6,0.
Polymer particles (toner particles) were prepared in the same manner as in Production Example 1 of the toner except that the rotation speed was changed to 00 rpm, and an external additive was externally added in the same manner as in Production Example 1 of the toner. No. 3 was prepared. Cyan toner No. 3 had a weight average particle size of 10.1 μm. Cyan toner No.
Table 3 shows the physical properties of No.3.

Toner Production Example 4 The following external additives were externally added to the polymer particles (toner particles) obtained in Toner Production Example 1 to form a positively chargeable cyan toner No. 4
Was prepared. The obtained cyan toner No. Table 3 shows the physical properties of the sample No. 4.

1.4 parts by weight of hydrophobic titanium oxide fine powder: BET specific surface area: 100 m ² / g Number average particle diameter: 45 nm 100 parts by weight of titanium oxide fine powder were subjected to hydrophobic treatment with 10 parts by weight of isobutyltrimethoxysilane. .

Toner Production Example 5 The following external additives were externally added to the polymer particles (toner particles) obtained in Toner Production Example 1, and positively charged cyan toner No. 1 was obtained. 5
Was prepared. The obtained cyan toner No. Table 3 shows the physical properties of No. 5.

(1) 0.3 parts by weight of hydrophilic silica fine powder: BET specific surface area: 200 m ² / g Number average particle diameter: 12 nm (2) 0.7 parts by weight of hydrophilic silica fine powder: BET specific surface area: 50 m ² / g Number average particle diameter 30 nm (3) Hydrophobic titanium oxide fine powder 0.4 part by weight: BET specific surface area 100 m ² / g Number average particle diameter 45 nm 100 parts by weight of titanium oxide fine powder and 10 parts by weight of isobutyltrimethoxysilane Hydrophobized.

Production Example 6 of Toner 16% by mole of terephthalic acid 18% by mole of fumaric acid 15% by mole of trimellitic anhydride 30% by mole of derivative A of bisphenol A

[0327]

Embedded image -Bisphenol A derivative B 18 mol%

[0328]

Embedded image

These are subjected to condensation polymerization to obtain Mn = 5000,
Mw = 38000, Tg = 60 ° C., acid value = 20 mg KO
A polyester resin having an H / g and an OH value of 16 mgKOH / g was obtained. 100 parts by weight of the polyester resin obtained above 4 parts by weight of a phthalocyanine pigment 4 parts by weight of a colorless quaternary ammonium salt are sufficiently premixed by a Henschel mixer, melt-kneaded by a twin-screw extruder, cooled, and then hammered. The mixture was roughly pulverized to about 1 to 2 mm using a mill, and then finely pulverized by a pulverizer using an air jet method. The obtained finely pulverized product was classified to obtain positively triboelectrically-chargeable cyan toner particles having a weight average particle size of 6.8 μm.

To the obtained cyan toner particles, three kinds of external additives were externally added in the same manner as in Example 1 to obtain a positively chargeable cyan toner N
o. 6 was prepared. Cyan toner No. Table 3 shows the physical properties of 6
Shown in

Toner Production Example 7 Magenta polymer particles (toner particles) were obtained in the same manner as in Toner Production Example 1, except that a quinacridone pigment was used instead of copper phthalocyanine. Three kinds of external additives were externally added to the obtained polymer particles in the same manner as in Example 1 to prepare a positively chargeable magenta toner. Table 3 shows the physical properties of the magenta toner.

Toner Production Example 8 Instead of copper phthalocyanine, C.I. I. Except that Pigment Yellow 93 was used, yellow polymer particles (toner particles) were obtained in the same manner as in Production Example 1 of the toner. Three kinds of external additives were externally added to the obtained polymer particles in the same manner as in Example 1 to prepare a positively chargeable yellow toner. Table 3 shows the physical properties of the yellow toner.

Toner Production Example 9 Black polymer particles (toner particles) were obtained in the same manner as in Toner Production Example 1 except that carbon black was used instead of copper phthalocyanine. Three kinds of external additives were externally added to the obtained polymer particles in the same manner as in Example 1 to prepare a positively chargeable black toner. Table 3 shows the physical properties of the black toner.

[0334]

[Table 3]

Example 17 92 parts by weight of carrier (I) and cyan toner No. No. 1 and 8 parts by weight of the two-component developer No. 1 1 was prepared.

Comparative Examples 11 to 20 92 parts by weight of the comparative carrier (i) and the cyan toner no.
1 was mixed with 8 parts by weight of Comparative Developer No. 1 in the same manner as in Example 17. 1 was prepared.

Similarly, the comparison carriers (ii) to (x) and cyan toner No. 1 and Comparative Two-Component Developer No. 1 2 to 10 were prepared.

Examples 18 to 32 Carriers (II) to (XVI) and cyan toner Nos.
In the same manner as in Example 17 except that the two-component developer No. 1 was used. 2 to 16 were prepared.

Example 33 92 parts by weight of carrier (I) and cyan toner No. 2 and 8 parts by weight of the two-component developer No. 2 in the same manner as in Example 17. 17 was prepared.

Examples 34 to 37 Carrier (I) and cyan toner no. In the same manner as in Example 17 except that the two-component developer Nos. 18 to 21 were prepared.

Examples 38 to 40 In the same manner as in Example 17 except that the carrier (I), magenta toner, yellow toner and black toner were used, the two-component developer Nos. 22 to 24 were prepared.

The two-component developer No. Nos. 1 to 24 and comparative two-component developer Nos. Table 4 shows the triboelectric charging characteristics of the toners 1 to 10.

[0343]

[Table 4]

Example 41 The carrier (I) prepared in Example 17 and the cyan toner N
o. And two-component developer No. 1 1 was introduced into the developing device 4 shown in FIG. Commercially available digital copier (GP30F, manufactured by Canon Inc., print speed 30 sheets / min)
Fig. 1
The developing device 4 shown in FIG. As a developing bias applied to the developing sleeve, a blank pulse shown in FIG. 2 was used.
The following magnetic particles 23 were used for the magnetic brush charging device for charging the amorphous silicon photosensitive drum.

Preparation of Magnetic Particles 5 parts by weight of MgO, 8 parts by weight of MnO, 4 parts by weight of SrO,
After 83 parts by weight of e ₂ O ₃ were each atomized, water was added and mixed, the mixture was granulated, fired at 1300 ° C., the particle size was adjusted, and ferrite magnetic particles having an average particle size of 28 μm (σ
₁₀₀₀ is 60 Am ² / kg, coercive force is 55 Oersted)
I got

A mixture of 100 parts by weight of the above magnetic particles and 10 parts by weight of isopropoxytriisostearoyl titanate in 99 parts by weight of hexane / 1 part by weight of water was processed so that the processing amount was 0.1 part by weight. The treatment yielded magnetic particles.

The magnetic particles have a volume resistance of 3 × 10 ⁷ Ω.
Cm and the weight loss on heating was 0.1 part by weight.

In the charging device, the photosensitive drum 1 is rotated in the counter direction at a peripheral speed of 120% of the peripheral speed of the photosensitive member, and a DC / AC electric field (+700 V, 1 kHz / 1.
2 kV _PP ) was applied thereto to charge the photosensitive drum 1.
The development contrast was set to 200 V, and the reversal contrast to fog was set to +150 V.

In the heat and pressure fixing device, a heating roller coated with a PFA resin to a thickness of 1.2 μm was used, and a PFA resin was coated to a thickness of 1.2 μm as the pressure roller.
Was used. The silicone oil applying means was removed from the heat and pressure fixing device, and oilless fixing was performed.

For image evaluation, an original image having an image area of 30% was digitally processed, a digital latent image was formed as an electrostatic image on an amorphous photosensitive drum, and the electrostatic image was formed using a positively chargeable toner by a reversal developing method. Was developed to form a cyan toner image.

Normal temperature and normal humidity (temperature 23 ° C., humidity 65% R
H), normal temperature and low humidity (temperature 23 ° C., humidity 10% RH), low temperature and low humidity (temperature 15 ° C., humidity 10% RH), and high temperature and high humidity (temperature 32.5 ° C., humidity 85% RH), respectively. An image output test of 30,000 sheets was performed. Tables 5 to 8 show the evaluation results.

An evaluation method is described below.

Image Density Image density was measured using a Macbeth densitometer RD918 type (Macbeth) equipped with an SPI filter.
the Densitometer RD918manu
facted by Macbeth Co. ) Was measured as the relative density of the image formed on plain paper.

A solid white image was formed on the carrier and a portion of the photosensitive drum between the developing section and the cleaner section was sampled by closely attaching a transparent adhesive tape to the sample, and was adhered on a photosensitive drum of 5 cm × 5 cm. Then, the number of magnetic carrier particles is counted, and the number of adhered carrier particles per 1 cm ² is calculated. A: less than 5 B: less than 5 to 10 C: less than 10 to 20 D: 20 or more

The average reflectance Dr (%) of plain paper before fog image formation was measured using a reflectometer (“REFLECTOME” manufactured by Tokyo Denshoku Co., Ltd.).
TER ODEL TC-6DS "). On the other hand, a solid white image was formed on plain paper, and the reflectance Ds (%) of the solid white image was measured. Fog (%)
Is calculated from the following equation: Fog (%) = Dr (%)-Ds (%) A: Less than 0.4% B: 0.4 to less than 0.8% C: 0.8 to less than 1.2% D: 1.2 to less than 1.8% E: 1.8% or more

Evaluation of Toner Scattering After a 30,000-sheet copy test was performed in a high-temperature, high-humidity environment, toner scattering in the apparatus was evaluated according to the following evaluation criteria. A: There is no scattering at all. B: A level with practically no problem, though there is some scattering. C: A level in which a large amount of scattered toner is present in the machine but has little effect on the image. D: Scattering is considerable and the image is contaminated, which is a practically problematic level. E: Scattering is severe.

Carrier Contamination (Degree of Spent) After a copy test of 30,000 sheets was performed in a normal temperature and low humidity environment, the surface of the magnetic carrier in the developing device was evaluated by SEM observation under the following evaluation criteria. A: There is no contamination at all. B: Slight contamination but no practical problem. C: A level in which a large amount of contaminated toner is present in the carrier, but has little effect on the image. D: Contamination is considerable, affecting the image and causing practical problems. E: Stain and image deterioration are severe.

Evaluation of Line Scattering A line image having a width of 1 mm was copied in each environment and evaluated according to the following evaluation criteria. A: There is no scattering at all. B: Slight scattering but no problem in practical use. C: Scattering is considerable, affecting the image and causing a practical problem. E: Scattering and image deterioration are severe.

Examples 42 to 61 The two-component developer Nos. 2
An image output test was performed in the same manner as in Example 41 using Sample Nos. 21 to 21.

Tables 5 to 8 show the evaluation results.

Comparative Examples 21 to 30 Comparative two-component developers N prepared in Comparative Examples 11 to 20
o. An image output test was performed in the same manner as in Example 41 using Samples 1 to 10.

Tables 5 to 8 show the evaluation results.

Embodiment 62 Each of the developing devices of the full-color image forming apparatus shown in FIG. Two-component developer N having 1
o. 1, two-component developer containing magenta toner
22, a two-component developer having a yellow toner; 2
No. 3 or a two-component developer having a black toner. 2
No. 4 was introduced and an image output test was performed in a full-color mode. As a result, a good full-color image was obtained, and the durability and environmental stability of a large number of sheets were good.

[0364]

[Table 5]

[0365]

[Table 6]

[0366]

[Table 7]

[0367]

[Table 8]

[0368]

Industrial Applicability The magnetic fine particle-dispersed resin carrier of the present invention is suitable for imparting triboelectric charge to a positively chargeable toner, hardly causes carrier contamination by the toner and external additives, and has a small load on the toner. It is excellent in the durability of a large number of sheets, and can maintain stable charging characteristics to the toner even under each environment.

[Brief description of the drawings]

FIG. 1 is a schematic view illustrating a preferred example of an image forming method of the present invention.

FIG. 2 is a diagram showing an alternating electric field used in Example 1.

FIG. 3 is a schematic explanatory view showing an example of a full-color image forming method.

FIG. 4 is a schematic explanatory view showing another example of the image forming apparatus for performing the image forming method of the present invention.

FIG. 5 is a schematic explanatory view showing another example of the image forming apparatus for performing the image forming method of the present invention.

FIG. 6 is a schematic diagram of a cell used for measuring a volume resistance value.

DESCRIPTION OF THE SYMBOLS 1 Electrostatic image carrier (photosensitive drum) 4 Developing device 11 Developer carrier (developing sleeve) 12 Magnet roller 13, 14 Developer transport screw 15 Regulator blade 17 Partition 18 Replenishment toner 19 Developer 19 a Toner 19b Carrier 20 Supply port 21 Magnet roller 22 Transport sleeve 23 Magnetic particles 24 Laser beam 25 Transfer material (recording material) 26 Bias applying means 27 Transfer blade 28 Toner density detection sensor 61a Photosensitive drum 62a Primary charger 63a Developing device 64a Transfer blade 65a Replenishing toner 67a Laser beam 68 Transfer material carrier 69 Separation charger 70 Fixing unit 71 Fixing roller 72 Pressure roller 73 Web 75, 76 Heating means 79 Transfer belt cleaning device 80 Driving roller 81 Belt driven Over La 82 belt discharger 83 registration rollers 85 toner concentration detecting sensor 121 lower electrode 122 upper electrode 123 insulator 124 ammeter 125 voltmeter 126 power supply 127 sample 128 the guide ring

──────────────────────────────────────────────────の Continued on the front page (51) Int.Cl. ⁷ Identification FI FI Theme Court ゛ (Reference) G03G 9/10 351 15/08 507X (72) Inventor Kenji Okado 3-30-2 Shimomaruko, Ota-ku, Tokyo F-term (reference) in Canon Inc. 2H005 AA06 AA08 AA15 AA21 AB06 BA03 BA05 BA06 BA11 BA15 CA02 CA07 CA08 CA11 CA14 CA15 CA25 CA26 CA28 CB03 CB04 CB07 CB13 DA03 EA01 EA02 EA05 EA06 EA07 EA10 AD02 AD03 AD03 AD03 GA13 GA17

Claims (145)

[Claims] 1. A magnetic fine particle-dispersed resin carrier in which the surface of a carrier core in which magnetic fine particles are dispersed in a first resin is coated with a second resin. , The true specific gravity is 2.
5 to 4.5, and 1000 × (10 ³ / 4π) · A
/ Mag (1000 oersted) magnetic field (σ ₁₀₀₀ ) measured in a magnetic field of 15 to 60 Am ² / kg (emu).
/ G) and is, residual magnetization (sigma _r) is 0.1~20Am ² /
kg (emu / g), the specific resistance value is 5 × 10 ^{11 to} 5 × 10 ¹⁵ Ω · cm, and (b) the first resin forming the carrier core has a methylene unit in the polymer chain. (-CH ₂ -) has a second resin coating the surface of the (c) a carrier core, fluoroalkyl unit, a methylene unit (-
CH ₂ -) and having at least an ester unit, (d) the surface of the carrier core, (i) a second resin and a coupling agent having at least a methylene unit (however, a coupling agent having a methylene unit and an amino group Or (ii) after a surface treatment with a coupling agent having at least a methylene unit (excluding a coupling agent having a methylene unit and an amino group). A magnetic fine particle-dispersed resin carrier, which is coated with a second resin. 2. The magnetic fine particle-dispersed resin carrier according to claim 1, wherein the carrier core has a true specific gravity of 2.5 to 4.5. 3. The magnetic fine particle-dispersed resin carrier according to claim 1, wherein the carrier core contains magnetic fine particles and nonmagnetic inorganic compound fine particles. 4. The magnetic fine particle-dispersed resin carrier according to claim 3, wherein the magnetic fine particles and the nonmagnetic inorganic compound fine particles are contained in a total amount of 70 to 99% by weight (based on the carrier). 5. The magnetic fine particle-dispersed resin carrier according to claim 3, wherein the magnetic fine particles and the nonmagnetic inorganic compound fine particles are contained in a total amount of 80 to 99% by weight (based on the carrier). 6. The non-magnetic inorganic compound fine particles have a higher specific resistance than the magnetic fine particles, and the number average particle diameter of the non-magnetic inorganic compound fine particles is larger than the number average particle diameter of the magnetic fine particles. 3. The magnetic fine particle dispersed resin carrier according to 1. 7. The magnetic fine particle-dispersed resin carrier according to claim 3, wherein the magnetic fine particles are contained in an amount of 30 to 95% by weight based on the total amount of the magnetic fine particles and the nonmagnetic inorganic compound fine particles. 8. The magnetic fine particle-dispersed resin carrier according to claim 1, wherein the magnetic fine particles are magnetic iron oxide fine particles. 9. The magnetic fine particle-dispersed resin carrier according to claim 3, wherein the nonmagnetic inorganic compound fine particles are nonmagnetic iron oxide fine particles. 10. The magnetic fine particle-dispersed resin carrier according to claim 1, wherein the magnetic fine particles are magnetic ferrite fine particles containing at least an iron element and a magnesium element. 11. The magnetic fine particle-dispersed resin carrier according to claim 1, wherein the magnetic fine particles are magnetite fine particles. 12. The magnetic fine particle-dispersed resin carrier according to claim 3, wherein the nonmagnetic inorganic compound fine particles are fine particles of hematite (α-Fe ₂ O ₃ ). 13. The carrier has a number average particle size of 15 to 6.
The magnetic fine particle-dispersed resin carrier according to any one of claims 1 to 12, wherein the magnetic fine particles have a number average particle size (r _a ) of 0.02 to 2 µm. 14. The magnetic fine particles have a number average particle diameter (r _a ) of 0.02 to 2 μm, the nonmagnetic inorganic compound fine particles have a number average particle diameter (r _b ) of 0.05 to 5 μm, and r _b
Magnetic fine particle-dispersed resin carrier according to any one of r 1.5 times or more _a greater claims 3 to 13. 15. The carrier has a true specific gravity of 3.0 to 4.0.
15. The magnetic fine particle-dispersed resin carrier according to any one of claims 1 to 14, wherein 16. The carrier has a residual magnetization (σ _r ) of 0.
^{3~10Am 2 / kg (emu / g} ) of magnetic fine particle-dispersed resin carrier according to any one of claims 1 to 15. 17. The carrier has a shape factor SF-1 of 10
The magnetic fine particle-dispersed resin carrier according to any one of claims 1 to 16, wherein the number is from 0 to 130. 18. The first resin is a vinyl resin, a polyester resin, an epoxy resin, a phenol resin, a urea resin,
18. The magnetic fine particle-dispersed resin carrier according to claim 1, which is a resin having a methylene unit selected from the group consisting of a polyurethane resin, a polyimide resin, a cellulose resin, and a polyether resin. 19. The magnetic fine particle-dispersed resin carrier according to claim 1, wherein the first resin is a thermosetting resin. 20. The magnetic fine particle-dispersed resin carrier according to claim 1, wherein the first resin is a thermoplastic resin having a methylene unit. 21. The magnetic fine particle-dispersed resin carrier according to claim 1, wherein the first resin is a phenol resin having a methylene unit. 22. The second resin has the following formula: [In the formula, m represents an integer of 0 to 20. And a perfluoroalkyl unit represented by the formula:
The magnetic fine particle-dispersed resin carrier according to any one of the above. 23. The second resin has the following formula: [Wherein, m represents an integer of 0 to 20, and n represents 1 to 15
Indicates an integer. And a unit represented by the formula:
23. A magnetic fine particle-dispersed resin carrier according to any one of the above items. 24. The second resin, wherein: [Wherein, m represents an integer of 0 to 20, and n represents 1 to 15
Indicates an integer. And a unit represented by the formula:
24. The magnetic fine particle-dispersed resin carrier according to any one of items 23 to 23. 25. The second resin, wherein: [Wherein, m represents an integer of 0 to 20, and n represents 1 to 15
Indicates an integer. And a unit represented by the formula:
25. The magnetic fine particle-dispersed resin carrier according to any one of items 24 to 24. 26. The second resin, wherein: [Wherein, m represents an integer of 0 to 20, and n represents 1 to 15
Indicates an integer. And a unit represented by the formula:
25. The magnetic fine particle-dispersed resin carrier according to any one of items 24 to 24. 27. The magnetic fine particle-dispersed resin carrier according to claim 1, wherein the second resin is a polymer or a copolymer of methacrylic acid or an ester thereof having a fluoroalkyl unit. 28. The magnetic fine particle-dispersed resin carrier according to claim 1, wherein the second resin is a polymer or a copolymer of acrylic acid or an ester thereof having a fluoroalkyl unit. 29. The method according to claim 1, wherein the second resin is a graft copolymer having a fluoroalkyl unit.
The magnetic fine particle-dispersed resin carrier according to any one of the above. 30. The second resin, wherein: [In the formula, R ₁ has hydrogen or a methyl group, R ₂ represents hydrogen or an alkyl group having 1 to 20 carbon atoms, and k represents an integer of 1 or more. And a unit represented by the following formula: The magnetic fine particle-dispersed resin carrier according to any one of claims 1 to 29, which is a graft copolymer having the following. 31. The second resin according to claim 1, wherein a weight average molecular weight of the soluble component of tetrahydrofuran (THF) is 20,000 to 300,000 by gel permeation chromatography (GPC). Magnetic fine particle dispersed resin carrier. 32. The second resin is a soluble component of THF, G
32. A chromatogram of PC having a main peak in a molecular weight region of 2,000 to 100,000.
The magnetic fine particle-dispersed resin carrier according to any one of the above. 33. The second resin is a soluble component G of THF.
33. The magnetic fine particle-dispersed resin carrier according to claim 1, which has a subpeak or a shoulder in a region of a molecular weight of 2,000 to 100,000 in a chromatogram of PC. 34. The second resin is a soluble component of THF, G
The chromatogram of PC has a main peak in the region of molecular weight of 20,000 to 100,000, and has a molecular weight of 2,000 to 1,000.
The magnetic fine particle-dispersed resin carrier according to any one of claims 1 to 33, which has a subpeak or a shoulder in a region of 9,000. 35. The coupling agent according to claim 1, wherein the coupling agent is a silane coupling agent or a titanium coupling agent.
The magnetic fine particle-dispersed resin carrier according to any one of the above. 36. A coupling agent comprising: γ-methacryloxypropyl trialkoxysilane, β- (3,4-epoxycyclohexyl) ethyl trialkoxysilane, γ
Glycidoxypropyl trialkoxysilane, γ-glycidoxypropylmethyl dialkoxysilane, γ-mercaptopropyl trialkoxysilane, γ-chloropropyl trialkoxysilane, isopropyltriisostearoyl titanate, isopropyltrialkylbenzenesulfonyl having a methylene unit The magnetic fine particle-dispersed resin carrier according to any one of claims 1 to 35, which is a silane coupling agent or a titanium coupling agent selected from titanate and isopropyl tris (dialkylpyrophosphate) titanate having a methylene unit. 37. The carrier core, wherein the second resin is applied in an amount of 0.01 to 5% by weight (based on carrier), and the coupling agent is applied in an amount of 0.01 to 5% by weight (based on carrier). 37. The magnetic fine particle-dispersed resin carrier according to any one of 1 to 36. 38. The first resin forming the carrier core has a hydroxyl group and / or a phenol group, and the residual group of the coupling agent is bonded to the surface of the carrier core by treatment with the coupling agent. Item 38. The magnetic fine particle-dispersed resin carrier according to any one of Items 1 to 37. 39. The magnetic fine particles have a specific resistance value A of 1 × 10 ^3.
4 to 1 × 10 ¹⁰ Ω · cm, and the nonmagnetic inorganic compound fine particles have a specific resistance value B of 1 × 10 ^{8 to} 1 × 10 ¹⁵ Ω · cm, and B is at least 10 times larger than A. 38
The magnetic fine particle-dispersed resin carrier according to any one of the above. 40. In a two-component developer having at least a positively chargeable toner having toner particles and an external additive and a magnetic fine particle dispersed resin carrier, the magnetic fine particle dispersed resin carrier is contained in the first resin. The surface of the carrier core in which the magnetic fine particles are dispersed is covered with a second resin, and (a) the magnetic fine particle-dispersed resin carrier has a true specific gravity of 2.
5 to 4.5, and 1000 × (10 ³ / 4π) · A
/ Mag (1000 oersted) magnetic field (σ ₁₀₀₀ ) measured in a magnetic field of 15 to 60 Am ² / kg (emu).
/ G) and is, residual magnetization (sigma _r) is 0.1~20Am ² /
kg (emu / g), the specific resistance value is 5 × 10 ^{11 to} 5 × 10 ¹⁵ Ω · cm, and (b) the first resin forming the carrier core has a methylene unit in the polymer chain. (-CH ₂ -) has a second resin coating the surface of the (c) a carrier core, fluoroalkyl unit, a methylene unit (-
CH ₂ -) and having at least an ester unit, (d) the surface of the carrier core, (i) a second resin and a coupling agent having at least a methylene unit (however, a coupling agent having a methylene unit and an amino group Or (ii) after a surface treatment with a coupling agent having at least a methylene unit (excluding a coupling agent having a methylene unit and an amino group). A two-component developer coated with a second resin. 41. The two-component developer according to claim 40, wherein the carrier core has a true specific gravity of 2.5 to 4.5. 42. The carrier core according to claim 40, wherein the carrier core contains magnetic fine particles and nonmagnetic inorganic compound fine particles.
2. The two-component developer according to item 1. 43. The two-component developer according to claim 42, wherein the magnetic fine particles and the nonmagnetic inorganic compound fine particles are contained in a total amount of 70 to 99% by weight (based on a carrier). 44. The two-component developer according to claim 42, wherein the magnetic fine particles and the nonmagnetic inorganic compound fine particles are contained in a total amount of 80 to 99% by weight (based on a carrier). 45. The nonmagnetic inorganic compound fine particles have a higher specific resistance than the magnetic fine particles, and the number average particle diameter of the nonmagnetic inorganic compound fine particles is larger than the number average particle diameter of the magnetic fine particles. 2. The two-component developer according to item 1. 46. The two-component developer according to claim 42, wherein the magnetic fine particles are contained in an amount of 30 to 95% by weight based on the total amount of the magnetic fine particles and the nonmagnetic inorganic compound fine particles. 47. The two-component developer according to claim 40, wherein the magnetic fine particles are magnetic iron oxide fine particles. 48. The two-component developer according to claim 42, wherein the nonmagnetic inorganic compound fine particles are nonmagnetic iron oxide fine particles. 49. The two-component developer according to claim 40, wherein the magnetic fine particles are magnetic ferrite fine particles containing at least an iron element and a magnesium element. 50. The two-component developer according to claim 40, wherein the magnetic fine particles are magnetite fine particles. 51. The two-component developer according to claim 42, wherein the nonmagnetic inorganic compound fine particles are fine particles of hematite (α-Fe ₂ O ₃ ). 52. The carrier has a number average particle size of 15 to 6.
52. The two-component developer according to claim 40, wherein the magnetic fine particles have a number average particle size (r _a ) of 0.02 to 2 μm. 53. The magnetic fine particles have a number average particle size (r _a ) of 0.02 to 2 μm, the nonmagnetic inorganic compound fine particles have a number average particle size (r _b ) of 0.05 to 5 μm, and r _b
Two-component developer according to any one of claims 42 to 52 is large 1.5 times or more than r _a is. 54. The carrier has a true specific gravity of 3.0 to 4.0.
54. The two-component developer according to claim 40, wherein the number is 3. 55. The carrier has a residual magnetization (σ _r ) of 0.5.
41. An amount of ^{3 to} 10 Am2 / kg (emu / g).
55. The two-component developer according to any one of items 54 to 54. 56. A carrier having a shape factor SF-1 of 10
The two-component developer according to any one of claims 40 to 55, which is 0 to 130. 57. The first resin is a vinyl resin, a polyester resin, an epoxy resin, a phenol resin, a urea resin,
57. A resin having a methylene unit selected from the group consisting of polyurethane resin, polyimide resin, cellulose resin and polyether resin.
The two-component developer according to any one of the above. 58. The two-component developer according to claim 40, wherein the first resin is a thermosetting resin. 59. The two-component developer according to claim 40, wherein the first resin is a thermoplastic resin having a methylene unit. 60. The two-component developer according to claim 40, wherein the first resin is a phenol resin having a methylene unit. 61. The second resin has the following formula: [In the formula, m represents an integer of 0 to 20. And a perfluoroalkyl unit represented by the formula:
0. The two-component developer according to any one of 0 to 1. 62. The second resin has the following formula: [Wherein, m represents an integer of 0 to 20, and n represents 1 to 15
Indicates an integer. 5. A unit according to claim 4,
62. The two-component developer according to any one of 0 to 61. 63. The second resin has the following formula: [Wherein, m represents an integer of 0 to 20, and n represents 1 to 15
Indicates an integer. 5. A unit according to claim 4,
The two-component developer according to any one of 0 to 62. 64. The second resin has the following formula: [Wherein, m represents an integer of 0 to 20, and n represents 1 to 15
Indicates an integer. 5. A unit according to claim 4,
A two-component developer according to any one of 0 to 63. 65. The second resin has the following formula: [Wherein, m represents an integer of 0 to 20, and n represents 1 to 15
Indicates an integer. 5. A unit according to claim 4,
A two-component developer according to any one of 0 to 63. 66. The two-component developer according to claim 40, wherein the second resin is a polymer or a copolymer of methacrylic acid having a fluoroalkyl unit or an ester thereof. 67. The two-component developer according to claim 40, wherein the second resin is a polymer or copolymer of acrylic acid or an ester thereof having a fluoroalkyl unit. 68. The second resin is a graft copolymer having a fluoroalkyl unit.
8. The two-component developer according to any one of the above items 7. 69. The second resin is represented by the following formula: [In the formula, R ₁ has hydrogen or a methyl group, R ₂ represents hydrogen or an alkyl group having 1 to 20 carbon atoms, and k represents an integer of 1 or more. And a unit represented by the following formula: 70. A graft copolymer having the following:
The two-component developer according to any one of the above. 70. The second resin according to claim 40, wherein the weight average molecular weight of the soluble component of tetrahydrofuran (THF) is 20,000 to 300,000 by gel permeation chromatography (GPC). Two-component developer. 71. The second resin is a soluble component of THF, G
The chromatogram of PC has a main peak in a molecular weight range of 2,000 to 100,000.
0. The two-component developer according to any one of 0 to 1. The second resin is a soluble component of THF, G
72. The two-component developer according to claim 40, wherein the two-component developer has a subpeak or a shoulder in a region of a molecular weight of 2,000 to 100,000 in a chromatogram of PC. 73. The second resin is a soluble component of THF, G
The chromatogram of PC has a main peak in the region of molecular weight of 20,000 to 100,000, and has a molecular weight of 2,000 to 1,000.
73. The two-component developer according to any one of claims 40 to 72, wherein the two-component developer has a subpeak or a shoulder in a region of 9,000. 74. The coupling agent according to claim 40, wherein the coupling agent is a silane coupling agent or a titanium coupling agent.
3. The two-component developer according to any one of 3. 75. The coupling agent may be γ-methacryloxypropyl trialkoxysilane, β- (3,4-epoxycyclohexyl) ethyl trialkoxysilane, γ
Glycidoxypropyl trialkoxysilane, γ-glycidoxypropylmethyl dialkoxysilane, γ-mercaptopropyl trialkoxysilane, γ-chloropropyl trialkoxysilane, isopropyltriisostearoyl titanate, isopropyltrialkylbenzenesulfonyl having a methylene unit 75. The two-component developer according to claim 40, which is a silane coupling agent or a titanium coupling agent selected from titanate and isopropyl tris (dialkylpyrophosphate) titanate having a methylene unit. 76. The carrier core, wherein the second resin is applied in an amount of 0.01 to 5% by weight (based on the carrier), and the coupling agent is applied in an amount of 0.01 to 5% by weight (based on the carrier). 75. The two-component developer according to any one of 40 to 75. 77. The first resin forming the carrier core has a hydroxyl group and / or a phenol group, and the residual group of the coupling agent is bonded to the surface of the carrier core by treatment with the coupling agent. Item 78. The two-component developer according to any one of Items 40 to 76. 78. The magnetic fine particles have a specific resistance value A of 1 × 10 ^3.
43 to 1 × 10 ¹⁰ Ω · cm, and the nonmagnetic inorganic compound fine particles have a specific resistance value B of 1 × 10 ^{8 to} 1 × 10 ¹⁵ Ω · cm, and B is 10 times or more larger than A. 7
8. The two-component developer according to any one of the above items 7. 79. The two-component developer according to claim 40, wherein the positively chargeable toner has a weight average particle diameter of 3.0 to 9.9 μm. 80. The two-component system according to claim 40, wherein the positively chargeable toner contains nigrosine, a nigrosine derivative, a triphenylmethane compound or an organic compound having a quaternary ammonium group. Agent. 81. The external additive has a number average particle size of 3 to 100.
81. The two-component developer according to any one of claims 40 to 80, wherein the particle diameter is nm. 82. The external additive has a BET specific surface area of 30-4.
The two-component developer according to any one of claims 40 to 81, wherein the developer is 00 m ² / g. 83. The two-component developer according to claim 40, wherein the external additive is a fine powder of a metal oxide or a fine powder of a composite of a metal oxide. The two-component developer according to any one of claims 40 to 83, wherein the external additive is a hydrophobic silica fine powder, a hydrophobic titanium oxide fine powder, or a hydrophobic alumina fine powder. A positively chargeable toner has a shape factor of SF-1.
The two-component developer according to any one of claims 40 to 84, wherein is a fine particle of hydrophobic silica as an external additive. 86. The positively chargeable toner has a shape factor of SF-1.
The two-component developer according to any one of claims 40 to 84, wherein the number is from 100 to 130. 87. The two-component developer according to claim 40, wherein the toner particles contain 1 to 40 parts by weight of a solid wax based on 100 parts by weight of the binder resin. 88. The external additive is added in an amount of 0.5 to 5.0 parts by weight based on 100 parts by weight of the toner particles.
90. The two-component developer according to any one of claims to 87. 89. The two-component developer according to claim 40, wherein the toner has a positive triboelectric charging property of +15 to +40 mC / kg with respect to the magnetic fine particle dispersed resin carrier. 90. The toner particles are polymerized toner particles,
The two-component developer according to any one of claims 40 to 89, wherein the carrier core of the magnetic fine particle-dispersed resin carrier is a polymerized carrier core. 91. An electrostatic image carrier is charged by a charging means, the charged electrostatic image carrier is exposed to form an electrostatic image on the electrostatic image carrier, and the electrostatic image is developed by two-component development. A toner image is formed on an electrostatic image carrier by development with a developing means having an agent, and the toner image on the electrostatic image carrier is transferred to a transfer material with or without an intermediate transfer member, and transferred. In the image forming method for fixing a toner image on a material by a heat and pressure fixing unit, the two-component developer includes at least a positively chargeable toner having toner particles and an external additive and a magnetic fine particle dispersed resin carrier. The magnetic fine particle-dispersed resin carrier has a carrier core in which magnetic fine particles are dispersed in a first resin, and the surface of the carrier core is coated with a second resin. Specific gravity is 2.
5 to 4.5, and 1000 × (10 ³ / 4π) · A
/ Mag (1000 oersted) magnetic field (σ ₁₀₀₀ ) measured in a magnetic field of 15 to 60 Am ² / kg (emu).
/ G) and is, residual magnetization (sigma _r) is 0.1~20Am ² /
kg (emu / g), the specific resistance value is 5 × 10 ^{11 to} 5 × 10 ¹⁵ Ω · cm, and (b) the first resin forming the carrier core has a methylene unit in the polymer chain. (-CH ₂ -) has a second resin coating the surface of the (c) a carrier core, fluoroalkyl unit, a methylene unit (-
CH ₂ -) and having at least an ester unit, (d) the surface of the carrier core, (i) a second resin and a coupling agent having at least a methylene unit (however, a coupling agent having a methylene unit and an amino group Or (ii) after a surface treatment with a coupling agent having at least a methylene unit (excluding a coupling agent having a methylene unit and an amino group). An image forming method characterized by being coated with a second resin. 92. The image forming method according to claim 91, wherein the carrier core has a true specific gravity of 2.5 to 4.5. 93. The carrier core according to claim 91, wherein the carrier core contains magnetic fine particles and non-magnetic inorganic compound fine particles.
2. The image forming method according to 1., 94. The image forming method according to claim 93, wherein the magnetic fine particles and the nonmagnetic inorganic compound fine particles are contained in a total amount of 70 to 99% by weight (based on a carrier). 95. The image forming method according to claim 93, wherein the magnetic fine particles and the nonmagnetic inorganic compound fine particles are contained in a total amount of 80 to 99% by weight (based on a carrier). 96. The nonmagnetic inorganic compound fine particles have a higher specific resistance than the magnetic fine particles, and the number average particle size of the nonmagnetic inorganic compound fine particles is larger than the number average particle size of the magnetic fine particles. 2. The image forming method according to 1., 97. The image forming method according to claim 93, wherein the magnetic fine particles are contained in an amount of 30 to 95% by weight based on the total amount of the magnetic fine particles and the nonmagnetic inorganic compound fine particles. 98. The image forming method according to claim 91, wherein the magnetic fine particles are magnetic iron oxide fine particles. 99. The image forming method according to claim 93, wherein the nonmagnetic inorganic compound fine particles are nonmagnetic iron oxide fine particles. 100. The image forming method according to claim 91, wherein the magnetic fine particles are magnetic ferrite fine particles containing at least an iron element and a magnesium element. The image forming method according to any one of claims 91 to 99, wherein the magnetic fine particles are magnetite fine particles. 102. The nonmagnetic inorganic compound fine particles are hematite (α-Fe ₂ O ₃ ) fine particles.
2. The image forming method according to any one of 1. 103. The image forming apparatus according to claim 91, wherein the carrier has a number average particle size of 15 to 60 μm, and the magnetic fine particles have a number average particle size (r _a ) of 0.02 to 2 μm. Method. 104. The magnetic fine particles have a number average particle diameter (r _a ).
Is 0.02 to 2 μm, and the nonmagnetic inorganic compound fine particles have a number average particle size (r _b ) of 0.05 to 5 μm;
r _b is greater claim 1.5 times or more r _a 93 to 10
3. The image forming method according to any one of 3. 105. The image forming method according to claim 91, wherein the carrier has a true specific gravity of 3.0 to 4.3. 106. The image forming method according to claim 91, wherein the carrier has a residual magnetization (σ _r ) of 0.3 to 10 Am ² / kg (emu / g). 107. The carrier has a shape factor SF-1 of 1
The image forming method according to any one of claims 91 to 106, wherein the number is from 00 to 130. 108. The first resin is a resin having a methylene unit selected from the group consisting of vinyl resin, polyester resin, epoxy resin, phenol resin, urea resin, polyurethane resin, polyimide resin, cellulose resin and polyether resin. The image forming method according to any one of claims 91 to 107, wherein: 109. The image forming method according to claim 91, wherein the first resin is a thermosetting resin. 110. The image forming method according to claim 91, wherein the first resin is a thermoplastic resin having a methylene unit. The image forming method according to any one of claims 91 to 107, wherein the first resin is a phenol resin having a methylene unit. 112. The second resin has the following formula: [In the formula, m represents an integer of 0 to 20. And a perfluoroalkyl unit represented by the formula:
12. The image forming method according to any one of 11. 113. The second resin is: [Wherein, m represents an integer of 0 to 20, and n represents 1 to 15
Indicates an integer. 10. A unit according to claim 9,
The image forming method according to any one of 1 to 112. 114. The second resin is: [Wherein, m represents an integer of 0 to 20, and n represents 1 to 15
Indicates an integer. 10. A unit according to claim 9,
114. The image forming method according to any one of 1 to 113. 115. The second resin has the following formula: [Wherein, m represents an integer of 0 to 20, and n represents 1 to 15
Indicates an integer. 10. A unit according to claim 9,
115. The image forming method according to any one of 1 to 114. 116. The second resin has the following formula: [Wherein, m represents an integer of 0 to 20, and n represents 1 to 15
Indicates an integer. 10. A unit according to claim 9,
115. The image forming method according to any one of 1 to 114. 117. The image forming method according to claim 91, wherein the second resin is a polymer or a copolymer of methacrylic acid or an ester thereof having a fluoroalkyl unit. 118. The image forming method according to claim 91, wherein the second resin is a polymer or a copolymer of acrylic acid having a fluoroalkyl unit or an ester thereof. The image forming method according to any one of claims 91 to 118, wherein the second resin is a graft copolymer having a fluoroalkyl unit. 120. The second resin has the following formula: [In the formula, R ₁ has hydrogen or a methyl group, R ₂ represents hydrogen or an alkyl group having 1 to 20 carbon atoms, and k represents an integer of 1 or more. And a unit represented by the following formula: And a graft copolymer having the following:
10. The image forming method according to any one of the above items 9. 121. The second resin according to any one of claims 91 to 120, wherein a weight average molecular weight of the soluble component of tetrahydrofuran (THF) is 20,000 to 300,000 by gel permeation chromatography (GPC). Image forming method. 122. The image forming apparatus according to claim 91, wherein the second resin has a main peak in a molecular weight region of 2,000 to 100,000 in a GPC chromatogram of a soluble component of THF. Method. 123. The image according to any one of claims 91 to 122, wherein the second resin has a subpeak or a shoulder in a molecular weight region of 2,000 to 100,000 in a GPC chromatogram of a soluble component of THF. Forming method. 124. The second resin has a molecular weight of 20,000 to 1010 in a GPC chromatogram of a soluble component of THF.
123. The image forming method according to claim 91, wherein the image forming method has a main peak in an area of 10,000 and a subpeak or a shoulder in an area of a molecular weight of 2,000 to 19,000. The image forming method according to any one of claims 91 to 124, wherein the coupling agent is a silane coupling agent or a titanium coupling agent. 126. A coupling agent comprising: γ-methacryloxypropyl trialkoxysilane, β- (3,4-epoxycyclohexyl) ethyl trialkoxysilane,
γ-glycidoxypropyl trialkoxysilane, γ-
Glycidoxypropylmethyldialkoxysilane, γ-
Silane coupling agent selected from mercaptopropyl trialkoxysilane, γ-chloropropyl trialkoxysilane, isopropyl triisostearoyl titanate, isopropyl trialkylbenzenesulfonyl titanate having methylene unit and isopropyl tris (dialkylpyrophosphate) titanate having methylene unit The image forming method according to any one of claims 91 to 125, wherein the image forming method is a titanium coupling agent. 127. The carrier core is coated with 0.01 to 5% by weight (based on carrier) of the second resin, and 0.01 to 5% by weight (based on carrier) of the coupling agent. 126. The image forming method according to any one of 91 to 126. 128. The first resin forming the carrier core has a hydroxyl group and / or a phenol group, and the residual group of the coupling agent is bonded to the surface of the carrier core by treatment with the coupling agent. Items 91 to 12
8. The image forming method according to any one of 7. 129. The magnetic fine particles have a specific resistance value A of 1 × 10
^{3 to} 1 × 10 ¹⁰ Ω · cm, and the nonmagnetic inorganic compound fine particles have a specific resistance value B of 1 × 10 ^{8 to} 1 × 10 ¹⁵ Ω · cm.
The image forming method according to any one of claims 93 to 128, wherein B is 10 times or more larger than A. 130. The image forming method according to claim 91, wherein the positively chargeable toner has a weight average particle diameter of 3.0 to 9.9 μm. 131. The image forming method according to claim 91, wherein the positively chargeable toner contains nigrosine, a nigrosine derivative, a triphenylmethane compound or an organic compound having a quaternary ammonium group. 132. The external additive has a number average particle size of 3 to 10.
The image forming method according to any one of claims 91 to 131, wherein the thickness is 0 nm. 133. The external additive has a BET specific surface area of 30 to 30.
The image forming method according to any one of claims 91 to 132, wherein the amount is 400 m ² / g. 134. The external additive is a fine powder of a metal oxide or a fine powder of a composite of a metal oxide.
3. The image forming method according to any one of 3. 135. The image forming method according to claim 91, wherein the external additive is a hydrophobic silica fine powder, a hydrophobic titanium oxide fine powder, or a hydrophobic alumina fine powder. 136. The positively chargeable toner has a shape factor SF-
1 is 100 to 140, and at least hydrophobic silica fine powder is used as an external additive.
5. The image forming method according to any one of 5. 137. The positively chargeable toner has a shape factor SF-
The image forming method according to any one of claims 91 to 135, wherein 1 is 100 to 130. 138. The image forming method according to claim 91, wherein the toner particles contain 1 to 40 parts by weight of a solid wax based on 100 parts by weight of a binder resin. 139. To 100 parts by weight of toner particles
10. The external additive is externally added in an amount of 0.5 to 5.0 parts by weight.
138. The image forming method according to any one of 1 to 138. 140. The image forming method according to claim 91, wherein the toner has a positive triboelectric charging property of +15 to +40 mC / kg to the magnetic fine particle dispersed resin carrier. 141. The image forming method according to claim 91, wherein the toner particles are polymerized toner particles, and the carrier core of the magnetic fine particle dispersed resin carrier is a polymerized carrier core. 142. The developing means has a developing sleeve containing a magnetic field generating means, and develops an electrostatic charge image with a two-component developer while applying an AC bias, a pulse bias or a blank pulse bias to the developing sleeve. The image forming method according to any one of claims 91 to 141. 143. The image forming method according to claim 91, wherein the electrostatic charge image is a digital latent image, and the digital latent image is developed by a reversal developing method. 144. The magnetic field generating means included in the developing means is a fixed magnet, and the strength of the magnetic field on the surface of the developing sleeve in the developing area is 500 to 1000 (10 ³ / 4π) · A / m.
144. The image forming method according to claim 91, wherein the electrostatic image is developed with a two-component developer under the condition of (Oersted). 145. The image forming method according to claim 91, wherein the electrostatic image carrier is a photosensitive drum having amorphous silicon or an amorphous silicon photosensitive layer.