JP2002062681A - Electrostatic charge image developing toner, and developer, method for forming image and device for image formation by using the same - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an electrostatic charge image developing toner, developer, method for forming images by using these and device for image formation such that no toner filming is caused on a photoreceptor or intermediate transfer body, therefore, no speckle is formed in an image by filming, proper gloss is obtained and profound and high-quality images can be obtained for a long time. SOLUTION: The electrostatic charge image developing toner is obtained by mixing composite organic fine particles prepared by depositing and fixing inorganic fine particles having 5 to 100 nm average particle size on the surfaces of organic fine particles having 0.1 to 5.0 μm average particle size in color particles which are prepared by polymerizing at least polymerizable monomers in a water-based medium and which contain a coloring agent and contain a release agent by 3 to 30 mass%.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a toner for developing an electrostatic image mainly used in a color copying machine or a color printer,
The present invention relates to a developer, an image forming method and an image forming apparatus using the same.

[0002]

2. Description of the Related Art At present, in a full-color image forming apparatus, a plurality of image forming units having a photosensitive drum (electrostatic image carrier drum) and a transfer unit as a core are arranged on an outer peripheral surface of a transfer belt. Each color toner image formed by the
The transfer material (image support,
The so-called tandem system, in which the image is transferred onto a recording paper or the like and is typically plain paper), or once transferred to an intermediate transfer member and then transferred to an image support, is becoming mainstream.

The tandem method has a great advantage in that the photosensitive drums are separately prepared corresponding to the toners of the respective color components, so that high-speed image formation can be performed without mixing the toners of the respective colors.

However, on the other hand, there still remains a problem in transferring the toner images of the respective color components onto a recording sheet in a multiplex manner without color shift and maintaining the quality for a long period of time. In particular, during image formation, toner particles are scattered at a position other than a predetermined position on recording paper to cause image deterioration, filming occurs on a photosensitive drum, a transfer belt, or an intermediate transfer body, and a photosensitive drum, a transfer belt, or an intermediate transfer body is formed. Is adversely affecting durability.

Therefore, in a tandem type image forming apparatus, a technique of increasing the contact surface between a photosensitive drum and a transfer belt and transferring an image before toner particles are scattered (Japanese Patent Laid-Open No. 63-118772). And Japanese Patent Application Laid-Open No. 53-82348 discloses a technique of using a roller and a corona charger as a transfer device to reduce or eliminate the frictional resistance of the transfer device against the transfer belt.

[0006]

As described above, countermeasures have been studied for the problems of the tandem system, however, there is no sufficient countermeasure so far, so there is a possibility that it will become a major problem in the future. .

The present invention has been made to solve the above problems. That is, an object of the present invention is to provide a long-term image that has no filming of toner on each photoreceptor and an intermediate transfer member, and thus has no image unevenness due to filming, has an appropriate gloss, and has a deep, high-quality image. An object of the present invention is to provide a toner and a developer for developing an electrostatic image, an image forming method using the same, and an image forming apparatus using the toner.

[0008]

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

[1] A colored particle obtained by polymerizing at least a polymerizable monomer in an aqueous medium, containing a colorant and containing a release agent in an amount of 3 to 30% by mass, has an average particle size of 0.1 to 3% by mass.
A toner for developing an electrostatic charge image, which is obtained by mixing composite organic fine particles having inorganic fine particles having a primary average particle diameter of 5 to 100 nm fixed on the surface of organic fine particles of 1 to 5.0 μm.

[2] A toner for developing an electrostatic image obtained by salting out / fusing composite resin particles constituting the colored particles produced by the multi-stage polymerization method, and in a region other than the outermost layer of the composite resin particles. The toner for developing an electrostatic image according to [1], further comprising a release agent.

[3] The resistance of the composite organic fine particles is 10 ⁸ or more.
The toner for developing an electrostatic image according to [1], wherein the toner has a density of 10 ¹¹ Ω · cm.

[4] A plurality of electrostatic image carriers on which toner images of different colors are formed on the peripheral surface are arranged along the transfer material transporting member, and are opposed to the respective electrostatic image carriers. Forming apparatus provided with an electrostatic transfer electric field imparting member for transferring a toner image to a transfer material by electrostatic force, at least a resin and a colorant and 3 to 30% by mass
Colored particles containing a release agent, the average particle size is 0.1 to
The average primary particle diameter is 5 to 5 μm on the surface of the organic fine particles.
An image forming apparatus using a toner obtained by adding and mixing composite organic fine particles having 100 nm of inorganic fine particles fixed thereto.

[5] A plurality of electrostatic image carriers on which toner images of different colors are formed on the peripheral surface are arranged along the intermediate transfer member, and the intermediate transfer is performed once from each of the electrostatic image carriers. After transferring the toner image to the body, the image forming apparatus is configured to re-transfer the toner image to a transfer material. In the image forming apparatus, at least a resin and a colorant, and a colored particle containing 3 to 30% by mass of a release agent, Average particle size is 0.1 to 5.0
The average primary particle size is 5 to 100 μm on the surface of organic fine particles.
An image forming apparatus using a toner obtained by adding and mixing composite organic fine particles to which inorganic fine particles of nm are fixed.

[6] An image forming method using the image forming apparatus described in [4], wherein the addition amount of the composite organic fine particles for at least one color toner is different from other toners.

[7] An image forming method using the image forming apparatus described in [5], wherein the addition amount of the composite organic fine particles for at least one color toner is different from those of the other three colors.

[8] An electrostatic image carrier, an electrostatic latent image forming means for forming an electrostatic latent image on the image carrier, and a toner image formed by applying toner to the electrostatic latent image A plurality of image forming units arranged in a row, an intermediate transfer body on which toner images formed for each of the image forming units are sequentially superimposedly transferred, and a superimposed transfer on the intermediate transfer body And a transfer unit for transferring the formed toner image to a transfer material, wherein at least one of the image forming units is a cleanerless image forming unit including a non-contact developing type developing unit, A toner holding unit for temporarily holding the residual toner remaining on the image carrier after the transfer to the transfer member, wherein the toner holding unit discharges the residual toner held at a predetermined timing; -In the image forming apparatus, the primary average particles are added to the colored particles containing at least a resin and a colorant and 3 to 30% by mass of a release agent, to the surface of the organic fine particles having an average particle size of 0.1 to 5.0 µm. An image forming apparatus using a toner obtained by adding and mixing composite organic fine particles to which inorganic fine particles having a diameter of 5 to 100 nm are fixed.

[0017]

[9] The toner for developing an electrostatic image according to [1], wherein the surface of the inorganic fine particles has the general formula (1)
A hydrophobic treatment with a compound represented by the formula:

As a typical method for producing the colored particles used in the present invention, various constituent materials such as a colorant and, if necessary, a release agent, a charge control agent, and a polymerization initiator are added to the polymerizable monomer. After addition, various constituent materials are dissolved or dispersed in the polymerizable monomer using a homogenizer, a sand mill, a sand grinder, an ultrasonic disperser, or the like. The polymerizable monomer in which these various constituent materials are dissolved or dispersed is dispersed in an aqueous medium containing a dispersion stabilizer into oil droplets of a desired size as a toner using a homomixer, a homogenizer, or the like. Thereafter, the stirring mechanism is moved to a reaction device, which is a stirring blade described later, and heated to cause the polymerization reaction to proceed. After completion of the reaction, the dispersion stabilizer is removed, filtered, washed,
The colored particles of the present invention are prepared by further drying.

The colored particles used in the present invention are produced by suspension polymerization or emulsion polymerization of a monomer in a solution to which an emulsion of necessary additives is added to produce fine polymer particles. After that, it can be produced by a method of adding an organic solvent, a flocculant, and the like to cause association. A method of preparing by mixing and dispersing with a dispersion liquid such as a release agent and a colorant necessary for the composition of the toner at the time of association, and dispersing toner constituent components such as a release agent and a colorant in a monomer. And then polymerized to form composite resin particles constituting the colored particles. Here, the association means that a plurality of composite resin particles and colorant particles constituting the resin particles or the colored particles are fused.

A preferred embodiment for producing the toner of the present invention is a method using composite resin particles. In this method, resin particles having a multilayer structure in which a coating layer made of a resin having a different molecular weight and / or composition from the resin forming the core particles is used so as to cover the surface of the core particles made of the resin. That is, the composite resin particles constituting the colored particles have a structure in which core particles made of a resin are present at the center thereof, and one or more coating layers cover the core particles. The outermost layer is the outermost layer in the present invention.

The molecular weight distribution of the composite resin particles constituting the colored particles is not monodisperse, but usually has a molecular weight gradient from the core particle to the outermost layer.

The multi-stage polymerization method for obtaining the composite resin particles constituting the colored particles of the present invention refers to the n-th (n)
= 0, 1, 2,...), On the surface of the resin particles having a coating layer. For this purpose, the former is used as a nucleus to carry out the polymerization reaction in the presence of a monomer for forming the (n + 1) th coating layer. Therefore, if n is 0, it means a two-stage multistage polymerization method, and if n is ≤1, it is a three-stage or more multistage polymerization method.

A plurality of resins having different compositions and / or molecular weights are present in the composite resin particles constituting the colored particles obtained by the multistage polymerization method as described above. Nevertheless, because the manufacturing method is very stable,
The toner produced by salting out / fusing the composite resin particles and the colorant particles constituting the colorant particles has very little variation in the composition, molecular weight, and surface characteristics among the toner particles. Further, since the polymerization reaction in the composite resin particles is reliably performed, there is no residual monomer or oligomer in the toner particles, and no odor is generated in the fixing step.

Furthermore, there is no variation in the presence of the release agent, and filming hardly occurs. Therefore, in the fixing step by the contact heating method, an image having a moderate glossiness without good adhesiveness to the image support (transfer material), no offset property of the toner on the roller, and no winding of the image support is caused. can get.

In the present invention, salting out / fusion refers to simultaneous occurrence of salting out (aggregation of particles) and fusion (loss of interface between particles), or an act of simultaneously causing salting out and fusion. .

In order to simultaneously carry out the salting out and the fusion, it is necessary to agglomerate the resin particles under a temperature condition not lower than the glass transition temperature (Tg).

The aqueous medium in the present invention means a medium containing at least 50% by mass of water. Also,
The term “colored particles” in the present invention refers to the toner particles produced by the above-described method before the external additives and the like are added.

The method for preparing the resin particles by associating or fusing them in an aqueous medium is not particularly limited. For example, JP-A-5-265252, JP-A-6-329947, and A method disclosed in Japanese Unexamined Patent Publication No. Hei 9-15904 can be exemplified.

That is, a method of associating a plurality of fine particles composed of a resin and a colorant with resin particles and dispersed particles of a constituent material such as a colorant, particularly after dispersing these particles in water using an emulsifier, At the same time as adding a coagulant having a critical coagulation concentration or more and salting out, simultaneously forming a fused particle by heating and fusing at a temperature equal to or higher than the glass transition temperature of the formed polymer itself, gradually growing the particle size, At the particle size, add a large amount of water to stop the particle size growth, and further heat and stir to smooth the particle surface and control the shape.
The toner of the present invention can be formed by heating and drying the particles in a fluidized state in a water-containing state. Here, an organic solvent that is infinitely soluble in water may be added together with the coagulant.

As the polymerizable monomer constituting the resin, styrene, o-methylstyrene, m-methylstyrene, p-methylstyrene, α-methylstyrene, p-chlorostyrene, 3,4- Dichlorostyrene,
p-phenylstyrene, p-ethylstyrene, 2,4-
Dimethylstyrene, p-tert-butylstyrene, p
-N-hexylstyrene, pn-octylstyrene,
pn-nonylstyrene, pn-decylstyrene, p
Styrene or a styrene derivative such as -n-dodecylstyrene, methyl methacrylate, ethyl methacrylate,
N-butyl methacrylate, isopropyl methacrylate,
Methacrylate derivatives such as isobutyl methacrylate, t-butyl methacrylate, n-octyl methacrylate, 2-ethylhexyl methacrylate, stearyl methacrylate, lauryl methacrylate, phenyl methacrylate, diethylaminoethyl methacrylate, and dimethylaminoethyl methacrylate. , Methyl acrylate, ethyl acrylate, isopropyl acrylate, n-butyl acrylate, t-butyl acrylate, isobutyl acrylate,
Acrylic ester derivatives such as n-octyl acrylate, 2-ethylhexyl acrylate, stearyl acrylate, lauryl acrylate, phenyl acrylate, and the like, olefins such as ethylene, propylene, and isobutylene, vinyl chloride, vinylidene chloride, and vinyl bromide , Vinyl fluoride such as vinyl fluoride and vinylidene fluoride; vinyl esters such as vinyl propionate, vinyl acetate and vinyl benzoate; vinyl ethers such as vinyl methyl ether and vinyl ethyl ether; vinyl methyl ketone and vinyl ethyl ketone , Vinyl ketones such as 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, acrylonitrile, Acrylonitrile, there are acrylic acid or methacrylic acid derivatives such as acrylamide. These vinyl monomers can be used alone or in combination.

Further, it is more preferable to use a polymerizable monomer constituting the resin in combination with one having an ionic dissociation group. For example, those having a substituent such as a carboxyl group, a sulfonic acid group, and a phosphoric acid group as a constituent group of a monomer, specifically, acrylic acid, methacrylic acid, maleic acid, itaconic acid, cinnamic acid, and fumaric acid. Acid, maleic acid monoalkyl ester, itaconic acid monoalkyl ester, styrenesulfonic acid, allylsulfosuccinic acid, 2-acrylamido-2-methylpropanesulfonic acid, acid phosphooxyethyl methacrylate, 3
-Chloro-2-acid phosphooxypropyl methacrylate and the like.

Further, divinylbenzene, ethylene glycol dimethacrylate, ethylene glycol diacrylate, diethylene glycol dimethacrylate, diethylene glycol diacrylate, triethylene glycol dimethacrylate, triethylene glycol diacrylate, neopentyl glycol dimethacrylate,
Polyfunctional vinyls such as neopentyl glycol diacrylate can be used to form a crosslinked resin.

These polymerizable monomers can be polymerized using a radical polymerization initiator. In this case, an oil-soluble polymerization initiator can be used in the suspension polymerization method. As the oil-soluble polymerization initiator, 2,2'-azobis- (2,4
-Dimethylvaleronitrile), 2,2'-azobisisobutyronitrile, 1,1'-azobis (cyclohexane-1-carbonitrile), 2,2'-azobis-4-methoxy-2,4-dimethylvalero Azo or diazo polymerization initiators such as nitrile and azobisisobutyronitrile, benzoyl peroxide, methyl ethyl ketone peroxide, diisopropyl peroxycarbonate, cumene hydroperoxide, t-butyl hydroperoxide, di-t-butyl peroxide , Dicumyl peroxide, 2,4-dichlorobenzoyl peroxide, lauroyl peroxide, 2,2-bis-
Examples thereof include peroxide-based polymerization initiators such as (4,4-t-butylperoxycyclohexyl) propane and tris- (t-butylperoxy) triazine, and polymer initiators having a peroxide in a side chain. .

When the 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.

Examples of the dispersion stabilizer include tricalcium phosphate, magnesium phosphate, zinc phosphate, aluminum phosphate, calcium carbonate, magnesium carbonate, calcium hydroxide, magnesium hydroxide, aluminum hydroxide, calcium metasilicate, and calcium sulfate. , Barium sulfate,
Bentonite, silica, alumina and the like can be mentioned. Further, a surfactant generally used as a surfactant such as polyvinyl alcohol, gelatin, methyl cellulose, sodium dodecylbenzenesulfonate, ethylene oxide adduct, and higher alcohol sodium sulfate can be used as a dispersion stabilizer.

As the resin excellent in the present invention, a resin having a glass transition point of 20 to 90 ° C. is preferable and a softening point of 8
The thing of 0-220 ° C is preferred. The glass transition point is measured by a differential calorimetric analysis method, and the softening point can be measured by a Koka flow tester. Furthermore, these resins have a number average molecular weight (Mn) of 10 as measured by gel permeation chromatography.
00 to 100000, weight average molecular weight (Mw) 200
Those having 0 to 1,000,000 are preferred. Further, as a molecular weight distribution, Mw / Mn is 1.5 to 100, particularly 1.8.
-70 are preferred.

The coagulant 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, zinc chloride, 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.
7, 601 (1960), edited by The Society of Polymer Science, Japan, and the like, and a detailed critical aggregation concentration can be determined.
As another method, a desired salt is added to the target particle dispersion at a different concentration, the 、 (zeta) potential of the dispersion is measured, and the salt concentration at which this value changes is defined as the critical aggregation concentration. You can also ask.

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.
It is better to add it at least twice, more preferably at least 1.5 times.

The infinitely soluble solvent means a solvent which is infinitely soluble in water, and in the present invention, a solvent which does not dissolve the formed resin is selected.
Specifically, methanol, ethanol, propanol,
Examples thereof include alcohols such as isopropanol, t-butanol, methoxyethanol and butoxyethanol, nitriles such as acetonitrile, and ethers such as dioxane. Particularly, ethanol, propanol and isopropanol are preferred.

The amount of the solvent to be infinitely dissolved is 1 to 100% by volume based on the polymer-containing dispersion to which the flocculant is added.
Is preferred.

In order to make the shape uniform, it is preferable to prepare a colored particle, and after the filtration, it is preferable to fluidly dry a slurry containing 10% by mass or more of water based on the particle. Those having a polar group in the polymer are preferred. It is considered that the reason for this is that the existing water exerts an effect of slightly swelling the polymer in which the polar group is present, so that it is particularly easy to make the shape uniform.

The toner of the present invention contains at least a resin and a colorant. If necessary, the toner of the present invention may contain a releasing agent or a charge control agent as a fixing property improving agent. Further, an external additive composed of inorganic fine particles, organic fine particles, and the like may be added to the toner particles containing the resin and the colorant as main components.

As a coloring agent used in the toner of the present invention, carbon black, a magnetic substance, a dye, a pigment and the like can be arbitrarily used. As the carbon black, channel black, furnace black, acetylene black, and the like can be used.
Thermal black, lamp black and the like are used. Ferromagnetic metals such as iron, nickel, and cobalt as magnetic materials,
Alloys containing these metals, compounds of ferromagnetic metals such as ferrite and magnetite, alloys that do not contain ferromagnetic metals but exhibit ferromagnetism by heat treatment, for example, Heusler such as manganese-copper-aluminum and manganese-copper-tin An alloy of a type called an alloy, 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 a mixture thereof can also be used. Examples of the pigment include C.I. I. Pigment Red 5, 48: 1, 53: 1, 57: 1, 122,
139, 144, 149, 166, 177,
178, 222, C.I. I. Pigment Orange 3
1, 43, C.I. I. Pigment Yellow 14, 1
7, 93, 94, 138, 156, 158,
180, 185, C.I. I. Pigment Green 7,
C. 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 adding polymer particles prepared by an emulsion polymerization method at the stage of aggregating by adding an aggregating agent to color the polymer, or a method of polymerizing a monomer is used. And a method of adding a colorant, polymerizing, and forming colored particles 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, a releasing agent is added as a fixing offset improving agent, and its amount needs to be 3 to 30% by mass based on the polymerizable monomer. Whether the amount of the release agent exceeds this range or is less than this range, various properties such as filming on the electrostatic latent image carrier and the intermediate transfer body are adversely affected.

The release agent is not particularly limited. Low molecular weight polypropylene (number average molecular weight = 1500 to 900
0), low molecular weight polyolefin wax such as low molecular weight polyethylene, paraffin wax, Fischer-Tropsch wax, ester wax and the like can be used. An ester wax represented by the following general formula can be suitably used.

R _1- (OCO-R ₂ ) _n n is an integer of 1 to 4, preferably 2 to 4, more preferably 3 or 4, and particularly preferably 4. R ₁ and R ₂ represent a hydrocarbon group which may have a substituent, and R ₁ has 1 to 40 carbon atoms, preferably 1 to 20 carbon atoms, more preferably 2 to 5 carbon atoms.
It is. Or, R ₂ has 1 to 40 carbon atoms, preferably 16 carbon atoms.
-30, more preferably 18-26.

Next, specific examples of the compounds will be described.

[0051]

Embedded image

[0052]

Embedded image

The addition amount is 1 to 3 with respect to the whole toner.
0 mass%, preferably 2 to 20 mass%, more preferably 3 to 15 mass%.

The toner of the present invention is obtained by dispersing a release agent in a monomer in an aqueous medium, polymerizing the dispersion, and forming particles containing the release agent in resin particles to form colorant particles. In addition, it is preferable to form a colored particle by salting out / fusion together to obtain a toner.

Various known charge control agents are likewise used.
What can be dispersed in an aqueous medium can also be used. Specific examples include a nigrosine dye, a metal salt of naphthenic acid or a higher fatty acid, an alkoxylated amine, a quaternary ammonium salt compound, an azo metal complex, a metal salt of salicylic acid, and a metal complex thereof.

The particles of the charge control agent and the fixability improver have a number average primary particle diameter of 10 to 500 in a dispersed state.
It is preferable to set it to about nm.

The toner obtained by fusing has a circularity of 0.930 to 0.98 represented by the following equation.
0, preferably 0.940 to 0.975.

Circularity = (circumferential length determined from equivalent circle diameter)
/ (Perimeter of particle projected image) It is preferable that the distribution of the shape factor is sharp, and the standard deviation of the circularity is 0.10.
The following is preferred, and the CV value calculated by the following formula is preferably less than 20, more preferably less than 10.

CV value = {(standard deviation of circularity) / (average circularity)} × 100 By setting the average circularity to 0.930 to 0.980, the shape of the toner can be made somewhat irregular. The heat transfer can be made more efficient, and the fixability can be further improved. That is, an average circularity of 0.9
When the ratio is 80 or less, the fixing property can be improved.
Further, by setting the average circularity to 0.930 or more, the degree of irregularity of the particles can be suppressed, and the friability of the particles due to stress during long-term use can be suppressed.

Further, it is preferable that the distribution of the shape factor is sharp, and the standard deviation of the circularity is 0.10 or less, so that a toner having a uniform shape can be obtained. Since it can be reduced, the effect of preventing the fixing device from being contaminated by improving the fixing rate and reducing the offset property is further exhibited. When the CV value is also less than 20%, a sharp shape distribution can be similarly obtained, and the effect of improving the fixing property can be more remarkably exhibited.

The method of measuring the shape factor is not limited.
Take a photo magnified 0 times, use an image analyzer,
The average circularity can be calculated by measuring the circularity of 500 toners and calculating the arithmetic average value. As a simple measurement method, FPIA-100 is used.
0 (manufactured by Toa Medical Electronics Co., Ltd.).

In order to control the shape, a proper process end time may be determined while monitoring the characteristics of toner particles (colored particles) whose shape is being controlled in a process such as association.

Monitoring means that a measuring device is incorporated in-line and the process conditions are controlled based on the measurement result. That is, for example, in the case of a polymerization toner formed by incorporating measurement of shape and the like in-line and associating or fusing resin particles in an aqueous medium, the shape and particle size are sequentially sampled in steps such as fusing. Is measured, and the reaction is stopped when the desired shape is obtained.

Although the monitoring method is not particularly limited, a flow type particle image analyzer FPIA-
2000 (manufactured by Toa Medical Electronics Co., Ltd.) can be used. This apparatus is suitable because the shape can be monitored by performing image processing in real time while passing the sample liquid. That is, a pump or the like is used from the reaction field to constantly monitor and measure the shape and the like, and stop the reaction when the desired shape and the like are obtained.

The volume average particle diameter of the toner of the present invention is measured by a Coulter Counter TA-II or a Coulter Multisizer (manufactured by Coulter). In the present invention, a Coulter Multisizer was used, connected to an interface (manufactured by Nikkaki) for outputting a particle size distribution and a personal computer. The aperture used in the Coulter Multisizer is 1
The particle size distribution and the average particle size were calculated by measuring the volume distribution of toner having a particle size of 2 μm or more using a particle having a size of 00 μm.

The toner of the present invention has a volume average particle diameter of 3 to 8 μm. When toner particles are formed by a polymerization method, the particle diameter can be controlled by the concentration of the coagulant, the amount of the organic solvent added, the fusing time, and the composition of the polymer itself.

The primary average particle diameter of the inorganic fine particles constituting the composite organic fine particles used in the present invention is preferably from 5 to 100 nm from the viewpoint of improving the cleaning property, the polishing property and the filming resistance. Incidentally, the primary average particle diameter of the inorganic fine particles, observed by a scanning electron microscope,
The number-based average particle size measured by image analysis.

The resistance of the composite organic fine particles of the present invention is 10 ⁷
Preferably ~10 ¹³ Ω · cm, particularly preferably 10 ⁸ ~10 ¹¹ Ω · cm because adhesion to members is appropriate.
When the resistance of the composite organic fine particles is less than 10 ⁷ Ω · cm, the charge of the toner leaks and causes fogging. 10 ¹³
If it is larger than Ω · cm, the adhesion to members such as the photoreceptor and the intermediate transfer member becomes excessive, which causes filming. The resistance measurement method indicates a value measured in a powder state under a condition in which a constant pressure is applied. In this measurement, a normal temperature and normal humidity environment (2
5 shows the volume resistivity measured at 5 ° C., 60% RH).

The other methods of measuring the resistance of each particle measured in the present invention were carried out at a temperature of 20 to 25 ° C. and a humidity of 50 ± 5% by the following method.

The static resistance of each particle was measured using an apparatus as shown in FIG. In the figure, 51 is a measurement particle layer (sample layer), 52 is an insulating pipe, 53 is a brass weight,
54 is a bottom plate made of brass, and 55 is an ohmmeter.

The static resistance was determined from the reading R (Ω) of the resistance meter, the cross-sectional area S (cm ² ) of the sample layer and the thickness t (cm) of the sample layer according to the following equation. In this measurement, 500 g
/ Cm ² is applied to the sample layer.

Static resistance (Ω · cm) = R × S / t Materials constituting the inorganic fine particles include silicon oxide, titanium oxide, aluminum oxide, zinc oxide, zirconium oxide,
Cerium oxide, tungsten oxide, antimony oxide, copper oxide, tellurium oxide, manganese oxide, barium titanate,
Strontium titanate, magnesium titanate, silicon nitride, carbon nitride and the like are used. In particular, 10 ⁸ to 10
^In order to obtain a resistance of ¹¹ Ω · cm, antimony-doped tin oxide or titanium oxide, silicon oxide, barium sulfate or antimony-free tin oxide using lattice defects coated with tin oxide or Preferred are coated titanium oxide, silicon oxide and barium sulfate particles.

The organic fine particles constituting the composite organic fine particles are as follows:
The resin particles are preferably made of an acrylic polymer, a styrene polymer, a styrene-acryl polymer, or the like.

The acrylic polymer constituting the organic fine particles is a homopolymer or a copolymer obtained by polymerizing a monomer selected from acrylic acid or acrylate, methacrylic acid or methacrylate. Acrylic monomers used to obtain such an acrylic polymer include acrylic acid, methyl acrylate, ethyl acrylate, n-butyl acrylate, isobutyl acrylate, propyl acrylate, and n-acrylate
-Octyl, dodecyl acrylate, lauryl acrylate, 2-ethylhexyl acrylate, stearyl acrylate, 2-chloroethyl acrylate, phenyl acrylate, α-methyl methyl acrylate, methacrylic acid, methyl methacrylate, ethyl methacrylate, methacryl Propyl acrylate, n-butyl methacrylate, isobutyl methacrylate, n-octyl methacrylate, dodecyl methacrylate, lauryl methacrylate, 2-ethylhexyl methacrylate, stearyl methacrylate, phenyl methacrylate, dimethylaminoethyl methacrylate, diethylamino methacrylate Ethyl and the like.

An acrylic polymer can be obtained from one or more of the above acrylic monomers. In the present invention, if necessary, one or more other monomers may be copolymerized. May be used. In this case, it is preferable to use an acrylic monomer in a proportion of 50% by mass or more in the monomer composition.

The styrene-based monomers used to obtain the styrene-based polymer constituting the organic fine particles include styrene, o-methylstyrene, m-methylstyrene and p-methylstyrene.
Methyl styrene, α-methyl styrene, p-ethyl styrene, 2,4-dimethyl styrene, pn-butyl styrene, p-tert-butyl styrene, pn-hexyl styrene, pn-octyl styrene, p- Examples thereof include n-nonylstyrene, pn-decylstyrene, pn-dodecylstyrene, p-methoxystyrene, p-phenylstyrene, p-chlorostyrene, and 3,4-dichlorostyrene.

A styrene-based polymer can be obtained from one or more of the above-mentioned styrene-based monomers. In the present invention, one or more other monomers may be copolymerized as necessary. May be used. In this case, it is preferable to use a styrene-based monomer in a proportion of 50% by mass or more in the monomer composition.

The styrene / acrylic copolymer constituting the organic fine particles is obtained by using one or more of the above acrylic monomers and one or more of the above styrene monomers. If necessary, one or more other monomers may be copolymerized. In this case, in the monomer composition, it is preferable to use the acrylic monomer and the styrene monomer in a ratio of 50% by mass or more.

Examples of the other monomers include acrylic acid or methacrylic acid derivatives such as acrylonitrile, methacrylonitrile and acrylamide; vinyl esters such as vinyl acetate, vinyl butyrate and vinyl benzoate; vinyl methyl ether and vinyl ethyl ether. And the like, vinyl ketones such as vinyl methyl ketone, diene such as butadiene and isoprene, unsaturated carboxylic acids such as maleic acid and fumaric acid, and the like. In particular, in order to obtain a resistance of 10 ⁸ to 10 ¹¹ Ω · cm, resin particles in which a surfactant on the surface of the particles is appropriately left in a washing step after emulsion polymerization of the resin particles may be used.

The average particle size of the organic fine particles constituting the composite organic fine particles is from 0.1 to 5.0 μm from the viewpoints of improvement in cleaning properties, prevention of filming, and stability of triboelectric charging.
Is preferred, and particularly preferably 0.2 to 3.0 μm. The average particle size of the organic fine particles can be measured by a laser diffraction particle size distribution analyzer “HELOS” equipped with a wet disperser.
The volume-based average particle size measured by (SYMPATEC). However, before measurement,
10 mg of organic fine particles were dispersed in 50 ml of water together with a surfactant, and then an ultrasonic homogenizer (output: 150
In W), a pre-treatment of dispersing for 1 to 10 minutes was performed while paying attention to re-aggregation due to heat generation.

The composite organic fine particles are formed on the surface of the organic fine particles.
Inorganic fine particles treated with the specific treatment compound are fixed. Here, the term “adhesion” means that the inorganic fine particles are not simply attached to the organic fine particles by electrostatic force, but the length of the portion of the inorganic fine particles embedded in the organic fine particles is 5 to 5.
95%. Such a state can be confirmed by observing the surface of the composite organic fine particles with a transmission electron microscope or a normal electron microscope.

In fixing the inorganic fine particles to the surface of the organic fine particles, it is preferable to first make the organic fine particles spherical, and then to fix the inorganic fine particles to the surface of the organic fine particles. This is because when the organic fine particles are spherical, the inorganic fine particles are uniformly fixed, and the release of the inorganic fine particles is effectively prevented.

Means for spheroidizing the organic fine particles include a method in which the organic fine particles are once melted by heat and then spray granulation, a method in which the hot-melted organic fine particles are jetted into water to form spheres, A method of synthesizing spherical organic fine particles by a polymerization method or an emulsion polymerization method, and the like.

Means for fixing the inorganic fine particles on the surface of the organic fine particles include a method of mixing the organic fine particles and the inorganic fine particles and then applying heat, and a so-called mechanochemical method of mechanically fixing the inorganic fine particles on the surface of the organic fine particles. Method is used. Specifically, the organic fine particles and the inorganic fine particles are mixed and stirred and mixed by a Henschel mixer, a V-type mixer, a turbular mixer, etc., and the inorganic fine particles are adhered to the surface of the organic fine particles by electrostatic force. A method in which the organic fine particles having the fine particles attached thereto are introduced into a heat treatment apparatus such as a nitro atomizer or a spray drier, and heat is applied to soften the surface of the organic fine particles to fix the inorganic fine particles to the surface. After attaching the inorganic fine particles, a device capable of imparting mechanical energy by remodeling an impact-type pulverizer, for example, an ng mill, a method of fixing the inorganic fine particles to the surface of the organic fine particles using a device such as a hybridizer, Are used.

In obtaining the composite organic fine particles, the compounding amount of the inorganic fine particles with respect to the organic fine particles may be an amount capable of uniformly covering the surface of the organic fine particles. In particular,
Although it depends on the specific gravity of the inorganic fine particles, it is usually 5 to 100% by mass, preferably 5 to 80% by mass based on the organic fine particles.
Of inorganic particles are used. If the proportion of the inorganic fine particles is too small, the cleaning property tends to decrease, and if the proportion of the inorganic fine particles is too large, the inorganic fine particles are easily released.

The above-mentioned composite organic fine particles are added to and mixed with the colored particles to form a toner. The compounding ratio of the composite organic fine particles is determined in proportion to the colored particles from the viewpoint of improving the cleaning property and the stability of triboelectric charging. Is preferably 0.01 to 5.0% by mass, and particularly preferably 0.01 to 2.0% by mass.

If the amount is small, cleaning failure (toner adhesion on the photoreceptor and black spots on the image) occurs. On the other hand, if the amount is excessive, the development is adversely affected, and for example, there is a possibility that a problem such as a decrease in density may occur.
When the average particle size of the colored particles is different, it is preferable to add the colored particles at a ratio of the surface area based on the surface area of the 11 μm particles. Specifically, for a 5.5 μm toner, the amount of addition is required to be four times. That is, it is advisable to add as the square of the ratio of the average particle diameter.

Materials Constituting Inorganic Particles Materials constituting inorganic fine particles include silicon oxide, titanium oxide, aluminum oxide, zinc oxide, zirconium oxide,
Cerium oxide, tungsten oxide, antimony oxide, copper oxide, tellurium oxide, manganese oxide, barium titanate,
There are titanium strontium oxide, magnesium titanate, silicon nitride, carbon nitride and the like.

Particularly preferred as these inorganic fine particles are titanium oxide, alumina oxide and zirconium oxide.
The reason for this is that these materials have a small surface area and little water absorption.

The inorganic fine particles constituting the composite organic fine particles are as follows:
Hydrophobic treatment is performed, and those having a hydrophobicity of 30 or more are particularly preferable. This degree of hydrophobicity is measured by a methanol wettability method.

As the hydrophobizing agent for the inorganic fine particles, a titanium coupling agent, a silane coupling agent, a long-chain carboxylic acid and its metal salt, a surfactant and the like are used. Particularly preferred are the compounds of the general formula (1).

Developer The toner of the present invention is preferably mixed with a carrier to form a two-component developer.

The magnetic particles constituting the carrier include:
A substance that is strongly magnetized in that direction by a magnetic field, for example, iron,
Ferrite, including magnetite, iron, nickel, metals or alloys that exhibit ferromagnetism such as cobalt or compounds containing these elements, alloys that do not contain ferromagnetic elements but become ferromagnetic by appropriate heat treatment, For example, an alloy of a kind called a Heusler alloy such as manganese-copper-aluminum or manganese-copper-tin, or particles made of chromium dioxide or the like can be used.

As the coating resin for the resin-coated carrier or the binder resin for the magnetic material-dispersed carrier, for example, a styrene-acrylic copolymer, a silicone compound, a fluorine resin, or the like can be suitably used.

The average particle size of the carrier is 20 to 200 μm
Is preferred, and particularly preferably 40 to 150 μm. When the average particle diameter is too small, the carrier adheres to the electrostatic latent image and a so-called carrier adhesion phenomenon that forms a fixed image occurs, and as a result, the image may be unclear. Flow may occur.

[0096]

DESCRIPTION OF THE PREFERRED EMBODIMENTS Image Forming Method and Image Forming Apparatus
1 Hereinafter, a description will be given using a tandem type full-color image forming apparatus of the present invention. FIG. 2 is a schematic sectional view of the present apparatus.

In the center of the inside of the apparatus, a driving roller 9 and a driven roller 8 having substantially the same size and rotated by a motor (not shown) are driven by a motor (not shown). An endless transfer belt 7 is stretched around the peripheral surfaces of the two rollers without slack. The transfer belt 7 is a film belt made of PVDF (polyvinylidene fluoride), PC (polycarbonate), or the like, or a rubber belt made of chloroprene rubber, urethane rubber, or the like. The belt has a width and the inner circumferential surface of the belt is in rolling friction with these rollers, so that the belt is driven to rotate in the direction of the arrow in FIG.

On the outward path side of the transfer belt 7, a photosensitive member carrying each color image of cyan (C), magenta (M), yellow (Y), and black (K) along the direction of the arrow from the driven roller 8 side. The body drums 1C to 1K are arranged close to each other in parallel with the drive roller 9 and the rotation axis thereof, and are driven and driven in synchronization with the drive of the transfer belt. Around the transfer belt, a cleaning device 16 is provided on the outer peripheral surface of the belt facing the driven roller 8 along the direction of the arrow, and a paper feed guide 10 and a suction charger 17 are provided downstream thereof. Further, a separation charger 12 is provided at a most downstream portion of the recording paper transporting path separated from the photosensitive drums 1C to 1K, and static elimination chargers 14 and 15 are sequentially provided at a transporting return path of the transfer belt 7.

The image forming units 20C to 20K are provided on the photosensitive drums 1C to 1K and the respective peripheral surfaces thereof with charging units 2C to 2K, image exposing units 3C to 3K, and developing units 4C to 4K.
K, transfer units 11C to 11K, cleaners 5C to 5K, and erasers 6C to 6K are arranged in this order in the rotation direction of the photosensitive drum.

The transfer units 11C to 11Y and 11K are transfer rollers that roll on the inner peripheral surface of the transfer belt.

Although not shown, the upper portion of the image forming apparatus includes an image reading section having a CCD scanner for reading a document image, an exposure lamp, a control unit, an image memory, etc., a polygon mirror and a plurality of lenses. An optical system that converts the read image into predetermined image data and guides the converted image data to the image forming units 20C to 20K is provided.

Next, the operation of the present apparatus will be described. Original image data for each of R (red), G (green), and B (blue) color components obtained by the CCD scanner of the original reading unit is subjected to data conversion processing in the control unit, and is converted into C, M, Y, and K images. Converted to data. The control unit temporarily stores the image data in the image memory.

On the other hand, in synchronization with the reading of the original image, the transfer material (sometimes referred to as an image support or a recording sheet, and any transfer material may be used) is directly under the suction charger 17 along the paper feed guide 10. Is transferred to the outer peripheral surface of the transfer belt 7. Then, the attraction charger 17 is electrostatically attracted onto the transfer belt 7 by the discharged positive charges, and is conveyed to the image forming units 20C to 20K. The image data once stored in the image memory is read out in synchronization with the transfer of the transfer material on the transfer belt 7, and is modulated into laser light by the control unit. The laser beam passes through the optical system, and the photosensitive drum 1C
１1K is exposed on the peripheral surface, and subsequently, the developing units 4C to 4K form the respective color toner component images on the peripheral surface. Thereafter, the formed color toner component images are transferred to transfer rollers 11C to 11K.
Are sequentially transferred from the peripheral surfaces of the photosensitive drums 1C to 1K to predetermined positions on the recording paper.

After the transfer, the recording paper is then discharged and separated from the transfer belt 7 by the electric field generated by the separation charger 12 with an AC power supply, and the image is fixed in the fixing unit 13 and discharged outside the apparatus.

After the recording paper is separated, the transfer belt 7 is neutralized by static elimination chargers 14 and 15 connected to an AC power supply, and the cleaning device 16 removes toner and the like adhering to the surface to clean the surface state. To be. In the above description, an example using a photosensitive drum has been described. However, the photosensitive member is a representative example of an electrostatic latent image carrier, but the present invention is not particularly limited to the photosensitive member. Further, the shape does not necessarily have to be a drum, but may be a belt or the like.
Similarly, the transfer belt 7 has been described as an example of a soft belt,
Similarly, any material can be used as long as it can support the transfer material, and for example, a drum shape may be used.

FIG. 3 shows another embodiment of the present invention.
FIG. 1 is a schematic cross-sectional view illustrating a periphery of a belt driving device of a tandem-type full-color image forming apparatus. In this embodiment, the operations of the corona chargers 18C to 18K in the drawing are the same as those of the transfer rollers 11C to 11K, and illustration and description of the main common parts are omitted. Corona Charger 1
8C to 18K are arranged on the inner peripheral surface of the transfer belt 7 so as to face the photosensitive drums 1C to 1K, respectively.
In substantially the same manner as in the above-described embodiment, the recording paper is conveyed on the transfer belt 7, and the images of the respective color toner components are transferred by the corona chargers 18C to 18K.

In the above-described embodiment, the transfer belt is used as a recording paper transporting body as a recording paper is transported on the transfer belt and an image is formed on the recording paper. However, the present invention is not limited to this. For example, an image may be directly transferred to the belt surface as a known intermediate transfer member instead of the transfer belt. However, in this case, a recording paper transport path is provided downstream of the rotation driving of the transfer belt, and the belt surface is brought into contact with the recording paper near the driving roller to transfer the image on the transfer belt to the recording paper. It is necessary to take measures such as fixing the image with a fixing device provided in the transport path and discharging the recording paper to a tray.

Image Forming Method and Image Forming Apparatus-2 An electrostatic image carrier, an electrostatic latent image forming means for forming an electrostatic latent image on the image carrier, and a method for applying toner to the electrostatic latent image A plurality of image forming units which are successively arranged and have a developing means for forming a toner image by means of an intermediate transfer member on which toner images formed for each of the image forming units are sequentially superimposed and transferred; A transfer unit for transferring a toner image superimposed and transferred on a transfer body to a recording body, wherein at least one of the image forming units includes:
A cleaner-less image forming unit including a developing unit of a non-contact developing type, comprising: a toner holding unit that temporarily holds residual toner remaining on the image carrier after transfer to the intermediate transfer body; An example in which the holding unit discharges the remaining toner held at a predetermined timing will be described below.

That is, in the present invention, an electrostatic latent image is formed on the image carrier by the electrostatic image forming means, and this electrostatic latent image is developed into a toner image by the developing means. Then, this toner image is primarily transferred to the intermediate transfer body. Next, after a toner image is also formed in another image forming unit, the toner image is transferred in a stacked manner on the intermediate transfer body. Thereafter, a similar process is repeated to form a toner image on the intermediate transfer member. Thereafter, the toner image formed on the intermediate transfer member is secondarily transferred to a recording member by a transfer unit, and is fixed, so that a required color image is copied and recorded.

Here, in each image forming unit, the toner not transferred to the intermediate transfer body remains on the image carrier after the toner image is primarily transferred to the intermediate transfer body. This residual toner is collected by the toner holding unit before the next image formation is performed. The residual toner collected by the toner holding unit is discharged at a predetermined timing. The predetermined timing is preferably a time of non-image formation in order to maintain high image quality. Further, when toner empty, image quality deterioration, or the like is detected, or by user input, residual toner may be discharged from the toner holding unit.

As described above, by providing the toner holding means for collecting the residual toner remaining on the image carrier after the primary transfer and discharging the residual toner at a predetermined timing, the cleanerless structure can be realized. Since the proper processing of the residual toner is performed, the residual toner after discharge does not exist at the exposure position and the development position on the image carrier at the time of image formation, and image quality deterioration such as roughness of a memory image or a halftone dot image is reduced. Color mixture of toner is prevented, and high image quality is maintained.
Further, since each image forming unit has a cleaner-less configuration and occupies a small volume, the printing speed is increased and the size is reduced by continuously arranging them. Note that the non-contact developing method is a developing method in which toner is caused to fly and developed by applying an AC bias in which an alternating voltage is superimposed on a DC voltage.

As shown in FIG. 4, an image reader IR for reading a document image is roughly divided, and a printing unit PR for printing the read image on a recording paper and reproducing it. The image reader IR reads the light information obtained by separating the original image into three primary colors of red (R), green (G), and blue (B) with a CCD sensor, and performs arithmetic processing on the image data. Is what you do. The printer unit PR includes a transport unit 20 that transports the recording paper P, and yellow (Y), magenta (M), cyan (C), and black (reproduced colors) on a transfer material (also referred to as recording paper P) as described above. (K) (hereinafter, color codes “Y, M,
C, K "are added as appropriate. ), Four image forming units 20Y, 20M, and 20 for forming four color images, respectively.
C, 20K, and an intermediate transfer belt 27.

The transport section includes a paper feed tray 21 for accommodating the transfer material P, and a secondary transfer roller 23 for secondarily transferring the superimposed transfer toner image formed on the intermediate transfer belt 27 to the recording paper P.
And a fixing device 13 for fixing the toner image secondary-transferred onto the recording paper P, a plurality of conveying rollers, and the like. The recording paper P is sent out at a predetermined timing and is conveyed at a constant speed. I have.

Image forming units 20Y, 20M, 20C, 20
K is for forming an image by the electrostatic copying method, and the photosensitive drums 1Y, 1M, 1C, 1 which are continuously arranged in parallel.
It is configured around K. Around the photosensitive drums, charging brushes 104Y, 104M, 104C, 104K for uniformly charging the surface of the photosensitive drum.
And a laser head 107 for forming a required electrostatic latent image on the photosensitive drums 1Y, 1M, 1C, 1K according to image information.
Y, 107M, 107C, and 107K, and developing devices 4Y, 4M, and 4 that fly toner to the electrostatic latent image for development
C, 4K and holding rollers 105Y, 105M, 1 for temporarily holding the toner remaining on each photosensitive drum after development.
05C, 105K, etc. are arranged. That is, the image forming apparatus is of a tandem type in which four cleanerless image forming units are continuously arranged in parallel, and the printing speed is increased and the apparatus is made compact.

Each of the photosensitive drums 1Y, 1M, 1C, 1
Immediately below K, primary transfer rollers 106Y, 106M, 106C, and 106K for primarily transferring the toner images visualized on the respective photoconductors to the intermediate transfer belt 27 are arranged. The intermediate transfer belt 27 has a capacity of 10 ⁶ to 10 ⁸ Ω · cm.
It is an endless belt having a certain surface resistivity.

Further, between the secondary transfer roller 23 and the primary transfer roller 106Y, the residual toner discharged from the holding roller 105 and the intermediate transfer belt 27 after the secondary transfer.
A cleaning device 16 having a cleaning blade 22 for removing and collecting the toner remaining on the cleaning device 16 is disposed.

Next, the operation of the image forming apparatus configured as described above will be described. First, based on the intensity level of light information of an image for each color component of red (R), green (G), and blue (B) obtained by the image reader section IR, the control section performs shading correction and density conversion. , Image processing such as edge enhancement. Then, the image data is converted into write image data of each reproduction color of yellow (Y), magenta (M), cyan (C), and black (K), and these yellow (Y), magenta (M), cyan (C), The black (K) image data is temporarily stored in the control unit.

Thereafter, based on the image data stored in the control section, the laser heads 107Y, 107M,
At 7C and 107K, laser light corresponding to each reproduced color is modulated and emitted. On the other hand, the photosensitive drums 1Y,
1M, 1C, 1K rotate in the direction of the arrow in the figure,
After the surface is uniformly charged by the charging brushes 104Y, 104M, 104C, and 104K, the surface is exposed and scanned by the laser light.

By such exposure, the electrostatic latent images corresponding to the respective reproduced colors formed on the respective photoconductors are developed by the developing units 4Y, 4M, 4C, and 4K containing the toners of the respective reproduced colors. Toner image. These toner images are sequentially superimposed on the intermediate transfer belt 27 by the primary transfer rollers 106Y, 106M, 106C, and 106K at the opposing portions of the photosensitive drums 1Y, 1M, 1C, and 1K and the intermediate transfer belt 27. Transcribed. Thereafter, the toner image superimposedly transferred on the intermediate transfer belt is conveyed to a portion facing the secondary transfer roller 23. Then, the toner image on the intermediate transfer belt 27 is secondary-transferred onto the recording paper P fed from the paper feed tray 21 by the secondary transfer roller 23. Thereafter, the recording paper P on which the toner image has been transferred is conveyed to the fixing device 13, where it is heated to melt the toner images of each color to form a full-color image and is fixed on the recording paper P.

On the other hand, the residual toner remaining on the photosensitive drums 1Y, 1M, 1C, and 1K after the primary transfer to the intermediate transfer belt 27 is removed from the holding rollers 105Y, 105M, 105C, and 1K.
At 05 K, the residual toner discharged from each holding roller and the toner remaining on the intermediate transfer belt 27 after the secondary transfer to the recording paper P are collected by the cleaning device 16.

Here, the processing of residual toner on the photosensitive drum in the cleaner-less image forming unit will be described in more detail. Since all the image forming units have the same configuration, the description will be omitted with the color symbols omitted.

First, -1200 V is applied to the charging brush 104 to charge the surface of the photosensitive drum 1 to about -700 V. At this time, the residual toner remaining on the photosensitive drum 1 after the primary transfer is also charged to the negative polarity at the same time. Therefore, by applying a voltage of about -300 V to the holding roller 105, all the residual toner is collected by the holding roller. You. Therefore, since no toner is present at the exposure position on the photosensitive drum 1, image quality deterioration such as roughness of a memory image or a halftone image does not occur. The electrostatic latent image thus formed is developed by the developing device 4. That is, a developing roller having a developing gap wider than the toner layer and set to 200 μm has a DC voltage of −300 V and an amplitude of 1500 V,
A developing bias in which an AC component having a frequency of 2 kHz is superimposed is applied, whereby the toner layer formed on the developing roller flies in the developing area and is applied to the electrostatic latent image, and the electrostatic layer formed on the photosensitive drum 1 is formed. The latent image is developed to form a toner image.

At this time, the photosensitive drum 1 is used for development.
0.9mg / cm ^TwoEnough concentration
Can be secured. In addition, suitable for the intermediate transfer belt 27
High transfer efficiency by applying high transfer voltage
Can be. Therefore, in the present embodiment, the primary transfer roller 1
-500 V was applied as a transfer voltage to the control circuit 06. like this
The primary transfer to the intermediate transfer belt 27 is performed directly on the recording paper.
Since the toner image is not transferred to P, there is no influence of the recording paper P
This is because transfer efficiency can be maintained. And high transfer efficiency
By securing, on the photosensitive drum 1 after the primary transfer
The amount of remaining toner can be reduced. This
As a result, a cleaner box for collecting residual toner
Even if the holding roller 10 is not provided for each image forming unit,
5 makes it possible to collect the residual toner.
You.

It is necessary to discharge and process the residual toner collected on the holding roller 105 during non-image formation.
When the collected residual toner is superimposed on the toner image by the transfer by the primary transfer roller 106, the collected residual toner comes into contact with the toner image of another color component, so that the collected residual toner is slightly mixed. For this reason, it cannot be returned to the developing device unlike a monochrome cleanerless image forming apparatus. Therefore, before the residual toner discharged from the holding roller 105 reaches the developing position, the developing bias control is performed in which the AC component of the developing bias is turned off and switched to only the DC component. As a result, the residual toner discharged from the holding roller passes through the developing position without being collected by the developing device 4, and color mixing of the toner is prevented.

Then, the above-described residual toner processing is repeatedly executed, and the residual toner is appropriately processed. As a result, there is no need to provide a cleaning box for collecting the residual toner for each image forming unit, so that cleanerlessness can be achieved.

According to the above-described image forming apparatus, the holding roller 105 for temporarily holding the residual toner remaining on the photosensitive drum 1 after the primary transfer is provided, and the residual toner is discharged from the holding roller 105 at a predetermined timing. By discharging the paper and collecting it in the cleaning device 16 provided on the intermediate transfer belt 27, each image forming unit 20 can be made cleaner-less while maintaining high image quality, and the occupied volume is reduced. Therefore, the size of the apparatus is reduced. Also, since this image forming apparatus is of a tandem type,
The printing speed has also been increased. Further, since the contact type charging brush 104 and the transfer rollers 106 and 23 are used, there is no environmental pollution due to generation of ozone.

This embodiment is merely an example.
It does not limit the invention in any way. Therefore, naturally, the present invention can be variously modified and modified without departing from the gist thereof. For example, in the first embodiment, the non-contact developing system is used as the developing units 4Y, 4M, 4C, and 4K, but the primary transfer is first performed on the intermediate transfer belt 27. Since the yellow component does not mix with other color components, a contact development system can be used. Further, the holding roller 105 may be disposed on either the upstream side or the downstream side with respect to the charging brush 104, and may be in contact with or integrated with the charging brush 104. Furthermore, instead of the charging brush, a film, a blade, a roller, or the like is used. Instead of the holding roller 5, a fiber brush, a magnetic brush, a film,
It is also possible to use a blade or the like. Note that the arrangement order of the image forming units, the applied voltage value, and the like are merely examples, and it is needless to say that the present invention is not limited to these.

[0128]

EXAMPLES Next, the present invention will be described in more detail with reference to embodiments, but, of course, the present invention is not limited to these embodiments.

[Preparation Example of Composite Organic Fine Particles] Preparation Example 1 of Composite Organic Fine Particles A primary particle diameter of 15 nm was determined for 100 g of styrene / acrylic organic fine particles (electric resistance: 6.6 × 10 ¹³ Ω · cm) having an average particle diameter of 1.0 μm. Of hydrophobic titanium oxide whose surface was treated with tetraoctyl titanate was added and mixed with a turbula mixer. Then, the peripheral speed was 100 m / h using a modified Hybridizer (manufactured by Nara Machinery Co., Ltd.).
By treating for 3 minutes under the conditions of sec, composite organic fine particles having titanium oxide fixed on the surface of the organic fine particles were produced. This is referred to as “composite organic fine particles 1”.

The electric resistance of the composite organic fine particles 1 was 8.8 × 1
It was 0 ¹² Ω · cm. Composite Organic Fine Particle Production Example 2 In the composite organic fine particle production example 1, the average particle diameter was 1.0.
Composite organic fine particles were obtained in the same manner except that organic fine particles having an average particle diameter of 2.0 μm were used instead of the organic fine particles of μm, and silica whose surface was treated with silicone oil was used. This is referred to as “composite organic fine particles 2”.

The electric resistance of the composite organic fine particles 2 was 7.2 × 1
0 ¹³ Ω · cm. Preparation Example 3 of Composite Organic Fine Particles In Preparation Example 1 of composite organic fine particles, titanium oxide particles having a primary particle diameter of 30 nm treated with tin oxide were used instead of hydrophobic titanium oxide (trade name: ET-300W, manufactured by Ishihara Sangyo Co., Ltd.). Other than that, composite organic fine particles were obtained in the same manner.
This is referred to as “composite organic fine particles 3”.

The electric resistance of the composite organic fine particles 3 is 5.6 × 1
Was 0 ⁹ Ω · cm. Preparation Example 4 of Composite Organic Fine Particles In Preparation Example 1 of composite organic fine particles, instead of hydrophobic titanium oxide, silica particles having a primary particle diameter of 50 nm and having a surface treated with tin oxide, trade name ES-650W (manufactured by Titanium Industry Co., Ltd.) were used. Other than that obtained the composite organic fine particle similarly. This is referred to as “composite organic fine particles 4”.

The electric resistance of the composite organic fine particles 4 is 4.8 × 1
Was 0 ⁸ Ω · cm. Preparation example 5 of composite organic fine particles In preparation 1 of composite organic fine particles, the electric resistance was 2.4 × 10
Composite organic fine particles were obtained in the same manner except that styrene / acrylic organic fine particles of ⁸ Ω · cm were used. This is referred to as “composite organic fine particles 5”.

The electrical resistance of the composite organic fine particles 4 was 7.7 × 1.
Was 0 ⁹ Ω · cm. Preparation of Colored Particles Anionic activator (sodium dodecyl sulfonate: SDS) was previously placed in a 5000 ml separable flask equipped with a stirrer, temperature sensor, cooling tube, and nitrogen introducing device.
A solution prepared by dissolving 3.8 g in ion-exchanged water (800 g) is added. The internal temperature was raised to 80 ° C. while stirring at a stirring speed of 230 rpm under a nitrogen stream. Styrene 1
A monomer solution composed of 42.0 g, n-butyl acrylate 41.0 g, and methacrylic acid 17.0 g was prepared.
Then, a polymerization initiator (potassium persulfate: KPS) 2.2
g was dissolved in 200 g of ion-exchanged water.
Thereafter, the temperature was raised to 75 ° C., the monomer solution was added dropwise in 1 hour, and the mixture was heated and stirred at 75 ° C. for 2 hours to produce latex particles. The process up to this point is called an HP process.

Separately, in a flask having a stirrer, 383.6 g of styrene and 140.0 g of n-butyl acrylate were used.
g, 36.4 g of methacrylic acid, and 5.6 g of n-octyl-3-mercaptopropionate, 200.0 g of Exemplified Compound 19 is heated to 80 ° C. and dissolved. Next, a solution in which 1.6 g of SDS was dissolved in 2000 ml of water was heated to 80 ° C., and Exemplified Compound 19 was heated to the monomer by a mechanical disperser (CLEARMIX) having a circulation path to the SDS aqueous solution. The solution was mixed and dispersed to prepare an emulsion containing emulsified particles having a uniform dispersed particle diameter.

Subsequently, 6.0 g of a polymerization initiator (KPS) was added to the dispersion containing the latex particles and ion-exchanged water 2 was added.
A solution dissolved in 40 ml was added, and 750 m of water was further added.
1 and heat to 80 ° C. Thereafter, the above-mentioned emulsion was added and reacted at 80 ° C. for 3 hours to prepare a latex in which an intermediate molecular weight substance was encapsulated using a high molecular weight substance as a core. This step is referred to as an MP step.

Further, KPS 22.8 was added to the latex.
g of styrene in 850 g of butyl acrylate and 25 g of butyl acrylate.
A solution obtained by mixing 2 g, 98 g of methacrylic acid and 32 g of n-octyl-3-mercaptopropionate is added dropwise over 1 hour. Then, the reaction was carried out for 2 hours to obtain desired latex particles. This reaction step is referred to as an LP step.

These latex particles are referred to as Latex 1 (content of Exemplified Compound 19: 10% by mass).

(Latex Preparation Example 2) A latex was obtained in the same manner as in Latex Preparation Example 1, except that the amount of Exemplified Compound 19 was changed to 160.0 g.

This was designated as Latex 2 (Exemplified Compound 1)
9 (3.6% by mass). (Latex Preparation Example 3)
A latex was prepared in the same manner except that the amount of Exemplified Compound 19 was changed to 500.0 g, and the amount of n-octyl-3-mercaptopropionate added in the MP step was changed from 5.6 g to 10.5.

This was designated as Latex 3 (Exemplified Compound 1)
9 content 25% by mass). (Comparative Latex Preparation Example 1) A latex was obtained in the same manner as in Latex Preparation Example 1, except that the amount of Exemplified Compound 19 was changed to 56.0 g.

This is designated as Comparative Latex 1 (content of Exemplified Compound 19: 2.8% by mass). (Comparative Latex Preparation Example 2) A latex was obtained in the same manner as in Latex Preparation Example 1, except that the amount of Exemplified Compound 19 was changed to 620.0 g.

This is designated as Comparative Latex 2 (content of Exemplified Compound 19: 31% by mass). (Example of Toner Preparation) Production of Colored Particles Bk 9.2 g of sodium n-dodecyl sulfate was added to deionized water 1
Stir and dissolve in 60 ml. To this solution, 20 g of Mogar L (carbon black manufactured by Cabot Corporation) was gradually added under stirring, and then dispersed using CLEARMIX. The particle diameter of the dispersion was measured using an electrophoresis light scattering photometer ELS-800 manufactured by Otsuka Electronics Co., Ltd.
It was 8 nm. This dispersion is referred to as “colorant dispersion Bk”.

1250 g of the above-mentioned "latex 1" to "comparative latex 2", 2000 ml of ion-exchanged water and "colorant dispersion Bk" were added to a 5-liter solution equipped with a temperature sensor, a cooling pipe, a nitrogen introducing device, and a stirring device. Stir in a four-necked flask. After adjusting to 30 ° C, 5
Mol / l of sodium hydroxide aqueous solution
Was adjusted to 11.0. Then, an aqueous solution in which 52.6 g of magnesium chloride hexahydrate was dissolved in 72 ml of ion-exchanged water was added at 30 ° C. for 10 minutes with stirring. afterwards,
After standing for 3 minutes, the temperature is raised, and the temperature is raised to 90 ° C. in 6 minutes (rate of temperature rise = 10 ° C./min). In this state, the particle size was measured with a Coulter counter TA-II, and when the volume average particle size became 6.5 μm, sodium chloride 1 was added.
An aqueous solution prepared by dissolving 15 g in 700 ml of ion-exchanged water was added to stop the particle growth.
The salting out / fusion is carried out in the range of ９５95 ° C. and the stirring time is changed from 1 hour to 10 hours. Then, 8 ° C / mi
After cooling to 30 ° C. under the condition of n, hydrochloric acid was added to adjust the pH to 2.0, and stirring was stopped. The resulting colored particles are filtered, washed repeatedly with ion exchanged water,
Dried with warm air at ℃, different colored particles of various shapes 1Bk
~ 2Bk of comparative colored particles were obtained. Table 1 below shows the reaction temperature and reaction time.

In the production examples of the colored particles, C.I. I. Solvent Ye
The same procedure was repeated except that LOW 93 was used, but “colored particles Y” and C.I. I. Pigment Red 122 except that Pigment Red 122 was used. I. Pigment Blue 153 is used except that Pigment Blue 153 is used.

Table 2 below shows the reaction temperature and reaction time.

[0147]

[Table 1]

[0148]

[Table 2]

Next, hydrophobic silica (number-average primary particle diameter = 1
0 nm, hydrophobicity = 63) of 0.4% by mass and hydrophobic titanium oxide (number average primary particle diameter = 25 nm, hydrophobicity = 6)
0) 0.8% by mass and composite organic fine particles were added as shown in Tables 3 and 4, and mixed with a Henschel mixer to obtain a toner. These are referred to as “toner 1Bk” to “comparative toner 3”.
C ".

[0150]

[Table 3]

[0151]

[Table 4]

A ferrite carrier coated with a silicone resin and having a volume average particle diameter of 60 μm was mixed with each of the above toners to prepare a developer having a toner concentration of 6%. These are referred to as “developer 1Bk” to “comparative developer 3C” corresponding to the toner.

The developers were combined in the configuration shown in Table 5 below. Using the developer prepared here, electrostatic latent image forming means for forming an electrostatic latent image on the image carrier, and developing means for applying toner to the electrostatic latent image to form a toner image A plurality of image forming units that are continuously arranged in parallel, an intermediate transfer body on which toner images formed for each of the image forming units are sequentially superimposed and transferred, and a toner image superimposedly transferred on the intermediate transfer body. The evaluation was carried out using a color copying machine having a transfer means for transferring to a recording medium. A Y / M / C / Bk developing unit is arranged around each of the stacked photoreceptors, and after developing each color on the photoreceptor, transferring each color onto the intermediate transfer body, and a full-color image on the intermediate transfer body Was formed, and then an intermediate transfer member was used which was transferred to paper as an image forming support. In addition, it has a cleaner-less image forming unit including a non-contact developing type developing unit,
In addition, a method is employed in which the residual toner retained at a predetermined timing is discharged from a toner retaining unit that temporarily retains the residual toner remaining on the image carrier after transfer to the intermediate transfer member.

As the fixing method, a pressure fixing type heat fixing device was used. Evaluation items <Photoconductor filming> The presence or absence of filming was determined by visual observation.

A: No fogging of the photoreceptor, no filming confirmed. A: Slight fogging of the photoreceptor, but no clear filming confirmed. X: Filming was confirmed on the photoreceptor.

<Image spots due to filming> Solid images of each color were output, and "Yes" and "No" were determined.

<Standard Gloss> The standard gloss is defined as a gloss meter VGS- at an incident angle of 75 ° in an image portion where the recording material is covered by 90% or more of the image forming material (toner for developing an electrostatic image). 1D (manufactured by Nippon Denshoku Industries Co., Ltd.).

When the standard glossiness exceeds 37, the surface specular reflection light component is too large, and a sufficient texture cannot be obtained, resulting in a shortage of reality. Standard glossiness is 17-37
Is considered good.

<Visual glossiness> ：: The image has a three-dimensional effect, and the characters are not shining and are easy to read. ：: Inferior to ◎, but excellent. ：: The image has a three-dimensional effect, but the characters are shining. Somewhat difficult to read ×: The image is rough and the stereoscopic effect is not felt.

[0160]

[Table 5]

As is clear from the above results, Examples 1 to 5 according to the present invention are excellent in all characteristics, but Comparative Examples 1 to 3 outside the present invention have problems.

[0162]

According to the present invention, filming of toner on each photoreceptor and the intermediate transfer member does not occur, and therefore, there is no image unevenness due to filming, moderate gloss, deep and high quality image. It is possible to provide an electrostatic image developing toner and a developer that can be obtained over a long period of time, and an image forming method and an image forming apparatus using the same.

[Brief description of the drawings]

FIG. 1 is a schematic diagram of an apparatus for measuring the resistance of each particle.

FIG. 2 is a schematic sectional view of a tandem type full-color image forming apparatus.

FIG. 3 is a schematic sectional view of a tandem type full-color image forming apparatus.

FIG. 4 is a schematic sectional view of a tandem type full-color image forming apparatus.

[Explanation of symbols]

 1, 1C, 1M, 1Y, 1K Photoconductor drum 2, 2C, 2M, 2Y, 2K Charger 3, 3C, 3M, 3Y, 3K Image exposure unit 4, 4, C, 4M, 4Y, 4K Developing unit 7 Transfer belt 8 Driven roller 9 Drive roller 11C, 11M, 11Y, 11K Transfer unit 13 Fixing unit 16 Cleaning unit 20, 20C, 20M, 20Y, 20K Image forming unit 27 Intermediate transfer belt

──────────────────────────────────────────────────続 き Continued on the front page (51) Int.Cl. ⁷ Identification symbol FI Theme coat ゛ (Reference) G03G 9/087 G03G 15/08 506A 15/01 15/16 15/08 506 9/08 361 15/16 381 384 (72) Inventor Hiroshi Yamazaki 2970 Ishikawa-cho, Hachioji-shi, Tokyo Konica Corporation (72) Inventor Kenji 2970 Ishikawa-cho, Hachioji-shi, Tokyo Konica Corporation F-term (reference) 2H005 AA06 AA08 AA21 AB03 AB06 CA13 CA14 CA26 EA01 EA05 EA07 2H030 AB02 AD01 AD03 BB22 BB42 BB43 BB71 2H032 AA05 AA15 BA05 BA09 2H077 AC13 AC16 AD02 AD06 BA07 EA15 GA13

Claims (9)

[Claims] An at least one polymerizable monomer is obtained by polymerizing the polymerizable monomer in an aqueous medium.
The colored particles containing 30% by mass have an average particle size of 0.1 to
The average primary particle diameter is 5 to 5 μm on the surface of the organic fine particles.
A toner for developing an electrostatic charge image, obtained by mixing composite organic fine particles having 100 nm of inorganic fine particles fixed thereon. 2. A toner for developing an electrostatic image obtained by salting out / fusing composite resin particles constituting colored particles produced by a multi-stage polymerization method, wherein the toner is separated from a region other than the outermost layer of the composite resin particles. 2. The composition according to claim 1, further comprising a mold agent.
The toner for developing an electrostatic image according to the above. 3. The composite organic fine particles have a resistance of 10 ⁸ to 10 ^11.
2. The electrostatic image developing toner according to claim 1, wherein the toner has an Ω · cm. 4. A plurality of electrostatic image carriers having toner images of different colors formed on a peripheral surface thereof are arranged along a transfer material carrier, and each electrostatic image carrier bears a corresponding one of the electrostatic image carriers. Forming apparatus provided with an electrostatic transfer electric field imparting member for transferring a toner image to a transfer material by electrostatic force, the colored particles containing at least a resin and a colorant, and 3 to 30% by mass of a release agent In addition, the average particle size is 0.1 to 5.0.
The average primary particle size is 5 to 100 μm on the surface of organic fine particles.
An image forming apparatus using a toner obtained by adding and mixing composite organic fine particles to which inorganic fine particles of nm are fixed. 5. A plurality of electrostatic image carriers on which toner images of different colors are formed on the peripheral surface are arranged along the intermediate transfer body. After the toner image is transferred to the transfer material, the toner image is re-transferred to a transfer material, and at least the resin and the colorant and the colored particles containing 3 to 30% by mass of the release agent are averaged. The toner is obtained by adding and mixing composite organic fine particles having inorganic fine particles having a primary average particle diameter of 5 to 100 nm fixed to the surface of organic fine particles having a particle diameter of 0.1 to 5.0 μm. Image forming apparatus. 6. An image forming method using the image forming apparatus according to claim 4, wherein the addition amount of the composite organic fine particles for at least one color toner is different from that of the other toners. 7. An image forming method using the image forming apparatus according to claim 5, wherein the addition amount of the composite organic fine particles is different for at least one color toner from the other three colors. 8. An electrostatic image carrier, an electrostatic latent image forming means for forming an electrostatic latent image on the image carrier, and a developing device for applying toner to the electrostatic latent image to form a toner image Means, a plurality of image forming units arranged in a row, an intermediate transfer member on which toner images formed for each of the image forming units are sequentially transferred in an overlapping manner, and an intermediate transfer member on which the toner images are transferred in an overlapping manner. And a transfer unit for transferring the transferred toner image onto a transfer material, at least one of the image forming units is a cleanerless image forming unit including a non-contact developing type developing unit, and the intermediate transfer A color image for temporarily discharging residual toner remaining on the image carrier after transfer to a body, wherein the toner retaining means discharges the residual toner retained at a predetermined timing; In the forming apparatus, the colored particles containing at least a resin and a coloring agent and 3 to 30% by mass of a releasing agent are added to the surface of organic fine particles having an average particle size of 0.1 to 5.0 μm, An image forming apparatus using a toner obtained by adding and mixing composite organic fine particles to which inorganic fine particles of 5 to 100 nm are fixed. 9. The toner for developing an electrostatic image according to claim 1, wherein the surface of the inorganic fine particles is subjected to a hydrophobic treatment with a compound represented by the following general formula (1). Developer. Formula (1) R-Si (OCH 3) 3 ( wherein, R, is an alkyl group or a carbon number of carbon atoms from 4 to 18 represents a phenyl group having 4 to 18.)