JP2002365841A - Method for producing toner by polymerization method - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a method for producing toner by polymerization method using a stirring blade of such optimum shape as to produce a circulating flow rate sufficient to prevent the formation of a thermal distribution in a stirring tank in a polymerization reaction step and as not to cause a vortex or suction of bubbles from a liquid surface. SOLUTION: The method for producing the toner comprising colored polymer particles obtained by dispersing a polymerizable monomer composition consisting essentially of a polymerizable monomer and a colorant in an aqueous dispersion medium and polymerizing the composition is characterized in that the polymerization step is carried out using a vertical stirring tank 1 and a stirring blade set in the stirring tank is a combination of an anchor blade 2 and a platelike blade 3 attached to the same rotating shaft 4 as that of the anchor blade 2.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

The present invention relates to a method for producing a polymerization toner used in electrophotography, electrostatic recording, magnetic recording, toner jet recording, and the like.

[0002]

2. Description of the Related Art Conventionally, as an electrophotographic method, U.S. Pat. No. 2,297,691 and Japanese Patent Publication No. 42-23910 are used.
Various methods have been proposed as described in Japanese Patent Application Laid-Open Nos. 43-24748 and 43-24748. In general, a photoconductive substance is used, and an electric latent image is formed on a photoreceptor by various means. Forming and then developing the latent image with toner,
After transferring the toner image to a transfer material such as paper as necessary,
The image is fixed by heat / pressure or the like to obtain a copied image.

[0003] The toner used in electrophotography has excellent fluidity and stable triboelectricity, and does not cause fogging on the photoreceptor or decrease in image density for a long period of time, enabling high quality printing. Is required. If the fluidity of the toner is poor, the supply of the developer becomes defective, and the image is blurred or the image density is reduced. In addition, cleaning failure occurs, the developer remains on the photoreceptor, and fogging occurs and filming with toner occurs. When a toner film is formed on the photoreceptor, white spots and black stains occur on the image, and the image quality is degraded. In order for the toner to exhibit excellent fluidity and form a high-quality image, it is desirable that the toner be spherical and have a sharp particle size distribution.

Conventionally, toners used for these purposes have generally been prepared by melting and mixing a colorant comprising a dye / pigment in a thermoplastic resin and uniformly dispersing the same, and then using a pulverizer or a classifier as a toner having a desired particle size. Has been manufactured.

[0005] Although this method can produce fairly good toners, it does have certain limitations, namely the choice of toner materials. For example, the material must be brittle enough to be comminuted in an economically reasonable manufacturing facility. However, if the material is made brittle to satisfy these requirements, the particle size distribution of the particles formed when the material is actually pulverized at a high speed is likely to be broad, and particularly the ratio of the formed fine particles is large. Problem arises. In order for a toner to exhibit satisfactory development characteristics, its particle size distribution must be somewhat narrow. Therefore, it is necessary to classify the particles obtained by grinding to remove coarse particles and fine particles. Therefore, in general, the yield is poor and the yield of toner is low in the pulverization method.

Further, such a highly brittle material is susceptible to further pulverization or pulverization when used for development in a copying machine or the like, which adversely affects the developability. Further, in this method, it is difficult to completely and uniformly disperse solid fine particles such as a colorant in a resin, and depending on the degree of dispersion, an increase in fog, a decrease in image density, and a problem of color mixing / transparency are caused. Great care must be taken in dispersing the colorant as this will cause defects. Further, exposure of the coloring agent to the fracture surface of the pulverized particles may cause fluctuations in development characteristics. Further, in the pulverization method, a spherical toner having a uniform surface cannot be produced, and it is difficult to obtain a satisfactory toner in terms of fluidity and triboelectricity.

[0007] In the toners obtained by these pulverization methods, there is a restriction in the case where a release agent such as wax is added. That is, in order to achieve a sufficient level of dispersibility of the release agent,
It is necessary to maintain a certain degree of viscosity at the kneading temperature with the resin, and to reduce the content of the release agent to about 5% by mass or less. Due to such restrictions, there is a limit in the fixing property / release property of the toner by the pulverization method.

In order to overcome the problems of the toner caused by these pulverization methods, Japanese Patent Publication Nos. 36-10231 and 43-1
Various polymerization toners and a method for producing the same have been proposed, including suspension polymerization toners disclosed in Japanese Patent Application Laid-Open Nos. 0799 and 51-14895 and the like. For example, in the case of a suspension polymerization method toner, a polymerizable monomer, a colorant, a release agent, a polymerization initiator, and if necessary, a crosslinking agent, a charge control agent, and other additives are uniformly dissolved or dispersed to form a unit. After the monomer composition, a continuous phase containing this monomer composition containing a dispersion stabilizer,
For example, the toner particles are dispersed in water using a suitable stirrer, and then a polymerization reaction is performed to obtain toner particles having a desired particle size.
Since this method does not include a pulverizing step at all, the toner does not need to be brittle, a soft material can be used as the resin, and the colorant is not exposed on the particle surface, and the like does not occur.
There is an advantage of having a uniform triboelectric charging property. Further, since the obtained toner has a relatively sharp particle size distribution, the classification step can be omitted. Even when the classification is required, the toner can be obtained in high yield. Furthermore, according to this method, in addition to the restrictions imposed on the above-mentioned pulverized toner, a release agent such as wax can be reliably included, and good fixing properties and anti-offset properties can be obtained. . The polymerized toner obtained by this method is spherical and has a uniform surface, so that it has good fluidity and transferability, exhibits good developing characteristics even after a large number of continuous developments, has little stress on the toner, The film is characterized in that filming is less likely to occur.

[0009]

In the production of a toner by the above-mentioned suspension polymerization method, the polymerization step is usually performed in a vertical stirring tank having a stirring means and a heating and cooling means (generally, a stirring speed of 1%).
(About 0 to 500 revolutions / minute). However, if the stirring and flowing state of the liquid is insufficient at this time, a stagnant portion where the liquid does not move so much occurs on the wall of the stirring tank or near the stirring shaft, and the inside of the tank is formed. Temperature distribution occurs. If there is a temperature distribution in the tank, there will be regions where the temperature will be partially high and the polymerization reaction will be promoted, and conversely, regions where the temperature will be low and the temperature will be suppressed, and the resulting polymer particles will have a degree of polymerization and molecular weight distribution. Becomes uneven. If these properties are non-uniform, toner characteristics such as triboelectricity and fixability are not stable, which is not preferable. In addition, if the temperature of the region where the temperature is partially high is higher than the glass transition temperature of the toner particles, coalescence of the toner particles may occur. This has an adverse effect on the toner characteristics such as the toner characteristics and the development characteristics when the image is evaluated, and unfavorably causes deterioration in product properties such as fluctuation in image density, generation of white stripes and fogging.

In order to solve the above problems, it is necessary to sufficiently stir and flow the liquid. The circulation flow rate generated by the stirring blade generally increases as the stirring speed increases,
If the stirring speed is too high, problems such as generation of vortex and entrainment of air bubbles from the liquid surface occur. Vortexing reduces the efficiency of stirring, and entrainment of air bubbles causes a foam separation phenomenon of the toner particles, and causes a phenomenon in which the toner particles aggregate and coalesce on the liquid surface. Further, when this adheres to the vicinity of the gas-liquid interface of the stirring tank wall, fusion occurs and deposits as scale-like deposits. When this deposit is peeled off and falls into the product, it is observed as irregularly shaped particles. If the proportion of the irregularly shaped particles in the product is large, the properties of the product are undesirably reduced as described above.

[0011] Further, if the scale-like deposit grows to a sufficient size and peels off / falls off, it may cause clogging or sticking at a pipe or valve connected to the stirring tank.
For this reason, frequent removal of the adhered substances is required, which lowers the operation rate of the manufacturing apparatus and leads to an increase in the cost of the product toner.

Accordingly, it is an object of the present invention to provide an optimum shape which does not cause thermal distribution in the stirring tank in the polymerization reaction step, and which has a sufficient circulation flow rate, and which does not cause vortexing or entrapment of air bubbles from the liquid surface. It is another object of the present invention to provide a method for producing a polymerization toner using a stirring blade.

[0013]

Means for Solving the Problems The inventors of the present invention have conducted intensive studies in order to solve the above-mentioned problems, and as a result, as a stirring blade installed in a vertical stirring tank used in the polymerization step, an anchor blade and a stirring blade are used. It has been found that by using a combination of plate-like blades mounted on the same rotating shaft, a sufficient flow state can be obtained, and an optimum stirring state without generation of vortex and entrainment of bubbles can be achieved.
According to this method, the liquid at the bottom of the stirring tank and the vicinity of the tank wall are efficiently flowed by the anchor blades, and the stirring flow of the other parts is supplemented by the plate-shaped blades. A good stirring state without a stagnation portion can be obtained even below.

Based on the above findings, the present inventors have completed the present invention. That is, according to the present invention, a polymerizable monomer composition comprising at least a polymerizable monomer and a colorant is polymerized in an aqueous dispersion medium to produce a polymerized toner comprising colored polymer particles. In the method,
The polymerization step is performed using a vertical stirring tank, wherein the stirring blades installed in the stirring tank are a combination of anchor blades and plate-like blades mounted on the same rotation axis as the blades. The present invention provides a method for producing a polymerization toner.

[0015]

BEST MODE FOR CARRYING OUT THE INVENTION Hereinafter, the present invention will be described in detail.

The method for producing the polymerization toner of the present invention is as follows. At least a colorant and, if necessary, a releasing agent, a charge control agent, a polymerization initiator, a crosslinking agent and other additives are added to the polymerizable monomer. A polymerizable monomer composition uniformly dissolved or dispersed by a commonly used stirrer, homogenizer, ultrasonic disperser or the like is mixed in a water phase containing a dispersion stabilizer with CLEARMIX (M Technic Co., Ltd.) Or a homomixer (manufactured by Tokushu Kika Kogyo Co., Ltd.) so that the droplets of the polymerizable monomer composition have the desired toner particle size. The stirring speed and time are adjusted to prepare a polymer particle suspension.

In the suspension polymerization method, it is usually preferable to use 100 to 3000 parts by weight of water as a dispersion medium with respect to 100 parts by weight of the polymerizable monomer composition. After preparing the polymer particle suspension using a stirrer having a high shear force, since the particle state is maintained by the action of the dispersion stabilizer, the polymerization step is performed by stirring such that the particles do not settle. continue.

The polymerization temperature is 40 ° C. or higher, generally 50 to
The polymerization is carried out at a temperature of 90 ° C. The temperature may be raised in the latter half of the polymerization reaction in order to obtain a desired molecular weight distribution. The medium may be distilled off by a distillation operation. The distillation operation can be performed under normal pressure or reduced pressure. After the completion of the polymerization reaction or the subsequent distillation operation, the generated toner particles are filtered / washed, and the dispersion stabilizer on the obtained particulate surface is removed by an acid and / or alkali treatment before or after this step. You can also. The toner particles finally separated from the liquid phase are dried by a known method.

As the polymerizable monomer used in the toner of the present invention, a vinyl polymerizable monomer capable of radical polymerization is used. As the vinyl polymerizable monomer, a monofunctional polymerizable monomer or a polyfunctional polymerizable monomer can be used.

Examples of the monofunctional polymerizable monomer include styrene, α-methylstyrene, β-methylstyrene, o-methylstyrene, m-methylstyrene, p-methylstyrene, 2,4-dimethylstyrene and p-methylstyrene. n-butylstyrene, p-tert-butylstyrene, pn-hexylstyrene, pn-octylstyrene, pn-nonylstyrene, pn-decylstyrene, pn-dodecylstyrene, p-methoxy Styrene, styrene derivatives such as p-phenylstyrene, methyl acrylate, ethyl acrylate, n-propyl acrylate, iso-propyl acrylate, n-butyl acrylate, iso
-Butyl acrylate, tert-butyl acrylate, n-amyl acrylate, n-hexyl acrylate, 2-ethylhexyl acrylate, n-octyl acrylate, n-nonyl acrylate, cyclohexyl acrylate, benzyl acrylate, dimethyl phosphate ethyl acrylate, diethyl phosphate ethyl Acrylic polymerizable monomers such as acrylate, dibutyl phosphate ethyl acrylate, 2-benzoyloxyethyl acrylate, methyl methacrylate, ethyl methacrylate, n-propyl methacrylate, iso-propyl methacrylate, n-butyl methacrylate, iso-butyl methacrylate, tert
-Butyl methacrylate, n-amyl methacrylate,
Methacrylic polymerizable monomers such as n-hexyl methacrylate, 2-ethylhexyl methacrylate, n-octyl methacrylate, n-nonyl methacrylate, diethyl phosphate ethyl methacrylate, dibutyl phosphate ethyl methacrylate, methylene aliphatic monocarboxylic acid esters, acetic acid Vinyl esters such as vinyl, vinyl propionate, vinyl butyrate, vinyl benzoate and vinyl formate; vinyl ethers such as vinyl methyl ether, vinyl ethyl ether and vinyl isobutyl ether; vinyl ketones such as vinyl methyl ketone, vinyl hexyl ketone and vinyl isopropyl ketone. No.

Examples of the polyfunctional polymerizable monomer include diethylene glycol diacrylate, triethylene glycol diacrylate, tetraethylene glycol diacrylate, polyethylene glycol diacrylate, and 1,6.
-Hexanediol diacrylate, neopentyl glycol diacrylate, tripropylene glycol diacrylate, polypropylene glycol diacrylate, 2,2'-bis (4- (acryloxydiethoxy) phenyl) propane, trimethylolpropane triacrylate, tetramethylolmethane Tetraacrylate, ethylene glycol dimethacrylate, diethylene glycol dimethacrylate, triethylene glycol dimethacrylate, tetraethylene glycol dimethacrylate, polyethylene glycol dimethacrylate, 1,3-butylene glycol dimethacrylate,
1,6-hexanediol dimethacrylate, neopentyl glycol dimethacrylate, polypropylene glycol dimethacrylate, 2,2′-bis (4- (methacryloxydiethoxy) phenyl) propane, 2,
2'-bis (4- (methacryloxypolyethoxy) phenyl) propane, trimethylolpropane trimethacrylate, tetramethylolmethanetetramethacrylate, divinylbenzene, divinylnaphthalene, divinylether and the like can be mentioned.

In the present invention, the above-mentioned monofunctional polymerizable monomers may be used alone or in combination of two or more, or the above-mentioned monofunctional polymerizable monomers and polyfunctional polymerizable monomers may be used in combination. To use. Among the above-mentioned monomers, it is preferable to use styrene or a styrene derivative alone or in combination, or to use them in combination with other monomers from the viewpoints of the developing characteristics and durability of the toner.

The coloring agent used in the present invention includes, for example, carbon black, iron black and C.I. I. Direct Red 1, C.I. I. Direct Red 4, C.I. I. Acid Red 1, C.I. I. Basic Red 1, C.I. I.
Modant Red 30, C.I. I. Direct Blue 1,
C. I. Direct Blue 2, C.I. I. Acid Blue 9, C.I. I. Acid Blue 15, C.I. I. Basic Blue 3, C.I. I. Basic Blue 5, C.I. I. Modant Blue 7, C.I. I. Direct Green 6, C.I.
I. Basic Green 4, C.I. I. Dyes such as Basic Green 6, yellow lead, cadmium yellow, mineral fast yellow, navel yellow, naphthol yellow S, Hansa yellow G, permanent yellow NC
G, tartrazine lake, molybdenum orange, permanent orange GTR, benzidine orange G, cadmium red, permanent red 4R, watching red calcium salt, brilliant carmine 3B, fast violet B, methyl violet lake, navy blue,
Pigments such as cobalt blue, alkali blue lake, Victoria blue lake, quinacridone, rhodamine lake, phthalocyanine blue, fast sky blue, pigment green B, malachite green lake, and final yellow green G.

In selecting a colorant, it is necessary to pay attention to the polymerization inhibitory property and the water phase transfer property of the colorant. Preferably, the colorant is subjected to a surface modification, for example, a hydrophobic treatment with a substance having no polymerization inhibition. Better to put it. In particular, attention must be paid to the use of dyes and carbon black since many of them have polymerization inhibitory properties. As a preferable method of surface-treating the dye system, a method of previously polymerizing a polymerizable monomer in the presence of these dyes is mentioned, and the obtained colored polymer is added to the polymerizable monomer composition. Further, regarding carbon black, in addition to the same treatment as the above-described dye, a graft treatment with a substance that reacts with the surface functional group of carbon black, for example, polyorganosiloxane may be performed.
In the present invention, a magnetic material may be added, but it is preferable to use a magnetic material that has been subjected to a surface treatment.

As the release agent, a wax in a solid state at room temperature is preferable, and a solid wax having a melting point of 40 to 100 ° C. is particularly preferable in terms of blocking resistance, durability of a large number of sheets, low-temperature fixing property, and offset resistance.

As the wax, paraffin wax,
Polyolefin wax, microcrystalline wax, polymethylene wax such as Fischer-Tropsch wax, amide wax, higher fatty acid, long-chain alcohol, ester wax and graft compounds thereof,
Derivatives such as block compounds are mentioned, and those having a sharp endothermic peak in a DSC endothermic curve from which low molecular weight components have been removed are preferred.

Preferred examples of the wax include linear alkyl alcohols having 15 to 100 carbon atoms, linear fatty acids, linear acid amides, linear esters, and montan derivatives. It is more preferable that impurities such as liquid fatty acids have been removed from these waxes in advance.

In order to improve the translucency of the fixed image,
Particularly, a solid ester wax is preferable, and a solid ester wax having a melting point of 40 to 100 ° C. is suitably used.

The release agent is preferably contained in an amount of 1 to 40 parts by mass, more preferably 4 to 30 parts by mass, per 100 parts by mass of the polymerizable monomer.

The toner of the present invention may contain a charge control agent. As the charge control agent, a known charge control agent can be used. For example, as a charge control agent that controls the toner to be negatively charged,
Organic metal compounds and chelate compounds are effective, and include monoazo dye metal compounds, acetylacetone metal compounds, aromatic hydroxycarboxylic acids, and aromatic dicarboxylic acid metal compounds. Other examples include aromatic hydroxycarboxylic acids, aromatic mono- and polycarboxylic acids and their metal salts, anhydrides, esters, and phenol derivatives such as bisphenol. Also, urea derivatives, mixed metal salicylic acid compounds, quaternary ammonium salts, calixarenes, silicon compounds, styrene-acrylic acid copolymers,
A styrene-methacrylic acid copolymer, a styrene-acryl-sulfonic acid copolymer, a non-metal carboxylic acid compound, and the like can be given.

The toner can be controlled to be positively charged by modifying the toner with nigrosine and a fatty acid metal salt, and quaternary such as tributylbenzylammonium-1-hydroxy-4-naphthosulfonate and tetrabutylammonium tetrafluoroborate. Onium salts such as ammonium salts and phosphonium salts, which are analogs thereof, and their lake pigments, triphenylmethane dyes and these lake pigments (as the lake-forming agent, phosphotungstic acid, phosphomolybdic acid, phosphotungsten molybdic acid) , Tannic acid, lauric acid, gallic acid, ferricyanide, ferrocyanide, etc.), metal salts of higher fatty acids,
Dibutyltin oxide, dioctyltin oxide,
There are diorganotin oxides such as dicyclohexyltin oxide, diorganotin borates such as dibutyltin borate, dioctyltin borate and dicyclohexyltin borate, and these can be used alone or in combination of two or more. Among these,
A charge control agent such as a nigrosine-based or quaternary ammonium salt is particularly preferably used.

These charge control agents include polymerizable monomers 10
It is good to use 0.01 to 20 parts by mass, more preferably 0.5 to 10 parts by mass with respect to 0 parts by mass.

A polymerization initiator can be used if necessary when polymerizing the polymerizable monomer. In the present invention, for example, 2,2′-azobis- (2,4-dimethylvaleronitrile), 2,2′-azobisisobutyronitrile, 1,1′-azobis (cyclohexane-1-carbonitrile), 2,2′-azobis-4-methoxy-2,
Azo-based polymerization initiators such as 4-dimethylvaleronitrile and azobisisobutyronitrile, benzoyl peroxide, methyl ethyl ketone peroxide, tert-butyl peroxy-2-ethylhexanoate, diisopropyl peroxy carbonate, cumene hydroperoxide , 2,4-dichlorobenzoyl peroxide,
A peroxide-based polymerization initiator such as lauroyl peroxide is used. Although the type of the initiator slightly varies depending on the polymerization method, it is used alone or in combination with reference to the 10-hour half-life temperature. The amount of the polymerization initiator varies depending on the desired degree of polymerization, but is generally used in an amount of 0.5 to 20 parts by mass per 100 parts by mass of the polymerizable monomer.

Examples of the crosslinking agent include divinylbenzene, 4,4′-divinylbiphenyl, ethylene glycol di (meth) acrylate, diethylene glycol di (meth) acrylate, glycidyl (meth) acrylate, and trimethylolpropane tri (meth) acrylate. Can be mentioned.

Examples of dispersion stabilizers for favorably dispersing the polymerizable monomer composition in an aqueous medium include, for example, inorganic oxides such as tricalcium phosphate, magnesium phosphate, aluminum phosphate, zinc phosphate, and the like. Examples include calcium carbonate, magnesium carbonate, calcium hydroxide, magnesium hydroxide, aluminum hydroxide, calcium metasilicate, calcium sulfate, barium sulfate, bentonite, silica, alumina, titania and the like. Examples of the organic compound include polyvinyl alcohol, gelatin, methylcellulose, methylhydroxypropylcellulose, ethylcellulose, sodium salts of carboxymethylcellulose, starch and the like. The dispersion stabilizer is preferably used in an amount of 0.2 to 10.0 parts by mass based on 100 parts by mass of the polymerizable monomer.

As these dispersion stabilizers, commercially available ones may be used as they are, but in order to obtain finely dispersed particles having a uniform particle size, the inorganic compound can also be formed under high-speed stirring in a dispersion medium. . For example, in the case of tricalcium phosphate, a dispersant suitable for a suspension polymerization method can be obtained by adding and mixing an aqueous solution of sodium phosphate and an aqueous solution of calcium chloride into water under high-speed stirring.

In order to make these dispersants finer, a surfactant of 0.001 to 0.1% by mass with respect to water may be used in combination. Specifically, commercially available nonionic, anionic, and cationic surfactants can be used, for example, sodium dodecyl sulfate, sodium tetradecyl sulfate, sodium pentadecyl sulfate, sodium octyl sulfate, sodium oleate, sodium laurate, potassium stearate, and olein. Calcium acid and the like are preferably used.

In the case of a polymerization method using an aqueous dispersion medium such as suspension polymerization, it is possible to promote the encapsulation of a release agent by adding a polar resin to the polymerizable monomer composition. it can. When a polar resin is present in the polymerizable monomer composition in the aqueous medium, the polar resin is likely to migrate to the vicinity of the interface between the aqueous medium and the polymerizable monomer composition due to a difference in hydrophilicity, so that the Polar resin will be unevenly distributed. As a result, the toner particles have a core-shell structure, and even when a large amount of the release agent is contained, the encapsulation of the release agent is improved.

As the polar resin, a saturated or unsaturated polyester-based resin is particularly preferable because the fluidity of the polar resin itself can be expected when the shell is formed unevenly on the toner surface. Polar resins include terephthalic acid, isophthalic acid, phthalic acid, fumaric acid, maleic acid,
Acid components such as malonic acid, succinic acid, glutaric acid, adipic acid, pimelic acid, suberic acid, azelaic acid, sebacic acid, succinic acid, cyclohexanedicarboxylic acid, trimellitic acid and ethylene glycol, diethylene glycol, triethylene Ethylene glycol, 1,2-propylene glycol, 1,3-propylene glycol, 1,
4-butanediol, neopentyl glycol, 1,4
-Alkylene glycols and polyalkylene glycols such as bis (hydroxymethyl) cyclohexane, bisphenol A, hydrogenated bisphenol, ethylene oxide adduct of bisphenol A, bisphenol A
And polycondensation with a polyhydric alcohol monomer such as propylene oxide adduct, glycerin, trimethylolpropane, and pentaerythritol.

In using the toner produced by the present invention, an external additive can be used for the purpose of imparting various properties. The external additive preferably has a particle size of 1/10 or less of the weight average particle size of the toner particles from the viewpoint of durability when added to the toner. The particle size of this additive
It means the average particle size obtained from observation with an electron microscope. Examples of the external additive include metal oxides (such as aluminum oxide, titanium oxide, strontium titanate, cerium oxide, magnesium oxide, chromium oxide, tin oxide, and zinc oxide), nitrides (such as silicon nitride), and carbides (such as silicon carbide). And the like, inorganic metal salts (calcium sulfate, barium sulfate, calcium carbonate, etc.), fatty acid metal salts (zinc stearate, calcium stearate, etc.), carbon black, silica and the like.

These external additives are used in an amount of 0.01 to 10 parts by mass, preferably 0.05 to 5 parts by mass, based on 100 parts by mass of the toner particles. The external additives may be used alone or in combination of two or more, but those subjected to a hydrophobic treatment are more preferable.

Further, the toner of the present invention can be used as a magnetic toner by containing a magnetic material. In this case, the magnetic material can also serve as a colorant. In the present invention, as a magnetic material contained in the magnetic toner, iron oxide such as magnetite, hematite, and ferrite, a metal such as iron, cobalt, and nickel, or a metal such as aluminum, cobalt, copper, lead, magnesium, and tin ,zinc,
Examples include alloys of metals such as antimony, beryllium, bismuth, cadmium, calcium, manganese, selenium, titanium, tungsten, and vanadium, and mixtures thereof.

These ferromagnetic substances preferably have an average particle diameter of 2 μm or less, preferably about 0.1 to 0.5 μm. The amount of the polymerizable monomer 10
The amount is preferably about 20 to 200 parts by mass with respect to 0 parts by mass, particularly preferably 40 to 150 parts by mass with respect to 100 parts by mass of the polymerizable monomer. Further, the magnetic characteristics at the time of application of 800 kA / m have a coercive force (Hc) of 1.6 to 24 kA / m and a saturation magnetization (σs) of 50.
~ ²⁰⁰ Am ² / kg, residual magnetization (σr) ² ~ ²⁰ Am ²
/ Kg is preferred.

In order to improve the dispersibility of these magnetic substances in the toner particles, it is also preferable that the surface is subjected to a hydrophobic treatment. For the hydrophobizing treatment, coupling agents such as a silane coupling agent and a titanium coupling agent are used, and among them, a silane coupling agent is preferably used. As the silane coupling agent, vinyltrimethoxysilane, vinyltriethoxysilane, γ-methacryloxypropyltrimethoxysilane, vinyltriacetoxysilane, methyltrimethoxysilane, methyltriethoxysilane, isobutyltrimethoxysilane, dimethyldimethoxysilane, dimethyl Examples thereof include diethoxysilane, trimethylmethoxysilane, hydroxypropyltrimethoxysilane, phenyltrimethoxysilane, n-hexadecyltrimethoxysilane, and n-octadecyltrimethoxysilane.

The toner of the present invention can be used in any developing system as a one-component or two-component developer. For example, in the case of a magnetic toner in which a magnetic material is contained in a toner as a one-component developer, there is a method in which a magnetic toner is transported and charged using a magnet built in a developing sleeve. When a non-magnetic toner containing no magnetic material is used, there is a method in which the toner is conveyed by forcibly triboelectrically charging the toner with a developing sleeve using a blade and a fur brush and attaching the toner to the sleeve.

On the other hand, when used as a generally used two-component developer, a carrier is used as a developer together with the toner of the present invention. The carrier used in the present invention is not particularly limited, but mainly iron, copper, zinc, nickel, cobalt, manganese,
It is composed of single and composite ferrites made of chromium. Carrier shape is also important because saturation magnetization and electric resistance can be controlled over a wide range.
It is preferable to select a flat or irregular shape and to control the fine structure of the carrier surface state, for example, the surface unevenness. In general, a method is used in which the inorganic oxide is calcined and granulated to generate carrier core particles in advance and then coat a resin.
In order to reduce the load on the toner of the carrier, a method of kneading the inorganic oxide and the resin, pulverizing and classifying to obtain a low-density dispersed carrier, or directly mixing the kneaded product of the inorganic oxide and the monomer with an aqueous medium It is also possible to use a method of obtaining a polymerized carrier by carrying out suspension polymerization in a solution to obtain a spherically dispersed carrier.

A system in which the surface of the carrier is coated with a resin or the like is particularly preferable. As the method, any conventionally known method such as a method of dissolving or suspending a coating material such as a resin in a solvent, coating and adhering to a carrier, and a method of simply mixing with a powder can be applied.

The substance fixed to the carrier surface varies depending on the toner material. Examples thereof include polytetrafluoroethylene, monochlorotrifluoroethylene polymer, polyvinylidene fluoride, silicone resin, polyester resin, and metal compounds of di-tert-butylsalicylic acid. It is appropriate to use styrene resin, acrylic resin, polyamide, polyvinyl butyral, nigrosine, aminoacrylate resin, basic dyes and lakes thereof, silica fine powder, alumina fine powder, or the like alone or in combination, but it is not always necessary to use this. Not restricted.

The treatment amount of the above compound is generally 0.1 to 30 parts by mass, preferably 0.5 to 20 parts by mass, per 100 parts by mass of the carrier.

The average particle size of these carriers is 10 to 100.
μm, preferably 20 to 50 μm.

Particularly preferred embodiments of the carrier include:
Cu-Zn-Fe ternary ferrite whose surface is a combination of a resin such as a fluorine resin and a styrene resin, for example, polyvinylidene fluoride and styrene-methyl methacrylate resin, polytetrafluoroethylene and styrene-methyl methacrylate A mixture of a resin, a fluorine-based copolymer and a styrene-based copolymer in a ratio of 90:10 to 20:80, preferably 70:30 to 30:70, and 0.01 to 5% by mass, preferably Is a coated ferrite carrier having an average particle size of 70% by mass or more in which 0.1% to 1% by mass of a carrier is coated by 250 mesh pass and 400 mesh on. As the fluorine-based copolymer, vinylidene fluoride-tetrafluoroethylene copolymer (10:90 to 9
0:10), and styrene-based copolymers such as styrene-2-ethylhexyl acrylate (20:80 to
80:20), styrene-2-ethylhexyl acrylate-methyl methacrylate (20-60: 5-30: 10)
To 50).

The coated laerlite carrier has a sharp particle size distribution, provides favorable triboelectricity to the toner of the present invention, and has the effect of improving electrophotographic properties.

When a two-component developer is prepared by mixing with the toner of the present invention, the mixing ratio is 2 to 15% by mass, preferably 4 to 13% by mass as the toner concentration in the developer.
In general, good results are obtained. When the toner concentration is less than 2% by mass, the image density is low and becomes impractical. When the toner concentration exceeds 15% by mass, fog and scattering in the machine are increased, and the useful life of the developer is shortened.

The magnetic properties of the carrier are preferably as follows. It is necessary that the intensity of magnetization at 80 kA / m after magnetic saturation is 30 to 300 Am ² / kg. In order to achieve higher image quality, it is preferably 100 to 250 Am ² / kg. 30
If it is larger than 0 Am ² / kg, it becomes difficult to obtain a high quality toner image. If it is less than 30 Am ² / kg, carrier adhesion is likely to occur because the magnetic binding force is reduced.

As the vertical stirring tank used in the production method according to the present invention, a general stirring tank having a flat bottom or a curved dish-shaped bottom can be selected. As the material of the vertical stirring tank, a commonly used material such as stainless steel, glass, or FRP can be used. These surfaces may be subjected to a treatment such as electrolytic polishing, fluorine-based resin coating, or glass lining. In addition, the stirring tank is provided with a stirring blade, a stirring blade rotating shaft, a temperature sensor, a raw material charging nozzle, a baffle plate, and the like, and these may also be made of the same material and the same surface treatment as the stirring tank. .

A preferred embodiment of the stirring blade used in the present invention will be described with reference to the drawings. FIG. 1 shows an embodiment of a vertical stirring tank and a stirring blade according to the present invention. In the figure, reference numeral 1 denotes a vertical stirring tank, reference numeral 2 denotes an anchor blade, reference numeral 3 denotes a plate-like blade, reference numeral 4 denotes a rotating shaft of the stirring blade, and reference numeral 5 denotes a liquid surface. Further, it is more preferable that the anchor blades and the plate-like blades are arranged such that both blade surfaces are orthogonal to each other from the viewpoint of stirring and mixing efficiency.

As shown in the plan view of FIG. 2, the anchor blade constituting the agitating blade according to the present invention more preferably has a twist that causes a flow toward the bottom of the tank due to rotation. Thereby, the effect of lifting from the tank bottom increases, and the effect of preventing stagnation near the tank bottom becomes more remarkable. In the figure,
Reference numeral 11 denotes a vertical stirring tank, reference numeral 12 denotes an anchor blade having a twist, reference numeral 13 denotes a plate-like blade, and reference numeral 14 denotes a rotating shaft of the stirring blade.

By installing one or more baffles in the stirring tank as shown in FIG. 3, the flow state can be further improved. In the figure, reference numeral 21 denotes a vertical stirring tank, and reference numeral 2 denotes
Reference numeral 2 denotes an anchor blade, reference numeral 23 denotes a plate-like blade, reference numeral 24 denotes a rotating shaft of a stirring blade, reference numeral 25 denotes a baffle plate, and reference numeral 26 denotes a liquid level. The symbol d is the blade outer diameter of the anchor blade, the symbol d 'is the blade outer diameter of the plate-like blade, the symbol b is the blade width of the anchor blade, and the symbol l is the center line of the stirring blade rotation axis to the baffle plate center line. Indicates the distance to.
The baffle is installed so as to satisfy d / 2−b>l> d ′ / 2, and at this time, the effect of the baffle can be maximized. When l> d / 2-b, there is a possibility that a stagnant portion may occur due to the relationship between the tank wall and the baffle plate, and when l <d ′ / 2, the effect of the baffle plate hardly occurs, which is not preferable.

The plate-like blade constituting the stirring blade according to the present invention comprises:
As shown in FIG. 4 (side view) and FIG. 5 (plan view), the blade surface can be arranged so as to have an angle with respect to the center line of the stirring shaft. In the figure, reference numeral 31 denotes a vertical stirring tank, reference numeral 32 denotes an anchor blade, reference numeral 33 denotes a plate-like blade, reference numeral 34 denotes a rotating shaft of the stirring blade, and reference numeral 35 denotes a liquid surface. By installing the plate-like blades in this manner, the flow in the vertical direction is generated by the rotation, and the effect of preventing the stagnation near the rotation axis of the stirring blade becomes more remarkable, which is preferable.

Another embodiment of the vertical stirring tank having a stirring blade according to the present invention is shown in FIG. 6 (side view) and FIG. 7 (plan view). In the figure, reference numeral 41 denotes a vertical stirring tank, reference numeral 42 denotes an anchor blade having a twist, reference numeral 43 denotes an inverted triangular shape, and the blade surface is installed so as to have an angle with respect to the center line of the rotation axis of the stirring blade. Reference numeral 44 denotes a rotating shaft of the stirring blade, reference numeral 45 denotes a cylindrical baffle plate having a plate-like portion at a lower end, and reference numeral 46 denotes a liquid level. In addition to the above-mentioned effects of the plate-shaped wings arranged such that the twisted anchor blades, baffle plates, and blade surfaces are at an angle with respect to the center line of the stirring shaft, the plate-shaped blades are formed in an inverted triangular shape. Thereby, an effect such as arranging plate-like blades having different blade diameters in multiple stages is produced, and the efficiency of stirring and mixing is increased.
Further, by providing the plate-shaped portion at the lower end of the baffle plate, the effect of the baffle plate against the discharge flow from the plate-like wings is enhanced, and the efficiency of stirring and mixing can be further improved.

[0061]

EXAMPLES Hereinafter, the present invention will be described specifically with reference to Examples and Comparative Examples, but the present invention is not limited thereto.

The following measurement methods were used in the examples.

(1) Measurement of Particle Size Distribution and Volume Average Particle Size In 100 to 150 ml of a 1% by mass aqueous sodium chloride solution, 0.1 to 5 ml of an alkylbenzene sulfonate is added as a surfactant, and a sample for measurement is added in an amount of 0.5 to 0.5 ml. ~ 50m
g was added. This solution was subjected to a dispersion treatment for about 1 to 3 minutes by an ultrasonic dispersing machine, and then subjected to a 2 μm aperture using a 100 μm aperture with a Coulter Multisizer (manufactured by Coulter).
The particle size distribution of particles of 〜40 μm was measured, and the volume average particle size was obtained therefrom.

(2) Image Quality Evaluation of the Image Quality of the Color Two-Component Developer The obtained toner particles were treated with a hydrophobic silica fine powder having a specific surface area of 200 m ² / g as measured by the BET method.
It was externally added so as to be 7% by mass. A ferrite carrier coated with an acrylic resin was mixed so that the externally added toner was 8% by mass to obtain a color two-component developer. In an environment in which this developer does not fluctuate, an image endurance test by continuous paper passing was performed using a full-color copying machine CLC700 manufactured by Canon, and fluctuations and unevenness in image density were visually evaluated.

Evaluation of image quality of monochrome one-component developer To the obtained toner particles, a hydrophobic silica fine powder having a specific surface area of 250 m ² / g measured by the BET method was used.
It was externally added so as to be 2% by mass to obtain a monochrome one-component developer. In an environment where the developer does not fluctuate, an image endurance test by continuous paper passing was performed using a laser printer LBP-1760 manufactured by Canon, and fluctuation and unevenness of image density were visually evaluated.

(3) Measurement of fog The measurement of fog was performed using a REFLECTROMETER MO.
It was measured using DEL TC-6DS (manufactured by Tokyo Denshoku Co., Ltd.) and calculated by the following equation. The smaller the value, the less fog. Fog (reflectance) (%) = reflectance of standard paper (%)-reflectance of non-image portion of sample (%)

(4) Measurement of Frictional Charge of Toner The triboelectric charge of the toner was measured in the following manner based on the blow-off method after the toner and the carrier were allowed to stand all day and night in a stable environment.

FIG. 8 is an explanatory view of an apparatus for measuring the triboelectric charge amount of toner. A mixture of a toner and a carrier in a mass ratio of 8:92, for which a triboelectric charge amount is to be measured, is 50 to 100 m
The mixture was placed in a 1-volume polyethylene bottle and shaken by hand 200 times to mix. About 0.2 g of this mixture is placed in a metal measuring container 52 having a 500-mesh screen 53 at the bottom, and a metal lid 54 is provided. At this time, the mass of the entire measurement container 52 is weighed and set as W ₁ (g). Next, the suction machine 51
(The part in contact with the measurement container 52 is an insulator.)
7, read the instruction of the vacuum gauge 55, and read the air volume control valve 56.
To adjust the pressure to 2450 Pa. In this state, the toner is sucked and removed for about 2 minutes. Assuming that the maximum value of the potential indicated by the electrometer 59 at this time is V (volt), the capacity of the condenser 58 is C (μF), and the mass of the whole measuring container after suction is W ₂ (g), the friction of this toner Charge amount (m
C / kg) is calculated as follows. Triboelectric charge (mC / kg) = C × VＣ (W ₁ −W ₂ )

(5) Abundance of deformed particles The toner particles were observed using a scanning electron microscope, and the abundance of deformed particles resulting from coalescence of the particles and adhering matter was calculated. The abundance (%) of the irregularly shaped particles is calculated as in the following equation. Abnormal particle existence ratio (%) = Number of irregular particles / Number of all particles × 100

Example 1 An aqueous dispersion medium and a polymerizable monomer composition were prepared as follows.

(Preparation of Aqueous Dispersion Medium) The following components were mixed and heated to 60 ° C. in a vessel having an internal volume of 160 liters.・ Water 98.4% by mass ・ Na ₃ PO ₄ 1.0% by mass

[0072] Then after the oxygen concentration in the container gas phase by introduction of nitrogen gas was 0.5% or less in the container, CaCl ₂ 0.
After adding 6% by mass, the number of rotations was 6,000 using a high-speed rotary shear stirrer CLEARMIX (manufactured by M Technique Co., Ltd.).
By stirring for 30 minutes at a revolution / minute, Ca ₃ (P
An aqueous dispersion medium containing O ₄ ) ₂ fine particles was obtained.

(Preparation of Polymerizable Monomer Composition Suspension) ・ Styrene monomer 63.9% by mass ・ N-butyl acrylate monomer 13.1% by mass ・ Quinacridone pigment 6.2% by mass ・3.9% by mass of unsaturated polyester resin ・ 0.2% by mass of divinylbenzene ・ 0.8% by mass of aluminum di-tert-butylsalicylate compound ・ 9.6% by mass of ester wax Parts, a quinacridone pigment and an aluminum di-tert-butylsalicylate compound were mixed and dispersed for 5 hours using a handy mill (manufactured by Mitsui Mining Co., Ltd.), and then the remaining styrene monomer and other components were added. The mixture was heated to 60 ° C. and mixed until it was sufficiently compatible. Thereafter, 2,2 ′ as a polymerization initiator was added thereto.
-Azobis (2,4-dimethylvaleronitrile) 2.3
% By mass was added to obtain a polymerizable monomer composition.

The above polymerizable monomer composition was charged into a previously prepared aqueous dispersion medium, and the CLEAR MIX was rotated at 6,000 rpm, and stirred for 12 minutes to suspend the polymerizable monomer composition. A liquid was obtained.

(Polymerization Step and Adhesion State) The suspension obtained in the above step was introduced into the vertical stirring tank shown in FIG. 1, and polymerization was carried out at a rotation speed of the stirring blade of 40 rpm and a liquid temperature of 60 ° C. Was. After 5 hours, the polymerization temperature was raised to 80 ° C., and the heating and stirring were continued for another 3 hours to complete the polymerization. After the temperature of the suspension has dropped, discharge the suspension from the stirring tank, add dilute hydrochloric acid to dissolve the dispersant fixed on the toner particle surface, separate the solid and liquid, wash with water, filter and dry. As a result, polymerized toner particles were obtained. After discharging the suspension, a total of 3 dry mass
0.7 g of scale-like deposits were observed,
There was no problem at all even if the toner was repeatedly manufactured without removing the attached matter.

(Evaluation of Toner) When the particle size distribution of the toner particles was measured, the volume average particle size was 7.2 μm, the particle size distribution was sharp, and the triboelectric charge amount was a good value of −43 mC / kg. . The abundance of the irregularly shaped particles was 1.0%.

Next, hydrophobic silica was externally added to the obtained toner particles, and a ferrite carrier coated with an acrylic resin was mixed to obtain a two-component developer. When an image output test was performed on 20,000 sheets, fog was 0.9%, and there was no fluctuation or unevenness in image density throughout, and a clear and excellent fixability image was obtained stably.

Example 2 As shown in FIG. 2, a toner was produced in exactly the same manner as in Example 1 except that a vertical stirring tank having a stirring blade having a twisted anchor blade was used. The amount of scale-like deposits in the stirring tank after the completion of the reaction was a total of 17.5 g in terms of dry mass, which was a level at which further continuous operation could be performed without removing the deposits. The abundance of the irregularly shaped particles was 0.5%. The volume average particle size of the toner particles was 7.3 μm, and the particle size distribution was almost the same as in Example 1. The triboelectric charge is -41
mC / kg.

Next, an image output test was performed on 20,000 sheets in the same manner as in Example 1. As a result, the fog was 0.6%, and there was no fluctuation or unevenness in the image density throughout, and a clear and excellent fixation image was obtained. Obtained stably.

Example 3 A vertical stirring tank shown in FIG. 3 (where d = 470 mm, b = 4
(0 mm, d '= 110 mm, 1 = 155 mm) except that the toner was manufactured in the same manner as in Example 1.
The amount of scale-like deposits in the stirring tank after the completion of the reaction was 12.2 g in total in terms of dry mass, which was a level at which further continuous operation was possible without removing the deposits. The abundance of the irregularly shaped particles was 0.4%. The volume average particle size of the toner particles was 7.5 μm, and the particle size distribution was almost the same as in Example 1. The triboelectric charge was -45 mC / kg.

Next, an image output test was performed on 20,000 sheets in the same manner as in Example 1. As a result, the fog was 0.4%, and there was no fluctuation and unevenness in the image density throughout, and a clear and excellent fixation image was obtained. Obtained stably.

Example 4 A toner was manufactured in exactly the same manner as in Example 1 except that the vertical stirring tank shown in FIGS. 4 (side view) and 5 (plan view) was used. The amount of scale-like deposits in the stirring tank after the completion of the reaction was a total of 24.6 g in terms of dry mass, which was a level at which further continuous operation could be performed without removing the deposits. The abundance of the irregularly shaped particles was 0.8%. The volume average particle size of the toner particles was 7.3 μm, and the particle size distribution was almost the same as in Example 1. The triboelectric charge was -40 mC / kg.

Next, an image output test was performed on 20,000 sheets in the same manner as in Example 1. As a result, fog was 0.7%, and there was no fluctuation or unevenness in the image density throughout, and a clear and excellent fixability image was obtained. Obtained stably.

Example 5 A toner was produced in exactly the same manner as in Example 1 except that the vertical stirring tank shown in FIG. 6 (side view) and FIG. 7 (plan view) was used. The amount of scale-like deposits in the stirring tank after the completion of the reaction was 8.5 g in total in terms of dry mass, and was at a level where further continuous operation could be performed without removing the deposits. The abundance of the irregularly shaped particles was 0.2%. The volume average particle size of the toner particles was 7.5 μm, and the particle size distribution was almost the same as in Example 1. The triboelectric charge was -41 mC / kg.

Next, an image output test was performed on 20,000 sheets in the same manner as in Example 1. As a result, the fog was 0.2%, and there was no fluctuation or unevenness in the image density throughout, and a clear and excellent fixability image was obtained. Obtained stably.

Comparative Example 1 A toner was produced in exactly the same manner as in Example 1, except that a vertical stirring tank provided only with a normal anchor blade as shown in FIG. 9 was used. In the figure, reference numeral 61 denotes a vertical stirring tank, reference numeral 62 denotes an anchor blade, reference numeral 63 denotes a rotating shaft of the stirring blade, and reference numeral 64 denotes a liquid surface. The amount of scale-like deposits in the stirring tank after the completion of the reaction was 140.4 g in total in terms of dry mass, was partially peeled off and dropped off, and it was a situation that the production could not be repeated unless the deposits were removed. The abundance of the irregularly shaped particles was 3.6%. When the particle size distribution of the toner particles was measured, the volume average particle size was 7.8 μm, and the particle size distribution was slightly broader than that in Example 1. The triboelectric charge was -30 mC / kg.

Next, when an image output test was performed on 20,000 sheets in the same manner as in Example 1, fog was found to be 1.9%, and white streaks and density unevenness were generated relatively early.

Comparative Example 2 A toner was produced in exactly the same manner as in Example 1, except that a normal vertical stirring tank provided with two ordinary paddle blades and a pair of baffles as shown in FIG. 10 was used. In the figure, reference numeral 71 denotes a vertical stirring tank, reference numeral 72 denotes two paddle blades, reference numeral 73 denotes a rotating shaft of the stirring blade, reference numeral 74 denotes a baffle plate, and reference numeral 75 denotes a liquid surface. The amount of scale-like deposits in the stirring tank after the completion of the reaction was 152.3 g in total in terms of dry mass, and some of the deposits were peeled off and dropped off, and the production could not be repeated unless the deposits were removed. The abundance of the irregularly shaped particles was 3.3%. When the particle size distribution of the toner particles was measured, the volume average particle size was 7.6.
At μm, the particle size distribution was slightly broader than in Example 1. The triboelectric charge was -34 mC / kg.

Next, when an image output test was performed on 20,000 sheets in the same manner as in Example 1, fog was 1.7%, and white streaks and density unevenness were generated relatively early.

Example 6 An aqueous dispersion medium and a polymerizable monomer composition were prepared as follows.

(Preparation of Aqueous Dispersion Medium) An aqueous dispersion medium was prepared in exactly the same manner as in Example 1 except that the composition was changed as follows.・ Water 98.1% by mass ・ Na ₃ PO ₄ 2% by mass ・ CaCl ₂ 0.7% by mass

(Preparation of Polymerizable Monomer Composition Suspension) Styrene monomer 38.4% by mass n-butyl acrylate monomer 10.8% by mass Silane-coupling-treated magnetic iron oxide particles 44 0.3% by mass ・ Unsaturated polyester resin 2.0% by mass ・ Saturated polyester resin 0.5% by mass ・ Monoazo dye iron compound 0.5% by mass ・ Ester wax 2.0% by mass Monostyrene of styrene among the above components Part of the body, silane-coupled magnetic iron oxide particles, and a monoazo dye iron compound were mixed and dispersed for 5 hours using a handy mill (manufactured by Mitsui Mining Co., Ltd.). The composition was added and heated to 60 ° C. and mixed until fully compatible. Thereafter, 1.5% by mass of tert-butyl peroxy-2-ethylhexanoate as a polymerization initiator was added thereto to obtain a polymerizable monomer composition.

The above polymerizable monomer composition is charged into a previously prepared aqueous dispersion medium, and the CLEAR MIX is rotated at 6,000 rpm, and stirred for 12 minutes to suspend the polymerizable monomer composition. A liquid was obtained.

(Polymerization Step and Adhesion State) The suspension obtained in the above step was introduced into the vertical stirring tank shown in FIG. 6 (side view) and FIG. rotation/
The polymerization was started at a liquid temperature of 60 ° C. for one minute. Immediately after that, the polymerization temperature was raised to 80 ° C. over 1 hour, and the heating and stirring were continued for another 5 hours to complete the polymerization. After the temperature of the suspension has dropped, discharge the suspension from the stirring tank, add dilute hydrochloric acid to dissolve the dispersant fixed on the toner particle surface, separate the solid and liquid, wash with water, filter and dry. As a result, polymerized toner particles were obtained.
After discharging the suspension, a total of 12.9 g of scale-like deposits in a dry mass was observed in the stirring tank, but this does not cause any problem even if the toner is repeatedly produced without removing the deposits. Level.

(Evaluation of Toner) When the particle size distribution of the toner particles was measured, the volume average particle size was 7.2 μm, the particle size distribution was sharp, and the triboelectric charge was a good value of −40 mC / kg. . The abundance of the irregularly shaped particles was 0.3%.

Next, hydrophobic silica was externally added to the obtained toner particles to obtain a one-component developer. When an image output test was performed on 20,000 sheets, the fog was 0.4%, and there was no fluctuation or unevenness in image density throughout, and a clear and excellent fixability image was obtained stably.

Comparative Example 3 A toner was produced in the same manner as in Example 6, except that the vertical stirring tank shown in FIG. 9 was used. The amount of scale-like deposits after the completion of the reaction was a total of 167.2 g in terms of dry mass, and a part thereof was peeled off and dropped off, so that the production could not be repeated unless the deposits were removed. The abundance of the irregularly shaped particles was 4.0%. The volume average particle size of the toner particles is 7.
At 3 μm, the particle size distribution was slightly broader than in Example 6. The triboelectric charge was -31 mC / kg.

Next, an image output test was performed on 20,000 sheets. As a result, fog was found to be 1.9%, and white streaks and density unevenness occurred from a relatively early stage. Filming was slightly observed on the photoreceptor.

[0099]

According to the present invention, in the suspension polymerization step in the production of the polymerization toner, the thermal unevenness and the liquid stagnation in the agitation tank are maintained while gently agitating such that air bubbles do not occur. This makes it possible to create a sufficient fluidized state that does not cause the occurrence of toner particles, to make the toner particle properties uniform, prevent scale-like deposits, and prevent the formation of irregularly shaped particles resulting from these. Therefore, it is possible to obtain a clear toner having excellent fixability without fluctuation or unevenness in image density when an image is formed. In addition, since the heat conduction is not hindered by the deposited substances and the pipes are not blocked due to the falling off of the substances, frequent removal of the substances is essentially unnecessary, and the productivity is improved.

[Brief description of the drawings]

FIG. 1 is a schematic view showing an embodiment of a vertical stirring tank and a stirring blade according to the present invention.

FIG. 2 is an explanatory view of an anchor wing having a twist.

FIG. 3 is an explanatory view of a stirring tank provided with a baffle plate.

FIG. 4 is an explanatory diagram of a plate-like wing.

FIG. 5 is an explanatory diagram of a plate-like wing.

FIG. 6 is a schematic view showing another embodiment of the vertical stirring tank according to the present invention.

FIG. 7 is a schematic view showing another embodiment of the vertical stirring tank according to the present invention.

FIG. 8 is an explanatory diagram of an apparatus for measuring a triboelectric charge amount of toner.

FIG. 9 is an explanatory view of a vertical stirring tank used in a comparative example.

FIG. 10 is an explanatory view of a vertical stirring tank used in a comparative example.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Vertical stirring tank 2 Anchor blade 3 Plate-like blade 4 Stirring blade rotation axis 5 Liquid surface

 ────────────────────────────────────────────────── ─── Continued on the front page (72) Inventor Takeshi Tsujino 3-30-2 Shimomaruko, Ota-ku, Tokyo F-term in Canon Inc. (reference) 2H005 AB06 4J011 DA03 DB16 DB19 JA14 JB26 PA03 PA22 PB25 PC07 PC15

Claims (6)

[Claims] 1. Production of a polymerized toner comprising colored polymer particles obtained by dispersing a polymerizable monomer composition comprising at least a polymerizable monomer and a colorant in an aqueous dispersion medium and conducting polymerization. In the method, the polymerization step is performed using a vertical stirring tank, and the stirring blades installed in the stirring tank are a combination of an anchor blade and a plate-like blade mounted on the same rotating shaft as the anchor blade. A method for producing a polymerization toner. 2. Anchor blades constituting said stirring blades are arranged such that both blade end surfaces are not on the same plane, and both blade ends are aligned with the center line of the rotation axis so that rotation causes a flow toward the bottom of the stirring tank. 2. The method according to claim 1, wherein the toner has a twist so as to be symmetric with respect to the toner. 3. The apparatus has at least one baffle plate, and has an outer diameter d of the anchor blade, a blade width b, a rotation diameter d ′ of the plate-like blade, and a center line of the baffle plate and a center line of a rotation axis of the stirring blade. Distance l is d / 2-b
3. The method according to claim 1, wherein the toner is arranged to satisfy>l> d ′ / 2. 4. 4. The stirring blade according to claim 1, wherein the blade surface of the plate-like blade constituting the stirring blade is disposed so as to have an angle with respect to the center line of the rotation axis of the stirring blade. Or a method for producing a polymerization toner. 5. The polymerization toner according to claim 1, wherein the plate-like wings constituting the stirring blade have a twist such that a vertical flow is generated by rotation. Production method. 6. The method for producing a polymerization toner according to claim 1, wherein the plate-like blade constituting the stirring blade has an inverted triangular shape.