JP2002131982A - Method for manufacturing toner - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a method for manufacturing a polymerization toner to prepare a toner of a small particle size which suppresses emission of odor during thermal fixing. SOLUTION: In the method for manufacturing toner including processes of suspension polymerization of radical polymerizable monomers containing a coloring agent and a chain transfer agent in at least a water-based medium and then filtering and cleaning, esters of pyruvic acid are added in the cleaning process to clean the toner.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for producing a polymerized toner having a small particle size and generating no odor during heat fixing.

[0002]

2. Description of the Related Art From the viewpoint of fixability, it is necessary to control the molecular weight distribution of a resin. For example, in order to print a hot offset, it is necessary to improve the elastic modulus at a high temperature, and it is preferable to increase the high molecular weight component. On the other hand, in order to improve the adhesiveness to an image forming support such as paper, it is preferable to increase the low molecular weight component. In order to satisfy such contradictory functions with a resin, it is necessary to expand the molecular weight distribution.

On the other hand, it is desired that toner particles be reduced in size from the viewpoint of high image quality. In recent years, polymerization toners have been devised as a method for producing small particle toners. In this polymerization method toner, a method of preparing an amorphous toner by associating or salting out and fusing resin particles and colorant particles as necessary, or dispersing a radical polymerizable monomer and a colorant,
Next, there is a method in which droplets are dispersed in an aqueous medium or the like so as to have a desired toner particle diameter, and suspension polymerization is performed.

[0004] At this time, in order to control the molecular weight distribution, a chain transfer agent is used to reduce the molecular weight.
Mercaptan compounds, especially dodecyl mercaptan compounds, are used as suitable chain transfer agents.

[0005] However, this material has a peculiar odor, and has a problem that the residual chain transfer agent volatilizes at the time of heat fixing to generate odor.

[0006] The problem of this odor has not been particularly regarded as a problem in a so-called pulverized toner obtained by dissolving, kneading and pulverizing a resin and a colorant.

As a countermeasure against this odor, the addition of a so-called fragrance is a conceivable general method. However, since this fragrance generates a specific odor separately, the mercaptan odor cannot be effectively prevented. On the contrary, there is a case that the odor is bad, and all of them cannot be used. Also,
Some materials are decomposed by heat, some are decomposed at the time of heat fixing, and some are decomposed at the time of being added to toner, and none of them has an effect of effectively suppressing odor.

[0008]

SUMMARY OF THE INVENTION Accordingly, it is an object of the present invention to provide a method for producing a polymerization toner for preparing a toner having a small particle diameter, which suppresses generation of odor during heat fixing.

[0009]

The present invention is achieved by the following means.

[0010] 1. A method for producing a toner having a step of subjecting a radical polymerizable monomer containing a colorant and a chain transfer agent to suspension polymerization in at least an aqueous medium, followed by filtration and washing, wherein pyruvate is added during the washing step. And producing a toner.

2. Resin particles obtained by emulsion polymerization or miniemulsion polymerization of a radical polymerizable monomer having at least a chain transfer agent in an aqueous medium using a water-soluble polymerization initiator are fused in an aqueous medium, and then filtered. A method for producing a toner, comprising a step of washing, wherein a pyruvic acid ester is added during the washing step for washing.

The present inventors have studied to chemically deodorize a bad smell generated by volatilization of the remaining chain transfer agent. As a method of chemically decomposing the malodor possessed by the chain transfer agent itself, there is a method of modifying the substituent of the malodor source by strong oxidation. However, this method has a problem that a material having high chemical activity must be used as a component for oxidation. Particularly, since the toner is used in an indoor environment such as an office, the use of a highly safe material is desired.

As a result of intensive studies, the present inventors have found that the odor of a chain transfer agent can be chemically neutralized by using a highly safe vegetable material.

That is, in the present invention, it has been found that a highly safe and effective deodorant effect can be obtained by using the following pyruvate esters.

[0015]

Embedded image

Here, R represents a linear, branched or cyclic C1-C18 alkyl, alkenyl, aryl or aralkyl group. More specifically, examples of the alkyl group include methyl, ethyl, propyl, isopropyl, butyl, isobutyl, amyl, isoamyl, hexyl, heptyl, octyl, nonyl, 2- Examples include groups such as an ethylhexyl group, a decyl group, a cyclopentyl group, and a cyclohexyl group. Examples of the aryl group include a phenyl group and a substituted phenyl group such as a tolyl group and a p-chlorophenyl group. Examples of the aralkyl group include a benzyl group, a phenethyl group, a phenylpropyl group, a methylbenzyl group, a dimethylbenzyl group, a trimethylbenzyl group, and a p-isopropylbenzyl group. Examples of the aralkyl group include a norbornyl group, a citronellyl group, and a geranyl group.

These compounds can be used alone or as a mixture. Pyruvic acid can be prepared by esterifying pyruvic acid by a known method, or by oxidizing lactate.

The method of use is to first emulsify pyruvates in water using a surfactant. Next, at the time of washing, the amount of pyruvate was 0.0
It is preferable that the toner particles are added to the washing liquid of the toner particles and washed so as to be about 01 to 1% by mass. The effect is increased by repeating this step, so that the step may be repeatedly washed.

Preferred examples of the chain transfer agent which can be deodorized by the pyruvic acid esters of the present invention include the following.

Formula (1) HS-R ₁ -COOR ₂ wherein R ₁ has ₁ to 10 carbon atoms which may have a substituent.
Is a hydrocarbon group. R ₂ is again carbon atoms, which may have a substituent represents a hydrocarbon group having 2 to 20.

Preferred examples include thioglycolates and 3-mercaptopropionates. Specific examples of the thioglycolic acid esters include ethyl thioglycolate, butyl thioglycolate, t-butyl thioglycolate, 2-ethylhexyl thioglycolate, octyl thioglycolate, isooctyl thioglycolate, and thioglycolic acid. Examples include 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, and thioglycolic acid ester of sorbitol. Can be. Examples of 3-mercaptopropionic esters include ethyl ester, octyl ester, decyl ester, dodecyl ester, pentaerythritol tetrakis ester, 3-mercaptopropionic ester of ethylene glycol, 3-mercaptopropionic ester of neopentyl glycol, and trimethylol Propane 3-mercaptopropionate, pentaerythritol 3-
Mercaptopropionate, sorbitol 3-
Mercaptopropionates can be mentioned.

General formula (2) HS-R ₃ wherein R ₃ has 1 to 20 carbon atoms which may have a substituent.
Represents a hydrocarbon group.

Examples of these compounds include n-octyl mercaptan, 2-ethylhexyl mercaptan,
-Dodecyl mercaptan, sec-dodecyl mercaptan, t-dodecyl mercaptan and the like.

The amount of these chain transfer agents depends on the molecular weight of the polymer to be obtained. That is, the amount of the chain transfer agent is relatively small when a polymer having a relatively high molecular weight is to be obtained, and the amount of the low molecular weight component is relatively small. Although used in a large amount, usually, 0.01 to the polymerizable monomer
Used in an amount of up to 5% by weight.

The toner of the present invention is prepared by suspension polymerization or emulsion polymerization of a monomer in a liquid to which an emulsion of necessary additives is added to produce fine polymerized resin particles. And a method of fusing by adding a coagulant or the like.

Thereafter, an emulsion obtained by emulsifying the pyruvic acid esters in water using a surfactant is used as a washing liquid during filtration and washing after polymerization reaction, salting-out and fusion reaction. As a result, it reacts with the chain transfer agent remaining on the surface of the colored particles, decomposing the odor component by chemical reaction,
It deodorizes.

The amount used is not particularly limited,
It is used as an emulsion of 0.1 to 20% by mass, and pyruvate itself is 0.001 to 1 with respect to the whole colored particles.
It is preferable to repeatedly add to the cleaning solution to wash the solution so as to have a concentration of about mass%, preferably about 0.002 to 0.5 mass%, and perform washing.

For example, in the suspension polymerization, a colorant and, if necessary, various components such as a release agent, a charge control agent, a polymerization initiator and a chain transfer agent are added to the polymerizable monomer, and the homogenizer is used. Various constituent materials are dissolved or dispersed in the polymerizable monomer by using 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, and the mixture is filtered and dried. At this stage, the pyruvate of the present invention is contained in the washing solution and washed. By further drying, the toner of the present invention can be prepared.

As a method for producing the toner of the present invention, a radical polymerizable monomer having at least a chain transfer agent is obtained by emulsion polymerization or miniemulsion polymerization using a water-soluble polymerization initiator in an aqueous medium. There is a method of producing a toner by fusing the resin particles obtained in an aqueous medium, and the method is not particularly limited.
252, JP-A-6-329947, and JP-A-9-15904.

That is, a method of associating a plurality of dispersed particles of a constituent material such as a resin particle and a colorant, or a plurality of fine particles composed of a resin and a colorant, particularly, after dispersing these 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 higher than the glass transition temperature of the formed polymer itself, gradually growing the particle size, At the particle size, a large amount of water was added to stop the particle size growth, and the shape was controlled by smoothing the particle surface while heating and stirring.
Filter and wash. At this stage, the pyruvate of the present invention is also contained in the washing solution and washed. By further drying, the toner of the present invention can be prepared.

The resin particles used in the production of these toners preferably have a mass average particle size of 50 to 2000 nm, and are characterized by being obtained by emulsion polymerization or miniemulsion polymerization, particularly preferably miniemulsion. It is a polymerization method.

The emulsion polymerization method referred to in the present invention refers to a method of mechanically dispersing a monomer in the presence of an emulsifier (also referred to as a surfactant) at a concentration higher than a critical micelle forming concentration (hereinafter abbreviated as CMC). Emulsification / dispersion, followed by the addition of mainly a water-soluble polymerization initiator, polymerization to form resin fine particles, and then association to produce resin particles of a desired size. The mini-emulsion polymerization method is a form of the emulsion polymerization method, and is a method of emulsifying at an emulsifier concentration of CMC or less. The polymerization initiator used at this time may be water-soluble or oil-soluble. For example, an oil-soluble polymerization initiator or a functional compound is allowed to coexist with a polymerizable monomer, and the polymerization is carried out in the presence of an emulsifier having a concentration of CMC or less. By performing the dispersion and polymerization in a controlled manner, the molecular diffusion of the functional additive and the like in the monomer particles is suppressed, and the polymerization proceeds only in the monomer oil droplets. It is particularly preferable because resin particles reliably contained therein can be obtained.

Specifically, in each of the above polymerization methods, a monomer solution in which a chain transfer agent and, if necessary, a release agent are dissolved is dispersed in an aqueous medium, and the molecular weight is adjusted with the chain transfer agent by each polymerization method. Performed, if necessary, after preparing a resin particle containing a release agent and the like, through the step of associating and fusing the resin particles in an aqueous medium using the resin particle dispersion, the obtained particles Is filtered from an aqueous medium to remove surfactants and the like. At this stage, the pyruvate of the present invention is contained in the washing solution as described above, washed, and the obtained particles are dried to dry the particles. An inventive toner is prepared.

In the present invention, the aqueous medium is composed of water as a main component and has a water content of 50% by mass or more. Examples of the solvent other than water include an organic solvent soluble in water, such as methanol, ethanol, isopropanol, butanol, acetone, methyl ethyl ketone, and tetrahydrofuran. Alcohol-based organic solvents such as methanol, ethanol, isopropanol and butanol, which are preferably organic solvents which do not dissolve the resin, are particularly preferred.

The disperser for performing the emulsification and dispersion is not particularly limited, and examples thereof include Clearmix, an ultrasonic disperser, a mechanical homogenizer, a Menton-Gaulin and a pressure homogenizer. .

As the emulsifier (also referred to as a surfactant),
Surfactants commonly used as surfactants such as sodium dodecylbenzenesulfonate, ethylene oxide adduct, and higher alcohol sodium sulfate can be used.

In addition, as dispersion stabilizers, tricalcium phosphate, magnesium phosphate, zinc phosphate, aluminum phosphate, calcium carbonate, magnesium carbonate, calcium hydroxide, magnesium hydroxide, aluminum hydroxide, calcium metasilicate, Examples thereof include calcium sulfate, barium sulfate, bentonite, silica, and alumina. Further, polyvinyl alcohol, gelatin, methyl cellulose, and the like can be used.

As the polymerizable monomer constituting the resin particles, styrene, o-methylstyrene, m-
Methylstyrene, p-methylstyrene, α-methylstyrene, p-chlorostyrene, 3,4-dichlorostyrene, p-phenylstyrene, p-ethylstyrene, 2,
Styrenes such as 4-dimethylstyrene, p-tert-butylstyrene, pn-hexylstyrene, pn-octylstyrene, pn-nonylstyrene, pn-decylstyrene, pn-dodecylstyrene Or styrene derivatives, methyl methacrylate, ethyl methacrylate, n-butyl methacrylate, isopropyl methacrylate, isobutyl methacrylate, t-butyl methacrylate, n-octyl methacrylate, 2-ethylhexyl methacrylate, stearyl methacrylate, methacrylic acid Methacrylate derivatives such as lauryl, phenyl methacrylate, diethylaminoethyl methacrylate, dimethylaminoethyl methacrylate, methyl acrylate, ethyl acrylate, isopropyl acrylate, n acrylate
-Butyl, t-butyl acrylate, isobutyl acrylate, n-octyl acrylate, 2-ethylhexyl acrylate, stearyl acrylate, lauryl acrylate,
Acrylate derivatives such as phenyl acrylate,
Ethylene, propylene, olefins such as isobutylene, vinyl chloride, vinylidene chloride, vinyl bromide, vinyl fluoride, halogenated vinyls such as vinylidene fluoride, vinyl propionate, vinyl acetate, vinyl esters such as vinyl benzoate, Vinyl ethers such as vinyl methyl ether and vinyl ethyl ether; vinyl ketones such as vinyl methyl ketone, vinyl ethyl ketone and vinyl hexyl ketone; N-vinyl compounds such as N-vinyl carbazole, N-vinyl indole and N-vinyl pyrrolidone; vinyl There are vinyl compounds such as naphthalene 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 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.

In the miniemulsion polymerization method, an oil-soluble polymerization initiator can be used in addition to the above-mentioned water-soluble polymerization initiator.

The resin excellent in the present invention preferably has a glass transition point of 20 to 90 ° C. and a softening point of 8 ° C.
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.

Further, when prepared by emulsion polymerization or mini-emulsion polymerization, these resin particles may be obtained by subjecting the resulting resin particles to emulsion polymerization conducted in the presence of a radically polymerizable monomer composition and a chain transfer agent. For example, by performing in two or more stages, 100,000 to 1,000,000
A high molecular weight component having a peak or shoulder in the region of 0;
It is preferable to use a resin containing both low molecular weight components having a peak or shoulder in a region of 1,000 to less than 20,000.

The method for measuring the molecular weight of a resin by GPC is described in US Pat.
It is a measurement by GPC (gel permeation chromatography) using HF as a solvent. That is, the measurement sample is 0.5 to 5 mg, more specifically, 1 mg of THF.
Is added and stirred at room temperature using a magnetic stirrer or the like to dissolve sufficiently. Next, after treating with a membrane filter having a pore size of 0.45 to 0.50 μm, the mixture is injected into GPC. The GPC measurement conditions were as follows: stabilize the column at 40 ° C., and set the THF to 1 m / min.
at a flow rate of 1 l / l and a sample at a concentration of 1 mg / ml
Inject μl and measure. The column is preferably used in combination with a commercially available polystyrene gel column. For example, Shodex GPC KF manufactured by Showa Denko KK
−801, 802, 803, 804, 805, 806,
807 or TSKgel G manufactured by Tosoh Corporation
1000H, G2000H, G3000H, G4000
H, G5000H, G6000H, G7000H, TS
Combinations of K guard columns can be mentioned. As a detector, a refractive index detector (IR
Detector) or a UV detector. In measuring the molecular weight of a sample, the molecular weight distribution of the sample is calculated using a calibration curve prepared using monodisperse polystyrene standard particles. As polystyrene for preparing a calibration curve, about 10 points may be used.

A release agent can be used for the resin used in the present invention. The release agent is not particularly limited. Low molecular weight polyolefin wax such as polypropylene and polystyrene, paraffin wax, Fischer-Tropsch wax, ester wax and the like can be used. Preferably, it is an ester wax represented by the following general formula.

[0048] _{R 4 - (OCOR 5) n} n is an integer from 1 to 4, preferably 2 to 4, more preferably 3 to 4, particularly preferably 4. R ₄ and R ₅ represent a hydrocarbon group which may have a substituent. R4 has 1 carbon atom
-40, preferably 1-20, more preferably 2-5 hydrocarbon groups. R ₅ is 1 to 40 carbon atoms, preferably 16-30, more preferably a hydrocarbon group of 18-26.

Examples of these compounds include, but are not limited to, the following.

[0050]

Embedded image

[0051]

Embedded image

The flocculant used for associating a plurality of resin particles and dispersed particles of a constituent material such as a colorant or fine particles composed of a resin and a colorant is not particularly limited. 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 Salts, iron, salts of trivalent metals such as aluminum and the like. Specific salts include sodium chloride, potassium chloride, lithium chloride, calcium chloride, zinc chloride,
Examples thereof include copper sulfate, magnesium sulfate, and manganese sulfate. These may be used in combination.

It is preferable to add these coagulants 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.

In order to make the shape uniform, it is preferable to prepare colored particles, and after filtration, carry out fluid drying of a slurry containing 10% by mass or more of water with respect to the particles. 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, but may contain a releasing agent or a charge control agent as a fixing property improving agent, if necessary. 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. Examples of the carbon black include channel black, furnace black, acetylene black, and the like.
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 coloring agent, 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 stage of polymerizing a monomer. 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.

The charge control agents are also various known ones.
What can be dispersed in water can 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 improving agent have a number average primary particle diameter of 10 to 50 in a dispersed state.
Preferably, the thickness is about 0 nm.

The toner has an average value (hereinafter also referred to as an average circularity) of a shape factor (circularity) represented by the following equation of 0.930 to 0.995, preferably 0.940 to 0.95.
990.

Shape factor = Circumference length of circle obtained from equivalent circle diameter / Circumference length of particle projected image Also, it is preferable that the distribution of the shape coefficient is sharp, and the standard deviation of the circularity is 0.10 or less. The standard deviation (CV value) of the shape factor calculated by the following formula needs to be less than 20%, and more preferably less than 10%.

Standard deviation (CV value) of shape coefficient = (standard deviation of circularity / average circularity) × 100 By setting the average circularity to 0.930 to 0.995, an irregular shape is obtained. And fixability to paper or the like can be ensured. 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 coefficient 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.
The average circularity can be calculated by taking a photograph enlarged to 00 times, measuring the circularity of 500 toners using an image analyzer, and calculating the arithmetic average value. In addition, as a simple measurement method, FPIA-2
000 (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.

The monitoring method is not particularly limited, but 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 by connecting an interface (manufactured by Nikkaki Co., Ltd.) for outputting a particle size distribution and a personal computer. The particle size distribution and the average particle size were calculated by measuring the volume distribution of toner having a size of 2 μm or more by using an aperture of 100 μm as the aperture used in the Coulter Multisizer.

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.

When the volume average particle diameter is 3 to 8 μm, in the fixing step, the number of toner particles having a large adhesive force which flies and adheres to the heating member to cause offset is reduced, and the transfer efficiency is increased. The halftone image quality is improved, and the image quality of fine lines and dots is improved.

Further, in the toner of the present invention, more effects can be exhibited by adding and using fine particles such as inorganic fine particles and organic fine particles as external additives. The reason for this is presumed that the embedding and detachment of the external additive can be effectively suppressed, so that the effect is remarkable.

As the inorganic fine particles, it is preferable to use inorganic oxide particles such as silica, titania and alumina. Further, it is preferable that these inorganic fine particles have been subjected to a hydrophobic treatment with a silane coupling agent, a titanium coupling agent or the like. preferable. The degree of the hydrophobizing treatment is not particularly limited, but a methanol wettability of 40 to 95 is preferable. Methanol wettability is to evaluate the wettability to methanol. In this method, an inorganic fine particle to be measured is added to 50 ml of distilled water placed in a beaker having a capacity of 200 ml.
Weigh 2 g and add. Methanol is slowly dropped from a burette whose tip is immersed in the liquid until the entire inorganic fine particles are wet with stirring slowly. 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 equation.

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

When the toner is used as a non-magnetic one-component toner, a developing device having a configuration in which a developer layer regulating member for forming a thin layer is pressed against a developer layer carrier is used. Develop with. The preferred mode is contact development.

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

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

The carrier is preferably a carrier further coated with a resin or a so-called resin-dispersed carrier in which magnetic particles are dispersed in a resin. Although there is no particular limitation on the resin composition for coating, 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 constituting the resin-dispersed carrier is not particularly limited, and a known resin can be used.
Acrylic resin, polyester resin, fluorine resin, phenol resin, and the like can be used.

As a preferred fixing method used in the present invention, a so-called contact heating method can be used. In particular, examples of the contact heating method include a heat and pressure fixing method, a heat roll fixing method, and a pressure contact heat fixing method in which fixing is performed by a rotating pressing member including a fixedly disposed heating element.

In the hot roll fixing system, a heat source is often provided inside a metal cylinder made of iron, aluminum, or the like whose surface is coated with tetrafluoroethylene or polytetrafluoroethylene-perfluoroalkoxyvinyl ether copolymer or the like. It is formed of an upper roller and a lower roller made of silicone rubber or the like. A typical example of the heat source is one having a linear heater and heating the surface temperature of the upper roller to about 120 to 200 ° C. In the fixing section, pressure is applied between the upper roller and the lower roller to deform the lower roller and form a so-called nip. The nip width is 1 to 10 mm, preferably 1.
5-7 mm. The fixing linear velocity is 40 mm / sec to 60
0 mm / sec is preferable. When the nip is narrow, heat cannot be uniformly applied to the toner, causing uneven fixing. On the other hand, if the nip width is wide, the melting of the resin is promoted, and a problem occurs in that the fixing offset becomes excessive.

A fixing cleaning mechanism may be provided for use. As this method, a method in which a silicone oil is supplied to a roller or a film after fixing, or a method in which a silicone oil-impregnated pad, roller, web or the like is used for cleaning can be used.

The above fixing device may be provided with a cleaning mechanism. As a cleaning method, a method of supplying various silicone oils to the fixing film or a method of cleaning with a pad, a roller, a web or the like impregnated with various silicone oils is used.

As the silicone oil, polydimethylsiloxane, polymethylphenylsiloxane, polydiphenylsiloxane and the like can be used. Further, a siloxane containing fluorine can also be suitably used.

[0085]

The present invention will be described below with reference to examples, but the present invention is not limited to these examples.

Example 1 (Latex Preparation Example 1) 7.08 g of an anionic activator (sodium dodecylbenzenesulfonate: 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. A solution dissolved in ion-exchanged water (2760 g) is added. While stirring at a stirring speed of 230 rpm under a nitrogen gas stream, the internal temperature was raised to 80 ° C.
Temperature. On the other hand, 112.0 g of styrene and 42.0 g of n-butyl acrylate
g, a monomer consisting of 10.9 g of methacrylic acid,
The mixture was heated to 80 ° C. and dissolved to prepare a monomer solution. The heated solution was mixed and dispersed by a mechanical disperser having a circulation path to produce emulsified particles having a uniform dispersed particle diameter. Next, a polymerization initiator (potassium persulfate: K
A solution in which 0.84 g of PS (PS) was dissolved in 200 g of ion-exchanged water was added, and the mixture was heated and stirred at 80 ° C. for 3 hours to prepare a latex. Subsequently, a polymerization initiator (KP
S) A solution obtained by dissolving 7.73 g in 240 ml of ion-exchanged water was added, and 15 minutes later, styrene 383.6 was added at 80 ° C.
g, n-butyl acrylate 140.0 g, methacrylic acid 36.4 g, tert-dodecyl mercaptan 13.
7 g of the mixture was added dropwise over 126 minutes. After dripping 6
After heating and stirring for 0 minutes, the mixture was cooled to 40 ° C. to obtain a latex. This is designated as "latex 1".

(Latex Preparation Example 2) A latex was prepared in the same manner as in Latex Preparation Example 1, except that 15.0 g of n-octyl-3-mercaptopropionate was used instead of tert-dodecyl mercaptan. This is designated as "latex 2".

(Production Example 1 of Colored Particles) 9.2 g of sodium n-dodecyl sulfate is dissolved in 160 ml of ion-exchanged water with stirring. 20 g of Regal 330R (carbon black manufactured by Cabot Corporation) is gradually added to this liquid with stirring, and then
Dispersed using CLEARMIX. The particle diameter of the dispersion was measured using an electrophoretic light scattering photometer ELS-800 manufactured by Otsuka Electronics Co., Ltd., and as a result, it was 112 nm in weight average diameter. This dispersion is referred to as “colorant dispersion 1”.

1250 g of the above-mentioned “latex 1”, 2000 ml of ion-exchanged water and “colorant dispersion liquid 1” were placed in a 5-liter four-necked flask equipped with a temperature sensor, a cooling tube, a nitrogen introducing device, and a stirring device and stirred. I do. After adjusting the temperature to 30 ° C., a 5 mol / liter aqueous sodium hydroxide solution was added to the solution to adjust the pH to 10.0. Then, an aqueous solution in which 52.6 g of magnesium chloride hexahydrate was dissolved in 72 ml of ion-exchanged water was stirred at 30 ° C. for 10 hours.
Minutes. Then, after leaving it to stand for 3 minutes, the temperature is raised and the temperature is raised to 90 ° C. in 6 minutes (heating rate 1
0 ° C./min). In this state, the particle size was measured with a Coulter Counter TAII. When the volume average particle size reached 6.5 μm, 115 g of sodium chloride was replaced with 700 ml of ion-exchanged water.
Is added thereto to stop the particle growth, and further, the mixture is heated and stirred at a liquid temperature of 90 ± 2 ° C. for 6 hours to carry out salting out / fusion. Thereafter, the mixture was cooled to 30 ° C. at 6 ° C./min, hydrochloric acid was added to adjust the pH to 2.0, and stirring was stopped. The resulting colored particles are filtered, washed with 1000 ml of ion-exchanged water, washed three times with 200 ml of an aqueous solution containing 1% by mass of ethyl pyruvate in an aqueous solution of 10% by mass of sodium dodecyl sulfate, and then washed with 1000 ml of ion-exchanged water. Washed. Then, it dried with 40 degreeC warm air and obtained the coloring particle. The colored particles obtained as described above are referred to as “colored particles 1”.

(Production Example 2 of Colored Particles) In Production Example 1 of colored particles, “latex 2” was used instead of “latex 1”.
Was used to obtain colored particles in the same manner. This is referred to as “colored particles 2”.

(Colored Particle Production Example 3) Colored particles were obtained in the same manner as in Colored Particle Production Example 1 except that isoamyl pyruvate was used instead of ethyl pyruvate. This is referred to as “colored particles 3”.

(Colored Particle Production Example 4) Colored particles were obtained in the same manner as in Colored Particle Production Example 1, except that benzyl pyruvate was used instead of ethyl pyruvate. This is referred to as “colored particles 4”.

(Colored Particle Production Example 5) Colored particles were obtained in the same manner as in Colored Particle Production Example 1, except that phenethyl pyruvate was used instead of ethyl pyruvate. This is referred to as “colored particles 5”.

(Colored Particle Production Example 6) Colored particles were obtained in the same manner as in Colored Particle Production Example 1, except that octyl pyruvate was used instead of ethyl pyruvate. This is referred to as “colored particles 6”.

(Colored Particle Production Example 7) Colored particles were obtained in the same manner as in Colored Particle Production Example 1, except that ethyl pyruvate was not used. This is referred to as “colored particles 7”.

(Production Example 8 of Colored Particles) High-speed stirrer (TK
710 parts by mass of ion-exchanged water and 450 parts by mass of a 0.1 mol / L aqueous solution of trisodium phosphate are added to a four-necked flask equipped with a homomixer, and the mixture is heated to 65 ° C. and stirred under a rotation speed of 120,000 rpm. 68 parts by mass of an aqueous 1.0 mol / l calcium chloride solution were gradually added to
An aqueous dispersion medium containing colloidal tricalcium phosphate was prepared. Then, 165 parts by mass of styrene monomer, n-
14 parts by mass of carbon black (Legal 330R) was added to 35 parts by mass of butyl acrylate, and 30 parts by mass of ester wax (19) was added to a dispersion liquid dispersed by a sand grinder, followed by dissolving at 80 ° C. Next, 2 parts by mass of tert-dodecyl mercaptan and 10 parts by mass of 2,2'-azobis (2,4-dimethylvaleronitrile) as a polymerization initiator were added to the aqueous dispersion medium under stirring conditions at a rotation speed of 12,000 rpm. And a solution containing the monomer was dispersed in water. Then, using a reactor having a stirring blade as shown in FIG.
The polymerization reaction was carried out for 10 hours under the stirring conditions of 5 ° C. and 200 rpm. At the end of the polymerization reaction, hydrochloric acid was added to remove tricalcium phosphate as a dispersion stabilizer, followed by filtration. Next, washing with 1,000 parts by mass of ion-exchanged water as a washing liquid, washing four times with 200 parts by mass of an aqueous solution containing 1% by mass of ethyl pyruvate in an aqueous solution of 10% by mass of sodium dodecyl sulfate, and then with 1000 parts by mass of ion-exchanged water Washed. Then, it dried with 40 degreeC warm air and obtained the coloring particle. The colored particles obtained as described above are referred to as “colored particles 8”.

(Colored Particle Production Example 9) Colored particles were obtained in the same manner as in Colored Particle Production Example 8 except that isoamyl pyruvate was used instead of ethyl pyruvate. This is referred to as “colored particles 9”.

(Production Example 10 of Colored Particles) Production Example 8 of Colored Particles
In the above, colored particles were obtained in the same manner except that benzyl pyruvate was used in place of ethyl pyruvate. This is referred to as “colored particles 10”.

(Production Example 11 of Colored Particles) Production Example 8 of Colored Particles
In the above, colored particles were obtained in the same manner except that phenethyl pyruvate was used in place of ethyl pyruvate. This is referred to as “colored particles 11”.

(Production Example 12 of Colored Particles) Production Example 8 of Colored Particles
In the above, colored particles were obtained in the same manner except that octyl pyruvate was used in place of ethyl pyruvate. This is referred to as “colored particles 9”.

(Colored Particle Production Example 13) Colored Particle Production Example 8
In the above, colored particles were obtained in the same manner except that ethyl pyruvate was not used. This is referred to as “colored particles 13”.

[0102]

[Table 1]

Next, each of the “colored particles 1” to “colored particles 13” is provided with a hydrophobic silica (number-average primary particle size of 12).
1% by mass and hydrophobic titanium oxide (number average primary particle diameter: 20 nm, hydrophobicity: 63) were added by 1% by mass, and mixed with a Henschel mixer to obtain a toner. These were designated as "Toner 1" to "Toner 13."
It should be noted that there is no difference between the colored particles and the toner in physical properties such as shape and particle diameter.

A ferrite carrier coated with a silicone resin and having a volume average particle diameter of 60 μm was mixed with each of the toners to prepare a developer having a toner concentration of 6%. These are referred to as “developer 1” to “developer 13” corresponding to the toner.

Using the developer prepared here, the configuration of the fixing device was changed to the configuration shown below using a digital copying machine Konica 7075, and a real-photo evaluation was performed.

As a fixing method, a pressure fixing type heat fixing device as shown in FIG. 2 was used. The specific configuration is as follows.

That is, the surface is PFA (tetrafluoroethylene-perfluoroalkyl vinyl ether copolymer)
Heating roller 10 (top) is a columnar 1.0 mm thick aluminum alloy core bar 11 having a heater 13 built in the center and having a 40 mm inner diameter and a total width of 310 mm, which is covered with a coating layer 12 (thickness: 120 μm). Roller)
Pressure roller 20 (lower roller) having a 2.0 mm thick iron core 21 having an inner diameter of 40 mm and a coating layer 22 (Asker C hardness 48: thickness 2 mm) having a surface similarly formed of sponge-like silicone rubber. have. The nip width was 5.8 mm. Using this fixing device, the printing linear velocity was set to 480 mm / sec.

Incidentally, polydiphenyl silicone (viscosity at 20 ° C. is 10 Pa · s
) Was impregnated with a web.

The fixing temperature was controlled by the surface temperature of the upper roll, and was set to 175 ° C. The amount of silicone oil applied was 0.1 mg / A4.

<Characteristics Evaluation> The fixing property was evaluated by printing an A4 halftone image (one having an image density of 1.0 as a relative reflection density when the density of the paper was set to "0"), and determining the fixing rate. It was measured. Fixing rate is defined as a fixed image wound with a “clothed cloth”
The image density change before and after rubbing with a weight of kg was calculated as a percentage.

Fixing rate (%) = (image density after rubbing) /
(Image density before rubbing) × 100 The surface temperature of the heating roller was 175 ° C. as a center value. In a closed room with a floor of 5m x 5m and a height of 2m, 1000 images were printed continuously at a set temperature of 175 ° C at a pixel rate of 15%, and the presence or absence of odor was evaluated by sensory evaluation. did. The presence or absence of odor was evaluated based on the number of persons who felt discomfort among the 30 evaluators.

[0112]

[Table 2]

[0113]

According to the present invention, a method for producing a polymerization toner free of odor during heat fixing can be obtained.

[Brief description of the drawings]

FIG. 1 shows a reactor equipped with a stirring blade used in the present invention.
The perspective view which shows an example.

FIG. 2 is a sectional view showing an example of a fixing device used in the present invention.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Heat exchange jacket 2 Stirring tank 3 Rotating shaft 4 Lower stirring blade 5 Upper stirring blade 6 Recording material 10 Heating roller 11 Core metal 12 Coating layer 13 Heater 20 Pressure roller 21 Core metal 22 Coating layer T Toner

 ────────────────────────────────────────────────── ─── Continued on the front page (72) Inventor Ken Omura 2970 Ishikawacho, Hachioji-shi, Tokyo Konica Corporation F-term (reference) 2H005 AA08 AB06 AB09 CA30 DA10 4J100 AA02P AA03P AA06P AB00P AB02P AB04P AB08P AC03P AC04P AC23P AC24P AC37P AE03P AF10P AG02P AG04P AG08P AL03P AL04P AL08P AM02P AM15P AQ06P AQ08P AQ12P AQ26P BC43P CA01 CA31 FA04 FA20 FA21 FA30 GA08 GC07 GC35 HA31 HC38 JA09

Claims (2)

[Claims] 1. A method for producing a toner comprising a step of subjecting a radical polymerizable monomer containing a colorant and a chain transfer agent to suspension polymerization in at least an aqueous medium, followed by filtration and washing. A method for producing a toner, comprising washing with an acid ester. 2. A resin particle obtained by emulsion polymerization or miniemulsion polymerization of a radical polymerizable monomer having at least a chain transfer agent in an aqueous medium using a water-soluble polymerization initiator is fused in an aqueous medium. A method for producing a toner, comprising a step of at least filtering and washing, wherein pyruvate is added during the washing step, followed by washing.