JPH1090950A - Electrostatic charge image developing toner, developer, and image forming method - Google Patents

Abstract

PROBLEM TO BE SOLVED: To improve the long-term stability of charging property and durability of toner by containing a colored particle having a BET specific area of a specified value or more and a fine particle having a number average primary grain size within a specified range in the toner. SOLUTION: This toner is formed of a colored particle having a BET specific area of 5m<2> /g or more and a fine particle having a number average primary grain size of 5-2000nm. The shielding ratio by fine particle on the colored particle surface is 5-80%. In a non-contact type developing part, for example, using this toner, a binary developer containing this tone is supported on a development carrier 2 having a magnet 2B therein by magnetic force, and carried to a development area 5 by the movement of a development sleeve 2A. In this carrying, a developer layer 6 is regulated in thickness so as not to make contact with a photoreceptor 1 in the development area 5 by a developer layer regulating member 4. The minimum space of the development area 5 is set larger than the thickness of the developer layer 5 carried to the area, for example, to about 100-1000μm.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an electrostatic image developing toner, a developer and an image forming method used in a copying machine, a printer and the like.

[0002]

2. Description of the Related Art In a typical example of an image forming process by an electrophotographic developing system, an electrostatic image is formed on an image forming body (generally, a photosensitive body, sometimes referred to as a photosensitive body) by charging and exposure. This electrostatic image is developed with a developer containing toner to form a toner image, and then this toner image is transferred to a transfer material and fixed to form a visible image.

[0003] As a developer used in such an image forming process, a two-component developer comprising a toner and a carrier is known, and the carrier constituting the two-component developer has an appropriate polarity for the toner, and An appropriate amount of triboelectric charge must be provided.

On the other hand, this image forming process is, for example,
It is used not only in copiers but also in fields such as printers, color copiers, color printers, and the like, and as these applications progress, demands on image quality are increasing.

To improve the image quality, it has been proposed to reduce the diameter of the toner itself. However, if the diameter is simply reduced, the fluidity of the toner is deteriorated, the charge rising characteristic is deteriorated, and problems such as fogging and toner scattering occur.

[0006] In order to solve this problem, studies have been made to increase the specific surface area of the colored particles themselves forming the toner particles, thereby improving the charge rising characteristics. However, this type of toner has a large change in chargeability due to the environment at the same time.
Practical application is difficult.

[0007] One of the problems in using small-diameter toner is "difference in front and rear edge density".

[0008] This is because the carrier conveyed together with the toner on the surface of the developing sleeve is re-conveyed to the developing area without being removed from the surface of the developing sleeve even after the toner is developed, whereby the carrier is re-conveyed to the developing area. Since the carrier does not carry a predetermined amount of toner, the image density gradually decreases from the leading end during output of one document.

In other words, when the diameter of the toner is reduced, the physical adhesion between the toner and the carrier is increased, so that phenomena such as deterioration of the developing property and deterioration of the fluidity of the developer occur. The problem of density differences appears more prominently.

[0010] Further, the reduced-diameter toner has a problem that it has high adhesion to the photoreceptor, causes poor cleaning from the photoreceptor, and causes image defects such as white spots and diagonal lines. I have.

[0011]

An object of the present invention is to provide a BE
In a toner using colored particles having a high T specific surface area,
(1) A first object of the present invention is to provide a developer and an image forming method capable of obtaining stable developability even when the environment fluctuates. (2) A second object of the present invention is to provide a developer and an image forming method. (3) A third object of the present invention is to provide a developer having a high developing property and a long period of time even in multi-sheet copying, such as white spots and oblique line breaks. An object of the present invention is to provide a developer free from image defects and an image forming method.

[0012]

The object of the present invention is achieved by adopting any one of the following constitutions.

(1) At least BET specific surface area is 5 m
² / g or more colored particles and a number average primary particle diameter of 5 to 20
A toner for developing electrostatic images, comprising fine particles having a diameter of 00 nm.

(2) The toner for developing an electrostatic charge image according to (1), wherein the concealing rate of the surface of the colored particles by the fine particles is 5 to 80%.

(3) In a toner for developing an electrostatic image composed of at least colored particles and fine particles and a developer composed of a carrier, the BET specific surface area of the colored particles is 5 m ² / g.
The number average primary particle diameter of the fine particles is 5 to 200.
A developer having a thickness of 0 nm.

(4) An image forming method for visualizing an electrostatic latent image formed on an image forming body using a developer,
The developer uses a toner for developing an electrostatic image composed of at least colored particles and fine particles, and a carrier. The BET specific surface area of the colored particles is 5 m ² / g or more, and the number average primary particle diameter of the fine particles is An image forming method having a thickness of 5 to 2000 nm.

(5) visualizing the electrostatic latent image formed on the image forming body using a developer, and forming the electrostatic latent image again on the image forming body carrying the toner image; Forming the electrostatic latent image into a toner image by using a developer to form a visible toner image, and repeating this process to form a plurality of color toner images on the image forming body; and In an image forming method including a step of collectively transferring a plurality of color toner images formed on a body onto a transfer material, the developer is an electrostatic image developing toner including at least colored particles and fine particles,
Carrier and the toner has a BET specific surface area of 5
m ² / g or more colored particles and number average primary particle diameter of 5 to 20
An image forming method comprising fine particles of 00 nm.

(6) At least a BET specific surface area of 5 m
² / g or more colored particles and a BET specific surface area of 30 to 60 m ²
/ G and a number average primary particle size of 60 to 150 nm
A toner for developing an electrostatic image, comprising: fine particles.

(7) The toner for developing an electrostatic image according to (6), wherein the opacity of the fine particles on the surface of the colored particles is 5 to 80%.

[0020] (8) The electrostatic image particulate toner for developing a BET specific surface area 30 to 60 m ² / g, number average primary particle diameter of fine particles (A) and the BET specific surface area is 60~150nm 80~400m ² / g, number average primary particle diameter is 5
The toner for developing an electrostatic image according to (6) or (7), comprising fine particles (B) having a diameter of 100 nm.

(9) In a toner for developing an electrostatic image composed of at least colored particles and fine particles and a developer composed of a carrier, the BET specific surface area of the colored particles is 5 m ² / g.
And the fine particles have a BET specific surface area of 30 to 60 m ^2.
/ G and a number average primary particle size of 60 to 150 nm
A developer, characterized in that:

(10) In an image forming method for visualizing an electrostatic latent image formed on an image forming body using a developer, the developer is an electrostatic image developing method comprising at least colored particles and fine particles. The toner has a BET specific surface area of 5 m ² / g or more, the fine particles have a BET specific surface area of 30 to 60 m ² / g, and a number average primary particle diameter of 60 to 150 nm. An image forming method, characterized in that:

(11) A step of developing the electrostatic latent image formed on the image forming body using a developer, and forming the electrostatic latent image on the image forming body carrying the toner image again. Forming the electrostatic latent image into a toner image by using a developer to form a visible toner image, and repeating this process to form a plurality of color toner images on the image forming body; and An image forming method including a step of batch-transferring a plurality of color toner images formed on a body onto a transfer material, wherein the developer comprises an electrostatic image developing toner including at least colored particles and fine particles, and a carrier. And the toner comprises colored particles having a BET specific surface area of 5 m ² / g or more and fine particles having a BET specific surface area of 30 to 60 m ² / g and a number average primary particle diameter of 60 to 150 nm. An image forming method comprising:

(12) In an electrostatic image developing toner comprising at least colored particles and fine particles, the colored particles having a BET specific surface area of 5 m ² / g or more and a number average primary particle diameter of 5 to 50 nm. Fine particles (A) and 6
A toner for developing an electrostatic image, comprising fine particles (B) having a size of 0 to 2000 nm.

(13) The toner for developing an electrostatic charge image according to (12), wherein a hiding ratio of the fine particles on the surface of the colored particles is 5 to 80%.

(14) In a toner for developing an electrostatic image composed of at least colored particles and fine particles and a developer composed of a carrier, the BET specific surface area of the colored particles is 5 m ² /
g or more, and the fine particles have a number average primary particle diameter of 5 to 50 n.
m. Fine particles (A) and 60-2000 nm fine particles (B).

(15) The electrostatic latent image formed on the image forming body is developed using a developer, and the formed toner image is transferred to a transfer material. In the image forming method of cleaning using a blade, a toner for developing an electrostatic image composed of at least colored particles and fine particles as the developer and a carrier, and the BET specific surface area of the colored particles is 5 m ² / g or more. A fine particle (A) having a number average primary particle diameter of 5 to 50 nm and a fine particle (B) having a number average primary particle diameter of 60 to 2000 nm.

(16) A step of visualizing the electrostatic latent image formed on the image forming body using a developer, and forming the electrostatic latent image again on the image forming body carrying the toner image. Forming the electrostatic latent image into a toner image by using a developer to form a visible toner image, and repeating this process to form a plurality of color toner images on the image forming body; and An image forming method including a step of batch-transferring a plurality of color toner images formed on a body onto a transfer material, wherein the developer comprises an electrostatic image developing toner including at least colored particles and fine particles, and a carrier. The toner has colored particles having a BET specific surface area of 5 m ² / g or more and a number average primary particle diameter of 5 m ² / g.
An image forming method comprising: fine particles (A) having a size of 50 to 50 nm and fine particles (B) having a size of 60 to 2000 nm.

With respect to the first object, the present invention finds that the object of the present invention can be achieved by using a toner having a large surface area as the toner and further using a fine particle having a specific particle size. The invention has been completed.

That is, by using colored particles having a large surface area and a BET specific surface area of 5 m ² / g or more, the amount of charged sites existing on the surface is increased, and the number average primary particle diameter is 5%. It has been found that by using a material having a thickness of 〜2000 nm, it is possible to stabilize the chargeability over a long period of time.

The colored particles have a BET specific surface area of 5 m.
If it is less than ² / g, the number of charged sites on the surface of the colored particles is insufficient, and it is not possible to secure the rising of charging. Further, if the number average primary particle diameter of the fine particles is less than 5 nm, the effect of imparting fluidity to the colored particles cannot be stably maintained. If the number average primary particle diameter exceeds 2,000 nm, the added fine particles exert the effect to be imparted. Can not.

Further, by specifying the amount of these fine particles present on the surface of the colored particles, that is, the concealment ratio, it is possible to maintain the chargeability and the durability in particular. Concealment rate is 5%
If it is less than 50%, the effect of the fine particles cannot be easily maintained because the amount of the fine particles present on the surface of the colored particles is small. Further, if the concealment ratio exceeds 80%, the fine particles cover the surface of the colored particles. In addition, the exposure of the surface of the colored particles is reduced, and the effect of the colored particles having a high BET specific surface area is hardly exhibited.

In the present invention, for the second object, high stability is achieved by using colored particles having a large BET specific surface area and further using external additives having a specific BET specific surface area as fine particles. Can be secured.

The fine particles have a BET specific surface area of 30 to 6
0 m ² / g, and the number average primary particle diameter is 60 to 150 n.
m. Although the reason for this is not clear, it is presumed that the use of fine particles having a large specific surface area as compared with the particle size will maintain a stable charging property imparting effect even when burial of the colored particles occurs. Is done. Further, it is presumed that burying itself can be suppressed by using a material having a large number average primary particle diameter, and that stability can be improved.

Further, by using fine particles having a smaller particle diameter in combination, it is possible to improve the flow characteristics possessed by the toner itself, and in particular, it is possible to improve the toner supply property in a high temperature and high humidity environment. As a result, it is possible to prevent a decrease in the fluidity of the toner that occurs in a high-temperature and high-humidity environment with a toner having a small particle diameter, and does not cause image unevenness.

For the third object, in the present invention, the charging property of the toner itself can be increased by increasing the BET specific surface area as a small particle size toner. By using the fine particles, the fluidity can be effectively imparted to the colored particles, and the rise of the charging property can be improved by the presence of the fine particles. Further, by adding fine particles having a large particle diameter, the adhesion of the toner to the photoconductor can be reduced, and as a result, in the so-called blade cleaning method, a decrease in the adhesion of the toner to the photoconductor can be expected, There is no problem caused by cleaning.

An embodiment of the present invention will be described more specifically.

BET specific surface area of colored particles BET specific surface area of colored particles of the present invention (toner particles are also BE
Since the measurement results of the T specific surface area are almost the same, the BET specific surface area of the toner may be hereinafter referred to as) 5 m ² / g
Above, preferably 5 to 80 m ² / g, more preferably 5 to 80 m ² / g.
４０40 m ² / g.

The BET specific surface area is measured by a one-point method of the nitrogen adsorption method, and a specific measuring device is Flowsorb 2300 (Shimadzu Corporation).

The colored particles of the present invention preferably contain at least a resin and a colorant, and if necessary, may contain a releasing agent or a charge control agent as a fixability improving agent. Further, the toner is obtained by adding an external additive composed of inorganic fine particles and organic fine particles to colored particles composed of a so-called resin and colorant.

The toner (colored particles) of the present invention has a BET specific surface area larger than particles usually obtained by a pulverization method.

The toner of the present invention is prepared, for example, by subjecting a monomer to emulsion polymerization in a liquid to which an emulsion of necessary additives is added to produce fine polymer particles. Can be produced by a method of adding and the like.

The method for producing the toner of the present invention is not particularly limited as described above.
-265252, Japanese Patent Application No. 5-116672, and Japanese Patent Application No. 6-223953 are used.

That is, a method of associating a plurality of fine particles composed of a resin, a colorant, and the like, in particular, dispersing them in water using an emulsifier, and then infinitely dissolving in a coagulant having a critical aggregation concentration or more and water. With an organic solvent. Further, the toner having the BET specific surface area of the present invention can be formed by heat-fusing the formed polymer itself at or above the glass transition temperature.

In the present invention, those used as monomers constituting the resin include, for example, styrene, o-methylstyrene, m-methylstyrene, p-methylstyrene, α
-Methylstyrene, p-chlorostyrene, 3,4-dichlorostyrene, p-phenylstyrene, p-ethylstyrene, 2,4-dimethylstyrene, pt-butylstyrene, pn-hexylstyrene, pn Styrene or styrene derivatives such as octylstyrene, pn-nonylstyrene, pn-decylstyrene, pn-dodecylstyrene, methyl methacrylate, ethyl methacrylate, n-butyl methacrylate, isopropyl methacrylate; Ethyl methacrylates such as isobutyl methacrylate, t-butyl methacrylate, n-octyl methacrylate, 2-ethylhexyl methacrylate, stearyl methacrylate, lauryl methacrylate, phenyl methacrylate, diethylaminoethyl methacrylate, and dimethylaminoethyl methacrylate Le derivatives, methyl acrylate, ethyl acrylate, isopropyl acrylate, n
-Butyl, t-butyl acrylate, isobutyl acrylate, n-octyl acrylate, 2-ethylhexyl acrylate, stearyl acrylate, lauryl acrylate,
Acrylic ester derivatives such as phenyl acrylate, ethylene, olefins such as propylene / isobutylene,
Halogen vinyls such as vinyl chloride, vinylidene chloride, vinyl bromide, vinyl fluoride, and vinylidene fluoride; vinyl esters such as vinyl propionate, vinyl acetate and vinyl benzoate; and vinyl ethers such as vinyl methyl ether and vinyl ethyl ether , Vinyl ketones such as vinyl methyl ketone, vinyl ethyl ketone and vinyl hexyl ketone, N-vinyl compounds such as N-vinyl carbazole, N-vinyl indole, N-vinyl pyrrolidone, vinyl compounds such as vinyl naphthalene and vinyl pyridine, There are acrylic acid or methacrylic acid derivatives such as acrylonitrile, methacrylonitrile, and acrylamide. These vinyl monomers can be used alone or in combination.

Further, it is more preferable to use a monomer having an ionic dissociating group as a monomer constituting the resin in combination. For example, a carboxyl group, a sulfonic group,
It has a substituent such as a phosphoric acid group as a constituent group of a monomer. Specifically, acrylic acid, methacrylic acid, maleic acid, itaconic acid, cinnamic acid, fumaric acid, monoalkyl maleate, itacone Acid monoalkyl esters, styrenesulfonic acid, allylsulfosuccinic acid,
2-acrylamide-2-methylpropanesulfonic acid, acid phosphooxyethyl methacrylate, 3-
Chloro-2-acid phosphooxypropyl methacrylate and the like can be mentioned.

Further, divinylbenzene, ethylene glycol dimethacrylate, ethylene glycol diacrylate, diethylene glycol dimethacrylate, diethylene glycol diacrylate, triethylene glycol dimethacrylate, triethylene glycol diacrylate, neopentyl glycol dimethacrylate, neopentyl glycol diacrylate, etc. Can be used as a crosslinked resin.

These monomers can be converted into a resin by using a radical polymerization initiator. In this case, an oil-soluble polymerization initiator can be used in the suspension polymerization method or the solution polymerization method.
As this oil-soluble polymerization initiator, azoisobutyronitrile, lauryl peroxide, benzoyl peroxide and the like can be used. When an emulsion polymerization method is used, a water-soluble radical polymerization initiator can be used. Examples of the water-soluble polymerization initiator include persulfates such as potassium persulfate and ammonium persulfate, azobisaminodipropane acetate, azobiscyanovaleric acid and salts thereof, and hydrogen peroxide.

The obtained resin has a glass transition point of 20.
It is preferably one having a softening point of 80 to 220 ° C. The glass transition point can be measured by a differential calorimetric analysis method, and the softening point can be measured by a Koka type flow tester. Further, as these resins, those having a number average molecular weight (Mn) of 1,000 to 100,000 and a weight average molecular weight (Mw) of 2,000 to 1,000,000 as measured by gel permeation chromatography are preferred. Further, as a molecular weight distribution, Mw / Mn is 1.5 to
100, particularly preferably 1.8 to 70.

The flocculant to be used is not particularly limited, but those selected from metal salts are preferably used. Specifically, as a monovalent metal, for example, a salt of an alkali metal such as sodium, potassium, and lithium, and as a divalent metal, for example, a salt of an alkaline earth metal such as calcium and magnesium, or a divalent metal such as manganese or copper Salt,
Examples include salts of trivalent metals such as iron and aluminum, and specific salts include sodium chloride, potassium chloride, lithium chloride, calcium chloride, inexpensive zinc, copper sulfate, magnesium sulfate, and manganese sulfate. Can be.
These may be used in combination.

It is preferable that these coagulants are added at a concentration higher than the critical coagulation concentration. The critical aggregation concentration is an index relating to the stability of the aqueous dispersion, and indicates the concentration at which aggregation occurs when a coagulant is added. This critical aggregation concentration is
It varies greatly depending on the emulsified component and the dispersant itself. For example, Seizo Okamura et al., “Polymer Chemistry 1
7, 601 (1960), edited by The Society of Polymer Science, Japan, and the like, and a detailed critical aggregation concentration can be determined. Further, as another method, a desired salt is added to the target particle dispersion at a different concentration, and the resulting dispersion is subjected to ζ (zeta).
The potential can be measured, and the salt concentration at which this value changes can be determined as the critical aggregation concentration.

The addition amount of the coagulant of the present invention may be not less than the critical coagulation concentration, but is preferably 1.2 to the critical coagulation concentration.
And more preferably 1.5 times or more.

The infinitely soluble solvent is a polymer dispersion containing a colorant, that is, a solvent that is infinitely soluble in water.
This solvent is selected so as not to dissolve the resin formed in the present invention. Specific examples include alcohols such as methanol, ethanol, propanol, isopropanol, t-butanol, methoxyethanol and butoxyethanol, nitriles such as acetonitrile, and ethers such as dioxane. Particularly, ethanol, propanol and isopropyl alcohol are preferred.

The amount of the solvent to be dissolved infinitely is 1 to 300% by volume based on the polymer-containing dispersion to which the flocculant has been added.
Is preferred.

Various methods can be used as the polymerization method for forming the resin used to form the toner of the present invention, and the above-mentioned emulsion polymerization method is particularly preferable.

As the colorant used in the toner of the present invention, carbon black, a magnetic substance, a dye, a pigment and the like can be arbitrarily used. Examples of the carbon black include channel black, furnace black, acetylene black, and thermal black lamp. Black or the like is used. As the magnetic material, ferromagnetic metals such as iron, nickel and cobalt, alloys containing these metals, compounds of ferromagnetic metals such as ferrite and magnetite, alloys which do not contain ferromagnetic metals but show ferromagnetism by heat treatment, For example, an alloy of a type called a Heusler alloy such as manganese-copper-aluminum, manganese-copper-tin, chromium dioxide, or the like can be used.

As the dye, C.I. I. Solvent Red 1, 49, 52, 58, 63, 111, 1
22, C.I. I. Solvent Yellow 19, 44, 7
7, 79, 81, 82, 93, 98, 10
3, 104, 112, 162, C.I. I. Solvent Blue 25, 36, 60, 70, 93, 9
5 and the like, and mixtures thereof can also be used. Examples of the pigment include C.I. I. Pigment Red 5,
48: 1, 53: 1, 57: 1, 122, 1
39, 144, 149, 166, 177, 1
78, 222, C.I. I. Pigment Orange 31, 43 and C.I. I. Pigment Yellow 14, 17, and 9
3, 94, 138, C.I. I. Pigment Green 7, C.I. I. Pigment Blue 15: 3, 60 and the like, and mixtures thereof can also be used. The number average primary particle size varies depending on the type, but
About 200 nm is preferable.

As a method of adding a colorant, a method of preparing a polymer itself by an emulsion polymerization method, and then adding the coagulant at the stage of coagulation to color the polymer, or a method of polymerizing a monomer. A method of adding a colorant at the stage of polymerization, polymerizing and coloring, or the like can be used. When the colorant is added at the stage of preparing the polymer, it is preferable to use the colorant after treating the surface with a coupling agent or the like so as not to inhibit the radical polymerizability.

Further, low molecular weight polypropylene (number average molecular weight = 1500 to 9000), low molecular weight polyethylene or the like may be added as a fixing property improving agent. Further, an azo-based metal complex, a quaternary ammonium salt, or the like may be used as a charge control agent.

The toner of the present invention can be produced by associating a plurality of the above-mentioned polymer particles. In this case, the dispersion liquid of the polymer particles is stirred with a metal as an aggregating agent. The salt can be obtained by adding the salt in an amount not less than the critical coagulation concentration, further adding a solvent (for example, isopropyl alcohol) that is infinitely soluble in water, and then performing a heat treatment at a temperature equal to or higher than the glass transition temperature of the polymer.

The particle size of the toner particles of the present invention is arbitrary, but a small particle size tends to exhibit the effects of the present invention, and a volume average particle size of 2 to 10 μm is preferable, and particularly 3 to 9 μm.
m is preferred. The particle size can be controlled by the concentration of the coagulant, the amount of the organic solvent added, and the composition of the polymer itself. The volume average particle size of the toner particles (colored particles) is measured by a Coulter Counter TA-II or a Coulter Multisizer.

The toner of the present invention is used, for example, when a magnetic material is contained and used as a one-component magnetic toner, when it is used as a two-component developer by mixing with a so-called carrier, or when a non-magnetic toner is used alone. Any of them can be suitably used, but it is preferable to use as a two-component developer used by mixing with a carrier.

As the carrier constituting the two-component developer, either an uncoated carrier composed of only magnetic material particles such as iron or ferrite, or a resin-coated carrier in which the surface of the magnetic material particles is coated with a resin or the like is used. Is also good. The average particle size of this carrier is 30 to 150 μm in volume average particle size.
m is preferred. The resin for coating is not particularly limited, and examples thereof include styrene-acrylic resin.

Structure of Fine Particles The fine particles used in the first invention can have a number average primary particle diameter of 5 to 2,000 nm. This number average primary particle size is observed by transmission electron microscope observation,
Shows what was measured by image analysis.

The fine particles used in the second invention have a BET specific surface area of 30 to 60 m ² / g and a number average primary particle diameter of 60 to 150 nm. Further, the BET specific surface area is 30 to 60 m ² / g, and the number average primary particle diameter is 60 to 60 m ² / g.
Fine particles (A) having a diameter of 150 nm and a BET specific surface area of 80 to
It is more preferable to use the particles in combination with the fine particles (B) having 400 m ² / g and a number average primary particle diameter of 5 to 100 nm.

The BET specific surface area is measured by the nitrogen adsorption one-point method, and is measured by Flowsorb 2300. Further, the number average primary particle size is a value observed by observation with a transmission electron microscope and measured by image analysis.

In order to increase the BET specific surface area with respect to the number average primary particle diameter, a method of preparing the fine particle core itself by, for example, a gas phase method may be mentioned. Specifically, there is a method of hydrolyzing a titanium coupling agent in a gas phase.

The fine particles used in the third invention are the fine particles (A) having a number average primary particle diameter of 5 to 50 nm and the fine particles (A) having a number average primary particle diameter of 5 to 50 nm.
This is a combination with the fine particles (B) having a size of 2000 nm. The number average primary particle diameter is observed by a transmission electron microscope and measured by image analysis.

The ratio between the fine particles (A) having a number average primary particle diameter of 5 to 50 nm and the fine particles (B) having a number average primary particle diameter of 5 to 50 nm is expressed by a weight ratio of fine particles (A): fine particles (B) = 5
95: 95-5 is preferred. More preferably, fine particles (A): fine particles (B) = 20-80: 80-20.

The opacity of the fine particles on the surface of the colored particles is preferably from 5 to 80%, more preferably from 30 to 65%.
%. If the concealing rate on the surface of the colored particles is less than this range, the effect of adding the fine particles may not be sufficiently exhibited, and if the concealing rate is large, the fine particles may cover the surface of the colored particles excessively. As a result, the adhesion of the colored particles to the transfer material may be reduced.

The concealing ratio as used herein means fine particles (external additives)
Indicates the ratio of how much the toner surface is hidden by the presence of.

The specific calculation method of the concealment ratio will be described below.

First, the number n of external additives that can be placed on one colored particle (toner particle) is determined.

This value is obtained by dividing the surface area of one toner determined from the BET specific surface area and the volume average particle diameter of the toner by the fine particles 1
It is determined by dividing the concealing area of each of the particles (a value of 1/2 of the total surface area of each of the particles determined from the number average particles of the fine particles).

N = Bt × (4/3) πRt ³ × ρt /
((1/2) 4πRa ² ) Next, the addition amount (limit addition amount) of the fine particles which cover the entire toner surface with the fine particles is calculated from this value.

Limit addition amount (wt%) = ((4/3) πR
a ³ × n × ρa) / ((4/3) πRt ³ × ρt + (4 /
3) πRa ³ × n × ρa) × 100 The percentage of the actual addition amount to the limit addition amount is defined as the hiding ratio.

Hiding ratio (%) = Actual addition amount (wt%) / Limit addition amount (wt%) × 100 In the above, the meaning of each symbol is summarized as follows.

Bt: BET specific surface area of toner particles (m ² / g) Rt: radius of toner particles calculated from volume average particle size of toner (μm) Ra: radius of fine particles calculated from number average particle size of fine particles ( μ
m) ρt: Specific gravity of the toner (g / cm ³ ) ρa: Specific gravity of the fine particles (g / cm ³ ) π: Pi The material constituting the inorganic fine particles includes various inorganic oxides,
Nitride, boride and the like are preferably used. For example, silica, alumina, titania, zirconia, barium titanate, aluminum titanate, strontium titanate,
Magnesium titanate, cerium oxide, zinc oxide, chromium oxide, cerium oxide, antimony oxide, tungsten oxide, tin oxide, tellurium oxide, manganese oxide, boron oxide, silicon carbide, boron carbide, titanium carbide, silicon nitride, titanium nitride, nitride Boron and the like.

Particularly preferred inorganic fine particles include silica, alumina, titania and zirconia. Although the reason for this is not clear, it can be mentioned that these particles have a high effect of imparting fluidity to the toner and have a high hardness as particles.

The inorganic fine particles are preferably added in an amount of 0.1 to 5% by weight, particularly preferably 0.2 to 2.0% by weight, based on the toner. If the added amount of the inorganic fine particles is too small, the effect of imparting fluidity to the toner is reduced, and if the added amount is too large, the inorganic fine particles are liberated to cause problems such as contamination of the band electrode.

Further, the inorganic fine particles may be subjected to a hydrophobic treatment. When performing the hydrophobizing treatment, it is preferable to perform hydrophobizing treatment with a so-called coupling agent such as various titanium coupling agents and silane coupling agents, and further, higher fatty acids such as aluminum stearate, zinc stearate, and calcium stearate. It is also preferable to perform a hydrophobic treatment with a metal salt.

Examples of materials for performing the hydrophobic treatment include various titanium coupling agents and silane coupling agents. Examples of the titanium coupling agent include tetrabutyl titanate, tetraoctyl titanate, isopropyl triisostearoyl titanate, isopropyl tridecylbenzenesulfonyl titanate, and bis (dioctyl pyrophosphate) oxyacetate titanate. Further, as a silane coupling agent, γ-
(2-aminoethyl) aminopropyltrimethoxysilane, γ- (2-aminoethyl) aminopropylmethyldimethoxysilane, γ-methacryloxypropyltrimethoxysilane, N-β- (N-vinylbenzylaminoethyl) γ-amino Propyltrimethoxysilane hydrochloride, hexamethyldisilazane, methyltrimethoxysilane, butyltrimethoxysilane, isobutyltrimethoxysilane, hexyltrimethoxysilane, octyltrimethoxysilane, decyltrimethoxysilane, dodecyltrimethoxysilane, phenyltrimethoxy Examples include silane, o-methylphenyltrimethoxysilane, p-methylphenyltrimethoxysilane, and the like.

These compounds are preferably added and coated in an amount of 1 to 10% by weight with respect to the inorganic fine particles, preferably 3 to 7% by weight. Further, these materials can be used in combination.

Examples of fatty acids and metal salts thereof include undecylic acid, lauric acid, tridecylic acid, dodecylic acid, myristic acid, palmitic acid, pentadecylic acid, stearic acid, heptadecylic acid, arachiic acid, montanic acid, oleic acid, linoleic acid, Long-chain fatty acids such as arachidonic acid are mentioned, and as metal salts thereof, zinc, iron, magnesium,
Salts with metals such as aluminum, calcium, sodium, lithium and the like can be mentioned.

The composition of the organic fine particles is not particularly limited. Generally, vinyl-based organic fine particles are preferable. The reason for this is that it can be easily produced by a production method such as an emulsion polymerization method or a suspension polymerization method. Specifically, styrene, o-methylstyrene, m-methylstyrene, p-methylstyrene, α-methylstyrene, p-chlorostyrene, 3,4-dichlorostyrene, p-phenylstyrene, p-ethylstyrene, , 4-dimethylstyrene, pt-butylstyrene, pn-hexylstyrene, pn-octylstyrene, pn-nonylstyrene, pn-decylstyrene and pn-dodecylstyrene. Styrene or styrene derivative, methyl methacrylate, ethyl methacrylate, n-butyl methacrylate, isopropyl methacrylate, isobutyl methacrylate, t-butyl methacrylate, n-octyl methacrylate, 2-ethylhexyl methacrylate, stearyl methacrylate, methacryl Lauryl acid, phenyl methacrylate, Acrylic acid diethylaminoethyl, methacrylate derivatives such as dimethylaminoethyl methacrylate, methyl acrylate, ethyl acrylate, isopropyl acrylate, n
-Butyl, t-butyl acrylate, isobutyl acrylate, n-octyl acrylate, 2-ethylhexyl acrylate, stearyl acrylate, lauryl acrylate,
Acrylic ester derivatives such as phenyl acrylate, dimethylaminoethyl acrylate, diethylaminoethyl acrylate, and the like can be cited as materials constituting the organic fine particles. These can be used alone or in combination.

Further, other materials for constituting the vinyl organic fine particles include olefins such as ethylene, propylene and isobutylene; halogen vinyls such as vinyl chloride, vinylidene chloride, vinyl bromide and vinyl fluoride;
Vinyl esters such as vinyl propionate, vinyl acetate and vinyl benzoate; vinyl ethers such as vinyl methyl ether and vinyl ethyl ether; vinyl ketones such as vinyl methyl ketone, vinyl ethyl ketone and vinyl hexyl ketone; N-vinyl carbazole; N-vinyl compounds such as vinylindole and N-vinylpyrrolidone, vinyl compounds such as vinylnaphthalene and vinylpyridine, acrylonitrile, methacrylonitrile, acrylamide, N-butylacrylamide, N, N-dibutylacrylamide, methacrylamide, N And acrylic acid or methacrylic acid derivatives such as -butylmethacrylamide and N-octadecylacrylamide. These vinyl monomers can be used alone or in combination.

Further, the organic fine particles need to be stable even when the developer is used for a long period of time.
For this purpose, it is preferable that the organic fine particles themselves are cross-linked by various cross-linking agents and used as a material having high hardness. Examples of the crosslinking agent include divinylbenzene, ethylene glycol diacrylate, diethylene glycol diacrylate, triethylene glycol diacrylate, ethylene glycol dimethacrylate, diethylene glycol dimethacrylate, triethylene glycol dimethacrylate, and the like. The amount of the crosslinking agent used is appropriately adjusted depending on the required degree of crosslinking, and is preferably used in an amount of 0.1 to 5% by weight based on the vinyl monomer. If the amount of the cross-linking agent is excessive, the hardness increases, but the brittleness becomes brittle, and on the contrary, there is a problem that the durability decreases. If the amount of the cross-linking agent is too small, the effect of the cross-linking agent cannot be exerted.

The organic fine particles can be produced by an emulsion polymerization method or a suspension polymerization method. The emulsion polymerization method is a method in which the above-mentioned monomer is added to water containing a surfactant and the mixture is emulsified and then polymerized.As the surfactant, sodium dodecylbenzenesulfonate, polyvinyl alcohol, an ethylene oxide adduct, or the like is used. Any substance that is used as a surfactant can be used and is not particularly limited. Further, a so-called non-emulsion polymerization method using a monomer having a surfactant function in itself is also suitable.

The polymerization initiator necessary for synthesizing organic fine particles includes peroxides such as benzoyl peroxide and lauryl peroxide, and azo-based polymerization initiators such as azobisisobutyronitrile and azobisisovaleronitrile. Agents. The addition amount of these is preferably 0.1 to 2% by weight based on the monomer. If the amount is less than this, the polymerization reaction becomes insufficient, and the problem of residual monomer itself occurs. In addition, when the amount is excessive, a decomposition product of the polymerization initiator remains and affects the chargeability, and furthermore, the polymerization reaction is too fast, resulting in a problem that the molecular weight becomes small.

The organic fine particles may be polymer fine particles such as polyurethane, polyurea, polyester, phenol formaldehyde condensate, and melamine / formaldehyde condensate.

The organic fine particles have a number average primary particle diameter of 1
It is preferably from 0 to 2000 nm, more preferably from 100 to
1500 nm. If the particle size is smaller than this, there is no effect of improving transferability. If the particle size is larger, the organic fine particles themselves are less likely to adhere to the toner. This causes a problem of contamination, and does not exert an effect on transfer.

The concealment ratio for the colored particles is preferably from 5 to 80%. If it exceeds this range, the fine particles are excessively present on the surface of the colored particles, and the fine particles are likely to be detached. As a result, image defects (for example, black spots) due to adhesion to the photoreceptor are caused. In some cases, there is a possibility that the adhesion to a transfer material such as paper is reduced at the time of fixing and the fixing rate is reduced. Further, when the concealing ratio is low, the absolute amount of the portion where the fine particles are not adhered increases, so that the insufficient charge rise as the toner or the sufficient charge amount may not be obtained.

In order to control the hiding ratio, it is not sufficient to simply adjust the amount of the fine particles to be added, and the hiding ratio can be controlled by controlling the mixing conditions with the colored particles. For example, the concealment ratio can be controlled by a method of uniformly attaching the particles using a medium such as glass beads or a method of uniformly mixing the colored particles and the fine particles using a high-speed stirring type mixing device. Examples of a mixing device using this medium include a turbuler mixer and a vibro mill, and examples of a high-speed stirring type mixing device include a Henschel mixer and a Nauta mixer.

Configuration of Image Forming Method The developing method in which the toner of the present invention can be used is not particularly limited, and it can be suitably used in a contact developing method or a non-contact developing method. For contact type development, the layer thickness of the developer having the toner of the present invention is preferably 0.1 to 8 mm, particularly preferably 0.4 to 5 mm in the development area. In this case, the gap between the photoconductor and the developer carrier is 0.15 to 7
mm, particularly preferably 0.2 to 4 mm.

In the non-contact type developing system, the developer layer formed on the developer carrying member does not come into contact with the photoreceptor. It is preferable to be formed by. In this method, a developer layer having a thickness of 20 to 500 μm is formed in a development region on the surface of the developer carrier, and a gap between the photoconductor and the developer carrier has a larger gap than the developer layer.

In particular, the toner of the present invention has a high charge rising property and is useful for a non-contact developing method. That is, in the non-contact developing method, since a change in the developing electric field is large, a small change in the charging greatly affects the development itself. For this reason, fluctuations in developability such as image quality and density are increased due to a minute change in toner charge amount. However, since the toner of the present invention has a high charge rising property, the change in charge is small, and a stable charge amount can be secured. Therefore, a stable image can be formed for a long time even by the non-contact developing method. it can.

In the non-contact developing method, a thin layer is formed by a magnetic blade using a magnetic force, a method of pressing a developer layer regulating rod against the surface of a developer carrying member, or the like. Further, there is a method in which a urethane blade, a phosphor bronze plate or the like is brought into contact with the surface of the developer carrier to regulate the developer layer. The pressing force of the pressing regulating member is preferably from 1 to 15 gf / mm. When the pressing force is small, the conveyance is likely to be unstable because the regulating force is insufficient. On the other hand, when the pressing force is large, the stress on the developer is increased, and the durability of the developer is likely to be reduced. A preferred range is 3 to 10 gf / mm.
Further, in the non-contact developing method, when a developing bias is applied at the time of development, either a method in which only a DC component is applied or a method in which an AC bias is applied may be used.

The size of the developer carrier is 10 mm in diameter.
Those having a size of ４０40 mm are preferred. When the diameter is small, the mixing of the developer is insufficient, and it is difficult to ensure sufficient mixing to give sufficient charge to the toner. When the diameter is large, the centrifugal force on the developer becomes large. ,
The problem of toner scattering is likely to occur.

Hereinafter, an example of the non-contact developing system will be described with reference to FIG.

FIG. 1 is a schematic view of a non-contact developing type developing section which can be suitably used in the image forming method of the present invention, wherein 1 is a photosensitive member, 2 is a developer carrier, and 3 is a toner of the present invention. Contained two-component developer, 4 is a developer layer regulating member, 5 is a development area, 6 is a developer layer, and 7 is a power supply for forming an alternating electric field.

The two-component developer containing the toner of the present invention is carried by a magnetic force on a developer carrier 2 having a magnet 2B therein, and is conveyed to the development area 5 by the movement of the development sleeve 2A. During the transport, the thickness of the developer layer 6 is regulated by the developer layer regulating member 4 so that the developer layer 6 does not come into contact with the photoconductor 1 in the developing area 5.

The minimum gap (Dsd) of the developing area 5 is determined by the thickness (preferably 20 to 5) of the developer layer 6 conveyed to the area.
00 μm), for example, about 100 to 1000 μm. The power source 7 for forming the alternating electric field is preferably an alternating current having a frequency of 1 to 10 kHz and a voltage of 1 to 3 kVp-p. The power supply 7 may have a configuration in which direct current is added in series to alternating current as necessary. 300 to 800 as DC voltage
V is preferred.

When the toner of the present invention is applied to a color image forming method, a method of forming a monochromatic image on a photoreceptor and transferring it to a sequential transfer material (usually plain paper, PET base, etc.) (this is a sequential transfer) Or a method in which a single-color image is developed a plurality of times on a photoreceptor to form a color image and then collectively transferred to a transfer material (this is referred to as a collective transfer method and is shown in FIG. 3). Method.

The image forming method in FIGS. 2 and 3 will be described in detail below.

As the developer carrier used in the present invention, as shown in FIGS. 1, 2 and 3, a developing device having a magnet 2B built in the carrier is used, and the surface of the developer carrier is constituted. As the developing sleeve 2A to be used, aluminum or aluminum or stainless steel whose surface is oxidized is used.

An example of the sequential transfer method shown in FIG. 2 will be described below.

Reference numeral 11 denotes a charger serving as a charging electrode, and reference numeral 12 denotes a developing unit including developing units for loading yellow, magenta, cyan, and black toners respectively, and is divided into four units corresponding to four color toners. . The basic configuration of these developing units is the same as the schematic diagram of the developing unit shown in FIG. Reference numeral 14 denotes a photosensitive drum, reference numeral 13 denotes a cleaning unit, and reference numeral 15 denotes a transfer drum for storing a transfer material for transferring a single color toner image formed on the photosensitive drum one by one. Reference numeral 16 denotes a transfer unit for transferring a transfer material onto which a toner image on a transfer drum is transferred. Reference numeral 17 denotes an attraction electrode provided inside the transfer drum 15 for performing corona discharge from the inside and electrostatically attracting the transfer material to the drum. , 18 are the photosensitive drums 14
A transfer pole for sequentially transferring the toner image formed thereon to the transfer drum, a separation pole 19 for separating the transfer material electrostatically attracted onto the transfer drum 15, and a transfer pole 20 remaining on the transfer drum after the transfer material is separated. It is a removal electrode for removing charges.

The charging device 11 places the photosensitive drum 14 on the photosensitive drum 14.
A uniform charge is formed, followed by imagewise exposure (means not shown) to form an electrostatic latent image. This electrostatic latent image is developed by a developing device that holds one color toner (for example, black toner) of the developing unit 12, and a one color toner image is formed on the photosensitive drum 14. On the other hand, the transfer material transported onto the transfer drum 15 by the transport unit 16 is electrostatically attracted onto the transfer drum by the attraction electrode 17 and transported to the transfer unit.

The toner image formed on the photosensitive drum 14 is transferred to the transferred transfer material at the transfer section. The toner remains on the photosensitive drum 14 after the transfer of the transfer image, and the remaining toner is cleaned by the cleaning unit 13 and used for the next process. When forming a multicolor image, a toner image of a plurality of colors is formed by development according to a similar process, and is transferred to the transfer drum 15 one by one. Eventually, a desired toner image is formed on the transfer material adsorbed on the transfer drum 15. The transfer material on which the desired toner image has been formed is peeled off by the peeling pole 19, and is conveyed to the fixing unit, where a final fixed multicolor toner image is obtained. On the other hand, the charge remaining on the transfer drum 15 is removed by the removing electrode 20 and used for the next image formation.

Next, the batch transfer method will be described with reference to FIG.

Description of each part of the apparatus is the same as that of the example of FIG. Here, reference numeral 21 denotes a transport unit that transfers the toner image while transporting the transported transfer material. An electric charge is uniformly formed on the photosensitive drum 14 by a charging electrode, and then an electrostatic latent image is formed by a latent image forming means (not shown). This electrostatic latent image is developed by a developing device holding one color toner (for example, black toner) of the developing unit 12,
A one-color toner image is formed on the photosensitive drum. In this example, the toner image is not transferred, and the charge is uniformly formed again by the charger 11 on the photosensitive drum having the toner image as it is, to further form an electrostatic latent image. The toner image is developed by a developing device having a toner of a different color from the above, and a toner image of another color is formed on the previous toner image. During this time, the cleaning unit 13,
The transfer pole 18 and the transport unit 21 do not operate, and the photosensitive drum 1
4 has been evacuated.

After the desired image formation is completed and a multicolor toner image is formed, the toner image on the photosensitive drum is transported by the transport unit 16 and further transferred onto the transfer material transported by the transport unit 21. Is transferred by the transfer pole 18. The transfer material carrying the transferred toner image is conveyed to a fixing unit (not shown) and fixed, and a final multicolor toner image is formed on the transfer material. After the transfer of the toner image, the toner remains on the photosensitive drum 14 so that it is cleaned by the cleaning unit 13 and used for the next image formation.

The toner image formed on the photoreceptor by the above-described various methods is transferred to a transfer material such as paper in a transfer step. The transfer method is not particularly limited, and various methods such as a so-called corona transfer method and a roller transfer method can be adopted.

Since the toner of the present invention has a high transfer efficiency and a small amount of toner remaining on the photoreceptor, for example, when used in a blade cleaning method, the pressing force of the blade against the photoreceptor can be reduced, and It also has effects such as being able to contribute to a longer life.

After transferring the toner image to the transfer material, the toner remaining on the photoconductor is removed by cleaning, and the photoconductor is repeatedly used in the next process.

The mechanism for cleaning in the present invention is not particularly limited, and any known cleaning mechanism such as a blade cleaning system, a magnetic brush cleaning system, or a fur brush cleaning system can be used. A preferred cleaning mechanism is a blade cleaning method using a so-called cleaning blade.

As this configuration, any of the configurations shown in FIGS. 4 and 5 can be used. 4 and 5, the cleaning blade 31 is held by a holder 33, and 1 is a photoconductor. θ is the angle formed by the holder 33 and the photoconductor 1, and is 10 to 10 in FIGS.
90 °, preferably 15 to 75 °. As a material forming the cleaning blade 31, it is preferable to use an elastic body such as silicone rubber or urethane rubber. In this case, it is preferable that the rubber hardness is 30 to 90 °.
The thickness of the cleaning blade 31 is preferably 1.5 to 5 mm, the length outside the holder is preferably 5 to 20 mm, and the pressure contact force on the photosensitive member is preferably 5 to 50 gf / mm.

[0118]

EXAMPLES The present invention will be described below in detail with reference to examples, but embodiments of the present invention are not limited thereto. In the text, “parts” means “parts by weight”.

Example 1 Production Example of Colored Particles 1-1. 10.67 g of carbon black (Mogal L: manufactured by Cabot) treated with an aluminum coupling agent (Prenact Al-M: manufactured by Ajinomoto Co.) was added to dodecyl. An aqueous dispersion of carbon black was prepared by adding 4.92 g of sodium sulfate to a solution of 120 ml of pure water and applying ultrasonic waves with stirring. An emulsified dispersion having a solid content of 20% by weight was prepared by emulsifying a low molecular weight polypropylene (number average molecular weight = 3200) with a surfactant while applying heat. The above carbon black dispersion is mixed with a low molecular weight polypropylene emulsified dispersion 4
3 g, and further, 98.1 g of styrene monomer, n
-Butyl methacrylate monomer 18.4 g, methacrylic acid monomer 6.1 g, t-dodecyl mercaptan
After adding 3 g and 850 ml of degassed pure water, the temperature was raised to 70 ° C. while stirring under a nitrogen stream. Then, 200 ml of pure water in which 4.1 g of potassium persulfate was dissolved was added and reacted at 70 ° C. for 6 hours. The resulting carbon black-containing colored particle dispersion is referred to as “dispersion 1-1”.
The primary particle size (light scattering electric permanent particle size analyzer ELS-800: manufactured by Otsuka Electronics Co., Ltd.) and molecular weight distribution (using GPC; molecular weight in terms of styrene) were measured.
The results are shown in Table 1 below. This “dispersion liquid 1-1” 600 m
of a 2.7 mol% aqueous potassium chloride solution per 160 l.
Then, 94 ml of isopropyl alcohol and 5.4 g of polyoxyethylene octyl phenyl ether (average degree of ethylene oxide is 10) dissolved in 40 ml of pure water were added. Thereafter, the temperature was raised to 85 ° C., and the reaction was performed for 6 hours. Then, after the completion of the reaction, the reaction solution was filtered, washed with water, and dried to obtain the colored particles of the present invention. This is referred to as “colored particle 1-1”.

Production Example 1-2 of Colored Particles In Production Example 1-1 of colored particles, C.I. I. Pigment Blu
e The colored particles of the present invention were obtained in the same manner except that 15: 3 was used. The dispersion obtained here is referred to as “dispersion 1-
2 ", and the colored particles are" colored particles 1-2 ".

Production Example 1-3 of Colored Particles In Production Example 1-1 of colored particles, C.I. I. Pigment Red
Colored particles of the present invention were obtained in the same manner except that 122 was used. The dispersion obtained here is referred to as “dispersion 1-3”, and the colored particles are referred to as “colored particles 1-3”.

Colored Particle Production Example 1-4 In the colored particle production example 1-1, C.I. I. Pigment Yel
Colored particles of the present invention were obtained in the same manner except that low 17 was used. The dispersion obtained here is referred to as “dispersion 1-
4 ", and the colored particles are referred to as" colored particles 1-4 ".

Colored Particle Production Example 1-5 The same procedure as in Colored Particle Production Example 1-1, except that “dispersion liquid 1-1” was used and the amount of isopropyl alcohol to be added was 125 ml
Other than the above, colored particles of the present invention were obtained in the same manner. This is referred to as “colored particles 1-5”.

Comparative Colored Particle Production Example 1-1 Styrene-n-butyl acrylate copolymer (copolymer ratio = 85: 15, weight average molecular weight = 63000) 100
Parts, 10 parts of carbon black and 5 parts of low molecular weight polypropylene (number average molecular weight = 3200) were added and kneaded.
After pulverization and classification, comparative colored particles were obtained. This is designated as “colored particles for comparison 1-1”.

Comparative Colored Particle Production Example 1-2 In Comparative Colored Particle Production Example 1-1, C.I. I. Pigment Blue 1
Comparative colored particles were obtained in the same manner except that 5: 3 was used.
This is referred to as “comparative colored particles 1-2”.

Comparative Colored Particle Production Example 1-3 In Comparative Colored Particle Production Example 1-1, C.I. I. Pigment Red 122
Comparative colored particles were obtained in the same manner except that was used. This is designated as “colored particles for comparison 1-3”.

Comparative Colored Particle Production Example 1-4 In Comparative Colored Particle Production Example 1-1, C.I. I. Pigment Yellow
Comparative colored particles were obtained in the same manner except that No. 17 was used. This is designated as “comparative colored particles 1-4”.

[0128] The above evaluation of the "dispersion 1-1" - "dispersion 1-4", "colored particles 1-1" - "colored particles 1-5", "Comparative colored particles 1
Various physical properties of "-1" to "colored particles for comparison 1-4" are shown in the following table.

[0129]

[Table 1]

[0130]

[Table 2]

Table 3 shows the fine particles used in the preparation of the toner.

[0132]

[Table 3]

The fine particles shown in Table 3 above were added to the above-mentioned colored particles and comparative colored particles to obtain the following toners. In addition, about the mixing method, it mixed using the Henschel mixer at the stirring peripheral speed of 40 m / sec.

[0134]

[Table 4]

Developer Preparation Examples Further, for “Toner 1-1” to “Toner 1-12” and “Comparative Toner 1-1” to “Comparative Toner 1-5”, styrene-acrylic resin was replaced with copper-zinc ferrite, respectively. (Volume average particle size = 45 μm) was mixed with the coated carrier to prepare a developer having a toner concentration of 5% by weight. In addition,
The developer number is “developer 1-1” to “developer 1-1” in the developer using “toner 1-1” to “toner 1-12”.
2 ”and“ Comparative Toner 1-1 ”to“ Comparative Toner 1-
The developer using “5” is “Comparative developer 1-1” to “Comparative developer 1-5” (the same applies to Examples 2 and 3).

( Evaluation ) As a combination of developers,
“Developer 1-1” to “Developer 1-4”, “Comparative developer 1”
-1 "to" Comparative developer 1-4 ", and" Developer 1-5 ".
"-1-12" and "Comparative developer 1-5" were used only with black developer.

An image forming apparatus basically having the mechanism shown in FIG. 3 (Konica 9028 Konica Corporation) was used. This uses a negatively charged photoreceptor and uses a reversal development method.

The evaluation was performed in a low-temperature, low-humidity environment (10 ° C., 20% R).
H) and a change in charge amount and a change in developability in a high-temperature and high-humidity environment (33 ° C., 85% RH). The results are shown below.

The charge amount indicates a charge amount measured by a blow-off method. For the developability, the amount of toner adhered on the photoreceptor was measured, and the amount of developed toner per unit area (mg / c
m ² ).

[0140]

[Table 5]

In Table 5, the developers 1-1 to 1 in the present invention are shown.
It can be seen that -12 has no problem in characteristics, whereas Comparative Developers 1-1 to 1-5 outside the present invention have problems in characteristics.

Example 2 Production Example of Colored Particles 2-1 10.67 g of carbon black (Mogal L: manufactured by Cabot) treated with an aluminum coupling agent (Prenact Al-M: manufactured by Ajinomoto Co.) was added to dodecyl. An aqueous dispersion of carbon black was prepared by adding 4.92 g of sodium sulfate to a solution of 120 ml of pure water and applying ultrasonic waves with stirring. An emulsified dispersion having a solid content of 20% by weight was prepared by emulsifying a low molecular weight polypropylene (number average molecular weight = 3200) with a surfactant while applying heat. The above carbon black dispersion is mixed with a low molecular weight polypropylene emulsified dispersion 4
3 g, and further, 98.1 g of styrene monomer, n
-Butyl methacrylate monomer 18.4 g, methacrylic acid monomer 6.1 g, t-dodecyl mercaptan
After adding 3 g and 850 ml of degassed pure water, the temperature was raised to 70 ° C. while stirring under a nitrogen stream. Then, 200 ml of pure water in which 4.1 g of potassium persulfate was dissolved was added and reacted at 70 ° C. for 6 hours. The obtained carbon black-containing colored particle dispersion is referred to as “dispersion 2-1”.
The primary particle size (light scattering electric permanent particle size analyzer ELS-800: manufactured by Otsuka Electronics Co., Ltd.) and molecular weight distribution (using GPC; molecular weight in terms of styrene) were measured.
The results are shown in Table 6 below. This “dispersion 2-1” 600 m
of a 2.7 mol% aqueous potassium chloride solution per 160 l.
Then, 94 ml of isopropyl alcohol and 5.4 g of polyoxyethylene octyl phenyl ether (average degree of ethylene oxide is 10) dissolved in 40 ml of pure water were added. Thereafter, the temperature was raised to 85 ° C., and the reaction was performed for 6 hours. Then, after the completion of the reaction, the reaction solution was filtered, washed with water, and dried to obtain the colored particles of the present invention. This is referred to as “colored particles 2-1”.

Production Example 2-2 of Colored Particles In Production Example 2-1 of colored particles, C.I. I. Pigment Blu
e The colored particles of the present invention were obtained in the same manner except that 15: 3 was used. The dispersion obtained here is referred to as “dispersion 2-
2 "and the colored particles are referred to as" colored particles 2-2 ".

Production Example 2-3 of Colored Particles In Production Example 2-1 of colored particles, C.I. I. Pigment Red
Colored particles of the present invention were obtained in the same manner except that 122 was used. The dispersion obtained here is referred to as “dispersion 2-3”, and the colored particles are referred to as “colored particles 2-3”.

Colored Particle Production Example 2-4 In the Colored Particle Production Example 2-1, C.I. I. Pigment Yel
Colored particles of the present invention were obtained in the same manner except that low 17 was used. The dispersion obtained here is referred to as “dispersion 2-
4 ", and the colored particles are" colored particles 2-4 ".

Colored Particle Production Example 2-5 The same procedure as in Colored Particle Production Example 2-1, except that “dispersion liquid 2-1” was used and the amount of isopropyl alcohol to be added was 125 ml
Other than the above, colored particles of the present invention were obtained in the same manner. This is referred to as “colored particles 2-5”.

Colored Particle Production Example 2-6 The same procedure as in Colored Particle Production Example 2-1 was repeated except that “dispersion liquid 2-1” was used and the amount of the added 2.7 mol% potassium chloride aqueous solution was 250 ml. Thus, the colored particles of the present invention were obtained. This is referred to as “colored particles 2-6”.

Colored Particle Production Example 2-7 The same procedure as in Colored Particle Production Example 2-1, except that “dispersion liquid 2-1” was used and the amount of isopropyl alcohol to be added was 72 ml,
The colored particles of the present invention were obtained in the same manner except that the amount of the 2.7 mol% aqueous potassium chloride solution was changed to 200 ml. This is referred to as “colored particles 2-7”.

Colored Particle Production Example 2-8 The same procedure as in Colored Particle Production Example 2-1, except that “dispersion liquid 2-1” was used and the amount of isopropyl alcohol to be added was 60 ml,
The colored particles of the present invention were obtained in the same manner except that the amount of the 2.7 mol% potassium chloride aqueous solution was changed to 180 ml. This is designated as "colored particles 2-8".

Comparative Colored Particle Production Example 2-1 Styrene-n-butyl acrylate copolymer (copolymer ratio = 85: 15, weight average molecular weight = 63000) 100
Parts, 10 parts of carbon black and 5 parts of low molecular weight polypropylene (number average molecular weight = 3200) were added and kneaded.
After pulverization and classification, comparative colored particles were obtained. This is designated as “colored particles for comparison 2-1”.

[0151] evaluation or more "dispersion 2-1" - "dispersion 2-4", "colored particles 2-1" - "colored particles 2-8", "Comparative colored particles 2
Various physical properties of "-1" are shown in the following table.

[0152]

[Table 6]

[0153]

[Table 7]

Table 8 below shows the fine particles used.

[0155]

[Table 8]

The toner was prepared by combining these fine particles with the above-mentioned colored particles. The preparation example is shown below.

[0157]

[Table 9]

[0158]

[Table 10]

A Cu-Zn ferrite carrier coated with the above toner and a styrene-acrylic resin (volume average particle size 4
5 μm) to prepare a developer having a toner concentration of 5.9 wt%.

The evaluation was made by Konica D made by Konica Corporation.
The evaluation was carried out in a non-contact developing system using C-7728. Note that a laminated organic photoconductor was used as the photoconductor, and development was performed by reversal development. Further, the cleaning method used is a blade cleaning method.

In order to evaluate the development start-up performance, a solid black image was printed in a high-temperature and high-humidity environment (33 ° C., 85% RH), and the front and rear edge density differences were measured. The image density was measured with a Macbeth reflection densitometer and indicated by the difference in density between the front end and the rear end. The results are shown below.

[0162]

[Table 11]

As shown in Table 11, the difference between the front and rear end densities of the developers 2-1 to 2-10 in the present invention is clearly small.

Example 3 Production of Colored Particles 1 Carbon black (Mogal L: manufactured by Cabot) was treated with an aluminum coupling agent (Prenact Al-M: manufactured by Ajinomoto Co.). 10.67 g of sodium dodecyl sulfate 4 An aqueous dispersion of carbon black was prepared by adding .92 g to a solution of 120 ml of pure water and applying ultrasonic waves with stirring. Further, a low-molecular-weight polypropylene (number-average molecular weight = 3200) is emulsified in water with a surfactant while applying heat, and has a solid content of 2%.
A 0% by weight emulsified dispersion was prepared. 43 g of a low molecular weight polypropylene emulsified dispersion in the above carbon black dispersion
Were further mixed, and 98.1 g of a styrene monomer, 18.4 g of an n-butyl methacrylate monomer, 6.1 g of a methacrylic acid monomer, and 3.3 g of t-dodecyl mercaptan were further added.
g, 850 ml of degassed pure water was added, and the temperature was raised to 70 ° C. while stirring under a nitrogen stream. Then, 200 ml of pure water in which 4.1 g of potassium persulfate was dissolved was added.
The reaction was performed at 70 ° C. for 6 hours. The resulting carbon black-containing colored particle dispersion is referred to as “dispersion 3-1”. The primary particle size (light scattering electric permanent particle size analyzer ELS-800: manufactured by Otsuka Electronics Co., Ltd.) and molecular weight distribution (using GPC; molecular weight in terms of styrene) were measured. The results are shown in Table 12 below. This “dispersion 3-1” 600 m
of a 2.7 mol% aqueous potassium chloride solution per 160 l.
Then, 94 ml of isopropyl alcohol and 5.4 g of polyoxyethylene octyl phenyl ether (average degree of ethylene oxide is 10) dissolved in 40 ml of pure water were added. Thereafter, the temperature was raised to 85 ° C., and the reaction was performed for 6 hours. Then, after the completion of the reaction, the reaction solution was filtered, washed with water, and dried to obtain the colored particles of the present invention. This is referred to as “colored particles 3-1”.

Colored Particle Production Example 3-2 In the Colored Particle Production Example 3-1, C.I. I. Pigment Blu
e The colored particles of the present invention were obtained in the same manner except that 15: 3 was used. The dispersion obtained here is referred to as “dispersion 3-
2 ", and the colored particles are referred to as" colored particles 3-2 ".

Colored Particle Production Example 3-3 In the Colored Particle Production Example 1, C.I. I. Pigment Red 1
Colored particles of the present invention were obtained in the same manner except that No. 22 was used.
The dispersion obtained here is referred to as “dispersion 3-3”.
The colored particles are referred to as “colored particles 3-3”.

Production Example of Colored Particles 3-4 In Production Example 1 of colored particles, C.I. I. Pigment Yellow
Except using w17, the colored particles of the present invention were obtained in the same manner. The dispersion obtained here is referred to as “dispersion 3-4”, and the colored particles are referred to as “colored particles 3-4”.

Colored Particle Production Example 3-5 The same procedure as in Colored Particle Production Example 3-1, except that “dispersion liquid 3-1” was used and the amount of isopropyl alcohol to be added was 125 ml
Other than the above, colored particles of the present invention were obtained in the same manner. This is referred to as “colored particles 3-5”.

Colored Particle Production Example 3-6 The same procedure as in Colored Particle Production Example 3-1, except that “dispersion liquid 3-1” was used and the amount of the added 2.7 mol% aqueous potassium chloride solution was 250 ml, was repeated. Thus, the colored particles of the present invention were obtained. This is referred to as “colored particles 3-6”.

Colored Particle Production Example 3-7 The same procedure as in Colored Particle Production Example 3-1, except that “dispersion liquid 3-1” was used and the amount of isopropyl alcohol to be added was 72 ml,
The colored particles of the present invention were obtained in the same manner except that the amount of the 2.7 mol% aqueous potassium chloride solution was changed to 200 ml. This is referred to as “colored particles 3-7”.

Production Example 3-8 of Colored Particles In Production Example 3-1 of colored particles, using “dispersion liquid 3-1”, the amount of isopropyl alcohol to be added was 60 ml.
The colored particles of the present invention were obtained in the same manner except that the amount of the 2.7 mol% potassium chloride aqueous solution was changed to 180 ml. This is referred to as “colored particles 3-8”.

Comparative Colored Particle Production Example 3-1 Styrene-n-butyl acrylate copolymer (copolymer ratio = 85: 15, weight average molecular weight = 63000) 100
Parts, 10 parts of carbon black and 5 parts of low molecular weight polypropylene (number average molecular weight = 3200) were added and kneaded.
After pulverization and classification, comparative colored particles were obtained. This is designated as “colored particles for comparison 3-1”.

[0173] The above evaluation of the "dispersion 3-1" - "dispersion 3-4", "colored particles 3-1" - "colored particles 3-8", "Comparative colored particles 3
Various physical properties of "-1" are shown in the following table.

[0174]

[Table 12]

[0175]

[Table 13]

The following table shows the fine particles used.

[0177]

[Table 14]

The fine particles shown in the above table were added to the above-mentioned colored particles to obtain the following toner. The following table shows a toner production example. In addition, about the mixing method of a coloring particle and a fine particle, using a Henschel mixer, stirring peripheral speed 40m
/ Sec for 10 minutes.

[0179]

[Table 15]

[0180]

[Table 16]

The above toner and a Cu—Zn ferrite carrier coated with a styrene-acrylic resin (with a volume average particle size of 4
5 μm) to prepare a developer having a toner concentration of 5.9 wt%.

The evaluation was made by Konica D made by Konica Corporation.
The evaluation was carried out in a non-contact developing system using C-7728. Note that a laminated organic photoconductor was used as the photoconductor, and development was performed by reversal development. Further, the cleaning method used is a blade cleaning method.

6% at low temperature and low humidity (10 ° C., 20% RH)
Printing was carried out continuously at a pixel ratio of 50,000 sheets, and image defects such as white spots and pass-through occurring in solid black portions on the image were evaluated in units of 1000 sheets. The following table shows the number of sheets at which image defects began to occur. The white spots have a diameter of 0.3 mm or more. Furthermore, the initial developability and resolution in a low-temperature and low-humidity environment were evaluated. The initial developability is obtained by converting the amount of toner (mg) developed on the photoreceptor per unit area (cm ² ). The resolution is determined by visually observing the break of the diagonal line when printing is performed with the main scanning line of 600 dpi.

The cleaning conditions were as shown in FIG. 5, the angle θ formed by the holder and the photosensitive member was 22 °, and urethane rubber was used as the material constituting the cleaning blade itself. The rubber hardness was 65 °, the thickness was 2 mm, and the length outside the holder was 8 mm. Further, the pressing force against the photoreceptor is 1
5 gf / cm.

A4 plain paper was used for the above evaluation.

[0186]

[Table 17]

As shown in Table 17, all of the developers 3-1 to 3-12 in the present invention are excellent in performance, but the performance of the comparative developers 3-1 to 3-4 is problematic. I understand.

[0188]

According to the present invention, the following effects have been obtained.

(1) The first toner, developer and image forming method of the present invention can obtain stable developability even if the environment changes.

(2) In the second toner, developer and image forming method of the present invention, a difference in leading edge density hardly occurs.

(3) The third toner, developer and image forming method of the present invention have high developability and have no image defects such as white spots and diagonal line breakage over a long period of time even when copying a large number of sheets.

[Brief description of the drawings]

FIG. 1 is a schematic diagram showing an example of a non-contact developing type developing unit.

FIG. 2 is a schematic diagram illustrating an example of a sequential transfer method.

FIG. 3 is a schematic view showing an example of a batch transfer method.

FIG. 4 is a schematic view showing an example of a blade cleaning system.

FIG. 5 is a schematic view showing another example of the blade cleaning method.

[Explanation of symbols]

 Reference Signs List 1 photoconductor 2 developer carrier 2A developing sleeve 2B magnet 3 two-component developer 4 developer layer regulating member 5 developing region 6 developer layer 7 power supply for forming alternating electric field 11 charger 12 developing unit 13 cleaning unit 14 Photoconductor drum 15 Transfer drum 16 Transport unit 17 Adsorption pole 18 Transfer pole 19 Stripping pole 20 Elimination electrode 21 Transport unit 31 Cleaning blade 33 Holder

 ──────────────────────────────────────────────────続 き Continued on the front page (72) Inventor Mikio Kamiyama 1 Konica Corporation, Sakuracho, Hino City, Tokyo

Claims (16)

[Claims] 1. At least a BET specific surface area of 5 m ² / g
The above colored particles and the number average primary particle diameter is 5 to 2000 n
m. Fine particles having a particle diameter of m. 2. The electrostatic image developing toner according to claim 1, wherein a hiding ratio of the fine particles on the surface of the colored particles is 5 to 80%. 3. A toner comprising a toner for developing an electrostatic image comprising at least colored particles and fine particles and a developer comprising a carrier, wherein the BET specific surface area of the colored particles is 5 m ² / g or more, and the number average primary particles of the fine particles are Particle size 5 to 2000 nm
A developer, characterized in that: 4. An image forming method for visualizing an electrostatic latent image formed on an image forming body using a developer, wherein the developer comprises at least colored particles and fine particles. BET of the colored particles using a toner and a carrier
An image forming method, wherein the specific surface area is 5 m ² / g or more, and the number average primary particle diameter of the fine particles is 5 to 2000 nm. 5. A step of visualizing an electrostatic latent image formed on the image forming body using a developer, and forming an electrostatic latent image again on the image forming body carrying the toner image. Using a developer to visualize the electrostatic latent image to form a toner image, and repeating this process to form a plurality of color toner images on the image forming body; and An image forming method including a step of collectively transferring a plurality of color toner images formed thereon onto a transfer material, wherein the developer comprises: a toner for developing an electrostatic image composed of at least colored particles and fine particles; and a carrier. And the toner has a BET specific surface area of 5 m ² /
g or more of colored particles and a number average primary particle diameter of 5 to 2000 n
m. Fine particles of m. 6. A BET specific surface area of at least 5 m ² / g.
The above colored particles and a BET specific surface area of 30 to 60 m ² / g
And a fine particle having a number average primary particle diameter of 60 to 150 nm. 7. The electrostatic image developing toner according to claim 6, wherein a hiding ratio of the fine particles on the surface of the colored particles is 5 to 80%. 8. The toner according to claim 1, wherein the fine particles of the toner for developing an electrostatic image are B.
Fine particles (A) having an ET specific surface area of 30 to 60 m ² / g and a number average primary particle diameter of 60 to 150 nm, and a BET specific surface area of 80 to 400 m ² / g and a number average primary particle diameter of 5 to 100
8. The electrostatic image developing toner according to claim 6, comprising fine particles (B) having a particle diameter of nm. 9. In a toner for developing an electrostatic image comprising at least colored particles and fine particles, and a developer comprising a carrier, the BET specific surface area of the colored particles is 5 m ² / g or more, and the fine particles have a BET specific surface area. A developer having a particle size of 30 to 60 m ² / g and a number average primary particle size of 60 to 150 nm. 10. An image forming method for visualizing an electrostatic latent image formed on an image forming body using a developer, wherein the developer is used for developing an electrostatic image comprising at least colored particles and fine particles. Using a toner and a carrier, BE of the colored particles
T specific surface area is 5 m ² / g or more, and the fine particles are BET
An image forming method, having a specific surface area of 30 to 60 m ² / g and a number average primary particle diameter of 60 to 150 nm. 11. A step of developing an electrostatic latent image formed on the image forming body using a developer, and forming an electrostatic latent image again on the image forming body carrying the toner image. Using a developer to visualize the electrostatic latent image to form a toner image, and repeating this process to form a plurality of color toner images on the image forming body; and An image forming method including a step of collectively transferring a plurality of color toner images formed thereon onto a transfer material, wherein the developer comprises: a toner for developing an electrostatic image composed of at least colored particles and fine particles; and a carrier. And the toner has a BET specific surface area of 5 m ^2.
/ G or more of the colored particles and the fine particles have a BET specific surface area of 30 to
60 m ² / g, and the number average primary particle size is 60 to 1
An image forming method comprising fine particles having a diameter of 50 nm. 12. In a toner for developing an electrostatic image comprising at least colored particles and fine particles, the BET of said colored particles
Colored particles having a specific surface area of 5 m ² / g or more; fine particles (A) having a number average primary particle diameter of 5 to 50 nm;
A toner for developing an electrostatic image, comprising fine particles (B) having a particle size of 000 nm. 13. The method according to claim 1, wherein a hiding ratio of the fine particles on the surface of the colored particles is 5 to 80%.
3. The toner for developing an electrostatic image according to 2. 14. A toner comprising an electrostatic charge image developing toner comprising at least colored particles and fine particles and a developer comprising a carrier, wherein the colored particles have a BET specific surface area of 5 m ² / g or more, and the fine particles are number average primary particles. A developer comprising fine particles (A) having a diameter of 5 to 50 nm and fine particles (B) having a diameter of 60 to 2000 nm. 15. An electrostatic latent image formed on an image forming body is developed using a developer, and the formed toner image is transferred to a transfer material. In an image forming method for cleaning using a toner, a toner for electrostatic image development comprising at least colored particles and fine particles as the developer and a carrier, and the BET specific surface area of the colored particles is 5 m ² / g or more, Fine particles (A) having a number average primary particle diameter of 5 to 50 nm and 60
An image forming method comprising: fine particles (B) having a particle size of from 2000 to 2000 nm. 16. A step of developing an electrostatic latent image formed on the image forming body using a developer, and forming an electrostatic latent image again on the image forming body carrying the toner image. Using a developer to visualize the electrostatic latent image to form a toner image, and repeating this process to form a plurality of color toner images on the image forming body; and An image forming method including a step of collectively transferring a plurality of color toner images formed thereon onto a transfer material, wherein the developer comprises: a toner for developing an electrostatic image composed of at least colored particles and fine particles; and a carrier. And the toner has a BET specific surface area of 5 m ^2.
/ G or more colored particles and a number average primary particle diameter of 5 to 50 n
m. Fine particles (A) and 60 to 2000 nm fine particles (B).