JP2003098745A - Electrostatic charge latent image developing toner and method of manufacturing the same and image forming method - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide electrostatic charge latent image developing toners by establishing a method of preparing small-grain size toners which do not give rise to a problem of odors by suppressing the generation of the odors during thermal fixing of the polymerization process toners and a method of manufacturing the same and an image forming method. SOLUTION: In the method of manufacturing the electrostatic charge latent image developing toners having a process of flocculating or fusing, in an aqueous medium, the resin particles obtained by subjecting a radial polymerizable monomer containing at least a chain transfer agent to emulsion polymerization or mini-emulsion polymerization using a water-soluble polymerization initiator in an aqueous medium, then a process of filtering and cleaning, the aqueous medium added with a deodorant is used during the flocculating or fusing process step.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an electrostatic latent image developing toner (hereinafter sometimes simply referred to as toner) mainly used in copying machines, printers, etc., a manufacturing method thereof, and an image forming method. .

[0002]

2. Description of the Related Art At present, an image forming method of an electrostatic latent image developing system represented by an electrophotographic system is mostly used for an image forming apparatus which requires high speed and high image quality.

The reason for this is that in addition to being able to obtain high-quality images at high speed, this system is capable of not only monochrome but also color image formation, durability and stability that can withstand long-term use. It depends on

An image forming apparatus using the electrostatic latent image developing system is
In many cases, the toner image is transferred onto the transfer material and then thermally fixed. However, in order to quickly fix the toner image with a small apparatus, a contact heating method in which the toner image is directly pressed against a heat roller or the like is adopted. .

However, in the case of fixing by the contact heating method, it is necessary for the toner resin used to control the molecular weight distribution from the viewpoint of fixing property. For example, it is necessary to improve the elastic modulus at high temperature in order to suppress high temperature offset to a heat roller or the like, and it is preferable to increase the high molecular weight component. On the other hand, in order to improve the adhesion to a transfer material such as paper (also referred to as an image forming support, which can fix and carry a toner image such as plain paper and processed paper), it is preferable to increase the low molecular weight component. In order to satisfy such contradictory functions with the resin, it is necessary to expand the molecular weight distribution.

At this time, it is also necessary to use a chain transfer agent to control the molecular weight distribution to lower the molecular weight. As a suitable chain transfer agent, a mercaptan type compound, particularly a dodecyl mercaptan type compound is used. However, this material has a peculiar odor, and the chain transfer agent remaining at the time of heat fixing is volatilized, causing a problem of odor generation.

This problem of odor has not been regarded as a problem in the so-called pulverized toner, which is conventionally produced by melt-kneading and pulverizing a resin and a colorant. However, it is a big problem in the case of the polymerized toner.

According to the recent tendency, it is desired that the toner has a small particle diameter in order to obtain high image quality. Therefore, as a method for producing a small particle size toner, a polymerization method toner has been extensively studied in recent years. In this polymerization toner, a method of preparing a toner by associating resin particles with colorant particles as necessary and aggregating or fusing them, or mixing a radical polymerizable monomer and a colorant, and then adding an aqueous medium There is a method in which droplets are dispersed to obtain a desired toner particle size and suspension polymerization is performed.

[0009]

SUMMARY OF THE INVENTION An object of the present invention is to establish a method for preparing a toner having a small particle size, which suppresses the generation of odor during heat fixing in a polymerization toner and does not cause an odor problem. An object of the present invention is to provide a toner for developing an electrostatic latent image, a method for manufacturing the same, and an image forming method.

[0010]

Means for Solving the Problems As a result of intensive studies by the present inventors, it was found that the object of the present invention can be achieved by adopting any one of the following constitutions.

[1] Resin particles obtained by emulsion polymerization or miniemulsion polymerization of a radically polymerizable monomer containing at least a chain transfer agent in a water-based medium using a water-soluble polymerization initiator In a method for producing an electrostatic latent image developing toner having a step of aggregating or fusing in a medium, followed by a step of filtering and washing, it is preferable to use an aqueous medium to which a deodorant is added during the aggregating or fusing step. A method for producing a toner for developing an electrostatic latent image.

[2] Resin particles obtained by emulsion polymerization or miniemulsion polymerization of a radically polymerizable monomer containing at least a chain transfer agent in a water-based medium using a water-soluble polymerization initiator, An electrostatic latent image developing toner obtained by aggregating or fusing in a medium, followed by filtration and washing, characterized by using an aqueous medium to which a deodorant is added at the time of the aggregating or fusing. Toner for electrostatic latent image development.

[3] At least the latent image formed on the electrostatic latent image carrier is developed with a developer containing a toner for electrostatic latent image development, and after visualization, the toner is transferred to a transfer material, and transferred. In the image forming method of thermally fixing the toner, the toner is prepared by emulsion polymerization or mini-emulsion polymerization of a radically polymerizable monomer containing at least a chain transfer agent in a water-based medium using a water-soluble polymerization initiator. An image forming method characterized in that it is a toner obtained by aggregating or fusing the obtained resin particles in an aqueous medium in the presence of a deodorant, followed by filtration and washing.

According to a study by the inventors, a deodorant used only at the time of cleaning can treat only odor substances existing on the surface. Therefore, it has been found that the odorous substance existing inside the toner is released during heat fixing, which causes odor.

Therefore, as a result of a study for removing the odor substance taken in, the deodorant is added in the aggregating or fusing step, and the aroma substance present in the inside is effectively treated by aggregating or fusing. I found that it can be removed.

Although the reason for this is not clear, when the deodorant is added to the aqueous medium in which the resin particles and the like are dispersed, the deodorant is adsorbed on the surface of the resin particles and the like. Then, the deodorant adsorbed on the resin particles or the like at the stage of aggregating or fusing is also taken into the colored particles at the same time, and the deodorant can be present inside. As a result, it is presumed that the deodorant existing inside reacts with the odorous substance to effectively deodorize.

For the above-mentioned reasons, it is preferable that the deodorant can be chemically bound to deodorize.

[0018]

BEST MODE FOR CARRYING OUT THE INVENTION The compounds and the like used in the present invention will be further described.

[Deodorant] Examples of the deodorant used in the present invention are as follows.

Glyoxal, glyoxalic acid, malic acid, pyruvic acid ester, protracted herb extracts described in JP-A-7-163645, especially diterpene compounds having a specific structure, deodorant KT-3S (Soda fragrance) and the like are preferable.

The amount of these deodorants added to the aqueous medium is 0.01 to 20% by mass, preferably 0.1 to 10% by mass, based on the aqueous medium.

Although these deodorants have a large deodorizing effect from the inside, the deodorant does not affect the surface and does not affect the electrophotographic characteristics.

[Chain Transfer Agent] In order to control the molecular weight of the toner resin, it is preferable to add a chain transfer agent, but those having the following structures are particularly preferable.

Preferred Examples of Chain Transfer Agent General Formula (1) HS-R ₁ -COOR ₂ wherein R ₁ has ₁ to 10 carbon atoms which may have a substituent.
R ₂ is a hydrocarbon group having 2 to 20 carbon atoms which may have a substituent.

Particularly preferred are thioglycolic acid esters and 3-mercaptopropionic acid esters. Specifically, as thioglycolates, ethyl thioglycolate, butyl thioglycolate, thioglycolic acid-t-butyl, thioglycolic acid-2-ethylhexyl, octyl thioglycolic acid, thioglycolic acid isooctyl, thioglycolic acid Decyl, dodecyl thioglycolate, thioglycolic acid ester of ethylene glycol, thioglycolic acid ester of neopentyl glycol, thioglycolic acid ester of trimethylolpropane, thioglycolic acid ester of pentaerythritol, thioglycolic acid ester of sorbitol. As the 3-mercaptopropionic acid esters, the ester moiety is ethyl ester, octyl ester, decyl ester, dodecyl ester, pentaerythritol. Of traxester, 3-mercaptopropionic acid ester of ethylene glycol, 3-mercaptopropionic acid ester of neopentyl glycol, 3-mercaptopropionic acid ester of trimethylolpropane, 3-mercaptopropionic acid ester of pentaerythritol, sorbitol 3-mercaptopropionic acid ester can be mentioned.

The amount used is 0.01 with respect to all the monomers.
5% by mass is preferable. Here the general formula _{(2) HS-R 3,} R 3 is carbon atoms, which may have a substituent 1 to 20
Is a hydrocarbon group.

N-octyl mercaptan, 2-ethylhexyl mercaptan, n-dodecyl mercaptan, se
Examples thereof include c-dodecyl mercaptan and t-dodecyl mercaptan.

[Polymerization Initiator] A water-soluble radical polymerization initiator is used in the present invention.
Examples thereof include persulfates such as potassium persulfate and ammonium persulfate, azobisaminodipropaneacetic acid salts, azobiscyanovaleric acid and its salts, and hydrogen peroxide.

[PH Adjusting Agent] For adjusting the pH, amines may be used. Preferred is chloramine T (p
-Toluene sulfone chloroamide sodium trihydrate).

The cleaning effect is exhibited when the pH of the cleaning liquid is in the range of 2-9. Particularly preferably, the pH is 3-8. The amount of washing water is not particularly limited, but is usually 2 to 100 times, preferably 5 to 30 times by mass of the toner.

[Characteristics of Toner Resin] As the excellent resin in the present invention, those having a glass transition point of 20 to 90 ° C. are preferable and those having a softening point of 80 to 220 ° C. are preferable.
The glass transition point is measured by a differential calorimetric method, and the softening point can be measured by a Koka type flow tester. Further, these resins have a number average molecular weight (Mn) of 1,000 to 10,000 as measured by gel permeation chromatography (GPC).
0, 2000-100000 in weight average molecular weight (Mw)
0 is preferable. Furthermore, as the molecular weight distribution, Mw
It is preferable that / Mn is 1.5 to 100, especially 1.8 to 70.

In order to prevent toner offset during heat fixing, the resin for toner has a molecular weight of 100,000 to
A resin containing both a high molecular weight component having a peak or shoulder in the region of 1,000,000 and a low molecular weight component having a peak or shoulder in the region of 1,000 to 20,000 is preferable.

The molecular weight of the resin can be measured by measuring the molecular weight by gel permeation chromatography.
It is measured using HF (tetrahydrofuran) as a solvent. That is, the measurement sample is 0.5 to 5 mg, more specifically 1 m.
1 ml of THF is added to g, and the mixture is stirred at room temperature using a magnetic stirrer or the like to sufficiently dissolve it.

Then, the pore size is 0.45 to 0.50 μ
m membrane filter and then injected into GPC. The measurement conditions of GPC were as follows: the column was stabilized at 40 ° C., THF was flowed at a flow rate of 1 ml / min, and 1 mg / m 2 was used.
About 100 μl of a sample having a concentration of 1 is injected and measured.

The column is preferably a combination of commercially available polystyrene gel columns. For example, Shodex GPC KF-801, 8 manufactured by Showa Denko KK
02, 803, 804, 805, 806, 807 combinations and TSKgel G1000H, G20 manufactured by Tosoh Corporation
00H, G3000H, G4000H, G5000H,
G6000H, G7000H, TSK guard c
It is possible to cite a combination of columns and the like. Also,
A refractive index detector (IR detector) or a UV detector may be used as the detector.

In measuring the molecular weight of the sample, the molecular weight distribution of the sample is calculated using a calibration curve prepared using monodisperse polystyrene standard particles. About 10 points may be used as polystyrene for preparing the calibration curve.

[Colorant] As the colorant used in the toner of the present invention, carbon black, a magnetic substance, a dye, a pigment or the like can be optionally used. Examples of the carbon black include channel black, furnace black, acetylene black, Thermal black, lamp black, etc. are used. Ferromagnetic metals such as iron, nickel and cobalt as magnetic materials, alloys containing these metals, ferrite, compounds of ferromagnetic metals such as magnetite, alloys that do not contain ferromagnetic metals but exhibit ferromagnetism by heat treatment, For example, manganese-copper-aluminum, manganese-copper-tin, and other types of alloys called Heusler alloys, chromium dioxide, and 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, ibid 79, ibid 81, ibid 82, ibid 93, ibid 98, ibid 10
3, 104, 112, 162, C.I. I. Solvent Blue 25, 36, 60, 70, 93, 9
5 and the like can be used, and a mixture thereof can also be used. As the pigment, C.I. I. Pigment Red 5,
48: 1, 53: 1, 57: 1, 122, 1
39, 144, 149, 166, 177, 1
78, ibid. 222, C.I. I. Pigment Orange 31, the same 43, C.I. I. Pigment Yellow 14, Same 17 and Same 9
3, ibid 94, ibid 138, ibid 156, ibid 158, ibid 18
0, 185, C.I. I. Pigment Green 7, C.I.
I. Pigment Blue 15: 3, 60 and the like, and a mixture thereof can also be used. The number average primary particle diameter varies depending on the type, but is generally 10 to 200 n.
About m is preferable.

The colorant may be added by adding polymer particles prepared by an emulsion polymerization method at the stage of aggregating or fusing by adding an aggregating agent, and coloring the polymer,
It is possible to use a method in which a coloring agent is added at the stage of polymerizing the monomer and polymerized to obtain colored particles. When the colorant is added at the stage of preparing the polymer, it is preferable that the surface is treated with a coupling agent or the like so as not to hinder radical polymerizability.

[Release Agent Contained in Toner] The release agent used in the present invention is not particularly limited. Low molecular weight polyolefin wax such as polypropylene and polyethylene, paraffin wax, Fischer-Tropsch wax, ester wax and the like can be used. The ester wax represented by the following general formula is preferable.

R ^1- (OCO-R ² ) _n n is an integer of 1 to 4, preferably 2 to 4, more preferably 3 to 4, and particularly preferably 4.

R ¹ and R ² represent a hydrocarbon group which may have a substituent. R ^1: a carbon number = 1-40, preferably 1-20, more preferably 2-5.

R ² : carbon number = 1-40, preferably 16
-30, and more preferably 18-26.

Next, specific compound examples will be shown.

[0045]

[Chemical 1]

[0046]

[Chemical 2]

The amount of addition is 1 to the whole toner.
It is 30% by mass, preferably 2 to 20% by mass, more preferably 3 to 15% by mass.

The toner of the present invention is a so-called mini toner in which a release agent is dissolved in a monomer and dispersed in water to polymerize to form particles containing the release agent in the resin particles. It can be produced by the emulsion polymerization method.

[Production Method of Toner of the Present Invention] In the toner of the present invention, a monomer is emulsion-polymerized in a liquid containing an emulsion of necessary additives to produce fine polymer particles. , An organic solvent, an aggregating agent, and the like can be added to associate with each other. A method of preparing by mixing with a dispersion liquid such as a release agent or a colorant necessary for the constitution of the toner at the time of aggregating or fusing and aggregating or fusing, or a releasing agent or a colorant in the monomer. Examples of the method include emulsion-polymerization after dispersing the toner constituent components. Here, aggregation or fusion means that a plurality of resin particles and colorant particles are associated with each other.

The aqueous medium as used in the present invention means a medium containing at least 50% by mass of water.

The specific method for producing the toner of the present invention is not particularly limited, but is described in, for example, Japanese Patent Application Laid-Open No. Hei 5-
No. 265252 and Japanese Patent Laid-Open No. 6-329947,
The method described in JP-A-9-15904 can be mentioned.

That is, a method of associating a plurality of resin particles and dispersed particles of a constituent material such as a colorant, or a plurality of fine particles composed of a resin and a colorant, especially after dispersing them in water using an emulsifier, At the same time as salting out by adding a coagulant at a critical coagulation concentration or higher, at the same time as the glass transition temperature of the formed polymer itself to heat fusion to form fused particles to gradually grow the particle size, When a particle size is reached, a large amount of water is added to stop the particle size growth, and the particle surface is smoothed while heating and stirring to control the shape, and the particles are heated and dried in a fluid state in a water-containing state. Thus, the toner of the present invention can be formed.
Here, an organic solvent that is infinitely soluble in water may be added simultaneously with the coagulant.

[Polymerizable Monomer Constituting Toner] What is used as the polymerizable monomer constituting the resin is styrene, o-methylstyrene, m-methylstyrene, p-methylstyrene, α-methylstyrene. Styrene, p-chlorostyrene, 3,4-dichlorostyrene, p-phenylstyrene, p-ethylstyrene, 2,4-dimethylstyrene,
Styrene or styrene derivative such as p-tert-butylstyrene, pn-hexylstyrene, pn-octylstyrene, pn-nonylstyrene, pn-decylstyrene, pn-dodecylstyrene, or styrene derivative, methacryl Methyl acid, ethyl methacrylate, n-butyl methacrylate, isopropyl methacrylate, isobutyl methacrylate, t-butyl methacrylate, n-octyl methacrylate, 2-ethylhexyl methacrylate, stearyl methacrylate, lauryl methacrylate, phenyl methacrylate. , Methacrylic acid ester derivatives such as diethylaminoethyl methacrylate and dimethylaminoethyl methacrylate, methyl acrylate, ethyl acrylate, isopropyl acrylate, n-butyl acrylate, t-acrylate
Butyl, isobutyl acrylate, n-octyl acrylate, 2-ethylhexyl acrylate, stearyl acrylate, lauryl acrylate, phenyl acrylate, etc.
Acrylic ester derivatives, olefins such as ethylene, propylene and isobutylene, vinyl chloride, vinylidene chloride, halogenated vinyls such as vinyl bromide, vinyl fluoride and vinylidene fluoride, vinyl propionate, vinyl acetate, vinyl benzoate, etc. Vinyl esters, vinyl methyl ether, vinyl ethyl ether and other vinyl ethers, vinyl methyl ketone, vinyl ethyl ketone, vinyl hexyl ketone and other vinyl ketones, N-vinyl carbazole, N-vinyl indole, N-vinyl pyrrolidone and other N There are vinyl compounds such as vinyl compounds, vinylnaphthalene and vinylpyridine, and 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 polymerizable monomer having an ionic dissociative group in combination as the polymerizable monomer constituting the resin. 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 the monomer, and specifically, acrylic acid, methacrylic acid,
Maleic acid, itaconic acid, cinnamic acid, fumaric 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 can be mentioned.

In order to make the shape uniform, it is preferable to prepare colored particles, filter and then fluidly dry a slurry in which 10% by mass or more of water is present relative to the particles. Those having a polar group in the polymer are preferred. It is considered that the reason for this is that since the existing water has an effect of swelling the existing water to some extent with respect to the polymer having the polar group, the homogenization of the shape is particularly likely to be achieved.

Further, divinylbenzene, ethylene glycol dimethacrylate, ethylene glycol diacrylate, diethylene glycol dimethacrylate, diethylene glycol diacrylate, triethylene glycol dimethacrylate, triethylene glycol diacrylate, neopentyl glycol dimethacrylate,
It is also possible to use a polyfunctional vinyl such as neopentyl glycol diacrylate to form a resin having a crosslinked structure.

[Aggregating Agent] The aggregating agent used is not particularly limited, but one selected from metal salts is preferably used. Specifically, monovalent metals such as salts of alkali metals such as sodium, potassium and lithium, divalent metals such as alkaline earth metal salts such as calcium and magnesium, divalent metals such as manganese and copper. And 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, manganese sulfate and the like. Can be mentioned. These may be used in combination.

It is preferable that these aggregating agents are added at a critical aggregating concentration or more. This critical coagulation concentration is an index relating to the stability of the aqueous dispersion, and indicates the concentration at which coagulation occurs when a coagulant is added. This critical aggregation concentration is
It greatly changes depending on the emulsified component and the dispersant itself. For example, Seizo Okamura et al., "Polymer Chemistry 1"
7, 601 (1960) edited by The Polymer Society of Japan ”and the like, and a detailed critical aggregation concentration can be obtained.
As another method, a desired salt is added to the target particle dispersion at different concentrations, the ζ (zeta) potential of the dispersion is measured, and the salt concentration at which this value changes is determined as the critical aggregation concentration. You can also ask.

The coagulant of the present invention may be added in an amount equal to or higher than the critical coagulation concentration, preferably 1.2 of the critical coagulation concentration.
It is better to add it at least twice, more preferably at least 1.5 times.

[Infinitely Dissolving Solvent] The above-mentioned infinitely dissolving solvent means a solvent infinitely dissolving in water, and this solvent is selected so as not to dissolve the resin formed in the present invention. . Specifically, methanol, ethanol, propanol, isopropanol, t
-Alcohols such as butanol, methoxyethanol, butoxyethanol, nitriles such as acetonitrile,
Ethers such as dioxane can be mentioned. Particularly, ethanol, propanol and isopropanol are preferable.

The amount of the solvent that dissolves infinitely is 1 to 100% by volume based on the polymer-containing dispersion liquid to which the coagulant is added.
Is preferred.

[Other Additives] The toner of the present invention contains at least a resin and a colorant, but may contain a charge control agent and the like, if necessary.

Similarly, the charge control agents are various known ones,
Moreover, the thing which can be disperse | distributed in water can be used. Specifically, nigrosine dyes, metal salts of naphthenic acid or higher fatty acids, alkoxylated amines,
Examples thereof include secondary ammonium salt compounds, azo-based metal complexes, salicylic acid metal salts or metal complexes thereof.

It is preferable that these charge control agents have a number average primary particle diameter of about 10 to 500 nm in a dispersed state.

Further, in the toner of the present invention, it is possible to exhibit more effects by adding fine particles such as inorganic fine particles and organic fine particles as an external additive.

As the inorganic fine particles, it is preferable to use inorganic oxide particles such as silica, titania and alumina, and these inorganic fine particles are subjected to a hydrophobic treatment with a silane coupling agent or a titanium coupling agent. preferable. The degree of hydrophobic treatment is not particularly limited, but methanol wettability of 40 to 95 is preferable. Methanol wettability is an evaluation of wettability with respect to methanol. In this method, 50 ml of distilled water placed in a beaker with an internal volume of 200 ml was charged with inorganic fine particles to be measured in an amount of 0.
Weigh 2 g and add. Methanol is dripped slowly from a buret whose tip is dipped in the liquid, with slow stirring until the whole inorganic fine particles become wet. When the amount of methanol required to completely wet the inorganic fine particles is a (ml), the degree of hydrophobicity is calculated by the following formula.

Hydrophobicity = {a / (a + 50)} × 100 The amount of the external additive added is 0.1 to 5% in the toner.
It is 0% by mass, preferably 0.5 to 4.0% by mass. Further, various external additives may be used in combination.

[Particle Size of Toner (Colored Particle)] The particle size of the toner of the present invention is preferably 3 to 8 μm in volume average particle size. When the toner particles are formed by a polymerization method, this particle size can be controlled by the concentration of the aggregating agent, the amount of the organic solvent added, the fusing time, and the composition of the polymer itself.

Since the volume average particle diameter is 3 to 8 μm, the toner image formed by development has high image quality,
In the fixing process, the amount of toner particles with large adhesiveness that fly and adhere to the heating member to generate offset is reduced, and the transfer efficiency is improved to improve the image quality of halftone and the image quality of fine lines and dots. To do.

Measurement conditions (1) Aperture: 100 μm (2) Sample preparation method: Electrolyte solution [ISOTON R-1
1 (manufactured by Coulter Scientific Japan)
An appropriate amount of a surfactant (neutral detergent) is added to 50 to 100 ml and stirred, and 10 to 20 mg of a measurement sample is added thereto. This system is prepared by subjecting it to an ultrasonic disperser for 1 minute.

[Developer and Developing Method] When used as a non-magnetic one-component toner, a developing device having a structure in which a developer layer regulating member for forming a thin layer is pressed against a developer layer carrier Use and develop with or without contact. The preferred method is contact development.

When used as a two-component developer, there is a system in which a developer comprising the toner of the present invention and a carrier is prepared and developed by contact or non-contact.

As the carrier constituting the two-component developer, as the magnetic particles, conventionally known materials such as metals such as iron, ferrite and magnetite, alloys of these metals and metals such as aluminum and lead are used. be able to.
Ferrite particles are particularly preferable. The volume average particle diameter of the magnetic particles is 15 to 100 μm, and more preferably 25 to 60 μm. The volume average particle diameter of the carrier can be typically measured by a laser diffraction particle size distribution measuring device “HELOS” (manufactured by SYMPATEC) equipped with a wet disperser.

The carrier is preferably one further coated with a resin or a so-called resin dispersion type carrier in which magnetic particles are dispersed in the resin. The resin composition for coating is not particularly limited, but for example, an olefin resin, a styrene resin, a styrene-acrylic resin, a silicone resin, an ester resin, a fluorine-containing polymer resin, or the like is used. The resin for forming the resin-dispersed carrier is not particularly limited, and known resins can be used, for example, styrene-
Acrylic resin, polyester resin, fluorine resin, phenol resin, etc. can be used.

[Fixing Method and Image Forming Method] As a suitable fixing method used in the present invention, a so-called contact heating method can be mentioned. In particular, as the contact heating method, a heat pressure fixing method, a heat roller fixing method, and a method of fixing with a rotating pressure member containing a fixedly arranged heating body can be mentioned. A specific example of the heat roller fixing method will be described later.

FIG. 1 is a sectional view showing an example of an image forming apparatus for explaining the image forming method of the present invention. Reference numeral 4 denotes a photoconductor drum which is an electrostatic latent image carrier, and is formed by forming an organic photoconductor (OPC) which is a photoconductor layer on an outer peripheral surface of a drum base made of aluminum, and has a predetermined speed in an arrow direction. To rotate.

In FIG. 1, exposure light is emitted from the semiconductor laser light source 1 based on the information read by a document reading device (not shown). This is distributed by the polygon mirror 2 in the direction perpendicular to the paper surface of FIG. 1, and is irradiated onto the surface of the photoconductor through the fθ lens 3 that corrects the image distortion to form an electrostatic latent image. The photoconductor drum 4 is uniformly charged in advance by the charger 5, and starts rotating clockwise in accordance with the timing of image exposure.

The electrostatic latent image on the surface of the photosensitive drum is the developing device 6
By the action of the transfer device 7, the developed image formed and formed is transferred onto the transfer paper (transfer material) 8 which is conveyed at the same timing. Further, the photosensitive drum 4 and the transfer paper 8 are separated by a separator (separation pole) 9, and the developed image is transferred and carried on the transfer paper 8 and guided to a fixing device 10 to be fixed.

The untransferred toner and the like remaining on the surface of the photoconductor are
It is cleaned by a cleaning device 11 of a cleaning blade type, the residual charge is removed by pre-charge exposure (PCL) 12, and it is uniformly charged again by the charging device 5 for the next image formation.

Next, the transfer paper is typically plain paper, but is not particularly limited as long as it can transfer the unfixed image after development, and of course, a PET base for OHP and the like are also included.

The cleaning blade 13 has a thickness of 1
A rubber-like elastic body of about 30 mm is used, and urethane rubber is most often used as the material. Since this is used in pressure contact with the photoconductor, it is easy to transfer heat. In the present invention, it is desirable to provide a releasing mechanism and keep it away from the photoconductor when the image forming operation is not performed.

The present invention can be preferably used for an image forming apparatus by an electrophotographic method, particularly an apparatus for forming an electrostatic latent image on a photosensitive member by a modulated beam modulated by digital image data from a computer or the like.

FIG. 2 is a sectional view showing an example of a fixing device used in the image forming method using the toner of the present invention. The fixing device 10 shown in FIG. And a roller 72. In addition,
In FIG. 2, T is a toner image formed on the transfer paper (image forming support).

The heating roller 71 has a coating layer 82 made of a fluororesin or an elastic body formed on the surface of a cored bar 81, and includes a heating member 75 made of a linear heater.

The core metal 81 is made of metal and has an inner diameter of 10 to 70 mm. The metal forming the core metal 81 is not particularly limited, but examples thereof include metals such as iron, aluminum and copper, and alloys thereof.

The core metal 81 has a wall thickness of 0.1 to 15 mm, and is determined in consideration of a balance between energy saving requirements (thinning) and strength (depending on constituent materials). For example,
In order for the core metal made of aluminum to maintain the same strength as the core metal made of iron of 0.57 mm, it is necessary to make the wall thickness 0.8 mm.

A halogen heater can be preferably used as the heating member 75. As a result, the surface temperature of the heating roller is usually 120 to 200 ° C.

The pressure roller 72 has a coating layer 84 made of an elastic material formed on the surface of the cored bar 83. Coating layer 84
There is no particular limitation on the elastic body constituting the rubber, and various soft rubbers such as urethane rubber and silicone rubber and sponge rubber can be mentioned. The silicone rubber and the silicone sponge rubber exemplified as the material constituting the coating layer 84 are exemplified. Is preferably used.

Asker C, which is an elastic material constituting the coating layer 84
The hardness is less than 80 °, preferably less than 70 °, and more preferably less than 60 °.

The thickness of the coating layer 84 is 0.1 to 30 mm.
And preferably 0.1 to 20 mm.

The contact load (total load) between the heating roller 71 and the pressure roller 72 is usually 40 to 350 N, preferably 50 to 300 N, and more preferably 50.
~ 250N. This contact load is applied to the heating roller 7
It is defined in consideration of the strength of 1 (thickness of the core metal 81), and for a heating roller having a core metal of, for example, 0.3 mm of iron, it is preferably 250 N or less.

A fixing cleaning mechanism may be added for use. As this method, a method of supplying silicone oil to a roller or a film after fixing, or a method of cleaning with a pad, roller, web, etc. impregnated with silicone oil can be used.

As the silicone oil, polydimethylsiloxane, polymethylphenylsiloxane, polydiphenylsiloxane, etc. can be used. Further, a siloxane containing fluorine can also be preferably used.

[0094]

EXAMPLES Next, the concrete constitution of the present invention and its effects will be shown and explained, but the embodiment of the present invention is not limited to this.

(Latex Preparation Example 1) 7.08 g of an anionic activator (sodium dodecylbenzene sulfonate: SDS) was previously placed in a 5000 ml separable flask equipped with a stirrer, a temperature sensor, a cooling tube, and a nitrogen introducing device.
Is added to ion-exchanged water (2760 g). The internal temperature was raised to 80 ° C. while stirring at a stirring speed of 230 rpm under a nitrogen stream.

On the other hand, 72.0 g of Exemplified Compound 19) was added to 115.1 g of styrene and 42.0 g of n-butyl acrylate.
g, in addition to the monomer consisting of 10.9 g of methacrylic acid, 8
It was heated to 0 ° C. and dissolved to prepare a monomer solution.

The above heating solution was mixed and dispersed by a mechanical disperser having a circulation route to prepare emulsified particles having a uniform dispersed particle diameter. Then, a solution prepared by dissolving 0.84 g of a polymerization initiator (potassium persulfate: KPS) in 200 g of ion-exchanged water was added, and heated and stirred at 80 ° C. for 3 hours to prepare latex particles. Subsequently, 7.73 g of a polymerization initiator (KPS) was further added to 240 ml of deionized water.
15 minutes later, 383.6 g of styrene and 140.0 of n-butyl acrylate were added at 80 ° C.
g, 36.4 g of methacrylic acid, and 13.7 g of tert-dodecyl mercaptan were added dropwise over 126 minutes. After completion of dropping, the mixture was heated and stirred for 60 minutes and then cooled to 40 ° C. to obtain latex particles.

Let these latex particles be latex 1. (Latex Preparation Example 2) In Latex Preparation Example 1,
15.0 g of n-octyl-3-mercaptopropionic acid ester instead of tert-dodecyl mercaptan
Latex particles were obtained in the same manner except that they were used. This is designated as latex 2.

(Colored particles 1) 9.2 g of sodium n-dodecyl sulfate is dissolved in 160 ml of ion-exchanged water with stirring.
To this solution, 20 g of Legal 330R (carbon black manufactured by Cabot Corporation) was gradually added with stirring, and then dispersed using CLEARMIX. As a result of measuring the particle diameter of the above-mentioned dispersion liquid using an electrophoretic light scattering photometer ELS-800 manufactured by Otsuka Electronics Co., Ltd., the weight average diameter was 112 nm.
This dispersion is referred to as "colorant dispersion 1".

1250 g of the above-mentioned “latex 1”, 2000 ml of ion-exchanged water containing the deodorant shown in the attached table, and “colorant dispersion 1” were attached to a temperature sensor, a cooling pipe, a nitrogen introducing device, and a stirring device. Place in a 4-liter four-necked flask and stir. After adjusting the temperature to 30 ° C., a 5 mol / liter sodium hydroxide aqueous solution was added to this solution to adjust the pH to 10.0.

Then, magnesium chloride hexahydrate 52.
An aqueous solution prepared by dissolving 6 g in 72 ml of ion-exchanged water was added at 30 ° C. for 10 minutes while stirring. Then, after standing for 3 minutes, the temperature rise is started and the liquid temperature is raised to 90 ° C. in 6 minutes (rate of temperature rise = 10 ° C./min). In that state, the particle size was measured with a Coulter Counter TA-II, and when the volume average particle size reached 6.5 μm, an aqueous solution prepared by dissolving 115 g of sodium chloride in 700 ml of ion-exchanged water was added to stop particle growth, Further, the mixture is continuously heated and stirred at a liquid temperature of 90 ° C. ± 2 ° C. for 6 hours to cause cohesive fusion. Then 6 ° C
It was cooled to 30 ° C. under the condition of / min. Then, the pH was adjusted to 6, filtered with a centrifuge, washed with ion-exchanged water, and then dried with hot air at 40 ° C. to obtain colored particles 1.

(Colored particles 11) Colored particles were obtained in the same manner except that "latex 2" was used instead of "latex 1" in the colored particles. This is designated as "colored particle 11".

(Colored Particles 2-10, 12-20, and 2
1, 22) Hereinafter, colored particles 2 to 10, 12 to 20, and 21, 22 were produced in the same manner as described above except for those shown in Table 1.

[0104]

[Table 1]

* TDM: t-dodecyl mercaptan (latex 1) * NOMP: n-octyl-3-mercaptopropionic acid ester (latex 2) Then, in the above "colored particles 1" to "colored particles 22", hydrophobic silica ( 1% by mass of number average primary particle size = 12 nm and hydrophobicity = 68 and hydrophobic titanium oxide (number average primary particle size = 20 nm, hydrophobicity = 63) were added and mixed by a Henschel mixer to prepare a toner. Obtained. These are designated as "toner 1" to "toner 22".

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%. Corresponding to the toner, these are "developer 1" to "developer 22".
And

Using the developer prepared as described above,
Using a digital copying machine Konica 7075 (manufactured by Konica), the configuration of the fixing device was changed to the configuration shown below, and the actual copying evaluation was performed.

As the fixing system, a pressure contact heating type fixing device was used. The specific configuration is as follows.

The surface is made of PFA (tetrafluoroethylene-
(Fluorine vinyl ether copolymer) tube coated (thickness: 120 μm), a heating roller (upper roller) of a columnar aluminum alloy having an inner diameter of 40 mm and a total width of 310 mm and a heater built in the central portion and a thickness of 1.0 mm. And a pressure roller (lower roller) having an iron cored bar having an inner diameter of 40 mm and a wall thickness of 2.0 mm, the surface of which is also made of sponge-like silicone rubber (Asker C hardness = 48: thickness 2 mm). ing. Nip width is 5.
It was 8 mm. Using this fixing device, the linear velocity of printing was set to 480 mm / sec.

[Characteristic Evaluation] A heating roller of the fixing device is set at a set temperature of 175 ° C. in a closed room having a length and width of 10 m × 10 m and a height of 2 m to continuously generate halftone images having a pixel ratio of 25%. After printing 10,000 sheets, the presence or absence of odor was evaluated by sensory evaluation. Regarding the presence or absence of odor, 20 evaluators were used and the number of people who felt the odor was evaluated.

[0111]

[Table 2]

From Table 2, it can be seen that no odor was sensed in Examples 1 to 20 in the present invention, and odors were severe in Comparative Examples 1 and 2 outside the present invention.

[0113]

According to the present invention, in the polymerization method toner,
It is possible to provide a toner for developing an electrostatic latent image, a method for producing the same, and an image forming method by establishing a method for preparing a small particle size toner that suppresses the generation of odor during heat fixing and does not generate an odor problem. .

[Brief description of drawings]

FIG. 1 is a cross-sectional configuration diagram showing an example of an image forming apparatus for explaining an image forming method of the present invention.

FIG. 2 is a schematic sectional view of a fixing device applied to the present invention.

[Explanation of symbols]

1 Semiconductor laser light source 2 polygon mirror 3 fθ lens 4 photoconductor drum 5 charger 6 developer 7 Transfer device 8 Transfer paper (transfer material) 9 separator 10 Fixing device 11 Cleaning device 12 Exposure before charging 13 Cleaning blade 71 heating roller 72 Pressure roller 75 Heating member 81 Core of heating roller 82 Coating layer for heating roller 83 Pressure roller core 84 Pressure roller coating layer

   ─────────────────────────────────────────────────── ─── Continued front page    (72) Inventor Hiroshi Yamazaki             2970 Ishikawa-cho, Hachioji-shi, Tokyo Konica stock             In the company F-term (reference) 2H005 AB03 AB06 CA30

Claims (3)

[Claims] 1. Resin particles obtained by emulsion polymerization or miniemulsion polymerization of a radically polymerizable monomer containing at least a chain transfer agent in a water-based medium using a water-soluble polymerization initiator, In the method for producing a toner for developing an electrostatic latent image, which comprises a step of aggregating or fusing in, and then a step of filtering and washing, an aqueous medium added with a deodorant during the aggregating or fusing step is used. And a method for producing a toner for developing an electrostatic latent image. 2. Resin particles obtained by emulsion polymerization or miniemulsion polymerization of a radically polymerizable monomer containing at least a chain transfer agent in a water-based medium using a water-soluble polymerization initiator, Agglomerate or fuse in,
A toner for developing an electrostatic latent image, which comprises using a water-based medium to which a deodorant is added at the time of aggregation or fusion in the toner for developing an electrostatic latent image obtained by filtration and washing. 3. A latent image formed on at least an electrostatic latent image carrier is developed with a developer containing toner for developing an electrostatic latent image,
In the image forming method, in which the toner is transferred to a transfer material after being visualized and the transferred toner is heat-fixed, a radical polymerizable monomer containing at least a chain transfer agent in the toner is used to initiate water-soluble polymerization in an aqueous medium. A toner obtained by using an agent to agglomerate or fuse resin particles obtained by emulsion polymerization or miniemulsion polymerization in an aqueous medium in the presence of a deodorant, and then filtering and washing. A characteristic image forming method.